diff options
Diffstat (limited to 'net/ipv4')
138 files changed, 105218 insertions, 0 deletions
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig new file mode 100644 index 000000000..23b06063e --- /dev/null +++ b/net/ipv4/Kconfig @@ -0,0 +1,754 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# IP configuration +# +config IP_MULTICAST + bool "IP: multicasting" + help + This is code for addressing several networked computers at once, + enlarging your kernel by about 2 KB. You need multicasting if you + intend to participate in the MBONE, a high bandwidth network on top + of the Internet which carries audio and video broadcasts. More + information about the MBONE is on the WWW at + <https://www.savetz.com/mbone/>. For most people, it's safe to say N. + +config IP_ADVANCED_ROUTER + bool "IP: advanced router" + help + If you intend to run your Linux box mostly as a router, i.e. as a + computer that forwards and redistributes network packets, say Y; you + will then be presented with several options that allow more precise + control about the routing process. + + The answer to this question won't directly affect the kernel: + answering N will just cause the configurator to skip all the + questions about advanced routing. + + Note that your box can only act as a router if you enable IP + forwarding in your kernel; you can do that by saying Y to "/proc + file system support" and "Sysctl support" below and executing the + line + + echo "1" > /proc/sys/net/ipv4/ip_forward + + at boot time after the /proc file system has been mounted. + + If you turn on IP forwarding, you should consider the rp_filter, which + automatically rejects incoming packets if the routing table entry + for their source address doesn't match the network interface they're + arriving on. This has security advantages because it prevents the + so-called IP spoofing, however it can pose problems if you use + asymmetric routing (packets from you to a host take a different path + than packets from that host to you) or if you operate a non-routing + host which has several IP addresses on different interfaces. To turn + rp_filter on use: + + echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter + or + echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter + + Note that some distributions enable it in startup scripts. + For details about rp_filter strict and loose mode read + <file:Documentation/networking/ip-sysctl.rst>. + + If unsure, say N here. + +config IP_FIB_TRIE_STATS + bool "FIB TRIE statistics" + depends on IP_ADVANCED_ROUTER + help + Keep track of statistics on structure of FIB TRIE table. + Useful for testing and measuring TRIE performance. + +config IP_MULTIPLE_TABLES + bool "IP: policy routing" + depends on IP_ADVANCED_ROUTER + select FIB_RULES + help + Normally, a router decides what to do with a received packet based + solely on the packet's final destination address. If you say Y here, + the Linux router will also be able to take the packet's source + address into account. Furthermore, the TOS (Type-Of-Service) field + of the packet can be used for routing decisions as well. + + If you need more information, see the Linux Advanced + Routing and Traffic Control documentation at + <https://lartc.org/howto/lartc.rpdb.html> + + If unsure, say N. + +config IP_ROUTE_MULTIPATH + bool "IP: equal cost multipath" + depends on IP_ADVANCED_ROUTER + help + Normally, the routing tables specify a single action to be taken in + a deterministic manner for a given packet. If you say Y here + however, it becomes possible to attach several actions to a packet + pattern, in effect specifying several alternative paths to travel + for those packets. The router considers all these paths to be of + equal "cost" and chooses one of them in a non-deterministic fashion + if a matching packet arrives. + +config IP_ROUTE_VERBOSE + bool "IP: verbose route monitoring" + depends on IP_ADVANCED_ROUTER + help + If you say Y here, which is recommended, then the kernel will print + verbose messages regarding the routing, for example warnings about + received packets which look strange and could be evidence of an + attack or a misconfigured system somewhere. The information is + handled by the klogd daemon which is responsible for kernel messages + ("man klogd"). + +config IP_ROUTE_CLASSID + bool + +config IP_PNP + bool "IP: kernel level autoconfiguration" + help + This enables automatic configuration of IP addresses of devices and + of the routing table during kernel boot, based on either information + supplied on the kernel command line or by BOOTP or RARP protocols. + You need to say Y only for diskless machines requiring network + access to boot (in which case you want to say Y to "Root file system + on NFS" as well), because all other machines configure the network + in their startup scripts. + +config IP_PNP_DHCP + bool "IP: DHCP support" + depends on IP_PNP + help + If you want your Linux box to mount its whole root file system (the + one containing the directory /) from some other computer over the + net via NFS and you want the IP address of your computer to be + discovered automatically at boot time using the DHCP protocol (a + special protocol designed for doing this job), say Y here. In case + the boot ROM of your network card was designed for booting Linux and + does DHCP itself, providing all necessary information on the kernel + command line, you can say N here. + + If unsure, say Y. Note that if you want to use DHCP, a DHCP server + must be operating on your network. Read + <file:Documentation/admin-guide/nfs/nfsroot.rst> for details. + +config IP_PNP_BOOTP + bool "IP: BOOTP support" + depends on IP_PNP + help + If you want your Linux box to mount its whole root file system (the + one containing the directory /) from some other computer over the + net via NFS and you want the IP address of your computer to be + discovered automatically at boot time using the BOOTP protocol (a + special protocol designed for doing this job), say Y here. In case + the boot ROM of your network card was designed for booting Linux and + does BOOTP itself, providing all necessary information on the kernel + command line, you can say N here. If unsure, say Y. Note that if you + want to use BOOTP, a BOOTP server must be operating on your network. + Read <file:Documentation/admin-guide/nfs/nfsroot.rst> for details. + +config IP_PNP_RARP + bool "IP: RARP support" + depends on IP_PNP + help + If you want your Linux box to mount its whole root file system (the + one containing the directory /) from some other computer over the + net via NFS and you want the IP address of your computer to be + discovered automatically at boot time using the RARP protocol (an + older protocol which is being obsoleted by BOOTP and DHCP), say Y + here. Note that if you want to use RARP, a RARP server must be + operating on your network. Read + <file:Documentation/admin-guide/nfs/nfsroot.rst> for details. + +config NET_IPIP + tristate "IP: tunneling" + select INET_TUNNEL + select NET_IP_TUNNEL + help + Tunneling means encapsulating data of one protocol type within + another protocol and sending it over a channel that understands the + encapsulating protocol. This particular tunneling driver implements + encapsulation of IP within IP, which sounds kind of pointless, but + can be useful if you want to make your (or some other) machine + appear on a different network than it physically is, or to use + mobile-IP facilities (allowing laptops to seamlessly move between + networks without changing their IP addresses). + + Saying Y to this option will produce two modules ( = code which can + be inserted in and removed from the running kernel whenever you + want). Most people won't need this and can say N. + +config NET_IPGRE_DEMUX + tristate "IP: GRE demultiplexer" + help + This is helper module to demultiplex GRE packets on GRE version field criteria. + Required by ip_gre and pptp modules. + +config NET_IP_TUNNEL + tristate + select DST_CACHE + select GRO_CELLS + default n + +config NET_IPGRE + tristate "IP: GRE tunnels over IP" + depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX + select NET_IP_TUNNEL + help + Tunneling means encapsulating data of one protocol type within + another protocol and sending it over a channel that understands the + encapsulating protocol. This particular tunneling driver implements + GRE (Generic Routing Encapsulation) and at this time allows + encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure. + This driver is useful if the other endpoint is a Cisco router: Cisco + likes GRE much better than the other Linux tunneling driver ("IP + tunneling" above). In addition, GRE allows multicast redistribution + through the tunnel. + +config NET_IPGRE_BROADCAST + bool "IP: broadcast GRE over IP" + depends on IP_MULTICAST && NET_IPGRE + help + One application of GRE/IP is to construct a broadcast WAN (Wide Area + Network), which looks like a normal Ethernet LAN (Local Area + Network), but can be distributed all over the Internet. If you want + to do that, say Y here and to "IP multicast routing" below. + +config IP_MROUTE_COMMON + bool + depends on IP_MROUTE || IPV6_MROUTE + +config IP_MROUTE + bool "IP: multicast routing" + depends on IP_MULTICAST + select IP_MROUTE_COMMON + help + This is used if you want your machine to act as a router for IP + packets that have several destination addresses. It is needed on the + MBONE, a high bandwidth network on top of the Internet which carries + audio and video broadcasts. In order to do that, you would most + likely run the program mrouted. If you haven't heard about it, you + don't need it. + +config IP_MROUTE_MULTIPLE_TABLES + bool "IP: multicast policy routing" + depends on IP_MROUTE && IP_ADVANCED_ROUTER + select FIB_RULES + help + Normally, a multicast router runs a userspace daemon and decides + what to do with a multicast packet based on the source and + destination addresses. If you say Y here, the multicast router + will also be able to take interfaces and packet marks into + account and run multiple instances of userspace daemons + simultaneously, each one handling a single table. + + If unsure, say N. + +config IP_PIMSM_V1 + bool "IP: PIM-SM version 1 support" + depends on IP_MROUTE + help + Kernel side support for Sparse Mode PIM (Protocol Independent + Multicast) version 1. This multicast routing protocol is used widely + because Cisco supports it. You need special software to use it + (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more + information about PIM. + + Say Y if you want to use PIM-SM v1. Note that you can say N here if + you just want to use Dense Mode PIM. + +config IP_PIMSM_V2 + bool "IP: PIM-SM version 2 support" + depends on IP_MROUTE + help + Kernel side support for Sparse Mode PIM version 2. In order to use + this, you need an experimental routing daemon supporting it (pimd or + gated-5). This routing protocol is not used widely, so say N unless + you want to play with it. + +config SYN_COOKIES + bool "IP: TCP syncookie support" + help + Normal TCP/IP networking is open to an attack known as "SYN + flooding". This denial-of-service attack prevents legitimate remote + users from being able to connect to your computer during an ongoing + attack and requires very little work from the attacker, who can + operate from anywhere on the Internet. + + SYN cookies provide protection against this type of attack. If you + say Y here, the TCP/IP stack will use a cryptographic challenge + protocol known as "SYN cookies" to enable legitimate users to + continue to connect, even when your machine is under attack. There + is no need for the legitimate users to change their TCP/IP software; + SYN cookies work transparently to them. For technical information + about SYN cookies, check out <https://cr.yp.to/syncookies.html>. + + If you are SYN flooded, the source address reported by the kernel is + likely to have been forged by the attacker; it is only reported as + an aid in tracing the packets to their actual source and should not + be taken as absolute truth. + + SYN cookies may prevent correct error reporting on clients when the + server is really overloaded. If this happens frequently better turn + them off. + + If you say Y here, you can disable SYN cookies at run time by + saying Y to "/proc file system support" and + "Sysctl support" below and executing the command + + echo 0 > /proc/sys/net/ipv4/tcp_syncookies + + after the /proc file system has been mounted. + + If unsure, say N. + +config NET_IPVTI + tristate "Virtual (secure) IP: tunneling" + depends on IPV6 || IPV6=n + select INET_TUNNEL + select NET_IP_TUNNEL + select XFRM + help + Tunneling means encapsulating data of one protocol type within + another protocol and sending it over a channel that understands the + encapsulating protocol. This can be used with xfrm mode tunnel to give + the notion of a secure tunnel for IPSEC and then use routing protocol + on top. + +config NET_UDP_TUNNEL + tristate + select NET_IP_TUNNEL + default n + +config NET_FOU + tristate "IP: Foo (IP protocols) over UDP" + select XFRM + select NET_UDP_TUNNEL + help + Foo over UDP allows any IP protocol to be directly encapsulated + over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP + network mechanisms and optimizations for UDP (such as ECMP + and RSS) can be leveraged to provide better service. + +config NET_FOU_IP_TUNNELS + bool "IP: FOU encapsulation of IP tunnels" + depends on NET_IPIP || NET_IPGRE || IPV6_SIT + select NET_FOU + help + Allow configuration of FOU or GUE encapsulation for IP tunnels. + When this option is enabled IP tunnels can be configured to use + FOU or GUE encapsulation. + +config INET_AH + tristate "IP: AH transformation" + select XFRM_AH + help + Support for IPsec AH (Authentication Header). + + AH can be used with various authentication algorithms. Besides + enabling AH support itself, this option enables the generic + implementations of the algorithms that RFC 8221 lists as MUST be + implemented. If you need any other algorithms, you'll need to enable + them in the crypto API. You should also enable accelerated + implementations of any needed algorithms when available. + + If unsure, say Y. + +config INET_ESP + tristate "IP: ESP transformation" + select XFRM_ESP + help + Support for IPsec ESP (Encapsulating Security Payload). + + ESP can be used with various encryption and authentication algorithms. + Besides enabling ESP support itself, this option enables the generic + implementations of the algorithms that RFC 8221 lists as MUST be + implemented. If you need any other algorithms, you'll need to enable + them in the crypto API. You should also enable accelerated + implementations of any needed algorithms when available. + + If unsure, say Y. + +config INET_ESP_OFFLOAD + tristate "IP: ESP transformation offload" + depends on INET_ESP + select XFRM_OFFLOAD + default n + help + Support for ESP transformation offload. This makes sense + only if this system really does IPsec and want to do it + with high throughput. A typical desktop system does not + need it, even if it does IPsec. + + If unsure, say N. + +config INET_ESPINTCP + bool "IP: ESP in TCP encapsulation (RFC 8229)" + depends on XFRM && INET_ESP + select STREAM_PARSER + select NET_SOCK_MSG + select XFRM_ESPINTCP + help + Support for RFC 8229 encapsulation of ESP and IKE over + TCP/IPv4 sockets. + + If unsure, say N. + +config INET_IPCOMP + tristate "IP: IPComp transformation" + select INET_XFRM_TUNNEL + select XFRM_IPCOMP + help + Support for IP Payload Compression Protocol (IPComp) (RFC3173), + typically needed for IPsec. + + If unsure, say Y. + +config INET_TABLE_PERTURB_ORDER + int "INET: Source port perturbation table size (as power of 2)" if EXPERT + default 16 + help + Source port perturbation table size (as power of 2) for + RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm. + + The default is almost always what you want. + Only change this if you know what you are doing. + +config INET_XFRM_TUNNEL + tristate + select INET_TUNNEL + default n + +config INET_TUNNEL + tristate + default n + +config INET_DIAG + tristate "INET: socket monitoring interface" + default y + help + Support for INET (TCP, DCCP, etc) socket monitoring interface used by + native Linux tools such as ss. ss is included in iproute2, currently + downloadable at: + + http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 + + If unsure, say Y. + +config INET_TCP_DIAG + depends on INET_DIAG + def_tristate INET_DIAG + +config INET_UDP_DIAG + tristate "UDP: socket monitoring interface" + depends on INET_DIAG && (IPV6 || IPV6=n) + default n + help + Support for UDP socket monitoring interface used by the ss tool. + If unsure, say Y. + +config INET_RAW_DIAG + tristate "RAW: socket monitoring interface" + depends on INET_DIAG && (IPV6 || IPV6=n) + default n + help + Support for RAW socket monitoring interface used by the ss tool. + If unsure, say Y. + +config INET_DIAG_DESTROY + bool "INET: allow privileged process to administratively close sockets" + depends on INET_DIAG + default n + help + Provides a SOCK_DESTROY operation that allows privileged processes + (e.g., a connection manager or a network administration tool such as + ss) to close sockets opened by other processes. Closing a socket in + this way interrupts any blocking read/write/connect operations on + the socket and causes future socket calls to behave as if the socket + had been disconnected. + If unsure, say N. + +menuconfig TCP_CONG_ADVANCED + bool "TCP: advanced congestion control" + help + Support for selection of various TCP congestion control + modules. + + Nearly all users can safely say no here, and a safe default + selection will be made (CUBIC with new Reno as a fallback). + + If unsure, say N. + +if TCP_CONG_ADVANCED + +config TCP_CONG_BIC + tristate "Binary Increase Congestion (BIC) control" + default m + help + BIC-TCP is a sender-side only change that ensures a linear RTT + fairness under large windows while offering both scalability and + bounded TCP-friendliness. The protocol combines two schemes + called additive increase and binary search increase. When the + congestion window is large, additive increase with a large + increment ensures linear RTT fairness as well as good + scalability. Under small congestion windows, binary search + increase provides TCP friendliness. + See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ + +config TCP_CONG_CUBIC + tristate "CUBIC TCP" + default y + help + This is version 2.0 of BIC-TCP which uses a cubic growth function + among other techniques. + See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf + +config TCP_CONG_WESTWOOD + tristate "TCP Westwood+" + default m + help + TCP Westwood+ is a sender-side only modification of the TCP Reno + protocol stack that optimizes the performance of TCP congestion + control. It is based on end-to-end bandwidth estimation to set + congestion window and slow start threshold after a congestion + episode. Using this estimation, TCP Westwood+ adaptively sets a + slow start threshold and a congestion window which takes into + account the bandwidth used at the time congestion is experienced. + TCP Westwood+ significantly increases fairness wrt TCP Reno in + wired networks and throughput over wireless links. + +config TCP_CONG_HTCP + tristate "H-TCP" + default m + help + H-TCP is a send-side only modifications of the TCP Reno + protocol stack that optimizes the performance of TCP + congestion control for high speed network links. It uses a + modeswitch to change the alpha and beta parameters of TCP Reno + based on network conditions and in a way so as to be fair with + other Reno and H-TCP flows. + +config TCP_CONG_HSTCP + tristate "High Speed TCP" + default n + help + Sally Floyd's High Speed TCP (RFC 3649) congestion control. + A modification to TCP's congestion control mechanism for use + with large congestion windows. A table indicates how much to + increase the congestion window by when an ACK is received. + For more detail see https://www.icir.org/floyd/hstcp.html + +config TCP_CONG_HYBLA + tristate "TCP-Hybla congestion control algorithm" + default n + help + TCP-Hybla is a sender-side only change that eliminates penalization of + long-RTT, large-bandwidth connections, like when satellite legs are + involved, especially when sharing a common bottleneck with normal + terrestrial connections. + +config TCP_CONG_VEGAS + tristate "TCP Vegas" + default n + help + TCP Vegas is a sender-side only change to TCP that anticipates + the onset of congestion by estimating the bandwidth. TCP Vegas + adjusts the sending rate by modifying the congestion + window. TCP Vegas should provide less packet loss, but it is + not as aggressive as TCP Reno. + +config TCP_CONG_NV + tristate "TCP NV" + default n + help + TCP NV is a follow up to TCP Vegas. It has been modified to deal with + 10G networks, measurement noise introduced by LRO, GRO and interrupt + coalescence. In addition, it will decrease its cwnd multiplicatively + instead of linearly. + + Note that in general congestion avoidance (cwnd decreased when # packets + queued grows) cannot coexist with congestion control (cwnd decreased only + when there is packet loss) due to fairness issues. One scenario when they + can coexist safely is when the CA flows have RTTs << CC flows RTTs. + + For further details see http://www.brakmo.org/networking/tcp-nv/ + +config TCP_CONG_SCALABLE + tristate "Scalable TCP" + default n + help + Scalable TCP is a sender-side only change to TCP which uses a + MIMD congestion control algorithm which has some nice scaling + properties, though is known to have fairness issues. + See http://www.deneholme.net/tom/scalable/ + +config TCP_CONG_LP + tristate "TCP Low Priority" + default n + help + TCP Low Priority (TCP-LP), a distributed algorithm whose goal is + to utilize only the excess network bandwidth as compared to the + ``fair share`` of bandwidth as targeted by TCP. + See http://www-ece.rice.edu/networks/TCP-LP/ + +config TCP_CONG_VENO + tristate "TCP Veno" + default n + help + TCP Veno is a sender-side only enhancement of TCP to obtain better + throughput over wireless networks. TCP Veno makes use of state + distinguishing to circumvent the difficult judgment of the packet loss + type. TCP Veno cuts down less congestion window in response to random + loss packets. + See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> + +config TCP_CONG_YEAH + tristate "YeAH TCP" + select TCP_CONG_VEGAS + default n + help + YeAH-TCP is a sender-side high-speed enabled TCP congestion control + algorithm, which uses a mixed loss/delay approach to compute the + congestion window. It's design goals target high efficiency, + internal, RTT and Reno fairness, resilience to link loss while + keeping network elements load as low as possible. + + For further details look here: + http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf + +config TCP_CONG_ILLINOIS + tristate "TCP Illinois" + default n + help + TCP-Illinois is a sender-side modification of TCP Reno for + high speed long delay links. It uses round-trip-time to + adjust the alpha and beta parameters to achieve a higher average + throughput and maintain fairness. + + For further details see: + http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html + +config TCP_CONG_DCTCP + tristate "DataCenter TCP (DCTCP)" + default n + help + DCTCP leverages Explicit Congestion Notification (ECN) in the network to + provide multi-bit feedback to the end hosts. It is designed to provide: + + - High burst tolerance (incast due to partition/aggregate), + - Low latency (short flows, queries), + - High throughput (continuous data updates, large file transfers) with + commodity, shallow-buffered switches. + + All switches in the data center network running DCTCP must support + ECN marking and be configured for marking when reaching defined switch + buffer thresholds. The default ECN marking threshold heuristic for + DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets + (~100KB) at 10Gbps, but might need further careful tweaking. + + For further details see: + http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf + +config TCP_CONG_CDG + tristate "CAIA Delay-Gradient (CDG)" + default n + help + CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies + the TCP sender in order to: + + o Use the delay gradient as a congestion signal. + o Back off with an average probability that is independent of the RTT. + o Coexist with flows that use loss-based congestion control. + o Tolerate packet loss unrelated to congestion. + + For further details see: + D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using + delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg + +config TCP_CONG_BBR + tristate "BBR TCP" + default n + help + + BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to + maximize network utilization and minimize queues. It builds an explicit + model of the bottleneck delivery rate and path round-trip propagation + delay. It tolerates packet loss and delay unrelated to congestion. It + can operate over LAN, WAN, cellular, wifi, or cable modem links. It can + coexist with flows that use loss-based congestion control, and can + operate with shallow buffers, deep buffers, bufferbloat, policers, or + AQM schemes that do not provide a delay signal. It requires the fq + ("Fair Queue") pacing packet scheduler. + +choice + prompt "Default TCP congestion control" + default DEFAULT_CUBIC + help + Select the TCP congestion control that will be used by default + for all connections. + + config DEFAULT_BIC + bool "Bic" if TCP_CONG_BIC=y + + config DEFAULT_CUBIC + bool "Cubic" if TCP_CONG_CUBIC=y + + config DEFAULT_HTCP + bool "Htcp" if TCP_CONG_HTCP=y + + config DEFAULT_HYBLA + bool "Hybla" if TCP_CONG_HYBLA=y + + config DEFAULT_VEGAS + bool "Vegas" if TCP_CONG_VEGAS=y + + config DEFAULT_VENO + bool "Veno" if TCP_CONG_VENO=y + + config DEFAULT_WESTWOOD + bool "Westwood" if TCP_CONG_WESTWOOD=y + + config DEFAULT_DCTCP + bool "DCTCP" if TCP_CONG_DCTCP=y + + config DEFAULT_CDG + bool "CDG" if TCP_CONG_CDG=y + + config DEFAULT_BBR + bool "BBR" if TCP_CONG_BBR=y + + config DEFAULT_RENO + bool "Reno" +endchoice + +endif + +config TCP_CONG_CUBIC + tristate + depends on !TCP_CONG_ADVANCED + default y + +config DEFAULT_TCP_CONG + string + default "bic" if DEFAULT_BIC + default "cubic" if DEFAULT_CUBIC + default "htcp" if DEFAULT_HTCP + default "hybla" if DEFAULT_HYBLA + default "vegas" if DEFAULT_VEGAS + default "westwood" if DEFAULT_WESTWOOD + default "veno" if DEFAULT_VENO + default "reno" if DEFAULT_RENO + default "dctcp" if DEFAULT_DCTCP + default "cdg" if DEFAULT_CDG + default "bbr" if DEFAULT_BBR + default "cubic" + +config TCP_MD5SIG + bool "TCP: MD5 Signature Option support (RFC2385)" + select CRYPTO + select CRYPTO_MD5 + help + RFC2385 specifies a method of giving MD5 protection to TCP sessions. + Its main (only?) use is to protect BGP sessions between core routers + on the Internet. + + If unsure, say N. diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile new file mode 100644 index 000000000..5b77a4688 --- /dev/null +++ b/net/ipv4/Makefile @@ -0,0 +1,73 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the Linux TCP/IP (INET) layer. +# + +obj-y := route.o inetpeer.o protocol.o \ + ip_input.o ip_fragment.o ip_forward.o ip_options.o \ + ip_output.o ip_sockglue.o inet_hashtables.o \ + inet_timewait_sock.o inet_connection_sock.o \ + tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \ + tcp_minisocks.o tcp_cong.o tcp_metrics.o tcp_fastopen.o \ + tcp_rate.o tcp_recovery.o tcp_ulp.o \ + tcp_offload.o datagram.o raw.o udp.o udplite.o \ + udp_offload.o arp.o icmp.o devinet.o af_inet.o igmp.o \ + fib_frontend.o fib_semantics.o fib_trie.o fib_notifier.o \ + inet_fragment.o ping.o ip_tunnel_core.o gre_offload.o \ + metrics.o netlink.o nexthop.o udp_tunnel_stub.o + +obj-$(CONFIG_BPFILTER) += bpfilter/ + +obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o +obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o +obj-$(CONFIG_PROC_FS) += proc.o +obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o +obj-$(CONFIG_IP_MROUTE) += ipmr.o +obj-$(CONFIG_IP_MROUTE_COMMON) += ipmr_base.o +obj-$(CONFIG_NET_IPIP) += ipip.o +gre-y := gre_demux.o +obj-$(CONFIG_NET_FOU) += fou.o +obj-$(CONFIG_NET_IPGRE_DEMUX) += gre.o +obj-$(CONFIG_NET_IPGRE) += ip_gre.o +udp_tunnel-y := udp_tunnel_core.o udp_tunnel_nic.o +obj-$(CONFIG_NET_UDP_TUNNEL) += udp_tunnel.o +obj-$(CONFIG_NET_IPVTI) += ip_vti.o +obj-$(CONFIG_SYN_COOKIES) += syncookies.o +obj-$(CONFIG_INET_AH) += ah4.o +obj-$(CONFIG_INET_ESP) += esp4.o +obj-$(CONFIG_INET_ESP_OFFLOAD) += esp4_offload.o +obj-$(CONFIG_INET_IPCOMP) += ipcomp.o +obj-$(CONFIG_INET_XFRM_TUNNEL) += xfrm4_tunnel.o +obj-$(CONFIG_INET_TUNNEL) += tunnel4.o +obj-$(CONFIG_IP_PNP) += ipconfig.o +obj-$(CONFIG_NETFILTER) += netfilter.o netfilter/ +obj-$(CONFIG_INET_DIAG) += inet_diag.o +obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o +obj-$(CONFIG_INET_UDP_DIAG) += udp_diag.o +obj-$(CONFIG_INET_RAW_DIAG) += raw_diag.o +obj-$(CONFIG_TCP_CONG_BBR) += tcp_bbr.o +obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o +obj-$(CONFIG_TCP_CONG_CDG) += tcp_cdg.o +obj-$(CONFIG_TCP_CONG_CUBIC) += tcp_cubic.o +obj-$(CONFIG_TCP_CONG_DCTCP) += tcp_dctcp.o +obj-$(CONFIG_TCP_CONG_WESTWOOD) += tcp_westwood.o +obj-$(CONFIG_TCP_CONG_HSTCP) += tcp_highspeed.o +obj-$(CONFIG_TCP_CONG_HYBLA) += tcp_hybla.o +obj-$(CONFIG_TCP_CONG_HTCP) += tcp_htcp.o +obj-$(CONFIG_TCP_CONG_VEGAS) += tcp_vegas.o +obj-$(CONFIG_TCP_CONG_NV) += tcp_nv.o +obj-$(CONFIG_TCP_CONG_VENO) += tcp_veno.o +obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o +obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o +obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o +obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o +obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o +obj-$(CONFIG_BPF_STREAM_PARSER) += udp_bpf.o +obj-$(CONFIG_NETLABEL) += cipso_ipv4.o + +obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \ + xfrm4_output.o xfrm4_protocol.o + +ifeq ($(CONFIG_BPF_JIT),y) +obj-$(CONFIG_BPF_SYSCALL) += bpf_tcp_ca.o +endif diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c new file mode 100644 index 000000000..acb488735 --- /dev/null +++ b/net/ipv4/af_inet.c @@ -0,0 +1,2094 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * PF_INET protocol family socket handler. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Florian La Roche, <flla@stud.uni-sb.de> + * Alan Cox, <A.Cox@swansea.ac.uk> + * + * Changes (see also sock.c) + * + * piggy, + * Karl Knutson : Socket protocol table + * A.N.Kuznetsov : Socket death error in accept(). + * John Richardson : Fix non blocking error in connect() + * so sockets that fail to connect + * don't return -EINPROGRESS. + * Alan Cox : Asynchronous I/O support + * Alan Cox : Keep correct socket pointer on sock + * structures + * when accept() ed + * Alan Cox : Semantics of SO_LINGER aren't state + * moved to close when you look carefully. + * With this fixed and the accept bug fixed + * some RPC stuff seems happier. + * Niibe Yutaka : 4.4BSD style write async I/O + * Alan Cox, + * Tony Gale : Fixed reuse semantics. + * Alan Cox : bind() shouldn't abort existing but dead + * sockets. Stops FTP netin:.. I hope. + * Alan Cox : bind() works correctly for RAW sockets. + * Note that FreeBSD at least was broken + * in this respect so be careful with + * compatibility tests... + * Alan Cox : routing cache support + * Alan Cox : memzero the socket structure for + * compactness. + * Matt Day : nonblock connect error handler + * Alan Cox : Allow large numbers of pending sockets + * (eg for big web sites), but only if + * specifically application requested. + * Alan Cox : New buffering throughout IP. Used + * dumbly. + * Alan Cox : New buffering now used smartly. + * Alan Cox : BSD rather than common sense + * interpretation of listen. + * Germano Caronni : Assorted small races. + * Alan Cox : sendmsg/recvmsg basic support. + * Alan Cox : Only sendmsg/recvmsg now supported. + * Alan Cox : Locked down bind (see security list). + * Alan Cox : Loosened bind a little. + * Mike McLagan : ADD/DEL DLCI Ioctls + * Willy Konynenberg : Transparent proxying support. + * David S. Miller : New socket lookup architecture. + * Some other random speedups. + * Cyrus Durgin : Cleaned up file for kmod hacks. + * Andi Kleen : Fix inet_stream_connect TCP race. + */ + +#define pr_fmt(fmt) "IPv4: " fmt + +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/kmod.h> +#include <linux/sched.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/capability.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/stat.h> +#include <linux/init.h> +#include <linux/poll.h> +#include <linux/netfilter_ipv4.h> +#include <linux/random.h> +#include <linux/slab.h> + +#include <linux/uaccess.h> + +#include <linux/inet.h> +#include <linux/igmp.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <net/checksum.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/arp.h> +#include <net/route.h> +#include <net/ip_fib.h> +#include <net/inet_connection_sock.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/udplite.h> +#include <net/ping.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/raw.h> +#include <net/icmp.h> +#include <net/inet_common.h> +#include <net/ip_tunnels.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/secure_seq.h> +#ifdef CONFIG_IP_MROUTE +#include <linux/mroute.h> +#endif +#include <net/l3mdev.h> +#include <net/compat.h> + +#include <trace/events/sock.h> + +/* The inetsw table contains everything that inet_create needs to + * build a new socket. + */ +static struct list_head inetsw[SOCK_MAX]; +static DEFINE_SPINLOCK(inetsw_lock); + +/* New destruction routine */ + +void inet_sock_destruct(struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + + __skb_queue_purge(&sk->sk_receive_queue); + if (sk->sk_rx_skb_cache) { + __kfree_skb(sk->sk_rx_skb_cache); + sk->sk_rx_skb_cache = NULL; + } + __skb_queue_purge(&sk->sk_error_queue); + + sk_mem_reclaim(sk); + + if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) { + pr_err("Attempt to release TCP socket in state %d %p\n", + sk->sk_state, sk); + return; + } + if (!sock_flag(sk, SOCK_DEAD)) { + pr_err("Attempt to release alive inet socket %p\n", sk); + return; + } + + WARN_ON(atomic_read(&sk->sk_rmem_alloc)); + WARN_ON(refcount_read(&sk->sk_wmem_alloc)); + WARN_ON(sk->sk_wmem_queued); + WARN_ON(sk->sk_forward_alloc); + + kfree(rcu_dereference_protected(inet->inet_opt, 1)); + dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1)); + dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1)); + sk_refcnt_debug_dec(sk); +} +EXPORT_SYMBOL(inet_sock_destruct); + +/* + * The routines beyond this point handle the behaviour of an AF_INET + * socket object. Mostly it punts to the subprotocols of IP to do + * the work. + */ + +/* + * Automatically bind an unbound socket. + */ + +static int inet_autobind(struct sock *sk) +{ + struct inet_sock *inet; + /* We may need to bind the socket. */ + lock_sock(sk); + inet = inet_sk(sk); + if (!inet->inet_num) { + if (sk->sk_prot->get_port(sk, 0)) { + release_sock(sk); + return -EAGAIN; + } + inet->inet_sport = htons(inet->inet_num); + } + release_sock(sk); + return 0; +} + +/* + * Move a socket into listening state. + */ +int inet_listen(struct socket *sock, int backlog) +{ + struct sock *sk = sock->sk; + unsigned char old_state; + int err, tcp_fastopen; + + lock_sock(sk); + + err = -EINVAL; + if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM) + goto out; + + old_state = sk->sk_state; + if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN))) + goto out; + + WRITE_ONCE(sk->sk_max_ack_backlog, backlog); + /* Really, if the socket is already in listen state + * we can only allow the backlog to be adjusted. + */ + if (old_state != TCP_LISTEN) { + /* Enable TFO w/o requiring TCP_FASTOPEN socket option. + * Note that only TCP sockets (SOCK_STREAM) will reach here. + * Also fastopen backlog may already been set via the option + * because the socket was in TCP_LISTEN state previously but + * was shutdown() rather than close(). + */ + tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen); + if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) && + (tcp_fastopen & TFO_SERVER_ENABLE) && + !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) { + fastopen_queue_tune(sk, backlog); + tcp_fastopen_init_key_once(sock_net(sk)); + } + + err = inet_csk_listen_start(sk, backlog); + if (err) + goto out; + tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL); + } + err = 0; + +out: + release_sock(sk); + return err; +} +EXPORT_SYMBOL(inet_listen); + +/* + * Create an inet socket. + */ + +static int inet_create(struct net *net, struct socket *sock, int protocol, + int kern) +{ + struct sock *sk; + struct inet_protosw *answer; + struct inet_sock *inet; + struct proto *answer_prot; + unsigned char answer_flags; + int try_loading_module = 0; + int err; + + if (protocol < 0 || protocol >= IPPROTO_MAX) + return -EINVAL; + + sock->state = SS_UNCONNECTED; + + /* Look for the requested type/protocol pair. */ +lookup_protocol: + err = -ESOCKTNOSUPPORT; + rcu_read_lock(); + list_for_each_entry_rcu(answer, &inetsw[sock->type], list) { + + err = 0; + /* Check the non-wild match. */ + if (protocol == answer->protocol) { + if (protocol != IPPROTO_IP) + break; + } else { + /* Check for the two wild cases. */ + if (IPPROTO_IP == protocol) { + protocol = answer->protocol; + break; + } + if (IPPROTO_IP == answer->protocol) + break; + } + err = -EPROTONOSUPPORT; + } + + if (unlikely(err)) { + if (try_loading_module < 2) { + rcu_read_unlock(); + /* + * Be more specific, e.g. net-pf-2-proto-132-type-1 + * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM) + */ + if (++try_loading_module == 1) + request_module("net-pf-%d-proto-%d-type-%d", + PF_INET, protocol, sock->type); + /* + * Fall back to generic, e.g. net-pf-2-proto-132 + * (net-pf-PF_INET-proto-IPPROTO_SCTP) + */ + else + request_module("net-pf-%d-proto-%d", + PF_INET, protocol); + goto lookup_protocol; + } else + goto out_rcu_unlock; + } + + err = -EPERM; + if (sock->type == SOCK_RAW && !kern && + !ns_capable(net->user_ns, CAP_NET_RAW)) + goto out_rcu_unlock; + + sock->ops = answer->ops; + answer_prot = answer->prot; + answer_flags = answer->flags; + rcu_read_unlock(); + + WARN_ON(!answer_prot->slab); + + err = -ENOBUFS; + sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern); + if (!sk) + goto out; + + err = 0; + if (INET_PROTOSW_REUSE & answer_flags) + sk->sk_reuse = SK_CAN_REUSE; + + inet = inet_sk(sk); + inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0; + + inet->nodefrag = 0; + + if (SOCK_RAW == sock->type) { + inet->inet_num = protocol; + if (IPPROTO_RAW == protocol) + inet->hdrincl = 1; + } + + if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc)) + inet->pmtudisc = IP_PMTUDISC_DONT; + else + inet->pmtudisc = IP_PMTUDISC_WANT; + + inet->inet_id = 0; + + sock_init_data(sock, sk); + + sk->sk_destruct = inet_sock_destruct; + sk->sk_protocol = protocol; + sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv; + + inet->uc_ttl = -1; + inet->mc_loop = 1; + inet->mc_ttl = 1; + inet->mc_all = 1; + inet->mc_index = 0; + inet->mc_list = NULL; + inet->rcv_tos = 0; + + sk_refcnt_debug_inc(sk); + + if (inet->inet_num) { + /* It assumes that any protocol which allows + * the user to assign a number at socket + * creation time automatically + * shares. + */ + inet->inet_sport = htons(inet->inet_num); + /* Add to protocol hash chains. */ + err = sk->sk_prot->hash(sk); + if (err) { + sk_common_release(sk); + goto out; + } + } + + if (sk->sk_prot->init) { + err = sk->sk_prot->init(sk); + if (err) { + sk_common_release(sk); + goto out; + } + } + + if (!kern) { + err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk); + if (err) { + sk_common_release(sk); + goto out; + } + } +out: + return err; +out_rcu_unlock: + rcu_read_unlock(); + goto out; +} + + +/* + * The peer socket should always be NULL (or else). When we call this + * function we are destroying the object and from then on nobody + * should refer to it. + */ +int inet_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + + if (sk) { + long timeout; + + if (!sk->sk_kern_sock) + BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk); + + /* Applications forget to leave groups before exiting */ + ip_mc_drop_socket(sk); + + /* If linger is set, we don't return until the close + * is complete. Otherwise we return immediately. The + * actually closing is done the same either way. + * + * If the close is due to the process exiting, we never + * linger.. + */ + timeout = 0; + if (sock_flag(sk, SOCK_LINGER) && + !(current->flags & PF_EXITING)) + timeout = sk->sk_lingertime; + sk->sk_prot->close(sk, timeout); + sock->sk = NULL; + } + return 0; +} +EXPORT_SYMBOL(inet_release); + +int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) +{ + struct sock *sk = sock->sk; + int err; + + /* If the socket has its own bind function then use it. (RAW) */ + if (sk->sk_prot->bind) { + return sk->sk_prot->bind(sk, uaddr, addr_len); + } + if (addr_len < sizeof(struct sockaddr_in)) + return -EINVAL; + + /* BPF prog is run before any checks are done so that if the prog + * changes context in a wrong way it will be caught. + */ + err = BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr); + if (err) + return err; + + return __inet_bind(sk, uaddr, addr_len, BIND_WITH_LOCK); +} +EXPORT_SYMBOL(inet_bind); + +int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, + u32 flags) +{ + struct sockaddr_in *addr = (struct sockaddr_in *)uaddr; + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + unsigned short snum; + int chk_addr_ret; + u32 tb_id = RT_TABLE_LOCAL; + int err; + + if (addr->sin_family != AF_INET) { + /* Compatibility games : accept AF_UNSPEC (mapped to AF_INET) + * only if s_addr is INADDR_ANY. + */ + err = -EAFNOSUPPORT; + if (addr->sin_family != AF_UNSPEC || + addr->sin_addr.s_addr != htonl(INADDR_ANY)) + goto out; + } + + tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id; + chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id); + + /* Not specified by any standard per-se, however it breaks too + * many applications when removed. It is unfortunate since + * allowing applications to make a non-local bind solves + * several problems with systems using dynamic addressing. + * (ie. your servers still start up even if your ISDN link + * is temporarily down) + */ + err = -EADDRNOTAVAIL; + if (!inet_can_nonlocal_bind(net, inet) && + addr->sin_addr.s_addr != htonl(INADDR_ANY) && + chk_addr_ret != RTN_LOCAL && + chk_addr_ret != RTN_MULTICAST && + chk_addr_ret != RTN_BROADCAST) + goto out; + + snum = ntohs(addr->sin_port); + err = -EACCES; + if (snum && inet_port_requires_bind_service(net, snum) && + !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) + goto out; + + /* We keep a pair of addresses. rcv_saddr is the one + * used by hash lookups, and saddr is used for transmit. + * + * In the BSD API these are the same except where it + * would be illegal to use them (multicast/broadcast) in + * which case the sending device address is used. + */ + if (flags & BIND_WITH_LOCK) + lock_sock(sk); + + /* Check these errors (active socket, double bind). */ + err = -EINVAL; + if (sk->sk_state != TCP_CLOSE || inet->inet_num) + goto out_release_sock; + + inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr; + if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) + inet->inet_saddr = 0; /* Use device */ + + /* Make sure we are allowed to bind here. */ + if (snum || !(inet->bind_address_no_port || + (flags & BIND_FORCE_ADDRESS_NO_PORT))) { + if (sk->sk_prot->get_port(sk, snum)) { + inet->inet_saddr = inet->inet_rcv_saddr = 0; + err = -EADDRINUSE; + goto out_release_sock; + } + if (!(flags & BIND_FROM_BPF)) { + err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); + if (err) { + inet->inet_saddr = inet->inet_rcv_saddr = 0; + goto out_release_sock; + } + } + } + + if (inet->inet_rcv_saddr) + sk->sk_userlocks |= SOCK_BINDADDR_LOCK; + if (snum) + sk->sk_userlocks |= SOCK_BINDPORT_LOCK; + inet->inet_sport = htons(inet->inet_num); + inet->inet_daddr = 0; + inet->inet_dport = 0; + sk_dst_reset(sk); + err = 0; +out_release_sock: + if (flags & BIND_WITH_LOCK) + release_sock(sk); +out: + return err; +} + +int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags) +{ + struct sock *sk = sock->sk; + int err; + + if (addr_len < sizeof(uaddr->sa_family)) + return -EINVAL; + if (uaddr->sa_family == AF_UNSPEC) + return sk->sk_prot->disconnect(sk, flags); + + if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) { + err = sk->sk_prot->pre_connect(sk, uaddr, addr_len); + if (err) + return err; + } + + if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk)) + return -EAGAIN; + return sk->sk_prot->connect(sk, uaddr, addr_len); +} +EXPORT_SYMBOL(inet_dgram_connect); + +static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias) +{ + DEFINE_WAIT_FUNC(wait, woken_wake_function); + + add_wait_queue(sk_sleep(sk), &wait); + sk->sk_write_pending += writebias; + sk->sk_wait_pending++; + + /* Basic assumption: if someone sets sk->sk_err, he _must_ + * change state of the socket from TCP_SYN_*. + * Connect() does not allow to get error notifications + * without closing the socket. + */ + while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { + release_sock(sk); + timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); + lock_sock(sk); + if (signal_pending(current) || !timeo) + break; + } + remove_wait_queue(sk_sleep(sk), &wait); + sk->sk_write_pending -= writebias; + sk->sk_wait_pending--; + return timeo; +} + +/* + * Connect to a remote host. There is regrettably still a little + * TCP 'magic' in here. + */ +int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags, int is_sendmsg) +{ + struct sock *sk = sock->sk; + int err; + long timeo; + + /* + * uaddr can be NULL and addr_len can be 0 if: + * sk is a TCP fastopen active socket and + * TCP_FASTOPEN_CONNECT sockopt is set and + * we already have a valid cookie for this socket. + * In this case, user can call write() after connect(). + * write() will invoke tcp_sendmsg_fastopen() which calls + * __inet_stream_connect(). + */ + if (uaddr) { + if (addr_len < sizeof(uaddr->sa_family)) + return -EINVAL; + + if (uaddr->sa_family == AF_UNSPEC) { + err = sk->sk_prot->disconnect(sk, flags); + sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; + goto out; + } + } + + switch (sock->state) { + default: + err = -EINVAL; + goto out; + case SS_CONNECTED: + err = -EISCONN; + goto out; + case SS_CONNECTING: + if (inet_sk(sk)->defer_connect) + err = is_sendmsg ? -EINPROGRESS : -EISCONN; + else + err = -EALREADY; + /* Fall out of switch with err, set for this state */ + break; + case SS_UNCONNECTED: + err = -EISCONN; + if (sk->sk_state != TCP_CLOSE) + goto out; + + if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) { + err = sk->sk_prot->pre_connect(sk, uaddr, addr_len); + if (err) + goto out; + } + + err = sk->sk_prot->connect(sk, uaddr, addr_len); + if (err < 0) + goto out; + + sock->state = SS_CONNECTING; + + if (!err && inet_sk(sk)->defer_connect) + goto out; + + /* Just entered SS_CONNECTING state; the only + * difference is that return value in non-blocking + * case is EINPROGRESS, rather than EALREADY. + */ + err = -EINPROGRESS; + break; + } + + timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { + int writebias = (sk->sk_protocol == IPPROTO_TCP) && + tcp_sk(sk)->fastopen_req && + tcp_sk(sk)->fastopen_req->data ? 1 : 0; + + /* Error code is set above */ + if (!timeo || !inet_wait_for_connect(sk, timeo, writebias)) + goto out; + + err = sock_intr_errno(timeo); + if (signal_pending(current)) + goto out; + } + + /* Connection was closed by RST, timeout, ICMP error + * or another process disconnected us. + */ + if (sk->sk_state == TCP_CLOSE) + goto sock_error; + + /* sk->sk_err may be not zero now, if RECVERR was ordered by user + * and error was received after socket entered established state. + * Hence, it is handled normally after connect() return successfully. + */ + + sock->state = SS_CONNECTED; + err = 0; +out: + return err; + +sock_error: + err = sock_error(sk) ? : -ECONNABORTED; + sock->state = SS_UNCONNECTED; + if (sk->sk_prot->disconnect(sk, flags)) + sock->state = SS_DISCONNECTING; + goto out; +} +EXPORT_SYMBOL(__inet_stream_connect); + +int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, + int addr_len, int flags) +{ + int err; + + lock_sock(sock->sk); + err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0); + release_sock(sock->sk); + return err; +} +EXPORT_SYMBOL(inet_stream_connect); + +/* + * Accept a pending connection. The TCP layer now gives BSD semantics. + */ + +int inet_accept(struct socket *sock, struct socket *newsock, int flags, + bool kern) +{ + struct sock *sk1 = sock->sk; + int err = -EINVAL; + struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern); + + if (!sk2) + goto do_err; + + lock_sock(sk2); + + sock_rps_record_flow(sk2); + WARN_ON(!((1 << sk2->sk_state) & + (TCPF_ESTABLISHED | TCPF_SYN_RECV | + TCPF_CLOSE_WAIT | TCPF_CLOSE))); + + sock_graft(sk2, newsock); + + newsock->state = SS_CONNECTED; + err = 0; + release_sock(sk2); +do_err: + return err; +} +EXPORT_SYMBOL(inet_accept); + +/* + * This does both peername and sockname. + */ +int inet_getname(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + struct sock *sk = sock->sk; + struct inet_sock *inet = inet_sk(sk); + DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr); + + sin->sin_family = AF_INET; + if (peer) { + if (!inet->inet_dport || + (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) && + peer == 1)) + return -ENOTCONN; + sin->sin_port = inet->inet_dport; + sin->sin_addr.s_addr = inet->inet_daddr; + } else { + __be32 addr = inet->inet_rcv_saddr; + if (!addr) + addr = inet->inet_saddr; + sin->sin_port = inet->inet_sport; + sin->sin_addr.s_addr = addr; + } + if (cgroup_bpf_enabled) + BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, + peer ? BPF_CGROUP_INET4_GETPEERNAME : + BPF_CGROUP_INET4_GETSOCKNAME, + NULL); + memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + return sizeof(*sin); +} +EXPORT_SYMBOL(inet_getname); + +int inet_send_prepare(struct sock *sk) +{ + sock_rps_record_flow(sk); + + /* We may need to bind the socket. */ + if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind && + inet_autobind(sk)) + return -EAGAIN; + + return 0; +} +EXPORT_SYMBOL_GPL(inet_send_prepare); + +int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) +{ + struct sock *sk = sock->sk; + + if (unlikely(inet_send_prepare(sk))) + return -EAGAIN; + + return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg, + sk, msg, size); +} +EXPORT_SYMBOL(inet_sendmsg); + +ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, + size_t size, int flags) +{ + struct sock *sk = sock->sk; + + if (unlikely(inet_send_prepare(sk))) + return -EAGAIN; + + if (sk->sk_prot->sendpage) + return sk->sk_prot->sendpage(sk, page, offset, size, flags); + return sock_no_sendpage(sock, page, offset, size, flags); +} +EXPORT_SYMBOL(inet_sendpage); + +INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *, + size_t, int, int, int *)); +int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, + int flags) +{ + struct sock *sk = sock->sk; + int addr_len = 0; + int err; + + if (likely(!(flags & MSG_ERRQUEUE))) + sock_rps_record_flow(sk); + + err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg, + sk, msg, size, flags & MSG_DONTWAIT, + flags & ~MSG_DONTWAIT, &addr_len); + if (err >= 0) + msg->msg_namelen = addr_len; + return err; +} +EXPORT_SYMBOL(inet_recvmsg); + +int inet_shutdown(struct socket *sock, int how) +{ + struct sock *sk = sock->sk; + int err = 0; + + /* This should really check to make sure + * the socket is a TCP socket. (WHY AC...) + */ + how++; /* maps 0->1 has the advantage of making bit 1 rcvs and + 1->2 bit 2 snds. + 2->3 */ + if ((how & ~SHUTDOWN_MASK) || !how) /* MAXINT->0 */ + return -EINVAL; + + lock_sock(sk); + if (sock->state == SS_CONNECTING) { + if ((1 << sk->sk_state) & + (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)) + sock->state = SS_DISCONNECTING; + else + sock->state = SS_CONNECTED; + } + + switch (sk->sk_state) { + case TCP_CLOSE: + err = -ENOTCONN; + /* Hack to wake up other listeners, who can poll for + EPOLLHUP, even on eg. unconnected UDP sockets -- RR */ + fallthrough; + default: + WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how); + if (sk->sk_prot->shutdown) + sk->sk_prot->shutdown(sk, how); + break; + + /* Remaining two branches are temporary solution for missing + * close() in multithreaded environment. It is _not_ a good idea, + * but we have no choice until close() is repaired at VFS level. + */ + case TCP_LISTEN: + if (!(how & RCV_SHUTDOWN)) + break; + fallthrough; + case TCP_SYN_SENT: + err = sk->sk_prot->disconnect(sk, O_NONBLOCK); + sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; + break; + } + + /* Wake up anyone sleeping in poll. */ + sk->sk_state_change(sk); + release_sock(sk); + return err; +} +EXPORT_SYMBOL(inet_shutdown); + +/* + * ioctl() calls you can issue on an INET socket. Most of these are + * device configuration and stuff and very rarely used. Some ioctls + * pass on to the socket itself. + * + * NOTE: I like the idea of a module for the config stuff. ie ifconfig + * loads the devconfigure module does its configuring and unloads it. + * There's a good 20K of config code hanging around the kernel. + */ + +int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) +{ + struct sock *sk = sock->sk; + int err = 0; + struct net *net = sock_net(sk); + void __user *p = (void __user *)arg; + struct ifreq ifr; + struct rtentry rt; + + switch (cmd) { + case SIOCADDRT: + case SIOCDELRT: + if (copy_from_user(&rt, p, sizeof(struct rtentry))) + return -EFAULT; + err = ip_rt_ioctl(net, cmd, &rt); + break; + case SIOCRTMSG: + err = -EINVAL; + break; + case SIOCDARP: + case SIOCGARP: + case SIOCSARP: + err = arp_ioctl(net, cmd, (void __user *)arg); + break; + case SIOCGIFADDR: + case SIOCGIFBRDADDR: + case SIOCGIFNETMASK: + case SIOCGIFDSTADDR: + case SIOCGIFPFLAGS: + if (copy_from_user(&ifr, p, sizeof(struct ifreq))) + return -EFAULT; + err = devinet_ioctl(net, cmd, &ifr); + if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq))) + err = -EFAULT; + break; + + case SIOCSIFADDR: + case SIOCSIFBRDADDR: + case SIOCSIFNETMASK: + case SIOCSIFDSTADDR: + case SIOCSIFPFLAGS: + case SIOCSIFFLAGS: + if (copy_from_user(&ifr, p, sizeof(struct ifreq))) + return -EFAULT; + err = devinet_ioctl(net, cmd, &ifr); + break; + default: + if (sk->sk_prot->ioctl) + err = sk->sk_prot->ioctl(sk, cmd, arg); + else + err = -ENOIOCTLCMD; + break; + } + return err; +} +EXPORT_SYMBOL(inet_ioctl); + +#ifdef CONFIG_COMPAT +static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd, + struct compat_rtentry __user *ur) +{ + compat_uptr_t rtdev; + struct rtentry rt; + + if (copy_from_user(&rt.rt_dst, &ur->rt_dst, + 3 * sizeof(struct sockaddr)) || + get_user(rt.rt_flags, &ur->rt_flags) || + get_user(rt.rt_metric, &ur->rt_metric) || + get_user(rt.rt_mtu, &ur->rt_mtu) || + get_user(rt.rt_window, &ur->rt_window) || + get_user(rt.rt_irtt, &ur->rt_irtt) || + get_user(rtdev, &ur->rt_dev)) + return -EFAULT; + + rt.rt_dev = compat_ptr(rtdev); + return ip_rt_ioctl(sock_net(sk), cmd, &rt); +} + +static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) +{ + void __user *argp = compat_ptr(arg); + struct sock *sk = sock->sk; + + switch (cmd) { + case SIOCADDRT: + case SIOCDELRT: + return inet_compat_routing_ioctl(sk, cmd, argp); + default: + if (!sk->sk_prot->compat_ioctl) + return -ENOIOCTLCMD; + return sk->sk_prot->compat_ioctl(sk, cmd, arg); + } +} +#endif /* CONFIG_COMPAT */ + +const struct proto_ops inet_stream_ops = { + .family = PF_INET, + .owner = THIS_MODULE, + .release = inet_release, + .bind = inet_bind, + .connect = inet_stream_connect, + .socketpair = sock_no_socketpair, + .accept = inet_accept, + .getname = inet_getname, + .poll = tcp_poll, + .ioctl = inet_ioctl, + .gettstamp = sock_gettstamp, + .listen = inet_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = inet_recvmsg, +#ifdef CONFIG_MMU + .mmap = tcp_mmap, +#endif + .sendpage = inet_sendpage, + .splice_read = tcp_splice_read, + .read_sock = tcp_read_sock, + .sendmsg_locked = tcp_sendmsg_locked, + .sendpage_locked = tcp_sendpage_locked, + .peek_len = tcp_peek_len, +#ifdef CONFIG_COMPAT + .compat_ioctl = inet_compat_ioctl, +#endif + .set_rcvlowat = tcp_set_rcvlowat, +}; +EXPORT_SYMBOL(inet_stream_ops); + +const struct proto_ops inet_dgram_ops = { + .family = PF_INET, + .owner = THIS_MODULE, + .release = inet_release, + .bind = inet_bind, + .connect = inet_dgram_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = inet_getname, + .poll = udp_poll, + .ioctl = inet_ioctl, + .gettstamp = sock_gettstamp, + .listen = sock_no_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = inet_recvmsg, + .mmap = sock_no_mmap, + .sendpage = inet_sendpage, + .set_peek_off = sk_set_peek_off, +#ifdef CONFIG_COMPAT + .compat_ioctl = inet_compat_ioctl, +#endif +}; +EXPORT_SYMBOL(inet_dgram_ops); + +/* + * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without + * udp_poll + */ +static const struct proto_ops inet_sockraw_ops = { + .family = PF_INET, + .owner = THIS_MODULE, + .release = inet_release, + .bind = inet_bind, + .connect = inet_dgram_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = inet_getname, + .poll = datagram_poll, + .ioctl = inet_ioctl, + .gettstamp = sock_gettstamp, + .listen = sock_no_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = inet_recvmsg, + .mmap = sock_no_mmap, + .sendpage = inet_sendpage, +#ifdef CONFIG_COMPAT + .compat_ioctl = inet_compat_ioctl, +#endif +}; + +static const struct net_proto_family inet_family_ops = { + .family = PF_INET, + .create = inet_create, + .owner = THIS_MODULE, +}; + +/* Upon startup we insert all the elements in inetsw_array[] into + * the linked list inetsw. + */ +static struct inet_protosw inetsw_array[] = +{ + { + .type = SOCK_STREAM, + .protocol = IPPROTO_TCP, + .prot = &tcp_prot, + .ops = &inet_stream_ops, + .flags = INET_PROTOSW_PERMANENT | + INET_PROTOSW_ICSK, + }, + + { + .type = SOCK_DGRAM, + .protocol = IPPROTO_UDP, + .prot = &udp_prot, + .ops = &inet_dgram_ops, + .flags = INET_PROTOSW_PERMANENT, + }, + + { + .type = SOCK_DGRAM, + .protocol = IPPROTO_ICMP, + .prot = &ping_prot, + .ops = &inet_sockraw_ops, + .flags = INET_PROTOSW_REUSE, + }, + + { + .type = SOCK_RAW, + .protocol = IPPROTO_IP, /* wild card */ + .prot = &raw_prot, + .ops = &inet_sockraw_ops, + .flags = INET_PROTOSW_REUSE, + } +}; + +#define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array) + +void inet_register_protosw(struct inet_protosw *p) +{ + struct list_head *lh; + struct inet_protosw *answer; + int protocol = p->protocol; + struct list_head *last_perm; + + spin_lock_bh(&inetsw_lock); + + if (p->type >= SOCK_MAX) + goto out_illegal; + + /* If we are trying to override a permanent protocol, bail. */ + last_perm = &inetsw[p->type]; + list_for_each(lh, &inetsw[p->type]) { + answer = list_entry(lh, struct inet_protosw, list); + /* Check only the non-wild match. */ + if ((INET_PROTOSW_PERMANENT & answer->flags) == 0) + break; + if (protocol == answer->protocol) + goto out_permanent; + last_perm = lh; + } + + /* Add the new entry after the last permanent entry if any, so that + * the new entry does not override a permanent entry when matched with + * a wild-card protocol. But it is allowed to override any existing + * non-permanent entry. This means that when we remove this entry, the + * system automatically returns to the old behavior. + */ + list_add_rcu(&p->list, last_perm); +out: + spin_unlock_bh(&inetsw_lock); + + return; + +out_permanent: + pr_err("Attempt to override permanent protocol %d\n", protocol); + goto out; + +out_illegal: + pr_err("Ignoring attempt to register invalid socket type %d\n", + p->type); + goto out; +} +EXPORT_SYMBOL(inet_register_protosw); + +void inet_unregister_protosw(struct inet_protosw *p) +{ + if (INET_PROTOSW_PERMANENT & p->flags) { + pr_err("Attempt to unregister permanent protocol %d\n", + p->protocol); + } else { + spin_lock_bh(&inetsw_lock); + list_del_rcu(&p->list); + spin_unlock_bh(&inetsw_lock); + + synchronize_net(); + } +} +EXPORT_SYMBOL(inet_unregister_protosw); + +static int inet_sk_reselect_saddr(struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + __be32 old_saddr = inet->inet_saddr; + __be32 daddr = inet->inet_daddr; + struct flowi4 *fl4; + struct rtable *rt; + __be32 new_saddr; + struct ip_options_rcu *inet_opt; + + inet_opt = rcu_dereference_protected(inet->inet_opt, + lockdep_sock_is_held(sk)); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + + /* Query new route. */ + fl4 = &inet->cork.fl.u.ip4; + rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk), + sk->sk_bound_dev_if, sk->sk_protocol, + inet->inet_sport, inet->inet_dport, sk); + if (IS_ERR(rt)) + return PTR_ERR(rt); + + sk_setup_caps(sk, &rt->dst); + + new_saddr = fl4->saddr; + + if (new_saddr == old_saddr) + return 0; + + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) { + pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n", + __func__, &old_saddr, &new_saddr); + } + + inet->inet_saddr = inet->inet_rcv_saddr = new_saddr; + + /* + * XXX The only one ugly spot where we need to + * XXX really change the sockets identity after + * XXX it has entered the hashes. -DaveM + * + * Besides that, it does not check for connection + * uniqueness. Wait for troubles. + */ + return __sk_prot_rehash(sk); +} + +int inet_sk_rebuild_header(struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0); + __be32 daddr; + struct ip_options_rcu *inet_opt; + struct flowi4 *fl4; + int err; + + /* Route is OK, nothing to do. */ + if (rt) + return 0; + + /* Reroute. */ + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + daddr = inet->inet_daddr; + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + rcu_read_unlock(); + fl4 = &inet->cork.fl.u.ip4; + rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr, + inet->inet_dport, inet->inet_sport, + sk->sk_protocol, RT_CONN_FLAGS(sk), + sk->sk_bound_dev_if); + if (!IS_ERR(rt)) { + err = 0; + sk_setup_caps(sk, &rt->dst); + } else { + err = PTR_ERR(rt); + + /* Routing failed... */ + sk->sk_route_caps = 0; + /* + * Other protocols have to map its equivalent state to TCP_SYN_SENT. + * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme + */ + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) || + sk->sk_state != TCP_SYN_SENT || + (sk->sk_userlocks & SOCK_BINDADDR_LOCK) || + (err = inet_sk_reselect_saddr(sk)) != 0) + sk->sk_err_soft = -err; + } + + return err; +} +EXPORT_SYMBOL(inet_sk_rebuild_header); + +void inet_sk_set_state(struct sock *sk, int state) +{ + trace_inet_sock_set_state(sk, sk->sk_state, state); + sk->sk_state = state; +} +EXPORT_SYMBOL(inet_sk_set_state); + +void inet_sk_state_store(struct sock *sk, int newstate) +{ + trace_inet_sock_set_state(sk, sk->sk_state, newstate); + smp_store_release(&sk->sk_state, newstate); +} + +struct sk_buff *inet_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + bool udpfrag = false, fixedid = false, gso_partial, encap; + struct sk_buff *segs = ERR_PTR(-EINVAL); + const struct net_offload *ops; + unsigned int offset = 0; + struct iphdr *iph; + int proto, tot_len; + int nhoff; + int ihl; + int id; + + skb_reset_network_header(skb); + nhoff = skb_network_header(skb) - skb_mac_header(skb); + if (unlikely(!pskb_may_pull(skb, sizeof(*iph)))) + goto out; + + iph = ip_hdr(skb); + ihl = iph->ihl * 4; + if (ihl < sizeof(*iph)) + goto out; + + id = ntohs(iph->id); + proto = iph->protocol; + + /* Warning: after this point, iph might be no longer valid */ + if (unlikely(!pskb_may_pull(skb, ihl))) + goto out; + __skb_pull(skb, ihl); + + encap = SKB_GSO_CB(skb)->encap_level > 0; + if (encap) + features &= skb->dev->hw_enc_features; + SKB_GSO_CB(skb)->encap_level += ihl; + + skb_reset_transport_header(skb); + + segs = ERR_PTR(-EPROTONOSUPPORT); + + if (!skb->encapsulation || encap) { + udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP); + fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID); + + /* fixed ID is invalid if DF bit is not set */ + if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF))) + goto out; + } + + ops = rcu_dereference(inet_offloads[proto]); + if (likely(ops && ops->callbacks.gso_segment)) { + segs = ops->callbacks.gso_segment(skb, features); + if (!segs) + skb->network_header = skb_mac_header(skb) + nhoff - skb->head; + } + + if (IS_ERR_OR_NULL(segs)) + goto out; + + gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); + + skb = segs; + do { + iph = (struct iphdr *)(skb_mac_header(skb) + nhoff); + if (udpfrag) { + iph->frag_off = htons(offset >> 3); + if (skb->next) + iph->frag_off |= htons(IP_MF); + offset += skb->len - nhoff - ihl; + tot_len = skb->len - nhoff; + } else if (skb_is_gso(skb)) { + if (!fixedid) { + iph->id = htons(id); + id += skb_shinfo(skb)->gso_segs; + } + + if (gso_partial) + tot_len = skb_shinfo(skb)->gso_size + + SKB_GSO_CB(skb)->data_offset + + skb->head - (unsigned char *)iph; + else + tot_len = skb->len - nhoff; + } else { + if (!fixedid) + iph->id = htons(id++); + tot_len = skb->len - nhoff; + } + iph->tot_len = htons(tot_len); + ip_send_check(iph); + if (encap) + skb_reset_inner_headers(skb); + skb->network_header = (u8 *)iph - skb->head; + skb_reset_mac_len(skb); + } while ((skb = skb->next)); + +out: + return segs; +} +EXPORT_SYMBOL(inet_gso_segment); + +static struct sk_buff *ipip_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4)) + return ERR_PTR(-EINVAL); + + return inet_gso_segment(skb, features); +} + +struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb) +{ + const struct net_offload *ops; + struct sk_buff *pp = NULL; + const struct iphdr *iph; + struct sk_buff *p; + unsigned int hlen; + unsigned int off; + unsigned int id; + int flush = 1; + int proto; + + off = skb_gro_offset(skb); + hlen = off + sizeof(*iph); + iph = skb_gro_header_fast(skb, off); + if (skb_gro_header_hard(skb, hlen)) { + iph = skb_gro_header_slow(skb, hlen, off); + if (unlikely(!iph)) + goto out; + } + + proto = iph->protocol; + + rcu_read_lock(); + ops = rcu_dereference(inet_offloads[proto]); + if (!ops || !ops->callbacks.gro_receive) + goto out_unlock; + + if (*(u8 *)iph != 0x45) + goto out_unlock; + + if (ip_is_fragment(iph)) + goto out_unlock; + + if (unlikely(ip_fast_csum((u8 *)iph, 5))) + goto out_unlock; + + id = ntohl(*(__be32 *)&iph->id); + flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF)); + id >>= 16; + + list_for_each_entry(p, head, list) { + struct iphdr *iph2; + u16 flush_id; + + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + iph2 = (struct iphdr *)(p->data + off); + /* The above works because, with the exception of the top + * (inner most) layer, we only aggregate pkts with the same + * hdr length so all the hdrs we'll need to verify will start + * at the same offset. + */ + if ((iph->protocol ^ iph2->protocol) | + ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) | + ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + + /* All fields must match except length and checksum. */ + NAPI_GRO_CB(p)->flush |= + (iph->ttl ^ iph2->ttl) | + (iph->tos ^ iph2->tos) | + ((iph->frag_off ^ iph2->frag_off) & htons(IP_DF)); + + NAPI_GRO_CB(p)->flush |= flush; + + /* We need to store of the IP ID check to be included later + * when we can verify that this packet does in fact belong + * to a given flow. + */ + flush_id = (u16)(id - ntohs(iph2->id)); + + /* This bit of code makes it much easier for us to identify + * the cases where we are doing atomic vs non-atomic IP ID + * checks. Specifically an atomic check can return IP ID + * values 0 - 0xFFFF, while a non-atomic check can only + * return 0 or 0xFFFF. + */ + if (!NAPI_GRO_CB(p)->is_atomic || + !(iph->frag_off & htons(IP_DF))) { + flush_id ^= NAPI_GRO_CB(p)->count; + flush_id = flush_id ? 0xFFFF : 0; + } + + /* If the previous IP ID value was based on an atomic + * datagram we can overwrite the value and ignore it. + */ + if (NAPI_GRO_CB(skb)->is_atomic) + NAPI_GRO_CB(p)->flush_id = flush_id; + else + NAPI_GRO_CB(p)->flush_id |= flush_id; + } + + NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF)); + NAPI_GRO_CB(skb)->flush |= flush; + skb_set_network_header(skb, off); + /* The above will be needed by the transport layer if there is one + * immediately following this IP hdr. + */ + + /* Note : No need to call skb_gro_postpull_rcsum() here, + * as we already checked checksum over ipv4 header was 0 + */ + skb_gro_pull(skb, sizeof(*iph)); + skb_set_transport_header(skb, skb_gro_offset(skb)); + + pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive, + ops->callbacks.gro_receive, head, skb); + +out_unlock: + rcu_read_unlock(); + +out: + skb_gro_flush_final(skb, pp, flush); + + return pp; +} +EXPORT_SYMBOL(inet_gro_receive); + +static struct sk_buff *ipip_gro_receive(struct list_head *head, + struct sk_buff *skb) +{ + if (NAPI_GRO_CB(skb)->encap_mark) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + + NAPI_GRO_CB(skb)->encap_mark = 1; + + return inet_gro_receive(head, skb); +} + +#define SECONDS_PER_DAY 86400 + +/* inet_current_timestamp - Return IP network timestamp + * + * Return milliseconds since midnight in network byte order. + */ +__be32 inet_current_timestamp(void) +{ + u32 secs; + u32 msecs; + struct timespec64 ts; + + ktime_get_real_ts64(&ts); + + /* Get secs since midnight. */ + (void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs); + /* Convert to msecs. */ + msecs = secs * MSEC_PER_SEC; + /* Convert nsec to msec. */ + msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC; + + /* Convert to network byte order. */ + return htonl(msecs); +} +EXPORT_SYMBOL(inet_current_timestamp); + +int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) +{ + if (sk->sk_family == AF_INET) + return ip_recv_error(sk, msg, len, addr_len); +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len); +#endif + return -EINVAL; +} + +int inet_gro_complete(struct sk_buff *skb, int nhoff) +{ + __be16 newlen = htons(skb->len - nhoff); + struct iphdr *iph = (struct iphdr *)(skb->data + nhoff); + const struct net_offload *ops; + int proto = iph->protocol; + int err = -ENOSYS; + + if (skb->encapsulation) { + skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP)); + skb_set_inner_network_header(skb, nhoff); + } + + csum_replace2(&iph->check, iph->tot_len, newlen); + iph->tot_len = newlen; + + rcu_read_lock(); + ops = rcu_dereference(inet_offloads[proto]); + if (WARN_ON(!ops || !ops->callbacks.gro_complete)) + goto out_unlock; + + /* Only need to add sizeof(*iph) to get to the next hdr below + * because any hdr with option will have been flushed in + * inet_gro_receive(). + */ + err = INDIRECT_CALL_2(ops->callbacks.gro_complete, + tcp4_gro_complete, udp4_gro_complete, + skb, nhoff + sizeof(*iph)); + +out_unlock: + rcu_read_unlock(); + + return err; +} +EXPORT_SYMBOL(inet_gro_complete); + +static int ipip_gro_complete(struct sk_buff *skb, int nhoff) +{ + skb->encapsulation = 1; + skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4; + return inet_gro_complete(skb, nhoff); +} + +int inet_ctl_sock_create(struct sock **sk, unsigned short family, + unsigned short type, unsigned char protocol, + struct net *net) +{ + struct socket *sock; + int rc = sock_create_kern(net, family, type, protocol, &sock); + + if (rc == 0) { + *sk = sock->sk; + (*sk)->sk_allocation = GFP_ATOMIC; + /* + * Unhash it so that IP input processing does not even see it, + * we do not wish this socket to see incoming packets. + */ + (*sk)->sk_prot->unhash(*sk); + } + return rc; +} +EXPORT_SYMBOL_GPL(inet_ctl_sock_create); + +u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt) +{ + return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt); +} +EXPORT_SYMBOL_GPL(snmp_get_cpu_field); + +unsigned long snmp_fold_field(void __percpu *mib, int offt) +{ + unsigned long res = 0; + int i; + + for_each_possible_cpu(i) + res += snmp_get_cpu_field(mib, i, offt); + return res; +} +EXPORT_SYMBOL_GPL(snmp_fold_field); + +#if BITS_PER_LONG==32 + +u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt, + size_t syncp_offset) +{ + void *bhptr; + struct u64_stats_sync *syncp; + u64 v; + unsigned int start; + + bhptr = per_cpu_ptr(mib, cpu); + syncp = (struct u64_stats_sync *)(bhptr + syncp_offset); + do { + start = u64_stats_fetch_begin_irq(syncp); + v = *(((u64 *)bhptr) + offt); + } while (u64_stats_fetch_retry_irq(syncp, start)); + + return v; +} +EXPORT_SYMBOL_GPL(snmp_get_cpu_field64); + +u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset) +{ + u64 res = 0; + int cpu; + + for_each_possible_cpu(cpu) { + res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset); + } + return res; +} +EXPORT_SYMBOL_GPL(snmp_fold_field64); +#endif + +#ifdef CONFIG_IP_MULTICAST +static const struct net_protocol igmp_protocol = { + .handler = igmp_rcv, + .netns_ok = 1, +}; +#endif + +static const struct net_protocol tcp_protocol = { + .handler = tcp_v4_rcv, + .err_handler = tcp_v4_err, + .no_policy = 1, + .netns_ok = 1, + .icmp_strict_tag_validation = 1, +}; + +static const struct net_protocol udp_protocol = { + .handler = udp_rcv, + .err_handler = udp_err, + .no_policy = 1, + .netns_ok = 1, +}; + +static const struct net_protocol icmp_protocol = { + .handler = icmp_rcv, + .err_handler = icmp_err, + .no_policy = 1, + .netns_ok = 1, +}; + +static __net_init int ipv4_mib_init_net(struct net *net) +{ + int i; + + net->mib.tcp_statistics = alloc_percpu(struct tcp_mib); + if (!net->mib.tcp_statistics) + goto err_tcp_mib; + net->mib.ip_statistics = alloc_percpu(struct ipstats_mib); + if (!net->mib.ip_statistics) + goto err_ip_mib; + + for_each_possible_cpu(i) { + struct ipstats_mib *af_inet_stats; + af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i); + u64_stats_init(&af_inet_stats->syncp); + } + + net->mib.net_statistics = alloc_percpu(struct linux_mib); + if (!net->mib.net_statistics) + goto err_net_mib; + net->mib.udp_statistics = alloc_percpu(struct udp_mib); + if (!net->mib.udp_statistics) + goto err_udp_mib; + net->mib.udplite_statistics = alloc_percpu(struct udp_mib); + if (!net->mib.udplite_statistics) + goto err_udplite_mib; + net->mib.icmp_statistics = alloc_percpu(struct icmp_mib); + if (!net->mib.icmp_statistics) + goto err_icmp_mib; + net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib), + GFP_KERNEL); + if (!net->mib.icmpmsg_statistics) + goto err_icmpmsg_mib; + + tcp_mib_init(net); + return 0; + +err_icmpmsg_mib: + free_percpu(net->mib.icmp_statistics); +err_icmp_mib: + free_percpu(net->mib.udplite_statistics); +err_udplite_mib: + free_percpu(net->mib.udp_statistics); +err_udp_mib: + free_percpu(net->mib.net_statistics); +err_net_mib: + free_percpu(net->mib.ip_statistics); +err_ip_mib: + free_percpu(net->mib.tcp_statistics); +err_tcp_mib: + return -ENOMEM; +} + +static __net_exit void ipv4_mib_exit_net(struct net *net) +{ + kfree(net->mib.icmpmsg_statistics); + free_percpu(net->mib.icmp_statistics); + free_percpu(net->mib.udplite_statistics); + free_percpu(net->mib.udp_statistics); + free_percpu(net->mib.net_statistics); + free_percpu(net->mib.ip_statistics); + free_percpu(net->mib.tcp_statistics); +#ifdef CONFIG_MPTCP + /* allocated on demand, see mptcp_init_sock() */ + free_percpu(net->mib.mptcp_statistics); +#endif +} + +static __net_initdata struct pernet_operations ipv4_mib_ops = { + .init = ipv4_mib_init_net, + .exit = ipv4_mib_exit_net, +}; + +static int __init init_ipv4_mibs(void) +{ + return register_pernet_subsys(&ipv4_mib_ops); +} + +static __net_init int inet_init_net(struct net *net) +{ + /* + * Set defaults for local port range + */ + seqlock_init(&net->ipv4.ip_local_ports.lock); + net->ipv4.ip_local_ports.range[0] = 32768; + net->ipv4.ip_local_ports.range[1] = 60999; + + seqlock_init(&net->ipv4.ping_group_range.lock); + /* + * Sane defaults - nobody may create ping sockets. + * Boot scripts should set this to distro-specific group. + */ + net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1); + net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0); + + /* Default values for sysctl-controlled parameters. + * We set them here, in case sysctl is not compiled. + */ + net->ipv4.sysctl_ip_default_ttl = IPDEFTTL; + net->ipv4.sysctl_ip_fwd_update_priority = 1; + net->ipv4.sysctl_ip_dynaddr = 0; + net->ipv4.sysctl_ip_early_demux = 1; + net->ipv4.sysctl_udp_early_demux = 1; + net->ipv4.sysctl_tcp_early_demux = 1; + net->ipv4.sysctl_nexthop_compat_mode = 1; +#ifdef CONFIG_SYSCTL + net->ipv4.sysctl_ip_prot_sock = PROT_SOCK; +#endif + + /* Some igmp sysctl, whose values are always used */ + net->ipv4.sysctl_igmp_max_memberships = 20; + net->ipv4.sysctl_igmp_max_msf = 10; + /* IGMP reports for link-local multicast groups are enabled by default */ + net->ipv4.sysctl_igmp_llm_reports = 1; + net->ipv4.sysctl_igmp_qrv = 2; + + return 0; +} + +static __net_initdata struct pernet_operations af_inet_ops = { + .init = inet_init_net, +}; + +static int __init init_inet_pernet_ops(void) +{ + return register_pernet_subsys(&af_inet_ops); +} + +static int ipv4_proc_init(void); + +/* + * IP protocol layer initialiser + */ + +static struct packet_offload ip_packet_offload __read_mostly = { + .type = cpu_to_be16(ETH_P_IP), + .callbacks = { + .gso_segment = inet_gso_segment, + .gro_receive = inet_gro_receive, + .gro_complete = inet_gro_complete, + }, +}; + +static const struct net_offload ipip_offload = { + .callbacks = { + .gso_segment = ipip_gso_segment, + .gro_receive = ipip_gro_receive, + .gro_complete = ipip_gro_complete, + }, +}; + +static int __init ipip_offload_init(void) +{ + return inet_add_offload(&ipip_offload, IPPROTO_IPIP); +} + +static int __init ipv4_offload_init(void) +{ + /* + * Add offloads + */ + if (udpv4_offload_init() < 0) + pr_crit("%s: Cannot add UDP protocol offload\n", __func__); + if (tcpv4_offload_init() < 0) + pr_crit("%s: Cannot add TCP protocol offload\n", __func__); + if (ipip_offload_init() < 0) + pr_crit("%s: Cannot add IPIP protocol offload\n", __func__); + + dev_add_offload(&ip_packet_offload); + return 0; +} + +fs_initcall(ipv4_offload_init); + +static struct packet_type ip_packet_type __read_mostly = { + .type = cpu_to_be16(ETH_P_IP), + .func = ip_rcv, + .list_func = ip_list_rcv, +}; + +static int __init inet_init(void) +{ + struct inet_protosw *q; + struct list_head *r; + int rc; + + sock_skb_cb_check_size(sizeof(struct inet_skb_parm)); + + rc = proto_register(&tcp_prot, 1); + if (rc) + goto out; + + rc = proto_register(&udp_prot, 1); + if (rc) + goto out_unregister_tcp_proto; + + rc = proto_register(&raw_prot, 1); + if (rc) + goto out_unregister_udp_proto; + + rc = proto_register(&ping_prot, 1); + if (rc) + goto out_unregister_raw_proto; + + /* + * Tell SOCKET that we are alive... + */ + + (void)sock_register(&inet_family_ops); + +#ifdef CONFIG_SYSCTL + ip_static_sysctl_init(); +#endif + + /* + * Add all the base protocols. + */ + + if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0) + pr_crit("%s: Cannot add ICMP protocol\n", __func__); + if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0) + pr_crit("%s: Cannot add UDP protocol\n", __func__); + if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0) + pr_crit("%s: Cannot add TCP protocol\n", __func__); +#ifdef CONFIG_IP_MULTICAST + if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0) + pr_crit("%s: Cannot add IGMP protocol\n", __func__); +#endif + + /* Register the socket-side information for inet_create. */ + for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r) + INIT_LIST_HEAD(r); + + for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q) + inet_register_protosw(q); + + /* + * Set the ARP module up + */ + + arp_init(); + + /* + * Set the IP module up + */ + + ip_init(); + + /* Initialise per-cpu ipv4 mibs */ + if (init_ipv4_mibs()) + panic("%s: Cannot init ipv4 mibs\n", __func__); + + /* Setup TCP slab cache for open requests. */ + tcp_init(); + + /* Setup UDP memory threshold */ + udp_init(); + + /* Add UDP-Lite (RFC 3828) */ + udplite4_register(); + + raw_init(); + + ping_init(); + + /* + * Set the ICMP layer up + */ + + if (icmp_init() < 0) + panic("Failed to create the ICMP control socket.\n"); + + /* + * Initialise the multicast router + */ +#if defined(CONFIG_IP_MROUTE) + if (ip_mr_init()) + pr_crit("%s: Cannot init ipv4 mroute\n", __func__); +#endif + + if (init_inet_pernet_ops()) + pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__); + + ipv4_proc_init(); + + ipfrag_init(); + + dev_add_pack(&ip_packet_type); + + ip_tunnel_core_init(); + + rc = 0; +out: + return rc; +out_unregister_raw_proto: + proto_unregister(&raw_prot); +out_unregister_udp_proto: + proto_unregister(&udp_prot); +out_unregister_tcp_proto: + proto_unregister(&tcp_prot); + goto out; +} + +fs_initcall(inet_init); + +/* ------------------------------------------------------------------------ */ + +#ifdef CONFIG_PROC_FS +static int __init ipv4_proc_init(void) +{ + int rc = 0; + + if (raw_proc_init()) + goto out_raw; + if (tcp4_proc_init()) + goto out_tcp; + if (udp4_proc_init()) + goto out_udp; + if (ping_proc_init()) + goto out_ping; + if (ip_misc_proc_init()) + goto out_misc; +out: + return rc; +out_misc: + ping_proc_exit(); +out_ping: + udp4_proc_exit(); +out_udp: + tcp4_proc_exit(); +out_tcp: + raw_proc_exit(); +out_raw: + rc = -ENOMEM; + goto out; +} + +#else /* CONFIG_PROC_FS */ +static int __init ipv4_proc_init(void) +{ + return 0; +} +#endif /* CONFIG_PROC_FS */ diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c new file mode 100644 index 000000000..36ed85bf2 --- /dev/null +++ b/net/ipv4/ah4.c @@ -0,0 +1,599 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define pr_fmt(fmt) "IPsec: " fmt + +#include <crypto/algapi.h> +#include <crypto/hash.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <net/ip.h> +#include <net/xfrm.h> +#include <net/ah.h> +#include <linux/crypto.h> +#include <linux/pfkeyv2.h> +#include <linux/scatterlist.h> +#include <net/icmp.h> +#include <net/protocol.h> + +struct ah_skb_cb { + struct xfrm_skb_cb xfrm; + void *tmp; +}; + +#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0])) + +static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, + unsigned int size) +{ + unsigned int len; + + len = size + crypto_ahash_digestsize(ahash) + + (crypto_ahash_alignmask(ahash) & + ~(crypto_tfm_ctx_alignment() - 1)); + + len = ALIGN(len, crypto_tfm_ctx_alignment()); + + len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); + len = ALIGN(len, __alignof__(struct scatterlist)); + + len += sizeof(struct scatterlist) * nfrags; + + return kmalloc(len, GFP_ATOMIC); +} + +static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset) +{ + return tmp + offset; +} + +static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, + unsigned int offset) +{ + return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); +} + +static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, + u8 *icv) +{ + struct ahash_request *req; + + req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), + crypto_tfm_ctx_alignment()); + + ahash_request_set_tfm(req, ahash); + + return req; +} + +static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, + struct ahash_request *req) +{ + return (void *)ALIGN((unsigned long)(req + 1) + + crypto_ahash_reqsize(ahash), + __alignof__(struct scatterlist)); +} + +/* Clear mutable options and find final destination to substitute + * into IP header for icv calculation. Options are already checked + * for validity, so paranoia is not required. */ + +static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr) +{ + unsigned char *optptr = (unsigned char *)(iph+1); + int l = iph->ihl*4 - sizeof(struct iphdr); + int optlen; + + while (l > 0) { + switch (*optptr) { + case IPOPT_END: + return 0; + case IPOPT_NOOP: + l--; + optptr++; + continue; + } + optlen = optptr[1]; + if (optlen<2 || optlen>l) + return -EINVAL; + switch (*optptr) { + case IPOPT_SEC: + case 0x85: /* Some "Extended Security" crap. */ + case IPOPT_CIPSO: + case IPOPT_RA: + case 0x80|21: /* RFC1770 */ + break; + case IPOPT_LSRR: + case IPOPT_SSRR: + if (optlen < 6) + return -EINVAL; + memcpy(daddr, optptr+optlen-4, 4); + fallthrough; + default: + memset(optptr, 0, optlen); + } + l -= optlen; + optptr += optlen; + } + return 0; +} + +static void ah_output_done(struct crypto_async_request *base, int err) +{ + u8 *icv; + struct iphdr *iph; + struct sk_buff *skb = base->data; + struct xfrm_state *x = skb_dst(skb)->xfrm; + struct ah_data *ahp = x->data; + struct iphdr *top_iph = ip_hdr(skb); + struct ip_auth_hdr *ah = ip_auth_hdr(skb); + int ihl = ip_hdrlen(skb); + + iph = AH_SKB_CB(skb)->tmp; + icv = ah_tmp_icv(ahp->ahash, iph, ihl); + memcpy(ah->auth_data, icv, ahp->icv_trunc_len); + + top_iph->tos = iph->tos; + top_iph->ttl = iph->ttl; + top_iph->frag_off = iph->frag_off; + if (top_iph->ihl != 5) { + top_iph->daddr = iph->daddr; + memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); + } + + kfree(AH_SKB_CB(skb)->tmp); + xfrm_output_resume(skb->sk, skb, err); +} + +static int ah_output(struct xfrm_state *x, struct sk_buff *skb) +{ + int err; + int nfrags; + int ihl; + u8 *icv; + struct sk_buff *trailer; + struct crypto_ahash *ahash; + struct ahash_request *req; + struct scatterlist *sg; + struct iphdr *iph, *top_iph; + struct ip_auth_hdr *ah; + struct ah_data *ahp; + int seqhi_len = 0; + __be32 *seqhi; + int sglists = 0; + struct scatterlist *seqhisg; + + ahp = x->data; + ahash = ahp->ahash; + + if ((err = skb_cow_data(skb, 0, &trailer)) < 0) + goto out; + nfrags = err; + + skb_push(skb, -skb_network_offset(skb)); + ah = ip_auth_hdr(skb); + ihl = ip_hdrlen(skb); + + if (x->props.flags & XFRM_STATE_ESN) { + sglists = 1; + seqhi_len = sizeof(*seqhi); + } + err = -ENOMEM; + iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + seqhi_len); + if (!iph) + goto out; + seqhi = (__be32 *)((char *)iph + ihl); + icv = ah_tmp_icv(ahash, seqhi, seqhi_len); + req = ah_tmp_req(ahash, icv); + sg = ah_req_sg(ahash, req); + seqhisg = sg + nfrags; + + memset(ah->auth_data, 0, ahp->icv_trunc_len); + + top_iph = ip_hdr(skb); + + iph->tos = top_iph->tos; + iph->ttl = top_iph->ttl; + iph->frag_off = top_iph->frag_off; + + if (top_iph->ihl != 5) { + iph->daddr = top_iph->daddr; + memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); + err = ip_clear_mutable_options(top_iph, &top_iph->daddr); + if (err) + goto out_free; + } + + ah->nexthdr = *skb_mac_header(skb); + *skb_mac_header(skb) = IPPROTO_AH; + + top_iph->tos = 0; + top_iph->tot_len = htons(skb->len); + top_iph->frag_off = 0; + top_iph->ttl = 0; + top_iph->check = 0; + + if (x->props.flags & XFRM_STATE_ALIGN4) + ah->hdrlen = (XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; + else + ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; + + ah->reserved = 0; + ah->spi = x->id.spi; + ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); + + sg_init_table(sg, nfrags + sglists); + err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); + if (unlikely(err < 0)) + goto out_free; + + if (x->props.flags & XFRM_STATE_ESN) { + /* Attach seqhi sg right after packet payload */ + *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); + sg_set_buf(seqhisg, seqhi, seqhi_len); + } + ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); + ahash_request_set_callback(req, 0, ah_output_done, skb); + + AH_SKB_CB(skb)->tmp = iph; + + err = crypto_ahash_digest(req); + if (err) { + if (err == -EINPROGRESS) + goto out; + + if (err == -ENOSPC) + err = NET_XMIT_DROP; + goto out_free; + } + + memcpy(ah->auth_data, icv, ahp->icv_trunc_len); + + top_iph->tos = iph->tos; + top_iph->ttl = iph->ttl; + top_iph->frag_off = iph->frag_off; + if (top_iph->ihl != 5) { + top_iph->daddr = iph->daddr; + memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); + } + +out_free: + kfree(iph); +out: + return err; +} + +static void ah_input_done(struct crypto_async_request *base, int err) +{ + u8 *auth_data; + u8 *icv; + struct iphdr *work_iph; + struct sk_buff *skb = base->data; + struct xfrm_state *x = xfrm_input_state(skb); + struct ah_data *ahp = x->data; + struct ip_auth_hdr *ah = ip_auth_hdr(skb); + int ihl = ip_hdrlen(skb); + int ah_hlen = (ah->hdrlen + 2) << 2; + + if (err) + goto out; + + work_iph = AH_SKB_CB(skb)->tmp; + auth_data = ah_tmp_auth(work_iph, ihl); + icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); + + err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; + if (err) + goto out; + + err = ah->nexthdr; + + skb->network_header += ah_hlen; + memcpy(skb_network_header(skb), work_iph, ihl); + __skb_pull(skb, ah_hlen + ihl); + + if (x->props.mode == XFRM_MODE_TUNNEL) + skb_reset_transport_header(skb); + else + skb_set_transport_header(skb, -ihl); +out: + kfree(AH_SKB_CB(skb)->tmp); + xfrm_input_resume(skb, err); +} + +static int ah_input(struct xfrm_state *x, struct sk_buff *skb) +{ + int ah_hlen; + int ihl; + int nexthdr; + int nfrags; + u8 *auth_data; + u8 *icv; + struct sk_buff *trailer; + struct crypto_ahash *ahash; + struct ahash_request *req; + struct scatterlist *sg; + struct iphdr *iph, *work_iph; + struct ip_auth_hdr *ah; + struct ah_data *ahp; + int err = -ENOMEM; + int seqhi_len = 0; + __be32 *seqhi; + int sglists = 0; + struct scatterlist *seqhisg; + + if (!pskb_may_pull(skb, sizeof(*ah))) + goto out; + + ah = (struct ip_auth_hdr *)skb->data; + ahp = x->data; + ahash = ahp->ahash; + + nexthdr = ah->nexthdr; + ah_hlen = (ah->hdrlen + 2) << 2; + + if (x->props.flags & XFRM_STATE_ALIGN4) { + if (ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_full_len) && + ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len)) + goto out; + } else { + if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && + ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) + goto out; + } + + if (!pskb_may_pull(skb, ah_hlen)) + goto out; + + /* We are going to _remove_ AH header to keep sockets happy, + * so... Later this can change. */ + if (skb_unclone(skb, GFP_ATOMIC)) + goto out; + + skb->ip_summed = CHECKSUM_NONE; + + + if ((err = skb_cow_data(skb, 0, &trailer)) < 0) + goto out; + nfrags = err; + + ah = (struct ip_auth_hdr *)skb->data; + iph = ip_hdr(skb); + ihl = ip_hdrlen(skb); + + if (x->props.flags & XFRM_STATE_ESN) { + sglists = 1; + seqhi_len = sizeof(*seqhi); + } + + work_iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + + ahp->icv_trunc_len + seqhi_len); + if (!work_iph) { + err = -ENOMEM; + goto out; + } + + seqhi = (__be32 *)((char *)work_iph + ihl); + auth_data = ah_tmp_auth(seqhi, seqhi_len); + icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len); + req = ah_tmp_req(ahash, icv); + sg = ah_req_sg(ahash, req); + seqhisg = sg + nfrags; + + memcpy(work_iph, iph, ihl); + memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); + memset(ah->auth_data, 0, ahp->icv_trunc_len); + + iph->ttl = 0; + iph->tos = 0; + iph->frag_off = 0; + iph->check = 0; + if (ihl > sizeof(*iph)) { + __be32 dummy; + err = ip_clear_mutable_options(iph, &dummy); + if (err) + goto out_free; + } + + skb_push(skb, ihl); + + sg_init_table(sg, nfrags + sglists); + err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); + if (unlikely(err < 0)) + goto out_free; + + if (x->props.flags & XFRM_STATE_ESN) { + /* Attach seqhi sg right after packet payload */ + *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; + sg_set_buf(seqhisg, seqhi, seqhi_len); + } + ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); + ahash_request_set_callback(req, 0, ah_input_done, skb); + + AH_SKB_CB(skb)->tmp = work_iph; + + err = crypto_ahash_digest(req); + if (err) { + if (err == -EINPROGRESS) + goto out; + + goto out_free; + } + + err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; + if (err) + goto out_free; + + skb->network_header += ah_hlen; + memcpy(skb_network_header(skb), work_iph, ihl); + __skb_pull(skb, ah_hlen + ihl); + if (x->props.mode == XFRM_MODE_TUNNEL) + skb_reset_transport_header(skb); + else + skb_set_transport_header(skb, -ihl); + + err = nexthdr; + +out_free: + kfree (work_iph); +out: + return err; +} + +static int ah4_err(struct sk_buff *skb, u32 info) +{ + struct net *net = dev_net(skb->dev); + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2)); + struct xfrm_state *x; + + switch (icmp_hdr(skb)->type) { + case ICMP_DEST_UNREACH: + if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) + return 0; + case ICMP_REDIRECT: + break; + default: + return 0; + } + + x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, + ah->spi, IPPROTO_AH, AF_INET); + if (!x) + return 0; + + if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) + ipv4_update_pmtu(skb, net, info, 0, IPPROTO_AH); + else + ipv4_redirect(skb, net, 0, IPPROTO_AH); + xfrm_state_put(x); + + return 0; +} + +static int ah_init_state(struct xfrm_state *x) +{ + struct ah_data *ahp = NULL; + struct xfrm_algo_desc *aalg_desc; + struct crypto_ahash *ahash; + + if (!x->aalg) + goto error; + + if (x->encap) + goto error; + + ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); + if (!ahp) + return -ENOMEM; + + ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); + if (IS_ERR(ahash)) + goto error; + + ahp->ahash = ahash; + if (crypto_ahash_setkey(ahash, x->aalg->alg_key, + (x->aalg->alg_key_len + 7) / 8)) + goto error; + + /* + * Lookup the algorithm description maintained by xfrm_algo, + * verify crypto transform properties, and store information + * we need for AH processing. This lookup cannot fail here + * after a successful crypto_alloc_ahash(). + */ + aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); + BUG_ON(!aalg_desc); + + if (aalg_desc->uinfo.auth.icv_fullbits/8 != + crypto_ahash_digestsize(ahash)) { + pr_info("%s: %s digestsize %u != %hu\n", + __func__, x->aalg->alg_name, + crypto_ahash_digestsize(ahash), + aalg_desc->uinfo.auth.icv_fullbits / 8); + goto error; + } + + ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; + ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; + + if (x->props.flags & XFRM_STATE_ALIGN4) + x->props.header_len = XFRM_ALIGN4(sizeof(struct ip_auth_hdr) + + ahp->icv_trunc_len); + else + x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + + ahp->icv_trunc_len); + if (x->props.mode == XFRM_MODE_TUNNEL) + x->props.header_len += sizeof(struct iphdr); + x->data = ahp; + + return 0; + +error: + if (ahp) { + crypto_free_ahash(ahp->ahash); + kfree(ahp); + } + return -EINVAL; +} + +static void ah_destroy(struct xfrm_state *x) +{ + struct ah_data *ahp = x->data; + + if (!ahp) + return; + + crypto_free_ahash(ahp->ahash); + kfree(ahp); +} + +static int ah4_rcv_cb(struct sk_buff *skb, int err) +{ + return 0; +} + +static const struct xfrm_type ah_type = +{ + .description = "AH4", + .owner = THIS_MODULE, + .proto = IPPROTO_AH, + .flags = XFRM_TYPE_REPLAY_PROT, + .init_state = ah_init_state, + .destructor = ah_destroy, + .input = ah_input, + .output = ah_output +}; + +static struct xfrm4_protocol ah4_protocol = { + .handler = xfrm4_rcv, + .input_handler = xfrm_input, + .cb_handler = ah4_rcv_cb, + .err_handler = ah4_err, + .priority = 0, +}; + +static int __init ah4_init(void) +{ + if (xfrm_register_type(&ah_type, AF_INET) < 0) { + pr_info("%s: can't add xfrm type\n", __func__); + return -EAGAIN; + } + if (xfrm4_protocol_register(&ah4_protocol, IPPROTO_AH) < 0) { + pr_info("%s: can't add protocol\n", __func__); + xfrm_unregister_type(&ah_type, AF_INET); + return -EAGAIN; + } + return 0; +} + +static void __exit ah4_fini(void) +{ + if (xfrm4_protocol_deregister(&ah4_protocol, IPPROTO_AH) < 0) + pr_info("%s: can't remove protocol\n", __func__); + xfrm_unregister_type(&ah_type, AF_INET); +} + +module_init(ah4_init); +module_exit(ah4_fini); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH); diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c new file mode 100644 index 000000000..83a47998c --- /dev/null +++ b/net/ipv4/arp.c @@ -0,0 +1,1462 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* linux/net/ipv4/arp.c + * + * Copyright (C) 1994 by Florian La Roche + * + * This module implements the Address Resolution Protocol ARP (RFC 826), + * which is used to convert IP addresses (or in the future maybe other + * high-level addresses) into a low-level hardware address (like an Ethernet + * address). + * + * Fixes: + * Alan Cox : Removed the Ethernet assumptions in + * Florian's code + * Alan Cox : Fixed some small errors in the ARP + * logic + * Alan Cox : Allow >4K in /proc + * Alan Cox : Make ARP add its own protocol entry + * Ross Martin : Rewrote arp_rcv() and arp_get_info() + * Stephen Henson : Add AX25 support to arp_get_info() + * Alan Cox : Drop data when a device is downed. + * Alan Cox : Use init_timer(). + * Alan Cox : Double lock fixes. + * Martin Seine : Move the arphdr structure + * to if_arp.h for compatibility. + * with BSD based programs. + * Andrew Tridgell : Added ARP netmask code and + * re-arranged proxy handling. + * Alan Cox : Changed to use notifiers. + * Niibe Yutaka : Reply for this device or proxies only. + * Alan Cox : Don't proxy across hardware types! + * Jonathan Naylor : Added support for NET/ROM. + * Mike Shaver : RFC1122 checks. + * Jonathan Naylor : Only lookup the hardware address for + * the correct hardware type. + * Germano Caronni : Assorted subtle races. + * Craig Schlenter : Don't modify permanent entry + * during arp_rcv. + * Russ Nelson : Tidied up a few bits. + * Alexey Kuznetsov: Major changes to caching and behaviour, + * eg intelligent arp probing and + * generation + * of host down events. + * Alan Cox : Missing unlock in device events. + * Eckes : ARP ioctl control errors. + * Alexey Kuznetsov: Arp free fix. + * Manuel Rodriguez: Gratuitous ARP. + * Jonathan Layes : Added arpd support through kerneld + * message queue (960314) + * Mike Shaver : /proc/sys/net/ipv4/arp_* support + * Mike McLagan : Routing by source + * Stuart Cheshire : Metricom and grat arp fixes + * *** FOR 2.1 clean this up *** + * Lawrence V. Stefani: (08/12/96) Added FDDI support. + * Alan Cox : Took the AP1000 nasty FDDI hack and + * folded into the mainstream FDDI code. + * Ack spit, Linus how did you allow that + * one in... + * Jes Sorensen : Make FDDI work again in 2.1.x and + * clean up the APFDDI & gen. FDDI bits. + * Alexey Kuznetsov: new arp state machine; + * now it is in net/core/neighbour.c. + * Krzysztof Halasa: Added Frame Relay ARP support. + * Arnaldo C. Melo : convert /proc/net/arp to seq_file + * Shmulik Hen: Split arp_send to arp_create and + * arp_xmit so intermediate drivers like + * bonding can change the skb before + * sending (e.g. insert 8021q tag). + * Harald Welte : convert to make use of jenkins hash + * Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/capability.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/mm.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/fddidevice.h> +#include <linux/if_arp.h> +#include <linux/skbuff.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/stat.h> +#include <linux/init.h> +#include <linux/net.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#ifdef CONFIG_SYSCTL +#include <linux/sysctl.h> +#endif + +#include <net/net_namespace.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/route.h> +#include <net/protocol.h> +#include <net/tcp.h> +#include <net/sock.h> +#include <net/arp.h> +#include <net/ax25.h> +#include <net/netrom.h> +#include <net/dst_metadata.h> +#include <net/ip_tunnels.h> + +#include <linux/uaccess.h> + +#include <linux/netfilter_arp.h> + +/* + * Interface to generic neighbour cache. + */ +static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd); +static bool arp_key_eq(const struct neighbour *n, const void *pkey); +static int arp_constructor(struct neighbour *neigh); +static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); +static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); +static void parp_redo(struct sk_buff *skb); +static int arp_is_multicast(const void *pkey); + +static const struct neigh_ops arp_generic_ops = { + .family = AF_INET, + .solicit = arp_solicit, + .error_report = arp_error_report, + .output = neigh_resolve_output, + .connected_output = neigh_connected_output, +}; + +static const struct neigh_ops arp_hh_ops = { + .family = AF_INET, + .solicit = arp_solicit, + .error_report = arp_error_report, + .output = neigh_resolve_output, + .connected_output = neigh_resolve_output, +}; + +static const struct neigh_ops arp_direct_ops = { + .family = AF_INET, + .output = neigh_direct_output, + .connected_output = neigh_direct_output, +}; + +struct neigh_table arp_tbl = { + .family = AF_INET, + .key_len = 4, + .protocol = cpu_to_be16(ETH_P_IP), + .hash = arp_hash, + .key_eq = arp_key_eq, + .constructor = arp_constructor, + .proxy_redo = parp_redo, + .is_multicast = arp_is_multicast, + .id = "arp_cache", + .parms = { + .tbl = &arp_tbl, + .reachable_time = 30 * HZ, + .data = { + [NEIGH_VAR_MCAST_PROBES] = 3, + [NEIGH_VAR_UCAST_PROBES] = 3, + [NEIGH_VAR_RETRANS_TIME] = 1 * HZ, + [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, + [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, + [NEIGH_VAR_GC_STALETIME] = 60 * HZ, + [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, + [NEIGH_VAR_PROXY_QLEN] = 64, + [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, + [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, + [NEIGH_VAR_LOCKTIME] = 1 * HZ, + }, + }, + .gc_interval = 30 * HZ, + .gc_thresh1 = 128, + .gc_thresh2 = 512, + .gc_thresh3 = 1024, +}; +EXPORT_SYMBOL(arp_tbl); + +int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) +{ + switch (dev->type) { + case ARPHRD_ETHER: + case ARPHRD_FDDI: + case ARPHRD_IEEE802: + ip_eth_mc_map(addr, haddr); + return 0; + case ARPHRD_INFINIBAND: + ip_ib_mc_map(addr, dev->broadcast, haddr); + return 0; + case ARPHRD_IPGRE: + ip_ipgre_mc_map(addr, dev->broadcast, haddr); + return 0; + default: + if (dir) { + memcpy(haddr, dev->broadcast, dev->addr_len); + return 0; + } + } + return -EINVAL; +} + + +static u32 arp_hash(const void *pkey, + const struct net_device *dev, + __u32 *hash_rnd) +{ + return arp_hashfn(pkey, dev, hash_rnd); +} + +static bool arp_key_eq(const struct neighbour *neigh, const void *pkey) +{ + return neigh_key_eq32(neigh, pkey); +} + +static int arp_constructor(struct neighbour *neigh) +{ + __be32 addr; + struct net_device *dev = neigh->dev; + struct in_device *in_dev; + struct neigh_parms *parms; + u32 inaddr_any = INADDR_ANY; + + if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) + memcpy(neigh->primary_key, &inaddr_any, arp_tbl.key_len); + + addr = *(__be32 *)neigh->primary_key; + rcu_read_lock(); + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) { + rcu_read_unlock(); + return -EINVAL; + } + + neigh->type = inet_addr_type_dev_table(dev_net(dev), dev, addr); + + parms = in_dev->arp_parms; + __neigh_parms_put(neigh->parms); + neigh->parms = neigh_parms_clone(parms); + rcu_read_unlock(); + + if (!dev->header_ops) { + neigh->nud_state = NUD_NOARP; + neigh->ops = &arp_direct_ops; + neigh->output = neigh_direct_output; + } else { + /* Good devices (checked by reading texts, but only Ethernet is + tested) + + ARPHRD_ETHER: (ethernet, apfddi) + ARPHRD_FDDI: (fddi) + ARPHRD_IEEE802: (tr) + ARPHRD_METRICOM: (strip) + ARPHRD_ARCNET: + etc. etc. etc. + + ARPHRD_IPDDP will also work, if author repairs it. + I did not it, because this driver does not work even + in old paradigm. + */ + + if (neigh->type == RTN_MULTICAST) { + neigh->nud_state = NUD_NOARP; + arp_mc_map(addr, neigh->ha, dev, 1); + } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { + neigh->nud_state = NUD_NOARP; + memcpy(neigh->ha, dev->dev_addr, dev->addr_len); + } else if (neigh->type == RTN_BROADCAST || + (dev->flags & IFF_POINTOPOINT)) { + neigh->nud_state = NUD_NOARP; + memcpy(neigh->ha, dev->broadcast, dev->addr_len); + } + + if (dev->header_ops->cache) + neigh->ops = &arp_hh_ops; + else + neigh->ops = &arp_generic_ops; + + if (neigh->nud_state & NUD_VALID) + neigh->output = neigh->ops->connected_output; + else + neigh->output = neigh->ops->output; + } + return 0; +} + +static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) +{ + dst_link_failure(skb); + kfree_skb(skb); +} + +/* Create and send an arp packet. */ +static void arp_send_dst(int type, int ptype, __be32 dest_ip, + struct net_device *dev, __be32 src_ip, + const unsigned char *dest_hw, + const unsigned char *src_hw, + const unsigned char *target_hw, + struct dst_entry *dst) +{ + struct sk_buff *skb; + + /* arp on this interface. */ + if (dev->flags & IFF_NOARP) + return; + + skb = arp_create(type, ptype, dest_ip, dev, src_ip, + dest_hw, src_hw, target_hw); + if (!skb) + return; + + skb_dst_set(skb, dst_clone(dst)); + arp_xmit(skb); +} + +void arp_send(int type, int ptype, __be32 dest_ip, + struct net_device *dev, __be32 src_ip, + const unsigned char *dest_hw, const unsigned char *src_hw, + const unsigned char *target_hw) +{ + arp_send_dst(type, ptype, dest_ip, dev, src_ip, dest_hw, src_hw, + target_hw, NULL); +} +EXPORT_SYMBOL(arp_send); + +static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) +{ + __be32 saddr = 0; + u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL; + struct net_device *dev = neigh->dev; + __be32 target = *(__be32 *)neigh->primary_key; + int probes = atomic_read(&neigh->probes); + struct in_device *in_dev; + struct dst_entry *dst = NULL; + + rcu_read_lock(); + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) { + rcu_read_unlock(); + return; + } + switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { + default: + case 0: /* By default announce any local IP */ + if (skb && inet_addr_type_dev_table(dev_net(dev), dev, + ip_hdr(skb)->saddr) == RTN_LOCAL) + saddr = ip_hdr(skb)->saddr; + break; + case 1: /* Restrict announcements of saddr in same subnet */ + if (!skb) + break; + saddr = ip_hdr(skb)->saddr; + if (inet_addr_type_dev_table(dev_net(dev), dev, + saddr) == RTN_LOCAL) { + /* saddr should be known to target */ + if (inet_addr_onlink(in_dev, target, saddr)) + break; + } + saddr = 0; + break; + case 2: /* Avoid secondary IPs, get a primary/preferred one */ + break; + } + rcu_read_unlock(); + + if (!saddr) + saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); + + probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); + if (probes < 0) { + if (!(neigh->nud_state & NUD_VALID)) + pr_debug("trying to ucast probe in NUD_INVALID\n"); + neigh_ha_snapshot(dst_ha, neigh, dev); + dst_hw = dst_ha; + } else { + probes -= NEIGH_VAR(neigh->parms, APP_PROBES); + if (probes < 0) { + neigh_app_ns(neigh); + return; + } + } + + if (skb && !(dev->priv_flags & IFF_XMIT_DST_RELEASE)) + dst = skb_dst(skb); + arp_send_dst(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, + dst_hw, dev->dev_addr, NULL, dst); +} + +static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) +{ + struct net *net = dev_net(in_dev->dev); + int scope; + + switch (IN_DEV_ARP_IGNORE(in_dev)) { + case 0: /* Reply, the tip is already validated */ + return 0; + case 1: /* Reply only if tip is configured on the incoming interface */ + sip = 0; + scope = RT_SCOPE_HOST; + break; + case 2: /* + * Reply only if tip is configured on the incoming interface + * and is in same subnet as sip + */ + scope = RT_SCOPE_HOST; + break; + case 3: /* Do not reply for scope host addresses */ + sip = 0; + scope = RT_SCOPE_LINK; + in_dev = NULL; + break; + case 4: /* Reserved */ + case 5: + case 6: + case 7: + return 0; + case 8: /* Do not reply */ + return 1; + default: + return 0; + } + return !inet_confirm_addr(net, in_dev, sip, tip, scope); +} + +static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) +{ + struct rtable *rt; + int flag = 0; + /*unsigned long now; */ + struct net *net = dev_net(dev); + + rt = ip_route_output(net, sip, tip, 0, l3mdev_master_ifindex_rcu(dev)); + if (IS_ERR(rt)) + return 1; + if (rt->dst.dev != dev) { + __NET_INC_STATS(net, LINUX_MIB_ARPFILTER); + flag = 1; + } + ip_rt_put(rt); + return flag; +} + +/* + * Check if we can use proxy ARP for this path + */ +static inline int arp_fwd_proxy(struct in_device *in_dev, + struct net_device *dev, struct rtable *rt) +{ + struct in_device *out_dev; + int imi, omi = -1; + + if (rt->dst.dev == dev) + return 0; + + if (!IN_DEV_PROXY_ARP(in_dev)) + return 0; + imi = IN_DEV_MEDIUM_ID(in_dev); + if (imi == 0) + return 1; + if (imi == -1) + return 0; + + /* place to check for proxy_arp for routes */ + + out_dev = __in_dev_get_rcu(rt->dst.dev); + if (out_dev) + omi = IN_DEV_MEDIUM_ID(out_dev); + + return omi != imi && omi != -1; +} + +/* + * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) + * + * RFC3069 supports proxy arp replies back to the same interface. This + * is done to support (ethernet) switch features, like RFC 3069, where + * the individual ports are not allowed to communicate with each + * other, BUT they are allowed to talk to the upstream router. As + * described in RFC 3069, it is possible to allow these hosts to + * communicate through the upstream router, by proxy_arp'ing. + * + * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" + * + * This technology is known by different names: + * In RFC 3069 it is called VLAN Aggregation. + * Cisco and Allied Telesyn call it Private VLAN. + * Hewlett-Packard call it Source-Port filtering or port-isolation. + * Ericsson call it MAC-Forced Forwarding (RFC Draft). + * + */ +static inline int arp_fwd_pvlan(struct in_device *in_dev, + struct net_device *dev, struct rtable *rt, + __be32 sip, __be32 tip) +{ + /* Private VLAN is only concerned about the same ethernet segment */ + if (rt->dst.dev != dev) + return 0; + + /* Don't reply on self probes (often done by windowz boxes)*/ + if (sip == tip) + return 0; + + if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) + return 1; + else + return 0; +} + +/* + * Interface to link layer: send routine and receive handler. + */ + +/* + * Create an arp packet. If dest_hw is not set, we create a broadcast + * message. + */ +struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, + struct net_device *dev, __be32 src_ip, + const unsigned char *dest_hw, + const unsigned char *src_hw, + const unsigned char *target_hw) +{ + struct sk_buff *skb; + struct arphdr *arp; + unsigned char *arp_ptr; + int hlen = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; + + /* + * Allocate a buffer + */ + + skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC); + if (!skb) + return NULL; + + skb_reserve(skb, hlen); + skb_reset_network_header(skb); + arp = skb_put(skb, arp_hdr_len(dev)); + skb->dev = dev; + skb->protocol = htons(ETH_P_ARP); + if (!src_hw) + src_hw = dev->dev_addr; + if (!dest_hw) + dest_hw = dev->broadcast; + + /* + * Fill the device header for the ARP frame + */ + if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) + goto out; + + /* + * Fill out the arp protocol part. + * + * The arp hardware type should match the device type, except for FDDI, + * which (according to RFC 1390) should always equal 1 (Ethernet). + */ + /* + * Exceptions everywhere. AX.25 uses the AX.25 PID value not the + * DIX code for the protocol. Make these device structure fields. + */ + switch (dev->type) { + default: + arp->ar_hrd = htons(dev->type); + arp->ar_pro = htons(ETH_P_IP); + break; + +#if IS_ENABLED(CONFIG_AX25) + case ARPHRD_AX25: + arp->ar_hrd = htons(ARPHRD_AX25); + arp->ar_pro = htons(AX25_P_IP); + break; + +#if IS_ENABLED(CONFIG_NETROM) + case ARPHRD_NETROM: + arp->ar_hrd = htons(ARPHRD_NETROM); + arp->ar_pro = htons(AX25_P_IP); + break; +#endif +#endif + +#if IS_ENABLED(CONFIG_FDDI) + case ARPHRD_FDDI: + arp->ar_hrd = htons(ARPHRD_ETHER); + arp->ar_pro = htons(ETH_P_IP); + break; +#endif + } + + arp->ar_hln = dev->addr_len; + arp->ar_pln = 4; + arp->ar_op = htons(type); + + arp_ptr = (unsigned char *)(arp + 1); + + memcpy(arp_ptr, src_hw, dev->addr_len); + arp_ptr += dev->addr_len; + memcpy(arp_ptr, &src_ip, 4); + arp_ptr += 4; + + switch (dev->type) { +#if IS_ENABLED(CONFIG_FIREWIRE_NET) + case ARPHRD_IEEE1394: + break; +#endif + default: + if (target_hw) + memcpy(arp_ptr, target_hw, dev->addr_len); + else + memset(arp_ptr, 0, dev->addr_len); + arp_ptr += dev->addr_len; + } + memcpy(arp_ptr, &dest_ip, 4); + + return skb; + +out: + kfree_skb(skb); + return NULL; +} +EXPORT_SYMBOL(arp_create); + +static int arp_xmit_finish(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + return dev_queue_xmit(skb); +} + +/* + * Send an arp packet. + */ +void arp_xmit(struct sk_buff *skb) +{ + /* Send it off, maybe filter it using firewalling first. */ + NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, + dev_net(skb->dev), NULL, skb, NULL, skb->dev, + arp_xmit_finish); +} +EXPORT_SYMBOL(arp_xmit); + +static bool arp_is_garp(struct net *net, struct net_device *dev, + int *addr_type, __be16 ar_op, + __be32 sip, __be32 tip, + unsigned char *sha, unsigned char *tha) +{ + bool is_garp = tip == sip; + + /* Gratuitous ARP _replies_ also require target hwaddr to be + * the same as source. + */ + if (is_garp && ar_op == htons(ARPOP_REPLY)) + is_garp = + /* IPv4 over IEEE 1394 doesn't provide target + * hardware address field in its ARP payload. + */ + tha && + !memcmp(tha, sha, dev->addr_len); + + if (is_garp) { + *addr_type = inet_addr_type_dev_table(net, dev, sip); + if (*addr_type != RTN_UNICAST) + is_garp = false; + } + return is_garp; +} + +/* + * Process an arp request. + */ + +static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + struct in_device *in_dev = __in_dev_get_rcu(dev); + struct arphdr *arp; + unsigned char *arp_ptr; + struct rtable *rt; + unsigned char *sha; + unsigned char *tha = NULL; + __be32 sip, tip; + u16 dev_type = dev->type; + int addr_type; + struct neighbour *n; + struct dst_entry *reply_dst = NULL; + bool is_garp = false; + + /* arp_rcv below verifies the ARP header and verifies the device + * is ARP'able. + */ + + if (!in_dev) + goto out_free_skb; + + arp = arp_hdr(skb); + + switch (dev_type) { + default: + if (arp->ar_pro != htons(ETH_P_IP) || + htons(dev_type) != arp->ar_hrd) + goto out_free_skb; + break; + case ARPHRD_ETHER: + case ARPHRD_FDDI: + case ARPHRD_IEEE802: + /* + * ETHERNET, and Fibre Channel (which are IEEE 802 + * devices, according to RFC 2625) devices will accept ARP + * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). + * This is the case also of FDDI, where the RFC 1390 says that + * FDDI devices should accept ARP hardware of (1) Ethernet, + * however, to be more robust, we'll accept both 1 (Ethernet) + * or 6 (IEEE 802.2) + */ + if ((arp->ar_hrd != htons(ARPHRD_ETHER) && + arp->ar_hrd != htons(ARPHRD_IEEE802)) || + arp->ar_pro != htons(ETH_P_IP)) + goto out_free_skb; + break; + case ARPHRD_AX25: + if (arp->ar_pro != htons(AX25_P_IP) || + arp->ar_hrd != htons(ARPHRD_AX25)) + goto out_free_skb; + break; + case ARPHRD_NETROM: + if (arp->ar_pro != htons(AX25_P_IP) || + arp->ar_hrd != htons(ARPHRD_NETROM)) + goto out_free_skb; + break; + } + + /* Understand only these message types */ + + if (arp->ar_op != htons(ARPOP_REPLY) && + arp->ar_op != htons(ARPOP_REQUEST)) + goto out_free_skb; + +/* + * Extract fields + */ + arp_ptr = (unsigned char *)(arp + 1); + sha = arp_ptr; + arp_ptr += dev->addr_len; + memcpy(&sip, arp_ptr, 4); + arp_ptr += 4; + switch (dev_type) { +#if IS_ENABLED(CONFIG_FIREWIRE_NET) + case ARPHRD_IEEE1394: + break; +#endif + default: + tha = arp_ptr; + arp_ptr += dev->addr_len; + } + memcpy(&tip, arp_ptr, 4); +/* + * Check for bad requests for 127.x.x.x and requests for multicast + * addresses. If this is one such, delete it. + */ + if (ipv4_is_multicast(tip) || + (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip))) + goto out_free_skb; + + /* + * For some 802.11 wireless deployments (and possibly other networks), + * there will be an ARP proxy and gratuitous ARP frames are attacks + * and thus should not be accepted. + */ + if (sip == tip && IN_DEV_ORCONF(in_dev, DROP_GRATUITOUS_ARP)) + goto out_free_skb; + +/* + * Special case: We must set Frame Relay source Q.922 address + */ + if (dev_type == ARPHRD_DLCI) + sha = dev->broadcast; + +/* + * Process entry. The idea here is we want to send a reply if it is a + * request for us or if it is a request for someone else that we hold + * a proxy for. We want to add an entry to our cache if it is a reply + * to us or if it is a request for our address. + * (The assumption for this last is that if someone is requesting our + * address, they are probably intending to talk to us, so it saves time + * if we cache their address. Their address is also probably not in + * our cache, since ours is not in their cache.) + * + * Putting this another way, we only care about replies if they are to + * us, in which case we add them to the cache. For requests, we care + * about those for us and those for our proxies. We reply to both, + * and in the case of requests for us we add the requester to the arp + * cache. + */ + + if (arp->ar_op == htons(ARPOP_REQUEST) && skb_metadata_dst(skb)) + reply_dst = (struct dst_entry *) + iptunnel_metadata_reply(skb_metadata_dst(skb), + GFP_ATOMIC); + + /* Special case: IPv4 duplicate address detection packet (RFC2131) */ + if (sip == 0) { + if (arp->ar_op == htons(ARPOP_REQUEST) && + inet_addr_type_dev_table(net, dev, tip) == RTN_LOCAL && + !arp_ignore(in_dev, sip, tip)) + arp_send_dst(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, + sha, dev->dev_addr, sha, reply_dst); + goto out_consume_skb; + } + + if (arp->ar_op == htons(ARPOP_REQUEST) && + ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { + + rt = skb_rtable(skb); + addr_type = rt->rt_type; + + if (addr_type == RTN_LOCAL) { + int dont_send; + + dont_send = arp_ignore(in_dev, sip, tip); + if (!dont_send && IN_DEV_ARPFILTER(in_dev)) + dont_send = arp_filter(sip, tip, dev); + if (!dont_send) { + n = neigh_event_ns(&arp_tbl, sha, &sip, dev); + if (n) { + arp_send_dst(ARPOP_REPLY, ETH_P_ARP, + sip, dev, tip, sha, + dev->dev_addr, sha, + reply_dst); + neigh_release(n); + } + } + goto out_consume_skb; + } else if (IN_DEV_FORWARD(in_dev)) { + if (addr_type == RTN_UNICAST && + (arp_fwd_proxy(in_dev, dev, rt) || + arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || + (rt->dst.dev != dev && + pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) { + n = neigh_event_ns(&arp_tbl, sha, &sip, dev); + if (n) + neigh_release(n); + + if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || + skb->pkt_type == PACKET_HOST || + NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) { + arp_send_dst(ARPOP_REPLY, ETH_P_ARP, + sip, dev, tip, sha, + dev->dev_addr, sha, + reply_dst); + } else { + pneigh_enqueue(&arp_tbl, + in_dev->arp_parms, skb); + goto out_free_dst; + } + goto out_consume_skb; + } + } + } + + /* Update our ARP tables */ + + n = __neigh_lookup(&arp_tbl, &sip, dev, 0); + + addr_type = -1; + if (n || IN_DEV_ARP_ACCEPT(in_dev)) { + is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op, + sip, tip, sha, tha); + } + + if (IN_DEV_ARP_ACCEPT(in_dev)) { + /* Unsolicited ARP is not accepted by default. + It is possible, that this option should be enabled for some + devices (strip is candidate) + */ + if (!n && + (is_garp || + (arp->ar_op == htons(ARPOP_REPLY) && + (addr_type == RTN_UNICAST || + (addr_type < 0 && + /* postpone calculation to as late as possible */ + inet_addr_type_dev_table(net, dev, sip) == + RTN_UNICAST))))) + n = __neigh_lookup(&arp_tbl, &sip, dev, 1); + } + + if (n) { + int state = NUD_REACHABLE; + int override; + + /* If several different ARP replies follows back-to-back, + use the FIRST one. It is possible, if several proxy + agents are active. Taking the first reply prevents + arp trashing and chooses the fastest router. + */ + override = time_after(jiffies, + n->updated + + NEIGH_VAR(n->parms, LOCKTIME)) || + is_garp; + + /* Broadcast replies and request packets + do not assert neighbour reachability. + */ + if (arp->ar_op != htons(ARPOP_REPLY) || + skb->pkt_type != PACKET_HOST) + state = NUD_STALE; + neigh_update(n, sha, state, + override ? NEIGH_UPDATE_F_OVERRIDE : 0, 0); + neigh_release(n); + } + +out_consume_skb: + consume_skb(skb); + +out_free_dst: + dst_release(reply_dst); + return NET_RX_SUCCESS; + +out_free_skb: + kfree_skb(skb); + return NET_RX_DROP; +} + +static void parp_redo(struct sk_buff *skb) +{ + arp_process(dev_net(skb->dev), NULL, skb); +} + +static int arp_is_multicast(const void *pkey) +{ + return ipv4_is_multicast(*((__be32 *)pkey)); +} + +/* + * Receive an arp request from the device layer. + */ + +static int arp_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + const struct arphdr *arp; + + /* do not tweak dropwatch on an ARP we will ignore */ + if (dev->flags & IFF_NOARP || + skb->pkt_type == PACKET_OTHERHOST || + skb->pkt_type == PACKET_LOOPBACK) + goto consumeskb; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + goto out_of_mem; + + /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ + if (!pskb_may_pull(skb, arp_hdr_len(dev))) + goto freeskb; + + arp = arp_hdr(skb); + if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4) + goto freeskb; + + memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); + + return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, + dev_net(dev), NULL, skb, dev, NULL, + arp_process); + +consumeskb: + consume_skb(skb); + return NET_RX_SUCCESS; +freeskb: + kfree_skb(skb); +out_of_mem: + return NET_RX_DROP; +} + +/* + * User level interface (ioctl) + */ + +/* + * Set (create) an ARP cache entry. + */ + +static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) +{ + if (!dev) { + IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; + return 0; + } + if (__in_dev_get_rtnl(dev)) { + IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); + return 0; + } + return -ENXIO; +} + +static int arp_req_set_public(struct net *net, struct arpreq *r, + struct net_device *dev) +{ + __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; + __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; + + if (mask && mask != htonl(0xFFFFFFFF)) + return -EINVAL; + if (!dev && (r->arp_flags & ATF_COM)) { + dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, + r->arp_ha.sa_data); + if (!dev) + return -ENODEV; + } + if (mask) { + if (!pneigh_lookup(&arp_tbl, net, &ip, dev, 1)) + return -ENOBUFS; + return 0; + } + + return arp_req_set_proxy(net, dev, 1); +} + +static int arp_req_set(struct net *net, struct arpreq *r, + struct net_device *dev) +{ + __be32 ip; + struct neighbour *neigh; + int err; + + if (r->arp_flags & ATF_PUBL) + return arp_req_set_public(net, r, dev); + + ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; + if (r->arp_flags & ATF_PERM) + r->arp_flags |= ATF_COM; + if (!dev) { + struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); + + if (IS_ERR(rt)) + return PTR_ERR(rt); + dev = rt->dst.dev; + ip_rt_put(rt); + if (!dev) + return -EINVAL; + } + switch (dev->type) { +#if IS_ENABLED(CONFIG_FDDI) + case ARPHRD_FDDI: + /* + * According to RFC 1390, FDDI devices should accept ARP + * hardware types of 1 (Ethernet). However, to be more + * robust, we'll accept hardware types of either 1 (Ethernet) + * or 6 (IEEE 802.2). + */ + if (r->arp_ha.sa_family != ARPHRD_FDDI && + r->arp_ha.sa_family != ARPHRD_ETHER && + r->arp_ha.sa_family != ARPHRD_IEEE802) + return -EINVAL; + break; +#endif + default: + if (r->arp_ha.sa_family != dev->type) + return -EINVAL; + break; + } + + neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); + err = PTR_ERR(neigh); + if (!IS_ERR(neigh)) { + unsigned int state = NUD_STALE; + if (r->arp_flags & ATF_PERM) + state = NUD_PERMANENT; + err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? + r->arp_ha.sa_data : NULL, state, + NEIGH_UPDATE_F_OVERRIDE | + NEIGH_UPDATE_F_ADMIN, 0); + neigh_release(neigh); + } + return err; +} + +static unsigned int arp_state_to_flags(struct neighbour *neigh) +{ + if (neigh->nud_state&NUD_PERMANENT) + return ATF_PERM | ATF_COM; + else if (neigh->nud_state&NUD_VALID) + return ATF_COM; + else + return 0; +} + +/* + * Get an ARP cache entry. + */ + +static int arp_req_get(struct arpreq *r, struct net_device *dev) +{ + __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; + struct neighbour *neigh; + int err = -ENXIO; + + neigh = neigh_lookup(&arp_tbl, &ip, dev); + if (neigh) { + if (!(neigh->nud_state & NUD_NOARP)) { + read_lock_bh(&neigh->lock); + memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); + r->arp_flags = arp_state_to_flags(neigh); + read_unlock_bh(&neigh->lock); + r->arp_ha.sa_family = dev->type; + strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); + err = 0; + } + neigh_release(neigh); + } + return err; +} + +int arp_invalidate(struct net_device *dev, __be32 ip, bool force) +{ + struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); + int err = -ENXIO; + struct neigh_table *tbl = &arp_tbl; + + if (neigh) { + if ((neigh->nud_state & NUD_VALID) && !force) { + neigh_release(neigh); + return 0; + } + + if (neigh->nud_state & ~NUD_NOARP) + err = neigh_update(neigh, NULL, NUD_FAILED, + NEIGH_UPDATE_F_OVERRIDE| + NEIGH_UPDATE_F_ADMIN, 0); + write_lock_bh(&tbl->lock); + neigh_release(neigh); + neigh_remove_one(neigh, tbl); + write_unlock_bh(&tbl->lock); + } + + return err; +} + +static int arp_req_delete_public(struct net *net, struct arpreq *r, + struct net_device *dev) +{ + __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; + __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; + + if (mask == htonl(0xFFFFFFFF)) + return pneigh_delete(&arp_tbl, net, &ip, dev); + + if (mask) + return -EINVAL; + + return arp_req_set_proxy(net, dev, 0); +} + +static int arp_req_delete(struct net *net, struct arpreq *r, + struct net_device *dev) +{ + __be32 ip; + + if (r->arp_flags & ATF_PUBL) + return arp_req_delete_public(net, r, dev); + + ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; + if (!dev) { + struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); + if (IS_ERR(rt)) + return PTR_ERR(rt); + dev = rt->dst.dev; + ip_rt_put(rt); + if (!dev) + return -EINVAL; + } + return arp_invalidate(dev, ip, true); +} + +/* + * Handle an ARP layer I/O control request. + */ + +int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) +{ + int err; + struct arpreq r; + struct net_device *dev = NULL; + + switch (cmd) { + case SIOCDARP: + case SIOCSARP: + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + fallthrough; + case SIOCGARP: + err = copy_from_user(&r, arg, sizeof(struct arpreq)); + if (err) + return -EFAULT; + break; + default: + return -EINVAL; + } + + if (r.arp_pa.sa_family != AF_INET) + return -EPFNOSUPPORT; + + if (!(r.arp_flags & ATF_PUBL) && + (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) + return -EINVAL; + if (!(r.arp_flags & ATF_NETMASK)) + ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = + htonl(0xFFFFFFFFUL); + rtnl_lock(); + if (r.arp_dev[0]) { + err = -ENODEV; + dev = __dev_get_by_name(net, r.arp_dev); + if (!dev) + goto out; + + /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ + if (!r.arp_ha.sa_family) + r.arp_ha.sa_family = dev->type; + err = -EINVAL; + if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) + goto out; + } else if (cmd == SIOCGARP) { + err = -ENODEV; + goto out; + } + + switch (cmd) { + case SIOCDARP: + err = arp_req_delete(net, &r, dev); + break; + case SIOCSARP: + err = arp_req_set(net, &r, dev); + break; + case SIOCGARP: + err = arp_req_get(&r, dev); + break; + } +out: + rtnl_unlock(); + if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) + err = -EFAULT; + return err; +} + +static int arp_netdev_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct netdev_notifier_change_info *change_info; + + switch (event) { + case NETDEV_CHANGEADDR: + neigh_changeaddr(&arp_tbl, dev); + rt_cache_flush(dev_net(dev)); + break; + case NETDEV_CHANGE: + change_info = ptr; + if (change_info->flags_changed & IFF_NOARP) + neigh_changeaddr(&arp_tbl, dev); + if (!netif_carrier_ok(dev)) + neigh_carrier_down(&arp_tbl, dev); + break; + default: + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block arp_netdev_notifier = { + .notifier_call = arp_netdev_event, +}; + +/* Note, that it is not on notifier chain. + It is necessary, that this routine was called after route cache will be + flushed. + */ +void arp_ifdown(struct net_device *dev) +{ + neigh_ifdown(&arp_tbl, dev); +} + + +/* + * Called once on startup. + */ + +static struct packet_type arp_packet_type __read_mostly = { + .type = cpu_to_be16(ETH_P_ARP), + .func = arp_rcv, +}; + +static int arp_proc_init(void); + +void __init arp_init(void) +{ + neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl); + + dev_add_pack(&arp_packet_type); + arp_proc_init(); +#ifdef CONFIG_SYSCTL + neigh_sysctl_register(NULL, &arp_tbl.parms, NULL); +#endif + register_netdevice_notifier(&arp_netdev_notifier); +} + +#ifdef CONFIG_PROC_FS +#if IS_ENABLED(CONFIG_AX25) + +/* ------------------------------------------------------------------------ */ +/* + * ax25 -> ASCII conversion + */ +static void ax2asc2(ax25_address *a, char *buf) +{ + char c, *s; + int n; + + for (n = 0, s = buf; n < 6; n++) { + c = (a->ax25_call[n] >> 1) & 0x7F; + + if (c != ' ') + *s++ = c; + } + + *s++ = '-'; + n = (a->ax25_call[6] >> 1) & 0x0F; + if (n > 9) { + *s++ = '1'; + n -= 10; + } + + *s++ = n + '0'; + *s++ = '\0'; + + if (*buf == '\0' || *buf == '-') { + buf[0] = '*'; + buf[1] = '\0'; + } +} +#endif /* CONFIG_AX25 */ + +#define HBUFFERLEN 30 + +static void arp_format_neigh_entry(struct seq_file *seq, + struct neighbour *n) +{ + char hbuffer[HBUFFERLEN]; + int k, j; + char tbuf[16]; + struct net_device *dev = n->dev; + int hatype = dev->type; + + read_lock(&n->lock); + /* Convert hardware address to XX:XX:XX:XX ... form. */ +#if IS_ENABLED(CONFIG_AX25) + if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) + ax2asc2((ax25_address *)n->ha, hbuffer); + else { +#endif + for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { + hbuffer[k++] = hex_asc_hi(n->ha[j]); + hbuffer[k++] = hex_asc_lo(n->ha[j]); + hbuffer[k++] = ':'; + } + if (k != 0) + --k; + hbuffer[k] = 0; +#if IS_ENABLED(CONFIG_AX25) + } +#endif + sprintf(tbuf, "%pI4", n->primary_key); + seq_printf(seq, "%-16s 0x%-10x0x%-10x%-17s * %s\n", + tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); + read_unlock(&n->lock); +} + +static void arp_format_pneigh_entry(struct seq_file *seq, + struct pneigh_entry *n) +{ + struct net_device *dev = n->dev; + int hatype = dev ? dev->type : 0; + char tbuf[16]; + + sprintf(tbuf, "%pI4", n->key); + seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", + tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", + dev ? dev->name : "*"); +} + +static int arp_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) { + seq_puts(seq, "IP address HW type Flags " + "HW address Mask Device\n"); + } else { + struct neigh_seq_state *state = seq->private; + + if (state->flags & NEIGH_SEQ_IS_PNEIGH) + arp_format_pneigh_entry(seq, v); + else + arp_format_neigh_entry(seq, v); + } + + return 0; +} + +static void *arp_seq_start(struct seq_file *seq, loff_t *pos) +{ + /* Don't want to confuse "arp -a" w/ magic entries, + * so we tell the generic iterator to skip NUD_NOARP. + */ + return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); +} + +/* ------------------------------------------------------------------------ */ + +static const struct seq_operations arp_seq_ops = { + .start = arp_seq_start, + .next = neigh_seq_next, + .stop = neigh_seq_stop, + .show = arp_seq_show, +}; + +/* ------------------------------------------------------------------------ */ + +static int __net_init arp_net_init(struct net *net) +{ + if (!proc_create_net("arp", 0444, net->proc_net, &arp_seq_ops, + sizeof(struct neigh_seq_state))) + return -ENOMEM; + return 0; +} + +static void __net_exit arp_net_exit(struct net *net) +{ + remove_proc_entry("arp", net->proc_net); +} + +static struct pernet_operations arp_net_ops = { + .init = arp_net_init, + .exit = arp_net_exit, +}; + +static int __init arp_proc_init(void) +{ + return register_pernet_subsys(&arp_net_ops); +} + +#else /* CONFIG_PROC_FS */ + +static int __init arp_proc_init(void) +{ + return 0; +} + +#endif /* CONFIG_PROC_FS */ diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c new file mode 100644 index 000000000..618954f82 --- /dev/null +++ b/net/ipv4/bpf_tcp_ca.c @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook */ + +#include <linux/types.h> +#include <linux/bpf_verifier.h> +#include <linux/bpf.h> +#include <linux/btf.h> +#include <linux/filter.h> +#include <net/tcp.h> +#include <net/bpf_sk_storage.h> + +static u32 optional_ops[] = { + offsetof(struct tcp_congestion_ops, init), + offsetof(struct tcp_congestion_ops, release), + offsetof(struct tcp_congestion_ops, set_state), + offsetof(struct tcp_congestion_ops, cwnd_event), + offsetof(struct tcp_congestion_ops, in_ack_event), + offsetof(struct tcp_congestion_ops, pkts_acked), + offsetof(struct tcp_congestion_ops, min_tso_segs), + offsetof(struct tcp_congestion_ops, sndbuf_expand), + offsetof(struct tcp_congestion_ops, cong_control), +}; + +static u32 unsupported_ops[] = { + offsetof(struct tcp_congestion_ops, get_info), +}; + +static const struct btf_type *tcp_sock_type; +static u32 tcp_sock_id, sock_id; + +static int bpf_tcp_ca_init(struct btf *btf) +{ + s32 type_id; + + type_id = btf_find_by_name_kind(btf, "sock", BTF_KIND_STRUCT); + if (type_id < 0) + return -EINVAL; + sock_id = type_id; + + type_id = btf_find_by_name_kind(btf, "tcp_sock", BTF_KIND_STRUCT); + if (type_id < 0) + return -EINVAL; + tcp_sock_id = type_id; + tcp_sock_type = btf_type_by_id(btf, tcp_sock_id); + + return 0; +} + +static bool is_optional(u32 member_offset) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(optional_ops); i++) { + if (member_offset == optional_ops[i]) + return true; + } + + return false; +} + +static bool is_unsupported(u32 member_offset) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(unsupported_ops); i++) { + if (member_offset == unsupported_ops[i]) + return true; + } + + return false; +} + +extern struct btf *btf_vmlinux; + +static bool bpf_tcp_ca_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) + return false; + if (type != BPF_READ) + return false; + if (off % size != 0) + return false; + + if (!btf_ctx_access(off, size, type, prog, info)) + return false; + + if (info->reg_type == PTR_TO_BTF_ID && info->btf_id == sock_id) + /* promote it to tcp_sock */ + info->btf_id = tcp_sock_id; + + return true; +} + +static int bpf_tcp_ca_btf_struct_access(struct bpf_verifier_log *log, + const struct btf_type *t, int off, + int size, enum bpf_access_type atype, + u32 *next_btf_id) +{ + size_t end; + + if (atype == BPF_READ) + return btf_struct_access(log, t, off, size, atype, next_btf_id); + + if (t != tcp_sock_type) { + bpf_log(log, "only read is supported\n"); + return -EACCES; + } + + switch (off) { + case bpf_ctx_range(struct inet_connection_sock, icsk_ca_priv): + end = offsetofend(struct inet_connection_sock, icsk_ca_priv); + break; + case offsetof(struct inet_connection_sock, icsk_ack.pending): + end = offsetofend(struct inet_connection_sock, + icsk_ack.pending); + break; + case offsetof(struct tcp_sock, snd_cwnd): + end = offsetofend(struct tcp_sock, snd_cwnd); + break; + case offsetof(struct tcp_sock, snd_cwnd_cnt): + end = offsetofend(struct tcp_sock, snd_cwnd_cnt); + break; + case offsetof(struct tcp_sock, snd_ssthresh): + end = offsetofend(struct tcp_sock, snd_ssthresh); + break; + case offsetof(struct tcp_sock, ecn_flags): + end = offsetofend(struct tcp_sock, ecn_flags); + break; + default: + bpf_log(log, "no write support to tcp_sock at off %d\n", off); + return -EACCES; + } + + if (off + size > end) { + bpf_log(log, + "write access at off %d with size %d beyond the member of tcp_sock ended at %zu\n", + off, size, end); + return -EACCES; + } + + return NOT_INIT; +} + +BPF_CALL_2(bpf_tcp_send_ack, struct tcp_sock *, tp, u32, rcv_nxt) +{ + /* bpf_tcp_ca prog cannot have NULL tp */ + __tcp_send_ack((struct sock *)tp, rcv_nxt); + return 0; +} + +static const struct bpf_func_proto bpf_tcp_send_ack_proto = { + .func = bpf_tcp_send_ack, + .gpl_only = false, + /* In case we want to report error later */ + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg1_btf_id = &tcp_sock_id, + .arg2_type = ARG_ANYTHING, +}; + +static const struct bpf_func_proto * +bpf_tcp_ca_get_func_proto(enum bpf_func_id func_id, + const struct bpf_prog *prog) +{ + switch (func_id) { + case BPF_FUNC_tcp_send_ack: + return &bpf_tcp_send_ack_proto; + case BPF_FUNC_sk_storage_get: + return &bpf_sk_storage_get_proto; + case BPF_FUNC_sk_storage_delete: + return &bpf_sk_storage_delete_proto; + default: + return bpf_base_func_proto(func_id); + } +} + +static const struct bpf_verifier_ops bpf_tcp_ca_verifier_ops = { + .get_func_proto = bpf_tcp_ca_get_func_proto, + .is_valid_access = bpf_tcp_ca_is_valid_access, + .btf_struct_access = bpf_tcp_ca_btf_struct_access, +}; + +static int bpf_tcp_ca_init_member(const struct btf_type *t, + const struct btf_member *member, + void *kdata, const void *udata) +{ + const struct tcp_congestion_ops *utcp_ca; + struct tcp_congestion_ops *tcp_ca; + int prog_fd; + u32 moff; + + utcp_ca = (const struct tcp_congestion_ops *)udata; + tcp_ca = (struct tcp_congestion_ops *)kdata; + + moff = btf_member_bit_offset(t, member) / 8; + switch (moff) { + case offsetof(struct tcp_congestion_ops, flags): + if (utcp_ca->flags & ~TCP_CONG_MASK) + return -EINVAL; + tcp_ca->flags = utcp_ca->flags; + return 1; + case offsetof(struct tcp_congestion_ops, name): + if (bpf_obj_name_cpy(tcp_ca->name, utcp_ca->name, + sizeof(tcp_ca->name)) <= 0) + return -EINVAL; + if (tcp_ca_find(utcp_ca->name)) + return -EEXIST; + return 1; + } + + if (!btf_type_resolve_func_ptr(btf_vmlinux, member->type, NULL)) + return 0; + + /* Ensure bpf_prog is provided for compulsory func ptr */ + prog_fd = (int)(*(unsigned long *)(udata + moff)); + if (!prog_fd && !is_optional(moff) && !is_unsupported(moff)) + return -EINVAL; + + return 0; +} + +static int bpf_tcp_ca_check_member(const struct btf_type *t, + const struct btf_member *member) +{ + if (is_unsupported(btf_member_bit_offset(t, member) / 8)) + return -ENOTSUPP; + return 0; +} + +static int bpf_tcp_ca_reg(void *kdata) +{ + return tcp_register_congestion_control(kdata); +} + +static void bpf_tcp_ca_unreg(void *kdata) +{ + tcp_unregister_congestion_control(kdata); +} + +/* Avoid sparse warning. It is only used in bpf_struct_ops.c. */ +extern struct bpf_struct_ops bpf_tcp_congestion_ops; + +struct bpf_struct_ops bpf_tcp_congestion_ops = { + .verifier_ops = &bpf_tcp_ca_verifier_ops, + .reg = bpf_tcp_ca_reg, + .unreg = bpf_tcp_ca_unreg, + .check_member = bpf_tcp_ca_check_member, + .init_member = bpf_tcp_ca_init_member, + .init = bpf_tcp_ca_init, + .name = "tcp_congestion_ops", +}; diff --git a/net/ipv4/bpfilter/Makefile b/net/ipv4/bpfilter/Makefile new file mode 100644 index 000000000..00af5305e --- /dev/null +++ b/net/ipv4/bpfilter/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_BPFILTER) += sockopt.o diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c new file mode 100644 index 000000000..1b34cb9a7 --- /dev/null +++ b/net/ipv4/bpfilter/sockopt.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/init.h> +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/bpfilter.h> +#include <uapi/linux/bpf.h> +#include <linux/wait.h> +#include <linux/kmod.h> +#include <linux/fs.h> +#include <linux/file.h> + +struct bpfilter_umh_ops bpfilter_ops; +EXPORT_SYMBOL_GPL(bpfilter_ops); + +void bpfilter_umh_cleanup(struct umd_info *info) +{ + fput(info->pipe_to_umh); + fput(info->pipe_from_umh); + put_pid(info->tgid); + info->tgid = NULL; +} +EXPORT_SYMBOL_GPL(bpfilter_umh_cleanup); + +static int bpfilter_mbox_request(struct sock *sk, int optname, sockptr_t optval, + unsigned int optlen, bool is_set) +{ + int err; + mutex_lock(&bpfilter_ops.lock); + if (!bpfilter_ops.sockopt) { + mutex_unlock(&bpfilter_ops.lock); + request_module("bpfilter"); + mutex_lock(&bpfilter_ops.lock); + + if (!bpfilter_ops.sockopt) { + err = -ENOPROTOOPT; + goto out; + } + } + if (bpfilter_ops.info.tgid && + thread_group_exited(bpfilter_ops.info.tgid)) + bpfilter_umh_cleanup(&bpfilter_ops.info); + + if (!bpfilter_ops.info.tgid) { + err = bpfilter_ops.start(); + if (err) + goto out; + } + err = bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set); +out: + mutex_unlock(&bpfilter_ops.lock); + return err; +} + +int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval, + unsigned int optlen) +{ + return bpfilter_mbox_request(sk, optname, optval, optlen, true); +} + +int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, + int __user *optlen) +{ + int len; + + if (get_user(len, optlen)) + return -EFAULT; + + return bpfilter_mbox_request(sk, optname, USER_SOCKPTR(optval), len, + false); +} + +static int __init bpfilter_sockopt_init(void) +{ + mutex_init(&bpfilter_ops.lock); + bpfilter_ops.info.tgid = NULL; + bpfilter_ops.info.driver_name = "bpfilter_umh"; + + return 0; +} +device_initcall(bpfilter_sockopt_init); diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c new file mode 100644 index 000000000..d4a416015 --- /dev/null +++ b/net/ipv4/cipso_ipv4.c @@ -0,0 +1,2296 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * CIPSO - Commercial IP Security Option + * + * This is an implementation of the CIPSO 2.2 protocol as specified in + * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in + * FIPS-188. While CIPSO never became a full IETF RFC standard many vendors + * have chosen to adopt the protocol and over the years it has become a + * de-facto standard for labeled networking. + * + * The CIPSO draft specification can be found in the kernel's Documentation + * directory as well as the following URL: + * https://tools.ietf.org/id/draft-ietf-cipso-ipsecurity-01.txt + * The FIPS-188 specification can be found at the following URL: + * https://www.itl.nist.gov/fipspubs/fip188.htm + * + * Author: Paul Moore <paul.moore@hp.com> + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 + */ + +#include <linux/init.h> +#include <linux/types.h> +#include <linux/rcupdate.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/jhash.h> +#include <linux/audit.h> +#include <linux/slab.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/tcp.h> +#include <net/netlabel.h> +#include <net/cipso_ipv4.h> +#include <linux/atomic.h> +#include <linux/bug.h> +#include <asm/unaligned.h> + +/* List of available DOI definitions */ +/* XXX - This currently assumes a minimal number of different DOIs in use, + * if in practice there are a lot of different DOIs this list should + * probably be turned into a hash table or something similar so we + * can do quick lookups. */ +static DEFINE_SPINLOCK(cipso_v4_doi_list_lock); +static LIST_HEAD(cipso_v4_doi_list); + +/* Label mapping cache */ +int cipso_v4_cache_enabled = 1; +int cipso_v4_cache_bucketsize = 10; +#define CIPSO_V4_CACHE_BUCKETBITS 7 +#define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS) +#define CIPSO_V4_CACHE_REORDERLIMIT 10 +struct cipso_v4_map_cache_bkt { + spinlock_t lock; + u32 size; + struct list_head list; +}; + +struct cipso_v4_map_cache_entry { + u32 hash; + unsigned char *key; + size_t key_len; + + struct netlbl_lsm_cache *lsm_data; + + u32 activity; + struct list_head list; +}; + +static struct cipso_v4_map_cache_bkt *cipso_v4_cache; + +/* Restricted bitmap (tag #1) flags */ +int cipso_v4_rbm_optfmt = 0; +int cipso_v4_rbm_strictvalid = 1; + +/* + * Protocol Constants + */ + +/* Maximum size of the CIPSO IP option, derived from the fact that the maximum + * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */ +#define CIPSO_V4_OPT_LEN_MAX 40 + +/* Length of the base CIPSO option, this includes the option type (1 byte), the + * option length (1 byte), and the DOI (4 bytes). */ +#define CIPSO_V4_HDR_LEN 6 + +/* Base length of the restrictive category bitmap tag (tag #1). */ +#define CIPSO_V4_TAG_RBM_BLEN 4 + +/* Base length of the enumerated category tag (tag #2). */ +#define CIPSO_V4_TAG_ENUM_BLEN 4 + +/* Base length of the ranged categories bitmap tag (tag #5). */ +#define CIPSO_V4_TAG_RNG_BLEN 4 +/* The maximum number of category ranges permitted in the ranged category tag + * (tag #5). You may note that the IETF draft states that the maximum number + * of category ranges is 7, but if the low end of the last category range is + * zero then it is possible to fit 8 category ranges because the zero should + * be omitted. */ +#define CIPSO_V4_TAG_RNG_CAT_MAX 8 + +/* Base length of the local tag (non-standard tag). + * Tag definition (may change between kernel versions) + * + * 0 8 16 24 32 + * +----------+----------+----------+----------+ + * | 10000000 | 00000110 | 32-bit secid value | + * +----------+----------+----------+----------+ + * | in (host byte order)| + * +----------+----------+ + * + */ +#define CIPSO_V4_TAG_LOC_BLEN 6 + +/* + * Helper Functions + */ + +/** + * cipso_v4_cache_entry_free - Frees a cache entry + * @entry: the entry to free + * + * Description: + * This function frees the memory associated with a cache entry including the + * LSM cache data if there are no longer any users, i.e. reference count == 0. + * + */ +static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry) +{ + if (entry->lsm_data) + netlbl_secattr_cache_free(entry->lsm_data); + kfree(entry->key); + kfree(entry); +} + +/** + * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache + * @key: the hash key + * @key_len: the length of the key in bytes + * + * Description: + * The CIPSO tag hashing function. Returns a 32-bit hash value. + * + */ +static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len) +{ + return jhash(key, key_len, 0); +} + +/* + * Label Mapping Cache Functions + */ + +/** + * cipso_v4_cache_init - Initialize the CIPSO cache + * + * Description: + * Initializes the CIPSO label mapping cache, this function should be called + * before any of the other functions defined in this file. Returns zero on + * success, negative values on error. + * + */ +static int __init cipso_v4_cache_init(void) +{ + u32 iter; + + cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS, + sizeof(struct cipso_v4_map_cache_bkt), + GFP_KERNEL); + if (!cipso_v4_cache) + return -ENOMEM; + + for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { + spin_lock_init(&cipso_v4_cache[iter].lock); + cipso_v4_cache[iter].size = 0; + INIT_LIST_HEAD(&cipso_v4_cache[iter].list); + } + + return 0; +} + +/** + * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache + * + * Description: + * Invalidates and frees any entries in the CIPSO cache. Returns zero on + * success and negative values on failure. + * + */ +void cipso_v4_cache_invalidate(void) +{ + struct cipso_v4_map_cache_entry *entry, *tmp_entry; + u32 iter; + + for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { + spin_lock_bh(&cipso_v4_cache[iter].lock); + list_for_each_entry_safe(entry, + tmp_entry, + &cipso_v4_cache[iter].list, list) { + list_del(&entry->list); + cipso_v4_cache_entry_free(entry); + } + cipso_v4_cache[iter].size = 0; + spin_unlock_bh(&cipso_v4_cache[iter].lock); + } +} + +/** + * cipso_v4_cache_check - Check the CIPSO cache for a label mapping + * @key: the buffer to check + * @key_len: buffer length in bytes + * @secattr: the security attribute struct to use + * + * Description: + * This function checks the cache to see if a label mapping already exists for + * the given key. If there is a match then the cache is adjusted and the + * @secattr struct is populated with the correct LSM security attributes. The + * cache is adjusted in the following manner if the entry is not already the + * first in the cache bucket: + * + * 1. The cache entry's activity counter is incremented + * 2. The previous (higher ranking) entry's activity counter is decremented + * 3. If the difference between the two activity counters is geater than + * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped + * + * Returns zero on success, -ENOENT for a cache miss, and other negative values + * on error. + * + */ +static int cipso_v4_cache_check(const unsigned char *key, + u32 key_len, + struct netlbl_lsm_secattr *secattr) +{ + u32 bkt; + struct cipso_v4_map_cache_entry *entry; + struct cipso_v4_map_cache_entry *prev_entry = NULL; + u32 hash; + + if (!READ_ONCE(cipso_v4_cache_enabled)) + return -ENOENT; + + hash = cipso_v4_map_cache_hash(key, key_len); + bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1); + spin_lock_bh(&cipso_v4_cache[bkt].lock); + list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) { + if (entry->hash == hash && + entry->key_len == key_len && + memcmp(entry->key, key, key_len) == 0) { + entry->activity += 1; + refcount_inc(&entry->lsm_data->refcount); + secattr->cache = entry->lsm_data; + secattr->flags |= NETLBL_SECATTR_CACHE; + secattr->type = NETLBL_NLTYPE_CIPSOV4; + if (!prev_entry) { + spin_unlock_bh(&cipso_v4_cache[bkt].lock); + return 0; + } + + if (prev_entry->activity > 0) + prev_entry->activity -= 1; + if (entry->activity > prev_entry->activity && + entry->activity - prev_entry->activity > + CIPSO_V4_CACHE_REORDERLIMIT) { + __list_del(entry->list.prev, entry->list.next); + __list_add(&entry->list, + prev_entry->list.prev, + &prev_entry->list); + } + + spin_unlock_bh(&cipso_v4_cache[bkt].lock); + return 0; + } + prev_entry = entry; + } + spin_unlock_bh(&cipso_v4_cache[bkt].lock); + + return -ENOENT; +} + +/** + * cipso_v4_cache_add - Add an entry to the CIPSO cache + * @cipso_ptr: pointer to CIPSO IP option + * @secattr: the packet's security attributes + * + * Description: + * Add a new entry into the CIPSO label mapping cache. Add the new entry to + * head of the cache bucket's list, if the cache bucket is out of room remove + * the last entry in the list first. It is important to note that there is + * currently no checking for duplicate keys. Returns zero on success, + * negative values on failure. + * + */ +int cipso_v4_cache_add(const unsigned char *cipso_ptr, + const struct netlbl_lsm_secattr *secattr) +{ + int bkt_size = READ_ONCE(cipso_v4_cache_bucketsize); + int ret_val = -EPERM; + u32 bkt; + struct cipso_v4_map_cache_entry *entry = NULL; + struct cipso_v4_map_cache_entry *old_entry = NULL; + u32 cipso_ptr_len; + + if (!READ_ONCE(cipso_v4_cache_enabled) || bkt_size <= 0) + return 0; + + cipso_ptr_len = cipso_ptr[1]; + + entry = kzalloc(sizeof(*entry), GFP_ATOMIC); + if (!entry) + return -ENOMEM; + entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC); + if (!entry->key) { + ret_val = -ENOMEM; + goto cache_add_failure; + } + entry->key_len = cipso_ptr_len; + entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len); + refcount_inc(&secattr->cache->refcount); + entry->lsm_data = secattr->cache; + + bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1); + spin_lock_bh(&cipso_v4_cache[bkt].lock); + if (cipso_v4_cache[bkt].size < bkt_size) { + list_add(&entry->list, &cipso_v4_cache[bkt].list); + cipso_v4_cache[bkt].size += 1; + } else { + old_entry = list_entry(cipso_v4_cache[bkt].list.prev, + struct cipso_v4_map_cache_entry, list); + list_del(&old_entry->list); + list_add(&entry->list, &cipso_v4_cache[bkt].list); + cipso_v4_cache_entry_free(old_entry); + } + spin_unlock_bh(&cipso_v4_cache[bkt].lock); + + return 0; + +cache_add_failure: + if (entry) + cipso_v4_cache_entry_free(entry); + return ret_val; +} + +/* + * DOI List Functions + */ + +/** + * cipso_v4_doi_search - Searches for a DOI definition + * @doi: the DOI to search for + * + * Description: + * Search the DOI definition list for a DOI definition with a DOI value that + * matches @doi. The caller is responsible for calling rcu_read_[un]lock(). + * Returns a pointer to the DOI definition on success and NULL on failure. + */ +static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi) +{ + struct cipso_v4_doi *iter; + + list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list) + if (iter->doi == doi && refcount_read(&iter->refcount)) + return iter; + return NULL; +} + +/** + * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine + * @doi_def: the DOI structure + * @audit_info: NetLabel audit information + * + * Description: + * The caller defines a new DOI for use by the CIPSO engine and calls this + * function to add it to the list of acceptable domains. The caller must + * ensure that the mapping table specified in @doi_def->map meets all of the + * requirements of the mapping type (see cipso_ipv4.h for details). Returns + * zero on success and non-zero on failure. + * + */ +int cipso_v4_doi_add(struct cipso_v4_doi *doi_def, + struct netlbl_audit *audit_info) +{ + int ret_val = -EINVAL; + u32 iter; + u32 doi; + u32 doi_type; + struct audit_buffer *audit_buf; + + doi = doi_def->doi; + doi_type = doi_def->type; + + if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN) + goto doi_add_return; + for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) { + switch (doi_def->tags[iter]) { + case CIPSO_V4_TAG_RBITMAP: + break; + case CIPSO_V4_TAG_RANGE: + case CIPSO_V4_TAG_ENUM: + if (doi_def->type != CIPSO_V4_MAP_PASS) + goto doi_add_return; + break; + case CIPSO_V4_TAG_LOCAL: + if (doi_def->type != CIPSO_V4_MAP_LOCAL) + goto doi_add_return; + break; + case CIPSO_V4_TAG_INVALID: + if (iter == 0) + goto doi_add_return; + break; + default: + goto doi_add_return; + } + } + + refcount_set(&doi_def->refcount, 1); + + spin_lock(&cipso_v4_doi_list_lock); + if (cipso_v4_doi_search(doi_def->doi)) { + spin_unlock(&cipso_v4_doi_list_lock); + ret_val = -EEXIST; + goto doi_add_return; + } + list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list); + spin_unlock(&cipso_v4_doi_list_lock); + ret_val = 0; + +doi_add_return: + audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info); + if (audit_buf) { + const char *type_str; + switch (doi_type) { + case CIPSO_V4_MAP_TRANS: + type_str = "trans"; + break; + case CIPSO_V4_MAP_PASS: + type_str = "pass"; + break; + case CIPSO_V4_MAP_LOCAL: + type_str = "local"; + break; + default: + type_str = "(unknown)"; + } + audit_log_format(audit_buf, + " cipso_doi=%u cipso_type=%s res=%u", + doi, type_str, ret_val == 0 ? 1 : 0); + audit_log_end(audit_buf); + } + + return ret_val; +} + +/** + * cipso_v4_doi_free - Frees a DOI definition + * @doi_def: the DOI definition + * + * Description: + * This function frees all of the memory associated with a DOI definition. + * + */ +void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) +{ + if (!doi_def) + return; + + switch (doi_def->type) { + case CIPSO_V4_MAP_TRANS: + kfree(doi_def->map.std->lvl.cipso); + kfree(doi_def->map.std->lvl.local); + kfree(doi_def->map.std->cat.cipso); + kfree(doi_def->map.std->cat.local); + kfree(doi_def->map.std); + break; + } + kfree(doi_def); +} + +/** + * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer + * @entry: the entry's RCU field + * + * Description: + * This function is designed to be used as a callback to the call_rcu() + * function so that the memory allocated to the DOI definition can be released + * safely. + * + */ +static void cipso_v4_doi_free_rcu(struct rcu_head *entry) +{ + struct cipso_v4_doi *doi_def; + + doi_def = container_of(entry, struct cipso_v4_doi, rcu); + cipso_v4_doi_free(doi_def); +} + +/** + * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine + * @doi: the DOI value + * @audit_info: NetLabel audit information + * + * Description: + * Removes a DOI definition from the CIPSO engine. The NetLabel routines will + * be called to release their own LSM domain mappings as well as our own + * domain list. Returns zero on success and negative values on failure. + * + */ +int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info) +{ + int ret_val; + struct cipso_v4_doi *doi_def; + struct audit_buffer *audit_buf; + + spin_lock(&cipso_v4_doi_list_lock); + doi_def = cipso_v4_doi_search(doi); + if (!doi_def) { + spin_unlock(&cipso_v4_doi_list_lock); + ret_val = -ENOENT; + goto doi_remove_return; + } + list_del_rcu(&doi_def->list); + spin_unlock(&cipso_v4_doi_list_lock); + + cipso_v4_doi_putdef(doi_def); + ret_val = 0; + +doi_remove_return: + audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info); + if (audit_buf) { + audit_log_format(audit_buf, + " cipso_doi=%u res=%u", + doi, ret_val == 0 ? 1 : 0); + audit_log_end(audit_buf); + } + + return ret_val; +} + +/** + * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition + * @doi: the DOI value + * + * Description: + * Searches for a valid DOI definition and if one is found it is returned to + * the caller. Otherwise NULL is returned. The caller must ensure that + * rcu_read_lock() is held while accessing the returned definition and the DOI + * definition reference count is decremented when the caller is done. + * + */ +struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi) +{ + struct cipso_v4_doi *doi_def; + + rcu_read_lock(); + doi_def = cipso_v4_doi_search(doi); + if (!doi_def) + goto doi_getdef_return; + if (!refcount_inc_not_zero(&doi_def->refcount)) + doi_def = NULL; + +doi_getdef_return: + rcu_read_unlock(); + return doi_def; +} + +/** + * cipso_v4_doi_putdef - Releases a reference for the given DOI definition + * @doi_def: the DOI definition + * + * Description: + * Releases a DOI definition reference obtained from cipso_v4_doi_getdef(). + * + */ +void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def) +{ + if (!doi_def) + return; + + if (!refcount_dec_and_test(&doi_def->refcount)) + return; + + cipso_v4_cache_invalidate(); + call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); +} + +/** + * cipso_v4_doi_walk - Iterate through the DOI definitions + * @skip_cnt: skip past this number of DOI definitions, updated + * @callback: callback for each DOI definition + * @cb_arg: argument for the callback function + * + * Description: + * Iterate over the DOI definition list, skipping the first @skip_cnt entries. + * For each entry call @callback, if @callback returns a negative value stop + * 'walking' through the list and return. Updates the value in @skip_cnt upon + * return. Returns zero on success, negative values on failure. + * + */ +int cipso_v4_doi_walk(u32 *skip_cnt, + int (*callback) (struct cipso_v4_doi *doi_def, void *arg), + void *cb_arg) +{ + int ret_val = -ENOENT; + u32 doi_cnt = 0; + struct cipso_v4_doi *iter_doi; + + rcu_read_lock(); + list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list) + if (refcount_read(&iter_doi->refcount) > 0) { + if (doi_cnt++ < *skip_cnt) + continue; + ret_val = callback(iter_doi, cb_arg); + if (ret_val < 0) { + doi_cnt--; + goto doi_walk_return; + } + } + +doi_walk_return: + rcu_read_unlock(); + *skip_cnt = doi_cnt; + return ret_val; +} + +/* + * Label Mapping Functions + */ + +/** + * cipso_v4_map_lvl_valid - Checks to see if the given level is understood + * @doi_def: the DOI definition + * @level: the level to check + * + * Description: + * Checks the given level against the given DOI definition and returns a + * negative value if the level does not have a valid mapping and a zero value + * if the level is defined by the DOI. + * + */ +static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level) +{ + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + return 0; + case CIPSO_V4_MAP_TRANS: + if ((level < doi_def->map.std->lvl.cipso_size) && + (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)) + return 0; + break; + } + + return -EFAULT; +} + +/** + * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network + * @doi_def: the DOI definition + * @host_lvl: the host MLS level + * @net_lvl: the network/CIPSO MLS level + * + * Description: + * Perform a label mapping to translate a local MLS level to the correct + * CIPSO level using the given DOI definition. Returns zero on success, + * negative values otherwise. + * + */ +static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def, + u32 host_lvl, + u32 *net_lvl) +{ + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + *net_lvl = host_lvl; + return 0; + case CIPSO_V4_MAP_TRANS: + if (host_lvl < doi_def->map.std->lvl.local_size && + doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) { + *net_lvl = doi_def->map.std->lvl.local[host_lvl]; + return 0; + } + return -EPERM; + } + + return -EINVAL; +} + +/** + * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host + * @doi_def: the DOI definition + * @net_lvl: the network/CIPSO MLS level + * @host_lvl: the host MLS level + * + * Description: + * Perform a label mapping to translate a CIPSO level to the correct local MLS + * level using the given DOI definition. Returns zero on success, negative + * values otherwise. + * + */ +static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def, + u32 net_lvl, + u32 *host_lvl) +{ + struct cipso_v4_std_map_tbl *map_tbl; + + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + *host_lvl = net_lvl; + return 0; + case CIPSO_V4_MAP_TRANS: + map_tbl = doi_def->map.std; + if (net_lvl < map_tbl->lvl.cipso_size && + map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) { + *host_lvl = doi_def->map.std->lvl.cipso[net_lvl]; + return 0; + } + return -EPERM; + } + + return -EINVAL; +} + +/** + * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid + * @doi_def: the DOI definition + * @bitmap: category bitmap + * @bitmap_len: bitmap length in bytes + * + * Description: + * Checks the given category bitmap against the given DOI definition and + * returns a negative value if any of the categories in the bitmap do not have + * a valid mapping and a zero value if all of the categories are valid. + * + */ +static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def, + const unsigned char *bitmap, + u32 bitmap_len) +{ + int cat = -1; + u32 bitmap_len_bits = bitmap_len * 8; + u32 cipso_cat_size; + u32 *cipso_array; + + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + return 0; + case CIPSO_V4_MAP_TRANS: + cipso_cat_size = doi_def->map.std->cat.cipso_size; + cipso_array = doi_def->map.std->cat.cipso; + for (;;) { + cat = netlbl_bitmap_walk(bitmap, + bitmap_len_bits, + cat + 1, + 1); + if (cat < 0) + break; + if (cat >= cipso_cat_size || + cipso_array[cat] >= CIPSO_V4_INV_CAT) + return -EFAULT; + } + + if (cat == -1) + return 0; + break; + } + + return -EFAULT; +} + +/** + * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network + * @doi_def: the DOI definition + * @secattr: the security attributes + * @net_cat: the zero'd out category bitmap in network/CIPSO format + * @net_cat_len: the length of the CIPSO bitmap in bytes + * + * Description: + * Perform a label mapping to translate a local MLS category bitmap to the + * correct CIPSO bitmap using the given DOI definition. Returns the minimum + * size in bytes of the network bitmap on success, negative values otherwise. + * + */ +static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *net_cat, + u32 net_cat_len) +{ + int host_spot = -1; + u32 net_spot = CIPSO_V4_INV_CAT; + u32 net_spot_max = 0; + u32 net_clen_bits = net_cat_len * 8; + u32 host_cat_size = 0; + u32 *host_cat_array = NULL; + + if (doi_def->type == CIPSO_V4_MAP_TRANS) { + host_cat_size = doi_def->map.std->cat.local_size; + host_cat_array = doi_def->map.std->cat.local; + } + + for (;;) { + host_spot = netlbl_catmap_walk(secattr->attr.mls.cat, + host_spot + 1); + if (host_spot < 0) + break; + + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + net_spot = host_spot; + break; + case CIPSO_V4_MAP_TRANS: + if (host_spot >= host_cat_size) + return -EPERM; + net_spot = host_cat_array[host_spot]; + if (net_spot >= CIPSO_V4_INV_CAT) + return -EPERM; + break; + } + if (net_spot >= net_clen_bits) + return -ENOSPC; + netlbl_bitmap_setbit(net_cat, net_spot, 1); + + if (net_spot > net_spot_max) + net_spot_max = net_spot; + } + + if (++net_spot_max % 8) + return net_spot_max / 8 + 1; + return net_spot_max / 8; +} + +/** + * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host + * @doi_def: the DOI definition + * @net_cat: the category bitmap in network/CIPSO format + * @net_cat_len: the length of the CIPSO bitmap in bytes + * @secattr: the security attributes + * + * Description: + * Perform a label mapping to translate a CIPSO bitmap to the correct local + * MLS category bitmap using the given DOI definition. Returns zero on + * success, negative values on failure. + * + */ +static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, + const unsigned char *net_cat, + u32 net_cat_len, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + int net_spot = -1; + u32 host_spot = CIPSO_V4_INV_CAT; + u32 net_clen_bits = net_cat_len * 8; + u32 net_cat_size = 0; + u32 *net_cat_array = NULL; + + if (doi_def->type == CIPSO_V4_MAP_TRANS) { + net_cat_size = doi_def->map.std->cat.cipso_size; + net_cat_array = doi_def->map.std->cat.cipso; + } + + for (;;) { + net_spot = netlbl_bitmap_walk(net_cat, + net_clen_bits, + net_spot + 1, + 1); + if (net_spot < 0) { + if (net_spot == -2) + return -EFAULT; + return 0; + } + + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + host_spot = net_spot; + break; + case CIPSO_V4_MAP_TRANS: + if (net_spot >= net_cat_size) + return -EPERM; + host_spot = net_cat_array[net_spot]; + if (host_spot >= CIPSO_V4_INV_CAT) + return -EPERM; + break; + } + ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat, + host_spot, + GFP_ATOMIC); + if (ret_val != 0) + return ret_val; + } + + return -EINVAL; +} + +/** + * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid + * @doi_def: the DOI definition + * @enumcat: category list + * @enumcat_len: length of the category list in bytes + * + * Description: + * Checks the given categories against the given DOI definition and returns a + * negative value if any of the categories do not have a valid mapping and a + * zero value if all of the categories are valid. + * + */ +static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def, + const unsigned char *enumcat, + u32 enumcat_len) +{ + u16 cat; + int cat_prev = -1; + u32 iter; + + if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01) + return -EFAULT; + + for (iter = 0; iter < enumcat_len; iter += 2) { + cat = get_unaligned_be16(&enumcat[iter]); + if (cat <= cat_prev) + return -EFAULT; + cat_prev = cat; + } + + return 0; +} + +/** + * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network + * @doi_def: the DOI definition + * @secattr: the security attributes + * @net_cat: the zero'd out category list in network/CIPSO format + * @net_cat_len: the length of the CIPSO category list in bytes + * + * Description: + * Perform a label mapping to translate a local MLS category bitmap to the + * correct CIPSO category list using the given DOI definition. Returns the + * size in bytes of the network category bitmap on success, negative values + * otherwise. + * + */ +static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *net_cat, + u32 net_cat_len) +{ + int cat = -1; + u32 cat_iter = 0; + + for (;;) { + cat = netlbl_catmap_walk(secattr->attr.mls.cat, cat + 1); + if (cat < 0) + break; + if ((cat_iter + 2) > net_cat_len) + return -ENOSPC; + + *((__be16 *)&net_cat[cat_iter]) = htons(cat); + cat_iter += 2; + } + + return cat_iter; +} + +/** + * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host + * @doi_def: the DOI definition + * @net_cat: the category list in network/CIPSO format + * @net_cat_len: the length of the CIPSO bitmap in bytes + * @secattr: the security attributes + * + * Description: + * Perform a label mapping to translate a CIPSO category list to the correct + * local MLS category bitmap using the given DOI definition. Returns zero on + * success, negative values on failure. + * + */ +static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def, + const unsigned char *net_cat, + u32 net_cat_len, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u32 iter; + + for (iter = 0; iter < net_cat_len; iter += 2) { + ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat, + get_unaligned_be16(&net_cat[iter]), + GFP_ATOMIC); + if (ret_val != 0) + return ret_val; + } + + return 0; +} + +/** + * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid + * @doi_def: the DOI definition + * @rngcat: category list + * @rngcat_len: length of the category list in bytes + * + * Description: + * Checks the given categories against the given DOI definition and returns a + * negative value if any of the categories do not have a valid mapping and a + * zero value if all of the categories are valid. + * + */ +static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def, + const unsigned char *rngcat, + u32 rngcat_len) +{ + u16 cat_high; + u16 cat_low; + u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1; + u32 iter; + + if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01) + return -EFAULT; + + for (iter = 0; iter < rngcat_len; iter += 4) { + cat_high = get_unaligned_be16(&rngcat[iter]); + if ((iter + 4) <= rngcat_len) + cat_low = get_unaligned_be16(&rngcat[iter + 2]); + else + cat_low = 0; + + if (cat_high > cat_prev) + return -EFAULT; + + cat_prev = cat_low; + } + + return 0; +} + +/** + * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network + * @doi_def: the DOI definition + * @secattr: the security attributes + * @net_cat: the zero'd out category list in network/CIPSO format + * @net_cat_len: the length of the CIPSO category list in bytes + * + * Description: + * Perform a label mapping to translate a local MLS category bitmap to the + * correct CIPSO category list using the given DOI definition. Returns the + * size in bytes of the network category bitmap on success, negative values + * otherwise. + * + */ +static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *net_cat, + u32 net_cat_len) +{ + int iter = -1; + u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2]; + u32 array_cnt = 0; + u32 cat_size = 0; + + /* make sure we don't overflow the 'array[]' variable */ + if (net_cat_len > + (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN)) + return -ENOSPC; + + for (;;) { + iter = netlbl_catmap_walk(secattr->attr.mls.cat, iter + 1); + if (iter < 0) + break; + cat_size += (iter == 0 ? 0 : sizeof(u16)); + if (cat_size > net_cat_len) + return -ENOSPC; + array[array_cnt++] = iter; + + iter = netlbl_catmap_walkrng(secattr->attr.mls.cat, iter); + if (iter < 0) + return -EFAULT; + cat_size += sizeof(u16); + if (cat_size > net_cat_len) + return -ENOSPC; + array[array_cnt++] = iter; + } + + for (iter = 0; array_cnt > 0;) { + *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]); + iter += 2; + array_cnt--; + if (array[array_cnt] != 0) { + *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]); + iter += 2; + } + } + + return cat_size; +} + +/** + * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host + * @doi_def: the DOI definition + * @net_cat: the category list in network/CIPSO format + * @net_cat_len: the length of the CIPSO bitmap in bytes + * @secattr: the security attributes + * + * Description: + * Perform a label mapping to translate a CIPSO category list to the correct + * local MLS category bitmap using the given DOI definition. Returns zero on + * success, negative values on failure. + * + */ +static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def, + const unsigned char *net_cat, + u32 net_cat_len, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u32 net_iter; + u16 cat_low; + u16 cat_high; + + for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) { + cat_high = get_unaligned_be16(&net_cat[net_iter]); + if ((net_iter + 4) <= net_cat_len) + cat_low = get_unaligned_be16(&net_cat[net_iter + 2]); + else + cat_low = 0; + + ret_val = netlbl_catmap_setrng(&secattr->attr.mls.cat, + cat_low, + cat_high, + GFP_ATOMIC); + if (ret_val != 0) + return ret_val; + } + + return 0; +} + +/* + * Protocol Handling Functions + */ + +/** + * cipso_v4_gentag_hdr - Generate a CIPSO option header + * @doi_def: the DOI definition + * @len: the total tag length in bytes, not including this header + * @buf: the CIPSO option buffer + * + * Description: + * Write a CIPSO header into the beginning of @buffer. + * + */ +static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def, + unsigned char *buf, + u32 len) +{ + buf[0] = IPOPT_CIPSO; + buf[1] = CIPSO_V4_HDR_LEN + len; + *(__be32 *)&buf[2] = htonl(doi_def->doi); +} + +/** + * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1) + * @doi_def: the DOI definition + * @secattr: the security attributes + * @buffer: the option buffer + * @buffer_len: length of buffer in bytes + * + * Description: + * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The + * actual buffer length may be larger than the indicated size due to + * translation between host and network category bitmaps. Returns the size of + * the tag on success, negative values on failure. + * + */ +static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *buffer, + u32 buffer_len) +{ + int ret_val; + u32 tag_len; + u32 level; + + if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0) + return -EPERM; + + ret_val = cipso_v4_map_lvl_hton(doi_def, + secattr->attr.mls.lvl, + &level); + if (ret_val != 0) + return ret_val; + + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + ret_val = cipso_v4_map_cat_rbm_hton(doi_def, + secattr, + &buffer[4], + buffer_len - 4); + if (ret_val < 0) + return ret_val; + + /* This will send packets using the "optimized" format when + * possible as specified in section 3.4.2.6 of the + * CIPSO draft. */ + if (READ_ONCE(cipso_v4_rbm_optfmt) && ret_val > 0 && + ret_val <= 10) + tag_len = 14; + else + tag_len = 4 + ret_val; + } else + tag_len = 4; + + buffer[0] = CIPSO_V4_TAG_RBITMAP; + buffer[1] = tag_len; + buffer[3] = level; + + return tag_len; +} + +/** + * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag + * @doi_def: the DOI definition + * @tag: the CIPSO tag + * @secattr: the security attributes + * + * Description: + * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security + * attributes in @secattr. Return zero on success, negatives values on + * failure. + * + */ +static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def, + const unsigned char *tag, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u8 tag_len = tag[1]; + u32 level; + + ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); + if (ret_val != 0) + return ret_val; + secattr->attr.mls.lvl = level; + secattr->flags |= NETLBL_SECATTR_MLS_LVL; + + if (tag_len > 4) { + ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def, + &tag[4], + tag_len - 4, + secattr); + if (ret_val != 0) { + netlbl_catmap_free(secattr->attr.mls.cat); + return ret_val; + } + + if (secattr->attr.mls.cat) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; + } + + return 0; +} + +/** + * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2) + * @doi_def: the DOI definition + * @secattr: the security attributes + * @buffer: the option buffer + * @buffer_len: length of buffer in bytes + * + * Description: + * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the + * size of the tag on success, negative values on failure. + * + */ +static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *buffer, + u32 buffer_len) +{ + int ret_val; + u32 tag_len; + u32 level; + + if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) + return -EPERM; + + ret_val = cipso_v4_map_lvl_hton(doi_def, + secattr->attr.mls.lvl, + &level); + if (ret_val != 0) + return ret_val; + + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + ret_val = cipso_v4_map_cat_enum_hton(doi_def, + secattr, + &buffer[4], + buffer_len - 4); + if (ret_val < 0) + return ret_val; + + tag_len = 4 + ret_val; + } else + tag_len = 4; + + buffer[0] = CIPSO_V4_TAG_ENUM; + buffer[1] = tag_len; + buffer[3] = level; + + return tag_len; +} + +/** + * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag + * @doi_def: the DOI definition + * @tag: the CIPSO tag + * @secattr: the security attributes + * + * Description: + * Parse a CIPSO enumerated tag (tag type #2) and return the security + * attributes in @secattr. Return zero on success, negatives values on + * failure. + * + */ +static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def, + const unsigned char *tag, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u8 tag_len = tag[1]; + u32 level; + + ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); + if (ret_val != 0) + return ret_val; + secattr->attr.mls.lvl = level; + secattr->flags |= NETLBL_SECATTR_MLS_LVL; + + if (tag_len > 4) { + ret_val = cipso_v4_map_cat_enum_ntoh(doi_def, + &tag[4], + tag_len - 4, + secattr); + if (ret_val != 0) { + netlbl_catmap_free(secattr->attr.mls.cat); + return ret_val; + } + + secattr->flags |= NETLBL_SECATTR_MLS_CAT; + } + + return 0; +} + +/** + * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5) + * @doi_def: the DOI definition + * @secattr: the security attributes + * @buffer: the option buffer + * @buffer_len: length of buffer in bytes + * + * Description: + * Generate a CIPSO option using the ranged tag, tag type #5. Returns the + * size of the tag on success, negative values on failure. + * + */ +static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *buffer, + u32 buffer_len) +{ + int ret_val; + u32 tag_len; + u32 level; + + if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) + return -EPERM; + + ret_val = cipso_v4_map_lvl_hton(doi_def, + secattr->attr.mls.lvl, + &level); + if (ret_val != 0) + return ret_val; + + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + ret_val = cipso_v4_map_cat_rng_hton(doi_def, + secattr, + &buffer[4], + buffer_len - 4); + if (ret_val < 0) + return ret_val; + + tag_len = 4 + ret_val; + } else + tag_len = 4; + + buffer[0] = CIPSO_V4_TAG_RANGE; + buffer[1] = tag_len; + buffer[3] = level; + + return tag_len; +} + +/** + * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag + * @doi_def: the DOI definition + * @tag: the CIPSO tag + * @secattr: the security attributes + * + * Description: + * Parse a CIPSO ranged tag (tag type #5) and return the security attributes + * in @secattr. Return zero on success, negatives values on failure. + * + */ +static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, + const unsigned char *tag, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u8 tag_len = tag[1]; + u32 level; + + ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); + if (ret_val != 0) + return ret_val; + secattr->attr.mls.lvl = level; + secattr->flags |= NETLBL_SECATTR_MLS_LVL; + + if (tag_len > 4) { + ret_val = cipso_v4_map_cat_rng_ntoh(doi_def, + &tag[4], + tag_len - 4, + secattr); + if (ret_val != 0) { + netlbl_catmap_free(secattr->attr.mls.cat); + return ret_val; + } + + if (secattr->attr.mls.cat) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; + } + + return 0; +} + +/** + * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard) + * @doi_def: the DOI definition + * @secattr: the security attributes + * @buffer: the option buffer + * @buffer_len: length of buffer in bytes + * + * Description: + * Generate a CIPSO option using the local tag. Returns the size of the tag + * on success, negative values on failure. + * + */ +static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *buffer, + u32 buffer_len) +{ + if (!(secattr->flags & NETLBL_SECATTR_SECID)) + return -EPERM; + + buffer[0] = CIPSO_V4_TAG_LOCAL; + buffer[1] = CIPSO_V4_TAG_LOC_BLEN; + *(u32 *)&buffer[2] = secattr->attr.secid; + + return CIPSO_V4_TAG_LOC_BLEN; +} + +/** + * cipso_v4_parsetag_loc - Parse a CIPSO local tag + * @doi_def: the DOI definition + * @tag: the CIPSO tag + * @secattr: the security attributes + * + * Description: + * Parse a CIPSO local tag and return the security attributes in @secattr. + * Return zero on success, negatives values on failure. + * + */ +static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def, + const unsigned char *tag, + struct netlbl_lsm_secattr *secattr) +{ + secattr->attr.secid = *(u32 *)&tag[2]; + secattr->flags |= NETLBL_SECATTR_SECID; + + return 0; +} + +/** + * cipso_v4_optptr - Find the CIPSO option in the packet + * @skb: the packet + * + * Description: + * Parse the packet's IP header looking for a CIPSO option. Returns a pointer + * to the start of the CIPSO option on success, NULL if one is not found. + * + */ +unsigned char *cipso_v4_optptr(const struct sk_buff *skb) +{ + const struct iphdr *iph = ip_hdr(skb); + unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]); + int optlen; + int taglen; + + for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) { + switch (optptr[0]) { + case IPOPT_END: + return NULL; + case IPOPT_NOOP: + taglen = 1; + break; + default: + taglen = optptr[1]; + } + if (!taglen || taglen > optlen) + return NULL; + if (optptr[0] == IPOPT_CIPSO) + return optptr; + + optlen -= taglen; + optptr += taglen; + } + + return NULL; +} + +/** + * cipso_v4_validate - Validate a CIPSO option + * @skb: the packet + * @option: the start of the option, on error it is set to point to the error + * + * Description: + * This routine is called to validate a CIPSO option, it checks all of the + * fields to ensure that they are at least valid, see the draft snippet below + * for details. If the option is valid then a zero value is returned and + * the value of @option is unchanged. If the option is invalid then a + * non-zero value is returned and @option is adjusted to point to the + * offending portion of the option. From the IETF draft ... + * + * "If any field within the CIPSO options, such as the DOI identifier, is not + * recognized the IP datagram is discarded and an ICMP 'parameter problem' + * (type 12) is generated and returned. The ICMP code field is set to 'bad + * parameter' (code 0) and the pointer is set to the start of the CIPSO field + * that is unrecognized." + * + */ +int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option) +{ + unsigned char *opt = *option; + unsigned char *tag; + unsigned char opt_iter; + unsigned char err_offset = 0; + u8 opt_len; + u8 tag_len; + struct cipso_v4_doi *doi_def = NULL; + u32 tag_iter; + + /* caller already checks for length values that are too large */ + opt_len = opt[1]; + if (opt_len < 8) { + err_offset = 1; + goto validate_return; + } + + rcu_read_lock(); + doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2])); + if (!doi_def) { + err_offset = 2; + goto validate_return_locked; + } + + opt_iter = CIPSO_V4_HDR_LEN; + tag = opt + opt_iter; + while (opt_iter < opt_len) { + for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];) + if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID || + ++tag_iter == CIPSO_V4_TAG_MAXCNT) { + err_offset = opt_iter; + goto validate_return_locked; + } + + if (opt_iter + 1 == opt_len) { + err_offset = opt_iter; + goto validate_return_locked; + } + tag_len = tag[1]; + if (tag_len > (opt_len - opt_iter)) { + err_offset = opt_iter + 1; + goto validate_return_locked; + } + + switch (tag[0]) { + case CIPSO_V4_TAG_RBITMAP: + if (tag_len < CIPSO_V4_TAG_RBM_BLEN) { + err_offset = opt_iter + 1; + goto validate_return_locked; + } + + /* We are already going to do all the verification + * necessary at the socket layer so from our point of + * view it is safe to turn these checks off (and less + * work), however, the CIPSO draft says we should do + * all the CIPSO validations here but it doesn't + * really specify _exactly_ what we need to validate + * ... so, just make it a sysctl tunable. */ + if (READ_ONCE(cipso_v4_rbm_strictvalid)) { + if (cipso_v4_map_lvl_valid(doi_def, + tag[3]) < 0) { + err_offset = opt_iter + 3; + goto validate_return_locked; + } + if (tag_len > CIPSO_V4_TAG_RBM_BLEN && + cipso_v4_map_cat_rbm_valid(doi_def, + &tag[4], + tag_len - 4) < 0) { + err_offset = opt_iter + 4; + goto validate_return_locked; + } + } + break; + case CIPSO_V4_TAG_ENUM: + if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) { + err_offset = opt_iter + 1; + goto validate_return_locked; + } + + if (cipso_v4_map_lvl_valid(doi_def, + tag[3]) < 0) { + err_offset = opt_iter + 3; + goto validate_return_locked; + } + if (tag_len > CIPSO_V4_TAG_ENUM_BLEN && + cipso_v4_map_cat_enum_valid(doi_def, + &tag[4], + tag_len - 4) < 0) { + err_offset = opt_iter + 4; + goto validate_return_locked; + } + break; + case CIPSO_V4_TAG_RANGE: + if (tag_len < CIPSO_V4_TAG_RNG_BLEN) { + err_offset = opt_iter + 1; + goto validate_return_locked; + } + + if (cipso_v4_map_lvl_valid(doi_def, + tag[3]) < 0) { + err_offset = opt_iter + 3; + goto validate_return_locked; + } + if (tag_len > CIPSO_V4_TAG_RNG_BLEN && + cipso_v4_map_cat_rng_valid(doi_def, + &tag[4], + tag_len - 4) < 0) { + err_offset = opt_iter + 4; + goto validate_return_locked; + } + break; + case CIPSO_V4_TAG_LOCAL: + /* This is a non-standard tag that we only allow for + * local connections, so if the incoming interface is + * not the loopback device drop the packet. Further, + * there is no legitimate reason for setting this from + * userspace so reject it if skb is NULL. */ + if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) { + err_offset = opt_iter; + goto validate_return_locked; + } + if (tag_len != CIPSO_V4_TAG_LOC_BLEN) { + err_offset = opt_iter + 1; + goto validate_return_locked; + } + break; + default: + err_offset = opt_iter; + goto validate_return_locked; + } + + tag += tag_len; + opt_iter += tag_len; + } + +validate_return_locked: + rcu_read_unlock(); +validate_return: + *option = opt + err_offset; + return err_offset; +} + +/** + * cipso_v4_error - Send the correct response for a bad packet + * @skb: the packet + * @error: the error code + * @gateway: CIPSO gateway flag + * + * Description: + * Based on the error code given in @error, send an ICMP error message back to + * the originating host. From the IETF draft ... + * + * "If the contents of the CIPSO [option] are valid but the security label is + * outside of the configured host or port label range, the datagram is + * discarded and an ICMP 'destination unreachable' (type 3) is generated and + * returned. The code field of the ICMP is set to 'communication with + * destination network administratively prohibited' (code 9) or to + * 'communication with destination host administratively prohibited' + * (code 10). The value of the code is dependent on whether the originator + * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The + * recipient of the ICMP message MUST be able to handle either value. The + * same procedure is performed if a CIPSO [option] can not be added to an + * IP packet because it is too large to fit in the IP options area." + * + * "If the error is triggered by receipt of an ICMP message, the message is + * discarded and no response is permitted (consistent with general ICMP + * processing rules)." + * + */ +void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway) +{ + unsigned char optbuf[sizeof(struct ip_options) + 40]; + struct ip_options *opt = (struct ip_options *)optbuf; + int res; + + if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES) + return; + + /* + * We might be called above the IP layer, + * so we can not use icmp_send and IPCB here. + */ + + memset(opt, 0, sizeof(struct ip_options)); + opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr); + rcu_read_lock(); + res = __ip_options_compile(dev_net(skb->dev), opt, skb, NULL); + rcu_read_unlock(); + + if (res) + return; + + if (gateway) + __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt); + else + __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt); +} + +/** + * cipso_v4_genopt - Generate a CIPSO option + * @buf: the option buffer + * @buf_len: the size of opt_buf + * @doi_def: the CIPSO DOI to use + * @secattr: the security attributes + * + * Description: + * Generate a CIPSO option using the DOI definition and security attributes + * passed to the function. Returns the length of the option on success and + * negative values on failure. + * + */ +static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u32 iter; + + if (buf_len <= CIPSO_V4_HDR_LEN) + return -ENOSPC; + + /* XXX - This code assumes only one tag per CIPSO option which isn't + * really a good assumption to make but since we only support the MAC + * tags right now it is a safe assumption. */ + iter = 0; + do { + memset(buf, 0, buf_len); + switch (doi_def->tags[iter]) { + case CIPSO_V4_TAG_RBITMAP: + ret_val = cipso_v4_gentag_rbm(doi_def, + secattr, + &buf[CIPSO_V4_HDR_LEN], + buf_len - CIPSO_V4_HDR_LEN); + break; + case CIPSO_V4_TAG_ENUM: + ret_val = cipso_v4_gentag_enum(doi_def, + secattr, + &buf[CIPSO_V4_HDR_LEN], + buf_len - CIPSO_V4_HDR_LEN); + break; + case CIPSO_V4_TAG_RANGE: + ret_val = cipso_v4_gentag_rng(doi_def, + secattr, + &buf[CIPSO_V4_HDR_LEN], + buf_len - CIPSO_V4_HDR_LEN); + break; + case CIPSO_V4_TAG_LOCAL: + ret_val = cipso_v4_gentag_loc(doi_def, + secattr, + &buf[CIPSO_V4_HDR_LEN], + buf_len - CIPSO_V4_HDR_LEN); + break; + default: + return -EPERM; + } + + iter++; + } while (ret_val < 0 && + iter < CIPSO_V4_TAG_MAXCNT && + doi_def->tags[iter] != CIPSO_V4_TAG_INVALID); + if (ret_val < 0) + return ret_val; + cipso_v4_gentag_hdr(doi_def, buf, ret_val); + return CIPSO_V4_HDR_LEN + ret_val; +} + +/** + * cipso_v4_sock_setattr - Add a CIPSO option to a socket + * @sk: the socket + * @doi_def: the CIPSO DOI to use + * @secattr: the specific security attributes of the socket + * + * Description: + * Set the CIPSO option on the given socket using the DOI definition and + * security attributes passed to the function. This function requires + * exclusive access to @sk, which means it either needs to be in the + * process of being created or locked. Returns zero on success and negative + * values on failure. + * + */ +int cipso_v4_sock_setattr(struct sock *sk, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -EPERM; + unsigned char *buf = NULL; + u32 buf_len; + u32 opt_len; + struct ip_options_rcu *old, *opt = NULL; + struct inet_sock *sk_inet; + struct inet_connection_sock *sk_conn; + + /* In the case of sock_create_lite(), the sock->sk field is not + * defined yet but it is not a problem as the only users of these + * "lite" PF_INET sockets are functions which do an accept() call + * afterwards so we will label the socket as part of the accept(). */ + if (!sk) + return 0; + + /* We allocate the maximum CIPSO option size here so we are probably + * being a little wasteful, but it makes our life _much_ easier later + * on and after all we are only talking about 40 bytes. */ + buf_len = CIPSO_V4_OPT_LEN_MAX; + buf = kmalloc(buf_len, GFP_ATOMIC); + if (!buf) { + ret_val = -ENOMEM; + goto socket_setattr_failure; + } + + ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (ret_val < 0) + goto socket_setattr_failure; + buf_len = ret_val; + + /* We can't use ip_options_get() directly because it makes a call to + * ip_options_get_alloc() which allocates memory with GFP_KERNEL and + * we won't always have CAP_NET_RAW even though we _always_ want to + * set the IPOPT_CIPSO option. */ + opt_len = (buf_len + 3) & ~3; + opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); + if (!opt) { + ret_val = -ENOMEM; + goto socket_setattr_failure; + } + memcpy(opt->opt.__data, buf, buf_len); + opt->opt.optlen = opt_len; + opt->opt.cipso = sizeof(struct iphdr); + kfree(buf); + buf = NULL; + + sk_inet = inet_sk(sk); + + old = rcu_dereference_protected(sk_inet->inet_opt, + lockdep_sock_is_held(sk)); + if (sk_inet->is_icsk) { + sk_conn = inet_csk(sk); + if (old) + sk_conn->icsk_ext_hdr_len -= old->opt.optlen; + sk_conn->icsk_ext_hdr_len += opt->opt.optlen; + sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); + } + rcu_assign_pointer(sk_inet->inet_opt, opt); + if (old) + kfree_rcu(old, rcu); + + return 0; + +socket_setattr_failure: + kfree(buf); + kfree(opt); + return ret_val; +} + +/** + * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket + * @req: the connection request socket + * @doi_def: the CIPSO DOI to use + * @secattr: the specific security attributes of the socket + * + * Description: + * Set the CIPSO option on the given socket using the DOI definition and + * security attributes passed to the function. Returns zero on success and + * negative values on failure. + * + */ +int cipso_v4_req_setattr(struct request_sock *req, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -EPERM; + unsigned char *buf = NULL; + u32 buf_len; + u32 opt_len; + struct ip_options_rcu *opt = NULL; + struct inet_request_sock *req_inet; + + /* We allocate the maximum CIPSO option size here so we are probably + * being a little wasteful, but it makes our life _much_ easier later + * on and after all we are only talking about 40 bytes. */ + buf_len = CIPSO_V4_OPT_LEN_MAX; + buf = kmalloc(buf_len, GFP_ATOMIC); + if (!buf) { + ret_val = -ENOMEM; + goto req_setattr_failure; + } + + ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (ret_val < 0) + goto req_setattr_failure; + buf_len = ret_val; + + /* We can't use ip_options_get() directly because it makes a call to + * ip_options_get_alloc() which allocates memory with GFP_KERNEL and + * we won't always have CAP_NET_RAW even though we _always_ want to + * set the IPOPT_CIPSO option. */ + opt_len = (buf_len + 3) & ~3; + opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); + if (!opt) { + ret_val = -ENOMEM; + goto req_setattr_failure; + } + memcpy(opt->opt.__data, buf, buf_len); + opt->opt.optlen = opt_len; + opt->opt.cipso = sizeof(struct iphdr); + kfree(buf); + buf = NULL; + + req_inet = inet_rsk(req); + opt = xchg((__force struct ip_options_rcu **)&req_inet->ireq_opt, opt); + if (opt) + kfree_rcu(opt, rcu); + + return 0; + +req_setattr_failure: + kfree(buf); + kfree(opt); + return ret_val; +} + +/** + * cipso_v4_delopt - Delete the CIPSO option from a set of IP options + * @opt_ptr: IP option pointer + * + * Description: + * Deletes the CIPSO IP option from a set of IP options and makes the necessary + * adjustments to the IP option structure. Returns zero on success, negative + * values on failure. + * + */ +static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr) +{ + struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1); + int hdr_delta = 0; + + if (!opt || opt->opt.cipso == 0) + return 0; + if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) { + u8 cipso_len; + u8 cipso_off; + unsigned char *cipso_ptr; + int iter; + int optlen_new; + + cipso_off = opt->opt.cipso - sizeof(struct iphdr); + cipso_ptr = &opt->opt.__data[cipso_off]; + cipso_len = cipso_ptr[1]; + + if (opt->opt.srr > opt->opt.cipso) + opt->opt.srr -= cipso_len; + if (opt->opt.rr > opt->opt.cipso) + opt->opt.rr -= cipso_len; + if (opt->opt.ts > opt->opt.cipso) + opt->opt.ts -= cipso_len; + if (opt->opt.router_alert > opt->opt.cipso) + opt->opt.router_alert -= cipso_len; + opt->opt.cipso = 0; + + memmove(cipso_ptr, cipso_ptr + cipso_len, + opt->opt.optlen - cipso_off - cipso_len); + + /* determining the new total option length is tricky because of + * the padding necessary, the only thing i can think to do at + * this point is walk the options one-by-one, skipping the + * padding at the end to determine the actual option size and + * from there we can determine the new total option length */ + iter = 0; + optlen_new = 0; + while (iter < opt->opt.optlen) + if (opt->opt.__data[iter] != IPOPT_NOP) { + iter += opt->opt.__data[iter + 1]; + optlen_new = iter; + } else + iter++; + hdr_delta = opt->opt.optlen; + opt->opt.optlen = (optlen_new + 3) & ~3; + hdr_delta -= opt->opt.optlen; + } else { + /* only the cipso option was present on the socket so we can + * remove the entire option struct */ + *opt_ptr = NULL; + hdr_delta = opt->opt.optlen; + kfree_rcu(opt, rcu); + } + + return hdr_delta; +} + +/** + * cipso_v4_sock_delattr - Delete the CIPSO option from a socket + * @sk: the socket + * + * Description: + * Removes the CIPSO option from a socket, if present. + * + */ +void cipso_v4_sock_delattr(struct sock *sk) +{ + struct inet_sock *sk_inet; + int hdr_delta; + + sk_inet = inet_sk(sk); + + hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt); + if (sk_inet->is_icsk && hdr_delta > 0) { + struct inet_connection_sock *sk_conn = inet_csk(sk); + sk_conn->icsk_ext_hdr_len -= hdr_delta; + sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); + } +} + +/** + * cipso_v4_req_delattr - Delete the CIPSO option from a request socket + * @req: the request socket + * + * Description: + * Removes the CIPSO option from a request socket, if present. + * + */ +void cipso_v4_req_delattr(struct request_sock *req) +{ + cipso_v4_delopt(&inet_rsk(req)->ireq_opt); +} + +/** + * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions + * @cipso: the CIPSO v4 option + * @secattr: the security attributes + * + * Description: + * Inspect @cipso and return the security attributes in @secattr. Returns zero + * on success and negative values on failure. + * + */ +int cipso_v4_getattr(const unsigned char *cipso, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -ENOMSG; + u32 doi; + struct cipso_v4_doi *doi_def; + + if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0) + return 0; + + doi = get_unaligned_be32(&cipso[2]); + rcu_read_lock(); + doi_def = cipso_v4_doi_search(doi); + if (!doi_def) + goto getattr_return; + /* XXX - This code assumes only one tag per CIPSO option which isn't + * really a good assumption to make but since we only support the MAC + * tags right now it is a safe assumption. */ + switch (cipso[6]) { + case CIPSO_V4_TAG_RBITMAP: + ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr); + break; + case CIPSO_V4_TAG_ENUM: + ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr); + break; + case CIPSO_V4_TAG_RANGE: + ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr); + break; + case CIPSO_V4_TAG_LOCAL: + ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr); + break; + } + if (ret_val == 0) + secattr->type = NETLBL_NLTYPE_CIPSOV4; + +getattr_return: + rcu_read_unlock(); + return ret_val; +} + +/** + * cipso_v4_sock_getattr - Get the security attributes from a sock + * @sk: the sock + * @secattr: the security attributes + * + * Description: + * Query @sk to see if there is a CIPSO option attached to the sock and if + * there is return the CIPSO security attributes in @secattr. This function + * requires that @sk be locked, or privately held, but it does not do any + * locking itself. Returns zero on success and negative values on failure. + * + */ +int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) +{ + struct ip_options_rcu *opt; + int res = -ENOMSG; + + rcu_read_lock(); + opt = rcu_dereference(inet_sk(sk)->inet_opt); + if (opt && opt->opt.cipso) + res = cipso_v4_getattr(opt->opt.__data + + opt->opt.cipso - + sizeof(struct iphdr), + secattr); + rcu_read_unlock(); + return res; +} + +/** + * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet + * @skb: the packet + * @doi_def: the DOI structure + * @secattr: the security attributes + * + * Description: + * Set the CIPSO option on the given packet based on the security attributes. + * Returns a pointer to the IP header on success and NULL on failure. + * + */ +int cipso_v4_skbuff_setattr(struct sk_buff *skb, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + struct iphdr *iph; + struct ip_options *opt = &IPCB(skb)->opt; + unsigned char buf[CIPSO_V4_OPT_LEN_MAX]; + u32 buf_len = CIPSO_V4_OPT_LEN_MAX; + u32 opt_len; + int len_delta; + + ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); + if (ret_val < 0) + return ret_val; + buf_len = ret_val; + opt_len = (buf_len + 3) & ~3; + + /* we overwrite any existing options to ensure that we have enough + * room for the CIPSO option, the reason is that we _need_ to guarantee + * that the security label is applied to the packet - we do the same + * thing when using the socket options and it hasn't caused a problem, + * if we need to we can always revisit this choice later */ + + len_delta = opt_len - opt->optlen; + /* if we don't ensure enough headroom we could panic on the skb_push() + * call below so make sure we have enough, we are also "mangling" the + * packet so we should probably do a copy-on-write call anyway */ + ret_val = skb_cow(skb, skb_headroom(skb) + len_delta); + if (ret_val < 0) + return ret_val; + + if (len_delta > 0) { + /* we assume that the header + opt->optlen have already been + * "pushed" in ip_options_build() or similar */ + iph = ip_hdr(skb); + skb_push(skb, len_delta); + memmove((char *)iph - len_delta, iph, iph->ihl << 2); + skb_reset_network_header(skb); + iph = ip_hdr(skb); + } else if (len_delta < 0) { + iph = ip_hdr(skb); + memset(iph + 1, IPOPT_NOP, opt->optlen); + } else + iph = ip_hdr(skb); + + if (opt->optlen > 0) + memset(opt, 0, sizeof(*opt)); + opt->optlen = opt_len; + opt->cipso = sizeof(struct iphdr); + opt->is_changed = 1; + + /* we have to do the following because we are being called from a + * netfilter hook which means the packet already has had the header + * fields populated and the checksum calculated - yes this means we + * are doing more work than needed but we do it to keep the core + * stack clean and tidy */ + memcpy(iph + 1, buf, buf_len); + if (opt_len > buf_len) + memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len); + if (len_delta != 0) { + iph->ihl = 5 + (opt_len >> 2); + iph->tot_len = htons(skb->len); + } + ip_send_check(iph); + + return 0; +} + +/** + * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet + * @skb: the packet + * + * Description: + * Removes any and all CIPSO options from the given packet. Returns zero on + * success, negative values on failure. + * + */ +int cipso_v4_skbuff_delattr(struct sk_buff *skb) +{ + int ret_val; + struct iphdr *iph; + struct ip_options *opt = &IPCB(skb)->opt; + unsigned char *cipso_ptr; + + if (opt->cipso == 0) + return 0; + + /* since we are changing the packet we should make a copy */ + ret_val = skb_cow(skb, skb_headroom(skb)); + if (ret_val < 0) + return ret_val; + + /* the easiest thing to do is just replace the cipso option with noop + * options since we don't change the size of the packet, although we + * still need to recalculate the checksum */ + + iph = ip_hdr(skb); + cipso_ptr = (unsigned char *)iph + opt->cipso; + memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]); + opt->cipso = 0; + opt->is_changed = 1; + + ip_send_check(iph); + + return 0; +} + +/* + * Setup Functions + */ + +/** + * cipso_v4_init - Initialize the CIPSO module + * + * Description: + * Initialize the CIPSO module and prepare it for use. Returns zero on success + * and negative values on failure. + * + */ +static int __init cipso_v4_init(void) +{ + int ret_val; + + ret_val = cipso_v4_cache_init(); + if (ret_val != 0) + panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n", + ret_val); + + return 0; +} + +subsys_initcall(cipso_v4_init); diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c new file mode 100644 index 000000000..112c6e892 --- /dev/null +++ b/net/ipv4/datagram.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * common UDP/RAW code + * Linux INET implementation + * + * Authors: + * Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/ip.h> +#include <linux/in.h> +#include <net/ip.h> +#include <net/sock.h> +#include <net/route.h> +#include <net/tcp_states.h> +#include <net/sock_reuseport.h> + +int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_in *usin = (struct sockaddr_in *) uaddr; + struct flowi4 *fl4; + struct rtable *rt; + __be32 saddr; + int oif; + int err; + + + if (addr_len < sizeof(*usin)) + return -EINVAL; + + if (usin->sin_family != AF_INET) + return -EAFNOSUPPORT; + + sk_dst_reset(sk); + + oif = sk->sk_bound_dev_if; + saddr = inet->inet_saddr; + if (ipv4_is_multicast(usin->sin_addr.s_addr)) { + if (!oif || netif_index_is_l3_master(sock_net(sk), oif)) + oif = inet->mc_index; + if (!saddr) + saddr = inet->mc_addr; + } + fl4 = &inet->cork.fl.u.ip4; + rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, + RT_CONN_FLAGS(sk), oif, + sk->sk_protocol, + inet->inet_sport, usin->sin_port, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + if (err == -ENETUNREACH) + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); + goto out; + } + + if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) { + ip_rt_put(rt); + err = -EACCES; + goto out; + } + if (!inet->inet_saddr) + inet->inet_saddr = fl4->saddr; /* Update source address */ + if (!inet->inet_rcv_saddr) { + inet->inet_rcv_saddr = fl4->saddr; + if (sk->sk_prot->rehash) + sk->sk_prot->rehash(sk); + } + inet->inet_daddr = fl4->daddr; + inet->inet_dport = usin->sin_port; + reuseport_has_conns_set(sk); + sk->sk_state = TCP_ESTABLISHED; + sk_set_txhash(sk); + inet->inet_id = prandom_u32(); + + sk_dst_set(sk, &rt->dst); + err = 0; +out: + return err; +} +EXPORT_SYMBOL(__ip4_datagram_connect); + +int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + int res; + + lock_sock(sk); + res = __ip4_datagram_connect(sk, uaddr, addr_len); + release_sock(sk); + return res; +} +EXPORT_SYMBOL(ip4_datagram_connect); + +/* Because UDP xmit path can manipulate sk_dst_cache without holding + * socket lock, we need to use sk_dst_set() here, + * even if we own the socket lock. + */ +void ip4_datagram_release_cb(struct sock *sk) +{ + const struct inet_sock *inet = inet_sk(sk); + const struct ip_options_rcu *inet_opt; + __be32 daddr = inet->inet_daddr; + struct dst_entry *dst; + struct flowi4 fl4; + struct rtable *rt; + + rcu_read_lock(); + + dst = __sk_dst_get(sk); + if (!dst || !dst->obsolete || dst->ops->check(dst, 0)) { + rcu_read_unlock(); + return; + } + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr, + inet->inet_saddr, inet->inet_dport, + inet->inet_sport, sk->sk_protocol, + RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); + + dst = !IS_ERR(rt) ? &rt->dst : NULL; + sk_dst_set(sk, dst); + + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(ip4_datagram_release_cb); diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c new file mode 100644 index 000000000..da1ca8081 --- /dev/null +++ b/net/ipv4/devinet.c @@ -0,0 +1,2780 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * NET3 IP device support routines. + * + * Derived from the IP parts of dev.c 1.0.19 + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * + * Additional Authors: + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + * Changes: + * Alexey Kuznetsov: pa_* fields are replaced with ifaddr + * lists. + * Cyrus Durgin: updated for kmod + * Matthias Andree: in devinet_ioctl, compare label and + * address (4.4BSD alias style support), + * fall back to comparing just the label + * if no match found. + */ + + +#include <linux/uaccess.h> +#include <linux/bitops.h> +#include <linux/capability.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/if_addr.h> +#include <linux/if_ether.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/skbuff.h> +#include <linux/init.h> +#include <linux/notifier.h> +#include <linux/inetdevice.h> +#include <linux/igmp.h> +#include <linux/slab.h> +#include <linux/hash.h> +#ifdef CONFIG_SYSCTL +#include <linux/sysctl.h> +#endif +#include <linux/kmod.h> +#include <linux/netconf.h> + +#include <net/arp.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/ip_fib.h> +#include <net/rtnetlink.h> +#include <net/net_namespace.h> +#include <net/addrconf.h> + +#define IPV6ONLY_FLAGS \ + (IFA_F_NODAD | IFA_F_OPTIMISTIC | IFA_F_DADFAILED | \ + IFA_F_HOMEADDRESS | IFA_F_TENTATIVE | \ + IFA_F_MANAGETEMPADDR | IFA_F_STABLE_PRIVACY) + +static struct ipv4_devconf ipv4_devconf = { + .data = { + [IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1, + [IPV4_DEVCONF_SEND_REDIRECTS - 1] = 1, + [IPV4_DEVCONF_SECURE_REDIRECTS - 1] = 1, + [IPV4_DEVCONF_SHARED_MEDIA - 1] = 1, + [IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL - 1] = 10000 /*ms*/, + [IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL - 1] = 1000 /*ms*/, + }, +}; + +static struct ipv4_devconf ipv4_devconf_dflt = { + .data = { + [IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1, + [IPV4_DEVCONF_SEND_REDIRECTS - 1] = 1, + [IPV4_DEVCONF_SECURE_REDIRECTS - 1] = 1, + [IPV4_DEVCONF_SHARED_MEDIA - 1] = 1, + [IPV4_DEVCONF_ACCEPT_SOURCE_ROUTE - 1] = 1, + [IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL - 1] = 10000 /*ms*/, + [IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL - 1] = 1000 /*ms*/, + }, +}; + +#define IPV4_DEVCONF_DFLT(net, attr) \ + IPV4_DEVCONF((*net->ipv4.devconf_dflt), attr) + +static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = { + [IFA_LOCAL] = { .type = NLA_U32 }, + [IFA_ADDRESS] = { .type = NLA_U32 }, + [IFA_BROADCAST] = { .type = NLA_U32 }, + [IFA_LABEL] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, + [IFA_CACHEINFO] = { .len = sizeof(struct ifa_cacheinfo) }, + [IFA_FLAGS] = { .type = NLA_U32 }, + [IFA_RT_PRIORITY] = { .type = NLA_U32 }, + [IFA_TARGET_NETNSID] = { .type = NLA_S32 }, +}; + +struct inet_fill_args { + u32 portid; + u32 seq; + int event; + unsigned int flags; + int netnsid; + int ifindex; +}; + +#define IN4_ADDR_HSIZE_SHIFT 8 +#define IN4_ADDR_HSIZE (1U << IN4_ADDR_HSIZE_SHIFT) + +static struct hlist_head inet_addr_lst[IN4_ADDR_HSIZE]; + +static u32 inet_addr_hash(const struct net *net, __be32 addr) +{ + u32 val = (__force u32) addr ^ net_hash_mix(net); + + return hash_32(val, IN4_ADDR_HSIZE_SHIFT); +} + +static void inet_hash_insert(struct net *net, struct in_ifaddr *ifa) +{ + u32 hash = inet_addr_hash(net, ifa->ifa_local); + + ASSERT_RTNL(); + hlist_add_head_rcu(&ifa->hash, &inet_addr_lst[hash]); +} + +static void inet_hash_remove(struct in_ifaddr *ifa) +{ + ASSERT_RTNL(); + hlist_del_init_rcu(&ifa->hash); +} + +/** + * __ip_dev_find - find the first device with a given source address. + * @net: the net namespace + * @addr: the source address + * @devref: if true, take a reference on the found device + * + * If a caller uses devref=false, it should be protected by RCU, or RTNL + */ +struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref) +{ + struct net_device *result = NULL; + struct in_ifaddr *ifa; + + rcu_read_lock(); + ifa = inet_lookup_ifaddr_rcu(net, addr); + if (!ifa) { + struct flowi4 fl4 = { .daddr = addr }; + struct fib_result res = { 0 }; + struct fib_table *local; + + /* Fallback to FIB local table so that communication + * over loopback subnets work. + */ + local = fib_get_table(net, RT_TABLE_LOCAL); + if (local && + !fib_table_lookup(local, &fl4, &res, FIB_LOOKUP_NOREF) && + res.type == RTN_LOCAL) + result = FIB_RES_DEV(res); + } else { + result = ifa->ifa_dev->dev; + } + if (result && devref) + dev_hold(result); + rcu_read_unlock(); + return result; +} +EXPORT_SYMBOL(__ip_dev_find); + +/* called under RCU lock */ +struct in_ifaddr *inet_lookup_ifaddr_rcu(struct net *net, __be32 addr) +{ + u32 hash = inet_addr_hash(net, addr); + struct in_ifaddr *ifa; + + hlist_for_each_entry_rcu(ifa, &inet_addr_lst[hash], hash) + if (ifa->ifa_local == addr && + net_eq(dev_net(ifa->ifa_dev->dev), net)) + return ifa; + + return NULL; +} + +static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32); + +static BLOCKING_NOTIFIER_HEAD(inetaddr_chain); +static BLOCKING_NOTIFIER_HEAD(inetaddr_validator_chain); +static void inet_del_ifa(struct in_device *in_dev, + struct in_ifaddr __rcu **ifap, + int destroy); +#ifdef CONFIG_SYSCTL +static int devinet_sysctl_register(struct in_device *idev); +static void devinet_sysctl_unregister(struct in_device *idev); +#else +static int devinet_sysctl_register(struct in_device *idev) +{ + return 0; +} +static void devinet_sysctl_unregister(struct in_device *idev) +{ +} +#endif + +/* Locks all the inet devices. */ + +static struct in_ifaddr *inet_alloc_ifa(void) +{ + return kzalloc(sizeof(struct in_ifaddr), GFP_KERNEL); +} + +static void inet_rcu_free_ifa(struct rcu_head *head) +{ + struct in_ifaddr *ifa = container_of(head, struct in_ifaddr, rcu_head); + if (ifa->ifa_dev) + in_dev_put(ifa->ifa_dev); + kfree(ifa); +} + +static void inet_free_ifa(struct in_ifaddr *ifa) +{ + call_rcu(&ifa->rcu_head, inet_rcu_free_ifa); +} + +void in_dev_finish_destroy(struct in_device *idev) +{ + struct net_device *dev = idev->dev; + + WARN_ON(idev->ifa_list); + WARN_ON(idev->mc_list); + kfree(rcu_dereference_protected(idev->mc_hash, 1)); +#ifdef NET_REFCNT_DEBUG + pr_debug("%s: %p=%s\n", __func__, idev, dev ? dev->name : "NIL"); +#endif + dev_put(dev); + if (!idev->dead) + pr_err("Freeing alive in_device %p\n", idev); + else + kfree(idev); +} +EXPORT_SYMBOL(in_dev_finish_destroy); + +static struct in_device *inetdev_init(struct net_device *dev) +{ + struct in_device *in_dev; + int err = -ENOMEM; + + ASSERT_RTNL(); + + in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL); + if (!in_dev) + goto out; + memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt, + sizeof(in_dev->cnf)); + in_dev->cnf.sysctl = NULL; + in_dev->dev = dev; + in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl); + if (!in_dev->arp_parms) + goto out_kfree; + if (IPV4_DEVCONF(in_dev->cnf, FORWARDING)) + dev_disable_lro(dev); + /* Reference in_dev->dev */ + dev_hold(dev); + /* Account for reference dev->ip_ptr (below) */ + refcount_set(&in_dev->refcnt, 1); + + err = devinet_sysctl_register(in_dev); + if (err) { + in_dev->dead = 1; + neigh_parms_release(&arp_tbl, in_dev->arp_parms); + in_dev_put(in_dev); + in_dev = NULL; + goto out; + } + ip_mc_init_dev(in_dev); + if (dev->flags & IFF_UP) + ip_mc_up(in_dev); + + /* we can receive as soon as ip_ptr is set -- do this last */ + rcu_assign_pointer(dev->ip_ptr, in_dev); +out: + return in_dev ?: ERR_PTR(err); +out_kfree: + kfree(in_dev); + in_dev = NULL; + goto out; +} + +static void in_dev_rcu_put(struct rcu_head *head) +{ + struct in_device *idev = container_of(head, struct in_device, rcu_head); + in_dev_put(idev); +} + +static void inetdev_destroy(struct in_device *in_dev) +{ + struct net_device *dev; + struct in_ifaddr *ifa; + + ASSERT_RTNL(); + + dev = in_dev->dev; + + in_dev->dead = 1; + + ip_mc_destroy_dev(in_dev); + + while ((ifa = rtnl_dereference(in_dev->ifa_list)) != NULL) { + inet_del_ifa(in_dev, &in_dev->ifa_list, 0); + inet_free_ifa(ifa); + } + + RCU_INIT_POINTER(dev->ip_ptr, NULL); + + devinet_sysctl_unregister(in_dev); + neigh_parms_release(&arp_tbl, in_dev->arp_parms); + arp_ifdown(dev); + + call_rcu(&in_dev->rcu_head, in_dev_rcu_put); +} + +int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b) +{ + const struct in_ifaddr *ifa; + + rcu_read_lock(); + in_dev_for_each_ifa_rcu(ifa, in_dev) { + if (inet_ifa_match(a, ifa)) { + if (!b || inet_ifa_match(b, ifa)) { + rcu_read_unlock(); + return 1; + } + } + } + rcu_read_unlock(); + return 0; +} + +static void __inet_del_ifa(struct in_device *in_dev, + struct in_ifaddr __rcu **ifap, + int destroy, struct nlmsghdr *nlh, u32 portid) +{ + struct in_ifaddr *promote = NULL; + struct in_ifaddr *ifa, *ifa1; + struct in_ifaddr __rcu **last_prim; + struct in_ifaddr *prev_prom = NULL; + int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev); + + ASSERT_RTNL(); + + ifa1 = rtnl_dereference(*ifap); + last_prim = ifap; + if (in_dev->dead) + goto no_promotions; + + /* 1. Deleting primary ifaddr forces deletion all secondaries + * unless alias promotion is set + **/ + + if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) { + struct in_ifaddr __rcu **ifap1 = &ifa1->ifa_next; + + while ((ifa = rtnl_dereference(*ifap1)) != NULL) { + if (!(ifa->ifa_flags & IFA_F_SECONDARY) && + ifa1->ifa_scope <= ifa->ifa_scope) + last_prim = &ifa->ifa_next; + + if (!(ifa->ifa_flags & IFA_F_SECONDARY) || + ifa1->ifa_mask != ifa->ifa_mask || + !inet_ifa_match(ifa1->ifa_address, ifa)) { + ifap1 = &ifa->ifa_next; + prev_prom = ifa; + continue; + } + + if (!do_promote) { + inet_hash_remove(ifa); + *ifap1 = ifa->ifa_next; + + rtmsg_ifa(RTM_DELADDR, ifa, nlh, portid); + blocking_notifier_call_chain(&inetaddr_chain, + NETDEV_DOWN, ifa); + inet_free_ifa(ifa); + } else { + promote = ifa; + break; + } + } + } + + /* On promotion all secondaries from subnet are changing + * the primary IP, we must remove all their routes silently + * and later to add them back with new prefsrc. Do this + * while all addresses are on the device list. + */ + for (ifa = promote; ifa; ifa = rtnl_dereference(ifa->ifa_next)) { + if (ifa1->ifa_mask == ifa->ifa_mask && + inet_ifa_match(ifa1->ifa_address, ifa)) + fib_del_ifaddr(ifa, ifa1); + } + +no_promotions: + /* 2. Unlink it */ + + *ifap = ifa1->ifa_next; + inet_hash_remove(ifa1); + + /* 3. Announce address deletion */ + + /* Send message first, then call notifier. + At first sight, FIB update triggered by notifier + will refer to already deleted ifaddr, that could confuse + netlink listeners. It is not true: look, gated sees + that route deleted and if it still thinks that ifaddr + is valid, it will try to restore deleted routes... Grr. + So that, this order is correct. + */ + rtmsg_ifa(RTM_DELADDR, ifa1, nlh, portid); + blocking_notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa1); + + if (promote) { + struct in_ifaddr *next_sec; + + next_sec = rtnl_dereference(promote->ifa_next); + if (prev_prom) { + struct in_ifaddr *last_sec; + + rcu_assign_pointer(prev_prom->ifa_next, next_sec); + + last_sec = rtnl_dereference(*last_prim); + rcu_assign_pointer(promote->ifa_next, last_sec); + rcu_assign_pointer(*last_prim, promote); + } + + promote->ifa_flags &= ~IFA_F_SECONDARY; + rtmsg_ifa(RTM_NEWADDR, promote, nlh, portid); + blocking_notifier_call_chain(&inetaddr_chain, + NETDEV_UP, promote); + for (ifa = next_sec; ifa; + ifa = rtnl_dereference(ifa->ifa_next)) { + if (ifa1->ifa_mask != ifa->ifa_mask || + !inet_ifa_match(ifa1->ifa_address, ifa)) + continue; + fib_add_ifaddr(ifa); + } + + } + if (destroy) + inet_free_ifa(ifa1); +} + +static void inet_del_ifa(struct in_device *in_dev, + struct in_ifaddr __rcu **ifap, + int destroy) +{ + __inet_del_ifa(in_dev, ifap, destroy, NULL, 0); +} + +static void check_lifetime(struct work_struct *work); + +static DECLARE_DELAYED_WORK(check_lifetime_work, check_lifetime); + +static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh, + u32 portid, struct netlink_ext_ack *extack) +{ + struct in_ifaddr __rcu **last_primary, **ifap; + struct in_device *in_dev = ifa->ifa_dev; + struct in_validator_info ivi; + struct in_ifaddr *ifa1; + int ret; + + ASSERT_RTNL(); + + if (!ifa->ifa_local) { + inet_free_ifa(ifa); + return 0; + } + + ifa->ifa_flags &= ~IFA_F_SECONDARY; + last_primary = &in_dev->ifa_list; + + /* Don't set IPv6 only flags to IPv4 addresses */ + ifa->ifa_flags &= ~IPV6ONLY_FLAGS; + + ifap = &in_dev->ifa_list; + ifa1 = rtnl_dereference(*ifap); + + while (ifa1) { + if (!(ifa1->ifa_flags & IFA_F_SECONDARY) && + ifa->ifa_scope <= ifa1->ifa_scope) + last_primary = &ifa1->ifa_next; + if (ifa1->ifa_mask == ifa->ifa_mask && + inet_ifa_match(ifa1->ifa_address, ifa)) { + if (ifa1->ifa_local == ifa->ifa_local) { + inet_free_ifa(ifa); + return -EEXIST; + } + if (ifa1->ifa_scope != ifa->ifa_scope) { + inet_free_ifa(ifa); + return -EINVAL; + } + ifa->ifa_flags |= IFA_F_SECONDARY; + } + + ifap = &ifa1->ifa_next; + ifa1 = rtnl_dereference(*ifap); + } + + /* Allow any devices that wish to register ifaddr validtors to weigh + * in now, before changes are committed. The rntl lock is serializing + * access here, so the state should not change between a validator call + * and a final notify on commit. This isn't invoked on promotion under + * the assumption that validators are checking the address itself, and + * not the flags. + */ + ivi.ivi_addr = ifa->ifa_address; + ivi.ivi_dev = ifa->ifa_dev; + ivi.extack = extack; + ret = blocking_notifier_call_chain(&inetaddr_validator_chain, + NETDEV_UP, &ivi); + ret = notifier_to_errno(ret); + if (ret) { + inet_free_ifa(ifa); + return ret; + } + + if (!(ifa->ifa_flags & IFA_F_SECONDARY)) { + prandom_seed((__force u32) ifa->ifa_local); + ifap = last_primary; + } + + rcu_assign_pointer(ifa->ifa_next, *ifap); + rcu_assign_pointer(*ifap, ifa); + + inet_hash_insert(dev_net(in_dev->dev), ifa); + + cancel_delayed_work(&check_lifetime_work); + queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, 0); + + /* Send message first, then call notifier. + Notifier will trigger FIB update, so that + listeners of netlink will know about new ifaddr */ + rtmsg_ifa(RTM_NEWADDR, ifa, nlh, portid); + blocking_notifier_call_chain(&inetaddr_chain, NETDEV_UP, ifa); + + return 0; +} + +static int inet_insert_ifa(struct in_ifaddr *ifa) +{ + return __inet_insert_ifa(ifa, NULL, 0, NULL); +} + +static int inet_set_ifa(struct net_device *dev, struct in_ifaddr *ifa) +{ + struct in_device *in_dev = __in_dev_get_rtnl(dev); + + ASSERT_RTNL(); + + if (!in_dev) { + inet_free_ifa(ifa); + return -ENOBUFS; + } + ipv4_devconf_setall(in_dev); + neigh_parms_data_state_setall(in_dev->arp_parms); + if (ifa->ifa_dev != in_dev) { + WARN_ON(ifa->ifa_dev); + in_dev_hold(in_dev); + ifa->ifa_dev = in_dev; + } + if (ipv4_is_loopback(ifa->ifa_local)) + ifa->ifa_scope = RT_SCOPE_HOST; + return inet_insert_ifa(ifa); +} + +/* Caller must hold RCU or RTNL : + * We dont take a reference on found in_device + */ +struct in_device *inetdev_by_index(struct net *net, int ifindex) +{ + struct net_device *dev; + struct in_device *in_dev = NULL; + + rcu_read_lock(); + dev = dev_get_by_index_rcu(net, ifindex); + if (dev) + in_dev = rcu_dereference_rtnl(dev->ip_ptr); + rcu_read_unlock(); + return in_dev; +} +EXPORT_SYMBOL(inetdev_by_index); + +/* Called only from RTNL semaphored context. No locks. */ + +struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix, + __be32 mask) +{ + struct in_ifaddr *ifa; + + ASSERT_RTNL(); + + in_dev_for_each_ifa_rtnl(ifa, in_dev) { + if (ifa->ifa_mask == mask && inet_ifa_match(prefix, ifa)) + return ifa; + } + return NULL; +} + +static int ip_mc_autojoin_config(struct net *net, bool join, + const struct in_ifaddr *ifa) +{ +#if defined(CONFIG_IP_MULTICAST) + struct ip_mreqn mreq = { + .imr_multiaddr.s_addr = ifa->ifa_address, + .imr_ifindex = ifa->ifa_dev->dev->ifindex, + }; + struct sock *sk = net->ipv4.mc_autojoin_sk; + int ret; + + ASSERT_RTNL(); + + lock_sock(sk); + if (join) + ret = ip_mc_join_group(sk, &mreq); + else + ret = ip_mc_leave_group(sk, &mreq); + release_sock(sk); + + return ret; +#else + return -EOPNOTSUPP; +#endif +} + +static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct in_ifaddr __rcu **ifap; + struct nlattr *tb[IFA_MAX+1]; + struct in_device *in_dev; + struct ifaddrmsg *ifm; + struct in_ifaddr *ifa; + + int err = -EINVAL; + + ASSERT_RTNL(); + + err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX, + ifa_ipv4_policy, extack); + if (err < 0) + goto errout; + + ifm = nlmsg_data(nlh); + in_dev = inetdev_by_index(net, ifm->ifa_index); + if (!in_dev) { + err = -ENODEV; + goto errout; + } + + for (ifap = &in_dev->ifa_list; (ifa = rtnl_dereference(*ifap)) != NULL; + ifap = &ifa->ifa_next) { + if (tb[IFA_LOCAL] && + ifa->ifa_local != nla_get_in_addr(tb[IFA_LOCAL])) + continue; + + if (tb[IFA_LABEL] && nla_strcmp(tb[IFA_LABEL], ifa->ifa_label)) + continue; + + if (tb[IFA_ADDRESS] && + (ifm->ifa_prefixlen != ifa->ifa_prefixlen || + !inet_ifa_match(nla_get_in_addr(tb[IFA_ADDRESS]), ifa))) + continue; + + if (ipv4_is_multicast(ifa->ifa_address)) + ip_mc_autojoin_config(net, false, ifa); + __inet_del_ifa(in_dev, ifap, 1, nlh, NETLINK_CB(skb).portid); + return 0; + } + + err = -EADDRNOTAVAIL; +errout: + return err; +} + +#define INFINITY_LIFE_TIME 0xFFFFFFFF + +static void check_lifetime(struct work_struct *work) +{ + unsigned long now, next, next_sec, next_sched; + struct in_ifaddr *ifa; + struct hlist_node *n; + int i; + + now = jiffies; + next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY); + + for (i = 0; i < IN4_ADDR_HSIZE; i++) { + bool change_needed = false; + + rcu_read_lock(); + hlist_for_each_entry_rcu(ifa, &inet_addr_lst[i], hash) { + unsigned long age; + + if (ifa->ifa_flags & IFA_F_PERMANENT) + continue; + + /* We try to batch several events at once. */ + age = (now - ifa->ifa_tstamp + + ADDRCONF_TIMER_FUZZ_MINUS) / HZ; + + if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME && + age >= ifa->ifa_valid_lft) { + change_needed = true; + } else if (ifa->ifa_preferred_lft == + INFINITY_LIFE_TIME) { + continue; + } else if (age >= ifa->ifa_preferred_lft) { + if (time_before(ifa->ifa_tstamp + + ifa->ifa_valid_lft * HZ, next)) + next = ifa->ifa_tstamp + + ifa->ifa_valid_lft * HZ; + + if (!(ifa->ifa_flags & IFA_F_DEPRECATED)) + change_needed = true; + } else if (time_before(ifa->ifa_tstamp + + ifa->ifa_preferred_lft * HZ, + next)) { + next = ifa->ifa_tstamp + + ifa->ifa_preferred_lft * HZ; + } + } + rcu_read_unlock(); + if (!change_needed) + continue; + rtnl_lock(); + hlist_for_each_entry_safe(ifa, n, &inet_addr_lst[i], hash) { + unsigned long age; + + if (ifa->ifa_flags & IFA_F_PERMANENT) + continue; + + /* We try to batch several events at once. */ + age = (now - ifa->ifa_tstamp + + ADDRCONF_TIMER_FUZZ_MINUS) / HZ; + + if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME && + age >= ifa->ifa_valid_lft) { + struct in_ifaddr __rcu **ifap; + struct in_ifaddr *tmp; + + ifap = &ifa->ifa_dev->ifa_list; + tmp = rtnl_dereference(*ifap); + while (tmp) { + if (tmp == ifa) { + inet_del_ifa(ifa->ifa_dev, + ifap, 1); + break; + } + ifap = &tmp->ifa_next; + tmp = rtnl_dereference(*ifap); + } + } else if (ifa->ifa_preferred_lft != + INFINITY_LIFE_TIME && + age >= ifa->ifa_preferred_lft && + !(ifa->ifa_flags & IFA_F_DEPRECATED)) { + ifa->ifa_flags |= IFA_F_DEPRECATED; + rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0); + } + } + rtnl_unlock(); + } + + next_sec = round_jiffies_up(next); + next_sched = next; + + /* If rounded timeout is accurate enough, accept it. */ + if (time_before(next_sec, next + ADDRCONF_TIMER_FUZZ)) + next_sched = next_sec; + + now = jiffies; + /* And minimum interval is ADDRCONF_TIMER_FUZZ_MAX. */ + if (time_before(next_sched, now + ADDRCONF_TIMER_FUZZ_MAX)) + next_sched = now + ADDRCONF_TIMER_FUZZ_MAX; + + queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, + next_sched - now); +} + +static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft, + __u32 prefered_lft) +{ + unsigned long timeout; + + ifa->ifa_flags &= ~(IFA_F_PERMANENT | IFA_F_DEPRECATED); + + timeout = addrconf_timeout_fixup(valid_lft, HZ); + if (addrconf_finite_timeout(timeout)) + ifa->ifa_valid_lft = timeout; + else + ifa->ifa_flags |= IFA_F_PERMANENT; + + timeout = addrconf_timeout_fixup(prefered_lft, HZ); + if (addrconf_finite_timeout(timeout)) { + if (timeout == 0) + ifa->ifa_flags |= IFA_F_DEPRECATED; + ifa->ifa_preferred_lft = timeout; + } + ifa->ifa_tstamp = jiffies; + if (!ifa->ifa_cstamp) + ifa->ifa_cstamp = ifa->ifa_tstamp; +} + +static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh, + __u32 *pvalid_lft, __u32 *pprefered_lft, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[IFA_MAX+1]; + struct in_ifaddr *ifa; + struct ifaddrmsg *ifm; + struct net_device *dev; + struct in_device *in_dev; + int err; + + err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX, + ifa_ipv4_policy, extack); + if (err < 0) + goto errout; + + ifm = nlmsg_data(nlh); + err = -EINVAL; + if (ifm->ifa_prefixlen > 32 || !tb[IFA_LOCAL]) + goto errout; + + dev = __dev_get_by_index(net, ifm->ifa_index); + err = -ENODEV; + if (!dev) + goto errout; + + in_dev = __in_dev_get_rtnl(dev); + err = -ENOBUFS; + if (!in_dev) + goto errout; + + ifa = inet_alloc_ifa(); + if (!ifa) + /* + * A potential indev allocation can be left alive, it stays + * assigned to its device and is destroy with it. + */ + goto errout; + + ipv4_devconf_setall(in_dev); + neigh_parms_data_state_setall(in_dev->arp_parms); + in_dev_hold(in_dev); + + if (!tb[IFA_ADDRESS]) + tb[IFA_ADDRESS] = tb[IFA_LOCAL]; + + INIT_HLIST_NODE(&ifa->hash); + ifa->ifa_prefixlen = ifm->ifa_prefixlen; + ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen); + ifa->ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) : + ifm->ifa_flags; + ifa->ifa_scope = ifm->ifa_scope; + ifa->ifa_dev = in_dev; + + ifa->ifa_local = nla_get_in_addr(tb[IFA_LOCAL]); + ifa->ifa_address = nla_get_in_addr(tb[IFA_ADDRESS]); + + if (tb[IFA_BROADCAST]) + ifa->ifa_broadcast = nla_get_in_addr(tb[IFA_BROADCAST]); + + if (tb[IFA_LABEL]) + nla_strlcpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ); + else + memcpy(ifa->ifa_label, dev->name, IFNAMSIZ); + + if (tb[IFA_RT_PRIORITY]) + ifa->ifa_rt_priority = nla_get_u32(tb[IFA_RT_PRIORITY]); + + if (tb[IFA_CACHEINFO]) { + struct ifa_cacheinfo *ci; + + ci = nla_data(tb[IFA_CACHEINFO]); + if (!ci->ifa_valid || ci->ifa_prefered > ci->ifa_valid) { + err = -EINVAL; + goto errout_free; + } + *pvalid_lft = ci->ifa_valid; + *pprefered_lft = ci->ifa_prefered; + } + + return ifa; + +errout_free: + inet_free_ifa(ifa); +errout: + return ERR_PTR(err); +} + +static struct in_ifaddr *find_matching_ifa(struct in_ifaddr *ifa) +{ + struct in_device *in_dev = ifa->ifa_dev; + struct in_ifaddr *ifa1; + + if (!ifa->ifa_local) + return NULL; + + in_dev_for_each_ifa_rtnl(ifa1, in_dev) { + if (ifa1->ifa_mask == ifa->ifa_mask && + inet_ifa_match(ifa1->ifa_address, ifa) && + ifa1->ifa_local == ifa->ifa_local) + return ifa1; + } + return NULL; +} + +static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct in_ifaddr *ifa; + struct in_ifaddr *ifa_existing; + __u32 valid_lft = INFINITY_LIFE_TIME; + __u32 prefered_lft = INFINITY_LIFE_TIME; + + ASSERT_RTNL(); + + ifa = rtm_to_ifaddr(net, nlh, &valid_lft, &prefered_lft, extack); + if (IS_ERR(ifa)) + return PTR_ERR(ifa); + + ifa_existing = find_matching_ifa(ifa); + if (!ifa_existing) { + /* It would be best to check for !NLM_F_CREATE here but + * userspace already relies on not having to provide this. + */ + set_ifa_lifetime(ifa, valid_lft, prefered_lft); + if (ifa->ifa_flags & IFA_F_MCAUTOJOIN) { + int ret = ip_mc_autojoin_config(net, true, ifa); + + if (ret < 0) { + inet_free_ifa(ifa); + return ret; + } + } + return __inet_insert_ifa(ifa, nlh, NETLINK_CB(skb).portid, + extack); + } else { + u32 new_metric = ifa->ifa_rt_priority; + + inet_free_ifa(ifa); + + if (nlh->nlmsg_flags & NLM_F_EXCL || + !(nlh->nlmsg_flags & NLM_F_REPLACE)) + return -EEXIST; + ifa = ifa_existing; + + if (ifa->ifa_rt_priority != new_metric) { + fib_modify_prefix_metric(ifa, new_metric); + ifa->ifa_rt_priority = new_metric; + } + + set_ifa_lifetime(ifa, valid_lft, prefered_lft); + cancel_delayed_work(&check_lifetime_work); + queue_delayed_work(system_power_efficient_wq, + &check_lifetime_work, 0); + rtmsg_ifa(RTM_NEWADDR, ifa, nlh, NETLINK_CB(skb).portid); + } + return 0; +} + +/* + * Determine a default network mask, based on the IP address. + */ + +static int inet_abc_len(__be32 addr) +{ + int rc = -1; /* Something else, probably a multicast. */ + + if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) + rc = 0; + else { + __u32 haddr = ntohl(addr); + if (IN_CLASSA(haddr)) + rc = 8; + else if (IN_CLASSB(haddr)) + rc = 16; + else if (IN_CLASSC(haddr)) + rc = 24; + else if (IN_CLASSE(haddr)) + rc = 32; + } + + return rc; +} + + +int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr) +{ + struct sockaddr_in sin_orig; + struct sockaddr_in *sin = (struct sockaddr_in *)&ifr->ifr_addr; + struct in_ifaddr __rcu **ifap = NULL; + struct in_device *in_dev; + struct in_ifaddr *ifa = NULL; + struct net_device *dev; + char *colon; + int ret = -EFAULT; + int tryaddrmatch = 0; + + ifr->ifr_name[IFNAMSIZ - 1] = 0; + + /* save original address for comparison */ + memcpy(&sin_orig, sin, sizeof(*sin)); + + colon = strchr(ifr->ifr_name, ':'); + if (colon) + *colon = 0; + + dev_load(net, ifr->ifr_name); + + switch (cmd) { + case SIOCGIFADDR: /* Get interface address */ + case SIOCGIFBRDADDR: /* Get the broadcast address */ + case SIOCGIFDSTADDR: /* Get the destination address */ + case SIOCGIFNETMASK: /* Get the netmask for the interface */ + /* Note that these ioctls will not sleep, + so that we do not impose a lock. + One day we will be forced to put shlock here (I mean SMP) + */ + tryaddrmatch = (sin_orig.sin_family == AF_INET); + memset(sin, 0, sizeof(*sin)); + sin->sin_family = AF_INET; + break; + + case SIOCSIFFLAGS: + ret = -EPERM; + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + goto out; + break; + case SIOCSIFADDR: /* Set interface address (and family) */ + case SIOCSIFBRDADDR: /* Set the broadcast address */ + case SIOCSIFDSTADDR: /* Set the destination address */ + case SIOCSIFNETMASK: /* Set the netmask for the interface */ + ret = -EPERM; + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + goto out; + ret = -EINVAL; + if (sin->sin_family != AF_INET) + goto out; + break; + default: + ret = -EINVAL; + goto out; + } + + rtnl_lock(); + + ret = -ENODEV; + dev = __dev_get_by_name(net, ifr->ifr_name); + if (!dev) + goto done; + + if (colon) + *colon = ':'; + + in_dev = __in_dev_get_rtnl(dev); + if (in_dev) { + if (tryaddrmatch) { + /* Matthias Andree */ + /* compare label and address (4.4BSD style) */ + /* note: we only do this for a limited set of ioctls + and only if the original address family was AF_INET. + This is checked above. */ + + for (ifap = &in_dev->ifa_list; + (ifa = rtnl_dereference(*ifap)) != NULL; + ifap = &ifa->ifa_next) { + if (!strcmp(ifr->ifr_name, ifa->ifa_label) && + sin_orig.sin_addr.s_addr == + ifa->ifa_local) { + break; /* found */ + } + } + } + /* we didn't get a match, maybe the application is + 4.3BSD-style and passed in junk so we fall back to + comparing just the label */ + if (!ifa) { + for (ifap = &in_dev->ifa_list; + (ifa = rtnl_dereference(*ifap)) != NULL; + ifap = &ifa->ifa_next) + if (!strcmp(ifr->ifr_name, ifa->ifa_label)) + break; + } + } + + ret = -EADDRNOTAVAIL; + if (!ifa && cmd != SIOCSIFADDR && cmd != SIOCSIFFLAGS) + goto done; + + switch (cmd) { + case SIOCGIFADDR: /* Get interface address */ + ret = 0; + sin->sin_addr.s_addr = ifa->ifa_local; + break; + + case SIOCGIFBRDADDR: /* Get the broadcast address */ + ret = 0; + sin->sin_addr.s_addr = ifa->ifa_broadcast; + break; + + case SIOCGIFDSTADDR: /* Get the destination address */ + ret = 0; + sin->sin_addr.s_addr = ifa->ifa_address; + break; + + case SIOCGIFNETMASK: /* Get the netmask for the interface */ + ret = 0; + sin->sin_addr.s_addr = ifa->ifa_mask; + break; + + case SIOCSIFFLAGS: + if (colon) { + ret = -EADDRNOTAVAIL; + if (!ifa) + break; + ret = 0; + if (!(ifr->ifr_flags & IFF_UP)) + inet_del_ifa(in_dev, ifap, 1); + break; + } + ret = dev_change_flags(dev, ifr->ifr_flags, NULL); + break; + + case SIOCSIFADDR: /* Set interface address (and family) */ + ret = -EINVAL; + if (inet_abc_len(sin->sin_addr.s_addr) < 0) + break; + + if (!ifa) { + ret = -ENOBUFS; + ifa = inet_alloc_ifa(); + if (!ifa) + break; + INIT_HLIST_NODE(&ifa->hash); + if (colon) + memcpy(ifa->ifa_label, ifr->ifr_name, IFNAMSIZ); + else + memcpy(ifa->ifa_label, dev->name, IFNAMSIZ); + } else { + ret = 0; + if (ifa->ifa_local == sin->sin_addr.s_addr) + break; + inet_del_ifa(in_dev, ifap, 0); + ifa->ifa_broadcast = 0; + ifa->ifa_scope = 0; + } + + ifa->ifa_address = ifa->ifa_local = sin->sin_addr.s_addr; + + if (!(dev->flags & IFF_POINTOPOINT)) { + ifa->ifa_prefixlen = inet_abc_len(ifa->ifa_address); + ifa->ifa_mask = inet_make_mask(ifa->ifa_prefixlen); + if ((dev->flags & IFF_BROADCAST) && + ifa->ifa_prefixlen < 31) + ifa->ifa_broadcast = ifa->ifa_address | + ~ifa->ifa_mask; + } else { + ifa->ifa_prefixlen = 32; + ifa->ifa_mask = inet_make_mask(32); + } + set_ifa_lifetime(ifa, INFINITY_LIFE_TIME, INFINITY_LIFE_TIME); + ret = inet_set_ifa(dev, ifa); + break; + + case SIOCSIFBRDADDR: /* Set the broadcast address */ + ret = 0; + if (ifa->ifa_broadcast != sin->sin_addr.s_addr) { + inet_del_ifa(in_dev, ifap, 0); + ifa->ifa_broadcast = sin->sin_addr.s_addr; + inet_insert_ifa(ifa); + } + break; + + case SIOCSIFDSTADDR: /* Set the destination address */ + ret = 0; + if (ifa->ifa_address == sin->sin_addr.s_addr) + break; + ret = -EINVAL; + if (inet_abc_len(sin->sin_addr.s_addr) < 0) + break; + ret = 0; + inet_del_ifa(in_dev, ifap, 0); + ifa->ifa_address = sin->sin_addr.s_addr; + inet_insert_ifa(ifa); + break; + + case SIOCSIFNETMASK: /* Set the netmask for the interface */ + + /* + * The mask we set must be legal. + */ + ret = -EINVAL; + if (bad_mask(sin->sin_addr.s_addr, 0)) + break; + ret = 0; + if (ifa->ifa_mask != sin->sin_addr.s_addr) { + __be32 old_mask = ifa->ifa_mask; + inet_del_ifa(in_dev, ifap, 0); + ifa->ifa_mask = sin->sin_addr.s_addr; + ifa->ifa_prefixlen = inet_mask_len(ifa->ifa_mask); + + /* See if current broadcast address matches + * with current netmask, then recalculate + * the broadcast address. Otherwise it's a + * funny address, so don't touch it since + * the user seems to know what (s)he's doing... + */ + if ((dev->flags & IFF_BROADCAST) && + (ifa->ifa_prefixlen < 31) && + (ifa->ifa_broadcast == + (ifa->ifa_local|~old_mask))) { + ifa->ifa_broadcast = (ifa->ifa_local | + ~sin->sin_addr.s_addr); + } + inet_insert_ifa(ifa); + } + break; + } +done: + rtnl_unlock(); +out: + return ret; +} + +int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size) +{ + struct in_device *in_dev = __in_dev_get_rtnl(dev); + const struct in_ifaddr *ifa; + struct ifreq ifr; + int done = 0; + + if (WARN_ON(size > sizeof(struct ifreq))) + goto out; + + if (!in_dev) + goto out; + + in_dev_for_each_ifa_rtnl(ifa, in_dev) { + if (!buf) { + done += size; + continue; + } + if (len < size) + break; + memset(&ifr, 0, sizeof(struct ifreq)); + strcpy(ifr.ifr_name, ifa->ifa_label); + + (*(struct sockaddr_in *)&ifr.ifr_addr).sin_family = AF_INET; + (*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr = + ifa->ifa_local; + + if (copy_to_user(buf + done, &ifr, size)) { + done = -EFAULT; + break; + } + len -= size; + done += size; + } +out: + return done; +} + +static __be32 in_dev_select_addr(const struct in_device *in_dev, + int scope) +{ + const struct in_ifaddr *ifa; + + in_dev_for_each_ifa_rcu(ifa, in_dev) { + if (ifa->ifa_flags & IFA_F_SECONDARY) + continue; + if (ifa->ifa_scope != RT_SCOPE_LINK && + ifa->ifa_scope <= scope) + return ifa->ifa_local; + } + + return 0; +} + +__be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope) +{ + const struct in_ifaddr *ifa; + __be32 addr = 0; + unsigned char localnet_scope = RT_SCOPE_HOST; + struct in_device *in_dev; + struct net *net = dev_net(dev); + int master_idx; + + rcu_read_lock(); + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + goto no_in_dev; + + if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev))) + localnet_scope = RT_SCOPE_LINK; + + in_dev_for_each_ifa_rcu(ifa, in_dev) { + if (ifa->ifa_flags & IFA_F_SECONDARY) + continue; + if (min(ifa->ifa_scope, localnet_scope) > scope) + continue; + if (!dst || inet_ifa_match(dst, ifa)) { + addr = ifa->ifa_local; + break; + } + if (!addr) + addr = ifa->ifa_local; + } + + if (addr) + goto out_unlock; +no_in_dev: + master_idx = l3mdev_master_ifindex_rcu(dev); + + /* For VRFs, the VRF device takes the place of the loopback device, + * with addresses on it being preferred. Note in such cases the + * loopback device will be among the devices that fail the master_idx + * equality check in the loop below. + */ + if (master_idx && + (dev = dev_get_by_index_rcu(net, master_idx)) && + (in_dev = __in_dev_get_rcu(dev))) { + addr = in_dev_select_addr(in_dev, scope); + if (addr) + goto out_unlock; + } + + /* Not loopback addresses on loopback should be preferred + in this case. It is important that lo is the first interface + in dev_base list. + */ + for_each_netdev_rcu(net, dev) { + if (l3mdev_master_ifindex_rcu(dev) != master_idx) + continue; + + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + continue; + + addr = in_dev_select_addr(in_dev, scope); + if (addr) + goto out_unlock; + } +out_unlock: + rcu_read_unlock(); + return addr; +} +EXPORT_SYMBOL(inet_select_addr); + +static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst, + __be32 local, int scope) +{ + unsigned char localnet_scope = RT_SCOPE_HOST; + const struct in_ifaddr *ifa; + __be32 addr = 0; + int same = 0; + + if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev))) + localnet_scope = RT_SCOPE_LINK; + + in_dev_for_each_ifa_rcu(ifa, in_dev) { + unsigned char min_scope = min(ifa->ifa_scope, localnet_scope); + + if (!addr && + (local == ifa->ifa_local || !local) && + min_scope <= scope) { + addr = ifa->ifa_local; + if (same) + break; + } + if (!same) { + same = (!local || inet_ifa_match(local, ifa)) && + (!dst || inet_ifa_match(dst, ifa)); + if (same && addr) { + if (local || !dst) + break; + /* Is the selected addr into dst subnet? */ + if (inet_ifa_match(addr, ifa)) + break; + /* No, then can we use new local src? */ + if (min_scope <= scope) { + addr = ifa->ifa_local; + break; + } + /* search for large dst subnet for addr */ + same = 0; + } + } + } + + return same ? addr : 0; +} + +/* + * Confirm that local IP address exists using wildcards: + * - net: netns to check, cannot be NULL + * - in_dev: only on this interface, NULL=any interface + * - dst: only in the same subnet as dst, 0=any dst + * - local: address, 0=autoselect the local address + * - scope: maximum allowed scope value for the local address + */ +__be32 inet_confirm_addr(struct net *net, struct in_device *in_dev, + __be32 dst, __be32 local, int scope) +{ + __be32 addr = 0; + struct net_device *dev; + + if (in_dev) + return confirm_addr_indev(in_dev, dst, local, scope); + + rcu_read_lock(); + for_each_netdev_rcu(net, dev) { + in_dev = __in_dev_get_rcu(dev); + if (in_dev) { + addr = confirm_addr_indev(in_dev, dst, local, scope); + if (addr) + break; + } + } + rcu_read_unlock(); + + return addr; +} +EXPORT_SYMBOL(inet_confirm_addr); + +/* + * Device notifier + */ + +int register_inetaddr_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&inetaddr_chain, nb); +} +EXPORT_SYMBOL(register_inetaddr_notifier); + +int unregister_inetaddr_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&inetaddr_chain, nb); +} +EXPORT_SYMBOL(unregister_inetaddr_notifier); + +int register_inetaddr_validator_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&inetaddr_validator_chain, nb); +} +EXPORT_SYMBOL(register_inetaddr_validator_notifier); + +int unregister_inetaddr_validator_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&inetaddr_validator_chain, + nb); +} +EXPORT_SYMBOL(unregister_inetaddr_validator_notifier); + +/* Rename ifa_labels for a device name change. Make some effort to preserve + * existing alias numbering and to create unique labels if possible. +*/ +static void inetdev_changename(struct net_device *dev, struct in_device *in_dev) +{ + struct in_ifaddr *ifa; + int named = 0; + + in_dev_for_each_ifa_rtnl(ifa, in_dev) { + char old[IFNAMSIZ], *dot; + + memcpy(old, ifa->ifa_label, IFNAMSIZ); + memcpy(ifa->ifa_label, dev->name, IFNAMSIZ); + if (named++ == 0) + goto skip; + dot = strchr(old, ':'); + if (!dot) { + sprintf(old, ":%d", named); + dot = old; + } + if (strlen(dot) + strlen(dev->name) < IFNAMSIZ) + strcat(ifa->ifa_label, dot); + else + strcpy(ifa->ifa_label + (IFNAMSIZ - strlen(dot) - 1), dot); +skip: + rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0); + } +} + +static void inetdev_send_gratuitous_arp(struct net_device *dev, + struct in_device *in_dev) + +{ + const struct in_ifaddr *ifa; + + in_dev_for_each_ifa_rtnl(ifa, in_dev) { + arp_send(ARPOP_REQUEST, ETH_P_ARP, + ifa->ifa_local, dev, + ifa->ifa_local, NULL, + dev->dev_addr, NULL); + } +} + +/* Called only under RTNL semaphore */ + +static int inetdev_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct in_device *in_dev = __in_dev_get_rtnl(dev); + + ASSERT_RTNL(); + + if (!in_dev) { + if (event == NETDEV_REGISTER) { + in_dev = inetdev_init(dev); + if (IS_ERR(in_dev)) + return notifier_from_errno(PTR_ERR(in_dev)); + if (dev->flags & IFF_LOOPBACK) { + IN_DEV_CONF_SET(in_dev, NOXFRM, 1); + IN_DEV_CONF_SET(in_dev, NOPOLICY, 1); + } + } else if (event == NETDEV_CHANGEMTU) { + /* Re-enabling IP */ + if (inetdev_valid_mtu(dev->mtu)) + in_dev = inetdev_init(dev); + } + goto out; + } + + switch (event) { + case NETDEV_REGISTER: + pr_debug("%s: bug\n", __func__); + RCU_INIT_POINTER(dev->ip_ptr, NULL); + break; + case NETDEV_UP: + if (!inetdev_valid_mtu(dev->mtu)) + break; + if (dev->flags & IFF_LOOPBACK) { + struct in_ifaddr *ifa = inet_alloc_ifa(); + + if (ifa) { + INIT_HLIST_NODE(&ifa->hash); + ifa->ifa_local = + ifa->ifa_address = htonl(INADDR_LOOPBACK); + ifa->ifa_prefixlen = 8; + ifa->ifa_mask = inet_make_mask(8); + in_dev_hold(in_dev); + ifa->ifa_dev = in_dev; + ifa->ifa_scope = RT_SCOPE_HOST; + memcpy(ifa->ifa_label, dev->name, IFNAMSIZ); + set_ifa_lifetime(ifa, INFINITY_LIFE_TIME, + INFINITY_LIFE_TIME); + ipv4_devconf_setall(in_dev); + neigh_parms_data_state_setall(in_dev->arp_parms); + inet_insert_ifa(ifa); + } + } + ip_mc_up(in_dev); + fallthrough; + case NETDEV_CHANGEADDR: + if (!IN_DEV_ARP_NOTIFY(in_dev)) + break; + fallthrough; + case NETDEV_NOTIFY_PEERS: + /* Send gratuitous ARP to notify of link change */ + inetdev_send_gratuitous_arp(dev, in_dev); + break; + case NETDEV_DOWN: + ip_mc_down(in_dev); + break; + case NETDEV_PRE_TYPE_CHANGE: + ip_mc_unmap(in_dev); + break; + case NETDEV_POST_TYPE_CHANGE: + ip_mc_remap(in_dev); + break; + case NETDEV_CHANGEMTU: + if (inetdev_valid_mtu(dev->mtu)) + break; + /* disable IP when MTU is not enough */ + fallthrough; + case NETDEV_UNREGISTER: + inetdev_destroy(in_dev); + break; + case NETDEV_CHANGENAME: + /* Do not notify about label change, this event is + * not interesting to applications using netlink. + */ + inetdev_changename(dev, in_dev); + + devinet_sysctl_unregister(in_dev); + devinet_sysctl_register(in_dev); + break; + } +out: + return NOTIFY_DONE; +} + +static struct notifier_block ip_netdev_notifier = { + .notifier_call = inetdev_event, +}; + +static size_t inet_nlmsg_size(void) +{ + return NLMSG_ALIGN(sizeof(struct ifaddrmsg)) + + nla_total_size(4) /* IFA_ADDRESS */ + + nla_total_size(4) /* IFA_LOCAL */ + + nla_total_size(4) /* IFA_BROADCAST */ + + nla_total_size(IFNAMSIZ) /* IFA_LABEL */ + + nla_total_size(4) /* IFA_FLAGS */ + + nla_total_size(4) /* IFA_RT_PRIORITY */ + + nla_total_size(sizeof(struct ifa_cacheinfo)); /* IFA_CACHEINFO */ +} + +static inline u32 cstamp_delta(unsigned long cstamp) +{ + return (cstamp - INITIAL_JIFFIES) * 100UL / HZ; +} + +static int put_cacheinfo(struct sk_buff *skb, unsigned long cstamp, + unsigned long tstamp, u32 preferred, u32 valid) +{ + struct ifa_cacheinfo ci; + + ci.cstamp = cstamp_delta(cstamp); + ci.tstamp = cstamp_delta(tstamp); + ci.ifa_prefered = preferred; + ci.ifa_valid = valid; + + return nla_put(skb, IFA_CACHEINFO, sizeof(ci), &ci); +} + +static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa, + struct inet_fill_args *args) +{ + struct ifaddrmsg *ifm; + struct nlmsghdr *nlh; + u32 preferred, valid; + + nlh = nlmsg_put(skb, args->portid, args->seq, args->event, sizeof(*ifm), + args->flags); + if (!nlh) + return -EMSGSIZE; + + ifm = nlmsg_data(nlh); + ifm->ifa_family = AF_INET; + ifm->ifa_prefixlen = ifa->ifa_prefixlen; + ifm->ifa_flags = ifa->ifa_flags; + ifm->ifa_scope = ifa->ifa_scope; + ifm->ifa_index = ifa->ifa_dev->dev->ifindex; + + if (args->netnsid >= 0 && + nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid)) + goto nla_put_failure; + + if (!(ifm->ifa_flags & IFA_F_PERMANENT)) { + preferred = ifa->ifa_preferred_lft; + valid = ifa->ifa_valid_lft; + if (preferred != INFINITY_LIFE_TIME) { + long tval = (jiffies - ifa->ifa_tstamp) / HZ; + + if (preferred > tval) + preferred -= tval; + else + preferred = 0; + if (valid != INFINITY_LIFE_TIME) { + if (valid > tval) + valid -= tval; + else + valid = 0; + } + } + } else { + preferred = INFINITY_LIFE_TIME; + valid = INFINITY_LIFE_TIME; + } + if ((ifa->ifa_address && + nla_put_in_addr(skb, IFA_ADDRESS, ifa->ifa_address)) || + (ifa->ifa_local && + nla_put_in_addr(skb, IFA_LOCAL, ifa->ifa_local)) || + (ifa->ifa_broadcast && + nla_put_in_addr(skb, IFA_BROADCAST, ifa->ifa_broadcast)) || + (ifa->ifa_label[0] && + nla_put_string(skb, IFA_LABEL, ifa->ifa_label)) || + nla_put_u32(skb, IFA_FLAGS, ifa->ifa_flags) || + (ifa->ifa_rt_priority && + nla_put_u32(skb, IFA_RT_PRIORITY, ifa->ifa_rt_priority)) || + put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp, + preferred, valid)) + goto nla_put_failure; + + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static int inet_valid_dump_ifaddr_req(const struct nlmsghdr *nlh, + struct inet_fill_args *fillargs, + struct net **tgt_net, struct sock *sk, + struct netlink_callback *cb) +{ + struct netlink_ext_ack *extack = cb->extack; + struct nlattr *tb[IFA_MAX+1]; + struct ifaddrmsg *ifm; + int err, i; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for address dump request"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for address dump request"); + return -EINVAL; + } + + fillargs->ifindex = ifm->ifa_index; + if (fillargs->ifindex) { + cb->answer_flags |= NLM_F_DUMP_FILTERED; + fillargs->flags |= NLM_F_DUMP_FILTERED; + } + + err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifm), tb, IFA_MAX, + ifa_ipv4_policy, extack); + if (err < 0) + return err; + + for (i = 0; i <= IFA_MAX; ++i) { + if (!tb[i]) + continue; + + if (i == IFA_TARGET_NETNSID) { + struct net *net; + + fillargs->netnsid = nla_get_s32(tb[i]); + + net = rtnl_get_net_ns_capable(sk, fillargs->netnsid); + if (IS_ERR(net)) { + fillargs->netnsid = -1; + NL_SET_ERR_MSG(extack, "ipv4: Invalid target network namespace id"); + return PTR_ERR(net); + } + *tgt_net = net; + } else { + NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in dump request"); + return -EINVAL; + } + } + + return 0; +} + +static int in_dev_dump_addr(struct in_device *in_dev, struct sk_buff *skb, + struct netlink_callback *cb, int s_ip_idx, + struct inet_fill_args *fillargs) +{ + struct in_ifaddr *ifa; + int ip_idx = 0; + int err; + + in_dev_for_each_ifa_rtnl(ifa, in_dev) { + if (ip_idx < s_ip_idx) { + ip_idx++; + continue; + } + err = inet_fill_ifaddr(skb, ifa, fillargs); + if (err < 0) + goto done; + + nl_dump_check_consistent(cb, nlmsg_hdr(skb)); + ip_idx++; + } + err = 0; + +done: + cb->args[2] = ip_idx; + + return err; +} + +static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb) +{ + const struct nlmsghdr *nlh = cb->nlh; + struct inet_fill_args fillargs = { + .portid = NETLINK_CB(cb->skb).portid, + .seq = nlh->nlmsg_seq, + .event = RTM_NEWADDR, + .flags = NLM_F_MULTI, + .netnsid = -1, + }; + struct net *net = sock_net(skb->sk); + struct net *tgt_net = net; + int h, s_h; + int idx, s_idx; + int s_ip_idx; + struct net_device *dev; + struct in_device *in_dev; + struct hlist_head *head; + int err = 0; + + s_h = cb->args[0]; + s_idx = idx = cb->args[1]; + s_ip_idx = cb->args[2]; + + if (cb->strict_check) { + err = inet_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net, + skb->sk, cb); + if (err < 0) + goto put_tgt_net; + + err = 0; + if (fillargs.ifindex) { + dev = __dev_get_by_index(tgt_net, fillargs.ifindex); + if (!dev) { + err = -ENODEV; + goto put_tgt_net; + } + + in_dev = __in_dev_get_rtnl(dev); + if (in_dev) { + err = in_dev_dump_addr(in_dev, skb, cb, s_ip_idx, + &fillargs); + } + goto put_tgt_net; + } + } + + for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { + idx = 0; + head = &tgt_net->dev_index_head[h]; + rcu_read_lock(); + cb->seq = atomic_read(&tgt_net->ipv4.dev_addr_genid) ^ + tgt_net->dev_base_seq; + hlist_for_each_entry_rcu(dev, head, index_hlist) { + if (idx < s_idx) + goto cont; + if (h > s_h || idx > s_idx) + s_ip_idx = 0; + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + goto cont; + + err = in_dev_dump_addr(in_dev, skb, cb, s_ip_idx, + &fillargs); + if (err < 0) { + rcu_read_unlock(); + goto done; + } +cont: + idx++; + } + rcu_read_unlock(); + } + +done: + cb->args[0] = h; + cb->args[1] = idx; +put_tgt_net: + if (fillargs.netnsid >= 0) + put_net(tgt_net); + + return skb->len ? : err; +} + +static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh, + u32 portid) +{ + struct inet_fill_args fillargs = { + .portid = portid, + .seq = nlh ? nlh->nlmsg_seq : 0, + .event = event, + .flags = 0, + .netnsid = -1, + }; + struct sk_buff *skb; + int err = -ENOBUFS; + struct net *net; + + net = dev_net(ifa->ifa_dev->dev); + skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL); + if (!skb) + goto errout; + + err = inet_fill_ifaddr(skb, ifa, &fillargs); + if (err < 0) { + /* -EMSGSIZE implies BUG in inet_nlmsg_size() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + rtnl_notify(skb, net, portid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL); + return; +errout: + if (err < 0) + rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err); +} + +static size_t inet_get_link_af_size(const struct net_device *dev, + u32 ext_filter_mask) +{ + struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr); + + if (!in_dev) + return 0; + + return nla_total_size(IPV4_DEVCONF_MAX * 4); /* IFLA_INET_CONF */ +} + +static int inet_fill_link_af(struct sk_buff *skb, const struct net_device *dev, + u32 ext_filter_mask) +{ + struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr); + struct nlattr *nla; + int i; + + if (!in_dev) + return -ENODATA; + + nla = nla_reserve(skb, IFLA_INET_CONF, IPV4_DEVCONF_MAX * 4); + if (!nla) + return -EMSGSIZE; + + for (i = 0; i < IPV4_DEVCONF_MAX; i++) + ((u32 *) nla_data(nla))[i] = in_dev->cnf.data[i]; + + return 0; +} + +static const struct nla_policy inet_af_policy[IFLA_INET_MAX+1] = { + [IFLA_INET_CONF] = { .type = NLA_NESTED }, +}; + +static int inet_validate_link_af(const struct net_device *dev, + const struct nlattr *nla) +{ + struct nlattr *a, *tb[IFLA_INET_MAX+1]; + int err, rem; + + if (dev && !__in_dev_get_rcu(dev)) + return -EAFNOSUPPORT; + + err = nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla, + inet_af_policy, NULL); + if (err < 0) + return err; + + if (tb[IFLA_INET_CONF]) { + nla_for_each_nested(a, tb[IFLA_INET_CONF], rem) { + int cfgid = nla_type(a); + + if (nla_len(a) < 4) + return -EINVAL; + + if (cfgid <= 0 || cfgid > IPV4_DEVCONF_MAX) + return -EINVAL; + } + } + + return 0; +} + +static int inet_set_link_af(struct net_device *dev, const struct nlattr *nla) +{ + struct in_device *in_dev = __in_dev_get_rcu(dev); + struct nlattr *a, *tb[IFLA_INET_MAX+1]; + int rem; + + if (!in_dev) + return -EAFNOSUPPORT; + + if (nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla, NULL, NULL) < 0) + return -EINVAL; + + if (tb[IFLA_INET_CONF]) { + nla_for_each_nested(a, tb[IFLA_INET_CONF], rem) + ipv4_devconf_set(in_dev, nla_type(a), nla_get_u32(a)); + } + + return 0; +} + +static int inet_netconf_msgsize_devconf(int type) +{ + int size = NLMSG_ALIGN(sizeof(struct netconfmsg)) + + nla_total_size(4); /* NETCONFA_IFINDEX */ + bool all = false; + + if (type == NETCONFA_ALL) + all = true; + + if (all || type == NETCONFA_FORWARDING) + size += nla_total_size(4); + if (all || type == NETCONFA_RP_FILTER) + size += nla_total_size(4); + if (all || type == NETCONFA_MC_FORWARDING) + size += nla_total_size(4); + if (all || type == NETCONFA_BC_FORWARDING) + size += nla_total_size(4); + if (all || type == NETCONFA_PROXY_NEIGH) + size += nla_total_size(4); + if (all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) + size += nla_total_size(4); + + return size; +} + +static int inet_netconf_fill_devconf(struct sk_buff *skb, int ifindex, + struct ipv4_devconf *devconf, u32 portid, + u32 seq, int event, unsigned int flags, + int type) +{ + struct nlmsghdr *nlh; + struct netconfmsg *ncm; + bool all = false; + + nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg), + flags); + if (!nlh) + return -EMSGSIZE; + + if (type == NETCONFA_ALL) + all = true; + + ncm = nlmsg_data(nlh); + ncm->ncm_family = AF_INET; + + if (nla_put_s32(skb, NETCONFA_IFINDEX, ifindex) < 0) + goto nla_put_failure; + + if (!devconf) + goto out; + + if ((all || type == NETCONFA_FORWARDING) && + nla_put_s32(skb, NETCONFA_FORWARDING, + IPV4_DEVCONF(*devconf, FORWARDING)) < 0) + goto nla_put_failure; + if ((all || type == NETCONFA_RP_FILTER) && + nla_put_s32(skb, NETCONFA_RP_FILTER, + IPV4_DEVCONF(*devconf, RP_FILTER)) < 0) + goto nla_put_failure; + if ((all || type == NETCONFA_MC_FORWARDING) && + nla_put_s32(skb, NETCONFA_MC_FORWARDING, + IPV4_DEVCONF(*devconf, MC_FORWARDING)) < 0) + goto nla_put_failure; + if ((all || type == NETCONFA_BC_FORWARDING) && + nla_put_s32(skb, NETCONFA_BC_FORWARDING, + IPV4_DEVCONF(*devconf, BC_FORWARDING)) < 0) + goto nla_put_failure; + if ((all || type == NETCONFA_PROXY_NEIGH) && + nla_put_s32(skb, NETCONFA_PROXY_NEIGH, + IPV4_DEVCONF(*devconf, PROXY_ARP)) < 0) + goto nla_put_failure; + if ((all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) && + nla_put_s32(skb, NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN, + IPV4_DEVCONF(*devconf, IGNORE_ROUTES_WITH_LINKDOWN)) < 0) + goto nla_put_failure; + +out: + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +void inet_netconf_notify_devconf(struct net *net, int event, int type, + int ifindex, struct ipv4_devconf *devconf) +{ + struct sk_buff *skb; + int err = -ENOBUFS; + + skb = nlmsg_new(inet_netconf_msgsize_devconf(type), GFP_KERNEL); + if (!skb) + goto errout; + + err = inet_netconf_fill_devconf(skb, ifindex, devconf, 0, 0, + event, 0, type); + if (err < 0) { + /* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + rtnl_notify(skb, net, 0, RTNLGRP_IPV4_NETCONF, NULL, GFP_KERNEL); + return; +errout: + if (err < 0) + rtnl_set_sk_err(net, RTNLGRP_IPV4_NETCONF, err); +} + +static const struct nla_policy devconf_ipv4_policy[NETCONFA_MAX+1] = { + [NETCONFA_IFINDEX] = { .len = sizeof(int) }, + [NETCONFA_FORWARDING] = { .len = sizeof(int) }, + [NETCONFA_RP_FILTER] = { .len = sizeof(int) }, + [NETCONFA_PROXY_NEIGH] = { .len = sizeof(int) }, + [NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN] = { .len = sizeof(int) }, +}; + +static int inet_netconf_valid_get_req(struct sk_buff *skb, + const struct nlmsghdr *nlh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + int i, err; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf get request"); + return -EINVAL; + } + + if (!netlink_strict_get_check(skb)) + return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg), + tb, NETCONFA_MAX, + devconf_ipv4_policy, extack); + + err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg), + tb, NETCONFA_MAX, + devconf_ipv4_policy, extack); + if (err) + return err; + + for (i = 0; i <= NETCONFA_MAX; i++) { + if (!tb[i]) + continue; + + switch (i) { + case NETCONFA_IFINDEX: + break; + default: + NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in netconf get request"); + return -EINVAL; + } + } + + return 0; +} + +static int inet_netconf_get_devconf(struct sk_buff *in_skb, + struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(in_skb->sk); + struct nlattr *tb[NETCONFA_MAX+1]; + struct sk_buff *skb; + struct ipv4_devconf *devconf; + struct in_device *in_dev; + struct net_device *dev; + int ifindex; + int err; + + err = inet_netconf_valid_get_req(in_skb, nlh, tb, extack); + if (err) + goto errout; + + err = -EINVAL; + if (!tb[NETCONFA_IFINDEX]) + goto errout; + + ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]); + switch (ifindex) { + case NETCONFA_IFINDEX_ALL: + devconf = net->ipv4.devconf_all; + break; + case NETCONFA_IFINDEX_DEFAULT: + devconf = net->ipv4.devconf_dflt; + break; + default: + dev = __dev_get_by_index(net, ifindex); + if (!dev) + goto errout; + in_dev = __in_dev_get_rtnl(dev); + if (!in_dev) + goto errout; + devconf = &in_dev->cnf; + break; + } + + err = -ENOBUFS; + skb = nlmsg_new(inet_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL); + if (!skb) + goto errout; + + err = inet_netconf_fill_devconf(skb, ifindex, devconf, + NETLINK_CB(in_skb).portid, + nlh->nlmsg_seq, RTM_NEWNETCONF, 0, + NETCONFA_ALL); + if (err < 0) { + /* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); +errout: + return err; +} + +static int inet_netconf_dump_devconf(struct sk_buff *skb, + struct netlink_callback *cb) +{ + const struct nlmsghdr *nlh = cb->nlh; + struct net *net = sock_net(skb->sk); + int h, s_h; + int idx, s_idx; + struct net_device *dev; + struct in_device *in_dev; + struct hlist_head *head; + + if (cb->strict_check) { + struct netlink_ext_ack *extack = cb->extack; + struct netconfmsg *ncm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ncm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid data after header in netconf dump request"); + return -EINVAL; + } + } + + s_h = cb->args[0]; + s_idx = idx = cb->args[1]; + + for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { + idx = 0; + head = &net->dev_index_head[h]; + rcu_read_lock(); + cb->seq = atomic_read(&net->ipv4.dev_addr_genid) ^ + net->dev_base_seq; + hlist_for_each_entry_rcu(dev, head, index_hlist) { + if (idx < s_idx) + goto cont; + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + goto cont; + + if (inet_netconf_fill_devconf(skb, dev->ifindex, + &in_dev->cnf, + NETLINK_CB(cb->skb).portid, + nlh->nlmsg_seq, + RTM_NEWNETCONF, + NLM_F_MULTI, + NETCONFA_ALL) < 0) { + rcu_read_unlock(); + goto done; + } + nl_dump_check_consistent(cb, nlmsg_hdr(skb)); +cont: + idx++; + } + rcu_read_unlock(); + } + if (h == NETDEV_HASHENTRIES) { + if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL, + net->ipv4.devconf_all, + NETLINK_CB(cb->skb).portid, + nlh->nlmsg_seq, + RTM_NEWNETCONF, NLM_F_MULTI, + NETCONFA_ALL) < 0) + goto done; + else + h++; + } + if (h == NETDEV_HASHENTRIES + 1) { + if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT, + net->ipv4.devconf_dflt, + NETLINK_CB(cb->skb).portid, + nlh->nlmsg_seq, + RTM_NEWNETCONF, NLM_F_MULTI, + NETCONFA_ALL) < 0) + goto done; + else + h++; + } +done: + cb->args[0] = h; + cb->args[1] = idx; + + return skb->len; +} + +#ifdef CONFIG_SYSCTL + +static void devinet_copy_dflt_conf(struct net *net, int i) +{ + struct net_device *dev; + + rcu_read_lock(); + for_each_netdev_rcu(net, dev) { + struct in_device *in_dev; + + in_dev = __in_dev_get_rcu(dev); + if (in_dev && !test_bit(i, in_dev->cnf.state)) + in_dev->cnf.data[i] = net->ipv4.devconf_dflt->data[i]; + } + rcu_read_unlock(); +} + +/* called with RTNL locked */ +static void inet_forward_change(struct net *net) +{ + struct net_device *dev; + int on = IPV4_DEVCONF_ALL(net, FORWARDING); + + IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on; + IPV4_DEVCONF_DFLT(net, FORWARDING) = on; + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_FORWARDING, + NETCONFA_IFINDEX_ALL, + net->ipv4.devconf_all); + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_FORWARDING, + NETCONFA_IFINDEX_DEFAULT, + net->ipv4.devconf_dflt); + + for_each_netdev(net, dev) { + struct in_device *in_dev; + + if (on) + dev_disable_lro(dev); + + in_dev = __in_dev_get_rtnl(dev); + if (in_dev) { + IN_DEV_CONF_SET(in_dev, FORWARDING, on); + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_FORWARDING, + dev->ifindex, &in_dev->cnf); + } + } +} + +static int devinet_conf_ifindex(struct net *net, struct ipv4_devconf *cnf) +{ + if (cnf == net->ipv4.devconf_dflt) + return NETCONFA_IFINDEX_DEFAULT; + else if (cnf == net->ipv4.devconf_all) + return NETCONFA_IFINDEX_ALL; + else { + struct in_device *idev + = container_of(cnf, struct in_device, cnf); + return idev->dev->ifindex; + } +} + +static int devinet_conf_proc(struct ctl_table *ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int old_value = *(int *)ctl->data; + int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); + int new_value = *(int *)ctl->data; + + if (write) { + struct ipv4_devconf *cnf = ctl->extra1; + struct net *net = ctl->extra2; + int i = (int *)ctl->data - cnf->data; + int ifindex; + + set_bit(i, cnf->state); + + if (cnf == net->ipv4.devconf_dflt) + devinet_copy_dflt_conf(net, i); + if (i == IPV4_DEVCONF_ACCEPT_LOCAL - 1 || + i == IPV4_DEVCONF_ROUTE_LOCALNET - 1) + if ((new_value == 0) && (old_value != 0)) + rt_cache_flush(net); + + if (i == IPV4_DEVCONF_BC_FORWARDING - 1 && + new_value != old_value) + rt_cache_flush(net); + + if (i == IPV4_DEVCONF_RP_FILTER - 1 && + new_value != old_value) { + ifindex = devinet_conf_ifindex(net, cnf); + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_RP_FILTER, + ifindex, cnf); + } + if (i == IPV4_DEVCONF_PROXY_ARP - 1 && + new_value != old_value) { + ifindex = devinet_conf_ifindex(net, cnf); + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_PROXY_NEIGH, + ifindex, cnf); + } + if (i == IPV4_DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN - 1 && + new_value != old_value) { + ifindex = devinet_conf_ifindex(net, cnf); + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN, + ifindex, cnf); + } + } + + return ret; +} + +static int devinet_sysctl_forward(struct ctl_table *ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int *valp = ctl->data; + int val = *valp; + loff_t pos = *ppos; + int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); + + if (write && *valp != val) { + struct net *net = ctl->extra2; + + if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) { + if (!rtnl_trylock()) { + /* Restore the original values before restarting */ + *valp = val; + *ppos = pos; + return restart_syscall(); + } + if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) { + inet_forward_change(net); + } else { + struct ipv4_devconf *cnf = ctl->extra1; + struct in_device *idev = + container_of(cnf, struct in_device, cnf); + if (*valp) + dev_disable_lro(idev->dev); + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_FORWARDING, + idev->dev->ifindex, + cnf); + } + rtnl_unlock(); + rt_cache_flush(net); + } else + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_FORWARDING, + NETCONFA_IFINDEX_DEFAULT, + net->ipv4.devconf_dflt); + } + + return ret; +} + +static int ipv4_doint_and_flush(struct ctl_table *ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int *valp = ctl->data; + int val = *valp; + int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); + struct net *net = ctl->extra2; + + if (write && *valp != val) + rt_cache_flush(net); + + return ret; +} + +#define DEVINET_SYSCTL_ENTRY(attr, name, mval, proc) \ + { \ + .procname = name, \ + .data = ipv4_devconf.data + \ + IPV4_DEVCONF_ ## attr - 1, \ + .maxlen = sizeof(int), \ + .mode = mval, \ + .proc_handler = proc, \ + .extra1 = &ipv4_devconf, \ + } + +#define DEVINET_SYSCTL_RW_ENTRY(attr, name) \ + DEVINET_SYSCTL_ENTRY(attr, name, 0644, devinet_conf_proc) + +#define DEVINET_SYSCTL_RO_ENTRY(attr, name) \ + DEVINET_SYSCTL_ENTRY(attr, name, 0444, devinet_conf_proc) + +#define DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, proc) \ + DEVINET_SYSCTL_ENTRY(attr, name, 0644, proc) + +#define DEVINET_SYSCTL_FLUSHING_ENTRY(attr, name) \ + DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, ipv4_doint_and_flush) + +static struct devinet_sysctl_table { + struct ctl_table_header *sysctl_header; + struct ctl_table devinet_vars[__IPV4_DEVCONF_MAX]; +} devinet_sysctl = { + .devinet_vars = { + DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding", + devinet_sysctl_forward), + DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"), + DEVINET_SYSCTL_RW_ENTRY(BC_FORWARDING, "bc_forwarding"), + + DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"), + DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"), + DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"), + DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"), + DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"), + DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE, + "accept_source_route"), + DEVINET_SYSCTL_RW_ENTRY(ACCEPT_LOCAL, "accept_local"), + DEVINET_SYSCTL_RW_ENTRY(SRC_VMARK, "src_valid_mark"), + DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"), + DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"), + DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"), + DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"), + DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"), + DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"), + DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"), + DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"), + DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"), + DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"), + DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP_PVLAN, "proxy_arp_pvlan"), + DEVINET_SYSCTL_RW_ENTRY(FORCE_IGMP_VERSION, + "force_igmp_version"), + DEVINET_SYSCTL_RW_ENTRY(IGMPV2_UNSOLICITED_REPORT_INTERVAL, + "igmpv2_unsolicited_report_interval"), + DEVINET_SYSCTL_RW_ENTRY(IGMPV3_UNSOLICITED_REPORT_INTERVAL, + "igmpv3_unsolicited_report_interval"), + DEVINET_SYSCTL_RW_ENTRY(IGNORE_ROUTES_WITH_LINKDOWN, + "ignore_routes_with_linkdown"), + DEVINET_SYSCTL_RW_ENTRY(DROP_GRATUITOUS_ARP, + "drop_gratuitous_arp"), + + DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"), + DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"), + DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES, + "promote_secondaries"), + DEVINET_SYSCTL_FLUSHING_ENTRY(ROUTE_LOCALNET, + "route_localnet"), + DEVINET_SYSCTL_FLUSHING_ENTRY(DROP_UNICAST_IN_L2_MULTICAST, + "drop_unicast_in_l2_multicast"), + }, +}; + +static int __devinet_sysctl_register(struct net *net, char *dev_name, + int ifindex, struct ipv4_devconf *p) +{ + int i; + struct devinet_sysctl_table *t; + char path[sizeof("net/ipv4/conf/") + IFNAMSIZ]; + + t = kmemdup(&devinet_sysctl, sizeof(*t), GFP_KERNEL); + if (!t) + goto out; + + for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) { + t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf; + t->devinet_vars[i].extra1 = p; + t->devinet_vars[i].extra2 = net; + } + + snprintf(path, sizeof(path), "net/ipv4/conf/%s", dev_name); + + t->sysctl_header = register_net_sysctl(net, path, t->devinet_vars); + if (!t->sysctl_header) + goto free; + + p->sysctl = t; + + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, + ifindex, p); + return 0; + +free: + kfree(t); +out: + return -ENOMEM; +} + +static void __devinet_sysctl_unregister(struct net *net, + struct ipv4_devconf *cnf, int ifindex) +{ + struct devinet_sysctl_table *t = cnf->sysctl; + + if (t) { + cnf->sysctl = NULL; + unregister_net_sysctl_table(t->sysctl_header); + kfree(t); + } + + inet_netconf_notify_devconf(net, RTM_DELNETCONF, 0, ifindex, NULL); +} + +static int devinet_sysctl_register(struct in_device *idev) +{ + int err; + + if (!sysctl_dev_name_is_allowed(idev->dev->name)) + return -EINVAL; + + err = neigh_sysctl_register(idev->dev, idev->arp_parms, NULL); + if (err) + return err; + err = __devinet_sysctl_register(dev_net(idev->dev), idev->dev->name, + idev->dev->ifindex, &idev->cnf); + if (err) + neigh_sysctl_unregister(idev->arp_parms); + return err; +} + +static void devinet_sysctl_unregister(struct in_device *idev) +{ + struct net *net = dev_net(idev->dev); + + __devinet_sysctl_unregister(net, &idev->cnf, idev->dev->ifindex); + neigh_sysctl_unregister(idev->arp_parms); +} + +static struct ctl_table ctl_forward_entry[] = { + { + .procname = "ip_forward", + .data = &ipv4_devconf.data[ + IPV4_DEVCONF_FORWARDING - 1], + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = devinet_sysctl_forward, + .extra1 = &ipv4_devconf, + .extra2 = &init_net, + }, + { }, +}; +#endif + +static __net_init int devinet_init_net(struct net *net) +{ + int err; + struct ipv4_devconf *all, *dflt; +#ifdef CONFIG_SYSCTL + struct ctl_table *tbl; + struct ctl_table_header *forw_hdr; +#endif + + err = -ENOMEM; + all = kmemdup(&ipv4_devconf, sizeof(ipv4_devconf), GFP_KERNEL); + if (!all) + goto err_alloc_all; + + dflt = kmemdup(&ipv4_devconf_dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL); + if (!dflt) + goto err_alloc_dflt; + +#ifdef CONFIG_SYSCTL + tbl = kmemdup(ctl_forward_entry, sizeof(ctl_forward_entry), GFP_KERNEL); + if (!tbl) + goto err_alloc_ctl; + + tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1]; + tbl[0].extra1 = all; + tbl[0].extra2 = net; +#endif + + if (!net_eq(net, &init_net)) { + switch (net_inherit_devconf()) { + case 3: + /* copy from the current netns */ + memcpy(all, current->nsproxy->net_ns->ipv4.devconf_all, + sizeof(ipv4_devconf)); + memcpy(dflt, + current->nsproxy->net_ns->ipv4.devconf_dflt, + sizeof(ipv4_devconf_dflt)); + break; + case 0: + case 1: + /* copy from init_net */ + memcpy(all, init_net.ipv4.devconf_all, + sizeof(ipv4_devconf)); + memcpy(dflt, init_net.ipv4.devconf_dflt, + sizeof(ipv4_devconf_dflt)); + break; + case 2: + /* use compiled values */ + break; + } + } + +#ifdef CONFIG_SYSCTL + err = __devinet_sysctl_register(net, "all", NETCONFA_IFINDEX_ALL, all); + if (err < 0) + goto err_reg_all; + + err = __devinet_sysctl_register(net, "default", + NETCONFA_IFINDEX_DEFAULT, dflt); + if (err < 0) + goto err_reg_dflt; + + err = -ENOMEM; + forw_hdr = register_net_sysctl(net, "net/ipv4", tbl); + if (!forw_hdr) + goto err_reg_ctl; + net->ipv4.forw_hdr = forw_hdr; +#endif + + net->ipv4.devconf_all = all; + net->ipv4.devconf_dflt = dflt; + return 0; + +#ifdef CONFIG_SYSCTL +err_reg_ctl: + __devinet_sysctl_unregister(net, dflt, NETCONFA_IFINDEX_DEFAULT); +err_reg_dflt: + __devinet_sysctl_unregister(net, all, NETCONFA_IFINDEX_ALL); +err_reg_all: + kfree(tbl); +err_alloc_ctl: +#endif + kfree(dflt); +err_alloc_dflt: + kfree(all); +err_alloc_all: + return err; +} + +static __net_exit void devinet_exit_net(struct net *net) +{ +#ifdef CONFIG_SYSCTL + struct ctl_table *tbl; + + tbl = net->ipv4.forw_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->ipv4.forw_hdr); + __devinet_sysctl_unregister(net, net->ipv4.devconf_dflt, + NETCONFA_IFINDEX_DEFAULT); + __devinet_sysctl_unregister(net, net->ipv4.devconf_all, + NETCONFA_IFINDEX_ALL); + kfree(tbl); +#endif + kfree(net->ipv4.devconf_dflt); + kfree(net->ipv4.devconf_all); +} + +static __net_initdata struct pernet_operations devinet_ops = { + .init = devinet_init_net, + .exit = devinet_exit_net, +}; + +static struct rtnl_af_ops inet_af_ops __read_mostly = { + .family = AF_INET, + .fill_link_af = inet_fill_link_af, + .get_link_af_size = inet_get_link_af_size, + .validate_link_af = inet_validate_link_af, + .set_link_af = inet_set_link_af, +}; + +void __init devinet_init(void) +{ + int i; + + for (i = 0; i < IN4_ADDR_HSIZE; i++) + INIT_HLIST_HEAD(&inet_addr_lst[i]); + + register_pernet_subsys(&devinet_ops); + register_netdevice_notifier(&ip_netdev_notifier); + + queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, 0); + + rtnl_af_register(&inet_af_ops); + + rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL, 0); + rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL, 0); + rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr, 0); + rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf, + inet_netconf_dump_devconf, 0); +} diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c new file mode 100644 index 000000000..412a3c153 --- /dev/null +++ b/net/ipv4/esp4.c @@ -0,0 +1,1249 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define pr_fmt(fmt) "IPsec: " fmt + +#include <crypto/aead.h> +#include <crypto/authenc.h> +#include <linux/err.h> +#include <linux/module.h> +#include <net/ip.h> +#include <net/xfrm.h> +#include <net/esp.h> +#include <linux/scatterlist.h> +#include <linux/kernel.h> +#include <linux/pfkeyv2.h> +#include <linux/rtnetlink.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/in6.h> +#include <net/icmp.h> +#include <net/protocol.h> +#include <net/udp.h> +#include <net/tcp.h> +#include <net/espintcp.h> + +#include <linux/highmem.h> + +struct esp_skb_cb { + struct xfrm_skb_cb xfrm; + void *tmp; +}; + +struct esp_output_extra { + __be32 seqhi; + u32 esphoff; +}; + +#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) + +/* + * Allocate an AEAD request structure with extra space for SG and IV. + * + * For alignment considerations the IV is placed at the front, followed + * by the request and finally the SG list. + * + * TODO: Use spare space in skb for this where possible. + */ +static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen) +{ + unsigned int len; + + len = extralen; + + len += crypto_aead_ivsize(aead); + + if (len) { + len += crypto_aead_alignmask(aead) & + ~(crypto_tfm_ctx_alignment() - 1); + len = ALIGN(len, crypto_tfm_ctx_alignment()); + } + + len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); + len = ALIGN(len, __alignof__(struct scatterlist)); + + len += sizeof(struct scatterlist) * nfrags; + + return kmalloc(len, GFP_ATOMIC); +} + +static inline void *esp_tmp_extra(void *tmp) +{ + return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); +} + +static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen) +{ + return crypto_aead_ivsize(aead) ? + PTR_ALIGN((u8 *)tmp + extralen, + crypto_aead_alignmask(aead) + 1) : tmp + extralen; +} + +static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) +{ + struct aead_request *req; + + req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), + crypto_tfm_ctx_alignment()); + aead_request_set_tfm(req, aead); + return req; +} + +static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, + struct aead_request *req) +{ + return (void *)ALIGN((unsigned long)(req + 1) + + crypto_aead_reqsize(aead), + __alignof__(struct scatterlist)); +} + +static void esp_ssg_unref(struct xfrm_state *x, void *tmp) +{ + struct esp_output_extra *extra = esp_tmp_extra(tmp); + struct crypto_aead *aead = x->data; + int extralen = 0; + u8 *iv; + struct aead_request *req; + struct scatterlist *sg; + + if (x->props.flags & XFRM_STATE_ESN) + extralen += sizeof(*extra); + + extra = esp_tmp_extra(tmp); + iv = esp_tmp_iv(aead, tmp, extralen); + req = esp_tmp_req(aead, iv); + + /* Unref skb_frag_pages in the src scatterlist if necessary. + * Skip the first sg which comes from skb->data. + */ + if (req->src != req->dst) + for (sg = sg_next(req->src); sg; sg = sg_next(sg)) + put_page(sg_page(sg)); +} + +#ifdef CONFIG_INET_ESPINTCP +struct esp_tcp_sk { + struct sock *sk; + struct rcu_head rcu; +}; + +static void esp_free_tcp_sk(struct rcu_head *head) +{ + struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu); + + sock_put(esk->sk); + kfree(esk); +} + +static struct sock *esp_find_tcp_sk(struct xfrm_state *x) +{ + struct xfrm_encap_tmpl *encap = x->encap; + struct esp_tcp_sk *esk; + __be16 sport, dport; + struct sock *nsk; + struct sock *sk; + + sk = rcu_dereference(x->encap_sk); + if (sk && sk->sk_state == TCP_ESTABLISHED) + return sk; + + spin_lock_bh(&x->lock); + sport = encap->encap_sport; + dport = encap->encap_dport; + nsk = rcu_dereference_protected(x->encap_sk, + lockdep_is_held(&x->lock)); + if (sk && sk == nsk) { + esk = kmalloc(sizeof(*esk), GFP_ATOMIC); + if (!esk) { + spin_unlock_bh(&x->lock); + return ERR_PTR(-ENOMEM); + } + RCU_INIT_POINTER(x->encap_sk, NULL); + esk->sk = sk; + call_rcu(&esk->rcu, esp_free_tcp_sk); + } + spin_unlock_bh(&x->lock); + + sk = inet_lookup_established(xs_net(x), &tcp_hashinfo, x->id.daddr.a4, + dport, x->props.saddr.a4, sport, 0); + if (!sk) + return ERR_PTR(-ENOENT); + + if (!tcp_is_ulp_esp(sk)) { + sock_put(sk); + return ERR_PTR(-EINVAL); + } + + spin_lock_bh(&x->lock); + nsk = rcu_dereference_protected(x->encap_sk, + lockdep_is_held(&x->lock)); + if (encap->encap_sport != sport || + encap->encap_dport != dport) { + sock_put(sk); + sk = nsk ?: ERR_PTR(-EREMCHG); + } else if (sk == nsk) { + sock_put(sk); + } else { + rcu_assign_pointer(x->encap_sk, sk); + } + spin_unlock_bh(&x->lock); + + return sk; +} + +static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb) +{ + struct sock *sk; + int err; + + rcu_read_lock(); + + sk = esp_find_tcp_sk(x); + err = PTR_ERR_OR_ZERO(sk); + if (err) + goto out; + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) + err = espintcp_queue_out(sk, skb); + else + err = espintcp_push_skb(sk, skb); + bh_unlock_sock(sk); + +out: + rcu_read_unlock(); + return err; +} + +static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct xfrm_state *x = dst->xfrm; + + return esp_output_tcp_finish(x, skb); +} + +static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb) +{ + int err; + + local_bh_disable(); + err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb); + local_bh_enable(); + + /* EINPROGRESS just happens to do the right thing. It + * actually means that the skb has been consumed and + * isn't coming back. + */ + return err ?: -EINPROGRESS; +} +#else +static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb) +{ + kfree_skb(skb); + + return -EOPNOTSUPP; +} +#endif + +static void esp_output_done(struct crypto_async_request *base, int err) +{ + struct sk_buff *skb = base->data; + struct xfrm_offload *xo = xfrm_offload(skb); + void *tmp; + struct xfrm_state *x; + + if (xo && (xo->flags & XFRM_DEV_RESUME)) { + struct sec_path *sp = skb_sec_path(skb); + + x = sp->xvec[sp->len - 1]; + } else { + x = skb_dst(skb)->xfrm; + } + + tmp = ESP_SKB_CB(skb)->tmp; + esp_ssg_unref(x, tmp); + kfree(tmp); + + if (xo && (xo->flags & XFRM_DEV_RESUME)) { + if (err) { + XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); + kfree_skb(skb); + return; + } + + skb_push(skb, skb->data - skb_mac_header(skb)); + secpath_reset(skb); + xfrm_dev_resume(skb); + } else { + if (!err && + x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP) + esp_output_tail_tcp(x, skb); + else + xfrm_output_resume(skb->sk, skb, err); + } +} + +/* Move ESP header back into place. */ +static void esp_restore_header(struct sk_buff *skb, unsigned int offset) +{ + struct ip_esp_hdr *esph = (void *)(skb->data + offset); + void *tmp = ESP_SKB_CB(skb)->tmp; + __be32 *seqhi = esp_tmp_extra(tmp); + + esph->seq_no = esph->spi; + esph->spi = *seqhi; +} + +static void esp_output_restore_header(struct sk_buff *skb) +{ + void *tmp = ESP_SKB_CB(skb)->tmp; + struct esp_output_extra *extra = esp_tmp_extra(tmp); + + esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - + sizeof(__be32)); +} + +static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb, + struct xfrm_state *x, + struct ip_esp_hdr *esph, + struct esp_output_extra *extra) +{ + /* For ESN we move the header forward by 4 bytes to + * accomodate the high bits. We will move it back after + * encryption. + */ + if ((x->props.flags & XFRM_STATE_ESN)) { + __u32 seqhi; + struct xfrm_offload *xo = xfrm_offload(skb); + + if (xo) + seqhi = xo->seq.hi; + else + seqhi = XFRM_SKB_CB(skb)->seq.output.hi; + + extra->esphoff = (unsigned char *)esph - + skb_transport_header(skb); + esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); + extra->seqhi = esph->spi; + esph->seq_no = htonl(seqhi); + } + + esph->spi = x->id.spi; + + return esph; +} + +static void esp_output_done_esn(struct crypto_async_request *base, int err) +{ + struct sk_buff *skb = base->data; + + esp_output_restore_header(skb); + esp_output_done(base, err); +} + +static struct ip_esp_hdr *esp_output_udp_encap(struct sk_buff *skb, + int encap_type, + struct esp_info *esp, + __be16 sport, + __be16 dport) +{ + struct udphdr *uh; + __be32 *udpdata32; + unsigned int len; + + len = skb->len + esp->tailen - skb_transport_offset(skb); + if (len + sizeof(struct iphdr) > IP_MAX_MTU) + return ERR_PTR(-EMSGSIZE); + + uh = (struct udphdr *)esp->esph; + uh->source = sport; + uh->dest = dport; + uh->len = htons(len); + uh->check = 0; + + *skb_mac_header(skb) = IPPROTO_UDP; + + if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) { + udpdata32 = (__be32 *)(uh + 1); + udpdata32[0] = udpdata32[1] = 0; + return (struct ip_esp_hdr *)(udpdata32 + 2); + } + + return (struct ip_esp_hdr *)(uh + 1); +} + +#ifdef CONFIG_INET_ESPINTCP +static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x, + struct sk_buff *skb, + struct esp_info *esp) +{ + __be16 *lenp = (void *)esp->esph; + struct ip_esp_hdr *esph; + unsigned int len; + struct sock *sk; + + len = skb->len + esp->tailen - skb_transport_offset(skb); + if (len > IP_MAX_MTU) + return ERR_PTR(-EMSGSIZE); + + rcu_read_lock(); + sk = esp_find_tcp_sk(x); + rcu_read_unlock(); + + if (IS_ERR(sk)) + return ERR_CAST(sk); + + *lenp = htons(len); + esph = (struct ip_esp_hdr *)(lenp + 1); + + return esph; +} +#else +static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x, + struct sk_buff *skb, + struct esp_info *esp) +{ + return ERR_PTR(-EOPNOTSUPP); +} +#endif + +static int esp_output_encap(struct xfrm_state *x, struct sk_buff *skb, + struct esp_info *esp) +{ + struct xfrm_encap_tmpl *encap = x->encap; + struct ip_esp_hdr *esph; + __be16 sport, dport; + int encap_type; + + spin_lock_bh(&x->lock); + sport = encap->encap_sport; + dport = encap->encap_dport; + encap_type = encap->encap_type; + spin_unlock_bh(&x->lock); + + switch (encap_type) { + default: + case UDP_ENCAP_ESPINUDP: + case UDP_ENCAP_ESPINUDP_NON_IKE: + esph = esp_output_udp_encap(skb, encap_type, esp, sport, dport); + break; + case TCP_ENCAP_ESPINTCP: + esph = esp_output_tcp_encap(x, skb, esp); + break; + } + + if (IS_ERR(esph)) + return PTR_ERR(esph); + + esp->esph = esph; + + return 0; +} + +int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) +{ + u8 *tail; + int nfrags; + int esph_offset; + struct page *page; + struct sk_buff *trailer; + int tailen = esp->tailen; + + /* this is non-NULL only with TCP/UDP Encapsulation */ + if (x->encap) { + int err = esp_output_encap(x, skb, esp); + + if (err < 0) + return err; + } + + if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE || + ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE) + goto cow; + + if (!skb_cloned(skb)) { + if (tailen <= skb_tailroom(skb)) { + nfrags = 1; + trailer = skb; + tail = skb_tail_pointer(trailer); + + goto skip_cow; + } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) + && !skb_has_frag_list(skb)) { + int allocsize; + struct sock *sk = skb->sk; + struct page_frag *pfrag = &x->xfrag; + + esp->inplace = false; + + allocsize = ALIGN(tailen, L1_CACHE_BYTES); + + spin_lock_bh(&x->lock); + + if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { + spin_unlock_bh(&x->lock); + goto cow; + } + + page = pfrag->page; + get_page(page); + + tail = page_address(page) + pfrag->offset; + + esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); + + nfrags = skb_shinfo(skb)->nr_frags; + + __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, + tailen); + skb_shinfo(skb)->nr_frags = ++nfrags; + + pfrag->offset = pfrag->offset + allocsize; + + spin_unlock_bh(&x->lock); + + nfrags++; + + skb->len += tailen; + skb->data_len += tailen; + skb->truesize += tailen; + if (sk && sk_fullsock(sk)) + refcount_add(tailen, &sk->sk_wmem_alloc); + + goto out; + } + } + +cow: + esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); + + nfrags = skb_cow_data(skb, tailen, &trailer); + if (nfrags < 0) + goto out; + tail = skb_tail_pointer(trailer); + esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); + +skip_cow: + esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); + pskb_put(skb, trailer, tailen); + +out: + return nfrags; +} +EXPORT_SYMBOL_GPL(esp_output_head); + +int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) +{ + u8 *iv; + int alen; + void *tmp; + int ivlen; + int assoclen; + int extralen; + struct page *page; + struct ip_esp_hdr *esph; + struct crypto_aead *aead; + struct aead_request *req; + struct scatterlist *sg, *dsg; + struct esp_output_extra *extra; + int err = -ENOMEM; + + assoclen = sizeof(struct ip_esp_hdr); + extralen = 0; + + if (x->props.flags & XFRM_STATE_ESN) { + extralen += sizeof(*extra); + assoclen += sizeof(__be32); + } + + aead = x->data; + alen = crypto_aead_authsize(aead); + ivlen = crypto_aead_ivsize(aead); + + tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); + if (!tmp) + goto error; + + extra = esp_tmp_extra(tmp); + iv = esp_tmp_iv(aead, tmp, extralen); + req = esp_tmp_req(aead, iv); + sg = esp_req_sg(aead, req); + + if (esp->inplace) + dsg = sg; + else + dsg = &sg[esp->nfrags]; + + esph = esp_output_set_extra(skb, x, esp->esph, extra); + esp->esph = esph; + + sg_init_table(sg, esp->nfrags); + err = skb_to_sgvec(skb, sg, + (unsigned char *)esph - skb->data, + assoclen + ivlen + esp->clen + alen); + if (unlikely(err < 0)) + goto error_free; + + if (!esp->inplace) { + int allocsize; + struct page_frag *pfrag = &x->xfrag; + + allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); + + spin_lock_bh(&x->lock); + if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { + spin_unlock_bh(&x->lock); + goto error_free; + } + + skb_shinfo(skb)->nr_frags = 1; + + page = pfrag->page; + get_page(page); + /* replace page frags in skb with new page */ + __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); + pfrag->offset = pfrag->offset + allocsize; + spin_unlock_bh(&x->lock); + + sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); + err = skb_to_sgvec(skb, dsg, + (unsigned char *)esph - skb->data, + assoclen + ivlen + esp->clen + alen); + if (unlikely(err < 0)) + goto error_free; + } + + if ((x->props.flags & XFRM_STATE_ESN)) + aead_request_set_callback(req, 0, esp_output_done_esn, skb); + else + aead_request_set_callback(req, 0, esp_output_done, skb); + + aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); + aead_request_set_ad(req, assoclen); + + memset(iv, 0, ivlen); + memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), + min(ivlen, 8)); + + ESP_SKB_CB(skb)->tmp = tmp; + err = crypto_aead_encrypt(req); + + switch (err) { + case -EINPROGRESS: + goto error; + + case -ENOSPC: + err = NET_XMIT_DROP; + break; + + case 0: + if ((x->props.flags & XFRM_STATE_ESN)) + esp_output_restore_header(skb); + } + + if (sg != dsg) + esp_ssg_unref(x, tmp); + + if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP) + err = esp_output_tail_tcp(x, skb); + +error_free: + kfree(tmp); +error: + return err; +} +EXPORT_SYMBOL_GPL(esp_output_tail); + +static int esp_output(struct xfrm_state *x, struct sk_buff *skb) +{ + int alen; + int blksize; + struct ip_esp_hdr *esph; + struct crypto_aead *aead; + struct esp_info esp; + + esp.inplace = true; + + esp.proto = *skb_mac_header(skb); + *skb_mac_header(skb) = IPPROTO_ESP; + + /* skb is pure payload to encrypt */ + + aead = x->data; + alen = crypto_aead_authsize(aead); + + esp.tfclen = 0; + if (x->tfcpad) { + struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); + u32 padto; + + padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached)); + if (skb->len < padto) + esp.tfclen = padto - skb->len; + } + blksize = ALIGN(crypto_aead_blocksize(aead), 4); + esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); + esp.plen = esp.clen - skb->len - esp.tfclen; + esp.tailen = esp.tfclen + esp.plen + alen; + + esp.esph = ip_esp_hdr(skb); + + esp.nfrags = esp_output_head(x, skb, &esp); + if (esp.nfrags < 0) + return esp.nfrags; + + esph = esp.esph; + esph->spi = x->id.spi; + + esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); + esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + + ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); + + skb_push(skb, -skb_network_offset(skb)); + + return esp_output_tail(x, skb, &esp); +} + +static inline int esp_remove_trailer(struct sk_buff *skb) +{ + struct xfrm_state *x = xfrm_input_state(skb); + struct xfrm_offload *xo = xfrm_offload(skb); + struct crypto_aead *aead = x->data; + int alen, hlen, elen; + int padlen, trimlen; + __wsum csumdiff; + u8 nexthdr[2]; + int ret; + + alen = crypto_aead_authsize(aead); + hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); + elen = skb->len - hlen; + + if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { + ret = xo->proto; + goto out; + } + + if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2)) + BUG(); + + ret = -EINVAL; + padlen = nexthdr[0]; + if (padlen + 2 + alen >= elen) { + net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", + padlen + 2, elen - alen); + goto out; + } + + trimlen = alen + padlen + 2; + if (skb->ip_summed == CHECKSUM_COMPLETE) { + csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); + skb->csum = csum_block_sub(skb->csum, csumdiff, + skb->len - trimlen); + } + ret = pskb_trim(skb, skb->len - trimlen); + if (unlikely(ret)) + return ret; + + ret = nexthdr[1]; + +out: + return ret; +} + +int esp_input_done2(struct sk_buff *skb, int err) +{ + const struct iphdr *iph; + struct xfrm_state *x = xfrm_input_state(skb); + struct xfrm_offload *xo = xfrm_offload(skb); + struct crypto_aead *aead = x->data; + int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); + int ihl; + + if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) + kfree(ESP_SKB_CB(skb)->tmp); + + if (unlikely(err)) + goto out; + + err = esp_remove_trailer(skb); + if (unlikely(err < 0)) + goto out; + + iph = ip_hdr(skb); + ihl = iph->ihl * 4; + + if (x->encap) { + struct xfrm_encap_tmpl *encap = x->encap; + struct tcphdr *th = (void *)(skb_network_header(skb) + ihl); + struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); + __be16 source; + + switch (x->encap->encap_type) { + case TCP_ENCAP_ESPINTCP: + source = th->source; + break; + case UDP_ENCAP_ESPINUDP: + case UDP_ENCAP_ESPINUDP_NON_IKE: + source = uh->source; + break; + default: + WARN_ON_ONCE(1); + err = -EINVAL; + goto out; + } + + /* + * 1) if the NAT-T peer's IP or port changed then + * advertize the change to the keying daemon. + * This is an inbound SA, so just compare + * SRC ports. + */ + if (iph->saddr != x->props.saddr.a4 || + source != encap->encap_sport) { + xfrm_address_t ipaddr; + + ipaddr.a4 = iph->saddr; + km_new_mapping(x, &ipaddr, source); + + /* XXX: perhaps add an extra + * policy check here, to see + * if we should allow or + * reject a packet from a + * different source + * address/port. + */ + } + + /* + * 2) ignore UDP/TCP checksums in case + * of NAT-T in Transport Mode, or + * perform other post-processing fixes + * as per draft-ietf-ipsec-udp-encaps-06, + * section 3.1.2 + */ + if (x->props.mode == XFRM_MODE_TRANSPORT) + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + + skb_pull_rcsum(skb, hlen); + if (x->props.mode == XFRM_MODE_TUNNEL) + skb_reset_transport_header(skb); + else + skb_set_transport_header(skb, -ihl); + + /* RFC4303: Drop dummy packets without any error */ + if (err == IPPROTO_NONE) + err = -EINVAL; + +out: + return err; +} +EXPORT_SYMBOL_GPL(esp_input_done2); + +static void esp_input_done(struct crypto_async_request *base, int err) +{ + struct sk_buff *skb = base->data; + + xfrm_input_resume(skb, esp_input_done2(skb, err)); +} + +static void esp_input_restore_header(struct sk_buff *skb) +{ + esp_restore_header(skb, 0); + __skb_pull(skb, 4); +} + +static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) +{ + struct xfrm_state *x = xfrm_input_state(skb); + struct ip_esp_hdr *esph; + + /* For ESN we move the header forward by 4 bytes to + * accomodate the high bits. We will move it back after + * decryption. + */ + if ((x->props.flags & XFRM_STATE_ESN)) { + esph = skb_push(skb, 4); + *seqhi = esph->spi; + esph->spi = esph->seq_no; + esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; + } +} + +static void esp_input_done_esn(struct crypto_async_request *base, int err) +{ + struct sk_buff *skb = base->data; + + esp_input_restore_header(skb); + esp_input_done(base, err); +} + +/* + * Note: detecting truncated vs. non-truncated authentication data is very + * expensive, so we only support truncated data, which is the recommended + * and common case. + */ +static int esp_input(struct xfrm_state *x, struct sk_buff *skb) +{ + struct crypto_aead *aead = x->data; + struct aead_request *req; + struct sk_buff *trailer; + int ivlen = crypto_aead_ivsize(aead); + int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; + int nfrags; + int assoclen; + int seqhilen; + __be32 *seqhi; + void *tmp; + u8 *iv; + struct scatterlist *sg; + int err = -EINVAL; + + if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) + goto out; + + if (elen <= 0) + goto out; + + assoclen = sizeof(struct ip_esp_hdr); + seqhilen = 0; + + if (x->props.flags & XFRM_STATE_ESN) { + seqhilen += sizeof(__be32); + assoclen += seqhilen; + } + + if (!skb_cloned(skb)) { + if (!skb_is_nonlinear(skb)) { + nfrags = 1; + + goto skip_cow; + } else if (!skb_has_frag_list(skb)) { + nfrags = skb_shinfo(skb)->nr_frags; + nfrags++; + + goto skip_cow; + } + } + + err = skb_cow_data(skb, 0, &trailer); + if (err < 0) + goto out; + + nfrags = err; + +skip_cow: + err = -ENOMEM; + tmp = esp_alloc_tmp(aead, nfrags, seqhilen); + if (!tmp) + goto out; + + ESP_SKB_CB(skb)->tmp = tmp; + seqhi = esp_tmp_extra(tmp); + iv = esp_tmp_iv(aead, tmp, seqhilen); + req = esp_tmp_req(aead, iv); + sg = esp_req_sg(aead, req); + + esp_input_set_header(skb, seqhi); + + sg_init_table(sg, nfrags); + err = skb_to_sgvec(skb, sg, 0, skb->len); + if (unlikely(err < 0)) { + kfree(tmp); + goto out; + } + + skb->ip_summed = CHECKSUM_NONE; + + if ((x->props.flags & XFRM_STATE_ESN)) + aead_request_set_callback(req, 0, esp_input_done_esn, skb); + else + aead_request_set_callback(req, 0, esp_input_done, skb); + + aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); + aead_request_set_ad(req, assoclen); + + err = crypto_aead_decrypt(req); + if (err == -EINPROGRESS) + goto out; + + if ((x->props.flags & XFRM_STATE_ESN)) + esp_input_restore_header(skb); + + err = esp_input_done2(skb, err); + +out: + return err; +} + +static int esp4_err(struct sk_buff *skb, u32 info) +{ + struct net *net = dev_net(skb->dev); + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); + struct xfrm_state *x; + + switch (icmp_hdr(skb)->type) { + case ICMP_DEST_UNREACH: + if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) + return 0; + case ICMP_REDIRECT: + break; + default: + return 0; + } + + x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, + esph->spi, IPPROTO_ESP, AF_INET); + if (!x) + return 0; + + if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) + ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP); + else + ipv4_redirect(skb, net, 0, IPPROTO_ESP); + xfrm_state_put(x); + + return 0; +} + +static void esp_destroy(struct xfrm_state *x) +{ + struct crypto_aead *aead = x->data; + + if (!aead) + return; + + crypto_free_aead(aead); +} + +static int esp_init_aead(struct xfrm_state *x) +{ + char aead_name[CRYPTO_MAX_ALG_NAME]; + struct crypto_aead *aead; + int err; + + err = -ENAMETOOLONG; + if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", + x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) + goto error; + + aead = crypto_alloc_aead(aead_name, 0, 0); + err = PTR_ERR(aead); + if (IS_ERR(aead)) + goto error; + + x->data = aead; + + err = crypto_aead_setkey(aead, x->aead->alg_key, + (x->aead->alg_key_len + 7) / 8); + if (err) + goto error; + + err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); + if (err) + goto error; + +error: + return err; +} + +static int esp_init_authenc(struct xfrm_state *x) +{ + struct crypto_aead *aead; + struct crypto_authenc_key_param *param; + struct rtattr *rta; + char *key; + char *p; + char authenc_name[CRYPTO_MAX_ALG_NAME]; + unsigned int keylen; + int err; + + err = -EINVAL; + if (!x->ealg) + goto error; + + err = -ENAMETOOLONG; + + if ((x->props.flags & XFRM_STATE_ESN)) { + if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, + "%s%sauthencesn(%s,%s)%s", + x->geniv ?: "", x->geniv ? "(" : "", + x->aalg ? x->aalg->alg_name : "digest_null", + x->ealg->alg_name, + x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) + goto error; + } else { + if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, + "%s%sauthenc(%s,%s)%s", + x->geniv ?: "", x->geniv ? "(" : "", + x->aalg ? x->aalg->alg_name : "digest_null", + x->ealg->alg_name, + x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) + goto error; + } + + aead = crypto_alloc_aead(authenc_name, 0, 0); + err = PTR_ERR(aead); + if (IS_ERR(aead)) + goto error; + + x->data = aead; + + keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + + (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); + err = -ENOMEM; + key = kmalloc(keylen, GFP_KERNEL); + if (!key) + goto error; + + p = key; + rta = (void *)p; + rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; + rta->rta_len = RTA_LENGTH(sizeof(*param)); + param = RTA_DATA(rta); + p += RTA_SPACE(sizeof(*param)); + + if (x->aalg) { + struct xfrm_algo_desc *aalg_desc; + + memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); + p += (x->aalg->alg_key_len + 7) / 8; + + aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); + BUG_ON(!aalg_desc); + + err = -EINVAL; + if (aalg_desc->uinfo.auth.icv_fullbits / 8 != + crypto_aead_authsize(aead)) { + pr_info("ESP: %s digestsize %u != %hu\n", + x->aalg->alg_name, + crypto_aead_authsize(aead), + aalg_desc->uinfo.auth.icv_fullbits / 8); + goto free_key; + } + + err = crypto_aead_setauthsize( + aead, x->aalg->alg_trunc_len / 8); + if (err) + goto free_key; + } + + param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); + memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); + + err = crypto_aead_setkey(aead, key, keylen); + +free_key: + kfree_sensitive(key); + +error: + return err; +} + +static int esp_init_state(struct xfrm_state *x) +{ + struct crypto_aead *aead; + u32 align; + int err; + + x->data = NULL; + + if (x->aead) + err = esp_init_aead(x); + else + err = esp_init_authenc(x); + + if (err) + goto error; + + aead = x->data; + + x->props.header_len = sizeof(struct ip_esp_hdr) + + crypto_aead_ivsize(aead); + if (x->props.mode == XFRM_MODE_TUNNEL) + x->props.header_len += sizeof(struct iphdr); + else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) + x->props.header_len += IPV4_BEET_PHMAXLEN; + if (x->encap) { + struct xfrm_encap_tmpl *encap = x->encap; + + switch (encap->encap_type) { + default: + err = -EINVAL; + goto error; + case UDP_ENCAP_ESPINUDP: + x->props.header_len += sizeof(struct udphdr); + break; + case UDP_ENCAP_ESPINUDP_NON_IKE: + x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); + break; +#ifdef CONFIG_INET_ESPINTCP + case TCP_ENCAP_ESPINTCP: + /* only the length field, TCP encap is done by + * the socket + */ + x->props.header_len += 2; + break; +#endif + } + } + + align = ALIGN(crypto_aead_blocksize(aead), 4); + x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); + +error: + return err; +} + +static int esp4_rcv_cb(struct sk_buff *skb, int err) +{ + return 0; +} + +static const struct xfrm_type esp_type = +{ + .description = "ESP4", + .owner = THIS_MODULE, + .proto = IPPROTO_ESP, + .flags = XFRM_TYPE_REPLAY_PROT, + .init_state = esp_init_state, + .destructor = esp_destroy, + .input = esp_input, + .output = esp_output, +}; + +static struct xfrm4_protocol esp4_protocol = { + .handler = xfrm4_rcv, + .input_handler = xfrm_input, + .cb_handler = esp4_rcv_cb, + .err_handler = esp4_err, + .priority = 0, +}; + +static int __init esp4_init(void) +{ + if (xfrm_register_type(&esp_type, AF_INET) < 0) { + pr_info("%s: can't add xfrm type\n", __func__); + return -EAGAIN; + } + if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { + pr_info("%s: can't add protocol\n", __func__); + xfrm_unregister_type(&esp_type, AF_INET); + return -EAGAIN; + } + return 0; +} + +static void __exit esp4_fini(void) +{ + if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) + pr_info("%s: can't remove protocol\n", __func__); + xfrm_unregister_type(&esp_type, AF_INET); +} + +module_init(esp4_init); +module_exit(esp4_fini); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c new file mode 100644 index 000000000..dc50764b0 --- /dev/null +++ b/net/ipv4/esp4_offload.c @@ -0,0 +1,384 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * IPV4 GSO/GRO offload support + * Linux INET implementation + * + * Copyright (C) 2016 secunet Security Networks AG + * Author: Steffen Klassert <steffen.klassert@secunet.com> + * + * ESP GRO support + */ + +#include <linux/skbuff.h> +#include <linux/init.h> +#include <net/protocol.h> +#include <crypto/aead.h> +#include <crypto/authenc.h> +#include <linux/err.h> +#include <linux/module.h> +#include <net/ip.h> +#include <net/xfrm.h> +#include <net/esp.h> +#include <linux/scatterlist.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <net/udp.h> + +static struct sk_buff *esp4_gro_receive(struct list_head *head, + struct sk_buff *skb) +{ + int offset = skb_gro_offset(skb); + struct xfrm_offload *xo; + struct xfrm_state *x; + __be32 seq; + __be32 spi; + int err; + + if (!pskb_pull(skb, offset)) + return NULL; + + if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0) + goto out; + + xo = xfrm_offload(skb); + if (!xo || !(xo->flags & CRYPTO_DONE)) { + struct sec_path *sp = secpath_set(skb); + + if (!sp) + goto out; + + if (sp->len == XFRM_MAX_DEPTH) + goto out_reset; + + x = xfrm_state_lookup(dev_net(skb->dev), skb->mark, + (xfrm_address_t *)&ip_hdr(skb)->daddr, + spi, IPPROTO_ESP, AF_INET); + if (!x) + goto out_reset; + + skb->mark = xfrm_smark_get(skb->mark, x); + + sp->xvec[sp->len++] = x; + sp->olen++; + + xo = xfrm_offload(skb); + if (!xo) + goto out_reset; + } + + xo->flags |= XFRM_GRO; + + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; + XFRM_SPI_SKB_CB(skb)->family = AF_INET; + XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr); + XFRM_SPI_SKB_CB(skb)->seq = seq; + + /* We don't need to handle errors from xfrm_input, it does all + * the error handling and frees the resources on error. */ + xfrm_input(skb, IPPROTO_ESP, spi, -2); + + return ERR_PTR(-EINPROGRESS); +out_reset: + secpath_reset(skb); +out: + skb_push(skb, offset); + NAPI_GRO_CB(skb)->same_flow = 0; + NAPI_GRO_CB(skb)->flush = 1; + + return NULL; +} + +static void esp4_gso_encap(struct xfrm_state *x, struct sk_buff *skb) +{ + struct ip_esp_hdr *esph; + struct iphdr *iph = ip_hdr(skb); + struct xfrm_offload *xo = xfrm_offload(skb); + int proto = iph->protocol; + + skb_push(skb, -skb_network_offset(skb)); + esph = ip_esp_hdr(skb); + *skb_mac_header(skb) = IPPROTO_ESP; + + esph->spi = x->id.spi; + esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); + + xo->proto = proto; +} + +static struct sk_buff *xfrm4_tunnel_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + __skb_push(skb, skb->mac_len); + return skb_mac_gso_segment(skb, features); +} + +static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + const struct net_offload *ops; + struct sk_buff *segs = ERR_PTR(-EINVAL); + struct xfrm_offload *xo = xfrm_offload(skb); + + skb->transport_header += x->props.header_len; + ops = rcu_dereference(inet_offloads[xo->proto]); + if (likely(ops && ops->callbacks.gso_segment)) + segs = ops->callbacks.gso_segment(skb, features); + + return segs; +} + +static struct sk_buff *xfrm4_beet_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + struct xfrm_offload *xo = xfrm_offload(skb); + struct sk_buff *segs = ERR_PTR(-EINVAL); + const struct net_offload *ops; + u8 proto = xo->proto; + + skb->transport_header += x->props.header_len; + + if (x->sel.family != AF_INET6) { + if (proto == IPPROTO_BEETPH) { + struct ip_beet_phdr *ph = + (struct ip_beet_phdr *)skb->data; + + skb->transport_header += ph->hdrlen * 8; + proto = ph->nexthdr; + } else { + skb->transport_header -= IPV4_BEET_PHMAXLEN; + } + } else { + __be16 frag; + + skb->transport_header += + ipv6_skip_exthdr(skb, 0, &proto, &frag); + if (proto == IPPROTO_TCP) + skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4; + } + + if (proto == IPPROTO_IPV6) + skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4; + + __skb_pull(skb, skb_transport_offset(skb)); + ops = rcu_dereference(inet_offloads[proto]); + if (likely(ops && ops->callbacks.gso_segment)) + segs = ops->callbacks.gso_segment(skb, features); + + return segs; +} + +static struct sk_buff *xfrm4_outer_mode_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + switch (x->outer_mode.encap) { + case XFRM_MODE_TUNNEL: + return xfrm4_tunnel_gso_segment(x, skb, features); + case XFRM_MODE_TRANSPORT: + return xfrm4_transport_gso_segment(x, skb, features); + case XFRM_MODE_BEET: + return xfrm4_beet_gso_segment(x, skb, features); + } + + return ERR_PTR(-EOPNOTSUPP); +} + +static struct sk_buff *esp4_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + struct xfrm_state *x; + struct ip_esp_hdr *esph; + struct crypto_aead *aead; + netdev_features_t esp_features = features; + struct xfrm_offload *xo = xfrm_offload(skb); + struct sec_path *sp; + + if (!xo) + return ERR_PTR(-EINVAL); + + if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP)) + return ERR_PTR(-EINVAL); + + sp = skb_sec_path(skb); + x = sp->xvec[sp->len - 1]; + aead = x->data; + esph = ip_esp_hdr(skb); + + if (esph->spi != x->id.spi) + return ERR_PTR(-EINVAL); + + if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) + return ERR_PTR(-EINVAL); + + __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)); + + skb->encap_hdr_csum = 1; + + if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) && + !(features & NETIF_F_HW_ESP)) || x->xso.dev != skb->dev) + esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK | + NETIF_F_SCTP_CRC); + else if (!(features & NETIF_F_HW_ESP_TX_CSUM) && + !(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM)) + esp_features = features & ~(NETIF_F_CSUM_MASK | + NETIF_F_SCTP_CRC); + + xo->flags |= XFRM_GSO_SEGMENT; + + return xfrm4_outer_mode_gso_segment(x, skb, esp_features); +} + +static int esp_input_tail(struct xfrm_state *x, struct sk_buff *skb) +{ + struct crypto_aead *aead = x->data; + struct xfrm_offload *xo = xfrm_offload(skb); + + if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead))) + return -EINVAL; + + if (!(xo->flags & CRYPTO_DONE)) + skb->ip_summed = CHECKSUM_NONE; + + return esp_input_done2(skb, 0); +} + +static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features) +{ + int err; + int alen; + int blksize; + struct xfrm_offload *xo; + struct ip_esp_hdr *esph; + struct crypto_aead *aead; + struct esp_info esp; + bool hw_offload = true; + __u32 seq; + + esp.inplace = true; + + xo = xfrm_offload(skb); + + if (!xo) + return -EINVAL; + + if ((!(features & NETIF_F_HW_ESP) && + !(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) || + x->xso.dev != skb->dev) { + xo->flags |= CRYPTO_FALLBACK; + hw_offload = false; + } + + esp.proto = xo->proto; + + /* skb is pure payload to encrypt */ + + aead = x->data; + alen = crypto_aead_authsize(aead); + + esp.tfclen = 0; + /* XXX: Add support for tfc padding here. */ + + blksize = ALIGN(crypto_aead_blocksize(aead), 4); + esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); + esp.plen = esp.clen - skb->len - esp.tfclen; + esp.tailen = esp.tfclen + esp.plen + alen; + + esp.esph = ip_esp_hdr(skb); + + + if (!hw_offload || (hw_offload && !skb_is_gso(skb))) { + esp.nfrags = esp_output_head(x, skb, &esp); + if (esp.nfrags < 0) + return esp.nfrags; + } + + seq = xo->seq.low; + + esph = esp.esph; + esph->spi = x->id.spi; + + skb_push(skb, -skb_network_offset(skb)); + + if (xo->flags & XFRM_GSO_SEGMENT) { + esph->seq_no = htonl(seq); + + if (!skb_is_gso(skb)) + xo->seq.low++; + else + xo->seq.low += skb_shinfo(skb)->gso_segs; + } + + if (xo->seq.low < seq) + xo->seq.hi++; + + esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32)); + + ip_hdr(skb)->tot_len = htons(skb->len); + ip_send_check(ip_hdr(skb)); + + if (hw_offload) { + if (!skb_ext_add(skb, SKB_EXT_SEC_PATH)) + return -ENOMEM; + + xo = xfrm_offload(skb); + if (!xo) + return -EINVAL; + + xo->flags |= XFRM_XMIT; + return 0; + } + + err = esp_output_tail(x, skb, &esp); + if (err) + return err; + + secpath_reset(skb); + + if (skb_needs_linearize(skb, skb->dev->features) && + __skb_linearize(skb)) + return -ENOMEM; + return 0; +} + +static const struct net_offload esp4_offload = { + .callbacks = { + .gro_receive = esp4_gro_receive, + .gso_segment = esp4_gso_segment, + }, +}; + +static const struct xfrm_type_offload esp_type_offload = { + .description = "ESP4 OFFLOAD", + .owner = THIS_MODULE, + .proto = IPPROTO_ESP, + .input_tail = esp_input_tail, + .xmit = esp_xmit, + .encap = esp4_gso_encap, +}; + +static int __init esp4_offload_init(void) +{ + if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) { + pr_info("%s: can't add xfrm type offload\n", __func__); + return -EAGAIN; + } + + return inet_add_offload(&esp4_offload, IPPROTO_ESP); +} + +static void __exit esp4_offload_exit(void) +{ + xfrm_unregister_type_offload(&esp_type_offload, AF_INET); + inet_del_offload(&esp4_offload, IPPROTO_ESP); +} + +module_init(esp4_offload_init); +module_exit(esp4_offload_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); +MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP); +MODULE_DESCRIPTION("IPV4 GSO/GRO offload support"); diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c new file mode 100644 index 000000000..41f890bf9 --- /dev/null +++ b/net/ipv4/fib_frontend.c @@ -0,0 +1,1635 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IPv4 Forwarding Information Base: FIB frontend. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/bitops.h> +#include <linux/capability.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/if_addr.h> +#include <linux/if_arp.h> +#include <linux/skbuff.h> +#include <linux/cache.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/slab.h> + +#include <net/ip.h> +#include <net/protocol.h> +#include <net/route.h> +#include <net/tcp.h> +#include <net/sock.h> +#include <net/arp.h> +#include <net/ip_fib.h> +#include <net/nexthop.h> +#include <net/rtnetlink.h> +#include <net/xfrm.h> +#include <net/l3mdev.h> +#include <net/lwtunnel.h> +#include <trace/events/fib.h> + +#ifndef CONFIG_IP_MULTIPLE_TABLES + +static int __net_init fib4_rules_init(struct net *net) +{ + struct fib_table *local_table, *main_table; + + main_table = fib_trie_table(RT_TABLE_MAIN, NULL); + if (!main_table) + return -ENOMEM; + + local_table = fib_trie_table(RT_TABLE_LOCAL, main_table); + if (!local_table) + goto fail; + + hlist_add_head_rcu(&local_table->tb_hlist, + &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); + hlist_add_head_rcu(&main_table->tb_hlist, + &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); + return 0; + +fail: + fib_free_table(main_table); + return -ENOMEM; +} +#else + +struct fib_table *fib_new_table(struct net *net, u32 id) +{ + struct fib_table *tb, *alias = NULL; + unsigned int h; + + if (id == 0) + id = RT_TABLE_MAIN; + tb = fib_get_table(net, id); + if (tb) + return tb; + + if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) + alias = fib_new_table(net, RT_TABLE_MAIN); + + tb = fib_trie_table(id, alias); + if (!tb) + return NULL; + + switch (id) { + case RT_TABLE_MAIN: + rcu_assign_pointer(net->ipv4.fib_main, tb); + break; + case RT_TABLE_DEFAULT: + rcu_assign_pointer(net->ipv4.fib_default, tb); + break; + default: + break; + } + + h = id & (FIB_TABLE_HASHSZ - 1); + hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); + return tb; +} +EXPORT_SYMBOL_GPL(fib_new_table); + +/* caller must hold either rtnl or rcu read lock */ +struct fib_table *fib_get_table(struct net *net, u32 id) +{ + struct fib_table *tb; + struct hlist_head *head; + unsigned int h; + + if (id == 0) + id = RT_TABLE_MAIN; + h = id & (FIB_TABLE_HASHSZ - 1); + + head = &net->ipv4.fib_table_hash[h]; + hlist_for_each_entry_rcu(tb, head, tb_hlist, + lockdep_rtnl_is_held()) { + if (tb->tb_id == id) + return tb; + } + return NULL; +} +#endif /* CONFIG_IP_MULTIPLE_TABLES */ + +static void fib_replace_table(struct net *net, struct fib_table *old, + struct fib_table *new) +{ +#ifdef CONFIG_IP_MULTIPLE_TABLES + switch (new->tb_id) { + case RT_TABLE_MAIN: + rcu_assign_pointer(net->ipv4.fib_main, new); + break; + case RT_TABLE_DEFAULT: + rcu_assign_pointer(net->ipv4.fib_default, new); + break; + default: + break; + } + +#endif + /* replace the old table in the hlist */ + hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist); +} + +int fib_unmerge(struct net *net) +{ + struct fib_table *old, *new, *main_table; + + /* attempt to fetch local table if it has been allocated */ + old = fib_get_table(net, RT_TABLE_LOCAL); + if (!old) + return 0; + + new = fib_trie_unmerge(old); + if (!new) + return -ENOMEM; + + /* table is already unmerged */ + if (new == old) + return 0; + + /* replace merged table with clean table */ + fib_replace_table(net, old, new); + fib_free_table(old); + + /* attempt to fetch main table if it has been allocated */ + main_table = fib_get_table(net, RT_TABLE_MAIN); + if (!main_table) + return 0; + + /* flush local entries from main table */ + fib_table_flush_external(main_table); + + return 0; +} + +void fib_flush(struct net *net) +{ + int flushed = 0; + unsigned int h; + + for (h = 0; h < FIB_TABLE_HASHSZ; h++) { + struct hlist_head *head = &net->ipv4.fib_table_hash[h]; + struct hlist_node *tmp; + struct fib_table *tb; + + hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) + flushed += fib_table_flush(net, tb, false); + } + + if (flushed) + rt_cache_flush(net); +} + +/* + * Find address type as if only "dev" was present in the system. If + * on_dev is NULL then all interfaces are taken into consideration. + */ +static inline unsigned int __inet_dev_addr_type(struct net *net, + const struct net_device *dev, + __be32 addr, u32 tb_id) +{ + struct flowi4 fl4 = { .daddr = addr }; + struct fib_result res; + unsigned int ret = RTN_BROADCAST; + struct fib_table *table; + + if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) + return RTN_BROADCAST; + if (ipv4_is_multicast(addr)) + return RTN_MULTICAST; + + rcu_read_lock(); + + table = fib_get_table(net, tb_id); + if (table) { + ret = RTN_UNICAST; + if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) { + struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0); + + if (!dev || dev == nhc->nhc_dev) + ret = res.type; + } + } + + rcu_read_unlock(); + return ret; +} + +unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) +{ + return __inet_dev_addr_type(net, NULL, addr, tb_id); +} +EXPORT_SYMBOL(inet_addr_type_table); + +unsigned int inet_addr_type(struct net *net, __be32 addr) +{ + return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL); +} +EXPORT_SYMBOL(inet_addr_type); + +unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, + __be32 addr) +{ + u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; + + return __inet_dev_addr_type(net, dev, addr, rt_table); +} +EXPORT_SYMBOL(inet_dev_addr_type); + +/* inet_addr_type with dev == NULL but using the table from a dev + * if one is associated + */ +unsigned int inet_addr_type_dev_table(struct net *net, + const struct net_device *dev, + __be32 addr) +{ + u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; + + return __inet_dev_addr_type(net, NULL, addr, rt_table); +} +EXPORT_SYMBOL(inet_addr_type_dev_table); + +__be32 fib_compute_spec_dst(struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + struct in_device *in_dev; + struct fib_result res; + struct rtable *rt; + struct net *net; + int scope; + + rt = skb_rtable(skb); + if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == + RTCF_LOCAL) + return ip_hdr(skb)->daddr; + + in_dev = __in_dev_get_rcu(dev); + + net = dev_net(dev); + + scope = RT_SCOPE_UNIVERSE; + if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { + bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); + struct flowi4 fl4 = { + .flowi4_iif = LOOPBACK_IFINDEX, + .flowi4_oif = l3mdev_master_ifindex_rcu(dev), + .daddr = ip_hdr(skb)->saddr, + .flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK, + .flowi4_scope = scope, + .flowi4_mark = vmark ? skb->mark : 0, + }; + if (!fib_lookup(net, &fl4, &res, 0)) + return fib_result_prefsrc(net, &res); + } else { + scope = RT_SCOPE_LINK; + } + + return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); +} + +bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) +{ + bool dev_match = false; +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (unlikely(fi->nh)) { + dev_match = nexthop_uses_dev(fi->nh, dev); + } else { + int ret; + + for (ret = 0; ret < fib_info_num_path(fi); ret++) { + const struct fib_nh_common *nhc = fib_info_nhc(fi, ret); + + if (nhc_l3mdev_matches_dev(nhc, dev)) { + dev_match = true; + break; + } + } + } +#else + if (fib_info_nhc(fi, 0)->nhc_dev == dev) + dev_match = true; +#endif + + return dev_match; +} +EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); + +/* Given (packet source, input interface) and optional (dst, oif, tos): + * - (main) check, that source is valid i.e. not broadcast or our local + * address. + * - figure out what "logical" interface this packet arrived + * and calculate "specific destination" address. + * - check, that packet arrived from expected physical interface. + * called with rcu_read_lock() + */ +static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, + u8 tos, int oif, struct net_device *dev, + int rpf, struct in_device *idev, u32 *itag) +{ + struct net *net = dev_net(dev); + struct flow_keys flkeys; + int ret, no_addr; + struct fib_result res; + struct flowi4 fl4; + bool dev_match; + + fl4.flowi4_oif = 0; + fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev); + if (!fl4.flowi4_iif) + fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; + fl4.daddr = src; + fl4.saddr = dst; + fl4.flowi4_tos = tos; + fl4.flowi4_scope = RT_SCOPE_UNIVERSE; + fl4.flowi4_tun_key.tun_id = 0; + fl4.flowi4_flags = 0; + fl4.flowi4_uid = sock_net_uid(net, NULL); + fl4.flowi4_multipath_hash = 0; + + no_addr = idev->ifa_list == NULL; + + fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; + if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) { + fl4.flowi4_proto = 0; + fl4.fl4_sport = 0; + fl4.fl4_dport = 0; + } else { + swap(fl4.fl4_sport, fl4.fl4_dport); + } + + if (fib_lookup(net, &fl4, &res, 0)) + goto last_resort; + if (res.type != RTN_UNICAST && + (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) + goto e_inval; + fib_combine_itag(itag, &res); + + dev_match = fib_info_nh_uses_dev(res.fi, dev); + /* This is not common, loopback packets retain skb_dst so normally they + * would not even hit this slow path. + */ + dev_match = dev_match || (res.type == RTN_LOCAL && + dev == net->loopback_dev); + if (dev_match) { + ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_LINK; + return ret; + } + if (no_addr) + goto last_resort; + if (rpf == 1) + goto e_rpf; + fl4.flowi4_oif = dev->ifindex; + + ret = 0; + if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { + if (res.type == RTN_UNICAST) + ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_LINK; + } + return ret; + +last_resort: + if (rpf) + goto e_rpf; + *itag = 0; + return 0; + +e_inval: + return -EINVAL; +e_rpf: + return -EXDEV; +} + +/* Ignore rp_filter for packets protected by IPsec. */ +int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, + u8 tos, int oif, struct net_device *dev, + struct in_device *idev, u32 *itag) +{ + int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); + struct net *net = dev_net(dev); + + if (!r && !fib_num_tclassid_users(net) && + (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { + if (IN_DEV_ACCEPT_LOCAL(idev)) + goto ok; + /* with custom local routes in place, checking local addresses + * only will be too optimistic, with custom rules, checking + * local addresses only can be too strict, e.g. due to vrf + */ + if (net->ipv4.fib_has_custom_local_routes || + fib4_has_custom_rules(net)) + goto full_check; + if (inet_lookup_ifaddr_rcu(net, src)) + return -EINVAL; + +ok: + *itag = 0; + return 0; + } + +full_check: + return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); +} + +static inline __be32 sk_extract_addr(struct sockaddr *addr) +{ + return ((struct sockaddr_in *) addr)->sin_addr.s_addr; +} + +static int put_rtax(struct nlattr *mx, int len, int type, u32 value) +{ + struct nlattr *nla; + + nla = (struct nlattr *) ((char *) mx + len); + nla->nla_type = type; + nla->nla_len = nla_attr_size(4); + *(u32 *) nla_data(nla) = value; + + return len + nla_total_size(4); +} + +static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, + struct fib_config *cfg) +{ + __be32 addr; + int plen; + + memset(cfg, 0, sizeof(*cfg)); + cfg->fc_nlinfo.nl_net = net; + + if (rt->rt_dst.sa_family != AF_INET) + return -EAFNOSUPPORT; + + /* + * Check mask for validity: + * a) it must be contiguous. + * b) destination must have all host bits clear. + * c) if application forgot to set correct family (AF_INET), + * reject request unless it is absolutely clear i.e. + * both family and mask are zero. + */ + plen = 32; + addr = sk_extract_addr(&rt->rt_dst); + if (!(rt->rt_flags & RTF_HOST)) { + __be32 mask = sk_extract_addr(&rt->rt_genmask); + + if (rt->rt_genmask.sa_family != AF_INET) { + if (mask || rt->rt_genmask.sa_family) + return -EAFNOSUPPORT; + } + + if (bad_mask(mask, addr)) + return -EINVAL; + + plen = inet_mask_len(mask); + } + + cfg->fc_dst_len = plen; + cfg->fc_dst = addr; + + if (cmd != SIOCDELRT) { + cfg->fc_nlflags = NLM_F_CREATE; + cfg->fc_protocol = RTPROT_BOOT; + } + + if (rt->rt_metric) + cfg->fc_priority = rt->rt_metric - 1; + + if (rt->rt_flags & RTF_REJECT) { + cfg->fc_scope = RT_SCOPE_HOST; + cfg->fc_type = RTN_UNREACHABLE; + return 0; + } + + cfg->fc_scope = RT_SCOPE_NOWHERE; + cfg->fc_type = RTN_UNICAST; + + if (rt->rt_dev) { + char *colon; + struct net_device *dev; + char devname[IFNAMSIZ]; + + if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) + return -EFAULT; + + devname[IFNAMSIZ-1] = 0; + colon = strchr(devname, ':'); + if (colon) + *colon = 0; + dev = __dev_get_by_name(net, devname); + if (!dev) + return -ENODEV; + cfg->fc_oif = dev->ifindex; + cfg->fc_table = l3mdev_fib_table(dev); + if (colon) { + const struct in_ifaddr *ifa; + struct in_device *in_dev; + + in_dev = __in_dev_get_rtnl(dev); + if (!in_dev) + return -ENODEV; + + *colon = ':'; + + rcu_read_lock(); + in_dev_for_each_ifa_rcu(ifa, in_dev) { + if (strcmp(ifa->ifa_label, devname) == 0) + break; + } + rcu_read_unlock(); + + if (!ifa) + return -ENODEV; + cfg->fc_prefsrc = ifa->ifa_local; + } + } + + addr = sk_extract_addr(&rt->rt_gateway); + if (rt->rt_gateway.sa_family == AF_INET && addr) { + unsigned int addr_type; + + cfg->fc_gw4 = addr; + cfg->fc_gw_family = AF_INET; + addr_type = inet_addr_type_table(net, addr, cfg->fc_table); + if (rt->rt_flags & RTF_GATEWAY && + addr_type == RTN_UNICAST) + cfg->fc_scope = RT_SCOPE_UNIVERSE; + } + + if (!cfg->fc_table) + cfg->fc_table = RT_TABLE_MAIN; + + if (cmd == SIOCDELRT) + return 0; + + if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) + return -EINVAL; + + if (cfg->fc_scope == RT_SCOPE_NOWHERE) + cfg->fc_scope = RT_SCOPE_LINK; + + if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { + struct nlattr *mx; + int len = 0; + + mx = kcalloc(3, nla_total_size(4), GFP_KERNEL); + if (!mx) + return -ENOMEM; + + if (rt->rt_flags & RTF_MTU) + len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); + + if (rt->rt_flags & RTF_WINDOW) + len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); + + if (rt->rt_flags & RTF_IRTT) + len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); + + cfg->fc_mx = mx; + cfg->fc_mx_len = len; + } + + return 0; +} + +/* + * Handle IP routing ioctl calls. + * These are used to manipulate the routing tables + */ +int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) +{ + struct fib_config cfg; + int err; + + switch (cmd) { + case SIOCADDRT: /* Add a route */ + case SIOCDELRT: /* Delete a route */ + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + rtnl_lock(); + err = rtentry_to_fib_config(net, cmd, rt, &cfg); + if (err == 0) { + struct fib_table *tb; + + if (cmd == SIOCDELRT) { + tb = fib_get_table(net, cfg.fc_table); + if (tb) + err = fib_table_delete(net, tb, &cfg, + NULL); + else + err = -ESRCH; + } else { + tb = fib_new_table(net, cfg.fc_table); + if (tb) + err = fib_table_insert(net, tb, + &cfg, NULL); + else + err = -ENOBUFS; + } + + /* allocated by rtentry_to_fib_config() */ + kfree(cfg.fc_mx); + } + rtnl_unlock(); + return err; + } + return -EINVAL; +} + +const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { + [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, + [RTA_DST] = { .type = NLA_U32 }, + [RTA_SRC] = { .type = NLA_U32 }, + [RTA_IIF] = { .type = NLA_U32 }, + [RTA_OIF] = { .type = NLA_U32 }, + [RTA_GATEWAY] = { .type = NLA_U32 }, + [RTA_PRIORITY] = { .type = NLA_U32 }, + [RTA_PREFSRC] = { .type = NLA_U32 }, + [RTA_METRICS] = { .type = NLA_NESTED }, + [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, + [RTA_FLOW] = { .type = NLA_U32 }, + [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, + [RTA_ENCAP] = { .type = NLA_NESTED }, + [RTA_UID] = { .type = NLA_U32 }, + [RTA_MARK] = { .type = NLA_U32 }, + [RTA_TABLE] = { .type = NLA_U32 }, + [RTA_IP_PROTO] = { .type = NLA_U8 }, + [RTA_SPORT] = { .type = NLA_U16 }, + [RTA_DPORT] = { .type = NLA_U16 }, + [RTA_NH_ID] = { .type = NLA_U32 }, +}; + +int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + struct rtvia *via; + int alen; + + if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { + NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA"); + return -EINVAL; + } + + via = nla_data(nla); + alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); + + switch (via->rtvia_family) { + case AF_INET: + if (alen != sizeof(__be32)) { + NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA"); + return -EINVAL; + } + cfg->fc_gw_family = AF_INET; + cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); + break; + case AF_INET6: +#if IS_ENABLED(CONFIG_IPV6) + if (alen != sizeof(struct in6_addr)) { + NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA"); + return -EINVAL; + } + cfg->fc_gw_family = AF_INET6; + cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); +#else + NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel"); + return -EINVAL; +#endif + break; + default: + NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA"); + return -EINVAL; + } + + return 0; +} + +static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, + struct nlmsghdr *nlh, struct fib_config *cfg, + struct netlink_ext_ack *extack) +{ + bool has_gw = false, has_via = false; + struct nlattr *attr; + int err, remaining; + struct rtmsg *rtm; + + err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, + rtm_ipv4_policy, extack); + if (err < 0) + goto errout; + + memset(cfg, 0, sizeof(*cfg)); + + rtm = nlmsg_data(nlh); + cfg->fc_dst_len = rtm->rtm_dst_len; + cfg->fc_tos = rtm->rtm_tos; + cfg->fc_table = rtm->rtm_table; + cfg->fc_protocol = rtm->rtm_protocol; + cfg->fc_scope = rtm->rtm_scope; + cfg->fc_type = rtm->rtm_type; + cfg->fc_flags = rtm->rtm_flags; + cfg->fc_nlflags = nlh->nlmsg_flags; + + cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; + cfg->fc_nlinfo.nlh = nlh; + cfg->fc_nlinfo.nl_net = net; + + if (cfg->fc_type > RTN_MAX) { + NL_SET_ERR_MSG(extack, "Invalid route type"); + err = -EINVAL; + goto errout; + } + + nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { + switch (nla_type(attr)) { + case RTA_DST: + cfg->fc_dst = nla_get_be32(attr); + break; + case RTA_OIF: + cfg->fc_oif = nla_get_u32(attr); + break; + case RTA_GATEWAY: + has_gw = true; + cfg->fc_gw4 = nla_get_be32(attr); + if (cfg->fc_gw4) + cfg->fc_gw_family = AF_INET; + break; + case RTA_VIA: + has_via = true; + err = fib_gw_from_via(cfg, attr, extack); + if (err) + goto errout; + break; + case RTA_PRIORITY: + cfg->fc_priority = nla_get_u32(attr); + break; + case RTA_PREFSRC: + cfg->fc_prefsrc = nla_get_be32(attr); + break; + case RTA_METRICS: + cfg->fc_mx = nla_data(attr); + cfg->fc_mx_len = nla_len(attr); + break; + case RTA_MULTIPATH: + err = lwtunnel_valid_encap_type_attr(nla_data(attr), + nla_len(attr), + extack); + if (err < 0) + goto errout; + cfg->fc_mp = nla_data(attr); + cfg->fc_mp_len = nla_len(attr); + break; + case RTA_FLOW: + cfg->fc_flow = nla_get_u32(attr); + break; + case RTA_TABLE: + cfg->fc_table = nla_get_u32(attr); + break; + case RTA_ENCAP: + cfg->fc_encap = attr; + break; + case RTA_ENCAP_TYPE: + cfg->fc_encap_type = nla_get_u16(attr); + err = lwtunnel_valid_encap_type(cfg->fc_encap_type, + extack); + if (err < 0) + goto errout; + break; + case RTA_NH_ID: + cfg->fc_nh_id = nla_get_u32(attr); + break; + } + } + + if (cfg->fc_nh_id) { + if (cfg->fc_oif || cfg->fc_gw_family || + cfg->fc_encap || cfg->fc_mp) { + NL_SET_ERR_MSG(extack, + "Nexthop specification and nexthop id are mutually exclusive"); + return -EINVAL; + } + } + + if (has_gw && has_via) { + NL_SET_ERR_MSG(extack, + "Nexthop configuration can not contain both GATEWAY and VIA"); + return -EINVAL; + } + + if (!cfg->fc_table) + cfg->fc_table = RT_TABLE_MAIN; + + return 0; +errout: + return err; +} + +static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct fib_config cfg; + struct fib_table *tb; + int err; + + err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); + if (err < 0) + goto errout; + + if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) { + NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); + err = -EINVAL; + goto errout; + } + + tb = fib_get_table(net, cfg.fc_table); + if (!tb) { + NL_SET_ERR_MSG(extack, "FIB table does not exist"); + err = -ESRCH; + goto errout; + } + + err = fib_table_delete(net, tb, &cfg, extack); +errout: + return err; +} + +static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct fib_config cfg; + struct fib_table *tb; + int err; + + err = rtm_to_fib_config(net, skb, nlh, &cfg, extack); + if (err < 0) + goto errout; + + tb = fib_new_table(net, cfg.fc_table); + if (!tb) { + err = -ENOBUFS; + goto errout; + } + + err = fib_table_insert(net, tb, &cfg, extack); + if (!err && cfg.fc_type == RTN_LOCAL) + net->ipv4.fib_has_custom_local_routes = true; +errout: + return err; +} + +int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, + struct fib_dump_filter *filter, + struct netlink_callback *cb) +{ + struct netlink_ext_ack *extack = cb->extack; + struct nlattr *tb[RTA_MAX + 1]; + struct rtmsg *rtm; + int err, i; + + ASSERT_RTNL(); + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { + NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request"); + return -EINVAL; + } + + rtm = nlmsg_data(nlh); + if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || + rtm->rtm_scope) { + NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request"); + return -EINVAL; + } + + if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { + NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request"); + return -EINVAL; + } + if (rtm->rtm_flags & RTM_F_CLONED) + filter->dump_routes = false; + else + filter->dump_exceptions = false; + + filter->flags = rtm->rtm_flags; + filter->protocol = rtm->rtm_protocol; + filter->rt_type = rtm->rtm_type; + filter->table_id = rtm->rtm_table; + + err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv4_policy, extack); + if (err < 0) + return err; + + for (i = 0; i <= RTA_MAX; ++i) { + int ifindex; + + if (!tb[i]) + continue; + + switch (i) { + case RTA_TABLE: + filter->table_id = nla_get_u32(tb[i]); + break; + case RTA_OIF: + ifindex = nla_get_u32(tb[i]); + filter->dev = __dev_get_by_index(net, ifindex); + if (!filter->dev) + return -ENODEV; + break; + default: + NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); + return -EINVAL; + } + } + + if (filter->flags || filter->protocol || filter->rt_type || + filter->table_id || filter->dev) { + filter->filter_set = 1; + cb->answer_flags = NLM_F_DUMP_FILTERED; + } + + return 0; +} +EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); + +static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct fib_dump_filter filter = { .dump_routes = true, + .dump_exceptions = true }; + const struct nlmsghdr *nlh = cb->nlh; + struct net *net = sock_net(skb->sk); + unsigned int h, s_h; + unsigned int e = 0, s_e; + struct fib_table *tb; + struct hlist_head *head; + int dumped = 0, err; + + if (cb->strict_check) { + err = ip_valid_fib_dump_req(net, nlh, &filter, cb); + if (err < 0) + return err; + } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { + struct rtmsg *rtm = nlmsg_data(nlh); + + filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); + } + + /* ipv4 does not use prefix flag */ + if (filter.flags & RTM_F_PREFIX) + return skb->len; + + if (filter.table_id) { + tb = fib_get_table(net, filter.table_id); + if (!tb) { + if (rtnl_msg_family(cb->nlh) != PF_INET) + return skb->len; + + NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist"); + return -ENOENT; + } + + rcu_read_lock(); + err = fib_table_dump(tb, skb, cb, &filter); + rcu_read_unlock(); + return skb->len ? : err; + } + + s_h = cb->args[0]; + s_e = cb->args[1]; + + rcu_read_lock(); + + for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { + e = 0; + head = &net->ipv4.fib_table_hash[h]; + hlist_for_each_entry_rcu(tb, head, tb_hlist) { + if (e < s_e) + goto next; + if (dumped) + memset(&cb->args[2], 0, sizeof(cb->args) - + 2 * sizeof(cb->args[0])); + err = fib_table_dump(tb, skb, cb, &filter); + if (err < 0) { + if (likely(skb->len)) + goto out; + + goto out_err; + } + dumped = 1; +next: + e++; + } + } +out: + err = skb->len; +out_err: + rcu_read_unlock(); + + cb->args[1] = e; + cb->args[0] = h; + + return err; +} + +/* Prepare and feed intra-kernel routing request. + * Really, it should be netlink message, but :-( netlink + * can be not configured, so that we feed it directly + * to fib engine. It is legal, because all events occur + * only when netlink is already locked. + */ +static void fib_magic(int cmd, int type, __be32 dst, int dst_len, + struct in_ifaddr *ifa, u32 rt_priority) +{ + struct net *net = dev_net(ifa->ifa_dev->dev); + u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev); + struct fib_table *tb; + struct fib_config cfg = { + .fc_protocol = RTPROT_KERNEL, + .fc_type = type, + .fc_dst = dst, + .fc_dst_len = dst_len, + .fc_priority = rt_priority, + .fc_prefsrc = ifa->ifa_local, + .fc_oif = ifa->ifa_dev->dev->ifindex, + .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, + .fc_nlinfo = { + .nl_net = net, + }, + }; + + if (!tb_id) + tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; + + tb = fib_new_table(net, tb_id); + if (!tb) + return; + + cfg.fc_table = tb->tb_id; + + if (type != RTN_LOCAL) + cfg.fc_scope = RT_SCOPE_LINK; + else + cfg.fc_scope = RT_SCOPE_HOST; + + if (cmd == RTM_NEWROUTE) + fib_table_insert(net, tb, &cfg, NULL); + else + fib_table_delete(net, tb, &cfg, NULL); +} + +void fib_add_ifaddr(struct in_ifaddr *ifa) +{ + struct in_device *in_dev = ifa->ifa_dev; + struct net_device *dev = in_dev->dev; + struct in_ifaddr *prim = ifa; + __be32 mask = ifa->ifa_mask; + __be32 addr = ifa->ifa_local; + __be32 prefix = ifa->ifa_address & mask; + + if (ifa->ifa_flags & IFA_F_SECONDARY) { + prim = inet_ifa_byprefix(in_dev, prefix, mask); + if (!prim) { + pr_warn("%s: bug: prim == NULL\n", __func__); + return; + } + } + + fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0); + + if (!(dev->flags & IFF_UP)) + return; + + /* Add broadcast address, if it is explicitly assigned. */ + if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) { + fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, + prim, 0); + arp_invalidate(dev, ifa->ifa_broadcast, false); + } + + if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && + (prefix != addr || ifa->ifa_prefixlen < 32)) { + if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) + fib_magic(RTM_NEWROUTE, + dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, + prefix, ifa->ifa_prefixlen, prim, + ifa->ifa_rt_priority); + + /* Add network specific broadcasts, when it takes a sense */ + if (ifa->ifa_prefixlen < 31) { + fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, + prim, 0); + fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, + 32, prim, 0); + arp_invalidate(dev, prefix | ~mask, false); + } + } +} + +void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) +{ + __be32 prefix = ifa->ifa_address & ifa->ifa_mask; + struct in_device *in_dev = ifa->ifa_dev; + struct net_device *dev = in_dev->dev; + + if (!(dev->flags & IFF_UP) || + ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || + ipv4_is_zeronet(prefix) || + (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) + return; + + /* add the new */ + fib_magic(RTM_NEWROUTE, + dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, + prefix, ifa->ifa_prefixlen, ifa, new_metric); + + /* delete the old */ + fib_magic(RTM_DELROUTE, + dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, + prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority); +} + +/* Delete primary or secondary address. + * Optionally, on secondary address promotion consider the addresses + * from subnet iprim as deleted, even if they are in device list. + * In this case the secondary ifa can be in device list. + */ +void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) +{ + struct in_device *in_dev = ifa->ifa_dev; + struct net_device *dev = in_dev->dev; + struct in_ifaddr *ifa1; + struct in_ifaddr *prim = ifa, *prim1 = NULL; + __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; + __be32 any = ifa->ifa_address & ifa->ifa_mask; +#define LOCAL_OK 1 +#define BRD_OK 2 +#define BRD0_OK 4 +#define BRD1_OK 8 + unsigned int ok = 0; + int subnet = 0; /* Primary network */ + int gone = 1; /* Address is missing */ + int same_prefsrc = 0; /* Another primary with same IP */ + + if (ifa->ifa_flags & IFA_F_SECONDARY) { + prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); + if (!prim) { + /* if the device has been deleted, we don't perform + * address promotion + */ + if (!in_dev->dead) + pr_warn("%s: bug: prim == NULL\n", __func__); + return; + } + if (iprim && iprim != prim) { + pr_warn("%s: bug: iprim != prim\n", __func__); + return; + } + } else if (!ipv4_is_zeronet(any) && + (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { + if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) + fib_magic(RTM_DELROUTE, + dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, + any, ifa->ifa_prefixlen, prim, 0); + subnet = 1; + } + + if (in_dev->dead) + goto no_promotions; + + /* Deletion is more complicated than add. + * We should take care of not to delete too much :-) + * + * Scan address list to be sure that addresses are really gone. + */ + rcu_read_lock(); + in_dev_for_each_ifa_rcu(ifa1, in_dev) { + if (ifa1 == ifa) { + /* promotion, keep the IP */ + gone = 0; + continue; + } + /* Ignore IFAs from our subnet */ + if (iprim && ifa1->ifa_mask == iprim->ifa_mask && + inet_ifa_match(ifa1->ifa_address, iprim)) + continue; + + /* Ignore ifa1 if it uses different primary IP (prefsrc) */ + if (ifa1->ifa_flags & IFA_F_SECONDARY) { + /* Another address from our subnet? */ + if (ifa1->ifa_mask == prim->ifa_mask && + inet_ifa_match(ifa1->ifa_address, prim)) + prim1 = prim; + else { + /* We reached the secondaries, so + * same_prefsrc should be determined. + */ + if (!same_prefsrc) + continue; + /* Search new prim1 if ifa1 is not + * using the current prim1 + */ + if (!prim1 || + ifa1->ifa_mask != prim1->ifa_mask || + !inet_ifa_match(ifa1->ifa_address, prim1)) + prim1 = inet_ifa_byprefix(in_dev, + ifa1->ifa_address, + ifa1->ifa_mask); + if (!prim1) + continue; + if (prim1->ifa_local != prim->ifa_local) + continue; + } + } else { + if (prim->ifa_local != ifa1->ifa_local) + continue; + prim1 = ifa1; + if (prim != prim1) + same_prefsrc = 1; + } + if (ifa->ifa_local == ifa1->ifa_local) + ok |= LOCAL_OK; + if (ifa->ifa_broadcast == ifa1->ifa_broadcast) + ok |= BRD_OK; + if (brd == ifa1->ifa_broadcast) + ok |= BRD1_OK; + if (any == ifa1->ifa_broadcast) + ok |= BRD0_OK; + /* primary has network specific broadcasts */ + if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { + __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; + __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; + + if (!ipv4_is_zeronet(any1)) { + if (ifa->ifa_broadcast == brd1 || + ifa->ifa_broadcast == any1) + ok |= BRD_OK; + if (brd == brd1 || brd == any1) + ok |= BRD1_OK; + if (any == brd1 || any == any1) + ok |= BRD0_OK; + } + } + } + rcu_read_unlock(); + +no_promotions: + if (!(ok & BRD_OK)) + fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, + prim, 0); + if (subnet && ifa->ifa_prefixlen < 31) { + if (!(ok & BRD1_OK)) + fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, + prim, 0); + if (!(ok & BRD0_OK)) + fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, + prim, 0); + } + if (!(ok & LOCAL_OK)) { + unsigned int addr_type; + + fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0); + + /* Check, that this local address finally disappeared. */ + addr_type = inet_addr_type_dev_table(dev_net(dev), dev, + ifa->ifa_local); + if (gone && addr_type != RTN_LOCAL) { + /* And the last, but not the least thing. + * We must flush stray FIB entries. + * + * First of all, we scan fib_info list searching + * for stray nexthop entries, then ignite fib_flush. + */ + if (fib_sync_down_addr(dev, ifa->ifa_local)) + fib_flush(dev_net(dev)); + } + } +#undef LOCAL_OK +#undef BRD_OK +#undef BRD0_OK +#undef BRD1_OK +} + +static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) +{ + + struct fib_result res; + struct flowi4 fl4 = { + .flowi4_mark = frn->fl_mark, + .daddr = frn->fl_addr, + .flowi4_tos = frn->fl_tos, + .flowi4_scope = frn->fl_scope, + }; + struct fib_table *tb; + + rcu_read_lock(); + + tb = fib_get_table(net, frn->tb_id_in); + + frn->err = -ENOENT; + if (tb) { + local_bh_disable(); + + frn->tb_id = tb->tb_id; + frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); + + if (!frn->err) { + frn->prefixlen = res.prefixlen; + frn->nh_sel = res.nh_sel; + frn->type = res.type; + frn->scope = res.scope; + } + local_bh_enable(); + } + + rcu_read_unlock(); +} + +static void nl_fib_input(struct sk_buff *skb) +{ + struct net *net; + struct fib_result_nl *frn; + struct nlmsghdr *nlh; + u32 portid; + + net = sock_net(skb->sk); + nlh = nlmsg_hdr(skb); + if (skb->len < nlmsg_total_size(sizeof(*frn)) || + skb->len < nlh->nlmsg_len || + nlmsg_len(nlh) < sizeof(*frn)) + return; + + skb = netlink_skb_clone(skb, GFP_KERNEL); + if (!skb) + return; + nlh = nlmsg_hdr(skb); + + frn = (struct fib_result_nl *) nlmsg_data(nlh); + nl_fib_lookup(net, frn); + + portid = NETLINK_CB(skb).portid; /* netlink portid */ + NETLINK_CB(skb).portid = 0; /* from kernel */ + NETLINK_CB(skb).dst_group = 0; /* unicast */ + netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); +} + +static int __net_init nl_fib_lookup_init(struct net *net) +{ + struct sock *sk; + struct netlink_kernel_cfg cfg = { + .input = nl_fib_input, + }; + + sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); + if (!sk) + return -EAFNOSUPPORT; + net->ipv4.fibnl = sk; + return 0; +} + +static void nl_fib_lookup_exit(struct net *net) +{ + netlink_kernel_release(net->ipv4.fibnl); + net->ipv4.fibnl = NULL; +} + +static void fib_disable_ip(struct net_device *dev, unsigned long event, + bool force) +{ + if (fib_sync_down_dev(dev, event, force)) + fib_flush(dev_net(dev)); + else + rt_cache_flush(dev_net(dev)); + arp_ifdown(dev); +} + +static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) +{ + struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; + struct net_device *dev = ifa->ifa_dev->dev; + struct net *net = dev_net(dev); + + switch (event) { + case NETDEV_UP: + fib_add_ifaddr(ifa); +#ifdef CONFIG_IP_ROUTE_MULTIPATH + fib_sync_up(dev, RTNH_F_DEAD); +#endif + atomic_inc(&net->ipv4.dev_addr_genid); + rt_cache_flush(dev_net(dev)); + break; + case NETDEV_DOWN: + fib_del_ifaddr(ifa, NULL); + atomic_inc(&net->ipv4.dev_addr_genid); + if (!ifa->ifa_dev->ifa_list) { + /* Last address was deleted from this interface. + * Disable IP. + */ + fib_disable_ip(dev, event, true); + } else { + rt_cache_flush(dev_net(dev)); + } + break; + } + return NOTIFY_DONE; +} + +static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct netdev_notifier_changeupper_info *upper_info = ptr; + struct netdev_notifier_info_ext *info_ext = ptr; + struct in_device *in_dev; + struct net *net = dev_net(dev); + struct in_ifaddr *ifa; + unsigned int flags; + + if (event == NETDEV_UNREGISTER) { + fib_disable_ip(dev, event, true); + rt_flush_dev(dev); + return NOTIFY_DONE; + } + + in_dev = __in_dev_get_rtnl(dev); + if (!in_dev) + return NOTIFY_DONE; + + switch (event) { + case NETDEV_UP: + in_dev_for_each_ifa_rtnl(ifa, in_dev) { + fib_add_ifaddr(ifa); + } +#ifdef CONFIG_IP_ROUTE_MULTIPATH + fib_sync_up(dev, RTNH_F_DEAD); +#endif + atomic_inc(&net->ipv4.dev_addr_genid); + rt_cache_flush(net); + break; + case NETDEV_DOWN: + fib_disable_ip(dev, event, false); + break; + case NETDEV_CHANGE: + flags = dev_get_flags(dev); + if (flags & (IFF_RUNNING | IFF_LOWER_UP)) + fib_sync_up(dev, RTNH_F_LINKDOWN); + else + fib_sync_down_dev(dev, event, false); + rt_cache_flush(net); + break; + case NETDEV_CHANGEMTU: + fib_sync_mtu(dev, info_ext->ext.mtu); + rt_cache_flush(net); + break; + case NETDEV_CHANGEUPPER: + upper_info = ptr; + /* flush all routes if dev is linked to or unlinked from + * an L3 master device (e.g., VRF) + */ + if (upper_info->upper_dev && + netif_is_l3_master(upper_info->upper_dev)) + fib_disable_ip(dev, NETDEV_DOWN, true); + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block fib_inetaddr_notifier = { + .notifier_call = fib_inetaddr_event, +}; + +static struct notifier_block fib_netdev_notifier = { + .notifier_call = fib_netdev_event, +}; + +static int __net_init ip_fib_net_init(struct net *net) +{ + int err; + size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; + + err = fib4_notifier_init(net); + if (err) + return err; + + /* Avoid false sharing : Use at least a full cache line */ + size = max_t(size_t, size, L1_CACHE_BYTES); + + net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); + if (!net->ipv4.fib_table_hash) { + err = -ENOMEM; + goto err_table_hash_alloc; + } + + err = fib4_rules_init(net); + if (err < 0) + goto err_rules_init; + return 0; + +err_rules_init: + kfree(net->ipv4.fib_table_hash); +err_table_hash_alloc: + fib4_notifier_exit(net); + return err; +} + +static void ip_fib_net_exit(struct net *net) +{ + int i; + + rtnl_lock(); +#ifdef CONFIG_IP_MULTIPLE_TABLES + RCU_INIT_POINTER(net->ipv4.fib_main, NULL); + RCU_INIT_POINTER(net->ipv4.fib_default, NULL); +#endif + /* Destroy the tables in reverse order to guarantee that the + * local table, ID 255, is destroyed before the main table, ID + * 254. This is necessary as the local table may contain + * references to data contained in the main table. + */ + for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { + struct hlist_head *head = &net->ipv4.fib_table_hash[i]; + struct hlist_node *tmp; + struct fib_table *tb; + + hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { + hlist_del(&tb->tb_hlist); + fib_table_flush(net, tb, true); + fib_free_table(tb); + } + } + +#ifdef CONFIG_IP_MULTIPLE_TABLES + fib4_rules_exit(net); +#endif + rtnl_unlock(); + kfree(net->ipv4.fib_table_hash); + fib4_notifier_exit(net); +} + +static int __net_init fib_net_init(struct net *net) +{ + int error; + +#ifdef CONFIG_IP_ROUTE_CLASSID + atomic_set(&net->ipv4.fib_num_tclassid_users, 0); +#endif + error = ip_fib_net_init(net); + if (error < 0) + goto out; + error = nl_fib_lookup_init(net); + if (error < 0) + goto out_nlfl; + error = fib_proc_init(net); + if (error < 0) + goto out_proc; +out: + return error; + +out_proc: + nl_fib_lookup_exit(net); +out_nlfl: + ip_fib_net_exit(net); + goto out; +} + +static void __net_exit fib_net_exit(struct net *net) +{ + fib_proc_exit(net); + nl_fib_lookup_exit(net); + ip_fib_net_exit(net); +} + +static struct pernet_operations fib_net_ops = { + .init = fib_net_init, + .exit = fib_net_exit, +}; + +void __init ip_fib_init(void) +{ + fib_trie_init(); + + register_pernet_subsys(&fib_net_ops); + + register_netdevice_notifier(&fib_netdev_notifier); + register_inetaddr_notifier(&fib_inetaddr_notifier); + + rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0); + rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0); + rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0); +} diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h new file mode 100644 index 000000000..818916b2a --- /dev/null +++ b/net/ipv4/fib_lookup.h @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _FIB_LOOKUP_H +#define _FIB_LOOKUP_H + +#include <linux/types.h> +#include <linux/list.h> +#include <net/ip_fib.h> +#include <net/nexthop.h> + +struct fib_alias { + struct hlist_node fa_list; + struct fib_info *fa_info; + u8 fa_tos; + u8 fa_type; + u8 fa_state; + u8 fa_slen; + u32 tb_id; + s16 fa_default; + u8 offload:1, + trap:1, + unused:6; + struct rcu_head rcu; +}; + +#define FA_S_ACCESSED 0x01 + +/* Dont write on fa_state unless needed, to keep it shared on all cpus */ +static inline void fib_alias_accessed(struct fib_alias *fa) +{ + if (!(fa->fa_state & FA_S_ACCESSED)) + fa->fa_state |= FA_S_ACCESSED; +} + +/* Exported by fib_semantics.c */ +void fib_release_info(struct fib_info *); +struct fib_info *fib_create_info(struct fib_config *cfg, + struct netlink_ext_ack *extack); +int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, + struct netlink_ext_ack *extack); +bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi); +int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, + struct fib_rt_info *fri, unsigned int flags); +void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, int dst_len, + u32 tb_id, const struct nl_info *info, unsigned int nlm_flags); + +static inline void fib_result_assign(struct fib_result *res, + struct fib_info *fi) +{ + /* we used to play games with refcounts, but we now use RCU */ + res->fi = fi; + res->nhc = fib_info_nhc(fi, 0); +} + +struct fib_prop { + int error; + u8 scope; +}; + +extern const struct fib_prop fib_props[RTN_MAX + 1]; + +#endif /* _FIB_LOOKUP_H */ diff --git a/net/ipv4/fib_notifier.c b/net/ipv4/fib_notifier.c new file mode 100644 index 000000000..0c28bd469 --- /dev/null +++ b/net/ipv4/fib_notifier.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/rtnetlink.h> +#include <linux/notifier.h> +#include <linux/socket.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <net/net_namespace.h> +#include <net/fib_notifier.h> +#include <net/netns/ipv4.h> +#include <net/ip_fib.h> + +int call_fib4_notifier(struct notifier_block *nb, + enum fib_event_type event_type, + struct fib_notifier_info *info) +{ + info->family = AF_INET; + return call_fib_notifier(nb, event_type, info); +} + +int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, + struct fib_notifier_info *info) +{ + ASSERT_RTNL(); + + info->family = AF_INET; + net->ipv4.fib_seq++; + return call_fib_notifiers(net, event_type, info); +} + +static unsigned int fib4_seq_read(struct net *net) +{ + ASSERT_RTNL(); + + return net->ipv4.fib_seq + fib4_rules_seq_read(net); +} + +static int fib4_dump(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + int err; + + err = fib4_rules_dump(net, nb, extack); + if (err) + return err; + + return fib_notify(net, nb, extack); +} + +static const struct fib_notifier_ops fib4_notifier_ops_template = { + .family = AF_INET, + .fib_seq_read = fib4_seq_read, + .fib_dump = fib4_dump, + .owner = THIS_MODULE, +}; + +int __net_init fib4_notifier_init(struct net *net) +{ + struct fib_notifier_ops *ops; + + net->ipv4.fib_seq = 0; + + ops = fib_notifier_ops_register(&fib4_notifier_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + net->ipv4.notifier_ops = ops; + + return 0; +} + +void __net_exit fib4_notifier_exit(struct net *net) +{ + fib_notifier_ops_unregister(net->ipv4.notifier_ops); +} diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c new file mode 100644 index 000000000..d279cb8ac --- /dev/null +++ b/net/ipv4/fib_rules.c @@ -0,0 +1,435 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IPv4 Forwarding Information Base: policy rules. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * Thomas Graf <tgraf@suug.ch> + * + * Fixes: + * Rani Assaf : local_rule cannot be deleted + * Marc Boucher : routing by fwmark + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/netdevice.h> +#include <linux/netlink.h> +#include <linux/inetdevice.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/rcupdate.h> +#include <linux/export.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/tcp.h> +#include <net/ip_fib.h> +#include <net/nexthop.h> +#include <net/fib_rules.h> +#include <linux/indirect_call_wrapper.h> + +struct fib4_rule { + struct fib_rule common; + u8 dst_len; + u8 src_len; + u8 tos; + __be32 src; + __be32 srcmask; + __be32 dst; + __be32 dstmask; +#ifdef CONFIG_IP_ROUTE_CLASSID + u32 tclassid; +#endif +}; + +static bool fib4_rule_matchall(const struct fib_rule *rule) +{ + struct fib4_rule *r = container_of(rule, struct fib4_rule, common); + + if (r->dst_len || r->src_len || r->tos) + return false; + return fib_rule_matchall(rule); +} + +bool fib4_rule_default(const struct fib_rule *rule) +{ + if (!fib4_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL || + rule->l3mdev) + return false; + if (rule->table != RT_TABLE_LOCAL && rule->table != RT_TABLE_MAIN && + rule->table != RT_TABLE_DEFAULT) + return false; + return true; +} +EXPORT_SYMBOL_GPL(fib4_rule_default); + +int fib4_rules_dump(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + return fib_rules_dump(net, nb, AF_INET, extack); +} + +unsigned int fib4_rules_seq_read(struct net *net) +{ + return fib_rules_seq_read(net, AF_INET); +} + +int __fib_lookup(struct net *net, struct flowi4 *flp, + struct fib_result *res, unsigned int flags) +{ + struct fib_lookup_arg arg = { + .result = res, + .flags = flags, + }; + int err; + + /* update flow if oif or iif point to device enslaved to l3mdev */ + l3mdev_update_flow(net, flowi4_to_flowi(flp)); + + err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg); +#ifdef CONFIG_IP_ROUTE_CLASSID + if (arg.rule) + res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid; + else + res->tclassid = 0; +#endif + + if (err == -ESRCH) + err = -ENETUNREACH; + + return err; +} +EXPORT_SYMBOL_GPL(__fib_lookup); + +INDIRECT_CALLABLE_SCOPE int fib4_rule_action(struct fib_rule *rule, + struct flowi *flp, int flags, + struct fib_lookup_arg *arg) +{ + int err = -EAGAIN; + struct fib_table *tbl; + u32 tb_id; + + switch (rule->action) { + case FR_ACT_TO_TBL: + break; + + case FR_ACT_UNREACHABLE: + return -ENETUNREACH; + + case FR_ACT_PROHIBIT: + return -EACCES; + + case FR_ACT_BLACKHOLE: + default: + return -EINVAL; + } + + rcu_read_lock(); + + tb_id = fib_rule_get_table(rule, arg); + tbl = fib_get_table(rule->fr_net, tb_id); + if (tbl) + err = fib_table_lookup(tbl, &flp->u.ip4, + (struct fib_result *)arg->result, + arg->flags); + + rcu_read_unlock(); + return err; +} + +INDIRECT_CALLABLE_SCOPE bool fib4_rule_suppress(struct fib_rule *rule, + int flags, + struct fib_lookup_arg *arg) +{ + struct fib_result *result = (struct fib_result *) arg->result; + struct net_device *dev = NULL; + + if (result->fi) { + struct fib_nh_common *nhc = fib_info_nhc(result->fi, 0); + + dev = nhc->nhc_dev; + } + + /* do not accept result if the route does + * not meet the required prefix length + */ + if (result->prefixlen <= rule->suppress_prefixlen) + goto suppress_route; + + /* do not accept result if the route uses a device + * belonging to a forbidden interface group + */ + if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup) + goto suppress_route; + + return false; + +suppress_route: + if (!(arg->flags & FIB_LOOKUP_NOREF)) + fib_info_put(result->fi); + return true; +} + +INDIRECT_CALLABLE_SCOPE int fib4_rule_match(struct fib_rule *rule, + struct flowi *fl, int flags) +{ + struct fib4_rule *r = (struct fib4_rule *) rule; + struct flowi4 *fl4 = &fl->u.ip4; + __be32 daddr = fl4->daddr; + __be32 saddr = fl4->saddr; + + if (((saddr ^ r->src) & r->srcmask) || + ((daddr ^ r->dst) & r->dstmask)) + return 0; + + if (r->tos && (r->tos != fl4->flowi4_tos)) + return 0; + + if (rule->ip_proto && (rule->ip_proto != fl4->flowi4_proto)) + return 0; + + if (fib_rule_port_range_set(&rule->sport_range) && + !fib_rule_port_inrange(&rule->sport_range, fl4->fl4_sport)) + return 0; + + if (fib_rule_port_range_set(&rule->dport_range) && + !fib_rule_port_inrange(&rule->dport_range, fl4->fl4_dport)) + return 0; + + return 1; +} + +static struct fib_table *fib_empty_table(struct net *net) +{ + u32 id = 1; + + while (1) { + if (!fib_get_table(net, id)) + return fib_new_table(net, id); + + if (id++ == RT_TABLE_MAX) + break; + } + return NULL; +} + +static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { + FRA_GENERIC_POLICY, + [FRA_FLOW] = { .type = NLA_U32 }, +}; + +static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, + struct fib_rule_hdr *frh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + int err = -EINVAL; + struct fib4_rule *rule4 = (struct fib4_rule *) rule; + + if (frh->tos & ~IPTOS_TOS_MASK) { + NL_SET_ERR_MSG(extack, "Invalid tos"); + goto errout; + } + + /* split local/main if they are not already split */ + err = fib_unmerge(net); + if (err) + goto errout; + + if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) { + if (rule->action == FR_ACT_TO_TBL) { + struct fib_table *table; + + table = fib_empty_table(net); + if (!table) { + err = -ENOBUFS; + goto errout; + } + + rule->table = table->tb_id; + } + } + + if (frh->src_len) + rule4->src = nla_get_in_addr(tb[FRA_SRC]); + + if (frh->dst_len) + rule4->dst = nla_get_in_addr(tb[FRA_DST]); + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (tb[FRA_FLOW]) { + rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); + if (rule4->tclassid) + atomic_inc(&net->ipv4.fib_num_tclassid_users); + } +#endif + + if (fib_rule_requires_fldissect(rule)) + net->ipv4.fib_rules_require_fldissect++; + + rule4->src_len = frh->src_len; + rule4->srcmask = inet_make_mask(rule4->src_len); + rule4->dst_len = frh->dst_len; + rule4->dstmask = inet_make_mask(rule4->dst_len); + rule4->tos = frh->tos; + + net->ipv4.fib_has_custom_rules = true; + + err = 0; +errout: + return err; +} + +static int fib4_rule_delete(struct fib_rule *rule) +{ + struct net *net = rule->fr_net; + int err; + + /* split local/main if they are not already split */ + err = fib_unmerge(net); + if (err) + goto errout; + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (((struct fib4_rule *)rule)->tclassid) + atomic_dec(&net->ipv4.fib_num_tclassid_users); +#endif + net->ipv4.fib_has_custom_rules = true; + + if (net->ipv4.fib_rules_require_fldissect && + fib_rule_requires_fldissect(rule)) + net->ipv4.fib_rules_require_fldissect--; +errout: + return err; +} + +static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, + struct nlattr **tb) +{ + struct fib4_rule *rule4 = (struct fib4_rule *) rule; + + if (frh->src_len && (rule4->src_len != frh->src_len)) + return 0; + + if (frh->dst_len && (rule4->dst_len != frh->dst_len)) + return 0; + + if (frh->tos && (rule4->tos != frh->tos)) + return 0; + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) + return 0; +#endif + + if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC]))) + return 0; + + if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST]))) + return 0; + + return 1; +} + +static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, + struct fib_rule_hdr *frh) +{ + struct fib4_rule *rule4 = (struct fib4_rule *) rule; + + frh->dst_len = rule4->dst_len; + frh->src_len = rule4->src_len; + frh->tos = rule4->tos; + + if ((rule4->dst_len && + nla_put_in_addr(skb, FRA_DST, rule4->dst)) || + (rule4->src_len && + nla_put_in_addr(skb, FRA_SRC, rule4->src))) + goto nla_put_failure; +#ifdef CONFIG_IP_ROUTE_CLASSID + if (rule4->tclassid && + nla_put_u32(skb, FRA_FLOW, rule4->tclassid)) + goto nla_put_failure; +#endif + return 0; + +nla_put_failure: + return -ENOBUFS; +} + +static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) +{ + return nla_total_size(4) /* dst */ + + nla_total_size(4) /* src */ + + nla_total_size(4); /* flow */ +} + +static void fib4_rule_flush_cache(struct fib_rules_ops *ops) +{ + rt_cache_flush(ops->fro_net); +} + +static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = { + .family = AF_INET, + .rule_size = sizeof(struct fib4_rule), + .addr_size = sizeof(u32), + .action = fib4_rule_action, + .suppress = fib4_rule_suppress, + .match = fib4_rule_match, + .configure = fib4_rule_configure, + .delete = fib4_rule_delete, + .compare = fib4_rule_compare, + .fill = fib4_rule_fill, + .nlmsg_payload = fib4_rule_nlmsg_payload, + .flush_cache = fib4_rule_flush_cache, + .nlgroup = RTNLGRP_IPV4_RULE, + .policy = fib4_rule_policy, + .owner = THIS_MODULE, +}; + +static int fib_default_rules_init(struct fib_rules_ops *ops) +{ + int err; + + err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0); + if (err < 0) + return err; + err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0); + if (err < 0) + return err; + err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0); + if (err < 0) + return err; + return 0; +} + +int __net_init fib4_rules_init(struct net *net) +{ + int err; + struct fib_rules_ops *ops; + + ops = fib_rules_register(&fib4_rules_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + + err = fib_default_rules_init(ops); + if (err < 0) + goto fail; + net->ipv4.rules_ops = ops; + net->ipv4.fib_has_custom_rules = false; + net->ipv4.fib_rules_require_fldissect = 0; + return 0; + +fail: + /* also cleans all rules already added */ + fib_rules_unregister(ops); + return err; +} + +void __net_exit fib4_rules_exit(struct net *net) +{ + fib_rules_unregister(net->ipv4.rules_ops); +} diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c new file mode 100644 index 000000000..bb5255178 --- /dev/null +++ b/net/ipv4/fib_semantics.c @@ -0,0 +1,2290 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IPv4 Forwarding Information Base: semantics. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + */ + +#include <linux/uaccess.h> +#include <linux/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/proc_fs.h> +#include <linux/skbuff.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/netlink.h> +#include <linux/hash.h> +#include <linux/nospec.h> + +#include <net/arp.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/route.h> +#include <net/tcp.h> +#include <net/sock.h> +#include <net/ip_fib.h> +#include <net/ip6_fib.h> +#include <net/nexthop.h> +#include <net/netlink.h> +#include <net/rtnh.h> +#include <net/lwtunnel.h> +#include <net/fib_notifier.h> +#include <net/addrconf.h> + +#include "fib_lookup.h" + +static DEFINE_SPINLOCK(fib_info_lock); +static struct hlist_head *fib_info_hash; +static struct hlist_head *fib_info_laddrhash; +static unsigned int fib_info_hash_size; +static unsigned int fib_info_cnt; + +#define DEVINDEX_HASHBITS 8 +#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) +static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; + +/* for_nexthops and change_nexthops only used when nexthop object + * is not set in a fib_info. The logic within can reference fib_nh. + */ +#ifdef CONFIG_IP_ROUTE_MULTIPATH + +#define for_nexthops(fi) { \ + int nhsel; const struct fib_nh *nh; \ + for (nhsel = 0, nh = (fi)->fib_nh; \ + nhsel < fib_info_num_path((fi)); \ + nh++, nhsel++) + +#define change_nexthops(fi) { \ + int nhsel; struct fib_nh *nexthop_nh; \ + for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ + nhsel < fib_info_num_path((fi)); \ + nexthop_nh++, nhsel++) + +#else /* CONFIG_IP_ROUTE_MULTIPATH */ + +/* Hope, that gcc will optimize it to get rid of dummy loop */ + +#define for_nexthops(fi) { \ + int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \ + for (nhsel = 0; nhsel < 1; nhsel++) + +#define change_nexthops(fi) { \ + int nhsel; \ + struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ + for (nhsel = 0; nhsel < 1; nhsel++) + +#endif /* CONFIG_IP_ROUTE_MULTIPATH */ + +#define endfor_nexthops(fi) } + + +const struct fib_prop fib_props[RTN_MAX + 1] = { + [RTN_UNSPEC] = { + .error = 0, + .scope = RT_SCOPE_NOWHERE, + }, + [RTN_UNICAST] = { + .error = 0, + .scope = RT_SCOPE_UNIVERSE, + }, + [RTN_LOCAL] = { + .error = 0, + .scope = RT_SCOPE_HOST, + }, + [RTN_BROADCAST] = { + .error = 0, + .scope = RT_SCOPE_LINK, + }, + [RTN_ANYCAST] = { + .error = 0, + .scope = RT_SCOPE_LINK, + }, + [RTN_MULTICAST] = { + .error = 0, + .scope = RT_SCOPE_UNIVERSE, + }, + [RTN_BLACKHOLE] = { + .error = -EINVAL, + .scope = RT_SCOPE_UNIVERSE, + }, + [RTN_UNREACHABLE] = { + .error = -EHOSTUNREACH, + .scope = RT_SCOPE_UNIVERSE, + }, + [RTN_PROHIBIT] = { + .error = -EACCES, + .scope = RT_SCOPE_UNIVERSE, + }, + [RTN_THROW] = { + .error = -EAGAIN, + .scope = RT_SCOPE_UNIVERSE, + }, + [RTN_NAT] = { + .error = -EINVAL, + .scope = RT_SCOPE_NOWHERE, + }, + [RTN_XRESOLVE] = { + .error = -EINVAL, + .scope = RT_SCOPE_NOWHERE, + }, +}; + +static void rt_fibinfo_free(struct rtable __rcu **rtp) +{ + struct rtable *rt = rcu_dereference_protected(*rtp, 1); + + if (!rt) + return; + + /* Not even needed : RCU_INIT_POINTER(*rtp, NULL); + * because we waited an RCU grace period before calling + * free_fib_info_rcu() + */ + + dst_dev_put(&rt->dst); + dst_release_immediate(&rt->dst); +} + +static void free_nh_exceptions(struct fib_nh_common *nhc) +{ + struct fnhe_hash_bucket *hash; + int i; + + hash = rcu_dereference_protected(nhc->nhc_exceptions, 1); + if (!hash) + return; + for (i = 0; i < FNHE_HASH_SIZE; i++) { + struct fib_nh_exception *fnhe; + + fnhe = rcu_dereference_protected(hash[i].chain, 1); + while (fnhe) { + struct fib_nh_exception *next; + + next = rcu_dereference_protected(fnhe->fnhe_next, 1); + + rt_fibinfo_free(&fnhe->fnhe_rth_input); + rt_fibinfo_free(&fnhe->fnhe_rth_output); + + kfree(fnhe); + + fnhe = next; + } + } + kfree(hash); +} + +static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp) +{ + int cpu; + + if (!rtp) + return; + + for_each_possible_cpu(cpu) { + struct rtable *rt; + + rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1); + if (rt) { + dst_dev_put(&rt->dst); + dst_release_immediate(&rt->dst); + } + } + free_percpu(rtp); +} + +void fib_nh_common_release(struct fib_nh_common *nhc) +{ + if (nhc->nhc_dev) + dev_put(nhc->nhc_dev); + + lwtstate_put(nhc->nhc_lwtstate); + rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output); + rt_fibinfo_free(&nhc->nhc_rth_input); + free_nh_exceptions(nhc); +} +EXPORT_SYMBOL_GPL(fib_nh_common_release); + +void fib_nh_release(struct net *net, struct fib_nh *fib_nh) +{ +#ifdef CONFIG_IP_ROUTE_CLASSID + if (fib_nh->nh_tclassid) + atomic_dec(&net->ipv4.fib_num_tclassid_users); +#endif + fib_nh_common_release(&fib_nh->nh_common); +} + +/* Release a nexthop info record */ +static void free_fib_info_rcu(struct rcu_head *head) +{ + struct fib_info *fi = container_of(head, struct fib_info, rcu); + + if (fi->nh) { + nexthop_put(fi->nh); + } else { + change_nexthops(fi) { + fib_nh_release(fi->fib_net, nexthop_nh); + } endfor_nexthops(fi); + } + + ip_fib_metrics_put(fi->fib_metrics); + + kfree(fi); +} + +void free_fib_info(struct fib_info *fi) +{ + if (fi->fib_dead == 0) { + pr_warn("Freeing alive fib_info %p\n", fi); + return; + } + + call_rcu(&fi->rcu, free_fib_info_rcu); +} +EXPORT_SYMBOL_GPL(free_fib_info); + +void fib_release_info(struct fib_info *fi) +{ + spin_lock_bh(&fib_info_lock); + if (fi && --fi->fib_treeref == 0) { + hlist_del(&fi->fib_hash); + + /* Paired with READ_ONCE() in fib_create_info(). */ + WRITE_ONCE(fib_info_cnt, fib_info_cnt - 1); + + if (fi->fib_prefsrc) + hlist_del(&fi->fib_lhash); + if (fi->nh) { + list_del(&fi->nh_list); + } else { + change_nexthops(fi) { + if (!nexthop_nh->fib_nh_dev) + continue; + hlist_del(&nexthop_nh->nh_hash); + } endfor_nexthops(fi) + } + /* Paired with READ_ONCE() from fib_table_lookup() */ + WRITE_ONCE(fi->fib_dead, 1); + fib_info_put(fi); + } + spin_unlock_bh(&fib_info_lock); +} + +static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi) +{ + const struct fib_nh *onh; + + if (fi->nh || ofi->nh) + return nexthop_cmp(fi->nh, ofi->nh) ? 0 : -1; + + if (ofi->fib_nhs == 0) + return 0; + + for_nexthops(fi) { + onh = fib_info_nh(ofi, nhsel); + + if (nh->fib_nh_oif != onh->fib_nh_oif || + nh->fib_nh_gw_family != onh->fib_nh_gw_family || + nh->fib_nh_scope != onh->fib_nh_scope || +#ifdef CONFIG_IP_ROUTE_MULTIPATH + nh->fib_nh_weight != onh->fib_nh_weight || +#endif +#ifdef CONFIG_IP_ROUTE_CLASSID + nh->nh_tclassid != onh->nh_tclassid || +#endif + lwtunnel_cmp_encap(nh->fib_nh_lws, onh->fib_nh_lws) || + ((nh->fib_nh_flags ^ onh->fib_nh_flags) & ~RTNH_COMPARE_MASK)) + return -1; + + if (nh->fib_nh_gw_family == AF_INET && + nh->fib_nh_gw4 != onh->fib_nh_gw4) + return -1; + + if (nh->fib_nh_gw_family == AF_INET6 && + ipv6_addr_cmp(&nh->fib_nh_gw6, &onh->fib_nh_gw6)) + return -1; + } endfor_nexthops(fi); + return 0; +} + +static inline unsigned int fib_devindex_hashfn(unsigned int val) +{ + return hash_32(val, DEVINDEX_HASHBITS); +} + +static struct hlist_head * +fib_info_devhash_bucket(const struct net_device *dev) +{ + u32 val = net_hash_mix(dev_net(dev)) ^ dev->ifindex; + + return &fib_info_devhash[fib_devindex_hashfn(val)]; +} + +static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope, + u32 prefsrc, u32 priority) +{ + unsigned int val = init_val; + + val ^= (protocol << 8) | scope; + val ^= prefsrc; + val ^= priority; + + return val; +} + +static unsigned int fib_info_hashfn_result(unsigned int val) +{ + unsigned int mask = (fib_info_hash_size - 1); + + return (val ^ (val >> 7) ^ (val >> 12)) & mask; +} + +static inline unsigned int fib_info_hashfn(struct fib_info *fi) +{ + unsigned int val; + + val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol, + fi->fib_scope, (__force u32)fi->fib_prefsrc, + fi->fib_priority); + + if (fi->nh) { + val ^= fib_devindex_hashfn(fi->nh->id); + } else { + for_nexthops(fi) { + val ^= fib_devindex_hashfn(nh->fib_nh_oif); + } endfor_nexthops(fi) + } + + return fib_info_hashfn_result(val); +} + +/* no metrics, only nexthop id */ +static struct fib_info *fib_find_info_nh(struct net *net, + const struct fib_config *cfg) +{ + struct hlist_head *head; + struct fib_info *fi; + unsigned int hash; + + hash = fib_info_hashfn_1(fib_devindex_hashfn(cfg->fc_nh_id), + cfg->fc_protocol, cfg->fc_scope, + (__force u32)cfg->fc_prefsrc, + cfg->fc_priority); + hash = fib_info_hashfn_result(hash); + head = &fib_info_hash[hash]; + + hlist_for_each_entry(fi, head, fib_hash) { + if (!net_eq(fi->fib_net, net)) + continue; + if (!fi->nh || fi->nh->id != cfg->fc_nh_id) + continue; + if (cfg->fc_protocol == fi->fib_protocol && + cfg->fc_scope == fi->fib_scope && + cfg->fc_prefsrc == fi->fib_prefsrc && + cfg->fc_priority == fi->fib_priority && + cfg->fc_type == fi->fib_type && + cfg->fc_table == fi->fib_tb_id && + !((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK)) + return fi; + } + + return NULL; +} + +static struct fib_info *fib_find_info(struct fib_info *nfi) +{ + struct hlist_head *head; + struct fib_info *fi; + unsigned int hash; + + hash = fib_info_hashfn(nfi); + head = &fib_info_hash[hash]; + + hlist_for_each_entry(fi, head, fib_hash) { + if (!net_eq(fi->fib_net, nfi->fib_net)) + continue; + if (fi->fib_nhs != nfi->fib_nhs) + continue; + if (nfi->fib_protocol == fi->fib_protocol && + nfi->fib_scope == fi->fib_scope && + nfi->fib_prefsrc == fi->fib_prefsrc && + nfi->fib_priority == fi->fib_priority && + nfi->fib_type == fi->fib_type && + nfi->fib_tb_id == fi->fib_tb_id && + memcmp(nfi->fib_metrics, fi->fib_metrics, + sizeof(u32) * RTAX_MAX) == 0 && + !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) && + nh_comp(fi, nfi) == 0) + return fi; + } + + return NULL; +} + +/* Check, that the gateway is already configured. + * Used only by redirect accept routine. + */ +int ip_fib_check_default(__be32 gw, struct net_device *dev) +{ + struct hlist_head *head; + struct fib_nh *nh; + + spin_lock(&fib_info_lock); + + head = fib_info_devhash_bucket(dev); + + hlist_for_each_entry(nh, head, nh_hash) { + if (nh->fib_nh_dev == dev && + nh->fib_nh_gw4 == gw && + !(nh->fib_nh_flags & RTNH_F_DEAD)) { + spin_unlock(&fib_info_lock); + return 0; + } + } + + spin_unlock(&fib_info_lock); + + return -1; +} + +static inline size_t fib_nlmsg_size(struct fib_info *fi) +{ + size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) + + nla_total_size(4) /* RTA_TABLE */ + + nla_total_size(4) /* RTA_DST */ + + nla_total_size(4) /* RTA_PRIORITY */ + + nla_total_size(4) /* RTA_PREFSRC */ + + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */ + unsigned int nhs = fib_info_num_path(fi); + + /* space for nested metrics */ + payload += nla_total_size((RTAX_MAX * nla_total_size(4))); + + if (fi->nh) + payload += nla_total_size(4); /* RTA_NH_ID */ + + if (nhs) { + size_t nh_encapsize = 0; + /* Also handles the special case nhs == 1 */ + + /* each nexthop is packed in an attribute */ + size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); + unsigned int i; + + /* may contain flow and gateway attribute */ + nhsize += 2 * nla_total_size(4); + + /* grab encap info */ + for (i = 0; i < fib_info_num_path(fi); i++) { + struct fib_nh_common *nhc = fib_info_nhc(fi, i); + + if (nhc->nhc_lwtstate) { + /* RTA_ENCAP_TYPE */ + nh_encapsize += lwtunnel_get_encap_size( + nhc->nhc_lwtstate); + /* RTA_ENCAP */ + nh_encapsize += nla_total_size(2); + } + } + + /* all nexthops are packed in a nested attribute */ + payload += nla_total_size((nhs * nhsize) + nh_encapsize); + + } + + return payload; +} + +void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, + int dst_len, u32 tb_id, const struct nl_info *info, + unsigned int nlm_flags) +{ + struct fib_rt_info fri; + struct sk_buff *skb; + u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; + int err = -ENOBUFS; + + skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); + if (!skb) + goto errout; + + fri.fi = fa->fa_info; + fri.tb_id = tb_id; + fri.dst = key; + fri.dst_len = dst_len; + fri.tos = fa->fa_tos; + fri.type = fa->fa_type; + fri.offload = fa->offload; + fri.trap = fa->trap; + err = fib_dump_info(skb, info->portid, seq, event, &fri, nlm_flags); + if (err < 0) { + /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE, + info->nlh, GFP_KERNEL); + return; +errout: + if (err < 0) + rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err); +} + +static int fib_detect_death(struct fib_info *fi, int order, + struct fib_info **last_resort, int *last_idx, + int dflt) +{ + const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); + struct neighbour *n; + int state = NUD_NONE; + + if (likely(nhc->nhc_gw_family == AF_INET)) + n = neigh_lookup(&arp_tbl, &nhc->nhc_gw.ipv4, nhc->nhc_dev); + else if (nhc->nhc_gw_family == AF_INET6) + n = neigh_lookup(ipv6_stub->nd_tbl, &nhc->nhc_gw.ipv6, + nhc->nhc_dev); + else + n = NULL; + + if (n) { + state = n->nud_state; + neigh_release(n); + } else { + return 0; + } + if (state == NUD_REACHABLE) + return 0; + if ((state & NUD_VALID) && order != dflt) + return 0; + if ((state & NUD_VALID) || + (*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) { + *last_resort = fi; + *last_idx = order; + } + return 1; +} + +int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc, + struct nlattr *encap, u16 encap_type, + void *cfg, gfp_t gfp_flags, + struct netlink_ext_ack *extack) +{ + int err; + + nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *, + gfp_flags); + if (!nhc->nhc_pcpu_rth_output) + return -ENOMEM; + + if (encap) { + struct lwtunnel_state *lwtstate; + + if (encap_type == LWTUNNEL_ENCAP_NONE) { + NL_SET_ERR_MSG(extack, "LWT encap type not specified"); + err = -EINVAL; + goto lwt_failure; + } + err = lwtunnel_build_state(net, encap_type, encap, + nhc->nhc_family, cfg, &lwtstate, + extack); + if (err) + goto lwt_failure; + + nhc->nhc_lwtstate = lwtstate_get(lwtstate); + } + + return 0; + +lwt_failure: + rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output); + nhc->nhc_pcpu_rth_output = NULL; + return err; +} +EXPORT_SYMBOL_GPL(fib_nh_common_init); + +int fib_nh_init(struct net *net, struct fib_nh *nh, + struct fib_config *cfg, int nh_weight, + struct netlink_ext_ack *extack) +{ + int err; + + nh->fib_nh_family = AF_INET; + + err = fib_nh_common_init(net, &nh->nh_common, cfg->fc_encap, + cfg->fc_encap_type, cfg, GFP_KERNEL, extack); + if (err) + return err; + + nh->fib_nh_oif = cfg->fc_oif; + nh->fib_nh_gw_family = cfg->fc_gw_family; + if (cfg->fc_gw_family == AF_INET) + nh->fib_nh_gw4 = cfg->fc_gw4; + else if (cfg->fc_gw_family == AF_INET6) + nh->fib_nh_gw6 = cfg->fc_gw6; + + nh->fib_nh_flags = cfg->fc_flags; + +#ifdef CONFIG_IP_ROUTE_CLASSID + nh->nh_tclassid = cfg->fc_flow; + if (nh->nh_tclassid) + atomic_inc(&net->ipv4.fib_num_tclassid_users); +#endif +#ifdef CONFIG_IP_ROUTE_MULTIPATH + nh->fib_nh_weight = nh_weight; +#endif + return 0; +} + +#ifdef CONFIG_IP_ROUTE_MULTIPATH + +static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining, + struct netlink_ext_ack *extack) +{ + int nhs = 0; + + while (rtnh_ok(rtnh, remaining)) { + nhs++; + rtnh = rtnh_next(rtnh, &remaining); + } + + /* leftover implies invalid nexthop configuration, discard it */ + if (remaining > 0) { + NL_SET_ERR_MSG(extack, + "Invalid nexthop configuration - extra data after nexthops"); + nhs = 0; + } + + return nhs; +} + +static int fib_gw_from_attr(__be32 *gw, struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + if (nla_len(nla) < sizeof(*gw)) { + NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_GATEWAY"); + return -EINVAL; + } + + *gw = nla_get_in_addr(nla); + + return 0; +} + +/* only called when fib_nh is integrated into fib_info */ +static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, + int remaining, struct fib_config *cfg, + struct netlink_ext_ack *extack) +{ + struct net *net = fi->fib_net; + struct fib_config fib_cfg; + struct fib_nh *nh; + int ret; + + change_nexthops(fi) { + int attrlen; + + memset(&fib_cfg, 0, sizeof(fib_cfg)); + + if (!rtnh_ok(rtnh, remaining)) { + NL_SET_ERR_MSG(extack, + "Invalid nexthop configuration - extra data after nexthop"); + return -EINVAL; + } + + if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { + NL_SET_ERR_MSG(extack, + "Invalid flags for nexthop - can not contain DEAD or LINKDOWN"); + return -EINVAL; + } + + fib_cfg.fc_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; + fib_cfg.fc_oif = rtnh->rtnh_ifindex; + + attrlen = rtnh_attrlen(rtnh); + if (attrlen > 0) { + struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); + + nla = nla_find(attrs, attrlen, RTA_GATEWAY); + nlav = nla_find(attrs, attrlen, RTA_VIA); + if (nla && nlav) { + NL_SET_ERR_MSG(extack, + "Nexthop configuration can not contain both GATEWAY and VIA"); + return -EINVAL; + } + if (nla) { + ret = fib_gw_from_attr(&fib_cfg.fc_gw4, nla, + extack); + if (ret) + goto errout; + + if (fib_cfg.fc_gw4) + fib_cfg.fc_gw_family = AF_INET; + } else if (nlav) { + ret = fib_gw_from_via(&fib_cfg, nlav, extack); + if (ret) + goto errout; + } + + nla = nla_find(attrs, attrlen, RTA_FLOW); + if (nla) { + if (nla_len(nla) < sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW"); + return -EINVAL; + } + fib_cfg.fc_flow = nla_get_u32(nla); + } + + fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); + /* RTA_ENCAP_TYPE length checked in + * lwtunnel_valid_encap_type_attr + */ + nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); + if (nla) + fib_cfg.fc_encap_type = nla_get_u16(nla); + } + + ret = fib_nh_init(net, nexthop_nh, &fib_cfg, + rtnh->rtnh_hops + 1, extack); + if (ret) + goto errout; + + rtnh = rtnh_next(rtnh, &remaining); + } endfor_nexthops(fi); + + ret = -EINVAL; + nh = fib_info_nh(fi, 0); + if (cfg->fc_oif && nh->fib_nh_oif != cfg->fc_oif) { + NL_SET_ERR_MSG(extack, + "Nexthop device index does not match RTA_OIF"); + goto errout; + } + if (cfg->fc_gw_family) { + if (cfg->fc_gw_family != nh->fib_nh_gw_family || + (cfg->fc_gw_family == AF_INET && + nh->fib_nh_gw4 != cfg->fc_gw4) || + (cfg->fc_gw_family == AF_INET6 && + ipv6_addr_cmp(&nh->fib_nh_gw6, &cfg->fc_gw6))) { + NL_SET_ERR_MSG(extack, + "Nexthop gateway does not match RTA_GATEWAY or RTA_VIA"); + goto errout; + } + } +#ifdef CONFIG_IP_ROUTE_CLASSID + if (cfg->fc_flow && nh->nh_tclassid != cfg->fc_flow) { + NL_SET_ERR_MSG(extack, + "Nexthop class id does not match RTA_FLOW"); + goto errout; + } +#endif + ret = 0; +errout: + return ret; +} + +/* only called when fib_nh is integrated into fib_info */ +static void fib_rebalance(struct fib_info *fi) +{ + int total; + int w; + + if (fib_info_num_path(fi) < 2) + return; + + total = 0; + for_nexthops(fi) { + if (nh->fib_nh_flags & RTNH_F_DEAD) + continue; + + if (ip_ignore_linkdown(nh->fib_nh_dev) && + nh->fib_nh_flags & RTNH_F_LINKDOWN) + continue; + + total += nh->fib_nh_weight; + } endfor_nexthops(fi); + + w = 0; + change_nexthops(fi) { + int upper_bound; + + if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) { + upper_bound = -1; + } else if (ip_ignore_linkdown(nexthop_nh->fib_nh_dev) && + nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) { + upper_bound = -1; + } else { + w += nexthop_nh->fib_nh_weight; + upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, + total) - 1; + } + + atomic_set(&nexthop_nh->fib_nh_upper_bound, upper_bound); + } endfor_nexthops(fi); +} +#else /* CONFIG_IP_ROUTE_MULTIPATH */ + +static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, + int remaining, struct fib_config *cfg, + struct netlink_ext_ack *extack) +{ + NL_SET_ERR_MSG(extack, "Multipath support not enabled in kernel"); + + return -EINVAL; +} + +#define fib_rebalance(fi) do { } while (0) + +#endif /* CONFIG_IP_ROUTE_MULTIPATH */ + +static int fib_encap_match(struct net *net, u16 encap_type, + struct nlattr *encap, + const struct fib_nh *nh, + const struct fib_config *cfg, + struct netlink_ext_ack *extack) +{ + struct lwtunnel_state *lwtstate; + int ret, result = 0; + + if (encap_type == LWTUNNEL_ENCAP_NONE) + return 0; + + ret = lwtunnel_build_state(net, encap_type, encap, AF_INET, + cfg, &lwtstate, extack); + if (!ret) { + result = lwtunnel_cmp_encap(lwtstate, nh->fib_nh_lws); + lwtstate_free(lwtstate); + } + + return result; +} + +int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, + struct netlink_ext_ack *extack) +{ +#ifdef CONFIG_IP_ROUTE_MULTIPATH + struct rtnexthop *rtnh; + int remaining; +#endif + + if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) + return 1; + + if (cfg->fc_nh_id) { + if (fi->nh && cfg->fc_nh_id == fi->nh->id) + return 0; + return 1; + } + + if (fi->nh) { + if (cfg->fc_oif || cfg->fc_gw_family || cfg->fc_mp) + return 1; + return 0; + } + + if (cfg->fc_oif || cfg->fc_gw_family) { + struct fib_nh *nh; + + nh = fib_info_nh(fi, 0); + if (cfg->fc_encap) { + if (fib_encap_match(net, cfg->fc_encap_type, + cfg->fc_encap, nh, cfg, extack)) + return 1; + } +#ifdef CONFIG_IP_ROUTE_CLASSID + if (cfg->fc_flow && + cfg->fc_flow != nh->nh_tclassid) + return 1; +#endif + if ((cfg->fc_oif && cfg->fc_oif != nh->fib_nh_oif) || + (cfg->fc_gw_family && + cfg->fc_gw_family != nh->fib_nh_gw_family)) + return 1; + + if (cfg->fc_gw_family == AF_INET && + cfg->fc_gw4 != nh->fib_nh_gw4) + return 1; + + if (cfg->fc_gw_family == AF_INET6 && + ipv6_addr_cmp(&cfg->fc_gw6, &nh->fib_nh_gw6)) + return 1; + + return 0; + } + +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (!cfg->fc_mp) + return 0; + + rtnh = cfg->fc_mp; + remaining = cfg->fc_mp_len; + + for_nexthops(fi) { + int attrlen; + + if (!rtnh_ok(rtnh, remaining)) + return -EINVAL; + + if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->fib_nh_oif) + return 1; + + attrlen = rtnh_attrlen(rtnh); + if (attrlen > 0) { + struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); + int err; + + nla = nla_find(attrs, attrlen, RTA_GATEWAY); + nlav = nla_find(attrs, attrlen, RTA_VIA); + if (nla && nlav) { + NL_SET_ERR_MSG(extack, + "Nexthop configuration can not contain both GATEWAY and VIA"); + return -EINVAL; + } + + if (nla) { + __be32 gw; + + err = fib_gw_from_attr(&gw, nla, extack); + if (err) + return err; + + if (nh->fib_nh_gw_family != AF_INET || + gw != nh->fib_nh_gw4) + return 1; + } else if (nlav) { + struct fib_config cfg2; + + err = fib_gw_from_via(&cfg2, nlav, extack); + if (err) + return err; + + switch (nh->fib_nh_gw_family) { + case AF_INET: + if (cfg2.fc_gw_family != AF_INET || + cfg2.fc_gw4 != nh->fib_nh_gw4) + return 1; + break; + case AF_INET6: + if (cfg2.fc_gw_family != AF_INET6 || + ipv6_addr_cmp(&cfg2.fc_gw6, + &nh->fib_nh_gw6)) + return 1; + break; + } + } + +#ifdef CONFIG_IP_ROUTE_CLASSID + nla = nla_find(attrs, attrlen, RTA_FLOW); + if (nla) { + if (nla_len(nla) < sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW"); + return -EINVAL; + } + if (nla_get_u32(nla) != nh->nh_tclassid) + return 1; + } +#endif + } + + rtnh = rtnh_next(rtnh, &remaining); + } endfor_nexthops(fi); +#endif + return 0; +} + +bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi) +{ + struct nlattr *nla; + int remaining; + + if (!cfg->fc_mx) + return true; + + nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { + int type = nla_type(nla); + u32 fi_val, val; + + if (!type) + continue; + if (type > RTAX_MAX) + return false; + + type = array_index_nospec(type, RTAX_MAX + 1); + if (type == RTAX_CC_ALGO) { + char tmp[TCP_CA_NAME_MAX]; + bool ecn_ca = false; + + nla_strlcpy(tmp, nla, sizeof(tmp)); + val = tcp_ca_get_key_by_name(fi->fib_net, tmp, &ecn_ca); + } else { + if (nla_len(nla) != sizeof(u32)) + return false; + val = nla_get_u32(nla); + } + + fi_val = fi->fib_metrics->metrics[type - 1]; + if (type == RTAX_FEATURES) + fi_val &= ~DST_FEATURE_ECN_CA; + + if (fi_val != val) + return false; + } + + return true; +} + +static int fib_check_nh_v6_gw(struct net *net, struct fib_nh *nh, + u32 table, struct netlink_ext_ack *extack) +{ + struct fib6_config cfg = { + .fc_table = table, + .fc_flags = nh->fib_nh_flags | RTF_GATEWAY, + .fc_ifindex = nh->fib_nh_oif, + .fc_gateway = nh->fib_nh_gw6, + }; + struct fib6_nh fib6_nh = {}; + int err; + + err = ipv6_stub->fib6_nh_init(net, &fib6_nh, &cfg, GFP_KERNEL, extack); + if (!err) { + nh->fib_nh_dev = fib6_nh.fib_nh_dev; + dev_hold(nh->fib_nh_dev); + nh->fib_nh_oif = nh->fib_nh_dev->ifindex; + nh->fib_nh_scope = RT_SCOPE_LINK; + + ipv6_stub->fib6_nh_release(&fib6_nh); + } + + return err; +} + +/* + * Picture + * ------- + * + * Semantics of nexthop is very messy by historical reasons. + * We have to take into account, that: + * a) gateway can be actually local interface address, + * so that gatewayed route is direct. + * b) gateway must be on-link address, possibly + * described not by an ifaddr, but also by a direct route. + * c) If both gateway and interface are specified, they should not + * contradict. + * d) If we use tunnel routes, gateway could be not on-link. + * + * Attempt to reconcile all of these (alas, self-contradictory) conditions + * results in pretty ugly and hairy code with obscure logic. + * + * I chose to generalized it instead, so that the size + * of code does not increase practically, but it becomes + * much more general. + * Every prefix is assigned a "scope" value: "host" is local address, + * "link" is direct route, + * [ ... "site" ... "interior" ... ] + * and "universe" is true gateway route with global meaning. + * + * Every prefix refers to a set of "nexthop"s (gw, oif), + * where gw must have narrower scope. This recursion stops + * when gw has LOCAL scope or if "nexthop" is declared ONLINK, + * which means that gw is forced to be on link. + * + * Code is still hairy, but now it is apparently logically + * consistent and very flexible. F.e. as by-product it allows + * to co-exists in peace independent exterior and interior + * routing processes. + * + * Normally it looks as following. + * + * {universe prefix} -> (gw, oif) [scope link] + * | + * |-> {link prefix} -> (gw, oif) [scope local] + * | + * |-> {local prefix} (terminal node) + */ +static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table, + u8 scope, struct netlink_ext_ack *extack) +{ + struct net_device *dev; + struct fib_result res; + int err = 0; + + if (nh->fib_nh_flags & RTNH_F_ONLINK) { + unsigned int addr_type; + + if (scope >= RT_SCOPE_LINK) { + NL_SET_ERR_MSG(extack, "Nexthop has invalid scope"); + return -EINVAL; + } + dev = __dev_get_by_index(net, nh->fib_nh_oif); + if (!dev) { + NL_SET_ERR_MSG(extack, "Nexthop device required for onlink"); + return -ENODEV; + } + if (!(dev->flags & IFF_UP)) { + NL_SET_ERR_MSG(extack, "Nexthop device is not up"); + return -ENETDOWN; + } + addr_type = inet_addr_type_dev_table(net, dev, nh->fib_nh_gw4); + if (addr_type != RTN_UNICAST) { + NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); + return -EINVAL; + } + if (!netif_carrier_ok(dev)) + nh->fib_nh_flags |= RTNH_F_LINKDOWN; + nh->fib_nh_dev = dev; + dev_hold(dev); + nh->fib_nh_scope = RT_SCOPE_LINK; + return 0; + } + rcu_read_lock(); + { + struct fib_table *tbl = NULL; + struct flowi4 fl4 = { + .daddr = nh->fib_nh_gw4, + .flowi4_scope = scope + 1, + .flowi4_oif = nh->fib_nh_oif, + .flowi4_iif = LOOPBACK_IFINDEX, + }; + + /* It is not necessary, but requires a bit of thinking */ + if (fl4.flowi4_scope < RT_SCOPE_LINK) + fl4.flowi4_scope = RT_SCOPE_LINK; + + if (table && table != RT_TABLE_MAIN) + tbl = fib_get_table(net, table); + + if (tbl) + err = fib_table_lookup(tbl, &fl4, &res, + FIB_LOOKUP_IGNORE_LINKSTATE | + FIB_LOOKUP_NOREF); + + /* on error or if no table given do full lookup. This + * is needed for example when nexthops are in the local + * table rather than the given table + */ + if (!tbl || err) { + err = fib_lookup(net, &fl4, &res, + FIB_LOOKUP_IGNORE_LINKSTATE); + } + + if (err) { + NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); + goto out; + } + } + + err = -EINVAL; + if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) { + NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); + goto out; + } + nh->fib_nh_scope = res.scope; + nh->fib_nh_oif = FIB_RES_OIF(res); + nh->fib_nh_dev = dev = FIB_RES_DEV(res); + if (!dev) { + NL_SET_ERR_MSG(extack, + "No egress device for nexthop gateway"); + goto out; + } + dev_hold(dev); + if (!netif_carrier_ok(dev)) + nh->fib_nh_flags |= RTNH_F_LINKDOWN; + err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN; +out: + rcu_read_unlock(); + return err; +} + +static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh, + struct netlink_ext_ack *extack) +{ + struct in_device *in_dev; + int err; + + if (nh->fib_nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) { + NL_SET_ERR_MSG(extack, + "Invalid flags for nexthop - PERVASIVE and ONLINK can not be set"); + return -EINVAL; + } + + rcu_read_lock(); + + err = -ENODEV; + in_dev = inetdev_by_index(net, nh->fib_nh_oif); + if (!in_dev) + goto out; + err = -ENETDOWN; + if (!(in_dev->dev->flags & IFF_UP)) { + NL_SET_ERR_MSG(extack, "Device for nexthop is not up"); + goto out; + } + + nh->fib_nh_dev = in_dev->dev; + dev_hold(nh->fib_nh_dev); + nh->fib_nh_scope = RT_SCOPE_LINK; + if (!netif_carrier_ok(nh->fib_nh_dev)) + nh->fib_nh_flags |= RTNH_F_LINKDOWN; + err = 0; +out: + rcu_read_unlock(); + return err; +} + +int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, + struct netlink_ext_ack *extack) +{ + int err; + + if (nh->fib_nh_gw_family == AF_INET) + err = fib_check_nh_v4_gw(net, nh, table, scope, extack); + else if (nh->fib_nh_gw_family == AF_INET6) + err = fib_check_nh_v6_gw(net, nh, table, extack); + else + err = fib_check_nh_nongw(net, nh, extack); + + return err; +} + +static inline unsigned int fib_laddr_hashfn(__be32 val) +{ + unsigned int mask = (fib_info_hash_size - 1); + + return ((__force u32)val ^ + ((__force u32)val >> 7) ^ + ((__force u32)val >> 14)) & mask; +} + +static struct hlist_head *fib_info_hash_alloc(int bytes) +{ + if (bytes <= PAGE_SIZE) + return kzalloc(bytes, GFP_KERNEL); + else + return (struct hlist_head *) + __get_free_pages(GFP_KERNEL | __GFP_ZERO, + get_order(bytes)); +} + +static void fib_info_hash_free(struct hlist_head *hash, int bytes) +{ + if (!hash) + return; + + if (bytes <= PAGE_SIZE) + kfree(hash); + else + free_pages((unsigned long) hash, get_order(bytes)); +} + +static void fib_info_hash_move(struct hlist_head *new_info_hash, + struct hlist_head *new_laddrhash, + unsigned int new_size) +{ + struct hlist_head *old_info_hash, *old_laddrhash; + unsigned int old_size = fib_info_hash_size; + unsigned int i, bytes; + + spin_lock_bh(&fib_info_lock); + old_info_hash = fib_info_hash; + old_laddrhash = fib_info_laddrhash; + fib_info_hash_size = new_size; + + for (i = 0; i < old_size; i++) { + struct hlist_head *head = &fib_info_hash[i]; + struct hlist_node *n; + struct fib_info *fi; + + hlist_for_each_entry_safe(fi, n, head, fib_hash) { + struct hlist_head *dest; + unsigned int new_hash; + + new_hash = fib_info_hashfn(fi); + dest = &new_info_hash[new_hash]; + hlist_add_head(&fi->fib_hash, dest); + } + } + fib_info_hash = new_info_hash; + + for (i = 0; i < old_size; i++) { + struct hlist_head *lhead = &fib_info_laddrhash[i]; + struct hlist_node *n; + struct fib_info *fi; + + hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) { + struct hlist_head *ldest; + unsigned int new_hash; + + new_hash = fib_laddr_hashfn(fi->fib_prefsrc); + ldest = &new_laddrhash[new_hash]; + hlist_add_head(&fi->fib_lhash, ldest); + } + } + fib_info_laddrhash = new_laddrhash; + + spin_unlock_bh(&fib_info_lock); + + bytes = old_size * sizeof(struct hlist_head *); + fib_info_hash_free(old_info_hash, bytes); + fib_info_hash_free(old_laddrhash, bytes); +} + +__be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc, + unsigned char scope) +{ + struct fib_nh *nh; + __be32 saddr; + + if (nhc->nhc_family != AF_INET) + return inet_select_addr(nhc->nhc_dev, 0, scope); + + nh = container_of(nhc, struct fib_nh, nh_common); + saddr = inet_select_addr(nh->fib_nh_dev, nh->fib_nh_gw4, scope); + + WRITE_ONCE(nh->nh_saddr, saddr); + WRITE_ONCE(nh->nh_saddr_genid, atomic_read(&net->ipv4.dev_addr_genid)); + + return saddr; +} + +__be32 fib_result_prefsrc(struct net *net, struct fib_result *res) +{ + struct fib_nh_common *nhc = res->nhc; + + if (res->fi->fib_prefsrc) + return res->fi->fib_prefsrc; + + if (nhc->nhc_family == AF_INET) { + struct fib_nh *nh; + + nh = container_of(nhc, struct fib_nh, nh_common); + if (READ_ONCE(nh->nh_saddr_genid) == + atomic_read(&net->ipv4.dev_addr_genid)) + return READ_ONCE(nh->nh_saddr); + } + + return fib_info_update_nhc_saddr(net, nhc, res->fi->fib_scope); +} + +static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc) +{ + if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || + fib_prefsrc != cfg->fc_dst) { + u32 tb_id = cfg->fc_table; + int rc; + + if (tb_id == RT_TABLE_MAIN) + tb_id = RT_TABLE_LOCAL; + + rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net, + fib_prefsrc, tb_id); + + if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) { + rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net, + fib_prefsrc, RT_TABLE_LOCAL); + } + + if (rc != RTN_LOCAL) + return false; + } + return true; +} + +struct fib_info *fib_create_info(struct fib_config *cfg, + struct netlink_ext_ack *extack) +{ + int err; + struct fib_info *fi = NULL; + struct nexthop *nh = NULL; + struct fib_info *ofi; + int nhs = 1; + struct net *net = cfg->fc_nlinfo.nl_net; + + if (cfg->fc_type > RTN_MAX) + goto err_inval; + + /* Fast check to catch the most weird cases */ + if (fib_props[cfg->fc_type].scope > cfg->fc_scope) { + NL_SET_ERR_MSG(extack, "Invalid scope"); + goto err_inval; + } + + if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { + NL_SET_ERR_MSG(extack, + "Invalid rtm_flags - can not contain DEAD or LINKDOWN"); + goto err_inval; + } + + if (cfg->fc_nh_id) { + if (!cfg->fc_mx) { + fi = fib_find_info_nh(net, cfg); + if (fi) { + fi->fib_treeref++; + return fi; + } + } + + nh = nexthop_find_by_id(net, cfg->fc_nh_id); + if (!nh) { + NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); + goto err_inval; + } + nhs = 0; + } + +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (cfg->fc_mp) { + nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack); + if (nhs == 0) + goto err_inval; + } +#endif + + err = -ENOBUFS; + + /* Paired with WRITE_ONCE() in fib_release_info() */ + if (READ_ONCE(fib_info_cnt) >= fib_info_hash_size) { + unsigned int new_size = fib_info_hash_size << 1; + struct hlist_head *new_info_hash; + struct hlist_head *new_laddrhash; + unsigned int bytes; + + if (!new_size) + new_size = 16; + bytes = new_size * sizeof(struct hlist_head *); + new_info_hash = fib_info_hash_alloc(bytes); + new_laddrhash = fib_info_hash_alloc(bytes); + if (!new_info_hash || !new_laddrhash) { + fib_info_hash_free(new_info_hash, bytes); + fib_info_hash_free(new_laddrhash, bytes); + } else + fib_info_hash_move(new_info_hash, new_laddrhash, new_size); + + if (!fib_info_hash_size) + goto failure; + } + + fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL); + if (!fi) + goto failure; + fi->fib_metrics = ip_fib_metrics_init(fi->fib_net, cfg->fc_mx, + cfg->fc_mx_len, extack); + if (IS_ERR(fi->fib_metrics)) { + err = PTR_ERR(fi->fib_metrics); + kfree(fi); + return ERR_PTR(err); + } + + fi->fib_net = net; + fi->fib_protocol = cfg->fc_protocol; + fi->fib_scope = cfg->fc_scope; + fi->fib_flags = cfg->fc_flags; + fi->fib_priority = cfg->fc_priority; + fi->fib_prefsrc = cfg->fc_prefsrc; + fi->fib_type = cfg->fc_type; + fi->fib_tb_id = cfg->fc_table; + + fi->fib_nhs = nhs; + if (nh) { + if (!nexthop_get(nh)) { + NL_SET_ERR_MSG(extack, "Nexthop has been deleted"); + err = -EINVAL; + } else { + err = 0; + fi->nh = nh; + } + } else { + change_nexthops(fi) { + nexthop_nh->nh_parent = fi; + } endfor_nexthops(fi) + + if (cfg->fc_mp) + err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg, + extack); + else + err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack); + } + + if (err != 0) + goto failure; + + if (fib_props[cfg->fc_type].error) { + if (cfg->fc_gw_family || cfg->fc_oif || cfg->fc_mp) { + NL_SET_ERR_MSG(extack, + "Gateway, device and multipath can not be specified for this route type"); + goto err_inval; + } + goto link_it; + } else { + switch (cfg->fc_type) { + case RTN_UNICAST: + case RTN_LOCAL: + case RTN_BROADCAST: + case RTN_ANYCAST: + case RTN_MULTICAST: + break; + default: + NL_SET_ERR_MSG(extack, "Invalid route type"); + goto err_inval; + } + } + + if (cfg->fc_scope > RT_SCOPE_HOST) { + NL_SET_ERR_MSG(extack, "Invalid scope"); + goto err_inval; + } + + if (fi->nh) { + err = fib_check_nexthop(fi->nh, cfg->fc_scope, extack); + if (err) + goto failure; + } else if (cfg->fc_scope == RT_SCOPE_HOST) { + struct fib_nh *nh = fi->fib_nh; + + /* Local address is added. */ + if (nhs != 1) { + NL_SET_ERR_MSG(extack, + "Route with host scope can not have multiple nexthops"); + goto err_inval; + } + if (nh->fib_nh_gw_family) { + NL_SET_ERR_MSG(extack, + "Route with host scope can not have a gateway"); + goto err_inval; + } + nh->fib_nh_scope = RT_SCOPE_NOWHERE; + nh->fib_nh_dev = dev_get_by_index(net, nh->fib_nh_oif); + err = -ENODEV; + if (!nh->fib_nh_dev) + goto failure; + } else { + int linkdown = 0; + + change_nexthops(fi) { + err = fib_check_nh(cfg->fc_nlinfo.nl_net, nexthop_nh, + cfg->fc_table, cfg->fc_scope, + extack); + if (err != 0) + goto failure; + if (nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) + linkdown++; + } endfor_nexthops(fi) + if (linkdown == fi->fib_nhs) + fi->fib_flags |= RTNH_F_LINKDOWN; + } + + if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) { + NL_SET_ERR_MSG(extack, "Invalid prefsrc address"); + goto err_inval; + } + + if (!fi->nh) { + change_nexthops(fi) { + fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common, + fi->fib_scope); + if (nexthop_nh->fib_nh_gw_family == AF_INET6) + fi->fib_nh_is_v6 = true; + } endfor_nexthops(fi) + + fib_rebalance(fi); + } + +link_it: + ofi = fib_find_info(fi); + if (ofi) { + /* fib_table_lookup() should not see @fi yet. */ + fi->fib_dead = 1; + free_fib_info(fi); + ofi->fib_treeref++; + return ofi; + } + + fi->fib_treeref++; + refcount_set(&fi->fib_clntref, 1); + spin_lock_bh(&fib_info_lock); + fib_info_cnt++; + hlist_add_head(&fi->fib_hash, + &fib_info_hash[fib_info_hashfn(fi)]); + if (fi->fib_prefsrc) { + struct hlist_head *head; + + head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; + hlist_add_head(&fi->fib_lhash, head); + } + if (fi->nh) { + list_add(&fi->nh_list, &nh->fi_list); + } else { + change_nexthops(fi) { + struct hlist_head *head; + + if (!nexthop_nh->fib_nh_dev) + continue; + head = fib_info_devhash_bucket(nexthop_nh->fib_nh_dev); + hlist_add_head(&nexthop_nh->nh_hash, head); + } endfor_nexthops(fi) + } + spin_unlock_bh(&fib_info_lock); + return fi; + +err_inval: + err = -EINVAL; + +failure: + if (fi) { + /* fib_table_lookup() should not see @fi yet. */ + fi->fib_dead = 1; + free_fib_info(fi); + } + + return ERR_PTR(err); +} + +int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc, + u8 rt_family, unsigned char *flags, bool skip_oif) +{ + if (nhc->nhc_flags & RTNH_F_DEAD) + *flags |= RTNH_F_DEAD; + + if (nhc->nhc_flags & RTNH_F_LINKDOWN) { + *flags |= RTNH_F_LINKDOWN; + + rcu_read_lock(); + switch (nhc->nhc_family) { + case AF_INET: + if (ip_ignore_linkdown(nhc->nhc_dev)) + *flags |= RTNH_F_DEAD; + break; + case AF_INET6: + if (ip6_ignore_linkdown(nhc->nhc_dev)) + *flags |= RTNH_F_DEAD; + break; + } + rcu_read_unlock(); + } + + switch (nhc->nhc_gw_family) { + case AF_INET: + if (nla_put_in_addr(skb, RTA_GATEWAY, nhc->nhc_gw.ipv4)) + goto nla_put_failure; + break; + case AF_INET6: + /* if gateway family does not match nexthop family + * gateway is encoded as RTA_VIA + */ + if (rt_family != nhc->nhc_gw_family) { + int alen = sizeof(struct in6_addr); + struct nlattr *nla; + struct rtvia *via; + + nla = nla_reserve(skb, RTA_VIA, alen + 2); + if (!nla) + goto nla_put_failure; + + via = nla_data(nla); + via->rtvia_family = AF_INET6; + memcpy(via->rtvia_addr, &nhc->nhc_gw.ipv6, alen); + } else if (nla_put_in6_addr(skb, RTA_GATEWAY, + &nhc->nhc_gw.ipv6) < 0) { + goto nla_put_failure; + } + break; + } + + *flags |= (nhc->nhc_flags & RTNH_F_ONLINK); + if (nhc->nhc_flags & RTNH_F_OFFLOAD) + *flags |= RTNH_F_OFFLOAD; + + if (!skip_oif && nhc->nhc_dev && + nla_put_u32(skb, RTA_OIF, nhc->nhc_dev->ifindex)) + goto nla_put_failure; + + if (nhc->nhc_lwtstate && + lwtunnel_fill_encap(skb, nhc->nhc_lwtstate, + RTA_ENCAP, RTA_ENCAP_TYPE) < 0) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} +EXPORT_SYMBOL_GPL(fib_nexthop_info); + +#if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6) +int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc, + int nh_weight, u8 rt_family, u32 nh_tclassid) +{ + const struct net_device *dev = nhc->nhc_dev; + struct rtnexthop *rtnh; + unsigned char flags = 0; + + rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); + if (!rtnh) + goto nla_put_failure; + + rtnh->rtnh_hops = nh_weight - 1; + rtnh->rtnh_ifindex = dev ? dev->ifindex : 0; + + if (fib_nexthop_info(skb, nhc, rt_family, &flags, true) < 0) + goto nla_put_failure; + + rtnh->rtnh_flags = flags; + + if (nh_tclassid && nla_put_u32(skb, RTA_FLOW, nh_tclassid)) + goto nla_put_failure; + + /* length of rtnetlink header + attributes */ + rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} +EXPORT_SYMBOL_GPL(fib_add_nexthop); +#endif + +#ifdef CONFIG_IP_ROUTE_MULTIPATH +static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) +{ + struct nlattr *mp; + + mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); + if (!mp) + goto nla_put_failure; + + if (unlikely(fi->nh)) { + if (nexthop_mpath_fill_node(skb, fi->nh, AF_INET) < 0) + goto nla_put_failure; + goto mp_end; + } + + for_nexthops(fi) { + u32 nh_tclassid = 0; +#ifdef CONFIG_IP_ROUTE_CLASSID + nh_tclassid = nh->nh_tclassid; +#endif + if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight, + AF_INET, nh_tclassid) < 0) + goto nla_put_failure; + } endfor_nexthops(fi); + +mp_end: + nla_nest_end(skb, mp); + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} +#else +static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) +{ + return 0; +} +#endif + +int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, + struct fib_rt_info *fri, unsigned int flags) +{ + unsigned int nhs = fib_info_num_path(fri->fi); + struct fib_info *fi = fri->fi; + u32 tb_id = fri->tb_id; + struct nlmsghdr *nlh; + struct rtmsg *rtm; + + nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); + if (!nlh) + return -EMSGSIZE; + + rtm = nlmsg_data(nlh); + rtm->rtm_family = AF_INET; + rtm->rtm_dst_len = fri->dst_len; + rtm->rtm_src_len = 0; + rtm->rtm_tos = fri->tos; + if (tb_id < 256) + rtm->rtm_table = tb_id; + else + rtm->rtm_table = RT_TABLE_COMPAT; + if (nla_put_u32(skb, RTA_TABLE, tb_id)) + goto nla_put_failure; + rtm->rtm_type = fri->type; + rtm->rtm_flags = fi->fib_flags; + rtm->rtm_scope = fi->fib_scope; + rtm->rtm_protocol = fi->fib_protocol; + + if (rtm->rtm_dst_len && + nla_put_in_addr(skb, RTA_DST, fri->dst)) + goto nla_put_failure; + if (fi->fib_priority && + nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority)) + goto nla_put_failure; + if (rtnetlink_put_metrics(skb, fi->fib_metrics->metrics) < 0) + goto nla_put_failure; + + if (fi->fib_prefsrc && + nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc)) + goto nla_put_failure; + + if (fi->nh) { + if (nla_put_u32(skb, RTA_NH_ID, fi->nh->id)) + goto nla_put_failure; + if (nexthop_is_blackhole(fi->nh)) + rtm->rtm_type = RTN_BLACKHOLE; + if (!READ_ONCE(fi->fib_net->ipv4.sysctl_nexthop_compat_mode)) + goto offload; + } + + if (nhs == 1) { + const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); + unsigned char flags = 0; + + if (fib_nexthop_info(skb, nhc, AF_INET, &flags, false) < 0) + goto nla_put_failure; + + rtm->rtm_flags = flags; +#ifdef CONFIG_IP_ROUTE_CLASSID + if (nhc->nhc_family == AF_INET) { + struct fib_nh *nh; + + nh = container_of(nhc, struct fib_nh, nh_common); + if (nh->nh_tclassid && + nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid)) + goto nla_put_failure; + } +#endif + } else { + if (fib_add_multipath(skb, fi) < 0) + goto nla_put_failure; + } + +offload: + if (fri->offload) + rtm->rtm_flags |= RTM_F_OFFLOAD; + if (fri->trap) + rtm->rtm_flags |= RTM_F_TRAP; + + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +/* + * Update FIB if: + * - local address disappeared -> we must delete all the entries + * referring to it. + * - device went down -> we must shutdown all nexthops going via it. + */ +int fib_sync_down_addr(struct net_device *dev, __be32 local) +{ + int ret = 0; + unsigned int hash = fib_laddr_hashfn(local); + struct hlist_head *head = &fib_info_laddrhash[hash]; + int tb_id = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN; + struct net *net = dev_net(dev); + struct fib_info *fi; + + if (!fib_info_laddrhash || local == 0) + return 0; + + hlist_for_each_entry(fi, head, fib_lhash) { + if (!net_eq(fi->fib_net, net) || + fi->fib_tb_id != tb_id) + continue; + if (fi->fib_prefsrc == local) { + fi->fib_flags |= RTNH_F_DEAD; + fi->pfsrc_removed = true; + ret++; + } + } + return ret; +} + +static int call_fib_nh_notifiers(struct fib_nh *nh, + enum fib_event_type event_type) +{ + bool ignore_link_down = ip_ignore_linkdown(nh->fib_nh_dev); + struct fib_nh_notifier_info info = { + .fib_nh = nh, + }; + + switch (event_type) { + case FIB_EVENT_NH_ADD: + if (nh->fib_nh_flags & RTNH_F_DEAD) + break; + if (ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) + break; + return call_fib4_notifiers(dev_net(nh->fib_nh_dev), event_type, + &info.info); + case FIB_EVENT_NH_DEL: + if ((ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) || + (nh->fib_nh_flags & RTNH_F_DEAD)) + return call_fib4_notifiers(dev_net(nh->fib_nh_dev), + event_type, &info.info); + default: + break; + } + + return NOTIFY_DONE; +} + +/* Update the PMTU of exceptions when: + * - the new MTU of the first hop becomes smaller than the PMTU + * - the old MTU was the same as the PMTU, and it limited discovery of + * larger MTUs on the path. With that limit raised, we can now + * discover larger MTUs + * A special case is locked exceptions, for which the PMTU is smaller + * than the minimal accepted PMTU: + * - if the new MTU is greater than the PMTU, don't make any change + * - otherwise, unlock and set PMTU + */ +void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig) +{ + struct fnhe_hash_bucket *bucket; + int i; + + bucket = rcu_dereference_protected(nhc->nhc_exceptions, 1); + if (!bucket) + return; + + for (i = 0; i < FNHE_HASH_SIZE; i++) { + struct fib_nh_exception *fnhe; + + for (fnhe = rcu_dereference_protected(bucket[i].chain, 1); + fnhe; + fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) { + if (fnhe->fnhe_mtu_locked) { + if (new <= fnhe->fnhe_pmtu) { + fnhe->fnhe_pmtu = new; + fnhe->fnhe_mtu_locked = false; + } + } else if (new < fnhe->fnhe_pmtu || + orig == fnhe->fnhe_pmtu) { + fnhe->fnhe_pmtu = new; + } + } + } +} + +void fib_sync_mtu(struct net_device *dev, u32 orig_mtu) +{ + struct hlist_head *head = fib_info_devhash_bucket(dev); + struct fib_nh *nh; + + hlist_for_each_entry(nh, head, nh_hash) { + if (nh->fib_nh_dev == dev) + fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu); + } +} + +/* Event force Flags Description + * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host + * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host + * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed + * NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed + * + * only used when fib_nh is built into fib_info + */ +int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force) +{ + struct hlist_head *head = fib_info_devhash_bucket(dev); + struct fib_info *prev_fi = NULL; + int scope = RT_SCOPE_NOWHERE; + struct fib_nh *nh; + int ret = 0; + + if (force) + scope = -1; + + hlist_for_each_entry(nh, head, nh_hash) { + struct fib_info *fi = nh->nh_parent; + int dead; + + BUG_ON(!fi->fib_nhs); + if (nh->fib_nh_dev != dev || fi == prev_fi) + continue; + prev_fi = fi; + dead = 0; + change_nexthops(fi) { + if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) + dead++; + else if (nexthop_nh->fib_nh_dev == dev && + nexthop_nh->fib_nh_scope != scope) { + switch (event) { + case NETDEV_DOWN: + case NETDEV_UNREGISTER: + nexthop_nh->fib_nh_flags |= RTNH_F_DEAD; + fallthrough; + case NETDEV_CHANGE: + nexthop_nh->fib_nh_flags |= RTNH_F_LINKDOWN; + break; + } + call_fib_nh_notifiers(nexthop_nh, + FIB_EVENT_NH_DEL); + dead++; + } +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (event == NETDEV_UNREGISTER && + nexthop_nh->fib_nh_dev == dev) { + dead = fi->fib_nhs; + break; + } +#endif + } endfor_nexthops(fi) + if (dead == fi->fib_nhs) { + switch (event) { + case NETDEV_DOWN: + case NETDEV_UNREGISTER: + fi->fib_flags |= RTNH_F_DEAD; + fallthrough; + case NETDEV_CHANGE: + fi->fib_flags |= RTNH_F_LINKDOWN; + break; + } + ret++; + } + + fib_rebalance(fi); + } + + return ret; +} + +/* Must be invoked inside of an RCU protected region. */ +static void fib_select_default(const struct flowi4 *flp, struct fib_result *res) +{ + struct fib_info *fi = NULL, *last_resort = NULL; + struct hlist_head *fa_head = res->fa_head; + struct fib_table *tb = res->table; + u8 slen = 32 - res->prefixlen; + int order = -1, last_idx = -1; + struct fib_alias *fa, *fa1 = NULL; + u32 last_prio = res->fi->fib_priority; + u8 last_tos = 0; + + hlist_for_each_entry_rcu(fa, fa_head, fa_list) { + struct fib_info *next_fi = fa->fa_info; + struct fib_nh_common *nhc; + + if (fa->fa_slen != slen) + continue; + if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) + continue; + if (fa->tb_id != tb->tb_id) + continue; + if (next_fi->fib_priority > last_prio && + fa->fa_tos == last_tos) { + if (last_tos) + continue; + break; + } + if (next_fi->fib_flags & RTNH_F_DEAD) + continue; + last_tos = fa->fa_tos; + last_prio = next_fi->fib_priority; + + if (next_fi->fib_scope != res->scope || + fa->fa_type != RTN_UNICAST) + continue; + + nhc = fib_info_nhc(next_fi, 0); + if (!nhc->nhc_gw_family || nhc->nhc_scope != RT_SCOPE_LINK) + continue; + + fib_alias_accessed(fa); + + if (!fi) { + if (next_fi != res->fi) + break; + fa1 = fa; + } else if (!fib_detect_death(fi, order, &last_resort, + &last_idx, fa1->fa_default)) { + fib_result_assign(res, fi); + fa1->fa_default = order; + goto out; + } + fi = next_fi; + order++; + } + + if (order <= 0 || !fi) { + if (fa1) + fa1->fa_default = -1; + goto out; + } + + if (!fib_detect_death(fi, order, &last_resort, &last_idx, + fa1->fa_default)) { + fib_result_assign(res, fi); + fa1->fa_default = order; + goto out; + } + + if (last_idx >= 0) + fib_result_assign(res, last_resort); + fa1->fa_default = last_idx; +out: + return; +} + +/* + * Dead device goes up. We wake up dead nexthops. + * It takes sense only on multipath routes. + * + * only used when fib_nh is built into fib_info + */ +int fib_sync_up(struct net_device *dev, unsigned char nh_flags) +{ + struct fib_info *prev_fi; + struct hlist_head *head; + struct fib_nh *nh; + int ret; + + if (!(dev->flags & IFF_UP)) + return 0; + + if (nh_flags & RTNH_F_DEAD) { + unsigned int flags = dev_get_flags(dev); + + if (flags & (IFF_RUNNING | IFF_LOWER_UP)) + nh_flags |= RTNH_F_LINKDOWN; + } + + prev_fi = NULL; + head = fib_info_devhash_bucket(dev); + ret = 0; + + hlist_for_each_entry(nh, head, nh_hash) { + struct fib_info *fi = nh->nh_parent; + int alive; + + BUG_ON(!fi->fib_nhs); + if (nh->fib_nh_dev != dev || fi == prev_fi) + continue; + + prev_fi = fi; + alive = 0; + change_nexthops(fi) { + if (!(nexthop_nh->fib_nh_flags & nh_flags)) { + alive++; + continue; + } + if (!nexthop_nh->fib_nh_dev || + !(nexthop_nh->fib_nh_dev->flags & IFF_UP)) + continue; + if (nexthop_nh->fib_nh_dev != dev || + !__in_dev_get_rtnl(dev)) + continue; + alive++; + nexthop_nh->fib_nh_flags &= ~nh_flags; + call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD); + } endfor_nexthops(fi) + + if (alive > 0) { + fi->fib_flags &= ~nh_flags; + ret++; + } + + fib_rebalance(fi); + } + + return ret; +} + +#ifdef CONFIG_IP_ROUTE_MULTIPATH +static bool fib_good_nh(const struct fib_nh *nh) +{ + int state = NUD_REACHABLE; + + if (nh->fib_nh_scope == RT_SCOPE_LINK) { + struct neighbour *n; + + rcu_read_lock_bh(); + + if (likely(nh->fib_nh_gw_family == AF_INET)) + n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev, + (__force u32)nh->fib_nh_gw4); + else if (nh->fib_nh_gw_family == AF_INET6) + n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, + &nh->fib_nh_gw6); + else + n = NULL; + if (n) + state = n->nud_state; + + rcu_read_unlock_bh(); + } + + return !!(state & NUD_VALID); +} + +void fib_select_multipath(struct fib_result *res, int hash) +{ + struct fib_info *fi = res->fi; + struct net *net = fi->fib_net; + bool first = false; + + if (unlikely(res->fi->nh)) { + nexthop_path_fib_result(res, hash); + return; + } + + change_nexthops(fi) { + if (READ_ONCE(net->ipv4.sysctl_fib_multipath_use_neigh)) { + if (!fib_good_nh(nexthop_nh)) + continue; + if (!first) { + res->nh_sel = nhsel; + res->nhc = &nexthop_nh->nh_common; + first = true; + } + } + + if (hash > atomic_read(&nexthop_nh->fib_nh_upper_bound)) + continue; + + res->nh_sel = nhsel; + res->nhc = &nexthop_nh->nh_common; + return; + } endfor_nexthops(fi); +} +#endif + +void fib_select_path(struct net *net, struct fib_result *res, + struct flowi4 *fl4, const struct sk_buff *skb) +{ + if (fl4->flowi4_oif && !(fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) + goto check_saddr; + +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (fib_info_num_path(res->fi) > 1) { + int h = fib_multipath_hash(net, fl4, skb, NULL); + + fib_select_multipath(res, h); + } + else +#endif + if (!res->prefixlen && + res->table->tb_num_default > 1 && + res->type == RTN_UNICAST) + fib_select_default(fl4, res); + +check_saddr: + if (!fl4->saddr) + fl4->saddr = fib_result_prefsrc(net, res); +} diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c new file mode 100644 index 000000000..3f4f6458d --- /dev/null +++ b/net/ipv4/fib_trie.c @@ -0,0 +1,3024 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * + * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet + * & Swedish University of Agricultural Sciences. + * + * Jens Laas <jens.laas@data.slu.se> Swedish University of + * Agricultural Sciences. + * + * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet + * + * This work is based on the LPC-trie which is originally described in: + * + * An experimental study of compression methods for dynamic tries + * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002. + * https://www.csc.kth.se/~snilsson/software/dyntrie2/ + * + * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson + * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999 + * + * Code from fib_hash has been reused which includes the following header: + * + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IPv4 FIB: lookup engine and maintenance routines. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + * Substantial contributions to this work comes from: + * + * David S. Miller, <davem@davemloft.net> + * Stephen Hemminger <shemminger@osdl.org> + * Paul E. McKenney <paulmck@us.ibm.com> + * Patrick McHardy <kaber@trash.net> + */ +#include <linux/cache.h> +#include <linux/uaccess.h> +#include <linux/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/proc_fs.h> +#include <linux/rcupdate.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <linux/vmalloc.h> +#include <linux/notifier.h> +#include <net/net_namespace.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/route.h> +#include <net/tcp.h> +#include <net/sock.h> +#include <net/ip_fib.h> +#include <net/fib_notifier.h> +#include <trace/events/fib.h> +#include "fib_lookup.h" + +static int call_fib_entry_notifier(struct notifier_block *nb, + enum fib_event_type event_type, u32 dst, + int dst_len, struct fib_alias *fa, + struct netlink_ext_ack *extack) +{ + struct fib_entry_notifier_info info = { + .info.extack = extack, + .dst = dst, + .dst_len = dst_len, + .fi = fa->fa_info, + .tos = fa->fa_tos, + .type = fa->fa_type, + .tb_id = fa->tb_id, + }; + return call_fib4_notifier(nb, event_type, &info.info); +} + +static int call_fib_entry_notifiers(struct net *net, + enum fib_event_type event_type, u32 dst, + int dst_len, struct fib_alias *fa, + struct netlink_ext_ack *extack) +{ + struct fib_entry_notifier_info info = { + .info.extack = extack, + .dst = dst, + .dst_len = dst_len, + .fi = fa->fa_info, + .tos = fa->fa_tos, + .type = fa->fa_type, + .tb_id = fa->tb_id, + }; + return call_fib4_notifiers(net, event_type, &info.info); +} + +#define MAX_STAT_DEPTH 32 + +#define KEYLENGTH (8*sizeof(t_key)) +#define KEY_MAX ((t_key)~0) + +typedef unsigned int t_key; + +#define IS_TRIE(n) ((n)->pos >= KEYLENGTH) +#define IS_TNODE(n) ((n)->bits) +#define IS_LEAF(n) (!(n)->bits) + +struct key_vector { + t_key key; + unsigned char pos; /* 2log(KEYLENGTH) bits needed */ + unsigned char bits; /* 2log(KEYLENGTH) bits needed */ + unsigned char slen; + union { + /* This list pointer if valid if (pos | bits) == 0 (LEAF) */ + struct hlist_head leaf; + /* This array is valid if (pos | bits) > 0 (TNODE) */ + struct key_vector __rcu *tnode[0]; + }; +}; + +struct tnode { + struct rcu_head rcu; + t_key empty_children; /* KEYLENGTH bits needed */ + t_key full_children; /* KEYLENGTH bits needed */ + struct key_vector __rcu *parent; + struct key_vector kv[1]; +#define tn_bits kv[0].bits +}; + +#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) +#define LEAF_SIZE TNODE_SIZE(1) + +#ifdef CONFIG_IP_FIB_TRIE_STATS +struct trie_use_stats { + unsigned int gets; + unsigned int backtrack; + unsigned int semantic_match_passed; + unsigned int semantic_match_miss; + unsigned int null_node_hit; + unsigned int resize_node_skipped; +}; +#endif + +struct trie_stat { + unsigned int totdepth; + unsigned int maxdepth; + unsigned int tnodes; + unsigned int leaves; + unsigned int nullpointers; + unsigned int prefixes; + unsigned int nodesizes[MAX_STAT_DEPTH]; +}; + +struct trie { + struct key_vector kv[1]; +#ifdef CONFIG_IP_FIB_TRIE_STATS + struct trie_use_stats __percpu *stats; +#endif +}; + +static struct key_vector *resize(struct trie *t, struct key_vector *tn); +static unsigned int tnode_free_size; + +/* + * synchronize_rcu after call_rcu for outstanding dirty memory; it should be + * especially useful before resizing the root node with PREEMPT_NONE configs; + * the value was obtained experimentally, aiming to avoid visible slowdown. + */ +unsigned int sysctl_fib_sync_mem = 512 * 1024; +unsigned int sysctl_fib_sync_mem_min = 64 * 1024; +unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024; + +static struct kmem_cache *fn_alias_kmem __ro_after_init; +static struct kmem_cache *trie_leaf_kmem __ro_after_init; + +static inline struct tnode *tn_info(struct key_vector *kv) +{ + return container_of(kv, struct tnode, kv[0]); +} + +/* caller must hold RTNL */ +#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent) +#define get_child(tn, i) rtnl_dereference((tn)->tnode[i]) + +/* caller must hold RCU read lock or RTNL */ +#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent) +#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i]) + +/* wrapper for rcu_assign_pointer */ +static inline void node_set_parent(struct key_vector *n, struct key_vector *tp) +{ + if (n) + rcu_assign_pointer(tn_info(n)->parent, tp); +} + +#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p) + +/* This provides us with the number of children in this node, in the case of a + * leaf this will return 0 meaning none of the children are accessible. + */ +static inline unsigned long child_length(const struct key_vector *tn) +{ + return (1ul << tn->bits) & ~(1ul); +} + +#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos) + +static inline unsigned long get_index(t_key key, struct key_vector *kv) +{ + unsigned long index = key ^ kv->key; + + if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos)) + return 0; + + return index >> kv->pos; +} + +/* To understand this stuff, an understanding of keys and all their bits is + * necessary. Every node in the trie has a key associated with it, but not + * all of the bits in that key are significant. + * + * Consider a node 'n' and its parent 'tp'. + * + * If n is a leaf, every bit in its key is significant. Its presence is + * necessitated by path compression, since during a tree traversal (when + * searching for a leaf - unless we are doing an insertion) we will completely + * ignore all skipped bits we encounter. Thus we need to verify, at the end of + * a potentially successful search, that we have indeed been walking the + * correct key path. + * + * Note that we can never "miss" the correct key in the tree if present by + * following the wrong path. Path compression ensures that segments of the key + * that are the same for all keys with a given prefix are skipped, but the + * skipped part *is* identical for each node in the subtrie below the skipped + * bit! trie_insert() in this implementation takes care of that. + * + * if n is an internal node - a 'tnode' here, the various parts of its key + * have many different meanings. + * + * Example: + * _________________________________________________________________ + * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C | + * ----------------------------------------------------------------- + * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 + * + * _________________________________________________________________ + * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u | + * ----------------------------------------------------------------- + * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + * + * tp->pos = 22 + * tp->bits = 3 + * n->pos = 13 + * n->bits = 4 + * + * First, let's just ignore the bits that come before the parent tp, that is + * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this + * point we do not use them for anything. + * + * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the + * index into the parent's child array. That is, they will be used to find + * 'n' among tp's children. + * + * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits + * for the node n. + * + * All the bits we have seen so far are significant to the node n. The rest + * of the bits are really not needed or indeed known in n->key. + * + * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into + * n's child array, and will of course be different for each child. + * + * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown + * at this point. + */ + +static const int halve_threshold = 25; +static const int inflate_threshold = 50; +static const int halve_threshold_root = 15; +static const int inflate_threshold_root = 30; + +static void __alias_free_mem(struct rcu_head *head) +{ + struct fib_alias *fa = container_of(head, struct fib_alias, rcu); + kmem_cache_free(fn_alias_kmem, fa); +} + +static inline void alias_free_mem_rcu(struct fib_alias *fa) +{ + call_rcu(&fa->rcu, __alias_free_mem); +} + +#define TNODE_VMALLOC_MAX \ + ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) + +static void __node_free_rcu(struct rcu_head *head) +{ + struct tnode *n = container_of(head, struct tnode, rcu); + + if (!n->tn_bits) + kmem_cache_free(trie_leaf_kmem, n); + else + kvfree(n); +} + +#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) + +static struct tnode *tnode_alloc(int bits) +{ + size_t size; + + /* verify bits is within bounds */ + if (bits > TNODE_VMALLOC_MAX) + return NULL; + + /* determine size and verify it is non-zero and didn't overflow */ + size = TNODE_SIZE(1ul << bits); + + if (size <= PAGE_SIZE) + return kzalloc(size, GFP_KERNEL); + else + return vzalloc(size); +} + +static inline void empty_child_inc(struct key_vector *n) +{ + tn_info(n)->empty_children++; + + if (!tn_info(n)->empty_children) + tn_info(n)->full_children++; +} + +static inline void empty_child_dec(struct key_vector *n) +{ + if (!tn_info(n)->empty_children) + tn_info(n)->full_children--; + + tn_info(n)->empty_children--; +} + +static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) +{ + struct key_vector *l; + struct tnode *kv; + + kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); + if (!kv) + return NULL; + + /* initialize key vector */ + l = kv->kv; + l->key = key; + l->pos = 0; + l->bits = 0; + l->slen = fa->fa_slen; + + /* link leaf to fib alias */ + INIT_HLIST_HEAD(&l->leaf); + hlist_add_head(&fa->fa_list, &l->leaf); + + return l; +} + +static struct key_vector *tnode_new(t_key key, int pos, int bits) +{ + unsigned int shift = pos + bits; + struct key_vector *tn; + struct tnode *tnode; + + /* verify bits and pos their msb bits clear and values are valid */ + BUG_ON(!bits || (shift > KEYLENGTH)); + + tnode = tnode_alloc(bits); + if (!tnode) + return NULL; + + pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), + sizeof(struct key_vector *) << bits); + + if (bits == KEYLENGTH) + tnode->full_children = 1; + else + tnode->empty_children = 1ul << bits; + + tn = tnode->kv; + tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; + tn->pos = pos; + tn->bits = bits; + tn->slen = pos; + + return tn; +} + +/* Check whether a tnode 'n' is "full", i.e. it is an internal node + * and no bits are skipped. See discussion in dyntree paper p. 6 + */ +static inline int tnode_full(struct key_vector *tn, struct key_vector *n) +{ + return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); +} + +/* Add a child at position i overwriting the old value. + * Update the value of full_children and empty_children. + */ +static void put_child(struct key_vector *tn, unsigned long i, + struct key_vector *n) +{ + struct key_vector *chi = get_child(tn, i); + int isfull, wasfull; + + BUG_ON(i >= child_length(tn)); + + /* update emptyChildren, overflow into fullChildren */ + if (!n && chi) + empty_child_inc(tn); + if (n && !chi) + empty_child_dec(tn); + + /* update fullChildren */ + wasfull = tnode_full(tn, chi); + isfull = tnode_full(tn, n); + + if (wasfull && !isfull) + tn_info(tn)->full_children--; + else if (!wasfull && isfull) + tn_info(tn)->full_children++; + + if (n && (tn->slen < n->slen)) + tn->slen = n->slen; + + rcu_assign_pointer(tn->tnode[i], n); +} + +static void update_children(struct key_vector *tn) +{ + unsigned long i; + + /* update all of the child parent pointers */ + for (i = child_length(tn); i;) { + struct key_vector *inode = get_child(tn, --i); + + if (!inode) + continue; + + /* Either update the children of a tnode that + * already belongs to us or update the child + * to point to ourselves. + */ + if (node_parent(inode) == tn) + update_children(inode); + else + node_set_parent(inode, tn); + } +} + +static inline void put_child_root(struct key_vector *tp, t_key key, + struct key_vector *n) +{ + if (IS_TRIE(tp)) + rcu_assign_pointer(tp->tnode[0], n); + else + put_child(tp, get_index(key, tp), n); +} + +static inline void tnode_free_init(struct key_vector *tn) +{ + tn_info(tn)->rcu.next = NULL; +} + +static inline void tnode_free_append(struct key_vector *tn, + struct key_vector *n) +{ + tn_info(n)->rcu.next = tn_info(tn)->rcu.next; + tn_info(tn)->rcu.next = &tn_info(n)->rcu; +} + +static void tnode_free(struct key_vector *tn) +{ + struct callback_head *head = &tn_info(tn)->rcu; + + while (head) { + head = head->next; + tnode_free_size += TNODE_SIZE(1ul << tn->bits); + node_free(tn); + + tn = container_of(head, struct tnode, rcu)->kv; + } + + if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) { + tnode_free_size = 0; + synchronize_rcu(); + } +} + +static struct key_vector *replace(struct trie *t, + struct key_vector *oldtnode, + struct key_vector *tn) +{ + struct key_vector *tp = node_parent(oldtnode); + unsigned long i; + + /* setup the parent pointer out of and back into this node */ + NODE_INIT_PARENT(tn, tp); + put_child_root(tp, tn->key, tn); + + /* update all of the child parent pointers */ + update_children(tn); + + /* all pointers should be clean so we are done */ + tnode_free(oldtnode); + + /* resize children now that oldtnode is freed */ + for (i = child_length(tn); i;) { + struct key_vector *inode = get_child(tn, --i); + + /* resize child node */ + if (tnode_full(tn, inode)) + tn = resize(t, inode); + } + + return tp; +} + +static struct key_vector *inflate(struct trie *t, + struct key_vector *oldtnode) +{ + struct key_vector *tn; + unsigned long i; + t_key m; + + pr_debug("In inflate\n"); + + tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); + if (!tn) + goto notnode; + + /* prepare oldtnode to be freed */ + tnode_free_init(oldtnode); + + /* Assemble all of the pointers in our cluster, in this case that + * represents all of the pointers out of our allocated nodes that + * point to existing tnodes and the links between our allocated + * nodes. + */ + for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { + struct key_vector *inode = get_child(oldtnode, --i); + struct key_vector *node0, *node1; + unsigned long j, k; + + /* An empty child */ + if (!inode) + continue; + + /* A leaf or an internal node with skipped bits */ + if (!tnode_full(oldtnode, inode)) { + put_child(tn, get_index(inode->key, tn), inode); + continue; + } + + /* drop the node in the old tnode free list */ + tnode_free_append(oldtnode, inode); + + /* An internal node with two children */ + if (inode->bits == 1) { + put_child(tn, 2 * i + 1, get_child(inode, 1)); + put_child(tn, 2 * i, get_child(inode, 0)); + continue; + } + + /* We will replace this node 'inode' with two new + * ones, 'node0' and 'node1', each with half of the + * original children. The two new nodes will have + * a position one bit further down the key and this + * means that the "significant" part of their keys + * (see the discussion near the top of this file) + * will differ by one bit, which will be "0" in + * node0's key and "1" in node1's key. Since we are + * moving the key position by one step, the bit that + * we are moving away from - the bit at position + * (tn->pos) - is the one that will differ between + * node0 and node1. So... we synthesize that bit in the + * two new keys. + */ + node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); + if (!node1) + goto nomem; + node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); + + tnode_free_append(tn, node1); + if (!node0) + goto nomem; + tnode_free_append(tn, node0); + + /* populate child pointers in new nodes */ + for (k = child_length(inode), j = k / 2; j;) { + put_child(node1, --j, get_child(inode, --k)); + put_child(node0, j, get_child(inode, j)); + put_child(node1, --j, get_child(inode, --k)); + put_child(node0, j, get_child(inode, j)); + } + + /* link new nodes to parent */ + NODE_INIT_PARENT(node1, tn); + NODE_INIT_PARENT(node0, tn); + + /* link parent to nodes */ + put_child(tn, 2 * i + 1, node1); + put_child(tn, 2 * i, node0); + } + + /* setup the parent pointers into and out of this node */ + return replace(t, oldtnode, tn); +nomem: + /* all pointers should be clean so we are done */ + tnode_free(tn); +notnode: + return NULL; +} + +static struct key_vector *halve(struct trie *t, + struct key_vector *oldtnode) +{ + struct key_vector *tn; + unsigned long i; + + pr_debug("In halve\n"); + + tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); + if (!tn) + goto notnode; + + /* prepare oldtnode to be freed */ + tnode_free_init(oldtnode); + + /* Assemble all of the pointers in our cluster, in this case that + * represents all of the pointers out of our allocated nodes that + * point to existing tnodes and the links between our allocated + * nodes. + */ + for (i = child_length(oldtnode); i;) { + struct key_vector *node1 = get_child(oldtnode, --i); + struct key_vector *node0 = get_child(oldtnode, --i); + struct key_vector *inode; + + /* At least one of the children is empty */ + if (!node1 || !node0) { + put_child(tn, i / 2, node1 ? : node0); + continue; + } + + /* Two nonempty children */ + inode = tnode_new(node0->key, oldtnode->pos, 1); + if (!inode) + goto nomem; + tnode_free_append(tn, inode); + + /* initialize pointers out of node */ + put_child(inode, 1, node1); + put_child(inode, 0, node0); + NODE_INIT_PARENT(inode, tn); + + /* link parent to node */ + put_child(tn, i / 2, inode); + } + + /* setup the parent pointers into and out of this node */ + return replace(t, oldtnode, tn); +nomem: + /* all pointers should be clean so we are done */ + tnode_free(tn); +notnode: + return NULL; +} + +static struct key_vector *collapse(struct trie *t, + struct key_vector *oldtnode) +{ + struct key_vector *n, *tp; + unsigned long i; + + /* scan the tnode looking for that one child that might still exist */ + for (n = NULL, i = child_length(oldtnode); !n && i;) + n = get_child(oldtnode, --i); + + /* compress one level */ + tp = node_parent(oldtnode); + put_child_root(tp, oldtnode->key, n); + node_set_parent(n, tp); + + /* drop dead node */ + node_free(oldtnode); + + return tp; +} + +static unsigned char update_suffix(struct key_vector *tn) +{ + unsigned char slen = tn->pos; + unsigned long stride, i; + unsigned char slen_max; + + /* only vector 0 can have a suffix length greater than or equal to + * tn->pos + tn->bits, the second highest node will have a suffix + * length at most of tn->pos + tn->bits - 1 + */ + slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen); + + /* search though the list of children looking for nodes that might + * have a suffix greater than the one we currently have. This is + * why we start with a stride of 2 since a stride of 1 would + * represent the nodes with suffix length equal to tn->pos + */ + for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { + struct key_vector *n = get_child(tn, i); + + if (!n || (n->slen <= slen)) + continue; + + /* update stride and slen based on new value */ + stride <<= (n->slen - slen); + slen = n->slen; + i &= ~(stride - 1); + + /* stop searching if we have hit the maximum possible value */ + if (slen >= slen_max) + break; + } + + tn->slen = slen; + + return slen; +} + +/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of + * the Helsinki University of Technology and Matti Tikkanen of Nokia + * Telecommunications, page 6: + * "A node is doubled if the ratio of non-empty children to all + * children in the *doubled* node is at least 'high'." + * + * 'high' in this instance is the variable 'inflate_threshold'. It + * is expressed as a percentage, so we multiply it with + * child_length() and instead of multiplying by 2 (since the + * child array will be doubled by inflate()) and multiplying + * the left-hand side by 100 (to handle the percentage thing) we + * multiply the left-hand side by 50. + * + * The left-hand side may look a bit weird: child_length(tn) + * - tn->empty_children is of course the number of non-null children + * in the current node. tn->full_children is the number of "full" + * children, that is non-null tnodes with a skip value of 0. + * All of those will be doubled in the resulting inflated tnode, so + * we just count them one extra time here. + * + * A clearer way to write this would be: + * + * to_be_doubled = tn->full_children; + * not_to_be_doubled = child_length(tn) - tn->empty_children - + * tn->full_children; + * + * new_child_length = child_length(tn) * 2; + * + * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / + * new_child_length; + * if (new_fill_factor >= inflate_threshold) + * + * ...and so on, tho it would mess up the while () loop. + * + * anyway, + * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= + * inflate_threshold + * + * avoid a division: + * 100 * (not_to_be_doubled + 2*to_be_doubled) >= + * inflate_threshold * new_child_length + * + * expand not_to_be_doubled and to_be_doubled, and shorten: + * 100 * (child_length(tn) - tn->empty_children + + * tn->full_children) >= inflate_threshold * new_child_length + * + * expand new_child_length: + * 100 * (child_length(tn) - tn->empty_children + + * tn->full_children) >= + * inflate_threshold * child_length(tn) * 2 + * + * shorten again: + * 50 * (tn->full_children + child_length(tn) - + * tn->empty_children) >= inflate_threshold * + * child_length(tn) + * + */ +static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) +{ + unsigned long used = child_length(tn); + unsigned long threshold = used; + + /* Keep root node larger */ + threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; + used -= tn_info(tn)->empty_children; + used += tn_info(tn)->full_children; + + /* if bits == KEYLENGTH then pos = 0, and will fail below */ + + return (used > 1) && tn->pos && ((50 * used) >= threshold); +} + +static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) +{ + unsigned long used = child_length(tn); + unsigned long threshold = used; + + /* Keep root node larger */ + threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; + used -= tn_info(tn)->empty_children; + + /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ + + return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); +} + +static inline bool should_collapse(struct key_vector *tn) +{ + unsigned long used = child_length(tn); + + used -= tn_info(tn)->empty_children; + + /* account for bits == KEYLENGTH case */ + if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) + used -= KEY_MAX; + + /* One child or none, time to drop us from the trie */ + return used < 2; +} + +#define MAX_WORK 10 +static struct key_vector *resize(struct trie *t, struct key_vector *tn) +{ +#ifdef CONFIG_IP_FIB_TRIE_STATS + struct trie_use_stats __percpu *stats = t->stats; +#endif + struct key_vector *tp = node_parent(tn); + unsigned long cindex = get_index(tn->key, tp); + int max_work = MAX_WORK; + + pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", + tn, inflate_threshold, halve_threshold); + + /* track the tnode via the pointer from the parent instead of + * doing it ourselves. This way we can let RCU fully do its + * thing without us interfering + */ + BUG_ON(tn != get_child(tp, cindex)); + + /* Double as long as the resulting node has a number of + * nonempty nodes that are above the threshold. + */ + while (should_inflate(tp, tn) && max_work) { + tp = inflate(t, tn); + if (!tp) { +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(stats->resize_node_skipped); +#endif + break; + } + + max_work--; + tn = get_child(tp, cindex); + } + + /* update parent in case inflate failed */ + tp = node_parent(tn); + + /* Return if at least one inflate is run */ + if (max_work != MAX_WORK) + return tp; + + /* Halve as long as the number of empty children in this + * node is above threshold. + */ + while (should_halve(tp, tn) && max_work) { + tp = halve(t, tn); + if (!tp) { +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(stats->resize_node_skipped); +#endif + break; + } + + max_work--; + tn = get_child(tp, cindex); + } + + /* Only one child remains */ + if (should_collapse(tn)) + return collapse(t, tn); + + /* update parent in case halve failed */ + return node_parent(tn); +} + +static void node_pull_suffix(struct key_vector *tn, unsigned char slen) +{ + unsigned char node_slen = tn->slen; + + while ((node_slen > tn->pos) && (node_slen > slen)) { + slen = update_suffix(tn); + if (node_slen == slen) + break; + + tn = node_parent(tn); + node_slen = tn->slen; + } +} + +static void node_push_suffix(struct key_vector *tn, unsigned char slen) +{ + while (tn->slen < slen) { + tn->slen = slen; + tn = node_parent(tn); + } +} + +/* rcu_read_lock needs to be hold by caller from readside */ +static struct key_vector *fib_find_node(struct trie *t, + struct key_vector **tp, u32 key) +{ + struct key_vector *pn, *n = t->kv; + unsigned long index = 0; + + do { + pn = n; + n = get_child_rcu(n, index); + + if (!n) + break; + + index = get_cindex(key, n); + + /* This bit of code is a bit tricky but it combines multiple + * checks into a single check. The prefix consists of the + * prefix plus zeros for the bits in the cindex. The index + * is the difference between the key and this value. From + * this we can actually derive several pieces of data. + * if (index >= (1ul << bits)) + * we have a mismatch in skip bits and failed + * else + * we know the value is cindex + * + * This check is safe even if bits == KEYLENGTH due to the + * fact that we can only allocate a node with 32 bits if a + * long is greater than 32 bits. + */ + if (index >= (1ul << n->bits)) { + n = NULL; + break; + } + + /* keep searching until we find a perfect match leaf or NULL */ + } while (IS_TNODE(n)); + + *tp = pn; + + return n; +} + +/* Return the first fib alias matching TOS with + * priority less than or equal to PRIO. + * If 'find_first' is set, return the first matching + * fib alias, regardless of TOS and priority. + */ +static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, + u8 tos, u32 prio, u32 tb_id, + bool find_first) +{ + struct fib_alias *fa; + + if (!fah) + return NULL; + + hlist_for_each_entry(fa, fah, fa_list) { + if (fa->fa_slen < slen) + continue; + if (fa->fa_slen != slen) + break; + if (fa->tb_id > tb_id) + continue; + if (fa->tb_id != tb_id) + break; + if (find_first) + return fa; + if (fa->fa_tos > tos) + continue; + if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos) + return fa; + } + + return NULL; +} + +static struct fib_alias * +fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri) +{ + u8 slen = KEYLENGTH - fri->dst_len; + struct key_vector *l, *tp; + struct fib_table *tb; + struct fib_alias *fa; + struct trie *t; + + tb = fib_get_table(net, fri->tb_id); + if (!tb) + return NULL; + + t = (struct trie *)tb->tb_data; + l = fib_find_node(t, &tp, be32_to_cpu(fri->dst)); + if (!l) + return NULL; + + hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { + if (fa->fa_slen == slen && fa->tb_id == fri->tb_id && + fa->fa_tos == fri->tos && fa->fa_info == fri->fi && + fa->fa_type == fri->type) + return fa; + } + + return NULL; +} + +void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri) +{ + struct fib_alias *fa_match; + + rcu_read_lock(); + + fa_match = fib_find_matching_alias(net, fri); + if (!fa_match) + goto out; + + fa_match->offload = fri->offload; + fa_match->trap = fri->trap; + +out: + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set); + +static void trie_rebalance(struct trie *t, struct key_vector *tn) +{ + while (!IS_TRIE(tn)) + tn = resize(t, tn); +} + +static int fib_insert_node(struct trie *t, struct key_vector *tp, + struct fib_alias *new, t_key key) +{ + struct key_vector *n, *l; + + l = leaf_new(key, new); + if (!l) + goto noleaf; + + /* retrieve child from parent node */ + n = get_child(tp, get_index(key, tp)); + + /* Case 2: n is a LEAF or a TNODE and the key doesn't match. + * + * Add a new tnode here + * first tnode need some special handling + * leaves us in position for handling as case 3 + */ + if (n) { + struct key_vector *tn; + + tn = tnode_new(key, __fls(key ^ n->key), 1); + if (!tn) + goto notnode; + + /* initialize routes out of node */ + NODE_INIT_PARENT(tn, tp); + put_child(tn, get_index(key, tn) ^ 1, n); + + /* start adding routes into the node */ + put_child_root(tp, key, tn); + node_set_parent(n, tn); + + /* parent now has a NULL spot where the leaf can go */ + tp = tn; + } + + /* Case 3: n is NULL, and will just insert a new leaf */ + node_push_suffix(tp, new->fa_slen); + NODE_INIT_PARENT(l, tp); + put_child_root(tp, key, l); + trie_rebalance(t, tp); + + return 0; +notnode: + node_free(l); +noleaf: + return -ENOMEM; +} + +static int fib_insert_alias(struct trie *t, struct key_vector *tp, + struct key_vector *l, struct fib_alias *new, + struct fib_alias *fa, t_key key) +{ + if (!l) + return fib_insert_node(t, tp, new, key); + + if (fa) { + hlist_add_before_rcu(&new->fa_list, &fa->fa_list); + } else { + struct fib_alias *last; + + hlist_for_each_entry(last, &l->leaf, fa_list) { + if (new->fa_slen < last->fa_slen) + break; + if ((new->fa_slen == last->fa_slen) && + (new->tb_id > last->tb_id)) + break; + fa = last; + } + + if (fa) + hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); + else + hlist_add_head_rcu(&new->fa_list, &l->leaf); + } + + /* if we added to the tail node then we need to update slen */ + if (l->slen < new->fa_slen) { + l->slen = new->fa_slen; + node_push_suffix(tp, new->fa_slen); + } + + return 0; +} + +static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack) +{ + if (plen > KEYLENGTH) { + NL_SET_ERR_MSG(extack, "Invalid prefix length"); + return false; + } + + if ((plen < KEYLENGTH) && (key << plen)) { + NL_SET_ERR_MSG(extack, + "Invalid prefix for given prefix length"); + return false; + } + + return true; +} + +static void fib_remove_alias(struct trie *t, struct key_vector *tp, + struct key_vector *l, struct fib_alias *old); + +/* Caller must hold RTNL. */ +int fib_table_insert(struct net *net, struct fib_table *tb, + struct fib_config *cfg, struct netlink_ext_ack *extack) +{ + struct trie *t = (struct trie *)tb->tb_data; + struct fib_alias *fa, *new_fa; + struct key_vector *l, *tp; + u16 nlflags = NLM_F_EXCL; + struct fib_info *fi; + u8 plen = cfg->fc_dst_len; + u8 slen = KEYLENGTH - plen; + u8 tos = cfg->fc_tos; + u32 key; + int err; + + key = ntohl(cfg->fc_dst); + + if (!fib_valid_key_len(key, plen, extack)) + return -EINVAL; + + pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); + + fi = fib_create_info(cfg, extack); + if (IS_ERR(fi)) { + err = PTR_ERR(fi); + goto err; + } + + l = fib_find_node(t, &tp, key); + fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority, + tb->tb_id, false) : NULL; + + /* Now fa, if non-NULL, points to the first fib alias + * with the same keys [prefix,tos,priority], if such key already + * exists or to the node before which we will insert new one. + * + * If fa is NULL, we will need to allocate a new one and + * insert to the tail of the section matching the suffix length + * of the new alias. + */ + + if (fa && fa->fa_tos == tos && + fa->fa_info->fib_priority == fi->fib_priority) { + struct fib_alias *fa_first, *fa_match; + + err = -EEXIST; + if (cfg->fc_nlflags & NLM_F_EXCL) + goto out; + + nlflags &= ~NLM_F_EXCL; + + /* We have 2 goals: + * 1. Find exact match for type, scope, fib_info to avoid + * duplicate routes + * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it + */ + fa_match = NULL; + fa_first = fa; + hlist_for_each_entry_from(fa, fa_list) { + if ((fa->fa_slen != slen) || + (fa->tb_id != tb->tb_id) || + (fa->fa_tos != tos)) + break; + if (fa->fa_info->fib_priority != fi->fib_priority) + break; + if (fa->fa_type == cfg->fc_type && + fa->fa_info == fi) { + fa_match = fa; + break; + } + } + + if (cfg->fc_nlflags & NLM_F_REPLACE) { + struct fib_info *fi_drop; + u8 state; + + nlflags |= NLM_F_REPLACE; + fa = fa_first; + if (fa_match) { + if (fa == fa_match) + err = 0; + goto out; + } + err = -ENOBUFS; + new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); + if (!new_fa) + goto out; + + fi_drop = fa->fa_info; + new_fa->fa_tos = fa->fa_tos; + new_fa->fa_info = fi; + new_fa->fa_type = cfg->fc_type; + state = fa->fa_state; + new_fa->fa_state = state & ~FA_S_ACCESSED; + new_fa->fa_slen = fa->fa_slen; + new_fa->tb_id = tb->tb_id; + new_fa->fa_default = -1; + new_fa->offload = 0; + new_fa->trap = 0; + + hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); + + if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0, + tb->tb_id, true) == new_fa) { + enum fib_event_type fib_event; + + fib_event = FIB_EVENT_ENTRY_REPLACE; + err = call_fib_entry_notifiers(net, fib_event, + key, plen, + new_fa, extack); + if (err) { + hlist_replace_rcu(&new_fa->fa_list, + &fa->fa_list); + goto out_free_new_fa; + } + } + + rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, + tb->tb_id, &cfg->fc_nlinfo, nlflags); + + alias_free_mem_rcu(fa); + + fib_release_info(fi_drop); + if (state & FA_S_ACCESSED) + rt_cache_flush(cfg->fc_nlinfo.nl_net); + + goto succeeded; + } + /* Error if we find a perfect match which + * uses the same scope, type, and nexthop + * information. + */ + if (fa_match) + goto out; + + if (cfg->fc_nlflags & NLM_F_APPEND) + nlflags |= NLM_F_APPEND; + else + fa = fa_first; + } + err = -ENOENT; + if (!(cfg->fc_nlflags & NLM_F_CREATE)) + goto out; + + nlflags |= NLM_F_CREATE; + err = -ENOBUFS; + new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); + if (!new_fa) + goto out; + + new_fa->fa_info = fi; + new_fa->fa_tos = tos; + new_fa->fa_type = cfg->fc_type; + new_fa->fa_state = 0; + new_fa->fa_slen = slen; + new_fa->tb_id = tb->tb_id; + new_fa->fa_default = -1; + new_fa->offload = 0; + new_fa->trap = 0; + + /* Insert new entry to the list. */ + err = fib_insert_alias(t, tp, l, new_fa, fa, key); + if (err) + goto out_free_new_fa; + + /* The alias was already inserted, so the node must exist. */ + l = l ? l : fib_find_node(t, &tp, key); + if (WARN_ON_ONCE(!l)) { + err = -ENOENT; + goto out_free_new_fa; + } + + if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) == + new_fa) { + enum fib_event_type fib_event; + + fib_event = FIB_EVENT_ENTRY_REPLACE; + err = call_fib_entry_notifiers(net, fib_event, key, plen, + new_fa, extack); + if (err) + goto out_remove_new_fa; + } + + if (!plen) + tb->tb_num_default++; + + rt_cache_flush(cfg->fc_nlinfo.nl_net); + rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, + &cfg->fc_nlinfo, nlflags); +succeeded: + return 0; + +out_remove_new_fa: + fib_remove_alias(t, tp, l, new_fa); +out_free_new_fa: + kmem_cache_free(fn_alias_kmem, new_fa); +out: + fib_release_info(fi); +err: + return err; +} + +static inline t_key prefix_mismatch(t_key key, struct key_vector *n) +{ + t_key prefix = n->key; + + return (key ^ prefix) & (prefix | -prefix); +} + +bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, + const struct flowi4 *flp) +{ + if (nhc->nhc_flags & RTNH_F_DEAD) + return false; + + if (ip_ignore_linkdown(nhc->nhc_dev) && + nhc->nhc_flags & RTNH_F_LINKDOWN && + !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) + return false; + + if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) { + if (flp->flowi4_oif && + flp->flowi4_oif != nhc->nhc_oif) + return false; + } + + return true; +} + +/* should be called with rcu_read_lock */ +int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, + struct fib_result *res, int fib_flags) +{ + struct trie *t = (struct trie *) tb->tb_data; +#ifdef CONFIG_IP_FIB_TRIE_STATS + struct trie_use_stats __percpu *stats = t->stats; +#endif + const t_key key = ntohl(flp->daddr); + struct key_vector *n, *pn; + struct fib_alias *fa; + unsigned long index; + t_key cindex; + + pn = t->kv; + cindex = 0; + + n = get_child_rcu(pn, cindex); + if (!n) { + trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN); + return -EAGAIN; + } + +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(stats->gets); +#endif + + /* Step 1: Travel to the longest prefix match in the trie */ + for (;;) { + index = get_cindex(key, n); + + /* This bit of code is a bit tricky but it combines multiple + * checks into a single check. The prefix consists of the + * prefix plus zeros for the "bits" in the prefix. The index + * is the difference between the key and this value. From + * this we can actually derive several pieces of data. + * if (index >= (1ul << bits)) + * we have a mismatch in skip bits and failed + * else + * we know the value is cindex + * + * This check is safe even if bits == KEYLENGTH due to the + * fact that we can only allocate a node with 32 bits if a + * long is greater than 32 bits. + */ + if (index >= (1ul << n->bits)) + break; + + /* we have found a leaf. Prefixes have already been compared */ + if (IS_LEAF(n)) + goto found; + + /* only record pn and cindex if we are going to be chopping + * bits later. Otherwise we are just wasting cycles. + */ + if (n->slen > n->pos) { + pn = n; + cindex = index; + } + + n = get_child_rcu(n, index); + if (unlikely(!n)) + goto backtrace; + } + + /* Step 2: Sort out leaves and begin backtracing for longest prefix */ + for (;;) { + /* record the pointer where our next node pointer is stored */ + struct key_vector __rcu **cptr = n->tnode; + + /* This test verifies that none of the bits that differ + * between the key and the prefix exist in the region of + * the lsb and higher in the prefix. + */ + if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) + goto backtrace; + + /* exit out and process leaf */ + if (unlikely(IS_LEAF(n))) + break; + + /* Don't bother recording parent info. Since we are in + * prefix match mode we will have to come back to wherever + * we started this traversal anyway + */ + + while ((n = rcu_dereference(*cptr)) == NULL) { +backtrace: +#ifdef CONFIG_IP_FIB_TRIE_STATS + if (!n) + this_cpu_inc(stats->null_node_hit); +#endif + /* If we are at cindex 0 there are no more bits for + * us to strip at this level so we must ascend back + * up one level to see if there are any more bits to + * be stripped there. + */ + while (!cindex) { + t_key pkey = pn->key; + + /* If we don't have a parent then there is + * nothing for us to do as we do not have any + * further nodes to parse. + */ + if (IS_TRIE(pn)) { + trace_fib_table_lookup(tb->tb_id, flp, + NULL, -EAGAIN); + return -EAGAIN; + } +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(stats->backtrack); +#endif + /* Get Child's index */ + pn = node_parent_rcu(pn); + cindex = get_index(pkey, pn); + } + + /* strip the least significant bit from the cindex */ + cindex &= cindex - 1; + + /* grab pointer for next child node */ + cptr = &pn->tnode[cindex]; + } + } + +found: + /* this line carries forward the xor from earlier in the function */ + index = key ^ n->key; + + /* Step 3: Process the leaf, if that fails fall back to backtracing */ + hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { + struct fib_info *fi = fa->fa_info; + struct fib_nh_common *nhc; + int nhsel, err; + + if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) { + if (index >= (1ul << fa->fa_slen)) + continue; + } + if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) + continue; + /* Paired with WRITE_ONCE() in fib_release_info() */ + if (READ_ONCE(fi->fib_dead)) + continue; + if (fa->fa_info->fib_scope < flp->flowi4_scope) + continue; + fib_alias_accessed(fa); + err = fib_props[fa->fa_type].error; + if (unlikely(err < 0)) { +out_reject: +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(stats->semantic_match_passed); +#endif + trace_fib_table_lookup(tb->tb_id, flp, NULL, err); + return err; + } + if (fi->fib_flags & RTNH_F_DEAD) + continue; + + if (unlikely(fi->nh)) { + if (nexthop_is_blackhole(fi->nh)) { + err = fib_props[RTN_BLACKHOLE].error; + goto out_reject; + } + + nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp, + &nhsel); + if (nhc) + goto set_result; + goto miss; + } + + for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { + nhc = fib_info_nhc(fi, nhsel); + + if (!fib_lookup_good_nhc(nhc, fib_flags, flp)) + continue; +set_result: + if (!(fib_flags & FIB_LOOKUP_NOREF)) + refcount_inc(&fi->fib_clntref); + + res->prefix = htonl(n->key); + res->prefixlen = KEYLENGTH - fa->fa_slen; + res->nh_sel = nhsel; + res->nhc = nhc; + res->type = fa->fa_type; + res->scope = fi->fib_scope; + res->fi = fi; + res->table = tb; + res->fa_head = &n->leaf; +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(stats->semantic_match_passed); +#endif + trace_fib_table_lookup(tb->tb_id, flp, nhc, err); + + return err; + } + } +miss: +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(stats->semantic_match_miss); +#endif + goto backtrace; +} +EXPORT_SYMBOL_GPL(fib_table_lookup); + +static void fib_remove_alias(struct trie *t, struct key_vector *tp, + struct key_vector *l, struct fib_alias *old) +{ + /* record the location of the previous list_info entry */ + struct hlist_node **pprev = old->fa_list.pprev; + struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); + + /* remove the fib_alias from the list */ + hlist_del_rcu(&old->fa_list); + + /* if we emptied the list this leaf will be freed and we can sort + * out parent suffix lengths as a part of trie_rebalance + */ + if (hlist_empty(&l->leaf)) { + if (tp->slen == l->slen) + node_pull_suffix(tp, tp->pos); + put_child_root(tp, l->key, NULL); + node_free(l); + trie_rebalance(t, tp); + return; + } + + /* only access fa if it is pointing at the last valid hlist_node */ + if (*pprev) + return; + + /* update the trie with the latest suffix length */ + l->slen = fa->fa_slen; + node_pull_suffix(tp, fa->fa_slen); +} + +static void fib_notify_alias_delete(struct net *net, u32 key, + struct hlist_head *fah, + struct fib_alias *fa_to_delete, + struct netlink_ext_ack *extack) +{ + struct fib_alias *fa_next, *fa_to_notify; + u32 tb_id = fa_to_delete->tb_id; + u8 slen = fa_to_delete->fa_slen; + enum fib_event_type fib_event; + + /* Do not notify if we do not care about the route. */ + if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete) + return; + + /* Determine if the route should be replaced by the next route in the + * list. + */ + fa_next = hlist_entry_safe(fa_to_delete->fa_list.next, + struct fib_alias, fa_list); + if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) { + fib_event = FIB_EVENT_ENTRY_REPLACE; + fa_to_notify = fa_next; + } else { + fib_event = FIB_EVENT_ENTRY_DEL; + fa_to_notify = fa_to_delete; + } + call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen, + fa_to_notify, extack); +} + +/* Caller must hold RTNL. */ +int fib_table_delete(struct net *net, struct fib_table *tb, + struct fib_config *cfg, struct netlink_ext_ack *extack) +{ + struct trie *t = (struct trie *) tb->tb_data; + struct fib_alias *fa, *fa_to_delete; + struct key_vector *l, *tp; + u8 plen = cfg->fc_dst_len; + u8 slen = KEYLENGTH - plen; + u8 tos = cfg->fc_tos; + u32 key; + + key = ntohl(cfg->fc_dst); + + if (!fib_valid_key_len(key, plen, extack)) + return -EINVAL; + + l = fib_find_node(t, &tp, key); + if (!l) + return -ESRCH; + + fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id, false); + if (!fa) + return -ESRCH; + + pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t); + + fa_to_delete = NULL; + hlist_for_each_entry_from(fa, fa_list) { + struct fib_info *fi = fa->fa_info; + + if ((fa->fa_slen != slen) || + (fa->tb_id != tb->tb_id) || + (fa->fa_tos != tos)) + break; + + if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && + (cfg->fc_scope == RT_SCOPE_NOWHERE || + fa->fa_info->fib_scope == cfg->fc_scope) && + (!cfg->fc_prefsrc || + fi->fib_prefsrc == cfg->fc_prefsrc) && + (!cfg->fc_protocol || + fi->fib_protocol == cfg->fc_protocol) && + fib_nh_match(net, cfg, fi, extack) == 0 && + fib_metrics_match(cfg, fi)) { + fa_to_delete = fa; + break; + } + } + + if (!fa_to_delete) + return -ESRCH; + + fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack); + rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, + &cfg->fc_nlinfo, 0); + + if (!plen) + tb->tb_num_default--; + + fib_remove_alias(t, tp, l, fa_to_delete); + + if (fa_to_delete->fa_state & FA_S_ACCESSED) + rt_cache_flush(cfg->fc_nlinfo.nl_net); + + fib_release_info(fa_to_delete->fa_info); + alias_free_mem_rcu(fa_to_delete); + return 0; +} + +/* Scan for the next leaf starting at the provided key value */ +static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) +{ + struct key_vector *pn, *n = *tn; + unsigned long cindex; + + /* this loop is meant to try and find the key in the trie */ + do { + /* record parent and next child index */ + pn = n; + cindex = (key > pn->key) ? get_index(key, pn) : 0; + + if (cindex >> pn->bits) + break; + + /* descend into the next child */ + n = get_child_rcu(pn, cindex++); + if (!n) + break; + + /* guarantee forward progress on the keys */ + if (IS_LEAF(n) && (n->key >= key)) + goto found; + } while (IS_TNODE(n)); + + /* this loop will search for the next leaf with a greater key */ + while (!IS_TRIE(pn)) { + /* if we exhausted the parent node we will need to climb */ + if (cindex >= (1ul << pn->bits)) { + t_key pkey = pn->key; + + pn = node_parent_rcu(pn); + cindex = get_index(pkey, pn) + 1; + continue; + } + + /* grab the next available node */ + n = get_child_rcu(pn, cindex++); + if (!n) + continue; + + /* no need to compare keys since we bumped the index */ + if (IS_LEAF(n)) + goto found; + + /* Rescan start scanning in new node */ + pn = n; + cindex = 0; + } + + *tn = pn; + return NULL; /* Root of trie */ +found: + /* if we are at the limit for keys just return NULL for the tnode */ + *tn = pn; + return n; +} + +static void fib_trie_free(struct fib_table *tb) +{ + struct trie *t = (struct trie *)tb->tb_data; + struct key_vector *pn = t->kv; + unsigned long cindex = 1; + struct hlist_node *tmp; + struct fib_alias *fa; + + /* walk trie in reverse order and free everything */ + for (;;) { + struct key_vector *n; + + if (!(cindex--)) { + t_key pkey = pn->key; + + if (IS_TRIE(pn)) + break; + + n = pn; + pn = node_parent(pn); + + /* drop emptied tnode */ + put_child_root(pn, n->key, NULL); + node_free(n); + + cindex = get_index(pkey, pn); + + continue; + } + + /* grab the next available node */ + n = get_child(pn, cindex); + if (!n) + continue; + + if (IS_TNODE(n)) { + /* record pn and cindex for leaf walking */ + pn = n; + cindex = 1ul << n->bits; + + continue; + } + + hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { + hlist_del_rcu(&fa->fa_list); + alias_free_mem_rcu(fa); + } + + put_child_root(pn, n->key, NULL); + node_free(n); + } + +#ifdef CONFIG_IP_FIB_TRIE_STATS + free_percpu(t->stats); +#endif + kfree(tb); +} + +struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) +{ + struct trie *ot = (struct trie *)oldtb->tb_data; + struct key_vector *l, *tp = ot->kv; + struct fib_table *local_tb; + struct fib_alias *fa; + struct trie *lt; + t_key key = 0; + + if (oldtb->tb_data == oldtb->__data) + return oldtb; + + local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); + if (!local_tb) + return NULL; + + lt = (struct trie *)local_tb->tb_data; + + while ((l = leaf_walk_rcu(&tp, key)) != NULL) { + struct key_vector *local_l = NULL, *local_tp; + + hlist_for_each_entry(fa, &l->leaf, fa_list) { + struct fib_alias *new_fa; + + if (local_tb->tb_id != fa->tb_id) + continue; + + /* clone fa for new local table */ + new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); + if (!new_fa) + goto out; + + memcpy(new_fa, fa, sizeof(*fa)); + + /* insert clone into table */ + if (!local_l) + local_l = fib_find_node(lt, &local_tp, l->key); + + if (fib_insert_alias(lt, local_tp, local_l, new_fa, + NULL, l->key)) { + kmem_cache_free(fn_alias_kmem, new_fa); + goto out; + } + } + + /* stop loop if key wrapped back to 0 */ + key = l->key + 1; + if (key < l->key) + break; + } + + return local_tb; +out: + fib_trie_free(local_tb); + + return NULL; +} + +/* Caller must hold RTNL */ +void fib_table_flush_external(struct fib_table *tb) +{ + struct trie *t = (struct trie *)tb->tb_data; + struct key_vector *pn = t->kv; + unsigned long cindex = 1; + struct hlist_node *tmp; + struct fib_alias *fa; + + /* walk trie in reverse order */ + for (;;) { + unsigned char slen = 0; + struct key_vector *n; + + if (!(cindex--)) { + t_key pkey = pn->key; + + /* cannot resize the trie vector */ + if (IS_TRIE(pn)) + break; + + /* update the suffix to address pulled leaves */ + if (pn->slen > pn->pos) + update_suffix(pn); + + /* resize completed node */ + pn = resize(t, pn); + cindex = get_index(pkey, pn); + + continue; + } + + /* grab the next available node */ + n = get_child(pn, cindex); + if (!n) + continue; + + if (IS_TNODE(n)) { + /* record pn and cindex for leaf walking */ + pn = n; + cindex = 1ul << n->bits; + + continue; + } + + hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { + /* if alias was cloned to local then we just + * need to remove the local copy from main + */ + if (tb->tb_id != fa->tb_id) { + hlist_del_rcu(&fa->fa_list); + alias_free_mem_rcu(fa); + continue; + } + + /* record local slen */ + slen = fa->fa_slen; + } + + /* update leaf slen */ + n->slen = slen; + + if (hlist_empty(&n->leaf)) { + put_child_root(pn, n->key, NULL); + node_free(n); + } + } +} + +/* Caller must hold RTNL. */ +int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all) +{ + struct trie *t = (struct trie *)tb->tb_data; + struct nl_info info = { .nl_net = net }; + struct key_vector *pn = t->kv; + unsigned long cindex = 1; + struct hlist_node *tmp; + struct fib_alias *fa; + int found = 0; + + /* walk trie in reverse order */ + for (;;) { + unsigned char slen = 0; + struct key_vector *n; + + if (!(cindex--)) { + t_key pkey = pn->key; + + /* cannot resize the trie vector */ + if (IS_TRIE(pn)) + break; + + /* update the suffix to address pulled leaves */ + if (pn->slen > pn->pos) + update_suffix(pn); + + /* resize completed node */ + pn = resize(t, pn); + cindex = get_index(pkey, pn); + + continue; + } + + /* grab the next available node */ + n = get_child(pn, cindex); + if (!n) + continue; + + if (IS_TNODE(n)) { + /* record pn and cindex for leaf walking */ + pn = n; + cindex = 1ul << n->bits; + + continue; + } + + hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { + struct fib_info *fi = fa->fa_info; + + if (!fi || tb->tb_id != fa->tb_id || + (!(fi->fib_flags & RTNH_F_DEAD) && + !fib_props[fa->fa_type].error)) { + slen = fa->fa_slen; + continue; + } + + /* Do not flush error routes if network namespace is + * not being dismantled + */ + if (!flush_all && fib_props[fa->fa_type].error) { + slen = fa->fa_slen; + continue; + } + + fib_notify_alias_delete(net, n->key, &n->leaf, fa, + NULL); + if (fi->pfsrc_removed) + rtmsg_fib(RTM_DELROUTE, htonl(n->key), fa, + KEYLENGTH - fa->fa_slen, tb->tb_id, &info, 0); + hlist_del_rcu(&fa->fa_list); + fib_release_info(fa->fa_info); + alias_free_mem_rcu(fa); + found++; + } + + /* update leaf slen */ + n->slen = slen; + + if (hlist_empty(&n->leaf)) { + put_child_root(pn, n->key, NULL); + node_free(n); + } + } + + pr_debug("trie_flush found=%d\n", found); + return found; +} + +/* derived from fib_trie_free */ +static void __fib_info_notify_update(struct net *net, struct fib_table *tb, + struct nl_info *info) +{ + struct trie *t = (struct trie *)tb->tb_data; + struct key_vector *pn = t->kv; + unsigned long cindex = 1; + struct fib_alias *fa; + + for (;;) { + struct key_vector *n; + + if (!(cindex--)) { + t_key pkey = pn->key; + + if (IS_TRIE(pn)) + break; + + pn = node_parent(pn); + cindex = get_index(pkey, pn); + continue; + } + + /* grab the next available node */ + n = get_child(pn, cindex); + if (!n) + continue; + + if (IS_TNODE(n)) { + /* record pn and cindex for leaf walking */ + pn = n; + cindex = 1ul << n->bits; + + continue; + } + + hlist_for_each_entry(fa, &n->leaf, fa_list) { + struct fib_info *fi = fa->fa_info; + + if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id) + continue; + + rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa, + KEYLENGTH - fa->fa_slen, tb->tb_id, + info, NLM_F_REPLACE); + + /* call_fib_entry_notifiers will be removed when + * in-kernel notifier is implemented and supported + * for nexthop objects + */ + call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, + n->key, + KEYLENGTH - fa->fa_slen, fa, + NULL); + } + } +} + +void fib_info_notify_update(struct net *net, struct nl_info *info) +{ + unsigned int h; + + for (h = 0; h < FIB_TABLE_HASHSZ; h++) { + struct hlist_head *head = &net->ipv4.fib_table_hash[h]; + struct fib_table *tb; + + hlist_for_each_entry_rcu(tb, head, tb_hlist, + lockdep_rtnl_is_held()) + __fib_info_notify_update(net, tb, info); + } +} + +static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb, + struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + struct fib_alias *fa; + int last_slen = -1; + int err; + + hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { + struct fib_info *fi = fa->fa_info; + + if (!fi) + continue; + + /* local and main table can share the same trie, + * so don't notify twice for the same entry. + */ + if (tb->tb_id != fa->tb_id) + continue; + + if (fa->fa_slen == last_slen) + continue; + + last_slen = fa->fa_slen; + err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE, + l->key, KEYLENGTH - fa->fa_slen, + fa, extack); + if (err) + return err; + } + return 0; +} + +static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + struct trie *t = (struct trie *)tb->tb_data; + struct key_vector *l, *tp = t->kv; + t_key key = 0; + int err; + + while ((l = leaf_walk_rcu(&tp, key)) != NULL) { + err = fib_leaf_notify(l, tb, nb, extack); + if (err) + return err; + + key = l->key + 1; + /* stop in case of wrap around */ + if (key < l->key) + break; + } + return 0; +} + +int fib_notify(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + unsigned int h; + int err; + + for (h = 0; h < FIB_TABLE_HASHSZ; h++) { + struct hlist_head *head = &net->ipv4.fib_table_hash[h]; + struct fib_table *tb; + + hlist_for_each_entry_rcu(tb, head, tb_hlist) { + err = fib_table_notify(tb, nb, extack); + if (err) + return err; + } + } + return 0; +} + +static void __trie_free_rcu(struct rcu_head *head) +{ + struct fib_table *tb = container_of(head, struct fib_table, rcu); +#ifdef CONFIG_IP_FIB_TRIE_STATS + struct trie *t = (struct trie *)tb->tb_data; + + if (tb->tb_data == tb->__data) + free_percpu(t->stats); +#endif /* CONFIG_IP_FIB_TRIE_STATS */ + kfree(tb); +} + +void fib_free_table(struct fib_table *tb) +{ + call_rcu(&tb->rcu, __trie_free_rcu); +} + +static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, + struct sk_buff *skb, struct netlink_callback *cb, + struct fib_dump_filter *filter) +{ + unsigned int flags = NLM_F_MULTI; + __be32 xkey = htonl(l->key); + int i, s_i, i_fa, s_fa, err; + struct fib_alias *fa; + + if (filter->filter_set || + !filter->dump_exceptions || !filter->dump_routes) + flags |= NLM_F_DUMP_FILTERED; + + s_i = cb->args[4]; + s_fa = cb->args[5]; + i = 0; + + /* rcu_read_lock is hold by caller */ + hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { + struct fib_info *fi = fa->fa_info; + + if (i < s_i) + goto next; + + i_fa = 0; + + if (tb->tb_id != fa->tb_id) + goto next; + + if (filter->filter_set) { + if (filter->rt_type && fa->fa_type != filter->rt_type) + goto next; + + if ((filter->protocol && + fi->fib_protocol != filter->protocol)) + goto next; + + if (filter->dev && + !fib_info_nh_uses_dev(fi, filter->dev)) + goto next; + } + + if (filter->dump_routes) { + if (!s_fa) { + struct fib_rt_info fri; + + fri.fi = fi; + fri.tb_id = tb->tb_id; + fri.dst = xkey; + fri.dst_len = KEYLENGTH - fa->fa_slen; + fri.tos = fa->fa_tos; + fri.type = fa->fa_type; + fri.offload = fa->offload; + fri.trap = fa->trap; + err = fib_dump_info(skb, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + RTM_NEWROUTE, &fri, flags); + if (err < 0) + goto stop; + } + + i_fa++; + } + + if (filter->dump_exceptions) { + err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi, + &i_fa, s_fa, flags); + if (err < 0) + goto stop; + } + +next: + i++; + } + + cb->args[4] = i; + return skb->len; + +stop: + cb->args[4] = i; + cb->args[5] = i_fa; + return err; +} + +/* rcu_read_lock needs to be hold by caller from readside */ +int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, + struct netlink_callback *cb, struct fib_dump_filter *filter) +{ + struct trie *t = (struct trie *)tb->tb_data; + struct key_vector *l, *tp = t->kv; + /* Dump starting at last key. + * Note: 0.0.0.0/0 (ie default) is first key. + */ + int count = cb->args[2]; + t_key key = cb->args[3]; + + /* First time here, count and key are both always 0. Count > 0 + * and key == 0 means the dump has wrapped around and we are done. + */ + if (count && !key) + return skb->len; + + while ((l = leaf_walk_rcu(&tp, key)) != NULL) { + int err; + + err = fn_trie_dump_leaf(l, tb, skb, cb, filter); + if (err < 0) { + cb->args[3] = key; + cb->args[2] = count; + return err; + } + + ++count; + key = l->key + 1; + + memset(&cb->args[4], 0, + sizeof(cb->args) - 4*sizeof(cb->args[0])); + + /* stop loop if key wrapped back to 0 */ + if (key < l->key) + break; + } + + cb->args[3] = key; + cb->args[2] = count; + + return skb->len; +} + +void __init fib_trie_init(void) +{ + fn_alias_kmem = kmem_cache_create("ip_fib_alias", + sizeof(struct fib_alias), + 0, SLAB_PANIC, NULL); + + trie_leaf_kmem = kmem_cache_create("ip_fib_trie", + LEAF_SIZE, + 0, SLAB_PANIC, NULL); +} + +struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) +{ + struct fib_table *tb; + struct trie *t; + size_t sz = sizeof(*tb); + + if (!alias) + sz += sizeof(struct trie); + + tb = kzalloc(sz, GFP_KERNEL); + if (!tb) + return NULL; + + tb->tb_id = id; + tb->tb_num_default = 0; + tb->tb_data = (alias ? alias->__data : tb->__data); + + if (alias) + return tb; + + t = (struct trie *) tb->tb_data; + t->kv[0].pos = KEYLENGTH; + t->kv[0].slen = KEYLENGTH; +#ifdef CONFIG_IP_FIB_TRIE_STATS + t->stats = alloc_percpu(struct trie_use_stats); + if (!t->stats) { + kfree(tb); + tb = NULL; + } +#endif + + return tb; +} + +#ifdef CONFIG_PROC_FS +/* Depth first Trie walk iterator */ +struct fib_trie_iter { + struct seq_net_private p; + struct fib_table *tb; + struct key_vector *tnode; + unsigned int index; + unsigned int depth; +}; + +static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) +{ + unsigned long cindex = iter->index; + struct key_vector *pn = iter->tnode; + t_key pkey; + + pr_debug("get_next iter={node=%p index=%d depth=%d}\n", + iter->tnode, iter->index, iter->depth); + + while (!IS_TRIE(pn)) { + while (cindex < child_length(pn)) { + struct key_vector *n = get_child_rcu(pn, cindex++); + + if (!n) + continue; + + if (IS_LEAF(n)) { + iter->tnode = pn; + iter->index = cindex; + } else { + /* push down one level */ + iter->tnode = n; + iter->index = 0; + ++iter->depth; + } + + return n; + } + + /* Current node exhausted, pop back up */ + pkey = pn->key; + pn = node_parent_rcu(pn); + cindex = get_index(pkey, pn) + 1; + --iter->depth; + } + + /* record root node so further searches know we are done */ + iter->tnode = pn; + iter->index = 0; + + return NULL; +} + +static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, + struct trie *t) +{ + struct key_vector *n, *pn; + + if (!t) + return NULL; + + pn = t->kv; + n = rcu_dereference(pn->tnode[0]); + if (!n) + return NULL; + + if (IS_TNODE(n)) { + iter->tnode = n; + iter->index = 0; + iter->depth = 1; + } else { + iter->tnode = pn; + iter->index = 0; + iter->depth = 0; + } + + return n; +} + +static void trie_collect_stats(struct trie *t, struct trie_stat *s) +{ + struct key_vector *n; + struct fib_trie_iter iter; + + memset(s, 0, sizeof(*s)); + + rcu_read_lock(); + for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { + if (IS_LEAF(n)) { + struct fib_alias *fa; + + s->leaves++; + s->totdepth += iter.depth; + if (iter.depth > s->maxdepth) + s->maxdepth = iter.depth; + + hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) + ++s->prefixes; + } else { + s->tnodes++; + if (n->bits < MAX_STAT_DEPTH) + s->nodesizes[n->bits]++; + s->nullpointers += tn_info(n)->empty_children; + } + } + rcu_read_unlock(); +} + +/* + * This outputs /proc/net/fib_triestats + */ +static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) +{ + unsigned int i, max, pointers, bytes, avdepth; + + if (stat->leaves) + avdepth = stat->totdepth*100 / stat->leaves; + else + avdepth = 0; + + seq_printf(seq, "\tAver depth: %u.%02d\n", + avdepth / 100, avdepth % 100); + seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); + + seq_printf(seq, "\tLeaves: %u\n", stat->leaves); + bytes = LEAF_SIZE * stat->leaves; + + seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); + bytes += sizeof(struct fib_alias) * stat->prefixes; + + seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); + bytes += TNODE_SIZE(0) * stat->tnodes; + + max = MAX_STAT_DEPTH; + while (max > 0 && stat->nodesizes[max-1] == 0) + max--; + + pointers = 0; + for (i = 1; i < max; i++) + if (stat->nodesizes[i] != 0) { + seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); + pointers += (1<<i) * stat->nodesizes[i]; + } + seq_putc(seq, '\n'); + seq_printf(seq, "\tPointers: %u\n", pointers); + + bytes += sizeof(struct key_vector *) * pointers; + seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); + seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); +} + +#ifdef CONFIG_IP_FIB_TRIE_STATS +static void trie_show_usage(struct seq_file *seq, + const struct trie_use_stats __percpu *stats) +{ + struct trie_use_stats s = { 0 }; + int cpu; + + /* loop through all of the CPUs and gather up the stats */ + for_each_possible_cpu(cpu) { + const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); + + s.gets += pcpu->gets; + s.backtrack += pcpu->backtrack; + s.semantic_match_passed += pcpu->semantic_match_passed; + s.semantic_match_miss += pcpu->semantic_match_miss; + s.null_node_hit += pcpu->null_node_hit; + s.resize_node_skipped += pcpu->resize_node_skipped; + } + + seq_printf(seq, "\nCounters:\n---------\n"); + seq_printf(seq, "gets = %u\n", s.gets); + seq_printf(seq, "backtracks = %u\n", s.backtrack); + seq_printf(seq, "semantic match passed = %u\n", + s.semantic_match_passed); + seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); + seq_printf(seq, "null node hit= %u\n", s.null_node_hit); + seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); +} +#endif /* CONFIG_IP_FIB_TRIE_STATS */ + +static void fib_table_print(struct seq_file *seq, struct fib_table *tb) +{ + if (tb->tb_id == RT_TABLE_LOCAL) + seq_puts(seq, "Local:\n"); + else if (tb->tb_id == RT_TABLE_MAIN) + seq_puts(seq, "Main:\n"); + else + seq_printf(seq, "Id %d:\n", tb->tb_id); +} + + +static int fib_triestat_seq_show(struct seq_file *seq, void *v) +{ + struct net *net = (struct net *)seq->private; + unsigned int h; + + seq_printf(seq, + "Basic info: size of leaf:" + " %zd bytes, size of tnode: %zd bytes.\n", + LEAF_SIZE, TNODE_SIZE(0)); + + rcu_read_lock(); + for (h = 0; h < FIB_TABLE_HASHSZ; h++) { + struct hlist_head *head = &net->ipv4.fib_table_hash[h]; + struct fib_table *tb; + + hlist_for_each_entry_rcu(tb, head, tb_hlist) { + struct trie *t = (struct trie *) tb->tb_data; + struct trie_stat stat; + + if (!t) + continue; + + fib_table_print(seq, tb); + + trie_collect_stats(t, &stat); + trie_show_stats(seq, &stat); +#ifdef CONFIG_IP_FIB_TRIE_STATS + trie_show_usage(seq, t->stats); +#endif + } + cond_resched_rcu(); + } + rcu_read_unlock(); + + return 0; +} + +static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) +{ + struct fib_trie_iter *iter = seq->private; + struct net *net = seq_file_net(seq); + loff_t idx = 0; + unsigned int h; + + for (h = 0; h < FIB_TABLE_HASHSZ; h++) { + struct hlist_head *head = &net->ipv4.fib_table_hash[h]; + struct fib_table *tb; + + hlist_for_each_entry_rcu(tb, head, tb_hlist) { + struct key_vector *n; + + for (n = fib_trie_get_first(iter, + (struct trie *) tb->tb_data); + n; n = fib_trie_get_next(iter)) + if (pos == idx++) { + iter->tb = tb; + return n; + } + } + } + + return NULL; +} + +static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(RCU) +{ + rcu_read_lock(); + return fib_trie_get_idx(seq, *pos); +} + +static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct fib_trie_iter *iter = seq->private; + struct net *net = seq_file_net(seq); + struct fib_table *tb = iter->tb; + struct hlist_node *tb_node; + unsigned int h; + struct key_vector *n; + + ++*pos; + /* next node in same table */ + n = fib_trie_get_next(iter); + if (n) + return n; + + /* walk rest of this hash chain */ + h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); + while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { + tb = hlist_entry(tb_node, struct fib_table, tb_hlist); + n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); + if (n) + goto found; + } + + /* new hash chain */ + while (++h < FIB_TABLE_HASHSZ) { + struct hlist_head *head = &net->ipv4.fib_table_hash[h]; + hlist_for_each_entry_rcu(tb, head, tb_hlist) { + n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); + if (n) + goto found; + } + } + return NULL; + +found: + iter->tb = tb; + return n; +} + +static void fib_trie_seq_stop(struct seq_file *seq, void *v) + __releases(RCU) +{ + rcu_read_unlock(); +} + +static void seq_indent(struct seq_file *seq, int n) +{ + while (n-- > 0) + seq_puts(seq, " "); +} + +static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) +{ + switch (s) { + case RT_SCOPE_UNIVERSE: return "universe"; + case RT_SCOPE_SITE: return "site"; + case RT_SCOPE_LINK: return "link"; + case RT_SCOPE_HOST: return "host"; + case RT_SCOPE_NOWHERE: return "nowhere"; + default: + snprintf(buf, len, "scope=%d", s); + return buf; + } +} + +static const char *const rtn_type_names[__RTN_MAX] = { + [RTN_UNSPEC] = "UNSPEC", + [RTN_UNICAST] = "UNICAST", + [RTN_LOCAL] = "LOCAL", + [RTN_BROADCAST] = "BROADCAST", + [RTN_ANYCAST] = "ANYCAST", + [RTN_MULTICAST] = "MULTICAST", + [RTN_BLACKHOLE] = "BLACKHOLE", + [RTN_UNREACHABLE] = "UNREACHABLE", + [RTN_PROHIBIT] = "PROHIBIT", + [RTN_THROW] = "THROW", + [RTN_NAT] = "NAT", + [RTN_XRESOLVE] = "XRESOLVE", +}; + +static inline const char *rtn_type(char *buf, size_t len, unsigned int t) +{ + if (t < __RTN_MAX && rtn_type_names[t]) + return rtn_type_names[t]; + snprintf(buf, len, "type %u", t); + return buf; +} + +/* Pretty print the trie */ +static int fib_trie_seq_show(struct seq_file *seq, void *v) +{ + const struct fib_trie_iter *iter = seq->private; + struct key_vector *n = v; + + if (IS_TRIE(node_parent_rcu(n))) + fib_table_print(seq, iter->tb); + + if (IS_TNODE(n)) { + __be32 prf = htonl(n->key); + + seq_indent(seq, iter->depth-1); + seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", + &prf, KEYLENGTH - n->pos - n->bits, n->bits, + tn_info(n)->full_children, + tn_info(n)->empty_children); + } else { + __be32 val = htonl(n->key); + struct fib_alias *fa; + + seq_indent(seq, iter->depth); + seq_printf(seq, " |-- %pI4\n", &val); + + hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { + char buf1[32], buf2[32]; + + seq_indent(seq, iter->depth + 1); + seq_printf(seq, " /%zu %s %s", + KEYLENGTH - fa->fa_slen, + rtn_scope(buf1, sizeof(buf1), + fa->fa_info->fib_scope), + rtn_type(buf2, sizeof(buf2), + fa->fa_type)); + if (fa->fa_tos) + seq_printf(seq, " tos=%d", fa->fa_tos); + seq_putc(seq, '\n'); + } + } + + return 0; +} + +static const struct seq_operations fib_trie_seq_ops = { + .start = fib_trie_seq_start, + .next = fib_trie_seq_next, + .stop = fib_trie_seq_stop, + .show = fib_trie_seq_show, +}; + +struct fib_route_iter { + struct seq_net_private p; + struct fib_table *main_tb; + struct key_vector *tnode; + loff_t pos; + t_key key; +}; + +static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, + loff_t pos) +{ + struct key_vector *l, **tp = &iter->tnode; + t_key key; + + /* use cached location of previously found key */ + if (iter->pos > 0 && pos >= iter->pos) { + key = iter->key; + } else { + iter->pos = 1; + key = 0; + } + + pos -= iter->pos; + + while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) { + key = l->key + 1; + iter->pos++; + l = NULL; + + /* handle unlikely case of a key wrap */ + if (!key) + break; + } + + if (l) + iter->key = l->key; /* remember it */ + else + iter->pos = 0; /* forget it */ + + return l; +} + +static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(RCU) +{ + struct fib_route_iter *iter = seq->private; + struct fib_table *tb; + struct trie *t; + + rcu_read_lock(); + + tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); + if (!tb) + return NULL; + + iter->main_tb = tb; + t = (struct trie *)tb->tb_data; + iter->tnode = t->kv; + + if (*pos != 0) + return fib_route_get_idx(iter, *pos); + + iter->pos = 0; + iter->key = KEY_MAX; + + return SEQ_START_TOKEN; +} + +static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct fib_route_iter *iter = seq->private; + struct key_vector *l = NULL; + t_key key = iter->key + 1; + + ++*pos; + + /* only allow key of 0 for start of sequence */ + if ((v == SEQ_START_TOKEN) || key) + l = leaf_walk_rcu(&iter->tnode, key); + + if (l) { + iter->key = l->key; + iter->pos++; + } else { + iter->pos = 0; + } + + return l; +} + +static void fib_route_seq_stop(struct seq_file *seq, void *v) + __releases(RCU) +{ + rcu_read_unlock(); +} + +static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi) +{ + unsigned int flags = 0; + + if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) + flags = RTF_REJECT; + if (fi) { + const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); + + if (nhc->nhc_gw.ipv4) + flags |= RTF_GATEWAY; + } + if (mask == htonl(0xFFFFFFFF)) + flags |= RTF_HOST; + flags |= RTF_UP; + return flags; +} + +/* + * This outputs /proc/net/route. + * The format of the file is not supposed to be changed + * and needs to be same as fib_hash output to avoid breaking + * legacy utilities + */ +static int fib_route_seq_show(struct seq_file *seq, void *v) +{ + struct fib_route_iter *iter = seq->private; + struct fib_table *tb = iter->main_tb; + struct fib_alias *fa; + struct key_vector *l = v; + __be32 prefix; + + if (v == SEQ_START_TOKEN) { + seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " + "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" + "\tWindow\tIRTT"); + return 0; + } + + prefix = htonl(l->key); + + hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { + struct fib_info *fi = fa->fa_info; + __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); + unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); + + if ((fa->fa_type == RTN_BROADCAST) || + (fa->fa_type == RTN_MULTICAST)) + continue; + + if (fa->tb_id != tb->tb_id) + continue; + + seq_setwidth(seq, 127); + + if (fi) { + struct fib_nh_common *nhc = fib_info_nhc(fi, 0); + __be32 gw = 0; + + if (nhc->nhc_gw_family == AF_INET) + gw = nhc->nhc_gw.ipv4; + + seq_printf(seq, + "%s\t%08X\t%08X\t%04X\t%d\t%u\t" + "%d\t%08X\t%d\t%u\t%u", + nhc->nhc_dev ? nhc->nhc_dev->name : "*", + prefix, gw, flags, 0, 0, + fi->fib_priority, + mask, + (fi->fib_advmss ? + fi->fib_advmss + 40 : 0), + fi->fib_window, + fi->fib_rtt >> 3); + } else { + seq_printf(seq, + "*\t%08X\t%08X\t%04X\t%d\t%u\t" + "%d\t%08X\t%d\t%u\t%u", + prefix, 0, flags, 0, 0, 0, + mask, 0, 0, 0); + } + seq_pad(seq, '\n'); + } + + return 0; +} + +static const struct seq_operations fib_route_seq_ops = { + .start = fib_route_seq_start, + .next = fib_route_seq_next, + .stop = fib_route_seq_stop, + .show = fib_route_seq_show, +}; + +int __net_init fib_proc_init(struct net *net) +{ + if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops, + sizeof(struct fib_trie_iter))) + goto out1; + + if (!proc_create_net_single("fib_triestat", 0444, net->proc_net, + fib_triestat_seq_show, NULL)) + goto out2; + + if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops, + sizeof(struct fib_route_iter))) + goto out3; + + return 0; + +out3: + remove_proc_entry("fib_triestat", net->proc_net); +out2: + remove_proc_entry("fib_trie", net->proc_net); +out1: + return -ENOMEM; +} + +void __net_exit fib_proc_exit(struct net *net) +{ + remove_proc_entry("fib_trie", net->proc_net); + remove_proc_entry("fib_triestat", net->proc_net); + remove_proc_entry("route", net->proc_net); +} + +#endif /* CONFIG_PROC_FS */ diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c new file mode 100644 index 000000000..e5f69b0bf --- /dev/null +++ b/net/ipv4/fou.c @@ -0,0 +1,1307 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/socket.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/icmp.h> +#include <linux/udp.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <net/genetlink.h> +#include <net/gue.h> +#include <net/fou.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/udp.h> +#include <net/udp_tunnel.h> +#include <net/xfrm.h> +#include <uapi/linux/fou.h> +#include <uapi/linux/genetlink.h> + +struct fou { + struct socket *sock; + u8 protocol; + u8 flags; + __be16 port; + u8 family; + u16 type; + struct list_head list; + struct rcu_head rcu; +}; + +#define FOU_F_REMCSUM_NOPARTIAL BIT(0) + +struct fou_cfg { + u16 type; + u8 protocol; + u8 flags; + struct udp_port_cfg udp_config; +}; + +static unsigned int fou_net_id; + +struct fou_net { + struct list_head fou_list; + struct mutex fou_lock; +}; + +static inline struct fou *fou_from_sock(struct sock *sk) +{ + return sk->sk_user_data; +} + +static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len) +{ + /* Remove 'len' bytes from the packet (UDP header and + * FOU header if present). + */ + if (fou->family == AF_INET) + ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len); + else + ipv6_hdr(skb)->payload_len = + htons(ntohs(ipv6_hdr(skb)->payload_len) - len); + + __skb_pull(skb, len); + skb_postpull_rcsum(skb, udp_hdr(skb), len); + skb_reset_transport_header(skb); + return iptunnel_pull_offloads(skb); +} + +static int fou_udp_recv(struct sock *sk, struct sk_buff *skb) +{ + struct fou *fou = fou_from_sock(sk); + + if (!fou) + return 1; + + if (fou_recv_pull(skb, fou, sizeof(struct udphdr))) + goto drop; + + return -fou->protocol; + +drop: + kfree_skb(skb); + return 0; +} + +static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr, + void *data, size_t hdrlen, u8 ipproto, + bool nopartial) +{ + __be16 *pd = data; + size_t start = ntohs(pd[0]); + size_t offset = ntohs(pd[1]); + size_t plen = sizeof(struct udphdr) + hdrlen + + max_t(size_t, offset + sizeof(u16), start); + + if (skb->remcsum_offload) + return guehdr; + + if (!pskb_may_pull(skb, plen)) + return NULL; + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + skb_remcsum_process(skb, (void *)guehdr + hdrlen, + start, offset, nopartial); + + return guehdr; +} + +static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr) +{ + /* No support yet */ + kfree_skb(skb); + return 0; +} + +static int gue_udp_recv(struct sock *sk, struct sk_buff *skb) +{ + struct fou *fou = fou_from_sock(sk); + size_t len, optlen, hdrlen; + struct guehdr *guehdr; + void *data; + u16 doffset = 0; + u8 proto_ctype; + + if (!fou) + return 1; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + if (!pskb_may_pull(skb, len)) + goto drop; + + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + switch (guehdr->version) { + case 0: /* Full GUE header present */ + break; + + case 1: { + /* Direct encapsulation of IPv4 or IPv6 */ + + int prot; + + switch (((struct iphdr *)guehdr)->version) { + case 4: + prot = IPPROTO_IPIP; + break; + case 6: + prot = IPPROTO_IPV6; + break; + default: + goto drop; + } + + if (fou_recv_pull(skb, fou, sizeof(struct udphdr))) + goto drop; + + return -prot; + } + + default: /* Undefined version */ + goto drop; + } + + optlen = guehdr->hlen << 2; + len += optlen; + + if (!pskb_may_pull(skb, len)) + goto drop; + + /* guehdr may change after pull */ + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + if (validate_gue_flags(guehdr, optlen)) + goto drop; + + hdrlen = sizeof(struct guehdr) + optlen; + + if (fou->family == AF_INET) + ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len); + else + ipv6_hdr(skb)->payload_len = + htons(ntohs(ipv6_hdr(skb)->payload_len) - len); + + /* Pull csum through the guehdr now . This can be used if + * there is a remote checksum offload. + */ + skb_postpull_rcsum(skb, udp_hdr(skb), len); + + data = &guehdr[1]; + + if (guehdr->flags & GUE_FLAG_PRIV) { + __be32 flags = *(__be32 *)(data + doffset); + + doffset += GUE_LEN_PRIV; + + if (flags & GUE_PFLAG_REMCSUM) { + guehdr = gue_remcsum(skb, guehdr, data + doffset, + hdrlen, guehdr->proto_ctype, + !!(fou->flags & + FOU_F_REMCSUM_NOPARTIAL)); + if (!guehdr) + goto drop; + + data = &guehdr[1]; + + doffset += GUE_PLEN_REMCSUM; + } + } + + if (unlikely(guehdr->control)) + return gue_control_message(skb, guehdr); + + proto_ctype = guehdr->proto_ctype; + __skb_pull(skb, sizeof(struct udphdr) + hdrlen); + skb_reset_transport_header(skb); + + if (iptunnel_pull_offloads(skb)) + goto drop; + + return -proto_ctype; + +drop: + kfree_skb(skb); + return 0; +} + +static struct sk_buff *fou_gro_receive(struct sock *sk, + struct list_head *head, + struct sk_buff *skb) +{ + u8 proto = fou_from_sock(sk)->protocol; + const struct net_offload **offloads; + const struct net_offload *ops; + struct sk_buff *pp = NULL; + + /* We can clear the encap_mark for FOU as we are essentially doing + * one of two possible things. We are either adding an L4 tunnel + * header to the outer L3 tunnel header, or we are simply + * treating the GRE tunnel header as though it is a UDP protocol + * specific header such as VXLAN or GENEVE. + */ + NAPI_GRO_CB(skb)->encap_mark = 0; + + /* Flag this frame as already having an outer encap header */ + NAPI_GRO_CB(skb)->is_fou = 1; + + rcu_read_lock(); + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (!ops || !ops->callbacks.gro_receive) + goto out_unlock; + + pp = call_gro_receive(ops->callbacks.gro_receive, head, skb); + +out_unlock: + rcu_read_unlock(); + + return pp; +} + +static int fou_gro_complete(struct sock *sk, struct sk_buff *skb, + int nhoff) +{ + const struct net_offload *ops; + u8 proto = fou_from_sock(sk)->protocol; + int err = -ENOSYS; + const struct net_offload **offloads; + + rcu_read_lock(); + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (WARN_ON(!ops || !ops->callbacks.gro_complete)) + goto out_unlock; + + err = ops->callbacks.gro_complete(skb, nhoff); + + skb_set_inner_mac_header(skb, nhoff); + +out_unlock: + rcu_read_unlock(); + + return err; +} + +static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off, + struct guehdr *guehdr, void *data, + size_t hdrlen, struct gro_remcsum *grc, + bool nopartial) +{ + __be16 *pd = data; + size_t start = ntohs(pd[0]); + size_t offset = ntohs(pd[1]); + + if (skb->remcsum_offload) + return guehdr; + + if (!NAPI_GRO_CB(skb)->csum_valid) + return NULL; + + guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen, + start, offset, grc, nopartial); + + skb->remcsum_offload = 1; + + return guehdr; +} + +static struct sk_buff *gue_gro_receive(struct sock *sk, + struct list_head *head, + struct sk_buff *skb) +{ + const struct net_offload **offloads; + const struct net_offload *ops; + struct sk_buff *pp = NULL; + struct sk_buff *p; + struct guehdr *guehdr; + size_t len, optlen, hdrlen, off; + void *data; + u16 doffset = 0; + int flush = 1; + struct fou *fou = fou_from_sock(sk); + struct gro_remcsum grc; + u8 proto; + + skb_gro_remcsum_init(&grc); + + off = skb_gro_offset(skb); + len = off + sizeof(*guehdr); + + guehdr = skb_gro_header_fast(skb, off); + if (skb_gro_header_hard(skb, len)) { + guehdr = skb_gro_header_slow(skb, len, off); + if (unlikely(!guehdr)) + goto out; + } + + switch (guehdr->version) { + case 0: + break; + case 1: + switch (((struct iphdr *)guehdr)->version) { + case 4: + proto = IPPROTO_IPIP; + break; + case 6: + proto = IPPROTO_IPV6; + break; + default: + goto out; + } + goto next_proto; + default: + goto out; + } + + optlen = guehdr->hlen << 2; + len += optlen; + + if (skb_gro_header_hard(skb, len)) { + guehdr = skb_gro_header_slow(skb, len, off); + if (unlikely(!guehdr)) + goto out; + } + + if (unlikely(guehdr->control) || guehdr->version != 0 || + validate_gue_flags(guehdr, optlen)) + goto out; + + hdrlen = sizeof(*guehdr) + optlen; + + /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr, + * this is needed if there is a remote checkcsum offload. + */ + skb_gro_postpull_rcsum(skb, guehdr, hdrlen); + + data = &guehdr[1]; + + if (guehdr->flags & GUE_FLAG_PRIV) { + __be32 flags = *(__be32 *)(data + doffset); + + doffset += GUE_LEN_PRIV; + + if (flags & GUE_PFLAG_REMCSUM) { + guehdr = gue_gro_remcsum(skb, off, guehdr, + data + doffset, hdrlen, &grc, + !!(fou->flags & + FOU_F_REMCSUM_NOPARTIAL)); + + if (!guehdr) + goto out; + + data = &guehdr[1]; + + doffset += GUE_PLEN_REMCSUM; + } + } + + skb_gro_pull(skb, hdrlen); + + list_for_each_entry(p, head, list) { + const struct guehdr *guehdr2; + + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + guehdr2 = (struct guehdr *)(p->data + off); + + /* Compare base GUE header to be equal (covers + * hlen, version, proto_ctype, and flags. + */ + if (guehdr->word != guehdr2->word) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + + /* Compare optional fields are the same. */ + if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1], + guehdr->hlen << 2)) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + } + + proto = guehdr->proto_ctype; + +next_proto: + + /* We can clear the encap_mark for GUE as we are essentially doing + * one of two possible things. We are either adding an L4 tunnel + * header to the outer L3 tunnel header, or we are simply + * treating the GRE tunnel header as though it is a UDP protocol + * specific header such as VXLAN or GENEVE. + */ + NAPI_GRO_CB(skb)->encap_mark = 0; + + /* Flag this frame as already having an outer encap header */ + NAPI_GRO_CB(skb)->is_fou = 1; + + rcu_read_lock(); + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive)) + goto out_unlock; + + pp = call_gro_receive(ops->callbacks.gro_receive, head, skb); + flush = 0; + +out_unlock: + rcu_read_unlock(); +out: + skb_gro_flush_final_remcsum(skb, pp, flush, &grc); + + return pp; +} + +static int gue_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff) +{ + const struct net_offload **offloads; + struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff); + const struct net_offload *ops; + unsigned int guehlen = 0; + u8 proto; + int err = -ENOENT; + + switch (guehdr->version) { + case 0: + proto = guehdr->proto_ctype; + guehlen = sizeof(*guehdr) + (guehdr->hlen << 2); + break; + case 1: + switch (((struct iphdr *)guehdr)->version) { + case 4: + proto = IPPROTO_IPIP; + break; + case 6: + proto = IPPROTO_IPV6; + break; + default: + return err; + } + break; + default: + return err; + } + + rcu_read_lock(); + offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[proto]); + if (WARN_ON(!ops || !ops->callbacks.gro_complete)) + goto out_unlock; + + err = ops->callbacks.gro_complete(skb, nhoff + guehlen); + + skb_set_inner_mac_header(skb, nhoff + guehlen); + +out_unlock: + rcu_read_unlock(); + return err; +} + +static bool fou_cfg_cmp(struct fou *fou, struct fou_cfg *cfg) +{ + struct sock *sk = fou->sock->sk; + struct udp_port_cfg *udp_cfg = &cfg->udp_config; + + if (fou->family != udp_cfg->family || + fou->port != udp_cfg->local_udp_port || + sk->sk_dport != udp_cfg->peer_udp_port || + sk->sk_bound_dev_if != udp_cfg->bind_ifindex) + return false; + + if (fou->family == AF_INET) { + if (sk->sk_rcv_saddr != udp_cfg->local_ip.s_addr || + sk->sk_daddr != udp_cfg->peer_ip.s_addr) + return false; + else + return true; +#if IS_ENABLED(CONFIG_IPV6) + } else { + if (ipv6_addr_cmp(&sk->sk_v6_rcv_saddr, &udp_cfg->local_ip6) || + ipv6_addr_cmp(&sk->sk_v6_daddr, &udp_cfg->peer_ip6)) + return false; + else + return true; +#endif + } + + return false; +} + +static int fou_add_to_port_list(struct net *net, struct fou *fou, + struct fou_cfg *cfg) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + struct fou *fout; + + mutex_lock(&fn->fou_lock); + list_for_each_entry(fout, &fn->fou_list, list) { + if (fou_cfg_cmp(fout, cfg)) { + mutex_unlock(&fn->fou_lock); + return -EALREADY; + } + } + + list_add(&fou->list, &fn->fou_list); + mutex_unlock(&fn->fou_lock); + + return 0; +} + +static void fou_release(struct fou *fou) +{ + struct socket *sock = fou->sock; + + list_del(&fou->list); + udp_tunnel_sock_release(sock); + + kfree_rcu(fou, rcu); +} + +static int fou_create(struct net *net, struct fou_cfg *cfg, + struct socket **sockp) +{ + struct socket *sock = NULL; + struct fou *fou = NULL; + struct sock *sk; + struct udp_tunnel_sock_cfg tunnel_cfg; + int err; + + /* Open UDP socket */ + err = udp_sock_create(net, &cfg->udp_config, &sock); + if (err < 0) + goto error; + + /* Allocate FOU port structure */ + fou = kzalloc(sizeof(*fou), GFP_KERNEL); + if (!fou) { + err = -ENOMEM; + goto error; + } + + sk = sock->sk; + + fou->port = cfg->udp_config.local_udp_port; + fou->family = cfg->udp_config.family; + fou->flags = cfg->flags; + fou->type = cfg->type; + fou->sock = sock; + + memset(&tunnel_cfg, 0, sizeof(tunnel_cfg)); + tunnel_cfg.encap_type = 1; + tunnel_cfg.sk_user_data = fou; + tunnel_cfg.encap_destroy = NULL; + + /* Initial for fou type */ + switch (cfg->type) { + case FOU_ENCAP_DIRECT: + tunnel_cfg.encap_rcv = fou_udp_recv; + tunnel_cfg.gro_receive = fou_gro_receive; + tunnel_cfg.gro_complete = fou_gro_complete; + fou->protocol = cfg->protocol; + break; + case FOU_ENCAP_GUE: + tunnel_cfg.encap_rcv = gue_udp_recv; + tunnel_cfg.gro_receive = gue_gro_receive; + tunnel_cfg.gro_complete = gue_gro_complete; + break; + default: + err = -EINVAL; + goto error; + } + + setup_udp_tunnel_sock(net, sock, &tunnel_cfg); + + sk->sk_allocation = GFP_ATOMIC; + + err = fou_add_to_port_list(net, fou, cfg); + if (err) + goto error; + + if (sockp) + *sockp = sock; + + return 0; + +error: + kfree(fou); + if (sock) + udp_tunnel_sock_release(sock); + + return err; +} + +static int fou_destroy(struct net *net, struct fou_cfg *cfg) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + int err = -EINVAL; + struct fou *fou; + + mutex_lock(&fn->fou_lock); + list_for_each_entry(fou, &fn->fou_list, list) { + if (fou_cfg_cmp(fou, cfg)) { + fou_release(fou); + err = 0; + break; + } + } + mutex_unlock(&fn->fou_lock); + + return err; +} + +static struct genl_family fou_nl_family; + +static const struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = { + [FOU_ATTR_PORT] = { .type = NLA_U16, }, + [FOU_ATTR_AF] = { .type = NLA_U8, }, + [FOU_ATTR_IPPROTO] = { .type = NLA_U8, }, + [FOU_ATTR_TYPE] = { .type = NLA_U8, }, + [FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, }, + [FOU_ATTR_LOCAL_V4] = { .type = NLA_U32, }, + [FOU_ATTR_PEER_V4] = { .type = NLA_U32, }, + [FOU_ATTR_LOCAL_V6] = { .len = sizeof(struct in6_addr), }, + [FOU_ATTR_PEER_V6] = { .len = sizeof(struct in6_addr), }, + [FOU_ATTR_PEER_PORT] = { .type = NLA_U16, }, + [FOU_ATTR_IFINDEX] = { .type = NLA_S32, }, +}; + +static int parse_nl_config(struct genl_info *info, + struct fou_cfg *cfg) +{ + bool has_local = false, has_peer = false; + struct nlattr *attr; + int ifindex; + __be16 port; + + memset(cfg, 0, sizeof(*cfg)); + + cfg->udp_config.family = AF_INET; + + if (info->attrs[FOU_ATTR_AF]) { + u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]); + + switch (family) { + case AF_INET: + break; + case AF_INET6: + cfg->udp_config.ipv6_v6only = 1; + break; + default: + return -EAFNOSUPPORT; + } + + cfg->udp_config.family = family; + } + + if (info->attrs[FOU_ATTR_PORT]) { + port = nla_get_be16(info->attrs[FOU_ATTR_PORT]); + cfg->udp_config.local_udp_port = port; + } + + if (info->attrs[FOU_ATTR_IPPROTO]) + cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]); + + if (info->attrs[FOU_ATTR_TYPE]) + cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]); + + if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL]) + cfg->flags |= FOU_F_REMCSUM_NOPARTIAL; + + if (cfg->udp_config.family == AF_INET) { + if (info->attrs[FOU_ATTR_LOCAL_V4]) { + attr = info->attrs[FOU_ATTR_LOCAL_V4]; + cfg->udp_config.local_ip.s_addr = nla_get_in_addr(attr); + has_local = true; + } + + if (info->attrs[FOU_ATTR_PEER_V4]) { + attr = info->attrs[FOU_ATTR_PEER_V4]; + cfg->udp_config.peer_ip.s_addr = nla_get_in_addr(attr); + has_peer = true; + } +#if IS_ENABLED(CONFIG_IPV6) + } else { + if (info->attrs[FOU_ATTR_LOCAL_V6]) { + attr = info->attrs[FOU_ATTR_LOCAL_V6]; + cfg->udp_config.local_ip6 = nla_get_in6_addr(attr); + has_local = true; + } + + if (info->attrs[FOU_ATTR_PEER_V6]) { + attr = info->attrs[FOU_ATTR_PEER_V6]; + cfg->udp_config.peer_ip6 = nla_get_in6_addr(attr); + has_peer = true; + } +#endif + } + + if (has_peer) { + if (info->attrs[FOU_ATTR_PEER_PORT]) { + port = nla_get_be16(info->attrs[FOU_ATTR_PEER_PORT]); + cfg->udp_config.peer_udp_port = port; + } else { + return -EINVAL; + } + } + + if (info->attrs[FOU_ATTR_IFINDEX]) { + if (!has_local) + return -EINVAL; + + ifindex = nla_get_s32(info->attrs[FOU_ATTR_IFINDEX]); + + cfg->udp_config.bind_ifindex = ifindex; + } + + return 0; +} + +static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct fou_cfg cfg; + int err; + + err = parse_nl_config(info, &cfg); + if (err) + return err; + + return fou_create(net, &cfg, NULL); +} + +static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct fou_cfg cfg; + int err; + + err = parse_nl_config(info, &cfg); + if (err) + return err; + + return fou_destroy(net, &cfg); +} + +static int fou_fill_info(struct fou *fou, struct sk_buff *msg) +{ + struct sock *sk = fou->sock->sk; + + if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) || + nla_put_be16(msg, FOU_ATTR_PORT, fou->port) || + nla_put_be16(msg, FOU_ATTR_PEER_PORT, sk->sk_dport) || + nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) || + nla_put_u8(msg, FOU_ATTR_TYPE, fou->type) || + nla_put_s32(msg, FOU_ATTR_IFINDEX, sk->sk_bound_dev_if)) + return -1; + + if (fou->flags & FOU_F_REMCSUM_NOPARTIAL) + if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL)) + return -1; + + if (fou->sock->sk->sk_family == AF_INET) { + if (nla_put_in_addr(msg, FOU_ATTR_LOCAL_V4, sk->sk_rcv_saddr)) + return -1; + + if (nla_put_in_addr(msg, FOU_ATTR_PEER_V4, sk->sk_daddr)) + return -1; +#if IS_ENABLED(CONFIG_IPV6) + } else { + if (nla_put_in6_addr(msg, FOU_ATTR_LOCAL_V6, + &sk->sk_v6_rcv_saddr)) + return -1; + + if (nla_put_in6_addr(msg, FOU_ATTR_PEER_V6, &sk->sk_v6_daddr)) + return -1; +#endif + } + + return 0; +} + +static int fou_dump_info(struct fou *fou, u32 portid, u32 seq, + u32 flags, struct sk_buff *skb, u8 cmd) +{ + void *hdr; + + hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd); + if (!hdr) + return -ENOMEM; + + if (fou_fill_info(fou, skb) < 0) + goto nla_put_failure; + + genlmsg_end(skb, hdr); + return 0; + +nla_put_failure: + genlmsg_cancel(skb, hdr); + return -EMSGSIZE; +} + +static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct fou_net *fn = net_generic(net, fou_net_id); + struct sk_buff *msg; + struct fou_cfg cfg; + struct fou *fout; + __be16 port; + u8 family; + int ret; + + ret = parse_nl_config(info, &cfg); + if (ret) + return ret; + port = cfg.udp_config.local_udp_port; + if (port == 0) + return -EINVAL; + + family = cfg.udp_config.family; + if (family != AF_INET && family != AF_INET6) + return -EINVAL; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = -ESRCH; + mutex_lock(&fn->fou_lock); + list_for_each_entry(fout, &fn->fou_list, list) { + if (fou_cfg_cmp(fout, &cfg)) { + ret = fou_dump_info(fout, info->snd_portid, + info->snd_seq, 0, msg, + info->genlhdr->cmd); + break; + } + } + mutex_unlock(&fn->fou_lock); + if (ret < 0) + goto out_free; + + return genlmsg_reply(msg, info); + +out_free: + nlmsg_free(msg); + return ret; +} + +static int fou_nl_dump(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + struct fou_net *fn = net_generic(net, fou_net_id); + struct fou *fout; + int idx = 0, ret; + + mutex_lock(&fn->fou_lock); + list_for_each_entry(fout, &fn->fou_list, list) { + if (idx++ < cb->args[0]) + continue; + ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, NLM_F_MULTI, + skb, FOU_CMD_GET); + if (ret) + break; + } + mutex_unlock(&fn->fou_lock); + + cb->args[0] = idx; + return skb->len; +} + +static const struct genl_small_ops fou_nl_ops[] = { + { + .cmd = FOU_CMD_ADD, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = fou_nl_cmd_add_port, + .flags = GENL_ADMIN_PERM, + }, + { + .cmd = FOU_CMD_DEL, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = fou_nl_cmd_rm_port, + .flags = GENL_ADMIN_PERM, + }, + { + .cmd = FOU_CMD_GET, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = fou_nl_cmd_get_port, + .dumpit = fou_nl_dump, + }, +}; + +static struct genl_family fou_nl_family __ro_after_init = { + .hdrsize = 0, + .name = FOU_GENL_NAME, + .version = FOU_GENL_VERSION, + .maxattr = FOU_ATTR_MAX, + .policy = fou_nl_policy, + .netnsok = true, + .module = THIS_MODULE, + .small_ops = fou_nl_ops, + .n_small_ops = ARRAY_SIZE(fou_nl_ops), +}; + +size_t fou_encap_hlen(struct ip_tunnel_encap *e) +{ + return sizeof(struct udphdr); +} +EXPORT_SYMBOL(fou_encap_hlen); + +size_t gue_encap_hlen(struct ip_tunnel_encap *e) +{ + size_t len; + bool need_priv = false; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + + if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) { + len += GUE_PLEN_REMCSUM; + need_priv = true; + } + + len += need_priv ? GUE_LEN_PRIV : 0; + + return len; +} +EXPORT_SYMBOL(gue_encap_hlen); + +int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, __be16 *sport, int type) +{ + int err; + + err = iptunnel_handle_offloads(skb, type); + if (err) + return err; + + *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev), + skb, 0, 0, false); + + return 0; +} +EXPORT_SYMBOL(__fou_build_header); + +int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, __be16 *sport, int type) +{ + struct guehdr *guehdr; + size_t hdrlen, optlen = 0; + void *data; + bool need_priv = false; + int err; + + if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) && + skb->ip_summed == CHECKSUM_PARTIAL) { + optlen += GUE_PLEN_REMCSUM; + type |= SKB_GSO_TUNNEL_REMCSUM; + need_priv = true; + } + + optlen += need_priv ? GUE_LEN_PRIV : 0; + + err = iptunnel_handle_offloads(skb, type); + if (err) + return err; + + /* Get source port (based on flow hash) before skb_push */ + *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev), + skb, 0, 0, false); + + hdrlen = sizeof(struct guehdr) + optlen; + + skb_push(skb, hdrlen); + + guehdr = (struct guehdr *)skb->data; + + guehdr->control = 0; + guehdr->version = 0; + guehdr->hlen = optlen >> 2; + guehdr->flags = 0; + guehdr->proto_ctype = *protocol; + + data = &guehdr[1]; + + if (need_priv) { + __be32 *flags = data; + + guehdr->flags |= GUE_FLAG_PRIV; + *flags = 0; + data += GUE_LEN_PRIV; + + if (type & SKB_GSO_TUNNEL_REMCSUM) { + u16 csum_start = skb_checksum_start_offset(skb); + __be16 *pd = data; + + if (csum_start < hdrlen) + return -EINVAL; + + csum_start -= hdrlen; + pd[0] = htons(csum_start); + pd[1] = htons(csum_start + skb->csum_offset); + + if (!skb_is_gso(skb)) { + skb->ip_summed = CHECKSUM_NONE; + skb->encapsulation = 0; + } + + *flags |= GUE_PFLAG_REMCSUM; + data += GUE_PLEN_REMCSUM; + } + + } + + return 0; +} +EXPORT_SYMBOL(__gue_build_header); + +#ifdef CONFIG_NET_FOU_IP_TUNNELS + +static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e, + struct flowi4 *fl4, u8 *protocol, __be16 sport) +{ + struct udphdr *uh; + + skb_push(skb, sizeof(struct udphdr)); + skb_reset_transport_header(skb); + + uh = udp_hdr(skb); + + uh->dest = e->dport; + uh->source = sport; + uh->len = htons(skb->len); + udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb, + fl4->saddr, fl4->daddr, skb->len); + + *protocol = IPPROTO_UDP; +} + +static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, struct flowi4 *fl4) +{ + int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM : + SKB_GSO_UDP_TUNNEL; + __be16 sport; + int err; + + err = __fou_build_header(skb, e, protocol, &sport, type); + if (err) + return err; + + fou_build_udp(skb, e, fl4, protocol, sport); + + return 0; +} + +static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, struct flowi4 *fl4) +{ + int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM : + SKB_GSO_UDP_TUNNEL; + __be16 sport; + int err; + + err = __gue_build_header(skb, e, protocol, &sport, type); + if (err) + return err; + + fou_build_udp(skb, e, fl4, protocol, sport); + + return 0; +} + +static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info) +{ + const struct net_protocol *ipprot = rcu_dereference(inet_protos[proto]); + + if (ipprot && ipprot->err_handler) { + if (!ipprot->err_handler(skb, info)) + return 0; + } + + return -ENOENT; +} + +static int gue_err(struct sk_buff *skb, u32 info) +{ + int transport_offset = skb_transport_offset(skb); + struct guehdr *guehdr; + size_t len, optlen; + int ret; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + if (!pskb_may_pull(skb, transport_offset + len)) + return -EINVAL; + + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + + switch (guehdr->version) { + case 0: /* Full GUE header present */ + break; + case 1: { + /* Direct encapsulation of IPv4 or IPv6 */ + skb_set_transport_header(skb, -(int)sizeof(struct icmphdr)); + + switch (((struct iphdr *)guehdr)->version) { + case 4: + ret = gue_err_proto_handler(IPPROTO_IPIP, skb, info); + goto out; +#if IS_ENABLED(CONFIG_IPV6) + case 6: + ret = gue_err_proto_handler(IPPROTO_IPV6, skb, info); + goto out; +#endif + default: + ret = -EOPNOTSUPP; + goto out; + } + } + default: /* Undefined version */ + return -EOPNOTSUPP; + } + + if (guehdr->control) + return -ENOENT; + + optlen = guehdr->hlen << 2; + + if (!pskb_may_pull(skb, transport_offset + len + optlen)) + return -EINVAL; + + guehdr = (struct guehdr *)&udp_hdr(skb)[1]; + if (validate_gue_flags(guehdr, optlen)) + return -EINVAL; + + /* Handling exceptions for direct UDP encapsulation in GUE would lead to + * recursion. Besides, this kind of encapsulation can't even be + * configured currently. Discard this. + */ + if (guehdr->proto_ctype == IPPROTO_UDP || + guehdr->proto_ctype == IPPROTO_UDPLITE) + return -EOPNOTSUPP; + + skb_set_transport_header(skb, -(int)sizeof(struct icmphdr)); + ret = gue_err_proto_handler(guehdr->proto_ctype, skb, info); + +out: + skb_set_transport_header(skb, transport_offset); + return ret; +} + + +static const struct ip_tunnel_encap_ops fou_iptun_ops = { + .encap_hlen = fou_encap_hlen, + .build_header = fou_build_header, + .err_handler = gue_err, +}; + +static const struct ip_tunnel_encap_ops gue_iptun_ops = { + .encap_hlen = gue_encap_hlen, + .build_header = gue_build_header, + .err_handler = gue_err, +}; + +static int ip_tunnel_encap_add_fou_ops(void) +{ + int ret; + + ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + if (ret < 0) { + pr_err("can't add fou ops\n"); + return ret; + } + + ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE); + if (ret < 0) { + pr_err("can't add gue ops\n"); + ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + return ret; + } + + return 0; +} + +static void ip_tunnel_encap_del_fou_ops(void) +{ + ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE); +} + +#else + +static int ip_tunnel_encap_add_fou_ops(void) +{ + return 0; +} + +static void ip_tunnel_encap_del_fou_ops(void) +{ +} + +#endif + +static __net_init int fou_init_net(struct net *net) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + + INIT_LIST_HEAD(&fn->fou_list); + mutex_init(&fn->fou_lock); + return 0; +} + +static __net_exit void fou_exit_net(struct net *net) +{ + struct fou_net *fn = net_generic(net, fou_net_id); + struct fou *fou, *next; + + /* Close all the FOU sockets */ + mutex_lock(&fn->fou_lock); + list_for_each_entry_safe(fou, next, &fn->fou_list, list) + fou_release(fou); + mutex_unlock(&fn->fou_lock); +} + +static struct pernet_operations fou_net_ops = { + .init = fou_init_net, + .exit = fou_exit_net, + .id = &fou_net_id, + .size = sizeof(struct fou_net), +}; + +static int __init fou_init(void) +{ + int ret; + + ret = register_pernet_device(&fou_net_ops); + if (ret) + goto exit; + + ret = genl_register_family(&fou_nl_family); + if (ret < 0) + goto unregister; + + ret = ip_tunnel_encap_add_fou_ops(); + if (ret == 0) + return 0; + + genl_unregister_family(&fou_nl_family); +unregister: + unregister_pernet_device(&fou_net_ops); +exit: + return ret; +} + +static void __exit fou_fini(void) +{ + ip_tunnel_encap_del_fou_ops(); + genl_unregister_family(&fou_nl_family); + unregister_pernet_device(&fou_net_ops); +} + +module_init(fou_init); +module_exit(fou_fini); +MODULE_AUTHOR("Tom Herbert <therbert@google.com>"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Foo over UDP"); diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c new file mode 100644 index 000000000..5d1e6fe9d --- /dev/null +++ b/net/ipv4/gre_demux.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * GRE over IPv4 demultiplexer driver + * + * Authors: Dmitry Kozlov (xeb@mail.ru) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/if.h> +#include <linux/icmp.h> +#include <linux/kernel.h> +#include <linux/kmod.h> +#include <linux/skbuff.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/netdevice.h> +#include <linux/if_tunnel.h> +#include <linux/spinlock.h> +#include <net/protocol.h> +#include <net/gre.h> +#include <net/erspan.h> + +#include <net/icmp.h> +#include <net/route.h> +#include <net/xfrm.h> + +static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly; + +int gre_add_protocol(const struct gre_protocol *proto, u8 version) +{ + if (version >= GREPROTO_MAX) + return -EINVAL; + + return (cmpxchg((const struct gre_protocol **)&gre_proto[version], NULL, proto) == NULL) ? + 0 : -EBUSY; +} +EXPORT_SYMBOL_GPL(gre_add_protocol); + +int gre_del_protocol(const struct gre_protocol *proto, u8 version) +{ + int ret; + + if (version >= GREPROTO_MAX) + return -EINVAL; + + ret = (cmpxchg((const struct gre_protocol **)&gre_proto[version], proto, NULL) == proto) ? + 0 : -EBUSY; + + if (ret) + return ret; + + synchronize_rcu(); + return 0; +} +EXPORT_SYMBOL_GPL(gre_del_protocol); + +/* Fills in tpi and returns header length to be pulled. + * Note that caller must use pskb_may_pull() before pulling GRE header. + */ +int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, + bool *csum_err, __be16 proto, int nhs) +{ + const struct gre_base_hdr *greh; + __be32 *options; + int hdr_len; + + if (unlikely(!pskb_may_pull(skb, nhs + sizeof(struct gre_base_hdr)))) + return -EINVAL; + + greh = (struct gre_base_hdr *)(skb->data + nhs); + if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) + return -EINVAL; + + tpi->flags = gre_flags_to_tnl_flags(greh->flags); + hdr_len = gre_calc_hlen(tpi->flags); + + if (!pskb_may_pull(skb, nhs + hdr_len)) + return -EINVAL; + + greh = (struct gre_base_hdr *)(skb->data + nhs); + tpi->proto = greh->protocol; + + options = (__be32 *)(greh + 1); + if (greh->flags & GRE_CSUM) { + if (!skb_checksum_simple_validate(skb)) { + skb_checksum_try_convert(skb, IPPROTO_GRE, + null_compute_pseudo); + } else if (csum_err) { + *csum_err = true; + return -EINVAL; + } + + options++; + } + + if (greh->flags & GRE_KEY) { + tpi->key = *options; + options++; + } else { + tpi->key = 0; + } + if (unlikely(greh->flags & GRE_SEQ)) { + tpi->seq = *options; + options++; + } else { + tpi->seq = 0; + } + /* WCCP version 1 and 2 protocol decoding. + * - Change protocol to IPv4/IPv6 + * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header + */ + if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { + u8 _val, *val; + + val = skb_header_pointer(skb, nhs + hdr_len, + sizeof(_val), &_val); + if (!val) + return -EINVAL; + tpi->proto = proto; + if ((*val & 0xF0) != 0x40) + hdr_len += 4; + } + tpi->hdr_len = hdr_len; + + /* ERSPAN ver 1 and 2 protocol sets GRE key field + * to 0 and sets the configured key in the + * inner erspan header field + */ + if ((greh->protocol == htons(ETH_P_ERSPAN) && hdr_len != 4) || + greh->protocol == htons(ETH_P_ERSPAN2)) { + struct erspan_base_hdr *ershdr; + + if (!pskb_may_pull(skb, nhs + hdr_len + sizeof(*ershdr))) + return -EINVAL; + + ershdr = (struct erspan_base_hdr *)(skb->data + nhs + hdr_len); + tpi->key = cpu_to_be32(get_session_id(ershdr)); + } + + return hdr_len; +} +EXPORT_SYMBOL(gre_parse_header); + +static int gre_rcv(struct sk_buff *skb) +{ + const struct gre_protocol *proto; + u8 ver; + int ret; + + if (!pskb_may_pull(skb, 12)) + goto drop; + + ver = skb->data[1]&0x7f; + if (ver >= GREPROTO_MAX) + goto drop; + + rcu_read_lock(); + proto = rcu_dereference(gre_proto[ver]); + if (!proto || !proto->handler) + goto drop_unlock; + ret = proto->handler(skb); + rcu_read_unlock(); + return ret; + +drop_unlock: + rcu_read_unlock(); +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +static int gre_err(struct sk_buff *skb, u32 info) +{ + const struct gre_protocol *proto; + const struct iphdr *iph = (const struct iphdr *)skb->data; + u8 ver = skb->data[(iph->ihl<<2) + 1]&0x7f; + int err = 0; + + if (ver >= GREPROTO_MAX) + return -EINVAL; + + rcu_read_lock(); + proto = rcu_dereference(gre_proto[ver]); + if (proto && proto->err_handler) + proto->err_handler(skb, info); + else + err = -EPROTONOSUPPORT; + rcu_read_unlock(); + + return err; +} + +static const struct net_protocol net_gre_protocol = { + .handler = gre_rcv, + .err_handler = gre_err, + .netns_ok = 1, +}; + +static int __init gre_init(void) +{ + pr_info("GRE over IPv4 demultiplexor driver\n"); + + if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) { + pr_err("can't add protocol\n"); + return -EAGAIN; + } + return 0; +} + +static void __exit gre_exit(void) +{ + inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); +} + +module_init(gre_init); +module_exit(gre_exit); + +MODULE_DESCRIPTION("GRE over IPv4 demultiplexer driver"); +MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)"); +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c new file mode 100644 index 000000000..e0a246575 --- /dev/null +++ b/net/ipv4/gre_offload.c @@ -0,0 +1,290 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IPV4 GSO/GRO offload support + * Linux INET implementation + * + * GRE GSO support + */ + +#include <linux/skbuff.h> +#include <linux/init.h> +#include <net/protocol.h> +#include <net/gre.h> + +static struct sk_buff *gre_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); + bool need_csum, need_recompute_csum, gso_partial; + struct sk_buff *segs = ERR_PTR(-EINVAL); + u16 mac_offset = skb->mac_header; + __be16 protocol = skb->protocol; + u16 mac_len = skb->mac_len; + int gre_offset, outer_hlen; + + if (!skb->encapsulation) + goto out; + + if (unlikely(tnl_hlen < sizeof(struct gre_base_hdr))) + goto out; + + if (unlikely(!pskb_may_pull(skb, tnl_hlen))) + goto out; + + /* setup inner skb. */ + skb->encapsulation = 0; + SKB_GSO_CB(skb)->encap_level = 0; + __skb_pull(skb, tnl_hlen); + skb_reset_mac_header(skb); + skb_set_network_header(skb, skb_inner_network_offset(skb)); + skb->mac_len = skb_inner_network_offset(skb); + skb->protocol = skb->inner_protocol; + + need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM); + need_recompute_csum = skb->csum_not_inet; + skb->encap_hdr_csum = need_csum; + + features &= skb->dev->hw_enc_features; + + /* segment inner packet. */ + segs = skb_mac_gso_segment(skb, features); + if (IS_ERR_OR_NULL(segs)) { + skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, + mac_len); + goto out; + } + + gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); + + outer_hlen = skb_tnl_header_len(skb); + gre_offset = outer_hlen - tnl_hlen; + skb = segs; + do { + struct gre_base_hdr *greh; + __sum16 *pcsum; + + /* Set up inner headers if we are offloading inner checksum */ + if (skb->ip_summed == CHECKSUM_PARTIAL) { + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + } + + skb->mac_len = mac_len; + skb->protocol = protocol; + + __skb_push(skb, outer_hlen); + skb_reset_mac_header(skb); + skb_set_network_header(skb, mac_len); + skb_set_transport_header(skb, gre_offset); + + if (!need_csum) + continue; + + greh = (struct gre_base_hdr *)skb_transport_header(skb); + pcsum = (__sum16 *)(greh + 1); + + if (gso_partial && skb_is_gso(skb)) { + unsigned int partial_adj; + + /* Adjust checksum to account for the fact that + * the partial checksum is based on actual size + * whereas headers should be based on MSS size. + */ + partial_adj = skb->len + skb_headroom(skb) - + SKB_GSO_CB(skb)->data_offset - + skb_shinfo(skb)->gso_size; + *pcsum = ~csum_fold((__force __wsum)htonl(partial_adj)); + } else { + *pcsum = 0; + } + + *(pcsum + 1) = 0; + if (need_recompute_csum && !skb_is_gso(skb)) { + __wsum csum; + + csum = skb_checksum(skb, gre_offset, + skb->len - gre_offset, 0); + *pcsum = csum_fold(csum); + } else { + *pcsum = gso_make_checksum(skb, 0); + } + } while ((skb = skb->next)); +out: + return segs; +} + +static struct sk_buff *gre_gro_receive(struct list_head *head, + struct sk_buff *skb) +{ + struct sk_buff *pp = NULL; + struct sk_buff *p; + const struct gre_base_hdr *greh; + unsigned int hlen, grehlen; + unsigned int off; + int flush = 1; + struct packet_offload *ptype; + __be16 type; + + if (NAPI_GRO_CB(skb)->encap_mark) + goto out; + + NAPI_GRO_CB(skb)->encap_mark = 1; + + off = skb_gro_offset(skb); + hlen = off + sizeof(*greh); + greh = skb_gro_header_fast(skb, off); + if (skb_gro_header_hard(skb, hlen)) { + greh = skb_gro_header_slow(skb, hlen, off); + if (unlikely(!greh)) + goto out; + } + + /* Only support version 0 and K (key), C (csum) flags. Note that + * although the support for the S (seq#) flag can be added easily + * for GRO, this is problematic for GSO hence can not be enabled + * here because a GRO pkt may end up in the forwarding path, thus + * requiring GSO support to break it up correctly. + */ + if ((greh->flags & ~(GRE_KEY|GRE_CSUM)) != 0) + goto out; + + /* We can only support GRE_CSUM if we can track the location of + * the GRE header. In the case of FOU/GUE we cannot because the + * outer UDP header displaces the GRE header leaving us in a state + * of limbo. + */ + if ((greh->flags & GRE_CSUM) && NAPI_GRO_CB(skb)->is_fou) + goto out; + + type = greh->protocol; + + rcu_read_lock(); + ptype = gro_find_receive_by_type(type); + if (!ptype) + goto out_unlock; + + grehlen = GRE_HEADER_SECTION; + + if (greh->flags & GRE_KEY) + grehlen += GRE_HEADER_SECTION; + + if (greh->flags & GRE_CSUM) + grehlen += GRE_HEADER_SECTION; + + hlen = off + grehlen; + if (skb_gro_header_hard(skb, hlen)) { + greh = skb_gro_header_slow(skb, hlen, off); + if (unlikely(!greh)) + goto out_unlock; + } + + /* Don't bother verifying checksum if we're going to flush anyway. */ + if ((greh->flags & GRE_CSUM) && !NAPI_GRO_CB(skb)->flush) { + if (skb_gro_checksum_simple_validate(skb)) + goto out_unlock; + + skb_gro_checksum_try_convert(skb, IPPROTO_GRE, + null_compute_pseudo); + } + + list_for_each_entry(p, head, list) { + const struct gre_base_hdr *greh2; + + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + /* The following checks are needed to ensure only pkts + * from the same tunnel are considered for aggregation. + * The criteria for "the same tunnel" includes: + * 1) same version (we only support version 0 here) + * 2) same protocol (we only support ETH_P_IP for now) + * 3) same set of flags + * 4) same key if the key field is present. + */ + greh2 = (struct gre_base_hdr *)(p->data + off); + + if (greh2->flags != greh->flags || + greh2->protocol != greh->protocol) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + if (greh->flags & GRE_KEY) { + /* compare keys */ + if (*(__be32 *)(greh2+1) != *(__be32 *)(greh+1)) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + } + } + + skb_gro_pull(skb, grehlen); + + /* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/ + skb_gro_postpull_rcsum(skb, greh, grehlen); + + pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb); + flush = 0; + +out_unlock: + rcu_read_unlock(); +out: + skb_gro_flush_final(skb, pp, flush); + + return pp; +} + +static int gre_gro_complete(struct sk_buff *skb, int nhoff) +{ + struct gre_base_hdr *greh = (struct gre_base_hdr *)(skb->data + nhoff); + struct packet_offload *ptype; + unsigned int grehlen = sizeof(*greh); + int err = -ENOENT; + __be16 type; + + skb->encapsulation = 1; + skb_shinfo(skb)->gso_type = SKB_GSO_GRE; + + type = greh->protocol; + if (greh->flags & GRE_KEY) + grehlen += GRE_HEADER_SECTION; + + if (greh->flags & GRE_CSUM) + grehlen += GRE_HEADER_SECTION; + + rcu_read_lock(); + ptype = gro_find_complete_by_type(type); + if (ptype) + err = ptype->callbacks.gro_complete(skb, nhoff + grehlen); + + rcu_read_unlock(); + + skb_set_inner_mac_header(skb, nhoff + grehlen); + + return err; +} + +static const struct net_offload gre_offload = { + .callbacks = { + .gso_segment = gre_gso_segment, + .gro_receive = gre_gro_receive, + .gro_complete = gre_gro_complete, + }, +}; + +static int __init gre_offload_init(void) +{ + int err; + + err = inet_add_offload(&gre_offload, IPPROTO_GRE); +#if IS_ENABLED(CONFIG_IPV6) + if (err) + return err; + + err = inet6_add_offload(&gre_offload, IPPROTO_GRE); + if (err) + inet_del_offload(&gre_offload, IPPROTO_GRE); +#endif + + return err; +} +device_initcall(gre_offload_init); diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c new file mode 100644 index 000000000..0bbc047e8 --- /dev/null +++ b/net/ipv4/icmp.c @@ -0,0 +1,1393 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * NET3: Implementation of the ICMP protocol layer. + * + * Alan Cox, <alan@lxorguk.ukuu.org.uk> + * + * Some of the function names and the icmp unreach table for this + * module were derived from [icmp.c 1.0.11 06/02/93] by + * Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting. + * Other than that this module is a complete rewrite. + * + * Fixes: + * Clemens Fruhwirth : introduce global icmp rate limiting + * with icmp type masking ability instead + * of broken per type icmp timeouts. + * Mike Shaver : RFC1122 checks. + * Alan Cox : Multicast ping reply as self. + * Alan Cox : Fix atomicity lockup in ip_build_xmit + * call. + * Alan Cox : Added 216,128 byte paths to the MTU + * code. + * Martin Mares : RFC1812 checks. + * Martin Mares : Can be configured to follow redirects + * if acting as a router _without_ a + * routing protocol (RFC 1812). + * Martin Mares : Echo requests may be configured to + * be ignored (RFC 1812). + * Martin Mares : Limitation of ICMP error message + * transmit rate (RFC 1812). + * Martin Mares : TOS and Precedence set correctly + * (RFC 1812). + * Martin Mares : Now copying as much data from the + * original packet as we can without + * exceeding 576 bytes (RFC 1812). + * Willy Konynenberg : Transparent proxying support. + * Keith Owens : RFC1191 correction for 4.2BSD based + * path MTU bug. + * Thomas Quinot : ICMP Dest Unreach codes up to 15 are + * valid (RFC 1812). + * Andi Kleen : Check all packet lengths properly + * and moved all kfree_skb() up to + * icmp_rcv. + * Andi Kleen : Move the rate limit bookkeeping + * into the dest entry and use a token + * bucket filter (thanks to ANK). Make + * the rates sysctl configurable. + * Yu Tianli : Fixed two ugly bugs in icmp_send + * - IP option length was accounted wrongly + * - ICMP header length was not accounted + * at all. + * Tristan Greaves : Added sysctl option to ignore bogus + * broadcast responses from broken routers. + * + * To Fix: + * + * - Should use skb_pull() instead of all the manual checking. + * This would also greatly simply some upper layer error handlers. --AK + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/fcntl.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/string.h> +#include <linux/netfilter_ipv4.h> +#include <linux/slab.h> +#include <net/snmp.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/protocol.h> +#include <net/icmp.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/raw.h> +#include <net/ping.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <linux/errno.h> +#include <linux/timer.h> +#include <linux/init.h> +#include <linux/uaccess.h> +#include <net/checksum.h> +#include <net/xfrm.h> +#include <net/inet_common.h> +#include <net/ip_fib.h> +#include <net/l3mdev.h> + +/* + * Build xmit assembly blocks + */ + +struct icmp_bxm { + struct sk_buff *skb; + int offset; + int data_len; + + struct { + struct icmphdr icmph; + __be32 times[3]; + } data; + int head_len; + struct ip_options_data replyopts; +}; + +/* An array of errno for error messages from dest unreach. */ +/* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */ + +const struct icmp_err icmp_err_convert[] = { + { + .errno = ENETUNREACH, /* ICMP_NET_UNREACH */ + .fatal = 0, + }, + { + .errno = EHOSTUNREACH, /* ICMP_HOST_UNREACH */ + .fatal = 0, + }, + { + .errno = ENOPROTOOPT /* ICMP_PROT_UNREACH */, + .fatal = 1, + }, + { + .errno = ECONNREFUSED, /* ICMP_PORT_UNREACH */ + .fatal = 1, + }, + { + .errno = EMSGSIZE, /* ICMP_FRAG_NEEDED */ + .fatal = 0, + }, + { + .errno = EOPNOTSUPP, /* ICMP_SR_FAILED */ + .fatal = 0, + }, + { + .errno = ENETUNREACH, /* ICMP_NET_UNKNOWN */ + .fatal = 1, + }, + { + .errno = EHOSTDOWN, /* ICMP_HOST_UNKNOWN */ + .fatal = 1, + }, + { + .errno = ENONET, /* ICMP_HOST_ISOLATED */ + .fatal = 1, + }, + { + .errno = ENETUNREACH, /* ICMP_NET_ANO */ + .fatal = 1, + }, + { + .errno = EHOSTUNREACH, /* ICMP_HOST_ANO */ + .fatal = 1, + }, + { + .errno = ENETUNREACH, /* ICMP_NET_UNR_TOS */ + .fatal = 0, + }, + { + .errno = EHOSTUNREACH, /* ICMP_HOST_UNR_TOS */ + .fatal = 0, + }, + { + .errno = EHOSTUNREACH, /* ICMP_PKT_FILTERED */ + .fatal = 1, + }, + { + .errno = EHOSTUNREACH, /* ICMP_PREC_VIOLATION */ + .fatal = 1, + }, + { + .errno = EHOSTUNREACH, /* ICMP_PREC_CUTOFF */ + .fatal = 1, + }, +}; +EXPORT_SYMBOL(icmp_err_convert); + +/* + * ICMP control array. This specifies what to do with each ICMP. + */ + +struct icmp_control { + bool (*handler)(struct sk_buff *skb); + short error; /* This ICMP is classed as an error message */ +}; + +static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1]; + +/* + * The ICMP socket(s). This is the most convenient way to flow control + * our ICMP output as well as maintain a clean interface throughout + * all layers. All Socketless IP sends will soon be gone. + * + * On SMP we have one ICMP socket per-cpu. + */ +static struct sock *icmp_sk(struct net *net) +{ + return this_cpu_read(*net->ipv4.icmp_sk); +} + +/* Called with BH disabled */ +static inline struct sock *icmp_xmit_lock(struct net *net) +{ + struct sock *sk; + + sk = icmp_sk(net); + + if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { + /* This can happen if the output path signals a + * dst_link_failure() for an outgoing ICMP packet. + */ + return NULL; + } + return sk; +} + +static inline void icmp_xmit_unlock(struct sock *sk) +{ + spin_unlock(&sk->sk_lock.slock); +} + +int sysctl_icmp_msgs_per_sec __read_mostly = 1000; +int sysctl_icmp_msgs_burst __read_mostly = 50; + +static struct { + spinlock_t lock; + u32 credit; + u32 stamp; +} icmp_global = { + .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock), +}; + +/** + * icmp_global_allow - Are we allowed to send one more ICMP message ? + * + * Uses a token bucket to limit our ICMP messages to ~sysctl_icmp_msgs_per_sec. + * Returns false if we reached the limit and can not send another packet. + * Note: called with BH disabled + */ +bool icmp_global_allow(void) +{ + u32 credit, delta, incr = 0, now = (u32)jiffies; + bool rc = false; + + /* Check if token bucket is empty and cannot be refilled + * without taking the spinlock. The READ_ONCE() are paired + * with the following WRITE_ONCE() in this same function. + */ + if (!READ_ONCE(icmp_global.credit)) { + delta = min_t(u32, now - READ_ONCE(icmp_global.stamp), HZ); + if (delta < HZ / 50) + return false; + } + + spin_lock(&icmp_global.lock); + delta = min_t(u32, now - icmp_global.stamp, HZ); + if (delta >= HZ / 50) { + incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ; + if (incr) + WRITE_ONCE(icmp_global.stamp, now); + } + credit = min_t(u32, icmp_global.credit + incr, + READ_ONCE(sysctl_icmp_msgs_burst)); + if (credit) { + /* We want to use a credit of one in average, but need to randomize + * it for security reasons. + */ + credit = max_t(int, credit - prandom_u32_max(3), 0); + rc = true; + } + WRITE_ONCE(icmp_global.credit, credit); + spin_unlock(&icmp_global.lock); + return rc; +} +EXPORT_SYMBOL(icmp_global_allow); + +static bool icmpv4_mask_allow(struct net *net, int type, int code) +{ + if (type > NR_ICMP_TYPES) + return true; + + /* Don't limit PMTU discovery. */ + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) + return true; + + /* Limit if icmp type is enabled in ratemask. */ + if (!((1 << type) & READ_ONCE(net->ipv4.sysctl_icmp_ratemask))) + return true; + + return false; +} + +static bool icmpv4_global_allow(struct net *net, int type, int code) +{ + if (icmpv4_mask_allow(net, type, code)) + return true; + + if (icmp_global_allow()) + return true; + + return false; +} + +/* + * Send an ICMP frame. + */ + +static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, + struct flowi4 *fl4, int type, int code) +{ + struct dst_entry *dst = &rt->dst; + struct inet_peer *peer; + bool rc = true; + int vif; + + if (icmpv4_mask_allow(net, type, code)) + goto out; + + /* No rate limit on loopback */ + if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) + goto out; + + vif = l3mdev_master_ifindex(dst->dev); + peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1); + rc = inet_peer_xrlim_allow(peer, + READ_ONCE(net->ipv4.sysctl_icmp_ratelimit)); + if (peer) + inet_putpeer(peer); +out: + return rc; +} + +/* + * Maintain the counters used in the SNMP statistics for outgoing ICMP + */ +void icmp_out_count(struct net *net, unsigned char type) +{ + ICMPMSGOUT_INC_STATS(net, type); + ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS); +} + +/* + * Checksum each fragment, and on the first include the headers and final + * checksum. + */ +static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, + struct sk_buff *skb) +{ + struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; + __wsum csum; + + csum = skb_copy_and_csum_bits(icmp_param->skb, + icmp_param->offset + offset, + to, len); + + skb->csum = csum_block_add(skb->csum, csum, odd); + if (icmp_pointers[icmp_param->data.icmph.type].error) + nf_ct_attach(skb, icmp_param->skb); + return 0; +} + +static void icmp_push_reply(struct icmp_bxm *icmp_param, + struct flowi4 *fl4, + struct ipcm_cookie *ipc, struct rtable **rt) +{ + struct sock *sk; + struct sk_buff *skb; + + sk = icmp_sk(dev_net((*rt)->dst.dev)); + if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param, + icmp_param->data_len+icmp_param->head_len, + icmp_param->head_len, + ipc, rt, MSG_DONTWAIT) < 0) { + __ICMP_INC_STATS(sock_net(sk), ICMP_MIB_OUTERRORS); + ip_flush_pending_frames(sk); + } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { + struct icmphdr *icmph = icmp_hdr(skb); + __wsum csum; + struct sk_buff *skb1; + + csum = csum_partial_copy_nocheck((void *)&icmp_param->data, + (char *)icmph, + icmp_param->head_len); + skb_queue_walk(&sk->sk_write_queue, skb1) { + csum = csum_add(csum, skb1->csum); + } + icmph->checksum = csum_fold(csum); + skb->ip_summed = CHECKSUM_NONE; + ip_push_pending_frames(sk, fl4); + } +} + +/* + * Driving logic for building and sending ICMP messages. + */ + +static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) +{ + struct ipcm_cookie ipc; + struct rtable *rt = skb_rtable(skb); + struct net *net = dev_net(rt->dst.dev); + struct flowi4 fl4; + struct sock *sk; + struct inet_sock *inet; + __be32 daddr, saddr; + u32 mark = IP4_REPLY_MARK(net, skb->mark); + int type = icmp_param->data.icmph.type; + int code = icmp_param->data.icmph.code; + + if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb)) + return; + + /* Needed by both icmp_global_allow and icmp_xmit_lock */ + local_bh_disable(); + + /* global icmp_msgs_per_sec */ + if (!icmpv4_global_allow(net, type, code)) + goto out_bh_enable; + + sk = icmp_xmit_lock(net); + if (!sk) + goto out_bh_enable; + inet = inet_sk(sk); + + icmp_param->data.icmph.checksum = 0; + + ipcm_init(&ipc); + inet->tos = ip_hdr(skb)->tos; + ipc.sockc.mark = mark; + daddr = ipc.addr = ip_hdr(skb)->saddr; + saddr = fib_compute_spec_dst(skb); + + if (icmp_param->replyopts.opt.opt.optlen) { + ipc.opt = &icmp_param->replyopts.opt; + if (ipc.opt->opt.srr) + daddr = icmp_param->replyopts.opt.opt.faddr; + } + memset(&fl4, 0, sizeof(fl4)); + fl4.daddr = daddr; + fl4.saddr = saddr; + fl4.flowi4_mark = mark; + fl4.flowi4_uid = sock_net_uid(net, NULL); + fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); + fl4.flowi4_proto = IPPROTO_ICMP; + fl4.flowi4_oif = l3mdev_master_ifindex(skb->dev); + security_skb_classify_flow(skb, flowi4_to_flowi_common(&fl4)); + rt = ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) + goto out_unlock; + if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + icmp_push_reply(icmp_param, &fl4, &ipc, &rt); + ip_rt_put(rt); +out_unlock: + icmp_xmit_unlock(sk); +out_bh_enable: + local_bh_enable(); +} + +/* + * The device used for looking up which routing table to use for sending an ICMP + * error is preferably the source whenever it is set, which should ensure the + * icmp error can be sent to the source host, else lookup using the routing + * table of the destination device, else use the main routing table (index 0). + */ +static struct net_device *icmp_get_route_lookup_dev(struct sk_buff *skb) +{ + struct net_device *route_lookup_dev = NULL; + + if (skb->dev) + route_lookup_dev = skb->dev; + else if (skb_dst(skb)) + route_lookup_dev = skb_dst(skb)->dev; + return route_lookup_dev; +} + +static struct rtable *icmp_route_lookup(struct net *net, + struct flowi4 *fl4, + struct sk_buff *skb_in, + const struct iphdr *iph, + __be32 saddr, u8 tos, u32 mark, + int type, int code, + struct icmp_bxm *param) +{ + struct net_device *route_lookup_dev; + struct rtable *rt, *rt2; + struct flowi4 fl4_dec; + int err; + + memset(fl4, 0, sizeof(*fl4)); + fl4->daddr = (param->replyopts.opt.opt.srr ? + param->replyopts.opt.opt.faddr : iph->saddr); + fl4->saddr = saddr; + fl4->flowi4_mark = mark; + fl4->flowi4_uid = sock_net_uid(net, NULL); + fl4->flowi4_tos = RT_TOS(tos); + fl4->flowi4_proto = IPPROTO_ICMP; + fl4->fl4_icmp_type = type; + fl4->fl4_icmp_code = code; + route_lookup_dev = icmp_get_route_lookup_dev(skb_in); + fl4->flowi4_oif = l3mdev_master_ifindex(route_lookup_dev); + + security_skb_classify_flow(skb_in, flowi4_to_flowi_common(fl4)); + rt = ip_route_output_key_hash(net, fl4, skb_in); + if (IS_ERR(rt)) + return rt; + + /* No need to clone since we're just using its address. */ + rt2 = rt; + + rt = (struct rtable *) xfrm_lookup(net, &rt->dst, + flowi4_to_flowi(fl4), NULL, 0); + if (!IS_ERR(rt)) { + if (rt != rt2) + return rt; + } else if (PTR_ERR(rt) == -EPERM) { + rt = NULL; + } else + return rt; + + err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET); + if (err) + goto relookup_failed; + + if (inet_addr_type_dev_table(net, route_lookup_dev, + fl4_dec.saddr) == RTN_LOCAL) { + rt2 = __ip_route_output_key(net, &fl4_dec); + if (IS_ERR(rt2)) + err = PTR_ERR(rt2); + } else { + struct flowi4 fl4_2 = {}; + unsigned long orefdst; + + fl4_2.daddr = fl4_dec.saddr; + rt2 = ip_route_output_key(net, &fl4_2); + if (IS_ERR(rt2)) { + err = PTR_ERR(rt2); + goto relookup_failed; + } + /* Ugh! */ + orefdst = skb_in->_skb_refdst; /* save old refdst */ + skb_dst_set(skb_in, NULL); + err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr, + RT_TOS(tos), rt2->dst.dev); + + dst_release(&rt2->dst); + rt2 = skb_rtable(skb_in); + skb_in->_skb_refdst = orefdst; /* restore old refdst */ + } + + if (err) + goto relookup_failed; + + rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, + flowi4_to_flowi(&fl4_dec), NULL, + XFRM_LOOKUP_ICMP); + if (!IS_ERR(rt2)) { + dst_release(&rt->dst); + memcpy(fl4, &fl4_dec, sizeof(*fl4)); + rt = rt2; + } else if (PTR_ERR(rt2) == -EPERM) { + if (rt) + dst_release(&rt->dst); + return rt2; + } else { + err = PTR_ERR(rt2); + goto relookup_failed; + } + return rt; + +relookup_failed: + if (rt) + return rt; + return ERR_PTR(err); +} + +/* + * Send an ICMP message in response to a situation + * + * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. + * MAY send more (we do). + * MUST NOT change this header information. + * MUST NOT reply to a multicast/broadcast IP address. + * MUST NOT reply to a multicast/broadcast MAC address. + * MUST reply to only the first fragment. + */ + +void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, + const struct ip_options *opt) +{ + struct iphdr *iph; + int room; + struct icmp_bxm icmp_param; + struct rtable *rt = skb_rtable(skb_in); + struct ipcm_cookie ipc; + struct flowi4 fl4; + __be32 saddr; + u8 tos; + u32 mark; + struct net *net; + struct sock *sk; + + if (!rt) + goto out; + + if (rt->dst.dev) + net = dev_net(rt->dst.dev); + else if (skb_in->dev) + net = dev_net(skb_in->dev); + else + goto out; + + /* + * Find the original header. It is expected to be valid, of course. + * Check this, icmp_send is called from the most obscure devices + * sometimes. + */ + iph = ip_hdr(skb_in); + + if ((u8 *)iph < skb_in->head || + (skb_network_header(skb_in) + sizeof(*iph)) > + skb_tail_pointer(skb_in)) + goto out; + + /* + * No replies to physical multicast/broadcast + */ + if (skb_in->pkt_type != PACKET_HOST) + goto out; + + /* + * Now check at the protocol level + */ + if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) + goto out; + + /* + * Only reply to fragment 0. We byte re-order the constant + * mask for efficiency. + */ + if (iph->frag_off & htons(IP_OFFSET)) + goto out; + + /* + * If we send an ICMP error to an ICMP error a mess would result.. + */ + if (icmp_pointers[type].error) { + /* + * We are an error, check if we are replying to an + * ICMP error + */ + if (iph->protocol == IPPROTO_ICMP) { + u8 _inner_type, *itp; + + itp = skb_header_pointer(skb_in, + skb_network_header(skb_in) + + (iph->ihl << 2) + + offsetof(struct icmphdr, + type) - + skb_in->data, + sizeof(_inner_type), + &_inner_type); + if (!itp) + goto out; + + /* + * Assume any unknown ICMP type is an error. This + * isn't specified by the RFC, but think about it.. + */ + if (*itp > NR_ICMP_TYPES || + icmp_pointers[*itp].error) + goto out; + } + } + + /* Needed by both icmp_global_allow and icmp_xmit_lock */ + local_bh_disable(); + + /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless + * incoming dev is loopback. If outgoing dev change to not be + * loopback, then peer ratelimit still work (in icmpv4_xrlim_allow) + */ + if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) && + !icmpv4_global_allow(net, type, code)) + goto out_bh_enable; + + sk = icmp_xmit_lock(net); + if (!sk) + goto out_bh_enable; + + /* + * Construct source address and options. + */ + + saddr = iph->daddr; + if (!(rt->rt_flags & RTCF_LOCAL)) { + struct net_device *dev = NULL; + + rcu_read_lock(); + if (rt_is_input_route(rt) && + net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) + dev = dev_get_by_index_rcu(net, inet_iif(skb_in)); + + if (dev) + saddr = inet_select_addr(dev, iph->saddr, + RT_SCOPE_LINK); + else + saddr = 0; + rcu_read_unlock(); + } + + tos = icmp_pointers[type].error ? (RT_TOS(iph->tos) | + IPTOS_PREC_INTERNETCONTROL) : + iph->tos; + mark = IP4_REPLY_MARK(net, skb_in->mark); + + if (__ip_options_echo(net, &icmp_param.replyopts.opt.opt, skb_in, opt)) + goto out_unlock; + + + /* + * Prepare data for ICMP header. + */ + + icmp_param.data.icmph.type = type; + icmp_param.data.icmph.code = code; + icmp_param.data.icmph.un.gateway = info; + icmp_param.data.icmph.checksum = 0; + icmp_param.skb = skb_in; + icmp_param.offset = skb_network_offset(skb_in); + inet_sk(sk)->tos = tos; + ipcm_init(&ipc); + ipc.addr = iph->saddr; + ipc.opt = &icmp_param.replyopts.opt; + ipc.sockc.mark = mark; + + rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark, + type, code, &icmp_param); + if (IS_ERR(rt)) + goto out_unlock; + + /* peer icmp_ratelimit */ + if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) + goto ende; + + /* RFC says return as much as we can without exceeding 576 bytes. */ + + room = dst_mtu(&rt->dst); + if (room > 576) + room = 576; + room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; + room -= sizeof(struct icmphdr); + /* Guard against tiny mtu. We need to include at least one + * IP network header for this message to make any sense. + */ + if (room <= (int)sizeof(struct iphdr)) + goto ende; + + icmp_param.data_len = skb_in->len - icmp_param.offset; + if (icmp_param.data_len > room) + icmp_param.data_len = room; + icmp_param.head_len = sizeof(struct icmphdr); + + /* if we don't have a source address at this point, fall back to the + * dummy address instead of sending out a packet with a source address + * of 0.0.0.0 + */ + if (!fl4.saddr) + fl4.saddr = htonl(INADDR_DUMMY); + + icmp_push_reply(&icmp_param, &fl4, &ipc, &rt); +ende: + ip_rt_put(rt); +out_unlock: + icmp_xmit_unlock(sk); +out_bh_enable: + local_bh_enable(); +out:; +} +EXPORT_SYMBOL(__icmp_send); + +#if IS_ENABLED(CONFIG_NF_NAT) +#include <net/netfilter/nf_conntrack.h> +void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info) +{ + struct sk_buff *cloned_skb = NULL; + struct ip_options opts = { 0 }; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + __be32 orig_ip; + + ct = nf_ct_get(skb_in, &ctinfo); + if (!ct || !(ct->status & IPS_SRC_NAT)) { + __icmp_send(skb_in, type, code, info, &opts); + return; + } + + if (skb_shared(skb_in)) + skb_in = cloned_skb = skb_clone(skb_in, GFP_ATOMIC); + + if (unlikely(!skb_in || skb_network_header(skb_in) < skb_in->head || + (skb_network_header(skb_in) + sizeof(struct iphdr)) > + skb_tail_pointer(skb_in) || skb_ensure_writable(skb_in, + skb_network_offset(skb_in) + sizeof(struct iphdr)))) + goto out; + + orig_ip = ip_hdr(skb_in)->saddr; + ip_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.ip; + __icmp_send(skb_in, type, code, info, &opts); + ip_hdr(skb_in)->saddr = orig_ip; +out: + consume_skb(cloned_skb); +} +EXPORT_SYMBOL(icmp_ndo_send); +#endif + +static void icmp_socket_deliver(struct sk_buff *skb, u32 info) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + const struct net_protocol *ipprot; + int protocol = iph->protocol; + + /* Checkin full IP header plus 8 bytes of protocol to + * avoid additional coding at protocol handlers. + */ + if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) { + __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS); + return; + } + + raw_icmp_error(skb, protocol, info); + + ipprot = rcu_dereference(inet_protos[protocol]); + if (ipprot && ipprot->err_handler) + ipprot->err_handler(skb, info); +} + +static bool icmp_tag_validation(int proto) +{ + bool ok; + + rcu_read_lock(); + ok = rcu_dereference(inet_protos[proto])->icmp_strict_tag_validation; + rcu_read_unlock(); + return ok; +} + +/* + * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEEDED, ICMP_QUENCH, and + * ICMP_PARAMETERPROB. + */ + +static bool icmp_unreach(struct sk_buff *skb) +{ + const struct iphdr *iph; + struct icmphdr *icmph; + struct net *net; + u32 info = 0; + + net = dev_net(skb_dst(skb)->dev); + + /* + * Incomplete header ? + * Only checks for the IP header, there should be an + * additional check for longer headers in upper levels. + */ + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + goto out_err; + + icmph = icmp_hdr(skb); + iph = (const struct iphdr *)skb->data; + + if (iph->ihl < 5) /* Mangled header, drop. */ + goto out_err; + + switch (icmph->type) { + case ICMP_DEST_UNREACH: + switch (icmph->code & 15) { + case ICMP_NET_UNREACH: + case ICMP_HOST_UNREACH: + case ICMP_PROT_UNREACH: + case ICMP_PORT_UNREACH: + break; + case ICMP_FRAG_NEEDED: + /* for documentation of the ip_no_pmtu_disc + * values please see + * Documentation/networking/ip-sysctl.rst + */ + switch (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc)) { + default: + net_dbg_ratelimited("%pI4: fragmentation needed and DF set\n", + &iph->daddr); + break; + case 2: + goto out; + case 3: + if (!icmp_tag_validation(iph->protocol)) + goto out; + fallthrough; + case 0: + info = ntohs(icmph->un.frag.mtu); + } + break; + case ICMP_SR_FAILED: + net_dbg_ratelimited("%pI4: Source Route Failed\n", + &iph->daddr); + break; + default: + break; + } + if (icmph->code > NR_ICMP_UNREACH) + goto out; + break; + case ICMP_PARAMETERPROB: + info = ntohl(icmph->un.gateway) >> 24; + break; + case ICMP_TIME_EXCEEDED: + __ICMP_INC_STATS(net, ICMP_MIB_INTIMEEXCDS); + if (icmph->code == ICMP_EXC_FRAGTIME) + goto out; + break; + } + + /* + * Throw it at our lower layers + * + * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed + * header. + * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the + * transport layer. + * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to + * transport layer. + */ + + /* + * Check the other end isn't violating RFC 1122. Some routers send + * bogus responses to broadcast frames. If you see this message + * first check your netmask matches at both ends, if it does then + * get the other vendor to fix their kit. + */ + + if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && + inet_addr_type_dev_table(net, skb->dev, iph->daddr) == RTN_BROADCAST) { + net_warn_ratelimited("%pI4 sent an invalid ICMP type %u, code %u error to a broadcast: %pI4 on %s\n", + &ip_hdr(skb)->saddr, + icmph->type, icmph->code, + &iph->daddr, skb->dev->name); + goto out; + } + + icmp_socket_deliver(skb, info); + +out: + return true; +out_err: + __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); + return false; +} + + +/* + * Handle ICMP_REDIRECT. + */ + +static bool icmp_redirect(struct sk_buff *skb) +{ + if (skb->len < sizeof(struct iphdr)) { + __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS); + return false; + } + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) { + /* there aught to be a stat */ + return false; + } + + icmp_socket_deliver(skb, ntohl(icmp_hdr(skb)->un.gateway)); + return true; +} + +/* + * Handle ICMP_ECHO ("ping") requests. + * + * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo + * requests. + * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be + * included in the reply. + * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring + * echo requests, MUST have default=NOT. + * See also WRT handling of options once they are done and working. + */ + +static bool icmp_echo(struct sk_buff *skb) +{ + struct net *net; + + net = dev_net(skb_dst(skb)->dev); + if (!net->ipv4.sysctl_icmp_echo_ignore_all) { + struct icmp_bxm icmp_param; + + icmp_param.data.icmph = *icmp_hdr(skb); + icmp_param.data.icmph.type = ICMP_ECHOREPLY; + icmp_param.skb = skb; + icmp_param.offset = 0; + icmp_param.data_len = skb->len; + icmp_param.head_len = sizeof(struct icmphdr); + icmp_reply(&icmp_param, skb); + } + /* should there be an ICMP stat for ignored echos? */ + return true; +} + +/* + * Handle ICMP Timestamp requests. + * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. + * SHOULD be in the kernel for minimum random latency. + * MUST be accurate to a few minutes. + * MUST be updated at least at 15Hz. + */ +static bool icmp_timestamp(struct sk_buff *skb) +{ + struct icmp_bxm icmp_param; + /* + * Too short. + */ + if (skb->len < 4) + goto out_err; + + /* + * Fill in the current time as ms since midnight UT: + */ + icmp_param.data.times[1] = inet_current_timestamp(); + icmp_param.data.times[2] = icmp_param.data.times[1]; + + BUG_ON(skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)); + + icmp_param.data.icmph = *icmp_hdr(skb); + icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; + icmp_param.data.icmph.code = 0; + icmp_param.skb = skb; + icmp_param.offset = 0; + icmp_param.data_len = 0; + icmp_param.head_len = sizeof(struct icmphdr) + 12; + icmp_reply(&icmp_param, skb); + return true; + +out_err: + __ICMP_INC_STATS(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); + return false; +} + +static bool icmp_discard(struct sk_buff *skb) +{ + /* pretend it was a success */ + return true; +} + +/* + * Deal with incoming ICMP packets. + */ +int icmp_rcv(struct sk_buff *skb) +{ + struct icmphdr *icmph; + struct rtable *rt = skb_rtable(skb); + struct net *net = dev_net(rt->dst.dev); + bool success; + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { + struct sec_path *sp = skb_sec_path(skb); + int nh; + + if (!(sp && sp->xvec[sp->len - 1]->props.flags & + XFRM_STATE_ICMP)) + goto drop; + + if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) + goto drop; + + nh = skb_network_offset(skb); + skb_set_network_header(skb, sizeof(*icmph)); + + if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) + goto drop; + + skb_set_network_header(skb, nh); + } + + __ICMP_INC_STATS(net, ICMP_MIB_INMSGS); + + if (skb_checksum_simple_validate(skb)) + goto csum_error; + + if (!pskb_pull(skb, sizeof(*icmph))) + goto error; + + icmph = icmp_hdr(skb); + + ICMPMSGIN_INC_STATS(net, icmph->type); + /* + * 18 is the highest 'known' ICMP type. Anything else is a mystery + * + * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently + * discarded. + */ + if (icmph->type > NR_ICMP_TYPES) + goto error; + + + /* + * Parse the ICMP message + */ + + if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { + /* + * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be + * silently ignored (we let user decide with a sysctl). + * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently + * discarded if to broadcast/multicast. + */ + if ((icmph->type == ICMP_ECHO || + icmph->type == ICMP_TIMESTAMP) && + net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { + goto error; + } + if (icmph->type != ICMP_ECHO && + icmph->type != ICMP_TIMESTAMP && + icmph->type != ICMP_ADDRESS && + icmph->type != ICMP_ADDRESSREPLY) { + goto error; + } + } + + success = icmp_pointers[icmph->type].handler(skb); + + if (success) { + consume_skb(skb); + return NET_RX_SUCCESS; + } + +drop: + kfree_skb(skb); + return NET_RX_DROP; +csum_error: + __ICMP_INC_STATS(net, ICMP_MIB_CSUMERRORS); +error: + __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); + goto drop; +} + +static bool ip_icmp_error_rfc4884_validate(const struct sk_buff *skb, int off) +{ + struct icmp_extobj_hdr *objh, _objh; + struct icmp_ext_hdr *exth, _exth; + u16 olen; + + exth = skb_header_pointer(skb, off, sizeof(_exth), &_exth); + if (!exth) + return false; + if (exth->version != 2) + return true; + + if (exth->checksum && + csum_fold(skb_checksum(skb, off, skb->len - off, 0))) + return false; + + off += sizeof(_exth); + while (off < skb->len) { + objh = skb_header_pointer(skb, off, sizeof(_objh), &_objh); + if (!objh) + return false; + + olen = ntohs(objh->length); + if (olen < sizeof(_objh)) + return false; + + off += olen; + if (off > skb->len) + return false; + } + + return true; +} + +void ip_icmp_error_rfc4884(const struct sk_buff *skb, + struct sock_ee_data_rfc4884 *out, + int thlen, int off) +{ + int hlen; + + /* original datagram headers: end of icmph to payload (skb->data) */ + hlen = -skb_transport_offset(skb) - thlen; + + /* per rfc 4884: minimal datagram length of 128 bytes */ + if (off < 128 || off < hlen) + return; + + /* kernel has stripped headers: return payload offset in bytes */ + off -= hlen; + if (off + sizeof(struct icmp_ext_hdr) > skb->len) + return; + + out->len = off; + + if (!ip_icmp_error_rfc4884_validate(skb, off)) + out->flags |= SO_EE_RFC4884_FLAG_INVALID; +} +EXPORT_SYMBOL_GPL(ip_icmp_error_rfc4884); + +int icmp_err(struct sk_buff *skb, u32 info) +{ + struct iphdr *iph = (struct iphdr *)skb->data; + int offset = iph->ihl<<2; + struct icmphdr *icmph = (struct icmphdr *)(skb->data + offset); + int type = icmp_hdr(skb)->type; + int code = icmp_hdr(skb)->code; + struct net *net = dev_net(skb->dev); + + /* + * Use ping_err to handle all icmp errors except those + * triggered by ICMP_ECHOREPLY which sent from kernel. + */ + if (icmph->type != ICMP_ECHOREPLY) { + ping_err(skb, offset, info); + return 0; + } + + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) + ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ICMP); + else if (type == ICMP_REDIRECT) + ipv4_redirect(skb, net, 0, IPPROTO_ICMP); + + return 0; +} + +/* + * This table is the definition of how we handle ICMP. + */ +static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { + [ICMP_ECHOREPLY] = { + .handler = ping_rcv, + }, + [1] = { + .handler = icmp_discard, + .error = 1, + }, + [2] = { + .handler = icmp_discard, + .error = 1, + }, + [ICMP_DEST_UNREACH] = { + .handler = icmp_unreach, + .error = 1, + }, + [ICMP_SOURCE_QUENCH] = { + .handler = icmp_unreach, + .error = 1, + }, + [ICMP_REDIRECT] = { + .handler = icmp_redirect, + .error = 1, + }, + [6] = { + .handler = icmp_discard, + .error = 1, + }, + [7] = { + .handler = icmp_discard, + .error = 1, + }, + [ICMP_ECHO] = { + .handler = icmp_echo, + }, + [9] = { + .handler = icmp_discard, + .error = 1, + }, + [10] = { + .handler = icmp_discard, + .error = 1, + }, + [ICMP_TIME_EXCEEDED] = { + .handler = icmp_unreach, + .error = 1, + }, + [ICMP_PARAMETERPROB] = { + .handler = icmp_unreach, + .error = 1, + }, + [ICMP_TIMESTAMP] = { + .handler = icmp_timestamp, + }, + [ICMP_TIMESTAMPREPLY] = { + .handler = icmp_discard, + }, + [ICMP_INFO_REQUEST] = { + .handler = icmp_discard, + }, + [ICMP_INFO_REPLY] = { + .handler = icmp_discard, + }, + [ICMP_ADDRESS] = { + .handler = icmp_discard, + }, + [ICMP_ADDRESSREPLY] = { + .handler = icmp_discard, + }, +}; + +static void __net_exit icmp_sk_exit(struct net *net) +{ + int i; + + for_each_possible_cpu(i) + inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i)); + free_percpu(net->ipv4.icmp_sk); + net->ipv4.icmp_sk = NULL; +} + +static int __net_init icmp_sk_init(struct net *net) +{ + int i, err; + + net->ipv4.icmp_sk = alloc_percpu(struct sock *); + if (!net->ipv4.icmp_sk) + return -ENOMEM; + + for_each_possible_cpu(i) { + struct sock *sk; + + err = inet_ctl_sock_create(&sk, PF_INET, + SOCK_RAW, IPPROTO_ICMP, net); + if (err < 0) + goto fail; + + *per_cpu_ptr(net->ipv4.icmp_sk, i) = sk; + + /* Enough space for 2 64K ICMP packets, including + * sk_buff/skb_shared_info struct overhead. + */ + sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); + + /* + * Speedup sock_wfree() + */ + sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); + inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; + } + + /* Control parameters for ECHO replies. */ + net->ipv4.sysctl_icmp_echo_ignore_all = 0; + net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; + + /* Control parameter - ignore bogus broadcast responses? */ + net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; + + /* + * Configurable global rate limit. + * + * ratelimit defines tokens/packet consumed for dst->rate_token + * bucket ratemask defines which icmp types are ratelimited by + * setting it's bit position. + * + * default: + * dest unreachable (3), source quench (4), + * time exceeded (11), parameter problem (12) + */ + + net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; + net->ipv4.sysctl_icmp_ratemask = 0x1818; + net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; + + return 0; + +fail: + icmp_sk_exit(net); + return err; +} + +static struct pernet_operations __net_initdata icmp_sk_ops = { + .init = icmp_sk_init, + .exit = icmp_sk_exit, +}; + +int __init icmp_init(void) +{ + return register_pernet_subsys(&icmp_sk_ops); +} diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c new file mode 100644 index 000000000..cb55fede0 --- /dev/null +++ b/net/ipv4/igmp.c @@ -0,0 +1,3101 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Linux NET3: Internet Group Management Protocol [IGMP] + * + * This code implements the IGMP protocol as defined in RFC1112. There has + * been a further revision of this protocol since which is now supported. + * + * If you have trouble with this module be careful what gcc you have used, + * the older version didn't come out right using gcc 2.5.8, the newer one + * seems to fall out with gcc 2.6.2. + * + * Authors: + * Alan Cox <alan@lxorguk.ukuu.org.uk> + * + * Fixes: + * + * Alan Cox : Added lots of __inline__ to optimise + * the memory usage of all the tiny little + * functions. + * Alan Cox : Dumped the header building experiment. + * Alan Cox : Minor tweaks ready for multicast routing + * and extended IGMP protocol. + * Alan Cox : Removed a load of inline directives. Gcc 2.5.8 + * writes utterly bogus code otherwise (sigh) + * fixed IGMP loopback to behave in the manner + * desired by mrouted, fixed the fact it has been + * broken since 1.3.6 and cleaned up a few minor + * points. + * + * Chih-Jen Chang : Tried to revise IGMP to Version 2 + * Tsu-Sheng Tsao E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu + * The enhancements are mainly based on Steve Deering's + * ipmulti-3.5 source code. + * Chih-Jen Chang : Added the igmp_get_mrouter_info and + * Tsu-Sheng Tsao igmp_set_mrouter_info to keep track of + * the mrouted version on that device. + * Chih-Jen Chang : Added the max_resp_time parameter to + * Tsu-Sheng Tsao igmp_heard_query(). Using this parameter + * to identify the multicast router version + * and do what the IGMP version 2 specified. + * Chih-Jen Chang : Added a timer to revert to IGMP V2 router + * Tsu-Sheng Tsao if the specified time expired. + * Alan Cox : Stop IGMP from 0.0.0.0 being accepted. + * Alan Cox : Use GFP_ATOMIC in the right places. + * Christian Daudt : igmp timer wasn't set for local group + * memberships but was being deleted, + * which caused a "del_timer() called + * from %p with timer not initialized\n" + * message (960131). + * Christian Daudt : removed del_timer from + * igmp_timer_expire function (960205). + * Christian Daudt : igmp_heard_report now only calls + * igmp_timer_expire if tm->running is + * true (960216). + * Malcolm Beattie : ttl comparison wrong in igmp_rcv made + * igmp_heard_query never trigger. Expiry + * miscalculation fixed in igmp_heard_query + * and random() made to return unsigned to + * prevent negative expiry times. + * Alexey Kuznetsov: Wrong group leaving behaviour, backport + * fix from pending 2.1.x patches. + * Alan Cox: Forget to enable FDDI support earlier. + * Alexey Kuznetsov: Fixed leaving groups on device down. + * Alexey Kuznetsov: Accordance to igmp-v2-06 draft. + * David L Stevens: IGMPv3 support, with help from + * Vinay Kulkarni + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/string.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/inetdevice.h> +#include <linux/igmp.h> +#include <linux/if_arp.h> +#include <linux/rtnetlink.h> +#include <linux/times.h> +#include <linux/pkt_sched.h> +#include <linux/byteorder/generic.h> + +#include <net/net_namespace.h> +#include <net/arp.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/route.h> +#include <net/sock.h> +#include <net/checksum.h> +#include <net/inet_common.h> +#include <linux/netfilter_ipv4.h> +#ifdef CONFIG_IP_MROUTE +#include <linux/mroute.h> +#endif +#ifdef CONFIG_PROC_FS +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#endif + +#ifdef CONFIG_IP_MULTICAST +/* Parameter names and values are taken from igmp-v2-06 draft */ + +#define IGMP_QUERY_INTERVAL (125*HZ) +#define IGMP_QUERY_RESPONSE_INTERVAL (10*HZ) + +#define IGMP_INITIAL_REPORT_DELAY (1) + +/* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs! + * IGMP specs require to report membership immediately after + * joining a group, but we delay the first report by a + * small interval. It seems more natural and still does not + * contradict to specs provided this delay is small enough. + */ + +#define IGMP_V1_SEEN(in_dev) \ + (IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \ + IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \ + ((in_dev)->mr_v1_seen && \ + time_before(jiffies, (in_dev)->mr_v1_seen))) +#define IGMP_V2_SEEN(in_dev) \ + (IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \ + IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \ + ((in_dev)->mr_v2_seen && \ + time_before(jiffies, (in_dev)->mr_v2_seen))) + +static int unsolicited_report_interval(struct in_device *in_dev) +{ + int interval_ms, interval_jiffies; + + if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) + interval_ms = IN_DEV_CONF_GET( + in_dev, + IGMPV2_UNSOLICITED_REPORT_INTERVAL); + else /* v3 */ + interval_ms = IN_DEV_CONF_GET( + in_dev, + IGMPV3_UNSOLICITED_REPORT_INTERVAL); + + interval_jiffies = msecs_to_jiffies(interval_ms); + + /* _timer functions can't handle a delay of 0 jiffies so ensure + * we always return a positive value. + */ + if (interval_jiffies <= 0) + interval_jiffies = 1; + return interval_jiffies; +} + +static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im, + gfp_t gfp); +static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im); +static void igmpv3_clear_delrec(struct in_device *in_dev); +static int sf_setstate(struct ip_mc_list *pmc); +static void sf_markstate(struct ip_mc_list *pmc); +#endif +static void ip_mc_clear_src(struct ip_mc_list *pmc); +static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode, + int sfcount, __be32 *psfsrc, int delta); + +static void ip_ma_put(struct ip_mc_list *im) +{ + if (refcount_dec_and_test(&im->refcnt)) { + in_dev_put(im->interface); + kfree_rcu(im, rcu); + } +} + +#define for_each_pmc_rcu(in_dev, pmc) \ + for (pmc = rcu_dereference(in_dev->mc_list); \ + pmc != NULL; \ + pmc = rcu_dereference(pmc->next_rcu)) + +#define for_each_pmc_rtnl(in_dev, pmc) \ + for (pmc = rtnl_dereference(in_dev->mc_list); \ + pmc != NULL; \ + pmc = rtnl_dereference(pmc->next_rcu)) + +static void ip_sf_list_clear_all(struct ip_sf_list *psf) +{ + struct ip_sf_list *next; + + while (psf) { + next = psf->sf_next; + kfree(psf); + psf = next; + } +} + +#ifdef CONFIG_IP_MULTICAST + +/* + * Timer management + */ + +static void igmp_stop_timer(struct ip_mc_list *im) +{ + spin_lock_bh(&im->lock); + if (del_timer(&im->timer)) + refcount_dec(&im->refcnt); + im->tm_running = 0; + im->reporter = 0; + im->unsolicit_count = 0; + spin_unlock_bh(&im->lock); +} + +/* It must be called with locked im->lock */ +static void igmp_start_timer(struct ip_mc_list *im, int max_delay) +{ + int tv = prandom_u32() % max_delay; + + im->tm_running = 1; + if (refcount_inc_not_zero(&im->refcnt)) { + if (mod_timer(&im->timer, jiffies + tv + 2)) + ip_ma_put(im); + } +} + +static void igmp_gq_start_timer(struct in_device *in_dev) +{ + int tv = prandom_u32() % in_dev->mr_maxdelay; + unsigned long exp = jiffies + tv + 2; + + if (in_dev->mr_gq_running && + time_after_eq(exp, (in_dev->mr_gq_timer).expires)) + return; + + in_dev->mr_gq_running = 1; + if (!mod_timer(&in_dev->mr_gq_timer, exp)) + in_dev_hold(in_dev); +} + +static void igmp_ifc_start_timer(struct in_device *in_dev, int delay) +{ + int tv = prandom_u32() % delay; + + if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2)) + in_dev_hold(in_dev); +} + +static void igmp_mod_timer(struct ip_mc_list *im, int max_delay) +{ + spin_lock_bh(&im->lock); + im->unsolicit_count = 0; + if (del_timer(&im->timer)) { + if ((long)(im->timer.expires-jiffies) < max_delay) { + add_timer(&im->timer); + im->tm_running = 1; + spin_unlock_bh(&im->lock); + return; + } + refcount_dec(&im->refcnt); + } + igmp_start_timer(im, max_delay); + spin_unlock_bh(&im->lock); +} + + +/* + * Send an IGMP report. + */ + +#define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4) + + +static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type, + int gdeleted, int sdeleted) +{ + switch (type) { + case IGMPV3_MODE_IS_INCLUDE: + case IGMPV3_MODE_IS_EXCLUDE: + if (gdeleted || sdeleted) + return 0; + if (!(pmc->gsquery && !psf->sf_gsresp)) { + if (pmc->sfmode == MCAST_INCLUDE) + return 1; + /* don't include if this source is excluded + * in all filters + */ + if (psf->sf_count[MCAST_INCLUDE]) + return type == IGMPV3_MODE_IS_INCLUDE; + return pmc->sfcount[MCAST_EXCLUDE] == + psf->sf_count[MCAST_EXCLUDE]; + } + return 0; + case IGMPV3_CHANGE_TO_INCLUDE: + if (gdeleted || sdeleted) + return 0; + return psf->sf_count[MCAST_INCLUDE] != 0; + case IGMPV3_CHANGE_TO_EXCLUDE: + if (gdeleted || sdeleted) + return 0; + if (pmc->sfcount[MCAST_EXCLUDE] == 0 || + psf->sf_count[MCAST_INCLUDE]) + return 0; + return pmc->sfcount[MCAST_EXCLUDE] == + psf->sf_count[MCAST_EXCLUDE]; + case IGMPV3_ALLOW_NEW_SOURCES: + if (gdeleted || !psf->sf_crcount) + return 0; + return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted; + case IGMPV3_BLOCK_OLD_SOURCES: + if (pmc->sfmode == MCAST_INCLUDE) + return gdeleted || (psf->sf_crcount && sdeleted); + return psf->sf_crcount && !gdeleted && !sdeleted; + } + return 0; +} + +static int +igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted) +{ + struct ip_sf_list *psf; + int scount = 0; + + for (psf = pmc->sources; psf; psf = psf->sf_next) { + if (!is_in(pmc, psf, type, gdeleted, sdeleted)) + continue; + scount++; + } + return scount; +} + +/* source address selection per RFC 3376 section 4.2.13 */ +static __be32 igmpv3_get_srcaddr(struct net_device *dev, + const struct flowi4 *fl4) +{ + struct in_device *in_dev = __in_dev_get_rcu(dev); + const struct in_ifaddr *ifa; + + if (!in_dev) + return htonl(INADDR_ANY); + + in_dev_for_each_ifa_rcu(ifa, in_dev) { + if (fl4->saddr == ifa->ifa_local) + return fl4->saddr; + } + + return htonl(INADDR_ANY); +} + +static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu) +{ + struct sk_buff *skb; + struct rtable *rt; + struct iphdr *pip; + struct igmpv3_report *pig; + struct net *net = dev_net(dev); + struct flowi4 fl4; + int hlen = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; + unsigned int size; + + size = min(mtu, IP_MAX_MTU); + while (1) { + skb = alloc_skb(size + hlen + tlen, + GFP_ATOMIC | __GFP_NOWARN); + if (skb) + break; + size >>= 1; + if (size < 256) + return NULL; + } + skb->priority = TC_PRIO_CONTROL; + + rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0, + 0, 0, + IPPROTO_IGMP, 0, dev->ifindex); + if (IS_ERR(rt)) { + kfree_skb(skb); + return NULL; + } + + skb_dst_set(skb, &rt->dst); + skb->dev = dev; + + skb_reserve(skb, hlen); + skb_tailroom_reserve(skb, mtu, tlen); + + skb_reset_network_header(skb); + pip = ip_hdr(skb); + skb_put(skb, sizeof(struct iphdr) + 4); + + pip->version = 4; + pip->ihl = (sizeof(struct iphdr)+4)>>2; + pip->tos = 0xc0; + pip->frag_off = htons(IP_DF); + pip->ttl = 1; + pip->daddr = fl4.daddr; + + rcu_read_lock(); + pip->saddr = igmpv3_get_srcaddr(dev, &fl4); + rcu_read_unlock(); + + pip->protocol = IPPROTO_IGMP; + pip->tot_len = 0; /* filled in later */ + ip_select_ident(net, skb, NULL); + ((u8 *)&pip[1])[0] = IPOPT_RA; + ((u8 *)&pip[1])[1] = 4; + ((u8 *)&pip[1])[2] = 0; + ((u8 *)&pip[1])[3] = 0; + + skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4; + skb_put(skb, sizeof(*pig)); + pig = igmpv3_report_hdr(skb); + pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT; + pig->resv1 = 0; + pig->csum = 0; + pig->resv2 = 0; + pig->ngrec = 0; + return skb; +} + +static int igmpv3_sendpack(struct sk_buff *skb) +{ + struct igmphdr *pig = igmp_hdr(skb); + const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb); + + pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen); + + return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); +} + +static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel) +{ + return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel); +} + +static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc, + int type, struct igmpv3_grec **ppgr, unsigned int mtu) +{ + struct net_device *dev = pmc->interface->dev; + struct igmpv3_report *pih; + struct igmpv3_grec *pgr; + + if (!skb) { + skb = igmpv3_newpack(dev, mtu); + if (!skb) + return NULL; + } + pgr = skb_put(skb, sizeof(struct igmpv3_grec)); + pgr->grec_type = type; + pgr->grec_auxwords = 0; + pgr->grec_nsrcs = 0; + pgr->grec_mca = pmc->multiaddr; + pih = igmpv3_report_hdr(skb); + pih->ngrec = htons(ntohs(pih->ngrec)+1); + *ppgr = pgr; + return skb; +} + +#define AVAILABLE(skb) ((skb) ? skb_availroom(skb) : 0) + +static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, + int type, int gdeleted, int sdeleted) +{ + struct net_device *dev = pmc->interface->dev; + struct net *net = dev_net(dev); + struct igmpv3_report *pih; + struct igmpv3_grec *pgr = NULL; + struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list; + int scount, stotal, first, isquery, truncate; + unsigned int mtu; + + if (pmc->multiaddr == IGMP_ALL_HOSTS) + return skb; + if (ipv4_is_local_multicast(pmc->multiaddr) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + return skb; + + mtu = READ_ONCE(dev->mtu); + if (mtu < IPV4_MIN_MTU) + return skb; + + isquery = type == IGMPV3_MODE_IS_INCLUDE || + type == IGMPV3_MODE_IS_EXCLUDE; + truncate = type == IGMPV3_MODE_IS_EXCLUDE || + type == IGMPV3_CHANGE_TO_EXCLUDE; + + stotal = scount = 0; + + psf_list = sdeleted ? &pmc->tomb : &pmc->sources; + + if (!*psf_list) + goto empty_source; + + pih = skb ? igmpv3_report_hdr(skb) : NULL; + + /* EX and TO_EX get a fresh packet, if needed */ + if (truncate) { + if (pih && pih->ngrec && + AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) { + if (skb) + igmpv3_sendpack(skb); + skb = igmpv3_newpack(dev, mtu); + } + } + first = 1; + psf_prev = NULL; + for (psf = *psf_list; psf; psf = psf_next) { + __be32 *psrc; + + psf_next = psf->sf_next; + + if (!is_in(pmc, psf, type, gdeleted, sdeleted)) { + psf_prev = psf; + continue; + } + + /* Based on RFC3376 5.1. Should not send source-list change + * records when there is a filter mode change. + */ + if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) || + (!gdeleted && pmc->crcount)) && + (type == IGMPV3_ALLOW_NEW_SOURCES || + type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) + goto decrease_sf_crcount; + + /* clear marks on query responses */ + if (isquery) + psf->sf_gsresp = 0; + + if (AVAILABLE(skb) < sizeof(__be32) + + first*sizeof(struct igmpv3_grec)) { + if (truncate && !first) + break; /* truncate these */ + if (pgr) + pgr->grec_nsrcs = htons(scount); + if (skb) + igmpv3_sendpack(skb); + skb = igmpv3_newpack(dev, mtu); + first = 1; + scount = 0; + } + if (first) { + skb = add_grhead(skb, pmc, type, &pgr, mtu); + first = 0; + } + if (!skb) + return NULL; + psrc = skb_put(skb, sizeof(__be32)); + *psrc = psf->sf_inaddr; + scount++; stotal++; + if ((type == IGMPV3_ALLOW_NEW_SOURCES || + type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) { +decrease_sf_crcount: + psf->sf_crcount--; + if ((sdeleted || gdeleted) && psf->sf_crcount == 0) { + if (psf_prev) + psf_prev->sf_next = psf->sf_next; + else + *psf_list = psf->sf_next; + kfree(psf); + continue; + } + } + psf_prev = psf; + } + +empty_source: + if (!stotal) { + if (type == IGMPV3_ALLOW_NEW_SOURCES || + type == IGMPV3_BLOCK_OLD_SOURCES) + return skb; + if (pmc->crcount || isquery) { + /* make sure we have room for group header */ + if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) { + igmpv3_sendpack(skb); + skb = NULL; /* add_grhead will get a new one */ + } + skb = add_grhead(skb, pmc, type, &pgr, mtu); + } + } + if (pgr) + pgr->grec_nsrcs = htons(scount); + + if (isquery) + pmc->gsquery = 0; /* clear query state on report */ + return skb; +} + +static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc) +{ + struct sk_buff *skb = NULL; + struct net *net = dev_net(in_dev->dev); + int type; + + if (!pmc) { + rcu_read_lock(); + for_each_pmc_rcu(in_dev, pmc) { + if (pmc->multiaddr == IGMP_ALL_HOSTS) + continue; + if (ipv4_is_local_multicast(pmc->multiaddr) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + continue; + spin_lock_bh(&pmc->lock); + if (pmc->sfcount[MCAST_EXCLUDE]) + type = IGMPV3_MODE_IS_EXCLUDE; + else + type = IGMPV3_MODE_IS_INCLUDE; + skb = add_grec(skb, pmc, type, 0, 0); + spin_unlock_bh(&pmc->lock); + } + rcu_read_unlock(); + } else { + spin_lock_bh(&pmc->lock); + if (pmc->sfcount[MCAST_EXCLUDE]) + type = IGMPV3_MODE_IS_EXCLUDE; + else + type = IGMPV3_MODE_IS_INCLUDE; + skb = add_grec(skb, pmc, type, 0, 0); + spin_unlock_bh(&pmc->lock); + } + if (!skb) + return 0; + return igmpv3_sendpack(skb); +} + +/* + * remove zero-count source records from a source filter list + */ +static void igmpv3_clear_zeros(struct ip_sf_list **ppsf) +{ + struct ip_sf_list *psf_prev, *psf_next, *psf; + + psf_prev = NULL; + for (psf = *ppsf; psf; psf = psf_next) { + psf_next = psf->sf_next; + if (psf->sf_crcount == 0) { + if (psf_prev) + psf_prev->sf_next = psf->sf_next; + else + *ppsf = psf->sf_next; + kfree(psf); + } else + psf_prev = psf; + } +} + +static void kfree_pmc(struct ip_mc_list *pmc) +{ + ip_sf_list_clear_all(pmc->sources); + ip_sf_list_clear_all(pmc->tomb); + kfree(pmc); +} + +static void igmpv3_send_cr(struct in_device *in_dev) +{ + struct ip_mc_list *pmc, *pmc_prev, *pmc_next; + struct sk_buff *skb = NULL; + int type, dtype; + + rcu_read_lock(); + spin_lock_bh(&in_dev->mc_tomb_lock); + + /* deleted MCA's */ + pmc_prev = NULL; + for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) { + pmc_next = pmc->next; + if (pmc->sfmode == MCAST_INCLUDE) { + type = IGMPV3_BLOCK_OLD_SOURCES; + dtype = IGMPV3_BLOCK_OLD_SOURCES; + skb = add_grec(skb, pmc, type, 1, 0); + skb = add_grec(skb, pmc, dtype, 1, 1); + } + if (pmc->crcount) { + if (pmc->sfmode == MCAST_EXCLUDE) { + type = IGMPV3_CHANGE_TO_INCLUDE; + skb = add_grec(skb, pmc, type, 1, 0); + } + pmc->crcount--; + if (pmc->crcount == 0) { + igmpv3_clear_zeros(&pmc->tomb); + igmpv3_clear_zeros(&pmc->sources); + } + } + if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) { + if (pmc_prev) + pmc_prev->next = pmc_next; + else + in_dev->mc_tomb = pmc_next; + in_dev_put(pmc->interface); + kfree_pmc(pmc); + } else + pmc_prev = pmc; + } + spin_unlock_bh(&in_dev->mc_tomb_lock); + + /* change recs */ + for_each_pmc_rcu(in_dev, pmc) { + spin_lock_bh(&pmc->lock); + if (pmc->sfcount[MCAST_EXCLUDE]) { + type = IGMPV3_BLOCK_OLD_SOURCES; + dtype = IGMPV3_ALLOW_NEW_SOURCES; + } else { + type = IGMPV3_ALLOW_NEW_SOURCES; + dtype = IGMPV3_BLOCK_OLD_SOURCES; + } + skb = add_grec(skb, pmc, type, 0, 0); + skb = add_grec(skb, pmc, dtype, 0, 1); /* deleted sources */ + + /* filter mode changes */ + if (pmc->crcount) { + if (pmc->sfmode == MCAST_EXCLUDE) + type = IGMPV3_CHANGE_TO_EXCLUDE; + else + type = IGMPV3_CHANGE_TO_INCLUDE; + skb = add_grec(skb, pmc, type, 0, 0); + pmc->crcount--; + } + spin_unlock_bh(&pmc->lock); + } + rcu_read_unlock(); + + if (!skb) + return; + (void) igmpv3_sendpack(skb); +} + +static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc, + int type) +{ + struct sk_buff *skb; + struct iphdr *iph; + struct igmphdr *ih; + struct rtable *rt; + struct net_device *dev = in_dev->dev; + struct net *net = dev_net(dev); + __be32 group = pmc ? pmc->multiaddr : 0; + struct flowi4 fl4; + __be32 dst; + int hlen, tlen; + + if (type == IGMPV3_HOST_MEMBERSHIP_REPORT) + return igmpv3_send_report(in_dev, pmc); + + if (ipv4_is_local_multicast(group) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + return 0; + + if (type == IGMP_HOST_LEAVE_MESSAGE) + dst = IGMP_ALL_ROUTER; + else + dst = group; + + rt = ip_route_output_ports(net, &fl4, NULL, dst, 0, + 0, 0, + IPPROTO_IGMP, 0, dev->ifindex); + if (IS_ERR(rt)) + return -1; + + hlen = LL_RESERVED_SPACE(dev); + tlen = dev->needed_tailroom; + skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC); + if (!skb) { + ip_rt_put(rt); + return -1; + } + skb->priority = TC_PRIO_CONTROL; + + skb_dst_set(skb, &rt->dst); + + skb_reserve(skb, hlen); + + skb_reset_network_header(skb); + iph = ip_hdr(skb); + skb_put(skb, sizeof(struct iphdr) + 4); + + iph->version = 4; + iph->ihl = (sizeof(struct iphdr)+4)>>2; + iph->tos = 0xc0; + iph->frag_off = htons(IP_DF); + iph->ttl = 1; + iph->daddr = dst; + iph->saddr = fl4.saddr; + iph->protocol = IPPROTO_IGMP; + ip_select_ident(net, skb, NULL); + ((u8 *)&iph[1])[0] = IPOPT_RA; + ((u8 *)&iph[1])[1] = 4; + ((u8 *)&iph[1])[2] = 0; + ((u8 *)&iph[1])[3] = 0; + + ih = skb_put(skb, sizeof(struct igmphdr)); + ih->type = type; + ih->code = 0; + ih->csum = 0; + ih->group = group; + ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr)); + + return ip_local_out(net, skb->sk, skb); +} + +static void igmp_gq_timer_expire(struct timer_list *t) +{ + struct in_device *in_dev = from_timer(in_dev, t, mr_gq_timer); + + in_dev->mr_gq_running = 0; + igmpv3_send_report(in_dev, NULL); + in_dev_put(in_dev); +} + +static void igmp_ifc_timer_expire(struct timer_list *t) +{ + struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer); + u32 mr_ifc_count; + + igmpv3_send_cr(in_dev); +restart: + mr_ifc_count = READ_ONCE(in_dev->mr_ifc_count); + + if (mr_ifc_count) { + if (cmpxchg(&in_dev->mr_ifc_count, + mr_ifc_count, + mr_ifc_count - 1) != mr_ifc_count) + goto restart; + igmp_ifc_start_timer(in_dev, + unsolicited_report_interval(in_dev)); + } + in_dev_put(in_dev); +} + +static void igmp_ifc_event(struct in_device *in_dev) +{ + struct net *net = dev_net(in_dev->dev); + if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) + return; + WRITE_ONCE(in_dev->mr_ifc_count, in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv)); + igmp_ifc_start_timer(in_dev, 1); +} + + +static void igmp_timer_expire(struct timer_list *t) +{ + struct ip_mc_list *im = from_timer(im, t, timer); + struct in_device *in_dev = im->interface; + + spin_lock(&im->lock); + im->tm_running = 0; + + if (im->unsolicit_count && --im->unsolicit_count) + igmp_start_timer(im, unsolicited_report_interval(in_dev)); + + im->reporter = 1; + spin_unlock(&im->lock); + + if (IGMP_V1_SEEN(in_dev)) + igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT); + else if (IGMP_V2_SEEN(in_dev)) + igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT); + else + igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT); + + ip_ma_put(im); +} + +/* mark EXCLUDE-mode sources */ +static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs) +{ + struct ip_sf_list *psf; + int i, scount; + + scount = 0; + for (psf = pmc->sources; psf; psf = psf->sf_next) { + if (scount == nsrcs) + break; + for (i = 0; i < nsrcs; i++) { + /* skip inactive filters */ + if (psf->sf_count[MCAST_INCLUDE] || + pmc->sfcount[MCAST_EXCLUDE] != + psf->sf_count[MCAST_EXCLUDE]) + break; + if (srcs[i] == psf->sf_inaddr) { + scount++; + break; + } + } + } + pmc->gsquery = 0; + if (scount == nsrcs) /* all sources excluded */ + return 0; + return 1; +} + +static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs) +{ + struct ip_sf_list *psf; + int i, scount; + + if (pmc->sfmode == MCAST_EXCLUDE) + return igmp_xmarksources(pmc, nsrcs, srcs); + + /* mark INCLUDE-mode sources */ + scount = 0; + for (psf = pmc->sources; psf; psf = psf->sf_next) { + if (scount == nsrcs) + break; + for (i = 0; i < nsrcs; i++) + if (srcs[i] == psf->sf_inaddr) { + psf->sf_gsresp = 1; + scount++; + break; + } + } + if (!scount) { + pmc->gsquery = 0; + return 0; + } + pmc->gsquery = 1; + return 1; +} + +/* return true if packet was dropped */ +static bool igmp_heard_report(struct in_device *in_dev, __be32 group) +{ + struct ip_mc_list *im; + struct net *net = dev_net(in_dev->dev); + + /* Timers are only set for non-local groups */ + + if (group == IGMP_ALL_HOSTS) + return false; + if (ipv4_is_local_multicast(group) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + return false; + + rcu_read_lock(); + for_each_pmc_rcu(in_dev, im) { + if (im->multiaddr == group) { + igmp_stop_timer(im); + break; + } + } + rcu_read_unlock(); + return false; +} + +/* return true if packet was dropped */ +static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb, + int len) +{ + struct igmphdr *ih = igmp_hdr(skb); + struct igmpv3_query *ih3 = igmpv3_query_hdr(skb); + struct ip_mc_list *im; + __be32 group = ih->group; + int max_delay; + int mark = 0; + struct net *net = dev_net(in_dev->dev); + + + if (len == 8) { + if (ih->code == 0) { + /* Alas, old v1 router presents here. */ + + max_delay = IGMP_QUERY_RESPONSE_INTERVAL; + in_dev->mr_v1_seen = jiffies + + (in_dev->mr_qrv * in_dev->mr_qi) + + in_dev->mr_qri; + group = 0; + } else { + /* v2 router present */ + max_delay = ih->code*(HZ/IGMP_TIMER_SCALE); + in_dev->mr_v2_seen = jiffies + + (in_dev->mr_qrv * in_dev->mr_qi) + + in_dev->mr_qri; + } + /* cancel the interface change timer */ + WRITE_ONCE(in_dev->mr_ifc_count, 0); + if (del_timer(&in_dev->mr_ifc_timer)) + __in_dev_put(in_dev); + /* clear deleted report items */ + igmpv3_clear_delrec(in_dev); + } else if (len < 12) { + return true; /* ignore bogus packet; freed by caller */ + } else if (IGMP_V1_SEEN(in_dev)) { + /* This is a v3 query with v1 queriers present */ + max_delay = IGMP_QUERY_RESPONSE_INTERVAL; + group = 0; + } else if (IGMP_V2_SEEN(in_dev)) { + /* this is a v3 query with v2 queriers present; + * Interpretation of the max_delay code is problematic here. + * A real v2 host would use ih_code directly, while v3 has a + * different encoding. We use the v3 encoding as more likely + * to be intended in a v3 query. + */ + max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE); + if (!max_delay) + max_delay = 1; /* can't mod w/ 0 */ + } else { /* v3 */ + if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) + return true; + + ih3 = igmpv3_query_hdr(skb); + if (ih3->nsrcs) { + if (!pskb_may_pull(skb, sizeof(struct igmpv3_query) + + ntohs(ih3->nsrcs)*sizeof(__be32))) + return true; + ih3 = igmpv3_query_hdr(skb); + } + + max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE); + if (!max_delay) + max_delay = 1; /* can't mod w/ 0 */ + in_dev->mr_maxdelay = max_delay; + + /* RFC3376, 4.1.6. QRV and 4.1.7. QQIC, when the most recently + * received value was zero, use the default or statically + * configured value. + */ + in_dev->mr_qrv = ih3->qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv); + in_dev->mr_qi = IGMPV3_QQIC(ih3->qqic)*HZ ?: IGMP_QUERY_INTERVAL; + + /* RFC3376, 8.3. Query Response Interval: + * The number of seconds represented by the [Query Response + * Interval] must be less than the [Query Interval]. + */ + if (in_dev->mr_qri >= in_dev->mr_qi) + in_dev->mr_qri = (in_dev->mr_qi/HZ - 1)*HZ; + + if (!group) { /* general query */ + if (ih3->nsrcs) + return true; /* no sources allowed */ + igmp_gq_start_timer(in_dev); + return false; + } + /* mark sources to include, if group & source-specific */ + mark = ih3->nsrcs != 0; + } + + /* + * - Start the timers in all of our membership records + * that the query applies to for the interface on + * which the query arrived excl. those that belong + * to a "local" group (224.0.0.X) + * - For timers already running check if they need to + * be reset. + * - Use the igmp->igmp_code field as the maximum + * delay possible + */ + rcu_read_lock(); + for_each_pmc_rcu(in_dev, im) { + int changed; + + if (group && group != im->multiaddr) + continue; + if (im->multiaddr == IGMP_ALL_HOSTS) + continue; + if (ipv4_is_local_multicast(im->multiaddr) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + continue; + spin_lock_bh(&im->lock); + if (im->tm_running) + im->gsquery = im->gsquery && mark; + else + im->gsquery = mark; + changed = !im->gsquery || + igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs); + spin_unlock_bh(&im->lock); + if (changed) + igmp_mod_timer(im, max_delay); + } + rcu_read_unlock(); + return false; +} + +/* called in rcu_read_lock() section */ +int igmp_rcv(struct sk_buff *skb) +{ + /* This basically follows the spec line by line -- see RFC1112 */ + struct igmphdr *ih; + struct net_device *dev = skb->dev; + struct in_device *in_dev; + int len = skb->len; + bool dropped = true; + + if (netif_is_l3_master(dev)) { + dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif); + if (!dev) + goto drop; + } + + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + goto drop; + + if (!pskb_may_pull(skb, sizeof(struct igmphdr))) + goto drop; + + if (skb_checksum_simple_validate(skb)) + goto drop; + + ih = igmp_hdr(skb); + switch (ih->type) { + case IGMP_HOST_MEMBERSHIP_QUERY: + dropped = igmp_heard_query(in_dev, skb, len); + break; + case IGMP_HOST_MEMBERSHIP_REPORT: + case IGMPV2_HOST_MEMBERSHIP_REPORT: + /* Is it our report looped back? */ + if (rt_is_output_route(skb_rtable(skb))) + break; + /* don't rely on MC router hearing unicast reports */ + if (skb->pkt_type == PACKET_MULTICAST || + skb->pkt_type == PACKET_BROADCAST) + dropped = igmp_heard_report(in_dev, ih->group); + break; + case IGMP_PIM: +#ifdef CONFIG_IP_PIMSM_V1 + return pim_rcv_v1(skb); +#endif + case IGMPV3_HOST_MEMBERSHIP_REPORT: + case IGMP_DVMRP: + case IGMP_TRACE: + case IGMP_HOST_LEAVE_MESSAGE: + case IGMP_MTRACE: + case IGMP_MTRACE_RESP: + break; + default: + break; + } + +drop: + if (dropped) + kfree_skb(skb); + else + consume_skb(skb); + return 0; +} + +#endif + + +/* + * Add a filter to a device + */ + +static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr) +{ + char buf[MAX_ADDR_LEN]; + struct net_device *dev = in_dev->dev; + + /* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG. + We will get multicast token leakage, when IFF_MULTICAST + is changed. This check should be done in ndo_set_rx_mode + routine. Something sort of: + if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; } + --ANK + */ + if (arp_mc_map(addr, buf, dev, 0) == 0) + dev_mc_add(dev, buf); +} + +/* + * Remove a filter from a device + */ + +static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr) +{ + char buf[MAX_ADDR_LEN]; + struct net_device *dev = in_dev->dev; + + if (arp_mc_map(addr, buf, dev, 0) == 0) + dev_mc_del(dev, buf); +} + +#ifdef CONFIG_IP_MULTICAST +/* + * deleted ip_mc_list manipulation + */ +static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im, + gfp_t gfp) +{ + struct ip_mc_list *pmc; + struct net *net = dev_net(in_dev->dev); + + /* this is an "ip_mc_list" for convenience; only the fields below + * are actually used. In particular, the refcnt and users are not + * used for management of the delete list. Using the same structure + * for deleted items allows change reports to use common code with + * non-deleted or query-response MCA's. + */ + pmc = kzalloc(sizeof(*pmc), gfp); + if (!pmc) + return; + spin_lock_init(&pmc->lock); + spin_lock_bh(&im->lock); + pmc->interface = im->interface; + in_dev_hold(in_dev); + pmc->multiaddr = im->multiaddr; + pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv); + pmc->sfmode = im->sfmode; + if (pmc->sfmode == MCAST_INCLUDE) { + struct ip_sf_list *psf; + + pmc->tomb = im->tomb; + pmc->sources = im->sources; + im->tomb = im->sources = NULL; + for (psf = pmc->sources; psf; psf = psf->sf_next) + psf->sf_crcount = pmc->crcount; + } + spin_unlock_bh(&im->lock); + + spin_lock_bh(&in_dev->mc_tomb_lock); + pmc->next = in_dev->mc_tomb; + in_dev->mc_tomb = pmc; + spin_unlock_bh(&in_dev->mc_tomb_lock); +} + +/* + * restore ip_mc_list deleted records + */ +static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im) +{ + struct ip_mc_list *pmc, *pmc_prev; + struct ip_sf_list *psf; + struct net *net = dev_net(in_dev->dev); + __be32 multiaddr = im->multiaddr; + + spin_lock_bh(&in_dev->mc_tomb_lock); + pmc_prev = NULL; + for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) { + if (pmc->multiaddr == multiaddr) + break; + pmc_prev = pmc; + } + if (pmc) { + if (pmc_prev) + pmc_prev->next = pmc->next; + else + in_dev->mc_tomb = pmc->next; + } + spin_unlock_bh(&in_dev->mc_tomb_lock); + + spin_lock_bh(&im->lock); + if (pmc) { + im->interface = pmc->interface; + if (im->sfmode == MCAST_INCLUDE) { + swap(im->tomb, pmc->tomb); + swap(im->sources, pmc->sources); + for (psf = im->sources; psf; psf = psf->sf_next) + psf->sf_crcount = in_dev->mr_qrv ?: + READ_ONCE(net->ipv4.sysctl_igmp_qrv); + } else { + im->crcount = in_dev->mr_qrv ?: + READ_ONCE(net->ipv4.sysctl_igmp_qrv); + } + in_dev_put(pmc->interface); + kfree_pmc(pmc); + } + spin_unlock_bh(&im->lock); +} + +/* + * flush ip_mc_list deleted records + */ +static void igmpv3_clear_delrec(struct in_device *in_dev) +{ + struct ip_mc_list *pmc, *nextpmc; + + spin_lock_bh(&in_dev->mc_tomb_lock); + pmc = in_dev->mc_tomb; + in_dev->mc_tomb = NULL; + spin_unlock_bh(&in_dev->mc_tomb_lock); + + for (; pmc; pmc = nextpmc) { + nextpmc = pmc->next; + ip_mc_clear_src(pmc); + in_dev_put(pmc->interface); + kfree_pmc(pmc); + } + /* clear dead sources, too */ + rcu_read_lock(); + for_each_pmc_rcu(in_dev, pmc) { + struct ip_sf_list *psf; + + spin_lock_bh(&pmc->lock); + psf = pmc->tomb; + pmc->tomb = NULL; + spin_unlock_bh(&pmc->lock); + ip_sf_list_clear_all(psf); + } + rcu_read_unlock(); +} +#endif + +static void __igmp_group_dropped(struct ip_mc_list *im, gfp_t gfp) +{ + struct in_device *in_dev = im->interface; +#ifdef CONFIG_IP_MULTICAST + struct net *net = dev_net(in_dev->dev); + int reporter; +#endif + + if (im->loaded) { + im->loaded = 0; + ip_mc_filter_del(in_dev, im->multiaddr); + } + +#ifdef CONFIG_IP_MULTICAST + if (im->multiaddr == IGMP_ALL_HOSTS) + return; + if (ipv4_is_local_multicast(im->multiaddr) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + return; + + reporter = im->reporter; + igmp_stop_timer(im); + + if (!in_dev->dead) { + if (IGMP_V1_SEEN(in_dev)) + return; + if (IGMP_V2_SEEN(in_dev)) { + if (reporter) + igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE); + return; + } + /* IGMPv3 */ + igmpv3_add_delrec(in_dev, im, gfp); + + igmp_ifc_event(in_dev); + } +#endif +} + +static void igmp_group_dropped(struct ip_mc_list *im) +{ + __igmp_group_dropped(im, GFP_KERNEL); +} + +static void igmp_group_added(struct ip_mc_list *im) +{ + struct in_device *in_dev = im->interface; +#ifdef CONFIG_IP_MULTICAST + struct net *net = dev_net(in_dev->dev); +#endif + + if (im->loaded == 0) { + im->loaded = 1; + ip_mc_filter_add(in_dev, im->multiaddr); + } + +#ifdef CONFIG_IP_MULTICAST + if (im->multiaddr == IGMP_ALL_HOSTS) + return; + if (ipv4_is_local_multicast(im->multiaddr) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + return; + + if (in_dev->dead) + return; + + im->unsolicit_count = READ_ONCE(net->ipv4.sysctl_igmp_qrv); + if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) { + spin_lock_bh(&im->lock); + igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY); + spin_unlock_bh(&im->lock); + return; + } + /* else, v3 */ + + /* Based on RFC3376 5.1, for newly added INCLUDE SSM, we should + * not send filter-mode change record as the mode should be from + * IN() to IN(A). + */ + if (im->sfmode == MCAST_EXCLUDE) + im->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv); + + igmp_ifc_event(in_dev); +#endif +} + + +/* + * Multicast list managers + */ + +static u32 ip_mc_hash(const struct ip_mc_list *im) +{ + return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG); +} + +static void ip_mc_hash_add(struct in_device *in_dev, + struct ip_mc_list *im) +{ + struct ip_mc_list __rcu **mc_hash; + u32 hash; + + mc_hash = rtnl_dereference(in_dev->mc_hash); + if (mc_hash) { + hash = ip_mc_hash(im); + im->next_hash = mc_hash[hash]; + rcu_assign_pointer(mc_hash[hash], im); + return; + } + + /* do not use a hash table for small number of items */ + if (in_dev->mc_count < 4) + return; + + mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG, + GFP_KERNEL); + if (!mc_hash) + return; + + for_each_pmc_rtnl(in_dev, im) { + hash = ip_mc_hash(im); + im->next_hash = mc_hash[hash]; + RCU_INIT_POINTER(mc_hash[hash], im); + } + + rcu_assign_pointer(in_dev->mc_hash, mc_hash); +} + +static void ip_mc_hash_remove(struct in_device *in_dev, + struct ip_mc_list *im) +{ + struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash); + struct ip_mc_list *aux; + + if (!mc_hash) + return; + mc_hash += ip_mc_hash(im); + while ((aux = rtnl_dereference(*mc_hash)) != im) + mc_hash = &aux->next_hash; + *mc_hash = im->next_hash; +} + + +/* + * A socket has joined a multicast group on device dev. + */ +static void ____ip_mc_inc_group(struct in_device *in_dev, __be32 addr, + unsigned int mode, gfp_t gfp) +{ + struct ip_mc_list *im; + + ASSERT_RTNL(); + + for_each_pmc_rtnl(in_dev, im) { + if (im->multiaddr == addr) { + im->users++; + ip_mc_add_src(in_dev, &addr, mode, 0, NULL, 0); + goto out; + } + } + + im = kzalloc(sizeof(*im), gfp); + if (!im) + goto out; + + im->users = 1; + im->interface = in_dev; + in_dev_hold(in_dev); + im->multiaddr = addr; + /* initial mode is (EX, empty) */ + im->sfmode = mode; + im->sfcount[mode] = 1; + refcount_set(&im->refcnt, 1); + spin_lock_init(&im->lock); +#ifdef CONFIG_IP_MULTICAST + timer_setup(&im->timer, igmp_timer_expire, 0); +#endif + + im->next_rcu = in_dev->mc_list; + in_dev->mc_count++; + rcu_assign_pointer(in_dev->mc_list, im); + + ip_mc_hash_add(in_dev, im); + +#ifdef CONFIG_IP_MULTICAST + igmpv3_del_delrec(in_dev, im); +#endif + igmp_group_added(im); + if (!in_dev->dead) + ip_rt_multicast_event(in_dev); +out: + return; +} + +void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr, gfp_t gfp) +{ + ____ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE, gfp); +} +EXPORT_SYMBOL(__ip_mc_inc_group); + +void ip_mc_inc_group(struct in_device *in_dev, __be32 addr) +{ + __ip_mc_inc_group(in_dev, addr, GFP_KERNEL); +} +EXPORT_SYMBOL(ip_mc_inc_group); + +static int ip_mc_check_iphdr(struct sk_buff *skb) +{ + const struct iphdr *iph; + unsigned int len; + unsigned int offset = skb_network_offset(skb) + sizeof(*iph); + + if (!pskb_may_pull(skb, offset)) + return -EINVAL; + + iph = ip_hdr(skb); + + if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph)) + return -EINVAL; + + offset += ip_hdrlen(skb) - sizeof(*iph); + + if (!pskb_may_pull(skb, offset)) + return -EINVAL; + + iph = ip_hdr(skb); + + if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) + return -EINVAL; + + len = skb_network_offset(skb) + ntohs(iph->tot_len); + if (skb->len < len || len < offset) + return -EINVAL; + + skb_set_transport_header(skb, offset); + + return 0; +} + +static int ip_mc_check_igmp_reportv3(struct sk_buff *skb) +{ + unsigned int len = skb_transport_offset(skb); + + len += sizeof(struct igmpv3_report); + + return ip_mc_may_pull(skb, len) ? 0 : -EINVAL; +} + +static int ip_mc_check_igmp_query(struct sk_buff *skb) +{ + unsigned int transport_len = ip_transport_len(skb); + unsigned int len; + + /* IGMPv{1,2}? */ + if (transport_len != sizeof(struct igmphdr)) { + /* or IGMPv3? */ + if (transport_len < sizeof(struct igmpv3_query)) + return -EINVAL; + + len = skb_transport_offset(skb) + sizeof(struct igmpv3_query); + if (!ip_mc_may_pull(skb, len)) + return -EINVAL; + } + + /* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer + * all-systems destination addresses (224.0.0.1) for general queries + */ + if (!igmp_hdr(skb)->group && + ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP)) + return -EINVAL; + + return 0; +} + +static int ip_mc_check_igmp_msg(struct sk_buff *skb) +{ + switch (igmp_hdr(skb)->type) { + case IGMP_HOST_LEAVE_MESSAGE: + case IGMP_HOST_MEMBERSHIP_REPORT: + case IGMPV2_HOST_MEMBERSHIP_REPORT: + return 0; + case IGMPV3_HOST_MEMBERSHIP_REPORT: + return ip_mc_check_igmp_reportv3(skb); + case IGMP_HOST_MEMBERSHIP_QUERY: + return ip_mc_check_igmp_query(skb); + default: + return -ENOMSG; + } +} + +static __sum16 ip_mc_validate_checksum(struct sk_buff *skb) +{ + return skb_checksum_simple_validate(skb); +} + +static int ip_mc_check_igmp_csum(struct sk_buff *skb) +{ + unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr); + unsigned int transport_len = ip_transport_len(skb); + struct sk_buff *skb_chk; + + if (!ip_mc_may_pull(skb, len)) + return -EINVAL; + + skb_chk = skb_checksum_trimmed(skb, transport_len, + ip_mc_validate_checksum); + if (!skb_chk) + return -EINVAL; + + if (skb_chk != skb) + kfree_skb(skb_chk); + + return 0; +} + +/** + * ip_mc_check_igmp - checks whether this is a sane IGMP packet + * @skb: the skb to validate + * + * Checks whether an IPv4 packet is a valid IGMP packet. If so sets + * skb transport header accordingly and returns zero. + * + * -EINVAL: A broken packet was detected, i.e. it violates some internet + * standard + * -ENOMSG: IP header validation succeeded but it is not an IGMP packet. + * -ENOMEM: A memory allocation failure happened. + * + * Caller needs to set the skb network header and free any returned skb if it + * differs from the provided skb. + */ +int ip_mc_check_igmp(struct sk_buff *skb) +{ + int ret = ip_mc_check_iphdr(skb); + + if (ret < 0) + return ret; + + if (ip_hdr(skb)->protocol != IPPROTO_IGMP) + return -ENOMSG; + + ret = ip_mc_check_igmp_csum(skb); + if (ret < 0) + return ret; + + return ip_mc_check_igmp_msg(skb); +} +EXPORT_SYMBOL(ip_mc_check_igmp); + +/* + * Resend IGMP JOIN report; used by netdev notifier. + */ +static void ip_mc_rejoin_groups(struct in_device *in_dev) +{ +#ifdef CONFIG_IP_MULTICAST + struct ip_mc_list *im; + int type; + struct net *net = dev_net(in_dev->dev); + + ASSERT_RTNL(); + + for_each_pmc_rtnl(in_dev, im) { + if (im->multiaddr == IGMP_ALL_HOSTS) + continue; + if (ipv4_is_local_multicast(im->multiaddr) && + !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports)) + continue; + + /* a failover is happening and switches + * must be notified immediately + */ + if (IGMP_V1_SEEN(in_dev)) + type = IGMP_HOST_MEMBERSHIP_REPORT; + else if (IGMP_V2_SEEN(in_dev)) + type = IGMPV2_HOST_MEMBERSHIP_REPORT; + else + type = IGMPV3_HOST_MEMBERSHIP_REPORT; + igmp_send_report(in_dev, im, type); + } +#endif +} + +/* + * A socket has left a multicast group on device dev + */ + +void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp) +{ + struct ip_mc_list *i; + struct ip_mc_list __rcu **ip; + + ASSERT_RTNL(); + + for (ip = &in_dev->mc_list; + (i = rtnl_dereference(*ip)) != NULL; + ip = &i->next_rcu) { + if (i->multiaddr == addr) { + if (--i->users == 0) { + ip_mc_hash_remove(in_dev, i); + *ip = i->next_rcu; + in_dev->mc_count--; + __igmp_group_dropped(i, gfp); + ip_mc_clear_src(i); + + if (!in_dev->dead) + ip_rt_multicast_event(in_dev); + + ip_ma_put(i); + return; + } + break; + } + } +} +EXPORT_SYMBOL(__ip_mc_dec_group); + +/* Device changing type */ + +void ip_mc_unmap(struct in_device *in_dev) +{ + struct ip_mc_list *pmc; + + ASSERT_RTNL(); + + for_each_pmc_rtnl(in_dev, pmc) + igmp_group_dropped(pmc); +} + +void ip_mc_remap(struct in_device *in_dev) +{ + struct ip_mc_list *pmc; + + ASSERT_RTNL(); + + for_each_pmc_rtnl(in_dev, pmc) { +#ifdef CONFIG_IP_MULTICAST + igmpv3_del_delrec(in_dev, pmc); +#endif + igmp_group_added(pmc); + } +} + +/* Device going down */ + +void ip_mc_down(struct in_device *in_dev) +{ + struct ip_mc_list *pmc; + + ASSERT_RTNL(); + + for_each_pmc_rtnl(in_dev, pmc) + igmp_group_dropped(pmc); + +#ifdef CONFIG_IP_MULTICAST + WRITE_ONCE(in_dev->mr_ifc_count, 0); + if (del_timer(&in_dev->mr_ifc_timer)) + __in_dev_put(in_dev); + in_dev->mr_gq_running = 0; + if (del_timer(&in_dev->mr_gq_timer)) + __in_dev_put(in_dev); +#endif + + ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS); +} + +#ifdef CONFIG_IP_MULTICAST +static void ip_mc_reset(struct in_device *in_dev) +{ + struct net *net = dev_net(in_dev->dev); + + in_dev->mr_qi = IGMP_QUERY_INTERVAL; + in_dev->mr_qri = IGMP_QUERY_RESPONSE_INTERVAL; + in_dev->mr_qrv = READ_ONCE(net->ipv4.sysctl_igmp_qrv); +} +#else +static void ip_mc_reset(struct in_device *in_dev) +{ +} +#endif + +void ip_mc_init_dev(struct in_device *in_dev) +{ + ASSERT_RTNL(); + +#ifdef CONFIG_IP_MULTICAST + timer_setup(&in_dev->mr_gq_timer, igmp_gq_timer_expire, 0); + timer_setup(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire, 0); +#endif + ip_mc_reset(in_dev); + + spin_lock_init(&in_dev->mc_tomb_lock); +} + +/* Device going up */ + +void ip_mc_up(struct in_device *in_dev) +{ + struct ip_mc_list *pmc; + + ASSERT_RTNL(); + + ip_mc_reset(in_dev); + ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS); + + for_each_pmc_rtnl(in_dev, pmc) { +#ifdef CONFIG_IP_MULTICAST + igmpv3_del_delrec(in_dev, pmc); +#endif + igmp_group_added(pmc); + } +} + +/* + * Device is about to be destroyed: clean up. + */ + +void ip_mc_destroy_dev(struct in_device *in_dev) +{ + struct ip_mc_list *i; + + ASSERT_RTNL(); + + /* Deactivate timers */ + ip_mc_down(in_dev); +#ifdef CONFIG_IP_MULTICAST + igmpv3_clear_delrec(in_dev); +#endif + + while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) { + in_dev->mc_list = i->next_rcu; + in_dev->mc_count--; + ip_mc_clear_src(i); + ip_ma_put(i); + } +} + +/* RTNL is locked */ +static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr) +{ + struct net_device *dev = NULL; + struct in_device *idev = NULL; + + if (imr->imr_ifindex) { + idev = inetdev_by_index(net, imr->imr_ifindex); + return idev; + } + if (imr->imr_address.s_addr) { + dev = __ip_dev_find(net, imr->imr_address.s_addr, false); + if (!dev) + return NULL; + } + + if (!dev) { + struct rtable *rt = ip_route_output(net, + imr->imr_multiaddr.s_addr, + 0, 0, 0); + if (!IS_ERR(rt)) { + dev = rt->dst.dev; + ip_rt_put(rt); + } + } + if (dev) { + imr->imr_ifindex = dev->ifindex; + idev = __in_dev_get_rtnl(dev); + } + return idev; +} + +/* + * Join a socket to a group + */ + +static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode, + __be32 *psfsrc) +{ + struct ip_sf_list *psf, *psf_prev; + int rv = 0; + + psf_prev = NULL; + for (psf = pmc->sources; psf; psf = psf->sf_next) { + if (psf->sf_inaddr == *psfsrc) + break; + psf_prev = psf; + } + if (!psf || psf->sf_count[sfmode] == 0) { + /* source filter not found, or count wrong => bug */ + return -ESRCH; + } + psf->sf_count[sfmode]--; + if (psf->sf_count[sfmode] == 0) { + ip_rt_multicast_event(pmc->interface); + } + if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) { +#ifdef CONFIG_IP_MULTICAST + struct in_device *in_dev = pmc->interface; + struct net *net = dev_net(in_dev->dev); +#endif + + /* no more filters for this source */ + if (psf_prev) + psf_prev->sf_next = psf->sf_next; + else + pmc->sources = psf->sf_next; +#ifdef CONFIG_IP_MULTICAST + if (psf->sf_oldin && + !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) { + psf->sf_crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv); + psf->sf_next = pmc->tomb; + pmc->tomb = psf; + rv = 1; + } else +#endif + kfree(psf); + } + return rv; +} + +#ifndef CONFIG_IP_MULTICAST +#define igmp_ifc_event(x) do { } while (0) +#endif + +static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode, + int sfcount, __be32 *psfsrc, int delta) +{ + struct ip_mc_list *pmc; + int changerec = 0; + int i, err; + + if (!in_dev) + return -ENODEV; + rcu_read_lock(); + for_each_pmc_rcu(in_dev, pmc) { + if (*pmca == pmc->multiaddr) + break; + } + if (!pmc) { + /* MCA not found?? bug */ + rcu_read_unlock(); + return -ESRCH; + } + spin_lock_bh(&pmc->lock); + rcu_read_unlock(); +#ifdef CONFIG_IP_MULTICAST + sf_markstate(pmc); +#endif + if (!delta) { + err = -EINVAL; + if (!pmc->sfcount[sfmode]) + goto out_unlock; + pmc->sfcount[sfmode]--; + } + err = 0; + for (i = 0; i < sfcount; i++) { + int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]); + + changerec |= rv > 0; + if (!err && rv < 0) + err = rv; + } + if (pmc->sfmode == MCAST_EXCLUDE && + pmc->sfcount[MCAST_EXCLUDE] == 0 && + pmc->sfcount[MCAST_INCLUDE]) { +#ifdef CONFIG_IP_MULTICAST + struct ip_sf_list *psf; + struct net *net = dev_net(in_dev->dev); +#endif + + /* filter mode change */ + pmc->sfmode = MCAST_INCLUDE; +#ifdef CONFIG_IP_MULTICAST + pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv); + WRITE_ONCE(in_dev->mr_ifc_count, pmc->crcount); + for (psf = pmc->sources; psf; psf = psf->sf_next) + psf->sf_crcount = 0; + igmp_ifc_event(pmc->interface); + } else if (sf_setstate(pmc) || changerec) { + igmp_ifc_event(pmc->interface); +#endif + } +out_unlock: + spin_unlock_bh(&pmc->lock); + return err; +} + +/* + * Add multicast single-source filter to the interface list + */ +static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode, + __be32 *psfsrc) +{ + struct ip_sf_list *psf, *psf_prev; + + psf_prev = NULL; + for (psf = pmc->sources; psf; psf = psf->sf_next) { + if (psf->sf_inaddr == *psfsrc) + break; + psf_prev = psf; + } + if (!psf) { + psf = kzalloc(sizeof(*psf), GFP_ATOMIC); + if (!psf) + return -ENOBUFS; + psf->sf_inaddr = *psfsrc; + if (psf_prev) { + psf_prev->sf_next = psf; + } else + pmc->sources = psf; + } + psf->sf_count[sfmode]++; + if (psf->sf_count[sfmode] == 1) { + ip_rt_multicast_event(pmc->interface); + } + return 0; +} + +#ifdef CONFIG_IP_MULTICAST +static void sf_markstate(struct ip_mc_list *pmc) +{ + struct ip_sf_list *psf; + int mca_xcount = pmc->sfcount[MCAST_EXCLUDE]; + + for (psf = pmc->sources; psf; psf = psf->sf_next) + if (pmc->sfcount[MCAST_EXCLUDE]) { + psf->sf_oldin = mca_xcount == + psf->sf_count[MCAST_EXCLUDE] && + !psf->sf_count[MCAST_INCLUDE]; + } else + psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0; +} + +static int sf_setstate(struct ip_mc_list *pmc) +{ + struct ip_sf_list *psf, *dpsf; + int mca_xcount = pmc->sfcount[MCAST_EXCLUDE]; + int qrv = pmc->interface->mr_qrv; + int new_in, rv; + + rv = 0; + for (psf = pmc->sources; psf; psf = psf->sf_next) { + if (pmc->sfcount[MCAST_EXCLUDE]) { + new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] && + !psf->sf_count[MCAST_INCLUDE]; + } else + new_in = psf->sf_count[MCAST_INCLUDE] != 0; + if (new_in) { + if (!psf->sf_oldin) { + struct ip_sf_list *prev = NULL; + + for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) { + if (dpsf->sf_inaddr == psf->sf_inaddr) + break; + prev = dpsf; + } + if (dpsf) { + if (prev) + prev->sf_next = dpsf->sf_next; + else + pmc->tomb = dpsf->sf_next; + kfree(dpsf); + } + psf->sf_crcount = qrv; + rv++; + } + } else if (psf->sf_oldin) { + + psf->sf_crcount = 0; + /* + * add or update "delete" records if an active filter + * is now inactive + */ + for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) + if (dpsf->sf_inaddr == psf->sf_inaddr) + break; + if (!dpsf) { + dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC); + if (!dpsf) + continue; + *dpsf = *psf; + /* pmc->lock held by callers */ + dpsf->sf_next = pmc->tomb; + pmc->tomb = dpsf; + } + dpsf->sf_crcount = qrv; + rv++; + } + } + return rv; +} +#endif + +/* + * Add multicast source filter list to the interface list + */ +static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode, + int sfcount, __be32 *psfsrc, int delta) +{ + struct ip_mc_list *pmc; + int isexclude; + int i, err; + + if (!in_dev) + return -ENODEV; + rcu_read_lock(); + for_each_pmc_rcu(in_dev, pmc) { + if (*pmca == pmc->multiaddr) + break; + } + if (!pmc) { + /* MCA not found?? bug */ + rcu_read_unlock(); + return -ESRCH; + } + spin_lock_bh(&pmc->lock); + rcu_read_unlock(); + +#ifdef CONFIG_IP_MULTICAST + sf_markstate(pmc); +#endif + isexclude = pmc->sfmode == MCAST_EXCLUDE; + if (!delta) + pmc->sfcount[sfmode]++; + err = 0; + for (i = 0; i < sfcount; i++) { + err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]); + if (err) + break; + } + if (err) { + int j; + + if (!delta) + pmc->sfcount[sfmode]--; + for (j = 0; j < i; j++) + (void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]); + } else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) { +#ifdef CONFIG_IP_MULTICAST + struct ip_sf_list *psf; + struct net *net = dev_net(pmc->interface->dev); + in_dev = pmc->interface; +#endif + + /* filter mode change */ + if (pmc->sfcount[MCAST_EXCLUDE]) + pmc->sfmode = MCAST_EXCLUDE; + else if (pmc->sfcount[MCAST_INCLUDE]) + pmc->sfmode = MCAST_INCLUDE; +#ifdef CONFIG_IP_MULTICAST + /* else no filters; keep old mode for reports */ + + pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv); + WRITE_ONCE(in_dev->mr_ifc_count, pmc->crcount); + for (psf = pmc->sources; psf; psf = psf->sf_next) + psf->sf_crcount = 0; + igmp_ifc_event(in_dev); + } else if (sf_setstate(pmc)) { + igmp_ifc_event(in_dev); +#endif + } + spin_unlock_bh(&pmc->lock); + return err; +} + +static void ip_mc_clear_src(struct ip_mc_list *pmc) +{ + struct ip_sf_list *tomb, *sources; + + spin_lock_bh(&pmc->lock); + tomb = pmc->tomb; + pmc->tomb = NULL; + sources = pmc->sources; + pmc->sources = NULL; + pmc->sfmode = MCAST_EXCLUDE; + pmc->sfcount[MCAST_INCLUDE] = 0; + pmc->sfcount[MCAST_EXCLUDE] = 1; + spin_unlock_bh(&pmc->lock); + + ip_sf_list_clear_all(tomb); + ip_sf_list_clear_all(sources); +} + +/* Join a multicast group + */ +static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr, + unsigned int mode) +{ + __be32 addr = imr->imr_multiaddr.s_addr; + struct ip_mc_socklist *iml, *i; + struct in_device *in_dev; + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + int ifindex; + int count = 0; + int err; + + ASSERT_RTNL(); + + if (!ipv4_is_multicast(addr)) + return -EINVAL; + + in_dev = ip_mc_find_dev(net, imr); + + if (!in_dev) { + err = -ENODEV; + goto done; + } + + err = -EADDRINUSE; + ifindex = imr->imr_ifindex; + for_each_pmc_rtnl(inet, i) { + if (i->multi.imr_multiaddr.s_addr == addr && + i->multi.imr_ifindex == ifindex) + goto done; + count++; + } + err = -ENOBUFS; + if (count >= READ_ONCE(net->ipv4.sysctl_igmp_max_memberships)) + goto done; + iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL); + if (!iml) + goto done; + + memcpy(&iml->multi, imr, sizeof(*imr)); + iml->next_rcu = inet->mc_list; + iml->sflist = NULL; + iml->sfmode = mode; + rcu_assign_pointer(inet->mc_list, iml); + ____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL); + err = 0; +done: + return err; +} + +/* Join ASM (Any-Source Multicast) group + */ +int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr) +{ + return __ip_mc_join_group(sk, imr, MCAST_EXCLUDE); +} +EXPORT_SYMBOL(ip_mc_join_group); + +/* Join SSM (Source-Specific Multicast) group + */ +int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr, + unsigned int mode) +{ + return __ip_mc_join_group(sk, imr, mode); +} + +static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml, + struct in_device *in_dev) +{ + struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist); + int err; + + if (!psf) { + /* any-source empty exclude case */ + return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr, + iml->sfmode, 0, NULL, 0); + } + err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr, + iml->sfmode, psf->sl_count, psf->sl_addr, 0); + RCU_INIT_POINTER(iml->sflist, NULL); + /* decrease mem now to avoid the memleak warning */ + atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc); + kfree_rcu(psf, rcu); + return err; +} + +int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr) +{ + struct inet_sock *inet = inet_sk(sk); + struct ip_mc_socklist *iml; + struct ip_mc_socklist __rcu **imlp; + struct in_device *in_dev; + struct net *net = sock_net(sk); + __be32 group = imr->imr_multiaddr.s_addr; + u32 ifindex; + int ret = -EADDRNOTAVAIL; + + ASSERT_RTNL(); + + in_dev = ip_mc_find_dev(net, imr); + if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) { + ret = -ENODEV; + goto out; + } + ifindex = imr->imr_ifindex; + for (imlp = &inet->mc_list; + (iml = rtnl_dereference(*imlp)) != NULL; + imlp = &iml->next_rcu) { + if (iml->multi.imr_multiaddr.s_addr != group) + continue; + if (ifindex) { + if (iml->multi.imr_ifindex != ifindex) + continue; + } else if (imr->imr_address.s_addr && imr->imr_address.s_addr != + iml->multi.imr_address.s_addr) + continue; + + (void) ip_mc_leave_src(sk, iml, in_dev); + + *imlp = iml->next_rcu; + + if (in_dev) + ip_mc_dec_group(in_dev, group); + + /* decrease mem now to avoid the memleak warning */ + atomic_sub(sizeof(*iml), &sk->sk_omem_alloc); + kfree_rcu(iml, rcu); + return 0; + } +out: + return ret; +} +EXPORT_SYMBOL(ip_mc_leave_group); + +int ip_mc_source(int add, int omode, struct sock *sk, struct + ip_mreq_source *mreqs, int ifindex) +{ + int err; + struct ip_mreqn imr; + __be32 addr = mreqs->imr_multiaddr; + struct ip_mc_socklist *pmc; + struct in_device *in_dev = NULL; + struct inet_sock *inet = inet_sk(sk); + struct ip_sf_socklist *psl; + struct net *net = sock_net(sk); + int leavegroup = 0; + int i, j, rv; + + if (!ipv4_is_multicast(addr)) + return -EINVAL; + + ASSERT_RTNL(); + + imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr; + imr.imr_address.s_addr = mreqs->imr_interface; + imr.imr_ifindex = ifindex; + in_dev = ip_mc_find_dev(net, &imr); + + if (!in_dev) { + err = -ENODEV; + goto done; + } + err = -EADDRNOTAVAIL; + + for_each_pmc_rtnl(inet, pmc) { + if ((pmc->multi.imr_multiaddr.s_addr == + imr.imr_multiaddr.s_addr) && + (pmc->multi.imr_ifindex == imr.imr_ifindex)) + break; + } + if (!pmc) { /* must have a prior join */ + err = -EINVAL; + goto done; + } + /* if a source filter was set, must be the same mode as before */ + if (pmc->sflist) { + if (pmc->sfmode != omode) { + err = -EINVAL; + goto done; + } + } else if (pmc->sfmode != omode) { + /* allow mode switches for empty-set filters */ + ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0); + ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0, + NULL, 0); + pmc->sfmode = omode; + } + + psl = rtnl_dereference(pmc->sflist); + if (!add) { + if (!psl) + goto done; /* err = -EADDRNOTAVAIL */ + rv = !0; + for (i = 0; i < psl->sl_count; i++) { + rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr, + sizeof(__be32)); + if (rv == 0) + break; + } + if (rv) /* source not found */ + goto done; /* err = -EADDRNOTAVAIL */ + + /* special case - (INCLUDE, empty) == LEAVE_GROUP */ + if (psl->sl_count == 1 && omode == MCAST_INCLUDE) { + leavegroup = 1; + goto done; + } + + /* update the interface filter */ + ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1, + &mreqs->imr_sourceaddr, 1); + + for (j = i+1; j < psl->sl_count; j++) + psl->sl_addr[j-1] = psl->sl_addr[j]; + psl->sl_count--; + err = 0; + goto done; + } + /* else, add a new source to the filter */ + + if (psl && psl->sl_count >= READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) { + err = -ENOBUFS; + goto done; + } + if (!psl || psl->sl_count == psl->sl_max) { + struct ip_sf_socklist *newpsl; + int count = IP_SFBLOCK; + + if (psl) + count += psl->sl_max; + newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL); + if (!newpsl) { + err = -ENOBUFS; + goto done; + } + newpsl->sl_max = count; + newpsl->sl_count = count - IP_SFBLOCK; + if (psl) { + for (i = 0; i < psl->sl_count; i++) + newpsl->sl_addr[i] = psl->sl_addr[i]; + /* decrease mem now to avoid the memleak warning */ + atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc); + } + rcu_assign_pointer(pmc->sflist, newpsl); + if (psl) + kfree_rcu(psl, rcu); + psl = newpsl; + } + rv = 1; /* > 0 for insert logic below if sl_count is 0 */ + for (i = 0; i < psl->sl_count; i++) { + rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr, + sizeof(__be32)); + if (rv == 0) + break; + } + if (rv == 0) /* address already there is an error */ + goto done; + for (j = psl->sl_count-1; j >= i; j--) + psl->sl_addr[j+1] = psl->sl_addr[j]; + psl->sl_addr[i] = mreqs->imr_sourceaddr; + psl->sl_count++; + err = 0; + /* update the interface list */ + ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1, + &mreqs->imr_sourceaddr, 1); +done: + if (leavegroup) + err = ip_mc_leave_group(sk, &imr); + return err; +} + +int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex) +{ + int err = 0; + struct ip_mreqn imr; + __be32 addr = msf->imsf_multiaddr; + struct ip_mc_socklist *pmc; + struct in_device *in_dev; + struct inet_sock *inet = inet_sk(sk); + struct ip_sf_socklist *newpsl, *psl; + struct net *net = sock_net(sk); + int leavegroup = 0; + + if (!ipv4_is_multicast(addr)) + return -EINVAL; + if (msf->imsf_fmode != MCAST_INCLUDE && + msf->imsf_fmode != MCAST_EXCLUDE) + return -EINVAL; + + ASSERT_RTNL(); + + imr.imr_multiaddr.s_addr = msf->imsf_multiaddr; + imr.imr_address.s_addr = msf->imsf_interface; + imr.imr_ifindex = ifindex; + in_dev = ip_mc_find_dev(net, &imr); + + if (!in_dev) { + err = -ENODEV; + goto done; + } + + /* special case - (INCLUDE, empty) == LEAVE_GROUP */ + if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) { + leavegroup = 1; + goto done; + } + + for_each_pmc_rtnl(inet, pmc) { + if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr && + pmc->multi.imr_ifindex == imr.imr_ifindex) + break; + } + if (!pmc) { /* must have a prior join */ + err = -EINVAL; + goto done; + } + if (msf->imsf_numsrc) { + newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc), + GFP_KERNEL); + if (!newpsl) { + err = -ENOBUFS; + goto done; + } + newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc; + memcpy(newpsl->sl_addr, msf->imsf_slist, + msf->imsf_numsrc * sizeof(msf->imsf_slist[0])); + err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr, + msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0); + if (err) { + sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max)); + goto done; + } + } else { + newpsl = NULL; + (void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr, + msf->imsf_fmode, 0, NULL, 0); + } + psl = rtnl_dereference(pmc->sflist); + if (psl) { + (void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode, + psl->sl_count, psl->sl_addr, 0); + /* decrease mem now to avoid the memleak warning */ + atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc); + } else { + (void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode, + 0, NULL, 0); + } + rcu_assign_pointer(pmc->sflist, newpsl); + if (psl) + kfree_rcu(psl, rcu); + pmc->sfmode = msf->imsf_fmode; + err = 0; +done: + if (leavegroup) + err = ip_mc_leave_group(sk, &imr); + return err; +} + +int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf, + struct ip_msfilter __user *optval, int __user *optlen) +{ + int err, len, count, copycount; + struct ip_mreqn imr; + __be32 addr = msf->imsf_multiaddr; + struct ip_mc_socklist *pmc; + struct in_device *in_dev; + struct inet_sock *inet = inet_sk(sk); + struct ip_sf_socklist *psl; + struct net *net = sock_net(sk); + + ASSERT_RTNL(); + + if (!ipv4_is_multicast(addr)) + return -EINVAL; + + imr.imr_multiaddr.s_addr = msf->imsf_multiaddr; + imr.imr_address.s_addr = msf->imsf_interface; + imr.imr_ifindex = 0; + in_dev = ip_mc_find_dev(net, &imr); + + if (!in_dev) { + err = -ENODEV; + goto done; + } + err = -EADDRNOTAVAIL; + + for_each_pmc_rtnl(inet, pmc) { + if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr && + pmc->multi.imr_ifindex == imr.imr_ifindex) + break; + } + if (!pmc) /* must have a prior join */ + goto done; + msf->imsf_fmode = pmc->sfmode; + psl = rtnl_dereference(pmc->sflist); + if (!psl) { + len = 0; + count = 0; + } else { + count = psl->sl_count; + } + copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc; + len = copycount * sizeof(psl->sl_addr[0]); + msf->imsf_numsrc = count; + if (put_user(IP_MSFILTER_SIZE(copycount), optlen) || + copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) { + return -EFAULT; + } + if (len && + copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len)) + return -EFAULT; + return 0; +done: + return err; +} + +int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf, + struct sockaddr_storage __user *p) +{ + int i, count, copycount; + struct sockaddr_in *psin; + __be32 addr; + struct ip_mc_socklist *pmc; + struct inet_sock *inet = inet_sk(sk); + struct ip_sf_socklist *psl; + + ASSERT_RTNL(); + + psin = (struct sockaddr_in *)&gsf->gf_group; + if (psin->sin_family != AF_INET) + return -EINVAL; + addr = psin->sin_addr.s_addr; + if (!ipv4_is_multicast(addr)) + return -EINVAL; + + for_each_pmc_rtnl(inet, pmc) { + if (pmc->multi.imr_multiaddr.s_addr == addr && + pmc->multi.imr_ifindex == gsf->gf_interface) + break; + } + if (!pmc) /* must have a prior join */ + return -EADDRNOTAVAIL; + gsf->gf_fmode = pmc->sfmode; + psl = rtnl_dereference(pmc->sflist); + count = psl ? psl->sl_count : 0; + copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc; + gsf->gf_numsrc = count; + for (i = 0; i < copycount; i++, p++) { + struct sockaddr_storage ss; + + psin = (struct sockaddr_in *)&ss; + memset(&ss, 0, sizeof(ss)); + psin->sin_family = AF_INET; + psin->sin_addr.s_addr = psl->sl_addr[i]; + if (copy_to_user(p, &ss, sizeof(ss))) + return -EFAULT; + } + return 0; +} + +/* + * check if a multicast source filter allows delivery for a given <src,dst,intf> + */ +int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, + int dif, int sdif) +{ + struct inet_sock *inet = inet_sk(sk); + struct ip_mc_socklist *pmc; + struct ip_sf_socklist *psl; + int i; + int ret; + + ret = 1; + if (!ipv4_is_multicast(loc_addr)) + goto out; + + rcu_read_lock(); + for_each_pmc_rcu(inet, pmc) { + if (pmc->multi.imr_multiaddr.s_addr == loc_addr && + (pmc->multi.imr_ifindex == dif || + (sdif && pmc->multi.imr_ifindex == sdif))) + break; + } + ret = inet->mc_all; + if (!pmc) + goto unlock; + psl = rcu_dereference(pmc->sflist); + ret = (pmc->sfmode == MCAST_EXCLUDE); + if (!psl) + goto unlock; + + for (i = 0; i < psl->sl_count; i++) { + if (psl->sl_addr[i] == rmt_addr) + break; + } + ret = 0; + if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count) + goto unlock; + if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count) + goto unlock; + ret = 1; +unlock: + rcu_read_unlock(); +out: + return ret; +} + +/* + * A socket is closing. + */ + +void ip_mc_drop_socket(struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + struct ip_mc_socklist *iml; + struct net *net = sock_net(sk); + + if (!inet->mc_list) + return; + + rtnl_lock(); + while ((iml = rtnl_dereference(inet->mc_list)) != NULL) { + struct in_device *in_dev; + + inet->mc_list = iml->next_rcu; + in_dev = inetdev_by_index(net, iml->multi.imr_ifindex); + (void) ip_mc_leave_src(sk, iml, in_dev); + if (in_dev) + ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr); + /* decrease mem now to avoid the memleak warning */ + atomic_sub(sizeof(*iml), &sk->sk_omem_alloc); + kfree_rcu(iml, rcu); + } + rtnl_unlock(); +} + +/* called with rcu_read_lock() */ +int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto) +{ + struct ip_mc_list *im; + struct ip_mc_list __rcu **mc_hash; + struct ip_sf_list *psf; + int rv = 0; + + mc_hash = rcu_dereference(in_dev->mc_hash); + if (mc_hash) { + u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG); + + for (im = rcu_dereference(mc_hash[hash]); + im != NULL; + im = rcu_dereference(im->next_hash)) { + if (im->multiaddr == mc_addr) + break; + } + } else { + for_each_pmc_rcu(in_dev, im) { + if (im->multiaddr == mc_addr) + break; + } + } + if (im && proto == IPPROTO_IGMP) { + rv = 1; + } else if (im) { + if (src_addr) { + spin_lock_bh(&im->lock); + for (psf = im->sources; psf; psf = psf->sf_next) { + if (psf->sf_inaddr == src_addr) + break; + } + if (psf) + rv = psf->sf_count[MCAST_INCLUDE] || + psf->sf_count[MCAST_EXCLUDE] != + im->sfcount[MCAST_EXCLUDE]; + else + rv = im->sfcount[MCAST_EXCLUDE] != 0; + spin_unlock_bh(&im->lock); + } else + rv = 1; /* unspecified source; tentatively allow */ + } + return rv; +} + +#if defined(CONFIG_PROC_FS) +struct igmp_mc_iter_state { + struct seq_net_private p; + struct net_device *dev; + struct in_device *in_dev; +}; + +#define igmp_mc_seq_private(seq) ((struct igmp_mc_iter_state *)(seq)->private) + +static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq) +{ + struct net *net = seq_file_net(seq); + struct ip_mc_list *im = NULL; + struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq); + + state->in_dev = NULL; + for_each_netdev_rcu(net, state->dev) { + struct in_device *in_dev; + + in_dev = __in_dev_get_rcu(state->dev); + if (!in_dev) + continue; + im = rcu_dereference(in_dev->mc_list); + if (im) { + state->in_dev = in_dev; + break; + } + } + return im; +} + +static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im) +{ + struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq); + + im = rcu_dereference(im->next_rcu); + while (!im) { + state->dev = next_net_device_rcu(state->dev); + if (!state->dev) { + state->in_dev = NULL; + break; + } + state->in_dev = __in_dev_get_rcu(state->dev); + if (!state->in_dev) + continue; + im = rcu_dereference(state->in_dev->mc_list); + } + return im; +} + +static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos) +{ + struct ip_mc_list *im = igmp_mc_get_first(seq); + if (im) + while (pos && (im = igmp_mc_get_next(seq, im)) != NULL) + --pos; + return pos ? NULL : im; +} + +static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(rcu) +{ + rcu_read_lock(); + return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; +} + +static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct ip_mc_list *im; + if (v == SEQ_START_TOKEN) + im = igmp_mc_get_first(seq); + else + im = igmp_mc_get_next(seq, v); + ++*pos; + return im; +} + +static void igmp_mc_seq_stop(struct seq_file *seq, void *v) + __releases(rcu) +{ + struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq); + + state->in_dev = NULL; + state->dev = NULL; + rcu_read_unlock(); +} + +static int igmp_mc_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_puts(seq, + "Idx\tDevice : Count Querier\tGroup Users Timer\tReporter\n"); + else { + struct ip_mc_list *im = (struct ip_mc_list *)v; + struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq); + char *querier; + long delta; + +#ifdef CONFIG_IP_MULTICAST + querier = IGMP_V1_SEEN(state->in_dev) ? "V1" : + IGMP_V2_SEEN(state->in_dev) ? "V2" : + "V3"; +#else + querier = "NONE"; +#endif + + if (rcu_access_pointer(state->in_dev->mc_list) == im) { + seq_printf(seq, "%d\t%-10s: %5d %7s\n", + state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier); + } + + delta = im->timer.expires - jiffies; + seq_printf(seq, + "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n", + im->multiaddr, im->users, + im->tm_running, + im->tm_running ? jiffies_delta_to_clock_t(delta) : 0, + im->reporter); + } + return 0; +} + +static const struct seq_operations igmp_mc_seq_ops = { + .start = igmp_mc_seq_start, + .next = igmp_mc_seq_next, + .stop = igmp_mc_seq_stop, + .show = igmp_mc_seq_show, +}; + +struct igmp_mcf_iter_state { + struct seq_net_private p; + struct net_device *dev; + struct in_device *idev; + struct ip_mc_list *im; +}; + +#define igmp_mcf_seq_private(seq) ((struct igmp_mcf_iter_state *)(seq)->private) + +static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq) +{ + struct net *net = seq_file_net(seq); + struct ip_sf_list *psf = NULL; + struct ip_mc_list *im = NULL; + struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq); + + state->idev = NULL; + state->im = NULL; + for_each_netdev_rcu(net, state->dev) { + struct in_device *idev; + idev = __in_dev_get_rcu(state->dev); + if (unlikely(!idev)) + continue; + im = rcu_dereference(idev->mc_list); + if (likely(im)) { + spin_lock_bh(&im->lock); + psf = im->sources; + if (likely(psf)) { + state->im = im; + state->idev = idev; + break; + } + spin_unlock_bh(&im->lock); + } + } + return psf; +} + +static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf) +{ + struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq); + + psf = psf->sf_next; + while (!psf) { + spin_unlock_bh(&state->im->lock); + state->im = state->im->next; + while (!state->im) { + state->dev = next_net_device_rcu(state->dev); + if (!state->dev) { + state->idev = NULL; + goto out; + } + state->idev = __in_dev_get_rcu(state->dev); + if (!state->idev) + continue; + state->im = rcu_dereference(state->idev->mc_list); + } + if (!state->im) + break; + spin_lock_bh(&state->im->lock); + psf = state->im->sources; + } +out: + return psf; +} + +static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos) +{ + struct ip_sf_list *psf = igmp_mcf_get_first(seq); + if (psf) + while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL) + --pos; + return pos ? NULL : psf; +} + +static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(rcu) +{ + rcu_read_lock(); + return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; +} + +static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct ip_sf_list *psf; + if (v == SEQ_START_TOKEN) + psf = igmp_mcf_get_first(seq); + else + psf = igmp_mcf_get_next(seq, v); + ++*pos; + return psf; +} + +static void igmp_mcf_seq_stop(struct seq_file *seq, void *v) + __releases(rcu) +{ + struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq); + if (likely(state->im)) { + spin_unlock_bh(&state->im->lock); + state->im = NULL; + } + state->idev = NULL; + state->dev = NULL; + rcu_read_unlock(); +} + +static int igmp_mcf_seq_show(struct seq_file *seq, void *v) +{ + struct ip_sf_list *psf = (struct ip_sf_list *)v; + struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq); + + if (v == SEQ_START_TOKEN) { + seq_puts(seq, "Idx Device MCA SRC INC EXC\n"); + } else { + seq_printf(seq, + "%3d %6.6s 0x%08x " + "0x%08x %6lu %6lu\n", + state->dev->ifindex, state->dev->name, + ntohl(state->im->multiaddr), + ntohl(psf->sf_inaddr), + psf->sf_count[MCAST_INCLUDE], + psf->sf_count[MCAST_EXCLUDE]); + } + return 0; +} + +static const struct seq_operations igmp_mcf_seq_ops = { + .start = igmp_mcf_seq_start, + .next = igmp_mcf_seq_next, + .stop = igmp_mcf_seq_stop, + .show = igmp_mcf_seq_show, +}; + +static int __net_init igmp_net_init(struct net *net) +{ + struct proc_dir_entry *pde; + int err; + + pde = proc_create_net("igmp", 0444, net->proc_net, &igmp_mc_seq_ops, + sizeof(struct igmp_mc_iter_state)); + if (!pde) + goto out_igmp; + pde = proc_create_net("mcfilter", 0444, net->proc_net, + &igmp_mcf_seq_ops, sizeof(struct igmp_mcf_iter_state)); + if (!pde) + goto out_mcfilter; + err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET, + SOCK_DGRAM, 0, net); + if (err < 0) { + pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n", + err); + goto out_sock; + } + + return 0; + +out_sock: + remove_proc_entry("mcfilter", net->proc_net); +out_mcfilter: + remove_proc_entry("igmp", net->proc_net); +out_igmp: + return -ENOMEM; +} + +static void __net_exit igmp_net_exit(struct net *net) +{ + remove_proc_entry("mcfilter", net->proc_net); + remove_proc_entry("igmp", net->proc_net); + inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk); +} + +static struct pernet_operations igmp_net_ops = { + .init = igmp_net_init, + .exit = igmp_net_exit, +}; +#endif + +static int igmp_netdev_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct in_device *in_dev; + + switch (event) { + case NETDEV_RESEND_IGMP: + in_dev = __in_dev_get_rtnl(dev); + if (in_dev) + ip_mc_rejoin_groups(in_dev); + break; + default: + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block igmp_notifier = { + .notifier_call = igmp_netdev_event, +}; + +int __init igmp_mc_init(void) +{ +#if defined(CONFIG_PROC_FS) + int err; + + err = register_pernet_subsys(&igmp_net_ops); + if (err) + return err; + err = register_netdevice_notifier(&igmp_notifier); + if (err) + goto reg_notif_fail; + return 0; + +reg_notif_fail: + unregister_pernet_subsys(&igmp_net_ops); + return err; +#else + return register_netdevice_notifier(&igmp_notifier); +#endif +} diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c new file mode 100644 index 000000000..5f71a1c74 --- /dev/null +++ b/net/ipv4/inet_connection_sock.c @@ -0,0 +1,1138 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Support for INET connection oriented protocols. + * + * Authors: See the TCP sources + */ + +#include <linux/module.h> +#include <linux/jhash.h> + +#include <net/inet_connection_sock.h> +#include <net/inet_hashtables.h> +#include <net/inet_timewait_sock.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/tcp_states.h> +#include <net/xfrm.h> +#include <net/tcp.h> +#include <net/sock_reuseport.h> +#include <net/addrconf.h> + +#if IS_ENABLED(CONFIG_IPV6) +/* match_sk*_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses + * if IPv6 only, and any IPv4 addresses + * if not IPv6 only + * match_sk*_wildcard == false: addresses must be exactly the same, i.e. + * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY, + * and 0.0.0.0 equals to 0.0.0.0 only + */ +static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6, + const struct in6_addr *sk2_rcv_saddr6, + __be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr, + bool sk1_ipv6only, bool sk2_ipv6only, + bool match_sk1_wildcard, + bool match_sk2_wildcard) +{ + int addr_type = ipv6_addr_type(sk1_rcv_saddr6); + int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED; + + /* if both are mapped, treat as IPv4 */ + if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) { + if (!sk2_ipv6only) { + if (sk1_rcv_saddr == sk2_rcv_saddr) + return true; + return (match_sk1_wildcard && !sk1_rcv_saddr) || + (match_sk2_wildcard && !sk2_rcv_saddr); + } + return false; + } + + if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY) + return true; + + if (addr_type2 == IPV6_ADDR_ANY && match_sk2_wildcard && + !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED)) + return true; + + if (addr_type == IPV6_ADDR_ANY && match_sk1_wildcard && + !(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED)) + return true; + + if (sk2_rcv_saddr6 && + ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6)) + return true; + + return false; +} +#endif + +/* match_sk*_wildcard == true: 0.0.0.0 equals to any IPv4 addresses + * match_sk*_wildcard == false: addresses must be exactly the same, i.e. + * 0.0.0.0 only equals to 0.0.0.0 + */ +static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr, + bool sk2_ipv6only, bool match_sk1_wildcard, + bool match_sk2_wildcard) +{ + if (!sk2_ipv6only) { + if (sk1_rcv_saddr == sk2_rcv_saddr) + return true; + return (match_sk1_wildcard && !sk1_rcv_saddr) || + (match_sk2_wildcard && !sk2_rcv_saddr); + } + return false; +} + +bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2, + bool match_wildcard) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr, + inet6_rcv_saddr(sk2), + sk->sk_rcv_saddr, + sk2->sk_rcv_saddr, + ipv6_only_sock(sk), + ipv6_only_sock(sk2), + match_wildcard, + match_wildcard); +#endif + return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr, + ipv6_only_sock(sk2), match_wildcard, + match_wildcard); +} +EXPORT_SYMBOL(inet_rcv_saddr_equal); + +bool inet_rcv_saddr_any(const struct sock *sk) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + return ipv6_addr_any(&sk->sk_v6_rcv_saddr); +#endif + return !sk->sk_rcv_saddr; +} + +void inet_get_local_port_range(struct net *net, int *low, int *high) +{ + unsigned int seq; + + do { + seq = read_seqbegin(&net->ipv4.ip_local_ports.lock); + + *low = net->ipv4.ip_local_ports.range[0]; + *high = net->ipv4.ip_local_ports.range[1]; + } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq)); +} +EXPORT_SYMBOL(inet_get_local_port_range); + +static int inet_csk_bind_conflict(const struct sock *sk, + const struct inet_bind_bucket *tb, + bool relax, bool reuseport_ok) +{ + struct sock *sk2; + bool reuse = sk->sk_reuse; + bool reuseport = !!sk->sk_reuseport; + kuid_t uid = sock_i_uid((struct sock *)sk); + + /* + * Unlike other sk lookup places we do not check + * for sk_net here, since _all_ the socks listed + * in tb->owners list belong to the same net - the + * one this bucket belongs to. + */ + + sk_for_each_bound(sk2, &tb->owners) { + int bound_dev_if2; + + if (sk == sk2) + continue; + bound_dev_if2 = READ_ONCE(sk2->sk_bound_dev_if); + if ((!sk->sk_bound_dev_if || + !bound_dev_if2 || + sk->sk_bound_dev_if == bound_dev_if2)) { + if (reuse && sk2->sk_reuse && + sk2->sk_state != TCP_LISTEN) { + if ((!relax || + (!reuseport_ok && + reuseport && sk2->sk_reuseport && + !rcu_access_pointer(sk->sk_reuseport_cb) && + (sk2->sk_state == TCP_TIME_WAIT || + uid_eq(uid, sock_i_uid(sk2))))) && + inet_rcv_saddr_equal(sk, sk2, true)) + break; + } else if (!reuseport_ok || + !reuseport || !sk2->sk_reuseport || + rcu_access_pointer(sk->sk_reuseport_cb) || + (sk2->sk_state != TCP_TIME_WAIT && + !uid_eq(uid, sock_i_uid(sk2)))) { + if (inet_rcv_saddr_equal(sk, sk2, true)) + break; + } + } + } + return sk2 != NULL; +} + +/* + * Find an open port number for the socket. Returns with the + * inet_bind_hashbucket lock held. + */ +static struct inet_bind_hashbucket * +inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret) +{ + struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo; + int port = 0; + struct inet_bind_hashbucket *head; + struct net *net = sock_net(sk); + bool relax = false; + int i, low, high, attempt_half; + struct inet_bind_bucket *tb; + u32 remaining, offset; + int l3mdev; + + l3mdev = inet_sk_bound_l3mdev(sk); +ports_exhausted: + attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0; +other_half_scan: + inet_get_local_port_range(net, &low, &high); + high++; /* [32768, 60999] -> [32768, 61000[ */ + if (high - low < 4) + attempt_half = 0; + if (attempt_half) { + int half = low + (((high - low) >> 2) << 1); + + if (attempt_half == 1) + high = half; + else + low = half; + } + remaining = high - low; + if (likely(remaining > 1)) + remaining &= ~1U; + + offset = prandom_u32() % remaining; + /* __inet_hash_connect() favors ports having @low parity + * We do the opposite to not pollute connect() users. + */ + offset |= 1U; + +other_parity_scan: + port = low + offset; + for (i = 0; i < remaining; i += 2, port += 2) { + if (unlikely(port >= high)) + port -= remaining; + if (inet_is_local_reserved_port(net, port)) + continue; + head = &hinfo->bhash[inet_bhashfn(net, port, + hinfo->bhash_size)]; + spin_lock_bh(&head->lock); + inet_bind_bucket_for_each(tb, &head->chain) + if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev && + tb->port == port) { + if (!inet_csk_bind_conflict(sk, tb, relax, false)) + goto success; + goto next_port; + } + tb = NULL; + goto success; +next_port: + spin_unlock_bh(&head->lock); + cond_resched(); + } + + offset--; + if (!(offset & 1)) + goto other_parity_scan; + + if (attempt_half == 1) { + /* OK we now try the upper half of the range */ + attempt_half = 2; + goto other_half_scan; + } + + if (READ_ONCE(net->ipv4.sysctl_ip_autobind_reuse) && !relax) { + /* We still have a chance to connect to different destinations */ + relax = true; + goto ports_exhausted; + } + return NULL; +success: + *port_ret = port; + *tb_ret = tb; + return head; +} + +static inline int sk_reuseport_match(struct inet_bind_bucket *tb, + struct sock *sk) +{ + kuid_t uid = sock_i_uid(sk); + + if (tb->fastreuseport <= 0) + return 0; + if (!sk->sk_reuseport) + return 0; + if (rcu_access_pointer(sk->sk_reuseport_cb)) + return 0; + if (!uid_eq(tb->fastuid, uid)) + return 0; + /* We only need to check the rcv_saddr if this tb was once marked + * without fastreuseport and then was reset, as we can only know that + * the fast_*rcv_saddr doesn't have any conflicts with the socks on the + * owners list. + */ + if (tb->fastreuseport == FASTREUSEPORT_ANY) + return 1; +#if IS_ENABLED(CONFIG_IPV6) + if (tb->fast_sk_family == AF_INET6) + return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr, + inet6_rcv_saddr(sk), + tb->fast_rcv_saddr, + sk->sk_rcv_saddr, + tb->fast_ipv6_only, + ipv6_only_sock(sk), true, false); +#endif + return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr, + ipv6_only_sock(sk), true, false); +} + +void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, + struct sock *sk) +{ + kuid_t uid = sock_i_uid(sk); + bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN; + + if (hlist_empty(&tb->owners)) { + tb->fastreuse = reuse; + if (sk->sk_reuseport) { + tb->fastreuseport = FASTREUSEPORT_ANY; + tb->fastuid = uid; + tb->fast_rcv_saddr = sk->sk_rcv_saddr; + tb->fast_ipv6_only = ipv6_only_sock(sk); + tb->fast_sk_family = sk->sk_family; +#if IS_ENABLED(CONFIG_IPV6) + tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr; +#endif + } else { + tb->fastreuseport = 0; + } + } else { + if (!reuse) + tb->fastreuse = 0; + if (sk->sk_reuseport) { + /* We didn't match or we don't have fastreuseport set on + * the tb, but we have sk_reuseport set on this socket + * and we know that there are no bind conflicts with + * this socket in this tb, so reset our tb's reuseport + * settings so that any subsequent sockets that match + * our current socket will be put on the fast path. + * + * If we reset we need to set FASTREUSEPORT_STRICT so we + * do extra checking for all subsequent sk_reuseport + * socks. + */ + if (!sk_reuseport_match(tb, sk)) { + tb->fastreuseport = FASTREUSEPORT_STRICT; + tb->fastuid = uid; + tb->fast_rcv_saddr = sk->sk_rcv_saddr; + tb->fast_ipv6_only = ipv6_only_sock(sk); + tb->fast_sk_family = sk->sk_family; +#if IS_ENABLED(CONFIG_IPV6) + tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr; +#endif + } + } else { + tb->fastreuseport = 0; + } + } +} + +/* Obtain a reference to a local port for the given sock, + * if snum is zero it means select any available local port. + * We try to allocate an odd port (and leave even ports for connect()) + */ +int inet_csk_get_port(struct sock *sk, unsigned short snum) +{ + bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN; + struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo; + int ret = 1, port = snum; + struct inet_bind_hashbucket *head; + struct net *net = sock_net(sk); + struct inet_bind_bucket *tb = NULL; + int l3mdev; + + l3mdev = inet_sk_bound_l3mdev(sk); + + if (!port) { + head = inet_csk_find_open_port(sk, &tb, &port); + if (!head) + return ret; + if (!tb) + goto tb_not_found; + goto success; + } + head = &hinfo->bhash[inet_bhashfn(net, port, + hinfo->bhash_size)]; + spin_lock_bh(&head->lock); + inet_bind_bucket_for_each(tb, &head->chain) + if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev && + tb->port == port) + goto tb_found; +tb_not_found: + tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, + net, head, port, l3mdev); + if (!tb) + goto fail_unlock; +tb_found: + if (!hlist_empty(&tb->owners)) { + if (sk->sk_reuse == SK_FORCE_REUSE) + goto success; + + if ((tb->fastreuse > 0 && reuse) || + sk_reuseport_match(tb, sk)) + goto success; + if (inet_csk_bind_conflict(sk, tb, true, true)) + goto fail_unlock; + } +success: + inet_csk_update_fastreuse(tb, sk); + + if (!inet_csk(sk)->icsk_bind_hash) + inet_bind_hash(sk, tb, port); + WARN_ON(inet_csk(sk)->icsk_bind_hash != tb); + ret = 0; + +fail_unlock: + spin_unlock_bh(&head->lock); + return ret; +} +EXPORT_SYMBOL_GPL(inet_csk_get_port); + +/* + * Wait for an incoming connection, avoid race conditions. This must be called + * with the socket locked. + */ +static int inet_csk_wait_for_connect(struct sock *sk, long timeo) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + DEFINE_WAIT(wait); + int err; + + /* + * True wake-one mechanism for incoming connections: only + * one process gets woken up, not the 'whole herd'. + * Since we do not 'race & poll' for established sockets + * anymore, the common case will execute the loop only once. + * + * Subtle issue: "add_wait_queue_exclusive()" will be added + * after any current non-exclusive waiters, and we know that + * it will always _stay_ after any new non-exclusive waiters + * because all non-exclusive waiters are added at the + * beginning of the wait-queue. As such, it's ok to "drop" + * our exclusiveness temporarily when we get woken up without + * having to remove and re-insert us on the wait queue. + */ + for (;;) { + prepare_to_wait_exclusive(sk_sleep(sk), &wait, + TASK_INTERRUPTIBLE); + release_sock(sk); + if (reqsk_queue_empty(&icsk->icsk_accept_queue)) + timeo = schedule_timeout(timeo); + sched_annotate_sleep(); + lock_sock(sk); + err = 0; + if (!reqsk_queue_empty(&icsk->icsk_accept_queue)) + break; + err = -EINVAL; + if (sk->sk_state != TCP_LISTEN) + break; + err = sock_intr_errno(timeo); + if (signal_pending(current)) + break; + err = -EAGAIN; + if (!timeo) + break; + } + finish_wait(sk_sleep(sk), &wait); + return err; +} + +/* + * This will accept the next outstanding connection. + */ +struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct request_sock_queue *queue = &icsk->icsk_accept_queue; + struct request_sock *req; + struct sock *newsk; + int error; + + lock_sock(sk); + + /* We need to make sure that this socket is listening, + * and that it has something pending. + */ + error = -EINVAL; + if (sk->sk_state != TCP_LISTEN) + goto out_err; + + /* Find already established connection */ + if (reqsk_queue_empty(queue)) { + long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); + + /* If this is a non blocking socket don't sleep */ + error = -EAGAIN; + if (!timeo) + goto out_err; + + error = inet_csk_wait_for_connect(sk, timeo); + if (error) + goto out_err; + } + req = reqsk_queue_remove(queue, sk); + newsk = req->sk; + + if (sk->sk_protocol == IPPROTO_TCP && + tcp_rsk(req)->tfo_listener) { + spin_lock_bh(&queue->fastopenq.lock); + if (tcp_rsk(req)->tfo_listener) { + /* We are still waiting for the final ACK from 3WHS + * so can't free req now. Instead, we set req->sk to + * NULL to signify that the child socket is taken + * so reqsk_fastopen_remove() will free the req + * when 3WHS finishes (or is aborted). + */ + req->sk = NULL; + req = NULL; + } + spin_unlock_bh(&queue->fastopenq.lock); + } + +out: + release_sock(sk); + if (newsk && mem_cgroup_sockets_enabled) { + int amt; + + /* atomically get the memory usage, set and charge the + * newsk->sk_memcg. + */ + lock_sock(newsk); + + /* The socket has not been accepted yet, no need to look at + * newsk->sk_wmem_queued. + */ + amt = sk_mem_pages(newsk->sk_forward_alloc + + atomic_read(&newsk->sk_rmem_alloc)); + mem_cgroup_sk_alloc(newsk); + if (newsk->sk_memcg && amt) + mem_cgroup_charge_skmem(newsk->sk_memcg, amt); + + release_sock(newsk); + } + if (req) + reqsk_put(req); + return newsk; +out_err: + newsk = NULL; + req = NULL; + *err = error; + goto out; +} +EXPORT_SYMBOL(inet_csk_accept); + +/* + * Using different timers for retransmit, delayed acks and probes + * We may wish use just one timer maintaining a list of expire jiffies + * to optimize. + */ +void inet_csk_init_xmit_timers(struct sock *sk, + void (*retransmit_handler)(struct timer_list *t), + void (*delack_handler)(struct timer_list *t), + void (*keepalive_handler)(struct timer_list *t)) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0); + timer_setup(&icsk->icsk_delack_timer, delack_handler, 0); + timer_setup(&sk->sk_timer, keepalive_handler, 0); + icsk->icsk_pending = icsk->icsk_ack.pending = 0; +} +EXPORT_SYMBOL(inet_csk_init_xmit_timers); + +void inet_csk_clear_xmit_timers(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + icsk->icsk_pending = icsk->icsk_ack.pending = 0; + + sk_stop_timer(sk, &icsk->icsk_retransmit_timer); + sk_stop_timer(sk, &icsk->icsk_delack_timer); + sk_stop_timer(sk, &sk->sk_timer); +} +EXPORT_SYMBOL(inet_csk_clear_xmit_timers); + +void inet_csk_delete_keepalive_timer(struct sock *sk) +{ + sk_stop_timer(sk, &sk->sk_timer); +} +EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); + +void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) +{ + sk_reset_timer(sk, &sk->sk_timer, jiffies + len); +} +EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); + +struct dst_entry *inet_csk_route_req(const struct sock *sk, + struct flowi4 *fl4, + const struct request_sock *req) +{ + const struct inet_request_sock *ireq = inet_rsk(req); + struct net *net = read_pnet(&ireq->ireq_net); + struct ip_options_rcu *opt; + struct rtable *rt; + + rcu_read_lock(); + opt = rcu_dereference(ireq->ireq_opt); + + flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, + sk->sk_protocol, inet_sk_flowi_flags(sk), + (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr, + ireq->ir_loc_addr, ireq->ir_rmt_port, + htons(ireq->ir_num), sk->sk_uid); + security_req_classify_flow(req, flowi4_to_flowi_common(fl4)); + rt = ip_route_output_flow(net, fl4, sk); + if (IS_ERR(rt)) + goto no_route; + if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) + goto route_err; + rcu_read_unlock(); + return &rt->dst; + +route_err: + ip_rt_put(rt); +no_route: + rcu_read_unlock(); + __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); + return NULL; +} +EXPORT_SYMBOL_GPL(inet_csk_route_req); + +struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, + struct sock *newsk, + const struct request_sock *req) +{ + const struct inet_request_sock *ireq = inet_rsk(req); + struct net *net = read_pnet(&ireq->ireq_net); + struct inet_sock *newinet = inet_sk(newsk); + struct ip_options_rcu *opt; + struct flowi4 *fl4; + struct rtable *rt; + + opt = rcu_dereference(ireq->ireq_opt); + fl4 = &newinet->cork.fl.u.ip4; + + flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, + sk->sk_protocol, inet_sk_flowi_flags(sk), + (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr, + ireq->ir_loc_addr, ireq->ir_rmt_port, + htons(ireq->ir_num), sk->sk_uid); + security_req_classify_flow(req, flowi4_to_flowi_common(fl4)); + rt = ip_route_output_flow(net, fl4, sk); + if (IS_ERR(rt)) + goto no_route; + if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) + goto route_err; + return &rt->dst; + +route_err: + ip_rt_put(rt); +no_route: + __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); + return NULL; +} +EXPORT_SYMBOL_GPL(inet_csk_route_child_sock); + +/* Decide when to expire the request and when to resend SYN-ACK */ +static void syn_ack_recalc(struct request_sock *req, + const int max_syn_ack_retries, + const u8 rskq_defer_accept, + int *expire, int *resend) +{ + if (!rskq_defer_accept) { + *expire = req->num_timeout >= max_syn_ack_retries; + *resend = 1; + return; + } + *expire = req->num_timeout >= max_syn_ack_retries && + (!inet_rsk(req)->acked || req->num_timeout >= rskq_defer_accept); + /* Do not resend while waiting for data after ACK, + * start to resend on end of deferring period to give + * last chance for data or ACK to create established socket. + */ + *resend = !inet_rsk(req)->acked || + req->num_timeout >= rskq_defer_accept - 1; +} + +int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req) +{ + int err = req->rsk_ops->rtx_syn_ack(parent, req); + + if (!err) + req->num_retrans++; + return err; +} +EXPORT_SYMBOL(inet_rtx_syn_ack); + +/* return true if req was found in the ehash table */ +static bool reqsk_queue_unlink(struct request_sock *req) +{ + struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo; + bool found = false; + + if (sk_hashed(req_to_sk(req))) { + spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash); + + spin_lock(lock); + found = __sk_nulls_del_node_init_rcu(req_to_sk(req)); + spin_unlock(lock); + } + if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer)) + reqsk_put(req); + return found; +} + +bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req) +{ + bool unlinked = reqsk_queue_unlink(req); + + if (unlinked) { + reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req); + reqsk_put(req); + } + return unlinked; +} +EXPORT_SYMBOL(inet_csk_reqsk_queue_drop); + +void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req) +{ + inet_csk_reqsk_queue_drop(sk, req); + reqsk_put(req); +} +EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put); + +static void reqsk_timer_handler(struct timer_list *t) +{ + struct request_sock *req = from_timer(req, t, rsk_timer); + struct sock *sk_listener = req->rsk_listener; + struct net *net = sock_net(sk_listener); + struct inet_connection_sock *icsk = inet_csk(sk_listener); + struct request_sock_queue *queue = &icsk->icsk_accept_queue; + int max_syn_ack_retries, qlen, expire = 0, resend = 0; + + if (inet_sk_state_load(sk_listener) != TCP_LISTEN) + goto drop; + + max_syn_ack_retries = READ_ONCE(icsk->icsk_syn_retries) ? : + READ_ONCE(net->ipv4.sysctl_tcp_synack_retries); + /* Normally all the openreqs are young and become mature + * (i.e. converted to established socket) for first timeout. + * If synack was not acknowledged for 1 second, it means + * one of the following things: synack was lost, ack was lost, + * rtt is high or nobody planned to ack (i.e. synflood). + * When server is a bit loaded, queue is populated with old + * open requests, reducing effective size of queue. + * When server is well loaded, queue size reduces to zero + * after several minutes of work. It is not synflood, + * it is normal operation. The solution is pruning + * too old entries overriding normal timeout, when + * situation becomes dangerous. + * + * Essentially, we reserve half of room for young + * embrions; and abort old ones without pity, if old + * ones are about to clog our table. + */ + qlen = reqsk_queue_len(queue); + if ((qlen << 1) > max(8U, READ_ONCE(sk_listener->sk_max_ack_backlog))) { + int young = reqsk_queue_len_young(queue) << 1; + + while (max_syn_ack_retries > 2) { + if (qlen < young) + break; + max_syn_ack_retries--; + young <<= 1; + } + } + syn_ack_recalc(req, max_syn_ack_retries, READ_ONCE(queue->rskq_defer_accept), + &expire, &resend); + req->rsk_ops->syn_ack_timeout(req); + if (!expire && + (!resend || + !inet_rtx_syn_ack(sk_listener, req) || + inet_rsk(req)->acked)) { + unsigned long timeo; + + if (req->num_timeout++ == 0) + atomic_dec(&queue->young); + timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); + mod_timer(&req->rsk_timer, jiffies + timeo); + return; + } +drop: + inet_csk_reqsk_queue_drop_and_put(sk_listener, req); +} + +static void reqsk_queue_hash_req(struct request_sock *req, + unsigned long timeout) +{ + timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED); + mod_timer(&req->rsk_timer, jiffies + timeout); + + inet_ehash_insert(req_to_sk(req), NULL, NULL); + /* before letting lookups find us, make sure all req fields + * are committed to memory and refcnt initialized. + */ + smp_wmb(); + refcount_set(&req->rsk_refcnt, 2 + 1); +} + +void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, + unsigned long timeout) +{ + reqsk_queue_hash_req(req, timeout); + inet_csk_reqsk_queue_added(sk); +} +EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); + +static void inet_clone_ulp(const struct request_sock *req, struct sock *newsk, + const gfp_t priority) +{ + struct inet_connection_sock *icsk = inet_csk(newsk); + + if (!icsk->icsk_ulp_ops) + return; + + if (icsk->icsk_ulp_ops->clone) + icsk->icsk_ulp_ops->clone(req, newsk, priority); +} + +/** + * inet_csk_clone_lock - clone an inet socket, and lock its clone + * @sk: the socket to clone + * @req: request_sock + * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) + * + * Caller must unlock socket even in error path (bh_unlock_sock(newsk)) + */ +struct sock *inet_csk_clone_lock(const struct sock *sk, + const struct request_sock *req, + const gfp_t priority) +{ + struct sock *newsk = sk_clone_lock(sk, priority); + + if (newsk) { + struct inet_connection_sock *newicsk = inet_csk(newsk); + + newsk->sk_wait_pending = 0; + inet_sk_set_state(newsk, TCP_SYN_RECV); + newicsk->icsk_bind_hash = NULL; + + inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port; + inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num; + inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num); + + /* listeners have SOCK_RCU_FREE, not the children */ + sock_reset_flag(newsk, SOCK_RCU_FREE); + + inet_sk(newsk)->mc_list = NULL; + + newsk->sk_mark = inet_rsk(req)->ir_mark; + atomic64_set(&newsk->sk_cookie, + atomic64_read(&inet_rsk(req)->ir_cookie)); + + newicsk->icsk_retransmits = 0; + newicsk->icsk_backoff = 0; + newicsk->icsk_probes_out = 0; + newicsk->icsk_probes_tstamp = 0; + + /* Deinitialize accept_queue to trap illegal accesses. */ + memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue)); + + inet_clone_ulp(req, newsk, priority); + + security_inet_csk_clone(newsk, req); + } + return newsk; +} +EXPORT_SYMBOL_GPL(inet_csk_clone_lock); + +/* + * At this point, there should be no process reference to this + * socket, and thus no user references at all. Therefore we + * can assume the socket waitqueue is inactive and nobody will + * try to jump onto it. + */ +void inet_csk_destroy_sock(struct sock *sk) +{ + WARN_ON(sk->sk_state != TCP_CLOSE); + WARN_ON(!sock_flag(sk, SOCK_DEAD)); + + /* It cannot be in hash table! */ + WARN_ON(!sk_unhashed(sk)); + + /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */ + WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash); + + sk->sk_prot->destroy(sk); + + sk_stream_kill_queues(sk); + + xfrm_sk_free_policy(sk); + + sk_refcnt_debug_release(sk); + + this_cpu_dec(*sk->sk_prot->orphan_count); + + sock_put(sk); +} +EXPORT_SYMBOL(inet_csk_destroy_sock); + +/* This function allows to force a closure of a socket after the call to + * tcp/dccp_create_openreq_child(). + */ +void inet_csk_prepare_forced_close(struct sock *sk) + __releases(&sk->sk_lock.slock) +{ + /* sk_clone_lock locked the socket and set refcnt to 2 */ + bh_unlock_sock(sk); + sock_put(sk); + inet_csk_prepare_for_destroy_sock(sk); + inet_sk(sk)->inet_num = 0; +} +EXPORT_SYMBOL(inet_csk_prepare_forced_close); + +static int inet_ulp_can_listen(const struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ulp_ops && !icsk->icsk_ulp_ops->clone) + return -EINVAL; + + return 0; +} + +int inet_csk_listen_start(struct sock *sk, int backlog) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_sock *inet = inet_sk(sk); + int err; + + err = inet_ulp_can_listen(sk); + if (unlikely(err)) + return err; + + reqsk_queue_alloc(&icsk->icsk_accept_queue); + + sk->sk_ack_backlog = 0; + inet_csk_delack_init(sk); + + /* There is race window here: we announce ourselves listening, + * but this transition is still not validated by get_port(). + * It is OK, because this socket enters to hash table only + * after validation is complete. + */ + err = -EADDRINUSE; + inet_sk_state_store(sk, TCP_LISTEN); + if (!sk->sk_prot->get_port(sk, inet->inet_num)) { + inet->inet_sport = htons(inet->inet_num); + + sk_dst_reset(sk); + err = sk->sk_prot->hash(sk); + + if (likely(!err)) + return 0; + } + + inet_sk_set_state(sk, TCP_CLOSE); + return err; +} +EXPORT_SYMBOL_GPL(inet_csk_listen_start); + +static void inet_child_forget(struct sock *sk, struct request_sock *req, + struct sock *child) +{ + sk->sk_prot->disconnect(child, O_NONBLOCK); + + sock_orphan(child); + + this_cpu_inc(*sk->sk_prot->orphan_count); + + if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) { + BUG_ON(rcu_access_pointer(tcp_sk(child)->fastopen_rsk) != req); + BUG_ON(sk != req->rsk_listener); + + /* Paranoid, to prevent race condition if + * an inbound pkt destined for child is + * blocked by sock lock in tcp_v4_rcv(). + * Also to satisfy an assertion in + * tcp_v4_destroy_sock(). + */ + RCU_INIT_POINTER(tcp_sk(child)->fastopen_rsk, NULL); + } + inet_csk_destroy_sock(child); +} + +struct sock *inet_csk_reqsk_queue_add(struct sock *sk, + struct request_sock *req, + struct sock *child) +{ + struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; + + spin_lock(&queue->rskq_lock); + if (unlikely(sk->sk_state != TCP_LISTEN)) { + inet_child_forget(sk, req, child); + child = NULL; + } else { + req->sk = child; + req->dl_next = NULL; + if (queue->rskq_accept_head == NULL) + WRITE_ONCE(queue->rskq_accept_head, req); + else + queue->rskq_accept_tail->dl_next = req; + queue->rskq_accept_tail = req; + sk_acceptq_added(sk); + } + spin_unlock(&queue->rskq_lock); + return child; +} +EXPORT_SYMBOL(inet_csk_reqsk_queue_add); + +struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, + struct request_sock *req, bool own_req) +{ + if (own_req) { + inet_csk_reqsk_queue_drop(sk, req); + reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req); + if (inet_csk_reqsk_queue_add(sk, req, child)) + return child; + } + /* Too bad, another child took ownership of the request, undo. */ + bh_unlock_sock(child); + sock_put(child); + return NULL; +} +EXPORT_SYMBOL(inet_csk_complete_hashdance); + +/* + * This routine closes sockets which have been at least partially + * opened, but not yet accepted. + */ +void inet_csk_listen_stop(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct request_sock_queue *queue = &icsk->icsk_accept_queue; + struct request_sock *next, *req; + + /* Following specs, it would be better either to send FIN + * (and enter FIN-WAIT-1, it is normal close) + * or to send active reset (abort). + * Certainly, it is pretty dangerous while synflood, but it is + * bad justification for our negligence 8) + * To be honest, we are not able to make either + * of the variants now. --ANK + */ + while ((req = reqsk_queue_remove(queue, sk)) != NULL) { + struct sock *child = req->sk; + + local_bh_disable(); + bh_lock_sock(child); + WARN_ON(sock_owned_by_user(child)); + sock_hold(child); + + inet_child_forget(sk, req, child); + reqsk_put(req); + bh_unlock_sock(child); + local_bh_enable(); + sock_put(child); + + cond_resched(); + } + if (queue->fastopenq.rskq_rst_head) { + /* Free all the reqs queued in rskq_rst_head. */ + spin_lock_bh(&queue->fastopenq.lock); + req = queue->fastopenq.rskq_rst_head; + queue->fastopenq.rskq_rst_head = NULL; + spin_unlock_bh(&queue->fastopenq.lock); + while (req != NULL) { + next = req->dl_next; + reqsk_put(req); + req = next; + } + } + WARN_ON_ONCE(sk->sk_ack_backlog); +} +EXPORT_SYMBOL_GPL(inet_csk_listen_stop); + +void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) +{ + struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; + const struct inet_sock *inet = inet_sk(sk); + + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = inet->inet_daddr; + sin->sin_port = inet->inet_dport; +} +EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr); + +static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl) +{ + const struct inet_sock *inet = inet_sk(sk); + const struct ip_options_rcu *inet_opt; + __be32 daddr = inet->inet_daddr; + struct flowi4 *fl4; + struct rtable *rt; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + fl4 = &fl->u.ip4; + rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, + inet->inet_saddr, inet->inet_dport, + inet->inet_sport, sk->sk_protocol, + RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); + if (IS_ERR(rt)) + rt = NULL; + if (rt) + sk_setup_caps(sk, &rt->dst); + rcu_read_unlock(); + + return &rt->dst; +} + +struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu) +{ + struct dst_entry *dst = __sk_dst_check(sk, 0); + struct inet_sock *inet = inet_sk(sk); + + if (!dst) { + dst = inet_csk_rebuild_route(sk, &inet->cork.fl); + if (!dst) + goto out; + } + dst->ops->update_pmtu(dst, sk, NULL, mtu, true); + + dst = __sk_dst_check(sk, 0); + if (!dst) + dst = inet_csk_rebuild_route(sk, &inet->cork.fl); +out: + return dst; +} +EXPORT_SYMBOL_GPL(inet_csk_update_pmtu); diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c new file mode 100644 index 000000000..fa9f1de58 --- /dev/null +++ b/net/ipv4/inet_diag.c @@ -0,0 +1,1479 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * inet_diag.c Module for monitoring INET transport protocols sockets. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/fcntl.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <linux/cache.h> +#include <linux/init.h> +#include <linux/time.h> + +#include <net/icmp.h> +#include <net/tcp.h> +#include <net/ipv6.h> +#include <net/inet_common.h> +#include <net/inet_connection_sock.h> +#include <net/inet_hashtables.h> +#include <net/inet_timewait_sock.h> +#include <net/inet6_hashtables.h> +#include <net/bpf_sk_storage.h> +#include <net/netlink.h> + +#include <linux/inet.h> +#include <linux/stddef.h> + +#include <linux/inet_diag.h> +#include <linux/sock_diag.h> + +static const struct inet_diag_handler **inet_diag_table; + +struct inet_diag_entry { + const __be32 *saddr; + const __be32 *daddr; + u16 sport; + u16 dport; + u16 family; + u16 userlocks; + u32 ifindex; + u32 mark; +#ifdef CONFIG_SOCK_CGROUP_DATA + u64 cgroup_id; +#endif +}; + +static DEFINE_MUTEX(inet_diag_table_mutex); + +static const struct inet_diag_handler *inet_diag_lock_handler(int proto) +{ + if (proto < 0 || proto >= IPPROTO_MAX) { + mutex_lock(&inet_diag_table_mutex); + return ERR_PTR(-ENOENT); + } + + if (!inet_diag_table[proto]) + sock_load_diag_module(AF_INET, proto); + + mutex_lock(&inet_diag_table_mutex); + if (!inet_diag_table[proto]) + return ERR_PTR(-ENOENT); + + return inet_diag_table[proto]; +} + +static void inet_diag_unlock_handler(const struct inet_diag_handler *handler) +{ + mutex_unlock(&inet_diag_table_mutex); +} + +void inet_diag_msg_common_fill(struct inet_diag_msg *r, struct sock *sk) +{ + r->idiag_family = sk->sk_family; + + r->id.idiag_sport = htons(sk->sk_num); + r->id.idiag_dport = sk->sk_dport; + r->id.idiag_if = sk->sk_bound_dev_if; + sock_diag_save_cookie(sk, r->id.idiag_cookie); + +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) { + *(struct in6_addr *)r->id.idiag_src = sk->sk_v6_rcv_saddr; + *(struct in6_addr *)r->id.idiag_dst = sk->sk_v6_daddr; + } else +#endif + { + memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src)); + memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst)); + + r->id.idiag_src[0] = sk->sk_rcv_saddr; + r->id.idiag_dst[0] = sk->sk_daddr; + } +} +EXPORT_SYMBOL_GPL(inet_diag_msg_common_fill); + +static size_t inet_sk_attr_size(struct sock *sk, + const struct inet_diag_req_v2 *req, + bool net_admin) +{ + const struct inet_diag_handler *handler; + size_t aux = 0; + + handler = inet_diag_table[req->sdiag_protocol]; + if (handler && handler->idiag_get_aux_size) + aux = handler->idiag_get_aux_size(sk, net_admin); + + return nla_total_size(sizeof(struct tcp_info)) + + nla_total_size(sizeof(struct inet_diag_msg)) + + inet_diag_msg_attrs_size() + + nla_total_size(sizeof(struct inet_diag_meminfo)) + + nla_total_size(SK_MEMINFO_VARS * sizeof(u32)) + + nla_total_size(TCP_CA_NAME_MAX) + + nla_total_size(sizeof(struct tcpvegas_info)) + + aux + + 64; +} + +int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb, + struct inet_diag_msg *r, int ext, + struct user_namespace *user_ns, + bool net_admin) +{ + const struct inet_sock *inet = inet_sk(sk); + struct inet_diag_sockopt inet_sockopt; + + if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown)) + goto errout; + + /* IPv6 dual-stack sockets use inet->tos for IPv4 connections, + * hence this needs to be included regardless of socket family. + */ + if (ext & (1 << (INET_DIAG_TOS - 1))) + if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0) + goto errout; + +#if IS_ENABLED(CONFIG_IPV6) + if (r->idiag_family == AF_INET6) { + if (ext & (1 << (INET_DIAG_TCLASS - 1))) + if (nla_put_u8(skb, INET_DIAG_TCLASS, + inet6_sk(sk)->tclass) < 0) + goto errout; + + if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) && + nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk))) + goto errout; + } +#endif + + if (net_admin && nla_put_u32(skb, INET_DIAG_MARK, sk->sk_mark)) + goto errout; + + if (ext & (1 << (INET_DIAG_CLASS_ID - 1)) || + ext & (1 << (INET_DIAG_TCLASS - 1))) { + u32 classid = 0; + +#ifdef CONFIG_SOCK_CGROUP_DATA + classid = sock_cgroup_classid(&sk->sk_cgrp_data); +#endif + /* Fallback to socket priority if class id isn't set. + * Classful qdiscs use it as direct reference to class. + * For cgroup2 classid is always zero. + */ + if (!classid) + classid = sk->sk_priority; + + if (nla_put_u32(skb, INET_DIAG_CLASS_ID, classid)) + goto errout; + } + +#ifdef CONFIG_SOCK_CGROUP_DATA + if (nla_put_u64_64bit(skb, INET_DIAG_CGROUP_ID, + cgroup_id(sock_cgroup_ptr(&sk->sk_cgrp_data)), + INET_DIAG_PAD)) + goto errout; +#endif + + r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk)); + r->idiag_inode = sock_i_ino(sk); + + memset(&inet_sockopt, 0, sizeof(inet_sockopt)); + inet_sockopt.recverr = inet->recverr; + inet_sockopt.is_icsk = inet->is_icsk; + inet_sockopt.freebind = inet->freebind; + inet_sockopt.hdrincl = inet->hdrincl; + inet_sockopt.mc_loop = inet->mc_loop; + inet_sockopt.transparent = inet->transparent; + inet_sockopt.mc_all = inet->mc_all; + inet_sockopt.nodefrag = inet->nodefrag; + inet_sockopt.bind_address_no_port = inet->bind_address_no_port; + inet_sockopt.recverr_rfc4884 = inet->recverr_rfc4884; + inet_sockopt.defer_connect = inet->defer_connect; + if (nla_put(skb, INET_DIAG_SOCKOPT, sizeof(inet_sockopt), + &inet_sockopt)) + goto errout; + + return 0; +errout: + return 1; +} +EXPORT_SYMBOL_GPL(inet_diag_msg_attrs_fill); + +static int inet_diag_parse_attrs(const struct nlmsghdr *nlh, int hdrlen, + struct nlattr **req_nlas) +{ + struct nlattr *nla; + int remaining; + + nlmsg_for_each_attr(nla, nlh, hdrlen, remaining) { + int type = nla_type(nla); + + if (type == INET_DIAG_REQ_PROTOCOL && nla_len(nla) != sizeof(u32)) + return -EINVAL; + + if (type < __INET_DIAG_REQ_MAX) + req_nlas[type] = nla; + } + return 0; +} + +static int inet_diag_get_protocol(const struct inet_diag_req_v2 *req, + const struct inet_diag_dump_data *data) +{ + if (data->req_nlas[INET_DIAG_REQ_PROTOCOL]) + return nla_get_u32(data->req_nlas[INET_DIAG_REQ_PROTOCOL]); + return req->sdiag_protocol; +} + +#define MAX_DUMP_ALLOC_SIZE (KMALLOC_MAX_SIZE - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) + +int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, + struct sk_buff *skb, struct netlink_callback *cb, + const struct inet_diag_req_v2 *req, + u16 nlmsg_flags, bool net_admin) +{ + const struct tcp_congestion_ops *ca_ops; + const struct inet_diag_handler *handler; + struct inet_diag_dump_data *cb_data; + int ext = req->idiag_ext; + struct inet_diag_msg *r; + struct nlmsghdr *nlh; + struct nlattr *attr; + void *info = NULL; + + cb_data = cb->data; + handler = inet_diag_table[inet_diag_get_protocol(req, cb_data)]; + BUG_ON(!handler); + + nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, + cb->nlh->nlmsg_type, sizeof(*r), nlmsg_flags); + if (!nlh) + return -EMSGSIZE; + + r = nlmsg_data(nlh); + BUG_ON(!sk_fullsock(sk)); + + inet_diag_msg_common_fill(r, sk); + r->idiag_state = sk->sk_state; + r->idiag_timer = 0; + r->idiag_retrans = 0; + r->idiag_expires = 0; + + if (inet_diag_msg_attrs_fill(sk, skb, r, ext, + sk_user_ns(NETLINK_CB(cb->skb).sk), + net_admin)) + goto errout; + + if (ext & (1 << (INET_DIAG_MEMINFO - 1))) { + struct inet_diag_meminfo minfo = { + .idiag_rmem = sk_rmem_alloc_get(sk), + .idiag_wmem = READ_ONCE(sk->sk_wmem_queued), + .idiag_fmem = sk->sk_forward_alloc, + .idiag_tmem = sk_wmem_alloc_get(sk), + }; + + if (nla_put(skb, INET_DIAG_MEMINFO, sizeof(minfo), &minfo) < 0) + goto errout; + } + + if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) + if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO)) + goto errout; + + /* + * RAW sockets might have user-defined protocols assigned, + * so report the one supplied on socket creation. + */ + if (sk->sk_type == SOCK_RAW) { + if (nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol)) + goto errout; + } + + if (!icsk) { + handler->idiag_get_info(sk, r, NULL); + goto out; + } + + if (icsk->icsk_pending == ICSK_TIME_RETRANS || + icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || + icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { + r->idiag_timer = 1; + r->idiag_retrans = icsk->icsk_retransmits; + r->idiag_expires = + jiffies_delta_to_msecs(icsk->icsk_timeout - jiffies); + } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { + r->idiag_timer = 4; + r->idiag_retrans = icsk->icsk_probes_out; + r->idiag_expires = + jiffies_delta_to_msecs(icsk->icsk_timeout - jiffies); + } else if (timer_pending(&sk->sk_timer)) { + r->idiag_timer = 2; + r->idiag_retrans = icsk->icsk_probes_out; + r->idiag_expires = + jiffies_delta_to_msecs(sk->sk_timer.expires - jiffies); + } + + if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) { + attr = nla_reserve_64bit(skb, INET_DIAG_INFO, + handler->idiag_info_size, + INET_DIAG_PAD); + if (!attr) + goto errout; + + info = nla_data(attr); + } + + if (ext & (1 << (INET_DIAG_CONG - 1))) { + int err = 0; + + rcu_read_lock(); + ca_ops = READ_ONCE(icsk->icsk_ca_ops); + if (ca_ops) + err = nla_put_string(skb, INET_DIAG_CONG, ca_ops->name); + rcu_read_unlock(); + if (err < 0) + goto errout; + } + + handler->idiag_get_info(sk, r, info); + + if (ext & (1 << (INET_DIAG_INFO - 1)) && handler->idiag_get_aux) + if (handler->idiag_get_aux(sk, net_admin, skb) < 0) + goto errout; + + if (sk->sk_state < TCP_TIME_WAIT) { + union tcp_cc_info info; + size_t sz = 0; + int attr; + + rcu_read_lock(); + ca_ops = READ_ONCE(icsk->icsk_ca_ops); + if (ca_ops && ca_ops->get_info) + sz = ca_ops->get_info(sk, ext, &attr, &info); + rcu_read_unlock(); + if (sz && nla_put(skb, attr, sz, &info) < 0) + goto errout; + } + + /* Keep it at the end for potential retry with a larger skb, + * or else do best-effort fitting, which is only done for the + * first_nlmsg. + */ + if (cb_data->bpf_stg_diag) { + bool first_nlmsg = ((unsigned char *)nlh == skb->data); + unsigned int prev_min_dump_alloc; + unsigned int total_nla_size = 0; + unsigned int msg_len; + int err; + + msg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; + err = bpf_sk_storage_diag_put(cb_data->bpf_stg_diag, sk, skb, + INET_DIAG_SK_BPF_STORAGES, + &total_nla_size); + + if (!err) + goto out; + + total_nla_size += msg_len; + prev_min_dump_alloc = cb->min_dump_alloc; + if (total_nla_size > prev_min_dump_alloc) + cb->min_dump_alloc = min_t(u32, total_nla_size, + MAX_DUMP_ALLOC_SIZE); + + if (!first_nlmsg) + goto errout; + + if (cb->min_dump_alloc > prev_min_dump_alloc) + /* Retry with pskb_expand_head() with + * __GFP_DIRECT_RECLAIM + */ + goto errout; + + WARN_ON_ONCE(total_nla_size <= prev_min_dump_alloc); + + /* Send what we have for this sk + * and move on to the next sk in the following + * dump() + */ + } + +out: + nlmsg_end(skb, nlh); + return 0; + +errout: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} +EXPORT_SYMBOL_GPL(inet_sk_diag_fill); + +static int inet_twsk_diag_fill(struct sock *sk, + struct sk_buff *skb, + struct netlink_callback *cb, + u16 nlmsg_flags) +{ + struct inet_timewait_sock *tw = inet_twsk(sk); + struct inet_diag_msg *r; + struct nlmsghdr *nlh; + long tmo; + + nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, cb->nlh->nlmsg_type, + sizeof(*r), nlmsg_flags); + if (!nlh) + return -EMSGSIZE; + + r = nlmsg_data(nlh); + BUG_ON(tw->tw_state != TCP_TIME_WAIT); + + inet_diag_msg_common_fill(r, sk); + r->idiag_retrans = 0; + + r->idiag_state = tw->tw_substate; + r->idiag_timer = 3; + tmo = tw->tw_timer.expires - jiffies; + r->idiag_expires = jiffies_delta_to_msecs(tmo); + r->idiag_rqueue = 0; + r->idiag_wqueue = 0; + r->idiag_uid = 0; + r->idiag_inode = 0; + + nlmsg_end(skb, nlh); + return 0; +} + +static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb, + struct netlink_callback *cb, + u16 nlmsg_flags, bool net_admin) +{ + struct request_sock *reqsk = inet_reqsk(sk); + struct inet_diag_msg *r; + struct nlmsghdr *nlh; + long tmo; + + nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, + cb->nlh->nlmsg_type, sizeof(*r), nlmsg_flags); + if (!nlh) + return -EMSGSIZE; + + r = nlmsg_data(nlh); + inet_diag_msg_common_fill(r, sk); + r->idiag_state = TCP_SYN_RECV; + r->idiag_timer = 1; + r->idiag_retrans = reqsk->num_retrans; + + BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) != + offsetof(struct sock, sk_cookie)); + + tmo = inet_reqsk(sk)->rsk_timer.expires - jiffies; + r->idiag_expires = jiffies_delta_to_msecs(tmo); + r->idiag_rqueue = 0; + r->idiag_wqueue = 0; + r->idiag_uid = 0; + r->idiag_inode = 0; + + if (net_admin && nla_put_u32(skb, INET_DIAG_MARK, + inet_rsk(reqsk)->ir_mark)) { + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; + } + + nlmsg_end(skb, nlh); + return 0; +} + +static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *r, + u16 nlmsg_flags, bool net_admin) +{ + if (sk->sk_state == TCP_TIME_WAIT) + return inet_twsk_diag_fill(sk, skb, cb, nlmsg_flags); + + if (sk->sk_state == TCP_NEW_SYN_RECV) + return inet_req_diag_fill(sk, skb, cb, nlmsg_flags, net_admin); + + return inet_sk_diag_fill(sk, inet_csk(sk), skb, cb, r, nlmsg_flags, + net_admin); +} + +struct sock *inet_diag_find_one_icsk(struct net *net, + struct inet_hashinfo *hashinfo, + const struct inet_diag_req_v2 *req) +{ + struct sock *sk; + + rcu_read_lock(); + if (req->sdiag_family == AF_INET) + sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[0], + req->id.idiag_dport, req->id.idiag_src[0], + req->id.idiag_sport, req->id.idiag_if); +#if IS_ENABLED(CONFIG_IPV6) + else if (req->sdiag_family == AF_INET6) { + if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) && + ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src)) + sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[3], + req->id.idiag_dport, req->id.idiag_src[3], + req->id.idiag_sport, req->id.idiag_if); + else + sk = inet6_lookup(net, hashinfo, NULL, 0, + (struct in6_addr *)req->id.idiag_dst, + req->id.idiag_dport, + (struct in6_addr *)req->id.idiag_src, + req->id.idiag_sport, + req->id.idiag_if); + } +#endif + else { + rcu_read_unlock(); + return ERR_PTR(-EINVAL); + } + rcu_read_unlock(); + if (!sk) + return ERR_PTR(-ENOENT); + + if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) { + sock_gen_put(sk); + return ERR_PTR(-ENOENT); + } + + return sk; +} +EXPORT_SYMBOL_GPL(inet_diag_find_one_icsk); + +int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *req) +{ + struct sk_buff *in_skb = cb->skb; + bool net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN); + struct net *net = sock_net(in_skb->sk); + struct sk_buff *rep; + struct sock *sk; + int err; + + sk = inet_diag_find_one_icsk(net, hashinfo, req); + if (IS_ERR(sk)) + return PTR_ERR(sk); + + rep = nlmsg_new(inet_sk_attr_size(sk, req, net_admin), GFP_KERNEL); + if (!rep) { + err = -ENOMEM; + goto out; + } + + err = sk_diag_fill(sk, rep, cb, req, 0, net_admin); + if (err < 0) { + WARN_ON(err == -EMSGSIZE); + nlmsg_free(rep); + goto out; + } + err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid, + MSG_DONTWAIT); + if (err > 0) + err = 0; + +out: + if (sk) + sock_gen_put(sk); + + return err; +} +EXPORT_SYMBOL_GPL(inet_diag_dump_one_icsk); + +static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb, + const struct nlmsghdr *nlh, + int hdrlen, + const struct inet_diag_req_v2 *req) +{ + const struct inet_diag_handler *handler; + struct inet_diag_dump_data dump_data; + int err, protocol; + + memset(&dump_data, 0, sizeof(dump_data)); + err = inet_diag_parse_attrs(nlh, hdrlen, dump_data.req_nlas); + if (err) + return err; + + protocol = inet_diag_get_protocol(req, &dump_data); + + handler = inet_diag_lock_handler(protocol); + if (IS_ERR(handler)) { + err = PTR_ERR(handler); + } else if (cmd == SOCK_DIAG_BY_FAMILY) { + struct netlink_callback cb = { + .nlh = nlh, + .skb = in_skb, + .data = &dump_data, + }; + err = handler->dump_one(&cb, req); + } else if (cmd == SOCK_DESTROY && handler->destroy) { + err = handler->destroy(in_skb, req); + } else { + err = -EOPNOTSUPP; + } + inet_diag_unlock_handler(handler); + + return err; +} + +static int bitstring_match(const __be32 *a1, const __be32 *a2, int bits) +{ + int words = bits >> 5; + + bits &= 0x1f; + + if (words) { + if (memcmp(a1, a2, words << 2)) + return 0; + } + if (bits) { + __be32 w1, w2; + __be32 mask; + + w1 = a1[words]; + w2 = a2[words]; + + mask = htonl((0xffffffff) << (32 - bits)); + + if ((w1 ^ w2) & mask) + return 0; + } + + return 1; +} + +static int inet_diag_bc_run(const struct nlattr *_bc, + const struct inet_diag_entry *entry) +{ + const void *bc = nla_data(_bc); + int len = nla_len(_bc); + + while (len > 0) { + int yes = 1; + const struct inet_diag_bc_op *op = bc; + + switch (op->code) { + case INET_DIAG_BC_NOP: + break; + case INET_DIAG_BC_JMP: + yes = 0; + break; + case INET_DIAG_BC_S_EQ: + yes = entry->sport == op[1].no; + break; + case INET_DIAG_BC_S_GE: + yes = entry->sport >= op[1].no; + break; + case INET_DIAG_BC_S_LE: + yes = entry->sport <= op[1].no; + break; + case INET_DIAG_BC_D_EQ: + yes = entry->dport == op[1].no; + break; + case INET_DIAG_BC_D_GE: + yes = entry->dport >= op[1].no; + break; + case INET_DIAG_BC_D_LE: + yes = entry->dport <= op[1].no; + break; + case INET_DIAG_BC_AUTO: + yes = !(entry->userlocks & SOCK_BINDPORT_LOCK); + break; + case INET_DIAG_BC_S_COND: + case INET_DIAG_BC_D_COND: { + const struct inet_diag_hostcond *cond; + const __be32 *addr; + + cond = (const struct inet_diag_hostcond *)(op + 1); + if (cond->port != -1 && + cond->port != (op->code == INET_DIAG_BC_S_COND ? + entry->sport : entry->dport)) { + yes = 0; + break; + } + + if (op->code == INET_DIAG_BC_S_COND) + addr = entry->saddr; + else + addr = entry->daddr; + + if (cond->family != AF_UNSPEC && + cond->family != entry->family) { + if (entry->family == AF_INET6 && + cond->family == AF_INET) { + if (addr[0] == 0 && addr[1] == 0 && + addr[2] == htonl(0xffff) && + bitstring_match(addr + 3, + cond->addr, + cond->prefix_len)) + break; + } + yes = 0; + break; + } + + if (cond->prefix_len == 0) + break; + if (bitstring_match(addr, cond->addr, + cond->prefix_len)) + break; + yes = 0; + break; + } + case INET_DIAG_BC_DEV_COND: { + u32 ifindex; + + ifindex = *((const u32 *)(op + 1)); + if (ifindex != entry->ifindex) + yes = 0; + break; + } + case INET_DIAG_BC_MARK_COND: { + struct inet_diag_markcond *cond; + + cond = (struct inet_diag_markcond *)(op + 1); + if ((entry->mark & cond->mask) != cond->mark) + yes = 0; + break; + } +#ifdef CONFIG_SOCK_CGROUP_DATA + case INET_DIAG_BC_CGROUP_COND: { + u64 cgroup_id; + + cgroup_id = get_unaligned((const u64 *)(op + 1)); + if (cgroup_id != entry->cgroup_id) + yes = 0; + break; + } +#endif + } + + if (yes) { + len -= op->yes; + bc += op->yes; + } else { + len -= op->no; + bc += op->no; + } + } + return len == 0; +} + +/* This helper is available for all sockets (ESTABLISH, TIMEWAIT, SYN_RECV) + */ +static void entry_fill_addrs(struct inet_diag_entry *entry, + const struct sock *sk) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) { + entry->saddr = sk->sk_v6_rcv_saddr.s6_addr32; + entry->daddr = sk->sk_v6_daddr.s6_addr32; + } else +#endif + { + entry->saddr = &sk->sk_rcv_saddr; + entry->daddr = &sk->sk_daddr; + } +} + +int inet_diag_bc_sk(const struct nlattr *bc, struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + struct inet_diag_entry entry; + + if (!bc) + return 1; + + entry.family = sk->sk_family; + entry_fill_addrs(&entry, sk); + entry.sport = inet->inet_num; + entry.dport = ntohs(inet->inet_dport); + entry.ifindex = sk->sk_bound_dev_if; + entry.userlocks = sk_fullsock(sk) ? sk->sk_userlocks : 0; + if (sk_fullsock(sk)) + entry.mark = sk->sk_mark; + else if (sk->sk_state == TCP_NEW_SYN_RECV) + entry.mark = inet_rsk(inet_reqsk(sk))->ir_mark; + else + entry.mark = 0; +#ifdef CONFIG_SOCK_CGROUP_DATA + entry.cgroup_id = sk_fullsock(sk) ? + cgroup_id(sock_cgroup_ptr(&sk->sk_cgrp_data)) : 0; +#endif + + return inet_diag_bc_run(bc, &entry); +} +EXPORT_SYMBOL_GPL(inet_diag_bc_sk); + +static int valid_cc(const void *bc, int len, int cc) +{ + while (len >= 0) { + const struct inet_diag_bc_op *op = bc; + + if (cc > len) + return 0; + if (cc == len) + return 1; + if (op->yes < 4 || op->yes & 3) + return 0; + len -= op->yes; + bc += op->yes; + } + return 0; +} + +/* data is u32 ifindex */ +static bool valid_devcond(const struct inet_diag_bc_op *op, int len, + int *min_len) +{ + /* Check ifindex space. */ + *min_len += sizeof(u32); + if (len < *min_len) + return false; + + return true; +} +/* Validate an inet_diag_hostcond. */ +static bool valid_hostcond(const struct inet_diag_bc_op *op, int len, + int *min_len) +{ + struct inet_diag_hostcond *cond; + int addr_len; + + /* Check hostcond space. */ + *min_len += sizeof(struct inet_diag_hostcond); + if (len < *min_len) + return false; + cond = (struct inet_diag_hostcond *)(op + 1); + + /* Check address family and address length. */ + switch (cond->family) { + case AF_UNSPEC: + addr_len = 0; + break; + case AF_INET: + addr_len = sizeof(struct in_addr); + break; + case AF_INET6: + addr_len = sizeof(struct in6_addr); + break; + default: + return false; + } + *min_len += addr_len; + if (len < *min_len) + return false; + + /* Check prefix length (in bits) vs address length (in bytes). */ + if (cond->prefix_len > 8 * addr_len) + return false; + + return true; +} + +/* Validate a port comparison operator. */ +static bool valid_port_comparison(const struct inet_diag_bc_op *op, + int len, int *min_len) +{ + /* Port comparisons put the port in a follow-on inet_diag_bc_op. */ + *min_len += sizeof(struct inet_diag_bc_op); + if (len < *min_len) + return false; + return true; +} + +static bool valid_markcond(const struct inet_diag_bc_op *op, int len, + int *min_len) +{ + *min_len += sizeof(struct inet_diag_markcond); + return len >= *min_len; +} + +#ifdef CONFIG_SOCK_CGROUP_DATA +static bool valid_cgroupcond(const struct inet_diag_bc_op *op, int len, + int *min_len) +{ + *min_len += sizeof(u64); + return len >= *min_len; +} +#endif + +static int inet_diag_bc_audit(const struct nlattr *attr, + const struct sk_buff *skb) +{ + bool net_admin = netlink_net_capable(skb, CAP_NET_ADMIN); + const void *bytecode, *bc; + int bytecode_len, len; + + if (!attr || nla_len(attr) < sizeof(struct inet_diag_bc_op)) + return -EINVAL; + + bytecode = bc = nla_data(attr); + len = bytecode_len = nla_len(attr); + + while (len > 0) { + int min_len = sizeof(struct inet_diag_bc_op); + const struct inet_diag_bc_op *op = bc; + + switch (op->code) { + case INET_DIAG_BC_S_COND: + case INET_DIAG_BC_D_COND: + if (!valid_hostcond(bc, len, &min_len)) + return -EINVAL; + break; + case INET_DIAG_BC_DEV_COND: + if (!valid_devcond(bc, len, &min_len)) + return -EINVAL; + break; + case INET_DIAG_BC_S_EQ: + case INET_DIAG_BC_S_GE: + case INET_DIAG_BC_S_LE: + case INET_DIAG_BC_D_EQ: + case INET_DIAG_BC_D_GE: + case INET_DIAG_BC_D_LE: + if (!valid_port_comparison(bc, len, &min_len)) + return -EINVAL; + break; + case INET_DIAG_BC_MARK_COND: + if (!net_admin) + return -EPERM; + if (!valid_markcond(bc, len, &min_len)) + return -EINVAL; + break; +#ifdef CONFIG_SOCK_CGROUP_DATA + case INET_DIAG_BC_CGROUP_COND: + if (!valid_cgroupcond(bc, len, &min_len)) + return -EINVAL; + break; +#endif + case INET_DIAG_BC_AUTO: + case INET_DIAG_BC_JMP: + case INET_DIAG_BC_NOP: + break; + default: + return -EINVAL; + } + + if (op->code != INET_DIAG_BC_NOP) { + if (op->no < min_len || op->no > len + 4 || op->no & 3) + return -EINVAL; + if (op->no < len && + !valid_cc(bytecode, bytecode_len, len - op->no)) + return -EINVAL; + } + + if (op->yes < min_len || op->yes > len + 4 || op->yes & 3) + return -EINVAL; + bc += op->yes; + len -= op->yes; + } + return len == 0 ? 0 : -EINVAL; +} + +static void twsk_build_assert(void) +{ + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_family) != + offsetof(struct sock, sk_family)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_num) != + offsetof(struct inet_sock, inet_num)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_dport) != + offsetof(struct inet_sock, inet_dport)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_rcv_saddr) != + offsetof(struct inet_sock, inet_rcv_saddr)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_daddr) != + offsetof(struct inet_sock, inet_daddr)); + +#if IS_ENABLED(CONFIG_IPV6) + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_rcv_saddr) != + offsetof(struct sock, sk_v6_rcv_saddr)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_daddr) != + offsetof(struct sock, sk_v6_daddr)); +#endif +} + +void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN); + struct inet_diag_dump_data *cb_data = cb->data; + struct net *net = sock_net(skb->sk); + u32 idiag_states = r->idiag_states; + int i, num, s_i, s_num; + struct nlattr *bc; + struct sock *sk; + + bc = cb_data->inet_diag_nla_bc; + if (idiag_states & TCPF_SYN_RECV) + idiag_states |= TCPF_NEW_SYN_RECV; + s_i = cb->args[1]; + s_num = num = cb->args[2]; + + if (cb->args[0] == 0) { + if (!(idiag_states & TCPF_LISTEN) || r->id.idiag_dport) + goto skip_listen_ht; + + for (i = s_i; i < INET_LHTABLE_SIZE; i++) { + struct inet_listen_hashbucket *ilb; + struct hlist_nulls_node *node; + + num = 0; + ilb = &hashinfo->listening_hash[i]; + spin_lock(&ilb->lock); + sk_nulls_for_each(sk, node, &ilb->nulls_head) { + struct inet_sock *inet = inet_sk(sk); + + if (!net_eq(sock_net(sk), net)) + continue; + + if (num < s_num) { + num++; + continue; + } + + if (r->sdiag_family != AF_UNSPEC && + sk->sk_family != r->sdiag_family) + goto next_listen; + + if (r->id.idiag_sport != inet->inet_sport && + r->id.idiag_sport) + goto next_listen; + + if (!inet_diag_bc_sk(bc, sk)) + goto next_listen; + + if (inet_sk_diag_fill(sk, inet_csk(sk), skb, + cb, r, NLM_F_MULTI, + net_admin) < 0) { + spin_unlock(&ilb->lock); + goto done; + } + +next_listen: + ++num; + } + spin_unlock(&ilb->lock); + + s_num = 0; + } +skip_listen_ht: + cb->args[0] = 1; + s_i = num = s_num = 0; + } + + if (!(idiag_states & ~TCPF_LISTEN)) + goto out; + +#define SKARR_SZ 16 + for (i = s_i; i <= hashinfo->ehash_mask; i++) { + struct inet_ehash_bucket *head = &hashinfo->ehash[i]; + spinlock_t *lock = inet_ehash_lockp(hashinfo, i); + struct hlist_nulls_node *node; + struct sock *sk_arr[SKARR_SZ]; + int num_arr[SKARR_SZ]; + int idx, accum, res; + + if (hlist_nulls_empty(&head->chain)) + continue; + + if (i > s_i) + s_num = 0; + +next_chunk: + num = 0; + accum = 0; + spin_lock_bh(lock); + sk_nulls_for_each(sk, node, &head->chain) { + int state; + + if (!net_eq(sock_net(sk), net)) + continue; + if (num < s_num) + goto next_normal; + state = (sk->sk_state == TCP_TIME_WAIT) ? + inet_twsk(sk)->tw_substate : sk->sk_state; + if (!(idiag_states & (1 << state))) + goto next_normal; + if (r->sdiag_family != AF_UNSPEC && + sk->sk_family != r->sdiag_family) + goto next_normal; + if (r->id.idiag_sport != htons(sk->sk_num) && + r->id.idiag_sport) + goto next_normal; + if (r->id.idiag_dport != sk->sk_dport && + r->id.idiag_dport) + goto next_normal; + twsk_build_assert(); + + if (!inet_diag_bc_sk(bc, sk)) + goto next_normal; + + if (!refcount_inc_not_zero(&sk->sk_refcnt)) + goto next_normal; + + num_arr[accum] = num; + sk_arr[accum] = sk; + if (++accum == SKARR_SZ) + break; +next_normal: + ++num; + } + spin_unlock_bh(lock); + res = 0; + for (idx = 0; idx < accum; idx++) { + if (res >= 0) { + res = sk_diag_fill(sk_arr[idx], skb, cb, r, + NLM_F_MULTI, net_admin); + if (res < 0) + num = num_arr[idx]; + } + sock_gen_put(sk_arr[idx]); + } + if (res < 0) + break; + cond_resched(); + if (accum == SKARR_SZ) { + s_num = num + 1; + goto next_chunk; + } + } + +done: + cb->args[1] = i; + cb->args[2] = num; +out: + ; +} +EXPORT_SYMBOL_GPL(inet_diag_dump_icsk); + +static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + struct inet_diag_dump_data *cb_data = cb->data; + const struct inet_diag_handler *handler; + u32 prev_min_dump_alloc; + int protocol, err = 0; + + protocol = inet_diag_get_protocol(r, cb_data); + +again: + prev_min_dump_alloc = cb->min_dump_alloc; + handler = inet_diag_lock_handler(protocol); + if (!IS_ERR(handler)) + handler->dump(skb, cb, r); + else + err = PTR_ERR(handler); + inet_diag_unlock_handler(handler); + + /* The skb is not large enough to fit one sk info and + * inet_sk_diag_fill() has requested for a larger skb. + */ + if (!skb->len && cb->min_dump_alloc > prev_min_dump_alloc) { + err = pskb_expand_head(skb, 0, cb->min_dump_alloc, GFP_KERNEL); + if (!err) + goto again; + } + + return err ? : skb->len; +} + +static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) +{ + return __inet_diag_dump(skb, cb, nlmsg_data(cb->nlh)); +} + +static int __inet_diag_dump_start(struct netlink_callback *cb, int hdrlen) +{ + const struct nlmsghdr *nlh = cb->nlh; + struct inet_diag_dump_data *cb_data; + struct sk_buff *skb = cb->skb; + struct nlattr *nla; + int err; + + cb_data = kzalloc(sizeof(*cb_data), GFP_KERNEL); + if (!cb_data) + return -ENOMEM; + + err = inet_diag_parse_attrs(nlh, hdrlen, cb_data->req_nlas); + if (err) { + kfree(cb_data); + return err; + } + nla = cb_data->inet_diag_nla_bc; + if (nla) { + err = inet_diag_bc_audit(nla, skb); + if (err) { + kfree(cb_data); + return err; + } + } + + nla = cb_data->inet_diag_nla_bpf_stgs; + if (nla) { + struct bpf_sk_storage_diag *bpf_stg_diag; + + bpf_stg_diag = bpf_sk_storage_diag_alloc(nla); + if (IS_ERR(bpf_stg_diag)) { + kfree(cb_data); + return PTR_ERR(bpf_stg_diag); + } + cb_data->bpf_stg_diag = bpf_stg_diag; + } + + cb->data = cb_data; + return 0; +} + +static int inet_diag_dump_start(struct netlink_callback *cb) +{ + return __inet_diag_dump_start(cb, sizeof(struct inet_diag_req_v2)); +} + +static int inet_diag_dump_start_compat(struct netlink_callback *cb) +{ + return __inet_diag_dump_start(cb, sizeof(struct inet_diag_req)); +} + +static int inet_diag_dump_done(struct netlink_callback *cb) +{ + struct inet_diag_dump_data *cb_data = cb->data; + + bpf_sk_storage_diag_free(cb_data->bpf_stg_diag); + kfree(cb->data); + + return 0; +} + +static int inet_diag_type2proto(int type) +{ + switch (type) { + case TCPDIAG_GETSOCK: + return IPPROTO_TCP; + case DCCPDIAG_GETSOCK: + return IPPROTO_DCCP; + default: + return 0; + } +} + +static int inet_diag_dump_compat(struct sk_buff *skb, + struct netlink_callback *cb) +{ + struct inet_diag_req *rc = nlmsg_data(cb->nlh); + struct inet_diag_req_v2 req; + + req.sdiag_family = AF_UNSPEC; /* compatibility */ + req.sdiag_protocol = inet_diag_type2proto(cb->nlh->nlmsg_type); + req.idiag_ext = rc->idiag_ext; + req.idiag_states = rc->idiag_states; + req.id = rc->id; + + return __inet_diag_dump(skb, cb, &req); +} + +static int inet_diag_get_exact_compat(struct sk_buff *in_skb, + const struct nlmsghdr *nlh) +{ + struct inet_diag_req *rc = nlmsg_data(nlh); + struct inet_diag_req_v2 req; + + req.sdiag_family = rc->idiag_family; + req.sdiag_protocol = inet_diag_type2proto(nlh->nlmsg_type); + req.idiag_ext = rc->idiag_ext; + req.idiag_states = rc->idiag_states; + req.id = rc->id; + + return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh, + sizeof(struct inet_diag_req), &req); +} + +static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh) +{ + int hdrlen = sizeof(struct inet_diag_req); + struct net *net = sock_net(skb->sk); + + if (nlh->nlmsg_type >= INET_DIAG_GETSOCK_MAX || + nlmsg_len(nlh) < hdrlen) + return -EINVAL; + + if (nlh->nlmsg_flags & NLM_F_DUMP) { + struct netlink_dump_control c = { + .start = inet_diag_dump_start_compat, + .done = inet_diag_dump_done, + .dump = inet_diag_dump_compat, + }; + return netlink_dump_start(net->diag_nlsk, skb, nlh, &c); + } + + return inet_diag_get_exact_compat(skb, nlh); +} + +static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h) +{ + int hdrlen = sizeof(struct inet_diag_req_v2); + struct net *net = sock_net(skb->sk); + + if (nlmsg_len(h) < hdrlen) + return -EINVAL; + + if (h->nlmsg_type == SOCK_DIAG_BY_FAMILY && + h->nlmsg_flags & NLM_F_DUMP) { + struct netlink_dump_control c = { + .start = inet_diag_dump_start, + .done = inet_diag_dump_done, + .dump = inet_diag_dump, + }; + return netlink_dump_start(net->diag_nlsk, skb, h, &c); + } + + return inet_diag_cmd_exact(h->nlmsg_type, skb, h, hdrlen, + nlmsg_data(h)); +} + +static +int inet_diag_handler_get_info(struct sk_buff *skb, struct sock *sk) +{ + const struct inet_diag_handler *handler; + struct nlmsghdr *nlh; + struct nlattr *attr; + struct inet_diag_msg *r; + void *info = NULL; + int err = 0; + + nlh = nlmsg_put(skb, 0, 0, SOCK_DIAG_BY_FAMILY, sizeof(*r), 0); + if (!nlh) + return -ENOMEM; + + r = nlmsg_data(nlh); + memset(r, 0, sizeof(*r)); + inet_diag_msg_common_fill(r, sk); + if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_STREAM) + r->id.idiag_sport = inet_sk(sk)->inet_sport; + r->idiag_state = sk->sk_state; + + if ((err = nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol))) { + nlmsg_cancel(skb, nlh); + return err; + } + + handler = inet_diag_lock_handler(sk->sk_protocol); + if (IS_ERR(handler)) { + inet_diag_unlock_handler(handler); + nlmsg_cancel(skb, nlh); + return PTR_ERR(handler); + } + + attr = handler->idiag_info_size + ? nla_reserve_64bit(skb, INET_DIAG_INFO, + handler->idiag_info_size, + INET_DIAG_PAD) + : NULL; + if (attr) + info = nla_data(attr); + + handler->idiag_get_info(sk, r, info); + inet_diag_unlock_handler(handler); + + nlmsg_end(skb, nlh); + return 0; +} + +static const struct sock_diag_handler inet_diag_handler = { + .family = AF_INET, + .dump = inet_diag_handler_cmd, + .get_info = inet_diag_handler_get_info, + .destroy = inet_diag_handler_cmd, +}; + +static const struct sock_diag_handler inet6_diag_handler = { + .family = AF_INET6, + .dump = inet_diag_handler_cmd, + .get_info = inet_diag_handler_get_info, + .destroy = inet_diag_handler_cmd, +}; + +int inet_diag_register(const struct inet_diag_handler *h) +{ + const __u16 type = h->idiag_type; + int err = -EINVAL; + + if (type >= IPPROTO_MAX) + goto out; + + mutex_lock(&inet_diag_table_mutex); + err = -EEXIST; + if (!inet_diag_table[type]) { + inet_diag_table[type] = h; + err = 0; + } + mutex_unlock(&inet_diag_table_mutex); +out: + return err; +} +EXPORT_SYMBOL_GPL(inet_diag_register); + +void inet_diag_unregister(const struct inet_diag_handler *h) +{ + const __u16 type = h->idiag_type; + + if (type >= IPPROTO_MAX) + return; + + mutex_lock(&inet_diag_table_mutex); + inet_diag_table[type] = NULL; + mutex_unlock(&inet_diag_table_mutex); +} +EXPORT_SYMBOL_GPL(inet_diag_unregister); + +static int __init inet_diag_init(void) +{ + const int inet_diag_table_size = (IPPROTO_MAX * + sizeof(struct inet_diag_handler *)); + int err = -ENOMEM; + + inet_diag_table = kzalloc(inet_diag_table_size, GFP_KERNEL); + if (!inet_diag_table) + goto out; + + err = sock_diag_register(&inet_diag_handler); + if (err) + goto out_free_nl; + + err = sock_diag_register(&inet6_diag_handler); + if (err) + goto out_free_inet; + + sock_diag_register_inet_compat(inet_diag_rcv_msg_compat); +out: + return err; + +out_free_inet: + sock_diag_unregister(&inet_diag_handler); +out_free_nl: + kfree(inet_diag_table); + goto out; +} + +static void __exit inet_diag_exit(void) +{ + sock_diag_unregister(&inet6_diag_handler); + sock_diag_unregister(&inet_diag_handler); + sock_diag_unregister_inet_compat(inet_diag_rcv_msg_compat); + kfree(inet_diag_table); +} + +module_init(inet_diag_init); +module_exit(inet_diag_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2 /* AF_INET */); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10 /* AF_INET6 */); diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c new file mode 100644 index 000000000..e0e8a65d5 --- /dev/null +++ b/net/ipv4/inet_fragment.c @@ -0,0 +1,570 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * inet fragments management + * + * Authors: Pavel Emelyanov <xemul@openvz.org> + * Started as consolidation of ipv4/ip_fragment.c, + * ipv6/reassembly. and ipv6 nf conntrack reassembly + */ + +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/module.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/random.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/slab.h> +#include <linux/rhashtable.h> + +#include <net/sock.h> +#include <net/inet_frag.h> +#include <net/inet_ecn.h> +#include <net/ip.h> +#include <net/ipv6.h> + +/* Use skb->cb to track consecutive/adjacent fragments coming at + * the end of the queue. Nodes in the rb-tree queue will + * contain "runs" of one or more adjacent fragments. + * + * Invariants: + * - next_frag is NULL at the tail of a "run"; + * - the head of a "run" has the sum of all fragment lengths in frag_run_len. + */ +struct ipfrag_skb_cb { + union { + struct inet_skb_parm h4; + struct inet6_skb_parm h6; + }; + struct sk_buff *next_frag; + int frag_run_len; +}; + +#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb)) + +static void fragcb_clear(struct sk_buff *skb) +{ + RB_CLEAR_NODE(&skb->rbnode); + FRAG_CB(skb)->next_frag = NULL; + FRAG_CB(skb)->frag_run_len = skb->len; +} + +/* Append skb to the last "run". */ +static void fragrun_append_to_last(struct inet_frag_queue *q, + struct sk_buff *skb) +{ + fragcb_clear(skb); + + FRAG_CB(q->last_run_head)->frag_run_len += skb->len; + FRAG_CB(q->fragments_tail)->next_frag = skb; + q->fragments_tail = skb; +} + +/* Create a new "run" with the skb. */ +static void fragrun_create(struct inet_frag_queue *q, struct sk_buff *skb) +{ + BUILD_BUG_ON(sizeof(struct ipfrag_skb_cb) > sizeof(skb->cb)); + fragcb_clear(skb); + + if (q->last_run_head) + rb_link_node(&skb->rbnode, &q->last_run_head->rbnode, + &q->last_run_head->rbnode.rb_right); + else + rb_link_node(&skb->rbnode, NULL, &q->rb_fragments.rb_node); + rb_insert_color(&skb->rbnode, &q->rb_fragments); + + q->fragments_tail = skb; + q->last_run_head = skb; +} + +/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements + * Value : 0xff if frame should be dropped. + * 0 or INET_ECN_CE value, to be ORed in to final iph->tos field + */ +const u8 ip_frag_ecn_table[16] = { + /* at least one fragment had CE, and others ECT_0 or ECT_1 */ + [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE, + [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE, + [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE, + + /* invalid combinations : drop frame */ + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff, + [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff, +}; +EXPORT_SYMBOL(ip_frag_ecn_table); + +int inet_frags_init(struct inet_frags *f) +{ + f->frags_cachep = kmem_cache_create(f->frags_cache_name, f->qsize, 0, 0, + NULL); + if (!f->frags_cachep) + return -ENOMEM; + + refcount_set(&f->refcnt, 1); + init_completion(&f->completion); + return 0; +} +EXPORT_SYMBOL(inet_frags_init); + +void inet_frags_fini(struct inet_frags *f) +{ + if (refcount_dec_and_test(&f->refcnt)) + complete(&f->completion); + + wait_for_completion(&f->completion); + + kmem_cache_destroy(f->frags_cachep); + f->frags_cachep = NULL; +} +EXPORT_SYMBOL(inet_frags_fini); + +/* called from rhashtable_free_and_destroy() at netns_frags dismantle */ +static void inet_frags_free_cb(void *ptr, void *arg) +{ + struct inet_frag_queue *fq = ptr; + int count; + + count = del_timer_sync(&fq->timer) ? 1 : 0; + + spin_lock_bh(&fq->lock); + if (!(fq->flags & INET_FRAG_COMPLETE)) { + fq->flags |= INET_FRAG_COMPLETE; + count++; + } else if (fq->flags & INET_FRAG_HASH_DEAD) { + count++; + } + spin_unlock_bh(&fq->lock); + + if (refcount_sub_and_test(count, &fq->refcnt)) + inet_frag_destroy(fq); +} + +static void fqdir_work_fn(struct work_struct *work) +{ + struct fqdir *fqdir = container_of(work, struct fqdir, destroy_work); + struct inet_frags *f = fqdir->f; + + rhashtable_free_and_destroy(&fqdir->rhashtable, inet_frags_free_cb, NULL); + + /* We need to make sure all ongoing call_rcu(..., inet_frag_destroy_rcu) + * have completed, since they need to dereference fqdir. + * Would it not be nice to have kfree_rcu_barrier() ? :) + */ + rcu_barrier(); + + if (refcount_dec_and_test(&f->refcnt)) + complete(&f->completion); + + kfree(fqdir); +} + +int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net) +{ + struct fqdir *fqdir = kzalloc(sizeof(*fqdir), GFP_KERNEL); + int res; + + if (!fqdir) + return -ENOMEM; + fqdir->f = f; + fqdir->net = net; + res = rhashtable_init(&fqdir->rhashtable, &fqdir->f->rhash_params); + if (res < 0) { + kfree(fqdir); + return res; + } + refcount_inc(&f->refcnt); + *fqdirp = fqdir; + return 0; +} +EXPORT_SYMBOL(fqdir_init); + +void fqdir_exit(struct fqdir *fqdir) +{ + INIT_WORK(&fqdir->destroy_work, fqdir_work_fn); + queue_work(system_wq, &fqdir->destroy_work); +} +EXPORT_SYMBOL(fqdir_exit); + +void inet_frag_kill(struct inet_frag_queue *fq) +{ + if (del_timer(&fq->timer)) + refcount_dec(&fq->refcnt); + + if (!(fq->flags & INET_FRAG_COMPLETE)) { + struct fqdir *fqdir = fq->fqdir; + + fq->flags |= INET_FRAG_COMPLETE; + rcu_read_lock(); + /* The RCU read lock provides a memory barrier + * guaranteeing that if fqdir->dead is false then + * the hash table destruction will not start until + * after we unlock. Paired with fqdir_pre_exit(). + */ + if (!READ_ONCE(fqdir->dead)) { + rhashtable_remove_fast(&fqdir->rhashtable, &fq->node, + fqdir->f->rhash_params); + refcount_dec(&fq->refcnt); + } else { + fq->flags |= INET_FRAG_HASH_DEAD; + } + rcu_read_unlock(); + } +} +EXPORT_SYMBOL(inet_frag_kill); + +static void inet_frag_destroy_rcu(struct rcu_head *head) +{ + struct inet_frag_queue *q = container_of(head, struct inet_frag_queue, + rcu); + struct inet_frags *f = q->fqdir->f; + + if (f->destructor) + f->destructor(q); + kmem_cache_free(f->frags_cachep, q); +} + +unsigned int inet_frag_rbtree_purge(struct rb_root *root) +{ + struct rb_node *p = rb_first(root); + unsigned int sum = 0; + + while (p) { + struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode); + + p = rb_next(p); + rb_erase(&skb->rbnode, root); + while (skb) { + struct sk_buff *next = FRAG_CB(skb)->next_frag; + + sum += skb->truesize; + kfree_skb(skb); + skb = next; + } + } + return sum; +} +EXPORT_SYMBOL(inet_frag_rbtree_purge); + +void inet_frag_destroy(struct inet_frag_queue *q) +{ + struct fqdir *fqdir; + unsigned int sum, sum_truesize = 0; + struct inet_frags *f; + + WARN_ON(!(q->flags & INET_FRAG_COMPLETE)); + WARN_ON(del_timer(&q->timer) != 0); + + /* Release all fragment data. */ + fqdir = q->fqdir; + f = fqdir->f; + sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments); + sum = sum_truesize + f->qsize; + + call_rcu(&q->rcu, inet_frag_destroy_rcu); + + sub_frag_mem_limit(fqdir, sum); +} +EXPORT_SYMBOL(inet_frag_destroy); + +static struct inet_frag_queue *inet_frag_alloc(struct fqdir *fqdir, + struct inet_frags *f, + void *arg) +{ + struct inet_frag_queue *q; + + q = kmem_cache_zalloc(f->frags_cachep, GFP_ATOMIC); + if (!q) + return NULL; + + q->fqdir = fqdir; + f->constructor(q, arg); + add_frag_mem_limit(fqdir, f->qsize); + + timer_setup(&q->timer, f->frag_expire, 0); + spin_lock_init(&q->lock); + refcount_set(&q->refcnt, 3); + + return q; +} + +static struct inet_frag_queue *inet_frag_create(struct fqdir *fqdir, + void *arg, + struct inet_frag_queue **prev) +{ + struct inet_frags *f = fqdir->f; + struct inet_frag_queue *q; + + q = inet_frag_alloc(fqdir, f, arg); + if (!q) { + *prev = ERR_PTR(-ENOMEM); + return NULL; + } + mod_timer(&q->timer, jiffies + fqdir->timeout); + + *prev = rhashtable_lookup_get_insert_key(&fqdir->rhashtable, &q->key, + &q->node, f->rhash_params); + if (*prev) { + q->flags |= INET_FRAG_COMPLETE; + inet_frag_kill(q); + inet_frag_destroy(q); + return NULL; + } + return q; +} + +/* TODO : call from rcu_read_lock() and no longer use refcount_inc_not_zero() */ +struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key) +{ + /* This pairs with WRITE_ONCE() in fqdir_pre_exit(). */ + long high_thresh = READ_ONCE(fqdir->high_thresh); + struct inet_frag_queue *fq = NULL, *prev; + + if (!high_thresh || frag_mem_limit(fqdir) > high_thresh) + return NULL; + + rcu_read_lock(); + + prev = rhashtable_lookup(&fqdir->rhashtable, key, fqdir->f->rhash_params); + if (!prev) + fq = inet_frag_create(fqdir, key, &prev); + if (!IS_ERR_OR_NULL(prev)) { + fq = prev; + if (!refcount_inc_not_zero(&fq->refcnt)) + fq = NULL; + } + rcu_read_unlock(); + return fq; +} +EXPORT_SYMBOL(inet_frag_find); + +int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, + int offset, int end) +{ + struct sk_buff *last = q->fragments_tail; + + /* RFC5722, Section 4, amended by Errata ID : 3089 + * When reassembling an IPv6 datagram, if + * one or more its constituent fragments is determined to be an + * overlapping fragment, the entire datagram (and any constituent + * fragments) MUST be silently discarded. + * + * Duplicates, however, should be ignored (i.e. skb dropped, but the + * queue/fragments kept for later reassembly). + */ + if (!last) + fragrun_create(q, skb); /* First fragment. */ + else if (last->ip_defrag_offset + last->len < end) { + /* This is the common case: skb goes to the end. */ + /* Detect and discard overlaps. */ + if (offset < last->ip_defrag_offset + last->len) + return IPFRAG_OVERLAP; + if (offset == last->ip_defrag_offset + last->len) + fragrun_append_to_last(q, skb); + else + fragrun_create(q, skb); + } else { + /* Binary search. Note that skb can become the first fragment, + * but not the last (covered above). + */ + struct rb_node **rbn, *parent; + + rbn = &q->rb_fragments.rb_node; + do { + struct sk_buff *curr; + int curr_run_end; + + parent = *rbn; + curr = rb_to_skb(parent); + curr_run_end = curr->ip_defrag_offset + + FRAG_CB(curr)->frag_run_len; + if (end <= curr->ip_defrag_offset) + rbn = &parent->rb_left; + else if (offset >= curr_run_end) + rbn = &parent->rb_right; + else if (offset >= curr->ip_defrag_offset && + end <= curr_run_end) + return IPFRAG_DUP; + else + return IPFRAG_OVERLAP; + } while (*rbn); + /* Here we have parent properly set, and rbn pointing to + * one of its NULL left/right children. Insert skb. + */ + fragcb_clear(skb); + rb_link_node(&skb->rbnode, parent, rbn); + rb_insert_color(&skb->rbnode, &q->rb_fragments); + } + + skb->ip_defrag_offset = offset; + + return IPFRAG_OK; +} +EXPORT_SYMBOL(inet_frag_queue_insert); + +void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, + struct sk_buff *parent) +{ + struct sk_buff *fp, *head = skb_rb_first(&q->rb_fragments); + struct sk_buff **nextp; + int delta; + + if (head != skb) { + fp = skb_clone(skb, GFP_ATOMIC); + if (!fp) + return NULL; + FRAG_CB(fp)->next_frag = FRAG_CB(skb)->next_frag; + if (RB_EMPTY_NODE(&skb->rbnode)) + FRAG_CB(parent)->next_frag = fp; + else + rb_replace_node(&skb->rbnode, &fp->rbnode, + &q->rb_fragments); + if (q->fragments_tail == skb) + q->fragments_tail = fp; + skb_morph(skb, head); + FRAG_CB(skb)->next_frag = FRAG_CB(head)->next_frag; + rb_replace_node(&head->rbnode, &skb->rbnode, + &q->rb_fragments); + consume_skb(head); + head = skb; + } + WARN_ON(head->ip_defrag_offset != 0); + + delta = -head->truesize; + + /* Head of list must not be cloned. */ + if (skb_unclone(head, GFP_ATOMIC)) + return NULL; + + delta += head->truesize; + if (delta) + add_frag_mem_limit(q->fqdir, delta); + + /* If the first fragment is fragmented itself, we split + * it to two chunks: the first with data and paged part + * and the second, holding only fragments. + */ + if (skb_has_frag_list(head)) { + struct sk_buff *clone; + int i, plen = 0; + + clone = alloc_skb(0, GFP_ATOMIC); + if (!clone) + return NULL; + skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; + skb_frag_list_init(head); + for (i = 0; i < skb_shinfo(head)->nr_frags; i++) + plen += skb_frag_size(&skb_shinfo(head)->frags[i]); + clone->data_len = head->data_len - plen; + clone->len = clone->data_len; + head->truesize += clone->truesize; + clone->csum = 0; + clone->ip_summed = head->ip_summed; + add_frag_mem_limit(q->fqdir, clone->truesize); + skb_shinfo(head)->frag_list = clone; + nextp = &clone->next; + } else { + nextp = &skb_shinfo(head)->frag_list; + } + + return nextp; +} +EXPORT_SYMBOL(inet_frag_reasm_prepare); + +void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, + void *reasm_data, bool try_coalesce) +{ + struct sk_buff **nextp = (struct sk_buff **)reasm_data; + struct rb_node *rbn; + struct sk_buff *fp; + int sum_truesize; + + skb_push(head, head->data - skb_network_header(head)); + + /* Traverse the tree in order, to build frag_list. */ + fp = FRAG_CB(head)->next_frag; + rbn = rb_next(&head->rbnode); + rb_erase(&head->rbnode, &q->rb_fragments); + + sum_truesize = head->truesize; + while (rbn || fp) { + /* fp points to the next sk_buff in the current run; + * rbn points to the next run. + */ + /* Go through the current run. */ + while (fp) { + struct sk_buff *next_frag = FRAG_CB(fp)->next_frag; + bool stolen; + int delta; + + sum_truesize += fp->truesize; + if (head->ip_summed != fp->ip_summed) + head->ip_summed = CHECKSUM_NONE; + else if (head->ip_summed == CHECKSUM_COMPLETE) + head->csum = csum_add(head->csum, fp->csum); + + if (try_coalesce && skb_try_coalesce(head, fp, &stolen, + &delta)) { + kfree_skb_partial(fp, stolen); + } else { + fp->prev = NULL; + memset(&fp->rbnode, 0, sizeof(fp->rbnode)); + fp->sk = NULL; + + head->data_len += fp->len; + head->len += fp->len; + head->truesize += fp->truesize; + + *nextp = fp; + nextp = &fp->next; + } + + fp = next_frag; + } + /* Move to the next run. */ + if (rbn) { + struct rb_node *rbnext = rb_next(rbn); + + fp = rb_to_skb(rbn); + rb_erase(rbn, &q->rb_fragments); + rbn = rbnext; + } + } + sub_frag_mem_limit(q->fqdir, sum_truesize); + + *nextp = NULL; + skb_mark_not_on_list(head); + head->prev = NULL; + head->tstamp = q->stamp; +} +EXPORT_SYMBOL(inet_frag_reasm_finish); + +struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q) +{ + struct sk_buff *head, *skb; + + head = skb_rb_first(&q->rb_fragments); + if (!head) + return NULL; + skb = FRAG_CB(head)->next_frag; + if (skb) + rb_replace_node(&head->rbnode, &skb->rbnode, + &q->rb_fragments); + else + rb_erase(&head->rbnode, &q->rb_fragments); + memset(&head->rbnode, 0, sizeof(head->rbnode)); + barrier(); + + if (head == q->fragments_tail) + q->fragments_tail = NULL; + + sub_frag_mem_limit(q->fqdir, head->truesize); + + return head; +} +EXPORT_SYMBOL(inet_frag_pull_head); diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c new file mode 100644 index 000000000..ad050f847 --- /dev/null +++ b/net/ipv4/inet_hashtables.c @@ -0,0 +1,949 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Generic INET transport hashtables + * + * Authors: Lotsa people, from code originally in tcp + */ + +#include <linux/module.h> +#include <linux/random.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/wait.h> +#include <linux/vmalloc.h> +#include <linux/memblock.h> + +#include <net/addrconf.h> +#include <net/inet_connection_sock.h> +#include <net/inet_hashtables.h> +#if IS_ENABLED(CONFIG_IPV6) +#include <net/inet6_hashtables.h> +#endif +#include <net/secure_seq.h> +#include <net/ip.h> +#include <net/tcp.h> +#include <net/sock_reuseport.h> + +static u32 inet_ehashfn(const struct net *net, const __be32 laddr, + const __u16 lport, const __be32 faddr, + const __be16 fport) +{ + static u32 inet_ehash_secret __read_mostly; + + net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret)); + + return __inet_ehashfn(laddr, lport, faddr, fport, + inet_ehash_secret + net_hash_mix(net)); +} + +/* This function handles inet_sock, but also timewait and request sockets + * for IPv4/IPv6. + */ +static u32 sk_ehashfn(const struct sock *sk) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6 && + !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) + return inet6_ehashfn(sock_net(sk), + &sk->sk_v6_rcv_saddr, sk->sk_num, + &sk->sk_v6_daddr, sk->sk_dport); +#endif + return inet_ehashfn(sock_net(sk), + sk->sk_rcv_saddr, sk->sk_num, + sk->sk_daddr, sk->sk_dport); +} + +/* + * Allocate and initialize a new local port bind bucket. + * The bindhash mutex for snum's hash chain must be held here. + */ +struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep, + struct net *net, + struct inet_bind_hashbucket *head, + const unsigned short snum, + int l3mdev) +{ + struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC); + + if (tb) { + write_pnet(&tb->ib_net, net); + tb->l3mdev = l3mdev; + tb->port = snum; + tb->fastreuse = 0; + tb->fastreuseport = 0; + INIT_HLIST_HEAD(&tb->owners); + hlist_add_head(&tb->node, &head->chain); + } + return tb; +} + +/* + * Caller must hold hashbucket lock for this tb with local BH disabled + */ +void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb) +{ + if (hlist_empty(&tb->owners)) { + __hlist_del(&tb->node); + kmem_cache_free(cachep, tb); + } +} + +void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, + const unsigned short snum) +{ + inet_sk(sk)->inet_num = snum; + sk_add_bind_node(sk, &tb->owners); + inet_csk(sk)->icsk_bind_hash = tb; +} + +/* + * Get rid of any references to a local port held by the given sock. + */ +static void __inet_put_port(struct sock *sk) +{ + struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; + const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num, + hashinfo->bhash_size); + struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash]; + struct inet_bind_bucket *tb; + + spin_lock(&head->lock); + tb = inet_csk(sk)->icsk_bind_hash; + __sk_del_bind_node(sk); + inet_csk(sk)->icsk_bind_hash = NULL; + inet_sk(sk)->inet_num = 0; + inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); + spin_unlock(&head->lock); +} + +void inet_put_port(struct sock *sk) +{ + local_bh_disable(); + __inet_put_port(sk); + local_bh_enable(); +} +EXPORT_SYMBOL(inet_put_port); + +int __inet_inherit_port(const struct sock *sk, struct sock *child) +{ + struct inet_hashinfo *table = sk->sk_prot->h.hashinfo; + unsigned short port = inet_sk(child)->inet_num; + const int bhash = inet_bhashfn(sock_net(sk), port, + table->bhash_size); + struct inet_bind_hashbucket *head = &table->bhash[bhash]; + struct inet_bind_bucket *tb; + int l3mdev; + + spin_lock(&head->lock); + tb = inet_csk(sk)->icsk_bind_hash; + if (unlikely(!tb)) { + spin_unlock(&head->lock); + return -ENOENT; + } + if (tb->port != port) { + l3mdev = inet_sk_bound_l3mdev(sk); + + /* NOTE: using tproxy and redirecting skbs to a proxy + * on a different listener port breaks the assumption + * that the listener socket's icsk_bind_hash is the same + * as that of the child socket. We have to look up or + * create a new bind bucket for the child here. */ + inet_bind_bucket_for_each(tb, &head->chain) { + if (net_eq(ib_net(tb), sock_net(sk)) && + tb->l3mdev == l3mdev && tb->port == port) + break; + } + if (!tb) { + tb = inet_bind_bucket_create(table->bind_bucket_cachep, + sock_net(sk), head, port, + l3mdev); + if (!tb) { + spin_unlock(&head->lock); + return -ENOMEM; + } + } + inet_csk_update_fastreuse(tb, child); + } + inet_bind_hash(child, tb, port); + spin_unlock(&head->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(__inet_inherit_port); + +static struct inet_listen_hashbucket * +inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk) +{ + u32 hash; + +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + hash = ipv6_portaddr_hash(sock_net(sk), + &sk->sk_v6_rcv_saddr, + inet_sk(sk)->inet_num); + else +#endif + hash = ipv4_portaddr_hash(sock_net(sk), + inet_sk(sk)->inet_rcv_saddr, + inet_sk(sk)->inet_num); + return inet_lhash2_bucket(h, hash); +} + +static void inet_hash2(struct inet_hashinfo *h, struct sock *sk) +{ + struct inet_listen_hashbucket *ilb2; + + if (!h->lhash2) + return; + + ilb2 = inet_lhash2_bucket_sk(h, sk); + + spin_lock(&ilb2->lock); + if (sk->sk_reuseport && sk->sk_family == AF_INET6) + hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, + &ilb2->head); + else + hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, + &ilb2->head); + ilb2->count++; + spin_unlock(&ilb2->lock); +} + +static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk) +{ + struct inet_listen_hashbucket *ilb2; + + if (!h->lhash2 || + WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node))) + return; + + ilb2 = inet_lhash2_bucket_sk(h, sk); + + spin_lock(&ilb2->lock); + hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node); + ilb2->count--; + spin_unlock(&ilb2->lock); +} + +static inline int compute_score(struct sock *sk, struct net *net, + const unsigned short hnum, const __be32 daddr, + const int dif, const int sdif) +{ + int score = -1; + + if (net_eq(sock_net(sk), net) && sk->sk_num == hnum && + !ipv6_only_sock(sk)) { + if (sk->sk_rcv_saddr != daddr) + return -1; + + if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) + return -1; + score = sk->sk_bound_dev_if ? 2 : 1; + + if (sk->sk_family == PF_INET) + score++; + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) + score++; + } + return score; +} + +static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk, + struct sk_buff *skb, int doff, + __be32 saddr, __be16 sport, + __be32 daddr, unsigned short hnum) +{ + struct sock *reuse_sk = NULL; + u32 phash; + + if (sk->sk_reuseport) { + phash = inet_ehashfn(net, daddr, hnum, saddr, sport); + reuse_sk = reuseport_select_sock(sk, phash, skb, doff); + } + return reuse_sk; +} + +/* + * Here are some nice properties to exploit here. The BSD API + * does not allow a listening sock to specify the remote port nor the + * remote address for the connection. So always assume those are both + * wildcarded during the search since they can never be otherwise. + */ + +/* called with rcu_read_lock() : No refcount taken on the socket */ +static struct sock *inet_lhash2_lookup(struct net *net, + struct inet_listen_hashbucket *ilb2, + struct sk_buff *skb, int doff, + const __be32 saddr, __be16 sport, + const __be32 daddr, const unsigned short hnum, + const int dif, const int sdif) +{ + struct inet_connection_sock *icsk; + struct sock *sk, *result = NULL; + int score, hiscore = 0; + + inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) { + sk = (struct sock *)icsk; + score = compute_score(sk, net, hnum, daddr, dif, sdif); + if (score > hiscore) { + result = lookup_reuseport(net, sk, skb, doff, + saddr, sport, daddr, hnum); + if (result) + return result; + + result = sk; + hiscore = score; + } + } + + return result; +} + +static inline struct sock *inet_lookup_run_bpf(struct net *net, + struct inet_hashinfo *hashinfo, + struct sk_buff *skb, int doff, + __be32 saddr, __be16 sport, + __be32 daddr, u16 hnum) +{ + struct sock *sk, *reuse_sk; + bool no_reuseport; + + if (hashinfo != &tcp_hashinfo) + return NULL; /* only TCP is supported */ + + no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_TCP, + saddr, sport, daddr, hnum, &sk); + if (no_reuseport || IS_ERR_OR_NULL(sk)) + return sk; + + reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum); + if (reuse_sk) + sk = reuse_sk; + return sk; +} + +struct sock *__inet_lookup_listener(struct net *net, + struct inet_hashinfo *hashinfo, + struct sk_buff *skb, int doff, + const __be32 saddr, __be16 sport, + const __be32 daddr, const unsigned short hnum, + const int dif, const int sdif) +{ + struct inet_listen_hashbucket *ilb2; + struct sock *result = NULL; + unsigned int hash2; + + /* Lookup redirect from BPF */ + if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { + result = inet_lookup_run_bpf(net, hashinfo, skb, doff, + saddr, sport, daddr, hnum); + if (result) + goto done; + } + + hash2 = ipv4_portaddr_hash(net, daddr, hnum); + ilb2 = inet_lhash2_bucket(hashinfo, hash2); + + result = inet_lhash2_lookup(net, ilb2, skb, doff, + saddr, sport, daddr, hnum, + dif, sdif); + if (result) + goto done; + + /* Lookup lhash2 with INADDR_ANY */ + hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); + ilb2 = inet_lhash2_bucket(hashinfo, hash2); + + result = inet_lhash2_lookup(net, ilb2, skb, doff, + saddr, sport, htonl(INADDR_ANY), hnum, + dif, sdif); +done: + if (IS_ERR(result)) + return NULL; + return result; +} +EXPORT_SYMBOL_GPL(__inet_lookup_listener); + +/* All sockets share common refcount, but have different destructors */ +void sock_gen_put(struct sock *sk) +{ + if (!refcount_dec_and_test(&sk->sk_refcnt)) + return; + + if (sk->sk_state == TCP_TIME_WAIT) + inet_twsk_free(inet_twsk(sk)); + else if (sk->sk_state == TCP_NEW_SYN_RECV) + reqsk_free(inet_reqsk(sk)); + else + sk_free(sk); +} +EXPORT_SYMBOL_GPL(sock_gen_put); + +void sock_edemux(struct sk_buff *skb) +{ + sock_gen_put(skb->sk); +} +EXPORT_SYMBOL(sock_edemux); + +struct sock *__inet_lookup_established(struct net *net, + struct inet_hashinfo *hashinfo, + const __be32 saddr, const __be16 sport, + const __be32 daddr, const u16 hnum, + const int dif, const int sdif) +{ + INET_ADDR_COOKIE(acookie, saddr, daddr); + const __portpair ports = INET_COMBINED_PORTS(sport, hnum); + struct sock *sk; + const struct hlist_nulls_node *node; + /* Optimize here for direct hit, only listening connections can + * have wildcards anyways. + */ + unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport); + unsigned int slot = hash & hashinfo->ehash_mask; + struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; + +begin: + sk_nulls_for_each_rcu(sk, node, &head->chain) { + if (sk->sk_hash != hash) + continue; + if (likely(INET_MATCH(net, sk, acookie, ports, dif, sdif))) { + if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) + goto out; + if (unlikely(!INET_MATCH(net, sk, acookie, + ports, dif, sdif))) { + sock_gen_put(sk); + goto begin; + } + goto found; + } + } + /* + * if the nulls value we got at the end of this lookup is + * not the expected one, we must restart lookup. + * We probably met an item that was moved to another chain. + */ + if (get_nulls_value(node) != slot) + goto begin; +out: + sk = NULL; +found: + return sk; +} +EXPORT_SYMBOL_GPL(__inet_lookup_established); + +/* called with local bh disabled */ +static int __inet_check_established(struct inet_timewait_death_row *death_row, + struct sock *sk, __u16 lport, + struct inet_timewait_sock **twp) +{ + struct inet_hashinfo *hinfo = death_row->hashinfo; + struct inet_sock *inet = inet_sk(sk); + __be32 daddr = inet->inet_rcv_saddr; + __be32 saddr = inet->inet_daddr; + int dif = sk->sk_bound_dev_if; + struct net *net = sock_net(sk); + int sdif = l3mdev_master_ifindex_by_index(net, dif); + INET_ADDR_COOKIE(acookie, saddr, daddr); + const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport); + unsigned int hash = inet_ehashfn(net, daddr, lport, + saddr, inet->inet_dport); + struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); + spinlock_t *lock = inet_ehash_lockp(hinfo, hash); + struct sock *sk2; + const struct hlist_nulls_node *node; + struct inet_timewait_sock *tw = NULL; + + spin_lock(lock); + + sk_nulls_for_each(sk2, node, &head->chain) { + if (sk2->sk_hash != hash) + continue; + + if (likely(INET_MATCH(net, sk2, acookie, ports, dif, sdif))) { + if (sk2->sk_state == TCP_TIME_WAIT) { + tw = inet_twsk(sk2); + if (twsk_unique(sk, sk2, twp)) + break; + } + goto not_unique; + } + } + + /* Must record num and sport now. Otherwise we will see + * in hash table socket with a funny identity. + */ + inet->inet_num = lport; + inet->inet_sport = htons(lport); + sk->sk_hash = hash; + WARN_ON(!sk_unhashed(sk)); + __sk_nulls_add_node_rcu(sk, &head->chain); + if (tw) { + sk_nulls_del_node_init_rcu((struct sock *)tw); + __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED); + } + spin_unlock(lock); + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); + + if (twp) { + *twp = tw; + } else if (tw) { + /* Silly. Should hash-dance instead... */ + inet_twsk_deschedule_put(tw); + } + return 0; + +not_unique: + spin_unlock(lock); + return -EADDRNOTAVAIL; +} + +static u64 inet_sk_port_offset(const struct sock *sk) +{ + const struct inet_sock *inet = inet_sk(sk); + + return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr, + inet->inet_daddr, + inet->inet_dport); +} + +/* Searches for an exsiting socket in the ehash bucket list. + * Returns true if found, false otherwise. + */ +static bool inet_ehash_lookup_by_sk(struct sock *sk, + struct hlist_nulls_head *list) +{ + const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num); + const int sdif = sk->sk_bound_dev_if; + const int dif = sk->sk_bound_dev_if; + const struct hlist_nulls_node *node; + struct net *net = sock_net(sk); + struct sock *esk; + + INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr); + + sk_nulls_for_each_rcu(esk, node, list) { + if (esk->sk_hash != sk->sk_hash) + continue; + if (sk->sk_family == AF_INET) { + if (unlikely(INET_MATCH(net, esk, acookie, + ports, dif, sdif))) { + return true; + } + } +#if IS_ENABLED(CONFIG_IPV6) + else if (sk->sk_family == AF_INET6) { + if (unlikely(inet6_match(net, esk, + &sk->sk_v6_daddr, + &sk->sk_v6_rcv_saddr, + ports, dif, sdif))) { + return true; + } + } +#endif + } + return false; +} + +/* Insert a socket into ehash, and eventually remove another one + * (The another one can be a SYN_RECV or TIMEWAIT) + * If an existing socket already exists, socket sk is not inserted, + * and sets found_dup_sk parameter to true. + */ +bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk) +{ + struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; + struct hlist_nulls_head *list; + struct inet_ehash_bucket *head; + spinlock_t *lock; + bool ret = true; + + WARN_ON_ONCE(!sk_unhashed(sk)); + + sk->sk_hash = sk_ehashfn(sk); + head = inet_ehash_bucket(hashinfo, sk->sk_hash); + list = &head->chain; + lock = inet_ehash_lockp(hashinfo, sk->sk_hash); + + spin_lock(lock); + if (osk) { + WARN_ON_ONCE(sk->sk_hash != osk->sk_hash); + ret = sk_nulls_del_node_init_rcu(osk); + } else if (found_dup_sk) { + *found_dup_sk = inet_ehash_lookup_by_sk(sk, list); + if (*found_dup_sk) + ret = false; + } + + if (ret) + __sk_nulls_add_node_rcu(sk, list); + + spin_unlock(lock); + + return ret; +} + +bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk) +{ + bool ok = inet_ehash_insert(sk, osk, found_dup_sk); + + if (ok) { + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); + } else { + this_cpu_inc(*sk->sk_prot->orphan_count); + inet_sk_set_state(sk, TCP_CLOSE); + sock_set_flag(sk, SOCK_DEAD); + inet_csk_destroy_sock(sk); + } + return ok; +} +EXPORT_SYMBOL_GPL(inet_ehash_nolisten); + +static int inet_reuseport_add_sock(struct sock *sk, + struct inet_listen_hashbucket *ilb) +{ + struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash; + const struct hlist_nulls_node *node; + struct sock *sk2; + kuid_t uid = sock_i_uid(sk); + + sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) { + if (sk2 != sk && + sk2->sk_family == sk->sk_family && + ipv6_only_sock(sk2) == ipv6_only_sock(sk) && + sk2->sk_bound_dev_if == sk->sk_bound_dev_if && + inet_csk(sk2)->icsk_bind_hash == tb && + sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && + inet_rcv_saddr_equal(sk, sk2, false)) + return reuseport_add_sock(sk, sk2, + inet_rcv_saddr_any(sk)); + } + + return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); +} + +int __inet_hash(struct sock *sk, struct sock *osk) +{ + struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; + struct inet_listen_hashbucket *ilb; + int err = 0; + + if (sk->sk_state != TCP_LISTEN) { + local_bh_disable(); + inet_ehash_nolisten(sk, osk, NULL); + local_bh_enable(); + return 0; + } + WARN_ON(!sk_unhashed(sk)); + ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; + + spin_lock(&ilb->lock); + if (sk->sk_reuseport) { + err = inet_reuseport_add_sock(sk, ilb); + if (err) + goto unlock; + } + if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && + sk->sk_family == AF_INET6) + __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head); + else + __sk_nulls_add_node_rcu(sk, &ilb->nulls_head); + inet_hash2(hashinfo, sk); + ilb->count++; + sock_set_flag(sk, SOCK_RCU_FREE); + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); +unlock: + spin_unlock(&ilb->lock); + + return err; +} +EXPORT_SYMBOL(__inet_hash); + +int inet_hash(struct sock *sk) +{ + int err = 0; + + if (sk->sk_state != TCP_CLOSE) + err = __inet_hash(sk, NULL); + + return err; +} +EXPORT_SYMBOL_GPL(inet_hash); + +static void __inet_unhash(struct sock *sk, struct inet_listen_hashbucket *ilb) +{ + if (sk_unhashed(sk)) + return; + + if (rcu_access_pointer(sk->sk_reuseport_cb)) + reuseport_detach_sock(sk); + if (ilb) { + struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; + + inet_unhash2(hashinfo, sk); + ilb->count--; + } + __sk_nulls_del_node_init_rcu(sk); + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); +} + +void inet_unhash(struct sock *sk) +{ + struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; + + if (sk_unhashed(sk)) + return; + + if (sk->sk_state == TCP_LISTEN) { + struct inet_listen_hashbucket *ilb; + + ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; + /* Don't disable bottom halves while acquiring the lock to + * avoid circular locking dependency on PREEMPT_RT. + */ + spin_lock(&ilb->lock); + __inet_unhash(sk, ilb); + spin_unlock(&ilb->lock); + } else { + spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash); + + spin_lock_bh(lock); + __inet_unhash(sk, NULL); + spin_unlock_bh(lock); + } +} +EXPORT_SYMBOL_GPL(inet_unhash); + +/* RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm + * Note that we use 32bit integers (vs RFC 'short integers') + * because 2^16 is not a multiple of num_ephemeral and this + * property might be used by clever attacker. + * + * RFC claims using TABLE_LENGTH=10 buckets gives an improvement, though + * attacks were since demonstrated, thus we use 65536 by default instead + * to really give more isolation and privacy, at the expense of 256kB + * of kernel memory. + */ +#define INET_TABLE_PERTURB_SIZE (1 << CONFIG_INET_TABLE_PERTURB_ORDER) +static u32 *table_perturb; + +int __inet_hash_connect(struct inet_timewait_death_row *death_row, + struct sock *sk, u64 port_offset, + int (*check_established)(struct inet_timewait_death_row *, + struct sock *, __u16, struct inet_timewait_sock **)) +{ + struct inet_hashinfo *hinfo = death_row->hashinfo; + struct inet_timewait_sock *tw = NULL; + struct inet_bind_hashbucket *head; + int port = inet_sk(sk)->inet_num; + struct net *net = sock_net(sk); + struct inet_bind_bucket *tb; + u32 remaining, offset; + int ret, i, low, high; + int l3mdev; + u32 index; + + if (port) { + local_bh_disable(); + ret = check_established(death_row, sk, port, NULL); + local_bh_enable(); + return ret; + } + + l3mdev = inet_sk_bound_l3mdev(sk); + + inet_get_local_port_range(net, &low, &high); + high++; /* [32768, 60999] -> [32768, 61000[ */ + remaining = high - low; + if (likely(remaining > 1)) + remaining &= ~1U; + + get_random_slow_once(table_perturb, + INET_TABLE_PERTURB_SIZE * sizeof(*table_perturb)); + index = port_offset & (INET_TABLE_PERTURB_SIZE - 1); + + offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32); + offset %= remaining; + + /* In first pass we try ports of @low parity. + * inet_csk_get_port() does the opposite choice. + */ + offset &= ~1U; +other_parity_scan: + port = low + offset; + for (i = 0; i < remaining; i += 2, port += 2) { + if (unlikely(port >= high)) + port -= remaining; + if (inet_is_local_reserved_port(net, port)) + continue; + head = &hinfo->bhash[inet_bhashfn(net, port, + hinfo->bhash_size)]; + spin_lock_bh(&head->lock); + + /* Does not bother with rcv_saddr checks, because + * the established check is already unique enough. + */ + inet_bind_bucket_for_each(tb, &head->chain) { + if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev && + tb->port == port) { + if (tb->fastreuse >= 0 || + tb->fastreuseport >= 0) + goto next_port; + WARN_ON(hlist_empty(&tb->owners)); + if (!check_established(death_row, sk, + port, &tw)) + goto ok; + goto next_port; + } + } + + tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, + net, head, port, l3mdev); + if (!tb) { + spin_unlock_bh(&head->lock); + return -ENOMEM; + } + tb->fastreuse = -1; + tb->fastreuseport = -1; + goto ok; +next_port: + spin_unlock_bh(&head->lock); + cond_resched(); + } + + offset++; + if ((offset & 1) && remaining > 1) + goto other_parity_scan; + + return -EADDRNOTAVAIL; + +ok: + /* Here we want to add a little bit of randomness to the next source + * port that will be chosen. We use a max() with a random here so that + * on low contention the randomness is maximal and on high contention + * it may be inexistent. + */ + i = max_t(int, i, (prandom_u32() & 7) * 2); + WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2); + + /* Head lock still held and bh's disabled */ + inet_bind_hash(sk, tb, port); + if (sk_unhashed(sk)) { + inet_sk(sk)->inet_sport = htons(port); + inet_ehash_nolisten(sk, (struct sock *)tw, NULL); + } + if (tw) + inet_twsk_bind_unhash(tw, hinfo); + spin_unlock(&head->lock); + if (tw) + inet_twsk_deschedule_put(tw); + local_bh_enable(); + return 0; +} + +/* + * Bind a port for a connect operation and hash it. + */ +int inet_hash_connect(struct inet_timewait_death_row *death_row, + struct sock *sk) +{ + u64 port_offset = 0; + + if (!inet_sk(sk)->inet_num) + port_offset = inet_sk_port_offset(sk); + return __inet_hash_connect(death_row, sk, port_offset, + __inet_check_established); +} +EXPORT_SYMBOL_GPL(inet_hash_connect); + +void inet_hashinfo_init(struct inet_hashinfo *h) +{ + int i; + + for (i = 0; i < INET_LHTABLE_SIZE; i++) { + spin_lock_init(&h->listening_hash[i].lock); + INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head, + i + LISTENING_NULLS_BASE); + h->listening_hash[i].count = 0; + } + + h->lhash2 = NULL; +} +EXPORT_SYMBOL_GPL(inet_hashinfo_init); + +static void init_hashinfo_lhash2(struct inet_hashinfo *h) +{ + int i; + + for (i = 0; i <= h->lhash2_mask; i++) { + spin_lock_init(&h->lhash2[i].lock); + INIT_HLIST_HEAD(&h->lhash2[i].head); + h->lhash2[i].count = 0; + } +} + +void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name, + unsigned long numentries, int scale, + unsigned long low_limit, + unsigned long high_limit) +{ + h->lhash2 = alloc_large_system_hash(name, + sizeof(*h->lhash2), + numentries, + scale, + 0, + NULL, + &h->lhash2_mask, + low_limit, + high_limit); + init_hashinfo_lhash2(h); + + /* this one is used for source ports of outgoing connections */ + table_perturb = kmalloc_array(INET_TABLE_PERTURB_SIZE, + sizeof(*table_perturb), GFP_KERNEL); + if (!table_perturb) + panic("TCP: failed to alloc table_perturb"); +} + +int inet_hashinfo2_init_mod(struct inet_hashinfo *h) +{ + h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL); + if (!h->lhash2) + return -ENOMEM; + + h->lhash2_mask = INET_LHTABLE_SIZE - 1; + /* INET_LHTABLE_SIZE must be a power of 2 */ + BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask); + + init_hashinfo_lhash2(h); + return 0; +} +EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod); + +int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo) +{ + unsigned int locksz = sizeof(spinlock_t); + unsigned int i, nblocks = 1; + + if (locksz != 0) { + /* allocate 2 cache lines or at least one spinlock per cpu */ + nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U); + nblocks = roundup_pow_of_two(nblocks * num_possible_cpus()); + + /* no more locks than number of hash buckets */ + nblocks = min(nblocks, hashinfo->ehash_mask + 1); + + hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL); + if (!hashinfo->ehash_locks) + return -ENOMEM; + + for (i = 0; i < nblocks; i++) + spin_lock_init(&hashinfo->ehash_locks[i]); + } + hashinfo->ehash_locks_mask = nblocks - 1; + return 0; +} +EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc); diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c new file mode 100644 index 000000000..c411c87ae --- /dev/null +++ b/net/ipv4/inet_timewait_sock.c @@ -0,0 +1,302 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Generic TIME_WAIT sockets functions + * + * From code orinally in TCP + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <net/inet_hashtables.h> +#include <net/inet_timewait_sock.h> +#include <net/ip.h> + + +/** + * inet_twsk_bind_unhash - unhash a timewait socket from bind hash + * @tw: timewait socket + * @hashinfo: hashinfo pointer + * + * unhash a timewait socket from bind hash, if hashed. + * bind hash lock must be held by caller. + * Returns 1 if caller should call inet_twsk_put() after lock release. + */ +void inet_twsk_bind_unhash(struct inet_timewait_sock *tw, + struct inet_hashinfo *hashinfo) +{ + struct inet_bind_bucket *tb = tw->tw_tb; + + if (!tb) + return; + + __hlist_del(&tw->tw_bind_node); + tw->tw_tb = NULL; + inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); + __sock_put((struct sock *)tw); +} + +/* Must be called with locally disabled BHs. */ +static void inet_twsk_kill(struct inet_timewait_sock *tw) +{ + struct inet_hashinfo *hashinfo = tw->tw_dr->hashinfo; + spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash); + struct inet_bind_hashbucket *bhead; + + spin_lock(lock); + sk_nulls_del_node_init_rcu((struct sock *)tw); + spin_unlock(lock); + + /* Disassociate with bind bucket. */ + bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num, + hashinfo->bhash_size)]; + + spin_lock(&bhead->lock); + inet_twsk_bind_unhash(tw, hashinfo); + spin_unlock(&bhead->lock); + + atomic_dec(&tw->tw_dr->tw_count); + inet_twsk_put(tw); +} + +void inet_twsk_free(struct inet_timewait_sock *tw) +{ + struct module *owner = tw->tw_prot->owner; + twsk_destructor((struct sock *)tw); +#ifdef SOCK_REFCNT_DEBUG + pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw); +#endif + kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw); + module_put(owner); +} + +void inet_twsk_put(struct inet_timewait_sock *tw) +{ + if (refcount_dec_and_test(&tw->tw_refcnt)) + inet_twsk_free(tw); +} +EXPORT_SYMBOL_GPL(inet_twsk_put); + +static void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw, + struct hlist_nulls_head *list) +{ + hlist_nulls_add_head_rcu(&tw->tw_node, list); +} + +static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, + struct hlist_head *list) +{ + hlist_add_head(&tw->tw_bind_node, list); +} + +/* + * Enter the time wait state. This is called with locally disabled BH. + * Essentially we whip up a timewait bucket, copy the relevant info into it + * from the SK, and mess with hash chains and list linkage. + */ +void inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, + struct inet_hashinfo *hashinfo) +{ + const struct inet_sock *inet = inet_sk(sk); + const struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, sk->sk_hash); + spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash); + struct inet_bind_hashbucket *bhead; + /* Step 1: Put TW into bind hash. Original socket stays there too. + Note, that any socket with inet->num != 0 MUST be bound in + binding cache, even if it is closed. + */ + bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->inet_num, + hashinfo->bhash_size)]; + spin_lock(&bhead->lock); + tw->tw_tb = icsk->icsk_bind_hash; + WARN_ON(!icsk->icsk_bind_hash); + inet_twsk_add_bind_node(tw, &tw->tw_tb->owners); + spin_unlock(&bhead->lock); + + spin_lock(lock); + + inet_twsk_add_node_rcu(tw, &ehead->chain); + + /* Step 3: Remove SK from hash chain */ + if (__sk_nulls_del_node_init_rcu(sk)) + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + + spin_unlock(lock); + + /* tw_refcnt is set to 3 because we have : + * - one reference for bhash chain. + * - one reference for ehash chain. + * - one reference for timer. + * We can use atomic_set() because prior spin_lock()/spin_unlock() + * committed into memory all tw fields. + * Also note that after this point, we lost our implicit reference + * so we are not allowed to use tw anymore. + */ + refcount_set(&tw->tw_refcnt, 3); +} +EXPORT_SYMBOL_GPL(inet_twsk_hashdance); + +static void tw_timer_handler(struct timer_list *t) +{ + struct inet_timewait_sock *tw = from_timer(tw, t, tw_timer); + + if (tw->tw_kill) + __NET_INC_STATS(twsk_net(tw), LINUX_MIB_TIMEWAITKILLED); + else + __NET_INC_STATS(twsk_net(tw), LINUX_MIB_TIMEWAITED); + inet_twsk_kill(tw); +} + +struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, + struct inet_timewait_death_row *dr, + const int state) +{ + struct inet_timewait_sock *tw; + + if (atomic_read(&dr->tw_count) >= dr->sysctl_max_tw_buckets) + return NULL; + + tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab, + GFP_ATOMIC); + if (tw) { + const struct inet_sock *inet = inet_sk(sk); + + tw->tw_dr = dr; + /* Give us an identity. */ + tw->tw_daddr = inet->inet_daddr; + tw->tw_rcv_saddr = inet->inet_rcv_saddr; + tw->tw_bound_dev_if = sk->sk_bound_dev_if; + tw->tw_tos = inet->tos; + tw->tw_num = inet->inet_num; + tw->tw_state = TCP_TIME_WAIT; + tw->tw_substate = state; + tw->tw_sport = inet->inet_sport; + tw->tw_dport = inet->inet_dport; + tw->tw_family = sk->sk_family; + tw->tw_reuse = sk->sk_reuse; + tw->tw_reuseport = sk->sk_reuseport; + tw->tw_hash = sk->sk_hash; + tw->tw_ipv6only = 0; + tw->tw_transparent = inet->transparent; + tw->tw_prot = sk->sk_prot_creator; + atomic64_set(&tw->tw_cookie, atomic64_read(&sk->sk_cookie)); + twsk_net_set(tw, sock_net(sk)); + timer_setup(&tw->tw_timer, tw_timer_handler, TIMER_PINNED); + /* + * Because we use RCU lookups, we should not set tw_refcnt + * to a non null value before everything is setup for this + * timewait socket. + */ + refcount_set(&tw->tw_refcnt, 0); + + __module_get(tw->tw_prot->owner); + } + + return tw; +} +EXPORT_SYMBOL_GPL(inet_twsk_alloc); + +/* These are always called from BH context. See callers in + * tcp_input.c to verify this. + */ + +/* This is for handling early-kills of TIME_WAIT sockets. + * Warning : consume reference. + * Caller should not access tw anymore. + */ +void inet_twsk_deschedule_put(struct inet_timewait_sock *tw) +{ + if (del_timer_sync(&tw->tw_timer)) + inet_twsk_kill(tw); + inet_twsk_put(tw); +} +EXPORT_SYMBOL(inet_twsk_deschedule_put); + +void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo, bool rearm) +{ + /* timeout := RTO * 3.5 + * + * 3.5 = 1+2+0.5 to wait for two retransmits. + * + * RATIONALE: if FIN arrived and we entered TIME-WAIT state, + * our ACK acking that FIN can be lost. If N subsequent retransmitted + * FINs (or previous seqments) are lost (probability of such event + * is p^(N+1), where p is probability to lose single packet and + * time to detect the loss is about RTO*(2^N - 1) with exponential + * backoff). Normal timewait length is calculated so, that we + * waited at least for one retransmitted FIN (maximal RTO is 120sec). + * [ BTW Linux. following BSD, violates this requirement waiting + * only for 60sec, we should wait at least for 240 secs. + * Well, 240 consumes too much of resources 8) + * ] + * This interval is not reduced to catch old duplicate and + * responces to our wandering segments living for two MSLs. + * However, if we use PAWS to detect + * old duplicates, we can reduce the interval to bounds required + * by RTO, rather than MSL. So, if peer understands PAWS, we + * kill tw bucket after 3.5*RTO (it is important that this number + * is greater than TS tick!) and detect old duplicates with help + * of PAWS. + */ + + tw->tw_kill = timeo <= 4*HZ; + if (!rearm) { + BUG_ON(mod_timer(&tw->tw_timer, jiffies + timeo)); + atomic_inc(&tw->tw_dr->tw_count); + } else { + mod_timer_pending(&tw->tw_timer, jiffies + timeo); + } +} +EXPORT_SYMBOL_GPL(__inet_twsk_schedule); + +void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family) +{ + struct inet_timewait_sock *tw; + struct sock *sk; + struct hlist_nulls_node *node; + unsigned int slot; + + for (slot = 0; slot <= hashinfo->ehash_mask; slot++) { + struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; +restart_rcu: + cond_resched(); + rcu_read_lock(); +restart: + sk_nulls_for_each_rcu(sk, node, &head->chain) { + if (sk->sk_state != TCP_TIME_WAIT) + continue; + tw = inet_twsk(sk); + if ((tw->tw_family != family) || + refcount_read(&twsk_net(tw)->count)) + continue; + + if (unlikely(!refcount_inc_not_zero(&tw->tw_refcnt))) + continue; + + if (unlikely((tw->tw_family != family) || + refcount_read(&twsk_net(tw)->count))) { + inet_twsk_put(tw); + goto restart; + } + + rcu_read_unlock(); + local_bh_disable(); + inet_twsk_deschedule_put(tw); + local_bh_enable(); + goto restart_rcu; + } + /* If the nulls value we got at the end of this lookup is + * not the expected one, we must restart lookup. + * We probably met an item that was moved to another chain. + */ + if (get_nulls_value(node) != slot) + goto restart; + rcu_read_unlock(); + } +} +EXPORT_SYMBOL_GPL(inet_twsk_purge); diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c new file mode 100644 index 000000000..a18668552 --- /dev/null +++ b/net/ipv4/inetpeer.c @@ -0,0 +1,315 @@ +/* + * INETPEER - A storage for permanent information about peers + * + * This source is covered by the GNU GPL, the same as all kernel sources. + * + * Authors: Andrey V. Savochkin <saw@msu.ru> + */ + +#include <linux/cache.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/random.h> +#include <linux/timer.h> +#include <linux/time.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/net.h> +#include <linux/workqueue.h> +#include <net/ip.h> +#include <net/inetpeer.h> +#include <net/secure_seq.h> + +/* + * Theory of operations. + * We keep one entry for each peer IP address. The nodes contains long-living + * information about the peer which doesn't depend on routes. + * + * Nodes are removed only when reference counter goes to 0. + * When it's happened the node may be removed when a sufficient amount of + * time has been passed since its last use. The less-recently-used entry can + * also be removed if the pool is overloaded i.e. if the total amount of + * entries is greater-or-equal than the threshold. + * + * Node pool is organised as an RB tree. + * Such an implementation has been chosen not just for fun. It's a way to + * prevent easy and efficient DoS attacks by creating hash collisions. A huge + * amount of long living nodes in a single hash slot would significantly delay + * lookups performed with disabled BHs. + * + * Serialisation issues. + * 1. Nodes may appear in the tree only with the pool lock held. + * 2. Nodes may disappear from the tree only with the pool lock held + * AND reference count being 0. + * 3. Global variable peer_total is modified under the pool lock. + * 4. struct inet_peer fields modification: + * rb_node: pool lock + * refcnt: atomically against modifications on other CPU; + * usually under some other lock to prevent node disappearing + * daddr: unchangeable + */ + +static struct kmem_cache *peer_cachep __ro_after_init; + +void inet_peer_base_init(struct inet_peer_base *bp) +{ + bp->rb_root = RB_ROOT; + seqlock_init(&bp->lock); + bp->total = 0; +} +EXPORT_SYMBOL_GPL(inet_peer_base_init); + +#define PEER_MAX_GC 32 + +/* Exported for sysctl_net_ipv4. */ +int inet_peer_threshold __read_mostly = 65536 + 128; /* start to throw entries more + * aggressively at this stage */ +int inet_peer_minttl __read_mostly = 120 * HZ; /* TTL under high load: 120 sec */ +int inet_peer_maxttl __read_mostly = 10 * 60 * HZ; /* usual time to live: 10 min */ + +/* Called from ip_output.c:ip_init */ +void __init inet_initpeers(void) +{ + struct sysinfo si; + + /* Use the straight interface to information about memory. */ + si_meminfo(&si); + /* The values below were suggested by Alexey Kuznetsov + * <kuznet@ms2.inr.ac.ru>. I don't have any opinion about the values + * myself. --SAW + */ + if (si.totalram <= (32768*1024)/PAGE_SIZE) + inet_peer_threshold >>= 1; /* max pool size about 1MB on IA32 */ + if (si.totalram <= (16384*1024)/PAGE_SIZE) + inet_peer_threshold >>= 1; /* about 512KB */ + if (si.totalram <= (8192*1024)/PAGE_SIZE) + inet_peer_threshold >>= 2; /* about 128KB */ + + peer_cachep = kmem_cache_create("inet_peer_cache", + sizeof(struct inet_peer), + 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, + NULL); +} + +/* Called with rcu_read_lock() or base->lock held */ +static struct inet_peer *lookup(const struct inetpeer_addr *daddr, + struct inet_peer_base *base, + unsigned int seq, + struct inet_peer *gc_stack[], + unsigned int *gc_cnt, + struct rb_node **parent_p, + struct rb_node ***pp_p) +{ + struct rb_node **pp, *parent, *next; + struct inet_peer *p; + + pp = &base->rb_root.rb_node; + parent = NULL; + while (1) { + int cmp; + + next = rcu_dereference_raw(*pp); + if (!next) + break; + parent = next; + p = rb_entry(parent, struct inet_peer, rb_node); + cmp = inetpeer_addr_cmp(daddr, &p->daddr); + if (cmp == 0) { + if (!refcount_inc_not_zero(&p->refcnt)) + break; + return p; + } + if (gc_stack) { + if (*gc_cnt < PEER_MAX_GC) + gc_stack[(*gc_cnt)++] = p; + } else if (unlikely(read_seqretry(&base->lock, seq))) { + break; + } + if (cmp == -1) + pp = &next->rb_left; + else + pp = &next->rb_right; + } + *parent_p = parent; + *pp_p = pp; + return NULL; +} + +static void inetpeer_free_rcu(struct rcu_head *head) +{ + kmem_cache_free(peer_cachep, container_of(head, struct inet_peer, rcu)); +} + +/* perform garbage collect on all items stacked during a lookup */ +static void inet_peer_gc(struct inet_peer_base *base, + struct inet_peer *gc_stack[], + unsigned int gc_cnt) +{ + int peer_threshold, peer_maxttl, peer_minttl; + struct inet_peer *p; + __u32 delta, ttl; + int i; + + peer_threshold = READ_ONCE(inet_peer_threshold); + peer_maxttl = READ_ONCE(inet_peer_maxttl); + peer_minttl = READ_ONCE(inet_peer_minttl); + + if (base->total >= peer_threshold) + ttl = 0; /* be aggressive */ + else + ttl = peer_maxttl - (peer_maxttl - peer_minttl) / HZ * + base->total / peer_threshold * HZ; + for (i = 0; i < gc_cnt; i++) { + p = gc_stack[i]; + + /* The READ_ONCE() pairs with the WRITE_ONCE() + * in inet_putpeer() + */ + delta = (__u32)jiffies - READ_ONCE(p->dtime); + + if (delta < ttl || !refcount_dec_if_one(&p->refcnt)) + gc_stack[i] = NULL; + } + for (i = 0; i < gc_cnt; i++) { + p = gc_stack[i]; + if (p) { + rb_erase(&p->rb_node, &base->rb_root); + base->total--; + call_rcu(&p->rcu, inetpeer_free_rcu); + } + } +} + +struct inet_peer *inet_getpeer(struct inet_peer_base *base, + const struct inetpeer_addr *daddr, + int create) +{ + struct inet_peer *p, *gc_stack[PEER_MAX_GC]; + struct rb_node **pp, *parent; + unsigned int gc_cnt, seq; + int invalidated; + + /* Attempt a lockless lookup first. + * Because of a concurrent writer, we might not find an existing entry. + */ + rcu_read_lock(); + seq = read_seqbegin(&base->lock); + p = lookup(daddr, base, seq, NULL, &gc_cnt, &parent, &pp); + invalidated = read_seqretry(&base->lock, seq); + rcu_read_unlock(); + + if (p) + return p; + + /* If no writer did a change during our lookup, we can return early. */ + if (!create && !invalidated) + return NULL; + + /* retry an exact lookup, taking the lock before. + * At least, nodes should be hot in our cache. + */ + parent = NULL; + write_seqlock_bh(&base->lock); + + gc_cnt = 0; + p = lookup(daddr, base, seq, gc_stack, &gc_cnt, &parent, &pp); + if (!p && create) { + p = kmem_cache_alloc(peer_cachep, GFP_ATOMIC); + if (p) { + p->daddr = *daddr; + p->dtime = (__u32)jiffies; + refcount_set(&p->refcnt, 2); + atomic_set(&p->rid, 0); + p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW; + p->rate_tokens = 0; + p->n_redirects = 0; + /* 60*HZ is arbitrary, but chosen enough high so that the first + * calculation of tokens is at its maximum. + */ + p->rate_last = jiffies - 60*HZ; + + rb_link_node(&p->rb_node, parent, pp); + rb_insert_color(&p->rb_node, &base->rb_root); + base->total++; + } + } + if (gc_cnt) + inet_peer_gc(base, gc_stack, gc_cnt); + write_sequnlock_bh(&base->lock); + + return p; +} +EXPORT_SYMBOL_GPL(inet_getpeer); + +void inet_putpeer(struct inet_peer *p) +{ + /* The WRITE_ONCE() pairs with itself (we run lockless) + * and the READ_ONCE() in inet_peer_gc() + */ + WRITE_ONCE(p->dtime, (__u32)jiffies); + + if (refcount_dec_and_test(&p->refcnt)) + call_rcu(&p->rcu, inetpeer_free_rcu); +} +EXPORT_SYMBOL_GPL(inet_putpeer); + +/* + * Check transmit rate limitation for given message. + * The rate information is held in the inet_peer entries now. + * This function is generic and could be used for other purposes + * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov. + * + * Note that the same inet_peer fields are modified by functions in + * route.c too, but these work for packet destinations while xrlim_allow + * works for icmp destinations. This means the rate limiting information + * for one "ip object" is shared - and these ICMPs are twice limited: + * by source and by destination. + * + * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate + * SHOULD allow setting of rate limits + * + * Shared between ICMPv4 and ICMPv6. + */ +#define XRLIM_BURST_FACTOR 6 +bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout) +{ + unsigned long now, token; + bool rc = false; + + if (!peer) + return true; + + token = peer->rate_tokens; + now = jiffies; + token += now - peer->rate_last; + peer->rate_last = now; + if (token > XRLIM_BURST_FACTOR * timeout) + token = XRLIM_BURST_FACTOR * timeout; + if (token >= timeout) { + token -= timeout; + rc = true; + } + peer->rate_tokens = token; + return rc; +} +EXPORT_SYMBOL(inet_peer_xrlim_allow); + +void inetpeer_invalidate_tree(struct inet_peer_base *base) +{ + struct rb_node *p = rb_first(&base->rb_root); + + while (p) { + struct inet_peer *peer = rb_entry(p, struct inet_peer, rb_node); + + p = rb_next(p); + rb_erase(&peer->rb_node, &base->rb_root); + inet_putpeer(peer); + cond_resched(); + } + + base->total = 0; +} +EXPORT_SYMBOL(inetpeer_invalidate_tree); diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c new file mode 100644 index 000000000..29730edda --- /dev/null +++ b/net/ipv4/ip_forward.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The IP forwarding functionality. + * + * Authors: see ip.c + * + * Fixes: + * Many : Split from ip.c , see ip_input.c for + * history. + * Dave Gregorich : NULL ip_rt_put fix for multicast + * routing. + * Jos Vos : Add call_out_firewall before sending, + * use output device for accounting. + * Jos Vos : Call forward firewall after routing + * (always use output device). + * Mike McLagan : Routing by source + */ + +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/icmp.h> +#include <linux/netdevice.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/icmp.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/netfilter_ipv4.h> +#include <net/checksum.h> +#include <linux/route.h> +#include <net/route.h> +#include <net/xfrm.h> + +static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu) +{ + if (skb->len <= mtu) + return false; + + if (unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0)) + return false; + + /* original fragment exceeds mtu and DF is set */ + if (unlikely(IPCB(skb)->frag_max_size > mtu)) + return true; + + if (skb->ignore_df) + return false; + + if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) + return false; + + return true; +} + + +static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct ip_options *opt = &(IPCB(skb)->opt); + + __IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS); + __IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len); + +#ifdef CONFIG_NET_SWITCHDEV + if (skb->offload_l3_fwd_mark) { + consume_skb(skb); + return 0; + } +#endif + + if (unlikely(opt->optlen)) + ip_forward_options(skb); + + skb->tstamp = 0; + return dst_output(net, sk, skb); +} + +int ip_forward(struct sk_buff *skb) +{ + u32 mtu; + struct iphdr *iph; /* Our header */ + struct rtable *rt; /* Route we use */ + struct ip_options *opt = &(IPCB(skb)->opt); + struct net *net; + + /* that should never happen */ + if (skb->pkt_type != PACKET_HOST) + goto drop; + + if (unlikely(skb->sk)) + goto drop; + + if (skb_warn_if_lro(skb)) + goto drop; + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb)) + goto drop; + + if (IPCB(skb)->opt.router_alert && ip_call_ra_chain(skb)) + return NET_RX_SUCCESS; + + skb_forward_csum(skb); + net = dev_net(skb->dev); + + /* + * According to the RFC, we must first decrease the TTL field. If + * that reaches zero, we must reply an ICMP control message telling + * that the packet's lifetime expired. + */ + if (ip_hdr(skb)->ttl <= 1) + goto too_many_hops; + + if (!xfrm4_route_forward(skb)) + goto drop; + + rt = skb_rtable(skb); + + if (opt->is_strictroute && rt->rt_uses_gateway) + goto sr_failed; + + IPCB(skb)->flags |= IPSKB_FORWARDED; + mtu = ip_dst_mtu_maybe_forward(&rt->dst, true); + if (ip_exceeds_mtu(skb, mtu)) { + IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + htonl(mtu)); + goto drop; + } + + /* We are about to mangle packet. Copy it! */ + if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+rt->dst.header_len)) + goto drop; + iph = ip_hdr(skb); + + /* Decrease ttl after skb cow done */ + ip_decrease_ttl(iph); + + /* + * We now generate an ICMP HOST REDIRECT giving the route + * we calculated. + */ + if (IPCB(skb)->flags & IPSKB_DOREDIRECT && !opt->srr && + !skb_sec_path(skb)) + ip_rt_send_redirect(skb); + + if (READ_ONCE(net->ipv4.sysctl_ip_fwd_update_priority)) + skb->priority = rt_tos2priority(iph->tos); + + return NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, + net, NULL, skb, skb->dev, rt->dst.dev, + ip_forward_finish); + +sr_failed: + /* + * Strict routing permits no gatewaying + */ + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_SR_FAILED, 0); + goto drop; + +too_many_hops: + /* Tell the sender its packet died... */ + __IP_INC_STATS(net, IPSTATS_MIB_INHDRERRORS); + icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0); +drop: + kfree_skb(skb); + return NET_RX_DROP; +} diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c new file mode 100644 index 000000000..fad803d2d --- /dev/null +++ b/net/ipv4/ip_fragment.c @@ -0,0 +1,752 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The IP fragmentation functionality. + * + * Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG> + * Alan Cox <alan@lxorguk.ukuu.org.uk> + * + * Fixes: + * Alan Cox : Split from ip.c , see ip_input.c for history. + * David S. Miller : Begin massive cleanup... + * Andi Kleen : Add sysctls. + * xxxx : Overlapfrag bug. + * Ultima : ip_expire() kernel panic. + * Bill Hawes : Frag accounting and evictor fixes. + * John McDonald : 0 length frag bug. + * Alexey Kuznetsov: SMP races, threading, cleanup. + * Patrick McHardy : LRU queue of frag heads for evictor. + */ + +#define pr_fmt(fmt) "IPv4: " fmt + +#include <linux/compiler.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/jiffies.h> +#include <linux/skbuff.h> +#include <linux/list.h> +#include <linux/ip.h> +#include <linux/icmp.h> +#include <linux/netdevice.h> +#include <linux/jhash.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <net/route.h> +#include <net/dst.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/checksum.h> +#include <net/inetpeer.h> +#include <net/inet_frag.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/inet.h> +#include <linux/netfilter_ipv4.h> +#include <net/inet_ecn.h> +#include <net/l3mdev.h> + +/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6 + * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c + * as well. Or notify me, at least. --ANK + */ +static const char ip_frag_cache_name[] = "ip4-frags"; + +/* Describe an entry in the "incomplete datagrams" queue. */ +struct ipq { + struct inet_frag_queue q; + + u8 ecn; /* RFC3168 support */ + u16 max_df_size; /* largest frag with DF set seen */ + int iif; + unsigned int rid; + struct inet_peer *peer; +}; + +static u8 ip4_frag_ecn(u8 tos) +{ + return 1 << (tos & INET_ECN_MASK); +} + +static struct inet_frags ip4_frags; + +static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, + struct sk_buff *prev_tail, struct net_device *dev); + + +static void ip4_frag_init(struct inet_frag_queue *q, const void *a) +{ + struct ipq *qp = container_of(q, struct ipq, q); + struct net *net = q->fqdir->net; + + const struct frag_v4_compare_key *key = a; + + q->key.v4 = *key; + qp->ecn = 0; + qp->peer = q->fqdir->max_dist ? + inet_getpeer_v4(net->ipv4.peers, key->saddr, key->vif, 1) : + NULL; +} + +static void ip4_frag_free(struct inet_frag_queue *q) +{ + struct ipq *qp; + + qp = container_of(q, struct ipq, q); + if (qp->peer) + inet_putpeer(qp->peer); +} + + +/* Destruction primitives. */ + +static void ipq_put(struct ipq *ipq) +{ + inet_frag_put(&ipq->q); +} + +/* Kill ipq entry. It is not destroyed immediately, + * because caller (and someone more) holds reference count. + */ +static void ipq_kill(struct ipq *ipq) +{ + inet_frag_kill(&ipq->q); +} + +static bool frag_expire_skip_icmp(u32 user) +{ + return user == IP_DEFRAG_AF_PACKET || + ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN, + __IP_DEFRAG_CONNTRACK_IN_END) || + ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN, + __IP_DEFRAG_CONNTRACK_BRIDGE_IN); +} + +/* + * Oops, a fragment queue timed out. Kill it and send an ICMP reply. + */ +static void ip_expire(struct timer_list *t) +{ + struct inet_frag_queue *frag = from_timer(frag, t, timer); + const struct iphdr *iph; + struct sk_buff *head = NULL; + struct net *net; + struct ipq *qp; + int err; + + qp = container_of(frag, struct ipq, q); + net = qp->q.fqdir->net; + + rcu_read_lock(); + + /* Paired with WRITE_ONCE() in fqdir_pre_exit(). */ + if (READ_ONCE(qp->q.fqdir->dead)) + goto out_rcu_unlock; + + spin_lock(&qp->q.lock); + + if (qp->q.flags & INET_FRAG_COMPLETE) + goto out; + + ipq_kill(qp); + __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); + __IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT); + + if (!(qp->q.flags & INET_FRAG_FIRST_IN)) + goto out; + + /* sk_buff::dev and sk_buff::rbnode are unionized. So we + * pull the head out of the tree in order to be able to + * deal with head->dev. + */ + head = inet_frag_pull_head(&qp->q); + if (!head) + goto out; + head->dev = dev_get_by_index_rcu(net, qp->iif); + if (!head->dev) + goto out; + + + /* skb has no dst, perform route lookup again */ + iph = ip_hdr(head); + err = ip_route_input_noref(head, iph->daddr, iph->saddr, + iph->tos, head->dev); + if (err) + goto out; + + /* Only an end host needs to send an ICMP + * "Fragment Reassembly Timeout" message, per RFC792. + */ + if (frag_expire_skip_icmp(qp->q.key.v4.user) && + (skb_rtable(head)->rt_type != RTN_LOCAL)) + goto out; + + spin_unlock(&qp->q.lock); + icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0); + goto out_rcu_unlock; + +out: + spin_unlock(&qp->q.lock); +out_rcu_unlock: + rcu_read_unlock(); + kfree_skb(head); + ipq_put(qp); +} + +/* Find the correct entry in the "incomplete datagrams" queue for + * this IP datagram, and create new one, if nothing is found. + */ +static struct ipq *ip_find(struct net *net, struct iphdr *iph, + u32 user, int vif) +{ + struct frag_v4_compare_key key = { + .saddr = iph->saddr, + .daddr = iph->daddr, + .user = user, + .vif = vif, + .id = iph->id, + .protocol = iph->protocol, + }; + struct inet_frag_queue *q; + + q = inet_frag_find(net->ipv4.fqdir, &key); + if (!q) + return NULL; + + return container_of(q, struct ipq, q); +} + +/* Is the fragment too far ahead to be part of ipq? */ +static int ip_frag_too_far(struct ipq *qp) +{ + struct inet_peer *peer = qp->peer; + unsigned int max = qp->q.fqdir->max_dist; + unsigned int start, end; + + int rc; + + if (!peer || !max) + return 0; + + start = qp->rid; + end = atomic_inc_return(&peer->rid); + qp->rid = end; + + rc = qp->q.fragments_tail && (end - start) > max; + + if (rc) + __IP_INC_STATS(qp->q.fqdir->net, IPSTATS_MIB_REASMFAILS); + + return rc; +} + +static int ip_frag_reinit(struct ipq *qp) +{ + unsigned int sum_truesize = 0; + + if (!mod_timer(&qp->q.timer, jiffies + qp->q.fqdir->timeout)) { + refcount_inc(&qp->q.refcnt); + return -ETIMEDOUT; + } + + sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments); + sub_frag_mem_limit(qp->q.fqdir, sum_truesize); + + qp->q.flags = 0; + qp->q.len = 0; + qp->q.meat = 0; + qp->q.rb_fragments = RB_ROOT; + qp->q.fragments_tail = NULL; + qp->q.last_run_head = NULL; + qp->iif = 0; + qp->ecn = 0; + + return 0; +} + +/* Add new segment to existing queue. */ +static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) +{ + struct net *net = qp->q.fqdir->net; + int ihl, end, flags, offset; + struct sk_buff *prev_tail; + struct net_device *dev; + unsigned int fragsize; + int err = -ENOENT; + u8 ecn; + + if (qp->q.flags & INET_FRAG_COMPLETE) + goto err; + + if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) && + unlikely(ip_frag_too_far(qp)) && + unlikely(err = ip_frag_reinit(qp))) { + ipq_kill(qp); + goto err; + } + + ecn = ip4_frag_ecn(ip_hdr(skb)->tos); + offset = ntohs(ip_hdr(skb)->frag_off); + flags = offset & ~IP_OFFSET; + offset &= IP_OFFSET; + offset <<= 3; /* offset is in 8-byte chunks */ + ihl = ip_hdrlen(skb); + + /* Determine the position of this fragment. */ + end = offset + skb->len - skb_network_offset(skb) - ihl; + err = -EINVAL; + + /* Is this the final fragment? */ + if ((flags & IP_MF) == 0) { + /* If we already have some bits beyond end + * or have different end, the segment is corrupted. + */ + if (end < qp->q.len || + ((qp->q.flags & INET_FRAG_LAST_IN) && end != qp->q.len)) + goto discard_qp; + qp->q.flags |= INET_FRAG_LAST_IN; + qp->q.len = end; + } else { + if (end&7) { + end &= ~7; + if (skb->ip_summed != CHECKSUM_UNNECESSARY) + skb->ip_summed = CHECKSUM_NONE; + } + if (end > qp->q.len) { + /* Some bits beyond end -> corruption. */ + if (qp->q.flags & INET_FRAG_LAST_IN) + goto discard_qp; + qp->q.len = end; + } + } + if (end == offset) + goto discard_qp; + + err = -ENOMEM; + if (!pskb_pull(skb, skb_network_offset(skb) + ihl)) + goto discard_qp; + + err = pskb_trim_rcsum(skb, end - offset); + if (err) + goto discard_qp; + + /* Note : skb->rbnode and skb->dev share the same location. */ + dev = skb->dev; + /* Makes sure compiler wont do silly aliasing games */ + barrier(); + + prev_tail = qp->q.fragments_tail; + err = inet_frag_queue_insert(&qp->q, skb, offset, end); + if (err) + goto insert_error; + + if (dev) + qp->iif = dev->ifindex; + + qp->q.stamp = skb->tstamp; + qp->q.meat += skb->len; + qp->ecn |= ecn; + add_frag_mem_limit(qp->q.fqdir, skb->truesize); + if (offset == 0) + qp->q.flags |= INET_FRAG_FIRST_IN; + + fragsize = skb->len + ihl; + + if (fragsize > qp->q.max_size) + qp->q.max_size = fragsize; + + if (ip_hdr(skb)->frag_off & htons(IP_DF) && + fragsize > qp->max_df_size) + qp->max_df_size = fragsize; + + if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && + qp->q.meat == qp->q.len) { + unsigned long orefdst = skb->_skb_refdst; + + skb->_skb_refdst = 0UL; + err = ip_frag_reasm(qp, skb, prev_tail, dev); + skb->_skb_refdst = orefdst; + if (err) + inet_frag_kill(&qp->q); + return err; + } + + skb_dst_drop(skb); + return -EINPROGRESS; + +insert_error: + if (err == IPFRAG_DUP) { + kfree_skb(skb); + return -EINVAL; + } + err = -EINVAL; + __IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS); +discard_qp: + inet_frag_kill(&qp->q); + __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); +err: + kfree_skb(skb); + return err; +} + +static bool ip_frag_coalesce_ok(const struct ipq *qp) +{ + return qp->q.key.v4.user == IP_DEFRAG_LOCAL_DELIVER; +} + +/* Build a new IP datagram from all its fragments. */ +static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, + struct sk_buff *prev_tail, struct net_device *dev) +{ + struct net *net = qp->q.fqdir->net; + struct iphdr *iph; + void *reasm_data; + int len, err; + u8 ecn; + + ipq_kill(qp); + + ecn = ip_frag_ecn_table[qp->ecn]; + if (unlikely(ecn == 0xff)) { + err = -EINVAL; + goto out_fail; + } + + /* Make the one we just received the head. */ + reasm_data = inet_frag_reasm_prepare(&qp->q, skb, prev_tail); + if (!reasm_data) + goto out_nomem; + + len = ip_hdrlen(skb) + qp->q.len; + err = -E2BIG; + if (len > 65535) + goto out_oversize; + + inet_frag_reasm_finish(&qp->q, skb, reasm_data, + ip_frag_coalesce_ok(qp)); + + skb->dev = dev; + IPCB(skb)->frag_max_size = max(qp->max_df_size, qp->q.max_size); + + iph = ip_hdr(skb); + iph->tot_len = htons(len); + iph->tos |= ecn; + + /* When we set IP_DF on a refragmented skb we must also force a + * call to ip_fragment to avoid forwarding a DF-skb of size s while + * original sender only sent fragments of size f (where f < s). + * + * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest + * frag seen to avoid sending tiny DF-fragments in case skb was built + * from one very small df-fragment and one large non-df frag. + */ + if (qp->max_df_size == qp->q.max_size) { + IPCB(skb)->flags |= IPSKB_FRAG_PMTU; + iph->frag_off = htons(IP_DF); + } else { + iph->frag_off = 0; + } + + ip_send_check(iph); + + __IP_INC_STATS(net, IPSTATS_MIB_REASMOKS); + qp->q.rb_fragments = RB_ROOT; + qp->q.fragments_tail = NULL; + qp->q.last_run_head = NULL; + return 0; + +out_nomem: + net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp); + err = -ENOMEM; + goto out_fail; +out_oversize: + net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->q.key.v4.saddr); +out_fail: + __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); + return err; +} + +/* Process an incoming IP datagram fragment. */ +int ip_defrag(struct net *net, struct sk_buff *skb, u32 user) +{ + struct net_device *dev = skb->dev ? : skb_dst(skb)->dev; + int vif = l3mdev_master_ifindex_rcu(dev); + struct ipq *qp; + + __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS); + skb_orphan(skb); + + /* Lookup (or create) queue header */ + qp = ip_find(net, ip_hdr(skb), user, vif); + if (qp) { + int ret; + + spin_lock(&qp->q.lock); + + ret = ip_frag_queue(qp, skb); + + spin_unlock(&qp->q.lock); + ipq_put(qp); + return ret; + } + + __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); + kfree_skb(skb); + return -ENOMEM; +} +EXPORT_SYMBOL(ip_defrag); + +struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) +{ + struct iphdr iph; + int netoff; + u32 len; + + if (skb->protocol != htons(ETH_P_IP)) + return skb; + + netoff = skb_network_offset(skb); + + if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0) + return skb; + + if (iph.ihl < 5 || iph.version != 4) + return skb; + + len = ntohs(iph.tot_len); + if (skb->len < netoff + len || len < (iph.ihl * 4)) + return skb; + + if (ip_is_fragment(&iph)) { + skb = skb_share_check(skb, GFP_ATOMIC); + if (skb) { + if (!pskb_may_pull(skb, netoff + iph.ihl * 4)) { + kfree_skb(skb); + return NULL; + } + if (pskb_trim_rcsum(skb, netoff + len)) { + kfree_skb(skb); + return NULL; + } + memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); + if (ip_defrag(net, skb, user)) + return NULL; + skb_clear_hash(skb); + } + } + return skb; +} +EXPORT_SYMBOL(ip_check_defrag); + +#ifdef CONFIG_SYSCTL +static int dist_min; + +static struct ctl_table ip4_frags_ns_ctl_table[] = { + { + .procname = "ipfrag_high_thresh", + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, + { + .procname = "ipfrag_low_thresh", + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, + { + .procname = "ipfrag_time", + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "ipfrag_max_dist", + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &dist_min, + }, + { } +}; + +/* secret interval has been deprecated */ +static int ip4_frags_secret_interval_unused; +static struct ctl_table ip4_frags_ctl_table[] = { + { + .procname = "ipfrag_secret_interval", + .data = &ip4_frags_secret_interval_unused, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { } +}; + +static int __net_init ip4_frags_ns_ctl_register(struct net *net) +{ + struct ctl_table *table; + struct ctl_table_header *hdr; + + table = ip4_frags_ns_ctl_table; + if (!net_eq(net, &init_net)) { + table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL); + if (!table) + goto err_alloc; + + } + table[0].data = &net->ipv4.fqdir->high_thresh; + table[0].extra1 = &net->ipv4.fqdir->low_thresh; + table[1].data = &net->ipv4.fqdir->low_thresh; + table[1].extra2 = &net->ipv4.fqdir->high_thresh; + table[2].data = &net->ipv4.fqdir->timeout; + table[3].data = &net->ipv4.fqdir->max_dist; + + hdr = register_net_sysctl(net, "net/ipv4", table); + if (!hdr) + goto err_reg; + + net->ipv4.frags_hdr = hdr; + return 0; + +err_reg: + if (!net_eq(net, &init_net)) + kfree(table); +err_alloc: + return -ENOMEM; +} + +static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net) +{ + struct ctl_table *table; + + table = net->ipv4.frags_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->ipv4.frags_hdr); + kfree(table); +} + +static void __init ip4_frags_ctl_register(void) +{ + register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table); +} +#else +static int ip4_frags_ns_ctl_register(struct net *net) +{ + return 0; +} + +static void ip4_frags_ns_ctl_unregister(struct net *net) +{ +} + +static void __init ip4_frags_ctl_register(void) +{ +} +#endif + +static int __net_init ipv4_frags_init_net(struct net *net) +{ + int res; + + res = fqdir_init(&net->ipv4.fqdir, &ip4_frags, net); + if (res < 0) + return res; + /* Fragment cache limits. + * + * The fragment memory accounting code, (tries to) account for + * the real memory usage, by measuring both the size of frag + * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue)) + * and the SKB's truesize. + * + * A 64K fragment consumes 129736 bytes (44*2944)+200 + * (1500 truesize == 2944, sizeof(struct ipq) == 200) + * + * We will commit 4MB at one time. Should we cross that limit + * we will prune down to 3MB, making room for approx 8 big 64K + * fragments 8x128k. + */ + net->ipv4.fqdir->high_thresh = 4 * 1024 * 1024; + net->ipv4.fqdir->low_thresh = 3 * 1024 * 1024; + /* + * Important NOTE! Fragment queue must be destroyed before MSL expires. + * RFC791 is wrong proposing to prolongate timer each fragment arrival + * by TTL. + */ + net->ipv4.fqdir->timeout = IP_FRAG_TIME; + + net->ipv4.fqdir->max_dist = 64; + + res = ip4_frags_ns_ctl_register(net); + if (res < 0) + fqdir_exit(net->ipv4.fqdir); + return res; +} + +static void __net_exit ipv4_frags_pre_exit_net(struct net *net) +{ + fqdir_pre_exit(net->ipv4.fqdir); +} + +static void __net_exit ipv4_frags_exit_net(struct net *net) +{ + ip4_frags_ns_ctl_unregister(net); + fqdir_exit(net->ipv4.fqdir); +} + +static struct pernet_operations ip4_frags_ops = { + .init = ipv4_frags_init_net, + .pre_exit = ipv4_frags_pre_exit_net, + .exit = ipv4_frags_exit_net, +}; + + +static u32 ip4_key_hashfn(const void *data, u32 len, u32 seed) +{ + return jhash2(data, + sizeof(struct frag_v4_compare_key) / sizeof(u32), seed); +} + +static u32 ip4_obj_hashfn(const void *data, u32 len, u32 seed) +{ + const struct inet_frag_queue *fq = data; + + return jhash2((const u32 *)&fq->key.v4, + sizeof(struct frag_v4_compare_key) / sizeof(u32), seed); +} + +static int ip4_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr) +{ + const struct frag_v4_compare_key *key = arg->key; + const struct inet_frag_queue *fq = ptr; + + return !!memcmp(&fq->key, key, sizeof(*key)); +} + +static const struct rhashtable_params ip4_rhash_params = { + .head_offset = offsetof(struct inet_frag_queue, node), + .key_offset = offsetof(struct inet_frag_queue, key), + .key_len = sizeof(struct frag_v4_compare_key), + .hashfn = ip4_key_hashfn, + .obj_hashfn = ip4_obj_hashfn, + .obj_cmpfn = ip4_obj_cmpfn, + .automatic_shrinking = true, +}; + +void __init ipfrag_init(void) +{ + ip4_frags.constructor = ip4_frag_init; + ip4_frags.destructor = ip4_frag_free; + ip4_frags.qsize = sizeof(struct ipq); + ip4_frags.frag_expire = ip_expire; + ip4_frags.frags_cache_name = ip_frag_cache_name; + ip4_frags.rhash_params = ip4_rhash_params; + if (inet_frags_init(&ip4_frags)) + panic("IP: failed to allocate ip4_frags cache\n"); + ip4_frags_ctl_register(); + register_pernet_subsys(&ip4_frags_ops); +} diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c new file mode 100644 index 000000000..a6ad0fe13 --- /dev/null +++ b/net/ipv4/ip_gre.c @@ -0,0 +1,1801 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Linux NET3: GRE over IP protocol decoder. + * + * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/capability.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/in.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/if_arp.h> +#include <linux/if_vlan.h> +#include <linux/init.h> +#include <linux/in6.h> +#include <linux/inetdevice.h> +#include <linux/igmp.h> +#include <linux/netfilter_ipv4.h> +#include <linux/etherdevice.h> +#include <linux/if_ether.h> + +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/protocol.h> +#include <net/ip_tunnels.h> +#include <net/arp.h> +#include <net/checksum.h> +#include <net/dsfield.h> +#include <net/inet_ecn.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/rtnetlink.h> +#include <net/gre.h> +#include <net/dst_metadata.h> +#include <net/erspan.h> + +/* + Problems & solutions + -------------------- + + 1. The most important issue is detecting local dead loops. + They would cause complete host lockup in transmit, which + would be "resolved" by stack overflow or, if queueing is enabled, + with infinite looping in net_bh. + + We cannot track such dead loops during route installation, + it is infeasible task. The most general solutions would be + to keep skb->encapsulation counter (sort of local ttl), + and silently drop packet when it expires. It is a good + solution, but it supposes maintaining new variable in ALL + skb, even if no tunneling is used. + + Current solution: xmit_recursion breaks dead loops. This is a percpu + counter, since when we enter the first ndo_xmit(), cpu migration is + forbidden. We force an exit if this counter reaches RECURSION_LIMIT + + 2. Networking dead loops would not kill routers, but would really + kill network. IP hop limit plays role of "t->recursion" in this case, + if we copy it from packet being encapsulated to upper header. + It is very good solution, but it introduces two problems: + + - Routing protocols, using packets with ttl=1 (OSPF, RIP2), + do not work over tunnels. + - traceroute does not work. I planned to relay ICMP from tunnel, + so that this problem would be solved and traceroute output + would even more informative. This idea appeared to be wrong: + only Linux complies to rfc1812 now (yes, guys, Linux is the only + true router now :-)), all routers (at least, in neighbourhood of mine) + return only 8 bytes of payload. It is the end. + + Hence, if we want that OSPF worked or traceroute said something reasonable, + we should search for another solution. + + One of them is to parse packet trying to detect inner encapsulation + made by our node. It is difficult or even impossible, especially, + taking into account fragmentation. TO be short, ttl is not solution at all. + + Current solution: The solution was UNEXPECTEDLY SIMPLE. + We force DF flag on tunnels with preconfigured hop limit, + that is ALL. :-) Well, it does not remove the problem completely, + but exponential growth of network traffic is changed to linear + (branches, that exceed pmtu are pruned) and tunnel mtu + rapidly degrades to value <68, where looping stops. + Yes, it is not good if there exists a router in the loop, + which does not force DF, even when encapsulating packets have DF set. + But it is not our problem! Nobody could accuse us, we made + all that we could make. Even if it is your gated who injected + fatal route to network, even if it were you who configured + fatal static route: you are innocent. :-) + + Alexey Kuznetsov. + */ + +static bool log_ecn_error = true; +module_param(log_ecn_error, bool, 0644); +MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); + +static struct rtnl_link_ops ipgre_link_ops __read_mostly; +static int ipgre_tunnel_init(struct net_device *dev); +static void erspan_build_header(struct sk_buff *skb, + u32 id, u32 index, + bool truncate, bool is_ipv4); + +static unsigned int ipgre_net_id __read_mostly; +static unsigned int gre_tap_net_id __read_mostly; +static unsigned int erspan_net_id __read_mostly; + +static int ipgre_err(struct sk_buff *skb, u32 info, + const struct tnl_ptk_info *tpi) +{ + + /* All the routers (except for Linux) return only + 8 bytes of packet payload. It means, that precise relaying of + ICMP in the real Internet is absolutely infeasible. + + Moreover, Cisco "wise men" put GRE key to the third word + in GRE header. It makes impossible maintaining even soft + state for keyed GRE tunnels with enabled checksum. Tell + them "thank you". + + Well, I wonder, rfc1812 was written by Cisco employee, + what the hell these idiots break standards established + by themselves??? + */ + struct net *net = dev_net(skb->dev); + struct ip_tunnel_net *itn; + const struct iphdr *iph; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + unsigned int data_len = 0; + struct ip_tunnel *t; + + if (tpi->proto == htons(ETH_P_TEB)) + itn = net_generic(net, gre_tap_net_id); + else if (tpi->proto == htons(ETH_P_ERSPAN) || + tpi->proto == htons(ETH_P_ERSPAN2)) + itn = net_generic(net, erspan_net_id); + else + itn = net_generic(net, ipgre_net_id); + + iph = (const struct iphdr *)(icmp_hdr(skb) + 1); + t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, + iph->daddr, iph->saddr, tpi->key); + + if (!t) + return -ENOENT; + + switch (type) { + default: + case ICMP_PARAMETERPROB: + return 0; + + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + case ICMP_PORT_UNREACH: + /* Impossible event. */ + return 0; + default: + /* All others are translated to HOST_UNREACH. + rfc2003 contains "deep thoughts" about NET_UNREACH, + I believe they are just ether pollution. --ANK + */ + break; + } + break; + + case ICMP_TIME_EXCEEDED: + if (code != ICMP_EXC_TTL) + return 0; + data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ + break; + + case ICMP_REDIRECT: + break; + } + +#if IS_ENABLED(CONFIG_IPV6) + if (tpi->proto == htons(ETH_P_IPV6) && + !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len, + type, data_len)) + return 0; +#endif + + if (t->parms.iph.daddr == 0 || + ipv4_is_multicast(t->parms.iph.daddr)) + return 0; + + if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) + return 0; + + if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) + t->err_count++; + else + t->err_count = 1; + t->err_time = jiffies; + + return 0; +} + +static void gre_err(struct sk_buff *skb, u32 info) +{ + /* All the routers (except for Linux) return only + * 8 bytes of packet payload. It means, that precise relaying of + * ICMP in the real Internet is absolutely infeasible. + * + * Moreover, Cisco "wise men" put GRE key to the third word + * in GRE header. It makes impossible maintaining even soft + * state for keyed + * GRE tunnels with enabled checksum. Tell them "thank you". + * + * Well, I wonder, rfc1812 was written by Cisco employee, + * what the hell these idiots break standards established + * by themselves??? + */ + + const struct iphdr *iph = (struct iphdr *)skb->data; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + struct tnl_ptk_info tpi; + + if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP), + iph->ihl * 4) < 0) + return; + + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { + ipv4_update_pmtu(skb, dev_net(skb->dev), info, + skb->dev->ifindex, IPPROTO_GRE); + return; + } + if (type == ICMP_REDIRECT) { + ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, + IPPROTO_GRE); + return; + } + + ipgre_err(skb, info, &tpi); +} + +static bool is_erspan_type1(int gre_hdr_len) +{ + /* Both ERSPAN type I (version 0) and type II (version 1) use + * protocol 0x88BE, but the type I has only 4-byte GRE header, + * while type II has 8-byte. + */ + return gre_hdr_len == 4; +} + +static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, + int gre_hdr_len) +{ + struct net *net = dev_net(skb->dev); + struct metadata_dst *tun_dst = NULL; + struct erspan_base_hdr *ershdr; + struct ip_tunnel_net *itn; + struct ip_tunnel *tunnel; + const struct iphdr *iph; + struct erspan_md2 *md2; + int ver; + int len; + + itn = net_generic(net, erspan_net_id); + iph = ip_hdr(skb); + if (is_erspan_type1(gre_hdr_len)) { + ver = 0; + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, + tpi->flags | TUNNEL_NO_KEY, + iph->saddr, iph->daddr, 0); + } else { + ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); + ver = ershdr->ver; + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, + tpi->flags | TUNNEL_KEY, + iph->saddr, iph->daddr, tpi->key); + } + + if (tunnel) { + if (is_erspan_type1(gre_hdr_len)) + len = gre_hdr_len; + else + len = gre_hdr_len + erspan_hdr_len(ver); + + if (unlikely(!pskb_may_pull(skb, len))) + return PACKET_REJECT; + + if (__iptunnel_pull_header(skb, + len, + htons(ETH_P_TEB), + false, false) < 0) + goto drop; + + if (tunnel->collect_md) { + struct erspan_metadata *pkt_md, *md; + struct ip_tunnel_info *info; + unsigned char *gh; + __be64 tun_id; + __be16 flags; + + tpi->flags |= TUNNEL_KEY; + flags = tpi->flags; + tun_id = key32_to_tunnel_id(tpi->key); + + tun_dst = ip_tun_rx_dst(skb, flags, + tun_id, sizeof(*md)); + if (!tun_dst) + return PACKET_REJECT; + + /* skb can be uncloned in __iptunnel_pull_header, so + * old pkt_md is no longer valid and we need to reset + * it + */ + gh = skb_network_header(skb) + + skb_network_header_len(skb); + pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len + + sizeof(*ershdr)); + md = ip_tunnel_info_opts(&tun_dst->u.tun_info); + md->version = ver; + md2 = &md->u.md2; + memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE : + ERSPAN_V2_MDSIZE); + + info = &tun_dst->u.tun_info; + info->key.tun_flags |= TUNNEL_ERSPAN_OPT; + info->options_len = sizeof(*md); + } + + skb_reset_mac_header(skb); + ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); + return PACKET_RCVD; + } + return PACKET_REJECT; + +drop: + kfree_skb(skb); + return PACKET_RCVD; +} + +static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, + struct ip_tunnel_net *itn, int hdr_len, bool raw_proto) +{ + struct metadata_dst *tun_dst = NULL; + const struct iphdr *iph; + struct ip_tunnel *tunnel; + + iph = ip_hdr(skb); + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags, + iph->saddr, iph->daddr, tpi->key); + + if (tunnel) { + const struct iphdr *tnl_params; + + if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, + raw_proto, false) < 0) + goto drop; + + if (tunnel->dev->type != ARPHRD_NONE) + skb_pop_mac_header(skb); + else + skb_reset_mac_header(skb); + + tnl_params = &tunnel->parms.iph; + if (tunnel->collect_md || tnl_params->daddr == 0) { + __be16 flags; + __be64 tun_id; + + flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); + tun_id = key32_to_tunnel_id(tpi->key); + tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0); + if (!tun_dst) + return PACKET_REJECT; + } + + ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); + return PACKET_RCVD; + } + return PACKET_NEXT; + +drop: + kfree_skb(skb); + return PACKET_RCVD; +} + +static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, + int hdr_len) +{ + struct net *net = dev_net(skb->dev); + struct ip_tunnel_net *itn; + int res; + + if (tpi->proto == htons(ETH_P_TEB)) + itn = net_generic(net, gre_tap_net_id); + else + itn = net_generic(net, ipgre_net_id); + + res = __ipgre_rcv(skb, tpi, itn, hdr_len, false); + if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) { + /* ipgre tunnels in collect metadata mode should receive + * also ETH_P_TEB traffic. + */ + itn = net_generic(net, ipgre_net_id); + res = __ipgre_rcv(skb, tpi, itn, hdr_len, true); + } + return res; +} + +static int gre_rcv(struct sk_buff *skb) +{ + struct tnl_ptk_info tpi; + bool csum_err = false; + int hdr_len; + +#ifdef CONFIG_NET_IPGRE_BROADCAST + if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { + /* Looped back packet, drop it! */ + if (rt_is_output_route(skb_rtable(skb))) + goto drop; + } +#endif + + hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); + if (hdr_len < 0) + goto drop; + + if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || + tpi.proto == htons(ETH_P_ERSPAN2))) { + if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) + return 0; + goto out; + } + + if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) + return 0; + +out: + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); +drop: + kfree_skb(skb); + return 0; +} + +static void __gre_xmit(struct sk_buff *skb, struct net_device *dev, + const struct iphdr *tnl_params, + __be16 proto) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + __be16 flags = tunnel->parms.o_flags; + + /* Push GRE header. */ + gre_build_header(skb, tunnel->tun_hlen, + flags, proto, tunnel->parms.o_key, + (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); + + ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); +} + +static int gre_handle_offloads(struct sk_buff *skb, bool csum) +{ + return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); +} + +static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, + __be16 proto) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct ip_tunnel_info *tun_info; + const struct ip_tunnel_key *key; + int tunnel_hlen; + __be16 flags; + + tun_info = skb_tunnel_info(skb); + if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || + ip_tunnel_info_af(tun_info) != AF_INET)) + goto err_free_skb; + + key = &tun_info->key; + tunnel_hlen = gre_calc_hlen(key->tun_flags); + + if (skb_cow_head(skb, dev->needed_headroom)) + goto err_free_skb; + + /* Push Tunnel header. */ + if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) + goto err_free_skb; + + flags = tun_info->key.tun_flags & + (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ); + gre_build_header(skb, tunnel_hlen, flags, proto, + tunnel_id_to_key32(tun_info->key.tun_id), + (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0); + + ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); + + return; + +err_free_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; +} + +static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct ip_tunnel_info *tun_info; + const struct ip_tunnel_key *key; + struct erspan_metadata *md; + bool truncate = false; + __be16 proto; + int tunnel_hlen; + int version; + int nhoff; + + tun_info = skb_tunnel_info(skb); + if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || + ip_tunnel_info_af(tun_info) != AF_INET)) + goto err_free_skb; + + key = &tun_info->key; + if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)) + goto err_free_skb; + if (tun_info->options_len < sizeof(*md)) + goto err_free_skb; + md = ip_tunnel_info_opts(tun_info); + + /* ERSPAN has fixed 8 byte GRE header */ + version = md->version; + tunnel_hlen = 8 + erspan_hdr_len(version); + + if (skb_cow_head(skb, dev->needed_headroom)) + goto err_free_skb; + + if (gre_handle_offloads(skb, false)) + goto err_free_skb; + + if (skb->len > dev->mtu + dev->hard_header_len) { + pskb_trim(skb, dev->mtu + dev->hard_header_len); + truncate = true; + } + + nhoff = skb_network_offset(skb); + if (skb->protocol == htons(ETH_P_IP) && + (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) + truncate = true; + + if (skb->protocol == htons(ETH_P_IPV6)) { + int thoff; + + if (skb_transport_header_was_set(skb)) + thoff = skb_transport_offset(skb); + else + thoff = nhoff + sizeof(struct ipv6hdr); + if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) + truncate = true; + } + + if (version == 1) { + erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), + ntohl(md->u.index), truncate, true); + proto = htons(ETH_P_ERSPAN); + } else if (version == 2) { + erspan_build_header_v2(skb, + ntohl(tunnel_id_to_key32(key->tun_id)), + md->u.md2.dir, + get_hwid(&md->u.md2), + truncate, true); + proto = htons(ETH_P_ERSPAN2); + } else { + goto err_free_skb; + } + + gre_build_header(skb, 8, TUNNEL_SEQ, + proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno))); + + ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen); + + return; + +err_free_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; +} + +static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb) +{ + struct ip_tunnel_info *info = skb_tunnel_info(skb); + const struct ip_tunnel_key *key; + struct rtable *rt; + struct flowi4 fl4; + + if (ip_tunnel_info_af(info) != AF_INET) + return -EINVAL; + + key = &info->key; + ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src, + tunnel_id_to_key32(key->tun_id), + key->tos & ~INET_ECN_MASK, 0, skb->mark, + skb_get_hash(skb)); + rt = ip_route_output_key(dev_net(dev), &fl4); + if (IS_ERR(rt)) + return PTR_ERR(rt); + + ip_rt_put(rt); + info->key.u.ipv4.src = fl4.saddr; + return 0; +} + +static netdev_tx_t ipgre_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + const struct iphdr *tnl_params; + + if (!pskb_inet_may_pull(skb)) + goto free_skb; + + if (tunnel->collect_md) { + gre_fb_xmit(skb, dev, skb->protocol); + return NETDEV_TX_OK; + } + + if (dev->header_ops) { + int pull_len = tunnel->hlen + sizeof(struct iphdr); + + if (skb_cow_head(skb, 0)) + goto free_skb; + + tnl_params = (const struct iphdr *)skb->data; + + if (!pskb_network_may_pull(skb, pull_len)) + goto free_skb; + + /* ip_tunnel_xmit() needs skb->data pointing to gre header. */ + skb_pull(skb, pull_len); + skb_reset_mac_header(skb); + + if (skb->ip_summed == CHECKSUM_PARTIAL && + skb_checksum_start(skb) < skb->data) + goto free_skb; + } else { + if (skb_cow_head(skb, dev->needed_headroom)) + goto free_skb; + + tnl_params = &tunnel->parms.iph; + } + + if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) + goto free_skb; + + __gre_xmit(skb, dev, tnl_params, skb->protocol); + return NETDEV_TX_OK; + +free_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; + return NETDEV_TX_OK; +} + +static netdev_tx_t erspan_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + bool truncate = false; + __be16 proto; + + if (!pskb_inet_may_pull(skb)) + goto free_skb; + + if (tunnel->collect_md) { + erspan_fb_xmit(skb, dev); + return NETDEV_TX_OK; + } + + if (gre_handle_offloads(skb, false)) + goto free_skb; + + if (skb_cow_head(skb, dev->needed_headroom)) + goto free_skb; + + if (skb->len > dev->mtu + dev->hard_header_len) { + pskb_trim(skb, dev->mtu + dev->hard_header_len); + truncate = true; + } + + /* Push ERSPAN header */ + if (tunnel->erspan_ver == 0) { + proto = htons(ETH_P_ERSPAN); + tunnel->parms.o_flags &= ~TUNNEL_SEQ; + } else if (tunnel->erspan_ver == 1) { + erspan_build_header(skb, ntohl(tunnel->parms.o_key), + tunnel->index, + truncate, true); + proto = htons(ETH_P_ERSPAN); + } else if (tunnel->erspan_ver == 2) { + erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key), + tunnel->dir, tunnel->hwid, + truncate, true); + proto = htons(ETH_P_ERSPAN2); + } else { + goto free_skb; + } + + tunnel->parms.o_flags &= ~TUNNEL_KEY; + __gre_xmit(skb, dev, &tunnel->parms.iph, proto); + return NETDEV_TX_OK; + +free_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; + return NETDEV_TX_OK; +} + +static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + if (!pskb_inet_may_pull(skb)) + goto free_skb; + + if (tunnel->collect_md) { + gre_fb_xmit(skb, dev, htons(ETH_P_TEB)); + return NETDEV_TX_OK; + } + + if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM))) + goto free_skb; + + if (skb_cow_head(skb, dev->needed_headroom)) + goto free_skb; + + __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); + return NETDEV_TX_OK; + +free_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; + return NETDEV_TX_OK; +} + +static void ipgre_link_update(struct net_device *dev, bool set_mtu) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + int len; + + len = tunnel->tun_hlen; + tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); + len = tunnel->tun_hlen - len; + tunnel->hlen = tunnel->hlen + len; + + if (dev->header_ops) + dev->hard_header_len += len; + else + dev->needed_headroom += len; + + if (set_mtu) + dev->mtu = max_t(int, dev->mtu - len, 68); + + if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { + if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || + tunnel->encap.type == TUNNEL_ENCAP_NONE) { + dev->features |= NETIF_F_GSO_SOFTWARE; + dev->hw_features |= NETIF_F_GSO_SOFTWARE; + } else { + dev->features &= ~NETIF_F_GSO_SOFTWARE; + dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; + } + dev->features |= NETIF_F_LLTX; + } else { + dev->hw_features &= ~NETIF_F_GSO_SOFTWARE; + dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE); + } +} + +static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, + int cmd) +{ + int err; + + if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { + if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE || + p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) || + ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING))) + return -EINVAL; + } + + p->i_flags = gre_flags_to_tnl_flags(p->i_flags); + p->o_flags = gre_flags_to_tnl_flags(p->o_flags); + + err = ip_tunnel_ctl(dev, p, cmd); + if (err) + return err; + + if (cmd == SIOCCHGTUNNEL) { + struct ip_tunnel *t = netdev_priv(dev); + + t->parms.i_flags = p->i_flags; + t->parms.o_flags = p->o_flags; + + if (strcmp(dev->rtnl_link_ops->kind, "erspan")) + ipgre_link_update(dev, true); + } + + p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); + p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); + return 0; +} + +/* Nice toy. Unfortunately, useless in real life :-) + It allows to construct virtual multiprotocol broadcast "LAN" + over the Internet, provided multicast routing is tuned. + + + I have no idea was this bicycle invented before me, + so that I had to set ARPHRD_IPGRE to a random value. + I have an impression, that Cisco could make something similar, + but this feature is apparently missing in IOS<=11.2(8). + + I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks + with broadcast 224.66.66.66. If you have access to mbone, play with me :-) + + ping -t 255 224.66.66.66 + + If nobody answers, mbone does not work. + + ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255 + ip addr add 10.66.66.<somewhat>/24 dev Universe + ifconfig Universe up + ifconfig Universe add fe80::<Your_real_addr>/10 + ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96 + ftp 10.66.66.66 + ... + ftp fec0:6666:6666::193.233.7.65 + ... + */ +static int ipgre_header(struct sk_buff *skb, struct net_device *dev, + unsigned short type, + const void *daddr, const void *saddr, unsigned int len) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct iphdr *iph; + struct gre_base_hdr *greh; + + iph = skb_push(skb, t->hlen + sizeof(*iph)); + greh = (struct gre_base_hdr *)(iph+1); + greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags); + greh->protocol = htons(type); + + memcpy(iph, &t->parms.iph, sizeof(struct iphdr)); + + /* Set the source hardware address. */ + if (saddr) + memcpy(&iph->saddr, saddr, 4); + if (daddr) + memcpy(&iph->daddr, daddr, 4); + if (iph->daddr) + return t->hlen + sizeof(*iph); + + return -(t->hlen + sizeof(*iph)); +} + +static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) +{ + const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); + memcpy(haddr, &iph->saddr, 4); + return 4; +} + +static const struct header_ops ipgre_header_ops = { + .create = ipgre_header, + .parse = ipgre_header_parse, +}; + +#ifdef CONFIG_NET_IPGRE_BROADCAST +static int ipgre_open(struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + + if (ipv4_is_multicast(t->parms.iph.daddr)) { + struct flowi4 fl4; + struct rtable *rt; + + rt = ip_route_output_gre(t->net, &fl4, + t->parms.iph.daddr, + t->parms.iph.saddr, + t->parms.o_key, + RT_TOS(t->parms.iph.tos), + t->parms.link); + if (IS_ERR(rt)) + return -EADDRNOTAVAIL; + dev = rt->dst.dev; + ip_rt_put(rt); + if (!__in_dev_get_rtnl(dev)) + return -EADDRNOTAVAIL; + t->mlink = dev->ifindex; + ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr); + } + return 0; +} + +static int ipgre_close(struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + + if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) { + struct in_device *in_dev; + in_dev = inetdev_by_index(t->net, t->mlink); + if (in_dev) + ip_mc_dec_group(in_dev, t->parms.iph.daddr); + } + return 0; +} +#endif + +static const struct net_device_ops ipgre_netdev_ops = { + .ndo_init = ipgre_tunnel_init, + .ndo_uninit = ip_tunnel_uninit, +#ifdef CONFIG_NET_IPGRE_BROADCAST + .ndo_open = ipgre_open, + .ndo_stop = ipgre_close, +#endif + .ndo_start_xmit = ipgre_xmit, + .ndo_do_ioctl = ip_tunnel_ioctl, + .ndo_change_mtu = ip_tunnel_change_mtu, + .ndo_get_stats64 = ip_tunnel_get_stats64, + .ndo_get_iflink = ip_tunnel_get_iflink, + .ndo_tunnel_ctl = ipgre_tunnel_ctl, +}; + +#define GRE_FEATURES (NETIF_F_SG | \ + NETIF_F_FRAGLIST | \ + NETIF_F_HIGHDMA | \ + NETIF_F_HW_CSUM) + +static void ipgre_tunnel_setup(struct net_device *dev) +{ + dev->netdev_ops = &ipgre_netdev_ops; + dev->type = ARPHRD_IPGRE; + ip_tunnel_setup(dev, ipgre_net_id); +} + +static void __gre_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel; + + tunnel = netdev_priv(dev); + tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); + tunnel->parms.iph.protocol = IPPROTO_GRE; + + tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; + dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph); + + dev->features |= GRE_FEATURES; + dev->hw_features |= GRE_FEATURES; + + if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) { + /* TCP offload with GRE SEQ is not supported, nor + * can we support 2 levels of outer headers requiring + * an update. + */ + if (!(tunnel->parms.o_flags & TUNNEL_CSUM) || + (tunnel->encap.type == TUNNEL_ENCAP_NONE)) { + dev->features |= NETIF_F_GSO_SOFTWARE; + dev->hw_features |= NETIF_F_GSO_SOFTWARE; + } + + /* Can use a lockless transmit, unless we generate + * output sequences + */ + dev->features |= NETIF_F_LLTX; + } +} + +static int ipgre_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct iphdr *iph = &tunnel->parms.iph; + + __gre_tunnel_init(dev); + + memcpy(dev->dev_addr, &iph->saddr, 4); + memcpy(dev->broadcast, &iph->daddr, 4); + + dev->flags = IFF_NOARP; + netif_keep_dst(dev); + dev->addr_len = 4; + + if (iph->daddr && !tunnel->collect_md) { +#ifdef CONFIG_NET_IPGRE_BROADCAST + if (ipv4_is_multicast(iph->daddr)) { + if (!iph->saddr) + return -EINVAL; + dev->flags = IFF_BROADCAST; + dev->header_ops = &ipgre_header_ops; + dev->hard_header_len = tunnel->hlen + sizeof(*iph); + dev->needed_headroom = 0; + } +#endif + } else if (!tunnel->collect_md) { + dev->header_ops = &ipgre_header_ops; + dev->hard_header_len = tunnel->hlen + sizeof(*iph); + dev->needed_headroom = 0; + } + + return ip_tunnel_init(dev); +} + +static const struct gre_protocol ipgre_protocol = { + .handler = gre_rcv, + .err_handler = gre_err, +}; + +static int __net_init ipgre_init_net(struct net *net) +{ + return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL); +} + +static void __net_exit ipgre_exit_batch_net(struct list_head *list_net) +{ + ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops); +} + +static struct pernet_operations ipgre_net_ops = { + .init = ipgre_init_net, + .exit_batch = ipgre_exit_batch_net, + .id = &ipgre_net_id, + .size = sizeof(struct ip_tunnel_net), +}; + +static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + __be16 flags; + + if (!data) + return 0; + + flags = 0; + if (data[IFLA_GRE_IFLAGS]) + flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); + if (data[IFLA_GRE_OFLAGS]) + flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); + if (flags & (GRE_VERSION|GRE_ROUTING)) + return -EINVAL; + + if (data[IFLA_GRE_COLLECT_METADATA] && + data[IFLA_GRE_ENCAP_TYPE] && + nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) + return -EINVAL; + + return 0; +} + +static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + __be32 daddr; + + if (tb[IFLA_ADDRESS]) { + if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) + return -EINVAL; + if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) + return -EADDRNOTAVAIL; + } + + if (!data) + goto out; + + if (data[IFLA_GRE_REMOTE]) { + memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); + if (!daddr) + return -EINVAL; + } + +out: + return ipgre_tunnel_validate(tb, data, extack); +} + +static int erspan_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + __be16 flags = 0; + int ret; + + if (!data) + return 0; + + ret = ipgre_tap_validate(tb, data, extack); + if (ret) + return ret; + + if (data[IFLA_GRE_ERSPAN_VER] && + nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0) + return 0; + + /* ERSPAN type II/III should only have GRE sequence and key flag */ + if (data[IFLA_GRE_OFLAGS]) + flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); + if (data[IFLA_GRE_IFLAGS]) + flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); + if (!data[IFLA_GRE_COLLECT_METADATA] && + flags != (GRE_SEQ | GRE_KEY)) + return -EINVAL; + + /* ERSPAN Session ID only has 10-bit. Since we reuse + * 32-bit key field as ID, check it's range. + */ + if (data[IFLA_GRE_IKEY] && + (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK)) + return -EINVAL; + + if (data[IFLA_GRE_OKEY] && + (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK)) + return -EINVAL; + + return 0; +} + +static int ipgre_netlink_parms(struct net_device *dev, + struct nlattr *data[], + struct nlattr *tb[], + struct ip_tunnel_parm *parms, + __u32 *fwmark) +{ + struct ip_tunnel *t = netdev_priv(dev); + + memset(parms, 0, sizeof(*parms)); + + parms->iph.protocol = IPPROTO_GRE; + + if (!data) + return 0; + + if (data[IFLA_GRE_LINK]) + parms->link = nla_get_u32(data[IFLA_GRE_LINK]); + + if (data[IFLA_GRE_IFLAGS]) + parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS])); + + if (data[IFLA_GRE_OFLAGS]) + parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS])); + + if (data[IFLA_GRE_IKEY]) + parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); + + if (data[IFLA_GRE_OKEY]) + parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); + + if (data[IFLA_GRE_LOCAL]) + parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]); + + if (data[IFLA_GRE_REMOTE]) + parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]); + + if (data[IFLA_GRE_TTL]) + parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); + + if (data[IFLA_GRE_TOS]) + parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); + + if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) { + if (t->ignore_df) + return -EINVAL; + parms->iph.frag_off = htons(IP_DF); + } + + if (data[IFLA_GRE_COLLECT_METADATA]) { + t->collect_md = true; + if (dev->type == ARPHRD_IPGRE) + dev->type = ARPHRD_NONE; + } + + if (data[IFLA_GRE_IGNORE_DF]) { + if (nla_get_u8(data[IFLA_GRE_IGNORE_DF]) + && (parms->iph.frag_off & htons(IP_DF))) + return -EINVAL; + t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]); + } + + if (data[IFLA_GRE_FWMARK]) + *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); + + return 0; +} + +static int erspan_netlink_parms(struct net_device *dev, + struct nlattr *data[], + struct nlattr *tb[], + struct ip_tunnel_parm *parms, + __u32 *fwmark) +{ + struct ip_tunnel *t = netdev_priv(dev); + int err; + + err = ipgre_netlink_parms(dev, data, tb, parms, fwmark); + if (err) + return err; + if (!data) + return 0; + + if (data[IFLA_GRE_ERSPAN_VER]) { + t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]); + + if (t->erspan_ver > 2) + return -EINVAL; + } + + if (t->erspan_ver == 1) { + if (data[IFLA_GRE_ERSPAN_INDEX]) { + t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]); + if (t->index & ~INDEX_MASK) + return -EINVAL; + } + } else if (t->erspan_ver == 2) { + if (data[IFLA_GRE_ERSPAN_DIR]) { + t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]); + if (t->dir & ~(DIR_MASK >> DIR_OFFSET)) + return -EINVAL; + } + if (data[IFLA_GRE_ERSPAN_HWID]) { + t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]); + if (t->hwid & ~(HWID_MASK >> HWID_OFFSET)) + return -EINVAL; + } + } + + return 0; +} + +/* This function returns true when ENCAP attributes are present in the nl msg */ +static bool ipgre_netlink_encap_parms(struct nlattr *data[], + struct ip_tunnel_encap *ipencap) +{ + bool ret = false; + + memset(ipencap, 0, sizeof(*ipencap)); + + if (!data) + return ret; + + if (data[IFLA_GRE_ENCAP_TYPE]) { + ret = true; + ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); + } + + if (data[IFLA_GRE_ENCAP_FLAGS]) { + ret = true; + ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); + } + + if (data[IFLA_GRE_ENCAP_SPORT]) { + ret = true; + ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); + } + + if (data[IFLA_GRE_ENCAP_DPORT]) { + ret = true; + ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); + } + + return ret; +} + +static int gre_tap_init(struct net_device *dev) +{ + __gre_tunnel_init(dev); + dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; + netif_keep_dst(dev); + + return ip_tunnel_init(dev); +} + +static const struct net_device_ops gre_tap_netdev_ops = { + .ndo_init = gre_tap_init, + .ndo_uninit = ip_tunnel_uninit, + .ndo_start_xmit = gre_tap_xmit, + .ndo_set_mac_address = eth_mac_addr, + .ndo_validate_addr = eth_validate_addr, + .ndo_change_mtu = ip_tunnel_change_mtu, + .ndo_get_stats64 = ip_tunnel_get_stats64, + .ndo_get_iflink = ip_tunnel_get_iflink, + .ndo_fill_metadata_dst = gre_fill_metadata_dst, +}; + +static int erspan_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + if (tunnel->erspan_ver == 0) + tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */ + else + tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */ + + tunnel->parms.iph.protocol = IPPROTO_GRE; + tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen + + erspan_hdr_len(tunnel->erspan_ver); + + dev->features |= GRE_FEATURES; + dev->hw_features |= GRE_FEATURES; + dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; + netif_keep_dst(dev); + + return ip_tunnel_init(dev); +} + +static const struct net_device_ops erspan_netdev_ops = { + .ndo_init = erspan_tunnel_init, + .ndo_uninit = ip_tunnel_uninit, + .ndo_start_xmit = erspan_xmit, + .ndo_set_mac_address = eth_mac_addr, + .ndo_validate_addr = eth_validate_addr, + .ndo_change_mtu = ip_tunnel_change_mtu, + .ndo_get_stats64 = ip_tunnel_get_stats64, + .ndo_get_iflink = ip_tunnel_get_iflink, + .ndo_fill_metadata_dst = gre_fill_metadata_dst, +}; + +static void ipgre_tap_setup(struct net_device *dev) +{ + ether_setup(dev); + dev->max_mtu = 0; + dev->netdev_ops = &gre_tap_netdev_ops; + dev->priv_flags &= ~IFF_TX_SKB_SHARING; + dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; + ip_tunnel_setup(dev, gre_tap_net_id); +} + +static int +ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[]) +{ + struct ip_tunnel_encap ipencap; + + if (ipgre_netlink_encap_parms(data, &ipencap)) { + struct ip_tunnel *t = netdev_priv(dev); + int err = ip_tunnel_encap_setup(t, &ipencap); + + if (err < 0) + return err; + } + + return 0; +} + +static int ipgre_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel_parm p; + __u32 fwmark = 0; + int err; + + err = ipgre_newlink_encap_setup(dev, data); + if (err) + return err; + + err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); + if (err < 0) + return err; + return ip_tunnel_newlink(dev, tb, &p, fwmark); +} + +static int erspan_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel_parm p; + __u32 fwmark = 0; + int err; + + err = ipgre_newlink_encap_setup(dev, data); + if (err) + return err; + + err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); + if (err) + return err; + return ip_tunnel_newlink(dev, tb, &p, fwmark); +} + +static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel *t = netdev_priv(dev); + __u32 fwmark = t->fwmark; + struct ip_tunnel_parm p; + int err; + + err = ipgre_newlink_encap_setup(dev, data); + if (err) + return err; + + err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark); + if (err < 0) + return err; + + err = ip_tunnel_changelink(dev, tb, &p, fwmark); + if (err < 0) + return err; + + t->parms.i_flags = p.i_flags; + t->parms.o_flags = p.o_flags; + + ipgre_link_update(dev, !tb[IFLA_MTU]); + + return 0; +} + +static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel *t = netdev_priv(dev); + __u32 fwmark = t->fwmark; + struct ip_tunnel_parm p; + int err; + + err = ipgre_newlink_encap_setup(dev, data); + if (err) + return err; + + err = erspan_netlink_parms(dev, data, tb, &p, &fwmark); + if (err < 0) + return err; + + err = ip_tunnel_changelink(dev, tb, &p, fwmark); + if (err < 0) + return err; + + t->parms.i_flags = p.i_flags; + t->parms.o_flags = p.o_flags; + + return 0; +} + +static size_t ipgre_get_size(const struct net_device *dev) +{ + return + /* IFLA_GRE_LINK */ + nla_total_size(4) + + /* IFLA_GRE_IFLAGS */ + nla_total_size(2) + + /* IFLA_GRE_OFLAGS */ + nla_total_size(2) + + /* IFLA_GRE_IKEY */ + nla_total_size(4) + + /* IFLA_GRE_OKEY */ + nla_total_size(4) + + /* IFLA_GRE_LOCAL */ + nla_total_size(4) + + /* IFLA_GRE_REMOTE */ + nla_total_size(4) + + /* IFLA_GRE_TTL */ + nla_total_size(1) + + /* IFLA_GRE_TOS */ + nla_total_size(1) + + /* IFLA_GRE_PMTUDISC */ + nla_total_size(1) + + /* IFLA_GRE_ENCAP_TYPE */ + nla_total_size(2) + + /* IFLA_GRE_ENCAP_FLAGS */ + nla_total_size(2) + + /* IFLA_GRE_ENCAP_SPORT */ + nla_total_size(2) + + /* IFLA_GRE_ENCAP_DPORT */ + nla_total_size(2) + + /* IFLA_GRE_COLLECT_METADATA */ + nla_total_size(0) + + /* IFLA_GRE_IGNORE_DF */ + nla_total_size(1) + + /* IFLA_GRE_FWMARK */ + nla_total_size(4) + + /* IFLA_GRE_ERSPAN_INDEX */ + nla_total_size(4) + + /* IFLA_GRE_ERSPAN_VER */ + nla_total_size(1) + + /* IFLA_GRE_ERSPAN_DIR */ + nla_total_size(1) + + /* IFLA_GRE_ERSPAN_HWID */ + nla_total_size(2) + + 0; +} + +static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_parm *p = &t->parms; + __be16 o_flags = p->o_flags; + + if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || + nla_put_be16(skb, IFLA_GRE_IFLAGS, + gre_tnl_flags_to_gre_flags(p->i_flags)) || + nla_put_be16(skb, IFLA_GRE_OFLAGS, + gre_tnl_flags_to_gre_flags(o_flags)) || + nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || + nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || + nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) || + nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) || + nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) || + nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) || + nla_put_u8(skb, IFLA_GRE_PMTUDISC, + !!(p->iph.frag_off & htons(IP_DF))) || + nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark)) + goto nla_put_failure; + + if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, + t->encap.type) || + nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, + t->encap.sport) || + nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, + t->encap.dport) || + nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, + t->encap.flags)) + goto nla_put_failure; + + if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df)) + goto nla_put_failure; + + if (t->collect_md) { + if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA)) + goto nla_put_failure; + } + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + + if (t->erspan_ver <= 2) { + if (t->erspan_ver != 0 && !t->collect_md) + t->parms.o_flags |= TUNNEL_KEY; + + if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver)) + goto nla_put_failure; + + if (t->erspan_ver == 1) { + if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index)) + goto nla_put_failure; + } else if (t->erspan_ver == 2) { + if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir)) + goto nla_put_failure; + if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid)) + goto nla_put_failure; + } + } + + return ipgre_fill_info(skb, dev); + +nla_put_failure: + return -EMSGSIZE; +} + +static void erspan_setup(struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + + ether_setup(dev); + dev->max_mtu = 0; + dev->netdev_ops = &erspan_netdev_ops; + dev->priv_flags &= ~IFF_TX_SKB_SHARING; + dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; + ip_tunnel_setup(dev, erspan_net_id); + t->erspan_ver = 1; +} + +static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { + [IFLA_GRE_LINK] = { .type = NLA_U32 }, + [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, + [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, + [IFLA_GRE_IKEY] = { .type = NLA_U32 }, + [IFLA_GRE_OKEY] = { .type = NLA_U32 }, + [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, + [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, + [IFLA_GRE_TTL] = { .type = NLA_U8 }, + [IFLA_GRE_TOS] = { .type = NLA_U8 }, + [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, + [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, + [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, + [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, + [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, + [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG }, + [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 }, + [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, + [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 }, + [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 }, + [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 }, + [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 }, +}; + +static struct rtnl_link_ops ipgre_link_ops __read_mostly = { + .kind = "gre", + .maxtype = IFLA_GRE_MAX, + .policy = ipgre_policy, + .priv_size = sizeof(struct ip_tunnel), + .setup = ipgre_tunnel_setup, + .validate = ipgre_tunnel_validate, + .newlink = ipgre_newlink, + .changelink = ipgre_changelink, + .dellink = ip_tunnel_dellink, + .get_size = ipgre_get_size, + .fill_info = ipgre_fill_info, + .get_link_net = ip_tunnel_get_link_net, +}; + +static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { + .kind = "gretap", + .maxtype = IFLA_GRE_MAX, + .policy = ipgre_policy, + .priv_size = sizeof(struct ip_tunnel), + .setup = ipgre_tap_setup, + .validate = ipgre_tap_validate, + .newlink = ipgre_newlink, + .changelink = ipgre_changelink, + .dellink = ip_tunnel_dellink, + .get_size = ipgre_get_size, + .fill_info = ipgre_fill_info, + .get_link_net = ip_tunnel_get_link_net, +}; + +static struct rtnl_link_ops erspan_link_ops __read_mostly = { + .kind = "erspan", + .maxtype = IFLA_GRE_MAX, + .policy = ipgre_policy, + .priv_size = sizeof(struct ip_tunnel), + .setup = erspan_setup, + .validate = erspan_validate, + .newlink = erspan_newlink, + .changelink = erspan_changelink, + .dellink = ip_tunnel_dellink, + .get_size = ipgre_get_size, + .fill_info = erspan_fill_info, + .get_link_net = ip_tunnel_get_link_net, +}; + +struct net_device *gretap_fb_dev_create(struct net *net, const char *name, + u8 name_assign_type) +{ + struct nlattr *tb[IFLA_MAX + 1]; + struct net_device *dev; + LIST_HEAD(list_kill); + struct ip_tunnel *t; + int err; + + memset(&tb, 0, sizeof(tb)); + + dev = rtnl_create_link(net, name, name_assign_type, + &ipgre_tap_ops, tb, NULL); + if (IS_ERR(dev)) + return dev; + + /* Configure flow based GRE device. */ + t = netdev_priv(dev); + t->collect_md = true; + + err = ipgre_newlink(net, dev, tb, NULL, NULL); + if (err < 0) { + free_netdev(dev); + return ERR_PTR(err); + } + + /* openvswitch users expect packet sizes to be unrestricted, + * so set the largest MTU we can. + */ + err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false); + if (err) + goto out; + + err = rtnl_configure_link(dev, NULL); + if (err < 0) + goto out; + + return dev; +out: + ip_tunnel_dellink(dev, &list_kill); + unregister_netdevice_many(&list_kill); + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(gretap_fb_dev_create); + +static int __net_init ipgre_tap_init_net(struct net *net) +{ + return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); +} + +static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net) +{ + ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops); +} + +static struct pernet_operations ipgre_tap_net_ops = { + .init = ipgre_tap_init_net, + .exit_batch = ipgre_tap_exit_batch_net, + .id = &gre_tap_net_id, + .size = sizeof(struct ip_tunnel_net), +}; + +static int __net_init erspan_init_net(struct net *net) +{ + return ip_tunnel_init_net(net, erspan_net_id, + &erspan_link_ops, "erspan0"); +} + +static void __net_exit erspan_exit_batch_net(struct list_head *net_list) +{ + ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops); +} + +static struct pernet_operations erspan_net_ops = { + .init = erspan_init_net, + .exit_batch = erspan_exit_batch_net, + .id = &erspan_net_id, + .size = sizeof(struct ip_tunnel_net), +}; + +static int __init ipgre_init(void) +{ + int err; + + pr_info("GRE over IPv4 tunneling driver\n"); + + err = register_pernet_device(&ipgre_net_ops); + if (err < 0) + return err; + + err = register_pernet_device(&ipgre_tap_net_ops); + if (err < 0) + goto pnet_tap_failed; + + err = register_pernet_device(&erspan_net_ops); + if (err < 0) + goto pnet_erspan_failed; + + err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); + if (err < 0) { + pr_info("%s: can't add protocol\n", __func__); + goto add_proto_failed; + } + + err = rtnl_link_register(&ipgre_link_ops); + if (err < 0) + goto rtnl_link_failed; + + err = rtnl_link_register(&ipgre_tap_ops); + if (err < 0) + goto tap_ops_failed; + + err = rtnl_link_register(&erspan_link_ops); + if (err < 0) + goto erspan_link_failed; + + return 0; + +erspan_link_failed: + rtnl_link_unregister(&ipgre_tap_ops); +tap_ops_failed: + rtnl_link_unregister(&ipgre_link_ops); +rtnl_link_failed: + gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); +add_proto_failed: + unregister_pernet_device(&erspan_net_ops); +pnet_erspan_failed: + unregister_pernet_device(&ipgre_tap_net_ops); +pnet_tap_failed: + unregister_pernet_device(&ipgre_net_ops); + return err; +} + +static void __exit ipgre_fini(void) +{ + rtnl_link_unregister(&ipgre_tap_ops); + rtnl_link_unregister(&ipgre_link_ops); + rtnl_link_unregister(&erspan_link_ops); + gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); + unregister_pernet_device(&ipgre_tap_net_ops); + unregister_pernet_device(&ipgre_net_ops); + unregister_pernet_device(&erspan_net_ops); +} + +module_init(ipgre_init); +module_exit(ipgre_fini); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK("gre"); +MODULE_ALIAS_RTNL_LINK("gretap"); +MODULE_ALIAS_RTNL_LINK("erspan"); +MODULE_ALIAS_NETDEV("gre0"); +MODULE_ALIAS_NETDEV("gretap0"); +MODULE_ALIAS_NETDEV("erspan0"); diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c new file mode 100644 index 000000000..372579686 --- /dev/null +++ b/net/ipv4/ip_input.c @@ -0,0 +1,657 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The Internet Protocol (IP) module. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Donald Becker, <becker@super.org> + * Alan Cox, <alan@lxorguk.ukuu.org.uk> + * Richard Underwood + * Stefan Becker, <stefanb@yello.ping.de> + * Jorge Cwik, <jorge@laser.satlink.net> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * + * Fixes: + * Alan Cox : Commented a couple of minor bits of surplus code + * Alan Cox : Undefining IP_FORWARD doesn't include the code + * (just stops a compiler warning). + * Alan Cox : Frames with >=MAX_ROUTE record routes, strict routes or loose routes + * are junked rather than corrupting things. + * Alan Cox : Frames to bad broadcast subnets are dumped + * We used to process them non broadcast and + * boy could that cause havoc. + * Alan Cox : ip_forward sets the free flag on the + * new frame it queues. Still crap because + * it copies the frame but at least it + * doesn't eat memory too. + * Alan Cox : Generic queue code and memory fixes. + * Fred Van Kempen : IP fragment support (borrowed from NET2E) + * Gerhard Koerting: Forward fragmented frames correctly. + * Gerhard Koerting: Fixes to my fix of the above 8-). + * Gerhard Koerting: IP interface addressing fix. + * Linus Torvalds : More robustness checks + * Alan Cox : Even more checks: Still not as robust as it ought to be + * Alan Cox : Save IP header pointer for later + * Alan Cox : ip option setting + * Alan Cox : Use ip_tos/ip_ttl settings + * Alan Cox : Fragmentation bogosity removed + * (Thanks to Mark.Bush@prg.ox.ac.uk) + * Dmitry Gorodchanin : Send of a raw packet crash fix. + * Alan Cox : Silly ip bug when an overlength + * fragment turns up. Now frees the + * queue. + * Linus Torvalds/ : Memory leakage on fragmentation + * Alan Cox : handling. + * Gerhard Koerting: Forwarding uses IP priority hints + * Teemu Rantanen : Fragment problems. + * Alan Cox : General cleanup, comments and reformat + * Alan Cox : SNMP statistics + * Alan Cox : BSD address rule semantics. Also see + * UDP as there is a nasty checksum issue + * if you do things the wrong way. + * Alan Cox : Always defrag, moved IP_FORWARD to the config.in file + * Alan Cox : IP options adjust sk->priority. + * Pedro Roque : Fix mtu/length error in ip_forward. + * Alan Cox : Avoid ip_chk_addr when possible. + * Richard Underwood : IP multicasting. + * Alan Cox : Cleaned up multicast handlers. + * Alan Cox : RAW sockets demultiplex in the BSD style. + * Gunther Mayer : Fix the SNMP reporting typo + * Alan Cox : Always in group 224.0.0.1 + * Pauline Middelink : Fast ip_checksum update when forwarding + * Masquerading support. + * Alan Cox : Multicast loopback error for 224.0.0.1 + * Alan Cox : IP_MULTICAST_LOOP option. + * Alan Cox : Use notifiers. + * Bjorn Ekwall : Removed ip_csum (from slhc.c too) + * Bjorn Ekwall : Moved ip_fast_csum to ip.h (inline!) + * Stefan Becker : Send out ICMP HOST REDIRECT + * Arnt Gulbrandsen : ip_build_xmit + * Alan Cox : Per socket routing cache + * Alan Cox : Fixed routing cache, added header cache. + * Alan Cox : Loopback didn't work right in original ip_build_xmit - fixed it. + * Alan Cox : Only send ICMP_REDIRECT if src/dest are the same net. + * Alan Cox : Incoming IP option handling. + * Alan Cox : Set saddr on raw output frames as per BSD. + * Alan Cox : Stopped broadcast source route explosions. + * Alan Cox : Can disable source routing + * Takeshi Sone : Masquerading didn't work. + * Dave Bonn,Alan Cox : Faster IP forwarding whenever possible. + * Alan Cox : Memory leaks, tramples, misc debugging. + * Alan Cox : Fixed multicast (by popular demand 8)) + * Alan Cox : Fixed forwarding (by even more popular demand 8)) + * Alan Cox : Fixed SNMP statistics [I think] + * Gerhard Koerting : IP fragmentation forwarding fix + * Alan Cox : Device lock against page fault. + * Alan Cox : IP_HDRINCL facility. + * Werner Almesberger : Zero fragment bug + * Alan Cox : RAW IP frame length bug + * Alan Cox : Outgoing firewall on build_xmit + * A.N.Kuznetsov : IP_OPTIONS support throughout the kernel + * Alan Cox : Multicast routing hooks + * Jos Vos : Do accounting *before* call_in_firewall + * Willy Konynenberg : Transparent proxying support + * + * To Fix: + * IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient + * and could be made very efficient with the addition of some virtual memory hacks to permit + * the allocation of a buffer that can then be 'grown' by twiddling page tables. + * Output fragmentation wants updating along with the buffer management to use a single + * interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet + * output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause + * fragmentation anyway. + */ + +#define pr_fmt(fmt) "IPv4: " fmt + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/slab.h> + +#include <linux/net.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/indirect_call_wrapper.h> + +#include <net/snmp.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/route.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/arp.h> +#include <net/icmp.h> +#include <net/raw.h> +#include <net/checksum.h> +#include <net/inet_ecn.h> +#include <linux/netfilter_ipv4.h> +#include <net/xfrm.h> +#include <linux/mroute.h> +#include <linux/netlink.h> +#include <net/dst_metadata.h> + +/* + * Process Router Attention IP option (RFC 2113) + */ +bool ip_call_ra_chain(struct sk_buff *skb) +{ + struct ip_ra_chain *ra; + u8 protocol = ip_hdr(skb)->protocol; + struct sock *last = NULL; + struct net_device *dev = skb->dev; + struct net *net = dev_net(dev); + + for (ra = rcu_dereference(net->ipv4.ra_chain); ra; ra = rcu_dereference(ra->next)) { + struct sock *sk = ra->sk; + + /* If socket is bound to an interface, only report + * the packet if it came from that interface. + */ + if (sk && inet_sk(sk)->inet_num == protocol && + (!sk->sk_bound_dev_if || + sk->sk_bound_dev_if == dev->ifindex)) { + if (ip_is_fragment(ip_hdr(skb))) { + if (ip_defrag(net, skb, IP_DEFRAG_CALL_RA_CHAIN)) + return true; + } + if (last) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + if (skb2) + raw_rcv(last, skb2); + } + last = sk; + } + } + + if (last) { + raw_rcv(last, skb); + return true; + } + return false; +} + +INDIRECT_CALLABLE_DECLARE(int udp_rcv(struct sk_buff *)); +INDIRECT_CALLABLE_DECLARE(int tcp_v4_rcv(struct sk_buff *)); +void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol) +{ + const struct net_protocol *ipprot; + int raw, ret; + +resubmit: + raw = raw_local_deliver(skb, protocol); + + ipprot = rcu_dereference(inet_protos[protocol]); + if (ipprot) { + if (!ipprot->no_policy) { + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { + kfree_skb(skb); + return; + } + nf_reset_ct(skb); + } + ret = INDIRECT_CALL_2(ipprot->handler, tcp_v4_rcv, udp_rcv, + skb); + if (ret < 0) { + protocol = -ret; + goto resubmit; + } + __IP_INC_STATS(net, IPSTATS_MIB_INDELIVERS); + } else { + if (!raw) { + if (xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { + __IP_INC_STATS(net, IPSTATS_MIB_INUNKNOWNPROTOS); + icmp_send(skb, ICMP_DEST_UNREACH, + ICMP_PROT_UNREACH, 0); + } + kfree_skb(skb); + } else { + __IP_INC_STATS(net, IPSTATS_MIB_INDELIVERS); + consume_skb(skb); + } + } +} + +static int ip_local_deliver_finish(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + __skb_pull(skb, skb_network_header_len(skb)); + + rcu_read_lock(); + ip_protocol_deliver_rcu(net, skb, ip_hdr(skb)->protocol); + rcu_read_unlock(); + + return 0; +} + +/* + * Deliver IP Packets to the higher protocol layers. + */ +int ip_local_deliver(struct sk_buff *skb) +{ + /* + * Reassemble IP fragments. + */ + struct net *net = dev_net(skb->dev); + + if (ip_is_fragment(ip_hdr(skb))) { + if (ip_defrag(net, skb, IP_DEFRAG_LOCAL_DELIVER)) + return 0; + } + + return NF_HOOK(NFPROTO_IPV4, NF_INET_LOCAL_IN, + net, NULL, skb, skb->dev, NULL, + ip_local_deliver_finish); +} + +static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev) +{ + struct ip_options *opt; + const struct iphdr *iph; + + /* It looks as overkill, because not all + IP options require packet mangling. + But it is the easiest for now, especially taking + into account that combination of IP options + and running sniffer is extremely rare condition. + --ANK (980813) + */ + if (skb_cow(skb, skb_headroom(skb))) { + __IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INDISCARDS); + goto drop; + } + + iph = ip_hdr(skb); + opt = &(IPCB(skb)->opt); + opt->optlen = iph->ihl*4 - sizeof(struct iphdr); + + if (ip_options_compile(dev_net(dev), opt, skb)) { + __IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INHDRERRORS); + goto drop; + } + + if (unlikely(opt->srr)) { + struct in_device *in_dev = __in_dev_get_rcu(dev); + + if (in_dev) { + if (!IN_DEV_SOURCE_ROUTE(in_dev)) { + if (IN_DEV_LOG_MARTIANS(in_dev)) + net_info_ratelimited("source route option %pI4 -> %pI4\n", + &iph->saddr, + &iph->daddr); + goto drop; + } + } + + if (ip_options_rcv_srr(skb, dev)) + goto drop; + } + + return false; +drop: + return true; +} + +static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph, + const struct sk_buff *hint) +{ + return hint && !skb_dst(skb) && ip_hdr(hint)->daddr == iph->daddr && + ip_hdr(hint)->tos == iph->tos; +} + +int tcp_v4_early_demux(struct sk_buff *skb); +int udp_v4_early_demux(struct sk_buff *skb); +static int ip_rcv_finish_core(struct net *net, struct sock *sk, + struct sk_buff *skb, struct net_device *dev, + const struct sk_buff *hint) +{ + const struct iphdr *iph = ip_hdr(skb); + struct rtable *rt; + int err; + + if (ip_can_use_hint(skb, iph, hint)) { + err = ip_route_use_hint(skb, iph->daddr, iph->saddr, iph->tos, + dev, hint); + if (unlikely(err)) + goto drop_error; + } + + if (READ_ONCE(net->ipv4.sysctl_ip_early_demux) && + !skb_dst(skb) && + !skb->sk && + !ip_is_fragment(iph)) { + switch (iph->protocol) { + case IPPROTO_TCP: + if (READ_ONCE(net->ipv4.sysctl_tcp_early_demux)) { + tcp_v4_early_demux(skb); + + /* must reload iph, skb->head might have changed */ + iph = ip_hdr(skb); + } + break; + case IPPROTO_UDP: + if (READ_ONCE(net->ipv4.sysctl_udp_early_demux)) { + err = udp_v4_early_demux(skb); + if (unlikely(err)) + goto drop_error; + + /* must reload iph, skb->head might have changed */ + iph = ip_hdr(skb); + } + break; + } + } + + /* + * Initialise the virtual path cache for the packet. It describes + * how the packet travels inside Linux networking. + */ + if (!skb_valid_dst(skb)) { + err = ip_route_input_noref(skb, iph->daddr, iph->saddr, + iph->tos, dev); + if (unlikely(err)) + goto drop_error; + } else { + struct in_device *in_dev = __in_dev_get_rcu(dev); + + if (in_dev && IN_DEV_ORCONF(in_dev, NOPOLICY)) + IPCB(skb)->flags |= IPSKB_NOPOLICY; + } + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (unlikely(skb_dst(skb)->tclassid)) { + struct ip_rt_acct *st = this_cpu_ptr(ip_rt_acct); + u32 idx = skb_dst(skb)->tclassid; + st[idx&0xFF].o_packets++; + st[idx&0xFF].o_bytes += skb->len; + st[(idx>>16)&0xFF].i_packets++; + st[(idx>>16)&0xFF].i_bytes += skb->len; + } +#endif + + if (iph->ihl > 5 && ip_rcv_options(skb, dev)) + goto drop; + + rt = skb_rtable(skb); + if (rt->rt_type == RTN_MULTICAST) { + __IP_UPD_PO_STATS(net, IPSTATS_MIB_INMCAST, skb->len); + } else if (rt->rt_type == RTN_BROADCAST) { + __IP_UPD_PO_STATS(net, IPSTATS_MIB_INBCAST, skb->len); + } else if (skb->pkt_type == PACKET_BROADCAST || + skb->pkt_type == PACKET_MULTICAST) { + struct in_device *in_dev = __in_dev_get_rcu(dev); + + /* RFC 1122 3.3.6: + * + * When a host sends a datagram to a link-layer broadcast + * address, the IP destination address MUST be a legal IP + * broadcast or IP multicast address. + * + * A host SHOULD silently discard a datagram that is received + * via a link-layer broadcast (see Section 2.4) but does not + * specify an IP multicast or broadcast destination address. + * + * This doesn't explicitly say L2 *broadcast*, but broadcast is + * in a way a form of multicast and the most common use case for + * this is 802.11 protecting against cross-station spoofing (the + * so-called "hole-196" attack) so do it for both. + */ + if (in_dev && + IN_DEV_ORCONF(in_dev, DROP_UNICAST_IN_L2_MULTICAST)) + goto drop; + } + + return NET_RX_SUCCESS; + +drop: + kfree_skb(skb); + return NET_RX_DROP; + +drop_error: + if (err == -EXDEV) + __NET_INC_STATS(net, LINUX_MIB_IPRPFILTER); + goto drop; +} + +static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + int ret; + + /* if ingress device is enslaved to an L3 master device pass the + * skb to its handler for processing + */ + skb = l3mdev_ip_rcv(skb); + if (!skb) + return NET_RX_SUCCESS; + + ret = ip_rcv_finish_core(net, sk, skb, dev, NULL); + if (ret != NET_RX_DROP) + ret = dst_input(skb); + return ret; +} + +/* + * Main IP Receive routine. + */ +static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net) +{ + const struct iphdr *iph; + u32 len; + + /* When the interface is in promisc. mode, drop all the crap + * that it receives, do not try to analyse it. + */ + if (skb->pkt_type == PACKET_OTHERHOST) + goto drop; + + __IP_UPD_PO_STATS(net, IPSTATS_MIB_IN, skb->len); + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) { + __IP_INC_STATS(net, IPSTATS_MIB_INDISCARDS); + goto out; + } + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + goto inhdr_error; + + iph = ip_hdr(skb); + + /* + * RFC1122: 3.2.1.2 MUST silently discard any IP frame that fails the checksum. + * + * Is the datagram acceptable? + * + * 1. Length at least the size of an ip header + * 2. Version of 4 + * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums] + * 4. Doesn't have a bogus length + */ + + if (iph->ihl < 5 || iph->version != 4) + goto inhdr_error; + + BUILD_BUG_ON(IPSTATS_MIB_ECT1PKTS != IPSTATS_MIB_NOECTPKTS + INET_ECN_ECT_1); + BUILD_BUG_ON(IPSTATS_MIB_ECT0PKTS != IPSTATS_MIB_NOECTPKTS + INET_ECN_ECT_0); + BUILD_BUG_ON(IPSTATS_MIB_CEPKTS != IPSTATS_MIB_NOECTPKTS + INET_ECN_CE); + __IP_ADD_STATS(net, + IPSTATS_MIB_NOECTPKTS + (iph->tos & INET_ECN_MASK), + max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs)); + + if (!pskb_may_pull(skb, iph->ihl*4)) + goto inhdr_error; + + iph = ip_hdr(skb); + + if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) + goto csum_error; + + len = ntohs(iph->tot_len); + if (skb->len < len) { + __IP_INC_STATS(net, IPSTATS_MIB_INTRUNCATEDPKTS); + goto drop; + } else if (len < (iph->ihl*4)) + goto inhdr_error; + + /* Our transport medium may have padded the buffer out. Now we know it + * is IP we can trim to the true length of the frame. + * Note this now means skb->len holds ntohs(iph->tot_len). + */ + if (pskb_trim_rcsum(skb, len)) { + __IP_INC_STATS(net, IPSTATS_MIB_INDISCARDS); + goto drop; + } + + iph = ip_hdr(skb); + skb->transport_header = skb->network_header + iph->ihl*4; + + /* Remove any debris in the socket control block */ + memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); + IPCB(skb)->iif = skb->skb_iif; + + /* Must drop socket now because of tproxy. */ + if (!skb_sk_is_prefetched(skb)) + skb_orphan(skb); + + return skb; + +csum_error: + __IP_INC_STATS(net, IPSTATS_MIB_CSUMERRORS); +inhdr_error: + __IP_INC_STATS(net, IPSTATS_MIB_INHDRERRORS); +drop: + kfree_skb(skb); +out: + return NULL; +} + +/* + * IP receive entry point + */ +int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, + struct net_device *orig_dev) +{ + struct net *net = dev_net(dev); + + skb = ip_rcv_core(skb, net); + if (skb == NULL) + return NET_RX_DROP; + + return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, + net, NULL, skb, dev, NULL, + ip_rcv_finish); +} + +static void ip_sublist_rcv_finish(struct list_head *head) +{ + struct sk_buff *skb, *next; + + list_for_each_entry_safe(skb, next, head, list) { + skb_list_del_init(skb); + dst_input(skb); + } +} + +static struct sk_buff *ip_extract_route_hint(const struct net *net, + struct sk_buff *skb, int rt_type) +{ + if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST || + IPCB(skb)->flags & IPSKB_MULTIPATH) + return NULL; + + return skb; +} + +static void ip_list_rcv_finish(struct net *net, struct sock *sk, + struct list_head *head) +{ + struct sk_buff *skb, *next, *hint = NULL; + struct dst_entry *curr_dst = NULL; + struct list_head sublist; + + INIT_LIST_HEAD(&sublist); + list_for_each_entry_safe(skb, next, head, list) { + struct net_device *dev = skb->dev; + struct dst_entry *dst; + + skb_list_del_init(skb); + /* if ingress device is enslaved to an L3 master device pass the + * skb to its handler for processing + */ + skb = l3mdev_ip_rcv(skb); + if (!skb) + continue; + if (ip_rcv_finish_core(net, sk, skb, dev, hint) == NET_RX_DROP) + continue; + + dst = skb_dst(skb); + if (curr_dst != dst) { + hint = ip_extract_route_hint(net, skb, + ((struct rtable *)dst)->rt_type); + + /* dispatch old sublist */ + if (!list_empty(&sublist)) + ip_sublist_rcv_finish(&sublist); + /* start new sublist */ + INIT_LIST_HEAD(&sublist); + curr_dst = dst; + } + list_add_tail(&skb->list, &sublist); + } + /* dispatch final sublist */ + ip_sublist_rcv_finish(&sublist); +} + +static void ip_sublist_rcv(struct list_head *head, struct net_device *dev, + struct net *net) +{ + NF_HOOK_LIST(NFPROTO_IPV4, NF_INET_PRE_ROUTING, net, NULL, + head, dev, NULL, ip_rcv_finish); + ip_list_rcv_finish(net, NULL, head); +} + +/* Receive a list of IP packets */ +void ip_list_rcv(struct list_head *head, struct packet_type *pt, + struct net_device *orig_dev) +{ + struct net_device *curr_dev = NULL; + struct net *curr_net = NULL; + struct sk_buff *skb, *next; + struct list_head sublist; + + INIT_LIST_HEAD(&sublist); + list_for_each_entry_safe(skb, next, head, list) { + struct net_device *dev = skb->dev; + struct net *net = dev_net(dev); + + skb_list_del_init(skb); + skb = ip_rcv_core(skb, net); + if (skb == NULL) + continue; + + if (curr_dev != dev || curr_net != net) { + /* dispatch old sublist */ + if (!list_empty(&sublist)) + ip_sublist_rcv(&sublist, curr_dev, curr_net); + /* start new sublist */ + INIT_LIST_HEAD(&sublist); + curr_dev = dev; + curr_net = net; + } + list_add_tail(&skb->list, &sublist); + } + /* dispatch final sublist */ + if (!list_empty(&sublist)) + ip_sublist_rcv(&sublist, curr_dev, curr_net); +} diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c new file mode 100644 index 000000000..da1b5038b --- /dev/null +++ b/net/ipv4/ip_options.c @@ -0,0 +1,654 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The options processing module for ip.c + * + * Authors: A.N.Kuznetsov + * + */ + +#define pr_fmt(fmt) "IPv4: " fmt + +#include <linux/capability.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <asm/unaligned.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/icmp.h> +#include <linux/netdevice.h> +#include <linux/rtnetlink.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/route.h> +#include <net/cipso_ipv4.h> +#include <net/ip_fib.h> + +/* + * Write options to IP header, record destination address to + * source route option, address of outgoing interface + * (we should already know it, so that this function is allowed be + * called only after routing decision) and timestamp, + * if we originate this datagram. + * + * daddr is real destination address, next hop is recorded in IP header. + * saddr is address of outgoing interface. + */ + +void ip_options_build(struct sk_buff *skb, struct ip_options *opt, + __be32 daddr, struct rtable *rt, int is_frag) +{ + unsigned char *iph = skb_network_header(skb); + + memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options)); + memcpy(iph + sizeof(struct iphdr), opt->__data, opt->optlen); + opt = &(IPCB(skb)->opt); + + if (opt->srr) + memcpy(iph + opt->srr + iph[opt->srr + 1] - 4, &daddr, 4); + + if (!is_frag) { + if (opt->rr_needaddr) + ip_rt_get_source(iph + opt->rr + iph[opt->rr + 2] - 5, skb, rt); + if (opt->ts_needaddr) + ip_rt_get_source(iph + opt->ts + iph[opt->ts + 2] - 9, skb, rt); + if (opt->ts_needtime) { + __be32 midtime; + + midtime = inet_current_timestamp(); + memcpy(iph + opt->ts + iph[opt->ts + 2] - 5, &midtime, 4); + } + return; + } + if (opt->rr) { + memset(iph + opt->rr, IPOPT_NOP, iph[opt->rr + 1]); + opt->rr = 0; + opt->rr_needaddr = 0; + } + if (opt->ts) { + memset(iph + opt->ts, IPOPT_NOP, iph[opt->ts + 1]); + opt->ts = 0; + opt->ts_needaddr = opt->ts_needtime = 0; + } +} + +/* + * Provided (sopt, skb) points to received options, + * build in dopt compiled option set appropriate for answering. + * i.e. invert SRR option, copy anothers, + * and grab room in RR/TS options. + * + * NOTE: dopt cannot point to skb. + */ + +int __ip_options_echo(struct net *net, struct ip_options *dopt, + struct sk_buff *skb, const struct ip_options *sopt) +{ + unsigned char *sptr, *dptr; + int soffset, doffset; + int optlen; + + memset(dopt, 0, sizeof(struct ip_options)); + + if (sopt->optlen == 0) + return 0; + + sptr = skb_network_header(skb); + dptr = dopt->__data; + + if (sopt->rr) { + optlen = sptr[sopt->rr+1]; + soffset = sptr[sopt->rr+2]; + dopt->rr = dopt->optlen + sizeof(struct iphdr); + memcpy(dptr, sptr+sopt->rr, optlen); + if (sopt->rr_needaddr && soffset <= optlen) { + if (soffset + 3 > optlen) + return -EINVAL; + dptr[2] = soffset + 4; + dopt->rr_needaddr = 1; + } + dptr += optlen; + dopt->optlen += optlen; + } + if (sopt->ts) { + optlen = sptr[sopt->ts+1]; + soffset = sptr[sopt->ts+2]; + dopt->ts = dopt->optlen + sizeof(struct iphdr); + memcpy(dptr, sptr+sopt->ts, optlen); + if (soffset <= optlen) { + if (sopt->ts_needaddr) { + if (soffset + 3 > optlen) + return -EINVAL; + dopt->ts_needaddr = 1; + soffset += 4; + } + if (sopt->ts_needtime) { + if (soffset + 3 > optlen) + return -EINVAL; + if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) { + dopt->ts_needtime = 1; + soffset += 4; + } else { + dopt->ts_needtime = 0; + + if (soffset + 7 <= optlen) { + __be32 addr; + + memcpy(&addr, dptr+soffset-1, 4); + if (inet_addr_type(net, addr) != RTN_UNICAST) { + dopt->ts_needtime = 1; + soffset += 8; + } + } + } + } + dptr[2] = soffset; + } + dptr += optlen; + dopt->optlen += optlen; + } + if (sopt->srr) { + unsigned char *start = sptr+sopt->srr; + __be32 faddr; + + optlen = start[1]; + soffset = start[2]; + doffset = 0; + if (soffset > optlen) + soffset = optlen + 1; + soffset -= 4; + if (soffset > 3) { + memcpy(&faddr, &start[soffset-1], 4); + for (soffset -= 4, doffset = 4; soffset > 3; soffset -= 4, doffset += 4) + memcpy(&dptr[doffset-1], &start[soffset-1], 4); + /* + * RFC1812 requires to fix illegal source routes. + */ + if (memcmp(&ip_hdr(skb)->saddr, + &start[soffset + 3], 4) == 0) + doffset -= 4; + } + if (doffset > 3) { + dopt->faddr = faddr; + dptr[0] = start[0]; + dptr[1] = doffset+3; + dptr[2] = 4; + dptr += doffset+3; + dopt->srr = dopt->optlen + sizeof(struct iphdr); + dopt->optlen += doffset+3; + dopt->is_strictroute = sopt->is_strictroute; + } + } + if (sopt->cipso) { + optlen = sptr[sopt->cipso+1]; + dopt->cipso = dopt->optlen+sizeof(struct iphdr); + memcpy(dptr, sptr+sopt->cipso, optlen); + dptr += optlen; + dopt->optlen += optlen; + } + while (dopt->optlen & 3) { + *dptr++ = IPOPT_END; + dopt->optlen++; + } + return 0; +} + +/* + * Options "fragmenting", just fill options not + * allowed in fragments with NOOPs. + * Simple and stupid 8), but the most efficient way. + */ + +void ip_options_fragment(struct sk_buff *skb) +{ + unsigned char *optptr = skb_network_header(skb) + sizeof(struct iphdr); + struct ip_options *opt = &(IPCB(skb)->opt); + int l = opt->optlen; + int optlen; + + while (l > 0) { + switch (*optptr) { + case IPOPT_END: + return; + case IPOPT_NOOP: + l--; + optptr++; + continue; + } + optlen = optptr[1]; + if (optlen < 2 || optlen > l) + return; + if (!IPOPT_COPIED(*optptr)) + memset(optptr, IPOPT_NOOP, optlen); + l -= optlen; + optptr += optlen; + } + opt->ts = 0; + opt->rr = 0; + opt->rr_needaddr = 0; + opt->ts_needaddr = 0; + opt->ts_needtime = 0; +} + +/* helper used by ip_options_compile() to call fib_compute_spec_dst() + * at most one time. + */ +static void spec_dst_fill(__be32 *spec_dst, struct sk_buff *skb) +{ + if (*spec_dst == htonl(INADDR_ANY)) + *spec_dst = fib_compute_spec_dst(skb); +} + +/* + * Verify options and fill pointers in struct options. + * Caller should clear *opt, and set opt->data. + * If opt == NULL, then skb->data should point to IP header. + */ + +int __ip_options_compile(struct net *net, + struct ip_options *opt, struct sk_buff *skb, + __be32 *info) +{ + __be32 spec_dst = htonl(INADDR_ANY); + unsigned char *pp_ptr = NULL; + struct rtable *rt = NULL; + unsigned char *optptr; + unsigned char *iph; + int optlen, l; + + if (skb) { + rt = skb_rtable(skb); + optptr = (unsigned char *)&(ip_hdr(skb)[1]); + } else + optptr = opt->__data; + iph = optptr - sizeof(struct iphdr); + + for (l = opt->optlen; l > 0; ) { + switch (*optptr) { + case IPOPT_END: + for (optptr++, l--; l > 0; optptr++, l--) { + if (*optptr != IPOPT_END) { + *optptr = IPOPT_END; + opt->is_changed = 1; + } + } + goto eol; + case IPOPT_NOOP: + l--; + optptr++; + continue; + } + if (unlikely(l < 2)) { + pp_ptr = optptr; + goto error; + } + optlen = optptr[1]; + if (optlen < 2 || optlen > l) { + pp_ptr = optptr; + goto error; + } + switch (*optptr) { + case IPOPT_SSRR: + case IPOPT_LSRR: + if (optlen < 3) { + pp_ptr = optptr + 1; + goto error; + } + if (optptr[2] < 4) { + pp_ptr = optptr + 2; + goto error; + } + /* NB: cf RFC-1812 5.2.4.1 */ + if (opt->srr) { + pp_ptr = optptr; + goto error; + } + if (!skb) { + if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) { + pp_ptr = optptr + 1; + goto error; + } + memcpy(&opt->faddr, &optptr[3], 4); + if (optlen > 7) + memmove(&optptr[3], &optptr[7], optlen-7); + } + opt->is_strictroute = (optptr[0] == IPOPT_SSRR); + opt->srr = optptr - iph; + break; + case IPOPT_RR: + if (opt->rr) { + pp_ptr = optptr; + goto error; + } + if (optlen < 3) { + pp_ptr = optptr + 1; + goto error; + } + if (optptr[2] < 4) { + pp_ptr = optptr + 2; + goto error; + } + if (optptr[2] <= optlen) { + if (optptr[2]+3 > optlen) { + pp_ptr = optptr + 2; + goto error; + } + if (rt) { + spec_dst_fill(&spec_dst, skb); + memcpy(&optptr[optptr[2]-1], &spec_dst, 4); + opt->is_changed = 1; + } + optptr[2] += 4; + opt->rr_needaddr = 1; + } + opt->rr = optptr - iph; + break; + case IPOPT_TIMESTAMP: + if (opt->ts) { + pp_ptr = optptr; + goto error; + } + if (optlen < 4) { + pp_ptr = optptr + 1; + goto error; + } + if (optptr[2] < 5) { + pp_ptr = optptr + 2; + goto error; + } + if (optptr[2] <= optlen) { + unsigned char *timeptr = NULL; + if (optptr[2]+3 > optlen) { + pp_ptr = optptr + 2; + goto error; + } + switch (optptr[3]&0xF) { + case IPOPT_TS_TSONLY: + if (skb) + timeptr = &optptr[optptr[2]-1]; + opt->ts_needtime = 1; + optptr[2] += 4; + break; + case IPOPT_TS_TSANDADDR: + if (optptr[2]+7 > optlen) { + pp_ptr = optptr + 2; + goto error; + } + if (rt) { + spec_dst_fill(&spec_dst, skb); + memcpy(&optptr[optptr[2]-1], &spec_dst, 4); + timeptr = &optptr[optptr[2]+3]; + } + opt->ts_needaddr = 1; + opt->ts_needtime = 1; + optptr[2] += 8; + break; + case IPOPT_TS_PRESPEC: + if (optptr[2]+7 > optlen) { + pp_ptr = optptr + 2; + goto error; + } + { + __be32 addr; + memcpy(&addr, &optptr[optptr[2]-1], 4); + if (inet_addr_type(net, addr) == RTN_UNICAST) + break; + if (skb) + timeptr = &optptr[optptr[2]+3]; + } + opt->ts_needtime = 1; + optptr[2] += 8; + break; + default: + if (!skb && !ns_capable(net->user_ns, CAP_NET_RAW)) { + pp_ptr = optptr + 3; + goto error; + } + break; + } + if (timeptr) { + __be32 midtime; + + midtime = inet_current_timestamp(); + memcpy(timeptr, &midtime, 4); + opt->is_changed = 1; + } + } else if ((optptr[3]&0xF) != IPOPT_TS_PRESPEC) { + unsigned int overflow = optptr[3]>>4; + if (overflow == 15) { + pp_ptr = optptr + 3; + goto error; + } + if (skb) { + optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4); + opt->is_changed = 1; + } + } + opt->ts = optptr - iph; + break; + case IPOPT_RA: + if (optlen < 4) { + pp_ptr = optptr + 1; + goto error; + } + if (optptr[2] == 0 && optptr[3] == 0) + opt->router_alert = optptr - iph; + break; + case IPOPT_CIPSO: + if ((!skb && !ns_capable(net->user_ns, CAP_NET_RAW)) || opt->cipso) { + pp_ptr = optptr; + goto error; + } + opt->cipso = optptr - iph; + if (cipso_v4_validate(skb, &optptr)) { + pp_ptr = optptr; + goto error; + } + break; + case IPOPT_SEC: + case IPOPT_SID: + default: + if (!skb && !ns_capable(net->user_ns, CAP_NET_RAW)) { + pp_ptr = optptr; + goto error; + } + break; + } + l -= optlen; + optptr += optlen; + } + +eol: + if (!pp_ptr) + return 0; + +error: + if (info) + *info = htonl((pp_ptr-iph)<<24); + return -EINVAL; +} +EXPORT_SYMBOL(__ip_options_compile); + +int ip_options_compile(struct net *net, + struct ip_options *opt, struct sk_buff *skb) +{ + int ret; + __be32 info; + + ret = __ip_options_compile(net, opt, skb, &info); + if (ret != 0 && skb) + icmp_send(skb, ICMP_PARAMETERPROB, 0, info); + return ret; +} +EXPORT_SYMBOL(ip_options_compile); + +/* + * Undo all the changes done by ip_options_compile(). + */ + +void ip_options_undo(struct ip_options *opt) +{ + if (opt->srr) { + unsigned char *optptr = opt->__data + opt->srr - sizeof(struct iphdr); + + memmove(optptr + 7, optptr + 3, optptr[1] - 7); + memcpy(optptr + 3, &opt->faddr, 4); + } + if (opt->rr_needaddr) { + unsigned char *optptr = opt->__data + opt->rr - sizeof(struct iphdr); + + optptr[2] -= 4; + memset(&optptr[optptr[2] - 1], 0, 4); + } + if (opt->ts) { + unsigned char *optptr = opt->__data + opt->ts - sizeof(struct iphdr); + + if (opt->ts_needtime) { + optptr[2] -= 4; + memset(&optptr[optptr[2] - 1], 0, 4); + if ((optptr[3] & 0xF) == IPOPT_TS_PRESPEC) + optptr[2] -= 4; + } + if (opt->ts_needaddr) { + optptr[2] -= 4; + memset(&optptr[optptr[2] - 1], 0, 4); + } + } +} + +int ip_options_get(struct net *net, struct ip_options_rcu **optp, + sockptr_t data, int optlen) +{ + struct ip_options_rcu *opt; + + opt = kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3), + GFP_KERNEL); + if (!opt) + return -ENOMEM; + if (optlen && copy_from_sockptr(opt->opt.__data, data, optlen)) { + kfree(opt); + return -EFAULT; + } + + while (optlen & 3) + opt->opt.__data[optlen++] = IPOPT_END; + opt->opt.optlen = optlen; + if (optlen && ip_options_compile(net, &opt->opt, NULL)) { + kfree(opt); + return -EINVAL; + } + kfree(*optp); + *optp = opt; + return 0; +} + +void ip_forward_options(struct sk_buff *skb) +{ + struct ip_options *opt = &(IPCB(skb)->opt); + unsigned char *optptr; + struct rtable *rt = skb_rtable(skb); + unsigned char *raw = skb_network_header(skb); + + if (opt->rr_needaddr) { + optptr = (unsigned char *)raw + opt->rr; + ip_rt_get_source(&optptr[optptr[2]-5], skb, rt); + opt->is_changed = 1; + } + if (opt->srr_is_hit) { + int srrptr, srrspace; + + optptr = raw + opt->srr; + + for ( srrptr = optptr[2], srrspace = optptr[1]; + srrptr <= srrspace; + srrptr += 4 + ) { + if (srrptr + 3 > srrspace) + break; + if (memcmp(&opt->nexthop, &optptr[srrptr-1], 4) == 0) + break; + } + if (srrptr + 3 <= srrspace) { + opt->is_changed = 1; + ip_hdr(skb)->daddr = opt->nexthop; + ip_rt_get_source(&optptr[srrptr-1], skb, rt); + optptr[2] = srrptr+4; + } else { + net_crit_ratelimited("%s(): Argh! Destination lost!\n", + __func__); + } + if (opt->ts_needaddr) { + optptr = raw + opt->ts; + ip_rt_get_source(&optptr[optptr[2]-9], skb, rt); + opt->is_changed = 1; + } + } + if (opt->is_changed) { + opt->is_changed = 0; + ip_send_check(ip_hdr(skb)); + } +} + +int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev) +{ + struct ip_options *opt = &(IPCB(skb)->opt); + int srrspace, srrptr; + __be32 nexthop; + struct iphdr *iph = ip_hdr(skb); + unsigned char *optptr = skb_network_header(skb) + opt->srr; + struct rtable *rt = skb_rtable(skb); + struct rtable *rt2; + unsigned long orefdst; + int err; + + if (!rt) + return 0; + + if (skb->pkt_type != PACKET_HOST) + return -EINVAL; + if (rt->rt_type == RTN_UNICAST) { + if (!opt->is_strictroute) + return 0; + icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24)); + return -EINVAL; + } + if (rt->rt_type != RTN_LOCAL) + return -EINVAL; + + for (srrptr = optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) { + if (srrptr + 3 > srrspace) { + icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24)); + return -EINVAL; + } + memcpy(&nexthop, &optptr[srrptr-1], 4); + + orefdst = skb->_skb_refdst; + skb_dst_set(skb, NULL); + err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, dev); + rt2 = skb_rtable(skb); + if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) { + skb_dst_drop(skb); + skb->_skb_refdst = orefdst; + return -EINVAL; + } + refdst_drop(orefdst); + if (rt2->rt_type != RTN_LOCAL) + break; + /* Superfast 8) loopback forward */ + iph->daddr = nexthop; + opt->is_changed = 1; + } + if (srrptr <= srrspace) { + opt->srr_is_hit = 1; + opt->nexthop = nexthop; + opt->is_changed = 1; + } + return 0; +} +EXPORT_SYMBOL(ip_options_rcv_srr); diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c new file mode 100644 index 000000000..a99c37410 --- /dev/null +++ b/net/ipv4/ip_output.c @@ -0,0 +1,1764 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The Internet Protocol (IP) output module. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Donald Becker, <becker@super.org> + * Alan Cox, <Alan.Cox@linux.org> + * Richard Underwood + * Stefan Becker, <stefanb@yello.ping.de> + * Jorge Cwik, <jorge@laser.satlink.net> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Hirokazu Takahashi, <taka@valinux.co.jp> + * + * See ip_input.c for original log + * + * Fixes: + * Alan Cox : Missing nonblock feature in ip_build_xmit. + * Mike Kilburn : htons() missing in ip_build_xmit. + * Bradford Johnson: Fix faulty handling of some frames when + * no route is found. + * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit + * (in case if packet not accepted by + * output firewall rules) + * Mike McLagan : Routing by source + * Alexey Kuznetsov: use new route cache + * Andi Kleen: Fix broken PMTU recovery and remove + * some redundant tests. + * Vitaly E. Lavrov : Transparent proxy revived after year coma. + * Andi Kleen : Replace ip_reply with ip_send_reply. + * Andi Kleen : Split fast and slow ip_build_xmit path + * for decreased register pressure on x86 + * and more readibility. + * Marc Boucher : When call_out_firewall returns FW_QUEUE, + * silently drop skb instead of failing with -EPERM. + * Detlev Wengorz : Copy protocol for fragments. + * Hirokazu Takahashi: HW checksumming for outgoing UDP + * datagrams. + * Hirokazu Takahashi: sendfile() on UDP works now. + */ + +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/highmem.h> +#include <linux/slab.h> + +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/proc_fs.h> +#include <linux/stat.h> +#include <linux/init.h> + +#include <net/snmp.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/route.h> +#include <net/xfrm.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/arp.h> +#include <net/icmp.h> +#include <net/checksum.h> +#include <net/inetpeer.h> +#include <net/inet_ecn.h> +#include <net/lwtunnel.h> +#include <linux/bpf-cgroup.h> +#include <linux/igmp.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_bridge.h> +#include <linux/netlink.h> +#include <linux/tcp.h> + +static int +ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, + unsigned int mtu, + int (*output)(struct net *, struct sock *, struct sk_buff *)); + +/* Generate a checksum for an outgoing IP datagram. */ +void ip_send_check(struct iphdr *iph) +{ + iph->check = 0; + iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); +} +EXPORT_SYMBOL(ip_send_check); + +int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct iphdr *iph = ip_hdr(skb); + + iph->tot_len = htons(skb->len); + ip_send_check(iph); + + /* if egress device is enslaved to an L3 master device pass the + * skb to its handler for processing + */ + skb = l3mdev_ip_out(sk, skb); + if (unlikely(!skb)) + return 0; + + skb->protocol = htons(ETH_P_IP); + + return nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, + net, sk, skb, NULL, skb_dst(skb)->dev, + dst_output); +} + +int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + int err; + + err = __ip_local_out(net, sk, skb); + if (likely(err == 1)) + err = dst_output(net, sk, skb); + + return err; +} +EXPORT_SYMBOL_GPL(ip_local_out); + +static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) +{ + int ttl = inet->uc_ttl; + + if (ttl < 0) + ttl = ip4_dst_hoplimit(dst); + return ttl; +} + +/* + * Add an ip header to a skbuff and send it out. + * + */ +int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, + __be32 saddr, __be32 daddr, struct ip_options_rcu *opt, + u8 tos) +{ + struct inet_sock *inet = inet_sk(sk); + struct rtable *rt = skb_rtable(skb); + struct net *net = sock_net(sk); + struct iphdr *iph; + + /* Build the IP header. */ + skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0)); + skb_reset_network_header(skb); + iph = ip_hdr(skb); + iph->version = 4; + iph->ihl = 5; + iph->tos = tos; + iph->ttl = ip_select_ttl(inet, &rt->dst); + iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr); + iph->saddr = saddr; + iph->protocol = sk->sk_protocol; + /* Do not bother generating IPID for small packets (eg SYNACK) */ + if (skb->len <= IPV4_MIN_MTU || ip_dont_fragment(sk, &rt->dst)) { + iph->frag_off = htons(IP_DF); + iph->id = 0; + } else { + iph->frag_off = 0; + /* TCP packets here are SYNACK with fat IPv4/TCP options. + * Avoid using the hashed IP ident generator. + */ + if (sk->sk_protocol == IPPROTO_TCP) + iph->id = (__force __be16)prandom_u32(); + else + __ip_select_ident(net, iph, 1); + } + + if (opt && opt->opt.optlen) { + iph->ihl += opt->opt.optlen>>2; + ip_options_build(skb, &opt->opt, daddr, rt, 0); + } + + skb->priority = sk->sk_priority; + if (!skb->mark) + skb->mark = sk->sk_mark; + + /* Send it out. */ + return ip_local_out(net, skb->sk, skb); +} +EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); + +static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct rtable *rt = (struct rtable *)dst; + struct net_device *dev = dst->dev; + unsigned int hh_len = LL_RESERVED_SPACE(dev); + struct neighbour *neigh; + bool is_v6gw = false; + + if (rt->rt_type == RTN_MULTICAST) { + IP_UPD_PO_STATS(net, IPSTATS_MIB_OUTMCAST, skb->len); + } else if (rt->rt_type == RTN_BROADCAST) + IP_UPD_PO_STATS(net, IPSTATS_MIB_OUTBCAST, skb->len); + + /* Be paranoid, rather than too clever. */ + if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { + struct sk_buff *skb2; + + skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); + if (!skb2) { + kfree_skb(skb); + return -ENOMEM; + } + if (skb->sk) + skb_set_owner_w(skb2, skb->sk); + consume_skb(skb); + skb = skb2; + } + + if (lwtunnel_xmit_redirect(dst->lwtstate)) { + int res = lwtunnel_xmit(skb); + + if (res != LWTUNNEL_XMIT_CONTINUE) + return res; + } + + rcu_read_lock_bh(); + neigh = ip_neigh_for_gw(rt, skb, &is_v6gw); + if (!IS_ERR(neigh)) { + int res; + + sock_confirm_neigh(skb, neigh); + /* if crossing protocols, can not use the cached header */ + res = neigh_output(neigh, skb, is_v6gw); + rcu_read_unlock_bh(); + return res; + } + rcu_read_unlock_bh(); + + net_dbg_ratelimited("%s: No header cache and no neighbour!\n", + __func__); + kfree_skb(skb); + return -EINVAL; +} + +static int ip_finish_output_gso(struct net *net, struct sock *sk, + struct sk_buff *skb, unsigned int mtu) +{ + struct sk_buff *segs, *nskb; + netdev_features_t features; + int ret = 0; + + /* common case: seglen is <= mtu + */ + if (skb_gso_validate_network_len(skb, mtu)) + return ip_finish_output2(net, sk, skb); + + /* Slowpath - GSO segment length exceeds the egress MTU. + * + * This can happen in several cases: + * - Forwarding of a TCP GRO skb, when DF flag is not set. + * - Forwarding of an skb that arrived on a virtualization interface + * (virtio-net/vhost/tap) with TSO/GSO size set by other network + * stack. + * - Local GSO skb transmitted on an NETIF_F_TSO tunnel stacked over an + * interface with a smaller MTU. + * - Arriving GRO skb (or GSO skb in a virtualized environment) that is + * bridged to a NETIF_F_TSO tunnel stacked over an interface with an + * insufficent MTU. + */ + features = netif_skb_features(skb); + BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_GSO_CB_OFFSET); + segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); + if (IS_ERR_OR_NULL(segs)) { + kfree_skb(skb); + return -ENOMEM; + } + + consume_skb(skb); + + skb_list_walk_safe(segs, segs, nskb) { + int err; + + skb_mark_not_on_list(segs); + err = ip_fragment(net, sk, segs, mtu, ip_finish_output2); + + if (err && ret == 0) + ret = err; + } + + return ret; +} + +static int __ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + unsigned int mtu; + +#if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) + /* Policy lookup after SNAT yielded a new policy */ + if (skb_dst(skb)->xfrm) { + IPCB(skb)->flags |= IPSKB_REROUTED; + return dst_output(net, sk, skb); + } +#endif + mtu = ip_skb_dst_mtu(sk, skb); + if (skb_is_gso(skb)) + return ip_finish_output_gso(net, sk, skb, mtu); + + if (skb->len > mtu || IPCB(skb)->frag_max_size) + return ip_fragment(net, sk, skb, mtu, ip_finish_output2); + + return ip_finish_output2(net, sk, skb); +} + +static int ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + int ret; + + ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); + switch (ret) { + case NET_XMIT_SUCCESS: + return __ip_finish_output(net, sk, skb); + case NET_XMIT_CN: + return __ip_finish_output(net, sk, skb) ? : ret; + default: + kfree_skb(skb); + return ret; + } +} + +static int ip_mc_finish_output(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + struct rtable *new_rt; + bool do_cn = false; + int ret, err; + + ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); + switch (ret) { + case NET_XMIT_CN: + do_cn = true; + fallthrough; + case NET_XMIT_SUCCESS: + break; + default: + kfree_skb(skb); + return ret; + } + + /* Reset rt_iif so that inet_iif() will return skb->skb_iif. Setting + * this to non-zero causes ipi_ifindex in in_pktinfo to be overwritten, + * see ipv4_pktinfo_prepare(). + */ + new_rt = rt_dst_clone(net->loopback_dev, skb_rtable(skb)); + if (new_rt) { + new_rt->rt_iif = 0; + skb_dst_drop(skb); + skb_dst_set(skb, &new_rt->dst); + } + + err = dev_loopback_xmit(net, sk, skb); + return (do_cn && err) ? ret : err; +} + +int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct rtable *rt = skb_rtable(skb); + struct net_device *dev = rt->dst.dev; + + /* + * If the indicated interface is up and running, send the packet. + */ + IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); + + skb->dev = dev; + skb->protocol = htons(ETH_P_IP); + + /* + * Multicasts are looped back for other local users + */ + + if (rt->rt_flags&RTCF_MULTICAST) { + if (sk_mc_loop(sk) +#ifdef CONFIG_IP_MROUTE + /* Small optimization: do not loopback not local frames, + which returned after forwarding; they will be dropped + by ip_mr_input in any case. + Note, that local frames are looped back to be delivered + to local recipients. + + This check is duplicated in ip_mr_input at the moment. + */ + && + ((rt->rt_flags & RTCF_LOCAL) || + !(IPCB(skb)->flags & IPSKB_FORWARDED)) +#endif + ) { + struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); + if (newskb) + NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, + net, sk, newskb, NULL, newskb->dev, + ip_mc_finish_output); + } + + /* Multicasts with ttl 0 must not go beyond the host */ + + if (ip_hdr(skb)->ttl == 0) { + kfree_skb(skb); + return 0; + } + } + + if (rt->rt_flags&RTCF_BROADCAST) { + struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); + if (newskb) + NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, + net, sk, newskb, NULL, newskb->dev, + ip_mc_finish_output); + } + + return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, + net, sk, skb, NULL, skb->dev, + ip_finish_output, + !(IPCB(skb)->flags & IPSKB_REROUTED)); +} + +int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev; + + IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); + + skb->dev = dev; + skb->protocol = htons(ETH_P_IP); + + return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, + net, sk, skb, indev, dev, + ip_finish_output, + !(IPCB(skb)->flags & IPSKB_REROUTED)); +} + +/* + * copy saddr and daddr, possibly using 64bit load/stores + * Equivalent to : + * iph->saddr = fl4->saddr; + * iph->daddr = fl4->daddr; + */ +static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4) +{ + BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) != + offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr)); + + iph->saddr = fl4->saddr; + iph->daddr = fl4->daddr; +} + +/* Note: skb->sk can be different from sk, in case of tunnels */ +int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, + __u8 tos) +{ + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + struct ip_options_rcu *inet_opt; + struct flowi4 *fl4; + struct rtable *rt; + struct iphdr *iph; + int res; + + /* Skip all of this if the packet is already routed, + * f.e. by something like SCTP. + */ + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + fl4 = &fl->u.ip4; + rt = skb_rtable(skb); + if (rt) + goto packet_routed; + + /* Make sure we can route this packet. */ + rt = (struct rtable *)__sk_dst_check(sk, 0); + if (!rt) { + __be32 daddr; + + /* Use correct destination address if we have options. */ + daddr = inet->inet_daddr; + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + + /* If this fails, retransmit mechanism of transport layer will + * keep trying until route appears or the connection times + * itself out. + */ + rt = ip_route_output_ports(net, fl4, sk, + daddr, inet->inet_saddr, + inet->inet_dport, + inet->inet_sport, + sk->sk_protocol, + RT_CONN_FLAGS_TOS(sk, tos), + sk->sk_bound_dev_if); + if (IS_ERR(rt)) + goto no_route; + sk_setup_caps(sk, &rt->dst); + } + skb_dst_set_noref(skb, &rt->dst); + +packet_routed: + if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_uses_gateway) + goto no_route; + + /* OK, we know where to send it, allocate and build IP header. */ + skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); + skb_reset_network_header(skb); + iph = ip_hdr(skb); + *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (tos & 0xff)); + if (ip_dont_fragment(sk, &rt->dst) && !skb->ignore_df) + iph->frag_off = htons(IP_DF); + else + iph->frag_off = 0; + iph->ttl = ip_select_ttl(inet, &rt->dst); + iph->protocol = sk->sk_protocol; + ip_copy_addrs(iph, fl4); + + /* Transport layer set skb->h.foo itself. */ + + if (inet_opt && inet_opt->opt.optlen) { + iph->ihl += inet_opt->opt.optlen >> 2; + ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); + } + + ip_select_ident_segs(net, skb, sk, + skb_shinfo(skb)->gso_segs ?: 1); + + /* TODO : should we use skb->sk here instead of sk ? */ + skb->priority = sk->sk_priority; + skb->mark = sk->sk_mark; + + res = ip_local_out(net, sk, skb); + rcu_read_unlock(); + return res; + +no_route: + rcu_read_unlock(); + IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); + kfree_skb(skb); + return -EHOSTUNREACH; +} +EXPORT_SYMBOL(__ip_queue_xmit); + +int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl) +{ + return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos); +} +EXPORT_SYMBOL(ip_queue_xmit); + +static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) +{ + to->pkt_type = from->pkt_type; + to->priority = from->priority; + to->protocol = from->protocol; + to->skb_iif = from->skb_iif; + skb_dst_drop(to); + skb_dst_copy(to, from); + to->dev = from->dev; + to->mark = from->mark; + + skb_copy_hash(to, from); + +#ifdef CONFIG_NET_SCHED + to->tc_index = from->tc_index; +#endif + nf_copy(to, from); + skb_ext_copy(to, from); +#if IS_ENABLED(CONFIG_IP_VS) + to->ipvs_property = from->ipvs_property; +#endif + skb_copy_secmark(to, from); +} + +static int ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, + unsigned int mtu, + int (*output)(struct net *, struct sock *, struct sk_buff *)) +{ + struct iphdr *iph = ip_hdr(skb); + + if ((iph->frag_off & htons(IP_DF)) == 0) + return ip_do_fragment(net, sk, skb, output); + + if (unlikely(!skb->ignore_df || + (IPCB(skb)->frag_max_size && + IPCB(skb)->frag_max_size > mtu))) { + IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + htonl(mtu)); + kfree_skb(skb); + return -EMSGSIZE; + } + + return ip_do_fragment(net, sk, skb, output); +} + +void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, + unsigned int hlen, struct ip_fraglist_iter *iter) +{ + unsigned int first_len = skb_pagelen(skb); + + iter->frag = skb_shinfo(skb)->frag_list; + skb_frag_list_init(skb); + + iter->offset = 0; + iter->iph = iph; + iter->hlen = hlen; + + skb->data_len = first_len - skb_headlen(skb); + skb->len = first_len; + iph->tot_len = htons(first_len); + iph->frag_off = htons(IP_MF); + ip_send_check(iph); +} +EXPORT_SYMBOL(ip_fraglist_init); + +void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter) +{ + unsigned int hlen = iter->hlen; + struct iphdr *iph = iter->iph; + struct sk_buff *frag; + + frag = iter->frag; + frag->ip_summed = CHECKSUM_NONE; + skb_reset_transport_header(frag); + __skb_push(frag, hlen); + skb_reset_network_header(frag); + memcpy(skb_network_header(frag), iph, hlen); + iter->iph = ip_hdr(frag); + iph = iter->iph; + iph->tot_len = htons(frag->len); + ip_copy_metadata(frag, skb); + iter->offset += skb->len - hlen; + iph->frag_off = htons(iter->offset >> 3); + if (frag->next) + iph->frag_off |= htons(IP_MF); + /* Ready, complete checksum */ + ip_send_check(iph); +} +EXPORT_SYMBOL(ip_fraglist_prepare); + +void ip_frag_init(struct sk_buff *skb, unsigned int hlen, + unsigned int ll_rs, unsigned int mtu, bool DF, + struct ip_frag_state *state) +{ + struct iphdr *iph = ip_hdr(skb); + + state->DF = DF; + state->hlen = hlen; + state->ll_rs = ll_rs; + state->mtu = mtu; + + state->left = skb->len - hlen; /* Space per frame */ + state->ptr = hlen; /* Where to start from */ + + state->offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; + state->not_last_frag = iph->frag_off & htons(IP_MF); +} +EXPORT_SYMBOL(ip_frag_init); + +static void ip_frag_ipcb(struct sk_buff *from, struct sk_buff *to, + bool first_frag) +{ + /* Copy the flags to each fragment. */ + IPCB(to)->flags = IPCB(from)->flags; + + /* ANK: dirty, but effective trick. Upgrade options only if + * the segment to be fragmented was THE FIRST (otherwise, + * options are already fixed) and make it ONCE + * on the initial skb, so that all the following fragments + * will inherit fixed options. + */ + if (first_frag) + ip_options_fragment(from); +} + +struct sk_buff *ip_frag_next(struct sk_buff *skb, struct ip_frag_state *state) +{ + unsigned int len = state->left; + struct sk_buff *skb2; + struct iphdr *iph; + + len = state->left; + /* IF: it doesn't fit, use 'mtu' - the data space left */ + if (len > state->mtu) + len = state->mtu; + /* IF: we are not sending up to and including the packet end + then align the next start on an eight byte boundary */ + if (len < state->left) { + len &= ~7; + } + + /* Allocate buffer */ + skb2 = alloc_skb(len + state->hlen + state->ll_rs, GFP_ATOMIC); + if (!skb2) + return ERR_PTR(-ENOMEM); + + /* + * Set up data on packet + */ + + ip_copy_metadata(skb2, skb); + skb_reserve(skb2, state->ll_rs); + skb_put(skb2, len + state->hlen); + skb_reset_network_header(skb2); + skb2->transport_header = skb2->network_header + state->hlen; + + /* + * Charge the memory for the fragment to any owner + * it might possess + */ + + if (skb->sk) + skb_set_owner_w(skb2, skb->sk); + + /* + * Copy the packet header into the new buffer. + */ + + skb_copy_from_linear_data(skb, skb_network_header(skb2), state->hlen); + + /* + * Copy a block of the IP datagram. + */ + if (skb_copy_bits(skb, state->ptr, skb_transport_header(skb2), len)) + BUG(); + state->left -= len; + + /* + * Fill in the new header fields. + */ + iph = ip_hdr(skb2); + iph->frag_off = htons((state->offset >> 3)); + if (state->DF) + iph->frag_off |= htons(IP_DF); + + /* + * Added AC : If we are fragmenting a fragment that's not the + * last fragment then keep MF on each bit + */ + if (state->left > 0 || state->not_last_frag) + iph->frag_off |= htons(IP_MF); + state->ptr += len; + state->offset += len; + + iph->tot_len = htons(len + state->hlen); + + ip_send_check(iph); + + return skb2; +} +EXPORT_SYMBOL(ip_frag_next); + +/* + * This IP datagram is too large to be sent in one piece. Break it up into + * smaller pieces (each of size equal to IP header plus + * a block of the data of the original IP data part) that will yet fit in a + * single device frame, and queue such a frame for sending. + */ + +int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, + int (*output)(struct net *, struct sock *, struct sk_buff *)) +{ + struct iphdr *iph; + struct sk_buff *skb2; + struct rtable *rt = skb_rtable(skb); + unsigned int mtu, hlen, ll_rs; + struct ip_fraglist_iter iter; + ktime_t tstamp = skb->tstamp; + struct ip_frag_state state; + int err = 0; + + /* for offloaded checksums cleanup checksum before fragmentation */ + if (skb->ip_summed == CHECKSUM_PARTIAL && + (err = skb_checksum_help(skb))) + goto fail; + + /* + * Point into the IP datagram header. + */ + + iph = ip_hdr(skb); + + mtu = ip_skb_dst_mtu(sk, skb); + if (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size < mtu) + mtu = IPCB(skb)->frag_max_size; + + /* + * Setup starting values. + */ + + hlen = iph->ihl * 4; + mtu = mtu - hlen; /* Size of data space */ + IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; + ll_rs = LL_RESERVED_SPACE(rt->dst.dev); + + /* When frag_list is given, use it. First, check its validity: + * some transformers could create wrong frag_list or break existing + * one, it is not prohibited. In this case fall back to copying. + * + * LATER: this step can be merged to real generation of fragments, + * we can switch to copy when see the first bad fragment. + */ + if (skb_has_frag_list(skb)) { + struct sk_buff *frag, *frag2; + unsigned int first_len = skb_pagelen(skb); + + if (first_len - hlen > mtu || + ((first_len - hlen) & 7) || + ip_is_fragment(iph) || + skb_cloned(skb) || + skb_headroom(skb) < ll_rs) + goto slow_path; + + skb_walk_frags(skb, frag) { + /* Correct geometry. */ + if (frag->len > mtu || + ((frag->len & 7) && frag->next) || + skb_headroom(frag) < hlen + ll_rs) + goto slow_path_clean; + + /* Partially cloned skb? */ + if (skb_shared(frag)) + goto slow_path_clean; + + BUG_ON(frag->sk); + if (skb->sk) { + frag->sk = skb->sk; + frag->destructor = sock_wfree; + } + skb->truesize -= frag->truesize; + } + + /* Everything is OK. Generate! */ + ip_fraglist_init(skb, iph, hlen, &iter); + + for (;;) { + /* Prepare header of the next frame, + * before previous one went down. */ + if (iter.frag) { + bool first_frag = (iter.offset == 0); + + IPCB(iter.frag)->flags = IPCB(skb)->flags; + ip_fraglist_prepare(skb, &iter); + if (first_frag && IPCB(skb)->opt.optlen) { + /* ipcb->opt is not populated for frags + * coming from __ip_make_skb(), + * ip_options_fragment() needs optlen + */ + IPCB(iter.frag)->opt.optlen = + IPCB(skb)->opt.optlen; + ip_options_fragment(iter.frag); + ip_send_check(iter.iph); + } + } + + skb->tstamp = tstamp; + err = output(net, sk, skb); + + if (!err) + IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); + if (err || !iter.frag) + break; + + skb = ip_fraglist_next(&iter); + } + + if (err == 0) { + IP_INC_STATS(net, IPSTATS_MIB_FRAGOKS); + return 0; + } + + kfree_skb_list(iter.frag); + + IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); + return err; + +slow_path_clean: + skb_walk_frags(skb, frag2) { + if (frag2 == frag) + break; + frag2->sk = NULL; + frag2->destructor = NULL; + skb->truesize += frag2->truesize; + } + } + +slow_path: + /* + * Fragment the datagram. + */ + + ip_frag_init(skb, hlen, ll_rs, mtu, IPCB(skb)->flags & IPSKB_FRAG_PMTU, + &state); + + /* + * Keep copying data until we run out. + */ + + while (state.left > 0) { + bool first_frag = (state.offset == 0); + + skb2 = ip_frag_next(skb, &state); + if (IS_ERR(skb2)) { + err = PTR_ERR(skb2); + goto fail; + } + ip_frag_ipcb(skb, skb2, first_frag); + + /* + * Put this fragment into the sending queue. + */ + skb2->tstamp = tstamp; + err = output(net, sk, skb2); + if (err) + goto fail; + + IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); + } + consume_skb(skb); + IP_INC_STATS(net, IPSTATS_MIB_FRAGOKS); + return err; + +fail: + kfree_skb(skb); + IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); + return err; +} +EXPORT_SYMBOL(ip_do_fragment); + +int +ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) +{ + struct msghdr *msg = from; + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + if (!copy_from_iter_full(to, len, &msg->msg_iter)) + return -EFAULT; + } else { + __wsum csum = 0; + if (!csum_and_copy_from_iter_full(to, len, &csum, &msg->msg_iter)) + return -EFAULT; + skb->csum = csum_block_add(skb->csum, csum, odd); + } + return 0; +} +EXPORT_SYMBOL(ip_generic_getfrag); + +static inline __wsum +csum_page(struct page *page, int offset, int copy) +{ + char *kaddr; + __wsum csum; + kaddr = kmap(page); + csum = csum_partial(kaddr + offset, copy, 0); + kunmap(page); + return csum; +} + +static int __ip_append_data(struct sock *sk, + struct flowi4 *fl4, + struct sk_buff_head *queue, + struct inet_cork *cork, + struct page_frag *pfrag, + int getfrag(void *from, char *to, int offset, + int len, int odd, struct sk_buff *skb), + void *from, int length, int transhdrlen, + unsigned int flags) +{ + struct inet_sock *inet = inet_sk(sk); + struct ubuf_info *uarg = NULL; + struct sk_buff *skb; + + struct ip_options *opt = cork->opt; + int hh_len; + int exthdrlen; + int mtu; + int copy; + int err; + int offset = 0; + unsigned int maxfraglen, fragheaderlen, maxnonfragsize; + int csummode = CHECKSUM_NONE; + struct rtable *rt = (struct rtable *)cork->dst; + unsigned int wmem_alloc_delta = 0; + bool paged, extra_uref = false; + u32 tskey = 0; + + skb = skb_peek_tail(queue); + + exthdrlen = !skb ? rt->dst.header_len : 0; + mtu = cork->gso_size ? IP_MAX_MTU : cork->fragsize; + paged = !!cork->gso_size; + + if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && + sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) + tskey = sk->sk_tskey++; + + hh_len = LL_RESERVED_SPACE(rt->dst.dev); + + fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); + maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; + maxnonfragsize = ip_sk_ignore_df(sk) ? IP_MAX_MTU : mtu; + + if (cork->length + length > maxnonfragsize - fragheaderlen) { + ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, + mtu - (opt ? opt->optlen : 0)); + return -EMSGSIZE; + } + + /* + * transhdrlen > 0 means that this is the first fragment and we wish + * it won't be fragmented in the future. + */ + if (transhdrlen && + length + fragheaderlen <= mtu && + rt->dst.dev->features & (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM) && + (!(flags & MSG_MORE) || cork->gso_size) && + (!exthdrlen || (rt->dst.dev->features & NETIF_F_HW_ESP_TX_CSUM))) + csummode = CHECKSUM_PARTIAL; + + if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { + uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb)); + if (!uarg) + return -ENOBUFS; + extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ + if (rt->dst.dev->features & NETIF_F_SG && + csummode == CHECKSUM_PARTIAL) { + paged = true; + } else { + uarg->zerocopy = 0; + skb_zcopy_set(skb, uarg, &extra_uref); + } + } + + cork->length += length; + + /* So, what's going on in the loop below? + * + * We use calculated fragment length to generate chained skb, + * each of segments is IP fragment ready for sending to network after + * adding appropriate IP header. + */ + + if (!skb) + goto alloc_new_skb; + + while (length > 0) { + /* Check if the remaining data fits into current packet. */ + copy = mtu - skb->len; + if (copy < length) + copy = maxfraglen - skb->len; + if (copy <= 0) { + char *data; + unsigned int datalen; + unsigned int fraglen; + unsigned int fraggap; + unsigned int alloclen, alloc_extra; + unsigned int pagedlen; + struct sk_buff *skb_prev; +alloc_new_skb: + skb_prev = skb; + if (skb_prev) + fraggap = skb_prev->len - maxfraglen; + else + fraggap = 0; + + /* + * If remaining data exceeds the mtu, + * we know we need more fragment(s). + */ + datalen = length + fraggap; + if (datalen > mtu - fragheaderlen) + datalen = maxfraglen - fragheaderlen; + fraglen = datalen + fragheaderlen; + pagedlen = 0; + + alloc_extra = hh_len + 15; + alloc_extra += exthdrlen; + + /* The last fragment gets additional space at tail. + * Note, with MSG_MORE we overallocate on fragments, + * because we have no idea what fragment will be + * the last. + */ + if (datalen == length + fraggap) + alloc_extra += rt->dst.trailer_len; + + if ((flags & MSG_MORE) && + !(rt->dst.dev->features&NETIF_F_SG)) + alloclen = mtu; + else if (!paged && + (fraglen + alloc_extra < SKB_MAX_ALLOC || + !(rt->dst.dev->features & NETIF_F_SG))) + alloclen = fraglen; + else { + alloclen = min_t(int, fraglen, MAX_HEADER); + pagedlen = fraglen - alloclen; + } + + alloclen += alloc_extra; + + if (transhdrlen) { + skb = sock_alloc_send_skb(sk, alloclen, + (flags & MSG_DONTWAIT), &err); + } else { + skb = NULL; + if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= + 2 * sk->sk_sndbuf) + skb = alloc_skb(alloclen, + sk->sk_allocation); + if (unlikely(!skb)) + err = -ENOBUFS; + } + if (!skb) + goto error; + + /* + * Fill in the control structures + */ + skb->ip_summed = csummode; + skb->csum = 0; + skb_reserve(skb, hh_len); + + /* + * Find where to start putting bytes. + */ + data = skb_put(skb, fraglen + exthdrlen - pagedlen); + skb_set_network_header(skb, exthdrlen); + skb->transport_header = (skb->network_header + + fragheaderlen); + data += fragheaderlen + exthdrlen; + + if (fraggap) { + skb->csum = skb_copy_and_csum_bits( + skb_prev, maxfraglen, + data + transhdrlen, fraggap); + skb_prev->csum = csum_sub(skb_prev->csum, + skb->csum); + data += fraggap; + pskb_trim_unique(skb_prev, maxfraglen); + } + + copy = datalen - transhdrlen - fraggap - pagedlen; + if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { + err = -EFAULT; + kfree_skb(skb); + goto error; + } + + offset += copy; + length -= copy + transhdrlen; + transhdrlen = 0; + exthdrlen = 0; + csummode = CHECKSUM_NONE; + + /* only the initial fragment is time stamped */ + skb_shinfo(skb)->tx_flags = cork->tx_flags; + cork->tx_flags = 0; + skb_shinfo(skb)->tskey = tskey; + tskey = 0; + skb_zcopy_set(skb, uarg, &extra_uref); + + if ((flags & MSG_CONFIRM) && !skb_prev) + skb_set_dst_pending_confirm(skb, 1); + + /* + * Put the packet on the pending queue. + */ + if (!skb->destructor) { + skb->destructor = sock_wfree; + skb->sk = sk; + wmem_alloc_delta += skb->truesize; + } + __skb_queue_tail(queue, skb); + continue; + } + + if (copy > length) + copy = length; + + if (!(rt->dst.dev->features&NETIF_F_SG) && + skb_tailroom(skb) >= copy) { + unsigned int off; + + off = skb->len; + if (getfrag(from, skb_put(skb, copy), + offset, copy, off, skb) < 0) { + __skb_trim(skb, off); + err = -EFAULT; + goto error; + } + } else if (!uarg || !uarg->zerocopy) { + int i = skb_shinfo(skb)->nr_frags; + + err = -ENOMEM; + if (!sk_page_frag_refill(sk, pfrag)) + goto error; + + if (!skb_can_coalesce(skb, i, pfrag->page, + pfrag->offset)) { + err = -EMSGSIZE; + if (i == MAX_SKB_FRAGS) + goto error; + + __skb_fill_page_desc(skb, i, pfrag->page, + pfrag->offset, 0); + skb_shinfo(skb)->nr_frags = ++i; + get_page(pfrag->page); + } + copy = min_t(int, copy, pfrag->size - pfrag->offset); + if (getfrag(from, + page_address(pfrag->page) + pfrag->offset, + offset, copy, skb->len, skb) < 0) + goto error_efault; + + pfrag->offset += copy; + skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); + skb->len += copy; + skb->data_len += copy; + skb->truesize += copy; + wmem_alloc_delta += copy; + } else { + err = skb_zerocopy_iter_dgram(skb, from, copy); + if (err < 0) + goto error; + } + offset += copy; + length -= copy; + } + + if (wmem_alloc_delta) + refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); + return 0; + +error_efault: + err = -EFAULT; +error: + if (uarg) + sock_zerocopy_put_abort(uarg, extra_uref); + cork->length -= length; + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); + refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); + return err; +} + +static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, + struct ipcm_cookie *ipc, struct rtable **rtp) +{ + struct ip_options_rcu *opt; + struct rtable *rt; + + rt = *rtp; + if (unlikely(!rt)) + return -EFAULT; + + /* + * setup for corking. + */ + opt = ipc->opt; + if (opt) { + if (!cork->opt) { + cork->opt = kmalloc(sizeof(struct ip_options) + 40, + sk->sk_allocation); + if (unlikely(!cork->opt)) + return -ENOBUFS; + } + memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); + cork->flags |= IPCORK_OPT; + cork->addr = ipc->addr; + } + + cork->fragsize = ip_sk_use_pmtu(sk) ? + dst_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu); + + if (!inetdev_valid_mtu(cork->fragsize)) + return -ENETUNREACH; + + cork->gso_size = ipc->gso_size; + + cork->dst = &rt->dst; + /* We stole this route, caller should not release it. */ + *rtp = NULL; + + cork->length = 0; + cork->ttl = ipc->ttl; + cork->tos = ipc->tos; + cork->mark = ipc->sockc.mark; + cork->priority = ipc->priority; + cork->transmit_time = ipc->sockc.transmit_time; + cork->tx_flags = 0; + sock_tx_timestamp(sk, ipc->sockc.tsflags, &cork->tx_flags); + + return 0; +} + +/* + * ip_append_data() and ip_append_page() can make one large IP datagram + * from many pieces of data. Each pieces will be holded on the socket + * until ip_push_pending_frames() is called. Each piece can be a page + * or non-page data. + * + * Not only UDP, other transport protocols - e.g. raw sockets - can use + * this interface potentially. + * + * LATER: length must be adjusted by pad at tail, when it is required. + */ +int ip_append_data(struct sock *sk, struct flowi4 *fl4, + int getfrag(void *from, char *to, int offset, int len, + int odd, struct sk_buff *skb), + void *from, int length, int transhdrlen, + struct ipcm_cookie *ipc, struct rtable **rtp, + unsigned int flags) +{ + struct inet_sock *inet = inet_sk(sk); + int err; + + if (flags&MSG_PROBE) + return 0; + + if (skb_queue_empty(&sk->sk_write_queue)) { + err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp); + if (err) + return err; + } else { + transhdrlen = 0; + } + + return __ip_append_data(sk, fl4, &sk->sk_write_queue, &inet->cork.base, + sk_page_frag(sk), getfrag, + from, length, transhdrlen, flags); +} + +ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, + int offset, size_t size, int flags) +{ + struct inet_sock *inet = inet_sk(sk); + struct sk_buff *skb; + struct rtable *rt; + struct ip_options *opt = NULL; + struct inet_cork *cork; + int hh_len; + int mtu; + int len; + int err; + unsigned int maxfraglen, fragheaderlen, fraggap, maxnonfragsize; + + if (inet->hdrincl) + return -EPERM; + + if (flags&MSG_PROBE) + return 0; + + if (skb_queue_empty(&sk->sk_write_queue)) + return -EINVAL; + + cork = &inet->cork.base; + rt = (struct rtable *)cork->dst; + if (cork->flags & IPCORK_OPT) + opt = cork->opt; + + if (!(rt->dst.dev->features & NETIF_F_SG)) + return -EOPNOTSUPP; + + hh_len = LL_RESERVED_SPACE(rt->dst.dev); + mtu = cork->gso_size ? IP_MAX_MTU : cork->fragsize; + + fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); + maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; + maxnonfragsize = ip_sk_ignore_df(sk) ? 0xFFFF : mtu; + + if (cork->length + size > maxnonfragsize - fragheaderlen) { + ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, + mtu - (opt ? opt->optlen : 0)); + return -EMSGSIZE; + } + + skb = skb_peek_tail(&sk->sk_write_queue); + if (!skb) + return -EINVAL; + + cork->length += size; + + while (size > 0) { + /* Check if the remaining data fits into current packet. */ + len = mtu - skb->len; + if (len < size) + len = maxfraglen - skb->len; + + if (len <= 0) { + struct sk_buff *skb_prev; + int alloclen; + + skb_prev = skb; + fraggap = skb_prev->len - maxfraglen; + + alloclen = fragheaderlen + hh_len + fraggap + 15; + skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); + if (unlikely(!skb)) { + err = -ENOBUFS; + goto error; + } + + /* + * Fill in the control structures + */ + skb->ip_summed = CHECKSUM_NONE; + skb->csum = 0; + skb_reserve(skb, hh_len); + + /* + * Find where to start putting bytes. + */ + skb_put(skb, fragheaderlen + fraggap); + skb_reset_network_header(skb); + skb->transport_header = (skb->network_header + + fragheaderlen); + if (fraggap) { + skb->csum = skb_copy_and_csum_bits(skb_prev, + maxfraglen, + skb_transport_header(skb), + fraggap); + skb_prev->csum = csum_sub(skb_prev->csum, + skb->csum); + pskb_trim_unique(skb_prev, maxfraglen); + } + + /* + * Put the packet on the pending queue. + */ + __skb_queue_tail(&sk->sk_write_queue, skb); + continue; + } + + if (len > size) + len = size; + + if (skb_append_pagefrags(skb, page, offset, len)) { + err = -EMSGSIZE; + goto error; + } + + if (skb->ip_summed == CHECKSUM_NONE) { + __wsum csum; + csum = csum_page(page, offset, len); + skb->csum = csum_block_add(skb->csum, csum, skb->len); + } + + skb->len += len; + skb->data_len += len; + skb->truesize += len; + refcount_add(len, &sk->sk_wmem_alloc); + offset += len; + size -= len; + } + return 0; + +error: + cork->length -= size; + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); + return err; +} + +static void ip_cork_release(struct inet_cork *cork) +{ + cork->flags &= ~IPCORK_OPT; + kfree(cork->opt); + cork->opt = NULL; + dst_release(cork->dst); + cork->dst = NULL; +} + +/* + * Combined all pending IP fragments on the socket as one IP datagram + * and push them out. + */ +struct sk_buff *__ip_make_skb(struct sock *sk, + struct flowi4 *fl4, + struct sk_buff_head *queue, + struct inet_cork *cork) +{ + struct sk_buff *skb, *tmp_skb; + struct sk_buff **tail_skb; + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + struct ip_options *opt = NULL; + struct rtable *rt = (struct rtable *)cork->dst; + struct iphdr *iph; + __be16 df = 0; + __u8 ttl; + + skb = __skb_dequeue(queue); + if (!skb) + goto out; + tail_skb = &(skb_shinfo(skb)->frag_list); + + /* move skb->data to ip header from ext header */ + if (skb->data < skb_network_header(skb)) + __skb_pull(skb, skb_network_offset(skb)); + while ((tmp_skb = __skb_dequeue(queue)) != NULL) { + __skb_pull(tmp_skb, skb_network_header_len(skb)); + *tail_skb = tmp_skb; + tail_skb = &(tmp_skb->next); + skb->len += tmp_skb->len; + skb->data_len += tmp_skb->len; + skb->truesize += tmp_skb->truesize; + tmp_skb->destructor = NULL; + tmp_skb->sk = NULL; + } + + /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow + * to fragment the frame generated here. No matter, what transforms + * how transforms change size of the packet, it will come out. + */ + skb->ignore_df = ip_sk_ignore_df(sk); + + /* DF bit is set when we want to see DF on outgoing frames. + * If ignore_df is set too, we still allow to fragment this frame + * locally. */ + if (inet->pmtudisc == IP_PMTUDISC_DO || + inet->pmtudisc == IP_PMTUDISC_PROBE || + (skb->len <= dst_mtu(&rt->dst) && + ip_dont_fragment(sk, &rt->dst))) + df = htons(IP_DF); + + if (cork->flags & IPCORK_OPT) + opt = cork->opt; + + if (cork->ttl != 0) + ttl = cork->ttl; + else if (rt->rt_type == RTN_MULTICAST) + ttl = inet->mc_ttl; + else + ttl = ip_select_ttl(inet, &rt->dst); + + iph = ip_hdr(skb); + iph->version = 4; + iph->ihl = 5; + iph->tos = (cork->tos != -1) ? cork->tos : inet->tos; + iph->frag_off = df; + iph->ttl = ttl; + iph->protocol = sk->sk_protocol; + ip_copy_addrs(iph, fl4); + ip_select_ident(net, skb, sk); + + if (opt) { + iph->ihl += opt->optlen >> 2; + ip_options_build(skb, opt, cork->addr, rt, 0); + } + + skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority; + skb->mark = cork->mark; + skb->tstamp = cork->transmit_time; + /* + * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec + * on dst refcount + */ + cork->dst = NULL; + skb_dst_set(skb, &rt->dst); + + if (iph->protocol == IPPROTO_ICMP) { + u8 icmp_type; + + /* For such sockets, transhdrlen is zero when do ip_append_data(), + * so icmphdr does not in skb linear region and can not get icmp_type + * by icmp_hdr(skb)->type. + */ + if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl) + icmp_type = fl4->fl4_icmp_type; + else + icmp_type = icmp_hdr(skb)->type; + icmp_out_count(net, icmp_type); + } + + ip_cork_release(cork); +out: + return skb; +} + +int ip_send_skb(struct net *net, struct sk_buff *skb) +{ + int err; + + err = ip_local_out(net, skb->sk, skb); + if (err) { + if (err > 0) + err = net_xmit_errno(err); + if (err) + IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); + } + + return err; +} + +int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4) +{ + struct sk_buff *skb; + + skb = ip_finish_skb(sk, fl4); + if (!skb) + return 0; + + /* Netfilter gets whole the not fragmented skb. */ + return ip_send_skb(sock_net(sk), skb); +} + +/* + * Throw away all pending data on the socket. + */ +static void __ip_flush_pending_frames(struct sock *sk, + struct sk_buff_head *queue, + struct inet_cork *cork) +{ + struct sk_buff *skb; + + while ((skb = __skb_dequeue_tail(queue)) != NULL) + kfree_skb(skb); + + ip_cork_release(cork); +} + +void ip_flush_pending_frames(struct sock *sk) +{ + __ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base); +} + +struct sk_buff *ip_make_skb(struct sock *sk, + struct flowi4 *fl4, + int getfrag(void *from, char *to, int offset, + int len, int odd, struct sk_buff *skb), + void *from, int length, int transhdrlen, + struct ipcm_cookie *ipc, struct rtable **rtp, + struct inet_cork *cork, unsigned int flags) +{ + struct sk_buff_head queue; + int err; + + if (flags & MSG_PROBE) + return NULL; + + __skb_queue_head_init(&queue); + + cork->flags = 0; + cork->addr = 0; + cork->opt = NULL; + err = ip_setup_cork(sk, cork, ipc, rtp); + if (err) + return ERR_PTR(err); + + err = __ip_append_data(sk, fl4, &queue, cork, + ¤t->task_frag, getfrag, + from, length, transhdrlen, flags); + if (err) { + __ip_flush_pending_frames(sk, &queue, cork); + return ERR_PTR(err); + } + + return __ip_make_skb(sk, fl4, &queue, cork); +} + +/* + * Fetch data from kernel space and fill in checksum if needed. + */ +static int ip_reply_glue_bits(void *dptr, char *to, int offset, + int len, int odd, struct sk_buff *skb) +{ + __wsum csum; + + csum = csum_partial_copy_nocheck(dptr+offset, to, len); + skb->csum = csum_block_add(skb->csum, csum, odd); + return 0; +} + +/* + * Generic function to send a packet as reply to another packet. + * Used to send some TCP resets/acks so far. + */ +void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, + const struct ip_options *sopt, + __be32 daddr, __be32 saddr, + const struct ip_reply_arg *arg, + unsigned int len, u64 transmit_time) +{ + struct ip_options_data replyopts; + struct ipcm_cookie ipc; + struct flowi4 fl4; + struct rtable *rt = skb_rtable(skb); + struct net *net = sock_net(sk); + struct sk_buff *nskb; + int err; + int oif; + + if (__ip_options_echo(net, &replyopts.opt.opt, skb, sopt)) + return; + + ipcm_init(&ipc); + ipc.addr = daddr; + ipc.sockc.transmit_time = transmit_time; + + if (replyopts.opt.opt.optlen) { + ipc.opt = &replyopts.opt; + + if (replyopts.opt.opt.srr) + daddr = replyopts.opt.opt.faddr; + } + + oif = arg->bound_dev_if; + if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) + oif = skb->skb_iif; + + flowi4_init_output(&fl4, oif, + IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark, + RT_TOS(arg->tos), + RT_SCOPE_UNIVERSE, ip_hdr(skb)->protocol, + ip_reply_arg_flowi_flags(arg), + daddr, saddr, + tcp_hdr(skb)->source, tcp_hdr(skb)->dest, + arg->uid); + security_skb_classify_flow(skb, flowi4_to_flowi_common(&fl4)); + rt = ip_route_output_flow(net, &fl4, sk); + if (IS_ERR(rt)) + return; + + inet_sk(sk)->tos = arg->tos & ~INET_ECN_MASK; + + sk->sk_protocol = ip_hdr(skb)->protocol; + sk->sk_bound_dev_if = arg->bound_dev_if; + sk->sk_sndbuf = READ_ONCE(sysctl_wmem_default); + ipc.sockc.mark = fl4.flowi4_mark; + err = ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, + len, 0, &ipc, &rt, MSG_DONTWAIT); + if (unlikely(err)) { + ip_flush_pending_frames(sk); + goto out; + } + + nskb = skb_peek(&sk->sk_write_queue); + if (nskb) { + if (arg->csumoffset >= 0) + *((__sum16 *)skb_transport_header(nskb) + + arg->csumoffset) = csum_fold(csum_add(nskb->csum, + arg->csum)); + nskb->ip_summed = CHECKSUM_NONE; + ip_push_pending_frames(sk, &fl4); + } +out: + ip_rt_put(rt); +} + +void __init ip_init(void) +{ + ip_rt_init(); + inet_initpeers(); + +#if defined(CONFIG_IP_MULTICAST) + igmp_mc_init(); +#endif +} diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c new file mode 100644 index 000000000..1b35afd32 --- /dev/null +++ b/net/ipv4/ip_sockglue.c @@ -0,0 +1,1795 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The IP to API glue. + * + * Authors: see ip.c + * + * Fixes: + * Many : Split from ip.c , see ip.c for history. + * Martin Mares : TOS setting fixed. + * Alan Cox : Fixed a couple of oopses in Martin's + * TOS tweaks. + * Mike McLagan : Routing by source + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/icmp.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/tcp_states.h> +#include <linux/udp.h> +#include <linux/igmp.h> +#include <linux/netfilter.h> +#include <linux/route.h> +#include <linux/mroute.h> +#include <net/inet_ecn.h> +#include <net/route.h> +#include <net/xfrm.h> +#include <net/compat.h> +#include <net/checksum.h> +#if IS_ENABLED(CONFIG_IPV6) +#include <net/transp_v6.h> +#endif +#include <net/ip_fib.h> + +#include <linux/errqueue.h> +#include <linux/uaccess.h> + +#include <linux/bpfilter.h> + +/* + * SOL_IP control messages. + */ + +static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) +{ + struct in_pktinfo info = *PKTINFO_SKB_CB(skb); + + info.ipi_addr.s_addr = ip_hdr(skb)->daddr; + + put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info); +} + +static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb) +{ + int ttl = ip_hdr(skb)->ttl; + put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl); +} + +static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb) +{ + put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos); +} + +static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb) +{ + if (IPCB(skb)->opt.optlen == 0) + return; + + put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen, + ip_hdr(skb) + 1); +} + + +static void ip_cmsg_recv_retopts(struct net *net, struct msghdr *msg, + struct sk_buff *skb) +{ + unsigned char optbuf[sizeof(struct ip_options) + 40]; + struct ip_options *opt = (struct ip_options *)optbuf; + + if (IPCB(skb)->opt.optlen == 0) + return; + + if (ip_options_echo(net, opt, skb)) { + msg->msg_flags |= MSG_CTRUNC; + return; + } + ip_options_undo(opt); + + put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data); +} + +static void ip_cmsg_recv_fragsize(struct msghdr *msg, struct sk_buff *skb) +{ + int val; + + if (IPCB(skb)->frag_max_size == 0) + return; + + val = IPCB(skb)->frag_max_size; + put_cmsg(msg, SOL_IP, IP_RECVFRAGSIZE, sizeof(val), &val); +} + +static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, + int tlen, int offset) +{ + __wsum csum = skb->csum; + + if (skb->ip_summed != CHECKSUM_COMPLETE) + return; + + if (offset != 0) { + int tend_off = skb_transport_offset(skb) + tlen; + csum = csum_sub(csum, skb_checksum(skb, tend_off, offset, 0)); + } + + put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum); +} + +static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) +{ + char *secdata; + u32 seclen, secid; + int err; + + err = security_socket_getpeersec_dgram(NULL, skb, &secid); + if (err) + return; + + err = security_secid_to_secctx(secid, &secdata, &seclen); + if (err) + return; + + put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata); + security_release_secctx(secdata, seclen); +} + +static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb) +{ + __be16 _ports[2], *ports; + struct sockaddr_in sin; + + /* All current transport protocols have the port numbers in the + * first four bytes of the transport header and this function is + * written with this assumption in mind. + */ + ports = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_ports), &_ports); + if (!ports) + return; + + sin.sin_family = AF_INET; + sin.sin_addr.s_addr = ip_hdr(skb)->daddr; + sin.sin_port = ports[1]; + memset(sin.sin_zero, 0, sizeof(sin.sin_zero)); + + put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin); +} + +void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, + struct sk_buff *skb, int tlen, int offset) +{ + struct inet_sock *inet = inet_sk(sk); + unsigned int flags = inet->cmsg_flags; + + /* Ordered by supposed usage frequency */ + if (flags & IP_CMSG_PKTINFO) { + ip_cmsg_recv_pktinfo(msg, skb); + + flags &= ~IP_CMSG_PKTINFO; + if (!flags) + return; + } + + if (flags & IP_CMSG_TTL) { + ip_cmsg_recv_ttl(msg, skb); + + flags &= ~IP_CMSG_TTL; + if (!flags) + return; + } + + if (flags & IP_CMSG_TOS) { + ip_cmsg_recv_tos(msg, skb); + + flags &= ~IP_CMSG_TOS; + if (!flags) + return; + } + + if (flags & IP_CMSG_RECVOPTS) { + ip_cmsg_recv_opts(msg, skb); + + flags &= ~IP_CMSG_RECVOPTS; + if (!flags) + return; + } + + if (flags & IP_CMSG_RETOPTS) { + ip_cmsg_recv_retopts(sock_net(sk), msg, skb); + + flags &= ~IP_CMSG_RETOPTS; + if (!flags) + return; + } + + if (flags & IP_CMSG_PASSSEC) { + ip_cmsg_recv_security(msg, skb); + + flags &= ~IP_CMSG_PASSSEC; + if (!flags) + return; + } + + if (flags & IP_CMSG_ORIGDSTADDR) { + ip_cmsg_recv_dstaddr(msg, skb); + + flags &= ~IP_CMSG_ORIGDSTADDR; + if (!flags) + return; + } + + if (flags & IP_CMSG_CHECKSUM) + ip_cmsg_recv_checksum(msg, skb, tlen, offset); + + if (flags & IP_CMSG_RECVFRAGSIZE) + ip_cmsg_recv_fragsize(msg, skb); +} +EXPORT_SYMBOL(ip_cmsg_recv_offset); + +int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc, + bool allow_ipv6) +{ + int err, val; + struct cmsghdr *cmsg; + struct net *net = sock_net(sk); + + for_each_cmsghdr(cmsg, msg) { + if (!CMSG_OK(msg, cmsg)) + return -EINVAL; +#if IS_ENABLED(CONFIG_IPV6) + if (allow_ipv6 && + cmsg->cmsg_level == SOL_IPV6 && + cmsg->cmsg_type == IPV6_PKTINFO) { + struct in6_pktinfo *src_info; + + if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info))) + return -EINVAL; + src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg); + if (!ipv6_addr_v4mapped(&src_info->ipi6_addr)) + return -EINVAL; + if (src_info->ipi6_ifindex) + ipc->oif = src_info->ipi6_ifindex; + ipc->addr = src_info->ipi6_addr.s6_addr32[3]; + continue; + } +#endif + if (cmsg->cmsg_level == SOL_SOCKET) { + err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc); + if (err) + return err; + continue; + } + + if (cmsg->cmsg_level != SOL_IP) + continue; + switch (cmsg->cmsg_type) { + case IP_RETOPTS: + err = cmsg->cmsg_len - sizeof(struct cmsghdr); + + /* Our caller is responsible for freeing ipc->opt */ + err = ip_options_get(net, &ipc->opt, + KERNEL_SOCKPTR(CMSG_DATA(cmsg)), + err < 40 ? err : 40); + if (err) + return err; + break; + case IP_PKTINFO: + { + struct in_pktinfo *info; + if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo))) + return -EINVAL; + info = (struct in_pktinfo *)CMSG_DATA(cmsg); + if (info->ipi_ifindex) + ipc->oif = info->ipi_ifindex; + ipc->addr = info->ipi_spec_dst.s_addr; + break; + } + case IP_TTL: + if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) + return -EINVAL; + val = *(int *)CMSG_DATA(cmsg); + if (val < 1 || val > 255) + return -EINVAL; + ipc->ttl = val; + break; + case IP_TOS: + if (cmsg->cmsg_len == CMSG_LEN(sizeof(int))) + val = *(int *)CMSG_DATA(cmsg); + else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8))) + val = *(u8 *)CMSG_DATA(cmsg); + else + return -EINVAL; + if (val < 0 || val > 255) + return -EINVAL; + ipc->tos = val; + ipc->priority = rt_tos2priority(ipc->tos); + break; + case IP_PROTOCOL: + if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) + return -EINVAL; + val = *(int *)CMSG_DATA(cmsg); + if (val < 1 || val > 255) + return -EINVAL; + ipc->protocol = val; + break; + default: + return -EINVAL; + } + } + return 0; +} + +static void ip_ra_destroy_rcu(struct rcu_head *head) +{ + struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu); + + sock_put(ra->saved_sk); + kfree(ra); +} + +int ip_ra_control(struct sock *sk, unsigned char on, + void (*destructor)(struct sock *)) +{ + struct ip_ra_chain *ra, *new_ra; + struct ip_ra_chain __rcu **rap; + struct net *net = sock_net(sk); + + if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW) + return -EINVAL; + + new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL; + if (on && !new_ra) + return -ENOMEM; + + mutex_lock(&net->ipv4.ra_mutex); + for (rap = &net->ipv4.ra_chain; + (ra = rcu_dereference_protected(*rap, + lockdep_is_held(&net->ipv4.ra_mutex))) != NULL; + rap = &ra->next) { + if (ra->sk == sk) { + if (on) { + mutex_unlock(&net->ipv4.ra_mutex); + kfree(new_ra); + return -EADDRINUSE; + } + /* dont let ip_call_ra_chain() use sk again */ + ra->sk = NULL; + RCU_INIT_POINTER(*rap, ra->next); + mutex_unlock(&net->ipv4.ra_mutex); + + if (ra->destructor) + ra->destructor(sk); + /* + * Delay sock_put(sk) and kfree(ra) after one rcu grace + * period. This guarantee ip_call_ra_chain() dont need + * to mess with socket refcounts. + */ + ra->saved_sk = sk; + call_rcu(&ra->rcu, ip_ra_destroy_rcu); + return 0; + } + } + if (!new_ra) { + mutex_unlock(&net->ipv4.ra_mutex); + return -ENOBUFS; + } + new_ra->sk = sk; + new_ra->destructor = destructor; + + RCU_INIT_POINTER(new_ra->next, ra); + rcu_assign_pointer(*rap, new_ra); + sock_hold(sk); + mutex_unlock(&net->ipv4.ra_mutex); + + return 0; +} + +static void ipv4_icmp_error_rfc4884(const struct sk_buff *skb, + struct sock_ee_data_rfc4884 *out) +{ + switch (icmp_hdr(skb)->type) { + case ICMP_DEST_UNREACH: + case ICMP_TIME_EXCEEDED: + case ICMP_PARAMETERPROB: + ip_icmp_error_rfc4884(skb, out, sizeof(struct icmphdr), + icmp_hdr(skb)->un.reserved[1] * 4); + } +} + +void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, + __be16 port, u32 info, u8 *payload) +{ + struct sock_exterr_skb *serr; + + skb = skb_clone(skb, GFP_ATOMIC); + if (!skb) + return; + + serr = SKB_EXT_ERR(skb); + serr->ee.ee_errno = err; + serr->ee.ee_origin = SO_EE_ORIGIN_ICMP; + serr->ee.ee_type = icmp_hdr(skb)->type; + serr->ee.ee_code = icmp_hdr(skb)->code; + serr->ee.ee_pad = 0; + serr->ee.ee_info = info; + serr->ee.ee_data = 0; + serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) - + skb_network_header(skb); + serr->port = port; + + if (skb_pull(skb, payload - skb->data)) { + if (inet_sk(sk)->recverr_rfc4884) + ipv4_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884); + + skb_reset_transport_header(skb); + if (sock_queue_err_skb(sk, skb) == 0) + return; + } + kfree_skb(skb); +} + +void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info) +{ + struct inet_sock *inet = inet_sk(sk); + struct sock_exterr_skb *serr; + struct iphdr *iph; + struct sk_buff *skb; + + if (!inet->recverr) + return; + + skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC); + if (!skb) + return; + + skb_put(skb, sizeof(struct iphdr)); + skb_reset_network_header(skb); + iph = ip_hdr(skb); + iph->daddr = daddr; + + serr = SKB_EXT_ERR(skb); + serr->ee.ee_errno = err; + serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL; + serr->ee.ee_type = 0; + serr->ee.ee_code = 0; + serr->ee.ee_pad = 0; + serr->ee.ee_info = info; + serr->ee.ee_data = 0; + serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb); + serr->port = port; + + __skb_pull(skb, skb_tail_pointer(skb) - skb->data); + skb_reset_transport_header(skb); + + if (sock_queue_err_skb(sk, skb)) + kfree_skb(skb); +} + +/* For some errors we have valid addr_offset even with zero payload and + * zero port. Also, addr_offset should be supported if port is set. + */ +static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr) +{ + return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP || + serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port; +} + +/* IPv4 supports cmsg on all imcp errors and some timestamps + * + * Timestamp code paths do not initialize the fields expected by cmsg: + * the PKTINFO fields in skb->cb[]. Fill those in here. + */ +static bool ipv4_datagram_support_cmsg(const struct sock *sk, + struct sk_buff *skb, + int ee_origin) +{ + struct in_pktinfo *info; + + if (ee_origin == SO_EE_ORIGIN_ICMP) + return true; + + if (ee_origin == SO_EE_ORIGIN_LOCAL) + return false; + + /* Support IP_PKTINFO on tstamp packets if requested, to correlate + * timestamp with egress dev. Not possible for packets without iif + * or without payload (SOF_TIMESTAMPING_OPT_TSONLY). + */ + info = PKTINFO_SKB_CB(skb); + if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) || + !info->ipi_ifindex) + return false; + + info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr; + return true; +} + +/* + * Handle MSG_ERRQUEUE + */ +int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) +{ + struct sock_exterr_skb *serr; + struct sk_buff *skb; + DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); + struct { + struct sock_extended_err ee; + struct sockaddr_in offender; + } errhdr; + int err; + int copied; + + err = -EAGAIN; + skb = sock_dequeue_err_skb(sk); + if (!skb) + goto out; + + copied = skb->len; + if (copied > len) { + msg->msg_flags |= MSG_TRUNC; + copied = len; + } + err = skb_copy_datagram_msg(skb, 0, msg, copied); + if (unlikely(err)) { + kfree_skb(skb); + return err; + } + sock_recv_timestamp(msg, sk, skb); + + serr = SKB_EXT_ERR(skb); + + if (sin && ipv4_datagram_support_addr(serr)) { + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) + + serr->addr_offset); + sin->sin_port = serr->port; + memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); + } + + memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err)); + sin = &errhdr.offender; + memset(sin, 0, sizeof(*sin)); + + if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) { + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = ip_hdr(skb)->saddr; + if (inet_sk(sk)->cmsg_flags) + ip_cmsg_recv(msg, skb); + } + + put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr); + + /* Now we could try to dump offended packet options */ + + msg->msg_flags |= MSG_ERRQUEUE; + err = copied; + + consume_skb(skb); +out: + return err; +} + +static void __ip_sock_set_tos(struct sock *sk, int val) +{ + if (sk->sk_type == SOCK_STREAM) { + val &= ~INET_ECN_MASK; + val |= inet_sk(sk)->tos & INET_ECN_MASK; + } + if (inet_sk(sk)->tos != val) { + inet_sk(sk)->tos = val; + sk->sk_priority = rt_tos2priority(val); + sk_dst_reset(sk); + } +} + +void ip_sock_set_tos(struct sock *sk, int val) +{ + lock_sock(sk); + __ip_sock_set_tos(sk, val); + release_sock(sk); +} +EXPORT_SYMBOL(ip_sock_set_tos); + +void ip_sock_set_freebind(struct sock *sk) +{ + lock_sock(sk); + inet_sk(sk)->freebind = true; + release_sock(sk); +} +EXPORT_SYMBOL(ip_sock_set_freebind); + +void ip_sock_set_recverr(struct sock *sk) +{ + lock_sock(sk); + inet_sk(sk)->recverr = true; + release_sock(sk); +} +EXPORT_SYMBOL(ip_sock_set_recverr); + +int ip_sock_set_mtu_discover(struct sock *sk, int val) +{ + if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT) + return -EINVAL; + lock_sock(sk); + inet_sk(sk)->pmtudisc = val; + release_sock(sk); + return 0; +} +EXPORT_SYMBOL(ip_sock_set_mtu_discover); + +void ip_sock_set_pktinfo(struct sock *sk) +{ + lock_sock(sk); + inet_sk(sk)->cmsg_flags |= IP_CMSG_PKTINFO; + release_sock(sk); +} +EXPORT_SYMBOL(ip_sock_set_pktinfo); + +/* + * Socket option code for IP. This is the end of the line after any + * TCP,UDP etc options on an IP socket. + */ +static bool setsockopt_needs_rtnl(int optname) +{ + switch (optname) { + case IP_ADD_MEMBERSHIP: + case IP_ADD_SOURCE_MEMBERSHIP: + case IP_BLOCK_SOURCE: + case IP_DROP_MEMBERSHIP: + case IP_DROP_SOURCE_MEMBERSHIP: + case IP_MSFILTER: + case IP_UNBLOCK_SOURCE: + case MCAST_BLOCK_SOURCE: + case MCAST_MSFILTER: + case MCAST_JOIN_GROUP: + case MCAST_JOIN_SOURCE_GROUP: + case MCAST_LEAVE_GROUP: + case MCAST_LEAVE_SOURCE_GROUP: + case MCAST_UNBLOCK_SOURCE: + return true; + } + return false; +} + +static int set_mcast_msfilter(struct sock *sk, int ifindex, + int numsrc, int fmode, + struct sockaddr_storage *group, + struct sockaddr_storage *list) +{ + int msize = IP_MSFILTER_SIZE(numsrc); + struct ip_msfilter *msf; + struct sockaddr_in *psin; + int err, i; + + msf = kmalloc(msize, GFP_KERNEL); + if (!msf) + return -ENOBUFS; + + psin = (struct sockaddr_in *)group; + if (psin->sin_family != AF_INET) + goto Eaddrnotavail; + msf->imsf_multiaddr = psin->sin_addr.s_addr; + msf->imsf_interface = 0; + msf->imsf_fmode = fmode; + msf->imsf_numsrc = numsrc; + for (i = 0; i < numsrc; ++i) { + psin = (struct sockaddr_in *)&list[i]; + + if (psin->sin_family != AF_INET) + goto Eaddrnotavail; + msf->imsf_slist[i] = psin->sin_addr.s_addr; + } + err = ip_mc_msfilter(sk, msf, ifindex); + kfree(msf); + return err; + +Eaddrnotavail: + kfree(msf); + return -EADDRNOTAVAIL; +} + +static int copy_group_source_from_sockptr(struct group_source_req *greqs, + sockptr_t optval, int optlen) +{ + if (in_compat_syscall()) { + struct compat_group_source_req gr32; + + if (optlen != sizeof(gr32)) + return -EINVAL; + if (copy_from_sockptr(&gr32, optval, sizeof(gr32))) + return -EFAULT; + greqs->gsr_interface = gr32.gsr_interface; + greqs->gsr_group = gr32.gsr_group; + greqs->gsr_source = gr32.gsr_source; + } else { + if (optlen != sizeof(*greqs)) + return -EINVAL; + if (copy_from_sockptr(greqs, optval, sizeof(*greqs))) + return -EFAULT; + } + + return 0; +} + +static int do_mcast_group_source(struct sock *sk, int optname, + sockptr_t optval, int optlen) +{ + struct group_source_req greqs; + struct ip_mreq_source mreqs; + struct sockaddr_in *psin; + int omode, add, err; + + err = copy_group_source_from_sockptr(&greqs, optval, optlen); + if (err) + return err; + + if (greqs.gsr_group.ss_family != AF_INET || + greqs.gsr_source.ss_family != AF_INET) + return -EADDRNOTAVAIL; + + psin = (struct sockaddr_in *)&greqs.gsr_group; + mreqs.imr_multiaddr = psin->sin_addr.s_addr; + psin = (struct sockaddr_in *)&greqs.gsr_source; + mreqs.imr_sourceaddr = psin->sin_addr.s_addr; + mreqs.imr_interface = 0; /* use index for mc_source */ + + if (optname == MCAST_BLOCK_SOURCE) { + omode = MCAST_EXCLUDE; + add = 1; + } else if (optname == MCAST_UNBLOCK_SOURCE) { + omode = MCAST_EXCLUDE; + add = 0; + } else if (optname == MCAST_JOIN_SOURCE_GROUP) { + struct ip_mreqn mreq; + + psin = (struct sockaddr_in *)&greqs.gsr_group; + mreq.imr_multiaddr = psin->sin_addr; + mreq.imr_address.s_addr = 0; + mreq.imr_ifindex = greqs.gsr_interface; + err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE); + if (err && err != -EADDRINUSE) + return err; + greqs.gsr_interface = mreq.imr_ifindex; + omode = MCAST_INCLUDE; + add = 1; + } else /* MCAST_LEAVE_SOURCE_GROUP */ { + omode = MCAST_INCLUDE; + add = 0; + } + return ip_mc_source(add, omode, sk, &mreqs, greqs.gsr_interface); +} + +static int ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval, int optlen) +{ + struct group_filter *gsf = NULL; + int err; + + if (optlen < GROUP_FILTER_SIZE(0)) + return -EINVAL; + if (optlen > READ_ONCE(sysctl_optmem_max)) + return -ENOBUFS; + + gsf = memdup_sockptr(optval, optlen); + if (IS_ERR(gsf)) + return PTR_ERR(gsf); + + /* numsrc >= (4G-140)/128 overflow in 32 bits */ + err = -ENOBUFS; + if (gsf->gf_numsrc >= 0x1ffffff || + gsf->gf_numsrc > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf)) + goto out_free_gsf; + + err = -EINVAL; + if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) + goto out_free_gsf; + + err = set_mcast_msfilter(sk, gsf->gf_interface, gsf->gf_numsrc, + gsf->gf_fmode, &gsf->gf_group, gsf->gf_slist); +out_free_gsf: + kfree(gsf); + return err; +} + +static int compat_ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval, + int optlen) +{ + const int size0 = offsetof(struct compat_group_filter, gf_slist); + struct compat_group_filter *gf32; + unsigned int n; + void *p; + int err; + + if (optlen < size0) + return -EINVAL; + if (optlen > READ_ONCE(sysctl_optmem_max) - 4) + return -ENOBUFS; + + p = kmalloc(optlen + 4, GFP_KERNEL); + if (!p) + return -ENOMEM; + gf32 = p + 4; /* we want ->gf_group and ->gf_slist aligned */ + + err = -EFAULT; + if (copy_from_sockptr(gf32, optval, optlen)) + goto out_free_gsf; + + /* numsrc >= (4G-140)/128 overflow in 32 bits */ + n = gf32->gf_numsrc; + err = -ENOBUFS; + if (n >= 0x1ffffff) + goto out_free_gsf; + + err = -EINVAL; + if (offsetof(struct compat_group_filter, gf_slist[n]) > optlen) + goto out_free_gsf; + + /* numsrc >= (4G-140)/128 overflow in 32 bits */ + err = -ENOBUFS; + if (n > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf)) + goto out_free_gsf; + err = set_mcast_msfilter(sk, gf32->gf_interface, n, gf32->gf_fmode, + &gf32->gf_group, gf32->gf_slist); +out_free_gsf: + kfree(p); + return err; +} + +static int ip_mcast_join_leave(struct sock *sk, int optname, + sockptr_t optval, int optlen) +{ + struct ip_mreqn mreq = { }; + struct sockaddr_in *psin; + struct group_req greq; + + if (optlen < sizeof(struct group_req)) + return -EINVAL; + if (copy_from_sockptr(&greq, optval, sizeof(greq))) + return -EFAULT; + + psin = (struct sockaddr_in *)&greq.gr_group; + if (psin->sin_family != AF_INET) + return -EINVAL; + mreq.imr_multiaddr = psin->sin_addr; + mreq.imr_ifindex = greq.gr_interface; + if (optname == MCAST_JOIN_GROUP) + return ip_mc_join_group(sk, &mreq); + return ip_mc_leave_group(sk, &mreq); +} + +static int compat_ip_mcast_join_leave(struct sock *sk, int optname, + sockptr_t optval, int optlen) +{ + struct compat_group_req greq; + struct ip_mreqn mreq = { }; + struct sockaddr_in *psin; + + if (optlen < sizeof(struct compat_group_req)) + return -EINVAL; + if (copy_from_sockptr(&greq, optval, sizeof(greq))) + return -EFAULT; + + psin = (struct sockaddr_in *)&greq.gr_group; + if (psin->sin_family != AF_INET) + return -EINVAL; + mreq.imr_multiaddr = psin->sin_addr; + mreq.imr_ifindex = greq.gr_interface; + + if (optname == MCAST_JOIN_GROUP) + return ip_mc_join_group(sk, &mreq); + return ip_mc_leave_group(sk, &mreq); +} + +static int do_ip_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + int val = 0, err; + bool needs_rtnl = setsockopt_needs_rtnl(optname); + + switch (optname) { + case IP_PKTINFO: + case IP_RECVTTL: + case IP_RECVOPTS: + case IP_RECVTOS: + case IP_RETOPTS: + case IP_TOS: + case IP_TTL: + case IP_HDRINCL: + case IP_MTU_DISCOVER: + case IP_RECVERR: + case IP_ROUTER_ALERT: + case IP_FREEBIND: + case IP_PASSSEC: + case IP_TRANSPARENT: + case IP_MINTTL: + case IP_NODEFRAG: + case IP_BIND_ADDRESS_NO_PORT: + case IP_UNICAST_IF: + case IP_MULTICAST_TTL: + case IP_MULTICAST_ALL: + case IP_MULTICAST_LOOP: + case IP_RECVORIGDSTADDR: + case IP_CHECKSUM: + case IP_RECVFRAGSIZE: + case IP_RECVERR_RFC4884: + if (optlen >= sizeof(int)) { + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + } else if (optlen >= sizeof(char)) { + unsigned char ucval; + + if (copy_from_sockptr(&ucval, optval, sizeof(ucval))) + return -EFAULT; + val = (int) ucval; + } + } + + /* If optlen==0, it is equivalent to val == 0 */ + + if (optname == IP_ROUTER_ALERT) + return ip_ra_control(sk, val ? 1 : 0, NULL); + if (ip_mroute_opt(optname)) + return ip_mroute_setsockopt(sk, optname, optval, optlen); + + err = 0; + if (needs_rtnl) + rtnl_lock(); + lock_sock(sk); + + switch (optname) { + case IP_OPTIONS: + { + struct ip_options_rcu *old, *opt = NULL; + + if (optlen > 40) + goto e_inval; + err = ip_options_get(sock_net(sk), &opt, optval, optlen); + if (err) + break; + old = rcu_dereference_protected(inet->inet_opt, + lockdep_sock_is_held(sk)); + if (inet->is_icsk) { + struct inet_connection_sock *icsk = inet_csk(sk); +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == PF_INET || + (!((1 << sk->sk_state) & + (TCPF_LISTEN | TCPF_CLOSE)) && + inet->inet_daddr != LOOPBACK4_IPV6)) { +#endif + if (old) + icsk->icsk_ext_hdr_len -= old->opt.optlen; + if (opt) + icsk->icsk_ext_hdr_len += opt->opt.optlen; + icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie); +#if IS_ENABLED(CONFIG_IPV6) + } +#endif + } + rcu_assign_pointer(inet->inet_opt, opt); + if (old) + kfree_rcu(old, rcu); + break; + } + case IP_PKTINFO: + if (val) + inet->cmsg_flags |= IP_CMSG_PKTINFO; + else + inet->cmsg_flags &= ~IP_CMSG_PKTINFO; + break; + case IP_RECVTTL: + if (val) + inet->cmsg_flags |= IP_CMSG_TTL; + else + inet->cmsg_flags &= ~IP_CMSG_TTL; + break; + case IP_RECVTOS: + if (val) + inet->cmsg_flags |= IP_CMSG_TOS; + else + inet->cmsg_flags &= ~IP_CMSG_TOS; + break; + case IP_RECVOPTS: + if (val) + inet->cmsg_flags |= IP_CMSG_RECVOPTS; + else + inet->cmsg_flags &= ~IP_CMSG_RECVOPTS; + break; + case IP_RETOPTS: + if (val) + inet->cmsg_flags |= IP_CMSG_RETOPTS; + else + inet->cmsg_flags &= ~IP_CMSG_RETOPTS; + break; + case IP_PASSSEC: + if (val) + inet->cmsg_flags |= IP_CMSG_PASSSEC; + else + inet->cmsg_flags &= ~IP_CMSG_PASSSEC; + break; + case IP_RECVORIGDSTADDR: + if (val) + inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR; + else + inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR; + break; + case IP_CHECKSUM: + if (val) { + if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) { + inet_inc_convert_csum(sk); + inet->cmsg_flags |= IP_CMSG_CHECKSUM; + } + } else { + if (inet->cmsg_flags & IP_CMSG_CHECKSUM) { + inet_dec_convert_csum(sk); + inet->cmsg_flags &= ~IP_CMSG_CHECKSUM; + } + } + break; + case IP_RECVFRAGSIZE: + if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM) + goto e_inval; + if (val) + inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE; + else + inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE; + break; + case IP_TOS: /* This sets both TOS and Precedence */ + __ip_sock_set_tos(sk, val); + break; + case IP_TTL: + if (optlen < 1) + goto e_inval; + if (val != -1 && (val < 1 || val > 255)) + goto e_inval; + inet->uc_ttl = val; + break; + case IP_HDRINCL: + if (sk->sk_type != SOCK_RAW) { + err = -ENOPROTOOPT; + break; + } + inet->hdrincl = val ? 1 : 0; + break; + case IP_NODEFRAG: + if (sk->sk_type != SOCK_RAW) { + err = -ENOPROTOOPT; + break; + } + inet->nodefrag = val ? 1 : 0; + break; + case IP_BIND_ADDRESS_NO_PORT: + inet->bind_address_no_port = val ? 1 : 0; + break; + case IP_MTU_DISCOVER: + if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT) + goto e_inval; + inet->pmtudisc = val; + break; + case IP_RECVERR: + inet->recverr = !!val; + if (!val) + skb_queue_purge(&sk->sk_error_queue); + break; + case IP_RECVERR_RFC4884: + if (val < 0 || val > 1) + goto e_inval; + inet->recverr_rfc4884 = !!val; + break; + case IP_MULTICAST_TTL: + if (sk->sk_type == SOCK_STREAM) + goto e_inval; + if (optlen < 1) + goto e_inval; + if (val == -1) + val = 1; + if (val < 0 || val > 255) + goto e_inval; + inet->mc_ttl = val; + break; + case IP_MULTICAST_LOOP: + if (optlen < 1) + goto e_inval; + inet->mc_loop = !!val; + break; + case IP_UNICAST_IF: + { + struct net_device *dev = NULL; + int ifindex; + int midx; + + if (optlen != sizeof(int)) + goto e_inval; + + ifindex = (__force int)ntohl((__force __be32)val); + if (ifindex == 0) { + inet->uc_index = 0; + err = 0; + break; + } + + dev = dev_get_by_index(sock_net(sk), ifindex); + err = -EADDRNOTAVAIL; + if (!dev) + break; + + midx = l3mdev_master_ifindex(dev); + dev_put(dev); + + err = -EINVAL; + if (sk->sk_bound_dev_if && midx != sk->sk_bound_dev_if) + break; + + inet->uc_index = ifindex; + err = 0; + break; + } + case IP_MULTICAST_IF: + { + struct ip_mreqn mreq; + struct net_device *dev = NULL; + int midx; + + if (sk->sk_type == SOCK_STREAM) + goto e_inval; + /* + * Check the arguments are allowable + */ + + if (optlen < sizeof(struct in_addr)) + goto e_inval; + + err = -EFAULT; + if (optlen >= sizeof(struct ip_mreqn)) { + if (copy_from_sockptr(&mreq, optval, sizeof(mreq))) + break; + } else { + memset(&mreq, 0, sizeof(mreq)); + if (optlen >= sizeof(struct ip_mreq)) { + if (copy_from_sockptr(&mreq, optval, + sizeof(struct ip_mreq))) + break; + } else if (optlen >= sizeof(struct in_addr)) { + if (copy_from_sockptr(&mreq.imr_address, optval, + sizeof(struct in_addr))) + break; + } + } + + if (!mreq.imr_ifindex) { + if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) { + inet->mc_index = 0; + inet->mc_addr = 0; + err = 0; + break; + } + dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr); + if (dev) + mreq.imr_ifindex = dev->ifindex; + } else + dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex); + + + err = -EADDRNOTAVAIL; + if (!dev) + break; + + midx = l3mdev_master_ifindex(dev); + + dev_put(dev); + + err = -EINVAL; + if (sk->sk_bound_dev_if && + mreq.imr_ifindex != sk->sk_bound_dev_if && + midx != sk->sk_bound_dev_if) + break; + + inet->mc_index = mreq.imr_ifindex; + inet->mc_addr = mreq.imr_address.s_addr; + err = 0; + break; + } + + case IP_ADD_MEMBERSHIP: + case IP_DROP_MEMBERSHIP: + { + struct ip_mreqn mreq; + + err = -EPROTO; + if (inet_sk(sk)->is_icsk) + break; + + if (optlen < sizeof(struct ip_mreq)) + goto e_inval; + err = -EFAULT; + if (optlen >= sizeof(struct ip_mreqn)) { + if (copy_from_sockptr(&mreq, optval, sizeof(mreq))) + break; + } else { + memset(&mreq, 0, sizeof(mreq)); + if (copy_from_sockptr(&mreq, optval, + sizeof(struct ip_mreq))) + break; + } + + if (optname == IP_ADD_MEMBERSHIP) + err = ip_mc_join_group(sk, &mreq); + else + err = ip_mc_leave_group(sk, &mreq); + break; + } + case IP_MSFILTER: + { + struct ip_msfilter *msf; + + if (optlen < IP_MSFILTER_SIZE(0)) + goto e_inval; + if (optlen > READ_ONCE(sysctl_optmem_max)) { + err = -ENOBUFS; + break; + } + msf = memdup_sockptr(optval, optlen); + if (IS_ERR(msf)) { + err = PTR_ERR(msf); + break; + } + /* numsrc >= (1G-4) overflow in 32 bits */ + if (msf->imsf_numsrc >= 0x3ffffffcU || + msf->imsf_numsrc > READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) { + kfree(msf); + err = -ENOBUFS; + break; + } + if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) { + kfree(msf); + err = -EINVAL; + break; + } + err = ip_mc_msfilter(sk, msf, 0); + kfree(msf); + break; + } + case IP_BLOCK_SOURCE: + case IP_UNBLOCK_SOURCE: + case IP_ADD_SOURCE_MEMBERSHIP: + case IP_DROP_SOURCE_MEMBERSHIP: + { + struct ip_mreq_source mreqs; + int omode, add; + + if (optlen != sizeof(struct ip_mreq_source)) + goto e_inval; + if (copy_from_sockptr(&mreqs, optval, sizeof(mreqs))) { + err = -EFAULT; + break; + } + if (optname == IP_BLOCK_SOURCE) { + omode = MCAST_EXCLUDE; + add = 1; + } else if (optname == IP_UNBLOCK_SOURCE) { + omode = MCAST_EXCLUDE; + add = 0; + } else if (optname == IP_ADD_SOURCE_MEMBERSHIP) { + struct ip_mreqn mreq; + + mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr; + mreq.imr_address.s_addr = mreqs.imr_interface; + mreq.imr_ifindex = 0; + err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE); + if (err && err != -EADDRINUSE) + break; + omode = MCAST_INCLUDE; + add = 1; + } else /* IP_DROP_SOURCE_MEMBERSHIP */ { + omode = MCAST_INCLUDE; + add = 0; + } + err = ip_mc_source(add, omode, sk, &mreqs, 0); + break; + } + case MCAST_JOIN_GROUP: + case MCAST_LEAVE_GROUP: + if (in_compat_syscall()) + err = compat_ip_mcast_join_leave(sk, optname, optval, + optlen); + else + err = ip_mcast_join_leave(sk, optname, optval, optlen); + break; + case MCAST_JOIN_SOURCE_GROUP: + case MCAST_LEAVE_SOURCE_GROUP: + case MCAST_BLOCK_SOURCE: + case MCAST_UNBLOCK_SOURCE: + err = do_mcast_group_source(sk, optname, optval, optlen); + break; + case MCAST_MSFILTER: + if (in_compat_syscall()) + err = compat_ip_set_mcast_msfilter(sk, optval, optlen); + else + err = ip_set_mcast_msfilter(sk, optval, optlen); + break; + case IP_MULTICAST_ALL: + if (optlen < 1) + goto e_inval; + if (val != 0 && val != 1) + goto e_inval; + inet->mc_all = val; + break; + + case IP_FREEBIND: + if (optlen < 1) + goto e_inval; + inet->freebind = !!val; + break; + + case IP_IPSEC_POLICY: + case IP_XFRM_POLICY: + err = -EPERM; + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) + break; + err = xfrm_user_policy(sk, optname, optval, optlen); + break; + + case IP_TRANSPARENT: + if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) && + !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) { + err = -EPERM; + break; + } + if (optlen < 1) + goto e_inval; + inet->transparent = !!val; + break; + + case IP_MINTTL: + if (optlen < 1) + goto e_inval; + if (val < 0 || val > 255) + goto e_inval; + inet->min_ttl = val; + break; + + default: + err = -ENOPROTOOPT; + break; + } + release_sock(sk); + if (needs_rtnl) + rtnl_unlock(); + return err; + +e_inval: + release_sock(sk); + if (needs_rtnl) + rtnl_unlock(); + return -EINVAL; +} + +/** + * ipv4_pktinfo_prepare - transfer some info from rtable to skb + * @sk: socket + * @skb: buffer + * + * To support IP_CMSG_PKTINFO option, we store rt_iif and specific + * destination in skb->cb[] before dst drop. + * This way, receiver doesn't make cache line misses to read rtable. + */ +void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb) +{ + struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb); + bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) || + ipv6_sk_rxinfo(sk); + + if (prepare && skb_rtable(skb)) { + /* skb->cb is overloaded: prior to this point it is IP{6}CB + * which has interface index (iif) as the first member of the + * underlying inet{6}_skb_parm struct. This code then overlays + * PKTINFO_SKB_CB and in_pktinfo also has iif as the first + * element so the iif is picked up from the prior IPCB. If iif + * is the loopback interface, then return the sending interface + * (e.g., process binds socket to eth0 for Tx which is + * redirected to loopback in the rtable/dst). + */ + struct rtable *rt = skb_rtable(skb); + bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags); + + if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX) + pktinfo->ipi_ifindex = inet_iif(skb); + else if (l3slave && rt && rt->rt_iif) + pktinfo->ipi_ifindex = rt->rt_iif; + + pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb); + } else { + pktinfo->ipi_ifindex = 0; + pktinfo->ipi_spec_dst.s_addr = 0; + } + skb_dst_drop(skb); +} + +int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, + unsigned int optlen) +{ + int err; + + if (level != SOL_IP) + return -ENOPROTOOPT; + + err = do_ip_setsockopt(sk, level, optname, optval, optlen); +#if IS_ENABLED(CONFIG_BPFILTER_UMH) + if (optname >= BPFILTER_IPT_SO_SET_REPLACE && + optname < BPFILTER_IPT_SET_MAX) + err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen); +#endif +#ifdef CONFIG_NETFILTER + /* we need to exclude all possible ENOPROTOOPTs except default case */ + if (err == -ENOPROTOOPT && optname != IP_HDRINCL && + optname != IP_IPSEC_POLICY && + optname != IP_XFRM_POLICY && + !ip_mroute_opt(optname)) + err = nf_setsockopt(sk, PF_INET, optname, optval, optlen); +#endif + return err; +} +EXPORT_SYMBOL(ip_setsockopt); + +/* + * Get the options. Note for future reference. The GET of IP options gets + * the _received_ ones. The set sets the _sent_ ones. + */ + +static bool getsockopt_needs_rtnl(int optname) +{ + switch (optname) { + case IP_MSFILTER: + case MCAST_MSFILTER: + return true; + } + return false; +} + +static int ip_get_mcast_msfilter(struct sock *sk, void __user *optval, + int __user *optlen, int len) +{ + const int size0 = offsetof(struct group_filter, gf_slist); + struct group_filter __user *p = optval; + struct group_filter gsf; + int num; + int err; + + if (len < size0) + return -EINVAL; + if (copy_from_user(&gsf, p, size0)) + return -EFAULT; + + num = gsf.gf_numsrc; + err = ip_mc_gsfget(sk, &gsf, p->gf_slist); + if (err) + return err; + if (gsf.gf_numsrc < num) + num = gsf.gf_numsrc; + if (put_user(GROUP_FILTER_SIZE(num), optlen) || + copy_to_user(p, &gsf, size0)) + return -EFAULT; + return 0; +} + +static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval, + int __user *optlen, int len) +{ + const int size0 = offsetof(struct compat_group_filter, gf_slist); + struct compat_group_filter __user *p = optval; + struct compat_group_filter gf32; + struct group_filter gf; + int num; + int err; + + if (len < size0) + return -EINVAL; + if (copy_from_user(&gf32, p, size0)) + return -EFAULT; + + gf.gf_interface = gf32.gf_interface; + gf.gf_fmode = gf32.gf_fmode; + num = gf.gf_numsrc = gf32.gf_numsrc; + gf.gf_group = gf32.gf_group; + + err = ip_mc_gsfget(sk, &gf, p->gf_slist); + if (err) + return err; + if (gf.gf_numsrc < num) + num = gf.gf_numsrc; + len = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32)); + if (put_user(len, optlen) || + put_user(gf.gf_fmode, &p->gf_fmode) || + put_user(gf.gf_numsrc, &p->gf_numsrc)) + return -EFAULT; + return 0; +} + +static int do_ip_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct inet_sock *inet = inet_sk(sk); + bool needs_rtnl = getsockopt_needs_rtnl(optname); + int val, err = 0; + int len; + + if (level != SOL_IP) + return -EOPNOTSUPP; + + if (ip_mroute_opt(optname)) + return ip_mroute_getsockopt(sk, optname, optval, optlen); + + if (get_user(len, optlen)) + return -EFAULT; + if (len < 0) + return -EINVAL; + + if (needs_rtnl) + rtnl_lock(); + lock_sock(sk); + + switch (optname) { + case IP_OPTIONS: + { + unsigned char optbuf[sizeof(struct ip_options)+40]; + struct ip_options *opt = (struct ip_options *)optbuf; + struct ip_options_rcu *inet_opt; + + inet_opt = rcu_dereference_protected(inet->inet_opt, + lockdep_sock_is_held(sk)); + opt->optlen = 0; + if (inet_opt) + memcpy(optbuf, &inet_opt->opt, + sizeof(struct ip_options) + + inet_opt->opt.optlen); + release_sock(sk); + + if (opt->optlen == 0) + return put_user(0, optlen); + + ip_options_undo(opt); + + len = min_t(unsigned int, len, opt->optlen); + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, opt->__data, len)) + return -EFAULT; + return 0; + } + case IP_PKTINFO: + val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0; + break; + case IP_RECVTTL: + val = (inet->cmsg_flags & IP_CMSG_TTL) != 0; + break; + case IP_RECVTOS: + val = (inet->cmsg_flags & IP_CMSG_TOS) != 0; + break; + case IP_RECVOPTS: + val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0; + break; + case IP_RETOPTS: + val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0; + break; + case IP_PASSSEC: + val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0; + break; + case IP_RECVORIGDSTADDR: + val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0; + break; + case IP_CHECKSUM: + val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0; + break; + case IP_RECVFRAGSIZE: + val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0; + break; + case IP_TOS: + val = inet->tos; + break; + case IP_TTL: + { + struct net *net = sock_net(sk); + val = (inet->uc_ttl == -1 ? + net->ipv4.sysctl_ip_default_ttl : + inet->uc_ttl); + break; + } + case IP_HDRINCL: + val = inet->hdrincl; + break; + case IP_NODEFRAG: + val = inet->nodefrag; + break; + case IP_BIND_ADDRESS_NO_PORT: + val = inet->bind_address_no_port; + break; + case IP_MTU_DISCOVER: + val = inet->pmtudisc; + break; + case IP_MTU: + { + struct dst_entry *dst; + val = 0; + dst = sk_dst_get(sk); + if (dst) { + val = dst_mtu(dst); + dst_release(dst); + } + if (!val) { + release_sock(sk); + return -ENOTCONN; + } + break; + } + case IP_RECVERR: + val = inet->recverr; + break; + case IP_RECVERR_RFC4884: + val = inet->recverr_rfc4884; + break; + case IP_MULTICAST_TTL: + val = inet->mc_ttl; + break; + case IP_MULTICAST_LOOP: + val = inet->mc_loop; + break; + case IP_UNICAST_IF: + val = (__force int)htonl((__u32) inet->uc_index); + break; + case IP_MULTICAST_IF: + { + struct in_addr addr; + len = min_t(unsigned int, len, sizeof(struct in_addr)); + addr.s_addr = inet->mc_addr; + release_sock(sk); + + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &addr, len)) + return -EFAULT; + return 0; + } + case IP_MSFILTER: + { + struct ip_msfilter msf; + + if (len < IP_MSFILTER_SIZE(0)) { + err = -EINVAL; + goto out; + } + if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) { + err = -EFAULT; + goto out; + } + err = ip_mc_msfget(sk, &msf, + (struct ip_msfilter __user *)optval, optlen); + goto out; + } + case MCAST_MSFILTER: + if (in_compat_syscall()) + err = compat_ip_get_mcast_msfilter(sk, optval, optlen, + len); + else + err = ip_get_mcast_msfilter(sk, optval, optlen, len); + goto out; + case IP_MULTICAST_ALL: + val = inet->mc_all; + break; + case IP_PKTOPTIONS: + { + struct msghdr msg; + + release_sock(sk); + + if (sk->sk_type != SOCK_STREAM) + return -ENOPROTOOPT; + + msg.msg_control_is_user = true; + msg.msg_control_user = optval; + msg.msg_controllen = len; + msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0; + + if (inet->cmsg_flags & IP_CMSG_PKTINFO) { + struct in_pktinfo info; + + info.ipi_addr.s_addr = inet->inet_rcv_saddr; + info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr; + info.ipi_ifindex = inet->mc_index; + put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info); + } + if (inet->cmsg_flags & IP_CMSG_TTL) { + int hlim = inet->mc_ttl; + put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim); + } + if (inet->cmsg_flags & IP_CMSG_TOS) { + int tos = inet->rcv_tos; + put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos); + } + len -= msg.msg_controllen; + return put_user(len, optlen); + } + case IP_FREEBIND: + val = inet->freebind; + break; + case IP_TRANSPARENT: + val = inet->transparent; + break; + case IP_MINTTL: + val = inet->min_ttl; + break; + case IP_PROTOCOL: + val = inet_sk(sk)->inet_num; + break; + default: + release_sock(sk); + return -ENOPROTOOPT; + } + release_sock(sk); + + if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) { + unsigned char ucval = (unsigned char)val; + len = 1; + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &ucval, 1)) + return -EFAULT; + } else { + len = min_t(unsigned int, sizeof(int), len); + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &val, len)) + return -EFAULT; + } + return 0; + +out: + release_sock(sk); + if (needs_rtnl) + rtnl_unlock(); + return err; +} + +int ip_getsockopt(struct sock *sk, int level, + int optname, char __user *optval, int __user *optlen) +{ + int err; + + err = do_ip_getsockopt(sk, level, optname, optval, optlen); + +#if IS_ENABLED(CONFIG_BPFILTER_UMH) + if (optname >= BPFILTER_IPT_SO_GET_INFO && + optname < BPFILTER_IPT_GET_MAX) + err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen); +#endif +#ifdef CONFIG_NETFILTER + /* we need to exclude all possible ENOPROTOOPTs except default case */ + if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS && + !ip_mroute_opt(optname)) { + int len; + + if (get_user(len, optlen)) + return -EFAULT; + + err = nf_getsockopt(sk, PF_INET, optname, optval, &len); + if (err >= 0) + err = put_user(len, optlen); + return err; + } +#endif + return err; +} +EXPORT_SYMBOL(ip_getsockopt); diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c new file mode 100644 index 000000000..99f70b990 --- /dev/null +++ b/net/ipv4/ip_tunnel.c @@ -0,0 +1,1279 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 Nicira, Inc. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/capability.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/in.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/if_arp.h> +#include <linux/init.h> +#include <linux/in6.h> +#include <linux/inetdevice.h> +#include <linux/igmp.h> +#include <linux/netfilter_ipv4.h> +#include <linux/etherdevice.h> +#include <linux/if_ether.h> +#include <linux/if_vlan.h> +#include <linux/rculist.h> +#include <linux/err.h> + +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/protocol.h> +#include <net/ip_tunnels.h> +#include <net/arp.h> +#include <net/checksum.h> +#include <net/dsfield.h> +#include <net/inet_ecn.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/rtnetlink.h> +#include <net/udp.h> +#include <net/dst_metadata.h> + +#if IS_ENABLED(CONFIG_IPV6) +#include <net/ipv6.h> +#include <net/ip6_fib.h> +#include <net/ip6_route.h> +#endif + +static unsigned int ip_tunnel_hash(__be32 key, __be32 remote) +{ + return hash_32((__force u32)key ^ (__force u32)remote, + IP_TNL_HASH_BITS); +} + +static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p, + __be16 flags, __be32 key) +{ + if (p->i_flags & TUNNEL_KEY) { + if (flags & TUNNEL_KEY) + return key == p->i_key; + else + /* key expected, none present */ + return false; + } else + return !(flags & TUNNEL_KEY); +} + +/* Fallback tunnel: no source, no destination, no key, no options + + Tunnel hash table: + We require exact key match i.e. if a key is present in packet + it will match only tunnel with the same key; if it is not present, + it will match only keyless tunnel. + + All keysless packets, if not matched configured keyless tunnels + will match fallback tunnel. + Given src, dst and key, find appropriate for input tunnel. +*/ +struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, + int link, __be16 flags, + __be32 remote, __be32 local, + __be32 key) +{ + struct ip_tunnel *t, *cand = NULL; + struct hlist_head *head; + struct net_device *ndev; + unsigned int hash; + + hash = ip_tunnel_hash(key, remote); + head = &itn->tunnels[hash]; + + hlist_for_each_entry_rcu(t, head, hash_node) { + if (local != t->parms.iph.saddr || + remote != t->parms.iph.daddr || + !(t->dev->flags & IFF_UP)) + continue; + + if (!ip_tunnel_key_match(&t->parms, flags, key)) + continue; + + if (t->parms.link == link) + return t; + else + cand = t; + } + + hlist_for_each_entry_rcu(t, head, hash_node) { + if (remote != t->parms.iph.daddr || + t->parms.iph.saddr != 0 || + !(t->dev->flags & IFF_UP)) + continue; + + if (!ip_tunnel_key_match(&t->parms, flags, key)) + continue; + + if (t->parms.link == link) + return t; + else if (!cand) + cand = t; + } + + hash = ip_tunnel_hash(key, 0); + head = &itn->tunnels[hash]; + + hlist_for_each_entry_rcu(t, head, hash_node) { + if ((local != t->parms.iph.saddr || t->parms.iph.daddr != 0) && + (local != t->parms.iph.daddr || !ipv4_is_multicast(local))) + continue; + + if (!(t->dev->flags & IFF_UP)) + continue; + + if (!ip_tunnel_key_match(&t->parms, flags, key)) + continue; + + if (t->parms.link == link) + return t; + else if (!cand) + cand = t; + } + + hlist_for_each_entry_rcu(t, head, hash_node) { + if ((!(flags & TUNNEL_NO_KEY) && t->parms.i_key != key) || + t->parms.iph.saddr != 0 || + t->parms.iph.daddr != 0 || + !(t->dev->flags & IFF_UP)) + continue; + + if (t->parms.link == link) + return t; + else if (!cand) + cand = t; + } + + if (cand) + return cand; + + t = rcu_dereference(itn->collect_md_tun); + if (t && t->dev->flags & IFF_UP) + return t; + + ndev = READ_ONCE(itn->fb_tunnel_dev); + if (ndev && ndev->flags & IFF_UP) + return netdev_priv(ndev); + + return NULL; +} +EXPORT_SYMBOL_GPL(ip_tunnel_lookup); + +static struct hlist_head *ip_bucket(struct ip_tunnel_net *itn, + struct ip_tunnel_parm *parms) +{ + unsigned int h; + __be32 remote; + __be32 i_key = parms->i_key; + + if (parms->iph.daddr && !ipv4_is_multicast(parms->iph.daddr)) + remote = parms->iph.daddr; + else + remote = 0; + + if (!(parms->i_flags & TUNNEL_KEY) && (parms->i_flags & VTI_ISVTI)) + i_key = 0; + + h = ip_tunnel_hash(i_key, remote); + return &itn->tunnels[h]; +} + +static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t) +{ + struct hlist_head *head = ip_bucket(itn, &t->parms); + + if (t->collect_md) + rcu_assign_pointer(itn->collect_md_tun, t); + hlist_add_head_rcu(&t->hash_node, head); +} + +static void ip_tunnel_del(struct ip_tunnel_net *itn, struct ip_tunnel *t) +{ + if (t->collect_md) + rcu_assign_pointer(itn->collect_md_tun, NULL); + hlist_del_init_rcu(&t->hash_node); +} + +static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn, + struct ip_tunnel_parm *parms, + int type) +{ + __be32 remote = parms->iph.daddr; + __be32 local = parms->iph.saddr; + __be32 key = parms->i_key; + __be16 flags = parms->i_flags; + int link = parms->link; + struct ip_tunnel *t = NULL; + struct hlist_head *head = ip_bucket(itn, parms); + + hlist_for_each_entry_rcu(t, head, hash_node) { + if (local == t->parms.iph.saddr && + remote == t->parms.iph.daddr && + link == t->parms.link && + type == t->dev->type && + ip_tunnel_key_match(&t->parms, flags, key)) + break; + } + return t; +} + +static struct net_device *__ip_tunnel_create(struct net *net, + const struct rtnl_link_ops *ops, + struct ip_tunnel_parm *parms) +{ + int err; + struct ip_tunnel *tunnel; + struct net_device *dev; + char name[IFNAMSIZ]; + + err = -E2BIG; + if (parms->name[0]) { + if (!dev_valid_name(parms->name)) + goto failed; + strlcpy(name, parms->name, IFNAMSIZ); + } else { + if (strlen(ops->kind) > (IFNAMSIZ - 3)) + goto failed; + strcpy(name, ops->kind); + strcat(name, "%d"); + } + + ASSERT_RTNL(); + dev = alloc_netdev(ops->priv_size, name, NET_NAME_UNKNOWN, ops->setup); + if (!dev) { + err = -ENOMEM; + goto failed; + } + dev_net_set(dev, net); + + dev->rtnl_link_ops = ops; + + tunnel = netdev_priv(dev); + tunnel->parms = *parms; + tunnel->net = net; + + err = register_netdevice(dev); + if (err) + goto failed_free; + + return dev; + +failed_free: + free_netdev(dev); +failed: + return ERR_PTR(err); +} + +static int ip_tunnel_bind_dev(struct net_device *dev) +{ + struct net_device *tdev = NULL; + struct ip_tunnel *tunnel = netdev_priv(dev); + const struct iphdr *iph; + int hlen = LL_MAX_HEADER; + int mtu = ETH_DATA_LEN; + int t_hlen = tunnel->hlen + sizeof(struct iphdr); + + iph = &tunnel->parms.iph; + + /* Guess output device to choose reasonable mtu and needed_headroom */ + if (iph->daddr) { + struct flowi4 fl4; + struct rtable *rt; + + ip_tunnel_init_flow(&fl4, iph->protocol, iph->daddr, + iph->saddr, tunnel->parms.o_key, + RT_TOS(iph->tos), tunnel->parms.link, + tunnel->fwmark, 0); + rt = ip_route_output_key(tunnel->net, &fl4); + + if (!IS_ERR(rt)) { + tdev = rt->dst.dev; + ip_rt_put(rt); + } + if (dev->type != ARPHRD_ETHER) + dev->flags |= IFF_POINTOPOINT; + + dst_cache_reset(&tunnel->dst_cache); + } + + if (!tdev && tunnel->parms.link) + tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); + + if (tdev) { + hlen = tdev->hard_header_len + tdev->needed_headroom; + mtu = min(tdev->mtu, IP_MAX_MTU); + } + + dev->needed_headroom = t_hlen + hlen; + mtu -= t_hlen + (dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0); + + if (mtu < IPV4_MIN_MTU) + mtu = IPV4_MIN_MTU; + + return mtu; +} + +static struct ip_tunnel *ip_tunnel_create(struct net *net, + struct ip_tunnel_net *itn, + struct ip_tunnel_parm *parms) +{ + struct ip_tunnel *nt; + struct net_device *dev; + int t_hlen; + int mtu; + int err; + + dev = __ip_tunnel_create(net, itn->rtnl_link_ops, parms); + if (IS_ERR(dev)) + return ERR_CAST(dev); + + mtu = ip_tunnel_bind_dev(dev); + err = dev_set_mtu(dev, mtu); + if (err) + goto err_dev_set_mtu; + + nt = netdev_priv(dev); + t_hlen = nt->hlen + sizeof(struct iphdr); + dev->min_mtu = ETH_MIN_MTU; + dev->max_mtu = IP_MAX_MTU - t_hlen; + if (dev->type == ARPHRD_ETHER) + dev->max_mtu -= dev->hard_header_len; + + ip_tunnel_add(itn, nt); + return nt; + +err_dev_set_mtu: + unregister_netdevice(dev); + return ERR_PTR(err); +} + +int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, + const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, + bool log_ecn_error) +{ + const struct iphdr *iph = ip_hdr(skb); + int err; + +#ifdef CONFIG_NET_IPGRE_BROADCAST + if (ipv4_is_multicast(iph->daddr)) { + tunnel->dev->stats.multicast++; + skb->pkt_type = PACKET_BROADCAST; + } +#endif + + if ((!(tpi->flags&TUNNEL_CSUM) && (tunnel->parms.i_flags&TUNNEL_CSUM)) || + ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) { + tunnel->dev->stats.rx_crc_errors++; + tunnel->dev->stats.rx_errors++; + goto drop; + } + + if (tunnel->parms.i_flags&TUNNEL_SEQ) { + if (!(tpi->flags&TUNNEL_SEQ) || + (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) { + tunnel->dev->stats.rx_fifo_errors++; + tunnel->dev->stats.rx_errors++; + goto drop; + } + tunnel->i_seqno = ntohl(tpi->seq) + 1; + } + + skb_set_network_header(skb, (tunnel->dev->type == ARPHRD_ETHER) ? ETH_HLEN : 0); + + err = IP_ECN_decapsulate(iph, skb); + if (unlikely(err)) { + if (log_ecn_error) + net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", + &iph->saddr, iph->tos); + if (err > 1) { + ++tunnel->dev->stats.rx_frame_errors; + ++tunnel->dev->stats.rx_errors; + goto drop; + } + } + + dev_sw_netstats_rx_add(tunnel->dev, skb->len); + skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev))); + + if (tunnel->dev->type == ARPHRD_ETHER) { + skb->protocol = eth_type_trans(skb, tunnel->dev); + skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN); + } else { + skb->dev = tunnel->dev; + } + + if (tun_dst) + skb_dst_set(skb, (struct dst_entry *)tun_dst); + + gro_cells_receive(&tunnel->gro_cells, skb); + return 0; + +drop: + if (tun_dst) + dst_release((struct dst_entry *)tun_dst); + kfree_skb(skb); + return 0; +} +EXPORT_SYMBOL_GPL(ip_tunnel_rcv); + +int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops, + unsigned int num) +{ + if (num >= MAX_IPTUN_ENCAP_OPS) + return -ERANGE; + + return !cmpxchg((const struct ip_tunnel_encap_ops **) + &iptun_encaps[num], + NULL, ops) ? 0 : -1; +} +EXPORT_SYMBOL(ip_tunnel_encap_add_ops); + +int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops, + unsigned int num) +{ + int ret; + + if (num >= MAX_IPTUN_ENCAP_OPS) + return -ERANGE; + + ret = (cmpxchg((const struct ip_tunnel_encap_ops **) + &iptun_encaps[num], + ops, NULL) == ops) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(ip_tunnel_encap_del_ops); + +int ip_tunnel_encap_setup(struct ip_tunnel *t, + struct ip_tunnel_encap *ipencap) +{ + int hlen; + + memset(&t->encap, 0, sizeof(t->encap)); + + hlen = ip_encap_hlen(ipencap); + if (hlen < 0) + return hlen; + + t->encap.type = ipencap->type; + t->encap.sport = ipencap->sport; + t->encap.dport = ipencap->dport; + t->encap.flags = ipencap->flags; + + t->encap_hlen = hlen; + t->hlen = t->encap_hlen + t->tun_hlen; + + return 0; +} +EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup); + +static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, + struct rtable *rt, __be16 df, + const struct iphdr *inner_iph, + int tunnel_hlen, __be32 dst, bool md) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + int pkt_size; + int mtu; + + tunnel_hlen = md ? tunnel_hlen : tunnel->hlen; + pkt_size = skb->len - tunnel_hlen; + pkt_size -= dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0; + + if (df) { + mtu = dst_mtu(&rt->dst) - (sizeof(struct iphdr) + tunnel_hlen); + mtu -= dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0; + } else { + mtu = skb_valid_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; + } + + if (skb_valid_dst(skb)) + skb_dst_update_pmtu_no_confirm(skb, mtu); + + if (skb->protocol == htons(ETH_P_IP)) { + if (!skb_is_gso(skb) && + (inner_iph->frag_off & htons(IP_DF)) && + mtu < pkt_size) { + icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); + return -E2BIG; + } + } +#if IS_ENABLED(CONFIG_IPV6) + else if (skb->protocol == htons(ETH_P_IPV6)) { + struct rt6_info *rt6; + __be32 daddr; + + rt6 = skb_valid_dst(skb) ? (struct rt6_info *)skb_dst(skb) : + NULL; + daddr = md ? dst : tunnel->parms.iph.daddr; + + if (rt6 && mtu < dst_mtu(skb_dst(skb)) && + mtu >= IPV6_MIN_MTU) { + if ((daddr && !ipv4_is_multicast(daddr)) || + rt6->rt6i_dst.plen == 128) { + rt6->rt6i_flags |= RTF_MODIFIED; + dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); + } + } + + if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && + mtu < pkt_size) { + icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); + return -E2BIG; + } + } +#endif + return 0; +} + +void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, + u8 proto, int tunnel_hlen) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + u32 headroom = sizeof(struct iphdr); + struct ip_tunnel_info *tun_info; + const struct ip_tunnel_key *key; + const struct iphdr *inner_iph; + struct rtable *rt = NULL; + struct flowi4 fl4; + __be16 df = 0; + u8 tos, ttl; + bool use_cache; + + tun_info = skb_tunnel_info(skb); + if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || + ip_tunnel_info_af(tun_info) != AF_INET)) + goto tx_error; + key = &tun_info->key; + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + inner_iph = (const struct iphdr *)skb_inner_network_header(skb); + tos = key->tos; + if (tos == 1) { + if (skb->protocol == htons(ETH_P_IP)) + tos = inner_iph->tos; + else if (skb->protocol == htons(ETH_P_IPV6)) + tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); + } + ip_tunnel_init_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src, + tunnel_id_to_key32(key->tun_id), RT_TOS(tos), + 0, skb->mark, skb_get_hash(skb)); + if (tunnel->encap.type != TUNNEL_ENCAP_NONE) + goto tx_error; + + use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); + if (use_cache) + rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl4.saddr); + if (!rt) { + rt = ip_route_output_key(tunnel->net, &fl4); + if (IS_ERR(rt)) { + dev->stats.tx_carrier_errors++; + goto tx_error; + } + if (use_cache) + dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, + fl4.saddr); + } + if (rt->dst.dev == dev) { + ip_rt_put(rt); + dev->stats.collisions++; + goto tx_error; + } + + if (key->tun_flags & TUNNEL_DONT_FRAGMENT) + df = htons(IP_DF); + if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, tunnel_hlen, + key->u.ipv4.dst, true)) { + ip_rt_put(rt); + goto tx_error; + } + + tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); + ttl = key->ttl; + if (ttl == 0) { + if (skb->protocol == htons(ETH_P_IP)) + ttl = inner_iph->ttl; + else if (skb->protocol == htons(ETH_P_IPV6)) + ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; + else + ttl = ip4_dst_hoplimit(&rt->dst); + } + + headroom += LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len; + if (headroom > READ_ONCE(dev->needed_headroom)) + WRITE_ONCE(dev->needed_headroom, headroom); + + if (skb_cow_head(skb, READ_ONCE(dev->needed_headroom))) { + ip_rt_put(rt); + goto tx_dropped; + } + iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, proto, tos, ttl, + df, !net_eq(tunnel->net, dev_net(dev))); + return; +tx_error: + dev->stats.tx_errors++; + goto kfree; +tx_dropped: + dev->stats.tx_dropped++; +kfree: + kfree_skb(skb); +} +EXPORT_SYMBOL_GPL(ip_md_tunnel_xmit); + +void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, + const struct iphdr *tnl_params, u8 protocol) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct ip_tunnel_info *tun_info = NULL; + const struct iphdr *inner_iph; + unsigned int max_headroom; /* The extra header space needed */ + struct rtable *rt = NULL; /* Route to the other host */ + bool use_cache = false; + struct flowi4 fl4; + bool md = false; + bool connected; + u8 tos, ttl; + __be32 dst; + __be16 df; + + inner_iph = (const struct iphdr *)skb_inner_network_header(skb); + connected = (tunnel->parms.iph.daddr != 0); + + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + + dst = tnl_params->daddr; + if (dst == 0) { + /* NBMA tunnel */ + + if (!skb_dst(skb)) { + dev->stats.tx_fifo_errors++; + goto tx_error; + } + + tun_info = skb_tunnel_info(skb); + if (tun_info && (tun_info->mode & IP_TUNNEL_INFO_TX) && + ip_tunnel_info_af(tun_info) == AF_INET && + tun_info->key.u.ipv4.dst) { + dst = tun_info->key.u.ipv4.dst; + md = true; + connected = true; + } + else if (skb->protocol == htons(ETH_P_IP)) { + rt = skb_rtable(skb); + dst = rt_nexthop(rt, inner_iph->daddr); + } +#if IS_ENABLED(CONFIG_IPV6) + else if (skb->protocol == htons(ETH_P_IPV6)) { + const struct in6_addr *addr6; + struct neighbour *neigh; + bool do_tx_error_icmp; + int addr_type; + + neigh = dst_neigh_lookup(skb_dst(skb), + &ipv6_hdr(skb)->daddr); + if (!neigh) + goto tx_error; + + addr6 = (const struct in6_addr *)&neigh->primary_key; + addr_type = ipv6_addr_type(addr6); + + if (addr_type == IPV6_ADDR_ANY) { + addr6 = &ipv6_hdr(skb)->daddr; + addr_type = ipv6_addr_type(addr6); + } + + if ((addr_type & IPV6_ADDR_COMPATv4) == 0) + do_tx_error_icmp = true; + else { + do_tx_error_icmp = false; + dst = addr6->s6_addr32[3]; + } + neigh_release(neigh); + if (do_tx_error_icmp) + goto tx_error_icmp; + } +#endif + else + goto tx_error; + + if (!md) + connected = false; + } + + tos = tnl_params->tos; + if (tos & 0x1) { + tos &= ~0x1; + if (skb->protocol == htons(ETH_P_IP)) { + tos = inner_iph->tos; + connected = false; + } else if (skb->protocol == htons(ETH_P_IPV6)) { + tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); + connected = false; + } + } + + ip_tunnel_init_flow(&fl4, protocol, dst, tnl_params->saddr, + tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link, + tunnel->fwmark, skb_get_hash(skb)); + + if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) + goto tx_error; + + if (connected && md) { + use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); + if (use_cache) + rt = dst_cache_get_ip4(&tun_info->dst_cache, + &fl4.saddr); + } else { + rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, + &fl4.saddr) : NULL; + } + + if (!rt) { + rt = ip_route_output_key(tunnel->net, &fl4); + + if (IS_ERR(rt)) { + dev->stats.tx_carrier_errors++; + goto tx_error; + } + if (use_cache) + dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, + fl4.saddr); + else if (!md && connected) + dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, + fl4.saddr); + } + + if (rt->dst.dev == dev) { + ip_rt_put(rt); + dev->stats.collisions++; + goto tx_error; + } + + df = tnl_params->frag_off; + if (skb->protocol == htons(ETH_P_IP) && !tunnel->ignore_df) + df |= (inner_iph->frag_off & htons(IP_DF)); + + if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, 0, 0, false)) { + ip_rt_put(rt); + goto tx_error; + } + + if (tunnel->err_count > 0) { + if (time_before(jiffies, + tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { + tunnel->err_count--; + + dst_link_failure(skb); + } else + tunnel->err_count = 0; + } + + tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); + ttl = tnl_params->ttl; + if (ttl == 0) { + if (skb->protocol == htons(ETH_P_IP)) + ttl = inner_iph->ttl; +#if IS_ENABLED(CONFIG_IPV6) + else if (skb->protocol == htons(ETH_P_IPV6)) + ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; +#endif + else + ttl = ip4_dst_hoplimit(&rt->dst); + } + + max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) + + rt->dst.header_len + ip_encap_hlen(&tunnel->encap); + if (max_headroom > READ_ONCE(dev->needed_headroom)) + WRITE_ONCE(dev->needed_headroom, max_headroom); + + if (skb_cow_head(skb, READ_ONCE(dev->needed_headroom))) { + ip_rt_put(rt); + dev->stats.tx_dropped++; + kfree_skb(skb); + return; + } + + iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, + df, !net_eq(tunnel->net, dev_net(dev))); + return; + +#if IS_ENABLED(CONFIG_IPV6) +tx_error_icmp: + dst_link_failure(skb); +#endif +tx_error: + dev->stats.tx_errors++; + kfree_skb(skb); +} +EXPORT_SYMBOL_GPL(ip_tunnel_xmit); + +static void ip_tunnel_update(struct ip_tunnel_net *itn, + struct ip_tunnel *t, + struct net_device *dev, + struct ip_tunnel_parm *p, + bool set_mtu, + __u32 fwmark) +{ + ip_tunnel_del(itn, t); + t->parms.iph.saddr = p->iph.saddr; + t->parms.iph.daddr = p->iph.daddr; + t->parms.i_key = p->i_key; + t->parms.o_key = p->o_key; + if (dev->type != ARPHRD_ETHER) { + memcpy(dev->dev_addr, &p->iph.saddr, 4); + memcpy(dev->broadcast, &p->iph.daddr, 4); + } + ip_tunnel_add(itn, t); + + t->parms.iph.ttl = p->iph.ttl; + t->parms.iph.tos = p->iph.tos; + t->parms.iph.frag_off = p->iph.frag_off; + + if (t->parms.link != p->link || t->fwmark != fwmark) { + int mtu; + + t->parms.link = p->link; + t->fwmark = fwmark; + mtu = ip_tunnel_bind_dev(dev); + if (set_mtu) + dev->mtu = mtu; + } + dst_cache_reset(&t->dst_cache); + netdev_state_change(dev); +} + +int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) +{ + int err = 0; + struct ip_tunnel *t = netdev_priv(dev); + struct net *net = t->net; + struct ip_tunnel_net *itn = net_generic(net, t->ip_tnl_net_id); + + switch (cmd) { + case SIOCGETTUNNEL: + if (dev == itn->fb_tunnel_dev) { + t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); + if (!t) + t = netdev_priv(dev); + } + memcpy(p, &t->parms, sizeof(*p)); + break; + + case SIOCADDTUNNEL: + case SIOCCHGTUNNEL: + err = -EPERM; + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + goto done; + if (p->iph.ttl) + p->iph.frag_off |= htons(IP_DF); + if (!(p->i_flags & VTI_ISVTI)) { + if (!(p->i_flags & TUNNEL_KEY)) + p->i_key = 0; + if (!(p->o_flags & TUNNEL_KEY)) + p->o_key = 0; + } + + t = ip_tunnel_find(itn, p, itn->type); + + if (cmd == SIOCADDTUNNEL) { + if (!t) { + t = ip_tunnel_create(net, itn, p); + err = PTR_ERR_OR_ZERO(t); + break; + } + + err = -EEXIST; + break; + } + if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { + if (t) { + if (t->dev != dev) { + err = -EEXIST; + break; + } + } else { + unsigned int nflags = 0; + + if (ipv4_is_multicast(p->iph.daddr)) + nflags = IFF_BROADCAST; + else if (p->iph.daddr) + nflags = IFF_POINTOPOINT; + + if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { + err = -EINVAL; + break; + } + + t = netdev_priv(dev); + } + } + + if (t) { + err = 0; + ip_tunnel_update(itn, t, dev, p, true, 0); + } else { + err = -ENOENT; + } + break; + + case SIOCDELTUNNEL: + err = -EPERM; + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + goto done; + + if (dev == itn->fb_tunnel_dev) { + err = -ENOENT; + t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); + if (!t) + goto done; + err = -EPERM; + if (t == netdev_priv(itn->fb_tunnel_dev)) + goto done; + dev = t->dev; + } + unregister_netdevice(dev); + err = 0; + break; + + default: + err = -EINVAL; + } + +done: + return err; +} +EXPORT_SYMBOL_GPL(ip_tunnel_ctl); + +int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) +{ + struct ip_tunnel_parm p; + int err; + + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) + return -EFAULT; + err = dev->netdev_ops->ndo_tunnel_ctl(dev, &p, cmd); + if (!err && copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) + return -EFAULT; + return err; +} +EXPORT_SYMBOL_GPL(ip_tunnel_ioctl); + +int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + int t_hlen = tunnel->hlen + sizeof(struct iphdr); + int max_mtu = IP_MAX_MTU - t_hlen; + + if (dev->type == ARPHRD_ETHER) + max_mtu -= dev->hard_header_len; + + if (new_mtu < ETH_MIN_MTU) + return -EINVAL; + + if (new_mtu > max_mtu) { + if (strict) + return -EINVAL; + + new_mtu = max_mtu; + } + + dev->mtu = new_mtu; + return 0; +} +EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu); + +int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu) +{ + return __ip_tunnel_change_mtu(dev, new_mtu, true); +} +EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu); + +static void ip_tunnel_dev_free(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + gro_cells_destroy(&tunnel->gro_cells); + dst_cache_destroy(&tunnel->dst_cache); + free_percpu(dev->tstats); +} + +void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct ip_tunnel_net *itn; + + itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); + + if (itn->fb_tunnel_dev != dev) { + ip_tunnel_del(itn, netdev_priv(dev)); + unregister_netdevice_queue(dev, head); + } +} +EXPORT_SYMBOL_GPL(ip_tunnel_dellink); + +struct net *ip_tunnel_get_link_net(const struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + return tunnel->net; +} +EXPORT_SYMBOL(ip_tunnel_get_link_net); + +int ip_tunnel_get_iflink(const struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + return tunnel->parms.link; +} +EXPORT_SYMBOL(ip_tunnel_get_iflink); + +int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, + struct rtnl_link_ops *ops, char *devname) +{ + struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id); + struct ip_tunnel_parm parms; + unsigned int i; + + itn->rtnl_link_ops = ops; + for (i = 0; i < IP_TNL_HASH_SIZE; i++) + INIT_HLIST_HEAD(&itn->tunnels[i]); + + if (!ops || !net_has_fallback_tunnels(net)) { + struct ip_tunnel_net *it_init_net; + + it_init_net = net_generic(&init_net, ip_tnl_net_id); + itn->type = it_init_net->type; + itn->fb_tunnel_dev = NULL; + return 0; + } + + memset(&parms, 0, sizeof(parms)); + if (devname) + strlcpy(parms.name, devname, IFNAMSIZ); + + rtnl_lock(); + itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); + /* FB netdevice is special: we have one, and only one per netns. + * Allowing to move it to another netns is clearly unsafe. + */ + if (!IS_ERR(itn->fb_tunnel_dev)) { + itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; + itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev); + ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev)); + itn->type = itn->fb_tunnel_dev->type; + } + rtnl_unlock(); + + return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev); +} +EXPORT_SYMBOL_GPL(ip_tunnel_init_net); + +static void ip_tunnel_destroy(struct net *net, struct ip_tunnel_net *itn, + struct list_head *head, + struct rtnl_link_ops *ops) +{ + struct net_device *dev, *aux; + int h; + + for_each_netdev_safe(net, dev, aux) + if (dev->rtnl_link_ops == ops) + unregister_netdevice_queue(dev, head); + + for (h = 0; h < IP_TNL_HASH_SIZE; h++) { + struct ip_tunnel *t; + struct hlist_node *n; + struct hlist_head *thead = &itn->tunnels[h]; + + hlist_for_each_entry_safe(t, n, thead, hash_node) + /* If dev is in the same netns, it has already + * been added to the list by the previous loop. + */ + if (!net_eq(dev_net(t->dev), net)) + unregister_netdevice_queue(t->dev, head); + } +} + +void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id, + struct rtnl_link_ops *ops) +{ + struct ip_tunnel_net *itn; + struct net *net; + LIST_HEAD(list); + + rtnl_lock(); + list_for_each_entry(net, net_list, exit_list) { + itn = net_generic(net, id); + ip_tunnel_destroy(net, itn, &list, ops); + } + unregister_netdevice_many(&list); + rtnl_unlock(); +} +EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets); + +int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], + struct ip_tunnel_parm *p, __u32 fwmark) +{ + struct ip_tunnel *nt; + struct net *net = dev_net(dev); + struct ip_tunnel_net *itn; + int mtu; + int err; + + nt = netdev_priv(dev); + itn = net_generic(net, nt->ip_tnl_net_id); + + if (nt->collect_md) { + if (rtnl_dereference(itn->collect_md_tun)) + return -EEXIST; + } else { + if (ip_tunnel_find(itn, p, dev->type)) + return -EEXIST; + } + + nt->net = net; + nt->parms = *p; + nt->fwmark = fwmark; + err = register_netdevice(dev); + if (err) + goto err_register_netdevice; + + if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) + eth_hw_addr_random(dev); + + mtu = ip_tunnel_bind_dev(dev); + if (tb[IFLA_MTU]) { + unsigned int max = IP_MAX_MTU - (nt->hlen + sizeof(struct iphdr)); + + if (dev->type == ARPHRD_ETHER) + max -= dev->hard_header_len; + + mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, max); + } + + err = dev_set_mtu(dev, mtu); + if (err) + goto err_dev_set_mtu; + + ip_tunnel_add(itn, nt); + return 0; + +err_dev_set_mtu: + unregister_netdevice(dev); +err_register_netdevice: + return err; +} +EXPORT_SYMBOL_GPL(ip_tunnel_newlink); + +int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], + struct ip_tunnel_parm *p, __u32 fwmark) +{ + struct ip_tunnel *t; + struct ip_tunnel *tunnel = netdev_priv(dev); + struct net *net = tunnel->net; + struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id); + + if (dev == itn->fb_tunnel_dev) + return -EINVAL; + + t = ip_tunnel_find(itn, p, dev->type); + + if (t) { + if (t->dev != dev) + return -EEXIST; + } else { + t = tunnel; + + if (dev->type != ARPHRD_ETHER) { + unsigned int nflags = 0; + + if (ipv4_is_multicast(p->iph.daddr)) + nflags = IFF_BROADCAST; + else if (p->iph.daddr) + nflags = IFF_POINTOPOINT; + + if ((dev->flags ^ nflags) & + (IFF_POINTOPOINT | IFF_BROADCAST)) + return -EINVAL; + } + } + + ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU], fwmark); + return 0; +} +EXPORT_SYMBOL_GPL(ip_tunnel_changelink); + +int ip_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct iphdr *iph = &tunnel->parms.iph; + int err; + + dev->needs_free_netdev = true; + dev->priv_destructor = ip_tunnel_dev_free; + dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); + if (!dev->tstats) + return -ENOMEM; + + err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); + if (err) { + free_percpu(dev->tstats); + return err; + } + + err = gro_cells_init(&tunnel->gro_cells, dev); + if (err) { + dst_cache_destroy(&tunnel->dst_cache); + free_percpu(dev->tstats); + return err; + } + + tunnel->dev = dev; + tunnel->net = dev_net(dev); + strcpy(tunnel->parms.name, dev->name); + iph->version = 4; + iph->ihl = 5; + + if (tunnel->collect_md) + netif_keep_dst(dev); + return 0; +} +EXPORT_SYMBOL_GPL(ip_tunnel_init); + +void ip_tunnel_uninit(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct net *net = tunnel->net; + struct ip_tunnel_net *itn; + + itn = net_generic(net, tunnel->ip_tnl_net_id); + ip_tunnel_del(itn, netdev_priv(dev)); + if (itn->fb_tunnel_dev == dev) + WRITE_ONCE(itn->fb_tunnel_dev, NULL); + + dst_cache_reset(&tunnel->dst_cache); +} +EXPORT_SYMBOL_GPL(ip_tunnel_uninit); + +/* Do least required initialization, rest of init is done in tunnel_init call */ +void ip_tunnel_setup(struct net_device *dev, unsigned int net_id) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + tunnel->ip_tnl_net_id = net_id; +} +EXPORT_SYMBOL_GPL(ip_tunnel_setup); + +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c new file mode 100644 index 000000000..da9a55c68 --- /dev/null +++ b/net/ipv4/ip_tunnel_core.c @@ -0,0 +1,1089 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 Nicira, Inc. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/in.h> +#include <linux/if_arp.h> +#include <linux/init.h> +#include <linux/in6.h> +#include <linux/inetdevice.h> +#include <linux/netfilter_ipv4.h> +#include <linux/etherdevice.h> +#include <linux/if_ether.h> +#include <linux/if_vlan.h> +#include <linux/static_key.h> + +#include <net/ip.h> +#include <net/icmp.h> +#include <net/protocol.h> +#include <net/ip_tunnels.h> +#include <net/ip6_tunnel.h> +#include <net/ip6_checksum.h> +#include <net/arp.h> +#include <net/checksum.h> +#include <net/dsfield.h> +#include <net/inet_ecn.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/rtnetlink.h> +#include <net/dst_metadata.h> +#include <net/geneve.h> +#include <net/vxlan.h> +#include <net/erspan.h> + +const struct ip_tunnel_encap_ops __rcu * + iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly; +EXPORT_SYMBOL(iptun_encaps); + +const struct ip6_tnl_encap_ops __rcu * + ip6tun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly; +EXPORT_SYMBOL(ip6tun_encaps); + +void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, + __be32 src, __be32 dst, __u8 proto, + __u8 tos, __u8 ttl, __be16 df, bool xnet) +{ + int pkt_len = skb->len - skb_inner_network_offset(skb); + struct net *net = dev_net(rt->dst.dev); + struct net_device *dev = skb->dev; + struct iphdr *iph; + int err; + + skb_scrub_packet(skb, xnet); + + skb_clear_hash_if_not_l4(skb); + skb_dst_set(skb, &rt->dst); + memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + + /* Push down and install the IP header. */ + skb_push(skb, sizeof(struct iphdr)); + skb_reset_network_header(skb); + + iph = ip_hdr(skb); + + iph->version = 4; + iph->ihl = sizeof(struct iphdr) >> 2; + iph->frag_off = ip_mtu_locked(&rt->dst) ? 0 : df; + iph->protocol = proto; + iph->tos = tos; + iph->daddr = dst; + iph->saddr = src; + iph->ttl = ttl; + __ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1); + + err = ip_local_out(net, sk, skb); + + if (dev) { + if (unlikely(net_xmit_eval(err))) + pkt_len = 0; + iptunnel_xmit_stats(dev, pkt_len); + } +} +EXPORT_SYMBOL_GPL(iptunnel_xmit); + +int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len, + __be16 inner_proto, bool raw_proto, bool xnet) +{ + if (unlikely(!pskb_may_pull(skb, hdr_len))) + return -ENOMEM; + + skb_pull_rcsum(skb, hdr_len); + + if (!raw_proto && inner_proto == htons(ETH_P_TEB)) { + struct ethhdr *eh; + + if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) + return -ENOMEM; + + eh = (struct ethhdr *)skb->data; + if (likely(eth_proto_is_802_3(eh->h_proto))) + skb->protocol = eh->h_proto; + else + skb->protocol = htons(ETH_P_802_2); + + } else { + skb->protocol = inner_proto; + } + + skb_clear_hash_if_not_l4(skb); + __vlan_hwaccel_clear_tag(skb); + skb_set_queue_mapping(skb, 0); + skb_scrub_packet(skb, xnet); + + return iptunnel_pull_offloads(skb); +} +EXPORT_SYMBOL_GPL(__iptunnel_pull_header); + +struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md, + gfp_t flags) +{ + struct metadata_dst *res; + struct ip_tunnel_info *dst, *src; + + if (!md || md->type != METADATA_IP_TUNNEL || + md->u.tun_info.mode & IP_TUNNEL_INFO_TX) + return NULL; + + src = &md->u.tun_info; + res = metadata_dst_alloc(src->options_len, METADATA_IP_TUNNEL, flags); + if (!res) + return NULL; + + dst = &res->u.tun_info; + dst->key.tun_id = src->key.tun_id; + if (src->mode & IP_TUNNEL_INFO_IPV6) + memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src, + sizeof(struct in6_addr)); + else + dst->key.u.ipv4.dst = src->key.u.ipv4.src; + dst->key.tun_flags = src->key.tun_flags; + dst->mode = src->mode | IP_TUNNEL_INFO_TX; + ip_tunnel_info_opts_set(dst, ip_tunnel_info_opts(src), + src->options_len, 0); + + return res; +} +EXPORT_SYMBOL_GPL(iptunnel_metadata_reply); + +int iptunnel_handle_offloads(struct sk_buff *skb, + int gso_type_mask) +{ + int err; + + if (likely(!skb->encapsulation)) { + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + } + + if (skb_is_gso(skb)) { + err = skb_header_unclone(skb, GFP_ATOMIC); + if (unlikely(err)) + return err; + skb_shinfo(skb)->gso_type |= gso_type_mask; + return 0; + } + + if (skb->ip_summed != CHECKSUM_PARTIAL) { + skb->ip_summed = CHECKSUM_NONE; + /* We clear encapsulation here to prevent badly-written + * drivers potentially deciding to offload an inner checksum + * if we set CHECKSUM_PARTIAL on the outer header. + * This should go away when the drivers are all fixed. + */ + skb->encapsulation = 0; + } + + return 0; +} +EXPORT_SYMBOL_GPL(iptunnel_handle_offloads); + +/** + * iptunnel_pmtud_build_icmp() - Build ICMP error message for PMTUD + * @skb: Original packet with L2 header + * @mtu: MTU value for ICMP error + * + * Return: length on success, negative error code if message couldn't be built. + */ +static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu) +{ + const struct iphdr *iph = ip_hdr(skb); + struct icmphdr *icmph; + struct iphdr *niph; + struct ethhdr eh; + int len, err; + + if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr))) + return -EINVAL; + + skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN); + pskb_pull(skb, ETH_HLEN); + skb_reset_network_header(skb); + + err = pskb_trim(skb, 576 - sizeof(*niph) - sizeof(*icmph)); + if (err) + return err; + + len = skb->len + sizeof(*icmph); + err = skb_cow(skb, sizeof(*niph) + sizeof(*icmph) + ETH_HLEN); + if (err) + return err; + + icmph = skb_push(skb, sizeof(*icmph)); + *icmph = (struct icmphdr) { + .type = ICMP_DEST_UNREACH, + .code = ICMP_FRAG_NEEDED, + .checksum = 0, + .un.frag.__unused = 0, + .un.frag.mtu = ntohs(mtu), + }; + icmph->checksum = csum_fold(skb_checksum(skb, 0, len, 0)); + skb_reset_transport_header(skb); + + niph = skb_push(skb, sizeof(*niph)); + *niph = (struct iphdr) { + .ihl = sizeof(*niph) / 4u, + .version = 4, + .tos = 0, + .tot_len = htons(len + sizeof(*niph)), + .id = 0, + .frag_off = htons(IP_DF), + .ttl = iph->ttl, + .protocol = IPPROTO_ICMP, + .saddr = iph->daddr, + .daddr = iph->saddr, + }; + ip_send_check(niph); + skb_reset_network_header(skb); + + skb->ip_summed = CHECKSUM_NONE; + + eth_header(skb, skb->dev, htons(eh.h_proto), eh.h_source, eh.h_dest, 0); + skb_reset_mac_header(skb); + + return skb->len; +} + +/** + * iptunnel_pmtud_check_icmp() - Trigger ICMP reply if needed and allowed + * @skb: Buffer being sent by encapsulation, L2 headers expected + * @mtu: Network MTU for path + * + * Return: 0 for no ICMP reply, length if built, negative value on error. + */ +static int iptunnel_pmtud_check_icmp(struct sk_buff *skb, int mtu) +{ + const struct icmphdr *icmph = icmp_hdr(skb); + const struct iphdr *iph = ip_hdr(skb); + + if (mtu < 576 || iph->frag_off != htons(IP_DF)) + return 0; + + if (ipv4_is_lbcast(iph->daddr) || ipv4_is_multicast(iph->daddr) || + ipv4_is_zeronet(iph->saddr) || ipv4_is_loopback(iph->saddr) || + ipv4_is_lbcast(iph->saddr) || ipv4_is_multicast(iph->saddr)) + return 0; + + if (iph->protocol == IPPROTO_ICMP && icmp_is_err(icmph->type)) + return 0; + + return iptunnel_pmtud_build_icmp(skb, mtu); +} + +#if IS_ENABLED(CONFIG_IPV6) +/** + * iptunnel_pmtud_build_icmpv6() - Build ICMPv6 error message for PMTUD + * @skb: Original packet with L2 header + * @mtu: MTU value for ICMPv6 error + * + * Return: length on success, negative error code if message couldn't be built. + */ +static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu) +{ + const struct ipv6hdr *ip6h = ipv6_hdr(skb); + struct icmp6hdr *icmp6h; + struct ipv6hdr *nip6h; + struct ethhdr eh; + int len, err; + __wsum csum; + + if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))) + return -EINVAL; + + skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN); + pskb_pull(skb, ETH_HLEN); + skb_reset_network_header(skb); + + err = pskb_trim(skb, IPV6_MIN_MTU - sizeof(*nip6h) - sizeof(*icmp6h)); + if (err) + return err; + + len = skb->len + sizeof(*icmp6h); + err = skb_cow(skb, sizeof(*nip6h) + sizeof(*icmp6h) + ETH_HLEN); + if (err) + return err; + + icmp6h = skb_push(skb, sizeof(*icmp6h)); + *icmp6h = (struct icmp6hdr) { + .icmp6_type = ICMPV6_PKT_TOOBIG, + .icmp6_code = 0, + .icmp6_cksum = 0, + .icmp6_mtu = htonl(mtu), + }; + skb_reset_transport_header(skb); + + nip6h = skb_push(skb, sizeof(*nip6h)); + *nip6h = (struct ipv6hdr) { + .priority = 0, + .version = 6, + .flow_lbl = { 0 }, + .payload_len = htons(len), + .nexthdr = IPPROTO_ICMPV6, + .hop_limit = ip6h->hop_limit, + .saddr = ip6h->daddr, + .daddr = ip6h->saddr, + }; + skb_reset_network_header(skb); + + csum = csum_partial(icmp6h, len, 0); + icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len, + IPPROTO_ICMPV6, csum); + + skb->ip_summed = CHECKSUM_NONE; + + eth_header(skb, skb->dev, htons(eh.h_proto), eh.h_source, eh.h_dest, 0); + skb_reset_mac_header(skb); + + return skb->len; +} + +/** + * iptunnel_pmtud_check_icmpv6() - Trigger ICMPv6 reply if needed and allowed + * @skb: Buffer being sent by encapsulation, L2 headers expected + * @mtu: Network MTU for path + * + * Return: 0 for no ICMPv6 reply, length if built, negative value on error. + */ +static int iptunnel_pmtud_check_icmpv6(struct sk_buff *skb, int mtu) +{ + const struct ipv6hdr *ip6h = ipv6_hdr(skb); + int stype = ipv6_addr_type(&ip6h->saddr); + u8 proto = ip6h->nexthdr; + __be16 frag_off; + int offset; + + if (mtu < IPV6_MIN_MTU) + return 0; + + if (stype == IPV6_ADDR_ANY || stype == IPV6_ADDR_MULTICAST || + stype == IPV6_ADDR_LOOPBACK) + return 0; + + offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto, + &frag_off); + if (offset < 0 || (frag_off & htons(~0x7))) + return 0; + + if (proto == IPPROTO_ICMPV6) { + struct icmp6hdr *icmp6h; + + if (!pskb_may_pull(skb, skb_network_header(skb) + + offset + 1 - skb->data)) + return 0; + + icmp6h = (struct icmp6hdr *)(skb_network_header(skb) + offset); + if (icmpv6_is_err(icmp6h->icmp6_type) || + icmp6h->icmp6_type == NDISC_REDIRECT) + return 0; + } + + return iptunnel_pmtud_build_icmpv6(skb, mtu); +} +#endif /* IS_ENABLED(CONFIG_IPV6) */ + +/** + * skb_tunnel_check_pmtu() - Check, update PMTU and trigger ICMP reply as needed + * @skb: Buffer being sent by encapsulation, L2 headers expected + * @encap_dst: Destination for tunnel encapsulation (outer IP) + * @headroom: Encapsulation header size, bytes + * @reply: Build matching ICMP or ICMPv6 message as a result + * + * L2 tunnel implementations that can carry IP and can be directly bridged + * (currently UDP tunnels) can't always rely on IP forwarding paths to handle + * PMTU discovery. In the bridged case, ICMP or ICMPv6 messages need to be built + * based on payload and sent back by the encapsulation itself. + * + * For routable interfaces, we just need to update the PMTU for the destination. + * + * Return: 0 if ICMP error not needed, length if built, negative value on error + */ +int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst, + int headroom, bool reply) +{ + u32 mtu = dst_mtu(encap_dst) - headroom; + + if ((skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) || + (!skb_is_gso(skb) && (skb->len - skb_network_offset(skb)) <= mtu)) + return 0; + + skb_dst_update_pmtu_no_confirm(skb, mtu); + + if (!reply || skb->pkt_type == PACKET_HOST) + return 0; + + if (skb->protocol == htons(ETH_P_IP)) + return iptunnel_pmtud_check_icmp(skb, mtu); + +#if IS_ENABLED(CONFIG_IPV6) + if (skb->protocol == htons(ETH_P_IPV6)) + return iptunnel_pmtud_check_icmpv6(skb, mtu); +#endif + return 0; +} +EXPORT_SYMBOL(skb_tunnel_check_pmtu); + +/* Often modified stats are per cpu, other are shared (netdev->stats) */ +void ip_tunnel_get_stats64(struct net_device *dev, + struct rtnl_link_stats64 *tot) +{ + netdev_stats_to_stats64(tot, &dev->stats); + dev_fetch_sw_netstats(tot, dev->tstats); +} +EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64); + +static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = { + [LWTUNNEL_IP_UNSPEC] = { .strict_start_type = LWTUNNEL_IP_OPTS }, + [LWTUNNEL_IP_ID] = { .type = NLA_U64 }, + [LWTUNNEL_IP_DST] = { .type = NLA_U32 }, + [LWTUNNEL_IP_SRC] = { .type = NLA_U32 }, + [LWTUNNEL_IP_TTL] = { .type = NLA_U8 }, + [LWTUNNEL_IP_TOS] = { .type = NLA_U8 }, + [LWTUNNEL_IP_FLAGS] = { .type = NLA_U16 }, + [LWTUNNEL_IP_OPTS] = { .type = NLA_NESTED }, +}; + +static const struct nla_policy ip_opts_policy[LWTUNNEL_IP_OPTS_MAX + 1] = { + [LWTUNNEL_IP_OPTS_GENEVE] = { .type = NLA_NESTED }, + [LWTUNNEL_IP_OPTS_VXLAN] = { .type = NLA_NESTED }, + [LWTUNNEL_IP_OPTS_ERSPAN] = { .type = NLA_NESTED }, +}; + +static const struct nla_policy +geneve_opt_policy[LWTUNNEL_IP_OPT_GENEVE_MAX + 1] = { + [LWTUNNEL_IP_OPT_GENEVE_CLASS] = { .type = NLA_U16 }, + [LWTUNNEL_IP_OPT_GENEVE_TYPE] = { .type = NLA_U8 }, + [LWTUNNEL_IP_OPT_GENEVE_DATA] = { .type = NLA_BINARY, .len = 128 }, +}; + +static const struct nla_policy +vxlan_opt_policy[LWTUNNEL_IP_OPT_VXLAN_MAX + 1] = { + [LWTUNNEL_IP_OPT_VXLAN_GBP] = { .type = NLA_U32 }, +}; + +static const struct nla_policy +erspan_opt_policy[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1] = { + [LWTUNNEL_IP_OPT_ERSPAN_VER] = { .type = NLA_U8 }, + [LWTUNNEL_IP_OPT_ERSPAN_INDEX] = { .type = NLA_U32 }, + [LWTUNNEL_IP_OPT_ERSPAN_DIR] = { .type = NLA_U8 }, + [LWTUNNEL_IP_OPT_ERSPAN_HWID] = { .type = NLA_U8 }, +}; + +static int ip_tun_parse_opts_geneve(struct nlattr *attr, + struct ip_tunnel_info *info, int opts_len, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[LWTUNNEL_IP_OPT_GENEVE_MAX + 1]; + int data_len, err; + + err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_GENEVE_MAX, attr, + geneve_opt_policy, extack); + if (err) + return err; + + if (!tb[LWTUNNEL_IP_OPT_GENEVE_CLASS] || + !tb[LWTUNNEL_IP_OPT_GENEVE_TYPE] || + !tb[LWTUNNEL_IP_OPT_GENEVE_DATA]) + return -EINVAL; + + attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA]; + data_len = nla_len(attr); + if (data_len % 4) + return -EINVAL; + + if (info) { + struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len; + + memcpy(opt->opt_data, nla_data(attr), data_len); + opt->length = data_len / 4; + attr = tb[LWTUNNEL_IP_OPT_GENEVE_CLASS]; + opt->opt_class = nla_get_be16(attr); + attr = tb[LWTUNNEL_IP_OPT_GENEVE_TYPE]; + opt->type = nla_get_u8(attr); + info->key.tun_flags |= TUNNEL_GENEVE_OPT; + } + + return sizeof(struct geneve_opt) + data_len; +} + +static int ip_tun_parse_opts_vxlan(struct nlattr *attr, + struct ip_tunnel_info *info, int opts_len, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[LWTUNNEL_IP_OPT_VXLAN_MAX + 1]; + int err; + + err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_VXLAN_MAX, attr, + vxlan_opt_policy, extack); + if (err) + return err; + + if (!tb[LWTUNNEL_IP_OPT_VXLAN_GBP]) + return -EINVAL; + + if (info) { + struct vxlan_metadata *md = + ip_tunnel_info_opts(info) + opts_len; + + attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP]; + md->gbp = nla_get_u32(attr); + md->gbp &= VXLAN_GBP_MASK; + info->key.tun_flags |= TUNNEL_VXLAN_OPT; + } + + return sizeof(struct vxlan_metadata); +} + +static int ip_tun_parse_opts_erspan(struct nlattr *attr, + struct ip_tunnel_info *info, int opts_len, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1]; + int err; + u8 ver; + + err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, attr, + erspan_opt_policy, extack); + if (err) + return err; + + if (!tb[LWTUNNEL_IP_OPT_ERSPAN_VER]) + return -EINVAL; + + ver = nla_get_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]); + if (ver == 1) { + if (!tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX]) + return -EINVAL; + } else if (ver == 2) { + if (!tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] || + !tb[LWTUNNEL_IP_OPT_ERSPAN_HWID]) + return -EINVAL; + } else { + return -EINVAL; + } + + if (info) { + struct erspan_metadata *md = + ip_tunnel_info_opts(info) + opts_len; + + md->version = ver; + if (ver == 1) { + attr = tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX]; + md->u.index = nla_get_be32(attr); + } else { + attr = tb[LWTUNNEL_IP_OPT_ERSPAN_DIR]; + md->u.md2.dir = nla_get_u8(attr); + attr = tb[LWTUNNEL_IP_OPT_ERSPAN_HWID]; + set_hwid(&md->u.md2, nla_get_u8(attr)); + } + + info->key.tun_flags |= TUNNEL_ERSPAN_OPT; + } + + return sizeof(struct erspan_metadata); +} + +static int ip_tun_parse_opts(struct nlattr *attr, struct ip_tunnel_info *info, + struct netlink_ext_ack *extack) +{ + int err, rem, opt_len, opts_len = 0, type = 0; + struct nlattr *nla; + + if (!attr) + return 0; + + err = nla_validate(nla_data(attr), nla_len(attr), LWTUNNEL_IP_OPTS_MAX, + ip_opts_policy, extack); + if (err) + return err; + + nla_for_each_attr(nla, nla_data(attr), nla_len(attr), rem) { + switch (nla_type(nla)) { + case LWTUNNEL_IP_OPTS_GENEVE: + if (type && type != TUNNEL_GENEVE_OPT) + return -EINVAL; + opt_len = ip_tun_parse_opts_geneve(nla, info, opts_len, + extack); + if (opt_len < 0) + return opt_len; + opts_len += opt_len; + if (opts_len > IP_TUNNEL_OPTS_MAX) + return -EINVAL; + type = TUNNEL_GENEVE_OPT; + break; + case LWTUNNEL_IP_OPTS_VXLAN: + if (type) + return -EINVAL; + opt_len = ip_tun_parse_opts_vxlan(nla, info, opts_len, + extack); + if (opt_len < 0) + return opt_len; + opts_len += opt_len; + type = TUNNEL_VXLAN_OPT; + break; + case LWTUNNEL_IP_OPTS_ERSPAN: + if (type) + return -EINVAL; + opt_len = ip_tun_parse_opts_erspan(nla, info, opts_len, + extack); + if (opt_len < 0) + return opt_len; + opts_len += opt_len; + type = TUNNEL_ERSPAN_OPT; + break; + default: + return -EINVAL; + } + } + + return opts_len; +} + +static int ip_tun_get_optlen(struct nlattr *attr, + struct netlink_ext_ack *extack) +{ + return ip_tun_parse_opts(attr, NULL, extack); +} + +static int ip_tun_set_opts(struct nlattr *attr, struct ip_tunnel_info *info, + struct netlink_ext_ack *extack) +{ + return ip_tun_parse_opts(attr, info, extack); +} + +static int ip_tun_build_state(struct net *net, struct nlattr *attr, + unsigned int family, const void *cfg, + struct lwtunnel_state **ts, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[LWTUNNEL_IP_MAX + 1]; + struct lwtunnel_state *new_state; + struct ip_tunnel_info *tun_info; + int err, opt_len; + + err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr, + ip_tun_policy, extack); + if (err < 0) + return err; + + opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP_OPTS], extack); + if (opt_len < 0) + return opt_len; + + new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len); + if (!new_state) + return -ENOMEM; + + new_state->type = LWTUNNEL_ENCAP_IP; + + tun_info = lwt_tun_info(new_state); + + err = ip_tun_set_opts(tb[LWTUNNEL_IP_OPTS], tun_info, extack); + if (err < 0) { + lwtstate_free(new_state); + return err; + } + +#ifdef CONFIG_DST_CACHE + err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL); + if (err) { + lwtstate_free(new_state); + return err; + } +#endif + + if (tb[LWTUNNEL_IP_ID]) + tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]); + + if (tb[LWTUNNEL_IP_DST]) + tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]); + + if (tb[LWTUNNEL_IP_SRC]) + tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]); + + if (tb[LWTUNNEL_IP_TTL]) + tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]); + + if (tb[LWTUNNEL_IP_TOS]) + tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]); + + if (tb[LWTUNNEL_IP_FLAGS]) + tun_info->key.tun_flags |= + (nla_get_be16(tb[LWTUNNEL_IP_FLAGS]) & + ~TUNNEL_OPTIONS_PRESENT); + + tun_info->mode = IP_TUNNEL_INFO_TX; + tun_info->options_len = opt_len; + + *ts = new_state; + + return 0; +} + +static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate) +{ +#ifdef CONFIG_DST_CACHE + struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate); + + dst_cache_destroy(&tun_info->dst_cache); +#endif +} + +static int ip_tun_fill_encap_opts_geneve(struct sk_buff *skb, + struct ip_tunnel_info *tun_info) +{ + struct geneve_opt *opt; + struct nlattr *nest; + int offset = 0; + + nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_GENEVE); + if (!nest) + return -ENOMEM; + + while (tun_info->options_len > offset) { + opt = ip_tunnel_info_opts(tun_info) + offset; + if (nla_put_be16(skb, LWTUNNEL_IP_OPT_GENEVE_CLASS, + opt->opt_class) || + nla_put_u8(skb, LWTUNNEL_IP_OPT_GENEVE_TYPE, opt->type) || + nla_put(skb, LWTUNNEL_IP_OPT_GENEVE_DATA, opt->length * 4, + opt->opt_data)) { + nla_nest_cancel(skb, nest); + return -ENOMEM; + } + offset += sizeof(*opt) + opt->length * 4; + } + + nla_nest_end(skb, nest); + return 0; +} + +static int ip_tun_fill_encap_opts_vxlan(struct sk_buff *skb, + struct ip_tunnel_info *tun_info) +{ + struct vxlan_metadata *md; + struct nlattr *nest; + + nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_VXLAN); + if (!nest) + return -ENOMEM; + + md = ip_tunnel_info_opts(tun_info); + if (nla_put_u32(skb, LWTUNNEL_IP_OPT_VXLAN_GBP, md->gbp)) { + nla_nest_cancel(skb, nest); + return -ENOMEM; + } + + nla_nest_end(skb, nest); + return 0; +} + +static int ip_tun_fill_encap_opts_erspan(struct sk_buff *skb, + struct ip_tunnel_info *tun_info) +{ + struct erspan_metadata *md; + struct nlattr *nest; + + nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_ERSPAN); + if (!nest) + return -ENOMEM; + + md = ip_tunnel_info_opts(tun_info); + if (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version)) + goto err; + + if (md->version == 1 && + nla_put_be32(skb, LWTUNNEL_IP_OPT_ERSPAN_INDEX, md->u.index)) + goto err; + + if (md->version == 2 && + (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_DIR, md->u.md2.dir) || + nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_HWID, + get_hwid(&md->u.md2)))) + goto err; + + nla_nest_end(skb, nest); + return 0; +err: + nla_nest_cancel(skb, nest); + return -ENOMEM; +} + +static int ip_tun_fill_encap_opts(struct sk_buff *skb, int type, + struct ip_tunnel_info *tun_info) +{ + struct nlattr *nest; + int err = 0; + + if (!(tun_info->key.tun_flags & TUNNEL_OPTIONS_PRESENT)) + return 0; + + nest = nla_nest_start_noflag(skb, type); + if (!nest) + return -ENOMEM; + + if (tun_info->key.tun_flags & TUNNEL_GENEVE_OPT) + err = ip_tun_fill_encap_opts_geneve(skb, tun_info); + else if (tun_info->key.tun_flags & TUNNEL_VXLAN_OPT) + err = ip_tun_fill_encap_opts_vxlan(skb, tun_info); + else if (tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT) + err = ip_tun_fill_encap_opts_erspan(skb, tun_info); + + if (err) { + nla_nest_cancel(skb, nest); + return err; + } + + nla_nest_end(skb, nest); + return 0; +} + +static int ip_tun_fill_encap_info(struct sk_buff *skb, + struct lwtunnel_state *lwtstate) +{ + struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate); + + if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id, + LWTUNNEL_IP_PAD) || + nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) || + nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) || + nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) || + nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) || + nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags) || + ip_tun_fill_encap_opts(skb, LWTUNNEL_IP_OPTS, tun_info)) + return -ENOMEM; + + return 0; +} + +static int ip_tun_opts_nlsize(struct ip_tunnel_info *info) +{ + int opt_len; + + if (!(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT)) + return 0; + + opt_len = nla_total_size(0); /* LWTUNNEL_IP_OPTS */ + if (info->key.tun_flags & TUNNEL_GENEVE_OPT) { + struct geneve_opt *opt; + int offset = 0; + + opt_len += nla_total_size(0); /* LWTUNNEL_IP_OPTS_GENEVE */ + while (info->options_len > offset) { + opt = ip_tunnel_info_opts(info) + offset; + opt_len += nla_total_size(2) /* OPT_GENEVE_CLASS */ + + nla_total_size(1) /* OPT_GENEVE_TYPE */ + + nla_total_size(opt->length * 4); + /* OPT_GENEVE_DATA */ + offset += sizeof(*opt) + opt->length * 4; + } + } else if (info->key.tun_flags & TUNNEL_VXLAN_OPT) { + opt_len += nla_total_size(0) /* LWTUNNEL_IP_OPTS_VXLAN */ + + nla_total_size(4); /* OPT_VXLAN_GBP */ + } else if (info->key.tun_flags & TUNNEL_ERSPAN_OPT) { + struct erspan_metadata *md = ip_tunnel_info_opts(info); + + opt_len += nla_total_size(0) /* LWTUNNEL_IP_OPTS_ERSPAN */ + + nla_total_size(1) /* OPT_ERSPAN_VER */ + + (md->version == 1 ? nla_total_size(4) + /* OPT_ERSPAN_INDEX (v1) */ + : nla_total_size(1) + + nla_total_size(1)); + /* OPT_ERSPAN_DIR + HWID (v2) */ + } + + return opt_len; +} + +static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate) +{ + return nla_total_size_64bit(8) /* LWTUNNEL_IP_ID */ + + nla_total_size(4) /* LWTUNNEL_IP_DST */ + + nla_total_size(4) /* LWTUNNEL_IP_SRC */ + + nla_total_size(1) /* LWTUNNEL_IP_TOS */ + + nla_total_size(1) /* LWTUNNEL_IP_TTL */ + + nla_total_size(2) /* LWTUNNEL_IP_FLAGS */ + + ip_tun_opts_nlsize(lwt_tun_info(lwtstate)); + /* LWTUNNEL_IP_OPTS */ +} + +static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b) +{ + struct ip_tunnel_info *info_a = lwt_tun_info(a); + struct ip_tunnel_info *info_b = lwt_tun_info(b); + + return memcmp(info_a, info_b, sizeof(info_a->key)) || + info_a->mode != info_b->mode || + info_a->options_len != info_b->options_len || + memcmp(ip_tunnel_info_opts(info_a), + ip_tunnel_info_opts(info_b), info_a->options_len); +} + +static const struct lwtunnel_encap_ops ip_tun_lwt_ops = { + .build_state = ip_tun_build_state, + .destroy_state = ip_tun_destroy_state, + .fill_encap = ip_tun_fill_encap_info, + .get_encap_size = ip_tun_encap_nlsize, + .cmp_encap = ip_tun_cmp_encap, + .owner = THIS_MODULE, +}; + +static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = { + [LWTUNNEL_IP6_UNSPEC] = { .strict_start_type = LWTUNNEL_IP6_OPTS }, + [LWTUNNEL_IP6_ID] = { .type = NLA_U64 }, + [LWTUNNEL_IP6_DST] = { .len = sizeof(struct in6_addr) }, + [LWTUNNEL_IP6_SRC] = { .len = sizeof(struct in6_addr) }, + [LWTUNNEL_IP6_HOPLIMIT] = { .type = NLA_U8 }, + [LWTUNNEL_IP6_TC] = { .type = NLA_U8 }, + [LWTUNNEL_IP6_FLAGS] = { .type = NLA_U16 }, + [LWTUNNEL_IP6_OPTS] = { .type = NLA_NESTED }, +}; + +static int ip6_tun_build_state(struct net *net, struct nlattr *attr, + unsigned int family, const void *cfg, + struct lwtunnel_state **ts, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[LWTUNNEL_IP6_MAX + 1]; + struct lwtunnel_state *new_state; + struct ip_tunnel_info *tun_info; + int err, opt_len; + + err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr, + ip6_tun_policy, extack); + if (err < 0) + return err; + + opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP6_OPTS], extack); + if (opt_len < 0) + return opt_len; + + new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len); + if (!new_state) + return -ENOMEM; + + new_state->type = LWTUNNEL_ENCAP_IP6; + + tun_info = lwt_tun_info(new_state); + + err = ip_tun_set_opts(tb[LWTUNNEL_IP6_OPTS], tun_info, extack); + if (err < 0) { + lwtstate_free(new_state); + return err; + } + + if (tb[LWTUNNEL_IP6_ID]) + tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]); + + if (tb[LWTUNNEL_IP6_DST]) + tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]); + + if (tb[LWTUNNEL_IP6_SRC]) + tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]); + + if (tb[LWTUNNEL_IP6_HOPLIMIT]) + tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]); + + if (tb[LWTUNNEL_IP6_TC]) + tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]); + + if (tb[LWTUNNEL_IP6_FLAGS]) + tun_info->key.tun_flags |= + (nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]) & + ~TUNNEL_OPTIONS_PRESENT); + + tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6; + tun_info->options_len = opt_len; + + *ts = new_state; + + return 0; +} + +static int ip6_tun_fill_encap_info(struct sk_buff *skb, + struct lwtunnel_state *lwtstate) +{ + struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate); + + if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id, + LWTUNNEL_IP6_PAD) || + nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) || + nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) || + nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) || + nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) || + nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags) || + ip_tun_fill_encap_opts(skb, LWTUNNEL_IP6_OPTS, tun_info)) + return -ENOMEM; + + return 0; +} + +static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate) +{ + return nla_total_size_64bit(8) /* LWTUNNEL_IP6_ID */ + + nla_total_size(16) /* LWTUNNEL_IP6_DST */ + + nla_total_size(16) /* LWTUNNEL_IP6_SRC */ + + nla_total_size(1) /* LWTUNNEL_IP6_HOPLIMIT */ + + nla_total_size(1) /* LWTUNNEL_IP6_TC */ + + nla_total_size(2) /* LWTUNNEL_IP6_FLAGS */ + + ip_tun_opts_nlsize(lwt_tun_info(lwtstate)); + /* LWTUNNEL_IP6_OPTS */ +} + +static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = { + .build_state = ip6_tun_build_state, + .fill_encap = ip6_tun_fill_encap_info, + .get_encap_size = ip6_tun_encap_nlsize, + .cmp_encap = ip_tun_cmp_encap, + .owner = THIS_MODULE, +}; + +void __init ip_tunnel_core_init(void) +{ + /* If you land here, make sure whether increasing ip_tunnel_info's + * options_len is a reasonable choice with its usage in front ends + * (f.e., it's part of flow keys, etc). + */ + BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255); + + lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP); + lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6); +} + +DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt); +EXPORT_SYMBOL(ip_tunnel_metadata_cnt); + +void ip_tunnel_need_metadata(void) +{ + static_branch_inc(&ip_tunnel_metadata_cnt); +} +EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata); + +void ip_tunnel_unneed_metadata(void) +{ + static_branch_dec(&ip_tunnel_metadata_cnt); +} +EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata); + +/* Returns either the correct skb->protocol value, or 0 if invalid. */ +__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb) +{ + if (skb_network_header(skb) >= skb->head && + (skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) && + ip_hdr(skb)->version == 4) + return htons(ETH_P_IP); + if (skb_network_header(skb) >= skb->head && + (skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) && + ipv6_hdr(skb)->version == 6) + return htons(ETH_P_IPV6); + return 0; +} +EXPORT_SYMBOL(ip_tunnel_parse_protocol); + +const struct header_ops ip_tunnel_header_ops = { .parse_protocol = ip_tunnel_parse_protocol }; +EXPORT_SYMBOL(ip_tunnel_header_ops); diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c new file mode 100644 index 000000000..90f349be4 --- /dev/null +++ b/net/ipv4/ip_vti.c @@ -0,0 +1,723 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Linux NET3: IP/IP protocol decoder modified to support + * virtual tunnel interface + * + * Authors: + * Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012 + */ + +/* + This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c + + For comments look at net/ipv4/ip_gre.c --ANK + */ + + +#include <linux/capability.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/uaccess.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/in.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/if_arp.h> +#include <linux/init.h> +#include <linux/netfilter_ipv4.h> +#include <linux/if_ether.h> +#include <linux/icmpv6.h> + +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/ip_tunnels.h> +#include <net/inet_ecn.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> + +static struct rtnl_link_ops vti_link_ops __read_mostly; + +static unsigned int vti_net_id __read_mostly; +static int vti_tunnel_init(struct net_device *dev); + +static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi, + int encap_type, bool update_skb_dev) +{ + struct ip_tunnel *tunnel; + const struct iphdr *iph = ip_hdr(skb); + struct net *net = dev_net(skb->dev); + struct ip_tunnel_net *itn = net_generic(net, vti_net_id); + + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, + iph->saddr, iph->daddr, 0); + if (tunnel) { + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto drop; + + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel; + + if (update_skb_dev) + skb->dev = tunnel->dev; + + return xfrm_input(skb, nexthdr, spi, encap_type); + } + + return -EINVAL; +drop: + kfree_skb(skb); + return 0; +} + +static int vti_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi, + int encap_type) +{ + return vti_input(skb, nexthdr, spi, encap_type, false); +} + +static int vti_rcv(struct sk_buff *skb, __be32 spi, bool update_skb_dev) +{ + XFRM_SPI_SKB_CB(skb)->family = AF_INET; + XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr); + + return vti_input(skb, ip_hdr(skb)->protocol, spi, 0, update_skb_dev); +} + +static int vti_rcv_proto(struct sk_buff *skb) +{ + return vti_rcv(skb, 0, false); +} + +static int vti_rcv_cb(struct sk_buff *skb, int err) +{ + unsigned short family; + struct net_device *dev; + struct xfrm_state *x; + const struct xfrm_mode *inner_mode; + struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4; + u32 orig_mark = skb->mark; + int ret; + + if (!tunnel) + return 1; + + dev = tunnel->dev; + + if (err) { + dev->stats.rx_errors++; + dev->stats.rx_dropped++; + + return 0; + } + + x = xfrm_input_state(skb); + + inner_mode = &x->inner_mode; + + if (x->sel.family == AF_UNSPEC) { + inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); + if (inner_mode == NULL) { + XFRM_INC_STATS(dev_net(skb->dev), + LINUX_MIB_XFRMINSTATEMODEERROR); + return -EINVAL; + } + } + + family = inner_mode->family; + + skb->mark = be32_to_cpu(tunnel->parms.i_key); + ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family); + skb->mark = orig_mark; + + if (!ret) + return -EPERM; + + skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev))); + skb->dev = dev; + dev_sw_netstats_rx_add(dev, skb->len); + + return 0; +} + +static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src) +{ + xfrm_address_t *daddr = (xfrm_address_t *)&dst; + xfrm_address_t *saddr = (xfrm_address_t *)&src; + + /* if there is no transform then this tunnel is not functional. + * Or if the xfrm is not mode tunnel. + */ + if (!x || x->props.mode != XFRM_MODE_TUNNEL || + x->props.family != AF_INET) + return false; + + if (!dst) + return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET); + + if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET)) + return false; + + return true; +} + +static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev, + struct flowi *fl) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct ip_tunnel_parm *parms = &tunnel->parms; + struct dst_entry *dst = skb_dst(skb); + struct net_device *tdev; /* Device to other host */ + int pkt_len = skb->len; + int err; + int mtu; + + if (!dst) { + switch (skb->protocol) { + case htons(ETH_P_IP): { + struct rtable *rt; + + fl->u.ip4.flowi4_oif = dev->ifindex; + fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC; + rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4); + if (IS_ERR(rt)) { + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + dst = &rt->dst; + skb_dst_set(skb, dst); + break; + } +#if IS_ENABLED(CONFIG_IPV6) + case htons(ETH_P_IPV6): + fl->u.ip6.flowi6_oif = dev->ifindex; + fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC; + dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6); + if (dst->error) { + dst_release(dst); + dst = NULL; + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + skb_dst_set(skb, dst); + break; +#endif + default: + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + } + + dst_hold(dst); + dst = xfrm_lookup_route(tunnel->net, dst, fl, NULL, 0); + if (IS_ERR(dst)) { + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + + if (dst->flags & DST_XFRM_QUEUE) + goto queued; + + if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) { + dev->stats.tx_carrier_errors++; + dst_release(dst); + goto tx_error_icmp; + } + + tdev = dst->dev; + + if (tdev == dev) { + dst_release(dst); + dev->stats.collisions++; + goto tx_error; + } + + mtu = dst_mtu(dst); + if (skb->len > mtu) { + skb_dst_update_pmtu_no_confirm(skb, mtu); + if (skb->protocol == htons(ETH_P_IP)) { + icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + htonl(mtu)); + } else { + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + + icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); + } + + dst_release(dst); + goto tx_error; + } + +queued: + skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev))); + skb_dst_set(skb, dst); + skb->dev = skb_dst(skb)->dev; + + err = dst_output(tunnel->net, skb->sk, skb); + if (net_xmit_eval(err) == 0) + err = pkt_len; + iptunnel_xmit_stats(dev, err); + return NETDEV_TX_OK; + +tx_error_icmp: + dst_link_failure(skb); +tx_error: + dev->stats.tx_errors++; + kfree_skb(skb); + return NETDEV_TX_OK; +} + +/* This function assumes it is being called from dev_queue_xmit() + * and that skb is filled properly by that function. + */ +static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct flowi fl; + + if (!pskb_inet_may_pull(skb)) + goto tx_err; + + memset(&fl, 0, sizeof(fl)); + + switch (skb->protocol) { + case htons(ETH_P_IP): + memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + xfrm_decode_session(skb, &fl, AF_INET); + break; + case htons(ETH_P_IPV6): + memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); + xfrm_decode_session(skb, &fl, AF_INET6); + break; + default: + goto tx_err; + } + + /* override mark with tunnel output key */ + fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key); + + return vti_xmit(skb, dev, &fl); + +tx_err: + dev->stats.tx_errors++; + kfree_skb(skb); + return NETDEV_TX_OK; +} + +static int vti4_err(struct sk_buff *skb, u32 info) +{ + __be32 spi; + __u32 mark; + struct xfrm_state *x; + struct ip_tunnel *tunnel; + struct ip_esp_hdr *esph; + struct ip_auth_hdr *ah ; + struct ip_comp_hdr *ipch; + struct net *net = dev_net(skb->dev); + const struct iphdr *iph = (const struct iphdr *)skb->data; + int protocol = iph->protocol; + struct ip_tunnel_net *itn = net_generic(net, vti_net_id); + + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, + iph->daddr, iph->saddr, 0); + if (!tunnel) + return -1; + + mark = be32_to_cpu(tunnel->parms.o_key); + + switch (protocol) { + case IPPROTO_ESP: + esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); + spi = esph->spi; + break; + case IPPROTO_AH: + ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2)); + spi = ah->spi; + break; + case IPPROTO_COMP: + ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2)); + spi = htonl(ntohs(ipch->cpi)); + break; + default: + return 0; + } + + switch (icmp_hdr(skb)->type) { + case ICMP_DEST_UNREACH: + if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) + return 0; + case ICMP_REDIRECT: + break; + default: + return 0; + } + + x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, + spi, protocol, AF_INET); + if (!x) + return 0; + + if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) + ipv4_update_pmtu(skb, net, info, 0, protocol); + else + ipv4_redirect(skb, net, 0, protocol); + xfrm_state_put(x); + + return 0; +} + +static int +vti_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) +{ + int err = 0; + + if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { + if (p->iph.version != 4 || p->iph.protocol != IPPROTO_IPIP || + p->iph.ihl != 5) + return -EINVAL; + } + + if (!(p->i_flags & GRE_KEY)) + p->i_key = 0; + if (!(p->o_flags & GRE_KEY)) + p->o_key = 0; + + p->i_flags = VTI_ISVTI; + + err = ip_tunnel_ctl(dev, p, cmd); + if (err) + return err; + + if (cmd != SIOCDELTUNNEL) { + p->i_flags |= GRE_KEY; + p->o_flags |= GRE_KEY; + } + return 0; +} + +static const struct net_device_ops vti_netdev_ops = { + .ndo_init = vti_tunnel_init, + .ndo_uninit = ip_tunnel_uninit, + .ndo_start_xmit = vti_tunnel_xmit, + .ndo_do_ioctl = ip_tunnel_ioctl, + .ndo_change_mtu = ip_tunnel_change_mtu, + .ndo_get_stats64 = ip_tunnel_get_stats64, + .ndo_get_iflink = ip_tunnel_get_iflink, + .ndo_tunnel_ctl = vti_tunnel_ctl, +}; + +static void vti_tunnel_setup(struct net_device *dev) +{ + dev->netdev_ops = &vti_netdev_ops; + dev->header_ops = &ip_tunnel_header_ops; + dev->type = ARPHRD_TUNNEL; + ip_tunnel_setup(dev, vti_net_id); +} + +static int vti_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct iphdr *iph = &tunnel->parms.iph; + + memcpy(dev->dev_addr, &iph->saddr, 4); + memcpy(dev->broadcast, &iph->daddr, 4); + + dev->flags = IFF_NOARP; + dev->addr_len = 4; + dev->features |= NETIF_F_LLTX; + netif_keep_dst(dev); + + return ip_tunnel_init(dev); +} + +static void __net_init vti_fb_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct iphdr *iph = &tunnel->parms.iph; + + iph->version = 4; + iph->protocol = IPPROTO_IPIP; + iph->ihl = 5; +} + +static struct xfrm4_protocol vti_esp4_protocol __read_mostly = { + .handler = vti_rcv_proto, + .input_handler = vti_input_proto, + .cb_handler = vti_rcv_cb, + .err_handler = vti4_err, + .priority = 100, +}; + +static struct xfrm4_protocol vti_ah4_protocol __read_mostly = { + .handler = vti_rcv_proto, + .input_handler = vti_input_proto, + .cb_handler = vti_rcv_cb, + .err_handler = vti4_err, + .priority = 100, +}; + +static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = { + .handler = vti_rcv_proto, + .input_handler = vti_input_proto, + .cb_handler = vti_rcv_cb, + .err_handler = vti4_err, + .priority = 100, +}; + +#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL) +static int vti_rcv_tunnel(struct sk_buff *skb) +{ + XFRM_SPI_SKB_CB(skb)->family = AF_INET; + XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr); + + return vti_input(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr, 0, false); +} + +static struct xfrm_tunnel vti_ipip_handler __read_mostly = { + .handler = vti_rcv_tunnel, + .cb_handler = vti_rcv_cb, + .err_handler = vti4_err, + .priority = 0, +}; + +#if IS_ENABLED(CONFIG_IPV6) +static struct xfrm_tunnel vti_ipip6_handler __read_mostly = { + .handler = vti_rcv_tunnel, + .cb_handler = vti_rcv_cb, + .err_handler = vti4_err, + .priority = 0, +}; +#endif +#endif + +static int __net_init vti_init_net(struct net *net) +{ + int err; + struct ip_tunnel_net *itn; + + err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0"); + if (err) + return err; + itn = net_generic(net, vti_net_id); + if (itn->fb_tunnel_dev) + vti_fb_tunnel_init(itn->fb_tunnel_dev); + return 0; +} + +static void __net_exit vti_exit_batch_net(struct list_head *list_net) +{ + ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops); +} + +static struct pernet_operations vti_net_ops = { + .init = vti_init_net, + .exit_batch = vti_exit_batch_net, + .id = &vti_net_id, + .size = sizeof(struct ip_tunnel_net), +}; + +static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + return 0; +} + +static void vti_netlink_parms(struct nlattr *data[], + struct ip_tunnel_parm *parms, + __u32 *fwmark) +{ + memset(parms, 0, sizeof(*parms)); + + parms->iph.protocol = IPPROTO_IPIP; + + if (!data) + return; + + parms->i_flags = VTI_ISVTI; + + if (data[IFLA_VTI_LINK]) + parms->link = nla_get_u32(data[IFLA_VTI_LINK]); + + if (data[IFLA_VTI_IKEY]) + parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); + + if (data[IFLA_VTI_OKEY]) + parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); + + if (data[IFLA_VTI_LOCAL]) + parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]); + + if (data[IFLA_VTI_REMOTE]) + parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]); + + if (data[IFLA_VTI_FWMARK]) + *fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]); +} + +static int vti_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel_parm parms; + __u32 fwmark = 0; + + vti_netlink_parms(data, &parms, &fwmark); + return ip_tunnel_newlink(dev, tb, &parms, fwmark); +} + +static int vti_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel *t = netdev_priv(dev); + __u32 fwmark = t->fwmark; + struct ip_tunnel_parm p; + + vti_netlink_parms(data, &p, &fwmark); + return ip_tunnel_changelink(dev, tb, &p, fwmark); +} + +static size_t vti_get_size(const struct net_device *dev) +{ + return + /* IFLA_VTI_LINK */ + nla_total_size(4) + + /* IFLA_VTI_IKEY */ + nla_total_size(4) + + /* IFLA_VTI_OKEY */ + nla_total_size(4) + + /* IFLA_VTI_LOCAL */ + nla_total_size(4) + + /* IFLA_VTI_REMOTE */ + nla_total_size(4) + + /* IFLA_VTI_FWMARK */ + nla_total_size(4) + + 0; +} + +static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_parm *p = &t->parms; + + if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) || + nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) || + nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) || + nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) || + nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) || + nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark)) + return -EMSGSIZE; + + return 0; +} + +static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = { + [IFLA_VTI_LINK] = { .type = NLA_U32 }, + [IFLA_VTI_IKEY] = { .type = NLA_U32 }, + [IFLA_VTI_OKEY] = { .type = NLA_U32 }, + [IFLA_VTI_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) }, + [IFLA_VTI_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) }, + [IFLA_VTI_FWMARK] = { .type = NLA_U32 }, +}; + +static struct rtnl_link_ops vti_link_ops __read_mostly = { + .kind = "vti", + .maxtype = IFLA_VTI_MAX, + .policy = vti_policy, + .priv_size = sizeof(struct ip_tunnel), + .setup = vti_tunnel_setup, + .validate = vti_tunnel_validate, + .newlink = vti_newlink, + .changelink = vti_changelink, + .dellink = ip_tunnel_dellink, + .get_size = vti_get_size, + .fill_info = vti_fill_info, + .get_link_net = ip_tunnel_get_link_net, +}; + +static int __init vti_init(void) +{ + const char *msg; + int err; + + pr_info("IPv4 over IPsec tunneling driver\n"); + + msg = "tunnel device"; + err = register_pernet_device(&vti_net_ops); + if (err < 0) + goto pernet_dev_failed; + + msg = "tunnel protocols"; + err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP); + if (err < 0) + goto xfrm_proto_esp_failed; + err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH); + if (err < 0) + goto xfrm_proto_ah_failed; + err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP); + if (err < 0) + goto xfrm_proto_comp_failed; + +#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL) + msg = "ipip tunnel"; + err = xfrm4_tunnel_register(&vti_ipip_handler, AF_INET); + if (err < 0) + goto xfrm_tunnel_ipip_failed; +#if IS_ENABLED(CONFIG_IPV6) + err = xfrm4_tunnel_register(&vti_ipip6_handler, AF_INET6); + if (err < 0) + goto xfrm_tunnel_ipip6_failed; +#endif +#endif + + msg = "netlink interface"; + err = rtnl_link_register(&vti_link_ops); + if (err < 0) + goto rtnl_link_failed; + + return err; + +rtnl_link_failed: +#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL) +#if IS_ENABLED(CONFIG_IPV6) + xfrm4_tunnel_deregister(&vti_ipip6_handler, AF_INET6); +xfrm_tunnel_ipip6_failed: +#endif + xfrm4_tunnel_deregister(&vti_ipip_handler, AF_INET); +xfrm_tunnel_ipip_failed: +#endif + xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP); +xfrm_proto_comp_failed: + xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH); +xfrm_proto_ah_failed: + xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP); +xfrm_proto_esp_failed: + unregister_pernet_device(&vti_net_ops); +pernet_dev_failed: + pr_err("vti init: failed to register %s\n", msg); + return err; +} + +static void __exit vti_fini(void) +{ + rtnl_link_unregister(&vti_link_ops); +#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL) +#if IS_ENABLED(CONFIG_IPV6) + xfrm4_tunnel_deregister(&vti_ipip6_handler, AF_INET6); +#endif + xfrm4_tunnel_deregister(&vti_ipip_handler, AF_INET); +#endif + xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP); + xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH); + xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP); + unregister_pernet_device(&vti_net_ops); +} + +module_init(vti_init); +module_exit(vti_fini); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK("vti"); +MODULE_ALIAS_NETDEV("ip_vti0"); diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c new file mode 100644 index 000000000..b42683212 --- /dev/null +++ b/net/ipv4/ipcomp.c @@ -0,0 +1,200 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IP Payload Compression Protocol (IPComp) - RFC3173. + * + * Copyright (c) 2003 James Morris <jmorris@intercode.com.au> + * + * Todo: + * - Tunable compression parameters. + * - Compression stats. + * - Adaptive compression. + */ +#include <linux/module.h> +#include <linux/err.h> +#include <linux/rtnetlink.h> +#include <net/ip.h> +#include <net/xfrm.h> +#include <net/icmp.h> +#include <net/ipcomp.h> +#include <net/protocol.h> +#include <net/sock.h> + +static int ipcomp4_err(struct sk_buff *skb, u32 info) +{ + struct net *net = dev_net(skb->dev); + __be32 spi; + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2)); + struct xfrm_state *x; + + switch (icmp_hdr(skb)->type) { + case ICMP_DEST_UNREACH: + if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) + return 0; + case ICMP_REDIRECT: + break; + default: + return 0; + } + + spi = htonl(ntohs(ipch->cpi)); + x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, + spi, IPPROTO_COMP, AF_INET); + if (!x) + return 0; + + if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) + ipv4_update_pmtu(skb, net, info, 0, IPPROTO_COMP); + else + ipv4_redirect(skb, net, 0, IPPROTO_COMP); + xfrm_state_put(x); + + return 0; +} + +/* We always hold one tunnel user reference to indicate a tunnel */ +static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x) +{ + struct net *net = xs_net(x); + struct xfrm_state *t; + + t = xfrm_state_alloc(net); + if (!t) + goto out; + + t->id.proto = IPPROTO_IPIP; + t->id.spi = x->props.saddr.a4; + t->id.daddr.a4 = x->id.daddr.a4; + memcpy(&t->sel, &x->sel, sizeof(t->sel)); + t->props.family = AF_INET; + t->props.mode = x->props.mode; + t->props.saddr.a4 = x->props.saddr.a4; + t->props.flags = x->props.flags; + t->props.extra_flags = x->props.extra_flags; + memcpy(&t->mark, &x->mark, sizeof(t->mark)); + t->if_id = x->if_id; + + if (xfrm_init_state(t)) + goto error; + + atomic_set(&t->tunnel_users, 1); +out: + return t; + +error: + t->km.state = XFRM_STATE_DEAD; + xfrm_state_put(t); + t = NULL; + goto out; +} + +/* + * Must be protected by xfrm_cfg_mutex. State and tunnel user references are + * always incremented on success. + */ +static int ipcomp_tunnel_attach(struct xfrm_state *x) +{ + struct net *net = xs_net(x); + int err = 0; + struct xfrm_state *t; + u32 mark = x->mark.v & x->mark.m; + + t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr.a4, + x->props.saddr.a4, IPPROTO_IPIP, AF_INET); + if (!t) { + t = ipcomp_tunnel_create(x); + if (!t) { + err = -EINVAL; + goto out; + } + xfrm_state_insert(t); + xfrm_state_hold(t); + } + x->tunnel = t; + atomic_inc(&t->tunnel_users); +out: + return err; +} + +static int ipcomp4_init_state(struct xfrm_state *x) +{ + int err = -EINVAL; + + x->props.header_len = 0; + switch (x->props.mode) { + case XFRM_MODE_TRANSPORT: + break; + case XFRM_MODE_TUNNEL: + x->props.header_len += sizeof(struct iphdr); + break; + default: + goto out; + } + + err = ipcomp_init_state(x); + if (err) + goto out; + + if (x->props.mode == XFRM_MODE_TUNNEL) { + err = ipcomp_tunnel_attach(x); + if (err) + goto out; + } + + err = 0; +out: + return err; +} + +static int ipcomp4_rcv_cb(struct sk_buff *skb, int err) +{ + return 0; +} + +static const struct xfrm_type ipcomp_type = { + .description = "IPCOMP4", + .owner = THIS_MODULE, + .proto = IPPROTO_COMP, + .init_state = ipcomp4_init_state, + .destructor = ipcomp_destroy, + .input = ipcomp_input, + .output = ipcomp_output +}; + +static struct xfrm4_protocol ipcomp4_protocol = { + .handler = xfrm4_rcv, + .input_handler = xfrm_input, + .cb_handler = ipcomp4_rcv_cb, + .err_handler = ipcomp4_err, + .priority = 0, +}; + +static int __init ipcomp4_init(void) +{ + if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) { + pr_info("%s: can't add xfrm type\n", __func__); + return -EAGAIN; + } + if (xfrm4_protocol_register(&ipcomp4_protocol, IPPROTO_COMP) < 0) { + pr_info("%s: can't add protocol\n", __func__); + xfrm_unregister_type(&ipcomp_type, AF_INET); + return -EAGAIN; + } + return 0; +} + +static void __exit ipcomp4_fini(void) +{ + if (xfrm4_protocol_deregister(&ipcomp4_protocol, IPPROTO_COMP) < 0) + pr_info("%s: can't remove protocol\n", __func__); + xfrm_unregister_type(&ipcomp_type, AF_INET); +} + +module_init(ipcomp4_init); +module_exit(ipcomp4_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173"); +MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>"); + +MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP); diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c new file mode 100644 index 000000000..213a1c915 --- /dev/null +++ b/net/ipv4/ipconfig.c @@ -0,0 +1,1815 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or + * user-supplied information to configure own IP address and routes. + * + * Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz> + * + * Derived from network configuration code in fs/nfs/nfsroot.c, + * originally Copyright (C) 1995, 1996 Gero Kuhlmann and me. + * + * BOOTP rewritten to construct and analyse packets itself instead + * of misusing the IP layer. num_bugs_causing_wrong_arp_replies--; + * -- MJ, December 1998 + * + * Fixed ip_auto_config_setup calling at startup in the new "Linker Magic" + * initialization scheme. + * - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999 + * + * DHCP support added. To users this looks like a whole separate + * protocol, but we know it's just a bag on the side of BOOTP. + * -- Chip Salzenberg <chip@valinux.com>, May 2000 + * + * Ported DHCP support from 2.2.16 to 2.4.0-test4 + * -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000 + * + * Merged changes from 2.2.19 into 2.4.3 + * -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001 + * + * Multiple Nameservers in /proc/net/pnp + * -- Josef Siemes <jsiemes@web.de>, Aug 2002 + * + * NTP servers in /proc/net/ipconfig/ntp_servers + * -- Chris Novakovic <chris@chrisn.me.uk>, April 2018 + */ + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/random.h> +#include <linux/init.h> +#include <linux/utsname.h> +#include <linux/in.h> +#include <linux/if.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/socket.h> +#include <linux/route.h> +#include <linux/udp.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/major.h> +#include <linux/root_dev.h> +#include <linux/delay.h> +#include <linux/nfs_fs.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <net/net_namespace.h> +#include <net/arp.h> +#include <net/dsa.h> +#include <net/ip.h> +#include <net/ipconfig.h> +#include <net/route.h> + +#include <linux/uaccess.h> +#include <net/checksum.h> +#include <asm/processor.h> + +#if defined(CONFIG_IP_PNP_DHCP) +#define IPCONFIG_DHCP +#endif +#if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP) +#define IPCONFIG_BOOTP +#endif +#if defined(CONFIG_IP_PNP_RARP) +#define IPCONFIG_RARP +#endif +#if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP) +#define IPCONFIG_DYNAMIC +#endif + +/* Define the friendly delay before and after opening net devices */ +#define CONF_POST_OPEN 10 /* After opening: 10 msecs */ + +/* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */ +#define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */ +#define CONF_SEND_RETRIES 6 /* Send six requests per open */ +#define CONF_BASE_TIMEOUT (HZ*2) /* Initial timeout: 2 seconds */ +#define CONF_TIMEOUT_RANDOM (HZ) /* Maximum amount of randomization */ +#define CONF_TIMEOUT_MULT *7/4 /* Rate of timeout growth */ +#define CONF_TIMEOUT_MAX (HZ*30) /* Maximum allowed timeout */ +#define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers + - '3' from resolv.h */ +#define CONF_NTP_SERVERS_MAX 3 /* Maximum number of NTP servers */ + +#define NONE cpu_to_be32(INADDR_NONE) +#define ANY cpu_to_be32(INADDR_ANY) + +/* Wait for carrier timeout default in seconds */ +static unsigned int carrier_timeout = 120; + +/* + * Public IP configuration + */ + +/* This is used by platforms which might be able to set the ipconfig + * variables using firmware environment vars. If this is set, it will + * ignore such firmware variables. + */ +int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */ + +static int ic_enable __initdata; /* IP config enabled? */ + +/* Protocol choice */ +int ic_proto_enabled __initdata = 0 +#ifdef IPCONFIG_BOOTP + | IC_BOOTP +#endif +#ifdef CONFIG_IP_PNP_DHCP + | IC_USE_DHCP +#endif +#ifdef IPCONFIG_RARP + | IC_RARP +#endif + ; + +static int ic_host_name_set __initdata; /* Host name set by us? */ + +__be32 ic_myaddr = NONE; /* My IP address */ +static __be32 ic_netmask = NONE; /* Netmask for local subnet */ +__be32 ic_gateway = NONE; /* Gateway IP address */ + +#ifdef IPCONFIG_DYNAMIC +static __be32 ic_addrservaddr = NONE; /* IP Address of the IP addresses'server */ +#endif + +__be32 ic_servaddr = NONE; /* Boot server IP address */ + +__be32 root_server_addr = NONE; /* Address of NFS server */ +u8 root_server_path[256] = { 0, }; /* Path to mount as root */ + +/* vendor class identifier */ +static char vendor_class_identifier[253] __initdata; + +#if defined(CONFIG_IP_PNP_DHCP) +static char dhcp_client_identifier[253] __initdata; +#endif + +/* Persistent data: */ + +#ifdef IPCONFIG_DYNAMIC +static int ic_proto_used; /* Protocol used, if any */ +#else +#define ic_proto_used 0 +#endif +static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */ +static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */ +static u8 ic_domain[64]; /* DNS (not NIS) domain name */ + +/* + * Private state. + */ + +/* Name of user-selected boot device */ +static char user_dev_name[IFNAMSIZ] __initdata = { 0, }; + +/* Protocols supported by available interfaces */ +static int ic_proto_have_if __initdata; + +/* MTU for boot device */ +static int ic_dev_mtu __initdata; + +#ifdef IPCONFIG_DYNAMIC +static DEFINE_SPINLOCK(ic_recv_lock); +static volatile int ic_got_reply __initdata; /* Proto(s) that replied */ +#endif +#ifdef IPCONFIG_DHCP +static int ic_dhcp_msgtype __initdata; /* DHCP msg type received */ +#endif + + +/* + * Network devices + */ + +struct ic_device { + struct ic_device *next; + struct net_device *dev; + unsigned short flags; + short able; + __be32 xid; +}; + +static struct ic_device *ic_first_dev __initdata; /* List of open device */ +static struct ic_device *ic_dev __initdata; /* Selected device */ + +static bool __init ic_is_init_dev(struct net_device *dev) +{ + if (dev->flags & IFF_LOOPBACK) + return false; + return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) : + (!(dev->flags & IFF_LOOPBACK) && + (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) && + strncmp(dev->name, "dummy", 5)); +} + +static int __init ic_open_devs(void) +{ + struct ic_device *d, **last; + struct net_device *dev; + unsigned short oflags; + unsigned long start, next_msg; + + last = &ic_first_dev; + rtnl_lock(); + + /* bring loopback and DSA master network devices up first */ + for_each_netdev(&init_net, dev) { + if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev)) + continue; + if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0) + pr_err("IP-Config: Failed to open %s\n", dev->name); + } + + for_each_netdev(&init_net, dev) { + if (ic_is_init_dev(dev)) { + int able = 0; + if (dev->mtu >= 364) + able |= IC_BOOTP; + else + pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n", + dev->name, dev->mtu); + if (!(dev->flags & IFF_NOARP)) + able |= IC_RARP; + able &= ic_proto_enabled; + if (ic_proto_enabled && !able) + continue; + oflags = dev->flags; + if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) { + pr_err("IP-Config: Failed to open %s\n", + dev->name); + continue; + } + if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) { + rtnl_unlock(); + return -ENOMEM; + } + d->dev = dev; + *last = d; + last = &d->next; + d->flags = oflags; + d->able = able; + if (able & IC_BOOTP) + get_random_bytes(&d->xid, sizeof(__be32)); + else + d->xid = 0; + ic_proto_have_if |= able; + pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n", + dev->name, able, d->xid); + } + } + + /* no point in waiting if we could not bring up at least one device */ + if (!ic_first_dev) + goto have_carrier; + + /* wait for a carrier on at least one device */ + start = jiffies; + next_msg = start + msecs_to_jiffies(20000); + while (time_before(jiffies, start + + msecs_to_jiffies(carrier_timeout * 1000))) { + int wait, elapsed; + + for_each_netdev(&init_net, dev) + if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) + goto have_carrier; + + msleep(1); + + if (time_before(jiffies, next_msg)) + continue; + + elapsed = jiffies_to_msecs(jiffies - start); + wait = (carrier_timeout * 1000 - elapsed + 500) / 1000; + pr_info("Waiting up to %d more seconds for network.\n", wait); + next_msg = jiffies + msecs_to_jiffies(20000); + } +have_carrier: + rtnl_unlock(); + + *last = NULL; + + if (!ic_first_dev) { + if (user_dev_name[0]) + pr_err("IP-Config: Device `%s' not found\n", + user_dev_name); + else + pr_err("IP-Config: No network devices available\n"); + return -ENODEV; + } + return 0; +} + +static void __init ic_close_devs(void) +{ + struct ic_device *d, *next; + struct net_device *dev; + + rtnl_lock(); + next = ic_first_dev; + while ((d = next)) { + next = d->next; + dev = d->dev; + if (d != ic_dev && !netdev_uses_dsa(dev)) { + pr_debug("IP-Config: Downing %s\n", dev->name); + dev_change_flags(dev, d->flags, NULL); + } + kfree(d); + } + rtnl_unlock(); +} + +/* + * Interface to various network functions. + */ + +static inline void +set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port) +{ + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = addr; + sin->sin_port = port; +} + +/* + * Set up interface addresses and routes. + */ + +static int __init ic_setup_if(void) +{ + struct ifreq ir; + struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr; + int err; + + memset(&ir, 0, sizeof(ir)); + strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name); + set_sockaddr(sin, ic_myaddr, 0); + if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) { + pr_err("IP-Config: Unable to set interface address (%d)\n", + err); + return -1; + } + set_sockaddr(sin, ic_netmask, 0); + if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) { + pr_err("IP-Config: Unable to set interface netmask (%d)\n", + err); + return -1; + } + set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0); + if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) { + pr_err("IP-Config: Unable to set interface broadcast address (%d)\n", + err); + return -1; + } + /* Handle the case where we need non-standard MTU on the boot link (a network + * using jumbo frames, for instance). If we can't set the mtu, don't error + * out, we'll try to muddle along. + */ + if (ic_dev_mtu != 0) { + rtnl_lock(); + if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0) + pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n", + ic_dev_mtu, err); + rtnl_unlock(); + } + return 0; +} + +static int __init ic_setup_routes(void) +{ + /* No need to setup device routes, only the default route... */ + + if (ic_gateway != NONE) { + struct rtentry rm; + int err; + + memset(&rm, 0, sizeof(rm)); + if ((ic_gateway ^ ic_myaddr) & ic_netmask) { + pr_err("IP-Config: Gateway not on directly connected network\n"); + return -1; + } + set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0); + set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0); + set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0); + rm.rt_flags = RTF_UP | RTF_GATEWAY; + if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) { + pr_err("IP-Config: Cannot add default route (%d)\n", + err); + return -1; + } + } + + return 0; +} + +/* + * Fill in default values for all missing parameters. + */ + +static int __init ic_defaults(void) +{ + /* + * At this point we have no userspace running so need not + * claim locks on system_utsname + */ + + if (!ic_host_name_set) + sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr); + + if (root_server_addr == NONE) + root_server_addr = ic_servaddr; + + if (ic_netmask == NONE) { + if (IN_CLASSA(ntohl(ic_myaddr))) + ic_netmask = htonl(IN_CLASSA_NET); + else if (IN_CLASSB(ntohl(ic_myaddr))) + ic_netmask = htonl(IN_CLASSB_NET); + else if (IN_CLASSC(ntohl(ic_myaddr))) + ic_netmask = htonl(IN_CLASSC_NET); + else if (IN_CLASSE(ntohl(ic_myaddr))) + ic_netmask = htonl(IN_CLASSE_NET); + else { + pr_err("IP-Config: Unable to guess netmask for address %pI4\n", + &ic_myaddr); + return -1; + } + pr_notice("IP-Config: Guessing netmask %pI4\n", + &ic_netmask); + } + + return 0; +} + +/* + * RARP support. + */ + +#ifdef IPCONFIG_RARP + +static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev); + +static struct packet_type rarp_packet_type __initdata = { + .type = cpu_to_be16(ETH_P_RARP), + .func = ic_rarp_recv, +}; + +static inline void __init ic_rarp_init(void) +{ + dev_add_pack(&rarp_packet_type); +} + +static inline void __init ic_rarp_cleanup(void) +{ + dev_remove_pack(&rarp_packet_type); +} + +/* + * Process received RARP packet. + */ +static int __init +ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) +{ + struct arphdr *rarp; + unsigned char *rarp_ptr; + __be32 sip, tip; + unsigned char *tha; /* t for "target" */ + struct ic_device *d; + + if (!net_eq(dev_net(dev), &init_net)) + goto drop; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + return NET_RX_DROP; + + if (!pskb_may_pull(skb, sizeof(struct arphdr))) + goto drop; + + /* Basic sanity checks can be done without the lock. */ + rarp = (struct arphdr *)skb_transport_header(skb); + + /* If this test doesn't pass, it's not IP, or we should + * ignore it anyway. + */ + if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd)) + goto drop; + + /* If it's not a RARP reply, delete it. */ + if (rarp->ar_op != htons(ARPOP_RREPLY)) + goto drop; + + /* If it's not Ethernet, delete it. */ + if (rarp->ar_pro != htons(ETH_P_IP)) + goto drop; + + if (!pskb_may_pull(skb, arp_hdr_len(dev))) + goto drop; + + /* OK, it is all there and looks valid, process... */ + rarp = (struct arphdr *)skb_transport_header(skb); + rarp_ptr = (unsigned char *) (rarp + 1); + + /* One reply at a time, please. */ + spin_lock(&ic_recv_lock); + + /* If we already have a reply, just drop the packet */ + if (ic_got_reply) + goto drop_unlock; + + /* Find the ic_device that the packet arrived on */ + d = ic_first_dev; + while (d && d->dev != dev) + d = d->next; + if (!d) + goto drop_unlock; /* should never happen */ + + /* Extract variable-width fields */ + rarp_ptr += dev->addr_len; + memcpy(&sip, rarp_ptr, 4); + rarp_ptr += 4; + tha = rarp_ptr; + rarp_ptr += dev->addr_len; + memcpy(&tip, rarp_ptr, 4); + + /* Discard packets which are not meant for us. */ + if (memcmp(tha, dev->dev_addr, dev->addr_len)) + goto drop_unlock; + + /* Discard packets which are not from specified server. */ + if (ic_servaddr != NONE && ic_servaddr != sip) + goto drop_unlock; + + /* We have a winner! */ + ic_dev = d; + if (ic_myaddr == NONE) + ic_myaddr = tip; + ic_servaddr = sip; + ic_addrservaddr = sip; + ic_got_reply = IC_RARP; + +drop_unlock: + /* Show's over. Nothing to see here. */ + spin_unlock(&ic_recv_lock); + +drop: + /* Throw the packet out. */ + kfree_skb(skb); + return 0; +} + + +/* + * Send RARP request packet over a single interface. + */ +static void __init ic_rarp_send_if(struct ic_device *d) +{ + struct net_device *dev = d->dev; + arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL, + dev->dev_addr, dev->dev_addr); +} +#endif + +/* + * Predefine Nameservers + */ +static inline void __init ic_nameservers_predef(void) +{ + int i; + + for (i = 0; i < CONF_NAMESERVERS_MAX; i++) + ic_nameservers[i] = NONE; +} + +/* Predefine NTP servers */ +static inline void __init ic_ntp_servers_predef(void) +{ + int i; + + for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) + ic_ntp_servers[i] = NONE; +} + +/* + * DHCP/BOOTP support. + */ + +#ifdef IPCONFIG_BOOTP + +struct bootp_pkt { /* BOOTP packet format */ + struct iphdr iph; /* IP header */ + struct udphdr udph; /* UDP header */ + u8 op; /* 1=request, 2=reply */ + u8 htype; /* HW address type */ + u8 hlen; /* HW address length */ + u8 hops; /* Used only by gateways */ + __be32 xid; /* Transaction ID */ + __be16 secs; /* Seconds since we started */ + __be16 flags; /* Just what it says */ + __be32 client_ip; /* Client's IP address if known */ + __be32 your_ip; /* Assigned IP address */ + __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */ + __be32 relay_ip; /* IP address of BOOTP relay */ + u8 hw_addr[16]; /* Client's HW address */ + u8 serv_name[64]; /* Server host name */ + u8 boot_file[128]; /* Name of boot file */ + u8 exten[312]; /* DHCP options / BOOTP vendor extensions */ +}; + +/* packet ops */ +#define BOOTP_REQUEST 1 +#define BOOTP_REPLY 2 + +/* DHCP message types */ +#define DHCPDISCOVER 1 +#define DHCPOFFER 2 +#define DHCPREQUEST 3 +#define DHCPDECLINE 4 +#define DHCPACK 5 +#define DHCPNAK 6 +#define DHCPRELEASE 7 +#define DHCPINFORM 8 + +static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev); + +static struct packet_type bootp_packet_type __initdata = { + .type = cpu_to_be16(ETH_P_IP), + .func = ic_bootp_recv, +}; + +/* + * Initialize DHCP/BOOTP extension fields in the request. + */ + +static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 }; + +#ifdef IPCONFIG_DHCP + +static void __init +ic_dhcp_init_options(u8 *options, struct ic_device *d) +{ + u8 mt = ((ic_servaddr == NONE) + ? DHCPDISCOVER : DHCPREQUEST); + u8 *e = options; + int len; + + pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name); + + memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */ + e += 4; + + *e++ = 53; /* DHCP message type */ + *e++ = 1; + *e++ = mt; + + if (mt == DHCPREQUEST) { + *e++ = 54; /* Server ID (IP address) */ + *e++ = 4; + memcpy(e, &ic_servaddr, 4); + e += 4; + + *e++ = 50; /* Requested IP address */ + *e++ = 4; + memcpy(e, &ic_myaddr, 4); + e += 4; + } + + /* always? */ + { + static const u8 ic_req_params[] = { + 1, /* Subnet mask */ + 3, /* Default gateway */ + 6, /* DNS server */ + 12, /* Host name */ + 15, /* Domain name */ + 17, /* Boot path */ + 26, /* MTU */ + 40, /* NIS domain name */ + 42, /* NTP servers */ + }; + + *e++ = 55; /* Parameter request list */ + *e++ = sizeof(ic_req_params); + memcpy(e, ic_req_params, sizeof(ic_req_params)); + e += sizeof(ic_req_params); + + if (ic_host_name_set) { + *e++ = 12; /* host-name */ + len = strlen(utsname()->nodename); + *e++ = len; + memcpy(e, utsname()->nodename, len); + e += len; + } + if (*vendor_class_identifier) { + pr_info("DHCP: sending class identifier \"%s\"\n", + vendor_class_identifier); + *e++ = 60; /* Class-identifier */ + len = strlen(vendor_class_identifier); + *e++ = len; + memcpy(e, vendor_class_identifier, len); + e += len; + } + len = strlen(dhcp_client_identifier + 1); + /* the minimum length of identifier is 2, include 1 byte type, + * and can not be larger than the length of options + */ + if (len >= 1 && len < 312 - (e - options) - 1) { + *e++ = 61; + *e++ = len + 1; + memcpy(e, dhcp_client_identifier, len + 1); + e += len + 1; + } + } + + *e++ = 255; /* End of the list */ +} + +#endif /* IPCONFIG_DHCP */ + +static void __init ic_bootp_init_ext(u8 *e) +{ + memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */ + e += 4; + *e++ = 1; /* Subnet mask request */ + *e++ = 4; + e += 4; + *e++ = 3; /* Default gateway request */ + *e++ = 4; + e += 4; +#if CONF_NAMESERVERS_MAX > 0 + *e++ = 6; /* (DNS) name server request */ + *e++ = 4 * CONF_NAMESERVERS_MAX; + e += 4 * CONF_NAMESERVERS_MAX; +#endif + *e++ = 12; /* Host name request */ + *e++ = 32; + e += 32; + *e++ = 40; /* NIS Domain name request */ + *e++ = 32; + e += 32; + *e++ = 17; /* Boot path */ + *e++ = 40; + e += 40; + + *e++ = 57; /* set extension buffer size for reply */ + *e++ = 2; + *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */ + *e++ = 150; + + *e++ = 255; /* End of the list */ +} + + +/* + * Initialize the DHCP/BOOTP mechanism. + */ +static inline void __init ic_bootp_init(void) +{ + /* Re-initialise all name servers and NTP servers to NONE, in case any + * were set via the "ip=" or "nfsaddrs=" kernel command line parameters: + * any IP addresses specified there will already have been decoded but + * are no longer needed + */ + ic_nameservers_predef(); + ic_ntp_servers_predef(); + + dev_add_pack(&bootp_packet_type); +} + + +/* + * DHCP/BOOTP cleanup. + */ +static inline void __init ic_bootp_cleanup(void) +{ + dev_remove_pack(&bootp_packet_type); +} + + +/* + * Send DHCP/BOOTP request to single interface. + */ +static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff) +{ + struct net_device *dev = d->dev; + struct sk_buff *skb; + struct bootp_pkt *b; + struct iphdr *h; + int hlen = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; + + /* Allocate packet */ + skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15, + GFP_KERNEL); + if (!skb) + return; + skb_reserve(skb, hlen); + b = skb_put_zero(skb, sizeof(struct bootp_pkt)); + + /* Construct IP header */ + skb_reset_network_header(skb); + h = ip_hdr(skb); + h->version = 4; + h->ihl = 5; + h->tot_len = htons(sizeof(struct bootp_pkt)); + h->frag_off = htons(IP_DF); + h->ttl = 64; + h->protocol = IPPROTO_UDP; + h->daddr = htonl(INADDR_BROADCAST); + h->check = ip_fast_csum((unsigned char *) h, h->ihl); + + /* Construct UDP header */ + b->udph.source = htons(68); + b->udph.dest = htons(67); + b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr)); + /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */ + + /* Construct DHCP/BOOTP header */ + b->op = BOOTP_REQUEST; + if (dev->type < 256) /* check for false types */ + b->htype = dev->type; + else if (dev->type == ARPHRD_FDDI) + b->htype = ARPHRD_ETHER; + else { + pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type, + dev->name); + b->htype = dev->type; /* can cause undefined behavior */ + } + + /* server_ip and your_ip address are both already zero per RFC2131 */ + b->hlen = dev->addr_len; + memcpy(b->hw_addr, dev->dev_addr, dev->addr_len); + b->secs = htons(jiffies_diff / HZ); + b->xid = d->xid; + + /* add DHCP options or BOOTP extensions */ +#ifdef IPCONFIG_DHCP + if (ic_proto_enabled & IC_USE_DHCP) + ic_dhcp_init_options(b->exten, d); + else +#endif + ic_bootp_init_ext(b->exten); + + /* Chain packet down the line... */ + skb->dev = dev; + skb->protocol = htons(ETH_P_IP); + if (dev_hard_header(skb, dev, ntohs(skb->protocol), + dev->broadcast, dev->dev_addr, skb->len) < 0) { + kfree_skb(skb); + printk("E"); + return; + } + + if (dev_queue_xmit(skb) < 0) + printk("E"); +} + + +/* + * Copy BOOTP-supplied string + */ +static int __init ic_bootp_string(char *dest, char *src, int len, int max) +{ + if (!len) + return 0; + if (len > max-1) + len = max-1; + memcpy(dest, src, len); + dest[len] = '\0'; + return 1; +} + + +/* + * Process BOOTP extensions. + */ +static void __init ic_do_bootp_ext(u8 *ext) +{ + u8 servers; + int i; + __be16 mtu; + + u8 *c; + + pr_debug("DHCP/BOOTP: Got extension %d:", *ext); + for (c=ext+2; c<ext+2+ext[1]; c++) + pr_debug(" %02x", *c); + pr_debug("\n"); + + switch (*ext++) { + case 1: /* Subnet mask */ + if (ic_netmask == NONE) + memcpy(&ic_netmask, ext+1, 4); + break; + case 3: /* Default gateway */ + if (ic_gateway == NONE) + memcpy(&ic_gateway, ext+1, 4); + break; + case 6: /* DNS server */ + servers= *ext/4; + if (servers > CONF_NAMESERVERS_MAX) + servers = CONF_NAMESERVERS_MAX; + for (i = 0; i < servers; i++) { + if (ic_nameservers[i] == NONE) + memcpy(&ic_nameservers[i], ext+1+4*i, 4); + } + break; + case 12: /* Host name */ + if (!ic_host_name_set) { + ic_bootp_string(utsname()->nodename, ext+1, *ext, + __NEW_UTS_LEN); + ic_host_name_set = 1; + } + break; + case 15: /* Domain name (DNS) */ + if (!ic_domain[0]) + ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain)); + break; + case 17: /* Root path */ + if (!root_server_path[0]) + ic_bootp_string(root_server_path, ext+1, *ext, + sizeof(root_server_path)); + break; + case 26: /* Interface MTU */ + memcpy(&mtu, ext+1, sizeof(mtu)); + ic_dev_mtu = ntohs(mtu); + break; + case 40: /* NIS Domain name (_not_ DNS) */ + ic_bootp_string(utsname()->domainname, ext+1, *ext, + __NEW_UTS_LEN); + break; + case 42: /* NTP servers */ + servers = *ext / 4; + if (servers > CONF_NTP_SERVERS_MAX) + servers = CONF_NTP_SERVERS_MAX; + for (i = 0; i < servers; i++) { + if (ic_ntp_servers[i] == NONE) + memcpy(&ic_ntp_servers[i], ext+1+4*i, 4); + } + break; + } +} + + +/* + * Receive BOOTP reply. + */ +static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) +{ + struct bootp_pkt *b; + struct iphdr *h; + struct ic_device *d; + int len, ext_len; + + if (!net_eq(dev_net(dev), &init_net)) + goto drop; + + /* Perform verifications before taking the lock. */ + if (skb->pkt_type == PACKET_OTHERHOST) + goto drop; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + return NET_RX_DROP; + + if (!pskb_may_pull(skb, + sizeof(struct iphdr) + + sizeof(struct udphdr))) + goto drop; + + b = (struct bootp_pkt *)skb_network_header(skb); + h = &b->iph; + + if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP) + goto drop; + + /* Fragments are not supported */ + if (ip_is_fragment(h)) { + net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n"); + goto drop; + } + + if (skb->len < ntohs(h->tot_len)) + goto drop; + + if (ip_fast_csum((char *) h, h->ihl)) + goto drop; + + if (b->udph.source != htons(67) || b->udph.dest != htons(68)) + goto drop; + + if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr)) + goto drop; + + len = ntohs(b->udph.len) - sizeof(struct udphdr); + ext_len = len - (sizeof(*b) - + sizeof(struct iphdr) - + sizeof(struct udphdr) - + sizeof(b->exten)); + if (ext_len < 0) + goto drop; + + /* Ok the front looks good, make sure we can get at the rest. */ + if (!pskb_may_pull(skb, skb->len)) + goto drop; + + b = (struct bootp_pkt *)skb_network_header(skb); + h = &b->iph; + + /* One reply at a time, please. */ + spin_lock(&ic_recv_lock); + + /* If we already have a reply, just drop the packet */ + if (ic_got_reply) + goto drop_unlock; + + /* Find the ic_device that the packet arrived on */ + d = ic_first_dev; + while (d && d->dev != dev) + d = d->next; + if (!d) + goto drop_unlock; /* should never happen */ + + /* Is it a reply to our BOOTP request? */ + if (b->op != BOOTP_REPLY || + b->xid != d->xid) { + net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n", + d->dev->name, b->op, b->xid); + goto drop_unlock; + } + + /* Parse extensions */ + if (ext_len >= 4 && + !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */ + u8 *end = (u8 *) b + ntohs(b->iph.tot_len); + u8 *ext; + +#ifdef IPCONFIG_DHCP + if (ic_proto_enabled & IC_USE_DHCP) { + __be32 server_id = NONE; + int mt = 0; + + ext = &b->exten[4]; + while (ext < end && *ext != 0xff) { + u8 *opt = ext++; + if (*opt == 0) /* Padding */ + continue; + ext += *ext + 1; + if (ext >= end) + break; + switch (*opt) { + case 53: /* Message type */ + if (opt[1]) + mt = opt[2]; + break; + case 54: /* Server ID (IP address) */ + if (opt[1] >= 4) + memcpy(&server_id, opt + 2, 4); + break; + } + } + + pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name); + + switch (mt) { + case DHCPOFFER: + /* While in the process of accepting one offer, + * ignore all others. + */ + if (ic_myaddr != NONE) + goto drop_unlock; + + /* Let's accept that offer. */ + ic_myaddr = b->your_ip; + ic_servaddr = server_id; + pr_debug("DHCP: Offered address %pI4 by server %pI4\n", + &ic_myaddr, &b->iph.saddr); + /* The DHCP indicated server address takes + * precedence over the bootp header one if + * they are different. + */ + if ((server_id != NONE) && + (b->server_ip != server_id)) + b->server_ip = ic_servaddr; + break; + + case DHCPACK: + if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0) + goto drop_unlock; + + /* Yeah! */ + break; + + default: + /* Urque. Forget it*/ + ic_myaddr = NONE; + ic_servaddr = NONE; + goto drop_unlock; + } + + ic_dhcp_msgtype = mt; + + } +#endif /* IPCONFIG_DHCP */ + + ext = &b->exten[4]; + while (ext < end && *ext != 0xff) { + u8 *opt = ext++; + if (*opt == 0) /* Padding */ + continue; + ext += *ext + 1; + if (ext < end) + ic_do_bootp_ext(opt); + } + } + + /* We have a winner! */ + ic_dev = d; + ic_myaddr = b->your_ip; + ic_servaddr = b->server_ip; + ic_addrservaddr = b->iph.saddr; + if (ic_gateway == NONE && b->relay_ip) + ic_gateway = b->relay_ip; + if (ic_nameservers[0] == NONE) + ic_nameservers[0] = ic_servaddr; + ic_got_reply = IC_BOOTP; + +drop_unlock: + /* Show's over. Nothing to see here. */ + spin_unlock(&ic_recv_lock); + +drop: + /* Throw the packet out. */ + kfree_skb(skb); + + return 0; +} + + +#endif + + +/* + * Dynamic IP configuration -- DHCP, BOOTP, RARP. + */ + +#ifdef IPCONFIG_DYNAMIC + +static int __init ic_dynamic(void) +{ + int retries; + struct ic_device *d; + unsigned long start_jiffies, timeout, jiff; + int do_bootp = ic_proto_have_if & IC_BOOTP; + int do_rarp = ic_proto_have_if & IC_RARP; + + /* + * If none of DHCP/BOOTP/RARP was selected, return with an error. + * This routine gets only called when some pieces of information + * are missing, and without DHCP/BOOTP/RARP we are unable to get it. + */ + if (!ic_proto_enabled) { + pr_err("IP-Config: Incomplete network configuration information\n"); + return -1; + } + +#ifdef IPCONFIG_BOOTP + if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP) + pr_err("DHCP/BOOTP: No suitable device found\n"); +#endif +#ifdef IPCONFIG_RARP + if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP) + pr_err("RARP: No suitable device found\n"); +#endif + + if (!ic_proto_have_if) + /* Error message already printed */ + return -1; + + /* + * Setup protocols + */ +#ifdef IPCONFIG_BOOTP + if (do_bootp) + ic_bootp_init(); +#endif +#ifdef IPCONFIG_RARP + if (do_rarp) + ic_rarp_init(); +#endif + + /* + * Send requests and wait, until we get an answer. This loop + * seems to be a terrible waste of CPU time, but actually there is + * only one process running at all, so we don't need to use any + * scheduler functions. + * [Actually we could now, but the nothing else running note still + * applies.. - AC] + */ + pr_notice("Sending %s%s%s requests .", + do_bootp + ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "", + (do_bootp && do_rarp) ? " and " : "", + do_rarp ? "RARP" : ""); + + start_jiffies = jiffies; + d = ic_first_dev; + retries = CONF_SEND_RETRIES; + get_random_bytes(&timeout, sizeof(timeout)); + timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM); + for (;;) { +#ifdef IPCONFIG_BOOTP + if (do_bootp && (d->able & IC_BOOTP)) + ic_bootp_send_if(d, jiffies - start_jiffies); +#endif +#ifdef IPCONFIG_RARP + if (do_rarp && (d->able & IC_RARP)) + ic_rarp_send_if(d); +#endif + + if (!d->next) { + jiff = jiffies + timeout; + while (time_before(jiffies, jiff) && !ic_got_reply) + schedule_timeout_uninterruptible(1); + } +#ifdef IPCONFIG_DHCP + /* DHCP isn't done until we get a DHCPACK. */ + if ((ic_got_reply & IC_BOOTP) && + (ic_proto_enabled & IC_USE_DHCP) && + ic_dhcp_msgtype != DHCPACK) { + ic_got_reply = 0; + /* continue on device that got the reply */ + d = ic_dev; + pr_cont(","); + continue; + } +#endif /* IPCONFIG_DHCP */ + + if (ic_got_reply) { + pr_cont(" OK\n"); + break; + } + + if ((d = d->next)) + continue; + + if (! --retries) { + pr_cont(" timed out!\n"); + break; + } + + d = ic_first_dev; + + timeout = timeout CONF_TIMEOUT_MULT; + if (timeout > CONF_TIMEOUT_MAX) + timeout = CONF_TIMEOUT_MAX; + + pr_cont("."); + } + +#ifdef IPCONFIG_BOOTP + if (do_bootp) + ic_bootp_cleanup(); +#endif +#ifdef IPCONFIG_RARP + if (do_rarp) + ic_rarp_cleanup(); +#endif + + if (!ic_got_reply) { + ic_myaddr = NONE; + return -1; + } + + pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n", + ((ic_got_reply & IC_RARP) ? "RARP" + : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"), + &ic_addrservaddr, &ic_myaddr); + + return 0; +} + +#endif /* IPCONFIG_DYNAMIC */ + +#ifdef CONFIG_PROC_FS +/* proc_dir_entry for /proc/net/ipconfig */ +static struct proc_dir_entry *ipconfig_dir; + +/* Name servers: */ +static int pnp_seq_show(struct seq_file *seq, void *v) +{ + int i; + + if (ic_proto_used & IC_PROTO) + seq_printf(seq, "#PROTO: %s\n", + (ic_proto_used & IC_RARP) ? "RARP" + : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP"); + else + seq_puts(seq, "#MANUAL\n"); + + if (ic_domain[0]) + seq_printf(seq, + "domain %s\n", ic_domain); + for (i = 0; i < CONF_NAMESERVERS_MAX; i++) { + if (ic_nameservers[i] != NONE) + seq_printf(seq, "nameserver %pI4\n", + &ic_nameservers[i]); + } + if (ic_servaddr != NONE) + seq_printf(seq, "bootserver %pI4\n", + &ic_servaddr); + return 0; +} + +/* Create the /proc/net/ipconfig directory */ +static int __init ipconfig_proc_net_init(void) +{ + ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net); + if (!ipconfig_dir) + return -ENOMEM; + + return 0; +} + +/* Create a new file under /proc/net/ipconfig */ +static int ipconfig_proc_net_create(const char *name, + const struct proc_ops *proc_ops) +{ + char *pname; + struct proc_dir_entry *p; + + if (!ipconfig_dir) + return -ENOMEM; + + pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name); + if (!pname) + return -ENOMEM; + + p = proc_create(pname, 0444, init_net.proc_net, proc_ops); + kfree(pname); + if (!p) + return -ENOMEM; + + return 0; +} + +/* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */ +static int ntp_servers_show(struct seq_file *seq, void *v) +{ + int i; + + for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) { + if (ic_ntp_servers[i] != NONE) + seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]); + } + return 0; +} +DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers); +#endif /* CONFIG_PROC_FS */ + +/* + * Extract IP address from the parameter string if needed. Note that we + * need to have root_server_addr set _before_ IPConfig gets called as it + * can override it. + */ +__be32 __init root_nfs_parse_addr(char *name) +{ + __be32 addr; + int octets = 0; + char *cp, *cq; + + cp = cq = name; + while (octets < 4) { + while (*cp >= '0' && *cp <= '9') + cp++; + if (cp == cq || cp - cq > 3) + break; + if (*cp == '.' || octets == 3) + octets++; + if (octets < 4) + cp++; + cq = cp; + } + if (octets == 4 && (*cp == ':' || *cp == '\0')) { + if (*cp == ':') + *cp++ = '\0'; + addr = in_aton(name); + memmove(name, cp, strlen(cp) + 1); + } else + addr = NONE; + + return addr; +} + +#define DEVICE_WAIT_MAX 12 /* 12 seconds */ + +static int __init wait_for_devices(void) +{ + int i; + + for (i = 0; i < DEVICE_WAIT_MAX; i++) { + struct net_device *dev; + int found = 0; + + /* make sure deferred device probes are finished */ + wait_for_device_probe(); + + rtnl_lock(); + for_each_netdev(&init_net, dev) { + if (ic_is_init_dev(dev)) { + found = 1; + break; + } + } + rtnl_unlock(); + if (found) + return 0; + ssleep(1); + } + return -ENODEV; +} + +/* + * IP Autoconfig dispatcher. + */ + +static int __init ip_auto_config(void) +{ + __be32 addr; +#ifdef IPCONFIG_DYNAMIC + int retries = CONF_OPEN_RETRIES; +#endif + int err; + unsigned int i, count; + + /* Initialise all name servers and NTP servers to NONE (but only if the + * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded, + * otherwise we'll overwrite the IP addresses specified there) + */ + if (ic_set_manually == 0) { + ic_nameservers_predef(); + ic_ntp_servers_predef(); + } + +#ifdef CONFIG_PROC_FS + proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show); + + if (ipconfig_proc_net_init() == 0) + ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops); +#endif /* CONFIG_PROC_FS */ + + if (!ic_enable) + return 0; + + pr_debug("IP-Config: Entered.\n"); +#ifdef IPCONFIG_DYNAMIC + try_try_again: +#endif + /* Wait for devices to appear */ + err = wait_for_devices(); + if (err) + return err; + + /* Setup all network devices */ + err = ic_open_devs(); + if (err) + return err; + + /* Give drivers a chance to settle */ + msleep(CONF_POST_OPEN); + + /* + * If the config information is insufficient (e.g., our IP address or + * IP address of the boot server is missing or we have multiple network + * interfaces and no default was set), use BOOTP or RARP to get the + * missing values. + */ + if (ic_myaddr == NONE || +#if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT) + (root_server_addr == NONE && + ic_servaddr == NONE && + (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) || +#endif + ic_first_dev->next) { +#ifdef IPCONFIG_DYNAMIC + if (ic_dynamic() < 0) { + ic_close_devs(); + + /* + * I don't know why, but sometimes the + * eepro100 driver (at least) gets upset and + * doesn't work the first time it's opened. + * But then if you close it and reopen it, it + * works just fine. So we need to try that at + * least once before giving up. + * + * Also, if the root will be NFS-mounted, we + * have nowhere to go if DHCP fails. So we + * just have to keep trying forever. + * + * -- Chip + */ +#ifdef CONFIG_ROOT_NFS + if (ROOT_DEV == Root_NFS) { + pr_err("IP-Config: Retrying forever (NFS root)...\n"); + goto try_try_again; + } +#endif +#ifdef CONFIG_CIFS_ROOT + if (ROOT_DEV == Root_CIFS) { + pr_err("IP-Config: Retrying forever (CIFS root)...\n"); + goto try_try_again; + } +#endif + + if (--retries) { + pr_err("IP-Config: Reopening network devices...\n"); + goto try_try_again; + } + + /* Oh, well. At least we tried. */ + pr_err("IP-Config: Auto-configuration of network failed\n"); + return -1; + } +#else /* !DYNAMIC */ + pr_err("IP-Config: Incomplete network configuration information\n"); + ic_close_devs(); + return -1; +#endif /* IPCONFIG_DYNAMIC */ + } else { + /* Device selected manually or only one device -> use it */ + ic_dev = ic_first_dev; + } + + addr = root_nfs_parse_addr(root_server_path); + if (root_server_addr == NONE) + root_server_addr = addr; + + /* + * Use defaults wherever applicable. + */ + if (ic_defaults() < 0) + return -1; + + /* + * Record which protocol was actually used. + */ +#ifdef IPCONFIG_DYNAMIC + ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP); +#endif + +#ifndef IPCONFIG_SILENT + /* + * Clue in the operator. + */ + pr_info("IP-Config: Complete:\n"); + + pr_info(" device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n", + ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr, + &ic_myaddr, &ic_netmask, &ic_gateway); + pr_info(" host=%s, domain=%s, nis-domain=%s\n", + utsname()->nodename, ic_domain, utsname()->domainname); + pr_info(" bootserver=%pI4, rootserver=%pI4, rootpath=%s", + &ic_servaddr, &root_server_addr, root_server_path); + if (ic_dev_mtu) + pr_cont(", mtu=%d", ic_dev_mtu); + /* Name servers (if any): */ + for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) { + if (ic_nameservers[i] != NONE) { + if (i == 0) + pr_info(" nameserver%u=%pI4", + i, &ic_nameservers[i]); + else + pr_cont(", nameserver%u=%pI4", + i, &ic_nameservers[i]); + + count++; + } + if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0) + pr_cont("\n"); + } + /* NTP servers (if any): */ + for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) { + if (ic_ntp_servers[i] != NONE) { + if (i == 0) + pr_info(" ntpserver%u=%pI4", + i, &ic_ntp_servers[i]); + else + pr_cont(", ntpserver%u=%pI4", + i, &ic_ntp_servers[i]); + + count++; + } + if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0) + pr_cont("\n"); + } +#endif /* !SILENT */ + + /* + * Close all network devices except the device we've + * autoconfigured and set up routes. + */ + if (ic_setup_if() < 0 || ic_setup_routes() < 0) + err = -1; + else + err = 0; + + ic_close_devs(); + + return err; +} + +late_initcall(ip_auto_config); + + +/* + * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel + * command line parameter. See Documentation/admin-guide/nfs/nfsroot.rst. + */ +static int __init ic_proto_name(char *name) +{ + if (!strcmp(name, "on") || !strcmp(name, "any")) { + return 1; + } + if (!strcmp(name, "off") || !strcmp(name, "none")) { + return 0; + } +#ifdef CONFIG_IP_PNP_DHCP + else if (!strncmp(name, "dhcp", 4)) { + char *client_id; + + ic_proto_enabled &= ~IC_RARP; + client_id = strstr(name, "dhcp,"); + if (client_id) { + char *v; + + client_id = client_id + 5; + v = strchr(client_id, ','); + if (!v) + return 1; + *v = 0; + if (kstrtou8(client_id, 0, dhcp_client_identifier)) + pr_debug("DHCP: Invalid client identifier type\n"); + strncpy(dhcp_client_identifier + 1, v + 1, 251); + *v = ','; + } + return 1; + } +#endif +#ifdef CONFIG_IP_PNP_BOOTP + else if (!strcmp(name, "bootp")) { + ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP); + return 1; + } +#endif +#ifdef CONFIG_IP_PNP_RARP + else if (!strcmp(name, "rarp")) { + ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP); + return 1; + } +#endif +#ifdef IPCONFIG_DYNAMIC + else if (!strcmp(name, "both")) { + ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */ + return 1; + } +#endif + return 0; +} + +static int __init ip_auto_config_setup(char *addrs) +{ + char *cp, *ip, *dp; + int num = 0; + + ic_set_manually = 1; + ic_enable = 1; + + /* + * If any dhcp, bootp etc options are set, leave autoconfig on + * and skip the below static IP processing. + */ + if (ic_proto_name(addrs)) + return 1; + + /* If no static IP is given, turn off autoconfig and bail. */ + if (*addrs == 0 || + strcmp(addrs, "off") == 0 || + strcmp(addrs, "none") == 0) { + ic_enable = 0; + return 1; + } + + /* Initialise all name servers and NTP servers to NONE */ + ic_nameservers_predef(); + ic_ntp_servers_predef(); + + /* Parse string for static IP assignment. */ + ip = addrs; + while (ip && *ip) { + if ((cp = strchr(ip, ':'))) + *cp++ = '\0'; + if (strlen(ip) > 0) { + pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip); + switch (num) { + case 0: + if ((ic_myaddr = in_aton(ip)) == ANY) + ic_myaddr = NONE; + break; + case 1: + if ((ic_servaddr = in_aton(ip)) == ANY) + ic_servaddr = NONE; + break; + case 2: + if ((ic_gateway = in_aton(ip)) == ANY) + ic_gateway = NONE; + break; + case 3: + if ((ic_netmask = in_aton(ip)) == ANY) + ic_netmask = NONE; + break; + case 4: + if ((dp = strchr(ip, '.'))) { + *dp++ = '\0'; + strlcpy(utsname()->domainname, dp, + sizeof(utsname()->domainname)); + } + strlcpy(utsname()->nodename, ip, + sizeof(utsname()->nodename)); + ic_host_name_set = 1; + break; + case 5: + strlcpy(user_dev_name, ip, sizeof(user_dev_name)); + break; + case 6: + if (ic_proto_name(ip) == 0 && + ic_myaddr == NONE) { + ic_enable = 0; + } + break; + case 7: + if (CONF_NAMESERVERS_MAX >= 1) { + ic_nameservers[0] = in_aton(ip); + if (ic_nameservers[0] == ANY) + ic_nameservers[0] = NONE; + } + break; + case 8: + if (CONF_NAMESERVERS_MAX >= 2) { + ic_nameservers[1] = in_aton(ip); + if (ic_nameservers[1] == ANY) + ic_nameservers[1] = NONE; + } + break; + case 9: + if (CONF_NTP_SERVERS_MAX >= 1) { + ic_ntp_servers[0] = in_aton(ip); + if (ic_ntp_servers[0] == ANY) + ic_ntp_servers[0] = NONE; + } + break; + } + } + ip = cp; + num++; + } + + return 1; +} +__setup("ip=", ip_auto_config_setup); + +static int __init nfsaddrs_config_setup(char *addrs) +{ + return ip_auto_config_setup(addrs); +} +__setup("nfsaddrs=", nfsaddrs_config_setup); + +static int __init vendor_class_identifier_setup(char *addrs) +{ + if (strlcpy(vendor_class_identifier, addrs, + sizeof(vendor_class_identifier)) + >= sizeof(vendor_class_identifier)) + pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n", + vendor_class_identifier); + return 1; +} +__setup("dhcpclass=", vendor_class_identifier_setup); + +static int __init set_carrier_timeout(char *str) +{ + ssize_t ret; + + if (!str) + return 0; + + ret = kstrtouint(str, 0, &carrier_timeout); + if (ret) + return 0; + + return 1; +} +__setup("carrier_timeout=", set_carrier_timeout); diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c new file mode 100644 index 000000000..75d35e76b --- /dev/null +++ b/net/ipv4/ipip.c @@ -0,0 +1,716 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Linux NET3: IP/IP protocol decoder. + * + * Authors: + * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 + * + * Fixes: + * Alan Cox : Merged and made usable non modular (its so tiny its silly as + * a module taking up 2 pages). + * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph) + * to keep ip_forward happy. + * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8). + * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL + * David Woodhouse : Perform some basic ICMP handling. + * IPIP Routing without decapsulation. + * Carlos Picoto : GRE over IP support + * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c. + * I do not want to merge them together. + */ + +/* tunnel.c: an IP tunnel driver + + The purpose of this driver is to provide an IP tunnel through + which you can tunnel network traffic transparently across subnets. + + This was written by looking at Nick Holloway's dummy driver + Thanks for the great code! + + -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 + + Minor tweaks: + Cleaned up the code a little and added some pre-1.3.0 tweaks. + dev->hard_header/hard_header_len changed to use no headers. + Comments/bracketing tweaked. + Made the tunnels use dev->name not tunnel: when error reporting. + Added tx_dropped stat + + -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95 + + Reworked: + Changed to tunnel to destination gateway in addition to the + tunnel's pointopoint address + Almost completely rewritten + Note: There is currently no firewall or ICMP handling done. + + -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96 + +*/ + +/* Things I wish I had known when writing the tunnel driver: + + When the tunnel_xmit() function is called, the skb contains the + packet to be sent (plus a great deal of extra info), and dev + contains the tunnel device that _we_ are. + + When we are passed a packet, we are expected to fill in the + source address with our source IP address. + + What is the proper way to allocate, copy and free a buffer? + After you allocate it, it is a "0 length" chunk of memory + starting at zero. If you want to add headers to the buffer + later, you'll have to call "skb_reserve(skb, amount)" with + the amount of memory you want reserved. Then, you call + "skb_put(skb, amount)" with the amount of space you want in + the buffer. skb_put() returns a pointer to the top (#0) of + that buffer. skb->len is set to the amount of space you have + "allocated" with skb_put(). You can then write up to skb->len + bytes to that buffer. If you need more, you can call skb_put() + again with the additional amount of space you need. You can + find out how much more space you can allocate by calling + "skb_tailroom(skb)". + Now, to add header space, call "skb_push(skb, header_len)". + This creates space at the beginning of the buffer and returns + a pointer to this new space. If later you need to strip a + header from a buffer, call "skb_pull(skb, header_len)". + skb_headroom() will return how much space is left at the top + of the buffer (before the main data). Remember, this headroom + space must be reserved before the skb_put() function is called. + */ + +/* + This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c + + For comments look at net/ipv4/ip_gre.c --ANK + */ + + +#include <linux/capability.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/in.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/if_arp.h> +#include <linux/init.h> +#include <linux/netfilter_ipv4.h> +#include <linux/if_ether.h> + +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/ip_tunnels.h> +#include <net/inet_ecn.h> +#include <net/xfrm.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/dst_metadata.h> + +static bool log_ecn_error = true; +module_param(log_ecn_error, bool, 0644); +MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); + +static unsigned int ipip_net_id __read_mostly; + +static int ipip_tunnel_init(struct net_device *dev); +static struct rtnl_link_ops ipip_link_ops __read_mostly; + +static int ipip_err(struct sk_buff *skb, u32 info) +{ + /* All the routers (except for Linux) return only + * 8 bytes of packet payload. It means, that precise relaying of + * ICMP in the real Internet is absolutely infeasible. + */ + struct net *net = dev_net(skb->dev); + struct ip_tunnel_net *itn = net_generic(net, ipip_net_id); + const struct iphdr *iph = (const struct iphdr *)skb->data; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + struct ip_tunnel *t; + int err = 0; + + t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, + iph->daddr, iph->saddr, 0); + if (!t) { + err = -ENOENT; + goto out; + } + + switch (type) { + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + /* Impossible event. */ + goto out; + default: + /* All others are translated to HOST_UNREACH. + * rfc2003 contains "deep thoughts" about NET_UNREACH, + * I believe they are just ether pollution. --ANK + */ + break; + } + break; + + case ICMP_TIME_EXCEEDED: + if (code != ICMP_EXC_TTL) + goto out; + break; + + case ICMP_REDIRECT: + break; + + default: + goto out; + } + + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { + ipv4_update_pmtu(skb, net, info, t->parms.link, iph->protocol); + goto out; + } + + if (type == ICMP_REDIRECT) { + ipv4_redirect(skb, net, t->parms.link, iph->protocol); + goto out; + } + + if (t->parms.iph.daddr == 0) { + err = -ENOENT; + goto out; + } + + if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) + goto out; + + if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) + t->err_count++; + else + t->err_count = 1; + t->err_time = jiffies; + +out: + return err; +} + +static const struct tnl_ptk_info ipip_tpi = { + /* no tunnel info required for ipip. */ + .proto = htons(ETH_P_IP), +}; + +#if IS_ENABLED(CONFIG_MPLS) +static const struct tnl_ptk_info mplsip_tpi = { + /* no tunnel info required for mplsip. */ + .proto = htons(ETH_P_MPLS_UC), +}; +#endif + +static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto) +{ + struct net *net = dev_net(skb->dev); + struct ip_tunnel_net *itn = net_generic(net, ipip_net_id); + struct metadata_dst *tun_dst = NULL; + struct ip_tunnel *tunnel; + const struct iphdr *iph; + + iph = ip_hdr(skb); + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, + iph->saddr, iph->daddr, 0); + if (tunnel) { + const struct tnl_ptk_info *tpi; + + if (tunnel->parms.iph.protocol != ipproto && + tunnel->parms.iph.protocol != 0) + goto drop; + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto drop; +#if IS_ENABLED(CONFIG_MPLS) + if (ipproto == IPPROTO_MPLS) + tpi = &mplsip_tpi; + else +#endif + tpi = &ipip_tpi; + if (iptunnel_pull_header(skb, 0, tpi->proto, false)) + goto drop; + if (tunnel->collect_md) { + tun_dst = ip_tun_rx_dst(skb, 0, 0, 0); + if (!tun_dst) + return 0; + } + return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error); + } + + return -1; + +drop: + kfree_skb(skb); + return 0; +} + +static int ipip_rcv(struct sk_buff *skb) +{ + return ipip_tunnel_rcv(skb, IPPROTO_IPIP); +} + +#if IS_ENABLED(CONFIG_MPLS) +static int mplsip_rcv(struct sk_buff *skb) +{ + return ipip_tunnel_rcv(skb, IPPROTO_MPLS); +} +#endif + +/* + * This function assumes it is being called from dev_queue_xmit() + * and that skb is filled properly by that function. + */ +static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + const struct iphdr *tiph = &tunnel->parms.iph; + u8 ipproto; + + if (!pskb_inet_may_pull(skb)) + goto tx_error; + + switch (skb->protocol) { + case htons(ETH_P_IP): + ipproto = IPPROTO_IPIP; + break; +#if IS_ENABLED(CONFIG_MPLS) + case htons(ETH_P_MPLS_UC): + ipproto = IPPROTO_MPLS; + break; +#endif + default: + goto tx_error; + } + + if (tiph->protocol != ipproto && tiph->protocol != 0) + goto tx_error; + + if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) + goto tx_error; + + skb_set_inner_ipproto(skb, ipproto); + + if (tunnel->collect_md) + ip_md_tunnel_xmit(skb, dev, ipproto, 0); + else + ip_tunnel_xmit(skb, dev, tiph, ipproto); + return NETDEV_TX_OK; + +tx_error: + kfree_skb(skb); + + dev->stats.tx_errors++; + return NETDEV_TX_OK; +} + +static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto) +{ + switch (ipproto) { + case 0: + case IPPROTO_IPIP: +#if IS_ENABLED(CONFIG_MPLS) + case IPPROTO_MPLS: +#endif + return true; + } + + return false; +} + +static int +ipip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) +{ + if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { + if (p->iph.version != 4 || + !ipip_tunnel_ioctl_verify_protocol(p->iph.protocol) || + p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF))) + return -EINVAL; + } + + p->i_key = p->o_key = 0; + p->i_flags = p->o_flags = 0; + return ip_tunnel_ctl(dev, p, cmd); +} + +static const struct net_device_ops ipip_netdev_ops = { + .ndo_init = ipip_tunnel_init, + .ndo_uninit = ip_tunnel_uninit, + .ndo_start_xmit = ipip_tunnel_xmit, + .ndo_do_ioctl = ip_tunnel_ioctl, + .ndo_change_mtu = ip_tunnel_change_mtu, + .ndo_get_stats64 = ip_tunnel_get_stats64, + .ndo_get_iflink = ip_tunnel_get_iflink, + .ndo_tunnel_ctl = ipip_tunnel_ctl, +}; + +#define IPIP_FEATURES (NETIF_F_SG | \ + NETIF_F_FRAGLIST | \ + NETIF_F_HIGHDMA | \ + NETIF_F_GSO_SOFTWARE | \ + NETIF_F_HW_CSUM) + +static void ipip_tunnel_setup(struct net_device *dev) +{ + dev->netdev_ops = &ipip_netdev_ops; + dev->header_ops = &ip_tunnel_header_ops; + + dev->type = ARPHRD_TUNNEL; + dev->flags = IFF_NOARP; + dev->addr_len = 4; + dev->features |= NETIF_F_LLTX; + netif_keep_dst(dev); + + dev->features |= IPIP_FEATURES; + dev->hw_features |= IPIP_FEATURES; + ip_tunnel_setup(dev, ipip_net_id); +} + +static int ipip_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); + memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); + + tunnel->tun_hlen = 0; + tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; + return ip_tunnel_init(dev); +} + +static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + u8 proto; + + if (!data || !data[IFLA_IPTUN_PROTO]) + return 0; + + proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); + if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0) + return -EINVAL; + + return 0; +} + +static void ipip_netlink_parms(struct nlattr *data[], + struct ip_tunnel_parm *parms, bool *collect_md, + __u32 *fwmark) +{ + memset(parms, 0, sizeof(*parms)); + + parms->iph.version = 4; + parms->iph.protocol = IPPROTO_IPIP; + parms->iph.ihl = 5; + *collect_md = false; + + if (!data) + return; + + if (data[IFLA_IPTUN_LINK]) + parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); + + if (data[IFLA_IPTUN_LOCAL]) + parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]); + + if (data[IFLA_IPTUN_REMOTE]) + parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]); + + if (data[IFLA_IPTUN_TTL]) { + parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); + if (parms->iph.ttl) + parms->iph.frag_off = htons(IP_DF); + } + + if (data[IFLA_IPTUN_TOS]) + parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); + + if (data[IFLA_IPTUN_PROTO]) + parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); + + if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) + parms->iph.frag_off = htons(IP_DF); + + if (data[IFLA_IPTUN_COLLECT_METADATA]) + *collect_md = true; + + if (data[IFLA_IPTUN_FWMARK]) + *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]); +} + +/* This function returns true when ENCAP attributes are present in the nl msg */ +static bool ipip_netlink_encap_parms(struct nlattr *data[], + struct ip_tunnel_encap *ipencap) +{ + bool ret = false; + + memset(ipencap, 0, sizeof(*ipencap)); + + if (!data) + return ret; + + if (data[IFLA_IPTUN_ENCAP_TYPE]) { + ret = true; + ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]); + } + + if (data[IFLA_IPTUN_ENCAP_FLAGS]) { + ret = true; + ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]); + } + + if (data[IFLA_IPTUN_ENCAP_SPORT]) { + ret = true; + ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]); + } + + if (data[IFLA_IPTUN_ENCAP_DPORT]) { + ret = true; + ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]); + } + + return ret; +} + +static int ipip_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_parm p; + struct ip_tunnel_encap ipencap; + __u32 fwmark = 0; + + if (ipip_netlink_encap_parms(data, &ipencap)) { + int err = ip_tunnel_encap_setup(t, &ipencap); + + if (err < 0) + return err; + } + + ipip_netlink_parms(data, &p, &t->collect_md, &fwmark); + return ip_tunnel_newlink(dev, tb, &p, fwmark); +} + +static int ipip_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_parm p; + struct ip_tunnel_encap ipencap; + bool collect_md; + __u32 fwmark = t->fwmark; + + if (ipip_netlink_encap_parms(data, &ipencap)) { + int err = ip_tunnel_encap_setup(t, &ipencap); + + if (err < 0) + return err; + } + + ipip_netlink_parms(data, &p, &collect_md, &fwmark); + if (collect_md) + return -EINVAL; + + if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || + (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) + return -EINVAL; + + return ip_tunnel_changelink(dev, tb, &p, fwmark); +} + +static size_t ipip_get_size(const struct net_device *dev) +{ + return + /* IFLA_IPTUN_LINK */ + nla_total_size(4) + + /* IFLA_IPTUN_LOCAL */ + nla_total_size(4) + + /* IFLA_IPTUN_REMOTE */ + nla_total_size(4) + + /* IFLA_IPTUN_TTL */ + nla_total_size(1) + + /* IFLA_IPTUN_TOS */ + nla_total_size(1) + + /* IFLA_IPTUN_PROTO */ + nla_total_size(1) + + /* IFLA_IPTUN_PMTUDISC */ + nla_total_size(1) + + /* IFLA_IPTUN_ENCAP_TYPE */ + nla_total_size(2) + + /* IFLA_IPTUN_ENCAP_FLAGS */ + nla_total_size(2) + + /* IFLA_IPTUN_ENCAP_SPORT */ + nla_total_size(2) + + /* IFLA_IPTUN_ENCAP_DPORT */ + nla_total_size(2) + + /* IFLA_IPTUN_COLLECT_METADATA */ + nla_total_size(0) + + /* IFLA_IPTUN_FWMARK */ + nla_total_size(4) + + 0; +} + +static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct ip_tunnel_parm *parm = &tunnel->parms; + + if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || + nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || + nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || + nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || + nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || + nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || + nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, + !!(parm->iph.frag_off & htons(IP_DF))) || + nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark)) + goto nla_put_failure; + + if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, + tunnel->encap.type) || + nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, + tunnel->encap.sport) || + nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, + tunnel->encap.dport) || + nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, + tunnel->encap.flags)) + goto nla_put_failure; + + if (tunnel->collect_md) + if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = { + [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, + [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, + [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, + [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, + [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, + [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, + [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, + [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 }, + [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 }, + [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 }, + [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 }, + [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG }, + [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 }, +}; + +static struct rtnl_link_ops ipip_link_ops __read_mostly = { + .kind = "ipip", + .maxtype = IFLA_IPTUN_MAX, + .policy = ipip_policy, + .priv_size = sizeof(struct ip_tunnel), + .setup = ipip_tunnel_setup, + .validate = ipip_tunnel_validate, + .newlink = ipip_newlink, + .changelink = ipip_changelink, + .dellink = ip_tunnel_dellink, + .get_size = ipip_get_size, + .fill_info = ipip_fill_info, + .get_link_net = ip_tunnel_get_link_net, +}; + +static struct xfrm_tunnel ipip_handler __read_mostly = { + .handler = ipip_rcv, + .err_handler = ipip_err, + .priority = 1, +}; + +#if IS_ENABLED(CONFIG_MPLS) +static struct xfrm_tunnel mplsip_handler __read_mostly = { + .handler = mplsip_rcv, + .err_handler = ipip_err, + .priority = 1, +}; +#endif + +static int __net_init ipip_init_net(struct net *net) +{ + return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0"); +} + +static void __net_exit ipip_exit_batch_net(struct list_head *list_net) +{ + ip_tunnel_delete_nets(list_net, ipip_net_id, &ipip_link_ops); +} + +static struct pernet_operations ipip_net_ops = { + .init = ipip_init_net, + .exit_batch = ipip_exit_batch_net, + .id = &ipip_net_id, + .size = sizeof(struct ip_tunnel_net), +}; + +static int __init ipip_init(void) +{ + int err; + + pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n"); + + err = register_pernet_device(&ipip_net_ops); + if (err < 0) + return err; + err = xfrm4_tunnel_register(&ipip_handler, AF_INET); + if (err < 0) { + pr_info("%s: can't register tunnel\n", __func__); + goto xfrm_tunnel_ipip_failed; + } +#if IS_ENABLED(CONFIG_MPLS) + err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS); + if (err < 0) { + pr_info("%s: can't register tunnel\n", __func__); + goto xfrm_tunnel_mplsip_failed; + } +#endif + err = rtnl_link_register(&ipip_link_ops); + if (err < 0) + goto rtnl_link_failed; + +out: + return err; + +rtnl_link_failed: +#if IS_ENABLED(CONFIG_MPLS) + xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS); +xfrm_tunnel_mplsip_failed: + +#endif + xfrm4_tunnel_deregister(&ipip_handler, AF_INET); +xfrm_tunnel_ipip_failed: + unregister_pernet_device(&ipip_net_ops); + goto out; +} + +static void __exit ipip_fini(void) +{ + rtnl_link_unregister(&ipip_link_ops); + if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) + pr_info("%s: can't deregister tunnel\n", __func__); +#if IS_ENABLED(CONFIG_MPLS) + if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS)) + pr_info("%s: can't deregister tunnel\n", __func__); +#endif + unregister_pernet_device(&ipip_net_ops); +} + +module_init(ipip_init); +module_exit(ipip_fini); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK("ipip"); +MODULE_ALIAS_NETDEV("tunl0"); diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c new file mode 100644 index 000000000..be1976536 --- /dev/null +++ b/net/ipv4/ipmr.c @@ -0,0 +1,3151 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IP multicast routing support for mrouted 3.6/3.8 + * + * (c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk> + * Linux Consultancy and Custom Driver Development + * + * Fixes: + * Michael Chastain : Incorrect size of copying. + * Alan Cox : Added the cache manager code + * Alan Cox : Fixed the clone/copy bug and device race. + * Mike McLagan : Routing by source + * Malcolm Beattie : Buffer handling fixes. + * Alexey Kuznetsov : Double buffer free and other fixes. + * SVR Anand : Fixed several multicast bugs and problems. + * Alexey Kuznetsov : Status, optimisations and more. + * Brad Parker : Better behaviour on mrouted upcall + * overflow. + * Carlos Picoto : PIMv1 Support + * Pavlin Ivanov Radoslavov: PIMv2 Registers must checksum only PIM header + * Relax this requirement to work with older peers. + */ + +#include <linux/uaccess.h> +#include <linux/types.h> +#include <linux/cache.h> +#include <linux/capability.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/kernel.h> +#include <linux/fcntl.h> +#include <linux/stat.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/inetdevice.h> +#include <linux/igmp.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/mroute.h> +#include <linux/init.h> +#include <linux/if_ether.h> +#include <linux/slab.h> +#include <net/net_namespace.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <linux/skbuff.h> +#include <net/route.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/raw.h> +#include <linux/notifier.h> +#include <linux/if_arp.h> +#include <linux/netfilter_ipv4.h> +#include <linux/compat.h> +#include <linux/export.h> +#include <linux/rhashtable.h> +#include <net/ip_tunnels.h> +#include <net/checksum.h> +#include <net/netlink.h> +#include <net/fib_rules.h> +#include <linux/netconf.h> +#include <net/rtnh.h> + +#include <linux/nospec.h> + +struct ipmr_rule { + struct fib_rule common; +}; + +struct ipmr_result { + struct mr_table *mrt; +}; + +/* Big lock, protecting vif table, mrt cache and mroute socket state. + * Note that the changes are semaphored via rtnl_lock. + */ + +static DEFINE_RWLOCK(mrt_lock); + +/* Multicast router control variables */ + +/* Special spinlock for queue of unresolved entries */ +static DEFINE_SPINLOCK(mfc_unres_lock); + +/* We return to original Alan's scheme. Hash table of resolved + * entries is changed only in process context and protected + * with weak lock mrt_lock. Queue of unresolved entries is protected + * with strong spinlock mfc_unres_lock. + * + * In this case data path is free of exclusive locks at all. + */ + +static struct kmem_cache *mrt_cachep __ro_after_init; + +static struct mr_table *ipmr_new_table(struct net *net, u32 id); +static void ipmr_free_table(struct mr_table *mrt); + +static void ip_mr_forward(struct net *net, struct mr_table *mrt, + struct net_device *dev, struct sk_buff *skb, + struct mfc_cache *cache, int local); +static int ipmr_cache_report(struct mr_table *mrt, + struct sk_buff *pkt, vifi_t vifi, int assert); +static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc, + int cmd); +static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt); +static void mroute_clean_tables(struct mr_table *mrt, int flags); +static void ipmr_expire_process(struct timer_list *t); + +#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES +#define ipmr_for_each_table(mrt, net) \ + list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list, \ + lockdep_rtnl_is_held() || \ + list_empty(&net->ipv4.mr_tables)) + +static struct mr_table *ipmr_mr_table_iter(struct net *net, + struct mr_table *mrt) +{ + struct mr_table *ret; + + if (!mrt) + ret = list_entry_rcu(net->ipv4.mr_tables.next, + struct mr_table, list); + else + ret = list_entry_rcu(mrt->list.next, + struct mr_table, list); + + if (&ret->list == &net->ipv4.mr_tables) + return NULL; + return ret; +} + +static struct mr_table *ipmr_get_table(struct net *net, u32 id) +{ + struct mr_table *mrt; + + ipmr_for_each_table(mrt, net) { + if (mrt->id == id) + return mrt; + } + return NULL; +} + +static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4, + struct mr_table **mrt) +{ + int err; + struct ipmr_result res; + struct fib_lookup_arg arg = { + .result = &res, + .flags = FIB_LOOKUP_NOREF, + }; + + /* update flow if oif or iif point to device enslaved to l3mdev */ + l3mdev_update_flow(net, flowi4_to_flowi(flp4)); + + err = fib_rules_lookup(net->ipv4.mr_rules_ops, + flowi4_to_flowi(flp4), 0, &arg); + if (err < 0) + return err; + *mrt = res.mrt; + return 0; +} + +static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp, + int flags, struct fib_lookup_arg *arg) +{ + struct ipmr_result *res = arg->result; + struct mr_table *mrt; + + switch (rule->action) { + case FR_ACT_TO_TBL: + break; + case FR_ACT_UNREACHABLE: + return -ENETUNREACH; + case FR_ACT_PROHIBIT: + return -EACCES; + case FR_ACT_BLACKHOLE: + default: + return -EINVAL; + } + + arg->table = fib_rule_get_table(rule, arg); + + mrt = ipmr_get_table(rule->fr_net, arg->table); + if (!mrt) + return -EAGAIN; + res->mrt = mrt; + return 0; +} + +static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) +{ + return 1; +} + +static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = { + FRA_GENERIC_POLICY, +}; + +static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb, + struct fib_rule_hdr *frh, struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + return 0; +} + +static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, + struct nlattr **tb) +{ + return 1; +} + +static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb, + struct fib_rule_hdr *frh) +{ + frh->dst_len = 0; + frh->src_len = 0; + frh->tos = 0; + return 0; +} + +static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = { + .family = RTNL_FAMILY_IPMR, + .rule_size = sizeof(struct ipmr_rule), + .addr_size = sizeof(u32), + .action = ipmr_rule_action, + .match = ipmr_rule_match, + .configure = ipmr_rule_configure, + .compare = ipmr_rule_compare, + .fill = ipmr_rule_fill, + .nlgroup = RTNLGRP_IPV4_RULE, + .policy = ipmr_rule_policy, + .owner = THIS_MODULE, +}; + +static int __net_init ipmr_rules_init(struct net *net) +{ + struct fib_rules_ops *ops; + struct mr_table *mrt; + int err; + + ops = fib_rules_register(&ipmr_rules_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + + INIT_LIST_HEAD(&net->ipv4.mr_tables); + + mrt = ipmr_new_table(net, RT_TABLE_DEFAULT); + if (IS_ERR(mrt)) { + err = PTR_ERR(mrt); + goto err1; + } + + err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0); + if (err < 0) + goto err2; + + net->ipv4.mr_rules_ops = ops; + return 0; + +err2: + rtnl_lock(); + ipmr_free_table(mrt); + rtnl_unlock(); +err1: + fib_rules_unregister(ops); + return err; +} + +static void __net_exit ipmr_rules_exit(struct net *net) +{ + struct mr_table *mrt, *next; + + rtnl_lock(); + list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) { + list_del(&mrt->list); + ipmr_free_table(mrt); + } + fib_rules_unregister(net->ipv4.mr_rules_ops); + rtnl_unlock(); +} + +static int ipmr_rules_dump(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack); +} + +static unsigned int ipmr_rules_seq_read(struct net *net) +{ + return fib_rules_seq_read(net, RTNL_FAMILY_IPMR); +} + +bool ipmr_rule_default(const struct fib_rule *rule) +{ + return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT; +} +EXPORT_SYMBOL(ipmr_rule_default); +#else +#define ipmr_for_each_table(mrt, net) \ + for (mrt = net->ipv4.mrt; mrt; mrt = NULL) + +static struct mr_table *ipmr_mr_table_iter(struct net *net, + struct mr_table *mrt) +{ + if (!mrt) + return net->ipv4.mrt; + return NULL; +} + +static struct mr_table *ipmr_get_table(struct net *net, u32 id) +{ + return net->ipv4.mrt; +} + +static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4, + struct mr_table **mrt) +{ + *mrt = net->ipv4.mrt; + return 0; +} + +static int __net_init ipmr_rules_init(struct net *net) +{ + struct mr_table *mrt; + + mrt = ipmr_new_table(net, RT_TABLE_DEFAULT); + if (IS_ERR(mrt)) + return PTR_ERR(mrt); + net->ipv4.mrt = mrt; + return 0; +} + +static void __net_exit ipmr_rules_exit(struct net *net) +{ + rtnl_lock(); + ipmr_free_table(net->ipv4.mrt); + net->ipv4.mrt = NULL; + rtnl_unlock(); +} + +static int ipmr_rules_dump(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + return 0; +} + +static unsigned int ipmr_rules_seq_read(struct net *net) +{ + return 0; +} + +bool ipmr_rule_default(const struct fib_rule *rule) +{ + return true; +} +EXPORT_SYMBOL(ipmr_rule_default); +#endif + +static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg, + const void *ptr) +{ + const struct mfc_cache_cmp_arg *cmparg = arg->key; + struct mfc_cache *c = (struct mfc_cache *)ptr; + + return cmparg->mfc_mcastgrp != c->mfc_mcastgrp || + cmparg->mfc_origin != c->mfc_origin; +} + +static const struct rhashtable_params ipmr_rht_params = { + .head_offset = offsetof(struct mr_mfc, mnode), + .key_offset = offsetof(struct mfc_cache, cmparg), + .key_len = sizeof(struct mfc_cache_cmp_arg), + .nelem_hint = 3, + .obj_cmpfn = ipmr_hash_cmp, + .automatic_shrinking = true, +}; + +static void ipmr_new_table_set(struct mr_table *mrt, + struct net *net) +{ +#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES + list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables); +#endif +} + +static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = { + .mfc_mcastgrp = htonl(INADDR_ANY), + .mfc_origin = htonl(INADDR_ANY), +}; + +static struct mr_table_ops ipmr_mr_table_ops = { + .rht_params = &ipmr_rht_params, + .cmparg_any = &ipmr_mr_table_ops_cmparg_any, +}; + +static struct mr_table *ipmr_new_table(struct net *net, u32 id) +{ + struct mr_table *mrt; + + /* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */ + if (id != RT_TABLE_DEFAULT && id >= 1000000000) + return ERR_PTR(-EINVAL); + + mrt = ipmr_get_table(net, id); + if (mrt) + return mrt; + + return mr_table_alloc(net, id, &ipmr_mr_table_ops, + ipmr_expire_process, ipmr_new_table_set); +} + +static void ipmr_free_table(struct mr_table *mrt) +{ + del_timer_sync(&mrt->ipmr_expire_timer); + mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC | + MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC); + rhltable_destroy(&mrt->mfc_hash); + kfree(mrt); +} + +/* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */ + +/* Initialize ipmr pimreg/tunnel in_device */ +static bool ipmr_init_vif_indev(const struct net_device *dev) +{ + struct in_device *in_dev; + + ASSERT_RTNL(); + + in_dev = __in_dev_get_rtnl(dev); + if (!in_dev) + return false; + ipv4_devconf_setall(in_dev); + neigh_parms_data_state_setall(in_dev->arp_parms); + IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0; + + return true; +} + +static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v) +{ + struct net_device *tunnel_dev, *new_dev; + struct ip_tunnel_parm p = { }; + int err; + + tunnel_dev = __dev_get_by_name(net, "tunl0"); + if (!tunnel_dev) + goto out; + + p.iph.daddr = v->vifc_rmt_addr.s_addr; + p.iph.saddr = v->vifc_lcl_addr.s_addr; + p.iph.version = 4; + p.iph.ihl = 5; + p.iph.protocol = IPPROTO_IPIP; + sprintf(p.name, "dvmrp%d", v->vifc_vifi); + + if (!tunnel_dev->netdev_ops->ndo_tunnel_ctl) + goto out; + err = tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p, + SIOCADDTUNNEL); + if (err) + goto out; + + new_dev = __dev_get_by_name(net, p.name); + if (!new_dev) + goto out; + + new_dev->flags |= IFF_MULTICAST; + if (!ipmr_init_vif_indev(new_dev)) + goto out_unregister; + if (dev_open(new_dev, NULL)) + goto out_unregister; + dev_hold(new_dev); + err = dev_set_allmulti(new_dev, 1); + if (err) { + dev_close(new_dev); + tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p, + SIOCDELTUNNEL); + dev_put(new_dev); + new_dev = ERR_PTR(err); + } + return new_dev; + +out_unregister: + unregister_netdevice(new_dev); +out: + return ERR_PTR(-ENOBUFS); +} + +#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2) +static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct net *net = dev_net(dev); + struct mr_table *mrt; + struct flowi4 fl4 = { + .flowi4_oif = dev->ifindex, + .flowi4_iif = skb->skb_iif ? : LOOPBACK_IFINDEX, + .flowi4_mark = skb->mark, + }; + int err; + + err = ipmr_fib_lookup(net, &fl4, &mrt); + if (err < 0) { + kfree_skb(skb); + return err; + } + + read_lock(&mrt_lock); + dev->stats.tx_bytes += skb->len; + dev->stats.tx_packets++; + ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT); + read_unlock(&mrt_lock); + kfree_skb(skb); + return NETDEV_TX_OK; +} + +static int reg_vif_get_iflink(const struct net_device *dev) +{ + return 0; +} + +static const struct net_device_ops reg_vif_netdev_ops = { + .ndo_start_xmit = reg_vif_xmit, + .ndo_get_iflink = reg_vif_get_iflink, +}; + +static void reg_vif_setup(struct net_device *dev) +{ + dev->type = ARPHRD_PIMREG; + dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 8; + dev->flags = IFF_NOARP; + dev->netdev_ops = ®_vif_netdev_ops; + dev->needs_free_netdev = true; + dev->features |= NETIF_F_NETNS_LOCAL; +} + +static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt) +{ + struct net_device *dev; + char name[IFNAMSIZ]; + + if (mrt->id == RT_TABLE_DEFAULT) + sprintf(name, "pimreg"); + else + sprintf(name, "pimreg%u", mrt->id); + + dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup); + + if (!dev) + return NULL; + + dev_net_set(dev, net); + + if (register_netdevice(dev)) { + free_netdev(dev); + return NULL; + } + + if (!ipmr_init_vif_indev(dev)) + goto failure; + if (dev_open(dev, NULL)) + goto failure; + + dev_hold(dev); + + return dev; + +failure: + unregister_netdevice(dev); + return NULL; +} + +/* called with rcu_read_lock() */ +static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb, + unsigned int pimlen) +{ + struct net_device *reg_dev = NULL; + struct iphdr *encap; + + encap = (struct iphdr *)(skb_transport_header(skb) + pimlen); + /* Check that: + * a. packet is really sent to a multicast group + * b. packet is not a NULL-REGISTER + * c. packet is not truncated + */ + if (!ipv4_is_multicast(encap->daddr) || + encap->tot_len == 0 || + ntohs(encap->tot_len) + pimlen > skb->len) + return 1; + + read_lock(&mrt_lock); + if (mrt->mroute_reg_vif_num >= 0) + reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev; + read_unlock(&mrt_lock); + + if (!reg_dev) + return 1; + + skb->mac_header = skb->network_header; + skb_pull(skb, (u8 *)encap - skb->data); + skb_reset_network_header(skb); + skb->protocol = htons(ETH_P_IP); + skb->ip_summed = CHECKSUM_NONE; + + skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev)); + + netif_rx(skb); + + return NET_RX_SUCCESS; +} +#else +static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt) +{ + return NULL; +} +#endif + +static int call_ipmr_vif_entry_notifiers(struct net *net, + enum fib_event_type event_type, + struct vif_device *vif, + vifi_t vif_index, u32 tb_id) +{ + return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type, + vif, vif_index, tb_id, + &net->ipv4.ipmr_seq); +} + +static int call_ipmr_mfc_entry_notifiers(struct net *net, + enum fib_event_type event_type, + struct mfc_cache *mfc, u32 tb_id) +{ + return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type, + &mfc->_c, tb_id, &net->ipv4.ipmr_seq); +} + +/** + * vif_delete - Delete a VIF entry + * @mrt: Table to delete from + * @vifi: VIF identifier to delete + * @notify: Set to 1, if the caller is a notifier_call + * @head: if unregistering the VIF, place it on this queue + */ +static int vif_delete(struct mr_table *mrt, int vifi, int notify, + struct list_head *head) +{ + struct net *net = read_pnet(&mrt->net); + struct vif_device *v; + struct net_device *dev; + struct in_device *in_dev; + + if (vifi < 0 || vifi >= mrt->maxvif) + return -EADDRNOTAVAIL; + + v = &mrt->vif_table[vifi]; + + if (VIF_EXISTS(mrt, vifi)) + call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, vifi, + mrt->id); + + write_lock_bh(&mrt_lock); + dev = v->dev; + v->dev = NULL; + + if (!dev) { + write_unlock_bh(&mrt_lock); + return -EADDRNOTAVAIL; + } + + if (vifi == mrt->mroute_reg_vif_num) + mrt->mroute_reg_vif_num = -1; + + if (vifi + 1 == mrt->maxvif) { + int tmp; + + for (tmp = vifi - 1; tmp >= 0; tmp--) { + if (VIF_EXISTS(mrt, tmp)) + break; + } + mrt->maxvif = tmp+1; + } + + write_unlock_bh(&mrt_lock); + + dev_set_allmulti(dev, -1); + + in_dev = __in_dev_get_rtnl(dev); + if (in_dev) { + IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--; + inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, + NETCONFA_MC_FORWARDING, + dev->ifindex, &in_dev->cnf); + ip_rt_multicast_event(in_dev); + } + + if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify) + unregister_netdevice_queue(dev, head); + + dev_put(dev); + return 0; +} + +static void ipmr_cache_free_rcu(struct rcu_head *head) +{ + struct mr_mfc *c = container_of(head, struct mr_mfc, rcu); + + kmem_cache_free(mrt_cachep, (struct mfc_cache *)c); +} + +static void ipmr_cache_free(struct mfc_cache *c) +{ + call_rcu(&c->_c.rcu, ipmr_cache_free_rcu); +} + +/* Destroy an unresolved cache entry, killing queued skbs + * and reporting error to netlink readers. + */ +static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c) +{ + struct net *net = read_pnet(&mrt->net); + struct sk_buff *skb; + struct nlmsgerr *e; + + atomic_dec(&mrt->cache_resolve_queue_len); + + while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) { + if (ip_hdr(skb)->version == 0) { + struct nlmsghdr *nlh = skb_pull(skb, + sizeof(struct iphdr)); + nlh->nlmsg_type = NLMSG_ERROR; + nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr)); + skb_trim(skb, nlh->nlmsg_len); + e = nlmsg_data(nlh); + e->error = -ETIMEDOUT; + memset(&e->msg, 0, sizeof(e->msg)); + + rtnl_unicast(skb, net, NETLINK_CB(skb).portid); + } else { + kfree_skb(skb); + } + } + + ipmr_cache_free(c); +} + +/* Timer process for the unresolved queue. */ +static void ipmr_expire_process(struct timer_list *t) +{ + struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer); + struct mr_mfc *c, *next; + unsigned long expires; + unsigned long now; + + if (!spin_trylock(&mfc_unres_lock)) { + mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10); + return; + } + + if (list_empty(&mrt->mfc_unres_queue)) + goto out; + + now = jiffies; + expires = 10*HZ; + + list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) { + if (time_after(c->mfc_un.unres.expires, now)) { + unsigned long interval = c->mfc_un.unres.expires - now; + if (interval < expires) + expires = interval; + continue; + } + + list_del(&c->list); + mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE); + ipmr_destroy_unres(mrt, (struct mfc_cache *)c); + } + + if (!list_empty(&mrt->mfc_unres_queue)) + mod_timer(&mrt->ipmr_expire_timer, jiffies + expires); + +out: + spin_unlock(&mfc_unres_lock); +} + +/* Fill oifs list. It is called under write locked mrt_lock. */ +static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache, + unsigned char *ttls) +{ + int vifi; + + cache->mfc_un.res.minvif = MAXVIFS; + cache->mfc_un.res.maxvif = 0; + memset(cache->mfc_un.res.ttls, 255, MAXVIFS); + + for (vifi = 0; vifi < mrt->maxvif; vifi++) { + if (VIF_EXISTS(mrt, vifi) && + ttls[vifi] && ttls[vifi] < 255) { + cache->mfc_un.res.ttls[vifi] = ttls[vifi]; + if (cache->mfc_un.res.minvif > vifi) + cache->mfc_un.res.minvif = vifi; + if (cache->mfc_un.res.maxvif <= vifi) + cache->mfc_un.res.maxvif = vifi + 1; + } + } + cache->mfc_un.res.lastuse = jiffies; +} + +static int vif_add(struct net *net, struct mr_table *mrt, + struct vifctl *vifc, int mrtsock) +{ + struct netdev_phys_item_id ppid = { }; + int vifi = vifc->vifc_vifi; + struct vif_device *v = &mrt->vif_table[vifi]; + struct net_device *dev; + struct in_device *in_dev; + int err; + + /* Is vif busy ? */ + if (VIF_EXISTS(mrt, vifi)) + return -EADDRINUSE; + + switch (vifc->vifc_flags) { + case VIFF_REGISTER: + if (!ipmr_pimsm_enabled()) + return -EINVAL; + /* Special Purpose VIF in PIM + * All the packets will be sent to the daemon + */ + if (mrt->mroute_reg_vif_num >= 0) + return -EADDRINUSE; + dev = ipmr_reg_vif(net, mrt); + if (!dev) + return -ENOBUFS; + err = dev_set_allmulti(dev, 1); + if (err) { + unregister_netdevice(dev); + dev_put(dev); + return err; + } + break; + case VIFF_TUNNEL: + dev = ipmr_new_tunnel(net, vifc); + if (IS_ERR(dev)) + return PTR_ERR(dev); + break; + case VIFF_USE_IFINDEX: + case 0: + if (vifc->vifc_flags == VIFF_USE_IFINDEX) { + dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex); + if (dev && !__in_dev_get_rtnl(dev)) { + dev_put(dev); + return -EADDRNOTAVAIL; + } + } else { + dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr); + } + if (!dev) + return -EADDRNOTAVAIL; + err = dev_set_allmulti(dev, 1); + if (err) { + dev_put(dev); + return err; + } + break; + default: + return -EINVAL; + } + + in_dev = __in_dev_get_rtnl(dev); + if (!in_dev) { + dev_put(dev); + return -EADDRNOTAVAIL; + } + IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++; + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, + dev->ifindex, &in_dev->cnf); + ip_rt_multicast_event(in_dev); + + /* Fill in the VIF structures */ + vif_device_init(v, dev, vifc->vifc_rate_limit, + vifc->vifc_threshold, + vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0), + (VIFF_TUNNEL | VIFF_REGISTER)); + + err = dev_get_port_parent_id(dev, &ppid, true); + if (err == 0) { + memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len); + v->dev_parent_id.id_len = ppid.id_len; + } else { + v->dev_parent_id.id_len = 0; + } + + v->local = vifc->vifc_lcl_addr.s_addr; + v->remote = vifc->vifc_rmt_addr.s_addr; + + /* And finish update writing critical data */ + write_lock_bh(&mrt_lock); + v->dev = dev; + if (v->flags & VIFF_REGISTER) + mrt->mroute_reg_vif_num = vifi; + if (vifi+1 > mrt->maxvif) + mrt->maxvif = vifi+1; + write_unlock_bh(&mrt_lock); + call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, vifi, mrt->id); + return 0; +} + +/* called with rcu_read_lock() */ +static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt, + __be32 origin, + __be32 mcastgrp) +{ + struct mfc_cache_cmp_arg arg = { + .mfc_mcastgrp = mcastgrp, + .mfc_origin = origin + }; + + return mr_mfc_find(mrt, &arg); +} + +/* Look for a (*,G) entry */ +static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt, + __be32 mcastgrp, int vifi) +{ + struct mfc_cache_cmp_arg arg = { + .mfc_mcastgrp = mcastgrp, + .mfc_origin = htonl(INADDR_ANY) + }; + + if (mcastgrp == htonl(INADDR_ANY)) + return mr_mfc_find_any_parent(mrt, vifi); + return mr_mfc_find_any(mrt, vifi, &arg); +} + +/* Look for a (S,G,iif) entry if parent != -1 */ +static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt, + __be32 origin, __be32 mcastgrp, + int parent) +{ + struct mfc_cache_cmp_arg arg = { + .mfc_mcastgrp = mcastgrp, + .mfc_origin = origin, + }; + + return mr_mfc_find_parent(mrt, &arg, parent); +} + +/* Allocate a multicast cache entry */ +static struct mfc_cache *ipmr_cache_alloc(void) +{ + struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL); + + if (c) { + c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1; + c->_c.mfc_un.res.minvif = MAXVIFS; + c->_c.free = ipmr_cache_free_rcu; + refcount_set(&c->_c.mfc_un.res.refcount, 1); + } + return c; +} + +static struct mfc_cache *ipmr_cache_alloc_unres(void) +{ + struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC); + + if (c) { + skb_queue_head_init(&c->_c.mfc_un.unres.unresolved); + c->_c.mfc_un.unres.expires = jiffies + 10 * HZ; + } + return c; +} + +/* A cache entry has gone into a resolved state from queued */ +static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt, + struct mfc_cache *uc, struct mfc_cache *c) +{ + struct sk_buff *skb; + struct nlmsgerr *e; + + /* Play the pending entries through our router */ + while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) { + if (ip_hdr(skb)->version == 0) { + struct nlmsghdr *nlh = skb_pull(skb, + sizeof(struct iphdr)); + + if (mr_fill_mroute(mrt, skb, &c->_c, + nlmsg_data(nlh)) > 0) { + nlh->nlmsg_len = skb_tail_pointer(skb) - + (u8 *)nlh; + } else { + nlh->nlmsg_type = NLMSG_ERROR; + nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr)); + skb_trim(skb, nlh->nlmsg_len); + e = nlmsg_data(nlh); + e->error = -EMSGSIZE; + memset(&e->msg, 0, sizeof(e->msg)); + } + + rtnl_unicast(skb, net, NETLINK_CB(skb).portid); + } else { + ip_mr_forward(net, mrt, skb->dev, skb, c, 0); + } + } +} + +/* Bounce a cache query up to mrouted and netlink. + * + * Called under mrt_lock. + */ +static int ipmr_cache_report(struct mr_table *mrt, + struct sk_buff *pkt, vifi_t vifi, int assert) +{ + const int ihl = ip_hdrlen(pkt); + struct sock *mroute_sk; + struct igmphdr *igmp; + struct igmpmsg *msg; + struct sk_buff *skb; + int ret; + + if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) + skb = skb_realloc_headroom(pkt, sizeof(struct iphdr)); + else + skb = alloc_skb(128, GFP_ATOMIC); + + if (!skb) + return -ENOBUFS; + + if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) { + /* Ugly, but we have no choice with this interface. + * Duplicate old header, fix ihl, length etc. + * And all this only to mangle msg->im_msgtype and + * to set msg->im_mbz to "mbz" :-) + */ + skb_push(skb, sizeof(struct iphdr)); + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + msg = (struct igmpmsg *)skb_network_header(skb); + memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr)); + msg->im_msgtype = assert; + msg->im_mbz = 0; + if (assert == IGMPMSG_WRVIFWHOLE) { + msg->im_vif = vifi; + msg->im_vif_hi = vifi >> 8; + } else { + msg->im_vif = mrt->mroute_reg_vif_num; + msg->im_vif_hi = mrt->mroute_reg_vif_num >> 8; + } + ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2; + ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) + + sizeof(struct iphdr)); + } else { + /* Copy the IP header */ + skb_set_network_header(skb, skb->len); + skb_put(skb, ihl); + skb_copy_to_linear_data(skb, pkt->data, ihl); + /* Flag to the kernel this is a route add */ + ip_hdr(skb)->protocol = 0; + msg = (struct igmpmsg *)skb_network_header(skb); + msg->im_vif = vifi; + msg->im_vif_hi = vifi >> 8; + skb_dst_set(skb, dst_clone(skb_dst(pkt))); + /* Add our header */ + igmp = skb_put(skb, sizeof(struct igmphdr)); + igmp->type = assert; + msg->im_msgtype = assert; + igmp->code = 0; + ip_hdr(skb)->tot_len = htons(skb->len); /* Fix the length */ + skb->transport_header = skb->network_header; + } + + rcu_read_lock(); + mroute_sk = rcu_dereference(mrt->mroute_sk); + if (!mroute_sk) { + rcu_read_unlock(); + kfree_skb(skb); + return -EINVAL; + } + + igmpmsg_netlink_event(mrt, skb); + + /* Deliver to mrouted */ + ret = sock_queue_rcv_skb(mroute_sk, skb); + rcu_read_unlock(); + if (ret < 0) { + net_warn_ratelimited("mroute: pending queue full, dropping entries\n"); + kfree_skb(skb); + } + + return ret; +} + +/* Queue a packet for resolution. It gets locked cache entry! */ +static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, + struct sk_buff *skb, struct net_device *dev) +{ + const struct iphdr *iph = ip_hdr(skb); + struct mfc_cache *c; + bool found = false; + int err; + + spin_lock_bh(&mfc_unres_lock); + list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) { + if (c->mfc_mcastgrp == iph->daddr && + c->mfc_origin == iph->saddr) { + found = true; + break; + } + } + + if (!found) { + /* Create a new entry if allowable */ + c = ipmr_cache_alloc_unres(); + if (!c) { + spin_unlock_bh(&mfc_unres_lock); + + kfree_skb(skb); + return -ENOBUFS; + } + + /* Fill in the new cache entry */ + c->_c.mfc_parent = -1; + c->mfc_origin = iph->saddr; + c->mfc_mcastgrp = iph->daddr; + + /* Reflect first query at mrouted. */ + err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE); + + if (err < 0) { + /* If the report failed throw the cache entry + out - Brad Parker + */ + spin_unlock_bh(&mfc_unres_lock); + + ipmr_cache_free(c); + kfree_skb(skb); + return err; + } + + atomic_inc(&mrt->cache_resolve_queue_len); + list_add(&c->_c.list, &mrt->mfc_unres_queue); + mroute_netlink_event(mrt, c, RTM_NEWROUTE); + + if (atomic_read(&mrt->cache_resolve_queue_len) == 1) + mod_timer(&mrt->ipmr_expire_timer, + c->_c.mfc_un.unres.expires); + } + + /* See if we can append the packet */ + if (c->_c.mfc_un.unres.unresolved.qlen > 3) { + kfree_skb(skb); + err = -ENOBUFS; + } else { + if (dev) { + skb->dev = dev; + skb->skb_iif = dev->ifindex; + } + skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb); + err = 0; + } + + spin_unlock_bh(&mfc_unres_lock); + return err; +} + +/* MFC cache manipulation by user space mroute daemon */ + +static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent) +{ + struct net *net = read_pnet(&mrt->net); + struct mfc_cache *c; + + /* The entries are added/deleted only under RTNL */ + rcu_read_lock(); + c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr, + mfc->mfcc_mcastgrp.s_addr, parent); + rcu_read_unlock(); + if (!c) + return -ENOENT; + rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params); + list_del_rcu(&c->_c.list); + call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id); + mroute_netlink_event(mrt, c, RTM_DELROUTE); + mr_cache_put(&c->_c); + + return 0; +} + +static int ipmr_mfc_add(struct net *net, struct mr_table *mrt, + struct mfcctl *mfc, int mrtsock, int parent) +{ + struct mfc_cache *uc, *c; + struct mr_mfc *_uc; + bool found; + int ret; + + if (mfc->mfcc_parent >= MAXVIFS) + return -ENFILE; + + /* The entries are added/deleted only under RTNL */ + rcu_read_lock(); + c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr, + mfc->mfcc_mcastgrp.s_addr, parent); + rcu_read_unlock(); + if (c) { + write_lock_bh(&mrt_lock); + c->_c.mfc_parent = mfc->mfcc_parent; + ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls); + if (!mrtsock) + c->_c.mfc_flags |= MFC_STATIC; + write_unlock_bh(&mrt_lock); + call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c, + mrt->id); + mroute_netlink_event(mrt, c, RTM_NEWROUTE); + return 0; + } + + if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) && + !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr)) + return -EINVAL; + + c = ipmr_cache_alloc(); + if (!c) + return -ENOMEM; + + c->mfc_origin = mfc->mfcc_origin.s_addr; + c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr; + c->_c.mfc_parent = mfc->mfcc_parent; + ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls); + if (!mrtsock) + c->_c.mfc_flags |= MFC_STATIC; + + ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode, + ipmr_rht_params); + if (ret) { + pr_err("ipmr: rhtable insert error %d\n", ret); + ipmr_cache_free(c); + return ret; + } + list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list); + /* Check to see if we resolved a queued list. If so we + * need to send on the frames and tidy up. + */ + found = false; + spin_lock_bh(&mfc_unres_lock); + list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) { + uc = (struct mfc_cache *)_uc; + if (uc->mfc_origin == c->mfc_origin && + uc->mfc_mcastgrp == c->mfc_mcastgrp) { + list_del(&_uc->list); + atomic_dec(&mrt->cache_resolve_queue_len); + found = true; + break; + } + } + if (list_empty(&mrt->mfc_unres_queue)) + del_timer(&mrt->ipmr_expire_timer); + spin_unlock_bh(&mfc_unres_lock); + + if (found) { + ipmr_cache_resolve(net, mrt, uc, c); + ipmr_cache_free(uc); + } + call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id); + mroute_netlink_event(mrt, c, RTM_NEWROUTE); + return 0; +} + +/* Close the multicast socket, and clear the vif tables etc */ +static void mroute_clean_tables(struct mr_table *mrt, int flags) +{ + struct net *net = read_pnet(&mrt->net); + struct mr_mfc *c, *tmp; + struct mfc_cache *cache; + LIST_HEAD(list); + int i; + + /* Shut down all active vif entries */ + if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) { + for (i = 0; i < mrt->maxvif; i++) { + if (((mrt->vif_table[i].flags & VIFF_STATIC) && + !(flags & MRT_FLUSH_VIFS_STATIC)) || + (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS))) + continue; + vif_delete(mrt, i, 0, &list); + } + unregister_netdevice_many(&list); + } + + /* Wipe the cache */ + if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) { + list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) { + if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) || + (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC))) + continue; + rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params); + list_del_rcu(&c->list); + cache = (struct mfc_cache *)c; + call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache, + mrt->id); + mroute_netlink_event(mrt, cache, RTM_DELROUTE); + mr_cache_put(c); + } + } + + if (flags & MRT_FLUSH_MFC) { + if (atomic_read(&mrt->cache_resolve_queue_len) != 0) { + spin_lock_bh(&mfc_unres_lock); + list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) { + list_del(&c->list); + cache = (struct mfc_cache *)c; + mroute_netlink_event(mrt, cache, RTM_DELROUTE); + ipmr_destroy_unres(mrt, cache); + } + spin_unlock_bh(&mfc_unres_lock); + } + } +} + +/* called from ip_ra_control(), before an RCU grace period, + * we dont need to call synchronize_rcu() here + */ +static void mrtsock_destruct(struct sock *sk) +{ + struct net *net = sock_net(sk); + struct mr_table *mrt; + + rtnl_lock(); + ipmr_for_each_table(mrt, net) { + if (sk == rtnl_dereference(mrt->mroute_sk)) { + IPV4_DEVCONF_ALL(net, MC_FORWARDING)--; + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_MC_FORWARDING, + NETCONFA_IFINDEX_ALL, + net->ipv4.devconf_all); + RCU_INIT_POINTER(mrt->mroute_sk, NULL); + mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC); + } + } + rtnl_unlock(); +} + +/* Socket options and virtual interface manipulation. The whole + * virtual interface system is a complete heap, but unfortunately + * that's how BSD mrouted happens to think. Maybe one day with a proper + * MOSPF/PIM router set up we can clean this up. + */ + +int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval, + unsigned int optlen) +{ + struct net *net = sock_net(sk); + int val, ret = 0, parent = 0; + struct mr_table *mrt; + struct vifctl vif; + struct mfcctl mfc; + bool do_wrvifwhole; + u32 uval; + + /* There's one exception to the lock - MRT_DONE which needs to unlock */ + rtnl_lock(); + if (sk->sk_type != SOCK_RAW || + inet_sk(sk)->inet_num != IPPROTO_IGMP) { + ret = -EOPNOTSUPP; + goto out_unlock; + } + + mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); + if (!mrt) { + ret = -ENOENT; + goto out_unlock; + } + if (optname != MRT_INIT) { + if (sk != rcu_access_pointer(mrt->mroute_sk) && + !ns_capable(net->user_ns, CAP_NET_ADMIN)) { + ret = -EACCES; + goto out_unlock; + } + } + + switch (optname) { + case MRT_INIT: + if (optlen != sizeof(int)) { + ret = -EINVAL; + break; + } + if (rtnl_dereference(mrt->mroute_sk)) { + ret = -EADDRINUSE; + break; + } + + ret = ip_ra_control(sk, 1, mrtsock_destruct); + if (ret == 0) { + rcu_assign_pointer(mrt->mroute_sk, sk); + IPV4_DEVCONF_ALL(net, MC_FORWARDING)++; + inet_netconf_notify_devconf(net, RTM_NEWNETCONF, + NETCONFA_MC_FORWARDING, + NETCONFA_IFINDEX_ALL, + net->ipv4.devconf_all); + } + break; + case MRT_DONE: + if (sk != rcu_access_pointer(mrt->mroute_sk)) { + ret = -EACCES; + } else { + /* We need to unlock here because mrtsock_destruct takes + * care of rtnl itself and we can't change that due to + * the IP_ROUTER_ALERT setsockopt which runs without it. + */ + rtnl_unlock(); + ret = ip_ra_control(sk, 0, NULL); + goto out; + } + break; + case MRT_ADD_VIF: + case MRT_DEL_VIF: + if (optlen != sizeof(vif)) { + ret = -EINVAL; + break; + } + if (copy_from_sockptr(&vif, optval, sizeof(vif))) { + ret = -EFAULT; + break; + } + if (vif.vifc_vifi >= MAXVIFS) { + ret = -ENFILE; + break; + } + if (optname == MRT_ADD_VIF) { + ret = vif_add(net, mrt, &vif, + sk == rtnl_dereference(mrt->mroute_sk)); + } else { + ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL); + } + break; + /* Manipulate the forwarding caches. These live + * in a sort of kernel/user symbiosis. + */ + case MRT_ADD_MFC: + case MRT_DEL_MFC: + parent = -1; + fallthrough; + case MRT_ADD_MFC_PROXY: + case MRT_DEL_MFC_PROXY: + if (optlen != sizeof(mfc)) { + ret = -EINVAL; + break; + } + if (copy_from_sockptr(&mfc, optval, sizeof(mfc))) { + ret = -EFAULT; + break; + } + if (parent == 0) + parent = mfc.mfcc_parent; + if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY) + ret = ipmr_mfc_delete(mrt, &mfc, parent); + else + ret = ipmr_mfc_add(net, mrt, &mfc, + sk == rtnl_dereference(mrt->mroute_sk), + parent); + break; + case MRT_FLUSH: + if (optlen != sizeof(val)) { + ret = -EINVAL; + break; + } + if (copy_from_sockptr(&val, optval, sizeof(val))) { + ret = -EFAULT; + break; + } + mroute_clean_tables(mrt, val); + break; + /* Control PIM assert. */ + case MRT_ASSERT: + if (optlen != sizeof(val)) { + ret = -EINVAL; + break; + } + if (copy_from_sockptr(&val, optval, sizeof(val))) { + ret = -EFAULT; + break; + } + mrt->mroute_do_assert = val; + break; + case MRT_PIM: + if (!ipmr_pimsm_enabled()) { + ret = -ENOPROTOOPT; + break; + } + if (optlen != sizeof(val)) { + ret = -EINVAL; + break; + } + if (copy_from_sockptr(&val, optval, sizeof(val))) { + ret = -EFAULT; + break; + } + + do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE); + val = !!val; + if (val != mrt->mroute_do_pim) { + mrt->mroute_do_pim = val; + mrt->mroute_do_assert = val; + mrt->mroute_do_wrvifwhole = do_wrvifwhole; + } + break; + case MRT_TABLE: + if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) { + ret = -ENOPROTOOPT; + break; + } + if (optlen != sizeof(uval)) { + ret = -EINVAL; + break; + } + if (copy_from_sockptr(&uval, optval, sizeof(uval))) { + ret = -EFAULT; + break; + } + + if (sk == rtnl_dereference(mrt->mroute_sk)) { + ret = -EBUSY; + } else { + mrt = ipmr_new_table(net, uval); + if (IS_ERR(mrt)) + ret = PTR_ERR(mrt); + else + raw_sk(sk)->ipmr_table = uval; + } + break; + /* Spurious command, or MRT_VERSION which you cannot set. */ + default: + ret = -ENOPROTOOPT; + } +out_unlock: + rtnl_unlock(); +out: + return ret; +} + +/* Getsock opt support for the multicast routing system. */ +int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen) +{ + int olr; + int val; + struct net *net = sock_net(sk); + struct mr_table *mrt; + + if (sk->sk_type != SOCK_RAW || + inet_sk(sk)->inet_num != IPPROTO_IGMP) + return -EOPNOTSUPP; + + mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); + if (!mrt) + return -ENOENT; + + switch (optname) { + case MRT_VERSION: + val = 0x0305; + break; + case MRT_PIM: + if (!ipmr_pimsm_enabled()) + return -ENOPROTOOPT; + val = mrt->mroute_do_pim; + break; + case MRT_ASSERT: + val = mrt->mroute_do_assert; + break; + default: + return -ENOPROTOOPT; + } + + if (get_user(olr, optlen)) + return -EFAULT; + olr = min_t(unsigned int, olr, sizeof(int)); + if (olr < 0) + return -EINVAL; + if (put_user(olr, optlen)) + return -EFAULT; + if (copy_to_user(optval, &val, olr)) + return -EFAULT; + return 0; +} + +/* The IP multicast ioctl support routines. */ +int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg) +{ + struct sioc_sg_req sr; + struct sioc_vif_req vr; + struct vif_device *vif; + struct mfc_cache *c; + struct net *net = sock_net(sk); + struct mr_table *mrt; + + mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); + if (!mrt) + return -ENOENT; + + switch (cmd) { + case SIOCGETVIFCNT: + if (copy_from_user(&vr, arg, sizeof(vr))) + return -EFAULT; + if (vr.vifi >= mrt->maxvif) + return -EINVAL; + vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); + read_lock(&mrt_lock); + vif = &mrt->vif_table[vr.vifi]; + if (VIF_EXISTS(mrt, vr.vifi)) { + vr.icount = vif->pkt_in; + vr.ocount = vif->pkt_out; + vr.ibytes = vif->bytes_in; + vr.obytes = vif->bytes_out; + read_unlock(&mrt_lock); + + if (copy_to_user(arg, &vr, sizeof(vr))) + return -EFAULT; + return 0; + } + read_unlock(&mrt_lock); + return -EADDRNOTAVAIL; + case SIOCGETSGCNT: + if (copy_from_user(&sr, arg, sizeof(sr))) + return -EFAULT; + + rcu_read_lock(); + c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr); + if (c) { + sr.pktcnt = c->_c.mfc_un.res.pkt; + sr.bytecnt = c->_c.mfc_un.res.bytes; + sr.wrong_if = c->_c.mfc_un.res.wrong_if; + rcu_read_unlock(); + + if (copy_to_user(arg, &sr, sizeof(sr))) + return -EFAULT; + return 0; + } + rcu_read_unlock(); + return -EADDRNOTAVAIL; + default: + return -ENOIOCTLCMD; + } +} + +#ifdef CONFIG_COMPAT +struct compat_sioc_sg_req { + struct in_addr src; + struct in_addr grp; + compat_ulong_t pktcnt; + compat_ulong_t bytecnt; + compat_ulong_t wrong_if; +}; + +struct compat_sioc_vif_req { + vifi_t vifi; /* Which iface */ + compat_ulong_t icount; + compat_ulong_t ocount; + compat_ulong_t ibytes; + compat_ulong_t obytes; +}; + +int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) +{ + struct compat_sioc_sg_req sr; + struct compat_sioc_vif_req vr; + struct vif_device *vif; + struct mfc_cache *c; + struct net *net = sock_net(sk); + struct mr_table *mrt; + + mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); + if (!mrt) + return -ENOENT; + + switch (cmd) { + case SIOCGETVIFCNT: + if (copy_from_user(&vr, arg, sizeof(vr))) + return -EFAULT; + if (vr.vifi >= mrt->maxvif) + return -EINVAL; + vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); + read_lock(&mrt_lock); + vif = &mrt->vif_table[vr.vifi]; + if (VIF_EXISTS(mrt, vr.vifi)) { + vr.icount = vif->pkt_in; + vr.ocount = vif->pkt_out; + vr.ibytes = vif->bytes_in; + vr.obytes = vif->bytes_out; + read_unlock(&mrt_lock); + + if (copy_to_user(arg, &vr, sizeof(vr))) + return -EFAULT; + return 0; + } + read_unlock(&mrt_lock); + return -EADDRNOTAVAIL; + case SIOCGETSGCNT: + if (copy_from_user(&sr, arg, sizeof(sr))) + return -EFAULT; + + rcu_read_lock(); + c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr); + if (c) { + sr.pktcnt = c->_c.mfc_un.res.pkt; + sr.bytecnt = c->_c.mfc_un.res.bytes; + sr.wrong_if = c->_c.mfc_un.res.wrong_if; + rcu_read_unlock(); + + if (copy_to_user(arg, &sr, sizeof(sr))) + return -EFAULT; + return 0; + } + rcu_read_unlock(); + return -EADDRNOTAVAIL; + default: + return -ENOIOCTLCMD; + } +} +#endif + +static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct net *net = dev_net(dev); + struct mr_table *mrt; + struct vif_device *v; + int ct; + + if (event != NETDEV_UNREGISTER) + return NOTIFY_DONE; + + ipmr_for_each_table(mrt, net) { + v = &mrt->vif_table[0]; + for (ct = 0; ct < mrt->maxvif; ct++, v++) { + if (v->dev == dev) + vif_delete(mrt, ct, 1, NULL); + } + } + return NOTIFY_DONE; +} + +static struct notifier_block ip_mr_notifier = { + .notifier_call = ipmr_device_event, +}; + +/* Encapsulate a packet by attaching a valid IPIP header to it. + * This avoids tunnel drivers and other mess and gives us the speed so + * important for multicast video. + */ +static void ip_encap(struct net *net, struct sk_buff *skb, + __be32 saddr, __be32 daddr) +{ + struct iphdr *iph; + const struct iphdr *old_iph = ip_hdr(skb); + + skb_push(skb, sizeof(struct iphdr)); + skb->transport_header = skb->network_header; + skb_reset_network_header(skb); + iph = ip_hdr(skb); + + iph->version = 4; + iph->tos = old_iph->tos; + iph->ttl = old_iph->ttl; + iph->frag_off = 0; + iph->daddr = daddr; + iph->saddr = saddr; + iph->protocol = IPPROTO_IPIP; + iph->ihl = 5; + iph->tot_len = htons(skb->len); + ip_select_ident(net, skb, NULL); + ip_send_check(iph); + + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + nf_reset_ct(skb); +} + +static inline int ipmr_forward_finish(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + struct ip_options *opt = &(IPCB(skb)->opt); + + IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS); + IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len); + + if (unlikely(opt->optlen)) + ip_forward_options(skb); + + return dst_output(net, sk, skb); +} + +#ifdef CONFIG_NET_SWITCHDEV +static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt, + int in_vifi, int out_vifi) +{ + struct vif_device *out_vif = &mrt->vif_table[out_vifi]; + struct vif_device *in_vif = &mrt->vif_table[in_vifi]; + + if (!skb->offload_l3_fwd_mark) + return false; + if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len) + return false; + return netdev_phys_item_id_same(&out_vif->dev_parent_id, + &in_vif->dev_parent_id); +} +#else +static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt, + int in_vifi, int out_vifi) +{ + return false; +} +#endif + +/* Processing handlers for ipmr_forward */ + +static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, + int in_vifi, struct sk_buff *skb, int vifi) +{ + const struct iphdr *iph = ip_hdr(skb); + struct vif_device *vif = &mrt->vif_table[vifi]; + struct net_device *dev; + struct rtable *rt; + struct flowi4 fl4; + int encap = 0; + + if (!vif->dev) + goto out_free; + + if (vif->flags & VIFF_REGISTER) { + vif->pkt_out++; + vif->bytes_out += skb->len; + vif->dev->stats.tx_bytes += skb->len; + vif->dev->stats.tx_packets++; + ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT); + goto out_free; + } + + if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi)) + goto out_free; + + if (vif->flags & VIFF_TUNNEL) { + rt = ip_route_output_ports(net, &fl4, NULL, + vif->remote, vif->local, + 0, 0, + IPPROTO_IPIP, + RT_TOS(iph->tos), vif->link); + if (IS_ERR(rt)) + goto out_free; + encap = sizeof(struct iphdr); + } else { + rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0, + 0, 0, + IPPROTO_IPIP, + RT_TOS(iph->tos), vif->link); + if (IS_ERR(rt)) + goto out_free; + } + + dev = rt->dst.dev; + + if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) { + /* Do not fragment multicasts. Alas, IPv4 does not + * allow to send ICMP, so that packets will disappear + * to blackhole. + */ + IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); + ip_rt_put(rt); + goto out_free; + } + + encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len; + + if (skb_cow(skb, encap)) { + ip_rt_put(rt); + goto out_free; + } + + vif->pkt_out++; + vif->bytes_out += skb->len; + + skb_dst_drop(skb); + skb_dst_set(skb, &rt->dst); + ip_decrease_ttl(ip_hdr(skb)); + + /* FIXME: forward and output firewalls used to be called here. + * What do we do with netfilter? -- RR + */ + if (vif->flags & VIFF_TUNNEL) { + ip_encap(net, skb, vif->local, vif->remote); + /* FIXME: extra output firewall step used to be here. --RR */ + vif->dev->stats.tx_packets++; + vif->dev->stats.tx_bytes += skb->len; + } + + IPCB(skb)->flags |= IPSKB_FORWARDED; + + /* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally + * not only before forwarding, but after forwarding on all output + * interfaces. It is clear, if mrouter runs a multicasting + * program, it should receive packets not depending to what interface + * program is joined. + * If we will not make it, the program will have to join on all + * interfaces. On the other hand, multihoming host (or router, but + * not mrouter) cannot join to more than one interface - it will + * result in receiving multiple packets. + */ + NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, + net, NULL, skb, skb->dev, dev, + ipmr_forward_finish); + return; + +out_free: + kfree_skb(skb); +} + +static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev) +{ + int ct; + + for (ct = mrt->maxvif-1; ct >= 0; ct--) { + if (mrt->vif_table[ct].dev == dev) + break; + } + return ct; +} + +/* "local" means that we should preserve one skb (for local delivery) */ +static void ip_mr_forward(struct net *net, struct mr_table *mrt, + struct net_device *dev, struct sk_buff *skb, + struct mfc_cache *c, int local) +{ + int true_vifi = ipmr_find_vif(mrt, dev); + int psend = -1; + int vif, ct; + + vif = c->_c.mfc_parent; + c->_c.mfc_un.res.pkt++; + c->_c.mfc_un.res.bytes += skb->len; + c->_c.mfc_un.res.lastuse = jiffies; + + if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) { + struct mfc_cache *cache_proxy; + + /* For an (*,G) entry, we only check that the incomming + * interface is part of the static tree. + */ + cache_proxy = mr_mfc_find_any_parent(mrt, vif); + if (cache_proxy && + cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255) + goto forward; + } + + /* Wrong interface: drop packet and (maybe) send PIM assert. */ + if (mrt->vif_table[vif].dev != dev) { + if (rt_is_output_route(skb_rtable(skb))) { + /* It is our own packet, looped back. + * Very complicated situation... + * + * The best workaround until routing daemons will be + * fixed is not to redistribute packet, if it was + * send through wrong interface. It means, that + * multicast applications WILL NOT work for + * (S,G), which have default multicast route pointing + * to wrong oif. In any case, it is not a good + * idea to use multicasting applications on router. + */ + goto dont_forward; + } + + c->_c.mfc_un.res.wrong_if++; + + if (true_vifi >= 0 && mrt->mroute_do_assert && + /* pimsm uses asserts, when switching from RPT to SPT, + * so that we cannot check that packet arrived on an oif. + * It is bad, but otherwise we would need to move pretty + * large chunk of pimd to kernel. Ough... --ANK + */ + (mrt->mroute_do_pim || + c->_c.mfc_un.res.ttls[true_vifi] < 255) && + time_after(jiffies, + c->_c.mfc_un.res.last_assert + + MFC_ASSERT_THRESH)) { + c->_c.mfc_un.res.last_assert = jiffies; + ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF); + if (mrt->mroute_do_wrvifwhole) + ipmr_cache_report(mrt, skb, true_vifi, + IGMPMSG_WRVIFWHOLE); + } + goto dont_forward; + } + +forward: + mrt->vif_table[vif].pkt_in++; + mrt->vif_table[vif].bytes_in += skb->len; + + /* Forward the frame */ + if (c->mfc_origin == htonl(INADDR_ANY) && + c->mfc_mcastgrp == htonl(INADDR_ANY)) { + if (true_vifi >= 0 && + true_vifi != c->_c.mfc_parent && + ip_hdr(skb)->ttl > + c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) { + /* It's an (*,*) entry and the packet is not coming from + * the upstream: forward the packet to the upstream + * only. + */ + psend = c->_c.mfc_parent; + goto last_forward; + } + goto dont_forward; + } + for (ct = c->_c.mfc_un.res.maxvif - 1; + ct >= c->_c.mfc_un.res.minvif; ct--) { + /* For (*,G) entry, don't forward to the incoming interface */ + if ((c->mfc_origin != htonl(INADDR_ANY) || + ct != true_vifi) && + ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) { + if (psend != -1) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + + if (skb2) + ipmr_queue_xmit(net, mrt, true_vifi, + skb2, psend); + } + psend = ct; + } + } +last_forward: + if (psend != -1) { + if (local) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + + if (skb2) + ipmr_queue_xmit(net, mrt, true_vifi, skb2, + psend); + } else { + ipmr_queue_xmit(net, mrt, true_vifi, skb, psend); + return; + } + } + +dont_forward: + if (!local) + kfree_skb(skb); +} + +static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb) +{ + struct rtable *rt = skb_rtable(skb); + struct iphdr *iph = ip_hdr(skb); + struct flowi4 fl4 = { + .daddr = iph->daddr, + .saddr = iph->saddr, + .flowi4_tos = RT_TOS(iph->tos), + .flowi4_oif = (rt_is_output_route(rt) ? + skb->dev->ifindex : 0), + .flowi4_iif = (rt_is_output_route(rt) ? + LOOPBACK_IFINDEX : + skb->dev->ifindex), + .flowi4_mark = skb->mark, + }; + struct mr_table *mrt; + int err; + + err = ipmr_fib_lookup(net, &fl4, &mrt); + if (err) + return ERR_PTR(err); + return mrt; +} + +/* Multicast packets for forwarding arrive here + * Called with rcu_read_lock(); + */ +int ip_mr_input(struct sk_buff *skb) +{ + struct mfc_cache *cache; + struct net *net = dev_net(skb->dev); + int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL; + struct mr_table *mrt; + struct net_device *dev; + + /* skb->dev passed in is the loX master dev for vrfs. + * As there are no vifs associated with loopback devices, + * get the proper interface that does have a vif associated with it. + */ + dev = skb->dev; + if (netif_is_l3_master(skb->dev)) { + dev = dev_get_by_index_rcu(net, IPCB(skb)->iif); + if (!dev) { + kfree_skb(skb); + return -ENODEV; + } + } + + /* Packet is looped back after forward, it should not be + * forwarded second time, but still can be delivered locally. + */ + if (IPCB(skb)->flags & IPSKB_FORWARDED) + goto dont_forward; + + mrt = ipmr_rt_fib_lookup(net, skb); + if (IS_ERR(mrt)) { + kfree_skb(skb); + return PTR_ERR(mrt); + } + if (!local) { + if (IPCB(skb)->opt.router_alert) { + if (ip_call_ra_chain(skb)) + return 0; + } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) { + /* IGMPv1 (and broken IGMPv2 implementations sort of + * Cisco IOS <= 11.2(8)) do not put router alert + * option to IGMP packets destined to routable + * groups. It is very bad, because it means + * that we can forward NO IGMP messages. + */ + struct sock *mroute_sk; + + mroute_sk = rcu_dereference(mrt->mroute_sk); + if (mroute_sk) { + nf_reset_ct(skb); + raw_rcv(mroute_sk, skb); + return 0; + } + } + } + + /* already under rcu_read_lock() */ + cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); + if (!cache) { + int vif = ipmr_find_vif(mrt, dev); + + if (vif >= 0) + cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr, + vif); + } + + /* No usable cache entry */ + if (!cache) { + int vif; + + if (local) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + ip_local_deliver(skb); + if (!skb2) + return -ENOBUFS; + skb = skb2; + } + + read_lock(&mrt_lock); + vif = ipmr_find_vif(mrt, dev); + if (vif >= 0) { + int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev); + read_unlock(&mrt_lock); + + return err2; + } + read_unlock(&mrt_lock); + kfree_skb(skb); + return -ENODEV; + } + + read_lock(&mrt_lock); + ip_mr_forward(net, mrt, dev, skb, cache, local); + read_unlock(&mrt_lock); + + if (local) + return ip_local_deliver(skb); + + return 0; + +dont_forward: + if (local) + return ip_local_deliver(skb); + kfree_skb(skb); + return 0; +} + +#ifdef CONFIG_IP_PIMSM_V1 +/* Handle IGMP messages of PIMv1 */ +int pim_rcv_v1(struct sk_buff *skb) +{ + struct igmphdr *pim; + struct net *net = dev_net(skb->dev); + struct mr_table *mrt; + + if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr))) + goto drop; + + pim = igmp_hdr(skb); + + mrt = ipmr_rt_fib_lookup(net, skb); + if (IS_ERR(mrt)) + goto drop; + if (!mrt->mroute_do_pim || + pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) + goto drop; + + if (__pim_rcv(mrt, skb, sizeof(*pim))) { +drop: + kfree_skb(skb); + } + return 0; +} +#endif + +#ifdef CONFIG_IP_PIMSM_V2 +static int pim_rcv(struct sk_buff *skb) +{ + struct pimreghdr *pim; + struct net *net = dev_net(skb->dev); + struct mr_table *mrt; + + if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr))) + goto drop; + + pim = (struct pimreghdr *)skb_transport_header(skb); + if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) || + (pim->flags & PIM_NULL_REGISTER) || + (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 && + csum_fold(skb_checksum(skb, 0, skb->len, 0)))) + goto drop; + + mrt = ipmr_rt_fib_lookup(net, skb); + if (IS_ERR(mrt)) + goto drop; + if (__pim_rcv(mrt, skb, sizeof(*pim))) { +drop: + kfree_skb(skb); + } + return 0; +} +#endif + +int ipmr_get_route(struct net *net, struct sk_buff *skb, + __be32 saddr, __be32 daddr, + struct rtmsg *rtm, u32 portid) +{ + struct mfc_cache *cache; + struct mr_table *mrt; + int err; + + mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); + if (!mrt) + return -ENOENT; + + rcu_read_lock(); + cache = ipmr_cache_find(mrt, saddr, daddr); + if (!cache && skb->dev) { + int vif = ipmr_find_vif(mrt, skb->dev); + + if (vif >= 0) + cache = ipmr_cache_find_any(mrt, daddr, vif); + } + if (!cache) { + struct sk_buff *skb2; + struct iphdr *iph; + struct net_device *dev; + int vif = -1; + + dev = skb->dev; + read_lock(&mrt_lock); + if (dev) + vif = ipmr_find_vif(mrt, dev); + if (vif < 0) { + read_unlock(&mrt_lock); + rcu_read_unlock(); + return -ENODEV; + } + + skb2 = skb_realloc_headroom(skb, sizeof(struct iphdr)); + if (!skb2) { + read_unlock(&mrt_lock); + rcu_read_unlock(); + return -ENOMEM; + } + + NETLINK_CB(skb2).portid = portid; + skb_push(skb2, sizeof(struct iphdr)); + skb_reset_network_header(skb2); + iph = ip_hdr(skb2); + iph->ihl = sizeof(struct iphdr) >> 2; + iph->saddr = saddr; + iph->daddr = daddr; + iph->version = 0; + err = ipmr_cache_unresolved(mrt, vif, skb2, dev); + read_unlock(&mrt_lock); + rcu_read_unlock(); + return err; + } + + read_lock(&mrt_lock); + err = mr_fill_mroute(mrt, skb, &cache->_c, rtm); + read_unlock(&mrt_lock); + rcu_read_unlock(); + return err; +} + +static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, + u32 portid, u32 seq, struct mfc_cache *c, int cmd, + int flags) +{ + struct nlmsghdr *nlh; + struct rtmsg *rtm; + int err; + + nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags); + if (!nlh) + return -EMSGSIZE; + + rtm = nlmsg_data(nlh); + rtm->rtm_family = RTNL_FAMILY_IPMR; + rtm->rtm_dst_len = 32; + rtm->rtm_src_len = 32; + rtm->rtm_tos = 0; + rtm->rtm_table = mrt->id; + if (nla_put_u32(skb, RTA_TABLE, mrt->id)) + goto nla_put_failure; + rtm->rtm_type = RTN_MULTICAST; + rtm->rtm_scope = RT_SCOPE_UNIVERSE; + if (c->_c.mfc_flags & MFC_STATIC) + rtm->rtm_protocol = RTPROT_STATIC; + else + rtm->rtm_protocol = RTPROT_MROUTED; + rtm->rtm_flags = 0; + + if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) || + nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp)) + goto nla_put_failure; + err = mr_fill_mroute(mrt, skb, &c->_c, rtm); + /* do not break the dump if cache is unresolved */ + if (err < 0 && err != -ENOENT) + goto nla_put_failure; + + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, + u32 portid, u32 seq, struct mr_mfc *c, int cmd, + int flags) +{ + return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c, + cmd, flags); +} + +static size_t mroute_msgsize(bool unresolved, int maxvif) +{ + size_t len = + NLMSG_ALIGN(sizeof(struct rtmsg)) + + nla_total_size(4) /* RTA_TABLE */ + + nla_total_size(4) /* RTA_SRC */ + + nla_total_size(4) /* RTA_DST */ + ; + + if (!unresolved) + len = len + + nla_total_size(4) /* RTA_IIF */ + + nla_total_size(0) /* RTA_MULTIPATH */ + + maxvif * NLA_ALIGN(sizeof(struct rtnexthop)) + /* RTA_MFC_STATS */ + + nla_total_size_64bit(sizeof(struct rta_mfc_stats)) + ; + + return len; +} + +static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc, + int cmd) +{ + struct net *net = read_pnet(&mrt->net); + struct sk_buff *skb; + int err = -ENOBUFS; + + skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS, + mrt->maxvif), + GFP_ATOMIC); + if (!skb) + goto errout; + + err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0); + if (err < 0) + goto errout; + + rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC); + return; + +errout: + kfree_skb(skb); + if (err < 0) + rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err); +} + +static size_t igmpmsg_netlink_msgsize(size_t payloadlen) +{ + size_t len = + NLMSG_ALIGN(sizeof(struct rtgenmsg)) + + nla_total_size(1) /* IPMRA_CREPORT_MSGTYPE */ + + nla_total_size(4) /* IPMRA_CREPORT_VIF_ID */ + + nla_total_size(4) /* IPMRA_CREPORT_SRC_ADDR */ + + nla_total_size(4) /* IPMRA_CREPORT_DST_ADDR */ + + nla_total_size(4) /* IPMRA_CREPORT_TABLE */ + /* IPMRA_CREPORT_PKT */ + + nla_total_size(payloadlen) + ; + + return len; +} + +static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt) +{ + struct net *net = read_pnet(&mrt->net); + struct nlmsghdr *nlh; + struct rtgenmsg *rtgenm; + struct igmpmsg *msg; + struct sk_buff *skb; + struct nlattr *nla; + int payloadlen; + + payloadlen = pkt->len - sizeof(struct igmpmsg); + msg = (struct igmpmsg *)skb_network_header(pkt); + + skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC); + if (!skb) + goto errout; + + nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT, + sizeof(struct rtgenmsg), 0); + if (!nlh) + goto errout; + rtgenm = nlmsg_data(nlh); + rtgenm->rtgen_family = RTNL_FAMILY_IPMR; + if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) || + nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif | (msg->im_vif_hi << 8)) || + nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR, + msg->im_src.s_addr) || + nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR, + msg->im_dst.s_addr) || + nla_put_u32(skb, IPMRA_CREPORT_TABLE, mrt->id)) + goto nla_put_failure; + + nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen); + if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg), + nla_data(nla), payloadlen)) + goto nla_put_failure; + + nlmsg_end(skb, nlh); + + rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC); + return; + +nla_put_failure: + nlmsg_cancel(skb, nlh); +errout: + kfree_skb(skb); + rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS); +} + +static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb, + const struct nlmsghdr *nlh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + struct rtmsg *rtm; + int i, err; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request"); + return -EINVAL; + } + + if (!netlink_strict_get_check(skb)) + return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv4_policy, extack); + + rtm = nlmsg_data(nlh); + if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || + (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || + rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol || + rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request"); + return -EINVAL; + } + + err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv4_policy, extack); + if (err) + return err; + + if ((tb[RTA_SRC] && !rtm->rtm_src_len) || + (tb[RTA_DST] && !rtm->rtm_dst_len)) { + NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); + return -EINVAL; + } + + for (i = 0; i <= RTA_MAX; i++) { + if (!tb[i]) + continue; + + switch (i) { + case RTA_SRC: + case RTA_DST: + case RTA_TABLE: + break; + default: + NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request"); + return -EINVAL; + } + } + + return 0; +} + +static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(in_skb->sk); + struct nlattr *tb[RTA_MAX + 1]; + struct sk_buff *skb = NULL; + struct mfc_cache *cache; + struct mr_table *mrt; + __be32 src, grp; + u32 tableid; + int err; + + err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack); + if (err < 0) + goto errout; + + src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; + grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; + tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0; + + mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT); + if (!mrt) { + err = -ENOENT; + goto errout_free; + } + + /* entries are added/deleted only under RTNL */ + rcu_read_lock(); + cache = ipmr_cache_find(mrt, src, grp); + rcu_read_unlock(); + if (!cache) { + err = -ENOENT; + goto errout_free; + } + + skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL); + if (!skb) { + err = -ENOBUFS; + goto errout_free; + } + + err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid, + nlh->nlmsg_seq, cache, + RTM_NEWROUTE, 0); + if (err < 0) + goto errout_free; + + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); + +errout: + return err; + +errout_free: + kfree_skb(skb); + goto errout; +} + +static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct fib_dump_filter filter = {}; + int err; + + if (cb->strict_check) { + err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh, + &filter, cb); + if (err < 0) + return err; + } + + if (filter.table_id) { + struct mr_table *mrt; + + mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id); + if (!mrt) { + if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR) + return skb->len; + + NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist"); + return -ENOENT; + } + err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute, + &mfc_unres_lock, &filter); + return skb->len ? : err; + } + + return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter, + _ipmr_fill_mroute, &mfc_unres_lock, &filter); +} + +static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = { + [RTA_SRC] = { .type = NLA_U32 }, + [RTA_DST] = { .type = NLA_U32 }, + [RTA_IIF] = { .type = NLA_U32 }, + [RTA_TABLE] = { .type = NLA_U32 }, + [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, +}; + +static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol) +{ + switch (rtm_protocol) { + case RTPROT_STATIC: + case RTPROT_MROUTED: + return true; + } + return false; +} + +static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc) +{ + struct rtnexthop *rtnh = nla_data(nla); + int remaining = nla_len(nla), vifi = 0; + + while (rtnh_ok(rtnh, remaining)) { + mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops; + if (++vifi == MAXVIFS) + break; + rtnh = rtnh_next(rtnh, &remaining); + } + + return remaining > 0 ? -EINVAL : vifi; +} + +/* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */ +static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh, + struct mfcctl *mfcc, int *mrtsock, + struct mr_table **mrtret, + struct netlink_ext_ack *extack) +{ + struct net_device *dev = NULL; + u32 tblid = RT_TABLE_DEFAULT; + struct mr_table *mrt; + struct nlattr *attr; + struct rtmsg *rtm; + int ret, rem; + + ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX, + rtm_ipmr_policy, extack); + if (ret < 0) + goto out; + rtm = nlmsg_data(nlh); + + ret = -EINVAL; + if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 || + rtm->rtm_type != RTN_MULTICAST || + rtm->rtm_scope != RT_SCOPE_UNIVERSE || + !ipmr_rtm_validate_proto(rtm->rtm_protocol)) + goto out; + + memset(mfcc, 0, sizeof(*mfcc)); + mfcc->mfcc_parent = -1; + ret = 0; + nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) { + switch (nla_type(attr)) { + case RTA_SRC: + mfcc->mfcc_origin.s_addr = nla_get_be32(attr); + break; + case RTA_DST: + mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr); + break; + case RTA_IIF: + dev = __dev_get_by_index(net, nla_get_u32(attr)); + if (!dev) { + ret = -ENODEV; + goto out; + } + break; + case RTA_MULTIPATH: + if (ipmr_nla_get_ttls(attr, mfcc) < 0) { + ret = -EINVAL; + goto out; + } + break; + case RTA_PREFSRC: + ret = 1; + break; + case RTA_TABLE: + tblid = nla_get_u32(attr); + break; + } + } + mrt = ipmr_get_table(net, tblid); + if (!mrt) { + ret = -ENOENT; + goto out; + } + *mrtret = mrt; + *mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0; + if (dev) + mfcc->mfcc_parent = ipmr_find_vif(mrt, dev); + +out: + return ret; +} + +/* takes care of both newroute and delroute */ +static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + int ret, mrtsock, parent; + struct mr_table *tbl; + struct mfcctl mfcc; + + mrtsock = 0; + tbl = NULL; + ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack); + if (ret < 0) + return ret; + + parent = ret ? mfcc.mfcc_parent : -1; + if (nlh->nlmsg_type == RTM_NEWROUTE) + return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent); + else + return ipmr_mfc_delete(tbl, &mfcc, parent); +} + +static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb) +{ + u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len); + + if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) || + nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) || + nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM, + mrt->mroute_reg_vif_num) || + nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT, + mrt->mroute_do_assert) || + nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) || + nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE, + mrt->mroute_do_wrvifwhole)) + return false; + + return true; +} + +static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb) +{ + struct nlattr *vif_nest; + struct vif_device *vif; + + /* if the VIF doesn't exist just continue */ + if (!VIF_EXISTS(mrt, vifid)) + return true; + + vif = &mrt->vif_table[vifid]; + vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF); + if (!vif_nest) + return false; + if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) || + nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) || + nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) || + nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in, + IPMRA_VIFA_PAD) || + nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out, + IPMRA_VIFA_PAD) || + nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in, + IPMRA_VIFA_PAD) || + nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out, + IPMRA_VIFA_PAD) || + nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) || + nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) { + nla_nest_cancel(skb, vif_nest); + return false; + } + nla_nest_end(skb, vif_nest); + + return true; +} + +static int ipmr_valid_dumplink(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ifinfomsg *ifm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags || + ifm->ifi_change || ifm->ifi_index) { + NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request"); + return -EINVAL; + } + + return 0; +} + +static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + struct nlmsghdr *nlh = NULL; + unsigned int t = 0, s_t; + unsigned int e = 0, s_e; + struct mr_table *mrt; + + if (cb->strict_check) { + int err = ipmr_valid_dumplink(cb->nlh, cb->extack); + + if (err < 0) + return err; + } + + s_t = cb->args[0]; + s_e = cb->args[1]; + + ipmr_for_each_table(mrt, net) { + struct nlattr *vifs, *af; + struct ifinfomsg *hdr; + u32 i; + + if (t < s_t) + goto skip_table; + nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, RTM_NEWLINK, + sizeof(*hdr), NLM_F_MULTI); + if (!nlh) + break; + + hdr = nlmsg_data(nlh); + memset(hdr, 0, sizeof(*hdr)); + hdr->ifi_family = RTNL_FAMILY_IPMR; + + af = nla_nest_start_noflag(skb, IFLA_AF_SPEC); + if (!af) { + nlmsg_cancel(skb, nlh); + goto out; + } + + if (!ipmr_fill_table(mrt, skb)) { + nlmsg_cancel(skb, nlh); + goto out; + } + + vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS); + if (!vifs) { + nla_nest_end(skb, af); + nlmsg_end(skb, nlh); + goto out; + } + for (i = 0; i < mrt->maxvif; i++) { + if (e < s_e) + goto skip_entry; + if (!ipmr_fill_vif(mrt, i, skb)) { + nla_nest_end(skb, vifs); + nla_nest_end(skb, af); + nlmsg_end(skb, nlh); + goto out; + } +skip_entry: + e++; + } + s_e = 0; + e = 0; + nla_nest_end(skb, vifs); + nla_nest_end(skb, af); + nlmsg_end(skb, nlh); +skip_table: + t++; + } + +out: + cb->args[1] = e; + cb->args[0] = t; + + return skb->len; +} + +#ifdef CONFIG_PROC_FS +/* The /proc interfaces to multicast routing : + * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif + */ + +static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(mrt_lock) +{ + struct mr_vif_iter *iter = seq->private; + struct net *net = seq_file_net(seq); + struct mr_table *mrt; + + mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); + if (!mrt) + return ERR_PTR(-ENOENT); + + iter->mrt = mrt; + + read_lock(&mrt_lock); + return mr_vif_seq_start(seq, pos); +} + +static void ipmr_vif_seq_stop(struct seq_file *seq, void *v) + __releases(mrt_lock) +{ + read_unlock(&mrt_lock); +} + +static int ipmr_vif_seq_show(struct seq_file *seq, void *v) +{ + struct mr_vif_iter *iter = seq->private; + struct mr_table *mrt = iter->mrt; + + if (v == SEQ_START_TOKEN) { + seq_puts(seq, + "Interface BytesIn PktsIn BytesOut PktsOut Flags Local Remote\n"); + } else { + const struct vif_device *vif = v; + const char *name = vif->dev ? + vif->dev->name : "none"; + + seq_printf(seq, + "%2td %-10s %8ld %7ld %8ld %7ld %05X %08X %08X\n", + vif - mrt->vif_table, + name, vif->bytes_in, vif->pkt_in, + vif->bytes_out, vif->pkt_out, + vif->flags, vif->local, vif->remote); + } + return 0; +} + +static const struct seq_operations ipmr_vif_seq_ops = { + .start = ipmr_vif_seq_start, + .next = mr_vif_seq_next, + .stop = ipmr_vif_seq_stop, + .show = ipmr_vif_seq_show, +}; + +static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct net *net = seq_file_net(seq); + struct mr_table *mrt; + + mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); + if (!mrt) + return ERR_PTR(-ENOENT); + + return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock); +} + +static int ipmr_mfc_seq_show(struct seq_file *seq, void *v) +{ + int n; + + if (v == SEQ_START_TOKEN) { + seq_puts(seq, + "Group Origin Iif Pkts Bytes Wrong Oifs\n"); + } else { + const struct mfc_cache *mfc = v; + const struct mr_mfc_iter *it = seq->private; + const struct mr_table *mrt = it->mrt; + + seq_printf(seq, "%08X %08X %-3hd", + (__force u32) mfc->mfc_mcastgrp, + (__force u32) mfc->mfc_origin, + mfc->_c.mfc_parent); + + if (it->cache != &mrt->mfc_unres_queue) { + seq_printf(seq, " %8lu %8lu %8lu", + mfc->_c.mfc_un.res.pkt, + mfc->_c.mfc_un.res.bytes, + mfc->_c.mfc_un.res.wrong_if); + for (n = mfc->_c.mfc_un.res.minvif; + n < mfc->_c.mfc_un.res.maxvif; n++) { + if (VIF_EXISTS(mrt, n) && + mfc->_c.mfc_un.res.ttls[n] < 255) + seq_printf(seq, + " %2d:%-3d", + n, mfc->_c.mfc_un.res.ttls[n]); + } + } else { + /* unresolved mfc_caches don't contain + * pkt, bytes and wrong_if values + */ + seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul); + } + seq_putc(seq, '\n'); + } + return 0; +} + +static const struct seq_operations ipmr_mfc_seq_ops = { + .start = ipmr_mfc_seq_start, + .next = mr_mfc_seq_next, + .stop = mr_mfc_seq_stop, + .show = ipmr_mfc_seq_show, +}; +#endif + +#ifdef CONFIG_IP_PIMSM_V2 +static const struct net_protocol pim_protocol = { + .handler = pim_rcv, + .netns_ok = 1, +}; +#endif + +static unsigned int ipmr_seq_read(struct net *net) +{ + ASSERT_RTNL(); + + return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net); +} + +static int ipmr_dump(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump, + ipmr_mr_table_iter, &mrt_lock, extack); +} + +static const struct fib_notifier_ops ipmr_notifier_ops_template = { + .family = RTNL_FAMILY_IPMR, + .fib_seq_read = ipmr_seq_read, + .fib_dump = ipmr_dump, + .owner = THIS_MODULE, +}; + +static int __net_init ipmr_notifier_init(struct net *net) +{ + struct fib_notifier_ops *ops; + + net->ipv4.ipmr_seq = 0; + + ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + net->ipv4.ipmr_notifier_ops = ops; + + return 0; +} + +static void __net_exit ipmr_notifier_exit(struct net *net) +{ + fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops); + net->ipv4.ipmr_notifier_ops = NULL; +} + +/* Setup for IP multicast routing */ +static int __net_init ipmr_net_init(struct net *net) +{ + int err; + + err = ipmr_notifier_init(net); + if (err) + goto ipmr_notifier_fail; + + err = ipmr_rules_init(net); + if (err < 0) + goto ipmr_rules_fail; + +#ifdef CONFIG_PROC_FS + err = -ENOMEM; + if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops, + sizeof(struct mr_vif_iter))) + goto proc_vif_fail; + if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops, + sizeof(struct mr_mfc_iter))) + goto proc_cache_fail; +#endif + return 0; + +#ifdef CONFIG_PROC_FS +proc_cache_fail: + remove_proc_entry("ip_mr_vif", net->proc_net); +proc_vif_fail: + ipmr_rules_exit(net); +#endif +ipmr_rules_fail: + ipmr_notifier_exit(net); +ipmr_notifier_fail: + return err; +} + +static void __net_exit ipmr_net_exit(struct net *net) +{ +#ifdef CONFIG_PROC_FS + remove_proc_entry("ip_mr_cache", net->proc_net); + remove_proc_entry("ip_mr_vif", net->proc_net); +#endif + ipmr_notifier_exit(net); + ipmr_rules_exit(net); +} + +static struct pernet_operations ipmr_net_ops = { + .init = ipmr_net_init, + .exit = ipmr_net_exit, +}; + +int __init ip_mr_init(void) +{ + int err; + + mrt_cachep = kmem_cache_create("ip_mrt_cache", + sizeof(struct mfc_cache), + 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, + NULL); + + err = register_pernet_subsys(&ipmr_net_ops); + if (err) + goto reg_pernet_fail; + + err = register_netdevice_notifier(&ip_mr_notifier); + if (err) + goto reg_notif_fail; +#ifdef CONFIG_IP_PIMSM_V2 + if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) { + pr_err("%s: can't add PIM protocol\n", __func__); + err = -EAGAIN; + goto add_proto_fail; + } +#endif + rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, + ipmr_rtm_getroute, ipmr_rtm_dumproute, 0); + rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE, + ipmr_rtm_route, NULL, 0); + rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE, + ipmr_rtm_route, NULL, 0); + + rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK, + NULL, ipmr_rtm_dumplink, 0); + return 0; + +#ifdef CONFIG_IP_PIMSM_V2 +add_proto_fail: + unregister_netdevice_notifier(&ip_mr_notifier); +#endif +reg_notif_fail: + unregister_pernet_subsys(&ipmr_net_ops); +reg_pernet_fail: + kmem_cache_destroy(mrt_cachep); + return err; +} diff --git a/net/ipv4/ipmr_base.c b/net/ipv4/ipmr_base.c new file mode 100644 index 000000000..aa8738a91 --- /dev/null +++ b/net/ipv4/ipmr_base.c @@ -0,0 +1,437 @@ +/* Linux multicast routing support + * Common logic shared by IPv4 [ipmr] and IPv6 [ip6mr] implementation + */ + +#include <linux/rhashtable.h> +#include <linux/mroute_base.h> + +/* Sets everything common except 'dev', since that is done under locking */ +void vif_device_init(struct vif_device *v, + struct net_device *dev, + unsigned long rate_limit, + unsigned char threshold, + unsigned short flags, + unsigned short get_iflink_mask) +{ + v->dev = NULL; + v->bytes_in = 0; + v->bytes_out = 0; + v->pkt_in = 0; + v->pkt_out = 0; + v->rate_limit = rate_limit; + v->flags = flags; + v->threshold = threshold; + if (v->flags & get_iflink_mask) + v->link = dev_get_iflink(dev); + else + v->link = dev->ifindex; +} +EXPORT_SYMBOL(vif_device_init); + +struct mr_table * +mr_table_alloc(struct net *net, u32 id, + struct mr_table_ops *ops, + void (*expire_func)(struct timer_list *t), + void (*table_set)(struct mr_table *mrt, + struct net *net)) +{ + struct mr_table *mrt; + int err; + + mrt = kzalloc(sizeof(*mrt), GFP_KERNEL); + if (!mrt) + return ERR_PTR(-ENOMEM); + mrt->id = id; + write_pnet(&mrt->net, net); + + mrt->ops = *ops; + err = rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params); + if (err) { + kfree(mrt); + return ERR_PTR(err); + } + INIT_LIST_HEAD(&mrt->mfc_cache_list); + INIT_LIST_HEAD(&mrt->mfc_unres_queue); + + timer_setup(&mrt->ipmr_expire_timer, expire_func, 0); + + mrt->mroute_reg_vif_num = -1; + table_set(mrt, net); + return mrt; +} +EXPORT_SYMBOL(mr_table_alloc); + +void *mr_mfc_find_parent(struct mr_table *mrt, void *hasharg, int parent) +{ + struct rhlist_head *tmp, *list; + struct mr_mfc *c; + + list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params); + rhl_for_each_entry_rcu(c, tmp, list, mnode) + if (parent == -1 || parent == c->mfc_parent) + return c; + + return NULL; +} +EXPORT_SYMBOL(mr_mfc_find_parent); + +void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi) +{ + struct rhlist_head *tmp, *list; + struct mr_mfc *c; + + list = rhltable_lookup(&mrt->mfc_hash, mrt->ops.cmparg_any, + *mrt->ops.rht_params); + rhl_for_each_entry_rcu(c, tmp, list, mnode) + if (c->mfc_un.res.ttls[vifi] < 255) + return c; + + return NULL; +} +EXPORT_SYMBOL(mr_mfc_find_any_parent); + +void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg) +{ + struct rhlist_head *tmp, *list; + struct mr_mfc *c, *proxy; + + list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params); + rhl_for_each_entry_rcu(c, tmp, list, mnode) { + if (c->mfc_un.res.ttls[vifi] < 255) + return c; + + /* It's ok if the vifi is part of the static tree */ + proxy = mr_mfc_find_any_parent(mrt, c->mfc_parent); + if (proxy && proxy->mfc_un.res.ttls[vifi] < 255) + return c; + } + + return mr_mfc_find_any_parent(mrt, vifi); +} +EXPORT_SYMBOL(mr_mfc_find_any); + +#ifdef CONFIG_PROC_FS +void *mr_vif_seq_idx(struct net *net, struct mr_vif_iter *iter, loff_t pos) +{ + struct mr_table *mrt = iter->mrt; + + for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) { + if (!VIF_EXISTS(mrt, iter->ct)) + continue; + if (pos-- == 0) + return &mrt->vif_table[iter->ct]; + } + return NULL; +} +EXPORT_SYMBOL(mr_vif_seq_idx); + +void *mr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct mr_vif_iter *iter = seq->private; + struct net *net = seq_file_net(seq); + struct mr_table *mrt = iter->mrt; + + ++*pos; + if (v == SEQ_START_TOKEN) + return mr_vif_seq_idx(net, iter, 0); + + while (++iter->ct < mrt->maxvif) { + if (!VIF_EXISTS(mrt, iter->ct)) + continue; + return &mrt->vif_table[iter->ct]; + } + return NULL; +} +EXPORT_SYMBOL(mr_vif_seq_next); + +void *mr_mfc_seq_idx(struct net *net, + struct mr_mfc_iter *it, loff_t pos) +{ + struct mr_table *mrt = it->mrt; + struct mr_mfc *mfc; + + rcu_read_lock(); + it->cache = &mrt->mfc_cache_list; + list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) + if (pos-- == 0) + return mfc; + rcu_read_unlock(); + + spin_lock_bh(it->lock); + it->cache = &mrt->mfc_unres_queue; + list_for_each_entry(mfc, it->cache, list) + if (pos-- == 0) + return mfc; + spin_unlock_bh(it->lock); + + it->cache = NULL; + return NULL; +} +EXPORT_SYMBOL(mr_mfc_seq_idx); + +void *mr_mfc_seq_next(struct seq_file *seq, void *v, + loff_t *pos) +{ + struct mr_mfc_iter *it = seq->private; + struct net *net = seq_file_net(seq); + struct mr_table *mrt = it->mrt; + struct mr_mfc *c = v; + + ++*pos; + + if (v == SEQ_START_TOKEN) + return mr_mfc_seq_idx(net, seq->private, 0); + + if (c->list.next != it->cache) + return list_entry(c->list.next, struct mr_mfc, list); + + if (it->cache == &mrt->mfc_unres_queue) + goto end_of_list; + + /* exhausted cache_array, show unresolved */ + rcu_read_unlock(); + it->cache = &mrt->mfc_unres_queue; + + spin_lock_bh(it->lock); + if (!list_empty(it->cache)) + return list_first_entry(it->cache, struct mr_mfc, list); + +end_of_list: + spin_unlock_bh(it->lock); + it->cache = NULL; + + return NULL; +} +EXPORT_SYMBOL(mr_mfc_seq_next); +#endif + +int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, + struct mr_mfc *c, struct rtmsg *rtm) +{ + struct rta_mfc_stats mfcs; + struct nlattr *mp_attr; + struct rtnexthop *nhp; + unsigned long lastuse; + int ct; + + /* If cache is unresolved, don't try to parse IIF and OIF */ + if (c->mfc_parent >= MAXVIFS) { + rtm->rtm_flags |= RTNH_F_UNRESOLVED; + return -ENOENT; + } + + if (VIF_EXISTS(mrt, c->mfc_parent) && + nla_put_u32(skb, RTA_IIF, + mrt->vif_table[c->mfc_parent].dev->ifindex) < 0) + return -EMSGSIZE; + + if (c->mfc_flags & MFC_OFFLOAD) + rtm->rtm_flags |= RTNH_F_OFFLOAD; + + mp_attr = nla_nest_start_noflag(skb, RTA_MULTIPATH); + if (!mp_attr) + return -EMSGSIZE; + + for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) { + if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) { + struct vif_device *vif; + + nhp = nla_reserve_nohdr(skb, sizeof(*nhp)); + if (!nhp) { + nla_nest_cancel(skb, mp_attr); + return -EMSGSIZE; + } + + nhp->rtnh_flags = 0; + nhp->rtnh_hops = c->mfc_un.res.ttls[ct]; + vif = &mrt->vif_table[ct]; + nhp->rtnh_ifindex = vif->dev->ifindex; + nhp->rtnh_len = sizeof(*nhp); + } + } + + nla_nest_end(skb, mp_attr); + + lastuse = READ_ONCE(c->mfc_un.res.lastuse); + lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0; + + mfcs.mfcs_packets = c->mfc_un.res.pkt; + mfcs.mfcs_bytes = c->mfc_un.res.bytes; + mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if; + if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) || + nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse), + RTA_PAD)) + return -EMSGSIZE; + + rtm->rtm_type = RTN_MULTICAST; + return 1; +} +EXPORT_SYMBOL(mr_fill_mroute); + +static bool mr_mfc_uses_dev(const struct mr_table *mrt, + const struct mr_mfc *c, + const struct net_device *dev) +{ + int ct; + + for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) { + if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) { + const struct vif_device *vif; + + vif = &mrt->vif_table[ct]; + if (vif->dev == dev) + return true; + } + } + return false; +} + +int mr_table_dump(struct mr_table *mrt, struct sk_buff *skb, + struct netlink_callback *cb, + int (*fill)(struct mr_table *mrt, struct sk_buff *skb, + u32 portid, u32 seq, struct mr_mfc *c, + int cmd, int flags), + spinlock_t *lock, struct fib_dump_filter *filter) +{ + unsigned int e = 0, s_e = cb->args[1]; + unsigned int flags = NLM_F_MULTI; + struct mr_mfc *mfc; + int err; + + if (filter->filter_set) + flags |= NLM_F_DUMP_FILTERED; + + list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) { + if (e < s_e) + goto next_entry; + if (filter->dev && + !mr_mfc_uses_dev(mrt, mfc, filter->dev)) + goto next_entry; + + err = fill(mrt, skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags); + if (err < 0) + goto out; +next_entry: + e++; + } + + spin_lock_bh(lock); + list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) { + if (e < s_e) + goto next_entry2; + if (filter->dev && + !mr_mfc_uses_dev(mrt, mfc, filter->dev)) + goto next_entry2; + + err = fill(mrt, skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags); + if (err < 0) { + spin_unlock_bh(lock); + goto out; + } +next_entry2: + e++; + } + spin_unlock_bh(lock); + err = 0; +out: + cb->args[1] = e; + return err; +} +EXPORT_SYMBOL(mr_table_dump); + +int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb, + struct mr_table *(*iter)(struct net *net, + struct mr_table *mrt), + int (*fill)(struct mr_table *mrt, + struct sk_buff *skb, + u32 portid, u32 seq, struct mr_mfc *c, + int cmd, int flags), + spinlock_t *lock, struct fib_dump_filter *filter) +{ + unsigned int t = 0, s_t = cb->args[0]; + struct net *net = sock_net(skb->sk); + struct mr_table *mrt; + int err; + + /* multicast does not track protocol or have route type other + * than RTN_MULTICAST + */ + if (filter->filter_set) { + if (filter->protocol || filter->flags || + (filter->rt_type && filter->rt_type != RTN_MULTICAST)) + return skb->len; + } + + rcu_read_lock(); + for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) { + if (t < s_t) + goto next_table; + + err = mr_table_dump(mrt, skb, cb, fill, lock, filter); + if (err < 0) + break; + cb->args[1] = 0; +next_table: + t++; + } + rcu_read_unlock(); + + cb->args[0] = t; + + return skb->len; +} +EXPORT_SYMBOL(mr_rtm_dumproute); + +int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family, + int (*rules_dump)(struct net *net, + struct notifier_block *nb, + struct netlink_ext_ack *extack), + struct mr_table *(*mr_iter)(struct net *net, + struct mr_table *mrt), + rwlock_t *mrt_lock, + struct netlink_ext_ack *extack) +{ + struct mr_table *mrt; + int err; + + err = rules_dump(net, nb, extack); + if (err) + return err; + + for (mrt = mr_iter(net, NULL); mrt; mrt = mr_iter(net, mrt)) { + struct vif_device *v = &mrt->vif_table[0]; + struct mr_mfc *mfc; + int vifi; + + /* Notifiy on table VIF entries */ + read_lock(mrt_lock); + for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) { + if (!v->dev) + continue; + + err = mr_call_vif_notifier(nb, family, + FIB_EVENT_VIF_ADD, + v, vifi, mrt->id, extack); + if (err) + break; + } + read_unlock(mrt_lock); + + if (err) + return err; + + /* Notify on table MFC entries */ + list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) { + err = mr_call_mfc_notifier(nb, family, + FIB_EVENT_ENTRY_ADD, + mfc, mrt->id, extack); + if (err) + return err; + } + } + + return 0; +} +EXPORT_SYMBOL(mr_dump); diff --git a/net/ipv4/metrics.c b/net/ipv4/metrics.c new file mode 100644 index 000000000..4966ac2aa --- /dev/null +++ b/net/ipv4/metrics.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/netlink.h> +#include <linux/nospec.h> +#include <linux/rtnetlink.h> +#include <linux/types.h> +#include <net/ip.h> +#include <net/net_namespace.h> +#include <net/tcp.h> + +static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, + int fc_mx_len, u32 *metrics, + struct netlink_ext_ack *extack) +{ + bool ecn_ca = false; + struct nlattr *nla; + int remaining; + + if (!fc_mx) + return 0; + + nla_for_each_attr(nla, fc_mx, fc_mx_len, remaining) { + int type = nla_type(nla); + u32 val; + + if (!type) + continue; + if (type > RTAX_MAX) { + NL_SET_ERR_MSG(extack, "Invalid metric type"); + return -EINVAL; + } + + type = array_index_nospec(type, RTAX_MAX + 1); + if (type == RTAX_CC_ALGO) { + char tmp[TCP_CA_NAME_MAX]; + + nla_strlcpy(tmp, nla, sizeof(tmp)); + val = tcp_ca_get_key_by_name(net, tmp, &ecn_ca); + if (val == TCP_CA_UNSPEC) { + NL_SET_ERR_MSG(extack, "Unknown tcp congestion algorithm"); + return -EINVAL; + } + } else { + if (nla_len(nla) != sizeof(u32)) { + NL_SET_ERR_MSG_ATTR(extack, nla, + "Invalid attribute in metrics"); + return -EINVAL; + } + val = nla_get_u32(nla); + } + if (type == RTAX_ADVMSS && val > 65535 - 40) + val = 65535 - 40; + if (type == RTAX_MTU && val > 65535 - 15) + val = 65535 - 15; + if (type == RTAX_HOPLIMIT && val > 255) + val = 255; + if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) { + NL_SET_ERR_MSG(extack, "Unknown flag set in feature mask in metrics attribute"); + return -EINVAL; + } + metrics[type - 1] = val; + } + + if (ecn_ca) + metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA; + + return 0; +} + +struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx, + int fc_mx_len, + struct netlink_ext_ack *extack) +{ + struct dst_metrics *fib_metrics; + int err; + + if (!fc_mx) + return (struct dst_metrics *)&dst_default_metrics; + + fib_metrics = kzalloc(sizeof(*fib_metrics), GFP_KERNEL); + if (unlikely(!fib_metrics)) + return ERR_PTR(-ENOMEM); + + err = ip_metrics_convert(net, fc_mx, fc_mx_len, fib_metrics->metrics, + extack); + if (!err) { + refcount_set(&fib_metrics->refcnt, 1); + } else { + kfree(fib_metrics); + fib_metrics = ERR_PTR(err); + } + + return fib_metrics; +} +EXPORT_SYMBOL_GPL(ip_fib_metrics_init); diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c new file mode 100644 index 000000000..7c841037c --- /dev/null +++ b/net/ipv4/netfilter.c @@ -0,0 +1,94 @@ +/* + * IPv4 specific functions of netfilter core + * + * Rusty Russell (C) 2000 -- This code is GPL. + * Patrick McHardy (C) 2006-2012 + */ +#include <linux/kernel.h> +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> +#include <linux/ip.h> +#include <linux/skbuff.h> +#include <linux/gfp.h> +#include <linux/export.h> +#include <net/route.h> +#include <net/xfrm.h> +#include <net/ip.h> +#include <net/netfilter/nf_queue.h> + +/* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */ +int ip_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb, unsigned int addr_type) +{ + const struct iphdr *iph = ip_hdr(skb); + struct rtable *rt; + struct flowi4 fl4 = {}; + __be32 saddr = iph->saddr; + __u8 flags; + struct net_device *dev = skb_dst(skb)->dev; + unsigned int hh_len; + + sk = sk_to_full_sk(sk); + flags = sk ? inet_sk_flowi_flags(sk) : 0; + + if (addr_type == RTN_UNSPEC) + addr_type = inet_addr_type_dev_table(net, dev, saddr); + if (addr_type == RTN_LOCAL || addr_type == RTN_UNICAST) + flags |= FLOWI_FLAG_ANYSRC; + else + saddr = 0; + + /* some non-standard hacks like ipt_REJECT.c:send_reset() can cause + * packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook. + */ + fl4.daddr = iph->daddr; + fl4.saddr = saddr; + fl4.flowi4_tos = RT_TOS(iph->tos); + fl4.flowi4_oif = sk ? sk->sk_bound_dev_if : 0; + if (!fl4.flowi4_oif) + fl4.flowi4_oif = l3mdev_master_ifindex(dev); + fl4.flowi4_mark = skb->mark; + fl4.flowi4_flags = flags; + rt = ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) + return PTR_ERR(rt); + + /* Drop old route. */ + skb_dst_drop(skb); + skb_dst_set(skb, &rt->dst); + + if (skb_dst(skb)->error) + return skb_dst(skb)->error; + +#ifdef CONFIG_XFRM + if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && + xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) { + struct dst_entry *dst = skb_dst(skb); + skb_dst_set(skb, NULL); + dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0); + if (IS_ERR(dst)) + return PTR_ERR(dst); + skb_dst_set(skb, dst); + } +#endif + + /* Change in oif may mean change in hh_len. */ + hh_len = skb_dst(skb)->dev->hard_header_len; + if (skb_headroom(skb) < hh_len && + pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)), + 0, GFP_ATOMIC)) + return -ENOMEM; + + return 0; +} +EXPORT_SYMBOL(ip_route_me_harder); + +int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl, + bool strict __always_unused) +{ + struct rtable *rt = ip_route_output_key(net, &fl->u.ip4); + if (IS_ERR(rt)) + return PTR_ERR(rt); + *dst = &rt->dst; + return 0; +} +EXPORT_SYMBOL_GPL(nf_ip_route); diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig new file mode 100644 index 000000000..a2f4f894b --- /dev/null +++ b/net/ipv4/netfilter/Kconfig @@ -0,0 +1,360 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# IP netfilter configuration +# + +menu "IP: Netfilter Configuration" + depends on INET && NETFILTER + +config NF_DEFRAG_IPV4 + tristate + default n + +config NF_SOCKET_IPV4 + tristate "IPv4 socket lookup support" + help + This option enables the IPv4 socket lookup infrastructure. This is + is required by the {ip,nf}tables socket match. + +config NF_TPROXY_IPV4 + tristate "IPv4 tproxy support" + +if NF_TABLES + +config NF_TABLES_IPV4 + bool "IPv4 nf_tables support" + help + This option enables the IPv4 support for nf_tables. + +if NF_TABLES_IPV4 + +config NFT_REJECT_IPV4 + select NF_REJECT_IPV4 + default NFT_REJECT + tristate + +config NFT_DUP_IPV4 + tristate "IPv4 nf_tables packet duplication support" + depends on !NF_CONNTRACK || NF_CONNTRACK + select NF_DUP_IPV4 + help + This module enables IPv4 packet duplication support for nf_tables. + +config NFT_FIB_IPV4 + select NFT_FIB + tristate "nf_tables fib / ip route lookup support" + help + This module enables IPv4 FIB lookups, e.g. for reverse path filtering. + It also allows query of the FIB for the route type, e.g. local, unicast, + multicast or blackhole. + +endif # NF_TABLES_IPV4 + +config NF_TABLES_ARP + bool "ARP nf_tables support" + select NETFILTER_FAMILY_ARP + help + This option enables the ARP support for nf_tables. + +endif # NF_TABLES + +config NF_FLOW_TABLE_IPV4 + tristate "Netfilter flow table IPv4 module" + depends on NF_FLOW_TABLE + help + This option adds the flow table IPv4 support. + + To compile it as a module, choose M here. + +config NF_DUP_IPV4 + tristate "Netfilter IPv4 packet duplication to alternate destination" + depends on !NF_CONNTRACK || NF_CONNTRACK + help + This option enables the nf_dup_ipv4 core, which duplicates an IPv4 + packet to be rerouted to another destination. + +config NF_LOG_ARP + tristate "ARP packet logging" + default m if NETFILTER_ADVANCED=n + select NF_LOG_COMMON + +config NF_LOG_IPV4 + tristate "IPv4 packet logging" + default m if NETFILTER_ADVANCED=n + select NF_LOG_COMMON + +config NF_REJECT_IPV4 + tristate "IPv4 packet rejection" + default m if NETFILTER_ADVANCED=n + +if NF_NAT +config NF_NAT_SNMP_BASIC + tristate "Basic SNMP-ALG support" + depends on NF_CONNTRACK_SNMP + depends on NETFILTER_ADVANCED + default NF_NAT && NF_CONNTRACK_SNMP + select ASN1 + help + + This module implements an Application Layer Gateway (ALG) for + SNMP payloads. In conjunction with NAT, it allows a network + management system to access multiple private networks with + conflicting addresses. It works by modifying IP addresses + inside SNMP payloads to match IP-layer NAT mapping. + + This is the "basic" form of SNMP-ALG, as described in RFC 2962 + + To compile it as a module, choose M here. If unsure, say N. + +config NF_NAT_PPTP + tristate + depends on NF_CONNTRACK + default NF_CONNTRACK_PPTP + +config NF_NAT_H323 + tristate + depends on NF_CONNTRACK + default NF_CONNTRACK_H323 + +endif # NF_NAT + +config IP_NF_IPTABLES + tristate "IP tables support (required for filtering/masq/NAT)" + default m if NETFILTER_ADVANCED=n + select NETFILTER_XTABLES + help + iptables is a general, extensible packet identification framework. + The packet filtering and full NAT (masquerading, port forwarding, + etc) subsystems now use this: say `Y' or `M' here if you want to use + either of those. + + To compile it as a module, choose M here. If unsure, say N. + +if IP_NF_IPTABLES + +# The matches. +config IP_NF_MATCH_AH + tristate '"ah" match support' + depends on NETFILTER_ADVANCED + help + This match extension allows you to match a range of SPIs + inside AH header of IPSec packets. + + To compile it as a module, choose M here. If unsure, say N. + +config IP_NF_MATCH_ECN + tristate '"ecn" match support' + depends on NETFILTER_ADVANCED + select NETFILTER_XT_MATCH_ECN + help + This is a backwards-compat option for the user's convenience + (e.g. when running oldconfig). It selects + CONFIG_NETFILTER_XT_MATCH_ECN. + +config IP_NF_MATCH_RPFILTER + tristate '"rpfilter" reverse path filter match support' + depends on NETFILTER_ADVANCED + depends on IP_NF_MANGLE || IP_NF_RAW + help + This option allows you to match packets whose replies would + go out via the interface the packet came in. + + To compile it as a module, choose M here. If unsure, say N. + The module will be called ipt_rpfilter. + +config IP_NF_MATCH_TTL + tristate '"ttl" match support' + depends on NETFILTER_ADVANCED + select NETFILTER_XT_MATCH_HL + help + This is a backwards-compat option for the user's convenience + (e.g. when running oldconfig). It selects + CONFIG_NETFILTER_XT_MATCH_HL. + +# `filter', generic and specific targets +config IP_NF_FILTER + tristate "Packet filtering" + default m if NETFILTER_ADVANCED=n + help + Packet filtering defines a table `filter', which has a series of + rules for simple packet filtering at local input, forwarding and + local output. See the man page for iptables(8). + + To compile it as a module, choose M here. If unsure, say N. + +config IP_NF_TARGET_REJECT + tristate "REJECT target support" + depends on IP_NF_FILTER + select NF_REJECT_IPV4 + default m if NETFILTER_ADVANCED=n + help + The REJECT target allows a filtering rule to specify that an ICMP + error should be issued in response to an incoming packet, rather + than silently being dropped. + + To compile it as a module, choose M here. If unsure, say N. + +config IP_NF_TARGET_SYNPROXY + tristate "SYNPROXY target support" + depends on NF_CONNTRACK && NETFILTER_ADVANCED + select NETFILTER_SYNPROXY + select SYN_COOKIES + help + The SYNPROXY target allows you to intercept TCP connections and + establish them using syncookies before they are passed on to the + server. This allows to avoid conntrack and server resource usage + during SYN-flood attacks. + + To compile it as a module, choose M here. If unsure, say N. + +# NAT + specific targets: nf_conntrack +config IP_NF_NAT + tristate "iptables NAT support" + depends on NF_CONNTRACK + default m if NETFILTER_ADVANCED=n + select NF_NAT + select NETFILTER_XT_NAT + help + This enables the `nat' table in iptables. This allows masquerading, + port forwarding and other forms of full Network Address Port + Translation. + + To compile it as a module, choose M here. If unsure, say N. + +if IP_NF_NAT + +config IP_NF_TARGET_MASQUERADE + tristate "MASQUERADE target support" + select NETFILTER_XT_TARGET_MASQUERADE + help + This is a backwards-compat option for the user's convenience + (e.g. when running oldconfig). It selects NETFILTER_XT_TARGET_MASQUERADE. + +config IP_NF_TARGET_NETMAP + tristate "NETMAP target support" + depends on NETFILTER_ADVANCED + select NETFILTER_XT_TARGET_NETMAP + help + This is a backwards-compat option for the user's convenience + (e.g. when running oldconfig). It selects + CONFIG_NETFILTER_XT_TARGET_NETMAP. + +config IP_NF_TARGET_REDIRECT + tristate "REDIRECT target support" + depends on NETFILTER_ADVANCED + select NETFILTER_XT_TARGET_REDIRECT + help + This is a backwards-compat option for the user's convenience + (e.g. when running oldconfig). It selects + CONFIG_NETFILTER_XT_TARGET_REDIRECT. + +endif # IP_NF_NAT + +# mangle + specific targets +config IP_NF_MANGLE + tristate "Packet mangling" + default m if NETFILTER_ADVANCED=n + help + This option adds a `mangle' table to iptables: see the man page for + iptables(8). This table is used for various packet alterations + which can effect how the packet is routed. + + To compile it as a module, choose M here. If unsure, say N. + +config IP_NF_TARGET_CLUSTERIP + tristate "CLUSTERIP target support" + depends on IP_NF_MANGLE + depends on NF_CONNTRACK + depends on NETFILTER_ADVANCED + select NF_CONNTRACK_MARK + select NETFILTER_FAMILY_ARP + help + The CLUSTERIP target allows you to build load-balancing clusters of + network servers without having a dedicated load-balancing + router/server/switch. + + To compile it as a module, choose M here. If unsure, say N. + +config IP_NF_TARGET_ECN + tristate "ECN target support" + depends on IP_NF_MANGLE + depends on NETFILTER_ADVANCED + help + This option adds a `ECN' target, which can be used in the iptables mangle + table. + + You can use this target to remove the ECN bits from the IPv4 header of + an IP packet. This is particularly useful, if you need to work around + existing ECN blackholes on the internet, but don't want to disable + ECN support in general. + + To compile it as a module, choose M here. If unsure, say N. + +config IP_NF_TARGET_TTL + tristate '"TTL" target support' + depends on NETFILTER_ADVANCED && IP_NF_MANGLE + select NETFILTER_XT_TARGET_HL + help + This is a backwards-compatible option for the user's convenience + (e.g. when running oldconfig). It selects + CONFIG_NETFILTER_XT_TARGET_HL. + +# raw + specific targets +config IP_NF_RAW + tristate 'raw table support (required for NOTRACK/TRACE)' + help + This option adds a `raw' table to iptables. This table is the very + first in the netfilter framework and hooks in at the PREROUTING + and OUTPUT chains. + + If you want to compile it as a module, say M here and read + <file:Documentation/kbuild/modules.rst>. If unsure, say `N'. + +# security table for MAC policy +config IP_NF_SECURITY + tristate "Security table" + depends on SECURITY + depends on NETFILTER_ADVANCED + help + This option adds a `security' table to iptables, for use + with Mandatory Access Control (MAC) policy. + + If unsure, say N. + +endif # IP_NF_IPTABLES + +# ARP tables +config IP_NF_ARPTABLES + tristate "ARP tables support" + select NETFILTER_XTABLES + select NETFILTER_FAMILY_ARP + depends on NETFILTER_ADVANCED + help + arptables is a general, extensible packet identification framework. + The ARP packet filtering and mangling (manipulation)subsystems + use this: say Y or M here if you want to use either of those. + + To compile it as a module, choose M here. If unsure, say N. + +if IP_NF_ARPTABLES + +config IP_NF_ARPFILTER + tristate "ARP packet filtering" + help + ARP packet filtering defines a table `filter', which has a series of + rules for simple ARP packet filtering at local input and + local output. On a bridge, you can also specify filtering rules + for forwarded ARP packets. See the man page for arptables(8). + + To compile it as a module, choose M here. If unsure, say N. + +config IP_NF_ARP_MANGLE + tristate "ARP payload mangling" + help + Allows altering the ARP packet payload: source and destination + hardware and network addresses. + +endif # IP_NF_ARPTABLES + +endmenu + diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile new file mode 100644 index 000000000..7c497c781 --- /dev/null +++ b/net/ipv4/netfilter/Makefile @@ -0,0 +1,61 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the netfilter modules on top of IPv4. +# + +# defrag +obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o + +obj-$(CONFIG_NF_SOCKET_IPV4) += nf_socket_ipv4.o +obj-$(CONFIG_NF_TPROXY_IPV4) += nf_tproxy_ipv4.o + +# logging +obj-$(CONFIG_NF_LOG_ARP) += nf_log_arp.o +obj-$(CONFIG_NF_LOG_IPV4) += nf_log_ipv4.o + +# reject +obj-$(CONFIG_NF_REJECT_IPV4) += nf_reject_ipv4.o + +# NAT helpers (nf_conntrack) +obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o +obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o + +nf_nat_snmp_basic-y := nf_nat_snmp_basic.asn1.o nf_nat_snmp_basic_main.o +$(obj)/nf_nat_snmp_basic_main.o: $(obj)/nf_nat_snmp_basic.asn1.h +obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o + +obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o +obj-$(CONFIG_NFT_FIB_IPV4) += nft_fib_ipv4.o +obj-$(CONFIG_NFT_DUP_IPV4) += nft_dup_ipv4.o + +# flow table support +obj-$(CONFIG_NF_FLOW_TABLE_IPV4) += nf_flow_table_ipv4.o + +# generic IP tables +obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o + +# the three instances of ip_tables +obj-$(CONFIG_IP_NF_FILTER) += iptable_filter.o +obj-$(CONFIG_IP_NF_MANGLE) += iptable_mangle.o +obj-$(CONFIG_IP_NF_NAT) += iptable_nat.o +obj-$(CONFIG_IP_NF_RAW) += iptable_raw.o +obj-$(CONFIG_IP_NF_SECURITY) += iptable_security.o + +# matches +obj-$(CONFIG_IP_NF_MATCH_AH) += ipt_ah.o +obj-$(CONFIG_IP_NF_MATCH_RPFILTER) += ipt_rpfilter.o + +# targets +obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o +obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_ECN.o +obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o +obj-$(CONFIG_IP_NF_TARGET_SYNPROXY) += ipt_SYNPROXY.o + +# generic ARP tables +obj-$(CONFIG_IP_NF_ARPTABLES) += arp_tables.o +obj-$(CONFIG_IP_NF_ARP_MANGLE) += arpt_mangle.o + +# just filtering instance of ARP tables for now +obj-$(CONFIG_IP_NF_ARPFILTER) += arptable_filter.o + +obj-$(CONFIG_NF_DUP_IPV4) += nf_dup_ipv4.o diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c new file mode 100644 index 000000000..d6d45d820 --- /dev/null +++ b/net/ipv4/netfilter/arp_tables.c @@ -0,0 +1,1642 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Packet matching code for ARP packets. + * + * Based heavily, if not almost entirely, upon ip_tables.c framework. + * + * Some ARP specific bits are: + * + * Copyright (C) 2002 David S. Miller (davem@redhat.com) + * Copyright (C) 2006-2009 Patrick McHardy <kaber@trash.net> + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/capability.h> +#include <linux/if_arp.h> +#include <linux/kmod.h> +#include <linux/vmalloc.h> +#include <linux/proc_fs.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/mutex.h> +#include <linux/err.h> +#include <net/compat.h> +#include <net/sock.h> +#include <linux/uaccess.h> + +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_arp/arp_tables.h> +#include "../../netfilter/xt_repldata.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); +MODULE_DESCRIPTION("arptables core"); + +void *arpt_alloc_initial_table(const struct xt_table *info) +{ + return xt_alloc_initial_table(arpt, ARPT); +} +EXPORT_SYMBOL_GPL(arpt_alloc_initial_table); + +static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap, + const char *hdr_addr, int len) +{ + int i, ret; + + if (len > ARPT_DEV_ADDR_LEN_MAX) + len = ARPT_DEV_ADDR_LEN_MAX; + + ret = 0; + for (i = 0; i < len; i++) + ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i]; + + return ret != 0; +} + +/* + * Unfortunately, _b and _mask are not aligned to an int (or long int) + * Some arches dont care, unrolling the loop is a win on them. + * For other arches, we only have a 16bit alignement. + */ +static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask) +{ +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + unsigned long ret = ifname_compare_aligned(_a, _b, _mask); +#else + unsigned long ret = 0; + const u16 *a = (const u16 *)_a; + const u16 *b = (const u16 *)_b; + const u16 *mask = (const u16 *)_mask; + int i; + + for (i = 0; i < IFNAMSIZ/sizeof(u16); i++) + ret |= (a[i] ^ b[i]) & mask[i]; +#endif + return ret; +} + +/* Returns whether packet matches rule or not. */ +static inline int arp_packet_match(const struct arphdr *arphdr, + struct net_device *dev, + const char *indev, + const char *outdev, + const struct arpt_arp *arpinfo) +{ + const char *arpptr = (char *)(arphdr + 1); + const char *src_devaddr, *tgt_devaddr; + __be32 src_ipaddr, tgt_ipaddr; + long ret; + + if (NF_INVF(arpinfo, ARPT_INV_ARPOP, + (arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop)) + return 0; + + if (NF_INVF(arpinfo, ARPT_INV_ARPHRD, + (arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd)) + return 0; + + if (NF_INVF(arpinfo, ARPT_INV_ARPPRO, + (arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro)) + return 0; + + if (NF_INVF(arpinfo, ARPT_INV_ARPHLN, + (arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln)) + return 0; + + src_devaddr = arpptr; + arpptr += dev->addr_len; + memcpy(&src_ipaddr, arpptr, sizeof(u32)); + arpptr += sizeof(u32); + tgt_devaddr = arpptr; + arpptr += dev->addr_len; + memcpy(&tgt_ipaddr, arpptr, sizeof(u32)); + + if (NF_INVF(arpinfo, ARPT_INV_SRCDEVADDR, + arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, + dev->addr_len)) || + NF_INVF(arpinfo, ARPT_INV_TGTDEVADDR, + arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, + dev->addr_len))) + return 0; + + if (NF_INVF(arpinfo, ARPT_INV_SRCIP, + (src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr) || + NF_INVF(arpinfo, ARPT_INV_TGTIP, + (tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr)) + return 0; + + /* Look for ifname matches. */ + ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask); + + if (NF_INVF(arpinfo, ARPT_INV_VIA_IN, ret != 0)) + return 0; + + ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask); + + if (NF_INVF(arpinfo, ARPT_INV_VIA_OUT, ret != 0)) + return 0; + + return 1; +} + +static inline int arp_checkentry(const struct arpt_arp *arp) +{ + if (arp->flags & ~ARPT_F_MASK) + return 0; + if (arp->invflags & ~ARPT_INV_MASK) + return 0; + + return 1; +} + +static unsigned int +arpt_error(struct sk_buff *skb, const struct xt_action_param *par) +{ + net_err_ratelimited("arp_tables: error: '%s'\n", + (const char *)par->targinfo); + + return NF_DROP; +} + +static inline const struct xt_entry_target * +arpt_get_target_c(const struct arpt_entry *e) +{ + return arpt_get_target((struct arpt_entry *)e); +} + +static inline struct arpt_entry * +get_entry(const void *base, unsigned int offset) +{ + return (struct arpt_entry *)(base + offset); +} + +static inline +struct arpt_entry *arpt_next_entry(const struct arpt_entry *entry) +{ + return (void *)entry + entry->next_offset; +} + +unsigned int arpt_do_table(struct sk_buff *skb, + const struct nf_hook_state *state, + struct xt_table *table) +{ + unsigned int hook = state->hook; + static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); + unsigned int verdict = NF_DROP; + const struct arphdr *arp; + struct arpt_entry *e, **jumpstack; + const char *indev, *outdev; + const void *table_base; + unsigned int cpu, stackidx = 0; + const struct xt_table_info *private; + struct xt_action_param acpar; + unsigned int addend; + + if (!pskb_may_pull(skb, arp_hdr_len(skb->dev))) + return NF_DROP; + + indev = state->in ? state->in->name : nulldevname; + outdev = state->out ? state->out->name : nulldevname; + + local_bh_disable(); + addend = xt_write_recseq_begin(); + private = READ_ONCE(table->private); /* Address dependency. */ + cpu = smp_processor_id(); + table_base = private->entries; + jumpstack = (struct arpt_entry **)private->jumpstack[cpu]; + + /* No TEE support for arptables, so no need to switch to alternate + * stack. All targets that reenter must return absolute verdicts. + */ + e = get_entry(table_base, private->hook_entry[hook]); + + acpar.state = state; + acpar.hotdrop = false; + + arp = arp_hdr(skb); + do { + const struct xt_entry_target *t; + struct xt_counters *counter; + + if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) { + e = arpt_next_entry(e); + continue; + } + + counter = xt_get_this_cpu_counter(&e->counters); + ADD_COUNTER(*counter, arp_hdr_len(skb->dev), 1); + + t = arpt_get_target_c(e); + + /* Standard target? */ + if (!t->u.kernel.target->target) { + int v; + + v = ((struct xt_standard_target *)t)->verdict; + if (v < 0) { + /* Pop from stack? */ + if (v != XT_RETURN) { + verdict = (unsigned int)(-v) - 1; + break; + } + if (stackidx == 0) { + e = get_entry(table_base, + private->underflow[hook]); + } else { + e = jumpstack[--stackidx]; + e = arpt_next_entry(e); + } + continue; + } + if (table_base + v + != arpt_next_entry(e)) { + if (unlikely(stackidx >= private->stacksize)) { + verdict = NF_DROP; + break; + } + jumpstack[stackidx++] = e; + } + + e = get_entry(table_base, v); + continue; + } + + acpar.target = t->u.kernel.target; + acpar.targinfo = t->data; + verdict = t->u.kernel.target->target(skb, &acpar); + + if (verdict == XT_CONTINUE) { + /* Target might have changed stuff. */ + arp = arp_hdr(skb); + e = arpt_next_entry(e); + } else { + /* Verdict */ + break; + } + } while (!acpar.hotdrop); + xt_write_recseq_end(addend); + local_bh_enable(); + + if (acpar.hotdrop) + return NF_DROP; + else + return verdict; +} + +/* All zeroes == unconditional rule. */ +static inline bool unconditional(const struct arpt_entry *e) +{ + static const struct arpt_arp uncond; + + return e->target_offset == sizeof(struct arpt_entry) && + memcmp(&e->arp, &uncond, sizeof(uncond)) == 0; +} + +/* Figures out from what hook each rule can be called: returns 0 if + * there are loops. Puts hook bitmask in comefrom. + */ +static int mark_source_chains(const struct xt_table_info *newinfo, + unsigned int valid_hooks, void *entry0, + unsigned int *offsets) +{ + unsigned int hook; + + /* No recursion; use packet counter to save back ptrs (reset + * to 0 as we leave), and comefrom to save source hook bitmask. + */ + for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) { + unsigned int pos = newinfo->hook_entry[hook]; + struct arpt_entry *e = entry0 + pos; + + if (!(valid_hooks & (1 << hook))) + continue; + + /* Set initial back pointer. */ + e->counters.pcnt = pos; + + for (;;) { + const struct xt_standard_target *t + = (void *)arpt_get_target_c(e); + int visited = e->comefrom & (1 << hook); + + if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) + return 0; + + e->comefrom + |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS)); + + /* Unconditional return/END. */ + if ((unconditional(e) && + (strcmp(t->target.u.user.name, + XT_STANDARD_TARGET) == 0) && + t->verdict < 0) || visited) { + unsigned int oldpos, size; + + /* Return: backtrack through the last + * big jump. + */ + do { + e->comefrom ^= (1<<NF_ARP_NUMHOOKS); + oldpos = pos; + pos = e->counters.pcnt; + e->counters.pcnt = 0; + + /* We're at the start. */ + if (pos == oldpos) + goto next; + + e = entry0 + pos; + } while (oldpos == pos + e->next_offset); + + /* Move along one */ + size = e->next_offset; + e = entry0 + pos + size; + if (pos + size >= newinfo->size) + return 0; + e->counters.pcnt = pos; + pos += size; + } else { + int newpos = t->verdict; + + if (strcmp(t->target.u.user.name, + XT_STANDARD_TARGET) == 0 && + newpos >= 0) { + /* This a jump; chase it. */ + if (!xt_find_jump_offset(offsets, newpos, + newinfo->number)) + return 0; + } else { + /* ... this is a fallthru */ + newpos = pos + e->next_offset; + if (newpos >= newinfo->size) + return 0; + } + e = entry0 + newpos; + e->counters.pcnt = pos; + pos = newpos; + } + } +next: ; + } + return 1; +} + +static int check_target(struct arpt_entry *e, struct net *net, const char *name) +{ + struct xt_entry_target *t = arpt_get_target(e); + struct xt_tgchk_param par = { + .net = net, + .table = name, + .entryinfo = e, + .target = t->u.kernel.target, + .targinfo = t->data, + .hook_mask = e->comefrom, + .family = NFPROTO_ARP, + }; + + return xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false); +} + +static int +find_check_entry(struct arpt_entry *e, struct net *net, const char *name, + unsigned int size, + struct xt_percpu_counter_alloc_state *alloc_state) +{ + struct xt_entry_target *t; + struct xt_target *target; + int ret; + + if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) + return -ENOMEM; + + t = arpt_get_target(e); + target = xt_request_find_target(NFPROTO_ARP, t->u.user.name, + t->u.user.revision); + if (IS_ERR(target)) { + ret = PTR_ERR(target); + goto out; + } + t->u.kernel.target = target; + + ret = check_target(e, net, name); + if (ret) + goto err; + return 0; +err: + module_put(t->u.kernel.target->me); +out: + xt_percpu_counter_free(&e->counters); + + return ret; +} + +static bool check_underflow(const struct arpt_entry *e) +{ + const struct xt_entry_target *t; + unsigned int verdict; + + if (!unconditional(e)) + return false; + t = arpt_get_target_c(e); + if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) + return false; + verdict = ((struct xt_standard_target *)t)->verdict; + verdict = -verdict - 1; + return verdict == NF_DROP || verdict == NF_ACCEPT; +} + +static inline int check_entry_size_and_hooks(struct arpt_entry *e, + struct xt_table_info *newinfo, + const unsigned char *base, + const unsigned char *limit, + const unsigned int *hook_entries, + const unsigned int *underflows, + unsigned int valid_hooks) +{ + unsigned int h; + int err; + + if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 || + (unsigned char *)e + sizeof(struct arpt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) + return -EINVAL; + + if (e->next_offset + < sizeof(struct arpt_entry) + sizeof(struct xt_entry_target)) + return -EINVAL; + + if (!arp_checkentry(&e->arp)) + return -EINVAL; + + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); + if (err) + return err; + + /* Check hooks & underflows */ + for (h = 0; h < NF_ARP_NUMHOOKS; h++) { + if (!(valid_hooks & (1 << h))) + continue; + if ((unsigned char *)e - base == hook_entries[h]) + newinfo->hook_entry[h] = hook_entries[h]; + if ((unsigned char *)e - base == underflows[h]) { + if (!check_underflow(e)) + return -EINVAL; + + newinfo->underflow[h] = underflows[h]; + } + } + + /* Clear counters and comefrom */ + e->counters = ((struct xt_counters) { 0, 0 }); + e->comefrom = 0; + return 0; +} + +static void cleanup_entry(struct arpt_entry *e, struct net *net) +{ + struct xt_tgdtor_param par; + struct xt_entry_target *t; + + t = arpt_get_target(e); + par.net = net; + par.target = t->u.kernel.target; + par.targinfo = t->data; + par.family = NFPROTO_ARP; + if (par.target->destroy != NULL) + par.target->destroy(&par); + module_put(par.target->me); + xt_percpu_counter_free(&e->counters); +} + +/* Checks and translates the user-supplied table segment (held in + * newinfo). + */ +static int translate_table(struct net *net, + struct xt_table_info *newinfo, + void *entry0, + const struct arpt_replace *repl) +{ + struct xt_percpu_counter_alloc_state alloc_state = { 0 }; + struct arpt_entry *iter; + unsigned int *offsets; + unsigned int i; + int ret = 0; + + newinfo->size = repl->size; + newinfo->number = repl->num_entries; + + /* Init all hooks to impossible value. */ + for (i = 0; i < NF_ARP_NUMHOOKS; i++) { + newinfo->hook_entry[i] = 0xFFFFFFFF; + newinfo->underflow[i] = 0xFFFFFFFF; + } + + offsets = xt_alloc_entry_offsets(newinfo->number); + if (!offsets) + return -ENOMEM; + i = 0; + + /* Walk through entries, checking offsets. */ + xt_entry_foreach(iter, entry0, newinfo->size) { + ret = check_entry_size_and_hooks(iter, newinfo, entry0, + entry0 + repl->size, + repl->hook_entry, + repl->underflow, + repl->valid_hooks); + if (ret != 0) + goto out_free; + if (i < repl->num_entries) + offsets[i] = (void *)iter - entry0; + ++i; + if (strcmp(arpt_get_target(iter)->u.user.name, + XT_ERROR_TARGET) == 0) + ++newinfo->stacksize; + } + + ret = -EINVAL; + if (i != repl->num_entries) + goto out_free; + + ret = xt_check_table_hooks(newinfo, repl->valid_hooks); + if (ret) + goto out_free; + + if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { + ret = -ELOOP; + goto out_free; + } + kvfree(offsets); + + /* Finally, each sanity check must pass */ + i = 0; + xt_entry_foreach(iter, entry0, newinfo->size) { + ret = find_check_entry(iter, net, repl->name, repl->size, + &alloc_state); + if (ret != 0) + break; + ++i; + } + + if (ret != 0) { + xt_entry_foreach(iter, entry0, newinfo->size) { + if (i-- == 0) + break; + cleanup_entry(iter, net); + } + return ret; + } + + return ret; + out_free: + kvfree(offsets); + return ret; +} + +static void get_counters(const struct xt_table_info *t, + struct xt_counters counters[]) +{ + struct arpt_entry *iter; + unsigned int cpu; + unsigned int i; + + for_each_possible_cpu(cpu) { + seqcount_t *s = &per_cpu(xt_recseq, cpu); + + i = 0; + xt_entry_foreach(iter, t->entries, t->size) { + struct xt_counters *tmp; + u64 bcnt, pcnt; + unsigned int start; + + tmp = xt_get_per_cpu_counter(&iter->counters, cpu); + do { + start = read_seqcount_begin(s); + bcnt = tmp->bcnt; + pcnt = tmp->pcnt; + } while (read_seqcount_retry(s, start)); + + ADD_COUNTER(counters[i], bcnt, pcnt); + ++i; + cond_resched(); + } + } +} + +static void get_old_counters(const struct xt_table_info *t, + struct xt_counters counters[]) +{ + struct arpt_entry *iter; + unsigned int cpu, i; + + for_each_possible_cpu(cpu) { + i = 0; + xt_entry_foreach(iter, t->entries, t->size) { + struct xt_counters *tmp; + + tmp = xt_get_per_cpu_counter(&iter->counters, cpu); + ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); + ++i; + } + cond_resched(); + } +} + +static struct xt_counters *alloc_counters(const struct xt_table *table) +{ + unsigned int countersize; + struct xt_counters *counters; + const struct xt_table_info *private = table->private; + + /* We need atomic snapshot of counters: rest doesn't change + * (other than comefrom, which userspace doesn't care + * about). + */ + countersize = sizeof(struct xt_counters) * private->number; + counters = vzalloc(countersize); + + if (counters == NULL) + return ERR_PTR(-ENOMEM); + + get_counters(private, counters); + + return counters; +} + +static int copy_entries_to_user(unsigned int total_size, + const struct xt_table *table, + void __user *userptr) +{ + unsigned int off, num; + const struct arpt_entry *e; + struct xt_counters *counters; + struct xt_table_info *private = table->private; + int ret = 0; + void *loc_cpu_entry; + + counters = alloc_counters(table); + if (IS_ERR(counters)) + return PTR_ERR(counters); + + loc_cpu_entry = private->entries; + + /* FIXME: use iterator macros --RR */ + /* ... then go back and fix counters and names */ + for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ + const struct xt_entry_target *t; + + e = loc_cpu_entry + off; + if (copy_to_user(userptr + off, e, sizeof(*e))) { + ret = -EFAULT; + goto free_counters; + } + if (copy_to_user(userptr + off + + offsetof(struct arpt_entry, counters), + &counters[num], + sizeof(counters[num])) != 0) { + ret = -EFAULT; + goto free_counters; + } + + t = arpt_get_target_c(e); + if (xt_target_to_user(t, userptr + off + e->target_offset)) { + ret = -EFAULT; + goto free_counters; + } + } + + free_counters: + vfree(counters); + return ret; +} + +#ifdef CONFIG_COMPAT +static void compat_standard_from_user(void *dst, const void *src) +{ + int v = *(compat_int_t *)src; + + if (v > 0) + v += xt_compat_calc_jump(NFPROTO_ARP, v); + memcpy(dst, &v, sizeof(v)); +} + +static int compat_standard_to_user(void __user *dst, const void *src) +{ + compat_int_t cv = *(int *)src; + + if (cv > 0) + cv -= xt_compat_calc_jump(NFPROTO_ARP, cv); + return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; +} + +static int compat_calc_entry(const struct arpt_entry *e, + const struct xt_table_info *info, + const void *base, struct xt_table_info *newinfo) +{ + const struct xt_entry_target *t; + unsigned int entry_offset; + int off, i, ret; + + off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); + entry_offset = (void *)e - base; + + t = arpt_get_target_c(e); + off += xt_compat_target_offset(t->u.kernel.target); + newinfo->size -= off; + ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off); + if (ret) + return ret; + + for (i = 0; i < NF_ARP_NUMHOOKS; i++) { + if (info->hook_entry[i] && + (e < (struct arpt_entry *)(base + info->hook_entry[i]))) + newinfo->hook_entry[i] -= off; + if (info->underflow[i] && + (e < (struct arpt_entry *)(base + info->underflow[i]))) + newinfo->underflow[i] -= off; + } + return 0; +} + +static int compat_table_info(const struct xt_table_info *info, + struct xt_table_info *newinfo) +{ + struct arpt_entry *iter; + const void *loc_cpu_entry; + int ret; + + if (!newinfo || !info) + return -EINVAL; + + /* we dont care about newinfo->entries */ + memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); + newinfo->initial_entries = 0; + loc_cpu_entry = info->entries; + ret = xt_compat_init_offsets(NFPROTO_ARP, info->number); + if (ret) + return ret; + xt_entry_foreach(iter, loc_cpu_entry, info->size) { + ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); + if (ret != 0) + return ret; + } + return 0; +} +#endif + +static int get_info(struct net *net, void __user *user, const int *len) +{ + char name[XT_TABLE_MAXNAMELEN]; + struct xt_table *t; + int ret; + + if (*len != sizeof(struct arpt_getinfo)) + return -EINVAL; + + if (copy_from_user(name, user, sizeof(name)) != 0) + return -EFAULT; + + name[XT_TABLE_MAXNAMELEN-1] = '\0'; +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + xt_compat_lock(NFPROTO_ARP); +#endif + t = xt_request_find_table_lock(net, NFPROTO_ARP, name); + if (!IS_ERR(t)) { + struct arpt_getinfo info; + const struct xt_table_info *private = t->private; +#ifdef CONFIG_COMPAT + struct xt_table_info tmp; + + if (in_compat_syscall()) { + ret = compat_table_info(private, &tmp); + xt_compat_flush_offsets(NFPROTO_ARP); + private = &tmp; + } +#endif + memset(&info, 0, sizeof(info)); + info.valid_hooks = t->valid_hooks; + memcpy(info.hook_entry, private->hook_entry, + sizeof(info.hook_entry)); + memcpy(info.underflow, private->underflow, + sizeof(info.underflow)); + info.num_entries = private->number; + info.size = private->size; + strcpy(info.name, name); + + if (copy_to_user(user, &info, *len) != 0) + ret = -EFAULT; + else + ret = 0; + xt_table_unlock(t); + module_put(t->me); + } else + ret = PTR_ERR(t); +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + xt_compat_unlock(NFPROTO_ARP); +#endif + return ret; +} + +static int get_entries(struct net *net, struct arpt_get_entries __user *uptr, + const int *len) +{ + int ret; + struct arpt_get_entries get; + struct xt_table *t; + + if (*len < sizeof(get)) + return -EINVAL; + if (copy_from_user(&get, uptr, sizeof(get)) != 0) + return -EFAULT; + if (*len != sizeof(struct arpt_get_entries) + get.size) + return -EINVAL; + + get.name[sizeof(get.name) - 1] = '\0'; + + t = xt_find_table_lock(net, NFPROTO_ARP, get.name); + if (!IS_ERR(t)) { + const struct xt_table_info *private = t->private; + + if (get.size == private->size) + ret = copy_entries_to_user(private->size, + t, uptr->entrytable); + else + ret = -EAGAIN; + + module_put(t->me); + xt_table_unlock(t); + } else + ret = PTR_ERR(t); + + return ret; +} + +static int __do_replace(struct net *net, const char *name, + unsigned int valid_hooks, + struct xt_table_info *newinfo, + unsigned int num_counters, + void __user *counters_ptr) +{ + int ret; + struct xt_table *t; + struct xt_table_info *oldinfo; + struct xt_counters *counters; + void *loc_cpu_old_entry; + struct arpt_entry *iter; + + ret = 0; + counters = xt_counters_alloc(num_counters); + if (!counters) { + ret = -ENOMEM; + goto out; + } + + t = xt_request_find_table_lock(net, NFPROTO_ARP, name); + if (IS_ERR(t)) { + ret = PTR_ERR(t); + goto free_newinfo_counters_untrans; + } + + /* You lied! */ + if (valid_hooks != t->valid_hooks) { + ret = -EINVAL; + goto put_module; + } + + oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); + if (!oldinfo) + goto put_module; + + /* Update module usage count based on number of rules */ + if ((oldinfo->number > oldinfo->initial_entries) || + (newinfo->number <= oldinfo->initial_entries)) + module_put(t->me); + if ((oldinfo->number > oldinfo->initial_entries) && + (newinfo->number <= oldinfo->initial_entries)) + module_put(t->me); + + xt_table_unlock(t); + + get_old_counters(oldinfo, counters); + + /* Decrease module usage counts and free resource */ + loc_cpu_old_entry = oldinfo->entries; + xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size) + cleanup_entry(iter, net); + + xt_free_table_info(oldinfo); + if (copy_to_user(counters_ptr, counters, + sizeof(struct xt_counters) * num_counters) != 0) { + /* Silent error, can't fail, new table is already in place */ + net_warn_ratelimited("arptables: counters copy to user failed while replacing table\n"); + } + vfree(counters); + return ret; + + put_module: + module_put(t->me); + xt_table_unlock(t); + free_newinfo_counters_untrans: + vfree(counters); + out: + return ret; +} + +static int do_replace(struct net *net, sockptr_t arg, unsigned int len) +{ + int ret; + struct arpt_replace tmp; + struct xt_table_info *newinfo; + void *loc_cpu_entry; + struct arpt_entry *iter; + + if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) + return -EFAULT; + + /* overflow check */ + if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) + return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + + tmp.name[sizeof(tmp.name)-1] = 0; + + newinfo = xt_alloc_table_info(tmp.size); + if (!newinfo) + return -ENOMEM; + + loc_cpu_entry = newinfo->entries; + if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), + tmp.size) != 0) { + ret = -EFAULT; + goto free_newinfo; + } + + ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); + if (ret != 0) + goto free_newinfo; + + ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, + tmp.num_counters, tmp.counters); + if (ret) + goto free_newinfo_untrans; + return 0; + + free_newinfo_untrans: + xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) + cleanup_entry(iter, net); + free_newinfo: + xt_free_table_info(newinfo); + return ret; +} + +static int do_add_counters(struct net *net, sockptr_t arg, unsigned int len) +{ + unsigned int i; + struct xt_counters_info tmp; + struct xt_counters *paddc; + struct xt_table *t; + const struct xt_table_info *private; + int ret = 0; + struct arpt_entry *iter; + unsigned int addend; + + paddc = xt_copy_counters(arg, len, &tmp); + if (IS_ERR(paddc)) + return PTR_ERR(paddc); + + t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name); + if (IS_ERR(t)) { + ret = PTR_ERR(t); + goto free; + } + + local_bh_disable(); + private = t->private; + if (private->number != tmp.num_counters) { + ret = -EINVAL; + goto unlock_up_free; + } + + i = 0; + + addend = xt_write_recseq_begin(); + xt_entry_foreach(iter, private->entries, private->size) { + struct xt_counters *tmp; + + tmp = xt_get_this_cpu_counter(&iter->counters); + ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); + ++i; + } + xt_write_recseq_end(addend); + unlock_up_free: + local_bh_enable(); + xt_table_unlock(t); + module_put(t->me); + free: + vfree(paddc); + + return ret; +} + +#ifdef CONFIG_COMPAT +struct compat_arpt_replace { + char name[XT_TABLE_MAXNAMELEN]; + u32 valid_hooks; + u32 num_entries; + u32 size; + u32 hook_entry[NF_ARP_NUMHOOKS]; + u32 underflow[NF_ARP_NUMHOOKS]; + u32 num_counters; + compat_uptr_t counters; + struct compat_arpt_entry entries[]; +}; + +static inline void compat_release_entry(struct compat_arpt_entry *e) +{ + struct xt_entry_target *t; + + t = compat_arpt_get_target(e); + module_put(t->u.kernel.target->me); +} + +static int +check_compat_entry_size_and_hooks(struct compat_arpt_entry *e, + struct xt_table_info *newinfo, + unsigned int *size, + const unsigned char *base, + const unsigned char *limit) +{ + struct xt_entry_target *t; + struct xt_target *target; + unsigned int entry_offset; + int ret, off; + + if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 || + (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) + return -EINVAL; + + if (e->next_offset < sizeof(struct compat_arpt_entry) + + sizeof(struct compat_xt_entry_target)) + return -EINVAL; + + if (!arp_checkentry(&e->arp)) + return -EINVAL; + + ret = xt_compat_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); + if (ret) + return ret; + + off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); + entry_offset = (void *)e - (void *)base; + + t = compat_arpt_get_target(e); + target = xt_request_find_target(NFPROTO_ARP, t->u.user.name, + t->u.user.revision); + if (IS_ERR(target)) { + ret = PTR_ERR(target); + goto out; + } + t->u.kernel.target = target; + + off += xt_compat_target_offset(target); + *size += off; + ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off); + if (ret) + goto release_target; + + return 0; + +release_target: + module_put(t->u.kernel.target->me); +out: + return ret; +} + +static void +compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr, + unsigned int *size, + struct xt_table_info *newinfo, unsigned char *base) +{ + struct xt_entry_target *t; + struct arpt_entry *de; + unsigned int origsize; + int h; + + origsize = *size; + de = *dstptr; + memcpy(de, e, sizeof(struct arpt_entry)); + memcpy(&de->counters, &e->counters, sizeof(e->counters)); + + *dstptr += sizeof(struct arpt_entry); + *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); + + de->target_offset = e->target_offset - (origsize - *size); + t = compat_arpt_get_target(e); + xt_compat_target_from_user(t, dstptr, size); + + de->next_offset = e->next_offset - (origsize - *size); + for (h = 0; h < NF_ARP_NUMHOOKS; h++) { + if ((unsigned char *)de - base < newinfo->hook_entry[h]) + newinfo->hook_entry[h] -= origsize - *size; + if ((unsigned char *)de - base < newinfo->underflow[h]) + newinfo->underflow[h] -= origsize - *size; + } +} + +static int translate_compat_table(struct net *net, + struct xt_table_info **pinfo, + void **pentry0, + const struct compat_arpt_replace *compatr) +{ + unsigned int i, j; + struct xt_table_info *newinfo, *info; + void *pos, *entry0, *entry1; + struct compat_arpt_entry *iter0; + struct arpt_replace repl; + unsigned int size; + int ret; + + info = *pinfo; + entry0 = *pentry0; + size = compatr->size; + info->number = compatr->num_entries; + + j = 0; + xt_compat_lock(NFPROTO_ARP); + ret = xt_compat_init_offsets(NFPROTO_ARP, compatr->num_entries); + if (ret) + goto out_unlock; + /* Walk through entries, checking offsets. */ + xt_entry_foreach(iter0, entry0, compatr->size) { + ret = check_compat_entry_size_and_hooks(iter0, info, &size, + entry0, + entry0 + compatr->size); + if (ret != 0) + goto out_unlock; + ++j; + } + + ret = -EINVAL; + if (j != compatr->num_entries) + goto out_unlock; + + ret = -ENOMEM; + newinfo = xt_alloc_table_info(size); + if (!newinfo) + goto out_unlock; + + memset(newinfo->entries, 0, size); + + newinfo->number = compatr->num_entries; + for (i = 0; i < NF_ARP_NUMHOOKS; i++) { + newinfo->hook_entry[i] = compatr->hook_entry[i]; + newinfo->underflow[i] = compatr->underflow[i]; + } + entry1 = newinfo->entries; + pos = entry1; + size = compatr->size; + xt_entry_foreach(iter0, entry0, compatr->size) + compat_copy_entry_from_user(iter0, &pos, &size, + newinfo, entry1); + + /* all module references in entry0 are now gone */ + + xt_compat_flush_offsets(NFPROTO_ARP); + xt_compat_unlock(NFPROTO_ARP); + + memcpy(&repl, compatr, sizeof(*compatr)); + + for (i = 0; i < NF_ARP_NUMHOOKS; i++) { + repl.hook_entry[i] = newinfo->hook_entry[i]; + repl.underflow[i] = newinfo->underflow[i]; + } + + repl.num_counters = 0; + repl.counters = NULL; + repl.size = newinfo->size; + ret = translate_table(net, newinfo, entry1, &repl); + if (ret) + goto free_newinfo; + + *pinfo = newinfo; + *pentry0 = entry1; + xt_free_table_info(info); + return 0; + +free_newinfo: + xt_free_table_info(newinfo); + return ret; +out_unlock: + xt_compat_flush_offsets(NFPROTO_ARP); + xt_compat_unlock(NFPROTO_ARP); + xt_entry_foreach(iter0, entry0, compatr->size) { + if (j-- == 0) + break; + compat_release_entry(iter0); + } + return ret; +} + +static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) +{ + int ret; + struct compat_arpt_replace tmp; + struct xt_table_info *newinfo; + void *loc_cpu_entry; + struct arpt_entry *iter; + + if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) + return -EFAULT; + + /* overflow check */ + if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) + return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + + tmp.name[sizeof(tmp.name)-1] = 0; + + newinfo = xt_alloc_table_info(tmp.size); + if (!newinfo) + return -ENOMEM; + + loc_cpu_entry = newinfo->entries; + if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), + tmp.size) != 0) { + ret = -EFAULT; + goto free_newinfo; + } + + ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); + if (ret != 0) + goto free_newinfo; + + ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, + tmp.num_counters, compat_ptr(tmp.counters)); + if (ret) + goto free_newinfo_untrans; + return 0; + + free_newinfo_untrans: + xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) + cleanup_entry(iter, net); + free_newinfo: + xt_free_table_info(newinfo); + return ret; +} + +static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr, + compat_uint_t *size, + struct xt_counters *counters, + unsigned int i) +{ + struct xt_entry_target *t; + struct compat_arpt_entry __user *ce; + u_int16_t target_offset, next_offset; + compat_uint_t origsize; + int ret; + + origsize = *size; + ce = *dstptr; + if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 || + copy_to_user(&ce->counters, &counters[i], + sizeof(counters[i])) != 0) + return -EFAULT; + + *dstptr += sizeof(struct compat_arpt_entry); + *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry); + + target_offset = e->target_offset - (origsize - *size); + + t = arpt_get_target(e); + ret = xt_compat_target_to_user(t, dstptr, size); + if (ret) + return ret; + next_offset = e->next_offset - (origsize - *size); + if (put_user(target_offset, &ce->target_offset) != 0 || + put_user(next_offset, &ce->next_offset) != 0) + return -EFAULT; + return 0; +} + +static int compat_copy_entries_to_user(unsigned int total_size, + struct xt_table *table, + void __user *userptr) +{ + struct xt_counters *counters; + const struct xt_table_info *private = table->private; + void __user *pos; + unsigned int size; + int ret = 0; + unsigned int i = 0; + struct arpt_entry *iter; + + counters = alloc_counters(table); + if (IS_ERR(counters)) + return PTR_ERR(counters); + + pos = userptr; + size = total_size; + xt_entry_foreach(iter, private->entries, total_size) { + ret = compat_copy_entry_to_user(iter, &pos, + &size, counters, i++); + if (ret != 0) + break; + } + vfree(counters); + return ret; +} + +struct compat_arpt_get_entries { + char name[XT_TABLE_MAXNAMELEN]; + compat_uint_t size; + struct compat_arpt_entry entrytable[]; +}; + +static int compat_get_entries(struct net *net, + struct compat_arpt_get_entries __user *uptr, + int *len) +{ + int ret; + struct compat_arpt_get_entries get; + struct xt_table *t; + + if (*len < sizeof(get)) + return -EINVAL; + if (copy_from_user(&get, uptr, sizeof(get)) != 0) + return -EFAULT; + if (*len != sizeof(struct compat_arpt_get_entries) + get.size) + return -EINVAL; + + get.name[sizeof(get.name) - 1] = '\0'; + + xt_compat_lock(NFPROTO_ARP); + t = xt_find_table_lock(net, NFPROTO_ARP, get.name); + if (!IS_ERR(t)) { + const struct xt_table_info *private = t->private; + struct xt_table_info info; + + ret = compat_table_info(private, &info); + if (!ret && get.size == info.size) { + ret = compat_copy_entries_to_user(private->size, + t, uptr->entrytable); + } else if (!ret) + ret = -EAGAIN; + + xt_compat_flush_offsets(NFPROTO_ARP); + module_put(t->me); + xt_table_unlock(t); + } else + ret = PTR_ERR(t); + + xt_compat_unlock(NFPROTO_ARP); + return ret; +} +#endif + +static int do_arpt_set_ctl(struct sock *sk, int cmd, sockptr_t arg, + unsigned int len) +{ + int ret; + + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + switch (cmd) { + case ARPT_SO_SET_REPLACE: +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = compat_do_replace(sock_net(sk), arg, len); + else +#endif + ret = do_replace(sock_net(sk), arg, len); + break; + + case ARPT_SO_SET_ADD_COUNTERS: + ret = do_add_counters(sock_net(sk), arg, len); + break; + + default: + ret = -EINVAL; + } + + return ret; +} + +static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) +{ + int ret; + + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + switch (cmd) { + case ARPT_SO_GET_INFO: + ret = get_info(sock_net(sk), user, len); + break; + + case ARPT_SO_GET_ENTRIES: +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = compat_get_entries(sock_net(sk), user, len); + else +#endif + ret = get_entries(sock_net(sk), user, len); + break; + + case ARPT_SO_GET_REVISION_TARGET: { + struct xt_get_revision rev; + + if (*len != sizeof(rev)) { + ret = -EINVAL; + break; + } + if (copy_from_user(&rev, user, sizeof(rev)) != 0) { + ret = -EFAULT; + break; + } + rev.name[sizeof(rev.name)-1] = 0; + + try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name, + rev.revision, 1, &ret), + "arpt_%s", rev.name); + break; + } + + default: + ret = -EINVAL; + } + + return ret; +} + +static void __arpt_unregister_table(struct net *net, struct xt_table *table) +{ + struct xt_table_info *private; + void *loc_cpu_entry; + struct module *table_owner = table->me; + struct arpt_entry *iter; + + private = xt_unregister_table(table); + + /* Decrease module usage counts and free resources */ + loc_cpu_entry = private->entries; + xt_entry_foreach(iter, loc_cpu_entry, private->size) + cleanup_entry(iter, net); + if (private->number > private->initial_entries) + module_put(table_owner); + xt_free_table_info(private); +} + +int arpt_register_table(struct net *net, + const struct xt_table *table, + const struct arpt_replace *repl, + const struct nf_hook_ops *ops, + struct xt_table **res) +{ + int ret; + struct xt_table_info *newinfo; + struct xt_table_info bootstrap = {0}; + void *loc_cpu_entry; + struct xt_table *new_table; + + newinfo = xt_alloc_table_info(repl->size); + if (!newinfo) + return -ENOMEM; + + loc_cpu_entry = newinfo->entries; + memcpy(loc_cpu_entry, repl->entries, repl->size); + + ret = translate_table(net, newinfo, loc_cpu_entry, repl); + if (ret != 0) + goto out_free; + + new_table = xt_register_table(net, table, &bootstrap, newinfo); + if (IS_ERR(new_table)) { + ret = PTR_ERR(new_table); + goto out_free; + } + + /* set res now, will see skbs right after nf_register_net_hooks */ + WRITE_ONCE(*res, new_table); + + ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); + if (ret != 0) { + __arpt_unregister_table(net, new_table); + *res = NULL; + } + + return ret; + +out_free: + xt_free_table_info(newinfo); + return ret; +} + +void arpt_unregister_table_pre_exit(struct net *net, struct xt_table *table, + const struct nf_hook_ops *ops) +{ + nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); +} +EXPORT_SYMBOL(arpt_unregister_table_pre_exit); + +void arpt_unregister_table(struct net *net, struct xt_table *table) +{ + __arpt_unregister_table(net, table); +} + +/* The built-in targets: standard (NULL) and error. */ +static struct xt_target arpt_builtin_tg[] __read_mostly = { + { + .name = XT_STANDARD_TARGET, + .targetsize = sizeof(int), + .family = NFPROTO_ARP, +#ifdef CONFIG_COMPAT + .compatsize = sizeof(compat_int_t), + .compat_from_user = compat_standard_from_user, + .compat_to_user = compat_standard_to_user, +#endif + }, + { + .name = XT_ERROR_TARGET, + .target = arpt_error, + .targetsize = XT_FUNCTION_MAXNAMELEN, + .family = NFPROTO_ARP, + }, +}; + +static struct nf_sockopt_ops arpt_sockopts = { + .pf = PF_INET, + .set_optmin = ARPT_BASE_CTL, + .set_optmax = ARPT_SO_SET_MAX+1, + .set = do_arpt_set_ctl, + .get_optmin = ARPT_BASE_CTL, + .get_optmax = ARPT_SO_GET_MAX+1, + .get = do_arpt_get_ctl, + .owner = THIS_MODULE, +}; + +static int __net_init arp_tables_net_init(struct net *net) +{ + return xt_proto_init(net, NFPROTO_ARP); +} + +static void __net_exit arp_tables_net_exit(struct net *net) +{ + xt_proto_fini(net, NFPROTO_ARP); +} + +static struct pernet_operations arp_tables_net_ops = { + .init = arp_tables_net_init, + .exit = arp_tables_net_exit, +}; + +static int __init arp_tables_init(void) +{ + int ret; + + ret = register_pernet_subsys(&arp_tables_net_ops); + if (ret < 0) + goto err1; + + /* No one else will be downing sem now, so we won't sleep */ + ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg)); + if (ret < 0) + goto err2; + + /* Register setsockopt */ + ret = nf_register_sockopt(&arpt_sockopts); + if (ret < 0) + goto err4; + + return 0; + +err4: + xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg)); +err2: + unregister_pernet_subsys(&arp_tables_net_ops); +err1: + return ret; +} + +static void __exit arp_tables_fini(void) +{ + nf_unregister_sockopt(&arpt_sockopts); + xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg)); + unregister_pernet_subsys(&arp_tables_net_ops); +} + +EXPORT_SYMBOL(arpt_register_table); +EXPORT_SYMBOL(arpt_unregister_table); +EXPORT_SYMBOL(arpt_do_table); + +module_init(arp_tables_init); +module_exit(arp_tables_fini); diff --git a/net/ipv4/netfilter/arpt_mangle.c b/net/ipv4/netfilter/arpt_mangle.c new file mode 100644 index 000000000..a4e07e5e9 --- /dev/null +++ b/net/ipv4/netfilter/arpt_mangle.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* module that allows mangling of the arp payload */ +#include <linux/module.h> +#include <linux/netfilter.h> +#include <linux/netfilter_arp/arpt_mangle.h> +#include <net/sock.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); +MODULE_DESCRIPTION("arptables arp payload mangle target"); + +static unsigned int +target(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct arpt_mangle *mangle = par->targinfo; + const struct arphdr *arp; + unsigned char *arpptr; + int pln, hln; + + if (skb_ensure_writable(skb, skb->len)) + return NF_DROP; + + arp = arp_hdr(skb); + arpptr = skb_network_header(skb) + sizeof(*arp); + pln = arp->ar_pln; + hln = arp->ar_hln; + /* We assume that pln and hln were checked in the match */ + if (mangle->flags & ARPT_MANGLE_SDEV) { + if (ARPT_DEV_ADDR_LEN_MAX < hln || + (arpptr + hln > skb_tail_pointer(skb))) + return NF_DROP; + memcpy(arpptr, mangle->src_devaddr, hln); + } + arpptr += hln; + if (mangle->flags & ARPT_MANGLE_SIP) { + if (ARPT_MANGLE_ADDR_LEN_MAX < pln || + (arpptr + pln > skb_tail_pointer(skb))) + return NF_DROP; + memcpy(arpptr, &mangle->u_s.src_ip, pln); + } + arpptr += pln; + if (mangle->flags & ARPT_MANGLE_TDEV) { + if (ARPT_DEV_ADDR_LEN_MAX < hln || + (arpptr + hln > skb_tail_pointer(skb))) + return NF_DROP; + memcpy(arpptr, mangle->tgt_devaddr, hln); + } + arpptr += hln; + if (mangle->flags & ARPT_MANGLE_TIP) { + if (ARPT_MANGLE_ADDR_LEN_MAX < pln || + (arpptr + pln > skb_tail_pointer(skb))) + return NF_DROP; + memcpy(arpptr, &mangle->u_t.tgt_ip, pln); + } + return mangle->target; +} + +static int checkentry(const struct xt_tgchk_param *par) +{ + const struct arpt_mangle *mangle = par->targinfo; + + if (mangle->flags & ~ARPT_MANGLE_MASK || + !(mangle->flags & ARPT_MANGLE_MASK)) + return -EINVAL; + + if (mangle->target != NF_DROP && mangle->target != NF_ACCEPT && + mangle->target != XT_CONTINUE) + return -EINVAL; + return 0; +} + +static struct xt_target arpt_mangle_reg __read_mostly = { + .name = "mangle", + .family = NFPROTO_ARP, + .target = target, + .targetsize = sizeof(struct arpt_mangle), + .checkentry = checkentry, + .me = THIS_MODULE, +}; + +static int __init arpt_mangle_init(void) +{ + return xt_register_target(&arpt_mangle_reg); +} + +static void __exit arpt_mangle_fini(void) +{ + xt_unregister_target(&arpt_mangle_reg); +} + +module_init(arpt_mangle_init); +module_exit(arpt_mangle_fini); diff --git a/net/ipv4/netfilter/arptable_filter.c b/net/ipv4/netfilter/arptable_filter.c new file mode 100644 index 000000000..6c300ba56 --- /dev/null +++ b/net/ipv4/netfilter/arptable_filter.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Filtering ARP tables module. + * + * Copyright (C) 2002 David S. Miller (davem@redhat.com) + * + */ + +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_arp/arp_tables.h> +#include <linux/slab.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); +MODULE_DESCRIPTION("arptables filter table"); + +#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \ + (1 << NF_ARP_FORWARD)) + +static int __net_init arptable_filter_table_init(struct net *net); + +static const struct xt_table packet_filter = { + .name = "filter", + .valid_hooks = FILTER_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_ARP, + .priority = NF_IP_PRI_FILTER, + .table_init = arptable_filter_table_init, +}; + +/* The work comes in here from netfilter.c */ +static unsigned int +arptable_filter_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return arpt_do_table(skb, state, state->net->ipv4.arptable_filter); +} + +static struct nf_hook_ops *arpfilter_ops __read_mostly; + +static int __net_init arptable_filter_table_init(struct net *net) +{ + struct arpt_replace *repl; + int err; + + if (net->ipv4.arptable_filter) + return 0; + + repl = arpt_alloc_initial_table(&packet_filter); + if (repl == NULL) + return -ENOMEM; + err = arpt_register_table(net, &packet_filter, repl, arpfilter_ops, + &net->ipv4.arptable_filter); + kfree(repl); + return err; +} + +static void __net_exit arptable_filter_net_pre_exit(struct net *net) +{ + if (net->ipv4.arptable_filter) + arpt_unregister_table_pre_exit(net, net->ipv4.arptable_filter, + arpfilter_ops); +} + +static void __net_exit arptable_filter_net_exit(struct net *net) +{ + if (!net->ipv4.arptable_filter) + return; + arpt_unregister_table(net, net->ipv4.arptable_filter); + net->ipv4.arptable_filter = NULL; +} + +static struct pernet_operations arptable_filter_net_ops = { + .exit = arptable_filter_net_exit, + .pre_exit = arptable_filter_net_pre_exit, +}; + +static int __init arptable_filter_init(void) +{ + int ret; + + arpfilter_ops = xt_hook_ops_alloc(&packet_filter, arptable_filter_hook); + if (IS_ERR(arpfilter_ops)) + return PTR_ERR(arpfilter_ops); + + ret = register_pernet_subsys(&arptable_filter_net_ops); + if (ret < 0) { + kfree(arpfilter_ops); + return ret; + } + + ret = arptable_filter_table_init(&init_net); + if (ret) { + unregister_pernet_subsys(&arptable_filter_net_ops); + kfree(arpfilter_ops); + } + + return ret; +} + +static void __exit arptable_filter_fini(void) +{ + unregister_pernet_subsys(&arptable_filter_net_ops); + kfree(arpfilter_ops); +} + +module_init(arptable_filter_init); +module_exit(arptable_filter_fini); diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c new file mode 100644 index 000000000..ec981618b --- /dev/null +++ b/net/ipv4/netfilter/ip_tables.c @@ -0,0 +1,1931 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Packet matching code. + * + * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling + * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> + * Copyright (C) 2006-2010 Patrick McHardy <kaber@trash.net> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/cache.h> +#include <linux/capability.h> +#include <linux/skbuff.h> +#include <linux/kmod.h> +#include <linux/vmalloc.h> +#include <linux/netdevice.h> +#include <linux/module.h> +#include <linux/icmp.h> +#include <net/ip.h> +#include <net/compat.h> +#include <linux/uaccess.h> +#include <linux/mutex.h> +#include <linux/proc_fs.h> +#include <linux/err.h> +#include <linux/cpumask.h> + +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <net/netfilter/nf_log.h> +#include "../../netfilter/xt_repldata.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("IPv4 packet filter"); +MODULE_ALIAS("ipt_icmp"); + +void *ipt_alloc_initial_table(const struct xt_table *info) +{ + return xt_alloc_initial_table(ipt, IPT); +} +EXPORT_SYMBOL_GPL(ipt_alloc_initial_table); + +/* Returns whether matches rule or not. */ +/* Performance critical - called for every packet */ +static inline bool +ip_packet_match(const struct iphdr *ip, + const char *indev, + const char *outdev, + const struct ipt_ip *ipinfo, + int isfrag) +{ + unsigned long ret; + + if (NF_INVF(ipinfo, IPT_INV_SRCIP, + (ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) || + NF_INVF(ipinfo, IPT_INV_DSTIP, + (ip->daddr & ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr)) + return false; + + ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask); + + if (NF_INVF(ipinfo, IPT_INV_VIA_IN, ret != 0)) + return false; + + ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask); + + if (NF_INVF(ipinfo, IPT_INV_VIA_OUT, ret != 0)) + return false; + + /* Check specific protocol */ + if (ipinfo->proto && + NF_INVF(ipinfo, IPT_INV_PROTO, ip->protocol != ipinfo->proto)) + return false; + + /* If we have a fragment rule but the packet is not a fragment + * then we return zero */ + if (NF_INVF(ipinfo, IPT_INV_FRAG, + (ipinfo->flags & IPT_F_FRAG) && !isfrag)) + return false; + + return true; +} + +static bool +ip_checkentry(const struct ipt_ip *ip) +{ + if (ip->flags & ~IPT_F_MASK) + return false; + if (ip->invflags & ~IPT_INV_MASK) + return false; + return true; +} + +static unsigned int +ipt_error(struct sk_buff *skb, const struct xt_action_param *par) +{ + net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); + + return NF_DROP; +} + +/* Performance critical */ +static inline struct ipt_entry * +get_entry(const void *base, unsigned int offset) +{ + return (struct ipt_entry *)(base + offset); +} + +/* All zeroes == unconditional rule. */ +/* Mildly perf critical (only if packet tracing is on) */ +static inline bool unconditional(const struct ipt_entry *e) +{ + static const struct ipt_ip uncond; + + return e->target_offset == sizeof(struct ipt_entry) && + memcmp(&e->ip, &uncond, sizeof(uncond)) == 0; +} + +/* for const-correctness */ +static inline const struct xt_entry_target * +ipt_get_target_c(const struct ipt_entry *e) +{ + return ipt_get_target((struct ipt_entry *)e); +} + +#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) +static const char *const hooknames[] = { + [NF_INET_PRE_ROUTING] = "PREROUTING", + [NF_INET_LOCAL_IN] = "INPUT", + [NF_INET_FORWARD] = "FORWARD", + [NF_INET_LOCAL_OUT] = "OUTPUT", + [NF_INET_POST_ROUTING] = "POSTROUTING", +}; + +enum nf_ip_trace_comments { + NF_IP_TRACE_COMMENT_RULE, + NF_IP_TRACE_COMMENT_RETURN, + NF_IP_TRACE_COMMENT_POLICY, +}; + +static const char *const comments[] = { + [NF_IP_TRACE_COMMENT_RULE] = "rule", + [NF_IP_TRACE_COMMENT_RETURN] = "return", + [NF_IP_TRACE_COMMENT_POLICY] = "policy", +}; + +static const struct nf_loginfo trace_loginfo = { + .type = NF_LOG_TYPE_LOG, + .u = { + .log = { + .level = 4, + .logflags = NF_LOG_DEFAULT_MASK, + }, + }, +}; + +/* Mildly perf critical (only if packet tracing is on) */ +static inline int +get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e, + const char *hookname, const char **chainname, + const char **comment, unsigned int *rulenum) +{ + const struct xt_standard_target *t = (void *)ipt_get_target_c(s); + + if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { + /* Head of user chain: ERROR target with chainname */ + *chainname = t->target.data; + (*rulenum) = 0; + } else if (s == e) { + (*rulenum)++; + + if (unconditional(s) && + strcmp(t->target.u.kernel.target->name, + XT_STANDARD_TARGET) == 0 && + t->verdict < 0) { + /* Tail of chains: STANDARD target (return/policy) */ + *comment = *chainname == hookname + ? comments[NF_IP_TRACE_COMMENT_POLICY] + : comments[NF_IP_TRACE_COMMENT_RETURN]; + } + return 1; + } else + (*rulenum)++; + + return 0; +} + +static void trace_packet(struct net *net, + const struct sk_buff *skb, + unsigned int hook, + const struct net_device *in, + const struct net_device *out, + const char *tablename, + const struct xt_table_info *private, + const struct ipt_entry *e) +{ + const struct ipt_entry *root; + const char *hookname, *chainname, *comment; + const struct ipt_entry *iter; + unsigned int rulenum = 0; + + root = get_entry(private->entries, private->hook_entry[hook]); + + hookname = chainname = hooknames[hook]; + comment = comments[NF_IP_TRACE_COMMENT_RULE]; + + xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) + if (get_chainname_rulenum(iter, e, hookname, + &chainname, &comment, &rulenum) != 0) + break; + + nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo, + "TRACE: %s:%s:%s:%u ", + tablename, chainname, comment, rulenum); +} +#endif + +static inline +struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry) +{ + return (void *)entry + entry->next_offset; +} + +/* Returns one of the generic firewall policies, like NF_ACCEPT. */ +unsigned int +ipt_do_table(struct sk_buff *skb, + const struct nf_hook_state *state, + struct xt_table *table) +{ + unsigned int hook = state->hook; + static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); + const struct iphdr *ip; + /* Initializing verdict to NF_DROP keeps gcc happy. */ + unsigned int verdict = NF_DROP; + const char *indev, *outdev; + const void *table_base; + struct ipt_entry *e, **jumpstack; + unsigned int stackidx, cpu; + const struct xt_table_info *private; + struct xt_action_param acpar; + unsigned int addend; + + /* Initialization */ + stackidx = 0; + ip = ip_hdr(skb); + indev = state->in ? state->in->name : nulldevname; + outdev = state->out ? state->out->name : nulldevname; + /* We handle fragments by dealing with the first fragment as + * if it was a normal packet. All other fragments are treated + * normally, except that they will NEVER match rules that ask + * things we don't know, ie. tcp syn flag or ports). If the + * rule is also a fragment-specific rule, non-fragments won't + * match it. */ + acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET; + acpar.thoff = ip_hdrlen(skb); + acpar.hotdrop = false; + acpar.state = state; + + WARN_ON(!(table->valid_hooks & (1 << hook))); + local_bh_disable(); + addend = xt_write_recseq_begin(); + private = READ_ONCE(table->private); /* Address dependency. */ + cpu = smp_processor_id(); + table_base = private->entries; + jumpstack = (struct ipt_entry **)private->jumpstack[cpu]; + + /* Switch to alternate jumpstack if we're being invoked via TEE. + * TEE issues XT_CONTINUE verdict on original skb so we must not + * clobber the jumpstack. + * + * For recursion via REJECT or SYNPROXY the stack will be clobbered + * but it is no problem since absolute verdict is issued by these. + */ + if (static_key_false(&xt_tee_enabled)) + jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); + + e = get_entry(table_base, private->hook_entry[hook]); + + do { + const struct xt_entry_target *t; + const struct xt_entry_match *ematch; + struct xt_counters *counter; + + WARN_ON(!e); + if (!ip_packet_match(ip, indev, outdev, + &e->ip, acpar.fragoff)) { + no_match: + e = ipt_next_entry(e); + continue; + } + + xt_ematch_foreach(ematch, e) { + acpar.match = ematch->u.kernel.match; + acpar.matchinfo = ematch->data; + if (!acpar.match->match(skb, &acpar)) + goto no_match; + } + + counter = xt_get_this_cpu_counter(&e->counters); + ADD_COUNTER(*counter, skb->len, 1); + + t = ipt_get_target_c(e); + WARN_ON(!t->u.kernel.target); + +#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) + /* The packet is traced: log it */ + if (unlikely(skb->nf_trace)) + trace_packet(state->net, skb, hook, state->in, + state->out, table->name, private, e); +#endif + /* Standard target? */ + if (!t->u.kernel.target->target) { + int v; + + v = ((struct xt_standard_target *)t)->verdict; + if (v < 0) { + /* Pop from stack? */ + if (v != XT_RETURN) { + verdict = (unsigned int)(-v) - 1; + break; + } + if (stackidx == 0) { + e = get_entry(table_base, + private->underflow[hook]); + } else { + e = jumpstack[--stackidx]; + e = ipt_next_entry(e); + } + continue; + } + if (table_base + v != ipt_next_entry(e) && + !(e->ip.flags & IPT_F_GOTO)) { + if (unlikely(stackidx >= private->stacksize)) { + verdict = NF_DROP; + break; + } + jumpstack[stackidx++] = e; + } + + e = get_entry(table_base, v); + continue; + } + + acpar.target = t->u.kernel.target; + acpar.targinfo = t->data; + + verdict = t->u.kernel.target->target(skb, &acpar); + if (verdict == XT_CONTINUE) { + /* Target might have changed stuff. */ + ip = ip_hdr(skb); + e = ipt_next_entry(e); + } else { + /* Verdict */ + break; + } + } while (!acpar.hotdrop); + + xt_write_recseq_end(addend); + local_bh_enable(); + + if (acpar.hotdrop) + return NF_DROP; + else return verdict; +} + +/* Figures out from what hook each rule can be called: returns 0 if + there are loops. Puts hook bitmask in comefrom. */ +static int +mark_source_chains(const struct xt_table_info *newinfo, + unsigned int valid_hooks, void *entry0, + unsigned int *offsets) +{ + unsigned int hook; + + /* No recursion; use packet counter to save back ptrs (reset + to 0 as we leave), and comefrom to save source hook bitmask */ + for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { + unsigned int pos = newinfo->hook_entry[hook]; + struct ipt_entry *e = entry0 + pos; + + if (!(valid_hooks & (1 << hook))) + continue; + + /* Set initial back pointer. */ + e->counters.pcnt = pos; + + for (;;) { + const struct xt_standard_target *t + = (void *)ipt_get_target_c(e); + int visited = e->comefrom & (1 << hook); + + if (e->comefrom & (1 << NF_INET_NUMHOOKS)) + return 0; + + e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); + + /* Unconditional return/END. */ + if ((unconditional(e) && + (strcmp(t->target.u.user.name, + XT_STANDARD_TARGET) == 0) && + t->verdict < 0) || visited) { + unsigned int oldpos, size; + + /* Return: backtrack through the last + big jump. */ + do { + e->comefrom ^= (1<<NF_INET_NUMHOOKS); + oldpos = pos; + pos = e->counters.pcnt; + e->counters.pcnt = 0; + + /* We're at the start. */ + if (pos == oldpos) + goto next; + + e = entry0 + pos; + } while (oldpos == pos + e->next_offset); + + /* Move along one */ + size = e->next_offset; + e = entry0 + pos + size; + if (pos + size >= newinfo->size) + return 0; + e->counters.pcnt = pos; + pos += size; + } else { + int newpos = t->verdict; + + if (strcmp(t->target.u.user.name, + XT_STANDARD_TARGET) == 0 && + newpos >= 0) { + /* This a jump; chase it. */ + if (!xt_find_jump_offset(offsets, newpos, + newinfo->number)) + return 0; + } else { + /* ... this is a fallthru */ + newpos = pos + e->next_offset; + if (newpos >= newinfo->size) + return 0; + } + e = entry0 + newpos; + e->counters.pcnt = pos; + pos = newpos; + } + } +next: ; + } + return 1; +} + +static void cleanup_match(struct xt_entry_match *m, struct net *net) +{ + struct xt_mtdtor_param par; + + par.net = net; + par.match = m->u.kernel.match; + par.matchinfo = m->data; + par.family = NFPROTO_IPV4; + if (par.match->destroy != NULL) + par.match->destroy(&par); + module_put(par.match->me); +} + +static int +check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) +{ + const struct ipt_ip *ip = par->entryinfo; + + par->match = m->u.kernel.match; + par->matchinfo = m->data; + + return xt_check_match(par, m->u.match_size - sizeof(*m), + ip->proto, ip->invflags & IPT_INV_PROTO); +} + +static int +find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) +{ + struct xt_match *match; + int ret; + + match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name, + m->u.user.revision); + if (IS_ERR(match)) + return PTR_ERR(match); + m->u.kernel.match = match; + + ret = check_match(m, par); + if (ret) + goto err; + + return 0; +err: + module_put(m->u.kernel.match->me); + return ret; +} + +static int check_target(struct ipt_entry *e, struct net *net, const char *name) +{ + struct xt_entry_target *t = ipt_get_target(e); + struct xt_tgchk_param par = { + .net = net, + .table = name, + .entryinfo = e, + .target = t->u.kernel.target, + .targinfo = t->data, + .hook_mask = e->comefrom, + .family = NFPROTO_IPV4, + }; + + return xt_check_target(&par, t->u.target_size - sizeof(*t), + e->ip.proto, e->ip.invflags & IPT_INV_PROTO); +} + +static int +find_check_entry(struct ipt_entry *e, struct net *net, const char *name, + unsigned int size, + struct xt_percpu_counter_alloc_state *alloc_state) +{ + struct xt_entry_target *t; + struct xt_target *target; + int ret; + unsigned int j; + struct xt_mtchk_param mtpar; + struct xt_entry_match *ematch; + + if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) + return -ENOMEM; + + j = 0; + memset(&mtpar, 0, sizeof(mtpar)); + mtpar.net = net; + mtpar.table = name; + mtpar.entryinfo = &e->ip; + mtpar.hook_mask = e->comefrom; + mtpar.family = NFPROTO_IPV4; + xt_ematch_foreach(ematch, e) { + ret = find_check_match(ematch, &mtpar); + if (ret != 0) + goto cleanup_matches; + ++j; + } + + t = ipt_get_target(e); + target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name, + t->u.user.revision); + if (IS_ERR(target)) { + ret = PTR_ERR(target); + goto cleanup_matches; + } + t->u.kernel.target = target; + + ret = check_target(e, net, name); + if (ret) + goto err; + + return 0; + err: + module_put(t->u.kernel.target->me); + cleanup_matches: + xt_ematch_foreach(ematch, e) { + if (j-- == 0) + break; + cleanup_match(ematch, net); + } + + xt_percpu_counter_free(&e->counters); + + return ret; +} + +static bool check_underflow(const struct ipt_entry *e) +{ + const struct xt_entry_target *t; + unsigned int verdict; + + if (!unconditional(e)) + return false; + t = ipt_get_target_c(e); + if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) + return false; + verdict = ((struct xt_standard_target *)t)->verdict; + verdict = -verdict - 1; + return verdict == NF_DROP || verdict == NF_ACCEPT; +} + +static int +check_entry_size_and_hooks(struct ipt_entry *e, + struct xt_table_info *newinfo, + const unsigned char *base, + const unsigned char *limit, + const unsigned int *hook_entries, + const unsigned int *underflows, + unsigned int valid_hooks) +{ + unsigned int h; + int err; + + if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 || + (unsigned char *)e + sizeof(struct ipt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) + return -EINVAL; + + if (e->next_offset + < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target)) + return -EINVAL; + + if (!ip_checkentry(&e->ip)) + return -EINVAL; + + err = xt_check_entry_offsets(e, e->elems, e->target_offset, + e->next_offset); + if (err) + return err; + + /* Check hooks & underflows */ + for (h = 0; h < NF_INET_NUMHOOKS; h++) { + if (!(valid_hooks & (1 << h))) + continue; + if ((unsigned char *)e - base == hook_entries[h]) + newinfo->hook_entry[h] = hook_entries[h]; + if ((unsigned char *)e - base == underflows[h]) { + if (!check_underflow(e)) + return -EINVAL; + + newinfo->underflow[h] = underflows[h]; + } + } + + /* Clear counters and comefrom */ + e->counters = ((struct xt_counters) { 0, 0 }); + e->comefrom = 0; + return 0; +} + +static void +cleanup_entry(struct ipt_entry *e, struct net *net) +{ + struct xt_tgdtor_param par; + struct xt_entry_target *t; + struct xt_entry_match *ematch; + + /* Cleanup all matches */ + xt_ematch_foreach(ematch, e) + cleanup_match(ematch, net); + t = ipt_get_target(e); + + par.net = net; + par.target = t->u.kernel.target; + par.targinfo = t->data; + par.family = NFPROTO_IPV4; + if (par.target->destroy != NULL) + par.target->destroy(&par); + module_put(par.target->me); + xt_percpu_counter_free(&e->counters); +} + +/* Checks and translates the user-supplied table segment (held in + newinfo) */ +static int +translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, + const struct ipt_replace *repl) +{ + struct xt_percpu_counter_alloc_state alloc_state = { 0 }; + struct ipt_entry *iter; + unsigned int *offsets; + unsigned int i; + int ret = 0; + + newinfo->size = repl->size; + newinfo->number = repl->num_entries; + + /* Init all hooks to impossible value. */ + for (i = 0; i < NF_INET_NUMHOOKS; i++) { + newinfo->hook_entry[i] = 0xFFFFFFFF; + newinfo->underflow[i] = 0xFFFFFFFF; + } + + offsets = xt_alloc_entry_offsets(newinfo->number); + if (!offsets) + return -ENOMEM; + i = 0; + /* Walk through entries, checking offsets. */ + xt_entry_foreach(iter, entry0, newinfo->size) { + ret = check_entry_size_and_hooks(iter, newinfo, entry0, + entry0 + repl->size, + repl->hook_entry, + repl->underflow, + repl->valid_hooks); + if (ret != 0) + goto out_free; + if (i < repl->num_entries) + offsets[i] = (void *)iter - entry0; + ++i; + if (strcmp(ipt_get_target(iter)->u.user.name, + XT_ERROR_TARGET) == 0) + ++newinfo->stacksize; + } + + ret = -EINVAL; + if (i != repl->num_entries) + goto out_free; + + ret = xt_check_table_hooks(newinfo, repl->valid_hooks); + if (ret) + goto out_free; + + if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { + ret = -ELOOP; + goto out_free; + } + kvfree(offsets); + + /* Finally, each sanity check must pass */ + i = 0; + xt_entry_foreach(iter, entry0, newinfo->size) { + ret = find_check_entry(iter, net, repl->name, repl->size, + &alloc_state); + if (ret != 0) + break; + ++i; + } + + if (ret != 0) { + xt_entry_foreach(iter, entry0, newinfo->size) { + if (i-- == 0) + break; + cleanup_entry(iter, net); + } + return ret; + } + + return ret; + out_free: + kvfree(offsets); + return ret; +} + +static void +get_counters(const struct xt_table_info *t, + struct xt_counters counters[]) +{ + struct ipt_entry *iter; + unsigned int cpu; + unsigned int i; + + for_each_possible_cpu(cpu) { + seqcount_t *s = &per_cpu(xt_recseq, cpu); + + i = 0; + xt_entry_foreach(iter, t->entries, t->size) { + struct xt_counters *tmp; + u64 bcnt, pcnt; + unsigned int start; + + tmp = xt_get_per_cpu_counter(&iter->counters, cpu); + do { + start = read_seqcount_begin(s); + bcnt = tmp->bcnt; + pcnt = tmp->pcnt; + } while (read_seqcount_retry(s, start)); + + ADD_COUNTER(counters[i], bcnt, pcnt); + ++i; /* macro does multi eval of i */ + cond_resched(); + } + } +} + +static void get_old_counters(const struct xt_table_info *t, + struct xt_counters counters[]) +{ + struct ipt_entry *iter; + unsigned int cpu, i; + + for_each_possible_cpu(cpu) { + i = 0; + xt_entry_foreach(iter, t->entries, t->size) { + const struct xt_counters *tmp; + + tmp = xt_get_per_cpu_counter(&iter->counters, cpu); + ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); + ++i; /* macro does multi eval of i */ + } + + cond_resched(); + } +} + +static struct xt_counters *alloc_counters(const struct xt_table *table) +{ + unsigned int countersize; + struct xt_counters *counters; + const struct xt_table_info *private = table->private; + + /* We need atomic snapshot of counters: rest doesn't change + (other than comefrom, which userspace doesn't care + about). */ + countersize = sizeof(struct xt_counters) * private->number; + counters = vzalloc(countersize); + + if (counters == NULL) + return ERR_PTR(-ENOMEM); + + get_counters(private, counters); + + return counters; +} + +static int +copy_entries_to_user(unsigned int total_size, + const struct xt_table *table, + void __user *userptr) +{ + unsigned int off, num; + const struct ipt_entry *e; + struct xt_counters *counters; + const struct xt_table_info *private = table->private; + int ret = 0; + const void *loc_cpu_entry; + + counters = alloc_counters(table); + if (IS_ERR(counters)) + return PTR_ERR(counters); + + loc_cpu_entry = private->entries; + + /* FIXME: use iterator macros --RR */ + /* ... then go back and fix counters and names */ + for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ + unsigned int i; + const struct xt_entry_match *m; + const struct xt_entry_target *t; + + e = loc_cpu_entry + off; + if (copy_to_user(userptr + off, e, sizeof(*e))) { + ret = -EFAULT; + goto free_counters; + } + if (copy_to_user(userptr + off + + offsetof(struct ipt_entry, counters), + &counters[num], + sizeof(counters[num])) != 0) { + ret = -EFAULT; + goto free_counters; + } + + for (i = sizeof(struct ipt_entry); + i < e->target_offset; + i += m->u.match_size) { + m = (void *)e + i; + + if (xt_match_to_user(m, userptr + off + i)) { + ret = -EFAULT; + goto free_counters; + } + } + + t = ipt_get_target_c(e); + if (xt_target_to_user(t, userptr + off + e->target_offset)) { + ret = -EFAULT; + goto free_counters; + } + } + + free_counters: + vfree(counters); + return ret; +} + +#ifdef CONFIG_COMPAT +static void compat_standard_from_user(void *dst, const void *src) +{ + int v = *(compat_int_t *)src; + + if (v > 0) + v += xt_compat_calc_jump(AF_INET, v); + memcpy(dst, &v, sizeof(v)); +} + +static int compat_standard_to_user(void __user *dst, const void *src) +{ + compat_int_t cv = *(int *)src; + + if (cv > 0) + cv -= xt_compat_calc_jump(AF_INET, cv); + return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; +} + +static int compat_calc_entry(const struct ipt_entry *e, + const struct xt_table_info *info, + const void *base, struct xt_table_info *newinfo) +{ + const struct xt_entry_match *ematch; + const struct xt_entry_target *t; + unsigned int entry_offset; + int off, i, ret; + + off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); + entry_offset = (void *)e - base; + xt_ematch_foreach(ematch, e) + off += xt_compat_match_offset(ematch->u.kernel.match); + t = ipt_get_target_c(e); + off += xt_compat_target_offset(t->u.kernel.target); + newinfo->size -= off; + ret = xt_compat_add_offset(AF_INET, entry_offset, off); + if (ret) + return ret; + + for (i = 0; i < NF_INET_NUMHOOKS; i++) { + if (info->hook_entry[i] && + (e < (struct ipt_entry *)(base + info->hook_entry[i]))) + newinfo->hook_entry[i] -= off; + if (info->underflow[i] && + (e < (struct ipt_entry *)(base + info->underflow[i]))) + newinfo->underflow[i] -= off; + } + return 0; +} + +static int compat_table_info(const struct xt_table_info *info, + struct xt_table_info *newinfo) +{ + struct ipt_entry *iter; + const void *loc_cpu_entry; + int ret; + + if (!newinfo || !info) + return -EINVAL; + + /* we dont care about newinfo->entries */ + memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); + newinfo->initial_entries = 0; + loc_cpu_entry = info->entries; + ret = xt_compat_init_offsets(AF_INET, info->number); + if (ret) + return ret; + xt_entry_foreach(iter, loc_cpu_entry, info->size) { + ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); + if (ret != 0) + return ret; + } + return 0; +} +#endif + +static int get_info(struct net *net, void __user *user, const int *len) +{ + char name[XT_TABLE_MAXNAMELEN]; + struct xt_table *t; + int ret; + + if (*len != sizeof(struct ipt_getinfo)) + return -EINVAL; + + if (copy_from_user(name, user, sizeof(name)) != 0) + return -EFAULT; + + name[XT_TABLE_MAXNAMELEN-1] = '\0'; +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + xt_compat_lock(AF_INET); +#endif + t = xt_request_find_table_lock(net, AF_INET, name); + if (!IS_ERR(t)) { + struct ipt_getinfo info; + const struct xt_table_info *private = t->private; +#ifdef CONFIG_COMPAT + struct xt_table_info tmp; + + if (in_compat_syscall()) { + ret = compat_table_info(private, &tmp); + xt_compat_flush_offsets(AF_INET); + private = &tmp; + } +#endif + memset(&info, 0, sizeof(info)); + info.valid_hooks = t->valid_hooks; + memcpy(info.hook_entry, private->hook_entry, + sizeof(info.hook_entry)); + memcpy(info.underflow, private->underflow, + sizeof(info.underflow)); + info.num_entries = private->number; + info.size = private->size; + strcpy(info.name, name); + + if (copy_to_user(user, &info, *len) != 0) + ret = -EFAULT; + else + ret = 0; + + xt_table_unlock(t); + module_put(t->me); + } else + ret = PTR_ERR(t); +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + xt_compat_unlock(AF_INET); +#endif + return ret; +} + +static int +get_entries(struct net *net, struct ipt_get_entries __user *uptr, + const int *len) +{ + int ret; + struct ipt_get_entries get; + struct xt_table *t; + + if (*len < sizeof(get)) + return -EINVAL; + if (copy_from_user(&get, uptr, sizeof(get)) != 0) + return -EFAULT; + if (*len != sizeof(struct ipt_get_entries) + get.size) + return -EINVAL; + get.name[sizeof(get.name) - 1] = '\0'; + + t = xt_find_table_lock(net, AF_INET, get.name); + if (!IS_ERR(t)) { + const struct xt_table_info *private = t->private; + if (get.size == private->size) + ret = copy_entries_to_user(private->size, + t, uptr->entrytable); + else + ret = -EAGAIN; + + module_put(t->me); + xt_table_unlock(t); + } else + ret = PTR_ERR(t); + + return ret; +} + +static int +__do_replace(struct net *net, const char *name, unsigned int valid_hooks, + struct xt_table_info *newinfo, unsigned int num_counters, + void __user *counters_ptr) +{ + int ret; + struct xt_table *t; + struct xt_table_info *oldinfo; + struct xt_counters *counters; + struct ipt_entry *iter; + + counters = xt_counters_alloc(num_counters); + if (!counters) { + ret = -ENOMEM; + goto out; + } + + t = xt_request_find_table_lock(net, AF_INET, name); + if (IS_ERR(t)) { + ret = PTR_ERR(t); + goto free_newinfo_counters_untrans; + } + + /* You lied! */ + if (valid_hooks != t->valid_hooks) { + ret = -EINVAL; + goto put_module; + } + + oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); + if (!oldinfo) + goto put_module; + + /* Update module usage count based on number of rules */ + if ((oldinfo->number > oldinfo->initial_entries) || + (newinfo->number <= oldinfo->initial_entries)) + module_put(t->me); + if ((oldinfo->number > oldinfo->initial_entries) && + (newinfo->number <= oldinfo->initial_entries)) + module_put(t->me); + + xt_table_unlock(t); + + get_old_counters(oldinfo, counters); + + /* Decrease module usage counts and free resource */ + xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) + cleanup_entry(iter, net); + + xt_free_table_info(oldinfo); + if (copy_to_user(counters_ptr, counters, + sizeof(struct xt_counters) * num_counters) != 0) { + /* Silent error, can't fail, new table is already in place */ + net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n"); + } + vfree(counters); + return 0; + + put_module: + module_put(t->me); + xt_table_unlock(t); + free_newinfo_counters_untrans: + vfree(counters); + out: + return ret; +} + +static int +do_replace(struct net *net, sockptr_t arg, unsigned int len) +{ + int ret; + struct ipt_replace tmp; + struct xt_table_info *newinfo; + void *loc_cpu_entry; + struct ipt_entry *iter; + + if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) + return -EFAULT; + + /* overflow check */ + if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) + return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + + tmp.name[sizeof(tmp.name)-1] = 0; + + newinfo = xt_alloc_table_info(tmp.size); + if (!newinfo) + return -ENOMEM; + + loc_cpu_entry = newinfo->entries; + if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), + tmp.size) != 0) { + ret = -EFAULT; + goto free_newinfo; + } + + ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); + if (ret != 0) + goto free_newinfo; + + ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, + tmp.num_counters, tmp.counters); + if (ret) + goto free_newinfo_untrans; + return 0; + + free_newinfo_untrans: + xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) + cleanup_entry(iter, net); + free_newinfo: + xt_free_table_info(newinfo); + return ret; +} + +static int +do_add_counters(struct net *net, sockptr_t arg, unsigned int len) +{ + unsigned int i; + struct xt_counters_info tmp; + struct xt_counters *paddc; + struct xt_table *t; + const struct xt_table_info *private; + int ret = 0; + struct ipt_entry *iter; + unsigned int addend; + + paddc = xt_copy_counters(arg, len, &tmp); + if (IS_ERR(paddc)) + return PTR_ERR(paddc); + + t = xt_find_table_lock(net, AF_INET, tmp.name); + if (IS_ERR(t)) { + ret = PTR_ERR(t); + goto free; + } + + local_bh_disable(); + private = t->private; + if (private->number != tmp.num_counters) { + ret = -EINVAL; + goto unlock_up_free; + } + + i = 0; + addend = xt_write_recseq_begin(); + xt_entry_foreach(iter, private->entries, private->size) { + struct xt_counters *tmp; + + tmp = xt_get_this_cpu_counter(&iter->counters); + ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); + ++i; + } + xt_write_recseq_end(addend); + unlock_up_free: + local_bh_enable(); + xt_table_unlock(t); + module_put(t->me); + free: + vfree(paddc); + + return ret; +} + +#ifdef CONFIG_COMPAT +struct compat_ipt_replace { + char name[XT_TABLE_MAXNAMELEN]; + u32 valid_hooks; + u32 num_entries; + u32 size; + u32 hook_entry[NF_INET_NUMHOOKS]; + u32 underflow[NF_INET_NUMHOOKS]; + u32 num_counters; + compat_uptr_t counters; /* struct xt_counters * */ + struct compat_ipt_entry entries[]; +}; + +static int +compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr, + unsigned int *size, struct xt_counters *counters, + unsigned int i) +{ + struct xt_entry_target *t; + struct compat_ipt_entry __user *ce; + u_int16_t target_offset, next_offset; + compat_uint_t origsize; + const struct xt_entry_match *ematch; + int ret = 0; + + origsize = *size; + ce = *dstptr; + if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 || + copy_to_user(&ce->counters, &counters[i], + sizeof(counters[i])) != 0) + return -EFAULT; + + *dstptr += sizeof(struct compat_ipt_entry); + *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); + + xt_ematch_foreach(ematch, e) { + ret = xt_compat_match_to_user(ematch, dstptr, size); + if (ret != 0) + return ret; + } + target_offset = e->target_offset - (origsize - *size); + t = ipt_get_target(e); + ret = xt_compat_target_to_user(t, dstptr, size); + if (ret) + return ret; + next_offset = e->next_offset - (origsize - *size); + if (put_user(target_offset, &ce->target_offset) != 0 || + put_user(next_offset, &ce->next_offset) != 0) + return -EFAULT; + return 0; +} + +static int +compat_find_calc_match(struct xt_entry_match *m, + const struct ipt_ip *ip, + int *size) +{ + struct xt_match *match; + + match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name, + m->u.user.revision); + if (IS_ERR(match)) + return PTR_ERR(match); + + m->u.kernel.match = match; + *size += xt_compat_match_offset(match); + return 0; +} + +static void compat_release_entry(struct compat_ipt_entry *e) +{ + struct xt_entry_target *t; + struct xt_entry_match *ematch; + + /* Cleanup all matches */ + xt_ematch_foreach(ematch, e) + module_put(ematch->u.kernel.match->me); + t = compat_ipt_get_target(e); + module_put(t->u.kernel.target->me); +} + +static int +check_compat_entry_size_and_hooks(struct compat_ipt_entry *e, + struct xt_table_info *newinfo, + unsigned int *size, + const unsigned char *base, + const unsigned char *limit) +{ + struct xt_entry_match *ematch; + struct xt_entry_target *t; + struct xt_target *target; + unsigned int entry_offset; + unsigned int j; + int ret, off; + + if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 || + (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) + return -EINVAL; + + if (e->next_offset < sizeof(struct compat_ipt_entry) + + sizeof(struct compat_xt_entry_target)) + return -EINVAL; + + if (!ip_checkentry(&e->ip)) + return -EINVAL; + + ret = xt_compat_check_entry_offsets(e, e->elems, + e->target_offset, e->next_offset); + if (ret) + return ret; + + off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); + entry_offset = (void *)e - (void *)base; + j = 0; + xt_ematch_foreach(ematch, e) { + ret = compat_find_calc_match(ematch, &e->ip, &off); + if (ret != 0) + goto release_matches; + ++j; + } + + t = compat_ipt_get_target(e); + target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name, + t->u.user.revision); + if (IS_ERR(target)) { + ret = PTR_ERR(target); + goto release_matches; + } + t->u.kernel.target = target; + + off += xt_compat_target_offset(target); + *size += off; + ret = xt_compat_add_offset(AF_INET, entry_offset, off); + if (ret) + goto out; + + return 0; + +out: + module_put(t->u.kernel.target->me); +release_matches: + xt_ematch_foreach(ematch, e) { + if (j-- == 0) + break; + module_put(ematch->u.kernel.match->me); + } + return ret; +} + +static void +compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, + unsigned int *size, + struct xt_table_info *newinfo, unsigned char *base) +{ + struct xt_entry_target *t; + struct ipt_entry *de; + unsigned int origsize; + int h; + struct xt_entry_match *ematch; + + origsize = *size; + de = *dstptr; + memcpy(de, e, sizeof(struct ipt_entry)); + memcpy(&de->counters, &e->counters, sizeof(e->counters)); + + *dstptr += sizeof(struct ipt_entry); + *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); + + xt_ematch_foreach(ematch, e) + xt_compat_match_from_user(ematch, dstptr, size); + + de->target_offset = e->target_offset - (origsize - *size); + t = compat_ipt_get_target(e); + xt_compat_target_from_user(t, dstptr, size); + + de->next_offset = e->next_offset - (origsize - *size); + + for (h = 0; h < NF_INET_NUMHOOKS; h++) { + if ((unsigned char *)de - base < newinfo->hook_entry[h]) + newinfo->hook_entry[h] -= origsize - *size; + if ((unsigned char *)de - base < newinfo->underflow[h]) + newinfo->underflow[h] -= origsize - *size; + } +} + +static int +translate_compat_table(struct net *net, + struct xt_table_info **pinfo, + void **pentry0, + const struct compat_ipt_replace *compatr) +{ + unsigned int i, j; + struct xt_table_info *newinfo, *info; + void *pos, *entry0, *entry1; + struct compat_ipt_entry *iter0; + struct ipt_replace repl; + unsigned int size; + int ret; + + info = *pinfo; + entry0 = *pentry0; + size = compatr->size; + info->number = compatr->num_entries; + + j = 0; + xt_compat_lock(AF_INET); + ret = xt_compat_init_offsets(AF_INET, compatr->num_entries); + if (ret) + goto out_unlock; + /* Walk through entries, checking offsets. */ + xt_entry_foreach(iter0, entry0, compatr->size) { + ret = check_compat_entry_size_and_hooks(iter0, info, &size, + entry0, + entry0 + compatr->size); + if (ret != 0) + goto out_unlock; + ++j; + } + + ret = -EINVAL; + if (j != compatr->num_entries) + goto out_unlock; + + ret = -ENOMEM; + newinfo = xt_alloc_table_info(size); + if (!newinfo) + goto out_unlock; + + memset(newinfo->entries, 0, size); + + newinfo->number = compatr->num_entries; + for (i = 0; i < NF_INET_NUMHOOKS; i++) { + newinfo->hook_entry[i] = compatr->hook_entry[i]; + newinfo->underflow[i] = compatr->underflow[i]; + } + entry1 = newinfo->entries; + pos = entry1; + size = compatr->size; + xt_entry_foreach(iter0, entry0, compatr->size) + compat_copy_entry_from_user(iter0, &pos, &size, + newinfo, entry1); + + /* all module references in entry0 are now gone. + * entry1/newinfo contains a 64bit ruleset that looks exactly as + * generated by 64bit userspace. + * + * Call standard translate_table() to validate all hook_entrys, + * underflows, check for loops, etc. + */ + xt_compat_flush_offsets(AF_INET); + xt_compat_unlock(AF_INET); + + memcpy(&repl, compatr, sizeof(*compatr)); + + for (i = 0; i < NF_INET_NUMHOOKS; i++) { + repl.hook_entry[i] = newinfo->hook_entry[i]; + repl.underflow[i] = newinfo->underflow[i]; + } + + repl.num_counters = 0; + repl.counters = NULL; + repl.size = newinfo->size; + ret = translate_table(net, newinfo, entry1, &repl); + if (ret) + goto free_newinfo; + + *pinfo = newinfo; + *pentry0 = entry1; + xt_free_table_info(info); + return 0; + +free_newinfo: + xt_free_table_info(newinfo); + return ret; +out_unlock: + xt_compat_flush_offsets(AF_INET); + xt_compat_unlock(AF_INET); + xt_entry_foreach(iter0, entry0, compatr->size) { + if (j-- == 0) + break; + compat_release_entry(iter0); + } + return ret; +} + +static int +compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) +{ + int ret; + struct compat_ipt_replace tmp; + struct xt_table_info *newinfo; + void *loc_cpu_entry; + struct ipt_entry *iter; + + if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) + return -EFAULT; + + /* overflow check */ + if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) + return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + + tmp.name[sizeof(tmp.name)-1] = 0; + + newinfo = xt_alloc_table_info(tmp.size); + if (!newinfo) + return -ENOMEM; + + loc_cpu_entry = newinfo->entries; + if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), + tmp.size) != 0) { + ret = -EFAULT; + goto free_newinfo; + } + + ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); + if (ret != 0) + goto free_newinfo; + + ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, + tmp.num_counters, compat_ptr(tmp.counters)); + if (ret) + goto free_newinfo_untrans; + return 0; + + free_newinfo_untrans: + xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) + cleanup_entry(iter, net); + free_newinfo: + xt_free_table_info(newinfo); + return ret; +} + +struct compat_ipt_get_entries { + char name[XT_TABLE_MAXNAMELEN]; + compat_uint_t size; + struct compat_ipt_entry entrytable[]; +}; + +static int +compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, + void __user *userptr) +{ + struct xt_counters *counters; + const struct xt_table_info *private = table->private; + void __user *pos; + unsigned int size; + int ret = 0; + unsigned int i = 0; + struct ipt_entry *iter; + + counters = alloc_counters(table); + if (IS_ERR(counters)) + return PTR_ERR(counters); + + pos = userptr; + size = total_size; + xt_entry_foreach(iter, private->entries, total_size) { + ret = compat_copy_entry_to_user(iter, &pos, + &size, counters, i++); + if (ret != 0) + break; + } + + vfree(counters); + return ret; +} + +static int +compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr, + int *len) +{ + int ret; + struct compat_ipt_get_entries get; + struct xt_table *t; + + if (*len < sizeof(get)) + return -EINVAL; + + if (copy_from_user(&get, uptr, sizeof(get)) != 0) + return -EFAULT; + + if (*len != sizeof(struct compat_ipt_get_entries) + get.size) + return -EINVAL; + + get.name[sizeof(get.name) - 1] = '\0'; + + xt_compat_lock(AF_INET); + t = xt_find_table_lock(net, AF_INET, get.name); + if (!IS_ERR(t)) { + const struct xt_table_info *private = t->private; + struct xt_table_info info; + ret = compat_table_info(private, &info); + if (!ret && get.size == info.size) + ret = compat_copy_entries_to_user(private->size, + t, uptr->entrytable); + else if (!ret) + ret = -EAGAIN; + + xt_compat_flush_offsets(AF_INET); + module_put(t->me); + xt_table_unlock(t); + } else + ret = PTR_ERR(t); + + xt_compat_unlock(AF_INET); + return ret; +} +#endif + +static int +do_ipt_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len) +{ + int ret; + + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + switch (cmd) { + case IPT_SO_SET_REPLACE: +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = compat_do_replace(sock_net(sk), arg, len); + else +#endif + ret = do_replace(sock_net(sk), arg, len); + break; + + case IPT_SO_SET_ADD_COUNTERS: + ret = do_add_counters(sock_net(sk), arg, len); + break; + + default: + ret = -EINVAL; + } + + return ret; +} + +static int +do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) +{ + int ret; + + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + switch (cmd) { + case IPT_SO_GET_INFO: + ret = get_info(sock_net(sk), user, len); + break; + + case IPT_SO_GET_ENTRIES: +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = compat_get_entries(sock_net(sk), user, len); + else +#endif + ret = get_entries(sock_net(sk), user, len); + break; + + case IPT_SO_GET_REVISION_MATCH: + case IPT_SO_GET_REVISION_TARGET: { + struct xt_get_revision rev; + int target; + + if (*len != sizeof(rev)) { + ret = -EINVAL; + break; + } + if (copy_from_user(&rev, user, sizeof(rev)) != 0) { + ret = -EFAULT; + break; + } + rev.name[sizeof(rev.name)-1] = 0; + + if (cmd == IPT_SO_GET_REVISION_TARGET) + target = 1; + else + target = 0; + + try_then_request_module(xt_find_revision(AF_INET, rev.name, + rev.revision, + target, &ret), + "ipt_%s", rev.name); + break; + } + + default: + ret = -EINVAL; + } + + return ret; +} + +static void __ipt_unregister_table(struct net *net, struct xt_table *table) +{ + struct xt_table_info *private; + void *loc_cpu_entry; + struct module *table_owner = table->me; + struct ipt_entry *iter; + + private = xt_unregister_table(table); + + /* Decrease module usage counts and free resources */ + loc_cpu_entry = private->entries; + xt_entry_foreach(iter, loc_cpu_entry, private->size) + cleanup_entry(iter, net); + if (private->number > private->initial_entries) + module_put(table_owner); + xt_free_table_info(private); +} + +int ipt_register_table(struct net *net, const struct xt_table *table, + const struct ipt_replace *repl, + const struct nf_hook_ops *ops, struct xt_table **res) +{ + int ret; + struct xt_table_info *newinfo; + struct xt_table_info bootstrap = {0}; + void *loc_cpu_entry; + struct xt_table *new_table; + + newinfo = xt_alloc_table_info(repl->size); + if (!newinfo) + return -ENOMEM; + + loc_cpu_entry = newinfo->entries; + memcpy(loc_cpu_entry, repl->entries, repl->size); + + ret = translate_table(net, newinfo, loc_cpu_entry, repl); + if (ret != 0) + goto out_free; + + new_table = xt_register_table(net, table, &bootstrap, newinfo); + if (IS_ERR(new_table)) { + ret = PTR_ERR(new_table); + goto out_free; + } + + /* set res now, will see skbs right after nf_register_net_hooks */ + WRITE_ONCE(*res, new_table); + if (!ops) + return 0; + + ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); + if (ret != 0) { + __ipt_unregister_table(net, new_table); + *res = NULL; + } + + return ret; + +out_free: + xt_free_table_info(newinfo); + return ret; +} + +void ipt_unregister_table_pre_exit(struct net *net, struct xt_table *table, + const struct nf_hook_ops *ops) +{ + nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); +} + +void ipt_unregister_table_exit(struct net *net, struct xt_table *table) +{ + __ipt_unregister_table(net, table); +} + +void ipt_unregister_table(struct net *net, struct xt_table *table, + const struct nf_hook_ops *ops) +{ + if (ops) + ipt_unregister_table_pre_exit(net, table, ops); + __ipt_unregister_table(net, table); +} + +/* Returns 1 if the type and code is matched by the range, 0 otherwise */ +static inline bool +icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, + u_int8_t type, u_int8_t code, + bool invert) +{ + return ((test_type == 0xFF) || + (type == test_type && code >= min_code && code <= max_code)) + ^ invert; +} + +static bool +icmp_match(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct icmphdr *ic; + struct icmphdr _icmph; + const struct ipt_icmp *icmpinfo = par->matchinfo; + + /* Must not be a fragment. */ + if (par->fragoff != 0) + return false; + + ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); + if (ic == NULL) { + /* We've been asked to examine this packet, and we + * can't. Hence, no choice but to drop. + */ + par->hotdrop = true; + return false; + } + + return icmp_type_code_match(icmpinfo->type, + icmpinfo->code[0], + icmpinfo->code[1], + ic->type, ic->code, + !!(icmpinfo->invflags&IPT_ICMP_INV)); +} + +static int icmp_checkentry(const struct xt_mtchk_param *par) +{ + const struct ipt_icmp *icmpinfo = par->matchinfo; + + /* Must specify no unknown invflags */ + return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0; +} + +static struct xt_target ipt_builtin_tg[] __read_mostly = { + { + .name = XT_STANDARD_TARGET, + .targetsize = sizeof(int), + .family = NFPROTO_IPV4, +#ifdef CONFIG_COMPAT + .compatsize = sizeof(compat_int_t), + .compat_from_user = compat_standard_from_user, + .compat_to_user = compat_standard_to_user, +#endif + }, + { + .name = XT_ERROR_TARGET, + .target = ipt_error, + .targetsize = XT_FUNCTION_MAXNAMELEN, + .family = NFPROTO_IPV4, + }, +}; + +static struct nf_sockopt_ops ipt_sockopts = { + .pf = PF_INET, + .set_optmin = IPT_BASE_CTL, + .set_optmax = IPT_SO_SET_MAX+1, + .set = do_ipt_set_ctl, + .get_optmin = IPT_BASE_CTL, + .get_optmax = IPT_SO_GET_MAX+1, + .get = do_ipt_get_ctl, + .owner = THIS_MODULE, +}; + +static struct xt_match ipt_builtin_mt[] __read_mostly = { + { + .name = "icmp", + .match = icmp_match, + .matchsize = sizeof(struct ipt_icmp), + .checkentry = icmp_checkentry, + .proto = IPPROTO_ICMP, + .family = NFPROTO_IPV4, + .me = THIS_MODULE, + }, +}; + +static int __net_init ip_tables_net_init(struct net *net) +{ + return xt_proto_init(net, NFPROTO_IPV4); +} + +static void __net_exit ip_tables_net_exit(struct net *net) +{ + xt_proto_fini(net, NFPROTO_IPV4); +} + +static struct pernet_operations ip_tables_net_ops = { + .init = ip_tables_net_init, + .exit = ip_tables_net_exit, +}; + +static int __init ip_tables_init(void) +{ + int ret; + + ret = register_pernet_subsys(&ip_tables_net_ops); + if (ret < 0) + goto err1; + + /* No one else will be downing sem now, so we won't sleep */ + ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); + if (ret < 0) + goto err2; + ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt)); + if (ret < 0) + goto err4; + + /* Register setsockopt */ + ret = nf_register_sockopt(&ipt_sockopts); + if (ret < 0) + goto err5; + + return 0; + +err5: + xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt)); +err4: + xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); +err2: + unregister_pernet_subsys(&ip_tables_net_ops); +err1: + return ret; +} + +static void __exit ip_tables_fini(void) +{ + nf_unregister_sockopt(&ipt_sockopts); + + xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt)); + xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); + unregister_pernet_subsys(&ip_tables_net_ops); +} + +EXPORT_SYMBOL(ipt_register_table); +EXPORT_SYMBOL(ipt_unregister_table); +EXPORT_SYMBOL(ipt_unregister_table_pre_exit); +EXPORT_SYMBOL(ipt_unregister_table_exit); +EXPORT_SYMBOL(ipt_do_table); +module_init(ip_tables_init); +module_exit(ip_tables_fini); diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c new file mode 100644 index 000000000..77e3b67e8 --- /dev/null +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -0,0 +1,911 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Cluster IP hashmark target + * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> + * based on ideas of Fabio Olive Leite <olive@unixforge.org> + * + * Development of this code funded by SuSE Linux AG, https://www.suse.com/ + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/jhash.h> +#include <linux/bitops.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/icmp.h> +#include <linux/if_arp.h> +#include <linux/seq_file.h> +#include <linux/refcount.h> +#include <linux/netfilter_arp.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv4/ipt_CLUSTERIP.h> +#include <net/netfilter/nf_conntrack.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/checksum.h> +#include <net/ip.h> + +#define CLUSTERIP_VERSION "0.8" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_DESCRIPTION("Xtables: CLUSTERIP target"); + +struct clusterip_config { + struct list_head list; /* list of all configs */ + refcount_t refcount; /* reference count */ + refcount_t entries; /* number of entries/rules + * referencing us */ + + __be32 clusterip; /* the IP address */ + u_int8_t clustermac[ETH_ALEN]; /* the MAC address */ + int ifindex; /* device ifindex */ + u_int16_t num_total_nodes; /* total number of nodes */ + unsigned long local_nodes; /* node number array */ + +#ifdef CONFIG_PROC_FS + struct proc_dir_entry *pde; /* proc dir entry */ +#endif + enum clusterip_hashmode hash_mode; /* which hashing mode */ + u_int32_t hash_initval; /* hash initialization */ + struct rcu_head rcu; /* for call_rcu */ + struct net *net; /* netns for pernet list */ + char ifname[IFNAMSIZ]; /* device ifname */ +}; + +#ifdef CONFIG_PROC_FS +static const struct proc_ops clusterip_proc_ops; +#endif + +struct clusterip_net { + struct list_head configs; + /* lock protects the configs list */ + spinlock_t lock; + +#ifdef CONFIG_PROC_FS + struct proc_dir_entry *procdir; + /* mutex protects the config->pde*/ + struct mutex mutex; +#endif +}; + +static unsigned int clusterip_net_id __read_mostly; +static inline struct clusterip_net *clusterip_pernet(struct net *net) +{ + return net_generic(net, clusterip_net_id); +} + +static inline void +clusterip_config_get(struct clusterip_config *c) +{ + refcount_inc(&c->refcount); +} + +static void clusterip_config_rcu_free(struct rcu_head *head) +{ + struct clusterip_config *config; + struct net_device *dev; + + config = container_of(head, struct clusterip_config, rcu); + dev = dev_get_by_name(config->net, config->ifname); + if (dev) { + dev_mc_del(dev, config->clustermac); + dev_put(dev); + } + kfree(config); +} + +static inline void +clusterip_config_put(struct clusterip_config *c) +{ + if (refcount_dec_and_test(&c->refcount)) + call_rcu(&c->rcu, clusterip_config_rcu_free); +} + +/* decrease the count of entries using/referencing this config. If last + * entry(rule) is removed, remove the config from lists, but don't free it + * yet, since proc-files could still be holding references */ +static inline void +clusterip_config_entry_put(struct clusterip_config *c) +{ + struct clusterip_net *cn = clusterip_pernet(c->net); + + local_bh_disable(); + if (refcount_dec_and_lock(&c->entries, &cn->lock)) { + list_del_rcu(&c->list); + spin_unlock(&cn->lock); + local_bh_enable(); + /* In case anyone still accesses the file, the open/close + * functions are also incrementing the refcount on their own, + * so it's safe to remove the entry even if it's in use. */ +#ifdef CONFIG_PROC_FS + mutex_lock(&cn->mutex); + if (cn->procdir) + proc_remove(c->pde); + mutex_unlock(&cn->mutex); +#endif + return; + } + local_bh_enable(); +} + +static struct clusterip_config * +__clusterip_config_find(struct net *net, __be32 clusterip) +{ + struct clusterip_config *c; + struct clusterip_net *cn = clusterip_pernet(net); + + list_for_each_entry_rcu(c, &cn->configs, list) { + if (c->clusterip == clusterip) + return c; + } + + return NULL; +} + +static inline struct clusterip_config * +clusterip_config_find_get(struct net *net, __be32 clusterip, int entry) +{ + struct clusterip_config *c; + + rcu_read_lock_bh(); + c = __clusterip_config_find(net, clusterip); + if (c) { +#ifdef CONFIG_PROC_FS + if (!c->pde) + c = NULL; + else +#endif + if (unlikely(!refcount_inc_not_zero(&c->refcount))) + c = NULL; + else if (entry) { + if (unlikely(!refcount_inc_not_zero(&c->entries))) { + clusterip_config_put(c); + c = NULL; + } + } + } + rcu_read_unlock_bh(); + + return c; +} + +static void +clusterip_config_init_nodelist(struct clusterip_config *c, + const struct ipt_clusterip_tgt_info *i) +{ + int n; + + for (n = 0; n < i->num_local_nodes; n++) + set_bit(i->local_nodes[n] - 1, &c->local_nodes); +} + +static int +clusterip_netdev_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct net *net = dev_net(dev); + struct clusterip_net *cn = clusterip_pernet(net); + struct clusterip_config *c; + + spin_lock_bh(&cn->lock); + list_for_each_entry_rcu(c, &cn->configs, list) { + switch (event) { + case NETDEV_REGISTER: + if (!strcmp(dev->name, c->ifname)) { + c->ifindex = dev->ifindex; + dev_mc_add(dev, c->clustermac); + } + break; + case NETDEV_UNREGISTER: + if (dev->ifindex == c->ifindex) { + dev_mc_del(dev, c->clustermac); + c->ifindex = -1; + } + break; + case NETDEV_CHANGENAME: + if (!strcmp(dev->name, c->ifname)) { + c->ifindex = dev->ifindex; + dev_mc_add(dev, c->clustermac); + } else if (dev->ifindex == c->ifindex) { + dev_mc_del(dev, c->clustermac); + c->ifindex = -1; + } + break; + } + } + spin_unlock_bh(&cn->lock); + + return NOTIFY_DONE; +} + +static struct clusterip_config * +clusterip_config_init(struct net *net, const struct ipt_clusterip_tgt_info *i, + __be32 ip, const char *iniface) +{ + struct clusterip_net *cn = clusterip_pernet(net); + struct clusterip_config *c; + struct net_device *dev; + int err; + + if (iniface[0] == '\0') { + pr_info("Please specify an interface name\n"); + return ERR_PTR(-EINVAL); + } + + c = kzalloc(sizeof(*c), GFP_ATOMIC); + if (!c) + return ERR_PTR(-ENOMEM); + + dev = dev_get_by_name(net, iniface); + if (!dev) { + pr_info("no such interface %s\n", iniface); + kfree(c); + return ERR_PTR(-ENOENT); + } + c->ifindex = dev->ifindex; + strcpy(c->ifname, dev->name); + memcpy(&c->clustermac, &i->clustermac, ETH_ALEN); + dev_mc_add(dev, c->clustermac); + dev_put(dev); + + c->clusterip = ip; + c->num_total_nodes = i->num_total_nodes; + clusterip_config_init_nodelist(c, i); + c->hash_mode = i->hash_mode; + c->hash_initval = i->hash_initval; + c->net = net; + refcount_set(&c->refcount, 1); + + spin_lock_bh(&cn->lock); + if (__clusterip_config_find(net, ip)) { + err = -EBUSY; + goto out_config_put; + } + + list_add_rcu(&c->list, &cn->configs); + spin_unlock_bh(&cn->lock); + +#ifdef CONFIG_PROC_FS + { + char buffer[16]; + + /* create proc dir entry */ + sprintf(buffer, "%pI4", &ip); + mutex_lock(&cn->mutex); + c->pde = proc_create_data(buffer, 0600, + cn->procdir, + &clusterip_proc_ops, c); + mutex_unlock(&cn->mutex); + if (!c->pde) { + err = -ENOMEM; + goto err; + } + } +#endif + + refcount_set(&c->entries, 1); + return c; + +#ifdef CONFIG_PROC_FS +err: +#endif + spin_lock_bh(&cn->lock); + list_del_rcu(&c->list); +out_config_put: + spin_unlock_bh(&cn->lock); + clusterip_config_put(c); + return ERR_PTR(err); +} + +#ifdef CONFIG_PROC_FS +static int +clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum) +{ + + if (nodenum == 0 || + nodenum > c->num_total_nodes) + return 1; + + /* check if we already have this number in our bitfield */ + if (test_and_set_bit(nodenum - 1, &c->local_nodes)) + return 1; + + return 0; +} + +static bool +clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum) +{ + if (nodenum == 0 || + nodenum > c->num_total_nodes) + return true; + + if (test_and_clear_bit(nodenum - 1, &c->local_nodes)) + return false; + + return true; +} +#endif + +static inline u_int32_t +clusterip_hashfn(const struct sk_buff *skb, + const struct clusterip_config *config) +{ + const struct iphdr *iph = ip_hdr(skb); + unsigned long hashval; + u_int16_t sport = 0, dport = 0; + int poff; + + poff = proto_ports_offset(iph->protocol); + if (poff >= 0) { + const u_int16_t *ports; + u16 _ports[2]; + + ports = skb_header_pointer(skb, iph->ihl * 4 + poff, 4, _ports); + if (ports) { + sport = ports[0]; + dport = ports[1]; + } + } else { + net_info_ratelimited("unknown protocol %u\n", iph->protocol); + } + + switch (config->hash_mode) { + case CLUSTERIP_HASHMODE_SIP: + hashval = jhash_1word(ntohl(iph->saddr), + config->hash_initval); + break; + case CLUSTERIP_HASHMODE_SIP_SPT: + hashval = jhash_2words(ntohl(iph->saddr), sport, + config->hash_initval); + break; + case CLUSTERIP_HASHMODE_SIP_SPT_DPT: + hashval = jhash_3words(ntohl(iph->saddr), sport, dport, + config->hash_initval); + break; + default: + /* to make gcc happy */ + hashval = 0; + /* This cannot happen, unless the check function wasn't called + * at rule load time */ + pr_info("unknown mode %u\n", config->hash_mode); + BUG(); + break; + } + + /* node numbers are 1..n, not 0..n */ + return reciprocal_scale(hashval, config->num_total_nodes) + 1; +} + +static inline int +clusterip_responsible(const struct clusterip_config *config, u_int32_t hash) +{ + return test_bit(hash - 1, &config->local_nodes); +} + +/*********************************************************************** + * IPTABLES TARGET + ***********************************************************************/ + +static unsigned int +clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo; + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + u_int32_t hash; + + /* don't need to clusterip_config_get() here, since refcount + * is only decremented by destroy() - and ip_tables guarantees + * that the ->target() function isn't called after ->destroy() */ + + ct = nf_ct_get(skb, &ctinfo); + if (ct == NULL) + return NF_DROP; + + /* special case: ICMP error handling. conntrack distinguishes between + * error messages (RELATED) and information requests (see below) */ + if (ip_hdr(skb)->protocol == IPPROTO_ICMP && + (ctinfo == IP_CT_RELATED || + ctinfo == IP_CT_RELATED_REPLY)) + return XT_CONTINUE; + + /* nf_conntrack_proto_icmp guarantees us that we only have ICMP_ECHO, + * TIMESTAMP, INFO_REQUEST or ICMP_ADDRESS type icmp packets from here + * on, which all have an ID field [relevant for hashing]. */ + + hash = clusterip_hashfn(skb, cipinfo->config); + + switch (ctinfo) { + case IP_CT_NEW: + WRITE_ONCE(ct->mark, hash); + break; + case IP_CT_RELATED: + case IP_CT_RELATED_REPLY: + /* FIXME: we don't handle expectations at the moment. + * They can arrive on a different node than + * the master connection (e.g. FTP passive mode) */ + case IP_CT_ESTABLISHED: + case IP_CT_ESTABLISHED_REPLY: + break; + default: /* Prevent gcc warnings */ + break; + } + +#ifdef DEBUG + nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); +#endif + pr_debug("hash=%u ct_hash=%u ", hash, READ_ONCE(ct->mark)); + if (!clusterip_responsible(cipinfo->config, hash)) { + pr_debug("not responsible\n"); + return NF_DROP; + } + pr_debug("responsible\n"); + + /* despite being received via linklayer multicast, this is + * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */ + skb->pkt_type = PACKET_HOST; + + return XT_CONTINUE; +} + +static int clusterip_tg_check(const struct xt_tgchk_param *par) +{ + struct ipt_clusterip_tgt_info *cipinfo = par->targinfo; + const struct ipt_entry *e = par->entryinfo; + struct clusterip_config *config; + int ret, i; + + if (par->nft_compat) { + pr_err("cannot use CLUSTERIP target from nftables compat\n"); + return -EOPNOTSUPP; + } + + if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP && + cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT && + cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) { + pr_info("unknown mode %u\n", cipinfo->hash_mode); + return -EINVAL; + + } + if (e->ip.dmsk.s_addr != htonl(0xffffffff) || + e->ip.dst.s_addr == 0) { + pr_info("Please specify destination IP\n"); + return -EINVAL; + } + if (cipinfo->num_local_nodes > ARRAY_SIZE(cipinfo->local_nodes)) { + pr_info("bad num_local_nodes %u\n", cipinfo->num_local_nodes); + return -EINVAL; + } + for (i = 0; i < cipinfo->num_local_nodes; i++) { + if (cipinfo->local_nodes[i] - 1 >= + sizeof(config->local_nodes) * 8) { + pr_info("bad local_nodes[%d] %u\n", + i, cipinfo->local_nodes[i]); + return -EINVAL; + } + } + + config = clusterip_config_find_get(par->net, e->ip.dst.s_addr, 1); + if (!config) { + if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) { + pr_info("no config found for %pI4, need 'new'\n", + &e->ip.dst.s_addr); + return -EINVAL; + } else { + config = clusterip_config_init(par->net, cipinfo, + e->ip.dst.s_addr, + e->ip.iniface); + if (IS_ERR(config)) + return PTR_ERR(config); + } + } else if (memcmp(&config->clustermac, &cipinfo->clustermac, ETH_ALEN)) { + clusterip_config_entry_put(config); + clusterip_config_put(config); + return -EINVAL; + } + + ret = nf_ct_netns_get(par->net, par->family); + if (ret < 0) { + pr_info("cannot load conntrack support for proto=%u\n", + par->family); + clusterip_config_entry_put(config); + clusterip_config_put(config); + return ret; + } + + if (!par->net->xt.clusterip_deprecated_warning) { + pr_info("ipt_CLUSTERIP is deprecated and it will removed soon, " + "use xt_cluster instead\n"); + par->net->xt.clusterip_deprecated_warning = true; + } + + cipinfo->config = config; + return ret; +} + +/* drop reference count of cluster config when rule is deleted */ +static void clusterip_tg_destroy(const struct xt_tgdtor_param *par) +{ + const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo; + + /* if no more entries are referencing the config, remove it + * from the list and destroy the proc entry */ + clusterip_config_entry_put(cipinfo->config); + + clusterip_config_put(cipinfo->config); + + nf_ct_netns_put(par->net, par->family); +} + +#ifdef CONFIG_COMPAT +struct compat_ipt_clusterip_tgt_info +{ + u_int32_t flags; + u_int8_t clustermac[6]; + u_int16_t num_total_nodes; + u_int16_t num_local_nodes; + u_int16_t local_nodes[CLUSTERIP_MAX_NODES]; + u_int32_t hash_mode; + u_int32_t hash_initval; + compat_uptr_t config; +}; +#endif /* CONFIG_COMPAT */ + +static struct xt_target clusterip_tg_reg __read_mostly = { + .name = "CLUSTERIP", + .family = NFPROTO_IPV4, + .target = clusterip_tg, + .checkentry = clusterip_tg_check, + .destroy = clusterip_tg_destroy, + .targetsize = sizeof(struct ipt_clusterip_tgt_info), + .usersize = offsetof(struct ipt_clusterip_tgt_info, config), +#ifdef CONFIG_COMPAT + .compatsize = sizeof(struct compat_ipt_clusterip_tgt_info), +#endif /* CONFIG_COMPAT */ + .me = THIS_MODULE +}; + + +/*********************************************************************** + * ARP MANGLING CODE + ***********************************************************************/ + +/* hardcoded for 48bit ethernet and 32bit ipv4 addresses */ +struct arp_payload { + u_int8_t src_hw[ETH_ALEN]; + __be32 src_ip; + u_int8_t dst_hw[ETH_ALEN]; + __be32 dst_ip; +} __packed; + +#ifdef DEBUG +static void arp_print(struct arp_payload *payload) +{ +#define HBUFFERLEN 30 + char hbuffer[HBUFFERLEN]; + int j, k; + + for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < ETH_ALEN; j++) { + hbuffer[k++] = hex_asc_hi(payload->src_hw[j]); + hbuffer[k++] = hex_asc_lo(payload->src_hw[j]); + hbuffer[k++] = ':'; + } + hbuffer[--k] = '\0'; + + pr_debug("src %pI4@%s, dst %pI4\n", + &payload->src_ip, hbuffer, &payload->dst_ip); +} +#endif + +static unsigned int +arp_mangle(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct arphdr *arp = arp_hdr(skb); + struct arp_payload *payload; + struct clusterip_config *c; + struct net *net = state->net; + + /* we don't care about non-ethernet and non-ipv4 ARP */ + if (arp->ar_hrd != htons(ARPHRD_ETHER) || + arp->ar_pro != htons(ETH_P_IP) || + arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN) + return NF_ACCEPT; + + /* we only want to mangle arp requests and replies */ + if (arp->ar_op != htons(ARPOP_REPLY) && + arp->ar_op != htons(ARPOP_REQUEST)) + return NF_ACCEPT; + + payload = (void *)(arp+1); + + /* if there is no clusterip configuration for the arp reply's + * source ip, we don't want to mangle it */ + c = clusterip_config_find_get(net, payload->src_ip, 0); + if (!c) + return NF_ACCEPT; + + /* normally the linux kernel always replies to arp queries of + * addresses on different interfacs. However, in the CLUSTERIP case + * this wouldn't work, since we didn't subscribe the mcast group on + * other interfaces */ + if (c->ifindex != state->out->ifindex) { + pr_debug("not mangling arp reply on different interface: cip'%d'-skb'%d'\n", + c->ifindex, state->out->ifindex); + clusterip_config_put(c); + return NF_ACCEPT; + } + + /* mangle reply hardware address */ + memcpy(payload->src_hw, c->clustermac, arp->ar_hln); + +#ifdef DEBUG + pr_debug("mangled arp reply: "); + arp_print(payload); +#endif + + clusterip_config_put(c); + + return NF_ACCEPT; +} + +static const struct nf_hook_ops cip_arp_ops = { + .hook = arp_mangle, + .pf = NFPROTO_ARP, + .hooknum = NF_ARP_OUT, + .priority = -1 +}; + +/*********************************************************************** + * PROC DIR HANDLING + ***********************************************************************/ + +#ifdef CONFIG_PROC_FS + +struct clusterip_seq_position { + unsigned int pos; /* position */ + unsigned int weight; /* number of bits set == size */ + unsigned int bit; /* current bit */ + unsigned long val; /* current value */ +}; + +static void *clusterip_seq_start(struct seq_file *s, loff_t *pos) +{ + struct clusterip_config *c = s->private; + unsigned int weight; + u_int32_t local_nodes; + struct clusterip_seq_position *idx; + + /* FIXME: possible race */ + local_nodes = c->local_nodes; + weight = hweight32(local_nodes); + if (*pos >= weight) + return NULL; + + idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL); + if (!idx) + return ERR_PTR(-ENOMEM); + + idx->pos = *pos; + idx->weight = weight; + idx->bit = ffs(local_nodes); + idx->val = local_nodes; + clear_bit(idx->bit - 1, &idx->val); + + return idx; +} + +static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct clusterip_seq_position *idx = v; + + *pos = ++idx->pos; + if (*pos >= idx->weight) { + kfree(v); + return NULL; + } + idx->bit = ffs(idx->val); + clear_bit(idx->bit - 1, &idx->val); + return idx; +} + +static void clusterip_seq_stop(struct seq_file *s, void *v) +{ + if (!IS_ERR(v)) + kfree(v); +} + +static int clusterip_seq_show(struct seq_file *s, void *v) +{ + struct clusterip_seq_position *idx = v; + + if (idx->pos != 0) + seq_putc(s, ','); + + seq_printf(s, "%u", idx->bit); + + if (idx->pos == idx->weight - 1) + seq_putc(s, '\n'); + + return 0; +} + +static const struct seq_operations clusterip_seq_ops = { + .start = clusterip_seq_start, + .next = clusterip_seq_next, + .stop = clusterip_seq_stop, + .show = clusterip_seq_show, +}; + +static int clusterip_proc_open(struct inode *inode, struct file *file) +{ + int ret = seq_open(file, &clusterip_seq_ops); + + if (!ret) { + struct seq_file *sf = file->private_data; + struct clusterip_config *c = PDE_DATA(inode); + + sf->private = c; + + clusterip_config_get(c); + } + + return ret; +} + +static int clusterip_proc_release(struct inode *inode, struct file *file) +{ + struct clusterip_config *c = PDE_DATA(inode); + int ret; + + ret = seq_release(inode, file); + + if (!ret) + clusterip_config_put(c); + + return ret; +} + +static ssize_t clusterip_proc_write(struct file *file, const char __user *input, + size_t size, loff_t *ofs) +{ + struct clusterip_config *c = PDE_DATA(file_inode(file)); +#define PROC_WRITELEN 10 + char buffer[PROC_WRITELEN+1]; + unsigned long nodenum; + int rc; + + if (size > PROC_WRITELEN) + return -EIO; + if (copy_from_user(buffer, input, size)) + return -EFAULT; + buffer[size] = 0; + + if (*buffer == '+') { + rc = kstrtoul(buffer+1, 10, &nodenum); + if (rc) + return rc; + if (clusterip_add_node(c, nodenum)) + return -ENOMEM; + } else if (*buffer == '-') { + rc = kstrtoul(buffer+1, 10, &nodenum); + if (rc) + return rc; + if (clusterip_del_node(c, nodenum)) + return -ENOENT; + } else + return -EIO; + + return size; +} + +static const struct proc_ops clusterip_proc_ops = { + .proc_open = clusterip_proc_open, + .proc_read = seq_read, + .proc_write = clusterip_proc_write, + .proc_lseek = seq_lseek, + .proc_release = clusterip_proc_release, +}; + +#endif /* CONFIG_PROC_FS */ + +static int clusterip_net_init(struct net *net) +{ + struct clusterip_net *cn = clusterip_pernet(net); + int ret; + + INIT_LIST_HEAD(&cn->configs); + + spin_lock_init(&cn->lock); + + ret = nf_register_net_hook(net, &cip_arp_ops); + if (ret < 0) + return ret; + +#ifdef CONFIG_PROC_FS + cn->procdir = proc_mkdir("ipt_CLUSTERIP", net->proc_net); + if (!cn->procdir) { + nf_unregister_net_hook(net, &cip_arp_ops); + pr_err("Unable to proc dir entry\n"); + return -ENOMEM; + } + mutex_init(&cn->mutex); +#endif /* CONFIG_PROC_FS */ + + return 0; +} + +static void clusterip_net_exit(struct net *net) +{ +#ifdef CONFIG_PROC_FS + struct clusterip_net *cn = clusterip_pernet(net); + + mutex_lock(&cn->mutex); + proc_remove(cn->procdir); + cn->procdir = NULL; + mutex_unlock(&cn->mutex); +#endif + nf_unregister_net_hook(net, &cip_arp_ops); +} + +static struct pernet_operations clusterip_net_ops = { + .init = clusterip_net_init, + .exit = clusterip_net_exit, + .id = &clusterip_net_id, + .size = sizeof(struct clusterip_net), +}; + +static struct notifier_block cip_netdev_notifier = { + .notifier_call = clusterip_netdev_event +}; + +static int __init clusterip_tg_init(void) +{ + int ret; + + ret = register_pernet_subsys(&clusterip_net_ops); + if (ret < 0) + return ret; + + ret = xt_register_target(&clusterip_tg_reg); + if (ret < 0) + goto cleanup_subsys; + + ret = register_netdevice_notifier(&cip_netdev_notifier); + if (ret < 0) + goto unregister_target; + + pr_info("ClusterIP Version %s loaded successfully\n", + CLUSTERIP_VERSION); + + return 0; + +unregister_target: + xt_unregister_target(&clusterip_tg_reg); +cleanup_subsys: + unregister_pernet_subsys(&clusterip_net_ops); + return ret; +} + +static void __exit clusterip_tg_exit(void) +{ + pr_info("ClusterIP Version %s unloading\n", CLUSTERIP_VERSION); + + unregister_netdevice_notifier(&cip_netdev_notifier); + xt_unregister_target(&clusterip_tg_reg); + unregister_pernet_subsys(&clusterip_net_ops); + + /* Wait for completion of call_rcu()'s (clusterip_config_rcu_free) */ + rcu_barrier(); +} + +module_init(clusterip_tg_init); +module_exit(clusterip_tg_exit); diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c new file mode 100644 index 000000000..5930d3b02 --- /dev/null +++ b/net/ipv4/netfilter/ipt_ECN.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* iptables module for the IPv4 and TCP ECN bits, Version 1.5 + * + * (C) 2002 by Harald Welte <laforge@netfilter.org> +*/ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/in.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <net/ip.h> +#include <linux/tcp.h> +#include <net/checksum.h> + +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv4/ipt_ECN.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag modification"); + +/* set ECT codepoint from IP header. + * return false if there was an error. */ +static inline bool +set_ect_ip(struct sk_buff *skb, const struct ipt_ECN_info *einfo) +{ + struct iphdr *iph = ip_hdr(skb); + + if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) { + __u8 oldtos; + if (skb_ensure_writable(skb, sizeof(struct iphdr))) + return false; + iph = ip_hdr(skb); + oldtos = iph->tos; + iph->tos &= ~IPT_ECN_IP_MASK; + iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK); + csum_replace2(&iph->check, htons(oldtos), htons(iph->tos)); + } + return true; +} + +/* Return false if there was an error. */ +static inline bool +set_ect_tcp(struct sk_buff *skb, const struct ipt_ECN_info *einfo) +{ + struct tcphdr _tcph, *tcph; + __be16 oldval; + + /* Not enough header? */ + tcph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph); + if (!tcph) + return false; + + if ((!(einfo->operation & IPT_ECN_OP_SET_ECE) || + tcph->ece == einfo->proto.tcp.ece) && + (!(einfo->operation & IPT_ECN_OP_SET_CWR) || + tcph->cwr == einfo->proto.tcp.cwr)) + return true; + + if (skb_ensure_writable(skb, ip_hdrlen(skb) + sizeof(*tcph))) + return false; + tcph = (void *)ip_hdr(skb) + ip_hdrlen(skb); + + oldval = ((__be16 *)tcph)[6]; + if (einfo->operation & IPT_ECN_OP_SET_ECE) + tcph->ece = einfo->proto.tcp.ece; + if (einfo->operation & IPT_ECN_OP_SET_CWR) + tcph->cwr = einfo->proto.tcp.cwr; + + inet_proto_csum_replace2(&tcph->check, skb, + oldval, ((__be16 *)tcph)[6], false); + return true; +} + +static unsigned int +ecn_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ipt_ECN_info *einfo = par->targinfo; + + if (einfo->operation & IPT_ECN_OP_SET_IP) + if (!set_ect_ip(skb, einfo)) + return NF_DROP; + + if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR) && + ip_hdr(skb)->protocol == IPPROTO_TCP) + if (!set_ect_tcp(skb, einfo)) + return NF_DROP; + + return XT_CONTINUE; +} + +static int ecn_tg_check(const struct xt_tgchk_param *par) +{ + const struct ipt_ECN_info *einfo = par->targinfo; + const struct ipt_entry *e = par->entryinfo; + + if (einfo->operation & IPT_ECN_OP_MASK) + return -EINVAL; + + if (einfo->ip_ect & ~IPT_ECN_IP_MASK) + return -EINVAL; + + if ((einfo->operation & (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)) && + (e->ip.proto != IPPROTO_TCP || (e->ip.invflags & XT_INV_PROTO))) { + pr_info_ratelimited("cannot use operation on non-tcp rule\n"); + return -EINVAL; + } + return 0; +} + +static struct xt_target ecn_tg_reg __read_mostly = { + .name = "ECN", + .family = NFPROTO_IPV4, + .target = ecn_tg, + .targetsize = sizeof(struct ipt_ECN_info), + .table = "mangle", + .checkentry = ecn_tg_check, + .me = THIS_MODULE, +}; + +static int __init ecn_tg_init(void) +{ + return xt_register_target(&ecn_tg_reg); +} + +static void __exit ecn_tg_exit(void) +{ + xt_unregister_target(&ecn_tg_reg); +} + +module_init(ecn_tg_init); +module_exit(ecn_tg_exit); diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c new file mode 100644 index 000000000..4b8840734 --- /dev/null +++ b/net/ipv4/netfilter/ipt_REJECT.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This is a module which is used for rejecting packets. + */ + +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <linux/icmp.h> +#include <net/icmp.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv4/ipt_REJECT.h> +#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) +#include <linux/netfilter_bridge.h> +#endif + +#include <net/netfilter/ipv4/nf_reject.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv4"); + +static unsigned int +reject_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ipt_reject_info *reject = par->targinfo; + int hook = xt_hooknum(par); + + switch (reject->with) { + case IPT_ICMP_NET_UNREACHABLE: + nf_send_unreach(skb, ICMP_NET_UNREACH, hook); + break; + case IPT_ICMP_HOST_UNREACHABLE: + nf_send_unreach(skb, ICMP_HOST_UNREACH, hook); + break; + case IPT_ICMP_PROT_UNREACHABLE: + nf_send_unreach(skb, ICMP_PROT_UNREACH, hook); + break; + case IPT_ICMP_PORT_UNREACHABLE: + nf_send_unreach(skb, ICMP_PORT_UNREACH, hook); + break; + case IPT_ICMP_NET_PROHIBITED: + nf_send_unreach(skb, ICMP_NET_ANO, hook); + break; + case IPT_ICMP_HOST_PROHIBITED: + nf_send_unreach(skb, ICMP_HOST_ANO, hook); + break; + case IPT_ICMP_ADMIN_PROHIBITED: + nf_send_unreach(skb, ICMP_PKT_FILTERED, hook); + break; + case IPT_TCP_RESET: + nf_send_reset(xt_net(par), par->state->sk, skb, hook); + break; + case IPT_ICMP_ECHOREPLY: + /* Doesn't happen. */ + break; + } + + return NF_DROP; +} + +static int reject_tg_check(const struct xt_tgchk_param *par) +{ + const struct ipt_reject_info *rejinfo = par->targinfo; + const struct ipt_entry *e = par->entryinfo; + + if (rejinfo->with == IPT_ICMP_ECHOREPLY) { + pr_info_ratelimited("ECHOREPLY no longer supported.\n"); + return -EINVAL; + } else if (rejinfo->with == IPT_TCP_RESET) { + /* Must specify that it's a TCP packet */ + if (e->ip.proto != IPPROTO_TCP || + (e->ip.invflags & XT_INV_PROTO)) { + pr_info_ratelimited("TCP_RESET invalid for non-tcp\n"); + return -EINVAL; + } + } + return 0; +} + +static struct xt_target reject_tg_reg __read_mostly = { + .name = "REJECT", + .family = NFPROTO_IPV4, + .target = reject_tg, + .targetsize = sizeof(struct ipt_reject_info), + .table = "filter", + .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) | + (1 << NF_INET_LOCAL_OUT), + .checkentry = reject_tg_check, + .me = THIS_MODULE, +}; + +static int __init reject_tg_init(void) +{ + return xt_register_target(&reject_tg_reg); +} + +static void __exit reject_tg_exit(void) +{ + xt_unregister_target(&reject_tg_reg); +} + +module_init(reject_tg_init); +module_exit(reject_tg_exit); diff --git a/net/ipv4/netfilter/ipt_SYNPROXY.c b/net/ipv4/netfilter/ipt_SYNPROXY.c new file mode 100644 index 000000000..f2984c7ee --- /dev/null +++ b/net/ipv4/netfilter/ipt_SYNPROXY.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 Patrick McHardy <kaber@trash.net> + */ + +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter/xt_SYNPROXY.h> + +#include <net/netfilter/nf_synproxy.h> + +static unsigned int +synproxy_tg4(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct xt_synproxy_info *info = par->targinfo; + struct net *net = xt_net(par); + struct synproxy_net *snet = synproxy_pernet(net); + struct synproxy_options opts = {}; + struct tcphdr *th, _th; + + if (nf_ip_checksum(skb, xt_hooknum(par), par->thoff, IPPROTO_TCP)) + return NF_DROP; + + th = skb_header_pointer(skb, par->thoff, sizeof(_th), &_th); + if (th == NULL) + return NF_DROP; + + if (!synproxy_parse_options(skb, par->thoff, th, &opts)) + return NF_DROP; + + if (th->syn && !(th->ack || th->fin || th->rst)) { + /* Initial SYN from client */ + this_cpu_inc(snet->stats->syn_received); + + if (th->ece && th->cwr) + opts.options |= XT_SYNPROXY_OPT_ECN; + + opts.options &= info->options; + opts.mss_encode = opts.mss_option; + opts.mss_option = info->mss; + if (opts.options & XT_SYNPROXY_OPT_TIMESTAMP) + synproxy_init_timestamp_cookie(info, &opts); + else + opts.options &= ~(XT_SYNPROXY_OPT_WSCALE | + XT_SYNPROXY_OPT_SACK_PERM | + XT_SYNPROXY_OPT_ECN); + + synproxy_send_client_synack(net, skb, th, &opts); + consume_skb(skb); + return NF_STOLEN; + } else if (th->ack && !(th->fin || th->rst || th->syn)) { + /* ACK from client */ + if (synproxy_recv_client_ack(net, skb, th, &opts, ntohl(th->seq))) { + consume_skb(skb); + return NF_STOLEN; + } else { + return NF_DROP; + } + } + + return XT_CONTINUE; +} + +static int synproxy_tg4_check(const struct xt_tgchk_param *par) +{ + struct synproxy_net *snet = synproxy_pernet(par->net); + const struct ipt_entry *e = par->entryinfo; + int err; + + if (e->ip.proto != IPPROTO_TCP || + e->ip.invflags & XT_INV_PROTO) + return -EINVAL; + + err = nf_ct_netns_get(par->net, par->family); + if (err) + return err; + + err = nf_synproxy_ipv4_init(snet, par->net); + if (err) { + nf_ct_netns_put(par->net, par->family); + return err; + } + + return err; +} + +static void synproxy_tg4_destroy(const struct xt_tgdtor_param *par) +{ + struct synproxy_net *snet = synproxy_pernet(par->net); + + nf_synproxy_ipv4_fini(snet, par->net); + nf_ct_netns_put(par->net, par->family); +} + +static struct xt_target synproxy_tg4_reg __read_mostly = { + .name = "SYNPROXY", + .family = NFPROTO_IPV4, + .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD), + .target = synproxy_tg4, + .targetsize = sizeof(struct xt_synproxy_info), + .checkentry = synproxy_tg4_check, + .destroy = synproxy_tg4_destroy, + .me = THIS_MODULE, +}; + +static int __init synproxy_tg4_init(void) +{ + return xt_register_target(&synproxy_tg4_reg); +} + +static void __exit synproxy_tg4_exit(void) +{ + xt_unregister_target(&synproxy_tg4_reg); +} + +module_init(synproxy_tg4_init); +module_exit(synproxy_tg4_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_DESCRIPTION("Intercept TCP connections and establish them using syncookies"); diff --git a/net/ipv4/netfilter/ipt_ah.c b/net/ipv4/netfilter/ipt_ah.c new file mode 100644 index 000000000..161ba412c --- /dev/null +++ b/net/ipv4/netfilter/ipt_ah.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Kernel module to match AH parameters. */ +/* (C) 1999-2000 Yon Uriarte <yon@astaro.de> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/in.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/ip.h> + +#include <linux/netfilter_ipv4/ipt_ah.h> +#include <linux/netfilter/x_tables.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Yon Uriarte <yon@astaro.de>"); +MODULE_DESCRIPTION("Xtables: IPv4 IPsec-AH SPI match"); + +/* Returns 1 if the spi is matched by the range, 0 otherwise */ +static inline bool +spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, bool invert) +{ + bool r; + pr_debug("spi_match:%c 0x%x <= 0x%x <= 0x%x\n", + invert ? '!' : ' ', min, spi, max); + r = (spi >= min && spi <= max) ^ invert; + pr_debug(" result %s\n", r ? "PASS" : "FAILED"); + return r; +} + +static bool ah_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + struct ip_auth_hdr _ahdr; + const struct ip_auth_hdr *ah; + const struct ipt_ah *ahinfo = par->matchinfo; + + /* Must not be a fragment. */ + if (par->fragoff != 0) + return false; + + ah = skb_header_pointer(skb, par->thoff, sizeof(_ahdr), &_ahdr); + if (ah == NULL) { + /* We've been asked to examine this packet, and we + * can't. Hence, no choice but to drop. + */ + pr_debug("Dropping evil AH tinygram.\n"); + par->hotdrop = true; + return false; + } + + return spi_match(ahinfo->spis[0], ahinfo->spis[1], + ntohl(ah->spi), + !!(ahinfo->invflags & IPT_AH_INV_SPI)); +} + +static int ah_mt_check(const struct xt_mtchk_param *par) +{ + const struct ipt_ah *ahinfo = par->matchinfo; + + /* Must specify no unknown invflags */ + if (ahinfo->invflags & ~IPT_AH_INV_MASK) { + pr_debug("unknown flags %X\n", ahinfo->invflags); + return -EINVAL; + } + return 0; +} + +static struct xt_match ah_mt_reg __read_mostly = { + .name = "ah", + .family = NFPROTO_IPV4, + .match = ah_mt, + .matchsize = sizeof(struct ipt_ah), + .proto = IPPROTO_AH, + .checkentry = ah_mt_check, + .me = THIS_MODULE, +}; + +static int __init ah_mt_init(void) +{ + return xt_register_match(&ah_mt_reg); +} + +static void __exit ah_mt_exit(void) +{ + xt_unregister_match(&ah_mt_reg); +} + +module_init(ah_mt_init); +module_exit(ah_mt_exit); diff --git a/net/ipv4/netfilter/ipt_rpfilter.c b/net/ipv4/netfilter/ipt_rpfilter.c new file mode 100644 index 000000000..8cd3224d9 --- /dev/null +++ b/net/ipv4/netfilter/ipt_rpfilter.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2011 Florian Westphal <fw@strlen.de> + * + * based on fib_frontend.c; Author: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/ip.h> +#include <net/ip.h> +#include <net/ip_fib.h> +#include <net/route.h> + +#include <linux/netfilter/xt_rpfilter.h> +#include <linux/netfilter/x_tables.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Florian Westphal <fw@strlen.de>"); +MODULE_DESCRIPTION("iptables: ipv4 reverse path filter match"); + +/* don't try to find route from mcast/bcast/zeronet */ +static __be32 rpfilter_get_saddr(__be32 addr) +{ + if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr) || + ipv4_is_zeronet(addr)) + return 0; + return addr; +} + +static bool rpfilter_lookup_reverse(struct net *net, struct flowi4 *fl4, + const struct net_device *dev, u8 flags) +{ + struct fib_result res; + int ret __maybe_unused; + + if (fib_lookup(net, fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE)) + return false; + + if (res.type != RTN_UNICAST) { + if (res.type != RTN_LOCAL || !(flags & XT_RPFILTER_ACCEPT_LOCAL)) + return false; + } + return fib_info_nh_uses_dev(res.fi, dev) || flags & XT_RPFILTER_LOOSE; +} + +static bool +rpfilter_is_loopback(const struct sk_buff *skb, const struct net_device *in) +{ + return skb->pkt_type == PACKET_LOOPBACK || in->flags & IFF_LOOPBACK; +} + +static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct xt_rpfilter_info *info; + const struct iphdr *iph; + struct flowi4 flow; + bool invert; + + info = par->matchinfo; + invert = info->flags & XT_RPFILTER_INVERT; + + if (rpfilter_is_loopback(skb, xt_in(par))) + return true ^ invert; + + iph = ip_hdr(skb); + if (ipv4_is_zeronet(iph->saddr)) { + if (ipv4_is_lbcast(iph->daddr) || + ipv4_is_local_multicast(iph->daddr)) + return true ^ invert; + } + + memset(&flow, 0, sizeof(flow)); + flow.flowi4_iif = LOOPBACK_IFINDEX; + flow.daddr = iph->saddr; + flow.saddr = rpfilter_get_saddr(iph->daddr); + flow.flowi4_mark = info->flags & XT_RPFILTER_VALID_MARK ? skb->mark : 0; + flow.flowi4_tos = iph->tos & IPTOS_RT_MASK; + flow.flowi4_scope = RT_SCOPE_UNIVERSE; + flow.flowi4_oif = l3mdev_master_ifindex_rcu(xt_in(par)); + + return rpfilter_lookup_reverse(xt_net(par), &flow, xt_in(par), info->flags) ^ invert; +} + +static int rpfilter_check(const struct xt_mtchk_param *par) +{ + const struct xt_rpfilter_info *info = par->matchinfo; + unsigned int options = ~XT_RPFILTER_OPTION_MASK; + if (info->flags & options) { + pr_info_ratelimited("unknown options\n"); + return -EINVAL; + } + + if (strcmp(par->table, "mangle") != 0 && + strcmp(par->table, "raw") != 0) { + pr_info_ratelimited("only valid in \'raw\' or \'mangle\' table, not \'%s\'\n", + par->table); + return -EINVAL; + } + + return 0; +} + +static struct xt_match rpfilter_mt_reg __read_mostly = { + .name = "rpfilter", + .family = NFPROTO_IPV4, + .checkentry = rpfilter_check, + .match = rpfilter_mt, + .matchsize = sizeof(struct xt_rpfilter_info), + .hooks = (1 << NF_INET_PRE_ROUTING), + .me = THIS_MODULE +}; + +static int __init rpfilter_mt_init(void) +{ + return xt_register_match(&rpfilter_mt_reg); +} + +static void __exit rpfilter_mt_exit(void) +{ + xt_unregister_match(&rpfilter_mt_reg); +} + +module_init(rpfilter_mt_init); +module_exit(rpfilter_mt_exit); diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c new file mode 100644 index 000000000..8f7bc1ee7 --- /dev/null +++ b/net/ipv4/netfilter/iptable_filter.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x. + * + * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling + * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/slab.h> +#include <net/ip.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("iptables filter table"); + +#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \ + (1 << NF_INET_FORWARD) | \ + (1 << NF_INET_LOCAL_OUT)) +static int __net_init iptable_filter_table_init(struct net *net); + +static const struct xt_table packet_filter = { + .name = "filter", + .valid_hooks = FILTER_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_IPV4, + .priority = NF_IP_PRI_FILTER, + .table_init = iptable_filter_table_init, +}; + +static unsigned int +iptable_filter_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return ipt_do_table(skb, state, state->net->ipv4.iptable_filter); +} + +static struct nf_hook_ops *filter_ops __read_mostly; + +/* Default to forward because I got too much mail already. */ +static bool forward __read_mostly = true; +module_param(forward, bool, 0000); + +static int __net_init iptable_filter_table_init(struct net *net) +{ + struct ipt_replace *repl; + int err; + + if (net->ipv4.iptable_filter) + return 0; + + repl = ipt_alloc_initial_table(&packet_filter); + if (repl == NULL) + return -ENOMEM; + /* Entry 1 is the FORWARD hook */ + ((struct ipt_standard *)repl->entries)[1].target.verdict = + forward ? -NF_ACCEPT - 1 : -NF_DROP - 1; + + err = ipt_register_table(net, &packet_filter, repl, filter_ops, + &net->ipv4.iptable_filter); + kfree(repl); + return err; +} + +static int __net_init iptable_filter_net_init(struct net *net) +{ + if (net == &init_net || !forward) + return iptable_filter_table_init(net); + + return 0; +} + +static void __net_exit iptable_filter_net_pre_exit(struct net *net) +{ + if (net->ipv4.iptable_filter) + ipt_unregister_table_pre_exit(net, net->ipv4.iptable_filter, + filter_ops); +} + +static void __net_exit iptable_filter_net_exit(struct net *net) +{ + if (!net->ipv4.iptable_filter) + return; + ipt_unregister_table_exit(net, net->ipv4.iptable_filter); + net->ipv4.iptable_filter = NULL; +} + +static struct pernet_operations iptable_filter_net_ops = { + .init = iptable_filter_net_init, + .pre_exit = iptable_filter_net_pre_exit, + .exit = iptable_filter_net_exit, +}; + +static int __init iptable_filter_init(void) +{ + int ret; + + filter_ops = xt_hook_ops_alloc(&packet_filter, iptable_filter_hook); + if (IS_ERR(filter_ops)) + return PTR_ERR(filter_ops); + + ret = register_pernet_subsys(&iptable_filter_net_ops); + if (ret < 0) + kfree(filter_ops); + + return ret; +} + +static void __exit iptable_filter_fini(void) +{ + unregister_pernet_subsys(&iptable_filter_net_ops); + kfree(filter_ops); +} + +module_init(iptable_filter_init); +module_exit(iptable_filter_fini); diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c new file mode 100644 index 000000000..833079589 --- /dev/null +++ b/net/ipv4/netfilter/iptable_mangle.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x. + * + * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling + * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> + */ +#include <linux/module.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <net/route.h> +#include <linux/ip.h> +#include <net/ip.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("iptables mangle table"); + +#define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \ + (1 << NF_INET_LOCAL_IN) | \ + (1 << NF_INET_FORWARD) | \ + (1 << NF_INET_LOCAL_OUT) | \ + (1 << NF_INET_POST_ROUTING)) + +static int __net_init iptable_mangle_table_init(struct net *net); + +static const struct xt_table packet_mangler = { + .name = "mangle", + .valid_hooks = MANGLE_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_IPV4, + .priority = NF_IP_PRI_MANGLE, + .table_init = iptable_mangle_table_init, +}; + +static unsigned int +ipt_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state) +{ + unsigned int ret; + const struct iphdr *iph; + u_int8_t tos; + __be32 saddr, daddr; + u_int32_t mark; + int err; + + /* Save things which could affect route */ + mark = skb->mark; + iph = ip_hdr(skb); + saddr = iph->saddr; + daddr = iph->daddr; + tos = iph->tos; + + ret = ipt_do_table(skb, state, state->net->ipv4.iptable_mangle); + /* Reroute for ANY change. */ + if (ret != NF_DROP && ret != NF_STOLEN) { + iph = ip_hdr(skb); + + if (iph->saddr != saddr || + iph->daddr != daddr || + skb->mark != mark || + iph->tos != tos) { + err = ip_route_me_harder(state->net, state->sk, skb, RTN_UNSPEC); + if (err < 0) + ret = NF_DROP_ERR(err); + } + } + + return ret; +} + +/* The work comes in here from netfilter.c. */ +static unsigned int +iptable_mangle_hook(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + if (state->hook == NF_INET_LOCAL_OUT) + return ipt_mangle_out(skb, state); + return ipt_do_table(skb, state, state->net->ipv4.iptable_mangle); +} + +static struct nf_hook_ops *mangle_ops __read_mostly; +static int __net_init iptable_mangle_table_init(struct net *net) +{ + struct ipt_replace *repl; + int ret; + + if (net->ipv4.iptable_mangle) + return 0; + + repl = ipt_alloc_initial_table(&packet_mangler); + if (repl == NULL) + return -ENOMEM; + ret = ipt_register_table(net, &packet_mangler, repl, mangle_ops, + &net->ipv4.iptable_mangle); + kfree(repl); + return ret; +} + +static void __net_exit iptable_mangle_net_pre_exit(struct net *net) +{ + if (net->ipv4.iptable_mangle) + ipt_unregister_table_pre_exit(net, net->ipv4.iptable_mangle, + mangle_ops); +} + +static void __net_exit iptable_mangle_net_exit(struct net *net) +{ + if (!net->ipv4.iptable_mangle) + return; + ipt_unregister_table_exit(net, net->ipv4.iptable_mangle); + net->ipv4.iptable_mangle = NULL; +} + +static struct pernet_operations iptable_mangle_net_ops = { + .pre_exit = iptable_mangle_net_pre_exit, + .exit = iptable_mangle_net_exit, +}; + +static int __init iptable_mangle_init(void) +{ + int ret; + + mangle_ops = xt_hook_ops_alloc(&packet_mangler, iptable_mangle_hook); + if (IS_ERR(mangle_ops)) { + ret = PTR_ERR(mangle_ops); + return ret; + } + + ret = register_pernet_subsys(&iptable_mangle_net_ops); + if (ret < 0) { + kfree(mangle_ops); + return ret; + } + + ret = iptable_mangle_table_init(&init_net); + if (ret) { + unregister_pernet_subsys(&iptable_mangle_net_ops); + kfree(mangle_ops); + } + + return ret; +} + +static void __exit iptable_mangle_fini(void) +{ + unregister_pernet_subsys(&iptable_mangle_net_ops); + kfree(mangle_ops); +} + +module_init(iptable_mangle_init); +module_exit(iptable_mangle_fini); diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c new file mode 100644 index 000000000..b0143b109 --- /dev/null +++ b/net/ipv4/netfilter/iptable_nat.c @@ -0,0 +1,156 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> + * (C) 2011 Patrick McHardy <kaber@trash.net> + */ + +#include <linux/module.h> +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/ip.h> +#include <net/ip.h> + +#include <net/netfilter/nf_nat.h> + +static int __net_init iptable_nat_table_init(struct net *net); + +static const struct xt_table nf_nat_ipv4_table = { + .name = "nat", + .valid_hooks = (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_POST_ROUTING) | + (1 << NF_INET_LOCAL_OUT) | + (1 << NF_INET_LOCAL_IN), + .me = THIS_MODULE, + .af = NFPROTO_IPV4, + .table_init = iptable_nat_table_init, +}; + +static unsigned int iptable_nat_do_chain(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return ipt_do_table(skb, state, state->net->ipv4.nat_table); +} + +static const struct nf_hook_ops nf_nat_ipv4_ops[] = { + { + .hook = iptable_nat_do_chain, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_PRE_ROUTING, + .priority = NF_IP_PRI_NAT_DST, + }, + { + .hook = iptable_nat_do_chain, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP_PRI_NAT_SRC, + }, + { + .hook = iptable_nat_do_chain, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_NAT_DST, + }, + { + .hook = iptable_nat_do_chain, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP_PRI_NAT_SRC, + }, +}; + +static int ipt_nat_register_lookups(struct net *net) +{ + int i, ret; + + for (i = 0; i < ARRAY_SIZE(nf_nat_ipv4_ops); i++) { + ret = nf_nat_ipv4_register_fn(net, &nf_nat_ipv4_ops[i]); + if (ret) { + while (i) + nf_nat_ipv4_unregister_fn(net, &nf_nat_ipv4_ops[--i]); + + return ret; + } + } + + return 0; +} + +static void ipt_nat_unregister_lookups(struct net *net) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(nf_nat_ipv4_ops); i++) + nf_nat_ipv4_unregister_fn(net, &nf_nat_ipv4_ops[i]); +} + +static int __net_init iptable_nat_table_init(struct net *net) +{ + struct ipt_replace *repl; + int ret; + + if (net->ipv4.nat_table) + return 0; + + repl = ipt_alloc_initial_table(&nf_nat_ipv4_table); + if (repl == NULL) + return -ENOMEM; + ret = ipt_register_table(net, &nf_nat_ipv4_table, repl, + NULL, &net->ipv4.nat_table); + if (ret < 0) { + kfree(repl); + return ret; + } + + ret = ipt_nat_register_lookups(net); + if (ret < 0) { + ipt_unregister_table(net, net->ipv4.nat_table, NULL); + net->ipv4.nat_table = NULL; + } + + kfree(repl); + return ret; +} + +static void __net_exit iptable_nat_net_pre_exit(struct net *net) +{ + if (net->ipv4.nat_table) + ipt_nat_unregister_lookups(net); +} + +static void __net_exit iptable_nat_net_exit(struct net *net) +{ + if (!net->ipv4.nat_table) + return; + ipt_unregister_table_exit(net, net->ipv4.nat_table); + net->ipv4.nat_table = NULL; +} + +static struct pernet_operations iptable_nat_net_ops = { + .pre_exit = iptable_nat_net_pre_exit, + .exit = iptable_nat_net_exit, +}; + +static int __init iptable_nat_init(void) +{ + int ret = register_pernet_subsys(&iptable_nat_net_ops); + + if (ret) + return ret; + + ret = iptable_nat_table_init(&init_net); + if (ret) + unregister_pernet_subsys(&iptable_nat_net_ops); + return ret; +} + +static void __exit iptable_nat_exit(void) +{ + unregister_pernet_subsys(&iptable_nat_net_ops); +} + +module_init(iptable_nat_init); +module_exit(iptable_nat_exit); + +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/netfilter/iptable_raw.c b/net/ipv4/netfilter/iptable_raw.c new file mode 100644 index 000000000..9abfe6bf2 --- /dev/null +++ b/net/ipv4/netfilter/iptable_raw.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT . + * + * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@netfilter.org> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/slab.h> +#include <net/ip.h> + +#define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT)) + +static int __net_init iptable_raw_table_init(struct net *net); + +static bool raw_before_defrag __read_mostly; +MODULE_PARM_DESC(raw_before_defrag, "Enable raw table before defrag"); +module_param(raw_before_defrag, bool, 0000); + +static const struct xt_table packet_raw = { + .name = "raw", + .valid_hooks = RAW_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_IPV4, + .priority = NF_IP_PRI_RAW, + .table_init = iptable_raw_table_init, +}; + +static const struct xt_table packet_raw_before_defrag = { + .name = "raw", + .valid_hooks = RAW_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_IPV4, + .priority = NF_IP_PRI_RAW_BEFORE_DEFRAG, + .table_init = iptable_raw_table_init, +}; + +/* The work comes in here from netfilter.c. */ +static unsigned int +iptable_raw_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return ipt_do_table(skb, state, state->net->ipv4.iptable_raw); +} + +static struct nf_hook_ops *rawtable_ops __read_mostly; + +static int __net_init iptable_raw_table_init(struct net *net) +{ + struct ipt_replace *repl; + const struct xt_table *table = &packet_raw; + int ret; + + if (raw_before_defrag) + table = &packet_raw_before_defrag; + + if (net->ipv4.iptable_raw) + return 0; + + repl = ipt_alloc_initial_table(table); + if (repl == NULL) + return -ENOMEM; + ret = ipt_register_table(net, table, repl, rawtable_ops, + &net->ipv4.iptable_raw); + kfree(repl); + return ret; +} + +static void __net_exit iptable_raw_net_pre_exit(struct net *net) +{ + if (net->ipv4.iptable_raw) + ipt_unregister_table_pre_exit(net, net->ipv4.iptable_raw, + rawtable_ops); +} + +static void __net_exit iptable_raw_net_exit(struct net *net) +{ + if (!net->ipv4.iptable_raw) + return; + ipt_unregister_table_exit(net, net->ipv4.iptable_raw); + net->ipv4.iptable_raw = NULL; +} + +static struct pernet_operations iptable_raw_net_ops = { + .pre_exit = iptable_raw_net_pre_exit, + .exit = iptable_raw_net_exit, +}; + +static int __init iptable_raw_init(void) +{ + int ret; + const struct xt_table *table = &packet_raw; + + if (raw_before_defrag) { + table = &packet_raw_before_defrag; + + pr_info("Enabling raw table before defrag\n"); + } + + rawtable_ops = xt_hook_ops_alloc(table, iptable_raw_hook); + if (IS_ERR(rawtable_ops)) + return PTR_ERR(rawtable_ops); + + ret = register_pernet_subsys(&iptable_raw_net_ops); + if (ret < 0) { + kfree(rawtable_ops); + return ret; + } + + ret = iptable_raw_table_init(&init_net); + if (ret) { + unregister_pernet_subsys(&iptable_raw_net_ops); + kfree(rawtable_ops); + } + + return ret; +} + +static void __exit iptable_raw_fini(void) +{ + unregister_pernet_subsys(&iptable_raw_net_ops); + kfree(rawtable_ops); +} + +module_init(iptable_raw_init); +module_exit(iptable_raw_fini); +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/netfilter/iptable_security.c b/net/ipv4/netfilter/iptable_security.c new file mode 100644 index 000000000..415c1975d --- /dev/null +++ b/net/ipv4/netfilter/iptable_security.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * "security" table + * + * This is for use by Mandatory Access Control (MAC) security models, + * which need to be able to manage security policy in separate context + * to DAC. + * + * Based on iptable_mangle.c + * + * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling + * Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org> + * Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com> + */ +#include <linux/module.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/slab.h> +#include <net/ip.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>"); +MODULE_DESCRIPTION("iptables security table, for MAC rules"); + +#define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) | \ + (1 << NF_INET_FORWARD) | \ + (1 << NF_INET_LOCAL_OUT) + +static int __net_init iptable_security_table_init(struct net *net); + +static const struct xt_table security_table = { + .name = "security", + .valid_hooks = SECURITY_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_IPV4, + .priority = NF_IP_PRI_SECURITY, + .table_init = iptable_security_table_init, +}; + +static unsigned int +iptable_security_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return ipt_do_table(skb, state, state->net->ipv4.iptable_security); +} + +static struct nf_hook_ops *sectbl_ops __read_mostly; + +static int __net_init iptable_security_table_init(struct net *net) +{ + struct ipt_replace *repl; + int ret; + + if (net->ipv4.iptable_security) + return 0; + + repl = ipt_alloc_initial_table(&security_table); + if (repl == NULL) + return -ENOMEM; + ret = ipt_register_table(net, &security_table, repl, sectbl_ops, + &net->ipv4.iptable_security); + kfree(repl); + return ret; +} + +static void __net_exit iptable_security_net_pre_exit(struct net *net) +{ + if (net->ipv4.iptable_security) + ipt_unregister_table_pre_exit(net, net->ipv4.iptable_security, + sectbl_ops); +} + +static void __net_exit iptable_security_net_exit(struct net *net) +{ + if (!net->ipv4.iptable_security) + return; + ipt_unregister_table_exit(net, net->ipv4.iptable_security); + net->ipv4.iptable_security = NULL; +} + +static struct pernet_operations iptable_security_net_ops = { + .pre_exit = iptable_security_net_pre_exit, + .exit = iptable_security_net_exit, +}; + +static int __init iptable_security_init(void) +{ + int ret; + + sectbl_ops = xt_hook_ops_alloc(&security_table, iptable_security_hook); + if (IS_ERR(sectbl_ops)) + return PTR_ERR(sectbl_ops); + + ret = register_pernet_subsys(&iptable_security_net_ops); + if (ret < 0) { + kfree(sectbl_ops); + return ret; + } + + ret = iptable_security_table_init(&init_net); + if (ret) { + unregister_pernet_subsys(&iptable_security_net_ops); + kfree(sectbl_ops); + } + + return ret; +} + +static void __exit iptable_security_fini(void) +{ + unregister_pernet_subsys(&iptable_security_net_ops); + kfree(sectbl_ops); +} + +module_init(iptable_security_init); +module_exit(iptable_security_fini); diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c new file mode 100644 index 000000000..8115611aa --- /dev/null +++ b/net/ipv4/netfilter/nf_defrag_ipv4.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> + */ + +#include <linux/types.h> +#include <linux/ip.h> +#include <linux/netfilter.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <net/netns/generic.h> +#include <net/route.h> +#include <net/ip.h> + +#include <linux/netfilter_bridge.h> +#include <linux/netfilter_ipv4.h> +#include <net/netfilter/ipv4/nf_defrag_ipv4.h> +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#include <net/netfilter/nf_conntrack.h> +#endif +#include <net/netfilter/nf_conntrack_zones.h> + +static DEFINE_MUTEX(defrag4_mutex); + +static int nf_ct_ipv4_gather_frags(struct net *net, struct sk_buff *skb, + u_int32_t user) +{ + int err; + + local_bh_disable(); + err = ip_defrag(net, skb, user); + local_bh_enable(); + + if (!err) + skb->ignore_df = 1; + + return err; +} + +static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum, + struct sk_buff *skb) +{ + u16 zone_id = NF_CT_DEFAULT_ZONE_ID; +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + if (skb_nfct(skb)) { + enum ip_conntrack_info ctinfo; + const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); + + zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo)); + } +#endif + if (nf_bridge_in_prerouting(skb)) + return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id; + + if (hooknum == NF_INET_PRE_ROUTING) + return IP_DEFRAG_CONNTRACK_IN + zone_id; + else + return IP_DEFRAG_CONNTRACK_OUT + zone_id; +} + +static unsigned int ipv4_conntrack_defrag(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk = skb->sk; + + if (sk && sk_fullsock(sk) && (sk->sk_family == PF_INET) && + inet_sk(sk)->nodefrag) + return NF_ACCEPT; + +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#if !IS_ENABLED(CONFIG_NF_NAT) + /* Previously seen (loopback)? Ignore. Do this before + fragment check. */ + if (skb_nfct(skb) && !nf_ct_is_template((struct nf_conn *)skb_nfct(skb))) + return NF_ACCEPT; +#endif + if (skb->_nfct == IP_CT_UNTRACKED) + return NF_ACCEPT; +#endif + /* Gather fragments. */ + if (ip_is_fragment(ip_hdr(skb))) { + enum ip_defrag_users user = + nf_ct_defrag_user(state->hook, skb); + + if (nf_ct_ipv4_gather_frags(state->net, skb, user)) + return NF_STOLEN; + } + return NF_ACCEPT; +} + +static const struct nf_hook_ops ipv4_defrag_ops[] = { + { + .hook = ipv4_conntrack_defrag, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_PRE_ROUTING, + .priority = NF_IP_PRI_CONNTRACK_DEFRAG, + }, + { + .hook = ipv4_conntrack_defrag, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_CONNTRACK_DEFRAG, + }, +}; + +static void __net_exit defrag4_net_exit(struct net *net) +{ + if (net->nf.defrag_ipv4) { + nf_unregister_net_hooks(net, ipv4_defrag_ops, + ARRAY_SIZE(ipv4_defrag_ops)); + net->nf.defrag_ipv4 = false; + } +} + +static struct pernet_operations defrag4_net_ops = { + .exit = defrag4_net_exit, +}; + +static int __init nf_defrag_init(void) +{ + return register_pernet_subsys(&defrag4_net_ops); +} + +static void __exit nf_defrag_fini(void) +{ + unregister_pernet_subsys(&defrag4_net_ops); +} + +int nf_defrag_ipv4_enable(struct net *net) +{ + int err = 0; + + might_sleep(); + + if (net->nf.defrag_ipv4) + return 0; + + mutex_lock(&defrag4_mutex); + if (net->nf.defrag_ipv4) + goto out_unlock; + + err = nf_register_net_hooks(net, ipv4_defrag_ops, + ARRAY_SIZE(ipv4_defrag_ops)); + if (err == 0) + net->nf.defrag_ipv4 = true; + + out_unlock: + mutex_unlock(&defrag4_mutex); + return err; +} +EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable); + +module_init(nf_defrag_init); +module_exit(nf_defrag_fini); + +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/netfilter/nf_dup_ipv4.c b/net/ipv4/netfilter/nf_dup_ipv4.c new file mode 100644 index 000000000..6cc5743c5 --- /dev/null +++ b/net/ipv4/netfilter/nf_dup_ipv4.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * (C) 2007 by Sebastian Claßen <sebastian.classen@freenet.ag> + * (C) 2007-2010 by Jan Engelhardt <jengelh@medozas.de> + * + * Extracted from xt_TEE.c + */ +#include <linux/ip.h> +#include <linux/module.h> +#include <linux/percpu.h> +#include <linux/route.h> +#include <linux/skbuff.h> +#include <linux/netfilter.h> +#include <net/checksum.h> +#include <net/icmp.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/netfilter/ipv4/nf_dup_ipv4.h> +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#include <net/netfilter/nf_conntrack.h> +#endif + +static bool nf_dup_ipv4_route(struct net *net, struct sk_buff *skb, + const struct in_addr *gw, int oif) +{ + const struct iphdr *iph = ip_hdr(skb); + struct rtable *rt; + struct flowi4 fl4; + + memset(&fl4, 0, sizeof(fl4)); + if (oif != -1) + fl4.flowi4_oif = oif; + + fl4.daddr = gw->s_addr; + fl4.flowi4_tos = RT_TOS(iph->tos); + fl4.flowi4_scope = RT_SCOPE_UNIVERSE; + fl4.flowi4_flags = FLOWI_FLAG_KNOWN_NH; + rt = ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) + return false; + + skb_dst_drop(skb); + skb_dst_set(skb, &rt->dst); + skb->dev = rt->dst.dev; + skb->protocol = htons(ETH_P_IP); + + return true; +} + +void nf_dup_ipv4(struct net *net, struct sk_buff *skb, unsigned int hooknum, + const struct in_addr *gw, int oif) +{ + struct iphdr *iph; + + if (this_cpu_read(nf_skb_duplicated)) + return; + /* + * Copy the skb, and route the copy. Will later return %XT_CONTINUE for + * the original skb, which should continue on its way as if nothing has + * happened. The copy should be independently delivered to the gateway. + */ + skb = pskb_copy(skb, GFP_ATOMIC); + if (skb == NULL) + return; + +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + /* Avoid counting cloned packets towards the original connection. */ + nf_reset_ct(skb); + nf_ct_set(skb, NULL, IP_CT_UNTRACKED); +#endif + /* + * If we are in PREROUTING/INPUT, decrease the TTL to mitigate potential + * loops between two hosts. + * + * Set %IP_DF so that the original source is notified of a potentially + * decreased MTU on the clone route. IPv6 does this too. + * + * IP header checksum will be recalculated at ip_local_out. + */ + iph = ip_hdr(skb); + iph->frag_off |= htons(IP_DF); + if (hooknum == NF_INET_PRE_ROUTING || + hooknum == NF_INET_LOCAL_IN) + --iph->ttl; + + if (nf_dup_ipv4_route(net, skb, gw, oif)) { + __this_cpu_write(nf_skb_duplicated, true); + ip_local_out(net, skb->sk, skb); + __this_cpu_write(nf_skb_duplicated, false); + } else { + kfree_skb(skb); + } +} +EXPORT_SYMBOL_GPL(nf_dup_ipv4); + +MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@freenet.ag>"); +MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); +MODULE_DESCRIPTION("nf_dup_ipv4: Duplicate IPv4 packet"); +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/netfilter/nf_flow_table_ipv4.c b/net/ipv4/netfilter/nf_flow_table_ipv4.c new file mode 100644 index 000000000..aba65fe90 --- /dev/null +++ b/net/ipv4/netfilter/nf_flow_table_ipv4.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netfilter.h> +#include <net/netfilter/nf_flow_table.h> +#include <net/netfilter/nf_tables.h> + +static struct nf_flowtable_type flowtable_ipv4 = { + .family = NFPROTO_IPV4, + .init = nf_flow_table_init, + .setup = nf_flow_table_offload_setup, + .action = nf_flow_rule_route_ipv4, + .free = nf_flow_table_free, + .hook = nf_flow_offload_ip_hook, + .owner = THIS_MODULE, +}; + +static int __init nf_flow_ipv4_module_init(void) +{ + nft_register_flowtable_type(&flowtable_ipv4); + + return 0; +} + +static void __exit nf_flow_ipv4_module_exit(void) +{ + nft_unregister_flowtable_type(&flowtable_ipv4); +} + +module_init(nf_flow_ipv4_module_init); +module_exit(nf_flow_ipv4_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_ALIAS_NF_FLOWTABLE(AF_INET); +MODULE_DESCRIPTION("Netfilter flow table support"); diff --git a/net/ipv4/netfilter/nf_log_arp.c b/net/ipv4/netfilter/nf_log_arp.c new file mode 100644 index 000000000..136030ad2 --- /dev/null +++ b/net/ipv4/netfilter/nf_log_arp.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * (C) 2014 by Pablo Neira Ayuso <pablo@netfilter.org> + * + * Based on code from ebt_log from: + * + * Bart De Schuymer <bdschuym@pandora.be> + * Harald Welte <laforge@netfilter.org> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/skbuff.h> +#include <linux/if_arp.h> +#include <linux/ip.h> +#include <net/route.h> + +#include <linux/netfilter.h> +#include <linux/netfilter/xt_LOG.h> +#include <net/netfilter/nf_log.h> + +static const struct nf_loginfo default_loginfo = { + .type = NF_LOG_TYPE_LOG, + .u = { + .log = { + .level = LOGLEVEL_NOTICE, + .logflags = NF_LOG_DEFAULT_MASK, + }, + }, +}; + +struct arppayload { + unsigned char mac_src[ETH_ALEN]; + unsigned char ip_src[4]; + unsigned char mac_dst[ETH_ALEN]; + unsigned char ip_dst[4]; +}; + +static void dump_arp_packet(struct nf_log_buf *m, + const struct nf_loginfo *info, + const struct sk_buff *skb, unsigned int nhoff) +{ + const struct arppayload *ap; + struct arppayload _arpp; + const struct arphdr *ah; + unsigned int logflags; + struct arphdr _arph; + + ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); + if (ah == NULL) { + nf_log_buf_add(m, "TRUNCATED"); + return; + } + + if (info->type == NF_LOG_TYPE_LOG) + logflags = info->u.log.logflags; + else + logflags = NF_LOG_DEFAULT_MASK; + + if (logflags & NF_LOG_MACDECODE) { + nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM ", + eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest); + nf_log_dump_vlan(m, skb); + nf_log_buf_add(m, "MACPROTO=%04x ", + ntohs(eth_hdr(skb)->h_proto)); + } + + nf_log_buf_add(m, "ARP HTYPE=%d PTYPE=0x%04x OPCODE=%d", + ntohs(ah->ar_hrd), ntohs(ah->ar_pro), ntohs(ah->ar_op)); + + /* If it's for Ethernet and the lengths are OK, then log the ARP + * payload. + */ + if (ah->ar_hrd != htons(ARPHRD_ETHER) || + ah->ar_hln != ETH_ALEN || + ah->ar_pln != sizeof(__be32)) + return; + + ap = skb_header_pointer(skb, sizeof(_arph), sizeof(_arpp), &_arpp); + if (ap == NULL) { + nf_log_buf_add(m, " INCOMPLETE [%zu bytes]", + skb->len - sizeof(_arph)); + return; + } + nf_log_buf_add(m, " MACSRC=%pM IPSRC=%pI4 MACDST=%pM IPDST=%pI4", + ap->mac_src, ap->ip_src, ap->mac_dst, ap->ip_dst); +} + +static void nf_log_arp_packet(struct net *net, u_int8_t pf, + unsigned int hooknum, const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *loginfo, + const char *prefix) +{ + struct nf_log_buf *m; + + /* FIXME: Disabled from containers until syslog ns is supported */ + if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) + return; + + m = nf_log_buf_open(); + + if (!loginfo) + loginfo = &default_loginfo; + + nf_log_dump_packet_common(m, pf, hooknum, skb, in, out, loginfo, + prefix); + dump_arp_packet(m, loginfo, skb, 0); + + nf_log_buf_close(m); +} + +static struct nf_logger nf_arp_logger __read_mostly = { + .name = "nf_log_arp", + .type = NF_LOG_TYPE_LOG, + .logfn = nf_log_arp_packet, + .me = THIS_MODULE, +}; + +static int __net_init nf_log_arp_net_init(struct net *net) +{ + return nf_log_set(net, NFPROTO_ARP, &nf_arp_logger); +} + +static void __net_exit nf_log_arp_net_exit(struct net *net) +{ + nf_log_unset(net, &nf_arp_logger); +} + +static struct pernet_operations nf_log_arp_net_ops = { + .init = nf_log_arp_net_init, + .exit = nf_log_arp_net_exit, +}; + +static int __init nf_log_arp_init(void) +{ + int ret; + + ret = register_pernet_subsys(&nf_log_arp_net_ops); + if (ret < 0) + return ret; + + ret = nf_log_register(NFPROTO_ARP, &nf_arp_logger); + if (ret < 0) { + pr_err("failed to register logger\n"); + goto err1; + } + + return 0; + +err1: + unregister_pernet_subsys(&nf_log_arp_net_ops); + return ret; +} + +static void __exit nf_log_arp_exit(void) +{ + unregister_pernet_subsys(&nf_log_arp_net_ops); + nf_log_unregister(&nf_arp_logger); +} + +module_init(nf_log_arp_init); +module_exit(nf_log_arp_exit); + +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_DESCRIPTION("Netfilter ARP packet logging"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NF_LOGGER(3, 0); diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c new file mode 100644 index 000000000..d07583fac --- /dev/null +++ b/net/ipv4/netfilter/nf_log_ipv4.c @@ -0,0 +1,395 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/skbuff.h> +#include <linux/if_arp.h> +#include <linux/ip.h> +#include <net/ipv6.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/tcp.h> +#include <net/route.h> + +#include <linux/netfilter.h> +#include <linux/netfilter/xt_LOG.h> +#include <net/netfilter/nf_log.h> + +static const struct nf_loginfo default_loginfo = { + .type = NF_LOG_TYPE_LOG, + .u = { + .log = { + .level = LOGLEVEL_NOTICE, + .logflags = NF_LOG_DEFAULT_MASK, + }, + }, +}; + +/* One level of recursion won't kill us */ +static void dump_ipv4_packet(struct net *net, struct nf_log_buf *m, + const struct nf_loginfo *info, + const struct sk_buff *skb, unsigned int iphoff) +{ + struct iphdr _iph; + const struct iphdr *ih; + unsigned int logflags; + + if (info->type == NF_LOG_TYPE_LOG) + logflags = info->u.log.logflags; + else + logflags = NF_LOG_DEFAULT_MASK; + + ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph); + if (ih == NULL) { + nf_log_buf_add(m, "TRUNCATED"); + return; + } + + /* Important fields: + * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */ + /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */ + nf_log_buf_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr); + + /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ + nf_log_buf_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ", + ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK, + ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id)); + + /* Max length: 6 "CE DF MF " */ + if (ntohs(ih->frag_off) & IP_CE) + nf_log_buf_add(m, "CE "); + if (ntohs(ih->frag_off) & IP_DF) + nf_log_buf_add(m, "DF "); + if (ntohs(ih->frag_off) & IP_MF) + nf_log_buf_add(m, "MF "); + + /* Max length: 11 "FRAG:65535 " */ + if (ntohs(ih->frag_off) & IP_OFFSET) + nf_log_buf_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET); + + if ((logflags & NF_LOG_IPOPT) && + ih->ihl * 4 > sizeof(struct iphdr)) { + const unsigned char *op; + unsigned char _opt[4 * 15 - sizeof(struct iphdr)]; + unsigned int i, optsize; + + optsize = ih->ihl * 4 - sizeof(struct iphdr); + op = skb_header_pointer(skb, iphoff+sizeof(_iph), + optsize, _opt); + if (op == NULL) { + nf_log_buf_add(m, "TRUNCATED"); + return; + } + + /* Max length: 127 "OPT (" 15*4*2chars ") " */ + nf_log_buf_add(m, "OPT ("); + for (i = 0; i < optsize; i++) + nf_log_buf_add(m, "%02X", op[i]); + nf_log_buf_add(m, ") "); + } + + switch (ih->protocol) { + case IPPROTO_TCP: + if (nf_log_dump_tcp_header(m, skb, ih->protocol, + ntohs(ih->frag_off) & IP_OFFSET, + iphoff+ih->ihl*4, logflags)) + return; + break; + case IPPROTO_UDP: + case IPPROTO_UDPLITE: + if (nf_log_dump_udp_header(m, skb, ih->protocol, + ntohs(ih->frag_off) & IP_OFFSET, + iphoff+ih->ihl*4)) + return; + break; + case IPPROTO_ICMP: { + struct icmphdr _icmph; + const struct icmphdr *ich; + static const size_t required_len[NR_ICMP_TYPES+1] + = { [ICMP_ECHOREPLY] = 4, + [ICMP_DEST_UNREACH] + = 8 + sizeof(struct iphdr), + [ICMP_SOURCE_QUENCH] + = 8 + sizeof(struct iphdr), + [ICMP_REDIRECT] + = 8 + sizeof(struct iphdr), + [ICMP_ECHO] = 4, + [ICMP_TIME_EXCEEDED] + = 8 + sizeof(struct iphdr), + [ICMP_PARAMETERPROB] + = 8 + sizeof(struct iphdr), + [ICMP_TIMESTAMP] = 20, + [ICMP_TIMESTAMPREPLY] = 20, + [ICMP_ADDRESS] = 12, + [ICMP_ADDRESSREPLY] = 12 }; + + /* Max length: 11 "PROTO=ICMP " */ + nf_log_buf_add(m, "PROTO=ICMP "); + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + ich = skb_header_pointer(skb, iphoff + ih->ihl * 4, + sizeof(_icmph), &_icmph); + if (ich == NULL) { + nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + /* Max length: 18 "TYPE=255 CODE=255 " */ + nf_log_buf_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code); + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + if (ich->type <= NR_ICMP_TYPES && + required_len[ich->type] && + skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) { + nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + switch (ich->type) { + case ICMP_ECHOREPLY: + case ICMP_ECHO: + /* Max length: 19 "ID=65535 SEQ=65535 " */ + nf_log_buf_add(m, "ID=%u SEQ=%u ", + ntohs(ich->un.echo.id), + ntohs(ich->un.echo.sequence)); + break; + + case ICMP_PARAMETERPROB: + /* Max length: 14 "PARAMETER=255 " */ + nf_log_buf_add(m, "PARAMETER=%u ", + ntohl(ich->un.gateway) >> 24); + break; + case ICMP_REDIRECT: + /* Max length: 24 "GATEWAY=255.255.255.255 " */ + nf_log_buf_add(m, "GATEWAY=%pI4 ", &ich->un.gateway); + fallthrough; + case ICMP_DEST_UNREACH: + case ICMP_SOURCE_QUENCH: + case ICMP_TIME_EXCEEDED: + /* Max length: 3+maxlen */ + if (!iphoff) { /* Only recurse once. */ + nf_log_buf_add(m, "["); + dump_ipv4_packet(net, m, info, skb, + iphoff + ih->ihl*4+sizeof(_icmph)); + nf_log_buf_add(m, "] "); + } + + /* Max length: 10 "MTU=65535 " */ + if (ich->type == ICMP_DEST_UNREACH && + ich->code == ICMP_FRAG_NEEDED) { + nf_log_buf_add(m, "MTU=%u ", + ntohs(ich->un.frag.mtu)); + } + } + break; + } + /* Max Length */ + case IPPROTO_AH: { + struct ip_auth_hdr _ahdr; + const struct ip_auth_hdr *ah; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + /* Max length: 9 "PROTO=AH " */ + nf_log_buf_add(m, "PROTO=AH "); + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + ah = skb_header_pointer(skb, iphoff+ih->ihl*4, + sizeof(_ahdr), &_ahdr); + if (ah == NULL) { + nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + /* Length: 15 "SPI=0xF1234567 " */ + nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi)); + break; + } + case IPPROTO_ESP: { + struct ip_esp_hdr _esph; + const struct ip_esp_hdr *eh; + + /* Max length: 10 "PROTO=ESP " */ + nf_log_buf_add(m, "PROTO=ESP "); + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + eh = skb_header_pointer(skb, iphoff+ih->ihl*4, + sizeof(_esph), &_esph); + if (eh == NULL) { + nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + /* Length: 15 "SPI=0xF1234567 " */ + nf_log_buf_add(m, "SPI=0x%x ", ntohl(eh->spi)); + break; + } + /* Max length: 10 "PROTO 255 " */ + default: + nf_log_buf_add(m, "PROTO=%u ", ih->protocol); + } + + /* Max length: 15 "UID=4294967295 " */ + if ((logflags & NF_LOG_UID) && !iphoff) + nf_log_dump_sk_uid_gid(net, m, skb->sk); + + /* Max length: 16 "MARK=0xFFFFFFFF " */ + if (!iphoff && skb->mark) + nf_log_buf_add(m, "MARK=0x%x ", skb->mark); + + /* Proto Max log string length */ + /* IP: 40+46+6+11+127 = 230 */ + /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */ + /* UDP: 10+max(25,20) = 35 */ + /* UDPLITE: 14+max(25,20) = 39 */ + /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */ + /* ESP: 10+max(25)+15 = 50 */ + /* AH: 9+max(25)+15 = 49 */ + /* unknown: 10 */ + + /* (ICMP allows recursion one level deep) */ + /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */ + /* maxlen = 230+ 91 + 230 + 252 = 803 */ +} + +static void dump_ipv4_mac_header(struct nf_log_buf *m, + const struct nf_loginfo *info, + const struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + unsigned int logflags = 0; + + if (info->type == NF_LOG_TYPE_LOG) + logflags = info->u.log.logflags; + + if (!(logflags & NF_LOG_MACDECODE)) + goto fallback; + + switch (dev->type) { + case ARPHRD_ETHER: + nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM ", + eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest); + nf_log_dump_vlan(m, skb); + nf_log_buf_add(m, "MACPROTO=%04x ", + ntohs(eth_hdr(skb)->h_proto)); + return; + default: + break; + } + +fallback: + nf_log_buf_add(m, "MAC="); + if (dev->hard_header_len && + skb->mac_header != skb->network_header) { + const unsigned char *p = skb_mac_header(skb); + unsigned int i; + + nf_log_buf_add(m, "%02x", *p++); + for (i = 1; i < dev->hard_header_len; i++, p++) + nf_log_buf_add(m, ":%02x", *p); + } + nf_log_buf_add(m, " "); +} + +static void nf_log_ip_packet(struct net *net, u_int8_t pf, + unsigned int hooknum, const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *loginfo, + const char *prefix) +{ + struct nf_log_buf *m; + + /* FIXME: Disabled from containers until syslog ns is supported */ + if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) + return; + + m = nf_log_buf_open(); + + if (!loginfo) + loginfo = &default_loginfo; + + nf_log_dump_packet_common(m, pf, hooknum, skb, in, + out, loginfo, prefix); + + if (in != NULL) + dump_ipv4_mac_header(m, loginfo, skb); + + dump_ipv4_packet(net, m, loginfo, skb, 0); + + nf_log_buf_close(m); +} + +static struct nf_logger nf_ip_logger __read_mostly = { + .name = "nf_log_ipv4", + .type = NF_LOG_TYPE_LOG, + .logfn = nf_log_ip_packet, + .me = THIS_MODULE, +}; + +static int __net_init nf_log_ipv4_net_init(struct net *net) +{ + return nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger); +} + +static void __net_exit nf_log_ipv4_net_exit(struct net *net) +{ + nf_log_unset(net, &nf_ip_logger); +} + +static struct pernet_operations nf_log_ipv4_net_ops = { + .init = nf_log_ipv4_net_init, + .exit = nf_log_ipv4_net_exit, +}; + +static int __init nf_log_ipv4_init(void) +{ + int ret; + + ret = register_pernet_subsys(&nf_log_ipv4_net_ops); + if (ret < 0) + return ret; + + ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger); + if (ret < 0) { + pr_err("failed to register logger\n"); + goto err1; + } + + return 0; + +err1: + unregister_pernet_subsys(&nf_log_ipv4_net_ops); + return ret; +} + +static void __exit nf_log_ipv4_exit(void) +{ + unregister_pernet_subsys(&nf_log_ipv4_net_ops); + nf_log_unregister(&nf_ip_logger); +} + +module_init(nf_log_ipv4_init); +module_exit(nf_log_ipv4_exit); + +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("Netfilter IPv4 packet logging"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NF_LOGGER(AF_INET, 0); diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c new file mode 100644 index 000000000..3e2685c12 --- /dev/null +++ b/net/ipv4/netfilter/nf_nat_h323.c @@ -0,0 +1,633 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * H.323 extension for NAT alteration. + * + * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net> + * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net> + * + * Based on the 'brute force' H.323 NAT module by + * Jozsef Kadlecsik <kadlec@netfilter.org> + */ + +#include <linux/module.h> +#include <linux/tcp.h> +#include <net/tcp.h> + +#include <net/netfilter/nf_nat.h> +#include <net/netfilter/nf_nat_helper.h> +#include <net/netfilter/nf_conntrack_helper.h> +#include <net/netfilter/nf_conntrack_expect.h> +#include <linux/netfilter/nf_conntrack_h323.h> + +/****************************************************************************/ +static int set_addr(struct sk_buff *skb, unsigned int protoff, + unsigned char **data, int dataoff, + unsigned int addroff, __be32 ip, __be16 port) +{ + enum ip_conntrack_info ctinfo; + struct nf_conn *ct = nf_ct_get(skb, &ctinfo); + struct { + __be32 ip; + __be16 port; + } __attribute__ ((__packed__)) buf; + const struct tcphdr *th; + struct tcphdr _tcph; + + buf.ip = ip; + buf.port = port; + addroff += dataoff; + + if (ip_hdr(skb)->protocol == IPPROTO_TCP) { + if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, + protoff, addroff, sizeof(buf), + (char *) &buf, sizeof(buf))) { + net_notice_ratelimited("nf_nat_h323: nf_nat_mangle_tcp_packet error\n"); + return -1; + } + + /* Relocate data pointer */ + th = skb_header_pointer(skb, ip_hdrlen(skb), + sizeof(_tcph), &_tcph); + if (th == NULL) + return -1; + *data = skb->data + ip_hdrlen(skb) + th->doff * 4 + dataoff; + } else { + if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, + protoff, addroff, sizeof(buf), + (char *) &buf, sizeof(buf))) { + net_notice_ratelimited("nf_nat_h323: nf_nat_mangle_udp_packet error\n"); + return -1; + } + /* nf_nat_mangle_udp_packet uses skb_ensure_writable() to copy + * or pull everything in a linear buffer, so we can safely + * use the skb pointers now */ + *data = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr); + } + + return 0; +} + +/****************************************************************************/ +static int set_h225_addr(struct sk_buff *skb, unsigned int protoff, + unsigned char **data, int dataoff, + TransportAddress *taddr, + union nf_inet_addr *addr, __be16 port) +{ + return set_addr(skb, protoff, data, dataoff, taddr->ipAddress.ip, + addr->ip, port); +} + +/****************************************************************************/ +static int set_h245_addr(struct sk_buff *skb, unsigned protoff, + unsigned char **data, int dataoff, + H245_TransportAddress *taddr, + union nf_inet_addr *addr, __be16 port) +{ + return set_addr(skb, protoff, data, dataoff, + taddr->unicastAddress.iPAddress.network, + addr->ip, port); +} + +/****************************************************************************/ +static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, unsigned char **data, + TransportAddress *taddr, int count) +{ + const struct nf_ct_h323_master *info = nfct_help_data(ct); + int dir = CTINFO2DIR(ctinfo); + int i; + __be16 port; + union nf_inet_addr addr; + + for (i = 0; i < count; i++) { + if (get_h225_addr(ct, *data, &taddr[i], &addr, &port)) { + if (addr.ip == ct->tuplehash[dir].tuple.src.u3.ip && + port == info->sig_port[dir]) { + /* GW->GK */ + + /* Fix for Gnomemeeting */ + if (i > 0 && + get_h225_addr(ct, *data, &taddr[0], + &addr, &port) && + (ntohl(addr.ip) & 0xff000000) == 0x7f000000) + i = 0; + + pr_debug("nf_nat_ras: set signal address %pI4:%hu->%pI4:%hu\n", + &addr.ip, port, + &ct->tuplehash[!dir].tuple.dst.u3.ip, + info->sig_port[!dir]); + return set_h225_addr(skb, protoff, data, 0, + &taddr[i], + &ct->tuplehash[!dir]. + tuple.dst.u3, + info->sig_port[!dir]); + } else if (addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip && + port == info->sig_port[dir]) { + /* GK->GW */ + pr_debug("nf_nat_ras: set signal address %pI4:%hu->%pI4:%hu\n", + &addr.ip, port, + &ct->tuplehash[!dir].tuple.src.u3.ip, + info->sig_port[!dir]); + return set_h225_addr(skb, protoff, data, 0, + &taddr[i], + &ct->tuplehash[!dir]. + tuple.src.u3, + info->sig_port[!dir]); + } + } + } + + return 0; +} + +/****************************************************************************/ +static int set_ras_addr(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, unsigned char **data, + TransportAddress *taddr, int count) +{ + int dir = CTINFO2DIR(ctinfo); + int i; + __be16 port; + union nf_inet_addr addr; + + for (i = 0; i < count; i++) { + if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) && + addr.ip == ct->tuplehash[dir].tuple.src.u3.ip && + port == ct->tuplehash[dir].tuple.src.u.udp.port) { + pr_debug("nf_nat_ras: set rasAddress %pI4:%hu->%pI4:%hu\n", + &addr.ip, ntohs(port), + &ct->tuplehash[!dir].tuple.dst.u3.ip, + ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port)); + return set_h225_addr(skb, protoff, data, 0, &taddr[i], + &ct->tuplehash[!dir].tuple.dst.u3, + ct->tuplehash[!dir].tuple. + dst.u.udp.port); + } + } + + return 0; +} + +/****************************************************************************/ +static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, unsigned char **data, int dataoff, + H245_TransportAddress *taddr, + __be16 port, __be16 rtp_port, + struct nf_conntrack_expect *rtp_exp, + struct nf_conntrack_expect *rtcp_exp) +{ + struct nf_ct_h323_master *info = nfct_help_data(ct); + int dir = CTINFO2DIR(ctinfo); + int i; + u_int16_t nated_port; + + /* Set expectations for NAT */ + rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port; + rtp_exp->expectfn = nf_nat_follow_master; + rtp_exp->dir = !dir; + rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port; + rtcp_exp->expectfn = nf_nat_follow_master; + rtcp_exp->dir = !dir; + + /* Lookup existing expects */ + for (i = 0; i < H323_RTP_CHANNEL_MAX; i++) { + if (info->rtp_port[i][dir] == rtp_port) { + /* Expected */ + + /* Use allocated ports first. This will refresh + * the expects */ + rtp_exp->tuple.dst.u.udp.port = info->rtp_port[i][dir]; + rtcp_exp->tuple.dst.u.udp.port = + htons(ntohs(info->rtp_port[i][dir]) + 1); + break; + } else if (info->rtp_port[i][dir] == 0) { + /* Not expected */ + break; + } + } + + /* Run out of expectations */ + if (i >= H323_RTP_CHANNEL_MAX) { + net_notice_ratelimited("nf_nat_h323: out of expectations\n"); + return 0; + } + + /* Try to get a pair of ports. */ + for (nated_port = ntohs(rtp_exp->tuple.dst.u.udp.port); + nated_port != 0; nated_port += 2) { + int ret; + + rtp_exp->tuple.dst.u.udp.port = htons(nated_port); + ret = nf_ct_expect_related(rtp_exp, 0); + if (ret == 0) { + rtcp_exp->tuple.dst.u.udp.port = + htons(nated_port + 1); + ret = nf_ct_expect_related(rtcp_exp, 0); + if (ret == 0) + break; + else if (ret == -EBUSY) { + nf_ct_unexpect_related(rtp_exp); + continue; + } else if (ret < 0) { + nf_ct_unexpect_related(rtp_exp); + nated_port = 0; + break; + } + } else if (ret != -EBUSY) { + nated_port = 0; + break; + } + } + + if (nated_port == 0) { /* No port available */ + net_notice_ratelimited("nf_nat_h323: out of RTP ports\n"); + return 0; + } + + /* Modify signal */ + if (set_h245_addr(skb, protoff, data, dataoff, taddr, + &ct->tuplehash[!dir].tuple.dst.u3, + htons((port & htons(1)) ? nated_port + 1 : + nated_port))) { + nf_ct_unexpect_related(rtp_exp); + nf_ct_unexpect_related(rtcp_exp); + return -1; + } + + /* Save ports */ + info->rtp_port[i][dir] = rtp_port; + info->rtp_port[i][!dir] = htons(nated_port); + + /* Success */ + pr_debug("nf_nat_h323: expect RTP %pI4:%hu->%pI4:%hu\n", + &rtp_exp->tuple.src.u3.ip, + ntohs(rtp_exp->tuple.src.u.udp.port), + &rtp_exp->tuple.dst.u3.ip, + ntohs(rtp_exp->tuple.dst.u.udp.port)); + pr_debug("nf_nat_h323: expect RTCP %pI4:%hu->%pI4:%hu\n", + &rtcp_exp->tuple.src.u3.ip, + ntohs(rtcp_exp->tuple.src.u.udp.port), + &rtcp_exp->tuple.dst.u3.ip, + ntohs(rtcp_exp->tuple.dst.u.udp.port)); + + return 0; +} + +/****************************************************************************/ +static int nat_t120(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, unsigned char **data, int dataoff, + H245_TransportAddress *taddr, __be16 port, + struct nf_conntrack_expect *exp) +{ + int dir = CTINFO2DIR(ctinfo); + u_int16_t nated_port = ntohs(port); + + /* Set expectations for NAT */ + exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; + exp->expectfn = nf_nat_follow_master; + exp->dir = !dir; + + /* Try to get same port: if not, try to change it. */ + for (; nated_port != 0; nated_port++) { + int ret; + + exp->tuple.dst.u.tcp.port = htons(nated_port); + ret = nf_ct_expect_related(exp, 0); + if (ret == 0) + break; + else if (ret != -EBUSY) { + nated_port = 0; + break; + } + } + + if (nated_port == 0) { /* No port available */ + net_notice_ratelimited("nf_nat_h323: out of TCP ports\n"); + return 0; + } + + /* Modify signal */ + if (set_h245_addr(skb, protoff, data, dataoff, taddr, + &ct->tuplehash[!dir].tuple.dst.u3, + htons(nated_port)) < 0) { + nf_ct_unexpect_related(exp); + return -1; + } + + pr_debug("nf_nat_h323: expect T.120 %pI4:%hu->%pI4:%hu\n", + &exp->tuple.src.u3.ip, + ntohs(exp->tuple.src.u.tcp.port), + &exp->tuple.dst.u3.ip, + ntohs(exp->tuple.dst.u.tcp.port)); + + return 0; +} + +/****************************************************************************/ +static int nat_h245(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, unsigned char **data, int dataoff, + TransportAddress *taddr, __be16 port, + struct nf_conntrack_expect *exp) +{ + struct nf_ct_h323_master *info = nfct_help_data(ct); + int dir = CTINFO2DIR(ctinfo); + u_int16_t nated_port = ntohs(port); + + /* Set expectations for NAT */ + exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; + exp->expectfn = nf_nat_follow_master; + exp->dir = !dir; + + /* Check existing expects */ + if (info->sig_port[dir] == port) + nated_port = ntohs(info->sig_port[!dir]); + + /* Try to get same port: if not, try to change it. */ + for (; nated_port != 0; nated_port++) { + int ret; + + exp->tuple.dst.u.tcp.port = htons(nated_port); + ret = nf_ct_expect_related(exp, 0); + if (ret == 0) + break; + else if (ret != -EBUSY) { + nated_port = 0; + break; + } + } + + if (nated_port == 0) { /* No port available */ + net_notice_ratelimited("nf_nat_q931: out of TCP ports\n"); + return 0; + } + + /* Modify signal */ + if (set_h225_addr(skb, protoff, data, dataoff, taddr, + &ct->tuplehash[!dir].tuple.dst.u3, + htons(nated_port))) { + nf_ct_unexpect_related(exp); + return -1; + } + + /* Save ports */ + info->sig_port[dir] = port; + info->sig_port[!dir] = htons(nated_port); + + pr_debug("nf_nat_q931: expect H.245 %pI4:%hu->%pI4:%hu\n", + &exp->tuple.src.u3.ip, + ntohs(exp->tuple.src.u.tcp.port), + &exp->tuple.dst.u3.ip, + ntohs(exp->tuple.dst.u.tcp.port)); + + return 0; +} + +/**************************************************************************** + * This conntrack expect function replaces nf_conntrack_q931_expect() + * which was set by nf_conntrack_h323.c. + ****************************************************************************/ +static void ip_nat_q931_expect(struct nf_conn *new, + struct nf_conntrack_expect *this) +{ + struct nf_nat_range2 range; + + if (this->tuple.src.u3.ip != 0) { /* Only accept calls from GK */ + nf_nat_follow_master(new, this); + return; + } + + /* This must be a fresh one. */ + BUG_ON(new->status & IPS_NAT_DONE_MASK); + + /* Change src to where master sends to */ + range.flags = NF_NAT_RANGE_MAP_IPS; + range.min_addr = range.max_addr = + new->tuplehash[!this->dir].tuple.src.u3; + nf_nat_setup_info(new, &range, NF_NAT_MANIP_SRC); + + /* For DST manip, map port here to where it's expected. */ + range.flags = (NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED); + range.min_proto = range.max_proto = this->saved_proto; + range.min_addr = range.max_addr = + new->master->tuplehash[!this->dir].tuple.src.u3; + nf_nat_setup_info(new, &range, NF_NAT_MANIP_DST); +} + +/****************************************************************************/ +static int nat_q931(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, unsigned char **data, + TransportAddress *taddr, int idx, + __be16 port, struct nf_conntrack_expect *exp) +{ + struct nf_ct_h323_master *info = nfct_help_data(ct); + int dir = CTINFO2DIR(ctinfo); + u_int16_t nated_port = ntohs(port); + union nf_inet_addr addr; + + /* Set expectations for NAT */ + exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; + exp->expectfn = ip_nat_q931_expect; + exp->dir = !dir; + + /* Check existing expects */ + if (info->sig_port[dir] == port) + nated_port = ntohs(info->sig_port[!dir]); + + /* Try to get same port: if not, try to change it. */ + for (; nated_port != 0; nated_port++) { + int ret; + + exp->tuple.dst.u.tcp.port = htons(nated_port); + ret = nf_ct_expect_related(exp, 0); + if (ret == 0) + break; + else if (ret != -EBUSY) { + nated_port = 0; + break; + } + } + + if (nated_port == 0) { /* No port available */ + net_notice_ratelimited("nf_nat_ras: out of TCP ports\n"); + return 0; + } + + /* Modify signal */ + if (set_h225_addr(skb, protoff, data, 0, &taddr[idx], + &ct->tuplehash[!dir].tuple.dst.u3, + htons(nated_port))) { + nf_ct_unexpect_related(exp); + return -1; + } + + /* Save ports */ + info->sig_port[dir] = port; + info->sig_port[!dir] = htons(nated_port); + + /* Fix for Gnomemeeting */ + if (idx > 0 && + get_h225_addr(ct, *data, &taddr[0], &addr, &port) && + (ntohl(addr.ip) & 0xff000000) == 0x7f000000) { + if (set_h225_addr(skb, protoff, data, 0, &taddr[0], + &ct->tuplehash[!dir].tuple.dst.u3, + info->sig_port[!dir])) { + nf_ct_unexpect_related(exp); + return -1; + } + } + + /* Success */ + pr_debug("nf_nat_ras: expect Q.931 %pI4:%hu->%pI4:%hu\n", + &exp->tuple.src.u3.ip, + ntohs(exp->tuple.src.u.tcp.port), + &exp->tuple.dst.u3.ip, + ntohs(exp->tuple.dst.u.tcp.port)); + + return 0; +} + +/****************************************************************************/ +static void ip_nat_callforwarding_expect(struct nf_conn *new, + struct nf_conntrack_expect *this) +{ + struct nf_nat_range2 range; + + /* This must be a fresh one. */ + BUG_ON(new->status & IPS_NAT_DONE_MASK); + + /* Change src to where master sends to */ + range.flags = NF_NAT_RANGE_MAP_IPS; + range.min_addr = range.max_addr = + new->tuplehash[!this->dir].tuple.src.u3; + nf_nat_setup_info(new, &range, NF_NAT_MANIP_SRC); + + /* For DST manip, map port here to where it's expected. */ + range.flags = (NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED); + range.min_proto = range.max_proto = this->saved_proto; + range.min_addr = range.max_addr = this->saved_addr; + nf_nat_setup_info(new, &range, NF_NAT_MANIP_DST); +} + +/****************************************************************************/ +static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, + unsigned char **data, int dataoff, + TransportAddress *taddr, __be16 port, + struct nf_conntrack_expect *exp) +{ + int dir = CTINFO2DIR(ctinfo); + u_int16_t nated_port; + + /* Set expectations for NAT */ + exp->saved_addr = exp->tuple.dst.u3; + exp->tuple.dst.u3.ip = ct->tuplehash[!dir].tuple.dst.u3.ip; + exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; + exp->expectfn = ip_nat_callforwarding_expect; + exp->dir = !dir; + + /* Try to get same port: if not, try to change it. */ + for (nated_port = ntohs(port); nated_port != 0; nated_port++) { + int ret; + + exp->tuple.dst.u.tcp.port = htons(nated_port); + ret = nf_ct_expect_related(exp, 0); + if (ret == 0) + break; + else if (ret != -EBUSY) { + nated_port = 0; + break; + } + } + + if (nated_port == 0) { /* No port available */ + net_notice_ratelimited("nf_nat_q931: out of TCP ports\n"); + return 0; + } + + /* Modify signal */ + if (set_h225_addr(skb, protoff, data, dataoff, taddr, + &ct->tuplehash[!dir].tuple.dst.u3, + htons(nated_port))) { + nf_ct_unexpect_related(exp); + return -1; + } + + /* Success */ + pr_debug("nf_nat_q931: expect Call Forwarding %pI4:%hu->%pI4:%hu\n", + &exp->tuple.src.u3.ip, + ntohs(exp->tuple.src.u.tcp.port), + &exp->tuple.dst.u3.ip, + ntohs(exp->tuple.dst.u.tcp.port)); + + return 0; +} + +static struct nf_ct_helper_expectfn q931_nat = { + .name = "Q.931", + .expectfn = ip_nat_q931_expect, +}; + +static struct nf_ct_helper_expectfn callforwarding_nat = { + .name = "callforwarding", + .expectfn = ip_nat_callforwarding_expect, +}; + +/****************************************************************************/ +static int __init init(void) +{ + BUG_ON(set_h245_addr_hook != NULL); + BUG_ON(set_h225_addr_hook != NULL); + BUG_ON(set_sig_addr_hook != NULL); + BUG_ON(set_ras_addr_hook != NULL); + BUG_ON(nat_rtp_rtcp_hook != NULL); + BUG_ON(nat_t120_hook != NULL); + BUG_ON(nat_h245_hook != NULL); + BUG_ON(nat_callforwarding_hook != NULL); + BUG_ON(nat_q931_hook != NULL); + + RCU_INIT_POINTER(set_h245_addr_hook, set_h245_addr); + RCU_INIT_POINTER(set_h225_addr_hook, set_h225_addr); + RCU_INIT_POINTER(set_sig_addr_hook, set_sig_addr); + RCU_INIT_POINTER(set_ras_addr_hook, set_ras_addr); + RCU_INIT_POINTER(nat_rtp_rtcp_hook, nat_rtp_rtcp); + RCU_INIT_POINTER(nat_t120_hook, nat_t120); + RCU_INIT_POINTER(nat_h245_hook, nat_h245); + RCU_INIT_POINTER(nat_callforwarding_hook, nat_callforwarding); + RCU_INIT_POINTER(nat_q931_hook, nat_q931); + nf_ct_helper_expectfn_register(&q931_nat); + nf_ct_helper_expectfn_register(&callforwarding_nat); + return 0; +} + +/****************************************************************************/ +static void __exit fini(void) +{ + RCU_INIT_POINTER(set_h245_addr_hook, NULL); + RCU_INIT_POINTER(set_h225_addr_hook, NULL); + RCU_INIT_POINTER(set_sig_addr_hook, NULL); + RCU_INIT_POINTER(set_ras_addr_hook, NULL); + RCU_INIT_POINTER(nat_rtp_rtcp_hook, NULL); + RCU_INIT_POINTER(nat_t120_hook, NULL); + RCU_INIT_POINTER(nat_h245_hook, NULL); + RCU_INIT_POINTER(nat_callforwarding_hook, NULL); + RCU_INIT_POINTER(nat_q931_hook, NULL); + nf_ct_helper_expectfn_unregister(&q931_nat); + nf_ct_helper_expectfn_unregister(&callforwarding_nat); + synchronize_rcu(); +} + +/****************************************************************************/ +module_init(init); +module_exit(fini); + +MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>"); +MODULE_DESCRIPTION("H.323 NAT helper"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NF_NAT_HELPER("h323"); diff --git a/net/ipv4/netfilter/nf_nat_pptp.c b/net/ipv4/netfilter/nf_nat_pptp.c new file mode 100644 index 000000000..3f248a19f --- /dev/null +++ b/net/ipv4/netfilter/nf_nat_pptp.c @@ -0,0 +1,324 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * nf_nat_pptp.c + * + * NAT support for PPTP (Point to Point Tunneling Protocol). + * PPTP is a protocol for creating virtual private networks. + * It is a specification defined by Microsoft and some vendors + * working with Microsoft. PPTP is built on top of a modified + * version of the Internet Generic Routing Encapsulation Protocol. + * GRE is defined in RFC 1701 and RFC 1702. Documentation of + * PPTP can be found in RFC 2637 + * + * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org> + * + * Development of this code funded by Astaro AG (http://www.astaro.com/) + * + * (C) 2006-2012 Patrick McHardy <kaber@trash.net> + * + * TODO: - NAT to a unique tuple, not to TCP source port + * (needs netfilter tuple reservation) + */ + +#include <linux/module.h> +#include <linux/tcp.h> + +#include <net/netfilter/nf_nat.h> +#include <net/netfilter/nf_nat_helper.h> +#include <net/netfilter/nf_conntrack_helper.h> +#include <net/netfilter/nf_conntrack_expect.h> +#include <net/netfilter/nf_conntrack_zones.h> +#include <linux/netfilter/nf_conntrack_proto_gre.h> +#include <linux/netfilter/nf_conntrack_pptp.h> + +#define NF_NAT_PPTP_VERSION "3.0" + +#define REQ_CID(req, off) (*(__be16 *)((char *)(req) + (off))) + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>"); +MODULE_DESCRIPTION("Netfilter NAT helper module for PPTP"); +MODULE_ALIAS_NF_NAT_HELPER("pptp"); + +static void pptp_nat_expected(struct nf_conn *ct, + struct nf_conntrack_expect *exp) +{ + struct net *net = nf_ct_net(ct); + const struct nf_conn *master = ct->master; + struct nf_conntrack_expect *other_exp; + struct nf_conntrack_tuple t = {}; + const struct nf_ct_pptp_master *ct_pptp_info; + const struct nf_nat_pptp *nat_pptp_info; + struct nf_nat_range2 range; + struct nf_conn_nat *nat; + + nat = nf_ct_nat_ext_add(ct); + if (WARN_ON_ONCE(!nat)) + return; + + nat_pptp_info = &nat->help.nat_pptp_info; + ct_pptp_info = nfct_help_data(master); + + /* And here goes the grand finale of corrosion... */ + if (exp->dir == IP_CT_DIR_ORIGINAL) { + pr_debug("we are PNS->PAC\n"); + /* therefore, build tuple for PAC->PNS */ + t.src.l3num = AF_INET; + t.src.u3.ip = master->tuplehash[!exp->dir].tuple.src.u3.ip; + t.src.u.gre.key = ct_pptp_info->pac_call_id; + t.dst.u3.ip = master->tuplehash[!exp->dir].tuple.dst.u3.ip; + t.dst.u.gre.key = ct_pptp_info->pns_call_id; + t.dst.protonum = IPPROTO_GRE; + } else { + pr_debug("we are PAC->PNS\n"); + /* build tuple for PNS->PAC */ + t.src.l3num = AF_INET; + t.src.u3.ip = master->tuplehash[!exp->dir].tuple.src.u3.ip; + t.src.u.gre.key = nat_pptp_info->pns_call_id; + t.dst.u3.ip = master->tuplehash[!exp->dir].tuple.dst.u3.ip; + t.dst.u.gre.key = nat_pptp_info->pac_call_id; + t.dst.protonum = IPPROTO_GRE; + } + + pr_debug("trying to unexpect other dir: "); + nf_ct_dump_tuple_ip(&t); + other_exp = nf_ct_expect_find_get(net, nf_ct_zone(ct), &t); + if (other_exp) { + nf_ct_unexpect_related(other_exp); + nf_ct_expect_put(other_exp); + pr_debug("success\n"); + } else { + pr_debug("not found!\n"); + } + + /* This must be a fresh one. */ + BUG_ON(ct->status & IPS_NAT_DONE_MASK); + + /* Change src to where master sends to */ + range.flags = NF_NAT_RANGE_MAP_IPS; + range.min_addr = range.max_addr + = ct->master->tuplehash[!exp->dir].tuple.dst.u3; + if (exp->dir == IP_CT_DIR_ORIGINAL) { + range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; + range.min_proto = range.max_proto = exp->saved_proto; + } + nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC); + + /* For DST manip, map port here to where it's expected. */ + range.flags = NF_NAT_RANGE_MAP_IPS; + range.min_addr = range.max_addr + = ct->master->tuplehash[!exp->dir].tuple.src.u3; + if (exp->dir == IP_CT_DIR_REPLY) { + range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; + range.min_proto = range.max_proto = exp->saved_proto; + } + nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST); +} + +/* outbound packets == from PNS to PAC */ +static int +pptp_outbound_pkt(struct sk_buff *skb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, + struct PptpControlHeader *ctlh, + union pptp_ctrl_union *pptpReq) + +{ + struct nf_ct_pptp_master *ct_pptp_info; + struct nf_conn_nat *nat = nfct_nat(ct); + struct nf_nat_pptp *nat_pptp_info; + u_int16_t msg; + __be16 new_callid; + unsigned int cid_off; + + if (WARN_ON_ONCE(!nat)) + return NF_DROP; + + nat_pptp_info = &nat->help.nat_pptp_info; + ct_pptp_info = nfct_help_data(ct); + + new_callid = ct_pptp_info->pns_call_id; + + switch (msg = ntohs(ctlh->messageType)) { + case PPTP_OUT_CALL_REQUEST: + cid_off = offsetof(union pptp_ctrl_union, ocreq.callID); + /* FIXME: ideally we would want to reserve a call ID + * here. current netfilter NAT core is not able to do + * this :( For now we use TCP source port. This breaks + * multiple calls within one control session */ + + /* save original call ID in nat_info */ + nat_pptp_info->pns_call_id = ct_pptp_info->pns_call_id; + + /* don't use tcph->source since we are at a DSTmanip + * hook (e.g. PREROUTING) and pkt is not mangled yet */ + new_callid = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port; + + /* save new call ID in ct info */ + ct_pptp_info->pns_call_id = new_callid; + break; + case PPTP_IN_CALL_REPLY: + cid_off = offsetof(union pptp_ctrl_union, icack.callID); + break; + case PPTP_CALL_CLEAR_REQUEST: + cid_off = offsetof(union pptp_ctrl_union, clrreq.callID); + break; + default: + pr_debug("unknown outbound packet 0x%04x:%s\n", msg, + pptp_msg_name(msg)); + fallthrough; + case PPTP_SET_LINK_INFO: + /* only need to NAT in case PAC is behind NAT box */ + case PPTP_START_SESSION_REQUEST: + case PPTP_START_SESSION_REPLY: + case PPTP_STOP_SESSION_REQUEST: + case PPTP_STOP_SESSION_REPLY: + case PPTP_ECHO_REQUEST: + case PPTP_ECHO_REPLY: + /* no need to alter packet */ + return NF_ACCEPT; + } + + /* only OUT_CALL_REQUEST, IN_CALL_REPLY, CALL_CLEAR_REQUEST pass + * down to here */ + pr_debug("altering call id from 0x%04x to 0x%04x\n", + ntohs(REQ_CID(pptpReq, cid_off)), ntohs(new_callid)); + + /* mangle packet */ + if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff, + cid_off + sizeof(struct pptp_pkt_hdr) + + sizeof(struct PptpControlHeader), + sizeof(new_callid), (char *)&new_callid, + sizeof(new_callid))) + return NF_DROP; + return NF_ACCEPT; +} + +static void +pptp_exp_gre(struct nf_conntrack_expect *expect_orig, + struct nf_conntrack_expect *expect_reply) +{ + const struct nf_conn *ct = expect_orig->master; + struct nf_conn_nat *nat = nfct_nat(ct); + struct nf_ct_pptp_master *ct_pptp_info; + struct nf_nat_pptp *nat_pptp_info; + + if (WARN_ON_ONCE(!nat)) + return; + + nat_pptp_info = &nat->help.nat_pptp_info; + ct_pptp_info = nfct_help_data(ct); + + /* save original PAC call ID in nat_info */ + nat_pptp_info->pac_call_id = ct_pptp_info->pac_call_id; + + /* alter expectation for PNS->PAC direction */ + expect_orig->saved_proto.gre.key = ct_pptp_info->pns_call_id; + expect_orig->tuple.src.u.gre.key = nat_pptp_info->pns_call_id; + expect_orig->tuple.dst.u.gre.key = ct_pptp_info->pac_call_id; + expect_orig->dir = IP_CT_DIR_ORIGINAL; + + /* alter expectation for PAC->PNS direction */ + expect_reply->saved_proto.gre.key = nat_pptp_info->pns_call_id; + expect_reply->tuple.src.u.gre.key = nat_pptp_info->pac_call_id; + expect_reply->tuple.dst.u.gre.key = ct_pptp_info->pns_call_id; + expect_reply->dir = IP_CT_DIR_REPLY; +} + +/* inbound packets == from PAC to PNS */ +static int +pptp_inbound_pkt(struct sk_buff *skb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int protoff, + struct PptpControlHeader *ctlh, + union pptp_ctrl_union *pptpReq) +{ + const struct nf_nat_pptp *nat_pptp_info; + struct nf_conn_nat *nat = nfct_nat(ct); + u_int16_t msg; + __be16 new_pcid; + unsigned int pcid_off; + + if (WARN_ON_ONCE(!nat)) + return NF_DROP; + + nat_pptp_info = &nat->help.nat_pptp_info; + new_pcid = nat_pptp_info->pns_call_id; + + switch (msg = ntohs(ctlh->messageType)) { + case PPTP_OUT_CALL_REPLY: + pcid_off = offsetof(union pptp_ctrl_union, ocack.peersCallID); + break; + case PPTP_IN_CALL_CONNECT: + pcid_off = offsetof(union pptp_ctrl_union, iccon.peersCallID); + break; + case PPTP_IN_CALL_REQUEST: + /* only need to nat in case PAC is behind NAT box */ + return NF_ACCEPT; + case PPTP_WAN_ERROR_NOTIFY: + pcid_off = offsetof(union pptp_ctrl_union, wanerr.peersCallID); + break; + case PPTP_CALL_DISCONNECT_NOTIFY: + pcid_off = offsetof(union pptp_ctrl_union, disc.callID); + break; + case PPTP_SET_LINK_INFO: + pcid_off = offsetof(union pptp_ctrl_union, setlink.peersCallID); + break; + default: + pr_debug("unknown inbound packet %s\n", pptp_msg_name(msg)); + fallthrough; + case PPTP_START_SESSION_REQUEST: + case PPTP_START_SESSION_REPLY: + case PPTP_STOP_SESSION_REQUEST: + case PPTP_STOP_SESSION_REPLY: + case PPTP_ECHO_REQUEST: + case PPTP_ECHO_REPLY: + /* no need to alter packet */ + return NF_ACCEPT; + } + + /* only OUT_CALL_REPLY, IN_CALL_CONNECT, IN_CALL_REQUEST, + * WAN_ERROR_NOTIFY, CALL_DISCONNECT_NOTIFY pass down here */ + + /* mangle packet */ + pr_debug("altering peer call id from 0x%04x to 0x%04x\n", + ntohs(REQ_CID(pptpReq, pcid_off)), ntohs(new_pcid)); + + if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff, + pcid_off + sizeof(struct pptp_pkt_hdr) + + sizeof(struct PptpControlHeader), + sizeof(new_pcid), (char *)&new_pcid, + sizeof(new_pcid))) + return NF_DROP; + return NF_ACCEPT; +} + +static int __init nf_nat_helper_pptp_init(void) +{ + BUG_ON(nf_nat_pptp_hook_outbound != NULL); + RCU_INIT_POINTER(nf_nat_pptp_hook_outbound, pptp_outbound_pkt); + + BUG_ON(nf_nat_pptp_hook_inbound != NULL); + RCU_INIT_POINTER(nf_nat_pptp_hook_inbound, pptp_inbound_pkt); + + BUG_ON(nf_nat_pptp_hook_exp_gre != NULL); + RCU_INIT_POINTER(nf_nat_pptp_hook_exp_gre, pptp_exp_gre); + + BUG_ON(nf_nat_pptp_hook_expectfn != NULL); + RCU_INIT_POINTER(nf_nat_pptp_hook_expectfn, pptp_nat_expected); + return 0; +} + +static void __exit nf_nat_helper_pptp_fini(void) +{ + RCU_INIT_POINTER(nf_nat_pptp_hook_expectfn, NULL); + RCU_INIT_POINTER(nf_nat_pptp_hook_exp_gre, NULL); + RCU_INIT_POINTER(nf_nat_pptp_hook_inbound, NULL); + RCU_INIT_POINTER(nf_nat_pptp_hook_outbound, NULL); + synchronize_rcu(); +} + +module_init(nf_nat_helper_pptp_init); +module_exit(nf_nat_helper_pptp_fini); diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.asn1 b/net/ipv4/netfilter/nf_nat_snmp_basic.asn1 new file mode 100644 index 000000000..24b73268f --- /dev/null +++ b/net/ipv4/netfilter/nf_nat_snmp_basic.asn1 @@ -0,0 +1,177 @@ +Message ::= + SEQUENCE { + version + INTEGER ({snmp_version}), + + community + OCTET STRING, + + pdu + PDUs + } + + +ObjectName ::= + OBJECT IDENTIFIER + +ObjectSyntax ::= + CHOICE { + simple + SimpleSyntax, + + application-wide + ApplicationSyntax + } + +SimpleSyntax ::= + CHOICE { + integer-value + INTEGER, + + string-value + OCTET STRING, + + objectID-value + OBJECT IDENTIFIER + } + +ApplicationSyntax ::= + CHOICE { + ipAddress-value + IpAddress, + + counter-value + Counter32, + + timeticks-value + TimeTicks, + + arbitrary-value + Opaque, + + big-counter-value + Counter64, + + unsigned-integer-value + Unsigned32 + } + +IpAddress ::= + [APPLICATION 0] + IMPLICIT OCTET STRING OPTIONAL ({snmp_helper}) + +Counter32 ::= + [APPLICATION 1] + IMPLICIT INTEGER OPTIONAL + +Unsigned32 ::= + [APPLICATION 2] + IMPLICIT INTEGER OPTIONAL + +Gauge32 ::= Unsigned32 OPTIONAL + +TimeTicks ::= + [APPLICATION 3] + IMPLICIT INTEGER OPTIONAL + +Opaque ::= + [APPLICATION 4] + IMPLICIT OCTET STRING OPTIONAL + +Counter64 ::= + [APPLICATION 6] + IMPLICIT INTEGER OPTIONAL + +PDUs ::= + CHOICE { + get-request + GetRequest-PDU, + + get-next-request + GetNextRequest-PDU, + + get-bulk-request + GetBulkRequest-PDU, + + response + Response-PDU, + + set-request + SetRequest-PDU, + + inform-request + InformRequest-PDU, + + snmpV2-trap + SNMPv2-Trap-PDU, + + report + Report-PDU + } + +GetRequest-PDU ::= + [0] IMPLICIT PDU OPTIONAL + +GetNextRequest-PDU ::= + [1] IMPLICIT PDU OPTIONAL + +Response-PDU ::= + [2] IMPLICIT PDU OPTIONAL + +SetRequest-PDU ::= + [3] IMPLICIT PDU OPTIONAL + +-- [4] is obsolete + +GetBulkRequest-PDU ::= + [5] IMPLICIT PDU OPTIONAL + +InformRequest-PDU ::= + [6] IMPLICIT PDU OPTIONAL + +SNMPv2-Trap-PDU ::= + [7] IMPLICIT PDU OPTIONAL + +Report-PDU ::= + [8] IMPLICIT PDU OPTIONAL + +PDU ::= + SEQUENCE { + request-id + INTEGER, + + error-status + INTEGER, + + error-index + INTEGER, + + variable-bindings + VarBindList + } + + +VarBind ::= + SEQUENCE { + name + ObjectName, + + CHOICE { + value + ObjectSyntax, + + unSpecified + NULL, + + noSuchObject + [0] IMPLICIT NULL, + + noSuchInstance + [1] IMPLICIT NULL, + + endOfMibView + [2] IMPLICIT NULL + } +} + +VarBindList ::= SEQUENCE OF VarBind diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic_main.c b/net/ipv4/netfilter/nf_nat_snmp_basic_main.c new file mode 100644 index 000000000..717b72650 --- /dev/null +++ b/net/ipv4/netfilter/nf_nat_snmp_basic_main.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * nf_nat_snmp_basic.c + * + * Basic SNMP Application Layer Gateway + * + * This IP NAT module is intended for use with SNMP network + * discovery and monitoring applications where target networks use + * conflicting private address realms. + * + * Static NAT is used to remap the networks from the view of the network + * management system at the IP layer, and this module remaps some application + * layer addresses to match. + * + * The simplest form of ALG is performed, where only tagged IP addresses + * are modified. The module does not need to be MIB aware and only scans + * messages at the ASN.1/BER level. + * + * Currently, only SNMPv1 and SNMPv2 are supported. + * + * More information on ALG and associated issues can be found in + * RFC 2962 + * + * The ASB.1/BER parsing code is derived from the gxsnmp package by Gregory + * McLean & Jochen Friedrich, stripped down for use in the kernel. + * + * Copyright (c) 2000 RP Internet (www.rpi.net.au). + * + * Author: James Morris <jmorris@intercode.com.au> + * + * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net> + */ +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <net/checksum.h> +#include <net/udp.h> + +#include <net/netfilter/nf_nat.h> +#include <net/netfilter/nf_conntrack_expect.h> +#include <net/netfilter/nf_conntrack_helper.h> +#include <linux/netfilter/nf_conntrack_snmp.h> +#include "nf_nat_snmp_basic.asn1.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>"); +MODULE_DESCRIPTION("Basic SNMP Application Layer Gateway"); +MODULE_ALIAS("ip_nat_snmp_basic"); +MODULE_ALIAS_NFCT_HELPER("snmp_trap"); + +#define SNMP_PORT 161 +#define SNMP_TRAP_PORT 162 + +static DEFINE_SPINLOCK(snmp_lock); + +struct snmp_ctx { + unsigned char *begin; + __sum16 *check; + __be32 from; + __be32 to; +}; + +static void fast_csum(struct snmp_ctx *ctx, unsigned char offset) +{ + unsigned char s[12] = {0,}; + int size; + + if (offset & 1) { + memcpy(&s[1], &ctx->from, 4); + memcpy(&s[7], &ctx->to, 4); + s[0] = ~0; + s[1] = ~s[1]; + s[2] = ~s[2]; + s[3] = ~s[3]; + s[4] = ~s[4]; + s[5] = ~0; + size = 12; + } else { + memcpy(&s[0], &ctx->from, 4); + memcpy(&s[4], &ctx->to, 4); + s[0] = ~s[0]; + s[1] = ~s[1]; + s[2] = ~s[2]; + s[3] = ~s[3]; + size = 8; + } + *ctx->check = csum_fold(csum_partial(s, size, + ~csum_unfold(*ctx->check))); +} + +int snmp_version(void *context, size_t hdrlen, unsigned char tag, + const void *data, size_t datalen) +{ + if (datalen != 1) + return -EINVAL; + if (*(unsigned char *)data > 1) + return -ENOTSUPP; + return 1; +} + +int snmp_helper(void *context, size_t hdrlen, unsigned char tag, + const void *data, size_t datalen) +{ + struct snmp_ctx *ctx = (struct snmp_ctx *)context; + __be32 *pdata; + + if (datalen != 4) + return -EINVAL; + pdata = (__be32 *)data; + if (*pdata == ctx->from) { + pr_debug("%s: %pI4 to %pI4\n", __func__, + (void *)&ctx->from, (void *)&ctx->to); + + if (*ctx->check) + fast_csum(ctx, (unsigned char *)data - ctx->begin); + *pdata = ctx->to; + } + + return 1; +} + +static int snmp_translate(struct nf_conn *ct, int dir, struct sk_buff *skb) +{ + struct iphdr *iph = ip_hdr(skb); + struct udphdr *udph = (struct udphdr *)((__be32 *)iph + iph->ihl); + u16 datalen = ntohs(udph->len) - sizeof(struct udphdr); + char *data = (unsigned char *)udph + sizeof(struct udphdr); + struct snmp_ctx ctx; + int ret; + + if (dir == IP_CT_DIR_ORIGINAL) { + ctx.from = ct->tuplehash[dir].tuple.src.u3.ip; + ctx.to = ct->tuplehash[!dir].tuple.dst.u3.ip; + } else { + ctx.from = ct->tuplehash[!dir].tuple.src.u3.ip; + ctx.to = ct->tuplehash[dir].tuple.dst.u3.ip; + } + + if (ctx.from == ctx.to) + return NF_ACCEPT; + + ctx.begin = (unsigned char *)udph + sizeof(struct udphdr); + ctx.check = &udph->check; + ret = asn1_ber_decoder(&nf_nat_snmp_basic_decoder, &ctx, data, datalen); + if (ret < 0) { + nf_ct_helper_log(skb, ct, "parser failed\n"); + return NF_DROP; + } + + return NF_ACCEPT; +} + +/* We don't actually set up expectations, just adjust internal IP + * addresses if this is being NATted + */ +static int help(struct sk_buff *skb, unsigned int protoff, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo) +{ + int dir = CTINFO2DIR(ctinfo); + unsigned int ret; + const struct iphdr *iph = ip_hdr(skb); + const struct udphdr *udph = (struct udphdr *)((__be32 *)iph + iph->ihl); + + /* SNMP replies and originating SNMP traps get mangled */ + if (udph->source == htons(SNMP_PORT) && dir != IP_CT_DIR_REPLY) + return NF_ACCEPT; + if (udph->dest == htons(SNMP_TRAP_PORT) && dir != IP_CT_DIR_ORIGINAL) + return NF_ACCEPT; + + /* No NAT? */ + if (!(ct->status & IPS_NAT_MASK)) + return NF_ACCEPT; + + /* Make sure the packet length is ok. So far, we were only guaranteed + * to have a valid length IP header plus 8 bytes, which means we have + * enough room for a UDP header. Just verify the UDP length field so we + * can mess around with the payload. + */ + if (ntohs(udph->len) != skb->len - (iph->ihl << 2)) { + nf_ct_helper_log(skb, ct, "dropping malformed packet\n"); + return NF_DROP; + } + + if (skb_ensure_writable(skb, skb->len)) { + nf_ct_helper_log(skb, ct, "cannot mangle packet"); + return NF_DROP; + } + + spin_lock_bh(&snmp_lock); + ret = snmp_translate(ct, dir, skb); + spin_unlock_bh(&snmp_lock); + return ret; +} + +static const struct nf_conntrack_expect_policy snmp_exp_policy = { + .max_expected = 0, + .timeout = 180, +}; + +static struct nf_conntrack_helper snmp_trap_helper __read_mostly = { + .me = THIS_MODULE, + .help = help, + .expect_policy = &snmp_exp_policy, + .name = "snmp_trap", + .tuple.src.l3num = AF_INET, + .tuple.src.u.udp.port = cpu_to_be16(SNMP_TRAP_PORT), + .tuple.dst.protonum = IPPROTO_UDP, +}; + +static int __init nf_nat_snmp_basic_init(void) +{ + BUG_ON(nf_nat_snmp_hook != NULL); + RCU_INIT_POINTER(nf_nat_snmp_hook, help); + + return nf_conntrack_helper_register(&snmp_trap_helper); +} + +static void __exit nf_nat_snmp_basic_fini(void) +{ + RCU_INIT_POINTER(nf_nat_snmp_hook, NULL); + synchronize_rcu(); + nf_conntrack_helper_unregister(&snmp_trap_helper); +} + +module_init(nf_nat_snmp_basic_init); +module_exit(nf_nat_snmp_basic_fini); diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c new file mode 100644 index 000000000..efe14a6a5 --- /dev/null +++ b/net/ipv4/netfilter/nf_reject_ipv4.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> + */ + +#include <linux/module.h> +#include <net/ip.h> +#include <net/tcp.h> +#include <net/route.h> +#include <net/dst.h> +#include <net/netfilter/ipv4/nf_reject.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_bridge.h> + +const struct tcphdr *nf_reject_ip_tcphdr_get(struct sk_buff *oldskb, + struct tcphdr *_oth, int hook) +{ + const struct tcphdr *oth; + + /* IP header checks: fragment. */ + if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET)) + return NULL; + + if (ip_hdr(oldskb)->protocol != IPPROTO_TCP) + return NULL; + + oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb), + sizeof(struct tcphdr), _oth); + if (oth == NULL) + return NULL; + + /* No RST for RST. */ + if (oth->rst) + return NULL; + + /* Check checksum */ + if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP)) + return NULL; + + return oth; +} +EXPORT_SYMBOL_GPL(nf_reject_ip_tcphdr_get); + +struct iphdr *nf_reject_iphdr_put(struct sk_buff *nskb, + const struct sk_buff *oldskb, + __u8 protocol, int ttl) +{ + struct iphdr *niph, *oiph = ip_hdr(oldskb); + + skb_reset_network_header(nskb); + niph = skb_put(nskb, sizeof(struct iphdr)); + niph->version = 4; + niph->ihl = sizeof(struct iphdr) / 4; + niph->tos = 0; + niph->id = 0; + niph->frag_off = htons(IP_DF); + niph->protocol = protocol; + niph->check = 0; + niph->saddr = oiph->daddr; + niph->daddr = oiph->saddr; + niph->ttl = ttl; + + nskb->protocol = htons(ETH_P_IP); + + return niph; +} +EXPORT_SYMBOL_GPL(nf_reject_iphdr_put); + +void nf_reject_ip_tcphdr_put(struct sk_buff *nskb, const struct sk_buff *oldskb, + const struct tcphdr *oth) +{ + struct iphdr *niph = ip_hdr(nskb); + struct tcphdr *tcph; + + skb_reset_transport_header(nskb); + tcph = skb_put_zero(nskb, sizeof(struct tcphdr)); + tcph->source = oth->dest; + tcph->dest = oth->source; + tcph->doff = sizeof(struct tcphdr) / 4; + + if (oth->ack) { + tcph->seq = oth->ack_seq; + } else { + tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin + + oldskb->len - ip_hdrlen(oldskb) - + (oth->doff << 2)); + tcph->ack = 1; + } + + tcph->rst = 1; + tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), niph->saddr, + niph->daddr, 0); + nskb->ip_summed = CHECKSUM_PARTIAL; + nskb->csum_start = (unsigned char *)tcph - nskb->head; + nskb->csum_offset = offsetof(struct tcphdr, check); +} +EXPORT_SYMBOL_GPL(nf_reject_ip_tcphdr_put); + +static int nf_reject_fill_skb_dst(struct sk_buff *skb_in) +{ + struct dst_entry *dst = NULL; + struct flowi fl; + + memset(&fl, 0, sizeof(struct flowi)); + fl.u.ip4.daddr = ip_hdr(skb_in)->saddr; + nf_ip_route(dev_net(skb_in->dev), &dst, &fl, false); + if (!dst) + return -1; + + skb_dst_set(skb_in, dst); + return 0; +} + +/* Send RST reply */ +void nf_send_reset(struct net *net, struct sock *sk, struct sk_buff *oldskb, + int hook) +{ + struct net_device *br_indev __maybe_unused; + struct sk_buff *nskb; + struct iphdr *niph; + const struct tcphdr *oth; + struct tcphdr _oth; + + oth = nf_reject_ip_tcphdr_get(oldskb, &_oth, hook); + if (!oth) + return; + + if (hook == NF_INET_PRE_ROUTING && nf_reject_fill_skb_dst(oldskb)) + return; + + if (skb_rtable(oldskb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) + return; + + nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) + + LL_MAX_HEADER, GFP_ATOMIC); + if (!nskb) + return; + + /* ip_route_me_harder expects skb->dst to be set */ + skb_dst_set_noref(nskb, skb_dst(oldskb)); + + nskb->mark = IP4_REPLY_MARK(net, oldskb->mark); + + skb_reserve(nskb, LL_MAX_HEADER); + niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP, + ip4_dst_hoplimit(skb_dst(nskb))); + nf_reject_ip_tcphdr_put(nskb, oldskb, oth); + if (ip_route_me_harder(net, sk, nskb, RTN_UNSPEC)) + goto free_nskb; + + niph = ip_hdr(nskb); + + /* "Never happens" */ + if (nskb->len > dst_mtu(skb_dst(nskb))) + goto free_nskb; + + nf_ct_attach(nskb, oldskb); + +#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) + /* If we use ip_local_out for bridged traffic, the MAC source on + * the RST will be ours, instead of the destination's. This confuses + * some routers/firewalls, and they drop the packet. So we need to + * build the eth header using the original destination's MAC as the + * source, and send the RST packet directly. + */ + br_indev = nf_bridge_get_physindev(oldskb); + if (br_indev) { + struct ethhdr *oeth = eth_hdr(oldskb); + + nskb->dev = br_indev; + niph->tot_len = htons(nskb->len); + ip_send_check(niph); + if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol), + oeth->h_source, oeth->h_dest, nskb->len) < 0) + goto free_nskb; + dev_queue_xmit(nskb); + } else +#endif + ip_local_out(net, nskb->sk, nskb); + + return; + + free_nskb: + kfree_skb(nskb); +} +EXPORT_SYMBOL_GPL(nf_send_reset); + +void nf_send_unreach(struct sk_buff *skb_in, int code, int hook) +{ + struct iphdr *iph = ip_hdr(skb_in); + u8 proto = iph->protocol; + + if (iph->frag_off & htons(IP_OFFSET)) + return; + + if (hook == NF_INET_PRE_ROUTING && nf_reject_fill_skb_dst(skb_in)) + return; + + if (skb_csum_unnecessary(skb_in) || !nf_reject_verify_csum(proto)) { + icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0); + return; + } + + if (nf_ip_checksum(skb_in, hook, ip_hdrlen(skb_in), proto) == 0) + icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0); +} +EXPORT_SYMBOL_GPL(nf_send_unreach); + +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/netfilter/nf_socket_ipv4.c b/net/ipv4/netfilter/nf_socket_ipv4.c new file mode 100644 index 000000000..2d42e4c35 --- /dev/null +++ b/net/ipv4/netfilter/nf_socket_ipv4.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2007-2008 BalaBit IT Ltd. + * Author: Krisztian Kovacs + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/skbuff.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/icmp.h> +#include <net/sock.h> +#include <net/inet_sock.h> +#include <net/netfilter/nf_socket.h> +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#include <net/netfilter/nf_conntrack.h> +#endif + +static int +extract_icmp4_fields(const struct sk_buff *skb, u8 *protocol, + __be32 *raddr, __be32 *laddr, + __be16 *rport, __be16 *lport) +{ + unsigned int outside_hdrlen = ip_hdrlen(skb); + struct iphdr *inside_iph, _inside_iph; + struct icmphdr *icmph, _icmph; + __be16 *ports, _ports[2]; + + icmph = skb_header_pointer(skb, outside_hdrlen, + sizeof(_icmph), &_icmph); + if (icmph == NULL) + return 1; + + if (!icmp_is_err(icmph->type)) + return 1; + + inside_iph = skb_header_pointer(skb, outside_hdrlen + + sizeof(struct icmphdr), + sizeof(_inside_iph), &_inside_iph); + if (inside_iph == NULL) + return 1; + + if (inside_iph->protocol != IPPROTO_TCP && + inside_iph->protocol != IPPROTO_UDP) + return 1; + + ports = skb_header_pointer(skb, outside_hdrlen + + sizeof(struct icmphdr) + + (inside_iph->ihl << 2), + sizeof(_ports), &_ports); + if (ports == NULL) + return 1; + + /* the inside IP packet is the one quoted from our side, thus + * its saddr is the local address */ + *protocol = inside_iph->protocol; + *laddr = inside_iph->saddr; + *lport = ports[0]; + *raddr = inside_iph->daddr; + *rport = ports[1]; + + return 0; +} + +static struct sock * +nf_socket_get_sock_v4(struct net *net, struct sk_buff *skb, const int doff, + const u8 protocol, + const __be32 saddr, const __be32 daddr, + const __be16 sport, const __be16 dport, + const struct net_device *in) +{ + switch (protocol) { + case IPPROTO_TCP: + return inet_lookup(net, &tcp_hashinfo, skb, doff, + saddr, sport, daddr, dport, + in->ifindex); + case IPPROTO_UDP: + return udp4_lib_lookup(net, saddr, sport, daddr, dport, + in->ifindex); + } + return NULL; +} + +struct sock *nf_sk_lookup_slow_v4(struct net *net, const struct sk_buff *skb, + const struct net_device *indev) +{ + __be32 daddr, saddr; + __be16 dport, sport; + const struct iphdr *iph = ip_hdr(skb); + struct sk_buff *data_skb = NULL; + u8 protocol; +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + enum ip_conntrack_info ctinfo; + struct nf_conn const *ct; +#endif + int doff = 0; + + if (iph->protocol == IPPROTO_UDP || iph->protocol == IPPROTO_TCP) { + struct tcphdr _hdr; + struct udphdr *hp; + + hp = skb_header_pointer(skb, ip_hdrlen(skb), + iph->protocol == IPPROTO_UDP ? + sizeof(*hp) : sizeof(_hdr), &_hdr); + if (hp == NULL) + return NULL; + + protocol = iph->protocol; + saddr = iph->saddr; + sport = hp->source; + daddr = iph->daddr; + dport = hp->dest; + data_skb = (struct sk_buff *)skb; + doff = iph->protocol == IPPROTO_TCP ? + ip_hdrlen(skb) + __tcp_hdrlen((struct tcphdr *)hp) : + ip_hdrlen(skb) + sizeof(*hp); + + } else if (iph->protocol == IPPROTO_ICMP) { + if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr, + &sport, &dport)) + return NULL; + } else { + return NULL; + } + +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + /* Do the lookup with the original socket address in + * case this is a reply packet of an established + * SNAT-ted connection. + */ + ct = nf_ct_get(skb, &ctinfo); + if (ct && + ((iph->protocol != IPPROTO_ICMP && + ctinfo == IP_CT_ESTABLISHED_REPLY) || + (iph->protocol == IPPROTO_ICMP && + ctinfo == IP_CT_RELATED_REPLY)) && + (ct->status & IPS_SRC_NAT_DONE)) { + + daddr = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip; + dport = (iph->protocol == IPPROTO_TCP) ? + ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.tcp.port : + ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port; + } +#endif + + return nf_socket_get_sock_v4(net, data_skb, doff, protocol, saddr, + daddr, sport, dport, indev); +} +EXPORT_SYMBOL_GPL(nf_sk_lookup_slow_v4); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler"); +MODULE_DESCRIPTION("Netfilter IPv4 socket lookup infrastructure"); diff --git a/net/ipv4/netfilter/nf_tproxy_ipv4.c b/net/ipv4/netfilter/nf_tproxy_ipv4.c new file mode 100644 index 000000000..61cb2341f --- /dev/null +++ b/net/ipv4/netfilter/nf_tproxy_ipv4.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2007-2008 BalaBit IT Ltd. + * Author: Krisztian Kovacs + */ + +#include <net/netfilter/nf_tproxy.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/inet_sock.h> +#include <linux/ip.h> +#include <net/checksum.h> +#include <net/udp.h> +#include <net/tcp.h> +#include <linux/inetdevice.h> + +struct sock * +nf_tproxy_handle_time_wait4(struct net *net, struct sk_buff *skb, + __be32 laddr, __be16 lport, struct sock *sk) +{ + const struct iphdr *iph = ip_hdr(skb); + struct tcphdr _hdr, *hp; + + hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr); + if (hp == NULL) { + inet_twsk_put(inet_twsk(sk)); + return NULL; + } + + if (hp->syn && !hp->rst && !hp->ack && !hp->fin) { + /* SYN to a TIME_WAIT socket, we'd rather redirect it + * to a listener socket if there's one */ + struct sock *sk2; + + sk2 = nf_tproxy_get_sock_v4(net, skb, iph->protocol, + iph->saddr, laddr ? laddr : iph->daddr, + hp->source, lport ? lport : hp->dest, + skb->dev, NF_TPROXY_LOOKUP_LISTENER); + if (sk2) { + nf_tproxy_twsk_deschedule_put(inet_twsk(sk)); + sk = sk2; + } + } + + return sk; +} +EXPORT_SYMBOL_GPL(nf_tproxy_handle_time_wait4); + +__be32 nf_tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr) +{ + const struct in_ifaddr *ifa; + struct in_device *indev; + __be32 laddr; + + if (user_laddr) + return user_laddr; + + laddr = 0; + indev = __in_dev_get_rcu(skb->dev); + + in_dev_for_each_ifa_rcu(ifa, indev) { + if (ifa->ifa_flags & IFA_F_SECONDARY) + continue; + + laddr = ifa->ifa_local; + break; + } + + return laddr ? laddr : daddr; +} +EXPORT_SYMBOL_GPL(nf_tproxy_laddr4); + +struct sock * +nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, + const u8 protocol, + const __be32 saddr, const __be32 daddr, + const __be16 sport, const __be16 dport, + const struct net_device *in, + const enum nf_tproxy_lookup_t lookup_type) +{ + struct sock *sk; + + switch (protocol) { + case IPPROTO_TCP: { + struct tcphdr _hdr, *hp; + + hp = skb_header_pointer(skb, ip_hdrlen(skb), + sizeof(struct tcphdr), &_hdr); + if (hp == NULL) + return NULL; + + switch (lookup_type) { + case NF_TPROXY_LOOKUP_LISTENER: + sk = inet_lookup_listener(net, &tcp_hashinfo, skb, + ip_hdrlen(skb) + + __tcp_hdrlen(hp), + saddr, sport, + daddr, dport, + in->ifindex, 0); + + if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + /* NOTE: we return listeners even if bound to + * 0.0.0.0, those are filtered out in + * xt_socket, since xt_TPROXY needs 0 bound + * listeners too + */ + break; + case NF_TPROXY_LOOKUP_ESTABLISHED: + sk = inet_lookup_established(net, &tcp_hashinfo, + saddr, sport, daddr, dport, + in->ifindex); + break; + default: + BUG(); + } + break; + } + case IPPROTO_UDP: + sk = udp4_lib_lookup(net, saddr, sport, daddr, dport, + in->ifindex); + if (sk) { + int connected = (sk->sk_state == TCP_ESTABLISHED); + int wildcard = (inet_sk(sk)->inet_rcv_saddr == 0); + + /* NOTE: we return listeners even if bound to + * 0.0.0.0, those are filtered out in + * xt_socket, since xt_TPROXY needs 0 bound + * listeners too + */ + if ((lookup_type == NF_TPROXY_LOOKUP_ESTABLISHED && + (!connected || wildcard)) || + (lookup_type == NF_TPROXY_LOOKUP_LISTENER && connected)) { + sock_put(sk); + sk = NULL; + } + } + break; + default: + WARN_ON(1); + sk = NULL; + } + + pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, lookup type: %d, sock %p\n", + protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), lookup_type, sk); + + return sk; +} +EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v4); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs"); +MODULE_DESCRIPTION("Netfilter IPv4 transparent proxy support"); diff --git a/net/ipv4/netfilter/nft_dup_ipv4.c b/net/ipv4/netfilter/nft_dup_ipv4.c new file mode 100644 index 000000000..aeb631760 --- /dev/null +++ b/net/ipv4/netfilter/nft_dup_ipv4.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org> + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/ipv4/nf_dup_ipv4.h> + +struct nft_dup_ipv4 { + u8 sreg_addr; + u8 sreg_dev; +}; + +static void nft_dup_ipv4_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_dup_ipv4 *priv = nft_expr_priv(expr); + struct in_addr gw = { + .s_addr = (__force __be32)regs->data[priv->sreg_addr], + }; + int oif = priv->sreg_dev ? regs->data[priv->sreg_dev] : -1; + + nf_dup_ipv4(nft_net(pkt), pkt->skb, nft_hook(pkt), &gw, oif); +} + +static int nft_dup_ipv4_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_dup_ipv4 *priv = nft_expr_priv(expr); + int err; + + if (tb[NFTA_DUP_SREG_ADDR] == NULL) + return -EINVAL; + + err = nft_parse_register_load(tb[NFTA_DUP_SREG_ADDR], &priv->sreg_addr, + sizeof(struct in_addr)); + if (err < 0) + return err; + + if (tb[NFTA_DUP_SREG_DEV]) + err = nft_parse_register_load(tb[NFTA_DUP_SREG_DEV], + &priv->sreg_dev, sizeof(int)); + + return err; +} + +static int nft_dup_ipv4_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + struct nft_dup_ipv4 *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_DUP_SREG_ADDR, priv->sreg_addr)) + goto nla_put_failure; + if (priv->sreg_dev && + nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev)) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_dup_ipv4_type; +static const struct nft_expr_ops nft_dup_ipv4_ops = { + .type = &nft_dup_ipv4_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_dup_ipv4)), + .eval = nft_dup_ipv4_eval, + .init = nft_dup_ipv4_init, + .dump = nft_dup_ipv4_dump, +}; + +static const struct nla_policy nft_dup_ipv4_policy[NFTA_DUP_MAX + 1] = { + [NFTA_DUP_SREG_ADDR] = { .type = NLA_U32 }, + [NFTA_DUP_SREG_DEV] = { .type = NLA_U32 }, +}; + +static struct nft_expr_type nft_dup_ipv4_type __read_mostly = { + .family = NFPROTO_IPV4, + .name = "dup", + .ops = &nft_dup_ipv4_ops, + .policy = nft_dup_ipv4_policy, + .maxattr = NFTA_DUP_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_dup_ipv4_module_init(void) +{ + return nft_register_expr(&nft_dup_ipv4_type); +} + +static void __exit nft_dup_ipv4_module_exit(void) +{ + nft_unregister_expr(&nft_dup_ipv4_type); +} + +module_init(nft_dup_ipv4_module_init); +module_exit(nft_dup_ipv4_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup"); +MODULE_DESCRIPTION("IPv4 nftables packet duplication support"); diff --git a/net/ipv4/netfilter/nft_fib_ipv4.c b/net/ipv4/netfilter/nft_fib_ipv4.c new file mode 100644 index 000000000..9e6f0f127 --- /dev/null +++ b/net/ipv4/netfilter/nft_fib_ipv4.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables_core.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/nft_fib.h> + +#include <net/ip_fib.h> +#include <net/route.h> + +/* don't try to find route from mcast/bcast/zeronet */ +static __be32 get_saddr(__be32 addr) +{ + if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr) || + ipv4_is_zeronet(addr)) + return 0; + return addr; +} + +#define DSCP_BITS 0xfc + +void nft_fib4_eval_type(const struct nft_expr *expr, struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_fib *priv = nft_expr_priv(expr); + int noff = skb_network_offset(pkt->skb); + u32 *dst = ®s->data[priv->dreg]; + const struct net_device *dev = NULL; + struct iphdr *iph, _iph; + __be32 addr; + + if (priv->flags & NFTA_FIB_F_IIF) + dev = nft_in(pkt); + else if (priv->flags & NFTA_FIB_F_OIF) + dev = nft_out(pkt); + + iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph); + if (!iph) { + regs->verdict.code = NFT_BREAK; + return; + } + + if (priv->flags & NFTA_FIB_F_DADDR) + addr = iph->daddr; + else + addr = iph->saddr; + + *dst = inet_dev_addr_type(nft_net(pkt), dev, addr); +} +EXPORT_SYMBOL_GPL(nft_fib4_eval_type); + +void nft_fib4_eval(const struct nft_expr *expr, struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_fib *priv = nft_expr_priv(expr); + int noff = skb_network_offset(pkt->skb); + u32 *dest = ®s->data[priv->dreg]; + struct iphdr *iph, _iph; + struct fib_result res; + struct flowi4 fl4 = { + .flowi4_scope = RT_SCOPE_UNIVERSE, + .flowi4_iif = LOOPBACK_IFINDEX, + }; + const struct net_device *oif; + const struct net_device *found; + + /* + * Do not set flowi4_oif, it restricts results (for example, asking + * for oif 3 will get RTN_UNICAST result even if the daddr exits + * on another interface. + * + * Search results for the desired outinterface instead. + */ + if (priv->flags & NFTA_FIB_F_OIF) + oif = nft_out(pkt); + else if (priv->flags & NFTA_FIB_F_IIF) + oif = nft_in(pkt); + else + oif = NULL; + + if (priv->flags & NFTA_FIB_F_IIF) + fl4.flowi4_oif = l3mdev_master_ifindex_rcu(oif); + + if (nft_hook(pkt) == NF_INET_PRE_ROUTING && + nft_fib_is_loopback(pkt->skb, nft_in(pkt))) { + nft_fib_store_result(dest, priv, nft_in(pkt)); + return; + } + + iph = skb_header_pointer(pkt->skb, noff, sizeof(_iph), &_iph); + if (!iph) { + regs->verdict.code = NFT_BREAK; + return; + } + + if (ipv4_is_zeronet(iph->saddr)) { + if (ipv4_is_lbcast(iph->daddr) || + ipv4_is_local_multicast(iph->daddr)) { + nft_fib_store_result(dest, priv, pkt->skb->dev); + return; + } + } + + if (priv->flags & NFTA_FIB_F_MARK) + fl4.flowi4_mark = pkt->skb->mark; + + fl4.flowi4_tos = iph->tos & DSCP_BITS; + + if (priv->flags & NFTA_FIB_F_DADDR) { + fl4.daddr = iph->daddr; + fl4.saddr = get_saddr(iph->saddr); + } else { + fl4.daddr = iph->saddr; + fl4.saddr = get_saddr(iph->daddr); + } + + *dest = 0; + + if (fib_lookup(nft_net(pkt), &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE)) + return; + + switch (res.type) { + case RTN_UNICAST: + break; + case RTN_LOCAL: /* Should not see RTN_LOCAL here */ + return; + default: + break; + } + + if (!oif) { + found = FIB_RES_DEV(res); + } else { + if (!fib_info_nh_uses_dev(res.fi, oif)) + return; + + found = oif; + } + + nft_fib_store_result(dest, priv, found); +} +EXPORT_SYMBOL_GPL(nft_fib4_eval); + +static struct nft_expr_type nft_fib4_type; + +static const struct nft_expr_ops nft_fib4_type_ops = { + .type = &nft_fib4_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)), + .eval = nft_fib4_eval_type, + .init = nft_fib_init, + .dump = nft_fib_dump, + .validate = nft_fib_validate, +}; + +static const struct nft_expr_ops nft_fib4_ops = { + .type = &nft_fib4_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)), + .eval = nft_fib4_eval, + .init = nft_fib_init, + .dump = nft_fib_dump, + .validate = nft_fib_validate, +}; + +static const struct nft_expr_ops * +nft_fib4_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + enum nft_fib_result result; + + if (!tb[NFTA_FIB_RESULT]) + return ERR_PTR(-EINVAL); + + result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT])); + + switch (result) { + case NFT_FIB_RESULT_OIF: + return &nft_fib4_ops; + case NFT_FIB_RESULT_OIFNAME: + return &nft_fib4_ops; + case NFT_FIB_RESULT_ADDRTYPE: + return &nft_fib4_type_ops; + default: + return ERR_PTR(-EOPNOTSUPP); + } +} + +static struct nft_expr_type nft_fib4_type __read_mostly = { + .name = "fib", + .select_ops = nft_fib4_select_ops, + .policy = nft_fib_policy, + .maxattr = NFTA_FIB_MAX, + .family = NFPROTO_IPV4, + .owner = THIS_MODULE, +}; + +static int __init nft_fib4_module_init(void) +{ + return nft_register_expr(&nft_fib4_type); +} + +static void __exit nft_fib4_module_exit(void) +{ + nft_unregister_expr(&nft_fib4_type); +} + +module_init(nft_fib4_module_init); +module_exit(nft_fib4_module_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Florian Westphal <fw@strlen.de>"); +MODULE_ALIAS_NFT_AF_EXPR(2, "fib"); +MODULE_DESCRIPTION("nftables fib / ip route lookup support"); diff --git a/net/ipv4/netfilter/nft_reject_ipv4.c b/net/ipv4/netfilter/nft_reject_ipv4.c new file mode 100644 index 000000000..55fc23a8f --- /dev/null +++ b/net/ipv4/netfilter/nft_reject_ipv4.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> + * Copyright (c) 2013 Eric Leblond <eric@regit.org> + * + * Development of this code funded by Astaro AG (http://www.astaro.com/) + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/ipv4/nf_reject.h> +#include <net/netfilter/nft_reject.h> + +static void nft_reject_ipv4_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_reject *priv = nft_expr_priv(expr); + + switch (priv->type) { + case NFT_REJECT_ICMP_UNREACH: + nf_send_unreach(pkt->skb, priv->icmp_code, nft_hook(pkt)); + break; + case NFT_REJECT_TCP_RST: + nf_send_reset(nft_net(pkt), nft_sk(pkt), pkt->skb, + nft_hook(pkt)); + break; + default: + break; + } + + regs->verdict.code = NF_DROP; +} + +static struct nft_expr_type nft_reject_ipv4_type; +static const struct nft_expr_ops nft_reject_ipv4_ops = { + .type = &nft_reject_ipv4_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_reject)), + .eval = nft_reject_ipv4_eval, + .init = nft_reject_init, + .dump = nft_reject_dump, + .validate = nft_reject_validate, +}; + +static struct nft_expr_type nft_reject_ipv4_type __read_mostly = { + .family = NFPROTO_IPV4, + .name = "reject", + .ops = &nft_reject_ipv4_ops, + .policy = nft_reject_policy, + .maxattr = NFTA_REJECT_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_reject_ipv4_module_init(void) +{ + return nft_register_expr(&nft_reject_ipv4_type); +} + +static void __exit nft_reject_ipv4_module_exit(void) +{ + nft_unregister_expr(&nft_reject_ipv4_type); +} + +module_init(nft_reject_ipv4_module_init); +module_exit(nft_reject_ipv4_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "reject"); +MODULE_DESCRIPTION("IPv4 packet rejection for nftables"); diff --git a/net/ipv4/netlink.c b/net/ipv4/netlink.c new file mode 100644 index 000000000..b920e1bdc --- /dev/null +++ b/net/ipv4/netlink.c @@ -0,0 +1,33 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <linux/types.h> +#include <net/net_namespace.h> +#include <net/netlink.h> +#include <linux/in6.h> +#include <net/ip.h> + +int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, + struct netlink_ext_ack *extack) +{ + *ip_proto = nla_get_u8(attr); + + switch (*ip_proto) { + case IPPROTO_TCP: + case IPPROTO_UDP: + return 0; + case IPPROTO_ICMP: + if (family != AF_INET) + break; + return 0; +#if IS_ENABLED(CONFIG_IPV6) + case IPPROTO_ICMPV6: + if (family != AF_INET6) + break; + return 0; +#endif + } + NL_SET_ERR_MSG(extack, "Unsupported ip proto"); + return -EOPNOTSUPP; +} +EXPORT_SYMBOL_GPL(rtm_getroute_parse_ip_proto); diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c new file mode 100644 index 000000000..7a0102a4b --- /dev/null +++ b/net/ipv4/nexthop.c @@ -0,0 +1,2053 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Generic nexthop implementation + * + * Copyright (c) 2017-19 Cumulus Networks + * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com> + */ + +#include <linux/nexthop.h> +#include <linux/rtnetlink.h> +#include <linux/slab.h> +#include <net/arp.h> +#include <net/ipv6_stubs.h> +#include <net/lwtunnel.h> +#include <net/ndisc.h> +#include <net/nexthop.h> +#include <net/route.h> +#include <net/sock.h> + +static void remove_nexthop(struct net *net, struct nexthop *nh, + struct nl_info *nlinfo); + +#define NH_DEV_HASHBITS 8 +#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS) + +static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = { + [NHA_ID] = { .type = NLA_U32 }, + [NHA_GROUP] = { .type = NLA_BINARY }, + [NHA_GROUP_TYPE] = { .type = NLA_U16 }, + [NHA_BLACKHOLE] = { .type = NLA_FLAG }, + [NHA_OIF] = { .type = NLA_U32 }, + [NHA_GATEWAY] = { .type = NLA_BINARY }, + [NHA_ENCAP_TYPE] = { .type = NLA_U16 }, + [NHA_ENCAP] = { .type = NLA_NESTED }, + [NHA_GROUPS] = { .type = NLA_FLAG }, + [NHA_MASTER] = { .type = NLA_U32 }, + [NHA_FDB] = { .type = NLA_FLAG }, +}; + +static int call_nexthop_notifiers(struct net *net, + enum nexthop_event_type event_type, + struct nexthop *nh) +{ + int err; + + err = blocking_notifier_call_chain(&net->nexthop.notifier_chain, + event_type, nh); + return notifier_to_errno(err); +} + +static unsigned int nh_dev_hashfn(unsigned int val) +{ + unsigned int mask = NH_DEV_HASHSIZE - 1; + + return (val ^ + (val >> NH_DEV_HASHBITS) ^ + (val >> (NH_DEV_HASHBITS * 2))) & mask; +} + +static void nexthop_devhash_add(struct net *net, struct nh_info *nhi) +{ + struct net_device *dev = nhi->fib_nhc.nhc_dev; + struct hlist_head *head; + unsigned int hash; + + WARN_ON(!dev); + + hash = nh_dev_hashfn(dev->ifindex); + head = &net->nexthop.devhash[hash]; + hlist_add_head(&nhi->dev_hash, head); +} + +static void nexthop_free_mpath(struct nexthop *nh) +{ + struct nh_group *nhg; + int i; + + nhg = rcu_dereference_raw(nh->nh_grp); + for (i = 0; i < nhg->num_nh; ++i) { + struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + + WARN_ON(!list_empty(&nhge->nh_list)); + nexthop_put(nhge->nh); + } + + WARN_ON(nhg->spare == nhg); + + kfree(nhg->spare); + kfree(nhg); +} + +static void nexthop_free_single(struct nexthop *nh) +{ + struct nh_info *nhi; + + nhi = rcu_dereference_raw(nh->nh_info); + switch (nhi->family) { + case AF_INET: + fib_nh_release(nh->net, &nhi->fib_nh); + break; + case AF_INET6: + ipv6_stub->fib6_nh_release(&nhi->fib6_nh); + break; + } + kfree(nhi); +} + +void nexthop_free_rcu(struct rcu_head *head) +{ + struct nexthop *nh = container_of(head, struct nexthop, rcu); + + if (nh->is_group) + nexthop_free_mpath(nh); + else + nexthop_free_single(nh); + + kfree(nh); +} +EXPORT_SYMBOL_GPL(nexthop_free_rcu); + +static struct nexthop *nexthop_alloc(void) +{ + struct nexthop *nh; + + nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL); + if (nh) { + INIT_LIST_HEAD(&nh->fi_list); + INIT_LIST_HEAD(&nh->f6i_list); + INIT_LIST_HEAD(&nh->grp_list); + INIT_LIST_HEAD(&nh->fdb_list); + } + return nh; +} + +static struct nh_group *nexthop_grp_alloc(u16 num_nh) +{ + struct nh_group *nhg; + + nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL); + if (nhg) + nhg->num_nh = num_nh; + + return nhg; +} + +static void nh_base_seq_inc(struct net *net) +{ + while (++net->nexthop.seq == 0) + ; +} + +/* no reference taken; rcu lock or rtnl must be held */ +struct nexthop *nexthop_find_by_id(struct net *net, u32 id) +{ + struct rb_node **pp, *parent = NULL, *next; + + pp = &net->nexthop.rb_root.rb_node; + while (1) { + struct nexthop *nh; + + next = rcu_dereference_raw(*pp); + if (!next) + break; + parent = next; + + nh = rb_entry(parent, struct nexthop, rb_node); + if (id < nh->id) + pp = &next->rb_left; + else if (id > nh->id) + pp = &next->rb_right; + else + return nh; + } + return NULL; +} +EXPORT_SYMBOL_GPL(nexthop_find_by_id); + +/* used for auto id allocation; called with rtnl held */ +static u32 nh_find_unused_id(struct net *net) +{ + u32 id_start = net->nexthop.last_id_allocated; + + while (1) { + net->nexthop.last_id_allocated++; + if (net->nexthop.last_id_allocated == id_start) + break; + + if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated)) + return net->nexthop.last_id_allocated; + } + return 0; +} + +static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg) +{ + struct nexthop_grp *p; + size_t len = nhg->num_nh * sizeof(*p); + struct nlattr *nla; + u16 group_type = 0; + int i; + + if (nhg->mpath) + group_type = NEXTHOP_GRP_TYPE_MPATH; + + if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type)) + goto nla_put_failure; + + nla = nla_reserve(skb, NHA_GROUP, len); + if (!nla) + goto nla_put_failure; + + p = nla_data(nla); + for (i = 0; i < nhg->num_nh; ++i) { + p->id = nhg->nh_entries[i].nh->id; + p->weight = nhg->nh_entries[i].weight - 1; + p += 1; + } + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh, + int event, u32 portid, u32 seq, unsigned int nlflags) +{ + struct fib6_nh *fib6_nh; + struct fib_nh *fib_nh; + struct nlmsghdr *nlh; + struct nh_info *nhi; + struct nhmsg *nhm; + + nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags); + if (!nlh) + return -EMSGSIZE; + + nhm = nlmsg_data(nlh); + nhm->nh_family = AF_UNSPEC; + nhm->nh_flags = nh->nh_flags; + nhm->nh_protocol = nh->protocol; + nhm->nh_scope = 0; + nhm->resvd = 0; + + if (nla_put_u32(skb, NHA_ID, nh->id)) + goto nla_put_failure; + + if (nh->is_group) { + struct nh_group *nhg = rtnl_dereference(nh->nh_grp); + + if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB)) + goto nla_put_failure; + if (nla_put_nh_group(skb, nhg)) + goto nla_put_failure; + goto out; + } + + nhi = rtnl_dereference(nh->nh_info); + nhm->nh_family = nhi->family; + if (nhi->reject_nh) { + if (nla_put_flag(skb, NHA_BLACKHOLE)) + goto nla_put_failure; + goto out; + } else if (nhi->fdb_nh) { + if (nla_put_flag(skb, NHA_FDB)) + goto nla_put_failure; + } else { + const struct net_device *dev; + + dev = nhi->fib_nhc.nhc_dev; + if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex)) + goto nla_put_failure; + } + + nhm->nh_scope = nhi->fib_nhc.nhc_scope; + switch (nhi->family) { + case AF_INET: + fib_nh = &nhi->fib_nh; + if (fib_nh->fib_nh_gw_family && + nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4)) + goto nla_put_failure; + break; + + case AF_INET6: + fib6_nh = &nhi->fib6_nh; + if (fib6_nh->fib_nh_gw_family && + nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6)) + goto nla_put_failure; + break; + } + + if (nhi->fib_nhc.nhc_lwtstate && + lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate, + NHA_ENCAP, NHA_ENCAP_TYPE) < 0) + goto nla_put_failure; + +out: + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static size_t nh_nlmsg_size_grp(struct nexthop *nh) +{ + struct nh_group *nhg = rtnl_dereference(nh->nh_grp); + size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh; + + return nla_total_size(sz) + + nla_total_size(2); /* NHA_GROUP_TYPE */ +} + +static size_t nh_nlmsg_size_single(struct nexthop *nh) +{ + struct nh_info *nhi = rtnl_dereference(nh->nh_info); + size_t sz; + + /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE + * are mutually exclusive + */ + sz = nla_total_size(4); /* NHA_OIF */ + + switch (nhi->family) { + case AF_INET: + if (nhi->fib_nh.fib_nh_gw_family) + sz += nla_total_size(4); /* NHA_GATEWAY */ + break; + + case AF_INET6: + /* NHA_GATEWAY */ + if (nhi->fib6_nh.fib_nh_gw_family) + sz += nla_total_size(sizeof(const struct in6_addr)); + break; + } + + if (nhi->fib_nhc.nhc_lwtstate) { + sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate); + sz += nla_total_size(2); /* NHA_ENCAP_TYPE */ + } + + return sz; +} + +static size_t nh_nlmsg_size(struct nexthop *nh) +{ + size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg)); + + sz += nla_total_size(4); /* NHA_ID */ + + if (nh->is_group) + sz += nh_nlmsg_size_grp(nh); + else + sz += nh_nlmsg_size_single(nh); + + return sz; +} + +static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info) +{ + unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0; + u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; + struct sk_buff *skb; + int err = -ENOBUFS; + + skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any()); + if (!skb) + goto errout; + + err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags); + if (err < 0) { + /* -EMSGSIZE implies BUG in nh_nlmsg_size() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + + rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP, + info->nlh, gfp_any()); + return; +errout: + if (err < 0) + rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err); +} + +static bool valid_group_nh(struct nexthop *nh, unsigned int npaths, + bool *is_fdb, struct netlink_ext_ack *extack) +{ + if (nh->is_group) { + struct nh_group *nhg = rtnl_dereference(nh->nh_grp); + + /* nested multipath (group within a group) is not + * supported + */ + if (nhg->mpath) { + NL_SET_ERR_MSG(extack, + "Multipath group can not be a nexthop within a group"); + return false; + } + *is_fdb = nhg->fdb_nh; + } else { + struct nh_info *nhi = rtnl_dereference(nh->nh_info); + + if (nhi->reject_nh && npaths > 1) { + NL_SET_ERR_MSG(extack, + "Blackhole nexthop can not be used in a group with more than 1 path"); + return false; + } + *is_fdb = nhi->fdb_nh; + } + + return true; +} + +static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family, + struct netlink_ext_ack *extack) +{ + struct nh_info *nhi; + + nhi = rtnl_dereference(nh->nh_info); + + if (!nhi->fdb_nh) { + NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops"); + return -EINVAL; + } + + if (*nh_family == AF_UNSPEC) { + *nh_family = nhi->family; + } else if (*nh_family != nhi->family) { + NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops"); + return -EINVAL; + } + + return 0; +} + +static int nh_check_attr_group(struct net *net, struct nlattr *tb[], + struct netlink_ext_ack *extack) +{ + unsigned int len = nla_len(tb[NHA_GROUP]); + u8 nh_family = AF_UNSPEC; + struct nexthop_grp *nhg; + unsigned int i, j; + u8 nhg_fdb = 0; + + if (!len || len & (sizeof(struct nexthop_grp) - 1)) { + NL_SET_ERR_MSG(extack, + "Invalid length for nexthop group attribute"); + return -EINVAL; + } + + /* convert len to number of nexthop ids */ + len /= sizeof(*nhg); + + nhg = nla_data(tb[NHA_GROUP]); + for (i = 0; i < len; ++i) { + if (nhg[i].resvd1 || nhg[i].resvd2) { + NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0"); + return -EINVAL; + } + if (nhg[i].weight > 254) { + NL_SET_ERR_MSG(extack, "Invalid value for weight"); + return -EINVAL; + } + for (j = i + 1; j < len; ++j) { + if (nhg[i].id == nhg[j].id) { + NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group"); + return -EINVAL; + } + } + } + + if (tb[NHA_FDB]) + nhg_fdb = 1; + nhg = nla_data(tb[NHA_GROUP]); + for (i = 0; i < len; ++i) { + struct nexthop *nh; + bool is_fdb_nh; + + nh = nexthop_find_by_id(net, nhg[i].id); + if (!nh) { + NL_SET_ERR_MSG(extack, "Invalid nexthop id"); + return -EINVAL; + } + if (!valid_group_nh(nh, len, &is_fdb_nh, extack)) + return -EINVAL; + + if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack)) + return -EINVAL; + + if (!nhg_fdb && is_fdb_nh) { + NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops"); + return -EINVAL; + } + } + for (i = NHA_GROUP_TYPE + 1; i < __NHA_MAX; ++i) { + if (!tb[i]) + continue; + if (i == NHA_FDB) + continue; + NL_SET_ERR_MSG(extack, + "No other attributes can be set in nexthop groups"); + return -EINVAL; + } + + return 0; +} + +static bool ipv6_good_nh(const struct fib6_nh *nh) +{ + int state = NUD_REACHABLE; + struct neighbour *n; + + rcu_read_lock_bh(); + + n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6); + if (n) + state = n->nud_state; + + rcu_read_unlock_bh(); + + return !!(state & NUD_VALID); +} + +static bool ipv4_good_nh(const struct fib_nh *nh) +{ + int state = NUD_REACHABLE; + struct neighbour *n; + + rcu_read_lock_bh(); + + n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev, + (__force u32)nh->fib_nh_gw4); + if (n) + state = n->nud_state; + + rcu_read_unlock_bh(); + + return !!(state & NUD_VALID); +} + +struct nexthop *nexthop_select_path(struct nexthop *nh, int hash) +{ + struct nexthop *rc = NULL; + struct nh_group *nhg; + int i; + + if (!nh->is_group) + return nh; + + nhg = rcu_dereference(nh->nh_grp); + for (i = 0; i < nhg->num_nh; ++i) { + struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + struct nh_info *nhi; + + if (hash > atomic_read(&nhge->upper_bound)) + continue; + + nhi = rcu_dereference(nhge->nh->nh_info); + if (nhi->fdb_nh) + return nhge->nh; + + /* nexthops always check if it is good and does + * not rely on a sysctl for this behavior + */ + switch (nhi->family) { + case AF_INET: + if (ipv4_good_nh(&nhi->fib_nh)) + return nhge->nh; + break; + case AF_INET6: + if (ipv6_good_nh(&nhi->fib6_nh)) + return nhge->nh; + break; + } + + if (!rc) + rc = nhge->nh; + } + + return rc; +} +EXPORT_SYMBOL_GPL(nexthop_select_path); + +int nexthop_for_each_fib6_nh(struct nexthop *nh, + int (*cb)(struct fib6_nh *nh, void *arg), + void *arg) +{ + struct nh_info *nhi; + int err; + + if (nh->is_group) { + struct nh_group *nhg; + int i; + + nhg = rcu_dereference_rtnl(nh->nh_grp); + for (i = 0; i < nhg->num_nh; i++) { + struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + + nhi = rcu_dereference_rtnl(nhge->nh->nh_info); + err = cb(&nhi->fib6_nh, arg); + if (err) + return err; + } + } else { + nhi = rcu_dereference_rtnl(nh->nh_info); + err = cb(&nhi->fib6_nh, arg); + if (err) + return err; + } + + return 0; +} +EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh); + +static int check_src_addr(const struct in6_addr *saddr, + struct netlink_ext_ack *extack) +{ + if (!ipv6_addr_any(saddr)) { + NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects"); + return -EINVAL; + } + return 0; +} + +int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg, + struct netlink_ext_ack *extack) +{ + struct nh_info *nhi; + bool is_fdb_nh; + + /* fib6_src is unique to a fib6_info and limits the ability to cache + * routes in fib6_nh within a nexthop that is potentially shared + * across multiple fib entries. If the config wants to use source + * routing it can not use nexthop objects. mlxsw also does not allow + * fib6_src on routes. + */ + if (cfg && check_src_addr(&cfg->fc_src, extack) < 0) + return -EINVAL; + + if (nh->is_group) { + struct nh_group *nhg; + + nhg = rtnl_dereference(nh->nh_grp); + if (nhg->has_v4) + goto no_v4_nh; + is_fdb_nh = nhg->fdb_nh; + } else { + nhi = rtnl_dereference(nh->nh_info); + if (nhi->family == AF_INET) + goto no_v4_nh; + is_fdb_nh = nhi->fdb_nh; + } + + if (is_fdb_nh) { + NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); + return -EINVAL; + } + + return 0; +no_v4_nh: + NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop"); + return -EINVAL; +} +EXPORT_SYMBOL_GPL(fib6_check_nexthop); + +/* if existing nexthop has ipv6 routes linked to it, need + * to verify this new spec works with ipv6 + */ +static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new, + struct netlink_ext_ack *extack) +{ + struct fib6_info *f6i; + + if (list_empty(&old->f6i_list)) + return 0; + + list_for_each_entry(f6i, &old->f6i_list, nh_list) { + if (check_src_addr(&f6i->fib6_src.addr, extack) < 0) + return -EINVAL; + } + + return fib6_check_nexthop(new, NULL, extack); +} + +static int nexthop_check_scope(struct nh_info *nhi, u8 scope, + struct netlink_ext_ack *extack) +{ + if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) { + NL_SET_ERR_MSG(extack, + "Route with host scope can not have a gateway"); + return -EINVAL; + } + + if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) { + NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop"); + return -EINVAL; + } + + return 0; +} + +/* Invoked by fib add code to verify nexthop by id is ok with + * config for prefix; parts of fib_check_nh not done when nexthop + * object is used. + */ +int fib_check_nexthop(struct nexthop *nh, u8 scope, + struct netlink_ext_ack *extack) +{ + struct nh_info *nhi; + int err = 0; + + if (nh->is_group) { + struct nh_group *nhg; + + nhg = rtnl_dereference(nh->nh_grp); + if (nhg->fdb_nh) { + NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); + err = -EINVAL; + goto out; + } + + if (scope == RT_SCOPE_HOST) { + NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops"); + err = -EINVAL; + goto out; + } + + /* all nexthops in a group have the same scope */ + nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info); + err = nexthop_check_scope(nhi, scope, extack); + } else { + nhi = rtnl_dereference(nh->nh_info); + if (nhi->fdb_nh) { + NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); + err = -EINVAL; + goto out; + } + err = nexthop_check_scope(nhi, scope, extack); + } + +out: + return err; +} + +static int fib_check_nh_list(struct nexthop *old, struct nexthop *new, + struct netlink_ext_ack *extack) +{ + struct fib_info *fi; + + list_for_each_entry(fi, &old->fi_list, nh_list) { + int err; + + err = fib_check_nexthop(new, fi->fib_scope, extack); + if (err) + return err; + } + return 0; +} + +static void nh_group_rebalance(struct nh_group *nhg) +{ + int total = 0; + int w = 0; + int i; + + for (i = 0; i < nhg->num_nh; ++i) + total += nhg->nh_entries[i].weight; + + for (i = 0; i < nhg->num_nh; ++i) { + struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + int upper_bound; + + w += nhge->weight; + upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1; + atomic_set(&nhge->upper_bound, upper_bound); + } +} + +static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge, + struct nl_info *nlinfo) +{ + struct nh_grp_entry *nhges, *new_nhges; + struct nexthop *nhp = nhge->nh_parent; + struct nexthop *nh = nhge->nh; + struct nh_group *nhg, *newg; + int i, j; + + WARN_ON(!nh); + + nhg = rtnl_dereference(nhp->nh_grp); + newg = nhg->spare; + + /* last entry, keep it visible and remove the parent */ + if (nhg->num_nh == 1) { + remove_nexthop(net, nhp, nlinfo); + return; + } + + newg->has_v4 = false; + newg->mpath = nhg->mpath; + newg->fdb_nh = nhg->fdb_nh; + newg->num_nh = nhg->num_nh; + + /* copy old entries to new except the one getting removed */ + nhges = nhg->nh_entries; + new_nhges = newg->nh_entries; + for (i = 0, j = 0; i < nhg->num_nh; ++i) { + struct nh_info *nhi; + + /* current nexthop getting removed */ + if (nhg->nh_entries[i].nh == nh) { + newg->num_nh--; + continue; + } + + nhi = rtnl_dereference(nhges[i].nh->nh_info); + if (nhi->family == AF_INET) + newg->has_v4 = true; + + list_del(&nhges[i].nh_list); + new_nhges[j].nh_parent = nhges[i].nh_parent; + new_nhges[j].nh = nhges[i].nh; + new_nhges[j].weight = nhges[i].weight; + list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list); + j++; + } + + nh_group_rebalance(newg); + rcu_assign_pointer(nhp->nh_grp, newg); + + list_del(&nhge->nh_list); + nexthop_put(nhge->nh); + + if (nlinfo) + nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo); +} + +static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh, + struct nl_info *nlinfo) +{ + struct nh_grp_entry *nhge, *tmp; + + list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list) + remove_nh_grp_entry(net, nhge, nlinfo); + + /* make sure all see the newly published array before releasing rtnl */ + synchronize_net(); +} + +static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo) +{ + struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp); + int i, num_nh = nhg->num_nh; + + for (i = 0; i < num_nh; ++i) { + struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + + if (WARN_ON(!nhge->nh)) + continue; + + list_del_init(&nhge->nh_list); + } +} + +/* not called for nexthop replace */ +static void __remove_nexthop_fib(struct net *net, struct nexthop *nh) +{ + struct fib6_info *f6i, *tmp; + bool do_flush = false; + struct fib_info *fi; + + list_for_each_entry(fi, &nh->fi_list, nh_list) { + fi->fib_flags |= RTNH_F_DEAD; + do_flush = true; + } + if (do_flush) + fib_flush(net); + + /* ip6_del_rt removes the entry from this list hence the _safe */ + list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) { + /* __ip6_del_rt does a release, so do a hold here */ + fib6_info_hold(f6i); + ipv6_stub->ip6_del_rt(net, f6i, + !READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)); + } +} + +static void __remove_nexthop(struct net *net, struct nexthop *nh, + struct nl_info *nlinfo) +{ + __remove_nexthop_fib(net, nh); + + if (nh->is_group) { + remove_nexthop_group(nh, nlinfo); + } else { + struct nh_info *nhi; + + nhi = rtnl_dereference(nh->nh_info); + if (nhi->fib_nhc.nhc_dev) + hlist_del(&nhi->dev_hash); + + remove_nexthop_from_groups(net, nh, nlinfo); + } +} + +static void remove_nexthop(struct net *net, struct nexthop *nh, + struct nl_info *nlinfo) +{ + call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh); + + /* remove from the tree */ + rb_erase(&nh->rb_node, &net->nexthop.rb_root); + + if (nlinfo) + nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo); + + __remove_nexthop(net, nh, nlinfo); + nh_base_seq_inc(net); + + nexthop_put(nh); +} + +/* if any FIB entries reference this nexthop, any dst entries + * need to be regenerated + */ +static void nh_rt_cache_flush(struct net *net, struct nexthop *nh, + struct nexthop *replaced_nh) +{ + struct fib6_info *f6i; + struct nh_group *nhg; + int i; + + if (!list_empty(&nh->fi_list)) + rt_cache_flush(net); + + list_for_each_entry(f6i, &nh->f6i_list, nh_list) + ipv6_stub->fib6_update_sernum(net, f6i); + + /* if an IPv6 group was replaced, we have to release all old + * dsts to make sure all refcounts are released + */ + if (!replaced_nh->is_group) + return; + + /* new dsts must use only the new nexthop group */ + synchronize_net(); + + nhg = rtnl_dereference(replaced_nh->nh_grp); + for (i = 0; i < nhg->num_nh; i++) { + struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + struct nh_info *nhi = rtnl_dereference(nhge->nh->nh_info); + + if (nhi->family == AF_INET6) + ipv6_stub->fib6_nh_release_dsts(&nhi->fib6_nh); + } +} + +static int replace_nexthop_grp(struct net *net, struct nexthop *old, + struct nexthop *new, + struct netlink_ext_ack *extack) +{ + struct nh_group *oldg, *newg; + int i; + + if (!new->is_group) { + NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop."); + return -EINVAL; + } + + oldg = rtnl_dereference(old->nh_grp); + newg = rtnl_dereference(new->nh_grp); + + /* update parents - used by nexthop code for cleanup */ + for (i = 0; i < newg->num_nh; i++) + newg->nh_entries[i].nh_parent = old; + + rcu_assign_pointer(old->nh_grp, newg); + + for (i = 0; i < oldg->num_nh; i++) + oldg->nh_entries[i].nh_parent = new; + + rcu_assign_pointer(new->nh_grp, oldg); + + return 0; +} + +static void nh_group_v4_update(struct nh_group *nhg) +{ + struct nh_grp_entry *nhges; + bool has_v4 = false; + int i; + + nhges = nhg->nh_entries; + for (i = 0; i < nhg->num_nh; i++) { + struct nh_info *nhi; + + nhi = rtnl_dereference(nhges[i].nh->nh_info); + if (nhi->family == AF_INET) + has_v4 = true; + } + nhg->has_v4 = has_v4; +} + +static int replace_nexthop_single(struct net *net, struct nexthop *old, + struct nexthop *new, + struct netlink_ext_ack *extack) +{ + struct nh_info *oldi, *newi; + + if (new->is_group) { + NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group."); + return -EINVAL; + } + + oldi = rtnl_dereference(old->nh_info); + newi = rtnl_dereference(new->nh_info); + + newi->nh_parent = old; + oldi->nh_parent = new; + + old->protocol = new->protocol; + old->nh_flags = new->nh_flags; + + rcu_assign_pointer(old->nh_info, newi); + rcu_assign_pointer(new->nh_info, oldi); + + /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially + * update IPv4 indication in all the groups using the nexthop. + */ + if (oldi->family == AF_INET && newi->family == AF_INET6) { + struct nh_grp_entry *nhge; + + list_for_each_entry(nhge, &old->grp_list, nh_list) { + struct nexthop *nhp = nhge->nh_parent; + struct nh_group *nhg; + + nhg = rtnl_dereference(nhp->nh_grp); + nh_group_v4_update(nhg); + } + } + + return 0; +} + +static void __nexthop_replace_notify(struct net *net, struct nexthop *nh, + struct nl_info *info) +{ + struct fib6_info *f6i; + + if (!list_empty(&nh->fi_list)) { + struct fib_info *fi; + + /* expectation is a few fib_info per nexthop and then + * a lot of routes per fib_info. So mark the fib_info + * and then walk the fib tables once + */ + list_for_each_entry(fi, &nh->fi_list, nh_list) + fi->nh_updated = true; + + fib_info_notify_update(net, info); + + list_for_each_entry(fi, &nh->fi_list, nh_list) + fi->nh_updated = false; + } + + list_for_each_entry(f6i, &nh->f6i_list, nh_list) + ipv6_stub->fib6_rt_update(net, f6i, info); +} + +/* send RTM_NEWROUTE with REPLACE flag set for all FIB entries + * linked to this nexthop and for all groups that the nexthop + * is a member of + */ +static void nexthop_replace_notify(struct net *net, struct nexthop *nh, + struct nl_info *info) +{ + struct nh_grp_entry *nhge; + + __nexthop_replace_notify(net, nh, info); + + list_for_each_entry(nhge, &nh->grp_list, nh_list) + __nexthop_replace_notify(net, nhge->nh_parent, info); +} + +static int replace_nexthop(struct net *net, struct nexthop *old, + struct nexthop *new, struct netlink_ext_ack *extack) +{ + bool new_is_reject = false; + struct nh_grp_entry *nhge; + int err; + + /* check that existing FIB entries are ok with the + * new nexthop definition + */ + err = fib_check_nh_list(old, new, extack); + if (err) + return err; + + err = fib6_check_nh_list(old, new, extack); + if (err) + return err; + + if (!new->is_group) { + struct nh_info *nhi = rtnl_dereference(new->nh_info); + + new_is_reject = nhi->reject_nh; + } + + list_for_each_entry(nhge, &old->grp_list, nh_list) { + /* if new nexthop is a blackhole, any groups using this + * nexthop cannot have more than 1 path + */ + if (new_is_reject && + nexthop_num_path(nhge->nh_parent) > 1) { + NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path"); + return -EINVAL; + } + + err = fib_check_nh_list(nhge->nh_parent, new, extack); + if (err) + return err; + + err = fib6_check_nh_list(nhge->nh_parent, new, extack); + if (err) + return err; + } + + if (old->is_group) + err = replace_nexthop_grp(net, old, new, extack); + else + err = replace_nexthop_single(net, old, new, extack); + + if (!err) { + nh_rt_cache_flush(net, old, new); + + __remove_nexthop(net, new, NULL); + nexthop_put(new); + } + + return err; +} + +/* called with rtnl_lock held */ +static int insert_nexthop(struct net *net, struct nexthop *new_nh, + struct nh_config *cfg, struct netlink_ext_ack *extack) +{ + struct rb_node **pp, *parent = NULL, *next; + struct rb_root *root = &net->nexthop.rb_root; + bool replace = !!(cfg->nlflags & NLM_F_REPLACE); + bool create = !!(cfg->nlflags & NLM_F_CREATE); + u32 new_id = new_nh->id; + int replace_notify = 0; + int rc = -EEXIST; + + pp = &root->rb_node; + while (1) { + struct nexthop *nh; + + next = *pp; + if (!next) + break; + + parent = next; + + nh = rb_entry(parent, struct nexthop, rb_node); + if (new_id < nh->id) { + pp = &next->rb_left; + } else if (new_id > nh->id) { + pp = &next->rb_right; + } else if (replace) { + rc = replace_nexthop(net, nh, new_nh, extack); + if (!rc) { + new_nh = nh; /* send notification with old nh */ + replace_notify = 1; + } + goto out; + } else { + /* id already exists and not a replace */ + goto out; + } + } + + if (replace && !create) { + NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists"); + rc = -ENOENT; + goto out; + } + + rb_link_node_rcu(&new_nh->rb_node, parent, pp); + rb_insert_color(&new_nh->rb_node, root); + rc = 0; +out: + if (!rc) { + nh_base_seq_inc(net); + nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); + if (replace_notify && + READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)) + nexthop_replace_notify(net, new_nh, &cfg->nlinfo); + } + + return rc; +} + +/* rtnl */ +/* remove all nexthops tied to a device being deleted */ +static void nexthop_flush_dev(struct net_device *dev, unsigned long event) +{ + unsigned int hash = nh_dev_hashfn(dev->ifindex); + struct net *net = dev_net(dev); + struct hlist_head *head = &net->nexthop.devhash[hash]; + struct hlist_node *n; + struct nh_info *nhi; + + hlist_for_each_entry_safe(nhi, n, head, dev_hash) { + if (nhi->fib_nhc.nhc_dev != dev) + continue; + + if (nhi->reject_nh && + (event == NETDEV_DOWN || event == NETDEV_CHANGE)) + continue; + + remove_nexthop(net, nhi->nh_parent, NULL); + } +} + +/* rtnl; called when net namespace is deleted */ +static void flush_all_nexthops(struct net *net) +{ + struct rb_root *root = &net->nexthop.rb_root; + struct rb_node *node; + struct nexthop *nh; + + while ((node = rb_first(root))) { + nh = rb_entry(node, struct nexthop, rb_node); + remove_nexthop(net, nh, NULL); + cond_resched(); + } +} + +static struct nexthop *nexthop_create_group(struct net *net, + struct nh_config *cfg) +{ + struct nlattr *grps_attr = cfg->nh_grp; + struct nexthop_grp *entry = nla_data(grps_attr); + u16 num_nh = nla_len(grps_attr) / sizeof(*entry); + struct nh_group *nhg; + struct nexthop *nh; + int i; + + if (WARN_ON(!num_nh)) + return ERR_PTR(-EINVAL); + + nh = nexthop_alloc(); + if (!nh) + return ERR_PTR(-ENOMEM); + + nh->is_group = 1; + + nhg = nexthop_grp_alloc(num_nh); + if (!nhg) { + kfree(nh); + return ERR_PTR(-ENOMEM); + } + + /* spare group used for removals */ + nhg->spare = nexthop_grp_alloc(num_nh); + if (!nhg->spare) { + kfree(nhg); + kfree(nh); + return ERR_PTR(-ENOMEM); + } + nhg->spare->spare = nhg; + + for (i = 0; i < nhg->num_nh; ++i) { + struct nexthop *nhe; + struct nh_info *nhi; + + nhe = nexthop_find_by_id(net, entry[i].id); + if (!nexthop_get(nhe)) + goto out_no_nh; + + nhi = rtnl_dereference(nhe->nh_info); + if (nhi->family == AF_INET) + nhg->has_v4 = true; + + nhg->nh_entries[i].nh = nhe; + nhg->nh_entries[i].weight = entry[i].weight + 1; + list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list); + nhg->nh_entries[i].nh_parent = nh; + } + + if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) { + nhg->mpath = 1; + nh_group_rebalance(nhg); + } + + if (cfg->nh_fdb) + nhg->fdb_nh = 1; + + rcu_assign_pointer(nh->nh_grp, nhg); + + return nh; + +out_no_nh: + for (i--; i >= 0; --i) { + list_del(&nhg->nh_entries[i].nh_list); + nexthop_put(nhg->nh_entries[i].nh); + } + + kfree(nhg->spare); + kfree(nhg); + kfree(nh); + + return ERR_PTR(-ENOENT); +} + +static int nh_create_ipv4(struct net *net, struct nexthop *nh, + struct nh_info *nhi, struct nh_config *cfg, + struct netlink_ext_ack *extack) +{ + struct fib_nh *fib_nh = &nhi->fib_nh; + struct fib_config fib_cfg = { + .fc_oif = cfg->nh_ifindex, + .fc_gw4 = cfg->gw.ipv4, + .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0, + .fc_flags = cfg->nh_flags, + .fc_nlinfo = cfg->nlinfo, + .fc_encap = cfg->nh_encap, + .fc_encap_type = cfg->nh_encap_type, + }; + u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN); + int err; + + err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack); + if (err) { + fib_nh_release(net, fib_nh); + goto out; + } + + if (nhi->fdb_nh) + goto out; + + /* sets nh_dev if successful */ + err = fib_check_nh(net, fib_nh, tb_id, 0, extack); + if (!err) { + nh->nh_flags = fib_nh->fib_nh_flags; + fib_info_update_nhc_saddr(net, &fib_nh->nh_common, + !fib_nh->fib_nh_scope ? 0 : fib_nh->fib_nh_scope - 1); + } else { + fib_nh_release(net, fib_nh); + } +out: + return err; +} + +static int nh_create_ipv6(struct net *net, struct nexthop *nh, + struct nh_info *nhi, struct nh_config *cfg, + struct netlink_ext_ack *extack) +{ + struct fib6_nh *fib6_nh = &nhi->fib6_nh; + struct fib6_config fib6_cfg = { + .fc_table = l3mdev_fib_table(cfg->dev), + .fc_ifindex = cfg->nh_ifindex, + .fc_gateway = cfg->gw.ipv6, + .fc_flags = cfg->nh_flags, + .fc_nlinfo = cfg->nlinfo, + .fc_encap = cfg->nh_encap, + .fc_encap_type = cfg->nh_encap_type, + .fc_is_fdb = cfg->nh_fdb, + }; + int err; + + if (!ipv6_addr_any(&cfg->gw.ipv6)) + fib6_cfg.fc_flags |= RTF_GATEWAY; + + /* sets nh_dev if successful */ + err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL, + extack); + if (err) { + /* IPv6 is not enabled, don't call fib6_nh_release */ + if (err == -EAFNOSUPPORT) + goto out; + ipv6_stub->fib6_nh_release(fib6_nh); + } else { + nh->nh_flags = fib6_nh->fib_nh_flags; + } +out: + return err; +} + +static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg, + struct netlink_ext_ack *extack) +{ + struct nh_info *nhi; + struct nexthop *nh; + int err = 0; + + nh = nexthop_alloc(); + if (!nh) + return ERR_PTR(-ENOMEM); + + nhi = kzalloc(sizeof(*nhi), GFP_KERNEL); + if (!nhi) { + kfree(nh); + return ERR_PTR(-ENOMEM); + } + + nh->nh_flags = cfg->nh_flags; + nh->net = net; + + nhi->nh_parent = nh; + nhi->family = cfg->nh_family; + nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK; + + if (cfg->nh_fdb) + nhi->fdb_nh = 1; + + if (cfg->nh_blackhole) { + nhi->reject_nh = 1; + cfg->nh_ifindex = net->loopback_dev->ifindex; + } + + switch (cfg->nh_family) { + case AF_INET: + err = nh_create_ipv4(net, nh, nhi, cfg, extack); + break; + case AF_INET6: + err = nh_create_ipv6(net, nh, nhi, cfg, extack); + break; + } + + if (err) { + kfree(nhi); + kfree(nh); + return ERR_PTR(err); + } + + /* add the entry to the device based hash */ + if (!nhi->fdb_nh) + nexthop_devhash_add(net, nhi); + + rcu_assign_pointer(nh->nh_info, nhi); + + return nh; +} + +/* called with rtnl lock held */ +static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg, + struct netlink_ext_ack *extack) +{ + struct nexthop *nh; + int err; + + if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) { + NL_SET_ERR_MSG(extack, "Replace requires nexthop id"); + return ERR_PTR(-EINVAL); + } + + if (!cfg->nh_id) { + cfg->nh_id = nh_find_unused_id(net); + if (!cfg->nh_id) { + NL_SET_ERR_MSG(extack, "No unused id"); + return ERR_PTR(-EINVAL); + } + } + + if (cfg->nh_grp) + nh = nexthop_create_group(net, cfg); + else + nh = nexthop_create(net, cfg, extack); + + if (IS_ERR(nh)) + return nh; + + refcount_set(&nh->refcnt, 1); + nh->id = cfg->nh_id; + nh->protocol = cfg->nh_protocol; + nh->net = net; + + err = insert_nexthop(net, nh, cfg, extack); + if (err) { + __remove_nexthop(net, nh, NULL); + nexthop_put(nh); + nh = ERR_PTR(err); + } + + return nh; +} + +static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, + struct nlmsghdr *nlh, struct nh_config *cfg, + struct netlink_ext_ack *extack) +{ + struct nhmsg *nhm = nlmsg_data(nlh); + struct nlattr *tb[NHA_MAX + 1]; + int err; + + err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy, + extack); + if (err < 0) + return err; + + err = -EINVAL; + if (nhm->resvd || nhm->nh_scope) { + NL_SET_ERR_MSG(extack, "Invalid values in ancillary header"); + goto out; + } + if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) { + NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header"); + goto out; + } + + switch (nhm->nh_family) { + case AF_INET: + case AF_INET6: + break; + case AF_UNSPEC: + if (tb[NHA_GROUP]) + break; + fallthrough; + default: + NL_SET_ERR_MSG(extack, "Invalid address family"); + goto out; + } + + if (tb[NHA_GROUPS] || tb[NHA_MASTER]) { + NL_SET_ERR_MSG(extack, "Invalid attributes in request"); + goto out; + } + + memset(cfg, 0, sizeof(*cfg)); + cfg->nlflags = nlh->nlmsg_flags; + cfg->nlinfo.portid = NETLINK_CB(skb).portid; + cfg->nlinfo.nlh = nlh; + cfg->nlinfo.nl_net = net; + + cfg->nh_family = nhm->nh_family; + cfg->nh_protocol = nhm->nh_protocol; + cfg->nh_flags = nhm->nh_flags; + + if (tb[NHA_ID]) + cfg->nh_id = nla_get_u32(tb[NHA_ID]); + + if (tb[NHA_FDB]) { + if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] || + tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) { + NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole"); + goto out; + } + if (nhm->nh_flags) { + NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header"); + goto out; + } + cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]); + } + + if (tb[NHA_GROUP]) { + if (nhm->nh_family != AF_UNSPEC) { + NL_SET_ERR_MSG(extack, "Invalid family for group"); + goto out; + } + cfg->nh_grp = tb[NHA_GROUP]; + + cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH; + if (tb[NHA_GROUP_TYPE]) + cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]); + + if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) { + NL_SET_ERR_MSG(extack, "Invalid group type"); + goto out; + } + err = nh_check_attr_group(net, tb, extack); + + /* no other attributes should be set */ + goto out; + } + + if (tb[NHA_BLACKHOLE]) { + if (tb[NHA_GATEWAY] || tb[NHA_OIF] || + tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) { + NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb"); + goto out; + } + + cfg->nh_blackhole = 1; + err = 0; + goto out; + } + + if (!cfg->nh_fdb && !tb[NHA_OIF]) { + NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops"); + goto out; + } + + if (!cfg->nh_fdb && tb[NHA_OIF]) { + cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]); + if (cfg->nh_ifindex) + cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex); + + if (!cfg->dev) { + NL_SET_ERR_MSG(extack, "Invalid device index"); + goto out; + } else if (!(cfg->dev->flags & IFF_UP)) { + NL_SET_ERR_MSG(extack, "Nexthop device is not up"); + err = -ENETDOWN; + goto out; + } else if (!netif_carrier_ok(cfg->dev)) { + NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down"); + err = -ENETDOWN; + goto out; + } + } + + err = -EINVAL; + if (tb[NHA_GATEWAY]) { + struct nlattr *gwa = tb[NHA_GATEWAY]; + + switch (cfg->nh_family) { + case AF_INET: + if (nla_len(gwa) != sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid gateway"); + goto out; + } + cfg->gw.ipv4 = nla_get_be32(gwa); + break; + case AF_INET6: + if (nla_len(gwa) != sizeof(struct in6_addr)) { + NL_SET_ERR_MSG(extack, "Invalid gateway"); + goto out; + } + cfg->gw.ipv6 = nla_get_in6_addr(gwa); + break; + default: + NL_SET_ERR_MSG(extack, + "Unknown address family for gateway"); + goto out; + } + } else { + /* device only nexthop (no gateway) */ + if (cfg->nh_flags & RTNH_F_ONLINK) { + NL_SET_ERR_MSG(extack, + "ONLINK flag can not be set for nexthop without a gateway"); + goto out; + } + } + + if (tb[NHA_ENCAP]) { + cfg->nh_encap = tb[NHA_ENCAP]; + + if (!tb[NHA_ENCAP_TYPE]) { + NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing"); + goto out; + } + + cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]); + err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack); + if (err < 0) + goto out; + + } else if (tb[NHA_ENCAP_TYPE]) { + NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing"); + goto out; + } + + + err = 0; +out: + return err; +} + +/* rtnl */ +static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct nh_config cfg; + struct nexthop *nh; + int err; + + err = rtm_to_nh_config(net, skb, nlh, &cfg, extack); + if (!err) { + nh = nexthop_add(net, &cfg, extack); + if (IS_ERR(nh)) + err = PTR_ERR(nh); + } + + return err; +} + +static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id, + struct netlink_ext_ack *extack) +{ + struct nhmsg *nhm = nlmsg_data(nlh); + struct nlattr *tb[NHA_MAX + 1]; + int err, i; + + err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy, + extack); + if (err < 0) + return err; + + err = -EINVAL; + for (i = 0; i < __NHA_MAX; ++i) { + if (!tb[i]) + continue; + + switch (i) { + case NHA_ID: + break; + default: + NL_SET_ERR_MSG_ATTR(extack, tb[i], + "Unexpected attribute in request"); + goto out; + } + } + if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { + NL_SET_ERR_MSG(extack, "Invalid values in header"); + goto out; + } + + if (!tb[NHA_ID]) { + NL_SET_ERR_MSG(extack, "Nexthop id is missing"); + goto out; + } + + *id = nla_get_u32(tb[NHA_ID]); + if (!(*id)) + NL_SET_ERR_MSG(extack, "Invalid nexthop id"); + else + err = 0; +out: + return err; +} + +/* rtnl */ +static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct nl_info nlinfo = { + .nlh = nlh, + .nl_net = net, + .portid = NETLINK_CB(skb).portid, + }; + struct nexthop *nh; + int err; + u32 id; + + err = nh_valid_get_del_req(nlh, &id, extack); + if (err) + return err; + + nh = nexthop_find_by_id(net, id); + if (!nh) + return -ENOENT; + + remove_nexthop(net, nh, &nlinfo); + + return 0; +} + +/* rtnl */ +static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(in_skb->sk); + struct sk_buff *skb = NULL; + struct nexthop *nh; + int err; + u32 id; + + err = nh_valid_get_del_req(nlh, &id, extack); + if (err) + return err; + + err = -ENOBUFS; + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb) + goto out; + + err = -ENOENT; + nh = nexthop_find_by_id(net, id); + if (!nh) + goto errout_free; + + err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid, + nlh->nlmsg_seq, 0); + if (err < 0) { + WARN_ON(err == -EMSGSIZE); + goto errout_free; + } + + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); +out: + return err; +errout_free: + kfree_skb(skb); + goto out; +} + +static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx, + bool group_filter, u8 family) +{ + const struct net_device *dev; + const struct nh_info *nhi; + + if (group_filter && !nh->is_group) + return true; + + if (!dev_idx && !master_idx && !family) + return false; + + if (nh->is_group) + return true; + + nhi = rtnl_dereference(nh->nh_info); + if (family && nhi->family != family) + return true; + + dev = nhi->fib_nhc.nhc_dev; + if (dev_idx && (!dev || dev->ifindex != dev_idx)) + return true; + + if (master_idx) { + struct net_device *master; + + if (!dev) + return true; + + master = netdev_master_upper_dev_get((struct net_device *)dev); + if (!master || master->ifindex != master_idx) + return true; + } + + return false; +} + +static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx, + int *master_idx, bool *group_filter, + bool *fdb_filter, struct netlink_callback *cb) +{ + struct netlink_ext_ack *extack = cb->extack; + struct nlattr *tb[NHA_MAX + 1]; + struct nhmsg *nhm; + int err, i; + u32 idx; + + err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy, + NULL); + if (err < 0) + return err; + + for (i = 0; i <= NHA_MAX; ++i) { + if (!tb[i]) + continue; + + switch (i) { + case NHA_OIF: + idx = nla_get_u32(tb[i]); + if (idx > INT_MAX) { + NL_SET_ERR_MSG(extack, "Invalid device index"); + return -EINVAL; + } + *dev_idx = idx; + break; + case NHA_MASTER: + idx = nla_get_u32(tb[i]); + if (idx > INT_MAX) { + NL_SET_ERR_MSG(extack, "Invalid master device index"); + return -EINVAL; + } + *master_idx = idx; + break; + case NHA_GROUPS: + *group_filter = true; + break; + case NHA_FDB: + *fdb_filter = true; + break; + default: + NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); + return -EINVAL; + } + } + + nhm = nlmsg_data(nlh); + if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { + NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request"); + return -EINVAL; + } + + return 0; +} + +/* rtnl */ +static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb) +{ + bool group_filter = false, fdb_filter = false; + struct nhmsg *nhm = nlmsg_data(cb->nlh); + int dev_filter_idx = 0, master_idx = 0; + struct net *net = sock_net(skb->sk); + struct rb_root *root = &net->nexthop.rb_root; + struct rb_node *node; + int idx = 0, s_idx; + int err; + + err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx, + &group_filter, &fdb_filter, cb); + if (err < 0) + return err; + + s_idx = cb->args[0]; + for (node = rb_first(root); node; node = rb_next(node)) { + struct nexthop *nh; + + if (idx < s_idx) + goto cont; + + nh = rb_entry(node, struct nexthop, rb_node); + if (nh_dump_filtered(nh, dev_filter_idx, master_idx, + group_filter, nhm->nh_family)) + goto cont; + + err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, NLM_F_MULTI); + if (err < 0) { + if (likely(skb->len)) + goto out; + + goto out_err; + } +cont: + idx++; + } + +out: + err = skb->len; +out_err: + cb->args[0] = idx; + cb->seq = net->nexthop.seq; + nl_dump_check_consistent(cb, nlmsg_hdr(skb)); + + return err; +} + +static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu) +{ + unsigned int hash = nh_dev_hashfn(dev->ifindex); + struct net *net = dev_net(dev); + struct hlist_head *head = &net->nexthop.devhash[hash]; + struct hlist_node *n; + struct nh_info *nhi; + + hlist_for_each_entry_safe(nhi, n, head, dev_hash) { + if (nhi->fib_nhc.nhc_dev == dev) { + if (nhi->family == AF_INET) + fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu, + orig_mtu); + } + } +} + +/* rtnl */ +static int nh_netdev_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct netdev_notifier_info_ext *info_ext; + + switch (event) { + case NETDEV_DOWN: + case NETDEV_UNREGISTER: + nexthop_flush_dev(dev, event); + break; + case NETDEV_CHANGE: + if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP))) + nexthop_flush_dev(dev, event); + break; + case NETDEV_CHANGEMTU: + info_ext = ptr; + nexthop_sync_mtu(dev, info_ext->ext.mtu); + rt_cache_flush(dev_net(dev)); + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block nh_netdev_notifier = { + .notifier_call = nh_netdev_event, +}; + +int register_nexthop_notifier(struct net *net, struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&net->nexthop.notifier_chain, + nb); +} +EXPORT_SYMBOL(register_nexthop_notifier); + +int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&net->nexthop.notifier_chain, + nb); +} +EXPORT_SYMBOL(unregister_nexthop_notifier); + +static void __net_exit nexthop_net_exit(struct net *net) +{ + rtnl_lock(); + flush_all_nexthops(net); + rtnl_unlock(); + kfree(net->nexthop.devhash); +} + +static int __net_init nexthop_net_init(struct net *net) +{ + size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE; + + net->nexthop.rb_root = RB_ROOT; + net->nexthop.devhash = kzalloc(sz, GFP_KERNEL); + if (!net->nexthop.devhash) + return -ENOMEM; + BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain); + + return 0; +} + +static struct pernet_operations nexthop_net_ops = { + .init = nexthop_net_init, + .exit = nexthop_net_exit, +}; + +static int __init nexthop_init(void) +{ + register_pernet_subsys(&nexthop_net_ops); + + register_netdevice_notifier(&nh_netdev_notifier); + + rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); + rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0); + rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop, + rtm_dump_nexthop, 0); + + rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); + rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); + + rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); + rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); + + return 0; +} +subsys_initcall(nexthop_init); diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c new file mode 100644 index 000000000..1bad851b3 --- /dev/null +++ b/net/ipv4/ping.c @@ -0,0 +1,1194 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * "Ping" sockets + * + * Based on ipv4/udp.c code. + * + * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6), + * Pavel Kankovsky (for Linux 2.4.32) + * + * Pavel gave all rights to bugs to Vasiliy, + * none of the bugs are Pavel's now. + */ + +#include <linux/uaccess.h> +#include <linux/types.h> +#include <linux/fcntl.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <net/snmp.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/protocol.h> +#include <linux/skbuff.h> +#include <linux/proc_fs.h> +#include <linux/export.h> +#include <net/sock.h> +#include <net/ping.h> +#include <net/udp.h> +#include <net/route.h> +#include <net/inet_common.h> +#include <net/checksum.h> + +#if IS_ENABLED(CONFIG_IPV6) +#include <linux/in6.h> +#include <linux/icmpv6.h> +#include <net/addrconf.h> +#include <net/ipv6.h> +#include <net/transp_v6.h> +#endif + +struct ping_table { + struct hlist_nulls_head hash[PING_HTABLE_SIZE]; + rwlock_t lock; +}; + +static struct ping_table ping_table; +struct pingv6_ops pingv6_ops; +EXPORT_SYMBOL_GPL(pingv6_ops); + +static u16 ping_port_rover; + +static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) +{ + u32 res = (num + net_hash_mix(net)) & mask; + + pr_debug("hash(%u) = %u\n", num, res); + return res; +} +EXPORT_SYMBOL_GPL(ping_hash); + +static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, + struct net *net, unsigned int num) +{ + return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; +} + +int ping_get_port(struct sock *sk, unsigned short ident) +{ + struct hlist_nulls_node *node; + struct hlist_nulls_head *hlist; + struct inet_sock *isk, *isk2; + struct sock *sk2 = NULL; + + isk = inet_sk(sk); + write_lock_bh(&ping_table.lock); + if (ident == 0) { + u32 i; + u16 result = ping_port_rover + 1; + + for (i = 0; i < (1L << 16); i++, result++) { + if (!result) + result++; /* avoid zero */ + hlist = ping_hashslot(&ping_table, sock_net(sk), + result); + ping_portaddr_for_each_entry(sk2, node, hlist) { + isk2 = inet_sk(sk2); + + if (isk2->inet_num == result) + goto next_port; + } + + /* found */ + ping_port_rover = ident = result; + break; +next_port: + ; + } + if (i >= (1L << 16)) + goto fail; + } else { + hlist = ping_hashslot(&ping_table, sock_net(sk), ident); + ping_portaddr_for_each_entry(sk2, node, hlist) { + isk2 = inet_sk(sk2); + + /* BUG? Why is this reuse and not reuseaddr? ping.c + * doesn't turn off SO_REUSEADDR, and it doesn't expect + * that other ping processes can steal its packets. + */ + if ((isk2->inet_num == ident) && + (sk2 != sk) && + (!sk2->sk_reuse || !sk->sk_reuse)) + goto fail; + } + } + + pr_debug("found port/ident = %d\n", ident); + isk->inet_num = ident; + if (sk_unhashed(sk)) { + pr_debug("was not hashed\n"); + sock_hold(sk); + hlist_nulls_add_head(&sk->sk_nulls_node, hlist); + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); + } + write_unlock_bh(&ping_table.lock); + return 0; + +fail: + write_unlock_bh(&ping_table.lock); + return 1; +} +EXPORT_SYMBOL_GPL(ping_get_port); + +int ping_hash(struct sock *sk) +{ + pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); + BUG(); /* "Please do not press this button again." */ + + return 0; +} + +void ping_unhash(struct sock *sk) +{ + struct inet_sock *isk = inet_sk(sk); + + pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); + write_lock_bh(&ping_table.lock); + if (sk_hashed(sk)) { + hlist_nulls_del(&sk->sk_nulls_node); + sk_nulls_node_init(&sk->sk_nulls_node); + sock_put(sk); + isk->inet_num = 0; + isk->inet_sport = 0; + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + } + write_unlock_bh(&ping_table.lock); +} +EXPORT_SYMBOL_GPL(ping_unhash); + +static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) +{ + struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); + struct sock *sk = NULL; + struct inet_sock *isk; + struct hlist_nulls_node *hnode; + int dif, sdif; + + if (skb->protocol == htons(ETH_P_IP)) { + dif = inet_iif(skb); + sdif = inet_sdif(skb); + pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", + (int)ident, &ip_hdr(skb)->daddr, dif); +#if IS_ENABLED(CONFIG_IPV6) + } else if (skb->protocol == htons(ETH_P_IPV6)) { + dif = inet6_iif(skb); + sdif = inet6_sdif(skb); + pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", + (int)ident, &ipv6_hdr(skb)->daddr, dif); +#endif + } else { + return NULL; + } + + read_lock_bh(&ping_table.lock); + + ping_portaddr_for_each_entry(sk, hnode, hslot) { + isk = inet_sk(sk); + + pr_debug("iterate\n"); + if (isk->inet_num != ident) + continue; + + if (skb->protocol == htons(ETH_P_IP) && + sk->sk_family == AF_INET) { + pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, + (int) isk->inet_num, &isk->inet_rcv_saddr, + sk->sk_bound_dev_if); + + if (isk->inet_rcv_saddr && + isk->inet_rcv_saddr != ip_hdr(skb)->daddr) + continue; +#if IS_ENABLED(CONFIG_IPV6) + } else if (skb->protocol == htons(ETH_P_IPV6) && + sk->sk_family == AF_INET6) { + + pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, + (int) isk->inet_num, + &sk->sk_v6_rcv_saddr, + sk->sk_bound_dev_if); + + if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && + !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, + &ipv6_hdr(skb)->daddr)) + continue; +#endif + } else { + continue; + } + + if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && + sk->sk_bound_dev_if != sdif) + continue; + + sock_hold(sk); + goto exit; + } + + sk = NULL; +exit: + read_unlock_bh(&ping_table.lock); + + return sk; +} + +static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, + kgid_t *high) +{ + kgid_t *data = net->ipv4.ping_group_range.range; + unsigned int seq; + + do { + seq = read_seqbegin(&net->ipv4.ping_group_range.lock); + + *low = data[0]; + *high = data[1]; + } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); +} + + +int ping_init_sock(struct sock *sk) +{ + struct net *net = sock_net(sk); + kgid_t group = current_egid(); + struct group_info *group_info; + int i; + kgid_t low, high; + int ret = 0; + + if (sk->sk_family == AF_INET6) + sk->sk_ipv6only = 1; + + inet_get_ping_group_range_net(net, &low, &high); + if (gid_lte(low, group) && gid_lte(group, high)) + return 0; + + group_info = get_current_groups(); + for (i = 0; i < group_info->ngroups; i++) { + kgid_t gid = group_info->gid[i]; + + if (gid_lte(low, gid) && gid_lte(gid, high)) + goto out_release_group; + } + + ret = -EACCES; + +out_release_group: + put_group_info(group_info); + return ret; +} +EXPORT_SYMBOL_GPL(ping_init_sock); + +void ping_close(struct sock *sk, long timeout) +{ + pr_debug("ping_close(sk=%p,sk->num=%u)\n", + inet_sk(sk), inet_sk(sk)->inet_num); + pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); + + sk_common_release(sk); +} +EXPORT_SYMBOL_GPL(ping_close); + +/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ +static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, + struct sockaddr *uaddr, int addr_len) +{ + struct net *net = sock_net(sk); + if (sk->sk_family == AF_INET) { + struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; + u32 tb_id = RT_TABLE_LOCAL; + int chk_addr_ret; + + if (addr_len < sizeof(*addr)) + return -EINVAL; + + if (addr->sin_family != AF_INET && + !(addr->sin_family == AF_UNSPEC && + addr->sin_addr.s_addr == htonl(INADDR_ANY))) + return -EAFNOSUPPORT; + + pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", + sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); + + if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) + chk_addr_ret = RTN_LOCAL; + else { + tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id; + chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id); + } + + if ((!inet_can_nonlocal_bind(net, isk) && + chk_addr_ret != RTN_LOCAL) || + chk_addr_ret == RTN_MULTICAST || + chk_addr_ret == RTN_BROADCAST) + return -EADDRNOTAVAIL; + +#if IS_ENABLED(CONFIG_IPV6) + } else if (sk->sk_family == AF_INET6) { + struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; + int addr_type, scoped, has_addr; + struct net_device *dev = NULL; + + if (addr_len < sizeof(*addr)) + return -EINVAL; + + if (addr->sin6_family != AF_INET6) + return -EAFNOSUPPORT; + + pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", + sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); + + addr_type = ipv6_addr_type(&addr->sin6_addr); + scoped = __ipv6_addr_needs_scope_id(addr_type); + if ((addr_type != IPV6_ADDR_ANY && + !(addr_type & IPV6_ADDR_UNICAST)) || + (scoped && !addr->sin6_scope_id)) + return -EINVAL; + + rcu_read_lock(); + if (addr->sin6_scope_id) { + dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); + if (!dev) { + rcu_read_unlock(); + return -ENODEV; + } + } + + if (!dev && sk->sk_bound_dev_if) { + dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); + if (!dev) { + rcu_read_unlock(); + return -ENODEV; + } + } + has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, + scoped); + rcu_read_unlock(); + + if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || + addr_type == IPV6_ADDR_ANY)) + return -EADDRNOTAVAIL; + + if (scoped) + sk->sk_bound_dev_if = addr->sin6_scope_id; +#endif + } else { + return -EAFNOSUPPORT; + } + return 0; +} + +static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) +{ + if (saddr->sa_family == AF_INET) { + struct inet_sock *isk = inet_sk(sk); + struct sockaddr_in *addr = (struct sockaddr_in *) saddr; + isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; +#if IS_ENABLED(CONFIG_IPV6) + } else if (saddr->sa_family == AF_INET6) { + struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; + struct ipv6_pinfo *np = inet6_sk(sk); + sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; +#endif + } +} + +/* + * We need our own bind because there are no privileged id's == local ports. + * Moreover, we don't allow binding to multi- and broadcast addresses. + */ + +int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct inet_sock *isk = inet_sk(sk); + unsigned short snum; + int err; + int dif = sk->sk_bound_dev_if; + + err = ping_check_bind_addr(sk, isk, uaddr, addr_len); + if (err) + return err; + + lock_sock(sk); + + err = -EINVAL; + if (isk->inet_num != 0) + goto out; + + err = -EADDRINUSE; + snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); + if (ping_get_port(sk, snum) != 0) { + /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ + sk->sk_bound_dev_if = dif; + goto out; + } + ping_set_saddr(sk, uaddr); + + pr_debug("after bind(): num = %hu, dif = %d\n", + isk->inet_num, + sk->sk_bound_dev_if); + + err = 0; + if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) + sk->sk_userlocks |= SOCK_BINDADDR_LOCK; +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) + sk->sk_userlocks |= SOCK_BINDADDR_LOCK; +#endif + + if (snum) + sk->sk_userlocks |= SOCK_BINDPORT_LOCK; + isk->inet_sport = htons(isk->inet_num); + isk->inet_daddr = 0; + isk->inet_dport = 0; + +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); +#endif + + sk_dst_reset(sk); +out: + release_sock(sk); + pr_debug("ping_v4_bind -> %d\n", err); + return err; +} +EXPORT_SYMBOL_GPL(ping_bind); + +/* + * Is this a supported type of ICMP message? + */ + +static inline int ping_supported(int family, int type, int code) +{ + return (family == AF_INET && type == ICMP_ECHO && code == 0) || + (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); +} + +/* + * This routine is called by the ICMP module when it gets some + * sort of error condition. + */ + +void ping_err(struct sk_buff *skb, int offset, u32 info) +{ + int family; + struct icmphdr *icmph; + struct inet_sock *inet_sock; + int type; + int code; + struct net *net = dev_net(skb->dev); + struct sock *sk; + int harderr; + int err; + + if (skb->protocol == htons(ETH_P_IP)) { + family = AF_INET; + type = icmp_hdr(skb)->type; + code = icmp_hdr(skb)->code; + icmph = (struct icmphdr *)(skb->data + offset); + } else if (skb->protocol == htons(ETH_P_IPV6)) { + family = AF_INET6; + type = icmp6_hdr(skb)->icmp6_type; + code = icmp6_hdr(skb)->icmp6_code; + icmph = (struct icmphdr *) (skb->data + offset); + } else { + BUG(); + } + + /* We assume the packet has already been checked by icmp_unreach */ + + if (!ping_supported(family, icmph->type, icmph->code)) + return; + + pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", + skb->protocol, type, code, ntohs(icmph->un.echo.id), + ntohs(icmph->un.echo.sequence)); + + sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); + if (!sk) { + pr_debug("no socket, dropping\n"); + return; /* No socket for error */ + } + pr_debug("err on socket %p\n", sk); + + err = 0; + harderr = 0; + inet_sock = inet_sk(sk); + + if (skb->protocol == htons(ETH_P_IP)) { + switch (type) { + default: + case ICMP_TIME_EXCEEDED: + err = EHOSTUNREACH; + break; + case ICMP_SOURCE_QUENCH: + /* This is not a real error but ping wants to see it. + * Report it with some fake errno. + */ + err = EREMOTEIO; + break; + case ICMP_PARAMETERPROB: + err = EPROTO; + harderr = 1; + break; + case ICMP_DEST_UNREACH: + if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ + ipv4_sk_update_pmtu(skb, sk, info); + if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { + err = EMSGSIZE; + harderr = 1; + break; + } + goto out; + } + err = EHOSTUNREACH; + if (code <= NR_ICMP_UNREACH) { + harderr = icmp_err_convert[code].fatal; + err = icmp_err_convert[code].errno; + } + break; + case ICMP_REDIRECT: + /* See ICMP_SOURCE_QUENCH */ + ipv4_sk_redirect(skb, sk); + err = EREMOTEIO; + break; + } +#if IS_ENABLED(CONFIG_IPV6) + } else if (skb->protocol == htons(ETH_P_IPV6)) { + harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); +#endif + } + + /* + * RFC1122: OK. Passes ICMP errors back to application, as per + * 4.1.3.3. + */ + if ((family == AF_INET && !inet_sock->recverr) || + (family == AF_INET6 && !inet6_sk(sk)->recverr)) { + if (!harderr || sk->sk_state != TCP_ESTABLISHED) + goto out; + } else { + if (family == AF_INET) { + ip_icmp_error(sk, skb, err, 0 /* no remote port */, + info, (u8 *)icmph); +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, + info, (u8 *)icmph); +#endif + } + } + sk->sk_err = err; + sk->sk_error_report(sk); +out: + sock_put(sk); +} +EXPORT_SYMBOL_GPL(ping_err); + +/* + * Copy and checksum an ICMP Echo packet from user space into a buffer + * starting from the payload. + */ + +int ping_getfrag(void *from, char *to, + int offset, int fraglen, int odd, struct sk_buff *skb) +{ + struct pingfakehdr *pfh = (struct pingfakehdr *)from; + + if (offset == 0) { + fraglen -= sizeof(struct icmphdr); + if (fraglen < 0) + BUG(); + if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), + fraglen, &pfh->wcheck, + &pfh->msg->msg_iter)) + return -EFAULT; + } else if (offset < sizeof(struct icmphdr)) { + BUG(); + } else { + if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, + &pfh->msg->msg_iter)) + return -EFAULT; + } + +#if IS_ENABLED(CONFIG_IPV6) + /* For IPv6, checksum each skb as we go along, as expected by + * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in + * wcheck, it will be finalized in ping_v4_push_pending_frames. + */ + if (pfh->family == AF_INET6) { + skb->csum = pfh->wcheck; + skb->ip_summed = CHECKSUM_NONE; + pfh->wcheck = 0; + } +#endif + + return 0; +} +EXPORT_SYMBOL_GPL(ping_getfrag); + +static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, + struct flowi4 *fl4) +{ + struct sk_buff *skb = skb_peek(&sk->sk_write_queue); + + if (!skb) + return 0; + pfh->wcheck = csum_partial((char *)&pfh->icmph, + sizeof(struct icmphdr), pfh->wcheck); + pfh->icmph.checksum = csum_fold(pfh->wcheck); + memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); + skb->ip_summed = CHECKSUM_NONE; + return ip_push_pending_frames(sk, fl4); +} + +int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, + void *user_icmph, size_t icmph_len) +{ + u8 type, code; + + if (len > 0xFFFF) + return -EMSGSIZE; + + /* Must have at least a full ICMP header. */ + if (len < icmph_len) + return -EINVAL; + + /* + * Check the flags. + */ + + /* Mirror BSD error message compatibility */ + if (msg->msg_flags & MSG_OOB) + return -EOPNOTSUPP; + + /* + * Fetch the ICMP header provided by the userland. + * iovec is modified! The ICMP header is consumed. + */ + if (memcpy_from_msg(user_icmph, msg, icmph_len)) + return -EFAULT; + + if (family == AF_INET) { + type = ((struct icmphdr *) user_icmph)->type; + code = ((struct icmphdr *) user_icmph)->code; +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + type = ((struct icmp6hdr *) user_icmph)->icmp6_type; + code = ((struct icmp6hdr *) user_icmph)->icmp6_code; +#endif + } else { + BUG(); + } + + if (!ping_supported(family, type, code)) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(ping_common_sendmsg); + +static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct net *net = sock_net(sk); + struct flowi4 fl4; + struct inet_sock *inet = inet_sk(sk); + struct ipcm_cookie ipc; + struct icmphdr user_icmph; + struct pingfakehdr pfh; + struct rtable *rt = NULL; + struct ip_options_data opt_copy; + int free = 0; + __be32 saddr, daddr, faddr; + u8 tos; + int err; + + pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); + + err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, + sizeof(user_icmph)); + if (err) + return err; + + /* + * Get and verify the address. + */ + + if (msg->msg_name) { + DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); + if (msg->msg_namelen < sizeof(*usin)) + return -EINVAL; + if (usin->sin_family != AF_INET) + return -EAFNOSUPPORT; + daddr = usin->sin_addr.s_addr; + /* no remote port */ + } else { + if (sk->sk_state != TCP_ESTABLISHED) + return -EDESTADDRREQ; + daddr = inet->inet_daddr; + /* no remote port */ + } + + ipcm_init_sk(&ipc, inet); + + if (msg->msg_controllen) { + err = ip_cmsg_send(sk, msg, &ipc, false); + if (unlikely(err)) { + kfree(ipc.opt); + return err; + } + if (ipc.opt) + free = 1; + } + if (!ipc.opt) { + struct ip_options_rcu *inet_opt; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) { + memcpy(&opt_copy, inet_opt, + sizeof(*inet_opt) + inet_opt->opt.optlen); + ipc.opt = &opt_copy.opt; + } + rcu_read_unlock(); + } + + saddr = ipc.addr; + ipc.addr = faddr = daddr; + + if (ipc.opt && ipc.opt->opt.srr) { + if (!daddr) { + err = -EINVAL; + goto out_free; + } + faddr = ipc.opt->opt.faddr; + } + tos = get_rttos(&ipc, inet); + if (sock_flag(sk, SOCK_LOCALROUTE) || + (msg->msg_flags & MSG_DONTROUTE) || + (ipc.opt && ipc.opt->opt.is_strictroute)) { + tos |= RTO_ONLINK; + } + + if (ipv4_is_multicast(daddr)) { + if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) + ipc.oif = inet->mc_index; + if (!saddr) + saddr = inet->mc_addr; + } else if (!ipc.oif) + ipc.oif = inet->uc_index; + + flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, + RT_SCOPE_UNIVERSE, sk->sk_protocol, + inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, + sk->sk_uid); + + fl4.fl4_icmp_type = user_icmph.type; + fl4.fl4_icmp_code = user_icmph.code; + + security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); + rt = ip_route_output_flow(net, &fl4, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + rt = NULL; + if (err == -ENETUNREACH) + IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); + goto out; + } + + err = -EACCES; + if ((rt->rt_flags & RTCF_BROADCAST) && + !sock_flag(sk, SOCK_BROADCAST)) + goto out; + + if (msg->msg_flags & MSG_CONFIRM) + goto do_confirm; +back_from_confirm: + + if (!ipc.addr) + ipc.addr = fl4.daddr; + + lock_sock(sk); + + pfh.icmph.type = user_icmph.type; /* already checked */ + pfh.icmph.code = user_icmph.code; /* ditto */ + pfh.icmph.checksum = 0; + pfh.icmph.un.echo.id = inet->inet_sport; + pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; + pfh.msg = msg; + pfh.wcheck = 0; + pfh.family = AF_INET; + + err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, + 0, &ipc, &rt, msg->msg_flags); + if (err) + ip_flush_pending_frames(sk); + else + err = ping_v4_push_pending_frames(sk, &pfh, &fl4); + release_sock(sk); + +out: + ip_rt_put(rt); +out_free: + if (free) + kfree(ipc.opt); + if (!err) { + icmp_out_count(sock_net(sk), user_icmph.type); + return len; + } + return err; + +do_confirm: + if (msg->msg_flags & MSG_PROBE) + dst_confirm_neigh(&rt->dst, &fl4.daddr); + if (!(msg->msg_flags & MSG_PROBE) || len) + goto back_from_confirm; + err = 0; + goto out; +} + +int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, + int flags, int *addr_len) +{ + struct inet_sock *isk = inet_sk(sk); + int family = sk->sk_family; + struct sk_buff *skb; + int copied, err; + + pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); + + err = -EOPNOTSUPP; + if (flags & MSG_OOB) + goto out; + + if (flags & MSG_ERRQUEUE) + return inet_recv_error(sk, msg, len, addr_len); + + skb = skb_recv_datagram(sk, flags, noblock, &err); + if (!skb) + goto out; + + copied = skb->len; + if (copied > len) { + msg->msg_flags |= MSG_TRUNC; + copied = len; + } + + /* Don't bother checking the checksum */ + err = skb_copy_datagram_msg(skb, 0, msg, copied); + if (err) + goto done; + + sock_recv_timestamp(msg, sk, skb); + + /* Copy the address and add cmsg data. */ + if (family == AF_INET) { + DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); + + if (sin) { + sin->sin_family = AF_INET; + sin->sin_port = 0 /* skb->h.uh->source */; + sin->sin_addr.s_addr = ip_hdr(skb)->saddr; + memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); + } + + if (isk->cmsg_flags) + ip_cmsg_recv(msg, skb); + +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + struct ipv6_pinfo *np = inet6_sk(sk); + struct ipv6hdr *ip6 = ipv6_hdr(skb); + DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); + + if (sin6) { + sin6->sin6_family = AF_INET6; + sin6->sin6_port = 0; + sin6->sin6_addr = ip6->saddr; + sin6->sin6_flowinfo = 0; + if (np->sndflow) + sin6->sin6_flowinfo = ip6_flowinfo(ip6); + sin6->sin6_scope_id = + ipv6_iface_scope_id(&sin6->sin6_addr, + inet6_iif(skb)); + *addr_len = sizeof(*sin6); + } + + if (inet6_sk(sk)->rxopt.all) + pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); + if (skb->protocol == htons(ETH_P_IPV6) && + inet6_sk(sk)->rxopt.all) + pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); + else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) + ip_cmsg_recv(msg, skb); +#endif + } else { + BUG(); + } + + err = copied; + +done: + skb_free_datagram(sk, skb); +out: + pr_debug("ping_recvmsg -> %d\n", err); + return err; +} +EXPORT_SYMBOL_GPL(ping_recvmsg); + +int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", + inet_sk(sk), inet_sk(sk)->inet_num, skb); + if (sock_queue_rcv_skb(sk, skb) < 0) { + kfree_skb(skb); + pr_debug("ping_queue_rcv_skb -> failed\n"); + return -1; + } + return 0; +} +EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); + + +/* + * All we need to do is get the socket. + */ + +bool ping_rcv(struct sk_buff *skb) +{ + struct sock *sk; + struct net *net = dev_net(skb->dev); + struct icmphdr *icmph = icmp_hdr(skb); + bool rc = false; + + /* We assume the packet has already been checked by icmp_rcv */ + + pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", + skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); + + /* Push ICMP header back */ + skb_push(skb, skb->data - (u8 *)icmph); + + sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); + if (sk) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + + pr_debug("rcv on socket %p\n", sk); + if (skb2 && !ping_queue_rcv_skb(sk, skb2)) + rc = true; + sock_put(sk); + } + + if (!rc) + pr_debug("no socket, dropping\n"); + + return rc; +} +EXPORT_SYMBOL_GPL(ping_rcv); + +struct proto ping_prot = { + .name = "PING", + .owner = THIS_MODULE, + .init = ping_init_sock, + .close = ping_close, + .connect = ip4_datagram_connect, + .disconnect = __udp_disconnect, + .setsockopt = ip_setsockopt, + .getsockopt = ip_getsockopt, + .sendmsg = ping_v4_sendmsg, + .recvmsg = ping_recvmsg, + .bind = ping_bind, + .backlog_rcv = ping_queue_rcv_skb, + .release_cb = ip4_datagram_release_cb, + .hash = ping_hash, + .unhash = ping_unhash, + .get_port = ping_get_port, + .obj_size = sizeof(struct inet_sock), +}; +EXPORT_SYMBOL(ping_prot); + +#ifdef CONFIG_PROC_FS + +static struct sock *ping_get_first(struct seq_file *seq, int start) +{ + struct sock *sk; + struct ping_iter_state *state = seq->private; + struct net *net = seq_file_net(seq); + + for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; + ++state->bucket) { + struct hlist_nulls_node *node; + struct hlist_nulls_head *hslot; + + hslot = &ping_table.hash[state->bucket]; + + if (hlist_nulls_empty(hslot)) + continue; + + sk_nulls_for_each(sk, node, hslot) { + if (net_eq(sock_net(sk), net) && + sk->sk_family == state->family) + goto found; + } + } + sk = NULL; +found: + return sk; +} + +static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) +{ + struct ping_iter_state *state = seq->private; + struct net *net = seq_file_net(seq); + + do { + sk = sk_nulls_next(sk); + } while (sk && (!net_eq(sock_net(sk), net))); + + if (!sk) + return ping_get_first(seq, state->bucket + 1); + return sk; +} + +static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) +{ + struct sock *sk = ping_get_first(seq, 0); + + if (sk) + while (pos && (sk = ping_get_next(seq, sk)) != NULL) + --pos; + return pos ? NULL : sk; +} + +void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) + __acquires(ping_table.lock) +{ + struct ping_iter_state *state = seq->private; + state->bucket = 0; + state->family = family; + + read_lock_bh(&ping_table.lock); + + return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; +} +EXPORT_SYMBOL_GPL(ping_seq_start); + +static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) +{ + return ping_seq_start(seq, pos, AF_INET); +} + +void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct sock *sk; + + if (v == SEQ_START_TOKEN) + sk = ping_get_idx(seq, 0); + else + sk = ping_get_next(seq, v); + + ++*pos; + return sk; +} +EXPORT_SYMBOL_GPL(ping_seq_next); + +void ping_seq_stop(struct seq_file *seq, void *v) + __releases(ping_table.lock) +{ + read_unlock_bh(&ping_table.lock); +} +EXPORT_SYMBOL_GPL(ping_seq_stop); + +static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, + int bucket) +{ + struct inet_sock *inet = inet_sk(sp); + __be32 dest = inet->inet_daddr; + __be32 src = inet->inet_rcv_saddr; + __u16 destp = ntohs(inet->inet_dport); + __u16 srcp = ntohs(inet->inet_sport); + + seq_printf(f, "%5d: %08X:%04X %08X:%04X" + " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", + bucket, src, srcp, dest, destp, sp->sk_state, + sk_wmem_alloc_get(sp), + sk_rmem_alloc_get(sp), + 0, 0L, 0, + from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), + 0, sock_i_ino(sp), + refcount_read(&sp->sk_refcnt), sp, + atomic_read(&sp->sk_drops)); +} + +static int ping_v4_seq_show(struct seq_file *seq, void *v) +{ + seq_setwidth(seq, 127); + if (v == SEQ_START_TOKEN) + seq_puts(seq, " sl local_address rem_address st tx_queue " + "rx_queue tr tm->when retrnsmt uid timeout " + "inode ref pointer drops"); + else { + struct ping_iter_state *state = seq->private; + + ping_v4_format_sock(v, seq, state->bucket); + } + seq_pad(seq, '\n'); + return 0; +} + +static const struct seq_operations ping_v4_seq_ops = { + .start = ping_v4_seq_start, + .show = ping_v4_seq_show, + .next = ping_seq_next, + .stop = ping_seq_stop, +}; + +static int __net_init ping_v4_proc_init_net(struct net *net) +{ + if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, + sizeof(struct ping_iter_state))) + return -ENOMEM; + return 0; +} + +static void __net_exit ping_v4_proc_exit_net(struct net *net) +{ + remove_proc_entry("icmp", net->proc_net); +} + +static struct pernet_operations ping_v4_net_ops = { + .init = ping_v4_proc_init_net, + .exit = ping_v4_proc_exit_net, +}; + +int __init ping_proc_init(void) +{ + return register_pernet_subsys(&ping_v4_net_ops); +} + +void ping_proc_exit(void) +{ + unregister_pernet_subsys(&ping_v4_net_ops); +} + +#endif + +void __init ping_init(void) +{ + int i; + + for (i = 0; i < PING_HTABLE_SIZE; i++) + INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); + rwlock_init(&ping_table.lock); +} diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c new file mode 100644 index 000000000..80d13d8f9 --- /dev/null +++ b/net/ipv4/proc.c @@ -0,0 +1,532 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * This file implements the various access functions for the + * PROC file system. It is mainly used for debugging and + * statistics. + * + * Authors: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Gerald J. Heim, <heim@peanuts.informatik.uni-tuebingen.de> + * Fred Baumgarten, <dc6iq@insu1.etec.uni-karlsruhe.de> + * Erik Schoenfelder, <schoenfr@ibr.cs.tu-bs.de> + * + * Fixes: + * Alan Cox : UDP sockets show the rxqueue/txqueue + * using hint flag for the netinfo. + * Pauline Middelink : identd support + * Alan Cox : Make /proc safer. + * Erik Schoenfelder : /proc/net/snmp + * Alan Cox : Handle dead sockets properly. + * Gerhard Koerting : Show both timers + * Alan Cox : Allow inode to be NULL (kernel socket) + * Andi Kleen : Add support for open_requests and + * split functions for more readibility. + * Andi Kleen : Add support for /proc/net/netstat + * Arnaldo C. Melo : Convert to seq_file + */ +#include <linux/types.h> +#include <net/net_namespace.h> +#include <net/icmp.h> +#include <net/protocol.h> +#include <net/tcp.h> +#include <net/mptcp.h> +#include <net/udp.h> +#include <net/udplite.h> +#include <linux/bottom_half.h> +#include <linux/inetdevice.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/export.h> +#include <net/sock.h> +#include <net/raw.h> + +#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX) + +/* + * Report socket allocation statistics [mea@utu.fi] + */ +static int sockstat_seq_show(struct seq_file *seq, void *v) +{ + struct net *net = seq->private; + int orphans, sockets; + + orphans = tcp_orphan_count_sum(); + sockets = proto_sockets_allocated_sum_positive(&tcp_prot); + + socket_seq_show(seq); + seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %ld\n", + sock_prot_inuse_get(net, &tcp_prot), orphans, + atomic_read(&net->ipv4.tcp_death_row.tw_count), sockets, + proto_memory_allocated(&tcp_prot)); + seq_printf(seq, "UDP: inuse %d mem %ld\n", + sock_prot_inuse_get(net, &udp_prot), + proto_memory_allocated(&udp_prot)); + seq_printf(seq, "UDPLITE: inuse %d\n", + sock_prot_inuse_get(net, &udplite_prot)); + seq_printf(seq, "RAW: inuse %d\n", + sock_prot_inuse_get(net, &raw_prot)); + seq_printf(seq, "FRAG: inuse %u memory %lu\n", + atomic_read(&net->ipv4.fqdir->rhashtable.nelems), + frag_mem_limit(net->ipv4.fqdir)); + return 0; +} + +/* snmp items */ +static const struct snmp_mib snmp4_ipstats_list[] = { + SNMP_MIB_ITEM("InReceives", IPSTATS_MIB_INPKTS), + SNMP_MIB_ITEM("InHdrErrors", IPSTATS_MIB_INHDRERRORS), + SNMP_MIB_ITEM("InAddrErrors", IPSTATS_MIB_INADDRERRORS), + SNMP_MIB_ITEM("ForwDatagrams", IPSTATS_MIB_OUTFORWDATAGRAMS), + SNMP_MIB_ITEM("InUnknownProtos", IPSTATS_MIB_INUNKNOWNPROTOS), + SNMP_MIB_ITEM("InDiscards", IPSTATS_MIB_INDISCARDS), + SNMP_MIB_ITEM("InDelivers", IPSTATS_MIB_INDELIVERS), + SNMP_MIB_ITEM("OutRequests", IPSTATS_MIB_OUTPKTS), + SNMP_MIB_ITEM("OutDiscards", IPSTATS_MIB_OUTDISCARDS), + SNMP_MIB_ITEM("OutNoRoutes", IPSTATS_MIB_OUTNOROUTES), + SNMP_MIB_ITEM("ReasmTimeout", IPSTATS_MIB_REASMTIMEOUT), + SNMP_MIB_ITEM("ReasmReqds", IPSTATS_MIB_REASMREQDS), + SNMP_MIB_ITEM("ReasmOKs", IPSTATS_MIB_REASMOKS), + SNMP_MIB_ITEM("ReasmFails", IPSTATS_MIB_REASMFAILS), + SNMP_MIB_ITEM("FragOKs", IPSTATS_MIB_FRAGOKS), + SNMP_MIB_ITEM("FragFails", IPSTATS_MIB_FRAGFAILS), + SNMP_MIB_ITEM("FragCreates", IPSTATS_MIB_FRAGCREATES), + SNMP_MIB_SENTINEL +}; + +/* Following items are displayed in /proc/net/netstat */ +static const struct snmp_mib snmp4_ipextstats_list[] = { + SNMP_MIB_ITEM("InNoRoutes", IPSTATS_MIB_INNOROUTES), + SNMP_MIB_ITEM("InTruncatedPkts", IPSTATS_MIB_INTRUNCATEDPKTS), + SNMP_MIB_ITEM("InMcastPkts", IPSTATS_MIB_INMCASTPKTS), + SNMP_MIB_ITEM("OutMcastPkts", IPSTATS_MIB_OUTMCASTPKTS), + SNMP_MIB_ITEM("InBcastPkts", IPSTATS_MIB_INBCASTPKTS), + SNMP_MIB_ITEM("OutBcastPkts", IPSTATS_MIB_OUTBCASTPKTS), + SNMP_MIB_ITEM("InOctets", IPSTATS_MIB_INOCTETS), + SNMP_MIB_ITEM("OutOctets", IPSTATS_MIB_OUTOCTETS), + SNMP_MIB_ITEM("InMcastOctets", IPSTATS_MIB_INMCASTOCTETS), + SNMP_MIB_ITEM("OutMcastOctets", IPSTATS_MIB_OUTMCASTOCTETS), + SNMP_MIB_ITEM("InBcastOctets", IPSTATS_MIB_INBCASTOCTETS), + SNMP_MIB_ITEM("OutBcastOctets", IPSTATS_MIB_OUTBCASTOCTETS), + /* Non RFC4293 fields */ + SNMP_MIB_ITEM("InCsumErrors", IPSTATS_MIB_CSUMERRORS), + SNMP_MIB_ITEM("InNoECTPkts", IPSTATS_MIB_NOECTPKTS), + SNMP_MIB_ITEM("InECT1Pkts", IPSTATS_MIB_ECT1PKTS), + SNMP_MIB_ITEM("InECT0Pkts", IPSTATS_MIB_ECT0PKTS), + SNMP_MIB_ITEM("InCEPkts", IPSTATS_MIB_CEPKTS), + SNMP_MIB_ITEM("ReasmOverlaps", IPSTATS_MIB_REASM_OVERLAPS), + SNMP_MIB_SENTINEL +}; + +static const struct { + const char *name; + int index; +} icmpmibmap[] = { + { "DestUnreachs", ICMP_DEST_UNREACH }, + { "TimeExcds", ICMP_TIME_EXCEEDED }, + { "ParmProbs", ICMP_PARAMETERPROB }, + { "SrcQuenchs", ICMP_SOURCE_QUENCH }, + { "Redirects", ICMP_REDIRECT }, + { "Echos", ICMP_ECHO }, + { "EchoReps", ICMP_ECHOREPLY }, + { "Timestamps", ICMP_TIMESTAMP }, + { "TimestampReps", ICMP_TIMESTAMPREPLY }, + { "AddrMasks", ICMP_ADDRESS }, + { "AddrMaskReps", ICMP_ADDRESSREPLY }, + { NULL, 0 } +}; + + +static const struct snmp_mib snmp4_tcp_list[] = { + SNMP_MIB_ITEM("RtoAlgorithm", TCP_MIB_RTOALGORITHM), + SNMP_MIB_ITEM("RtoMin", TCP_MIB_RTOMIN), + SNMP_MIB_ITEM("RtoMax", TCP_MIB_RTOMAX), + SNMP_MIB_ITEM("MaxConn", TCP_MIB_MAXCONN), + SNMP_MIB_ITEM("ActiveOpens", TCP_MIB_ACTIVEOPENS), + SNMP_MIB_ITEM("PassiveOpens", TCP_MIB_PASSIVEOPENS), + SNMP_MIB_ITEM("AttemptFails", TCP_MIB_ATTEMPTFAILS), + SNMP_MIB_ITEM("EstabResets", TCP_MIB_ESTABRESETS), + SNMP_MIB_ITEM("CurrEstab", TCP_MIB_CURRESTAB), + SNMP_MIB_ITEM("InSegs", TCP_MIB_INSEGS), + SNMP_MIB_ITEM("OutSegs", TCP_MIB_OUTSEGS), + SNMP_MIB_ITEM("RetransSegs", TCP_MIB_RETRANSSEGS), + SNMP_MIB_ITEM("InErrs", TCP_MIB_INERRS), + SNMP_MIB_ITEM("OutRsts", TCP_MIB_OUTRSTS), + SNMP_MIB_ITEM("InCsumErrors", TCP_MIB_CSUMERRORS), + SNMP_MIB_SENTINEL +}; + +static const struct snmp_mib snmp4_udp_list[] = { + SNMP_MIB_ITEM("InDatagrams", UDP_MIB_INDATAGRAMS), + SNMP_MIB_ITEM("NoPorts", UDP_MIB_NOPORTS), + SNMP_MIB_ITEM("InErrors", UDP_MIB_INERRORS), + SNMP_MIB_ITEM("OutDatagrams", UDP_MIB_OUTDATAGRAMS), + SNMP_MIB_ITEM("RcvbufErrors", UDP_MIB_RCVBUFERRORS), + SNMP_MIB_ITEM("SndbufErrors", UDP_MIB_SNDBUFERRORS), + SNMP_MIB_ITEM("InCsumErrors", UDP_MIB_CSUMERRORS), + SNMP_MIB_ITEM("IgnoredMulti", UDP_MIB_IGNOREDMULTI), + SNMP_MIB_SENTINEL +}; + +static const struct snmp_mib snmp4_net_list[] = { + SNMP_MIB_ITEM("SyncookiesSent", LINUX_MIB_SYNCOOKIESSENT), + SNMP_MIB_ITEM("SyncookiesRecv", LINUX_MIB_SYNCOOKIESRECV), + SNMP_MIB_ITEM("SyncookiesFailed", LINUX_MIB_SYNCOOKIESFAILED), + SNMP_MIB_ITEM("EmbryonicRsts", LINUX_MIB_EMBRYONICRSTS), + SNMP_MIB_ITEM("PruneCalled", LINUX_MIB_PRUNECALLED), + SNMP_MIB_ITEM("RcvPruned", LINUX_MIB_RCVPRUNED), + SNMP_MIB_ITEM("OfoPruned", LINUX_MIB_OFOPRUNED), + SNMP_MIB_ITEM("OutOfWindowIcmps", LINUX_MIB_OUTOFWINDOWICMPS), + SNMP_MIB_ITEM("LockDroppedIcmps", LINUX_MIB_LOCKDROPPEDICMPS), + SNMP_MIB_ITEM("ArpFilter", LINUX_MIB_ARPFILTER), + SNMP_MIB_ITEM("TW", LINUX_MIB_TIMEWAITED), + SNMP_MIB_ITEM("TWRecycled", LINUX_MIB_TIMEWAITRECYCLED), + SNMP_MIB_ITEM("TWKilled", LINUX_MIB_TIMEWAITKILLED), + SNMP_MIB_ITEM("PAWSActive", LINUX_MIB_PAWSACTIVEREJECTED), + SNMP_MIB_ITEM("PAWSEstab", LINUX_MIB_PAWSESTABREJECTED), + SNMP_MIB_ITEM("DelayedACKs", LINUX_MIB_DELAYEDACKS), + SNMP_MIB_ITEM("DelayedACKLocked", LINUX_MIB_DELAYEDACKLOCKED), + SNMP_MIB_ITEM("DelayedACKLost", LINUX_MIB_DELAYEDACKLOST), + SNMP_MIB_ITEM("ListenOverflows", LINUX_MIB_LISTENOVERFLOWS), + SNMP_MIB_ITEM("ListenDrops", LINUX_MIB_LISTENDROPS), + SNMP_MIB_ITEM("TCPHPHits", LINUX_MIB_TCPHPHITS), + SNMP_MIB_ITEM("TCPPureAcks", LINUX_MIB_TCPPUREACKS), + SNMP_MIB_ITEM("TCPHPAcks", LINUX_MIB_TCPHPACKS), + SNMP_MIB_ITEM("TCPRenoRecovery", LINUX_MIB_TCPRENORECOVERY), + SNMP_MIB_ITEM("TCPSackRecovery", LINUX_MIB_TCPSACKRECOVERY), + SNMP_MIB_ITEM("TCPSACKReneging", LINUX_MIB_TCPSACKRENEGING), + SNMP_MIB_ITEM("TCPSACKReorder", LINUX_MIB_TCPSACKREORDER), + SNMP_MIB_ITEM("TCPRenoReorder", LINUX_MIB_TCPRENOREORDER), + SNMP_MIB_ITEM("TCPTSReorder", LINUX_MIB_TCPTSREORDER), + SNMP_MIB_ITEM("TCPFullUndo", LINUX_MIB_TCPFULLUNDO), + SNMP_MIB_ITEM("TCPPartialUndo", LINUX_MIB_TCPPARTIALUNDO), + SNMP_MIB_ITEM("TCPDSACKUndo", LINUX_MIB_TCPDSACKUNDO), + SNMP_MIB_ITEM("TCPLossUndo", LINUX_MIB_TCPLOSSUNDO), + SNMP_MIB_ITEM("TCPLostRetransmit", LINUX_MIB_TCPLOSTRETRANSMIT), + SNMP_MIB_ITEM("TCPRenoFailures", LINUX_MIB_TCPRENOFAILURES), + SNMP_MIB_ITEM("TCPSackFailures", LINUX_MIB_TCPSACKFAILURES), + SNMP_MIB_ITEM("TCPLossFailures", LINUX_MIB_TCPLOSSFAILURES), + SNMP_MIB_ITEM("TCPFastRetrans", LINUX_MIB_TCPFASTRETRANS), + SNMP_MIB_ITEM("TCPSlowStartRetrans", LINUX_MIB_TCPSLOWSTARTRETRANS), + SNMP_MIB_ITEM("TCPTimeouts", LINUX_MIB_TCPTIMEOUTS), + SNMP_MIB_ITEM("TCPLossProbes", LINUX_MIB_TCPLOSSPROBES), + SNMP_MIB_ITEM("TCPLossProbeRecovery", LINUX_MIB_TCPLOSSPROBERECOVERY), + SNMP_MIB_ITEM("TCPRenoRecoveryFail", LINUX_MIB_TCPRENORECOVERYFAIL), + SNMP_MIB_ITEM("TCPSackRecoveryFail", LINUX_MIB_TCPSACKRECOVERYFAIL), + SNMP_MIB_ITEM("TCPRcvCollapsed", LINUX_MIB_TCPRCVCOLLAPSED), + SNMP_MIB_ITEM("TCPBacklogCoalesce", LINUX_MIB_TCPBACKLOGCOALESCE), + SNMP_MIB_ITEM("TCPDSACKOldSent", LINUX_MIB_TCPDSACKOLDSENT), + SNMP_MIB_ITEM("TCPDSACKOfoSent", LINUX_MIB_TCPDSACKOFOSENT), + SNMP_MIB_ITEM("TCPDSACKRecv", LINUX_MIB_TCPDSACKRECV), + SNMP_MIB_ITEM("TCPDSACKOfoRecv", LINUX_MIB_TCPDSACKOFORECV), + SNMP_MIB_ITEM("TCPAbortOnData", LINUX_MIB_TCPABORTONDATA), + SNMP_MIB_ITEM("TCPAbortOnClose", LINUX_MIB_TCPABORTONCLOSE), + SNMP_MIB_ITEM("TCPAbortOnMemory", LINUX_MIB_TCPABORTONMEMORY), + SNMP_MIB_ITEM("TCPAbortOnTimeout", LINUX_MIB_TCPABORTONTIMEOUT), + SNMP_MIB_ITEM("TCPAbortOnLinger", LINUX_MIB_TCPABORTONLINGER), + SNMP_MIB_ITEM("TCPAbortFailed", LINUX_MIB_TCPABORTFAILED), + SNMP_MIB_ITEM("TCPMemoryPressures", LINUX_MIB_TCPMEMORYPRESSURES), + SNMP_MIB_ITEM("TCPMemoryPressuresChrono", LINUX_MIB_TCPMEMORYPRESSURESCHRONO), + SNMP_MIB_ITEM("TCPSACKDiscard", LINUX_MIB_TCPSACKDISCARD), + SNMP_MIB_ITEM("TCPDSACKIgnoredOld", LINUX_MIB_TCPDSACKIGNOREDOLD), + SNMP_MIB_ITEM("TCPDSACKIgnoredNoUndo", LINUX_MIB_TCPDSACKIGNOREDNOUNDO), + SNMP_MIB_ITEM("TCPSpuriousRTOs", LINUX_MIB_TCPSPURIOUSRTOS), + SNMP_MIB_ITEM("TCPMD5NotFound", LINUX_MIB_TCPMD5NOTFOUND), + SNMP_MIB_ITEM("TCPMD5Unexpected", LINUX_MIB_TCPMD5UNEXPECTED), + SNMP_MIB_ITEM("TCPMD5Failure", LINUX_MIB_TCPMD5FAILURE), + SNMP_MIB_ITEM("TCPSackShifted", LINUX_MIB_SACKSHIFTED), + SNMP_MIB_ITEM("TCPSackMerged", LINUX_MIB_SACKMERGED), + SNMP_MIB_ITEM("TCPSackShiftFallback", LINUX_MIB_SACKSHIFTFALLBACK), + SNMP_MIB_ITEM("TCPBacklogDrop", LINUX_MIB_TCPBACKLOGDROP), + SNMP_MIB_ITEM("PFMemallocDrop", LINUX_MIB_PFMEMALLOCDROP), + SNMP_MIB_ITEM("TCPMinTTLDrop", LINUX_MIB_TCPMINTTLDROP), + SNMP_MIB_ITEM("TCPDeferAcceptDrop", LINUX_MIB_TCPDEFERACCEPTDROP), + SNMP_MIB_ITEM("IPReversePathFilter", LINUX_MIB_IPRPFILTER), + SNMP_MIB_ITEM("TCPTimeWaitOverflow", LINUX_MIB_TCPTIMEWAITOVERFLOW), + SNMP_MIB_ITEM("TCPReqQFullDoCookies", LINUX_MIB_TCPREQQFULLDOCOOKIES), + SNMP_MIB_ITEM("TCPReqQFullDrop", LINUX_MIB_TCPREQQFULLDROP), + SNMP_MIB_ITEM("TCPRetransFail", LINUX_MIB_TCPRETRANSFAIL), + SNMP_MIB_ITEM("TCPRcvCoalesce", LINUX_MIB_TCPRCVCOALESCE), + SNMP_MIB_ITEM("TCPOFOQueue", LINUX_MIB_TCPOFOQUEUE), + SNMP_MIB_ITEM("TCPOFODrop", LINUX_MIB_TCPOFODROP), + SNMP_MIB_ITEM("TCPOFOMerge", LINUX_MIB_TCPOFOMERGE), + SNMP_MIB_ITEM("TCPChallengeACK", LINUX_MIB_TCPCHALLENGEACK), + SNMP_MIB_ITEM("TCPSYNChallenge", LINUX_MIB_TCPSYNCHALLENGE), + SNMP_MIB_ITEM("TCPFastOpenActive", LINUX_MIB_TCPFASTOPENACTIVE), + SNMP_MIB_ITEM("TCPFastOpenActiveFail", LINUX_MIB_TCPFASTOPENACTIVEFAIL), + SNMP_MIB_ITEM("TCPFastOpenPassive", LINUX_MIB_TCPFASTOPENPASSIVE), + SNMP_MIB_ITEM("TCPFastOpenPassiveFail", LINUX_MIB_TCPFASTOPENPASSIVEFAIL), + SNMP_MIB_ITEM("TCPFastOpenListenOverflow", LINUX_MIB_TCPFASTOPENLISTENOVERFLOW), + SNMP_MIB_ITEM("TCPFastOpenCookieReqd", LINUX_MIB_TCPFASTOPENCOOKIEREQD), + SNMP_MIB_ITEM("TCPFastOpenBlackhole", LINUX_MIB_TCPFASTOPENBLACKHOLE), + SNMP_MIB_ITEM("TCPSpuriousRtxHostQueues", LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES), + SNMP_MIB_ITEM("BusyPollRxPackets", LINUX_MIB_BUSYPOLLRXPACKETS), + SNMP_MIB_ITEM("TCPAutoCorking", LINUX_MIB_TCPAUTOCORKING), + SNMP_MIB_ITEM("TCPFromZeroWindowAdv", LINUX_MIB_TCPFROMZEROWINDOWADV), + SNMP_MIB_ITEM("TCPToZeroWindowAdv", LINUX_MIB_TCPTOZEROWINDOWADV), + SNMP_MIB_ITEM("TCPWantZeroWindowAdv", LINUX_MIB_TCPWANTZEROWINDOWADV), + SNMP_MIB_ITEM("TCPSynRetrans", LINUX_MIB_TCPSYNRETRANS), + SNMP_MIB_ITEM("TCPOrigDataSent", LINUX_MIB_TCPORIGDATASENT), + SNMP_MIB_ITEM("TCPHystartTrainDetect", LINUX_MIB_TCPHYSTARTTRAINDETECT), + SNMP_MIB_ITEM("TCPHystartTrainCwnd", LINUX_MIB_TCPHYSTARTTRAINCWND), + SNMP_MIB_ITEM("TCPHystartDelayDetect", LINUX_MIB_TCPHYSTARTDELAYDETECT), + SNMP_MIB_ITEM("TCPHystartDelayCwnd", LINUX_MIB_TCPHYSTARTDELAYCWND), + SNMP_MIB_ITEM("TCPACKSkippedSynRecv", LINUX_MIB_TCPACKSKIPPEDSYNRECV), + SNMP_MIB_ITEM("TCPACKSkippedPAWS", LINUX_MIB_TCPACKSKIPPEDPAWS), + SNMP_MIB_ITEM("TCPACKSkippedSeq", LINUX_MIB_TCPACKSKIPPEDSEQ), + SNMP_MIB_ITEM("TCPACKSkippedFinWait2", LINUX_MIB_TCPACKSKIPPEDFINWAIT2), + SNMP_MIB_ITEM("TCPACKSkippedTimeWait", LINUX_MIB_TCPACKSKIPPEDTIMEWAIT), + SNMP_MIB_ITEM("TCPACKSkippedChallenge", LINUX_MIB_TCPACKSKIPPEDCHALLENGE), + SNMP_MIB_ITEM("TCPWinProbe", LINUX_MIB_TCPWINPROBE), + SNMP_MIB_ITEM("TCPKeepAlive", LINUX_MIB_TCPKEEPALIVE), + SNMP_MIB_ITEM("TCPMTUPFail", LINUX_MIB_TCPMTUPFAIL), + SNMP_MIB_ITEM("TCPMTUPSuccess", LINUX_MIB_TCPMTUPSUCCESS), + SNMP_MIB_ITEM("TCPDelivered", LINUX_MIB_TCPDELIVERED), + SNMP_MIB_ITEM("TCPDeliveredCE", LINUX_MIB_TCPDELIVEREDCE), + SNMP_MIB_ITEM("TCPAckCompressed", LINUX_MIB_TCPACKCOMPRESSED), + SNMP_MIB_ITEM("TCPZeroWindowDrop", LINUX_MIB_TCPZEROWINDOWDROP), + SNMP_MIB_ITEM("TCPRcvQDrop", LINUX_MIB_TCPRCVQDROP), + SNMP_MIB_ITEM("TCPWqueueTooBig", LINUX_MIB_TCPWQUEUETOOBIG), + SNMP_MIB_ITEM("TCPFastOpenPassiveAltKey", LINUX_MIB_TCPFASTOPENPASSIVEALTKEY), + SNMP_MIB_ITEM("TcpTimeoutRehash", LINUX_MIB_TCPTIMEOUTREHASH), + SNMP_MIB_ITEM("TcpDuplicateDataRehash", LINUX_MIB_TCPDUPLICATEDATAREHASH), + SNMP_MIB_ITEM("TCPDSACKRecvSegs", LINUX_MIB_TCPDSACKRECVSEGS), + SNMP_MIB_ITEM("TCPDSACKIgnoredDubious", LINUX_MIB_TCPDSACKIGNOREDDUBIOUS), + SNMP_MIB_SENTINEL +}; + +static void icmpmsg_put_line(struct seq_file *seq, unsigned long *vals, + unsigned short *type, int count) +{ + int j; + + if (count) { + seq_puts(seq, "\nIcmpMsg:"); + for (j = 0; j < count; ++j) + seq_printf(seq, " %sType%u", + type[j] & 0x100 ? "Out" : "In", + type[j] & 0xff); + seq_puts(seq, "\nIcmpMsg:"); + for (j = 0; j < count; ++j) + seq_printf(seq, " %lu", vals[j]); + } +} + +static void icmpmsg_put(struct seq_file *seq) +{ +#define PERLINE 16 + + int i, count; + unsigned short type[PERLINE]; + unsigned long vals[PERLINE], val; + struct net *net = seq->private; + + count = 0; + for (i = 0; i < ICMPMSG_MIB_MAX; i++) { + val = atomic_long_read(&net->mib.icmpmsg_statistics->mibs[i]); + if (val) { + type[count] = i; + vals[count++] = val; + } + if (count == PERLINE) { + icmpmsg_put_line(seq, vals, type, count); + count = 0; + } + } + icmpmsg_put_line(seq, vals, type, count); + +#undef PERLINE +} + +static void icmp_put(struct seq_file *seq) +{ + int i; + struct net *net = seq->private; + atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs; + + seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors"); + for (i = 0; icmpmibmap[i].name; i++) + seq_printf(seq, " In%s", icmpmibmap[i].name); + seq_puts(seq, " OutMsgs OutErrors"); + for (i = 0; icmpmibmap[i].name; i++) + seq_printf(seq, " Out%s", icmpmibmap[i].name); + seq_printf(seq, "\nIcmp: %lu %lu %lu", + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS), + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS), + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS)); + for (i = 0; icmpmibmap[i].name; i++) + seq_printf(seq, " %lu", + atomic_long_read(ptr + icmpmibmap[i].index)); + seq_printf(seq, " %lu %lu", + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS), + snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS)); + for (i = 0; icmpmibmap[i].name; i++) + seq_printf(seq, " %lu", + atomic_long_read(ptr + (icmpmibmap[i].index | 0x100))); +} + +/* + * Called from the PROCfs module. This outputs /proc/net/snmp. + */ +static int snmp_seq_show_ipstats(struct seq_file *seq, void *v) +{ + struct net *net = seq->private; + u64 buff64[IPSTATS_MIB_MAX]; + int i; + + memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64)); + + seq_puts(seq, "Ip: Forwarding DefaultTTL"); + for (i = 0; snmp4_ipstats_list[i].name; i++) + seq_printf(seq, " %s", snmp4_ipstats_list[i].name); + + seq_printf(seq, "\nIp: %d %d", + IPV4_DEVCONF_ALL(net, FORWARDING) ? 1 : 2, + net->ipv4.sysctl_ip_default_ttl); + + BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0); + snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list, + net->mib.ip_statistics, + offsetof(struct ipstats_mib, syncp)); + for (i = 0; snmp4_ipstats_list[i].name; i++) + seq_printf(seq, " %llu", buff64[i]); + + return 0; +} + +static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v) +{ + unsigned long buff[TCPUDP_MIB_MAX]; + struct net *net = seq->private; + int i; + + memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); + + seq_puts(seq, "\nTcp:"); + for (i = 0; snmp4_tcp_list[i].name; i++) + seq_printf(seq, " %s", snmp4_tcp_list[i].name); + + seq_puts(seq, "\nTcp:"); + snmp_get_cpu_field_batch(buff, snmp4_tcp_list, + net->mib.tcp_statistics); + for (i = 0; snmp4_tcp_list[i].name; i++) { + /* MaxConn field is signed, RFC 2012 */ + if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN) + seq_printf(seq, " %ld", buff[i]); + else + seq_printf(seq, " %lu", buff[i]); + } + + memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); + + snmp_get_cpu_field_batch(buff, snmp4_udp_list, + net->mib.udp_statistics); + seq_puts(seq, "\nUdp:"); + for (i = 0; snmp4_udp_list[i].name; i++) + seq_printf(seq, " %s", snmp4_udp_list[i].name); + seq_puts(seq, "\nUdp:"); + for (i = 0; snmp4_udp_list[i].name; i++) + seq_printf(seq, " %lu", buff[i]); + + memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); + + /* the UDP and UDP-Lite MIBs are the same */ + seq_puts(seq, "\nUdpLite:"); + snmp_get_cpu_field_batch(buff, snmp4_udp_list, + net->mib.udplite_statistics); + for (i = 0; snmp4_udp_list[i].name; i++) + seq_printf(seq, " %s", snmp4_udp_list[i].name); + seq_puts(seq, "\nUdpLite:"); + for (i = 0; snmp4_udp_list[i].name; i++) + seq_printf(seq, " %lu", buff[i]); + + seq_putc(seq, '\n'); + return 0; +} + +static int snmp_seq_show(struct seq_file *seq, void *v) +{ + snmp_seq_show_ipstats(seq, v); + + icmp_put(seq); /* RFC 2011 compatibility */ + icmpmsg_put(seq); + + snmp_seq_show_tcp_udp(seq, v); + + return 0; +} + +/* + * Output /proc/net/netstat + */ +static int netstat_seq_show(struct seq_file *seq, void *v) +{ + int i; + struct net *net = seq->private; + + seq_puts(seq, "TcpExt:"); + for (i = 0; snmp4_net_list[i].name; i++) + seq_printf(seq, " %s", snmp4_net_list[i].name); + + seq_puts(seq, "\nTcpExt:"); + for (i = 0; snmp4_net_list[i].name; i++) + seq_printf(seq, " %lu", + snmp_fold_field(net->mib.net_statistics, + snmp4_net_list[i].entry)); + + seq_puts(seq, "\nIpExt:"); + for (i = 0; snmp4_ipextstats_list[i].name; i++) + seq_printf(seq, " %s", snmp4_ipextstats_list[i].name); + + seq_puts(seq, "\nIpExt:"); + for (i = 0; snmp4_ipextstats_list[i].name; i++) + seq_printf(seq, " %llu", + snmp_fold_field64(net->mib.ip_statistics, + snmp4_ipextstats_list[i].entry, + offsetof(struct ipstats_mib, syncp))); + + seq_putc(seq, '\n'); + mptcp_seq_show(seq); + return 0; +} + +static __net_init int ip_proc_init_net(struct net *net) +{ + if (!proc_create_net_single("sockstat", 0444, net->proc_net, + sockstat_seq_show, NULL)) + goto out_sockstat; + if (!proc_create_net_single("netstat", 0444, net->proc_net, + netstat_seq_show, NULL)) + goto out_netstat; + if (!proc_create_net_single("snmp", 0444, net->proc_net, snmp_seq_show, + NULL)) + goto out_snmp; + + return 0; + +out_snmp: + remove_proc_entry("netstat", net->proc_net); +out_netstat: + remove_proc_entry("sockstat", net->proc_net); +out_sockstat: + return -ENOMEM; +} + +static __net_exit void ip_proc_exit_net(struct net *net) +{ + remove_proc_entry("snmp", net->proc_net); + remove_proc_entry("netstat", net->proc_net); + remove_proc_entry("sockstat", net->proc_net); +} + +static __net_initdata struct pernet_operations ip_proc_ops = { + .init = ip_proc_init_net, + .exit = ip_proc_exit_net, +}; + +int __init ip_misc_proc_init(void) +{ + return register_pernet_subsys(&ip_proc_ops); +} diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c new file mode 100644 index 000000000..9a8c08926 --- /dev/null +++ b/net/ipv4/protocol.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * INET protocol dispatch tables. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * + * Fixes: + * Alan Cox : Ahah! udp icmp errors don't work because + * udp_err is never called! + * Alan Cox : Added new fields for init and ready for + * proper fragmentation (_NO_ 4K limits!) + * Richard Colella : Hang on hash collision + * Vince Laviano : Modified inet_del_protocol() to correctly + * maintain copy bit. + */ +#include <linux/cache.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/spinlock.h> +#include <net/protocol.h> + +struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly; +EXPORT_SYMBOL(inet_protos); +const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly; +EXPORT_SYMBOL(inet_offloads); + +int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol) +{ + if (!prot->netns_ok) { + pr_err("Protocol %u is not namespace aware, cannot register.\n", + protocol); + return -EINVAL; + } + + return !cmpxchg((const struct net_protocol **)&inet_protos[protocol], + NULL, prot) ? 0 : -1; +} +EXPORT_SYMBOL(inet_add_protocol); + +int inet_add_offload(const struct net_offload *prot, unsigned char protocol) +{ + return !cmpxchg((const struct net_offload **)&inet_offloads[protocol], + NULL, prot) ? 0 : -1; +} +EXPORT_SYMBOL(inet_add_offload); + +int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol) +{ + int ret; + + ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol], + prot, NULL) == prot) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(inet_del_protocol); + +int inet_del_offload(const struct net_offload *prot, unsigned char protocol) +{ + int ret; + + ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol], + prot, NULL) == prot) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(inet_del_offload); diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c new file mode 100644 index 000000000..650da4d8f --- /dev/null +++ b/net/ipv4/raw.c @@ -0,0 +1,1142 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * RAW - implementation of IP "raw" sockets. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * + * Fixes: + * Alan Cox : verify_area() fixed up + * Alan Cox : ICMP error handling + * Alan Cox : EMSGSIZE if you send too big a packet + * Alan Cox : Now uses generic datagrams and shared + * skbuff library. No more peek crashes, + * no more backlogs + * Alan Cox : Checks sk->broadcast. + * Alan Cox : Uses skb_free_datagram/skb_copy_datagram + * Alan Cox : Raw passes ip options too + * Alan Cox : Setsocketopt added + * Alan Cox : Fixed error return for broadcasts + * Alan Cox : Removed wake_up calls + * Alan Cox : Use ttl/tos + * Alan Cox : Cleaned up old debugging + * Alan Cox : Use new kernel side addresses + * Arnt Gulbrandsen : Fixed MSG_DONTROUTE in raw sockets. + * Alan Cox : BSD style RAW socket demultiplexing. + * Alan Cox : Beginnings of mrouted support. + * Alan Cox : Added IP_HDRINCL option. + * Alan Cox : Skip broadcast check if BSDism set. + * David S. Miller : New socket lookup architecture. + */ + +#include <linux/types.h> +#include <linux/atomic.h> +#include <asm/byteorder.h> +#include <asm/current.h> +#include <linux/uaccess.h> +#include <asm/ioctls.h> +#include <linux/stddef.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/spinlock.h> +#include <linux/sockios.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/mroute.h> +#include <linux/netdevice.h> +#include <linux/in_route.h> +#include <linux/route.h> +#include <linux/skbuff.h> +#include <linux/igmp.h> +#include <net/net_namespace.h> +#include <net/dst.h> +#include <net/sock.h> +#include <linux/ip.h> +#include <linux/net.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/raw.h> +#include <net/snmp.h> +#include <net/tcp_states.h> +#include <net/inet_common.h> +#include <net/checksum.h> +#include <net/xfrm.h> +#include <linux/rtnetlink.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> +#include <linux/compat.h> +#include <linux/uio.h> + +struct raw_frag_vec { + struct msghdr *msg; + union { + struct icmphdr icmph; + char c[1]; + } hdr; + int hlen; +}; + +struct raw_hashinfo raw_v4_hashinfo = { + .lock = __RW_LOCK_UNLOCKED(raw_v4_hashinfo.lock), +}; +EXPORT_SYMBOL_GPL(raw_v4_hashinfo); + +int raw_hash_sk(struct sock *sk) +{ + struct raw_hashinfo *h = sk->sk_prot->h.raw_hash; + struct hlist_head *head; + + head = &h->ht[inet_sk(sk)->inet_num & (RAW_HTABLE_SIZE - 1)]; + + write_lock_bh(&h->lock); + sk_add_node(sk, head); + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); + write_unlock_bh(&h->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(raw_hash_sk); + +void raw_unhash_sk(struct sock *sk) +{ + struct raw_hashinfo *h = sk->sk_prot->h.raw_hash; + + write_lock_bh(&h->lock); + if (sk_del_node_init(sk)) + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + write_unlock_bh(&h->lock); +} +EXPORT_SYMBOL_GPL(raw_unhash_sk); + +struct sock *__raw_v4_lookup(struct net *net, struct sock *sk, + unsigned short num, __be32 raddr, __be32 laddr, + int dif, int sdif) +{ + sk_for_each_from(sk) { + struct inet_sock *inet = inet_sk(sk); + + if (net_eq(sock_net(sk), net) && inet->inet_num == num && + !(inet->inet_daddr && inet->inet_daddr != raddr) && + !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) && + raw_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) + goto found; /* gotcha */ + } + sk = NULL; +found: + return sk; +} +EXPORT_SYMBOL_GPL(__raw_v4_lookup); + +/* + * 0 - deliver + * 1 - block + */ +static int icmp_filter(const struct sock *sk, const struct sk_buff *skb) +{ + struct icmphdr _hdr; + const struct icmphdr *hdr; + + hdr = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_hdr), &_hdr); + if (!hdr) + return 1; + + if (hdr->type < 32) { + __u32 data = raw_sk(sk)->filter.data; + + return ((1U << hdr->type) & data) != 0; + } + + /* Do not block unknown ICMP types */ + return 0; +} + +/* IP input processing comes here for RAW socket delivery. + * Caller owns SKB, so we must make clones. + * + * RFC 1122: SHOULD pass TOS value up to the transport layer. + * -> It does. And not only TOS, but all IP header. + */ +static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash) +{ + int sdif = inet_sdif(skb); + int dif = inet_iif(skb); + struct sock *sk; + struct hlist_head *head; + int delivered = 0; + struct net *net; + + read_lock(&raw_v4_hashinfo.lock); + head = &raw_v4_hashinfo.ht[hash]; + if (hlist_empty(head)) + goto out; + + net = dev_net(skb->dev); + sk = __raw_v4_lookup(net, __sk_head(head), iph->protocol, + iph->saddr, iph->daddr, dif, sdif); + + while (sk) { + delivered = 1; + if ((iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) && + ip_mc_sf_allow(sk, iph->daddr, iph->saddr, + skb->dev->ifindex, sdif)) { + struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC); + + /* Not releasing hash table! */ + if (clone) + raw_rcv(sk, clone); + } + sk = __raw_v4_lookup(net, sk_next(sk), iph->protocol, + iph->saddr, iph->daddr, + dif, sdif); + } +out: + read_unlock(&raw_v4_hashinfo.lock); + return delivered; +} + +int raw_local_deliver(struct sk_buff *skb, int protocol) +{ + int hash; + struct sock *raw_sk; + + hash = protocol & (RAW_HTABLE_SIZE - 1); + raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]); + + /* If there maybe a raw socket we must check - if not we + * don't care less + */ + if (raw_sk && !raw_v4_input(skb, ip_hdr(skb), hash)) + raw_sk = NULL; + + return raw_sk != NULL; + +} + +static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info) +{ + struct inet_sock *inet = inet_sk(sk); + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + int err = 0; + int harderr = 0; + + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) + ipv4_sk_update_pmtu(skb, sk, info); + else if (type == ICMP_REDIRECT) { + ipv4_sk_redirect(skb, sk); + return; + } + + /* Report error on raw socket, if: + 1. User requested ip_recverr. + 2. Socket is connected (otherwise the error indication + is useless without ip_recverr and error is hard. + */ + if (!inet->recverr && sk->sk_state != TCP_ESTABLISHED) + return; + + switch (type) { + default: + case ICMP_TIME_EXCEEDED: + err = EHOSTUNREACH; + break; + case ICMP_SOURCE_QUENCH: + return; + case ICMP_PARAMETERPROB: + err = EPROTO; + harderr = 1; + break; + case ICMP_DEST_UNREACH: + err = EHOSTUNREACH; + if (code > NR_ICMP_UNREACH) + break; + if (code == ICMP_FRAG_NEEDED) { + harderr = inet->pmtudisc != IP_PMTUDISC_DONT; + err = EMSGSIZE; + } else { + err = icmp_err_convert[code].errno; + harderr = icmp_err_convert[code].fatal; + } + } + + if (inet->recverr) { + const struct iphdr *iph = (const struct iphdr *)skb->data; + u8 *payload = skb->data + (iph->ihl << 2); + + if (inet->hdrincl) + payload = skb->data; + ip_icmp_error(sk, skb, err, 0, info, payload); + } + + if (inet->recverr || harderr) { + sk->sk_err = err; + sk->sk_error_report(sk); + } +} + +void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info) +{ + int hash; + struct sock *raw_sk; + const struct iphdr *iph; + struct net *net; + + hash = protocol & (RAW_HTABLE_SIZE - 1); + + read_lock(&raw_v4_hashinfo.lock); + raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]); + if (raw_sk) { + int dif = skb->dev->ifindex; + int sdif = inet_sdif(skb); + + iph = (const struct iphdr *)skb->data; + net = dev_net(skb->dev); + + while ((raw_sk = __raw_v4_lookup(net, raw_sk, protocol, + iph->daddr, iph->saddr, + dif, sdif)) != NULL) { + raw_err(raw_sk, skb, info); + raw_sk = sk_next(raw_sk); + iph = (const struct iphdr *)skb->data; + } + } + read_unlock(&raw_v4_hashinfo.lock); +} + +static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + /* Charge it to the socket. */ + + ipv4_pktinfo_prepare(sk, skb); + if (sock_queue_rcv_skb(sk, skb) < 0) { + kfree_skb(skb); + return NET_RX_DROP; + } + + return NET_RX_SUCCESS; +} + +int raw_rcv(struct sock *sk, struct sk_buff *skb) +{ + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) { + atomic_inc(&sk->sk_drops); + kfree_skb(skb); + return NET_RX_DROP; + } + nf_reset_ct(skb); + + skb_push(skb, skb->data - skb_network_header(skb)); + + raw_rcv_skb(sk, skb); + return 0; +} + +static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4, + struct msghdr *msg, size_t length, + struct rtable **rtp, unsigned int flags, + const struct sockcm_cookie *sockc) +{ + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + struct iphdr *iph; + struct sk_buff *skb; + unsigned int iphlen; + int err; + struct rtable *rt = *rtp; + int hlen, tlen; + + if (length > rt->dst.dev->mtu) { + ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, + rt->dst.dev->mtu); + return -EMSGSIZE; + } + if (length < sizeof(struct iphdr)) + return -EINVAL; + + if (flags&MSG_PROBE) + goto out; + + hlen = LL_RESERVED_SPACE(rt->dst.dev); + tlen = rt->dst.dev->needed_tailroom; + skb = sock_alloc_send_skb(sk, + length + hlen + tlen + 15, + flags & MSG_DONTWAIT, &err); + if (!skb) + goto error; + skb_reserve(skb, hlen); + + skb->priority = sk->sk_priority; + skb->mark = sockc->mark; + skb->tstamp = sockc->transmit_time; + skb_dst_set(skb, &rt->dst); + *rtp = NULL; + + skb_reset_network_header(skb); + iph = ip_hdr(skb); + skb_put(skb, length); + + skb->ip_summed = CHECKSUM_NONE; + + skb_setup_tx_timestamp(skb, sockc->tsflags); + + if (flags & MSG_CONFIRM) + skb_set_dst_pending_confirm(skb, 1); + + skb->transport_header = skb->network_header; + err = -EFAULT; + if (memcpy_from_msg(iph, msg, length)) + goto error_free; + + iphlen = iph->ihl * 4; + + /* + * We don't want to modify the ip header, but we do need to + * be sure that it won't cause problems later along the network + * stack. Specifically we want to make sure that iph->ihl is a + * sane value. If ihl points beyond the length of the buffer passed + * in, reject the frame as invalid + */ + err = -EINVAL; + if (iphlen > length) + goto error_free; + + if (iphlen >= sizeof(*iph)) { + if (!iph->saddr) + iph->saddr = fl4->saddr; + iph->check = 0; + iph->tot_len = htons(length); + if (!iph->id) + ip_select_ident(net, skb, NULL); + + iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); + skb->transport_header += iphlen; + if (iph->protocol == IPPROTO_ICMP && + length >= iphlen + sizeof(struct icmphdr)) + icmp_out_count(net, ((struct icmphdr *) + skb_transport_header(skb))->type); + } + + err = NF_HOOK(NFPROTO_IPV4, NF_INET_LOCAL_OUT, + net, sk, skb, NULL, rt->dst.dev, + dst_output); + if (err > 0) + err = net_xmit_errno(err); + if (err) + goto error; +out: + return 0; + +error_free: + kfree_skb(skb); +error: + IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); + if (err == -ENOBUFS && !inet->recverr) + err = 0; + return err; +} + +static int raw_probe_proto_opt(struct raw_frag_vec *rfv, struct flowi4 *fl4) +{ + int err; + + if (fl4->flowi4_proto != IPPROTO_ICMP) + return 0; + + /* We only need the first two bytes. */ + rfv->hlen = 2; + + err = memcpy_from_msg(rfv->hdr.c, rfv->msg, rfv->hlen); + if (err) + return err; + + fl4->fl4_icmp_type = rfv->hdr.icmph.type; + fl4->fl4_icmp_code = rfv->hdr.icmph.code; + + return 0; +} + +static int raw_getfrag(void *from, char *to, int offset, int len, int odd, + struct sk_buff *skb) +{ + struct raw_frag_vec *rfv = from; + + if (offset < rfv->hlen) { + int copy = min(rfv->hlen - offset, len); + + if (skb->ip_summed == CHECKSUM_PARTIAL) + memcpy(to, rfv->hdr.c + offset, copy); + else + skb->csum = csum_block_add( + skb->csum, + csum_partial_copy_nocheck(rfv->hdr.c + offset, + to, copy), + odd); + + odd = 0; + offset += copy; + to += copy; + len -= copy; + + if (!len) + return 0; + } + + offset -= rfv->hlen; + + return ip_generic_getfrag(rfv->msg, to, offset, len, odd, skb); +} + +static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct inet_sock *inet = inet_sk(sk); + struct net *net = sock_net(sk); + struct ipcm_cookie ipc; + struct rtable *rt = NULL; + struct flowi4 fl4; + int free = 0; + __be32 daddr; + __be32 saddr; + u8 tos; + int err; + struct ip_options_data opt_copy; + struct raw_frag_vec rfv; + int hdrincl; + + err = -EMSGSIZE; + if (len > 0xFFFF) + goto out; + + /* hdrincl should be READ_ONCE(inet->hdrincl) + * but READ_ONCE() doesn't work with bit fields. + * Doing this indirectly yields the same result. + */ + hdrincl = inet->hdrincl; + hdrincl = READ_ONCE(hdrincl); + /* + * Check the flags. + */ + + err = -EOPNOTSUPP; + if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message */ + goto out; /* compatibility */ + + /* + * Get and verify the address. + */ + + if (msg->msg_namelen) { + DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); + err = -EINVAL; + if (msg->msg_namelen < sizeof(*usin)) + goto out; + if (usin->sin_family != AF_INET) { + pr_info_once("%s: %s forgot to set AF_INET. Fix it!\n", + __func__, current->comm); + err = -EAFNOSUPPORT; + if (usin->sin_family) + goto out; + } + daddr = usin->sin_addr.s_addr; + /* ANK: I did not forget to get protocol from port field. + * I just do not know, who uses this weirdness. + * IP_HDRINCL is much more convenient. + */ + } else { + err = -EDESTADDRREQ; + if (sk->sk_state != TCP_ESTABLISHED) + goto out; + daddr = inet->inet_daddr; + } + + ipcm_init_sk(&ipc, inet); + /* Keep backward compat */ + if (hdrincl) + ipc.protocol = IPPROTO_RAW; + + if (msg->msg_controllen) { + err = ip_cmsg_send(sk, msg, &ipc, false); + if (unlikely(err)) { + kfree(ipc.opt); + goto out; + } + if (ipc.opt) + free = 1; + } + + saddr = ipc.addr; + ipc.addr = daddr; + + if (!ipc.opt) { + struct ip_options_rcu *inet_opt; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) { + memcpy(&opt_copy, inet_opt, + sizeof(*inet_opt) + inet_opt->opt.optlen); + ipc.opt = &opt_copy.opt; + } + rcu_read_unlock(); + } + + if (ipc.opt) { + err = -EINVAL; + /* Linux does not mangle headers on raw sockets, + * so that IP options + IP_HDRINCL is non-sense. + */ + if (hdrincl) + goto done; + if (ipc.opt->opt.srr) { + if (!daddr) + goto done; + daddr = ipc.opt->opt.faddr; + } + } + tos = get_rtconn_flags(&ipc, sk); + if (msg->msg_flags & MSG_DONTROUTE) + tos |= RTO_ONLINK; + + if (ipv4_is_multicast(daddr)) { + if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) + ipc.oif = inet->mc_index; + if (!saddr) + saddr = inet->mc_addr; + } else if (!ipc.oif) { + ipc.oif = inet->uc_index; + } else if (ipv4_is_lbcast(daddr) && inet->uc_index) { + /* oif is set, packet is to local broadcast + * and uc_index is set. oif is most likely set + * by sk_bound_dev_if. If uc_index != oif check if the + * oif is an L3 master and uc_index is an L3 slave. + * If so, we want to allow the send using the uc_index. + */ + if (ipc.oif != inet->uc_index && + ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk), + inet->uc_index)) { + ipc.oif = inet->uc_index; + } + } + + flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, + RT_SCOPE_UNIVERSE, + hdrincl ? ipc.protocol : sk->sk_protocol, + inet_sk_flowi_flags(sk) | + (hdrincl ? FLOWI_FLAG_KNOWN_NH : 0), + daddr, saddr, 0, 0, sk->sk_uid); + + if (!hdrincl) { + rfv.msg = msg; + rfv.hlen = 0; + + err = raw_probe_proto_opt(&rfv, &fl4); + if (err) + goto done; + } + + security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); + rt = ip_route_output_flow(net, &fl4, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + rt = NULL; + goto done; + } + + err = -EACCES; + if (rt->rt_flags & RTCF_BROADCAST && !sock_flag(sk, SOCK_BROADCAST)) + goto done; + + if (msg->msg_flags & MSG_CONFIRM) + goto do_confirm; +back_from_confirm: + + if (hdrincl) + err = raw_send_hdrinc(sk, &fl4, msg, len, + &rt, msg->msg_flags, &ipc.sockc); + + else { + if (!ipc.addr) + ipc.addr = fl4.daddr; + lock_sock(sk); + err = ip_append_data(sk, &fl4, raw_getfrag, + &rfv, len, 0, + &ipc, &rt, msg->msg_flags); + if (err) + ip_flush_pending_frames(sk); + else if (!(msg->msg_flags & MSG_MORE)) { + err = ip_push_pending_frames(sk, &fl4); + if (err == -ENOBUFS && !inet->recverr) + err = 0; + } + release_sock(sk); + } +done: + if (free) + kfree(ipc.opt); + ip_rt_put(rt); + +out: + if (err < 0) + return err; + return len; + +do_confirm: + if (msg->msg_flags & MSG_PROBE) + dst_confirm_neigh(&rt->dst, &fl4.daddr); + if (!(msg->msg_flags & MSG_PROBE) || len) + goto back_from_confirm; + err = 0; + goto done; +} + +static void raw_close(struct sock *sk, long timeout) +{ + /* + * Raw sockets may have direct kernel references. Kill them. + */ + ip_ra_control(sk, 0, NULL); + + sk_common_release(sk); +} + +static void raw_destroy(struct sock *sk) +{ + lock_sock(sk); + ip_flush_pending_frames(sk); + release_sock(sk); +} + +/* This gets rid of all the nasties in af_inet. -DaveM */ +static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; + u32 tb_id = RT_TABLE_LOCAL; + int ret = -EINVAL; + int chk_addr_ret; + + lock_sock(sk); + if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_in)) + goto out; + + if (sk->sk_bound_dev_if) + tb_id = l3mdev_fib_table_by_index(sock_net(sk), + sk->sk_bound_dev_if) ? : tb_id; + + chk_addr_ret = inet_addr_type_table(sock_net(sk), addr->sin_addr.s_addr, + tb_id); + + ret = -EADDRNOTAVAIL; + if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL && + chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) + goto out; + inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr; + if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) + inet->inet_saddr = 0; /* Use device */ + sk_dst_reset(sk); + ret = 0; +out: + release_sock(sk); + return ret; +} + +/* + * This should be easy, if there is something there + * we return it, otherwise we block. + */ + +static int raw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int noblock, int flags, int *addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + size_t copied = 0; + int err = -EOPNOTSUPP; + DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); + struct sk_buff *skb; + + if (flags & MSG_OOB) + goto out; + + if (flags & MSG_ERRQUEUE) { + err = ip_recv_error(sk, msg, len, addr_len); + goto out; + } + + skb = skb_recv_datagram(sk, flags, noblock, &err); + if (!skb) + goto out; + + copied = skb->len; + if (len < copied) { + msg->msg_flags |= MSG_TRUNC; + copied = len; + } + + err = skb_copy_datagram_msg(skb, 0, msg, copied); + if (err) + goto done; + + sock_recv_ts_and_drops(msg, sk, skb); + + /* Copy the address. */ + if (sin) { + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = ip_hdr(skb)->saddr; + sin->sin_port = 0; + memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); + } + if (inet->cmsg_flags) + ip_cmsg_recv(msg, skb); + if (flags & MSG_TRUNC) + copied = skb->len; +done: + skb_free_datagram(sk, skb); +out: + if (err) + return err; + return copied; +} + +static int raw_sk_init(struct sock *sk) +{ + struct raw_sock *rp = raw_sk(sk); + + if (inet_sk(sk)->inet_num == IPPROTO_ICMP) + memset(&rp->filter, 0, sizeof(rp->filter)); + return 0; +} + +static int raw_seticmpfilter(struct sock *sk, sockptr_t optval, int optlen) +{ + if (optlen > sizeof(struct icmp_filter)) + optlen = sizeof(struct icmp_filter); + if (copy_from_sockptr(&raw_sk(sk)->filter, optval, optlen)) + return -EFAULT; + return 0; +} + +static int raw_geticmpfilter(struct sock *sk, char __user *optval, int __user *optlen) +{ + int len, ret = -EFAULT; + + if (get_user(len, optlen)) + goto out; + ret = -EINVAL; + if (len < 0) + goto out; + if (len > sizeof(struct icmp_filter)) + len = sizeof(struct icmp_filter); + ret = -EFAULT; + if (put_user(len, optlen) || + copy_to_user(optval, &raw_sk(sk)->filter, len)) + goto out; + ret = 0; +out: return ret; +} + +static int do_raw_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + if (optname == ICMP_FILTER) { + if (inet_sk(sk)->inet_num != IPPROTO_ICMP) + return -EOPNOTSUPP; + else + return raw_seticmpfilter(sk, optval, optlen); + } + return -ENOPROTOOPT; +} + +static int raw_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + if (level != SOL_RAW) + return ip_setsockopt(sk, level, optname, optval, optlen); + return do_raw_setsockopt(sk, level, optname, optval, optlen); +} + +static int do_raw_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + if (optname == ICMP_FILTER) { + if (inet_sk(sk)->inet_num != IPPROTO_ICMP) + return -EOPNOTSUPP; + else + return raw_geticmpfilter(sk, optval, optlen); + } + return -ENOPROTOOPT; +} + +static int raw_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + if (level != SOL_RAW) + return ip_getsockopt(sk, level, optname, optval, optlen); + return do_raw_getsockopt(sk, level, optname, optval, optlen); +} + +static int raw_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + switch (cmd) { + case SIOCOUTQ: { + int amount = sk_wmem_alloc_get(sk); + + return put_user(amount, (int __user *)arg); + } + case SIOCINQ: { + struct sk_buff *skb; + int amount = 0; + + spin_lock_bh(&sk->sk_receive_queue.lock); + skb = skb_peek(&sk->sk_receive_queue); + if (skb) + amount = skb->len; + spin_unlock_bh(&sk->sk_receive_queue.lock); + return put_user(amount, (int __user *)arg); + } + + default: +#ifdef CONFIG_IP_MROUTE + return ipmr_ioctl(sk, cmd, (void __user *)arg); +#else + return -ENOIOCTLCMD; +#endif + } +} + +#ifdef CONFIG_COMPAT +static int compat_raw_ioctl(struct sock *sk, unsigned int cmd, unsigned long arg) +{ + switch (cmd) { + case SIOCOUTQ: + case SIOCINQ: + return -ENOIOCTLCMD; + default: +#ifdef CONFIG_IP_MROUTE + return ipmr_compat_ioctl(sk, cmd, compat_ptr(arg)); +#else + return -ENOIOCTLCMD; +#endif + } +} +#endif + +int raw_abort(struct sock *sk, int err) +{ + lock_sock(sk); + + sk->sk_err = err; + sk->sk_error_report(sk); + __udp_disconnect(sk, 0); + + release_sock(sk); + + return 0; +} +EXPORT_SYMBOL_GPL(raw_abort); + +struct proto raw_prot = { + .name = "RAW", + .owner = THIS_MODULE, + .close = raw_close, + .destroy = raw_destroy, + .connect = ip4_datagram_connect, + .disconnect = __udp_disconnect, + .ioctl = raw_ioctl, + .init = raw_sk_init, + .setsockopt = raw_setsockopt, + .getsockopt = raw_getsockopt, + .sendmsg = raw_sendmsg, + .recvmsg = raw_recvmsg, + .bind = raw_bind, + .backlog_rcv = raw_rcv_skb, + .release_cb = ip4_datagram_release_cb, + .hash = raw_hash_sk, + .unhash = raw_unhash_sk, + .obj_size = sizeof(struct raw_sock), + .useroffset = offsetof(struct raw_sock, filter), + .usersize = sizeof_field(struct raw_sock, filter), + .h.raw_hash = &raw_v4_hashinfo, +#ifdef CONFIG_COMPAT + .compat_ioctl = compat_raw_ioctl, +#endif + .diag_destroy = raw_abort, +}; + +#ifdef CONFIG_PROC_FS +static struct sock *raw_get_first(struct seq_file *seq) +{ + struct sock *sk; + struct raw_hashinfo *h = PDE_DATA(file_inode(seq->file)); + struct raw_iter_state *state = raw_seq_private(seq); + + for (state->bucket = 0; state->bucket < RAW_HTABLE_SIZE; + ++state->bucket) { + sk_for_each(sk, &h->ht[state->bucket]) + if (sock_net(sk) == seq_file_net(seq)) + goto found; + } + sk = NULL; +found: + return sk; +} + +static struct sock *raw_get_next(struct seq_file *seq, struct sock *sk) +{ + struct raw_hashinfo *h = PDE_DATA(file_inode(seq->file)); + struct raw_iter_state *state = raw_seq_private(seq); + + do { + sk = sk_next(sk); +try_again: + ; + } while (sk && sock_net(sk) != seq_file_net(seq)); + + if (!sk && ++state->bucket < RAW_HTABLE_SIZE) { + sk = sk_head(&h->ht[state->bucket]); + goto try_again; + } + return sk; +} + +static struct sock *raw_get_idx(struct seq_file *seq, loff_t pos) +{ + struct sock *sk = raw_get_first(seq); + + if (sk) + while (pos && (sk = raw_get_next(seq, sk)) != NULL) + --pos; + return pos ? NULL : sk; +} + +void *raw_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(&h->lock) +{ + struct raw_hashinfo *h = PDE_DATA(file_inode(seq->file)); + + read_lock(&h->lock); + return *pos ? raw_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; +} +EXPORT_SYMBOL_GPL(raw_seq_start); + +void *raw_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct sock *sk; + + if (v == SEQ_START_TOKEN) + sk = raw_get_first(seq); + else + sk = raw_get_next(seq, v); + ++*pos; + return sk; +} +EXPORT_SYMBOL_GPL(raw_seq_next); + +void raw_seq_stop(struct seq_file *seq, void *v) + __releases(&h->lock) +{ + struct raw_hashinfo *h = PDE_DATA(file_inode(seq->file)); + + read_unlock(&h->lock); +} +EXPORT_SYMBOL_GPL(raw_seq_stop); + +static void raw_sock_seq_show(struct seq_file *seq, struct sock *sp, int i) +{ + struct inet_sock *inet = inet_sk(sp); + __be32 dest = inet->inet_daddr, + src = inet->inet_rcv_saddr; + __u16 destp = 0, + srcp = inet->inet_num; + + seq_printf(seq, "%4d: %08X:%04X %08X:%04X" + " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n", + i, src, srcp, dest, destp, sp->sk_state, + sk_wmem_alloc_get(sp), + sk_rmem_alloc_get(sp), + 0, 0L, 0, + from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)), + 0, sock_i_ino(sp), + refcount_read(&sp->sk_refcnt), sp, atomic_read(&sp->sk_drops)); +} + +static int raw_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_printf(seq, " sl local_address rem_address st tx_queue " + "rx_queue tr tm->when retrnsmt uid timeout " + "inode ref pointer drops\n"); + else + raw_sock_seq_show(seq, v, raw_seq_private(seq)->bucket); + return 0; +} + +static const struct seq_operations raw_seq_ops = { + .start = raw_seq_start, + .next = raw_seq_next, + .stop = raw_seq_stop, + .show = raw_seq_show, +}; + +static __net_init int raw_init_net(struct net *net) +{ + if (!proc_create_net_data("raw", 0444, net->proc_net, &raw_seq_ops, + sizeof(struct raw_iter_state), &raw_v4_hashinfo)) + return -ENOMEM; + + return 0; +} + +static __net_exit void raw_exit_net(struct net *net) +{ + remove_proc_entry("raw", net->proc_net); +} + +static __net_initdata struct pernet_operations raw_net_ops = { + .init = raw_init_net, + .exit = raw_exit_net, +}; + +int __init raw_proc_init(void) +{ + return register_pernet_subsys(&raw_net_ops); +} + +void __init raw_proc_exit(void) +{ + unregister_pernet_subsys(&raw_net_ops); +} +#endif /* CONFIG_PROC_FS */ + +static void raw_sysctl_init_net(struct net *net) +{ +#ifdef CONFIG_NET_L3_MASTER_DEV + net->ipv4.sysctl_raw_l3mdev_accept = 1; +#endif +} + +static int __net_init raw_sysctl_init(struct net *net) +{ + raw_sysctl_init_net(net); + return 0; +} + +static struct pernet_operations __net_initdata raw_sysctl_ops = { + .init = raw_sysctl_init, +}; + +void __init raw_init(void) +{ + raw_sysctl_init_net(&init_net); + if (register_pernet_subsys(&raw_sysctl_ops)) + panic("RAW: failed to init sysctl parameters.\n"); +} diff --git a/net/ipv4/raw_diag.c b/net/ipv4/raw_diag.c new file mode 100644 index 000000000..1b5b8af27 --- /dev/null +++ b/net/ipv4/raw_diag.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/module.h> + +#include <linux/inet_diag.h> +#include <linux/sock_diag.h> + +#include <net/inet_sock.h> +#include <net/raw.h> +#include <net/rawv6.h> + +#ifdef pr_fmt +# undef pr_fmt +#endif + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +static struct raw_hashinfo * +raw_get_hashinfo(const struct inet_diag_req_v2 *r) +{ + if (r->sdiag_family == AF_INET) { + return &raw_v4_hashinfo; +#if IS_ENABLED(CONFIG_IPV6) + } else if (r->sdiag_family == AF_INET6) { + return &raw_v6_hashinfo; +#endif + } else { + return ERR_PTR(-EINVAL); + } +} + +/* + * Due to requirement of not breaking user API we can't simply + * rename @pad field in inet_diag_req_v2 structure, instead + * use helper to figure it out. + */ + +static struct sock *raw_lookup(struct net *net, struct sock *from, + const struct inet_diag_req_v2 *req) +{ + struct inet_diag_req_raw *r = (void *)req; + struct sock *sk = NULL; + + if (r->sdiag_family == AF_INET) + sk = __raw_v4_lookup(net, from, r->sdiag_raw_protocol, + r->id.idiag_dst[0], + r->id.idiag_src[0], + r->id.idiag_if, 0); +#if IS_ENABLED(CONFIG_IPV6) + else + sk = __raw_v6_lookup(net, from, r->sdiag_raw_protocol, + (const struct in6_addr *)r->id.idiag_src, + (const struct in6_addr *)r->id.idiag_dst, + r->id.idiag_if, 0); +#endif + return sk; +} + +static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r) +{ + struct raw_hashinfo *hashinfo = raw_get_hashinfo(r); + struct sock *sk = NULL, *s; + int slot; + + if (IS_ERR(hashinfo)) + return ERR_CAST(hashinfo); + + read_lock(&hashinfo->lock); + for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) { + sk_for_each(s, &hashinfo->ht[slot]) { + sk = raw_lookup(net, s, r); + if (sk) { + /* + * Grab it and keep until we fill + * diag meaage to be reported, so + * caller should call sock_put then. + * We can do that because we're keeping + * hashinfo->lock here. + */ + sock_hold(sk); + goto out_unlock; + } + } + } +out_unlock: + read_unlock(&hashinfo->lock); + + return sk ? sk : ERR_PTR(-ENOENT); +} + +static int raw_diag_dump_one(struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + struct sk_buff *in_skb = cb->skb; + struct sk_buff *rep; + struct sock *sk; + struct net *net; + int err; + + net = sock_net(in_skb->sk); + sk = raw_sock_get(net, r); + if (IS_ERR(sk)) + return PTR_ERR(sk); + + rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) + + inet_diag_msg_attrs_size() + + nla_total_size(sizeof(struct inet_diag_meminfo)) + 64, + GFP_KERNEL); + if (!rep) { + sock_put(sk); + return -ENOMEM; + } + + err = inet_sk_diag_fill(sk, NULL, rep, cb, r, 0, + netlink_net_capable(in_skb, CAP_NET_ADMIN)); + sock_put(sk); + + if (err < 0) { + kfree_skb(rep); + return err; + } + + err = netlink_unicast(net->diag_nlsk, rep, + NETLINK_CB(in_skb).portid, + MSG_DONTWAIT); + if (err > 0) + err = 0; + return err; +} + +static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *r, + struct nlattr *bc, bool net_admin) +{ + if (!inet_diag_bc_sk(bc, sk)) + return 0; + + return inet_sk_diag_fill(sk, NULL, skb, cb, r, NLM_F_MULTI, net_admin); +} + +static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN); + struct raw_hashinfo *hashinfo = raw_get_hashinfo(r); + struct net *net = sock_net(skb->sk); + struct inet_diag_dump_data *cb_data; + int num, s_num, slot, s_slot; + struct sock *sk = NULL; + struct nlattr *bc; + + if (IS_ERR(hashinfo)) + return; + + cb_data = cb->data; + bc = cb_data->inet_diag_nla_bc; + s_slot = cb->args[0]; + num = s_num = cb->args[1]; + + read_lock(&hashinfo->lock); + for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) { + num = 0; + + sk_for_each(sk, &hashinfo->ht[slot]) { + struct inet_sock *inet = inet_sk(sk); + + if (!net_eq(sock_net(sk), net)) + continue; + if (num < s_num) + goto next; + if (sk->sk_family != r->sdiag_family) + goto next; + if (r->id.idiag_sport != inet->inet_sport && + r->id.idiag_sport) + goto next; + if (r->id.idiag_dport != inet->inet_dport && + r->id.idiag_dport) + goto next; + if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) + goto out_unlock; +next: + num++; + } + } + +out_unlock: + read_unlock(&hashinfo->lock); + + cb->args[0] = slot; + cb->args[1] = num; +} + +static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r, + void *info) +{ + r->idiag_rqueue = sk_rmem_alloc_get(sk); + r->idiag_wqueue = sk_wmem_alloc_get(sk); +} + +#ifdef CONFIG_INET_DIAG_DESTROY +static int raw_diag_destroy(struct sk_buff *in_skb, + const struct inet_diag_req_v2 *r) +{ + struct net *net = sock_net(in_skb->sk); + struct sock *sk; + int err; + + sk = raw_sock_get(net, r); + if (IS_ERR(sk)) + return PTR_ERR(sk); + err = sock_diag_destroy(sk, ECONNABORTED); + sock_put(sk); + return err; +} +#endif + +static const struct inet_diag_handler raw_diag_handler = { + .dump = raw_diag_dump, + .dump_one = raw_diag_dump_one, + .idiag_get_info = raw_diag_get_info, + .idiag_type = IPPROTO_RAW, + .idiag_info_size = 0, +#ifdef CONFIG_INET_DIAG_DESTROY + .destroy = raw_diag_destroy, +#endif +}; + +static void __always_unused __check_inet_diag_req_raw(void) +{ + /* + * Make sure the two structures are identical, + * except the @pad field. + */ +#define __offset_mismatch(m1, m2) \ + (offsetof(struct inet_diag_req_v2, m1) != \ + offsetof(struct inet_diag_req_raw, m2)) + + BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) != + sizeof(struct inet_diag_req_raw)); + BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family)); + BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol)); + BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext)); + BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol)); + BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states)); + BUILD_BUG_ON(__offset_mismatch(id, id)); +#undef __offset_mismatch +} + +static int __init raw_diag_init(void) +{ + return inet_diag_register(&raw_diag_handler); +} + +static void __exit raw_diag_exit(void) +{ + inet_diag_unregister(&raw_diag_handler); +} + +module_init(raw_diag_init); +module_exit(raw_diag_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */); diff --git a/net/ipv4/route.c b/net/ipv4/route.c new file mode 100644 index 000000000..d360c7d70 --- /dev/null +++ b/net/ipv4/route.c @@ -0,0 +1,3685 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * ROUTE - implementation of the IP router. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Linus Torvalds, <Linus.Torvalds@helsinki.fi> + * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + * Fixes: + * Alan Cox : Verify area fixes. + * Alan Cox : cli() protects routing changes + * Rui Oliveira : ICMP routing table updates + * (rco@di.uminho.pt) Routing table insertion and update + * Linus Torvalds : Rewrote bits to be sensible + * Alan Cox : Added BSD route gw semantics + * Alan Cox : Super /proc >4K + * Alan Cox : MTU in route table + * Alan Cox : MSS actually. Also added the window + * clamper. + * Sam Lantinga : Fixed route matching in rt_del() + * Alan Cox : Routing cache support. + * Alan Cox : Removed compatibility cruft. + * Alan Cox : RTF_REJECT support. + * Alan Cox : TCP irtt support. + * Jonathan Naylor : Added Metric support. + * Miquel van Smoorenburg : BSD API fixes. + * Miquel van Smoorenburg : Metrics. + * Alan Cox : Use __u32 properly + * Alan Cox : Aligned routing errors more closely with BSD + * our system is still very different. + * Alan Cox : Faster /proc handling + * Alexey Kuznetsov : Massive rework to support tree based routing, + * routing caches and better behaviour. + * + * Olaf Erb : irtt wasn't being copied right. + * Bjorn Ekwall : Kerneld route support. + * Alan Cox : Multicast fixed (I hope) + * Pavel Krauz : Limited broadcast fixed + * Mike McLagan : Routing by source + * Alexey Kuznetsov : End of old history. Split to fib.c and + * route.c and rewritten from scratch. + * Andi Kleen : Load-limit warning messages. + * Vitaly E. Lavrov : Transparent proxy revived after year coma. + * Vitaly E. Lavrov : Race condition in ip_route_input_slow. + * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. + * Vladimir V. Ivanov : IP rule info (flowid) is really useful. + * Marc Boucher : routing by fwmark + * Robert Olsson : Added rt_cache statistics + * Arnaldo C. Melo : Convert proc stuff to seq_file + * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. + * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect + * Ilia Sotnikov : Removed TOS from hash calculations + */ + +#define pr_fmt(fmt) "IPv4: " fmt + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/memblock.h> +#include <linux/string.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/proc_fs.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/inetdevice.h> +#include <linux/igmp.h> +#include <linux/pkt_sched.h> +#include <linux/mroute.h> +#include <linux/netfilter_ipv4.h> +#include <linux/random.h> +#include <linux/rcupdate.h> +#include <linux/times.h> +#include <linux/slab.h> +#include <linux/jhash.h> +#include <net/dst.h> +#include <net/dst_metadata.h> +#include <net/net_namespace.h> +#include <net/protocol.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/inetpeer.h> +#include <net/sock.h> +#include <net/ip_fib.h> +#include <net/nexthop.h> +#include <net/arp.h> +#include <net/tcp.h> +#include <net/icmp.h> +#include <net/xfrm.h> +#include <net/lwtunnel.h> +#include <net/netevent.h> +#include <net/rtnetlink.h> +#ifdef CONFIG_SYSCTL +#include <linux/sysctl.h> +#endif +#include <net/secure_seq.h> +#include <net/ip_tunnels.h> +#include <net/l3mdev.h> + +#include "fib_lookup.h" + +#define RT_FL_TOS(oldflp4) \ + ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) + +#define RT_GC_TIMEOUT (300*HZ) + +static int ip_rt_max_size; +static int ip_rt_redirect_number __read_mostly = 9; +static int ip_rt_redirect_load __read_mostly = HZ / 50; +static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); +static int ip_rt_error_cost __read_mostly = HZ; +static int ip_rt_error_burst __read_mostly = 5 * HZ; +static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; +static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; +static int ip_rt_min_advmss __read_mostly = 256; + +static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; + +/* + * Interface to generic destination cache. + */ + +static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); +static unsigned int ipv4_default_advmss(const struct dst_entry *dst); +static unsigned int ipv4_mtu(const struct dst_entry *dst); +static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); +static void ipv4_link_failure(struct sk_buff *skb); +static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu, + bool confirm_neigh); +static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb); +static void ipv4_dst_destroy(struct dst_entry *dst); + +static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) +{ + WARN_ON(1); + return NULL; +} + +static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, + struct sk_buff *skb, + const void *daddr); +static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); + +static struct dst_ops ipv4_dst_ops = { + .family = AF_INET, + .check = ipv4_dst_check, + .default_advmss = ipv4_default_advmss, + .mtu = ipv4_mtu, + .cow_metrics = ipv4_cow_metrics, + .destroy = ipv4_dst_destroy, + .negative_advice = ipv4_negative_advice, + .link_failure = ipv4_link_failure, + .update_pmtu = ip_rt_update_pmtu, + .redirect = ip_do_redirect, + .local_out = __ip_local_out, + .neigh_lookup = ipv4_neigh_lookup, + .confirm_neigh = ipv4_confirm_neigh, +}; + +#define ECN_OR_COST(class) TC_PRIO_##class + +const __u8 ip_tos2prio[16] = { + TC_PRIO_BESTEFFORT, + ECN_OR_COST(BESTEFFORT), + TC_PRIO_BESTEFFORT, + ECN_OR_COST(BESTEFFORT), + TC_PRIO_BULK, + ECN_OR_COST(BULK), + TC_PRIO_BULK, + ECN_OR_COST(BULK), + TC_PRIO_INTERACTIVE, + ECN_OR_COST(INTERACTIVE), + TC_PRIO_INTERACTIVE, + ECN_OR_COST(INTERACTIVE), + TC_PRIO_INTERACTIVE_BULK, + ECN_OR_COST(INTERACTIVE_BULK), + TC_PRIO_INTERACTIVE_BULK, + ECN_OR_COST(INTERACTIVE_BULK) +}; +EXPORT_SYMBOL(ip_tos2prio); + +static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); +#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) + +#ifdef CONFIG_PROC_FS +static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) +{ + if (*pos) + return NULL; + return SEQ_START_TOKEN; +} + +static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + ++*pos; + return NULL; +} + +static void rt_cache_seq_stop(struct seq_file *seq, void *v) +{ +} + +static int rt_cache_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_printf(seq, "%-127s\n", + "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" + "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" + "HHUptod\tSpecDst"); + return 0; +} + +static const struct seq_operations rt_cache_seq_ops = { + .start = rt_cache_seq_start, + .next = rt_cache_seq_next, + .stop = rt_cache_seq_stop, + .show = rt_cache_seq_show, +}; + +static int rt_cache_seq_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &rt_cache_seq_ops); +} + +static const struct proc_ops rt_cache_proc_ops = { + .proc_open = rt_cache_seq_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = seq_release, +}; + + +static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) +{ + int cpu; + + if (*pos == 0) + return SEQ_START_TOKEN; + + for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { + if (!cpu_possible(cpu)) + continue; + *pos = cpu+1; + return &per_cpu(rt_cache_stat, cpu); + } + return NULL; +} + +static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + int cpu; + + for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { + if (!cpu_possible(cpu)) + continue; + *pos = cpu+1; + return &per_cpu(rt_cache_stat, cpu); + } + (*pos)++; + return NULL; + +} + +static void rt_cpu_seq_stop(struct seq_file *seq, void *v) +{ + +} + +static int rt_cpu_seq_show(struct seq_file *seq, void *v) +{ + struct rt_cache_stat *st = v; + + if (v == SEQ_START_TOKEN) { + seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); + return 0; + } + + seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " + " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", + dst_entries_get_slow(&ipv4_dst_ops), + 0, /* st->in_hit */ + st->in_slow_tot, + st->in_slow_mc, + st->in_no_route, + st->in_brd, + st->in_martian_dst, + st->in_martian_src, + + 0, /* st->out_hit */ + st->out_slow_tot, + st->out_slow_mc, + + 0, /* st->gc_total */ + 0, /* st->gc_ignored */ + 0, /* st->gc_goal_miss */ + 0, /* st->gc_dst_overflow */ + 0, /* st->in_hlist_search */ + 0 /* st->out_hlist_search */ + ); + return 0; +} + +static const struct seq_operations rt_cpu_seq_ops = { + .start = rt_cpu_seq_start, + .next = rt_cpu_seq_next, + .stop = rt_cpu_seq_stop, + .show = rt_cpu_seq_show, +}; + + +static int rt_cpu_seq_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &rt_cpu_seq_ops); +} + +static const struct proc_ops rt_cpu_proc_ops = { + .proc_open = rt_cpu_seq_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = seq_release, +}; + +#ifdef CONFIG_IP_ROUTE_CLASSID +static int rt_acct_proc_show(struct seq_file *m, void *v) +{ + struct ip_rt_acct *dst, *src; + unsigned int i, j; + + dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); + if (!dst) + return -ENOMEM; + + for_each_possible_cpu(i) { + src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); + for (j = 0; j < 256; j++) { + dst[j].o_bytes += src[j].o_bytes; + dst[j].o_packets += src[j].o_packets; + dst[j].i_bytes += src[j].i_bytes; + dst[j].i_packets += src[j].i_packets; + } + } + + seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); + kfree(dst); + return 0; +} +#endif + +static int __net_init ip_rt_do_proc_init(struct net *net) +{ + struct proc_dir_entry *pde; + + pde = proc_create("rt_cache", 0444, net->proc_net, + &rt_cache_proc_ops); + if (!pde) + goto err1; + + pde = proc_create("rt_cache", 0444, + net->proc_net_stat, &rt_cpu_proc_ops); + if (!pde) + goto err2; + +#ifdef CONFIG_IP_ROUTE_CLASSID + pde = proc_create_single("rt_acct", 0, net->proc_net, + rt_acct_proc_show); + if (!pde) + goto err3; +#endif + return 0; + +#ifdef CONFIG_IP_ROUTE_CLASSID +err3: + remove_proc_entry("rt_cache", net->proc_net_stat); +#endif +err2: + remove_proc_entry("rt_cache", net->proc_net); +err1: + return -ENOMEM; +} + +static void __net_exit ip_rt_do_proc_exit(struct net *net) +{ + remove_proc_entry("rt_cache", net->proc_net_stat); + remove_proc_entry("rt_cache", net->proc_net); +#ifdef CONFIG_IP_ROUTE_CLASSID + remove_proc_entry("rt_acct", net->proc_net); +#endif +} + +static struct pernet_operations ip_rt_proc_ops __net_initdata = { + .init = ip_rt_do_proc_init, + .exit = ip_rt_do_proc_exit, +}; + +static int __init ip_rt_proc_init(void) +{ + return register_pernet_subsys(&ip_rt_proc_ops); +} + +#else +static inline int ip_rt_proc_init(void) +{ + return 0; +} +#endif /* CONFIG_PROC_FS */ + +static inline bool rt_is_expired(const struct rtable *rth) +{ + return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); +} + +void rt_cache_flush(struct net *net) +{ + rt_genid_bump_ipv4(net); +} + +static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, + struct sk_buff *skb, + const void *daddr) +{ + const struct rtable *rt = container_of(dst, struct rtable, dst); + struct net_device *dev = dst->dev; + struct neighbour *n; + + rcu_read_lock_bh(); + + if (likely(rt->rt_gw_family == AF_INET)) { + n = ip_neigh_gw4(dev, rt->rt_gw4); + } else if (rt->rt_gw_family == AF_INET6) { + n = ip_neigh_gw6(dev, &rt->rt_gw6); + } else { + __be32 pkey; + + pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); + n = ip_neigh_gw4(dev, pkey); + } + + if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) + n = NULL; + + rcu_read_unlock_bh(); + + return n; +} + +static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) +{ + const struct rtable *rt = container_of(dst, struct rtable, dst); + struct net_device *dev = dst->dev; + const __be32 *pkey = daddr; + + if (rt->rt_gw_family == AF_INET) { + pkey = (const __be32 *)&rt->rt_gw4; + } else if (rt->rt_gw_family == AF_INET6) { + return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); + } else if (!daddr || + (rt->rt_flags & + (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { + return; + } + __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); +} + +/* Hash tables of size 2048..262144 depending on RAM size. + * Each bucket uses 8 bytes. + */ +static u32 ip_idents_mask __read_mostly; +static atomic_t *ip_idents __read_mostly; +static u32 *ip_tstamps __read_mostly; + +/* In order to protect privacy, we add a perturbation to identifiers + * if one generator is seldom used. This makes hard for an attacker + * to infer how many packets were sent between two points in time. + */ +u32 ip_idents_reserve(u32 hash, int segs) +{ + u32 bucket, old, now = (u32)jiffies; + atomic_t *p_id; + u32 *p_tstamp; + u32 delta = 0; + + bucket = hash & ip_idents_mask; + p_tstamp = ip_tstamps + bucket; + p_id = ip_idents + bucket; + old = READ_ONCE(*p_tstamp); + + if (old != now && cmpxchg(p_tstamp, old, now) == old) + delta = prandom_u32_max(now - old); + + /* If UBSAN reports an error there, please make sure your compiler + * supports -fno-strict-overflow before reporting it that was a bug + * in UBSAN, and it has been fixed in GCC-8. + */ + return atomic_add_return(segs + delta, p_id) - segs; +} +EXPORT_SYMBOL(ip_idents_reserve); + +void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) +{ + u32 hash, id; + + /* Note the following code is not safe, but this is okay. */ + if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) + get_random_bytes(&net->ipv4.ip_id_key, + sizeof(net->ipv4.ip_id_key)); + + hash = siphash_3u32((__force u32)iph->daddr, + (__force u32)iph->saddr, + iph->protocol, + &net->ipv4.ip_id_key); + id = ip_idents_reserve(hash, segs); + iph->id = htons(id); +} +EXPORT_SYMBOL(__ip_select_ident); + +static void ip_rt_fix_tos(struct flowi4 *fl4) +{ + __u8 tos = RT_FL_TOS(fl4); + + fl4->flowi4_tos = tos & IPTOS_RT_MASK; + fl4->flowi4_scope = tos & RTO_ONLINK ? + RT_SCOPE_LINK : RT_SCOPE_UNIVERSE; +} + +static void __build_flow_key(const struct net *net, struct flowi4 *fl4, + const struct sock *sk, + const struct iphdr *iph, + int oif, u8 tos, + u8 prot, u32 mark, int flow_flags) +{ + if (sk) { + const struct inet_sock *inet = inet_sk(sk); + + oif = sk->sk_bound_dev_if; + mark = sk->sk_mark; + tos = RT_CONN_FLAGS(sk); + prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; + } + flowi4_init_output(fl4, oif, mark, tos, + RT_SCOPE_UNIVERSE, prot, + flow_flags, + iph->daddr, iph->saddr, 0, 0, + sock_net_uid(net, sk)); +} + +static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, + const struct sock *sk) +{ + const struct net *net = dev_net(skb->dev); + const struct iphdr *iph = ip_hdr(skb); + int oif = skb->dev->ifindex; + u8 tos = RT_TOS(iph->tos); + u8 prot = iph->protocol; + u32 mark = skb->mark; + + __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); +} + +static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) +{ + const struct inet_sock *inet = inet_sk(sk); + const struct ip_options_rcu *inet_opt; + __be32 daddr = inet->inet_daddr; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, + inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, + inet_sk_flowi_flags(sk), + daddr, inet->inet_saddr, 0, 0, sk->sk_uid); + rcu_read_unlock(); +} + +static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, + const struct sk_buff *skb) +{ + if (skb) + build_skb_flow_key(fl4, skb, sk); + else + build_sk_flow_key(fl4, sk); +} + +static DEFINE_SPINLOCK(fnhe_lock); + +static void fnhe_flush_routes(struct fib_nh_exception *fnhe) +{ + struct rtable *rt; + + rt = rcu_dereference(fnhe->fnhe_rth_input); + if (rt) { + RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); + dst_dev_put(&rt->dst); + dst_release(&rt->dst); + } + rt = rcu_dereference(fnhe->fnhe_rth_output); + if (rt) { + RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); + dst_dev_put(&rt->dst); + dst_release(&rt->dst); + } +} + +static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) +{ + struct fib_nh_exception __rcu **fnhe_p, **oldest_p; + struct fib_nh_exception *fnhe, *oldest = NULL; + + for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { + fnhe = rcu_dereference_protected(*fnhe_p, + lockdep_is_held(&fnhe_lock)); + if (!fnhe) + break; + if (!oldest || + time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { + oldest = fnhe; + oldest_p = fnhe_p; + } + } + fnhe_flush_routes(oldest); + *oldest_p = oldest->fnhe_next; + kfree_rcu(oldest, rcu); +} + +static u32 fnhe_hashfun(__be32 daddr) +{ + static siphash_key_t fnhe_hash_key __read_mostly; + u64 hval; + + net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); + hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); + return hash_64(hval, FNHE_HASH_SHIFT); +} + +static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) +{ + rt->rt_pmtu = fnhe->fnhe_pmtu; + rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; + rt->dst.expires = fnhe->fnhe_expires; + + if (fnhe->fnhe_gw) { + rt->rt_flags |= RTCF_REDIRECTED; + rt->rt_uses_gateway = 1; + rt->rt_gw_family = AF_INET; + rt->rt_gw4 = fnhe->fnhe_gw; + } +} + +static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, + __be32 gw, u32 pmtu, bool lock, + unsigned long expires) +{ + struct fnhe_hash_bucket *hash; + struct fib_nh_exception *fnhe; + struct rtable *rt; + u32 genid, hval; + unsigned int i; + int depth; + + genid = fnhe_genid(dev_net(nhc->nhc_dev)); + hval = fnhe_hashfun(daddr); + + spin_lock_bh(&fnhe_lock); + + hash = rcu_dereference(nhc->nhc_exceptions); + if (!hash) { + hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); + if (!hash) + goto out_unlock; + rcu_assign_pointer(nhc->nhc_exceptions, hash); + } + + hash += hval; + + depth = 0; + for (fnhe = rcu_dereference(hash->chain); fnhe; + fnhe = rcu_dereference(fnhe->fnhe_next)) { + if (fnhe->fnhe_daddr == daddr) + break; + depth++; + } + + if (fnhe) { + if (fnhe->fnhe_genid != genid) + fnhe->fnhe_genid = genid; + if (gw) + fnhe->fnhe_gw = gw; + if (pmtu) { + fnhe->fnhe_pmtu = pmtu; + fnhe->fnhe_mtu_locked = lock; + } + fnhe->fnhe_expires = max(1UL, expires); + /* Update all cached dsts too */ + rt = rcu_dereference(fnhe->fnhe_rth_input); + if (rt) + fill_route_from_fnhe(rt, fnhe); + rt = rcu_dereference(fnhe->fnhe_rth_output); + if (rt) + fill_route_from_fnhe(rt, fnhe); + } else { + /* Randomize max depth to avoid some side channels attacks. */ + int max_depth = FNHE_RECLAIM_DEPTH + + prandom_u32_max(FNHE_RECLAIM_DEPTH); + + while (depth > max_depth) { + fnhe_remove_oldest(hash); + depth--; + } + + fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); + if (!fnhe) + goto out_unlock; + + fnhe->fnhe_next = hash->chain; + + fnhe->fnhe_genid = genid; + fnhe->fnhe_daddr = daddr; + fnhe->fnhe_gw = gw; + fnhe->fnhe_pmtu = pmtu; + fnhe->fnhe_mtu_locked = lock; + fnhe->fnhe_expires = max(1UL, expires); + + rcu_assign_pointer(hash->chain, fnhe); + + /* Exception created; mark the cached routes for the nexthop + * stale, so anyone caching it rechecks if this exception + * applies to them. + */ + rt = rcu_dereference(nhc->nhc_rth_input); + if (rt) + rt->dst.obsolete = DST_OBSOLETE_KILL; + + for_each_possible_cpu(i) { + struct rtable __rcu **prt; + prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); + rt = rcu_dereference(*prt); + if (rt) + rt->dst.obsolete = DST_OBSOLETE_KILL; + } + } + + fnhe->fnhe_stamp = jiffies; + +out_unlock: + spin_unlock_bh(&fnhe_lock); +} + +static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, + bool kill_route) +{ + __be32 new_gw = icmp_hdr(skb)->un.gateway; + __be32 old_gw = ip_hdr(skb)->saddr; + struct net_device *dev = skb->dev; + struct in_device *in_dev; + struct fib_result res; + struct neighbour *n; + struct net *net; + + switch (icmp_hdr(skb)->code & 7) { + case ICMP_REDIR_NET: + case ICMP_REDIR_NETTOS: + case ICMP_REDIR_HOST: + case ICMP_REDIR_HOSTTOS: + break; + + default: + return; + } + + if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) + return; + + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + return; + + net = dev_net(dev); + if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || + ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || + ipv4_is_zeronet(new_gw)) + goto reject_redirect; + + if (!IN_DEV_SHARED_MEDIA(in_dev)) { + if (!inet_addr_onlink(in_dev, new_gw, old_gw)) + goto reject_redirect; + if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) + goto reject_redirect; + } else { + if (inet_addr_type(net, new_gw) != RTN_UNICAST) + goto reject_redirect; + } + + n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); + if (!n) + n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); + if (!IS_ERR(n)) { + if (!(n->nud_state & NUD_VALID)) { + neigh_event_send(n, NULL); + } else { + if (fib_lookup(net, fl4, &res, 0) == 0) { + struct fib_nh_common *nhc; + + fib_select_path(net, &res, fl4, skb); + nhc = FIB_RES_NHC(res); + update_or_create_fnhe(nhc, fl4->daddr, new_gw, + 0, false, + jiffies + ip_rt_gc_timeout); + } + if (kill_route) + rt->dst.obsolete = DST_OBSOLETE_KILL; + call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); + } + neigh_release(n); + } + return; + +reject_redirect: +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (IN_DEV_LOG_MARTIANS(in_dev)) { + const struct iphdr *iph = (const struct iphdr *) skb->data; + __be32 daddr = iph->daddr; + __be32 saddr = iph->saddr; + + net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" + " Advised path = %pI4 -> %pI4\n", + &old_gw, dev->name, &new_gw, + &saddr, &daddr); + } +#endif + ; +} + +static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) +{ + struct rtable *rt; + struct flowi4 fl4; + const struct iphdr *iph = (const struct iphdr *) skb->data; + struct net *net = dev_net(skb->dev); + int oif = skb->dev->ifindex; + u8 tos = RT_TOS(iph->tos); + u8 prot = iph->protocol; + u32 mark = skb->mark; + + rt = (struct rtable *) dst; + + __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); + ip_rt_fix_tos(&fl4); + __ip_do_redirect(rt, skb, &fl4, true); +} + +static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) +{ + struct rtable *rt = (struct rtable *)dst; + struct dst_entry *ret = dst; + + if (rt) { + if (dst->obsolete > 0) { + ip_rt_put(rt); + ret = NULL; + } else if ((rt->rt_flags & RTCF_REDIRECTED) || + rt->dst.expires) { + ip_rt_put(rt); + ret = NULL; + } + } + return ret; +} + +/* + * Algorithm: + * 1. The first ip_rt_redirect_number redirects are sent + * with exponential backoff, then we stop sending them at all, + * assuming that the host ignores our redirects. + * 2. If we did not see packets requiring redirects + * during ip_rt_redirect_silence, we assume that the host + * forgot redirected route and start to send redirects again. + * + * This algorithm is much cheaper and more intelligent than dumb load limiting + * in icmp.c. + * + * NOTE. Do not forget to inhibit load limiting for redirects (redundant) + * and "frag. need" (breaks PMTU discovery) in icmp.c. + */ + +void ip_rt_send_redirect(struct sk_buff *skb) +{ + struct rtable *rt = skb_rtable(skb); + struct in_device *in_dev; + struct inet_peer *peer; + struct net *net; + int log_martians; + int vif; + + rcu_read_lock(); + in_dev = __in_dev_get_rcu(rt->dst.dev); + if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { + rcu_read_unlock(); + return; + } + log_martians = IN_DEV_LOG_MARTIANS(in_dev); + vif = l3mdev_master_ifindex_rcu(rt->dst.dev); + rcu_read_unlock(); + + net = dev_net(rt->dst.dev); + peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); + if (!peer) { + icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, + rt_nexthop(rt, ip_hdr(skb)->daddr)); + return; + } + + /* No redirected packets during ip_rt_redirect_silence; + * reset the algorithm. + */ + if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { + peer->rate_tokens = 0; + peer->n_redirects = 0; + } + + /* Too many ignored redirects; do not send anything + * set dst.rate_last to the last seen redirected packet. + */ + if (peer->n_redirects >= ip_rt_redirect_number) { + peer->rate_last = jiffies; + goto out_put_peer; + } + + /* Check for load limit; set rate_last to the latest sent + * redirect. + */ + if (peer->n_redirects == 0 || + time_after(jiffies, + (peer->rate_last + + (ip_rt_redirect_load << peer->n_redirects)))) { + __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); + + icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); + peer->rate_last = jiffies; + ++peer->n_redirects; +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (log_martians && + peer->n_redirects == ip_rt_redirect_number) + net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", + &ip_hdr(skb)->saddr, inet_iif(skb), + &ip_hdr(skb)->daddr, &gw); +#endif + } +out_put_peer: + inet_putpeer(peer); +} + +static int ip_error(struct sk_buff *skb) +{ + struct rtable *rt = skb_rtable(skb); + struct net_device *dev = skb->dev; + struct in_device *in_dev; + struct inet_peer *peer; + unsigned long now; + struct net *net; + bool send; + int code; + + if (netif_is_l3_master(skb->dev)) { + dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); + if (!dev) + goto out; + } + + in_dev = __in_dev_get_rcu(dev); + + /* IP on this device is disabled. */ + if (!in_dev) + goto out; + + net = dev_net(rt->dst.dev); + if (!IN_DEV_FORWARD(in_dev)) { + switch (rt->dst.error) { + case EHOSTUNREACH: + __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); + break; + + case ENETUNREACH: + __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); + break; + } + goto out; + } + + switch (rt->dst.error) { + case EINVAL: + default: + goto out; + case EHOSTUNREACH: + code = ICMP_HOST_UNREACH; + break; + case ENETUNREACH: + code = ICMP_NET_UNREACH; + __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); + break; + case EACCES: + code = ICMP_PKT_FILTERED; + break; + } + + peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, + l3mdev_master_ifindex(skb->dev), 1); + + send = true; + if (peer) { + now = jiffies; + peer->rate_tokens += now - peer->rate_last; + if (peer->rate_tokens > ip_rt_error_burst) + peer->rate_tokens = ip_rt_error_burst; + peer->rate_last = now; + if (peer->rate_tokens >= ip_rt_error_cost) + peer->rate_tokens -= ip_rt_error_cost; + else + send = false; + inet_putpeer(peer); + } + if (send) + icmp_send(skb, ICMP_DEST_UNREACH, code, 0); + +out: kfree_skb(skb); + return 0; +} + +static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) +{ + struct dst_entry *dst = &rt->dst; + struct net *net = dev_net(dst->dev); + struct fib_result res; + bool lock = false; + u32 old_mtu; + + if (ip_mtu_locked(dst)) + return; + + old_mtu = ipv4_mtu(dst); + if (old_mtu < mtu) + return; + + if (mtu < ip_rt_min_pmtu) { + lock = true; + mtu = min(old_mtu, ip_rt_min_pmtu); + } + + if (rt->rt_pmtu == mtu && !lock && + time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) + return; + + rcu_read_lock(); + if (fib_lookup(net, fl4, &res, 0) == 0) { + struct fib_nh_common *nhc; + + fib_select_path(net, &res, fl4, NULL); + nhc = FIB_RES_NHC(res); + update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, + jiffies + ip_rt_mtu_expires); + } + rcu_read_unlock(); +} + +static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu, + bool confirm_neigh) +{ + struct rtable *rt = (struct rtable *) dst; + struct flowi4 fl4; + + ip_rt_build_flow_key(&fl4, sk, skb); + ip_rt_fix_tos(&fl4); + + /* Don't make lookup fail for bridged encapsulations */ + if (skb && netif_is_any_bridge_port(skb->dev)) + fl4.flowi4_oif = 0; + + __ip_rt_update_pmtu(rt, &fl4, mtu); +} + +void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, + int oif, u8 protocol) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct flowi4 fl4; + struct rtable *rt; + u32 mark = IP4_REPLY_MARK(net, skb->mark); + + __build_flow_key(net, &fl4, NULL, iph, oif, + RT_TOS(iph->tos), protocol, mark, 0); + rt = __ip_route_output_key(net, &fl4); + if (!IS_ERR(rt)) { + __ip_rt_update_pmtu(rt, &fl4, mtu); + ip_rt_put(rt); + } +} +EXPORT_SYMBOL_GPL(ipv4_update_pmtu); + +static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct flowi4 fl4; + struct rtable *rt; + + __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); + + if (!fl4.flowi4_mark) + fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); + + rt = __ip_route_output_key(sock_net(sk), &fl4); + if (!IS_ERR(rt)) { + __ip_rt_update_pmtu(rt, &fl4, mtu); + ip_rt_put(rt); + } +} + +void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct flowi4 fl4; + struct rtable *rt; + struct dst_entry *odst = NULL; + bool new = false; + struct net *net = sock_net(sk); + + bh_lock_sock(sk); + + if (!ip_sk_accept_pmtu(sk)) + goto out; + + odst = sk_dst_get(sk); + + if (sock_owned_by_user(sk) || !odst) { + __ipv4_sk_update_pmtu(skb, sk, mtu); + goto out; + } + + __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); + + rt = (struct rtable *)odst; + if (odst->obsolete && !odst->ops->check(odst, 0)) { + rt = ip_route_output_flow(sock_net(sk), &fl4, sk); + if (IS_ERR(rt)) + goto out; + + new = true; + } else { + ip_rt_fix_tos(&fl4); + } + + __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); + + if (!dst_check(&rt->dst, 0)) { + if (new) + dst_release(&rt->dst); + + rt = ip_route_output_flow(sock_net(sk), &fl4, sk); + if (IS_ERR(rt)) + goto out; + + new = true; + } + + if (new) + sk_dst_set(sk, &rt->dst); + +out: + bh_unlock_sock(sk); + dst_release(odst); +} +EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); + +void ipv4_redirect(struct sk_buff *skb, struct net *net, + int oif, u8 protocol) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct flowi4 fl4; + struct rtable *rt; + + __build_flow_key(net, &fl4, NULL, iph, oif, + RT_TOS(iph->tos), protocol, 0, 0); + rt = __ip_route_output_key(net, &fl4); + if (!IS_ERR(rt)) { + __ip_do_redirect(rt, skb, &fl4, false); + ip_rt_put(rt); + } +} +EXPORT_SYMBOL_GPL(ipv4_redirect); + +void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct flowi4 fl4; + struct rtable *rt; + struct net *net = sock_net(sk); + + __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); + rt = __ip_route_output_key(net, &fl4); + if (!IS_ERR(rt)) { + __ip_do_redirect(rt, skb, &fl4, false); + ip_rt_put(rt); + } +} +EXPORT_SYMBOL_GPL(ipv4_sk_redirect); + +static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) +{ + struct rtable *rt = (struct rtable *) dst; + + /* All IPV4 dsts are created with ->obsolete set to the value + * DST_OBSOLETE_FORCE_CHK which forces validation calls down + * into this function always. + * + * When a PMTU/redirect information update invalidates a route, + * this is indicated by setting obsolete to DST_OBSOLETE_KILL or + * DST_OBSOLETE_DEAD. + */ + if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) + return NULL; + return dst; +} + +static void ipv4_send_dest_unreach(struct sk_buff *skb) +{ + struct net_device *dev; + struct ip_options opt; + int res; + + /* Recompile ip options since IPCB may not be valid anymore. + * Also check we have a reasonable ipv4 header. + */ + if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || + ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) + return; + + memset(&opt, 0, sizeof(opt)); + if (ip_hdr(skb)->ihl > 5) { + if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) + return; + opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); + + rcu_read_lock(); + dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; + res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); + rcu_read_unlock(); + + if (res) + return; + } + __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); +} + +static void ipv4_link_failure(struct sk_buff *skb) +{ + struct rtable *rt; + + ipv4_send_dest_unreach(skb); + + rt = skb_rtable(skb); + if (rt) + dst_set_expires(&rt->dst, 0); +} + +static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + pr_debug("%s: %pI4 -> %pI4, %s\n", + __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, + skb->dev ? skb->dev->name : "?"); + kfree_skb(skb); + WARN_ON(1); + return 0; +} + +/* + We do not cache source address of outgoing interface, + because it is used only by IP RR, TS and SRR options, + so that it out of fast path. + + BTW remember: "addr" is allowed to be not aligned + in IP options! + */ + +void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) +{ + __be32 src; + + if (rt_is_output_route(rt)) + src = ip_hdr(skb)->saddr; + else { + struct fib_result res; + struct iphdr *iph = ip_hdr(skb); + struct flowi4 fl4 = { + .daddr = iph->daddr, + .saddr = iph->saddr, + .flowi4_tos = RT_TOS(iph->tos), + .flowi4_oif = rt->dst.dev->ifindex, + .flowi4_iif = skb->dev->ifindex, + .flowi4_mark = skb->mark, + }; + + rcu_read_lock(); + if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) + src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); + else + src = inet_select_addr(rt->dst.dev, + rt_nexthop(rt, iph->daddr), + RT_SCOPE_UNIVERSE); + rcu_read_unlock(); + } + memcpy(addr, &src, 4); +} + +#ifdef CONFIG_IP_ROUTE_CLASSID +static void set_class_tag(struct rtable *rt, u32 tag) +{ + if (!(rt->dst.tclassid & 0xFFFF)) + rt->dst.tclassid |= tag & 0xFFFF; + if (!(rt->dst.tclassid & 0xFFFF0000)) + rt->dst.tclassid |= tag & 0xFFFF0000; +} +#endif + +static unsigned int ipv4_default_advmss(const struct dst_entry *dst) +{ + unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); + unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, + ip_rt_min_advmss); + + return min(advmss, IPV4_MAX_PMTU - header_size); +} + +static unsigned int ipv4_mtu(const struct dst_entry *dst) +{ + const struct rtable *rt = (const struct rtable *)dst; + unsigned int mtu = rt->rt_pmtu; + + if (!mtu || time_after_eq(jiffies, rt->dst.expires)) + mtu = dst_metric_raw(dst, RTAX_MTU); + + if (mtu) + goto out; + + mtu = READ_ONCE(dst->dev->mtu); + + if (unlikely(ip_mtu_locked(dst))) { + if (rt->rt_uses_gateway && mtu > 576) + mtu = 576; + } + +out: + mtu = min_t(unsigned int, mtu, IP_MAX_MTU); + + return mtu - lwtunnel_headroom(dst->lwtstate, mtu); +} + +static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) +{ + struct fnhe_hash_bucket *hash; + struct fib_nh_exception *fnhe, __rcu **fnhe_p; + u32 hval = fnhe_hashfun(daddr); + + spin_lock_bh(&fnhe_lock); + + hash = rcu_dereference_protected(nhc->nhc_exceptions, + lockdep_is_held(&fnhe_lock)); + hash += hval; + + fnhe_p = &hash->chain; + fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); + while (fnhe) { + if (fnhe->fnhe_daddr == daddr) { + rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( + fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); + /* set fnhe_daddr to 0 to ensure it won't bind with + * new dsts in rt_bind_exception(). + */ + fnhe->fnhe_daddr = 0; + fnhe_flush_routes(fnhe); + kfree_rcu(fnhe, rcu); + break; + } + fnhe_p = &fnhe->fnhe_next; + fnhe = rcu_dereference_protected(fnhe->fnhe_next, + lockdep_is_held(&fnhe_lock)); + } + + spin_unlock_bh(&fnhe_lock); +} + +static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, + __be32 daddr) +{ + struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); + struct fib_nh_exception *fnhe; + u32 hval; + + if (!hash) + return NULL; + + hval = fnhe_hashfun(daddr); + + for (fnhe = rcu_dereference(hash[hval].chain); fnhe; + fnhe = rcu_dereference(fnhe->fnhe_next)) { + if (fnhe->fnhe_daddr == daddr) { + if (fnhe->fnhe_expires && + time_after(jiffies, fnhe->fnhe_expires)) { + ip_del_fnhe(nhc, daddr); + break; + } + return fnhe; + } + } + return NULL; +} + +/* MTU selection: + * 1. mtu on route is locked - use it + * 2. mtu from nexthop exception + * 3. mtu from egress device + */ + +u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) +{ + struct fib_nh_common *nhc = res->nhc; + struct net_device *dev = nhc->nhc_dev; + struct fib_info *fi = res->fi; + u32 mtu = 0; + + if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || + fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) + mtu = fi->fib_mtu; + + if (likely(!mtu)) { + struct fib_nh_exception *fnhe; + + fnhe = find_exception(nhc, daddr); + if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) + mtu = fnhe->fnhe_pmtu; + } + + if (likely(!mtu)) + mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); + + return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); +} + +static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, + __be32 daddr, const bool do_cache) +{ + bool ret = false; + + spin_lock_bh(&fnhe_lock); + + if (daddr == fnhe->fnhe_daddr) { + struct rtable __rcu **porig; + struct rtable *orig; + int genid = fnhe_genid(dev_net(rt->dst.dev)); + + if (rt_is_input_route(rt)) + porig = &fnhe->fnhe_rth_input; + else + porig = &fnhe->fnhe_rth_output; + orig = rcu_dereference(*porig); + + if (fnhe->fnhe_genid != genid) { + fnhe->fnhe_genid = genid; + fnhe->fnhe_gw = 0; + fnhe->fnhe_pmtu = 0; + fnhe->fnhe_expires = 0; + fnhe->fnhe_mtu_locked = false; + fnhe_flush_routes(fnhe); + orig = NULL; + } + fill_route_from_fnhe(rt, fnhe); + if (!rt->rt_gw4) { + rt->rt_gw4 = daddr; + rt->rt_gw_family = AF_INET; + } + + if (do_cache) { + dst_hold(&rt->dst); + rcu_assign_pointer(*porig, rt); + if (orig) { + dst_dev_put(&orig->dst); + dst_release(&orig->dst); + } + ret = true; + } + + fnhe->fnhe_stamp = jiffies; + } + spin_unlock_bh(&fnhe_lock); + + return ret; +} + +static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) +{ + struct rtable *orig, *prev, **p; + bool ret = true; + + if (rt_is_input_route(rt)) { + p = (struct rtable **)&nhc->nhc_rth_input; + } else { + p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); + } + orig = *p; + + /* hold dst before doing cmpxchg() to avoid race condition + * on this dst + */ + dst_hold(&rt->dst); + prev = cmpxchg(p, orig, rt); + if (prev == orig) { + if (orig) { + rt_add_uncached_list(orig); + dst_release(&orig->dst); + } + } else { + dst_release(&rt->dst); + ret = false; + } + + return ret; +} + +struct uncached_list { + spinlock_t lock; + struct list_head head; +}; + +static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); + +void rt_add_uncached_list(struct rtable *rt) +{ + struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); + + rt->rt_uncached_list = ul; + + spin_lock_bh(&ul->lock); + list_add_tail(&rt->rt_uncached, &ul->head); + spin_unlock_bh(&ul->lock); +} + +void rt_del_uncached_list(struct rtable *rt) +{ + if (!list_empty(&rt->rt_uncached)) { + struct uncached_list *ul = rt->rt_uncached_list; + + spin_lock_bh(&ul->lock); + list_del(&rt->rt_uncached); + spin_unlock_bh(&ul->lock); + } +} + +static void ipv4_dst_destroy(struct dst_entry *dst) +{ + struct rtable *rt = (struct rtable *)dst; + + ip_dst_metrics_put(dst); + rt_del_uncached_list(rt); +} + +void rt_flush_dev(struct net_device *dev) +{ + struct rtable *rt; + int cpu; + + for_each_possible_cpu(cpu) { + struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); + + spin_lock_bh(&ul->lock); + list_for_each_entry(rt, &ul->head, rt_uncached) { + if (rt->dst.dev != dev) + continue; + rt->dst.dev = blackhole_netdev; + dev_hold(rt->dst.dev); + dev_put(dev); + } + spin_unlock_bh(&ul->lock); + } +} + +static bool rt_cache_valid(const struct rtable *rt) +{ + return rt && + rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && + !rt_is_expired(rt); +} + +static void rt_set_nexthop(struct rtable *rt, __be32 daddr, + const struct fib_result *res, + struct fib_nh_exception *fnhe, + struct fib_info *fi, u16 type, u32 itag, + const bool do_cache) +{ + bool cached = false; + + if (fi) { + struct fib_nh_common *nhc = FIB_RES_NHC(*res); + + if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { + rt->rt_uses_gateway = 1; + rt->rt_gw_family = nhc->nhc_gw_family; + /* only INET and INET6 are supported */ + if (likely(nhc->nhc_gw_family == AF_INET)) + rt->rt_gw4 = nhc->nhc_gw.ipv4; + else + rt->rt_gw6 = nhc->nhc_gw.ipv6; + } + + ip_dst_init_metrics(&rt->dst, fi->fib_metrics); + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (nhc->nhc_family == AF_INET) { + struct fib_nh *nh; + + nh = container_of(nhc, struct fib_nh, nh_common); + rt->dst.tclassid = nh->nh_tclassid; + } +#endif + rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); + if (unlikely(fnhe)) + cached = rt_bind_exception(rt, fnhe, daddr, do_cache); + else if (do_cache) + cached = rt_cache_route(nhc, rt); + if (unlikely(!cached)) { + /* Routes we intend to cache in nexthop exception or + * FIB nexthop have the DST_NOCACHE bit clear. + * However, if we are unsuccessful at storing this + * route into the cache we really need to set it. + */ + if (!rt->rt_gw4) { + rt->rt_gw_family = AF_INET; + rt->rt_gw4 = daddr; + } + rt_add_uncached_list(rt); + } + } else + rt_add_uncached_list(rt); + +#ifdef CONFIG_IP_ROUTE_CLASSID +#ifdef CONFIG_IP_MULTIPLE_TABLES + set_class_tag(rt, res->tclassid); +#endif + set_class_tag(rt, itag); +#endif +} + +struct rtable *rt_dst_alloc(struct net_device *dev, + unsigned int flags, u16 type, + bool nopolicy, bool noxfrm) +{ + struct rtable *rt; + + rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, + (nopolicy ? DST_NOPOLICY : 0) | + (noxfrm ? DST_NOXFRM : 0)); + + if (rt) { + rt->rt_genid = rt_genid_ipv4(dev_net(dev)); + rt->rt_flags = flags; + rt->rt_type = type; + rt->rt_is_input = 0; + rt->rt_iif = 0; + rt->rt_pmtu = 0; + rt->rt_mtu_locked = 0; + rt->rt_uses_gateway = 0; + rt->rt_gw_family = 0; + rt->rt_gw4 = 0; + INIT_LIST_HEAD(&rt->rt_uncached); + + rt->dst.output = ip_output; + if (flags & RTCF_LOCAL) + rt->dst.input = ip_local_deliver; + } + + return rt; +} +EXPORT_SYMBOL(rt_dst_alloc); + +struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) +{ + struct rtable *new_rt; + + new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, + rt->dst.flags); + + if (new_rt) { + new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); + new_rt->rt_flags = rt->rt_flags; + new_rt->rt_type = rt->rt_type; + new_rt->rt_is_input = rt->rt_is_input; + new_rt->rt_iif = rt->rt_iif; + new_rt->rt_pmtu = rt->rt_pmtu; + new_rt->rt_mtu_locked = rt->rt_mtu_locked; + new_rt->rt_gw_family = rt->rt_gw_family; + if (rt->rt_gw_family == AF_INET) + new_rt->rt_gw4 = rt->rt_gw4; + else if (rt->rt_gw_family == AF_INET6) + new_rt->rt_gw6 = rt->rt_gw6; + INIT_LIST_HEAD(&new_rt->rt_uncached); + + new_rt->dst.input = rt->dst.input; + new_rt->dst.output = rt->dst.output; + new_rt->dst.error = rt->dst.error; + new_rt->dst.lastuse = jiffies; + new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); + } + return new_rt; +} +EXPORT_SYMBOL(rt_dst_clone); + +/* called in rcu_read_lock() section */ +int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev, + struct in_device *in_dev, u32 *itag) +{ + int err; + + /* Primary sanity checks. */ + if (!in_dev) + return -EINVAL; + + if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || + skb->protocol != htons(ETH_P_IP)) + return -EINVAL; + + if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) + return -EINVAL; + + if (ipv4_is_zeronet(saddr)) { + if (!ipv4_is_local_multicast(daddr) && + ip_hdr(skb)->protocol != IPPROTO_IGMP) + return -EINVAL; + } else { + err = fib_validate_source(skb, saddr, 0, tos, 0, dev, + in_dev, itag); + if (err < 0) + return err; + } + return 0; +} + +/* called in rcu_read_lock() section */ +static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev, int our) +{ + struct in_device *in_dev = __in_dev_get_rcu(dev); + unsigned int flags = RTCF_MULTICAST; + struct rtable *rth; + bool no_policy; + u32 itag = 0; + int err; + + err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); + if (err) + return err; + + if (our) + flags |= RTCF_LOCAL; + + no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); + if (no_policy) + IPCB(skb)->flags |= IPSKB_NOPOLICY; + + rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, + no_policy, false); + if (!rth) + return -ENOBUFS; + +#ifdef CONFIG_IP_ROUTE_CLASSID + rth->dst.tclassid = itag; +#endif + rth->dst.output = ip_rt_bug; + rth->rt_is_input= 1; + +#ifdef CONFIG_IP_MROUTE + if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) + rth->dst.input = ip_mr_input; +#endif + RT_CACHE_STAT_INC(in_slow_mc); + + skb_dst_drop(skb); + skb_dst_set(skb, &rth->dst); + return 0; +} + + +static void ip_handle_martian_source(struct net_device *dev, + struct in_device *in_dev, + struct sk_buff *skb, + __be32 daddr, + __be32 saddr) +{ + RT_CACHE_STAT_INC(in_martian_src); +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { + /* + * RFC1812 recommendation, if source is martian, + * the only hint is MAC header. + */ + pr_warn("martian source %pI4 from %pI4, on dev %s\n", + &daddr, &saddr, dev->name); + if (dev->hard_header_len && skb_mac_header_was_set(skb)) { + print_hex_dump(KERN_WARNING, "ll header: ", + DUMP_PREFIX_OFFSET, 16, 1, + skb_mac_header(skb), + dev->hard_header_len, false); + } + } +#endif +} + +/* called in rcu_read_lock() section */ +static int __mkroute_input(struct sk_buff *skb, + const struct fib_result *res, + struct in_device *in_dev, + __be32 daddr, __be32 saddr, u32 tos) +{ + struct fib_nh_common *nhc = FIB_RES_NHC(*res); + struct net_device *dev = nhc->nhc_dev; + struct fib_nh_exception *fnhe; + struct rtable *rth; + int err; + struct in_device *out_dev; + bool do_cache, no_policy; + u32 itag = 0; + + /* get a working reference to the output device */ + out_dev = __in_dev_get_rcu(dev); + if (!out_dev) { + net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); + return -EINVAL; + } + + err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), + in_dev->dev, in_dev, &itag); + if (err < 0) { + ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, + saddr); + + goto cleanup; + } + + do_cache = res->fi && !itag; + if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && + skb->protocol == htons(ETH_P_IP)) { + __be32 gw; + + gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; + if (IN_DEV_SHARED_MEDIA(out_dev) || + inet_addr_onlink(out_dev, saddr, gw)) + IPCB(skb)->flags |= IPSKB_DOREDIRECT; + } + + if (skb->protocol != htons(ETH_P_IP)) { + /* Not IP (i.e. ARP). Do not create route, if it is + * invalid for proxy arp. DNAT routes are always valid. + * + * Proxy arp feature have been extended to allow, ARP + * replies back to the same interface, to support + * Private VLAN switch technologies. See arp.c. + */ + if (out_dev == in_dev && + IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { + err = -EINVAL; + goto cleanup; + } + } + + no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); + if (no_policy) + IPCB(skb)->flags |= IPSKB_NOPOLICY; + + fnhe = find_exception(nhc, daddr); + if (do_cache) { + if (fnhe) + rth = rcu_dereference(fnhe->fnhe_rth_input); + else + rth = rcu_dereference(nhc->nhc_rth_input); + if (rt_cache_valid(rth)) { + skb_dst_set_noref(skb, &rth->dst); + goto out; + } + } + + rth = rt_dst_alloc(out_dev->dev, 0, res->type, no_policy, + IN_DEV_ORCONF(out_dev, NOXFRM)); + if (!rth) { + err = -ENOBUFS; + goto cleanup; + } + + rth->rt_is_input = 1; + RT_CACHE_STAT_INC(in_slow_tot); + + rth->dst.input = ip_forward; + + rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, + do_cache); + lwtunnel_set_redirect(&rth->dst); + skb_dst_set(skb, &rth->dst); +out: + err = 0; + cleanup: + return err; +} + +#ifdef CONFIG_IP_ROUTE_MULTIPATH +/* To make ICMP packets follow the right flow, the multipath hash is + * calculated from the inner IP addresses. + */ +static void ip_multipath_l3_keys(const struct sk_buff *skb, + struct flow_keys *hash_keys) +{ + const struct iphdr *outer_iph = ip_hdr(skb); + const struct iphdr *key_iph = outer_iph; + const struct iphdr *inner_iph; + const struct icmphdr *icmph; + struct iphdr _inner_iph; + struct icmphdr _icmph; + + if (likely(outer_iph->protocol != IPPROTO_ICMP)) + goto out; + + if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) + goto out; + + icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), + &_icmph); + if (!icmph) + goto out; + + if (!icmp_is_err(icmph->type)) + goto out; + + inner_iph = skb_header_pointer(skb, + outer_iph->ihl * 4 + sizeof(_icmph), + sizeof(_inner_iph), &_inner_iph); + if (!inner_iph) + goto out; + + key_iph = inner_iph; +out: + hash_keys->addrs.v4addrs.src = key_iph->saddr; + hash_keys->addrs.v4addrs.dst = key_iph->daddr; +} + +/* if skb is set it will be used and fl4 can be NULL */ +int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, + const struct sk_buff *skb, struct flow_keys *flkeys) +{ + u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; + struct flow_keys hash_keys; + u32 mhash; + + switch (net->ipv4.sysctl_fib_multipath_hash_policy) { + case 0: + memset(&hash_keys, 0, sizeof(hash_keys)); + hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + if (skb) { + ip_multipath_l3_keys(skb, &hash_keys); + } else { + hash_keys.addrs.v4addrs.src = fl4->saddr; + hash_keys.addrs.v4addrs.dst = fl4->daddr; + } + break; + case 1: + /* skb is currently provided only when forwarding */ + if (skb) { + unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; + struct flow_keys keys; + + /* short-circuit if we already have L4 hash present */ + if (skb->l4_hash) + return skb_get_hash_raw(skb) >> 1; + + memset(&hash_keys, 0, sizeof(hash_keys)); + + if (!flkeys) { + skb_flow_dissect_flow_keys(skb, &keys, flag); + flkeys = &keys; + } + + hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; + hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; + hash_keys.ports.src = flkeys->ports.src; + hash_keys.ports.dst = flkeys->ports.dst; + hash_keys.basic.ip_proto = flkeys->basic.ip_proto; + } else { + memset(&hash_keys, 0, sizeof(hash_keys)); + hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + hash_keys.addrs.v4addrs.src = fl4->saddr; + hash_keys.addrs.v4addrs.dst = fl4->daddr; + hash_keys.ports.src = fl4->fl4_sport; + hash_keys.ports.dst = fl4->fl4_dport; + hash_keys.basic.ip_proto = fl4->flowi4_proto; + } + break; + case 2: + memset(&hash_keys, 0, sizeof(hash_keys)); + /* skb is currently provided only when forwarding */ + if (skb) { + struct flow_keys keys; + + skb_flow_dissect_flow_keys(skb, &keys, 0); + /* Inner can be v4 or v6 */ + if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { + hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; + hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; + } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { + hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; + hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; + hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; + hash_keys.tags.flow_label = keys.tags.flow_label; + hash_keys.basic.ip_proto = keys.basic.ip_proto; + } else { + /* Same as case 0 */ + hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + ip_multipath_l3_keys(skb, &hash_keys); + } + } else { + /* Same as case 0 */ + hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; + hash_keys.addrs.v4addrs.src = fl4->saddr; + hash_keys.addrs.v4addrs.dst = fl4->daddr; + } + break; + } + mhash = flow_hash_from_keys(&hash_keys); + + if (multipath_hash) + mhash = jhash_2words(mhash, multipath_hash, 0); + + return mhash >> 1; +} +#endif /* CONFIG_IP_ROUTE_MULTIPATH */ + +static int ip_mkroute_input(struct sk_buff *skb, + struct fib_result *res, + struct in_device *in_dev, + __be32 daddr, __be32 saddr, u32 tos, + struct flow_keys *hkeys) +{ +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (res->fi && fib_info_num_path(res->fi) > 1) { + int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); + + fib_select_multipath(res, h); + IPCB(skb)->flags |= IPSKB_MULTIPATH; + } +#endif + + /* create a routing cache entry */ + return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); +} + +/* Implements all the saddr-related checks as ip_route_input_slow(), + * assuming daddr is valid and the destination is not a local broadcast one. + * Uses the provided hint instead of performing a route lookup. + */ +int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev, + const struct sk_buff *hint) +{ + struct in_device *in_dev = __in_dev_get_rcu(dev); + struct rtable *rt = skb_rtable(hint); + struct net *net = dev_net(dev); + int err = -EINVAL; + u32 tag = 0; + + if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) + goto martian_source; + + if (ipv4_is_zeronet(saddr)) + goto martian_source; + + if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) + goto martian_source; + + if (rt->rt_type != RTN_LOCAL) + goto skip_validate_source; + + tos &= IPTOS_RT_MASK; + err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); + if (err < 0) + goto martian_source; + +skip_validate_source: + skb_dst_copy(skb, hint); + return 0; + +martian_source: + ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); + return err; +} + +/* get device for dst_alloc with local routes */ +static struct net_device *ip_rt_get_dev(struct net *net, + const struct fib_result *res) +{ + struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; + struct net_device *dev = NULL; + + if (nhc) + dev = l3mdev_master_dev_rcu(nhc->nhc_dev); + + return dev ? : net->loopback_dev; +} + +/* + * NOTE. We drop all the packets that has local source + * addresses, because every properly looped back packet + * must have correct destination already attached by output routine. + * Changes in the enforced policies must be applied also to + * ip_route_use_hint(). + * + * Such approach solves two big problems: + * 1. Not simplex devices are handled properly. + * 2. IP spoofing attempts are filtered with 100% of guarantee. + * called with rcu_read_lock() + */ + +static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev, + struct fib_result *res) +{ + struct in_device *in_dev = __in_dev_get_rcu(dev); + struct flow_keys *flkeys = NULL, _flkeys; + struct net *net = dev_net(dev); + struct ip_tunnel_info *tun_info; + int err = -EINVAL; + unsigned int flags = 0; + u32 itag = 0; + struct rtable *rth; + struct flowi4 fl4; + bool do_cache = true; + bool no_policy; + + /* IP on this device is disabled. */ + + if (!in_dev) + goto out; + + /* Check for the most weird martians, which can be not detected + by fib_lookup. + */ + + tun_info = skb_tunnel_info(skb); + if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) + fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; + else + fl4.flowi4_tun_key.tun_id = 0; + skb_dst_drop(skb); + + if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) + goto martian_source; + + res->fi = NULL; + res->table = NULL; + if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) + goto brd_input; + + /* Accept zero addresses only to limited broadcast; + * I even do not know to fix it or not. Waiting for complains :-) + */ + if (ipv4_is_zeronet(saddr)) + goto martian_source; + + if (ipv4_is_zeronet(daddr)) + goto martian_destination; + + /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), + * and call it once if daddr or/and saddr are loopback addresses + */ + if (ipv4_is_loopback(daddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) + goto martian_destination; + } else if (ipv4_is_loopback(saddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) + goto martian_source; + } + + /* + * Now we are ready to route packet. + */ + fl4.flowi4_oif = 0; + fl4.flowi4_iif = dev->ifindex; + fl4.flowi4_mark = skb->mark; + fl4.flowi4_tos = tos; + fl4.flowi4_scope = RT_SCOPE_UNIVERSE; + fl4.flowi4_flags = 0; + fl4.daddr = daddr; + fl4.saddr = saddr; + fl4.flowi4_uid = sock_net_uid(net, NULL); + fl4.flowi4_multipath_hash = 0; + + if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { + flkeys = &_flkeys; + } else { + fl4.flowi4_proto = 0; + fl4.fl4_sport = 0; + fl4.fl4_dport = 0; + } + + err = fib_lookup(net, &fl4, res, 0); + if (err != 0) { + if (!IN_DEV_FORWARD(in_dev)) + err = -EHOSTUNREACH; + goto no_route; + } + + if (res->type == RTN_BROADCAST) { + if (IN_DEV_BFORWARD(in_dev)) + goto make_route; + /* not do cache if bc_forwarding is enabled */ + if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) + do_cache = false; + goto brd_input; + } + + if (res->type == RTN_LOCAL) { + err = fib_validate_source(skb, saddr, daddr, tos, + 0, dev, in_dev, &itag); + if (err < 0) + goto martian_source; + goto local_input; + } + + if (!IN_DEV_FORWARD(in_dev)) { + err = -EHOSTUNREACH; + goto no_route; + } + if (res->type != RTN_UNICAST) + goto martian_destination; + +make_route: + err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); +out: return err; + +brd_input: + if (skb->protocol != htons(ETH_P_IP)) + goto e_inval; + + if (!ipv4_is_zeronet(saddr)) { + err = fib_validate_source(skb, saddr, 0, tos, 0, dev, + in_dev, &itag); + if (err < 0) + goto martian_source; + } + flags |= RTCF_BROADCAST; + res->type = RTN_BROADCAST; + RT_CACHE_STAT_INC(in_brd); + +local_input: + no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); + if (no_policy) + IPCB(skb)->flags |= IPSKB_NOPOLICY; + + do_cache &= res->fi && !itag; + if (do_cache) { + struct fib_nh_common *nhc = FIB_RES_NHC(*res); + + rth = rcu_dereference(nhc->nhc_rth_input); + if (rt_cache_valid(rth)) { + skb_dst_set_noref(skb, &rth->dst); + err = 0; + goto out; + } + } + + rth = rt_dst_alloc(ip_rt_get_dev(net, res), + flags | RTCF_LOCAL, res->type, + no_policy, false); + if (!rth) + goto e_nobufs; + + rth->dst.output= ip_rt_bug; +#ifdef CONFIG_IP_ROUTE_CLASSID + rth->dst.tclassid = itag; +#endif + rth->rt_is_input = 1; + + RT_CACHE_STAT_INC(in_slow_tot); + if (res->type == RTN_UNREACHABLE) { + rth->dst.input= ip_error; + rth->dst.error= -err; + rth->rt_flags &= ~RTCF_LOCAL; + } + + if (do_cache) { + struct fib_nh_common *nhc = FIB_RES_NHC(*res); + + rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); + if (lwtunnel_input_redirect(rth->dst.lwtstate)) { + WARN_ON(rth->dst.input == lwtunnel_input); + rth->dst.lwtstate->orig_input = rth->dst.input; + rth->dst.input = lwtunnel_input; + } + + if (unlikely(!rt_cache_route(nhc, rth))) + rt_add_uncached_list(rth); + } + skb_dst_set(skb, &rth->dst); + err = 0; + goto out; + +no_route: + RT_CACHE_STAT_INC(in_no_route); + res->type = RTN_UNREACHABLE; + res->fi = NULL; + res->table = NULL; + goto local_input; + + /* + * Do not cache martian addresses: they should be logged (RFC1812) + */ +martian_destination: + RT_CACHE_STAT_INC(in_martian_dst); +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (IN_DEV_LOG_MARTIANS(in_dev)) + net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", + &daddr, &saddr, dev->name); +#endif + +e_inval: + err = -EINVAL; + goto out; + +e_nobufs: + err = -ENOBUFS; + goto out; + +martian_source: + ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); + goto out; +} + +int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev) +{ + struct fib_result res; + int err; + + tos &= IPTOS_RT_MASK; + rcu_read_lock(); + err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); + rcu_read_unlock(); + + return err; +} +EXPORT_SYMBOL(ip_route_input_noref); + +/* called with rcu_read_lock held */ +int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev, struct fib_result *res) +{ + /* Multicast recognition logic is moved from route cache to here. + The problem was that too many Ethernet cards have broken/missing + hardware multicast filters :-( As result the host on multicasting + network acquires a lot of useless route cache entries, sort of + SDR messages from all the world. Now we try to get rid of them. + Really, provided software IP multicast filter is organized + reasonably (at least, hashed), it does not result in a slowdown + comparing with route cache reject entries. + Note, that multicast routers are not affected, because + route cache entry is created eventually. + */ + if (ipv4_is_multicast(daddr)) { + struct in_device *in_dev = __in_dev_get_rcu(dev); + int our = 0; + int err = -EINVAL; + + if (!in_dev) + return err; + our = ip_check_mc_rcu(in_dev, daddr, saddr, + ip_hdr(skb)->protocol); + + /* check l3 master if no match yet */ + if (!our && netif_is_l3_slave(dev)) { + struct in_device *l3_in_dev; + + l3_in_dev = __in_dev_get_rcu(skb->dev); + if (l3_in_dev) + our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, + ip_hdr(skb)->protocol); + } + + if (our +#ifdef CONFIG_IP_MROUTE + || + (!ipv4_is_local_multicast(daddr) && + IN_DEV_MFORWARD(in_dev)) +#endif + ) { + err = ip_route_input_mc(skb, daddr, saddr, + tos, dev, our); + } + return err; + } + + return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); +} + +/* called with rcu_read_lock() */ +static struct rtable *__mkroute_output(const struct fib_result *res, + const struct flowi4 *fl4, int orig_oif, + struct net_device *dev_out, + unsigned int flags) +{ + struct fib_info *fi = res->fi; + struct fib_nh_exception *fnhe; + struct in_device *in_dev; + u16 type = res->type; + struct rtable *rth; + bool do_cache; + + in_dev = __in_dev_get_rcu(dev_out); + if (!in_dev) + return ERR_PTR(-EINVAL); + + if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) + if (ipv4_is_loopback(fl4->saddr) && + !(dev_out->flags & IFF_LOOPBACK) && + !netif_is_l3_master(dev_out)) + return ERR_PTR(-EINVAL); + + if (ipv4_is_lbcast(fl4->daddr)) + type = RTN_BROADCAST; + else if (ipv4_is_multicast(fl4->daddr)) + type = RTN_MULTICAST; + else if (ipv4_is_zeronet(fl4->daddr)) + return ERR_PTR(-EINVAL); + + if (dev_out->flags & IFF_LOOPBACK) + flags |= RTCF_LOCAL; + + do_cache = true; + if (type == RTN_BROADCAST) { + flags |= RTCF_BROADCAST | RTCF_LOCAL; + fi = NULL; + } else if (type == RTN_MULTICAST) { + flags |= RTCF_MULTICAST | RTCF_LOCAL; + if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, + fl4->flowi4_proto)) + flags &= ~RTCF_LOCAL; + else + do_cache = false; + /* If multicast route do not exist use + * default one, but do not gateway in this case. + * Yes, it is hack. + */ + if (fi && res->prefixlen < 4) + fi = NULL; + } else if ((type == RTN_LOCAL) && (orig_oif != 0) && + (orig_oif != dev_out->ifindex)) { + /* For local routes that require a particular output interface + * we do not want to cache the result. Caching the result + * causes incorrect behaviour when there are multiple source + * addresses on the interface, the end result being that if the + * intended recipient is waiting on that interface for the + * packet he won't receive it because it will be delivered on + * the loopback interface and the IP_PKTINFO ipi_ifindex will + * be set to the loopback interface as well. + */ + do_cache = false; + } + + fnhe = NULL; + do_cache &= fi != NULL; + if (fi) { + struct fib_nh_common *nhc = FIB_RES_NHC(*res); + struct rtable __rcu **prth; + + fnhe = find_exception(nhc, fl4->daddr); + if (!do_cache) + goto add; + if (fnhe) { + prth = &fnhe->fnhe_rth_output; + } else { + if (unlikely(fl4->flowi4_flags & + FLOWI_FLAG_KNOWN_NH && + !(nhc->nhc_gw_family && + nhc->nhc_scope == RT_SCOPE_LINK))) { + do_cache = false; + goto add; + } + prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); + } + rth = rcu_dereference(*prth); + if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) + return rth; + } + +add: + rth = rt_dst_alloc(dev_out, flags, type, + IN_DEV_ORCONF(in_dev, NOPOLICY), + IN_DEV_ORCONF(in_dev, NOXFRM)); + if (!rth) + return ERR_PTR(-ENOBUFS); + + rth->rt_iif = orig_oif; + + RT_CACHE_STAT_INC(out_slow_tot); + + if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { + if (flags & RTCF_LOCAL && + !(dev_out->flags & IFF_LOOPBACK)) { + rth->dst.output = ip_mc_output; + RT_CACHE_STAT_INC(out_slow_mc); + } +#ifdef CONFIG_IP_MROUTE + if (type == RTN_MULTICAST) { + if (IN_DEV_MFORWARD(in_dev) && + !ipv4_is_local_multicast(fl4->daddr)) { + rth->dst.input = ip_mr_input; + rth->dst.output = ip_mc_output; + } + } +#endif + } + + rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); + lwtunnel_set_redirect(&rth->dst); + + return rth; +} + +/* + * Major route resolver routine. + */ + +struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, + const struct sk_buff *skb) +{ + struct fib_result res = { + .type = RTN_UNSPEC, + .fi = NULL, + .table = NULL, + .tclassid = 0, + }; + struct rtable *rth; + + fl4->flowi4_iif = LOOPBACK_IFINDEX; + ip_rt_fix_tos(fl4); + + rcu_read_lock(); + rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); + rcu_read_unlock(); + + return rth; +} +EXPORT_SYMBOL_GPL(ip_route_output_key_hash); + +struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, + struct fib_result *res, + const struct sk_buff *skb) +{ + struct net_device *dev_out = NULL; + int orig_oif = fl4->flowi4_oif; + unsigned int flags = 0; + struct rtable *rth; + int err; + + if (fl4->saddr) { + if (ipv4_is_multicast(fl4->saddr) || + ipv4_is_lbcast(fl4->saddr) || + ipv4_is_zeronet(fl4->saddr)) { + rth = ERR_PTR(-EINVAL); + goto out; + } + + rth = ERR_PTR(-ENETUNREACH); + + /* I removed check for oif == dev_out->oif here. + It was wrong for two reasons: + 1. ip_dev_find(net, saddr) can return wrong iface, if saddr + is assigned to multiple interfaces. + 2. Moreover, we are allowed to send packets with saddr + of another iface. --ANK + */ + + if (fl4->flowi4_oif == 0 && + (ipv4_is_multicast(fl4->daddr) || + ipv4_is_lbcast(fl4->daddr))) { + /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ + dev_out = __ip_dev_find(net, fl4->saddr, false); + if (!dev_out) + goto out; + + /* Special hack: user can direct multicasts + and limited broadcast via necessary interface + without fiddling with IP_MULTICAST_IF or IP_PKTINFO. + This hack is not just for fun, it allows + vic,vat and friends to work. + They bind socket to loopback, set ttl to zero + and expect that it will work. + From the viewpoint of routing cache they are broken, + because we are not allowed to build multicast path + with loopback source addr (look, routing cache + cannot know, that ttl is zero, so that packet + will not leave this host and route is valid). + Luckily, this hack is good workaround. + */ + + fl4->flowi4_oif = dev_out->ifindex; + goto make_route; + } + + if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { + /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ + if (!__ip_dev_find(net, fl4->saddr, false)) + goto out; + } + } + + + if (fl4->flowi4_oif) { + dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); + rth = ERR_PTR(-ENODEV); + if (!dev_out) + goto out; + + /* RACE: Check return value of inet_select_addr instead. */ + if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { + rth = ERR_PTR(-ENETUNREACH); + goto out; + } + if (ipv4_is_local_multicast(fl4->daddr) || + ipv4_is_lbcast(fl4->daddr) || + fl4->flowi4_proto == IPPROTO_IGMP) { + if (!fl4->saddr) + fl4->saddr = inet_select_addr(dev_out, 0, + RT_SCOPE_LINK); + goto make_route; + } + if (!fl4->saddr) { + if (ipv4_is_multicast(fl4->daddr)) + fl4->saddr = inet_select_addr(dev_out, 0, + fl4->flowi4_scope); + else if (!fl4->daddr) + fl4->saddr = inet_select_addr(dev_out, 0, + RT_SCOPE_HOST); + } + } + + if (!fl4->daddr) { + fl4->daddr = fl4->saddr; + if (!fl4->daddr) + fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); + dev_out = net->loopback_dev; + fl4->flowi4_oif = LOOPBACK_IFINDEX; + res->type = RTN_LOCAL; + flags |= RTCF_LOCAL; + goto make_route; + } + + err = fib_lookup(net, fl4, res, 0); + if (err) { + res->fi = NULL; + res->table = NULL; + if (fl4->flowi4_oif && + (ipv4_is_multicast(fl4->daddr) || + !netif_index_is_l3_master(net, fl4->flowi4_oif))) { + /* Apparently, routing tables are wrong. Assume, + that the destination is on link. + + WHY? DW. + Because we are allowed to send to iface + even if it has NO routes and NO assigned + addresses. When oif is specified, routing + tables are looked up with only one purpose: + to catch if destination is gatewayed, rather than + direct. Moreover, if MSG_DONTROUTE is set, + we send packet, ignoring both routing tables + and ifaddr state. --ANK + + + We could make it even if oif is unknown, + likely IPv6, but we do not. + */ + + if (fl4->saddr == 0) + fl4->saddr = inet_select_addr(dev_out, 0, + RT_SCOPE_LINK); + res->type = RTN_UNICAST; + goto make_route; + } + rth = ERR_PTR(err); + goto out; + } + + if (res->type == RTN_LOCAL) { + if (!fl4->saddr) { + if (res->fi->fib_prefsrc) + fl4->saddr = res->fi->fib_prefsrc; + else + fl4->saddr = fl4->daddr; + } + + /* L3 master device is the loopback for that domain */ + dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : + net->loopback_dev; + + /* make sure orig_oif points to fib result device even + * though packet rx/tx happens over loopback or l3mdev + */ + orig_oif = FIB_RES_OIF(*res); + + fl4->flowi4_oif = dev_out->ifindex; + flags |= RTCF_LOCAL; + goto make_route; + } + + fib_select_path(net, res, fl4, skb); + + dev_out = FIB_RES_DEV(*res); + +make_route: + rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); + +out: + return rth; +} + +static struct dst_ops ipv4_dst_blackhole_ops = { + .family = AF_INET, + .default_advmss = ipv4_default_advmss, + .neigh_lookup = ipv4_neigh_lookup, + .check = dst_blackhole_check, + .cow_metrics = dst_blackhole_cow_metrics, + .update_pmtu = dst_blackhole_update_pmtu, + .redirect = dst_blackhole_redirect, + .mtu = dst_blackhole_mtu, +}; + +struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) +{ + struct rtable *ort = (struct rtable *) dst_orig; + struct rtable *rt; + + rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); + if (rt) { + struct dst_entry *new = &rt->dst; + + new->__use = 1; + new->input = dst_discard; + new->output = dst_discard_out; + + new->dev = net->loopback_dev; + if (new->dev) + dev_hold(new->dev); + + rt->rt_is_input = ort->rt_is_input; + rt->rt_iif = ort->rt_iif; + rt->rt_pmtu = ort->rt_pmtu; + rt->rt_mtu_locked = ort->rt_mtu_locked; + + rt->rt_genid = rt_genid_ipv4(net); + rt->rt_flags = ort->rt_flags; + rt->rt_type = ort->rt_type; + rt->rt_uses_gateway = ort->rt_uses_gateway; + rt->rt_gw_family = ort->rt_gw_family; + if (rt->rt_gw_family == AF_INET) + rt->rt_gw4 = ort->rt_gw4; + else if (rt->rt_gw_family == AF_INET6) + rt->rt_gw6 = ort->rt_gw6; + + INIT_LIST_HEAD(&rt->rt_uncached); + } + + dst_release(dst_orig); + + return rt ? &rt->dst : ERR_PTR(-ENOMEM); +} + +struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, + const struct sock *sk) +{ + struct rtable *rt = __ip_route_output_key(net, flp4); + + if (IS_ERR(rt)) + return rt; + + if (flp4->flowi4_proto) { + flp4->flowi4_oif = rt->dst.dev->ifindex; + rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, + flowi4_to_flowi(flp4), + sk, 0); + } + + return rt; +} +EXPORT_SYMBOL_GPL(ip_route_output_flow); + +struct rtable *ip_route_output_tunnel(struct sk_buff *skb, + struct net_device *dev, + struct net *net, __be32 *saddr, + const struct ip_tunnel_info *info, + u8 protocol, bool use_cache) +{ +#ifdef CONFIG_DST_CACHE + struct dst_cache *dst_cache; +#endif + struct rtable *rt = NULL; + struct flowi4 fl4; + __u8 tos; + +#ifdef CONFIG_DST_CACHE + dst_cache = (struct dst_cache *)&info->dst_cache; + if (use_cache) { + rt = dst_cache_get_ip4(dst_cache, saddr); + if (rt) + return rt; + } +#endif + memset(&fl4, 0, sizeof(fl4)); + fl4.flowi4_mark = skb->mark; + fl4.flowi4_proto = protocol; + fl4.daddr = info->key.u.ipv4.dst; + fl4.saddr = info->key.u.ipv4.src; + tos = info->key.tos; + fl4.flowi4_tos = RT_TOS(tos); + + rt = ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) { + netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); + return ERR_PTR(-ENETUNREACH); + } + if (rt->dst.dev == dev) { /* is this necessary? */ + netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); + ip_rt_put(rt); + return ERR_PTR(-ELOOP); + } +#ifdef CONFIG_DST_CACHE + if (use_cache) + dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); +#endif + *saddr = fl4.saddr; + return rt; +} +EXPORT_SYMBOL_GPL(ip_route_output_tunnel); + +/* called with rcu_read_lock held */ +static int rt_fill_info(struct net *net, __be32 dst, __be32 src, + struct rtable *rt, u32 table_id, struct flowi4 *fl4, + struct sk_buff *skb, u32 portid, u32 seq, + unsigned int flags) +{ + struct rtmsg *r; + struct nlmsghdr *nlh; + unsigned long expires = 0; + u32 error; + u32 metrics[RTAX_MAX]; + + nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); + if (!nlh) + return -EMSGSIZE; + + r = nlmsg_data(nlh); + r->rtm_family = AF_INET; + r->rtm_dst_len = 32; + r->rtm_src_len = 0; + r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; + r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; + if (nla_put_u32(skb, RTA_TABLE, table_id)) + goto nla_put_failure; + r->rtm_type = rt->rt_type; + r->rtm_scope = RT_SCOPE_UNIVERSE; + r->rtm_protocol = RTPROT_UNSPEC; + r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; + if (rt->rt_flags & RTCF_NOTIFY) + r->rtm_flags |= RTM_F_NOTIFY; + if (IPCB(skb)->flags & IPSKB_DOREDIRECT) + r->rtm_flags |= RTCF_DOREDIRECT; + + if (nla_put_in_addr(skb, RTA_DST, dst)) + goto nla_put_failure; + if (src) { + r->rtm_src_len = 32; + if (nla_put_in_addr(skb, RTA_SRC, src)) + goto nla_put_failure; + } + if (rt->dst.dev && + nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) + goto nla_put_failure; +#ifdef CONFIG_IP_ROUTE_CLASSID + if (rt->dst.tclassid && + nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) + goto nla_put_failure; +#endif + if (fl4 && !rt_is_input_route(rt) && + fl4->saddr != src) { + if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) + goto nla_put_failure; + } + if (rt->rt_uses_gateway) { + if (rt->rt_gw_family == AF_INET && + nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { + goto nla_put_failure; + } else if (rt->rt_gw_family == AF_INET6) { + int alen = sizeof(struct in6_addr); + struct nlattr *nla; + struct rtvia *via; + + nla = nla_reserve(skb, RTA_VIA, alen + 2); + if (!nla) + goto nla_put_failure; + + via = nla_data(nla); + via->rtvia_family = AF_INET6; + memcpy(via->rtvia_addr, &rt->rt_gw6, alen); + } + } + + expires = rt->dst.expires; + if (expires) { + unsigned long now = jiffies; + + if (time_before(now, expires)) + expires -= now; + else + expires = 0; + } + + memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); + if (rt->rt_pmtu && expires) + metrics[RTAX_MTU - 1] = rt->rt_pmtu; + if (rt->rt_mtu_locked && expires) + metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); + if (rtnetlink_put_metrics(skb, metrics) < 0) + goto nla_put_failure; + + if (fl4) { + if (fl4->flowi4_mark && + nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) + goto nla_put_failure; + + if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && + nla_put_u32(skb, RTA_UID, + from_kuid_munged(current_user_ns(), + fl4->flowi4_uid))) + goto nla_put_failure; + + if (rt_is_input_route(rt)) { +#ifdef CONFIG_IP_MROUTE + if (ipv4_is_multicast(dst) && + !ipv4_is_local_multicast(dst) && + IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { + int err = ipmr_get_route(net, skb, + fl4->saddr, fl4->daddr, + r, portid); + + if (err <= 0) { + if (err == 0) + return 0; + goto nla_put_failure; + } + } else +#endif + if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) + goto nla_put_failure; + } + } + + error = rt->dst.error; + + if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) + goto nla_put_failure; + + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, + struct netlink_callback *cb, u32 table_id, + struct fnhe_hash_bucket *bucket, int genid, + int *fa_index, int fa_start, unsigned int flags) +{ + int i; + + for (i = 0; i < FNHE_HASH_SIZE; i++) { + struct fib_nh_exception *fnhe; + + for (fnhe = rcu_dereference(bucket[i].chain); fnhe; + fnhe = rcu_dereference(fnhe->fnhe_next)) { + struct rtable *rt; + int err; + + if (*fa_index < fa_start) + goto next; + + if (fnhe->fnhe_genid != genid) + goto next; + + if (fnhe->fnhe_expires && + time_after(jiffies, fnhe->fnhe_expires)) + goto next; + + rt = rcu_dereference(fnhe->fnhe_rth_input); + if (!rt) + rt = rcu_dereference(fnhe->fnhe_rth_output); + if (!rt) + goto next; + + err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, + table_id, NULL, skb, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, flags); + if (err) + return err; +next: + (*fa_index)++; + } + } + + return 0; +} + +int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, + u32 table_id, struct fib_info *fi, + int *fa_index, int fa_start, unsigned int flags) +{ + struct net *net = sock_net(cb->skb->sk); + int nhsel, genid = fnhe_genid(net); + + for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { + struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); + struct fnhe_hash_bucket *bucket; + int err; + + if (nhc->nhc_flags & RTNH_F_DEAD) + continue; + + rcu_read_lock(); + bucket = rcu_dereference(nhc->nhc_exceptions); + err = 0; + if (bucket) + err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, + genid, fa_index, fa_start, + flags); + rcu_read_unlock(); + if (err) + return err; + } + + return 0; +} + +static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, + u8 ip_proto, __be16 sport, + __be16 dport) +{ + struct sk_buff *skb; + struct iphdr *iph; + + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb) + return NULL; + + /* Reserve room for dummy headers, this skb can pass + * through good chunk of routing engine. + */ + skb_reset_mac_header(skb); + skb_reset_network_header(skb); + skb->protocol = htons(ETH_P_IP); + iph = skb_put(skb, sizeof(struct iphdr)); + iph->protocol = ip_proto; + iph->saddr = src; + iph->daddr = dst; + iph->version = 0x4; + iph->frag_off = 0; + iph->ihl = 0x5; + skb_set_transport_header(skb, skb->len); + + switch (iph->protocol) { + case IPPROTO_UDP: { + struct udphdr *udph; + + udph = skb_put_zero(skb, sizeof(struct udphdr)); + udph->source = sport; + udph->dest = dport; + udph->len = htons(sizeof(struct udphdr)); + udph->check = 0; + break; + } + case IPPROTO_TCP: { + struct tcphdr *tcph; + + tcph = skb_put_zero(skb, sizeof(struct tcphdr)); + tcph->source = sport; + tcph->dest = dport; + tcph->doff = sizeof(struct tcphdr) / 4; + tcph->rst = 1; + tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), + src, dst, 0); + break; + } + case IPPROTO_ICMP: { + struct icmphdr *icmph; + + icmph = skb_put_zero(skb, sizeof(struct icmphdr)); + icmph->type = ICMP_ECHO; + icmph->code = 0; + } + } + + return skb; +} + +static int inet_rtm_valid_getroute_req(struct sk_buff *skb, + const struct nlmsghdr *nlh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + struct rtmsg *rtm; + int i, err; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { + NL_SET_ERR_MSG(extack, + "ipv4: Invalid header for route get request"); + return -EINVAL; + } + + if (!netlink_strict_get_check(skb)) + return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv4_policy, extack); + + rtm = nlmsg_data(nlh); + if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || + (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || + rtm->rtm_table || rtm->rtm_protocol || + rtm->rtm_scope || rtm->rtm_type) { + NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); + return -EINVAL; + } + + if (rtm->rtm_flags & ~(RTM_F_NOTIFY | + RTM_F_LOOKUP_TABLE | + RTM_F_FIB_MATCH)) { + NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); + return -EINVAL; + } + + err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv4_policy, extack); + if (err) + return err; + + if ((tb[RTA_SRC] && !rtm->rtm_src_len) || + (tb[RTA_DST] && !rtm->rtm_dst_len)) { + NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); + return -EINVAL; + } + + for (i = 0; i <= RTA_MAX; i++) { + if (!tb[i]) + continue; + + switch (i) { + case RTA_IIF: + case RTA_OIF: + case RTA_SRC: + case RTA_DST: + case RTA_IP_PROTO: + case RTA_SPORT: + case RTA_DPORT: + case RTA_MARK: + case RTA_UID: + break; + default: + NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); + return -EINVAL; + } + } + + return 0; +} + +static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(in_skb->sk); + struct nlattr *tb[RTA_MAX+1]; + u32 table_id = RT_TABLE_MAIN; + __be16 sport = 0, dport = 0; + struct fib_result res = {}; + u8 ip_proto = IPPROTO_UDP; + struct rtable *rt = NULL; + struct sk_buff *skb; + struct rtmsg *rtm; + struct flowi4 fl4 = {}; + __be32 dst = 0; + __be32 src = 0; + kuid_t uid; + u32 iif; + int err; + int mark; + + err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); + if (err < 0) + return err; + + rtm = nlmsg_data(nlh); + src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; + dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; + iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; + mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; + if (tb[RTA_UID]) + uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); + else + uid = (iif ? INVALID_UID : current_uid()); + + if (tb[RTA_IP_PROTO]) { + err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], + &ip_proto, AF_INET, extack); + if (err) + return err; + } + + if (tb[RTA_SPORT]) + sport = nla_get_be16(tb[RTA_SPORT]); + + if (tb[RTA_DPORT]) + dport = nla_get_be16(tb[RTA_DPORT]); + + skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); + if (!skb) + return -ENOBUFS; + + fl4.daddr = dst; + fl4.saddr = src; + fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; + fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; + fl4.flowi4_mark = mark; + fl4.flowi4_uid = uid; + if (sport) + fl4.fl4_sport = sport; + if (dport) + fl4.fl4_dport = dport; + fl4.flowi4_proto = ip_proto; + + rcu_read_lock(); + + if (iif) { + struct net_device *dev; + + dev = dev_get_by_index_rcu(net, iif); + if (!dev) { + err = -ENODEV; + goto errout_rcu; + } + + fl4.flowi4_iif = iif; /* for rt_fill_info */ + skb->dev = dev; + skb->mark = mark; + err = ip_route_input_rcu(skb, dst, src, + rtm->rtm_tos & IPTOS_RT_MASK, dev, + &res); + + rt = skb_rtable(skb); + if (err == 0 && rt->dst.error) + err = -rt->dst.error; + } else { + fl4.flowi4_iif = LOOPBACK_IFINDEX; + skb->dev = net->loopback_dev; + rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); + err = 0; + if (IS_ERR(rt)) + err = PTR_ERR(rt); + else + skb_dst_set(skb, &rt->dst); + } + + if (err) + goto errout_rcu; + + if (rtm->rtm_flags & RTM_F_NOTIFY) + rt->rt_flags |= RTCF_NOTIFY; + + if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) + table_id = res.table ? res.table->tb_id : 0; + + /* reset skb for netlink reply msg */ + skb_trim(skb, 0); + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + skb_reset_mac_header(skb); + + if (rtm->rtm_flags & RTM_F_FIB_MATCH) { + struct fib_rt_info fri; + + if (!res.fi) { + err = fib_props[res.type].error; + if (!err) + err = -EHOSTUNREACH; + goto errout_rcu; + } + fri.fi = res.fi; + fri.tb_id = table_id; + fri.dst = res.prefix; + fri.dst_len = res.prefixlen; + fri.tos = fl4.flowi4_tos; + fri.type = rt->rt_type; + fri.offload = 0; + fri.trap = 0; + if (res.fa_head) { + struct fib_alias *fa; + + hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { + u8 slen = 32 - fri.dst_len; + + if (fa->fa_slen == slen && + fa->tb_id == fri.tb_id && + fa->fa_tos == fri.tos && + fa->fa_info == res.fi && + fa->fa_type == fri.type) { + fri.offload = fa->offload; + fri.trap = fa->trap; + break; + } + } + } + err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, + nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); + } else { + err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, + NETLINK_CB(in_skb).portid, + nlh->nlmsg_seq, 0); + } + if (err < 0) + goto errout_rcu; + + rcu_read_unlock(); + + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); + +errout_free: + return err; +errout_rcu: + rcu_read_unlock(); + kfree_skb(skb); + goto errout_free; +} + +void ip_rt_multicast_event(struct in_device *in_dev) +{ + rt_cache_flush(dev_net(in_dev->dev)); +} + +#ifdef CONFIG_SYSCTL +static int ip_rt_gc_interval __read_mostly = 60 * HZ; +static int ip_rt_gc_min_interval __read_mostly = HZ / 2; +static int ip_rt_gc_elasticity __read_mostly = 8; +static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; + +static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct net *net = (struct net *)__ctl->extra1; + + if (write) { + rt_cache_flush(net); + fnhe_genid_bump(net); + return 0; + } + + return -EINVAL; +} + +static struct ctl_table ipv4_route_table[] = { + { + .procname = "gc_thresh", + .data = &ipv4_dst_ops.gc_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "max_size", + .data = &ip_rt_max_size, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + /* Deprecated. Use gc_min_interval_ms */ + + .procname = "gc_min_interval", + .data = &ip_rt_gc_min_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "gc_min_interval_ms", + .data = &ip_rt_gc_min_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_ms_jiffies, + }, + { + .procname = "gc_timeout", + .data = &ip_rt_gc_timeout, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "gc_interval", + .data = &ip_rt_gc_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "redirect_load", + .data = &ip_rt_redirect_load, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "redirect_number", + .data = &ip_rt_redirect_number, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "redirect_silence", + .data = &ip_rt_redirect_silence, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "error_cost", + .data = &ip_rt_error_cost, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "error_burst", + .data = &ip_rt_error_burst, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "gc_elasticity", + .data = &ip_rt_gc_elasticity, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "mtu_expires", + .data = &ip_rt_mtu_expires, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "min_pmtu", + .data = &ip_rt_min_pmtu, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &ip_min_valid_pmtu, + }, + { + .procname = "min_adv_mss", + .data = &ip_rt_min_advmss, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static const char ipv4_route_flush_procname[] = "flush"; + +static struct ctl_table ipv4_route_flush_table[] = { + { + .procname = ipv4_route_flush_procname, + .maxlen = sizeof(int), + .mode = 0200, + .proc_handler = ipv4_sysctl_rtcache_flush, + }, + { }, +}; + +static __net_init int sysctl_route_net_init(struct net *net) +{ + struct ctl_table *tbl; + + tbl = ipv4_route_flush_table; + if (!net_eq(net, &init_net)) { + tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); + if (!tbl) + goto err_dup; + + /* Don't export non-whitelisted sysctls to unprivileged users */ + if (net->user_ns != &init_user_ns) { + if (tbl[0].procname != ipv4_route_flush_procname) + tbl[0].procname = NULL; + } + } + tbl[0].extra1 = net; + + net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); + if (!net->ipv4.route_hdr) + goto err_reg; + return 0; + +err_reg: + if (tbl != ipv4_route_flush_table) + kfree(tbl); +err_dup: + return -ENOMEM; +} + +static __net_exit void sysctl_route_net_exit(struct net *net) +{ + struct ctl_table *tbl; + + tbl = net->ipv4.route_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->ipv4.route_hdr); + BUG_ON(tbl == ipv4_route_flush_table); + kfree(tbl); +} + +static __net_initdata struct pernet_operations sysctl_route_ops = { + .init = sysctl_route_net_init, + .exit = sysctl_route_net_exit, +}; +#endif + +static __net_init int rt_genid_init(struct net *net) +{ + atomic_set(&net->ipv4.rt_genid, 0); + atomic_set(&net->fnhe_genid, 0); + atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); + return 0; +} + +static __net_initdata struct pernet_operations rt_genid_ops = { + .init = rt_genid_init, +}; + +static int __net_init ipv4_inetpeer_init(struct net *net) +{ + struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); + + if (!bp) + return -ENOMEM; + inet_peer_base_init(bp); + net->ipv4.peers = bp; + return 0; +} + +static void __net_exit ipv4_inetpeer_exit(struct net *net) +{ + struct inet_peer_base *bp = net->ipv4.peers; + + net->ipv4.peers = NULL; + inetpeer_invalidate_tree(bp); + kfree(bp); +} + +static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { + .init = ipv4_inetpeer_init, + .exit = ipv4_inetpeer_exit, +}; + +#ifdef CONFIG_IP_ROUTE_CLASSID +struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; +#endif /* CONFIG_IP_ROUTE_CLASSID */ + +int __init ip_rt_init(void) +{ + void *idents_hash; + int cpu; + + /* For modern hosts, this will use 2 MB of memory */ + idents_hash = alloc_large_system_hash("IP idents", + sizeof(*ip_idents) + sizeof(*ip_tstamps), + 0, + 16, /* one bucket per 64 KB */ + HASH_ZERO, + NULL, + &ip_idents_mask, + 2048, + 256*1024); + + ip_idents = idents_hash; + + prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); + + ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); + + for_each_possible_cpu(cpu) { + struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); + + INIT_LIST_HEAD(&ul->head); + spin_lock_init(&ul->lock); + } +#ifdef CONFIG_IP_ROUTE_CLASSID + ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); + if (!ip_rt_acct) + panic("IP: failed to allocate ip_rt_acct\n"); +#endif + + ipv4_dst_ops.kmem_cachep = + kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, + SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + + ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; + + if (dst_entries_init(&ipv4_dst_ops) < 0) + panic("IP: failed to allocate ipv4_dst_ops counter\n"); + + if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) + panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); + + ipv4_dst_ops.gc_thresh = ~0; + ip_rt_max_size = INT_MAX; + + devinet_init(); + ip_fib_init(); + + if (ip_rt_proc_init()) + pr_err("Unable to create route proc files\n"); +#ifdef CONFIG_XFRM + xfrm_init(); + xfrm4_init(); +#endif + rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, + RTNL_FLAG_DOIT_UNLOCKED); + +#ifdef CONFIG_SYSCTL + register_pernet_subsys(&sysctl_route_ops); +#endif + register_pernet_subsys(&rt_genid_ops); + register_pernet_subsys(&ipv4_inetpeer_ops); + return 0; +} + +#ifdef CONFIG_SYSCTL +/* + * We really need to sanitize the damn ipv4 init order, then all + * this nonsense will go away. + */ +void __init ip_static_sysctl_init(void) +{ + register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); +} +#endif diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c new file mode 100644 index 000000000..cc860f2dc --- /dev/null +++ b/net/ipv4/syncookies.c @@ -0,0 +1,451 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Syncookies implementation for the Linux kernel + * + * Copyright (C) 1997 Andi Kleen + * Based on ideas by D.J.Bernstein and Eric Schenk. + */ + +#include <linux/tcp.h> +#include <linux/slab.h> +#include <linux/random.h> +#include <linux/siphash.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <net/secure_seq.h> +#include <net/tcp.h> +#include <net/route.h> + +static siphash_key_t syncookie_secret[2] __read_mostly; + +#define COOKIEBITS 24 /* Upper bits store count */ +#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1) + +/* TCP Timestamp: 6 lowest bits of timestamp sent in the cookie SYN-ACK + * stores TCP options: + * + * MSB LSB + * | 31 ... 6 | 5 | 4 | 3 2 1 0 | + * | Timestamp | ECN | SACK | WScale | + * + * When we receive a valid cookie-ACK, we look at the echoed tsval (if + * any) to figure out which TCP options we should use for the rebuilt + * connection. + * + * A WScale setting of '0xf' (which is an invalid scaling value) + * means that original syn did not include the TCP window scaling option. + */ +#define TS_OPT_WSCALE_MASK 0xf +#define TS_OPT_SACK BIT(4) +#define TS_OPT_ECN BIT(5) +/* There is no TS_OPT_TIMESTAMP: + * if ACK contains timestamp option, we already know it was + * requested/supported by the syn/synack exchange. + */ +#define TSBITS 6 + +static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport, + u32 count, int c) +{ + net_get_random_once(syncookie_secret, sizeof(syncookie_secret)); + return siphash_4u32((__force u32)saddr, (__force u32)daddr, + (__force u32)sport << 16 | (__force u32)dport, + count, &syncookie_secret[c]); +} + + +/* + * when syncookies are in effect and tcp timestamps are enabled we encode + * tcp options in the lower bits of the timestamp value that will be + * sent in the syn-ack. + * Since subsequent timestamps use the normal tcp_time_stamp value, we + * must make sure that the resulting initial timestamp is <= tcp_time_stamp. + */ +u64 cookie_init_timestamp(struct request_sock *req, u64 now) +{ + const struct inet_request_sock *ireq = inet_rsk(req); + u64 ts, ts_now = tcp_ns_to_ts(now); + u32 options = 0; + + options = ireq->wscale_ok ? ireq->snd_wscale : TS_OPT_WSCALE_MASK; + if (ireq->sack_ok) + options |= TS_OPT_SACK; + if (ireq->ecn_ok) + options |= TS_OPT_ECN; + + ts = (ts_now >> TSBITS) << TSBITS; + ts |= options; + if (ts > ts_now) + ts -= (1UL << TSBITS); + + return ts * (NSEC_PER_SEC / TCP_TS_HZ); +} + + +static __u32 secure_tcp_syn_cookie(__be32 saddr, __be32 daddr, __be16 sport, + __be16 dport, __u32 sseq, __u32 data) +{ + /* + * Compute the secure sequence number. + * The output should be: + * HASH(sec1,saddr,sport,daddr,dport,sec1) + sseq + (count * 2^24) + * + (HASH(sec2,saddr,sport,daddr,dport,count,sec2) % 2^24). + * Where sseq is their sequence number and count increases every + * minute by 1. + * As an extra hack, we add a small "data" value that encodes the + * MSS into the second hash value. + */ + u32 count = tcp_cookie_time(); + return (cookie_hash(saddr, daddr, sport, dport, 0, 0) + + sseq + (count << COOKIEBITS) + + ((cookie_hash(saddr, daddr, sport, dport, count, 1) + data) + & COOKIEMASK)); +} + +/* + * This retrieves the small "data" value from the syncookie. + * If the syncookie is bad, the data returned will be out of + * range. This must be checked by the caller. + * + * The count value used to generate the cookie must be less than + * MAX_SYNCOOKIE_AGE minutes in the past. + * The return value (__u32)-1 if this test fails. + */ +static __u32 check_tcp_syn_cookie(__u32 cookie, __be32 saddr, __be32 daddr, + __be16 sport, __be16 dport, __u32 sseq) +{ + u32 diff, count = tcp_cookie_time(); + + /* Strip away the layers from the cookie */ + cookie -= cookie_hash(saddr, daddr, sport, dport, 0, 0) + sseq; + + /* Cookie is now reduced to (count * 2^24) ^ (hash % 2^24) */ + diff = (count - (cookie >> COOKIEBITS)) & ((__u32) -1 >> COOKIEBITS); + if (diff >= MAX_SYNCOOKIE_AGE) + return (__u32)-1; + + return (cookie - + cookie_hash(saddr, daddr, sport, dport, count - diff, 1)) + & COOKIEMASK; /* Leaving the data behind */ +} + +/* + * MSS Values are chosen based on the 2011 paper + * 'An Analysis of TCP Maximum Segement Sizes' by S. Alcock and R. Nelson. + * Values .. + * .. lower than 536 are rare (< 0.2%) + * .. between 537 and 1299 account for less than < 1.5% of observed values + * .. in the 1300-1349 range account for about 15 to 20% of observed mss values + * .. exceeding 1460 are very rare (< 0.04%) + * + * 1460 is the single most frequently announced mss value (30 to 46% depending + * on monitor location). Table must be sorted. + */ +static __u16 const msstab[] = { + 536, + 1300, + 1440, /* 1440, 1452: PPPoE */ + 1460, +}; + +/* + * Generate a syncookie. mssp points to the mss, which is returned + * rounded down to the value encoded in the cookie. + */ +u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, + u16 *mssp) +{ + int mssind; + const __u16 mss = *mssp; + + for (mssind = ARRAY_SIZE(msstab) - 1; mssind ; mssind--) + if (mss >= msstab[mssind]) + break; + *mssp = msstab[mssind]; + + return secure_tcp_syn_cookie(iph->saddr, iph->daddr, + th->source, th->dest, ntohl(th->seq), + mssind); +} +EXPORT_SYMBOL_GPL(__cookie_v4_init_sequence); + +__u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mssp) +{ + const struct iphdr *iph = ip_hdr(skb); + const struct tcphdr *th = tcp_hdr(skb); + + return __cookie_v4_init_sequence(iph, th, mssp); +} + +/* + * Check if a ack sequence number is a valid syncookie. + * Return the decoded mss if it is, or 0 if not. + */ +int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, + u32 cookie) +{ + __u32 seq = ntohl(th->seq) - 1; + __u32 mssind = check_tcp_syn_cookie(cookie, iph->saddr, iph->daddr, + th->source, th->dest, seq); + + return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0; +} +EXPORT_SYMBOL_GPL(__cookie_v4_check); + +struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst, u32 tsoff) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct sock *child; + bool own_req; + + child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, + NULL, &own_req); + if (child) { + refcount_set(&req->rsk_refcnt, 1); + tcp_sk(child)->tsoffset = tsoff; + sock_rps_save_rxhash(child, skb); + + if (rsk_drop_req(req)) { + reqsk_put(req); + return child; + } + + if (inet_csk_reqsk_queue_add(sk, req, child)) + return child; + + bh_unlock_sock(child); + sock_put(child); + } + __reqsk_free(req); + + return NULL; +} +EXPORT_SYMBOL(tcp_get_cookie_sock); + +/* + * when syncookies are in effect and tcp timestamps are enabled we stored + * additional tcp options in the timestamp. + * This extracts these options from the timestamp echo. + * + * return false if we decode a tcp option that is disabled + * on the host. + */ +bool cookie_timestamp_decode(const struct net *net, + struct tcp_options_received *tcp_opt) +{ + /* echoed timestamp, lowest bits contain options */ + u32 options = tcp_opt->rcv_tsecr; + + if (!tcp_opt->saw_tstamp) { + tcp_clear_options(tcp_opt); + return true; + } + + if (!READ_ONCE(net->ipv4.sysctl_tcp_timestamps)) + return false; + + tcp_opt->sack_ok = (options & TS_OPT_SACK) ? TCP_SACK_SEEN : 0; + + if (tcp_opt->sack_ok && !READ_ONCE(net->ipv4.sysctl_tcp_sack)) + return false; + + if ((options & TS_OPT_WSCALE_MASK) == TS_OPT_WSCALE_MASK) + return true; /* no window scaling */ + + tcp_opt->wscale_ok = 1; + tcp_opt->snd_wscale = options & TS_OPT_WSCALE_MASK; + + return READ_ONCE(net->ipv4.sysctl_tcp_window_scaling) != 0; +} +EXPORT_SYMBOL(cookie_timestamp_decode); + +bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt, + const struct net *net, const struct dst_entry *dst) +{ + bool ecn_ok = tcp_opt->rcv_tsecr & TS_OPT_ECN; + + if (!ecn_ok) + return false; + + if (net->ipv4.sysctl_tcp_ecn) + return true; + + return dst_feature(dst, RTAX_FEATURE_ECN); +} +EXPORT_SYMBOL(cookie_ecn_ok); + +struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, + const struct tcp_request_sock_ops *af_ops, + struct sock *sk, + struct sk_buff *skb) +{ + struct tcp_request_sock *treq; + struct request_sock *req; + + if (sk_is_mptcp(sk)) + req = mptcp_subflow_reqsk_alloc(ops, sk, false); + else + req = inet_reqsk_alloc(ops, sk, false); + + if (!req) + return NULL; + + treq = tcp_rsk(req); + + /* treq->af_specific might be used to perform TCP_MD5 lookup */ + treq->af_specific = af_ops; + + treq->syn_tos = TCP_SKB_CB(skb)->ip_dsfield; +#if IS_ENABLED(CONFIG_MPTCP) + treq->is_mptcp = sk_is_mptcp(sk); + if (treq->is_mptcp) { + int err = mptcp_subflow_init_cookie_req(req, sk, skb); + + if (err) { + reqsk_free(req); + return NULL; + } + } +#endif + + return req; +} +EXPORT_SYMBOL_GPL(cookie_tcp_reqsk_alloc); + +/* On input, sk is a listener. + * Output is listener if incoming packet would not create a child + * NULL if memory could not be allocated. + */ +struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) +{ + struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; + struct tcp_options_received tcp_opt; + struct inet_request_sock *ireq; + struct tcp_request_sock *treq; + struct tcp_sock *tp = tcp_sk(sk); + const struct tcphdr *th = tcp_hdr(skb); + __u32 cookie = ntohl(th->ack_seq) - 1; + struct sock *ret = sk; + struct request_sock *req; + int full_space, mss; + struct rtable *rt; + __u8 rcv_wscale; + struct flowi4 fl4; + u32 tsoff = 0; + + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) || + !th->ack || th->rst) + goto out; + + if (tcp_synq_no_recent_overflow(sk)) + goto out; + + mss = __cookie_v4_check(ip_hdr(skb), th, cookie); + if (mss == 0) { + __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED); + goto out; + } + + __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV); + + /* check for timestamp cookie support */ + memset(&tcp_opt, 0, sizeof(tcp_opt)); + tcp_parse_options(sock_net(sk), skb, &tcp_opt, 0, NULL); + + if (tcp_opt.saw_tstamp && tcp_opt.rcv_tsecr) { + tsoff = secure_tcp_ts_off(sock_net(sk), + ip_hdr(skb)->daddr, + ip_hdr(skb)->saddr); + tcp_opt.rcv_tsecr -= tsoff; + } + + if (!cookie_timestamp_decode(sock_net(sk), &tcp_opt)) + goto out; + + ret = NULL; + req = cookie_tcp_reqsk_alloc(&tcp_request_sock_ops, + &tcp_request_sock_ipv4_ops, sk, skb); + if (!req) + goto out; + + ireq = inet_rsk(req); + treq = tcp_rsk(req); + treq->rcv_isn = ntohl(th->seq) - 1; + treq->snt_isn = cookie; + treq->ts_off = 0; + treq->txhash = net_tx_rndhash(); + req->mss = mss; + ireq->ir_num = ntohs(th->dest); + ireq->ir_rmt_port = th->source; + sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); + sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); + ireq->ir_mark = inet_request_mark(sk, skb); + ireq->snd_wscale = tcp_opt.snd_wscale; + ireq->sack_ok = tcp_opt.sack_ok; + ireq->wscale_ok = tcp_opt.wscale_ok; + ireq->tstamp_ok = tcp_opt.saw_tstamp; + req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0; + treq->snt_synack = 0; + treq->tfo_listener = false; + + if (IS_ENABLED(CONFIG_SMC)) + ireq->smc_ok = 0; + + ireq->ir_iif = inet_request_bound_dev_if(sk, skb); + + /* We throwed the options of the initial SYN away, so we hope + * the ACK carries the same options again (see RFC1122 4.2.3.8) + */ + RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(sock_net(sk), skb)); + + if (security_inet_conn_request(sk, skb, req)) { + reqsk_free(req); + goto out; + } + + req->num_retrans = 0; + + /* + * We need to lookup the route here to get at the correct + * window size. We should better make sure that the window size + * hasn't changed since we received the original syn, but I see + * no easy way to do this. + */ + flowi4_init_output(&fl4, ireq->ir_iif, ireq->ir_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, IPPROTO_TCP, + inet_sk_flowi_flags(sk), + opt->srr ? opt->faddr : ireq->ir_rmt_addr, + ireq->ir_loc_addr, th->source, th->dest, sk->sk_uid); + security_req_classify_flow(req, flowi4_to_flowi_common(&fl4)); + rt = ip_route_output_key(sock_net(sk), &fl4); + if (IS_ERR(rt)) { + reqsk_free(req); + goto out; + } + + /* Try to redo what tcp_v4_send_synack did. */ + req->rsk_window_clamp = tp->window_clamp ? :dst_metric(&rt->dst, RTAX_WINDOW); + /* limit the window selection if the user enforce a smaller rx buffer */ + full_space = tcp_full_space(sk); + if (sk->sk_userlocks & SOCK_RCVBUF_LOCK && + (req->rsk_window_clamp > full_space || req->rsk_window_clamp == 0)) + req->rsk_window_clamp = full_space; + + tcp_select_initial_window(sk, full_space, req->mss, + &req->rsk_rcv_wnd, &req->rsk_window_clamp, + ireq->wscale_ok, &rcv_wscale, + dst_metric(&rt->dst, RTAX_INITRWND)); + + ireq->rcv_wscale = rcv_wscale; + ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, sock_net(sk), &rt->dst); + + ret = tcp_get_cookie_sock(sk, skb, req, &rt->dst, tsoff); + /* ip_queue_xmit() depends on our flow being setup + * Normal sockets get it right from inet_csk_route_child_sock() + */ + if (ret) + inet_sk(ret)->cork.fl.u.ip4 = fl4; +out: return ret; +} diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c new file mode 100644 index 000000000..59ba518a8 --- /dev/null +++ b/net/ipv4/sysctl_net_ipv4.c @@ -0,0 +1,1392 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem. + * + * Begun April 1, 1996, Mike Shaver. + * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS] + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/sysctl.h> +#include <linux/igmp.h> +#include <linux/inetdevice.h> +#include <linux/seqlock.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/nsproxy.h> +#include <linux/swap.h> +#include <net/snmp.h> +#include <net/icmp.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/cipso_ipv4.h> +#include <net/inet_frag.h> +#include <net/ping.h> +#include <net/protocol.h> +#include <net/netevent.h> + +static int two = 2; +static int four = 4; +static int thousand = 1000; +static int tcp_retr1_max = 255; +static int ip_local_port_range_min[] = { 1, 1 }; +static int ip_local_port_range_max[] = { 65535, 65535 }; +static int tcp_adv_win_scale_min = -31; +static int tcp_adv_win_scale_max = 31; +static int tcp_app_win_max = 31; +static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS; +static int tcp_min_snd_mss_max = 65535; +static int ip_privileged_port_min; +static int ip_privileged_port_max = 65535; +static int ip_ttl_min = 1; +static int ip_ttl_max = 255; +static int tcp_syn_retries_min = 1; +static int tcp_syn_retries_max = MAX_TCP_SYNCNT; +static int ip_ping_group_range_min[] = { 0, 0 }; +static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX }; +static int comp_sack_nr_max = 255; +static u32 u32_max_div_HZ = UINT_MAX / HZ; +static int one_day_secs = 24 * 3600; + +/* obsolete */ +static int sysctl_tcp_low_latency __read_mostly; + +/* Update system visible IP port range */ +static void set_local_port_range(struct net *net, int range[2]) +{ + bool same_parity = !((range[0] ^ range[1]) & 1); + + write_seqlock_bh(&net->ipv4.ip_local_ports.lock); + if (same_parity && !net->ipv4.ip_local_ports.warned) { + net->ipv4.ip_local_ports.warned = true; + pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n"); + } + net->ipv4.ip_local_ports.range[0] = range[0]; + net->ipv4.ip_local_ports.range[1] = range[1]; + write_sequnlock_bh(&net->ipv4.ip_local_ports.lock); +} + +/* Validate changes from /proc interface. */ +static int ipv4_local_port_range(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct net *net = + container_of(table->data, struct net, ipv4.ip_local_ports.range); + int ret; + int range[2]; + struct ctl_table tmp = { + .data = &range, + .maxlen = sizeof(range), + .mode = table->mode, + .extra1 = &ip_local_port_range_min, + .extra2 = &ip_local_port_range_max, + }; + + inet_get_local_port_range(net, &range[0], &range[1]); + + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + + if (write && ret == 0) { + /* Ensure that the upper limit is not smaller than the lower, + * and that the lower does not encroach upon the privileged + * port limit. + */ + if ((range[1] < range[0]) || + (range[0] < READ_ONCE(net->ipv4.sysctl_ip_prot_sock))) + ret = -EINVAL; + else + set_local_port_range(net, range); + } + + return ret; +} + +/* Validate changes from /proc interface. */ +static int ipv4_privileged_ports(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct net *net = container_of(table->data, struct net, + ipv4.sysctl_ip_prot_sock); + int ret; + int pports; + int range[2]; + struct ctl_table tmp = { + .data = &pports, + .maxlen = sizeof(pports), + .mode = table->mode, + .extra1 = &ip_privileged_port_min, + .extra2 = &ip_privileged_port_max, + }; + + pports = READ_ONCE(net->ipv4.sysctl_ip_prot_sock); + + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + + if (write && ret == 0) { + inet_get_local_port_range(net, &range[0], &range[1]); + /* Ensure that the local port range doesn't overlap with the + * privileged port range. + */ + if (range[0] < pports) + ret = -EINVAL; + else + WRITE_ONCE(net->ipv4.sysctl_ip_prot_sock, pports); + } + + return ret; +} + +static void inet_get_ping_group_range_table(struct ctl_table *table, kgid_t *low, kgid_t *high) +{ + kgid_t *data = table->data; + struct net *net = + container_of(table->data, struct net, ipv4.ping_group_range.range); + unsigned int seq; + do { + seq = read_seqbegin(&net->ipv4.ping_group_range.lock); + + *low = data[0]; + *high = data[1]; + } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); +} + +/* Update system visible IP port range */ +static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t high) +{ + kgid_t *data = table->data; + struct net *net = + container_of(table->data, struct net, ipv4.ping_group_range.range); + write_seqlock(&net->ipv4.ping_group_range.lock); + data[0] = low; + data[1] = high; + write_sequnlock(&net->ipv4.ping_group_range.lock); +} + +/* Validate changes from /proc interface. */ +static int ipv4_ping_group_range(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct user_namespace *user_ns = current_user_ns(); + int ret; + gid_t urange[2]; + kgid_t low, high; + struct ctl_table tmp = { + .data = &urange, + .maxlen = sizeof(urange), + .mode = table->mode, + .extra1 = &ip_ping_group_range_min, + .extra2 = &ip_ping_group_range_max, + }; + + inet_get_ping_group_range_table(table, &low, &high); + urange[0] = from_kgid_munged(user_ns, low); + urange[1] = from_kgid_munged(user_ns, high); + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + + if (write && ret == 0) { + low = make_kgid(user_ns, urange[0]); + high = make_kgid(user_ns, urange[1]); + if (!gid_valid(low) || !gid_valid(high)) + return -EINVAL; + if (urange[1] < urange[0] || gid_lt(high, low)) { + low = make_kgid(&init_user_ns, 1); + high = make_kgid(&init_user_ns, 0); + } + set_ping_group_range(table, low, high); + } + + return ret; +} + +static int ipv4_fwd_update_priority(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct net *net; + int ret; + + net = container_of(table->data, struct net, + ipv4.sysctl_ip_fwd_update_priority); + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + if (write && ret == 0) + call_netevent_notifiers(NETEVENT_IPV4_FWD_UPDATE_PRIORITY_UPDATE, + net); + + return ret; +} + +static int proc_tcp_congestion_control(struct ctl_table *ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct net *net = container_of(ctl->data, struct net, + ipv4.tcp_congestion_control); + char val[TCP_CA_NAME_MAX]; + struct ctl_table tbl = { + .data = val, + .maxlen = TCP_CA_NAME_MAX, + }; + int ret; + + tcp_get_default_congestion_control(net, val); + + ret = proc_dostring(&tbl, write, buffer, lenp, ppos); + if (write && ret == 0) + ret = tcp_set_default_congestion_control(net, val); + return ret; +} + +static int proc_tcp_available_congestion_control(struct ctl_table *ctl, + int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, }; + int ret; + + tbl.data = kmalloc(tbl.maxlen, GFP_USER); + if (!tbl.data) + return -ENOMEM; + tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX); + ret = proc_dostring(&tbl, write, buffer, lenp, ppos); + kfree(tbl.data); + return ret; +} + +static int proc_allowed_congestion_control(struct ctl_table *ctl, + int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX }; + int ret; + + tbl.data = kmalloc(tbl.maxlen, GFP_USER); + if (!tbl.data) + return -ENOMEM; + + tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen); + ret = proc_dostring(&tbl, write, buffer, lenp, ppos); + if (write && ret == 0) + ret = tcp_set_allowed_congestion_control(tbl.data); + kfree(tbl.data); + return ret; +} + +static int sscanf_key(char *buf, __le32 *key) +{ + u32 user_key[4]; + int i, ret = 0; + + if (sscanf(buf, "%x-%x-%x-%x", user_key, user_key + 1, + user_key + 2, user_key + 3) != 4) { + ret = -EINVAL; + } else { + for (i = 0; i < ARRAY_SIZE(user_key); i++) + key[i] = cpu_to_le32(user_key[i]); + } + pr_debug("proc TFO key set 0x%x-%x-%x-%x <- 0x%s: %u\n", + user_key[0], user_key[1], user_key[2], user_key[3], buf, ret); + + return ret; +} + +static int proc_tcp_fastopen_key(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct net *net = container_of(table->data, struct net, + ipv4.sysctl_tcp_fastopen); + /* maxlen to print the list of keys in hex (*2), with dashes + * separating doublewords and a comma in between keys. + */ + struct ctl_table tbl = { .maxlen = ((TCP_FASTOPEN_KEY_LENGTH * + 2 * TCP_FASTOPEN_KEY_MAX) + + (TCP_FASTOPEN_KEY_MAX * 5)) }; + u32 user_key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u32)]; + __le32 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(__le32)]; + char *backup_data; + int ret, i = 0, off = 0, n_keys; + + tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL); + if (!tbl.data) + return -ENOMEM; + + n_keys = tcp_fastopen_get_cipher(net, NULL, (u64 *)key); + if (!n_keys) { + memset(&key[0], 0, TCP_FASTOPEN_KEY_LENGTH); + n_keys = 1; + } + + for (i = 0; i < n_keys * 4; i++) + user_key[i] = le32_to_cpu(key[i]); + + for (i = 0; i < n_keys; i++) { + off += snprintf(tbl.data + off, tbl.maxlen - off, + "%08x-%08x-%08x-%08x", + user_key[i * 4], + user_key[i * 4 + 1], + user_key[i * 4 + 2], + user_key[i * 4 + 3]); + + if (WARN_ON_ONCE(off >= tbl.maxlen - 1)) + break; + + if (i + 1 < n_keys) + off += snprintf(tbl.data + off, tbl.maxlen - off, ","); + } + + ret = proc_dostring(&tbl, write, buffer, lenp, ppos); + + if (write && ret == 0) { + backup_data = strchr(tbl.data, ','); + if (backup_data) { + *backup_data = '\0'; + backup_data++; + } + if (sscanf_key(tbl.data, key)) { + ret = -EINVAL; + goto bad_key; + } + if (backup_data) { + if (sscanf_key(backup_data, key + 4)) { + ret = -EINVAL; + goto bad_key; + } + } + tcp_fastopen_reset_cipher(net, NULL, key, + backup_data ? key + 4 : NULL); + } + +bad_key: + kfree(tbl.data); + return ret; +} + +static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table, + int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + struct net *net = container_of(table->data, struct net, + ipv4.sysctl_tcp_fastopen_blackhole_timeout); + int ret; + + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + if (write && ret == 0) + atomic_set(&net->ipv4.tfo_active_disable_times, 0); + + return ret; +} + +static int proc_tcp_available_ulp(struct ctl_table *ctl, + int write, void *buffer, size_t *lenp, + loff_t *ppos) +{ + struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, }; + int ret; + + tbl.data = kmalloc(tbl.maxlen, GFP_USER); + if (!tbl.data) + return -ENOMEM; + tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX); + ret = proc_dostring(&tbl, write, buffer, lenp, ppos); + kfree(tbl.data); + + return ret; +} + +#ifdef CONFIG_IP_ROUTE_MULTIPATH +static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write, + void *buffer, size_t *lenp, + loff_t *ppos) +{ + struct net *net = container_of(table->data, struct net, + ipv4.sysctl_fib_multipath_hash_policy); + int ret; + + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + if (write && ret == 0) + call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net); + + return ret; +} +#endif + +static struct ctl_table ipv4_table[] = { + { + .procname = "tcp_max_orphans", + .data = &sysctl_tcp_max_orphans, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "inet_peer_threshold", + .data = &inet_peer_threshold, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "inet_peer_minttl", + .data = &inet_peer_minttl, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "inet_peer_maxttl", + .data = &inet_peer_maxttl, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "tcp_mem", + .maxlen = sizeof(sysctl_tcp_mem), + .data = &sysctl_tcp_mem, + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, + { + .procname = "tcp_low_latency", + .data = &sysctl_tcp_low_latency, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, +#ifdef CONFIG_NETLABEL + { + .procname = "cipso_cache_enable", + .data = &cipso_v4_cache_enabled, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "cipso_cache_bucket_size", + .data = &cipso_v4_cache_bucketsize, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "cipso_rbm_optfmt", + .data = &cipso_v4_rbm_optfmt, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "cipso_rbm_strictvalid", + .data = &cipso_v4_rbm_strictvalid, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, +#endif /* CONFIG_NETLABEL */ + { + .procname = "tcp_available_ulp", + .maxlen = TCP_ULP_BUF_MAX, + .mode = 0444, + .proc_handler = proc_tcp_available_ulp, + }, + { + .procname = "icmp_msgs_per_sec", + .data = &sysctl_icmp_msgs_per_sec, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + }, + { + .procname = "icmp_msgs_burst", + .data = &sysctl_icmp_msgs_burst, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + }, + { + .procname = "udp_mem", + .data = &sysctl_udp_mem, + .maxlen = sizeof(sysctl_udp_mem), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, + { + .procname = "fib_sync_mem", + .data = &sysctl_fib_sync_mem, + .maxlen = sizeof(sysctl_fib_sync_mem), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra1 = &sysctl_fib_sync_mem_min, + .extra2 = &sysctl_fib_sync_mem_max, + }, + { + .procname = "tcp_rx_skb_cache", + .data = &tcp_rx_skb_cache_key.key, + .mode = 0644, + .proc_handler = proc_do_static_key, + }, + { + .procname = "tcp_tx_skb_cache", + .data = &tcp_tx_skb_cache_key.key, + .mode = 0644, + .proc_handler = proc_do_static_key, + }, + { } +}; + +static struct ctl_table ipv4_net_table[] = { + { + .procname = "icmp_echo_ignore_all", + .data = &init_net.ipv4.sysctl_icmp_echo_ignore_all, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "icmp_echo_ignore_broadcasts", + .data = &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "icmp_ignore_bogus_error_responses", + .data = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "icmp_errors_use_inbound_ifaddr", + .data = &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "icmp_ratelimit", + .data = &init_net.ipv4.sysctl_icmp_ratelimit, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_ms_jiffies, + }, + { + .procname = "icmp_ratemask", + .data = &init_net.ipv4.sysctl_icmp_ratemask, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "ping_group_range", + .data = &init_net.ipv4.ping_group_range.range, + .maxlen = sizeof(gid_t)*2, + .mode = 0644, + .proc_handler = ipv4_ping_group_range, + }, +#ifdef CONFIG_NET_L3_MASTER_DEV + { + .procname = "raw_l3mdev_accept", + .data = &init_net.ipv4.sysctl_raw_l3mdev_accept, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +#endif + { + .procname = "tcp_ecn", + .data = &init_net.ipv4.sysctl_tcp_ecn, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_ecn_fallback", + .data = &init_net.ipv4.sysctl_tcp_ecn_fallback, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "ip_dynaddr", + .data = &init_net.ipv4.sysctl_ip_dynaddr, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "ip_early_demux", + .data = &init_net.ipv4.sysctl_ip_early_demux, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "udp_early_demux", + .data = &init_net.ipv4.sysctl_udp_early_demux, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + }, + { + .procname = "tcp_early_demux", + .data = &init_net.ipv4.sysctl_tcp_early_demux, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + }, + { + .procname = "nexthop_compat_mode", + .data = &init_net.ipv4.sysctl_nexthop_compat_mode, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "ip_default_ttl", + .data = &init_net.ipv4.sysctl_ip_default_ttl, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = &ip_ttl_min, + .extra2 = &ip_ttl_max, + }, + { + .procname = "ip_local_port_range", + .maxlen = sizeof(init_net.ipv4.ip_local_ports.range), + .data = &init_net.ipv4.ip_local_ports.range, + .mode = 0644, + .proc_handler = ipv4_local_port_range, + }, + { + .procname = "ip_local_reserved_ports", + .data = &init_net.ipv4.sysctl_local_reserved_ports, + .maxlen = 65536, + .mode = 0644, + .proc_handler = proc_do_large_bitmap, + }, + { + .procname = "ip_no_pmtu_disc", + .data = &init_net.ipv4.sysctl_ip_no_pmtu_disc, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "ip_forward_use_pmtu", + .data = &init_net.ipv4.sysctl_ip_fwd_use_pmtu, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "ip_forward_update_priority", + .data = &init_net.ipv4.sysctl_ip_fwd_update_priority, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = ipv4_fwd_update_priority, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "ip_nonlocal_bind", + .data = &init_net.ipv4.sysctl_ip_nonlocal_bind, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "ip_autobind_reuse", + .data = &init_net.ipv4.sysctl_ip_autobind_reuse, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "fwmark_reflect", + .data = &init_net.ipv4.sysctl_fwmark_reflect, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_fwmark_accept", + .data = &init_net.ipv4.sysctl_tcp_fwmark_accept, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, +#ifdef CONFIG_NET_L3_MASTER_DEV + { + .procname = "tcp_l3mdev_accept", + .data = &init_net.ipv4.sysctl_tcp_l3mdev_accept, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +#endif + { + .procname = "tcp_mtu_probing", + .data = &init_net.ipv4.sysctl_tcp_mtu_probing, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_base_mss", + .data = &init_net.ipv4.sysctl_tcp_base_mss, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "tcp_min_snd_mss", + .data = &init_net.ipv4.sysctl_tcp_min_snd_mss, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &tcp_min_snd_mss_min, + .extra2 = &tcp_min_snd_mss_max, + }, + { + .procname = "tcp_mtu_probe_floor", + .data = &init_net.ipv4.sysctl_tcp_mtu_probe_floor, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &tcp_min_snd_mss_min, + .extra2 = &tcp_min_snd_mss_max, + }, + { + .procname = "tcp_probe_threshold", + .data = &init_net.ipv4.sysctl_tcp_probe_threshold, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "tcp_probe_interval", + .data = &init_net.ipv4.sysctl_tcp_probe_interval, + .maxlen = sizeof(u32), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra2 = &u32_max_div_HZ, + }, + { + .procname = "igmp_link_local_mcast_reports", + .data = &init_net.ipv4.sysctl_igmp_llm_reports, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "igmp_max_memberships", + .data = &init_net.ipv4.sysctl_igmp_max_memberships, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "igmp_max_msf", + .data = &init_net.ipv4.sysctl_igmp_max_msf, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, +#ifdef CONFIG_IP_MULTICAST + { + .procname = "igmp_qrv", + .data = &init_net.ipv4.sysctl_igmp_qrv, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE + }, +#endif + { + .procname = "tcp_congestion_control", + .data = &init_net.ipv4.tcp_congestion_control, + .mode = 0644, + .maxlen = TCP_CA_NAME_MAX, + .proc_handler = proc_tcp_congestion_control, + }, + { + .procname = "tcp_available_congestion_control", + .maxlen = TCP_CA_BUF_MAX, + .mode = 0444, + .proc_handler = proc_tcp_available_congestion_control, + }, + { + .procname = "tcp_allowed_congestion_control", + .maxlen = TCP_CA_BUF_MAX, + .mode = 0644, + .proc_handler = proc_allowed_congestion_control, + }, + { + .procname = "tcp_keepalive_time", + .data = &init_net.ipv4.sysctl_tcp_keepalive_time, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "tcp_keepalive_probes", + .data = &init_net.ipv4.sysctl_tcp_keepalive_probes, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_keepalive_intvl", + .data = &init_net.ipv4.sysctl_tcp_keepalive_intvl, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "tcp_syn_retries", + .data = &init_net.ipv4.sysctl_tcp_syn_retries, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = &tcp_syn_retries_min, + .extra2 = &tcp_syn_retries_max + }, + { + .procname = "tcp_synack_retries", + .data = &init_net.ipv4.sysctl_tcp_synack_retries, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, +#ifdef CONFIG_SYN_COOKIES + { + .procname = "tcp_syncookies", + .data = &init_net.ipv4.sysctl_tcp_syncookies, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, +#endif + { + .procname = "tcp_migrate_req", + .data = &init_net.ipv4.sysctl_tcp_migrate_req, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE + }, + { + .procname = "tcp_reordering", + .data = &init_net.ipv4.sysctl_tcp_reordering, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "tcp_retries1", + .data = &init_net.ipv4.sysctl_tcp_retries1, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra2 = &tcp_retr1_max + }, + { + .procname = "tcp_retries2", + .data = &init_net.ipv4.sysctl_tcp_retries2, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_orphan_retries", + .data = &init_net.ipv4.sysctl_tcp_orphan_retries, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_fin_timeout", + .data = &init_net.ipv4.sysctl_tcp_fin_timeout, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "tcp_notsent_lowat", + .data = &init_net.ipv4.sysctl_tcp_notsent_lowat, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_douintvec, + }, + { + .procname = "tcp_tw_reuse", + .data = &init_net.ipv4.sysctl_tcp_tw_reuse, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &two, + }, + { + .procname = "tcp_max_tw_buckets", + .data = &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "tcp_max_syn_backlog", + .data = &init_net.ipv4.sysctl_max_syn_backlog, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "tcp_fastopen", + .data = &init_net.ipv4.sysctl_tcp_fastopen, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "tcp_fastopen_key", + .mode = 0600, + .data = &init_net.ipv4.sysctl_tcp_fastopen, + /* maxlen to print the list of keys in hex (*2), with dashes + * separating doublewords and a comma in between keys. + */ + .maxlen = ((TCP_FASTOPEN_KEY_LENGTH * + 2 * TCP_FASTOPEN_KEY_MAX) + + (TCP_FASTOPEN_KEY_MAX * 5)), + .proc_handler = proc_tcp_fastopen_key, + }, + { + .procname = "tcp_fastopen_blackhole_timeout_sec", + .data = &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_tfo_blackhole_detect_timeout, + .extra1 = SYSCTL_ZERO, + }, +#ifdef CONFIG_IP_ROUTE_MULTIPATH + { + .procname = "fib_multipath_use_neigh", + .data = &init_net.ipv4.sysctl_fib_multipath_use_neigh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "fib_multipath_hash_policy", + .data = &init_net.ipv4.sysctl_fib_multipath_hash_policy, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_fib_multipath_hash_policy, + .extra1 = SYSCTL_ZERO, + .extra2 = &two, + }, +#endif + { + .procname = "ip_unprivileged_port_start", + .maxlen = sizeof(int), + .data = &init_net.ipv4.sysctl_ip_prot_sock, + .mode = 0644, + .proc_handler = ipv4_privileged_ports, + }, +#ifdef CONFIG_NET_L3_MASTER_DEV + { + .procname = "udp_l3mdev_accept", + .data = &init_net.ipv4.sysctl_udp_l3mdev_accept, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +#endif + { + .procname = "tcp_sack", + .data = &init_net.ipv4.sysctl_tcp_sack, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_window_scaling", + .data = &init_net.ipv4.sysctl_tcp_window_scaling, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_timestamps", + .data = &init_net.ipv4.sysctl_tcp_timestamps, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_early_retrans", + .data = &init_net.ipv4.sysctl_tcp_early_retrans, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &four, + }, + { + .procname = "tcp_recovery", + .data = &init_net.ipv4.sysctl_tcp_recovery, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_thin_linear_timeouts", + .data = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_slow_start_after_idle", + .data = &init_net.ipv4.sysctl_tcp_slow_start_after_idle, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_retrans_collapse", + .data = &init_net.ipv4.sysctl_tcp_retrans_collapse, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_stdurg", + .data = &init_net.ipv4.sysctl_tcp_stdurg, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_rfc1337", + .data = &init_net.ipv4.sysctl_tcp_rfc1337, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_abort_on_overflow", + .data = &init_net.ipv4.sysctl_tcp_abort_on_overflow, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_fack", + .data = &init_net.ipv4.sysctl_tcp_fack, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_max_reordering", + .data = &init_net.ipv4.sysctl_tcp_max_reordering, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "tcp_dsack", + .data = &init_net.ipv4.sysctl_tcp_dsack, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_app_win", + .data = &init_net.ipv4.sysctl_tcp_app_win, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &tcp_app_win_max, + }, + { + .procname = "tcp_adv_win_scale", + .data = &init_net.ipv4.sysctl_tcp_adv_win_scale, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &tcp_adv_win_scale_min, + .extra2 = &tcp_adv_win_scale_max, + }, + { + .procname = "tcp_frto", + .data = &init_net.ipv4.sysctl_tcp_frto, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_no_metrics_save", + .data = &init_net.ipv4.sysctl_tcp_nometrics_save, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_no_ssthresh_metrics_save", + .data = &init_net.ipv4.sysctl_tcp_no_ssthresh_metrics_save, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "tcp_moderate_rcvbuf", + .data = &init_net.ipv4.sysctl_tcp_moderate_rcvbuf, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_tso_win_divisor", + .data = &init_net.ipv4.sysctl_tcp_tso_win_divisor, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_workaround_signed_windows", + .data = &init_net.ipv4.sysctl_tcp_workaround_signed_windows, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + }, + { + .procname = "tcp_limit_output_bytes", + .data = &init_net.ipv4.sysctl_tcp_limit_output_bytes, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "tcp_challenge_ack_limit", + .data = &init_net.ipv4.sysctl_tcp_challenge_ack_limit, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "tcp_min_tso_segs", + .data = &init_net.ipv4.sysctl_tcp_min_tso_segs, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ONE, + }, + { + .procname = "tcp_min_rtt_wlen", + .data = &init_net.ipv4.sysctl_tcp_min_rtt_wlen, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &one_day_secs + }, + { + .procname = "tcp_autocorking", + .data = &init_net.ipv4.sysctl_tcp_autocorking, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "tcp_invalid_ratelimit", + .data = &init_net.ipv4.sysctl_tcp_invalid_ratelimit, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_ms_jiffies, + }, + { + .procname = "tcp_pacing_ss_ratio", + .data = &init_net.ipv4.sysctl_tcp_pacing_ss_ratio, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &thousand, + }, + { + .procname = "tcp_pacing_ca_ratio", + .data = &init_net.ipv4.sysctl_tcp_pacing_ca_ratio, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &thousand, + }, + { + .procname = "tcp_wmem", + .data = &init_net.ipv4.sysctl_tcp_wmem, + .maxlen = sizeof(init_net.ipv4.sysctl_tcp_wmem), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE, + }, + { + .procname = "tcp_rmem", + .data = &init_net.ipv4.sysctl_tcp_rmem, + .maxlen = sizeof(init_net.ipv4.sysctl_tcp_rmem), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE, + }, + { + .procname = "tcp_comp_sack_delay_ns", + .data = &init_net.ipv4.sysctl_tcp_comp_sack_delay_ns, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, + { + .procname = "tcp_comp_sack_slack_ns", + .data = &init_net.ipv4.sysctl_tcp_comp_sack_slack_ns, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + }, + { + .procname = "tcp_comp_sack_nr", + .data = &init_net.ipv4.sysctl_tcp_comp_sack_nr, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &comp_sack_nr_max, + }, + { + .procname = "tcp_reflect_tos", + .data = &init_net.ipv4.sysctl_tcp_reflect_tos, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "udp_rmem_min", + .data = &init_net.ipv4.sysctl_udp_rmem_min, + .maxlen = sizeof(init_net.ipv4.sysctl_udp_rmem_min), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE + }, + { + .procname = "udp_wmem_min", + .data = &init_net.ipv4.sysctl_udp_wmem_min, + .maxlen = sizeof(init_net.ipv4.sysctl_udp_wmem_min), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE + }, + { } +}; + +static __net_init int ipv4_sysctl_init_net(struct net *net) +{ + struct ctl_table *table; + + table = ipv4_net_table; + if (!net_eq(net, &init_net)) { + int i; + + table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL); + if (!table) + goto err_alloc; + + for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) { + if (table[i].data) { + /* Update the variables to point into + * the current struct net + */ + table[i].data += (void *)net - (void *)&init_net; + } else { + /* Entries without data pointer are global; + * Make them read-only in non-init_net ns + */ + table[i].mode &= ~0222; + } + } + } + + net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table); + if (!net->ipv4.ipv4_hdr) + goto err_reg; + + net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL); + if (!net->ipv4.sysctl_local_reserved_ports) + goto err_ports; + + return 0; + +err_ports: + unregister_net_sysctl_table(net->ipv4.ipv4_hdr); +err_reg: + if (!net_eq(net, &init_net)) + kfree(table); +err_alloc: + return -ENOMEM; +} + +static __net_exit void ipv4_sysctl_exit_net(struct net *net) +{ + struct ctl_table *table; + + kfree(net->ipv4.sysctl_local_reserved_ports); + table = net->ipv4.ipv4_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->ipv4.ipv4_hdr); + kfree(table); +} + +static __net_initdata struct pernet_operations ipv4_sysctl_ops = { + .init = ipv4_sysctl_init_net, + .exit = ipv4_sysctl_exit_net, +}; + +static __init int sysctl_ipv4_init(void) +{ + struct ctl_table_header *hdr; + + hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table); + if (!hdr) + return -ENOMEM; + + if (register_pernet_subsys(&ipv4_sysctl_ops)) { + unregister_net_sysctl_table(hdr); + return -ENOMEM; + } + + return 0; +} + +__initcall(sysctl_ipv4_init); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c new file mode 100644 index 000000000..3dd9b76f4 --- /dev/null +++ b/net/ipv4/tcp.c @@ -0,0 +1,4366 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Implementation of the Transmission Control Protocol(TCP). + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * Corey Minyard <wf-rch!minyard@relay.EU.net> + * Florian La Roche, <flla@stud.uni-sb.de> + * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> + * Linus Torvalds, <torvalds@cs.helsinki.fi> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Matthew Dillon, <dillon@apollo.west.oic.com> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Jorge Cwik, <jorge@laser.satlink.net> + * + * Fixes: + * Alan Cox : Numerous verify_area() calls + * Alan Cox : Set the ACK bit on a reset + * Alan Cox : Stopped it crashing if it closed while + * sk->inuse=1 and was trying to connect + * (tcp_err()). + * Alan Cox : All icmp error handling was broken + * pointers passed where wrong and the + * socket was looked up backwards. Nobody + * tested any icmp error code obviously. + * Alan Cox : tcp_err() now handled properly. It + * wakes people on errors. poll + * behaves and the icmp error race + * has gone by moving it into sock.c + * Alan Cox : tcp_send_reset() fixed to work for + * everything not just packets for + * unknown sockets. + * Alan Cox : tcp option processing. + * Alan Cox : Reset tweaked (still not 100%) [Had + * syn rule wrong] + * Herp Rosmanith : More reset fixes + * Alan Cox : No longer acks invalid rst frames. + * Acking any kind of RST is right out. + * Alan Cox : Sets an ignore me flag on an rst + * receive otherwise odd bits of prattle + * escape still + * Alan Cox : Fixed another acking RST frame bug. + * Should stop LAN workplace lockups. + * Alan Cox : Some tidyups using the new skb list + * facilities + * Alan Cox : sk->keepopen now seems to work + * Alan Cox : Pulls options out correctly on accepts + * Alan Cox : Fixed assorted sk->rqueue->next errors + * Alan Cox : PSH doesn't end a TCP read. Switched a + * bit to skb ops. + * Alan Cox : Tidied tcp_data to avoid a potential + * nasty. + * Alan Cox : Added some better commenting, as the + * tcp is hard to follow + * Alan Cox : Removed incorrect check for 20 * psh + * Michael O'Reilly : ack < copied bug fix. + * Johannes Stille : Misc tcp fixes (not all in yet). + * Alan Cox : FIN with no memory -> CRASH + * Alan Cox : Added socket option proto entries. + * Also added awareness of them to accept. + * Alan Cox : Added TCP options (SOL_TCP) + * Alan Cox : Switched wakeup calls to callbacks, + * so the kernel can layer network + * sockets. + * Alan Cox : Use ip_tos/ip_ttl settings. + * Alan Cox : Handle FIN (more) properly (we hope). + * Alan Cox : RST frames sent on unsynchronised + * state ack error. + * Alan Cox : Put in missing check for SYN bit. + * Alan Cox : Added tcp_select_window() aka NET2E + * window non shrink trick. + * Alan Cox : Added a couple of small NET2E timer + * fixes + * Charles Hedrick : TCP fixes + * Toomas Tamm : TCP window fixes + * Alan Cox : Small URG fix to rlogin ^C ack fight + * Charles Hedrick : Rewrote most of it to actually work + * Linus : Rewrote tcp_read() and URG handling + * completely + * Gerhard Koerting: Fixed some missing timer handling + * Matthew Dillon : Reworked TCP machine states as per RFC + * Gerhard Koerting: PC/TCP workarounds + * Adam Caldwell : Assorted timer/timing errors + * Matthew Dillon : Fixed another RST bug + * Alan Cox : Move to kernel side addressing changes. + * Alan Cox : Beginning work on TCP fastpathing + * (not yet usable) + * Arnt Gulbrandsen: Turbocharged tcp_check() routine. + * Alan Cox : TCP fast path debugging + * Alan Cox : Window clamping + * Michael Riepe : Bug in tcp_check() + * Matt Dillon : More TCP improvements and RST bug fixes + * Matt Dillon : Yet more small nasties remove from the + * TCP code (Be very nice to this man if + * tcp finally works 100%) 8) + * Alan Cox : BSD accept semantics. + * Alan Cox : Reset on closedown bug. + * Peter De Schrijver : ENOTCONN check missing in tcp_sendto(). + * Michael Pall : Handle poll() after URG properly in + * all cases. + * Michael Pall : Undo the last fix in tcp_read_urg() + * (multi URG PUSH broke rlogin). + * Michael Pall : Fix the multi URG PUSH problem in + * tcp_readable(), poll() after URG + * works now. + * Michael Pall : recv(...,MSG_OOB) never blocks in the + * BSD api. + * Alan Cox : Changed the semantics of sk->socket to + * fix a race and a signal problem with + * accept() and async I/O. + * Alan Cox : Relaxed the rules on tcp_sendto(). + * Yury Shevchuk : Really fixed accept() blocking problem. + * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for + * clients/servers which listen in on + * fixed ports. + * Alan Cox : Cleaned the above up and shrank it to + * a sensible code size. + * Alan Cox : Self connect lockup fix. + * Alan Cox : No connect to multicast. + * Ross Biro : Close unaccepted children on master + * socket close. + * Alan Cox : Reset tracing code. + * Alan Cox : Spurious resets on shutdown. + * Alan Cox : Giant 15 minute/60 second timer error + * Alan Cox : Small whoops in polling before an + * accept. + * Alan Cox : Kept the state trace facility since + * it's handy for debugging. + * Alan Cox : More reset handler fixes. + * Alan Cox : Started rewriting the code based on + * the RFC's for other useful protocol + * references see: Comer, KA9Q NOS, and + * for a reference on the difference + * between specifications and how BSD + * works see the 4.4lite source. + * A.N.Kuznetsov : Don't time wait on completion of tidy + * close. + * Linus Torvalds : Fin/Shutdown & copied_seq changes. + * Linus Torvalds : Fixed BSD port reuse to work first syn + * Alan Cox : Reimplemented timers as per the RFC + * and using multiple timers for sanity. + * Alan Cox : Small bug fixes, and a lot of new + * comments. + * Alan Cox : Fixed dual reader crash by locking + * the buffers (much like datagram.c) + * Alan Cox : Fixed stuck sockets in probe. A probe + * now gets fed up of retrying without + * (even a no space) answer. + * Alan Cox : Extracted closing code better + * Alan Cox : Fixed the closing state machine to + * resemble the RFC. + * Alan Cox : More 'per spec' fixes. + * Jorge Cwik : Even faster checksumming. + * Alan Cox : tcp_data() doesn't ack illegal PSH + * only frames. At least one pc tcp stack + * generates them. + * Alan Cox : Cache last socket. + * Alan Cox : Per route irtt. + * Matt Day : poll()->select() match BSD precisely on error + * Alan Cox : New buffers + * Marc Tamsky : Various sk->prot->retransmits and + * sk->retransmits misupdating fixed. + * Fixed tcp_write_timeout: stuck close, + * and TCP syn retries gets used now. + * Mark Yarvis : In tcp_read_wakeup(), don't send an + * ack if state is TCP_CLOSED. + * Alan Cox : Look up device on a retransmit - routes may + * change. Doesn't yet cope with MSS shrink right + * but it's a start! + * Marc Tamsky : Closing in closing fixes. + * Mike Shaver : RFC1122 verifications. + * Alan Cox : rcv_saddr errors. + * Alan Cox : Block double connect(). + * Alan Cox : Small hooks for enSKIP. + * Alexey Kuznetsov: Path MTU discovery. + * Alan Cox : Support soft errors. + * Alan Cox : Fix MTU discovery pathological case + * when the remote claims no mtu! + * Marc Tamsky : TCP_CLOSE fix. + * Colin (G3TNE) : Send a reset on syn ack replies in + * window but wrong (fixes NT lpd problems) + * Pedro Roque : Better TCP window handling, delayed ack. + * Joerg Reuter : No modification of locked buffers in + * tcp_do_retransmit() + * Eric Schenk : Changed receiver side silly window + * avoidance algorithm to BSD style + * algorithm. This doubles throughput + * against machines running Solaris, + * and seems to result in general + * improvement. + * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD + * Willy Konynenberg : Transparent proxying support. + * Mike McLagan : Routing by source + * Keith Owens : Do proper merging with partial SKB's in + * tcp_do_sendmsg to avoid burstiness. + * Eric Schenk : Fix fast close down bug with + * shutdown() followed by close(). + * Andi Kleen : Make poll agree with SIGIO + * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and + * lingertime == 0 (RFC 793 ABORT Call) + * Hirokazu Takahashi : Use copy_from_user() instead of + * csum_and_copy_from_user() if possible. + * + * Description of States: + * + * TCP_SYN_SENT sent a connection request, waiting for ack + * + * TCP_SYN_RECV received a connection request, sent ack, + * waiting for final ack in three-way handshake. + * + * TCP_ESTABLISHED connection established + * + * TCP_FIN_WAIT1 our side has shutdown, waiting to complete + * transmission of remaining buffered data + * + * TCP_FIN_WAIT2 all buffered data sent, waiting for remote + * to shutdown + * + * TCP_CLOSING both sides have shutdown but we still have + * data we have to finish sending + * + * TCP_TIME_WAIT timeout to catch resent junk before entering + * closed, can only be entered from FIN_WAIT2 + * or CLOSING. Required because the other end + * may not have gotten our last ACK causing it + * to retransmit the data packet (which we ignore) + * + * TCP_CLOSE_WAIT remote side has shutdown and is waiting for + * us to finish writing our data and to shutdown + * (we have to close() to move on to LAST_ACK) + * + * TCP_LAST_ACK out side has shutdown after remote has + * shutdown. There may still be data in our + * buffer that we have to finish sending + * + * TCP_CLOSE socket is finished + */ + +#define pr_fmt(fmt) "TCP: " fmt + +#include <crypto/hash.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/fcntl.h> +#include <linux/poll.h> +#include <linux/inet_diag.h> +#include <linux/init.h> +#include <linux/fs.h> +#include <linux/skbuff.h> +#include <linux/scatterlist.h> +#include <linux/splice.h> +#include <linux/net.h> +#include <linux/socket.h> +#include <linux/random.h> +#include <linux/memblock.h> +#include <linux/highmem.h> +#include <linux/swap.h> +#include <linux/cache.h> +#include <linux/err.h> +#include <linux/time.h> +#include <linux/slab.h> +#include <linux/errqueue.h> +#include <linux/static_key.h> + +#include <net/icmp.h> +#include <net/inet_common.h> +#include <net/tcp.h> +#include <net/mptcp.h> +#include <net/xfrm.h> +#include <net/ip.h> +#include <net/sock.h> + +#include <linux/uaccess.h> +#include <asm/ioctls.h> +#include <net/busy_poll.h> + +DEFINE_PER_CPU(unsigned int, tcp_orphan_count); +EXPORT_PER_CPU_SYMBOL_GPL(tcp_orphan_count); + +long sysctl_tcp_mem[3] __read_mostly; +EXPORT_SYMBOL(sysctl_tcp_mem); + +atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ +EXPORT_SYMBOL(tcp_memory_allocated); + +#if IS_ENABLED(CONFIG_SMC) +DEFINE_STATIC_KEY_FALSE(tcp_have_smc); +EXPORT_SYMBOL(tcp_have_smc); +#endif + +/* + * Current number of TCP sockets. + */ +struct percpu_counter tcp_sockets_allocated; +EXPORT_SYMBOL(tcp_sockets_allocated); + +/* + * TCP splice context + */ +struct tcp_splice_state { + struct pipe_inode_info *pipe; + size_t len; + unsigned int flags; +}; + +/* + * Pressure flag: try to collapse. + * Technical note: it is used by multiple contexts non atomically. + * All the __sk_mem_schedule() is of this nature: accounting + * is strict, actions are advisory and have some latency. + */ +unsigned long tcp_memory_pressure __read_mostly; +EXPORT_SYMBOL_GPL(tcp_memory_pressure); + +DEFINE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key); +EXPORT_SYMBOL(tcp_rx_skb_cache_key); + +DEFINE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key); + +void tcp_enter_memory_pressure(struct sock *sk) +{ + unsigned long val; + + if (READ_ONCE(tcp_memory_pressure)) + return; + val = jiffies; + + if (!val) + val--; + if (!cmpxchg(&tcp_memory_pressure, 0, val)) + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); +} +EXPORT_SYMBOL_GPL(tcp_enter_memory_pressure); + +void tcp_leave_memory_pressure(struct sock *sk) +{ + unsigned long val; + + if (!READ_ONCE(tcp_memory_pressure)) + return; + val = xchg(&tcp_memory_pressure, 0); + if (val) + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURESCHRONO, + jiffies_to_msecs(jiffies - val)); +} +EXPORT_SYMBOL_GPL(tcp_leave_memory_pressure); + +/* Convert seconds to retransmits based on initial and max timeout */ +static u8 secs_to_retrans(int seconds, int timeout, int rto_max) +{ + u8 res = 0; + + if (seconds > 0) { + int period = timeout; + + res = 1; + while (seconds > period && res < 255) { + res++; + timeout <<= 1; + if (timeout > rto_max) + timeout = rto_max; + period += timeout; + } + } + return res; +} + +/* Convert retransmits to seconds based on initial and max timeout */ +static int retrans_to_secs(u8 retrans, int timeout, int rto_max) +{ + int period = 0; + + if (retrans > 0) { + period = timeout; + while (--retrans) { + timeout <<= 1; + if (timeout > rto_max) + timeout = rto_max; + period += timeout; + } + } + return period; +} + +static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp) +{ + u32 rate = READ_ONCE(tp->rate_delivered); + u32 intv = READ_ONCE(tp->rate_interval_us); + u64 rate64 = 0; + + if (rate && intv) { + rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC; + do_div(rate64, intv); + } + return rate64; +} + +/* Address-family independent initialization for a tcp_sock. + * + * NOTE: A lot of things set to zero explicitly by call to + * sk_alloc() so need not be done here. + */ +void tcp_init_sock(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + + tp->out_of_order_queue = RB_ROOT; + sk->tcp_rtx_queue = RB_ROOT; + tcp_init_xmit_timers(sk); + INIT_LIST_HEAD(&tp->tsq_node); + INIT_LIST_HEAD(&tp->tsorted_sent_queue); + + icsk->icsk_rto = TCP_TIMEOUT_INIT; + icsk->icsk_rto_min = TCP_RTO_MIN; + icsk->icsk_delack_max = TCP_DELACK_MAX; + tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); + minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U); + + /* So many TCP implementations out there (incorrectly) count the + * initial SYN frame in their delayed-ACK and congestion control + * algorithms that we must have the following bandaid to talk + * efficiently to them. -DaveM + */ + tp->snd_cwnd = TCP_INIT_CWND; + + /* There's a bubble in the pipe until at least the first ACK. */ + tp->app_limited = ~0U; + tp->rate_app_limited = 1; + + /* See draft-stevens-tcpca-spec-01 for discussion of the + * initialization of these values. + */ + tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; + tp->snd_cwnd_clamp = ~0; + tp->mss_cache = TCP_MSS_DEFAULT; + + tp->reordering = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reordering); + tcp_assign_congestion_control(sk); + + tp->tsoffset = 0; + tp->rack.reo_wnd_steps = 1; + + sk->sk_write_space = sk_stream_write_space; + sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); + + icsk->icsk_sync_mss = tcp_sync_mss; + + WRITE_ONCE(sk->sk_sndbuf, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[1])); + WRITE_ONCE(sk->sk_rcvbuf, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[1])); + + sk_sockets_allocated_inc(sk); + sk->sk_route_forced_caps = NETIF_F_GSO; +} +EXPORT_SYMBOL(tcp_init_sock); + +static void tcp_tx_timestamp(struct sock *sk, u16 tsflags) +{ + struct sk_buff *skb = tcp_write_queue_tail(sk); + + if (tsflags && skb) { + struct skb_shared_info *shinfo = skb_shinfo(skb); + struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); + + sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags); + if (tsflags & SOF_TIMESTAMPING_TX_ACK) + tcb->txstamp_ack = 1; + if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) + shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; + } +} + +static inline bool tcp_stream_is_readable(const struct tcp_sock *tp, + int target, struct sock *sk) +{ + int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); + + if (avail > 0) { + if (avail >= target) + return true; + if (tcp_rmem_pressure(sk)) + return true; + if (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss) + return true; + } + if (sk->sk_prot->stream_memory_read) + return sk->sk_prot->stream_memory_read(sk); + return false; +} + +/* + * Wait for a TCP event. + * + * Note that we don't need to lock the socket, as the upper poll layers + * take care of normal races (between the test and the event) and we don't + * go look at any of the socket buffers directly. + */ +__poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait) +{ + __poll_t mask; + struct sock *sk = sock->sk; + const struct tcp_sock *tp = tcp_sk(sk); + u8 shutdown; + int state; + + sock_poll_wait(file, sock, wait); + + state = inet_sk_state_load(sk); + if (state == TCP_LISTEN) + return inet_csk_listen_poll(sk); + + /* Socket is not locked. We are protected from async events + * by poll logic and correct handling of state changes + * made by other threads is impossible in any case. + */ + + mask = 0; + + /* + * EPOLLHUP is certainly not done right. But poll() doesn't + * have a notion of HUP in just one direction, and for a + * socket the read side is more interesting. + * + * Some poll() documentation says that EPOLLHUP is incompatible + * with the EPOLLOUT/POLLWR flags, so somebody should check this + * all. But careful, it tends to be safer to return too many + * bits than too few, and you can easily break real applications + * if you don't tell them that something has hung up! + * + * Check-me. + * + * Check number 1. EPOLLHUP is _UNMASKABLE_ event (see UNIX98 and + * our fs/select.c). It means that after we received EOF, + * poll always returns immediately, making impossible poll() on write() + * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP + * if and only if shutdown has been made in both directions. + * Actually, it is interesting to look how Solaris and DUX + * solve this dilemma. I would prefer, if EPOLLHUP were maskable, + * then we could set it on SND_SHUTDOWN. BTW examples given + * in Stevens' books assume exactly this behaviour, it explains + * why EPOLLHUP is incompatible with EPOLLOUT. --ANK + * + * NOTE. Check for TCP_CLOSE is added. The goal is to prevent + * blocking on fresh not-connected or disconnected socket. --ANK + */ + shutdown = READ_ONCE(sk->sk_shutdown); + if (shutdown == SHUTDOWN_MASK || state == TCP_CLOSE) + mask |= EPOLLHUP; + if (shutdown & RCV_SHUTDOWN) + mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; + + /* Connected or passive Fast Open socket? */ + if (state != TCP_SYN_SENT && + (state != TCP_SYN_RECV || rcu_access_pointer(tp->fastopen_rsk))) { + int target = sock_rcvlowat(sk, 0, INT_MAX); + + if (READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq) && + !sock_flag(sk, SOCK_URGINLINE) && + tp->urg_data) + target++; + + if (tcp_stream_is_readable(tp, target, sk)) + mask |= EPOLLIN | EPOLLRDNORM; + + if (!(shutdown & SEND_SHUTDOWN)) { + if (__sk_stream_is_writeable(sk, 1)) { + mask |= EPOLLOUT | EPOLLWRNORM; + } else { /* send SIGIO later */ + sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + + /* Race breaker. If space is freed after + * wspace test but before the flags are set, + * IO signal will be lost. Memory barrier + * pairs with the input side. + */ + smp_mb__after_atomic(); + if (__sk_stream_is_writeable(sk, 1)) + mask |= EPOLLOUT | EPOLLWRNORM; + } + } else + mask |= EPOLLOUT | EPOLLWRNORM; + + if (tp->urg_data & TCP_URG_VALID) + mask |= EPOLLPRI; + } else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) { + /* Active TCP fastopen socket with defer_connect + * Return EPOLLOUT so application can call write() + * in order for kernel to generate SYN+data + */ + mask |= EPOLLOUT | EPOLLWRNORM; + } + /* This barrier is coupled with smp_wmb() in tcp_reset() */ + smp_rmb(); + if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue)) + mask |= EPOLLERR; + + return mask; +} +EXPORT_SYMBOL(tcp_poll); + +int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + struct tcp_sock *tp = tcp_sk(sk); + int answ; + bool slow; + + switch (cmd) { + case SIOCINQ: + if (sk->sk_state == TCP_LISTEN) + return -EINVAL; + + slow = lock_sock_fast(sk); + answ = tcp_inq(sk); + unlock_sock_fast(sk, slow); + break; + case SIOCATMARK: + answ = tp->urg_data && + READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq); + break; + case SIOCOUTQ: + if (sk->sk_state == TCP_LISTEN) + return -EINVAL; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) + answ = 0; + else + answ = READ_ONCE(tp->write_seq) - tp->snd_una; + break; + case SIOCOUTQNSD: + if (sk->sk_state == TCP_LISTEN) + return -EINVAL; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) + answ = 0; + else + answ = READ_ONCE(tp->write_seq) - + READ_ONCE(tp->snd_nxt); + break; + default: + return -ENOIOCTLCMD; + } + + return put_user(answ, (int __user *)arg); +} +EXPORT_SYMBOL(tcp_ioctl); + +static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) +{ + TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; + tp->pushed_seq = tp->write_seq; +} + +static inline bool forced_push(const struct tcp_sock *tp) +{ + return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); +} + +static void skb_entail(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); + + skb->csum = 0; + tcb->seq = tcb->end_seq = tp->write_seq; + tcb->tcp_flags = TCPHDR_ACK; + tcb->sacked = 0; + __skb_header_release(skb); + tcp_add_write_queue_tail(sk, skb); + sk_wmem_queued_add(sk, skb->truesize); + sk_mem_charge(sk, skb->truesize); + if (tp->nonagle & TCP_NAGLE_PUSH) + tp->nonagle &= ~TCP_NAGLE_PUSH; + + tcp_slow_start_after_idle_check(sk); +} + +static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) +{ + if (flags & MSG_OOB) + tp->snd_up = tp->write_seq; +} + +/* If a not yet filled skb is pushed, do not send it if + * we have data packets in Qdisc or NIC queues : + * Because TX completion will happen shortly, it gives a chance + * to coalesce future sendmsg() payload into this skb, without + * need for a timer, and with no latency trade off. + * As packets containing data payload have a bigger truesize + * than pure acks (dataless) packets, the last checks prevent + * autocorking if we only have an ACK in Qdisc/NIC queues, + * or if TX completion was delayed after we processed ACK packet. + */ +static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, + int size_goal) +{ + return skb->len < size_goal && + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_autocorking) && + !tcp_rtx_queue_empty(sk) && + refcount_read(&sk->sk_wmem_alloc) > skb->truesize; +} + +void tcp_push(struct sock *sk, int flags, int mss_now, + int nonagle, int size_goal) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + + skb = tcp_write_queue_tail(sk); + if (!skb) + return; + if (!(flags & MSG_MORE) || forced_push(tp)) + tcp_mark_push(tp, skb); + + tcp_mark_urg(tp, flags); + + if (tcp_should_autocork(sk, skb, size_goal)) { + + /* avoid atomic op if TSQ_THROTTLED bit is already set */ + if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); + set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags); + } + /* It is possible TX completion already happened + * before we set TSQ_THROTTLED. + */ + if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize) + return; + } + + if (flags & MSG_MORE) + nonagle = TCP_NAGLE_CORK; + + __tcp_push_pending_frames(sk, mss_now, nonagle); +} + +static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, + unsigned int offset, size_t len) +{ + struct tcp_splice_state *tss = rd_desc->arg.data; + int ret; + + ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe, + min(rd_desc->count, len), tss->flags); + if (ret > 0) + rd_desc->count -= ret; + return ret; +} + +static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) +{ + /* Store TCP splice context information in read_descriptor_t. */ + read_descriptor_t rd_desc = { + .arg.data = tss, + .count = tss->len, + }; + + return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); +} + +/** + * tcp_splice_read - splice data from TCP socket to a pipe + * @sock: socket to splice from + * @ppos: position (not valid) + * @pipe: pipe to splice to + * @len: number of bytes to splice + * @flags: splice modifier flags + * + * Description: + * Will read pages from given socket and fill them into a pipe. + * + **/ +ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + struct sock *sk = sock->sk; + struct tcp_splice_state tss = { + .pipe = pipe, + .len = len, + .flags = flags, + }; + long timeo; + ssize_t spliced; + int ret; + + sock_rps_record_flow(sk); + /* + * We can't seek on a socket input + */ + if (unlikely(*ppos)) + return -ESPIPE; + + ret = spliced = 0; + + lock_sock(sk); + + timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); + while (tss.len) { + ret = __tcp_splice_read(sk, &tss); + if (ret < 0) + break; + else if (!ret) { + if (spliced) + break; + if (sock_flag(sk, SOCK_DONE)) + break; + if (sk->sk_err) { + ret = sock_error(sk); + break; + } + if (sk->sk_shutdown & RCV_SHUTDOWN) + break; + if (sk->sk_state == TCP_CLOSE) { + /* + * This occurs when user tries to read + * from never connected socket. + */ + ret = -ENOTCONN; + break; + } + if (!timeo) { + ret = -EAGAIN; + break; + } + /* if __tcp_splice_read() got nothing while we have + * an skb in receive queue, we do not want to loop. + * This might happen with URG data. + */ + if (!skb_queue_empty(&sk->sk_receive_queue)) + break; + sk_wait_data(sk, &timeo, NULL); + if (signal_pending(current)) { + ret = sock_intr_errno(timeo); + break; + } + continue; + } + tss.len -= ret; + spliced += ret; + + if (!timeo) + break; + release_sock(sk); + lock_sock(sk); + + if (sk->sk_err || sk->sk_state == TCP_CLOSE || + (sk->sk_shutdown & RCV_SHUTDOWN) || + signal_pending(current)) + break; + } + + release_sock(sk); + + if (spliced) + return spliced; + + return ret; +} +EXPORT_SYMBOL(tcp_splice_read); + +struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, + bool force_schedule) +{ + struct sk_buff *skb; + + if (likely(!size)) { + skb = sk->sk_tx_skb_cache; + if (skb) { + skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); + sk->sk_tx_skb_cache = NULL; + pskb_trim(skb, 0); + INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); + skb_shinfo(skb)->tx_flags = 0; + memset(TCP_SKB_CB(skb), 0, sizeof(struct tcp_skb_cb)); + return skb; + } + } + /* The TCP header must be at least 32-bit aligned. */ + size = ALIGN(size, 4); + + if (unlikely(tcp_under_memory_pressure(sk))) + sk_mem_reclaim_partial(sk); + + skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); + if (likely(skb)) { + bool mem_scheduled; + + if (force_schedule) { + mem_scheduled = true; + sk_forced_mem_schedule(sk, skb->truesize); + } else { + mem_scheduled = sk_wmem_schedule(sk, skb->truesize); + } + if (likely(mem_scheduled)) { + skb_reserve(skb, sk->sk_prot->max_header); + /* + * Make sure that we have exactly size bytes + * available to the caller, no more, no less. + */ + skb->reserved_tailroom = skb->end - skb->tail - size; + INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); + return skb; + } + __kfree_skb(skb); + } else { + sk->sk_prot->enter_memory_pressure(sk); + sk_stream_moderate_sndbuf(sk); + } + return NULL; +} + +static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, + int large_allowed) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 new_size_goal, size_goal; + + if (!large_allowed) + return mss_now; + + /* Note : tcp_tso_autosize() will eventually split this later */ + new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER; + new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal); + + /* We try hard to avoid divides here */ + size_goal = tp->gso_segs * mss_now; + if (unlikely(new_size_goal < size_goal || + new_size_goal >= size_goal + mss_now)) { + tp->gso_segs = min_t(u16, new_size_goal / mss_now, + sk->sk_gso_max_segs); + size_goal = tp->gso_segs * mss_now; + } + + return max(size_goal, mss_now); +} + +int tcp_send_mss(struct sock *sk, int *size_goal, int flags) +{ + int mss_now; + + mss_now = tcp_current_mss(sk); + *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); + + return mss_now; +} + +/* In some cases, both sendpage() and sendmsg() could have added + * an skb to the write queue, but failed adding payload on it. + * We need to remove it to consume less memory, but more + * importantly be able to generate EPOLLOUT for Edge Trigger epoll() + * users. + */ +static void tcp_remove_empty_skb(struct sock *sk, struct sk_buff *skb) +{ + if (skb && TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { + tcp_unlink_write_queue(skb, sk); + if (tcp_write_queue_empty(sk)) + tcp_chrono_stop(sk, TCP_CHRONO_BUSY); + sk_wmem_free_skb(sk, skb); + } +} + +ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, + size_t size, int flags) +{ + struct tcp_sock *tp = tcp_sk(sk); + int mss_now, size_goal; + int err; + ssize_t copied; + long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); + + if (IS_ENABLED(CONFIG_DEBUG_VM) && + WARN_ONCE(!sendpage_ok(page), + "page must not be a Slab one and have page_count > 0")) + return -EINVAL; + + /* Wait for a connection to finish. One exception is TCP Fast Open + * (passive side) where data is allowed to be sent before a connection + * is fully established. + */ + if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && + !tcp_passive_fastopen(sk)) { + err = sk_stream_wait_connect(sk, &timeo); + if (err != 0) + goto out_err; + } + + sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); + + mss_now = tcp_send_mss(sk, &size_goal, flags); + copied = 0; + + err = -EPIPE; + if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) + goto out_err; + + while (size > 0) { + struct sk_buff *skb = tcp_write_queue_tail(sk); + int copy, i; + bool can_coalesce; + + if (!skb || (copy = size_goal - skb->len) <= 0 || + !tcp_skb_can_collapse_to(skb)) { +new_segment: + if (!sk_stream_memory_free(sk)) + goto wait_for_space; + + skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, + tcp_rtx_and_write_queues_empty(sk)); + if (!skb) + goto wait_for_space; + +#ifdef CONFIG_TLS_DEVICE + skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED); +#endif + skb_entail(sk, skb); + copy = size_goal; + } + + if (copy > size) + copy = size; + + i = skb_shinfo(skb)->nr_frags; + can_coalesce = skb_can_coalesce(skb, i, page, offset); + if (!can_coalesce && i >= sysctl_max_skb_frags) { + tcp_mark_push(tp, skb); + goto new_segment; + } + if (!sk_wmem_schedule(sk, copy)) + goto wait_for_space; + + if (can_coalesce) { + skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); + } else { + get_page(page); + skb_fill_page_desc(skb, i, page, offset, copy); + } + + if (!(flags & MSG_NO_SHARED_FRAGS)) + skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; + + skb->len += copy; + skb->data_len += copy; + skb->truesize += copy; + sk_wmem_queued_add(sk, copy); + sk_mem_charge(sk, copy); + skb->ip_summed = CHECKSUM_PARTIAL; + WRITE_ONCE(tp->write_seq, tp->write_seq + copy); + TCP_SKB_CB(skb)->end_seq += copy; + tcp_skb_pcount_set(skb, 0); + + if (!copied) + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; + + copied += copy; + offset += copy; + size -= copy; + if (!size) + goto out; + + if (skb->len < size_goal || (flags & MSG_OOB)) + continue; + + if (forced_push(tp)) { + tcp_mark_push(tp, skb); + __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); + } else if (skb == tcp_send_head(sk)) + tcp_push_one(sk, mss_now); + continue; + +wait_for_space: + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + tcp_push(sk, flags & ~MSG_MORE, mss_now, + TCP_NAGLE_PUSH, size_goal); + + err = sk_stream_wait_memory(sk, &timeo); + if (err != 0) + goto do_error; + + mss_now = tcp_send_mss(sk, &size_goal, flags); + } + +out: + if (copied) { + tcp_tx_timestamp(sk, sk->sk_tsflags); + if (!(flags & MSG_SENDPAGE_NOTLAST)) + tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); + } + return copied; + +do_error: + tcp_remove_empty_skb(sk, tcp_write_queue_tail(sk)); + if (copied) + goto out; +out_err: + /* make sure we wake any epoll edge trigger waiter */ + if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) { + sk->sk_write_space(sk); + tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); + } + return sk_stream_error(sk, flags, err); +} +EXPORT_SYMBOL_GPL(do_tcp_sendpages); + +int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset, + size_t size, int flags) +{ + if (!(sk->sk_route_caps & NETIF_F_SG)) + return sock_no_sendpage_locked(sk, page, offset, size, flags); + + tcp_rate_check_app_limited(sk); /* is sending application-limited? */ + + return do_tcp_sendpages(sk, page, offset, size, flags); +} +EXPORT_SYMBOL_GPL(tcp_sendpage_locked); + +int tcp_sendpage(struct sock *sk, struct page *page, int offset, + size_t size, int flags) +{ + int ret; + + lock_sock(sk); + ret = tcp_sendpage_locked(sk, page, offset, size, flags); + release_sock(sk); + + return ret; +} +EXPORT_SYMBOL(tcp_sendpage); + +void tcp_free_fastopen_req(struct tcp_sock *tp) +{ + if (tp->fastopen_req) { + kfree(tp->fastopen_req); + tp->fastopen_req = NULL; + } +} + +static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, + int *copied, size_t size, + struct ubuf_info *uarg) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_sock *inet = inet_sk(sk); + struct sockaddr *uaddr = msg->msg_name; + int err, flags; + + if (!(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen) & + TFO_CLIENT_ENABLE) || + (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) && + uaddr->sa_family == AF_UNSPEC)) + return -EOPNOTSUPP; + if (tp->fastopen_req) + return -EALREADY; /* Another Fast Open is in progress */ + + tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), + sk->sk_allocation); + if (unlikely(!tp->fastopen_req)) + return -ENOBUFS; + tp->fastopen_req->data = msg; + tp->fastopen_req->size = size; + tp->fastopen_req->uarg = uarg; + + if (inet->defer_connect) { + err = tcp_connect(sk); + /* Same failure procedure as in tcp_v4/6_connect */ + if (err) { + tcp_set_state(sk, TCP_CLOSE); + inet->inet_dport = 0; + sk->sk_route_caps = 0; + } + } + flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; + err = __inet_stream_connect(sk->sk_socket, uaddr, + msg->msg_namelen, flags, 1); + /* fastopen_req could already be freed in __inet_stream_connect + * if the connection times out or gets rst + */ + if (tp->fastopen_req) { + *copied = tp->fastopen_req->copied; + tcp_free_fastopen_req(tp); + inet->defer_connect = 0; + } + return err; +} + +int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct ubuf_info *uarg = NULL; + struct sk_buff *skb; + struct sockcm_cookie sockc; + int flags, err, copied = 0; + int mss_now = 0, size_goal, copied_syn = 0; + int process_backlog = 0; + bool zc = false; + long timeo; + + flags = msg->msg_flags; + + if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) { + skb = tcp_write_queue_tail(sk); + uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb)); + if (!uarg) { + err = -ENOBUFS; + goto out_err; + } + + zc = sk->sk_route_caps & NETIF_F_SG; + if (!zc) + uarg->zerocopy = 0; + } + + if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) && + !tp->repair) { + err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size, uarg); + if (err == -EINPROGRESS && copied_syn > 0) + goto out; + else if (err) + goto out_err; + } + + timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); + + tcp_rate_check_app_limited(sk); /* is sending application-limited? */ + + /* Wait for a connection to finish. One exception is TCP Fast Open + * (passive side) where data is allowed to be sent before a connection + * is fully established. + */ + if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && + !tcp_passive_fastopen(sk)) { + err = sk_stream_wait_connect(sk, &timeo); + if (err != 0) + goto do_error; + } + + if (unlikely(tp->repair)) { + if (tp->repair_queue == TCP_RECV_QUEUE) { + copied = tcp_send_rcvq(sk, msg, size); + goto out_nopush; + } + + err = -EINVAL; + if (tp->repair_queue == TCP_NO_QUEUE) + goto out_err; + + /* 'common' sending to sendq */ + } + + sockcm_init(&sockc, sk); + if (msg->msg_controllen) { + err = sock_cmsg_send(sk, msg, &sockc); + if (unlikely(err)) { + err = -EINVAL; + goto out_err; + } + } + + /* This should be in poll */ + sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); + + /* Ok commence sending. */ + copied = 0; + +restart: + mss_now = tcp_send_mss(sk, &size_goal, flags); + + err = -EPIPE; + if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) + goto do_error; + + while (msg_data_left(msg)) { + int copy = 0; + + skb = tcp_write_queue_tail(sk); + if (skb) + copy = size_goal - skb->len; + + if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) { + bool first_skb; + +new_segment: + if (!sk_stream_memory_free(sk)) + goto wait_for_space; + + if (unlikely(process_backlog >= 16)) { + process_backlog = 0; + if (sk_flush_backlog(sk)) + goto restart; + } + first_skb = tcp_rtx_and_write_queues_empty(sk); + skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, + first_skb); + if (!skb) + goto wait_for_space; + + process_backlog++; + skb->ip_summed = CHECKSUM_PARTIAL; + + skb_entail(sk, skb); + copy = size_goal; + + /* All packets are restored as if they have + * already been sent. skb_mstamp_ns isn't set to + * avoid wrong rtt estimation. + */ + if (tp->repair) + TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED; + } + + /* Try to append data to the end of skb. */ + if (copy > msg_data_left(msg)) + copy = msg_data_left(msg); + + /* Where to copy to? */ + if (skb_availroom(skb) > 0 && !zc) { + /* We have some space in skb head. Superb! */ + copy = min_t(int, copy, skb_availroom(skb)); + err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy); + if (err) + goto do_fault; + } else if (!zc) { + bool merge = true; + int i = skb_shinfo(skb)->nr_frags; + struct page_frag *pfrag = sk_page_frag(sk); + + if (!sk_page_frag_refill(sk, pfrag)) + goto wait_for_space; + + if (!skb_can_coalesce(skb, i, pfrag->page, + pfrag->offset)) { + if (i >= sysctl_max_skb_frags) { + tcp_mark_push(tp, skb); + goto new_segment; + } + merge = false; + } + + copy = min_t(int, copy, pfrag->size - pfrag->offset); + + if (!sk_wmem_schedule(sk, copy)) + goto wait_for_space; + + err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, + pfrag->page, + pfrag->offset, + copy); + if (err) + goto do_error; + + /* Update the skb. */ + if (merge) { + skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); + } else { + skb_fill_page_desc(skb, i, pfrag->page, + pfrag->offset, copy); + page_ref_inc(pfrag->page); + } + pfrag->offset += copy; + } else { + if (!sk_wmem_schedule(sk, copy)) + goto wait_for_space; + + err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg); + if (err == -EMSGSIZE || err == -EEXIST) { + tcp_mark_push(tp, skb); + goto new_segment; + } + if (err < 0) + goto do_error; + copy = err; + } + + if (!copied) + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; + + WRITE_ONCE(tp->write_seq, tp->write_seq + copy); + TCP_SKB_CB(skb)->end_seq += copy; + tcp_skb_pcount_set(skb, 0); + + copied += copy; + if (!msg_data_left(msg)) { + if (unlikely(flags & MSG_EOR)) + TCP_SKB_CB(skb)->eor = 1; + goto out; + } + + if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair)) + continue; + + if (forced_push(tp)) { + tcp_mark_push(tp, skb); + __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); + } else if (skb == tcp_send_head(sk)) + tcp_push_one(sk, mss_now); + continue; + +wait_for_space: + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + if (copied) + tcp_push(sk, flags & ~MSG_MORE, mss_now, + TCP_NAGLE_PUSH, size_goal); + + err = sk_stream_wait_memory(sk, &timeo); + if (err != 0) + goto do_error; + + mss_now = tcp_send_mss(sk, &size_goal, flags); + } + +out: + if (copied) { + tcp_tx_timestamp(sk, sockc.tsflags); + tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); + } +out_nopush: + sock_zerocopy_put(uarg); + return copied + copied_syn; + +do_error: + skb = tcp_write_queue_tail(sk); +do_fault: + tcp_remove_empty_skb(sk, skb); + + if (copied + copied_syn) + goto out; +out_err: + sock_zerocopy_put_abort(uarg, true); + err = sk_stream_error(sk, flags, err); + /* make sure we wake any epoll edge trigger waiter */ + if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) { + sk->sk_write_space(sk); + tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); + } + return err; +} +EXPORT_SYMBOL_GPL(tcp_sendmsg_locked); + +int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) +{ + int ret; + + lock_sock(sk); + ret = tcp_sendmsg_locked(sk, msg, size); + release_sock(sk); + + return ret; +} +EXPORT_SYMBOL(tcp_sendmsg); + +/* + * Handle reading urgent data. BSD has very simple semantics for + * this, no blocking and very strange errors 8) + */ + +static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* No URG data to read. */ + if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || + tp->urg_data == TCP_URG_READ) + return -EINVAL; /* Yes this is right ! */ + + if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) + return -ENOTCONN; + + if (tp->urg_data & TCP_URG_VALID) { + int err = 0; + char c = tp->urg_data; + + if (!(flags & MSG_PEEK)) + tp->urg_data = TCP_URG_READ; + + /* Read urgent data. */ + msg->msg_flags |= MSG_OOB; + + if (len > 0) { + if (!(flags & MSG_TRUNC)) + err = memcpy_to_msg(msg, &c, 1); + len = 1; + } else + msg->msg_flags |= MSG_TRUNC; + + return err ? -EFAULT : len; + } + + if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) + return 0; + + /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and + * the available implementations agree in this case: + * this call should never block, independent of the + * blocking state of the socket. + * Mike <pall@rz.uni-karlsruhe.de> + */ + return -EAGAIN; +} + +static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len) +{ + struct sk_buff *skb; + int copied = 0, err = 0; + + /* XXX -- need to support SO_PEEK_OFF */ + + skb_rbtree_walk(skb, &sk->tcp_rtx_queue) { + err = skb_copy_datagram_msg(skb, 0, msg, skb->len); + if (err) + return err; + copied += skb->len; + } + + skb_queue_walk(&sk->sk_write_queue, skb) { + err = skb_copy_datagram_msg(skb, 0, msg, skb->len); + if (err) + break; + + copied += skb->len; + } + + return err ?: copied; +} + +/* Clean up the receive buffer for full frames taken by the user, + * then send an ACK if necessary. COPIED is the number of bytes + * tcp_recvmsg has given to the user so far, it speeds up the + * calculation of whether or not we must ACK for the sake of + * a window update. + */ +void tcp_cleanup_rbuf(struct sock *sk, int copied) +{ + struct tcp_sock *tp = tcp_sk(sk); + bool time_to_ack = false; + + struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); + + WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), + "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", + tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); + + if (inet_csk_ack_scheduled(sk)) { + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (/* Once-per-two-segments ACK was not sent by tcp_input.c */ + tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || + /* + * If this read emptied read buffer, we send ACK, if + * connection is not bidirectional, user drained + * receive buffer and there was a small segment + * in queue. + */ + (copied > 0 && + ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || + ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && + !inet_csk_in_pingpong_mode(sk))) && + !atomic_read(&sk->sk_rmem_alloc))) + time_to_ack = true; + } + + /* We send an ACK if we can now advertise a non-zero window + * which has been raised "significantly". + * + * Even if window raised up to infinity, do not send window open ACK + * in states, where we will not receive more. It is useless. + */ + if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { + __u32 rcv_window_now = tcp_receive_window(tp); + + /* Optimize, __tcp_select_window() is not cheap. */ + if (2*rcv_window_now <= tp->window_clamp) { + __u32 new_window = __tcp_select_window(sk); + + /* Send ACK now, if this read freed lots of space + * in our buffer. Certainly, new_window is new window. + * We can advertise it now, if it is not less than current one. + * "Lots" means "at least twice" here. + */ + if (new_window && new_window >= 2 * rcv_window_now) + time_to_ack = true; + } + } + if (time_to_ack) + tcp_send_ack(sk); +} + +static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) +{ + struct sk_buff *skb; + u32 offset; + + while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { + offset = seq - TCP_SKB_CB(skb)->seq; + if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { + pr_err_once("%s: found a SYN, please report !\n", __func__); + offset--; + } + if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) { + *off = offset; + return skb; + } + /* This looks weird, but this can happen if TCP collapsing + * splitted a fat GRO packet, while we released socket lock + * in skb_splice_bits() + */ + sk_eat_skb(sk, skb); + } + return NULL; +} + +/* + * This routine provides an alternative to tcp_recvmsg() for routines + * that would like to handle copying from skbuffs directly in 'sendfile' + * fashion. + * Note: + * - It is assumed that the socket was locked by the caller. + * - The routine does not block. + * - At present, there is no support for reading OOB data + * or for 'peeking' the socket using this routine + * (although both would be easy to implement). + */ +int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor) +{ + struct sk_buff *skb; + struct tcp_sock *tp = tcp_sk(sk); + u32 seq = tp->copied_seq; + u32 offset; + int copied = 0; + + if (sk->sk_state == TCP_LISTEN) + return -ENOTCONN; + while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { + if (offset < skb->len) { + int used; + size_t len; + + len = skb->len - offset; + /* Stop reading if we hit a patch of urgent data */ + if (tp->urg_data) { + u32 urg_offset = tp->urg_seq - seq; + if (urg_offset < len) + len = urg_offset; + if (!len) + break; + } + used = recv_actor(desc, skb, offset, len); + if (used <= 0) { + if (!copied) + copied = used; + break; + } + if (WARN_ON_ONCE(used > len)) + used = len; + seq += used; + copied += used; + offset += used; + + /* If recv_actor drops the lock (e.g. TCP splice + * receive) the skb pointer might be invalid when + * getting here: tcp_collapse might have deleted it + * while aggregating skbs from the socket queue. + */ + skb = tcp_recv_skb(sk, seq - 1, &offset); + if (!skb) + break; + /* TCP coalescing might have appended data to the skb. + * Try to splice more frags + */ + if (offset + 1 != skb->len) + continue; + } + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) { + sk_eat_skb(sk, skb); + ++seq; + break; + } + sk_eat_skb(sk, skb); + if (!desc->count) + break; + WRITE_ONCE(tp->copied_seq, seq); + } + WRITE_ONCE(tp->copied_seq, seq); + + tcp_rcv_space_adjust(sk); + + /* Clean up data we have read: This will do ACK frames. */ + if (copied > 0) { + tcp_recv_skb(sk, seq, &offset); + tcp_cleanup_rbuf(sk, copied); + } + return copied; +} +EXPORT_SYMBOL(tcp_read_sock); + +int tcp_peek_len(struct socket *sock) +{ + return tcp_inq(sock->sk); +} +EXPORT_SYMBOL(tcp_peek_len); + +/* Make sure sk_rcvbuf is big enough to satisfy SO_RCVLOWAT hint */ +int tcp_set_rcvlowat(struct sock *sk, int val) +{ + int cap; + + if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) + cap = sk->sk_rcvbuf >> 1; + else + cap = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2]) >> 1; + val = min(val, cap); + WRITE_ONCE(sk->sk_rcvlowat, val ? : 1); + + /* Check if we need to signal EPOLLIN right now */ + tcp_data_ready(sk); + + if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) + return 0; + + val <<= 1; + if (val > sk->sk_rcvbuf) { + WRITE_ONCE(sk->sk_rcvbuf, val); + tcp_sk(sk)->window_clamp = tcp_win_from_space(sk, val); + } + return 0; +} +EXPORT_SYMBOL(tcp_set_rcvlowat); + +#ifdef CONFIG_MMU +static const struct vm_operations_struct tcp_vm_ops = { +}; + +int tcp_mmap(struct file *file, struct socket *sock, + struct vm_area_struct *vma) +{ + if (vma->vm_flags & (VM_WRITE | VM_EXEC)) + return -EPERM; + vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC); + + /* Instruct vm_insert_page() to not mmap_read_lock(mm) */ + vma->vm_flags |= VM_MIXEDMAP; + + vma->vm_ops = &tcp_vm_ops; + return 0; +} +EXPORT_SYMBOL(tcp_mmap); + +static skb_frag_t *skb_advance_to_frag(struct sk_buff *skb, u32 offset_skb, + u32 *offset_frag) +{ + skb_frag_t *frag; + + if (unlikely(offset_skb >= skb->len)) + return NULL; + + offset_skb -= skb_headlen(skb); + if ((int)offset_skb < 0 || skb_has_frag_list(skb)) + return NULL; + + frag = skb_shinfo(skb)->frags; + while (offset_skb) { + if (skb_frag_size(frag) > offset_skb) { + *offset_frag = offset_skb; + return frag; + } + offset_skb -= skb_frag_size(frag); + ++frag; + } + *offset_frag = 0; + return frag; +} + +static int tcp_copy_straggler_data(struct tcp_zerocopy_receive *zc, + struct sk_buff *skb, u32 copylen, + u32 *offset, u32 *seq) +{ + unsigned long copy_address = (unsigned long)zc->copybuf_address; + struct msghdr msg = {}; + struct iovec iov; + int err; + + if (copy_address != zc->copybuf_address) + return -EINVAL; + + err = import_single_range(READ, (void __user *)copy_address, + copylen, &iov, &msg.msg_iter); + if (err) + return err; + err = skb_copy_datagram_msg(skb, *offset, &msg, copylen); + if (err) + return err; + zc->recv_skip_hint -= copylen; + *offset += copylen; + *seq += copylen; + return (__s32)copylen; +} + +static int tcp_zerocopy_handle_leftover_data(struct tcp_zerocopy_receive *zc, + struct sock *sk, + struct sk_buff *skb, + u32 *seq, + s32 copybuf_len) +{ + u32 offset, copylen = min_t(u32, copybuf_len, zc->recv_skip_hint); + + if (!copylen) + return 0; + /* skb is null if inq < PAGE_SIZE. */ + if (skb) + offset = *seq - TCP_SKB_CB(skb)->seq; + else + skb = tcp_recv_skb(sk, *seq, &offset); + + zc->copybuf_len = tcp_copy_straggler_data(zc, skb, copylen, &offset, + seq); + return zc->copybuf_len < 0 ? 0 : copylen; +} + +static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma, + struct page **pages, + unsigned long pages_to_map, + unsigned long *insert_addr, + u32 *length_with_pending, + u32 *seq, + struct tcp_zerocopy_receive *zc) +{ + unsigned long pages_remaining = pages_to_map; + int bytes_mapped; + int ret; + + ret = vm_insert_pages(vma, *insert_addr, pages, &pages_remaining); + bytes_mapped = PAGE_SIZE * (pages_to_map - pages_remaining); + /* Even if vm_insert_pages fails, it may have partially succeeded in + * mapping (some but not all of the pages). + */ + *seq += bytes_mapped; + *insert_addr += bytes_mapped; + if (ret) { + /* But if vm_insert_pages did fail, we have to unroll some state + * we speculatively touched before. + */ + const int bytes_not_mapped = PAGE_SIZE * pages_remaining; + *length_with_pending -= bytes_not_mapped; + zc->recv_skip_hint += bytes_not_mapped; + } + return ret; +} + +static int tcp_zerocopy_receive(struct sock *sk, + struct tcp_zerocopy_receive *zc) +{ + u32 length = 0, offset, vma_len, avail_len, aligned_len, copylen = 0; + unsigned long address = (unsigned long)zc->address; + s32 copybuf_len = zc->copybuf_len; + struct tcp_sock *tp = tcp_sk(sk); + #define PAGE_BATCH_SIZE 8 + struct page *pages[PAGE_BATCH_SIZE]; + const skb_frag_t *frags = NULL; + struct vm_area_struct *vma; + struct sk_buff *skb = NULL; + unsigned long pg_idx = 0; + unsigned long curr_addr; + u32 seq = tp->copied_seq; + int inq = tcp_inq(sk); + int ret; + + zc->copybuf_len = 0; + + if (address & (PAGE_SIZE - 1) || address != zc->address) + return -EINVAL; + + if (sk->sk_state == TCP_LISTEN) + return -ENOTCONN; + + sock_rps_record_flow(sk); + + mmap_read_lock(current->mm); + + vma = find_vma(current->mm, address); + if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops) { + mmap_read_unlock(current->mm); + return -EINVAL; + } + vma_len = min_t(unsigned long, zc->length, vma->vm_end - address); + avail_len = min_t(u32, vma_len, inq); + aligned_len = avail_len & ~(PAGE_SIZE - 1); + if (aligned_len) { + zap_page_range(vma, address, aligned_len); + zc->length = aligned_len; + zc->recv_skip_hint = 0; + } else { + zc->length = avail_len; + zc->recv_skip_hint = avail_len; + } + ret = 0; + curr_addr = address; + while (length + PAGE_SIZE <= zc->length) { + if (zc->recv_skip_hint < PAGE_SIZE) { + u32 offset_frag; + + /* If we're here, finish the current batch. */ + if (pg_idx) { + ret = tcp_zerocopy_vm_insert_batch(vma, pages, + pg_idx, + &curr_addr, + &length, + &seq, zc); + if (ret) + goto out; + pg_idx = 0; + } + if (skb) { + if (zc->recv_skip_hint > 0) + break; + skb = skb->next; + offset = seq - TCP_SKB_CB(skb)->seq; + } else { + skb = tcp_recv_skb(sk, seq, &offset); + } + zc->recv_skip_hint = skb->len - offset; + frags = skb_advance_to_frag(skb, offset, &offset_frag); + if (!frags || offset_frag) + break; + } + if (skb_frag_size(frags) != PAGE_SIZE || skb_frag_off(frags)) { + int remaining = zc->recv_skip_hint; + + while (remaining && (skb_frag_size(frags) != PAGE_SIZE || + skb_frag_off(frags))) { + remaining -= skb_frag_size(frags); + frags++; + } + zc->recv_skip_hint -= remaining; + break; + } + pages[pg_idx] = skb_frag_page(frags); + pg_idx++; + length += PAGE_SIZE; + zc->recv_skip_hint -= PAGE_SIZE; + frags++; + if (pg_idx == PAGE_BATCH_SIZE) { + ret = tcp_zerocopy_vm_insert_batch(vma, pages, pg_idx, + &curr_addr, &length, + &seq, zc); + if (ret) + goto out; + pg_idx = 0; + } + } + if (pg_idx) { + ret = tcp_zerocopy_vm_insert_batch(vma, pages, pg_idx, + &curr_addr, &length, &seq, + zc); + } +out: + mmap_read_unlock(current->mm); + /* Try to copy straggler data. */ + if (!ret) + copylen = tcp_zerocopy_handle_leftover_data(zc, sk, skb, &seq, + copybuf_len); + + if (length + copylen) { + WRITE_ONCE(tp->copied_seq, seq); + tcp_rcv_space_adjust(sk); + + /* Clean up data we have read: This will do ACK frames. */ + tcp_recv_skb(sk, seq, &offset); + tcp_cleanup_rbuf(sk, length + copylen); + ret = 0; + if (length == zc->length) + zc->recv_skip_hint = 0; + } else { + if (!zc->recv_skip_hint && sock_flag(sk, SOCK_DONE)) + ret = -EIO; + } + zc->length = length; + return ret; +} +#endif + +static void tcp_update_recv_tstamps(struct sk_buff *skb, + struct scm_timestamping_internal *tss) +{ + if (skb->tstamp) + tss->ts[0] = ktime_to_timespec64(skb->tstamp); + else + tss->ts[0] = (struct timespec64) {0}; + + if (skb_hwtstamps(skb)->hwtstamp) + tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp); + else + tss->ts[2] = (struct timespec64) {0}; +} + +/* Similar to __sock_recv_timestamp, but does not require an skb */ +static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, + struct scm_timestamping_internal *tss) +{ + int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW); + bool has_timestamping = false; + + if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) { + if (sock_flag(sk, SOCK_RCVTSTAMP)) { + if (sock_flag(sk, SOCK_RCVTSTAMPNS)) { + if (new_tstamp) { + struct __kernel_timespec kts = { + .tv_sec = tss->ts[0].tv_sec, + .tv_nsec = tss->ts[0].tv_nsec, + }; + put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW, + sizeof(kts), &kts); + } else { + struct __kernel_old_timespec ts_old = { + .tv_sec = tss->ts[0].tv_sec, + .tv_nsec = tss->ts[0].tv_nsec, + }; + put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD, + sizeof(ts_old), &ts_old); + } + } else { + if (new_tstamp) { + struct __kernel_sock_timeval stv = { + .tv_sec = tss->ts[0].tv_sec, + .tv_usec = tss->ts[0].tv_nsec / 1000, + }; + put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW, + sizeof(stv), &stv); + } else { + struct __kernel_old_timeval tv = { + .tv_sec = tss->ts[0].tv_sec, + .tv_usec = tss->ts[0].tv_nsec / 1000, + }; + put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD, + sizeof(tv), &tv); + } + } + } + + if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) + has_timestamping = true; + else + tss->ts[0] = (struct timespec64) {0}; + } + + if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) { + if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) + has_timestamping = true; + else + tss->ts[2] = (struct timespec64) {0}; + } + + if (has_timestamping) { + tss->ts[1] = (struct timespec64) {0}; + if (sock_flag(sk, SOCK_TSTAMP_NEW)) + put_cmsg_scm_timestamping64(msg, tss); + else + put_cmsg_scm_timestamping(msg, tss); + } +} + +static int tcp_inq_hint(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + u32 copied_seq = READ_ONCE(tp->copied_seq); + u32 rcv_nxt = READ_ONCE(tp->rcv_nxt); + int inq; + + inq = rcv_nxt - copied_seq; + if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) { + lock_sock(sk); + inq = tp->rcv_nxt - tp->copied_seq; + release_sock(sk); + } + /* After receiving a FIN, tell the user-space to continue reading + * by returning a non-zero inq. + */ + if (inq == 0 && sock_flag(sk, SOCK_DONE)) + inq = 1; + return inq; +} + +/* + * This routine copies from a sock struct into the user buffer. + * + * Technical note: in 2.3 we work on _locked_ socket, so that + * tricks with *seq access order and skb->users are not required. + * Probably, code can be easily improved even more. + */ + +int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, + int flags, int *addr_len) +{ + struct tcp_sock *tp = tcp_sk(sk); + int copied = 0; + u32 peek_seq; + u32 *seq; + unsigned long used; + int err, inq; + int target; /* Read at least this many bytes */ + long timeo; + struct sk_buff *skb, *last; + u32 urg_hole = 0; + struct scm_timestamping_internal tss; + int cmsg_flags; + + if (unlikely(flags & MSG_ERRQUEUE)) + return inet_recv_error(sk, msg, len, addr_len); + + if (sk_can_busy_loop(sk) && skb_queue_empty_lockless(&sk->sk_receive_queue) && + (sk->sk_state == TCP_ESTABLISHED)) + sk_busy_loop(sk, nonblock); + + lock_sock(sk); + + err = -ENOTCONN; + if (sk->sk_state == TCP_LISTEN) + goto out; + + cmsg_flags = tp->recvmsg_inq ? 1 : 0; + timeo = sock_rcvtimeo(sk, nonblock); + + /* Urgent data needs to be handled specially. */ + if (flags & MSG_OOB) + goto recv_urg; + + if (unlikely(tp->repair)) { + err = -EPERM; + if (!(flags & MSG_PEEK)) + goto out; + + if (tp->repair_queue == TCP_SEND_QUEUE) + goto recv_sndq; + + err = -EINVAL; + if (tp->repair_queue == TCP_NO_QUEUE) + goto out; + + /* 'common' recv queue MSG_PEEK-ing */ + } + + seq = &tp->copied_seq; + if (flags & MSG_PEEK) { + peek_seq = tp->copied_seq; + seq = &peek_seq; + } + + target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); + + do { + u32 offset; + + /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ + if (tp->urg_data && tp->urg_seq == *seq) { + if (copied) + break; + if (signal_pending(current)) { + copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; + break; + } + } + + /* Next get a buffer. */ + + last = skb_peek_tail(&sk->sk_receive_queue); + skb_queue_walk(&sk->sk_receive_queue, skb) { + last = skb; + /* Now that we have two receive queues this + * shouldn't happen. + */ + if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), + "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n", + *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, + flags)) + break; + + offset = *seq - TCP_SKB_CB(skb)->seq; + if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { + pr_err_once("%s: found a SYN, please report !\n", __func__); + offset--; + } + if (offset < skb->len) + goto found_ok_skb; + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) + goto found_fin_ok; + WARN(!(flags & MSG_PEEK), + "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n", + *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); + } + + /* Well, if we have backlog, try to process it now yet. */ + + if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) + break; + + if (copied) { + if (sk->sk_err || + sk->sk_state == TCP_CLOSE || + (sk->sk_shutdown & RCV_SHUTDOWN) || + !timeo || + signal_pending(current)) + break; + } else { + if (sock_flag(sk, SOCK_DONE)) + break; + + if (sk->sk_err) { + copied = sock_error(sk); + break; + } + + if (sk->sk_shutdown & RCV_SHUTDOWN) + break; + + if (sk->sk_state == TCP_CLOSE) { + /* This occurs when user tries to read + * from never connected socket. + */ + copied = -ENOTCONN; + break; + } + + if (!timeo) { + copied = -EAGAIN; + break; + } + + if (signal_pending(current)) { + copied = sock_intr_errno(timeo); + break; + } + } + + tcp_cleanup_rbuf(sk, copied); + + if (copied >= target) { + /* Do not sleep, just process backlog. */ + release_sock(sk); + lock_sock(sk); + } else { + sk_wait_data(sk, &timeo, last); + } + + if ((flags & MSG_PEEK) && + (peek_seq - copied - urg_hole != tp->copied_seq)) { + net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", + current->comm, + task_pid_nr(current)); + peek_seq = tp->copied_seq; + } + continue; + +found_ok_skb: + /* Ok so how much can we use? */ + used = skb->len - offset; + if (len < used) + used = len; + + /* Do we have urgent data here? */ + if (tp->urg_data) { + u32 urg_offset = tp->urg_seq - *seq; + if (urg_offset < used) { + if (!urg_offset) { + if (!sock_flag(sk, SOCK_URGINLINE)) { + WRITE_ONCE(*seq, *seq + 1); + urg_hole++; + offset++; + used--; + if (!used) + goto skip_copy; + } + } else + used = urg_offset; + } + } + + if (!(flags & MSG_TRUNC)) { + err = skb_copy_datagram_msg(skb, offset, msg, used); + if (err) { + /* Exception. Bailout! */ + if (!copied) + copied = -EFAULT; + break; + } + } + + WRITE_ONCE(*seq, *seq + used); + copied += used; + len -= used; + + tcp_rcv_space_adjust(sk); + +skip_copy: + if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { + tp->urg_data = 0; + tcp_fast_path_check(sk); + } + + if (TCP_SKB_CB(skb)->has_rxtstamp) { + tcp_update_recv_tstamps(skb, &tss); + cmsg_flags |= 2; + } + + if (used + offset < skb->len) + continue; + + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) + goto found_fin_ok; + if (!(flags & MSG_PEEK)) + sk_eat_skb(sk, skb); + continue; + +found_fin_ok: + /* Process the FIN. */ + WRITE_ONCE(*seq, *seq + 1); + if (!(flags & MSG_PEEK)) + sk_eat_skb(sk, skb); + break; + } while (len > 0); + + /* According to UNIX98, msg_name/msg_namelen are ignored + * on connected socket. I was just happy when found this 8) --ANK + */ + + /* Clean up data we have read: This will do ACK frames. */ + tcp_cleanup_rbuf(sk, copied); + + release_sock(sk); + + if (cmsg_flags) { + if (cmsg_flags & 2) + tcp_recv_timestamp(msg, sk, &tss); + if (cmsg_flags & 1) { + inq = tcp_inq_hint(sk); + put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq); + } + } + + return copied; + +out: + release_sock(sk); + return err; + +recv_urg: + err = tcp_recv_urg(sk, msg, len, flags); + goto out; + +recv_sndq: + err = tcp_peek_sndq(sk, msg, len); + goto out; +} +EXPORT_SYMBOL(tcp_recvmsg); + +void tcp_set_state(struct sock *sk, int state) +{ + int oldstate = sk->sk_state; + + /* We defined a new enum for TCP states that are exported in BPF + * so as not force the internal TCP states to be frozen. The + * following checks will detect if an internal state value ever + * differs from the BPF value. If this ever happens, then we will + * need to remap the internal value to the BPF value before calling + * tcp_call_bpf_2arg. + */ + BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED); + BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT); + BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV); + BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1); + BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2); + BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT); + BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE); + BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT); + BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK); + BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN); + BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING); + BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV); + BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES); + + if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG)) + tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state); + + switch (state) { + case TCP_ESTABLISHED: + if (oldstate != TCP_ESTABLISHED) + TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); + break; + + case TCP_CLOSE: + if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) + TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); + + sk->sk_prot->unhash(sk); + if (inet_csk(sk)->icsk_bind_hash && + !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) + inet_put_port(sk); + fallthrough; + default: + if (oldstate == TCP_ESTABLISHED) + TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); + } + + /* Change state AFTER socket is unhashed to avoid closed + * socket sitting in hash tables. + */ + inet_sk_state_store(sk, state); +} +EXPORT_SYMBOL_GPL(tcp_set_state); + +/* + * State processing on a close. This implements the state shift for + * sending our FIN frame. Note that we only send a FIN for some + * states. A shutdown() may have already sent the FIN, or we may be + * closed. + */ + +static const unsigned char new_state[16] = { + /* current state: new state: action: */ + [0 /* (Invalid) */] = TCP_CLOSE, + [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, + [TCP_SYN_SENT] = TCP_CLOSE, + [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, + [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, + [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, + [TCP_TIME_WAIT] = TCP_CLOSE, + [TCP_CLOSE] = TCP_CLOSE, + [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, + [TCP_LAST_ACK] = TCP_LAST_ACK, + [TCP_LISTEN] = TCP_CLOSE, + [TCP_CLOSING] = TCP_CLOSING, + [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ +}; + +static int tcp_close_state(struct sock *sk) +{ + int next = (int)new_state[sk->sk_state]; + int ns = next & TCP_STATE_MASK; + + tcp_set_state(sk, ns); + + return next & TCP_ACTION_FIN; +} + +/* + * Shutdown the sending side of a connection. Much like close except + * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). + */ + +void tcp_shutdown(struct sock *sk, int how) +{ + /* We need to grab some memory, and put together a FIN, + * and then put it into the queue to be sent. + * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. + */ + if (!(how & SEND_SHUTDOWN)) + return; + + /* If we've already sent a FIN, or it's a closed state, skip this. */ + if ((1 << sk->sk_state) & + (TCPF_ESTABLISHED | TCPF_SYN_SENT | + TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { + /* Clear out any half completed packets. FIN if needed. */ + if (tcp_close_state(sk)) + tcp_send_fin(sk); + } +} +EXPORT_SYMBOL(tcp_shutdown); + +int tcp_orphan_count_sum(void) +{ + int i, total = 0; + + for_each_possible_cpu(i) + total += per_cpu(tcp_orphan_count, i); + + return max(total, 0); +} + +static int tcp_orphan_cache; +static struct timer_list tcp_orphan_timer; +#define TCP_ORPHAN_TIMER_PERIOD msecs_to_jiffies(100) + +static void tcp_orphan_update(struct timer_list *unused) +{ + WRITE_ONCE(tcp_orphan_cache, tcp_orphan_count_sum()); + mod_timer(&tcp_orphan_timer, jiffies + TCP_ORPHAN_TIMER_PERIOD); +} + +static bool tcp_too_many_orphans(int shift) +{ + return READ_ONCE(tcp_orphan_cache) << shift > + READ_ONCE(sysctl_tcp_max_orphans); +} + +bool tcp_check_oom(struct sock *sk, int shift) +{ + bool too_many_orphans, out_of_socket_memory; + + too_many_orphans = tcp_too_many_orphans(shift); + out_of_socket_memory = tcp_out_of_memory(sk); + + if (too_many_orphans) + net_info_ratelimited("too many orphaned sockets\n"); + if (out_of_socket_memory) + net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); + return too_many_orphans || out_of_socket_memory; +} + +void __tcp_close(struct sock *sk, long timeout) +{ + struct sk_buff *skb; + int data_was_unread = 0; + int state; + + WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK); + + if (sk->sk_state == TCP_LISTEN) { + tcp_set_state(sk, TCP_CLOSE); + + /* Special case. */ + inet_csk_listen_stop(sk); + + goto adjudge_to_death; + } + + /* We need to flush the recv. buffs. We do this only on the + * descriptor close, not protocol-sourced closes, because the + * reader process may not have drained the data yet! + */ + while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { + u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; + + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) + len--; + data_was_unread += len; + __kfree_skb(skb); + } + + sk_mem_reclaim(sk); + + /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ + if (sk->sk_state == TCP_CLOSE) + goto adjudge_to_death; + + /* As outlined in RFC 2525, section 2.17, we send a RST here because + * data was lost. To witness the awful effects of the old behavior of + * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk + * GET in an FTP client, suspend the process, wait for the client to + * advertise a zero window, then kill -9 the FTP client, wheee... + * Note: timeout is always zero in such a case. + */ + if (unlikely(tcp_sk(sk)->repair)) { + sk->sk_prot->disconnect(sk, 0); + } else if (data_was_unread) { + /* Unread data was tossed, zap the connection. */ + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); + tcp_set_state(sk, TCP_CLOSE); + tcp_send_active_reset(sk, sk->sk_allocation); + } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { + /* Check zero linger _after_ checking for unread data. */ + sk->sk_prot->disconnect(sk, 0); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); + } else if (tcp_close_state(sk)) { + /* We FIN if the application ate all the data before + * zapping the connection. + */ + + /* RED-PEN. Formally speaking, we have broken TCP state + * machine. State transitions: + * + * TCP_ESTABLISHED -> TCP_FIN_WAIT1 + * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) + * TCP_CLOSE_WAIT -> TCP_LAST_ACK + * + * are legal only when FIN has been sent (i.e. in window), + * rather than queued out of window. Purists blame. + * + * F.e. "RFC state" is ESTABLISHED, + * if Linux state is FIN-WAIT-1, but FIN is still not sent. + * + * The visible declinations are that sometimes + * we enter time-wait state, when it is not required really + * (harmless), do not send active resets, when they are + * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when + * they look as CLOSING or LAST_ACK for Linux) + * Probably, I missed some more holelets. + * --ANK + * XXX (TFO) - To start off we don't support SYN+ACK+FIN + * in a single packet! (May consider it later but will + * probably need API support or TCP_CORK SYN-ACK until + * data is written and socket is closed.) + */ + tcp_send_fin(sk); + } + + sk_stream_wait_close(sk, timeout); + +adjudge_to_death: + state = sk->sk_state; + sock_hold(sk); + sock_orphan(sk); + + local_bh_disable(); + bh_lock_sock(sk); + /* remove backlog if any, without releasing ownership. */ + __release_sock(sk); + + this_cpu_inc(tcp_orphan_count); + + /* Have we already been destroyed by a softirq or backlog? */ + if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) + goto out; + + /* This is a (useful) BSD violating of the RFC. There is a + * problem with TCP as specified in that the other end could + * keep a socket open forever with no application left this end. + * We use a 1 minute timeout (about the same as BSD) then kill + * our end. If they send after that then tough - BUT: long enough + * that we won't make the old 4*rto = almost no time - whoops + * reset mistake. + * + * Nope, it was not mistake. It is really desired behaviour + * f.e. on http servers, when such sockets are useless, but + * consume significant resources. Let's do it with special + * linger2 option. --ANK + */ + + if (sk->sk_state == TCP_FIN_WAIT2) { + struct tcp_sock *tp = tcp_sk(sk); + if (tp->linger2 < 0) { + tcp_set_state(sk, TCP_CLOSE); + tcp_send_active_reset(sk, GFP_ATOMIC); + __NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPABORTONLINGER); + } else { + const int tmo = tcp_fin_time(sk); + + if (tmo > TCP_TIMEWAIT_LEN) { + inet_csk_reset_keepalive_timer(sk, + tmo - TCP_TIMEWAIT_LEN); + } else { + tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); + goto out; + } + } + } + if (sk->sk_state != TCP_CLOSE) { + sk_mem_reclaim(sk); + if (tcp_check_oom(sk, 0)) { + tcp_set_state(sk, TCP_CLOSE); + tcp_send_active_reset(sk, GFP_ATOMIC); + __NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPABORTONMEMORY); + } else if (!check_net(sock_net(sk))) { + /* Not possible to send reset; just close */ + tcp_set_state(sk, TCP_CLOSE); + } + } + + if (sk->sk_state == TCP_CLOSE) { + struct request_sock *req; + + req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, + lockdep_sock_is_held(sk)); + /* We could get here with a non-NULL req if the socket is + * aborted (e.g., closed with unread data) before 3WHS + * finishes. + */ + if (req) + reqsk_fastopen_remove(sk, req, false); + inet_csk_destroy_sock(sk); + } + /* Otherwise, socket is reprieved until protocol close. */ + +out: + bh_unlock_sock(sk); + local_bh_enable(); +} + +void tcp_close(struct sock *sk, long timeout) +{ + lock_sock(sk); + __tcp_close(sk, timeout); + release_sock(sk); + sock_put(sk); +} +EXPORT_SYMBOL(tcp_close); + +/* These states need RST on ABORT according to RFC793 */ + +static inline bool tcp_need_reset(int state) +{ + return (1 << state) & + (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | + TCPF_FIN_WAIT2 | TCPF_SYN_RECV); +} + +static void tcp_rtx_queue_purge(struct sock *sk) +{ + struct rb_node *p = rb_first(&sk->tcp_rtx_queue); + + tcp_sk(sk)->highest_sack = NULL; + while (p) { + struct sk_buff *skb = rb_to_skb(p); + + p = rb_next(p); + /* Since we are deleting whole queue, no need to + * list_del(&skb->tcp_tsorted_anchor) + */ + tcp_rtx_queue_unlink(skb, sk); + sk_wmem_free_skb(sk, skb); + } +} + +void tcp_write_queue_purge(struct sock *sk) +{ + struct sk_buff *skb; + + tcp_chrono_stop(sk, TCP_CHRONO_BUSY); + while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { + tcp_skb_tsorted_anchor_cleanup(skb); + sk_wmem_free_skb(sk, skb); + } + tcp_rtx_queue_purge(sk); + skb = sk->sk_tx_skb_cache; + if (skb) { + __kfree_skb(skb); + sk->sk_tx_skb_cache = NULL; + } + INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue); + sk_mem_reclaim(sk); + tcp_clear_all_retrans_hints(tcp_sk(sk)); + tcp_sk(sk)->packets_out = 0; + inet_csk(sk)->icsk_backoff = 0; +} + +int tcp_disconnect(struct sock *sk, int flags) +{ + struct inet_sock *inet = inet_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + int old_state = sk->sk_state; + u32 seq; + + /* Deny disconnect if other threads are blocked in sk_wait_event() + * or inet_wait_for_connect(). + */ + if (sk->sk_wait_pending) + return -EBUSY; + + if (old_state != TCP_CLOSE) + tcp_set_state(sk, TCP_CLOSE); + + /* ABORT function of RFC793 */ + if (old_state == TCP_LISTEN) { + inet_csk_listen_stop(sk); + } else if (unlikely(tp->repair)) { + sk->sk_err = ECONNABORTED; + } else if (tcp_need_reset(old_state) || + (tp->snd_nxt != tp->write_seq && + (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { + /* The last check adjusts for discrepancy of Linux wrt. RFC + * states + */ + tcp_send_active_reset(sk, gfp_any()); + sk->sk_err = ECONNRESET; + } else if (old_state == TCP_SYN_SENT) + sk->sk_err = ECONNRESET; + + tcp_clear_xmit_timers(sk); + __skb_queue_purge(&sk->sk_receive_queue); + if (sk->sk_rx_skb_cache) { + __kfree_skb(sk->sk_rx_skb_cache); + sk->sk_rx_skb_cache = NULL; + } + WRITE_ONCE(tp->copied_seq, tp->rcv_nxt); + tp->urg_data = 0; + tcp_write_queue_purge(sk); + tcp_fastopen_active_disable_ofo_check(sk); + skb_rbtree_purge(&tp->out_of_order_queue); + + inet->inet_dport = 0; + + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + inet_reset_saddr(sk); + + WRITE_ONCE(sk->sk_shutdown, 0); + sock_reset_flag(sk, SOCK_DONE); + tp->srtt_us = 0; + tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); + tp->rcv_rtt_last_tsecr = 0; + + seq = tp->write_seq + tp->max_window + 2; + if (!seq) + seq = 1; + WRITE_ONCE(tp->write_seq, seq); + + icsk->icsk_backoff = 0; + icsk->icsk_probes_out = 0; + icsk->icsk_probes_tstamp = 0; + icsk->icsk_rto = TCP_TIMEOUT_INIT; + icsk->icsk_rto_min = TCP_RTO_MIN; + icsk->icsk_delack_max = TCP_DELACK_MAX; + tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; + tp->snd_cwnd = TCP_INIT_CWND; + tp->snd_cwnd_cnt = 0; + tp->is_cwnd_limited = 0; + tp->max_packets_out = 0; + tp->window_clamp = 0; + tp->delivered = 0; + tp->delivered_ce = 0; + if (icsk->icsk_ca_ops->release) + icsk->icsk_ca_ops->release(sk); + memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv)); + icsk->icsk_ca_initialized = 0; + tcp_set_ca_state(sk, TCP_CA_Open); + tp->is_sack_reneg = 0; + tcp_clear_retrans(tp); + tp->total_retrans = 0; + inet_csk_delack_init(sk); + /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 + * issue in __tcp_select_window() + */ + icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; + memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); + __sk_dst_reset(sk); + dst_release(xchg((__force struct dst_entry **)&sk->sk_rx_dst, NULL)); + tcp_saved_syn_free(tp); + tp->compressed_ack = 0; + tp->segs_in = 0; + tp->segs_out = 0; + tp->bytes_sent = 0; + tp->bytes_acked = 0; + tp->bytes_received = 0; + tp->bytes_retrans = 0; + tp->data_segs_in = 0; + tp->data_segs_out = 0; + tp->duplicate_sack[0].start_seq = 0; + tp->duplicate_sack[0].end_seq = 0; + tp->dsack_dups = 0; + tp->reord_seen = 0; + tp->retrans_out = 0; + tp->sacked_out = 0; + tp->tlp_high_seq = 0; + tp->last_oow_ack_time = 0; + /* There's a bubble in the pipe until at least the first ACK. */ + tp->app_limited = ~0U; + tp->rate_app_limited = 1; + tp->rack.mstamp = 0; + tp->rack.advanced = 0; + tp->rack.reo_wnd_steps = 1; + tp->rack.last_delivered = 0; + tp->rack.reo_wnd_persist = 0; + tp->rack.dsack_seen = 0; + tp->syn_data_acked = 0; + tp->rx_opt.saw_tstamp = 0; + tp->rx_opt.dsack = 0; + tp->rx_opt.num_sacks = 0; + tp->rcv_ooopack = 0; + + + /* Clean up fastopen related fields */ + tcp_free_fastopen_req(tp); + inet->defer_connect = 0; + tp->fastopen_client_fail = 0; + + WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); + + if (sk->sk_frag.page) { + put_page(sk->sk_frag.page); + sk->sk_frag.page = NULL; + sk->sk_frag.offset = 0; + } + + sk->sk_error_report(sk); + return 0; +} +EXPORT_SYMBOL(tcp_disconnect); + +static inline bool tcp_can_repair_sock(const struct sock *sk) +{ + return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && + (sk->sk_state != TCP_LISTEN); +} + +static int tcp_repair_set_window(struct tcp_sock *tp, sockptr_t optbuf, int len) +{ + struct tcp_repair_window opt; + + if (!tp->repair) + return -EPERM; + + if (len != sizeof(opt)) + return -EINVAL; + + if (copy_from_sockptr(&opt, optbuf, sizeof(opt))) + return -EFAULT; + + if (opt.max_window < opt.snd_wnd) + return -EINVAL; + + if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd)) + return -EINVAL; + + if (after(opt.rcv_wup, tp->rcv_nxt)) + return -EINVAL; + + tp->snd_wl1 = opt.snd_wl1; + tp->snd_wnd = opt.snd_wnd; + tp->max_window = opt.max_window; + + tp->rcv_wnd = opt.rcv_wnd; + tp->rcv_wup = opt.rcv_wup; + + return 0; +} + +static int tcp_repair_options_est(struct sock *sk, sockptr_t optbuf, + unsigned int len) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_repair_opt opt; + size_t offset = 0; + + while (len >= sizeof(opt)) { + if (copy_from_sockptr_offset(&opt, optbuf, offset, sizeof(opt))) + return -EFAULT; + + offset += sizeof(opt); + len -= sizeof(opt); + + switch (opt.opt_code) { + case TCPOPT_MSS: + tp->rx_opt.mss_clamp = opt.opt_val; + tcp_mtup_init(sk); + break; + case TCPOPT_WINDOW: + { + u16 snd_wscale = opt.opt_val & 0xFFFF; + u16 rcv_wscale = opt.opt_val >> 16; + + if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE) + return -EFBIG; + + tp->rx_opt.snd_wscale = snd_wscale; + tp->rx_opt.rcv_wscale = rcv_wscale; + tp->rx_opt.wscale_ok = 1; + } + break; + case TCPOPT_SACK_PERM: + if (opt.opt_val != 0) + return -EINVAL; + + tp->rx_opt.sack_ok |= TCP_SACK_SEEN; + break; + case TCPOPT_TIMESTAMP: + if (opt.opt_val != 0) + return -EINVAL; + + tp->rx_opt.tstamp_ok = 1; + break; + } + } + + return 0; +} + +DEFINE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); +EXPORT_SYMBOL(tcp_tx_delay_enabled); + +static void tcp_enable_tx_delay(void) +{ + if (!static_branch_unlikely(&tcp_tx_delay_enabled)) { + static int __tcp_tx_delay_enabled = 0; + + if (cmpxchg(&__tcp_tx_delay_enabled, 0, 1) == 0) { + static_branch_enable(&tcp_tx_delay_enabled); + pr_info("TCP_TX_DELAY enabled\n"); + } + } +} + +/* When set indicates to always queue non-full frames. Later the user clears + * this option and we transmit any pending partial frames in the queue. This is + * meant to be used alongside sendfile() to get properly filled frames when the + * user (for example) must write out headers with a write() call first and then + * use sendfile to send out the data parts. + * + * TCP_CORK can be set together with TCP_NODELAY and it is stronger than + * TCP_NODELAY. + */ +static void __tcp_sock_set_cork(struct sock *sk, bool on) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (on) { + tp->nonagle |= TCP_NAGLE_CORK; + } else { + tp->nonagle &= ~TCP_NAGLE_CORK; + if (tp->nonagle & TCP_NAGLE_OFF) + tp->nonagle |= TCP_NAGLE_PUSH; + tcp_push_pending_frames(sk); + } +} + +void tcp_sock_set_cork(struct sock *sk, bool on) +{ + lock_sock(sk); + __tcp_sock_set_cork(sk, on); + release_sock(sk); +} +EXPORT_SYMBOL(tcp_sock_set_cork); + +/* TCP_NODELAY is weaker than TCP_CORK, so that this option on corked socket is + * remembered, but it is not activated until cork is cleared. + * + * However, when TCP_NODELAY is set we make an explicit push, which overrides + * even TCP_CORK for currently queued segments. + */ +static void __tcp_sock_set_nodelay(struct sock *sk, bool on) +{ + if (on) { + tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; + tcp_push_pending_frames(sk); + } else { + tcp_sk(sk)->nonagle &= ~TCP_NAGLE_OFF; + } +} + +void tcp_sock_set_nodelay(struct sock *sk) +{ + lock_sock(sk); + __tcp_sock_set_nodelay(sk, true); + release_sock(sk); +} +EXPORT_SYMBOL(tcp_sock_set_nodelay); + +static void __tcp_sock_set_quickack(struct sock *sk, int val) +{ + if (!val) { + inet_csk_enter_pingpong_mode(sk); + return; + } + + inet_csk_exit_pingpong_mode(sk); + if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && + inet_csk_ack_scheduled(sk)) { + inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_PUSHED; + tcp_cleanup_rbuf(sk, 1); + if (!(val & 1)) + inet_csk_enter_pingpong_mode(sk); + } +} + +void tcp_sock_set_quickack(struct sock *sk, int val) +{ + lock_sock(sk); + __tcp_sock_set_quickack(sk, val); + release_sock(sk); +} +EXPORT_SYMBOL(tcp_sock_set_quickack); + +int tcp_sock_set_syncnt(struct sock *sk, int val) +{ + if (val < 1 || val > MAX_TCP_SYNCNT) + return -EINVAL; + + lock_sock(sk); + WRITE_ONCE(inet_csk(sk)->icsk_syn_retries, val); + release_sock(sk); + return 0; +} +EXPORT_SYMBOL(tcp_sock_set_syncnt); + +void tcp_sock_set_user_timeout(struct sock *sk, u32 val) +{ + lock_sock(sk); + WRITE_ONCE(inet_csk(sk)->icsk_user_timeout, val); + release_sock(sk); +} +EXPORT_SYMBOL(tcp_sock_set_user_timeout); + +int tcp_sock_set_keepidle_locked(struct sock *sk, int val) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (val < 1 || val > MAX_TCP_KEEPIDLE) + return -EINVAL; + + /* Paired with WRITE_ONCE() in keepalive_time_when() */ + WRITE_ONCE(tp->keepalive_time, val * HZ); + if (sock_flag(sk, SOCK_KEEPOPEN) && + !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { + u32 elapsed = keepalive_time_elapsed(tp); + + if (tp->keepalive_time > elapsed) + elapsed = tp->keepalive_time - elapsed; + else + elapsed = 0; + inet_csk_reset_keepalive_timer(sk, elapsed); + } + + return 0; +} + +int tcp_sock_set_keepidle(struct sock *sk, int val) +{ + int err; + + lock_sock(sk); + err = tcp_sock_set_keepidle_locked(sk, val); + release_sock(sk); + return err; +} +EXPORT_SYMBOL(tcp_sock_set_keepidle); + +int tcp_sock_set_keepintvl(struct sock *sk, int val) +{ + if (val < 1 || val > MAX_TCP_KEEPINTVL) + return -EINVAL; + + lock_sock(sk); + WRITE_ONCE(tcp_sk(sk)->keepalive_intvl, val * HZ); + release_sock(sk); + return 0; +} +EXPORT_SYMBOL(tcp_sock_set_keepintvl); + +int tcp_sock_set_keepcnt(struct sock *sk, int val) +{ + if (val < 1 || val > MAX_TCP_KEEPCNT) + return -EINVAL; + + lock_sock(sk); + /* Paired with READ_ONCE() in keepalive_probes() */ + WRITE_ONCE(tcp_sk(sk)->keepalive_probes, val); + release_sock(sk); + return 0; +} +EXPORT_SYMBOL(tcp_sock_set_keepcnt); + +/* + * Socket option code for TCP. + */ +static int do_tcp_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + struct net *net = sock_net(sk); + int val; + int err = 0; + + /* These are data/string values, all the others are ints */ + switch (optname) { + case TCP_CONGESTION: { + char name[TCP_CA_NAME_MAX]; + + if (optlen < 1) + return -EINVAL; + + val = strncpy_from_sockptr(name, optval, + min_t(long, TCP_CA_NAME_MAX-1, optlen)); + if (val < 0) + return -EFAULT; + name[val] = 0; + + lock_sock(sk); + err = tcp_set_congestion_control(sk, name, true, + ns_capable(sock_net(sk)->user_ns, + CAP_NET_ADMIN)); + release_sock(sk); + return err; + } + case TCP_ULP: { + char name[TCP_ULP_NAME_MAX]; + + if (optlen < 1) + return -EINVAL; + + val = strncpy_from_sockptr(name, optval, + min_t(long, TCP_ULP_NAME_MAX - 1, + optlen)); + if (val < 0) + return -EFAULT; + name[val] = 0; + + lock_sock(sk); + err = tcp_set_ulp(sk, name); + release_sock(sk); + return err; + } + case TCP_FASTOPEN_KEY: { + __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH]; + __u8 *backup_key = NULL; + + /* Allow a backup key as well to facilitate key rotation + * First key is the active one. + */ + if (optlen != TCP_FASTOPEN_KEY_LENGTH && + optlen != TCP_FASTOPEN_KEY_BUF_LENGTH) + return -EINVAL; + + if (copy_from_sockptr(key, optval, optlen)) + return -EFAULT; + + if (optlen == TCP_FASTOPEN_KEY_BUF_LENGTH) + backup_key = key + TCP_FASTOPEN_KEY_LENGTH; + + return tcp_fastopen_reset_cipher(net, sk, key, backup_key); + } + default: + /* fallthru */ + break; + } + + if (optlen < sizeof(int)) + return -EINVAL; + + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + lock_sock(sk); + + switch (optname) { + case TCP_MAXSEG: + /* Values greater than interface MTU won't take effect. However + * at the point when this call is done we typically don't yet + * know which interface is going to be used + */ + if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) { + err = -EINVAL; + break; + } + tp->rx_opt.user_mss = val; + break; + + case TCP_NODELAY: + __tcp_sock_set_nodelay(sk, val); + break; + + case TCP_THIN_LINEAR_TIMEOUTS: + if (val < 0 || val > 1) + err = -EINVAL; + else + tp->thin_lto = val; + break; + + case TCP_THIN_DUPACK: + if (val < 0 || val > 1) + err = -EINVAL; + break; + + case TCP_REPAIR: + if (!tcp_can_repair_sock(sk)) + err = -EPERM; + else if (val == TCP_REPAIR_ON) { + tp->repair = 1; + sk->sk_reuse = SK_FORCE_REUSE; + tp->repair_queue = TCP_NO_QUEUE; + } else if (val == TCP_REPAIR_OFF) { + tp->repair = 0; + sk->sk_reuse = SK_NO_REUSE; + tcp_send_window_probe(sk); + } else if (val == TCP_REPAIR_OFF_NO_WP) { + tp->repair = 0; + sk->sk_reuse = SK_NO_REUSE; + } else + err = -EINVAL; + + break; + + case TCP_REPAIR_QUEUE: + if (!tp->repair) + err = -EPERM; + else if ((unsigned int)val < TCP_QUEUES_NR) + tp->repair_queue = val; + else + err = -EINVAL; + break; + + case TCP_QUEUE_SEQ: + if (sk->sk_state != TCP_CLOSE) { + err = -EPERM; + } else if (tp->repair_queue == TCP_SEND_QUEUE) { + if (!tcp_rtx_queue_empty(sk)) + err = -EPERM; + else + WRITE_ONCE(tp->write_seq, val); + } else if (tp->repair_queue == TCP_RECV_QUEUE) { + if (tp->rcv_nxt != tp->copied_seq) { + err = -EPERM; + } else { + WRITE_ONCE(tp->rcv_nxt, val); + WRITE_ONCE(tp->copied_seq, val); + } + } else { + err = -EINVAL; + } + break; + + case TCP_REPAIR_OPTIONS: + if (!tp->repair) + err = -EINVAL; + else if (sk->sk_state == TCP_ESTABLISHED && !tp->bytes_sent) + err = tcp_repair_options_est(sk, optval, optlen); + else + err = -EPERM; + break; + + case TCP_CORK: + __tcp_sock_set_cork(sk, val); + break; + + case TCP_KEEPIDLE: + err = tcp_sock_set_keepidle_locked(sk, val); + break; + case TCP_KEEPINTVL: + if (val < 1 || val > MAX_TCP_KEEPINTVL) + err = -EINVAL; + else + WRITE_ONCE(tp->keepalive_intvl, val * HZ); + break; + case TCP_KEEPCNT: + if (val < 1 || val > MAX_TCP_KEEPCNT) + err = -EINVAL; + else + WRITE_ONCE(tp->keepalive_probes, val); + break; + case TCP_SYNCNT: + if (val < 1 || val > MAX_TCP_SYNCNT) + err = -EINVAL; + else + WRITE_ONCE(icsk->icsk_syn_retries, val); + break; + + case TCP_SAVE_SYN: + /* 0: disable, 1: enable, 2: start from ether_header */ + if (val < 0 || val > 2) + err = -EINVAL; + else + tp->save_syn = val; + break; + + case TCP_LINGER2: + if (val < 0) + WRITE_ONCE(tp->linger2, -1); + else if (val > TCP_FIN_TIMEOUT_MAX / HZ) + WRITE_ONCE(tp->linger2, TCP_FIN_TIMEOUT_MAX); + else + WRITE_ONCE(tp->linger2, val * HZ); + break; + + case TCP_DEFER_ACCEPT: + /* Translate value in seconds to number of retransmits */ + WRITE_ONCE(icsk->icsk_accept_queue.rskq_defer_accept, + secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, + TCP_RTO_MAX / HZ)); + break; + + case TCP_WINDOW_CLAMP: + if (!val) { + if (sk->sk_state != TCP_CLOSE) { + err = -EINVAL; + break; + } + tp->window_clamp = 0; + } else + tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? + SOCK_MIN_RCVBUF / 2 : val; + break; + + case TCP_QUICKACK: + __tcp_sock_set_quickack(sk, val); + break; + +#ifdef CONFIG_TCP_MD5SIG + case TCP_MD5SIG: + case TCP_MD5SIG_EXT: + err = tp->af_specific->md5_parse(sk, optname, optval, optlen); + break; +#endif + case TCP_USER_TIMEOUT: + /* Cap the max time in ms TCP will retry or probe the window + * before giving up and aborting (ETIMEDOUT) a connection. + */ + if (val < 0) + err = -EINVAL; + else + WRITE_ONCE(icsk->icsk_user_timeout, val); + break; + + case TCP_FASTOPEN: + if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | + TCPF_LISTEN))) { + tcp_fastopen_init_key_once(net); + + fastopen_queue_tune(sk, val); + } else { + err = -EINVAL; + } + break; + case TCP_FASTOPEN_CONNECT: + if (val > 1 || val < 0) { + err = -EINVAL; + } else if (READ_ONCE(net->ipv4.sysctl_tcp_fastopen) & + TFO_CLIENT_ENABLE) { + if (sk->sk_state == TCP_CLOSE) + tp->fastopen_connect = val; + else + err = -EINVAL; + } else { + err = -EOPNOTSUPP; + } + break; + case TCP_FASTOPEN_NO_COOKIE: + if (val > 1 || val < 0) + err = -EINVAL; + else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) + err = -EINVAL; + else + tp->fastopen_no_cookie = val; + break; + case TCP_TIMESTAMP: + if (!tp->repair) + err = -EPERM; + else + tp->tsoffset = val - tcp_time_stamp_raw(); + break; + case TCP_REPAIR_WINDOW: + err = tcp_repair_set_window(tp, optval, optlen); + break; + case TCP_NOTSENT_LOWAT: + WRITE_ONCE(tp->notsent_lowat, val); + sk->sk_write_space(sk); + break; + case TCP_INQ: + if (val > 1 || val < 0) + err = -EINVAL; + else + tp->recvmsg_inq = val; + break; + case TCP_TX_DELAY: + if (val) + tcp_enable_tx_delay(); + WRITE_ONCE(tp->tcp_tx_delay, val); + break; + default: + err = -ENOPROTOOPT; + break; + } + + release_sock(sk); + return err; +} + +int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, + unsigned int optlen) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (level != SOL_TCP) + return icsk->icsk_af_ops->setsockopt(sk, level, optname, + optval, optlen); + return do_tcp_setsockopt(sk, level, optname, optval, optlen); +} +EXPORT_SYMBOL(tcp_setsockopt); + +static void tcp_get_info_chrono_stats(const struct tcp_sock *tp, + struct tcp_info *info) +{ + u64 stats[__TCP_CHRONO_MAX], total = 0; + enum tcp_chrono i; + + for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) { + stats[i] = tp->chrono_stat[i - 1]; + if (i == tp->chrono_type) + stats[i] += tcp_jiffies32 - tp->chrono_start; + stats[i] *= USEC_PER_SEC / HZ; + total += stats[i]; + } + + info->tcpi_busy_time = total; + info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED]; + info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED]; +} + +/* Return information about state of tcp endpoint in API format. */ +void tcp_get_info(struct sock *sk, struct tcp_info *info) +{ + const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ + const struct inet_connection_sock *icsk = inet_csk(sk); + unsigned long rate; + u32 now; + u64 rate64; + bool slow; + + memset(info, 0, sizeof(*info)); + if (sk->sk_type != SOCK_STREAM) + return; + + info->tcpi_state = inet_sk_state_load(sk); + + /* Report meaningful fields for all TCP states, including listeners */ + rate = READ_ONCE(sk->sk_pacing_rate); + rate64 = (rate != ~0UL) ? rate : ~0ULL; + info->tcpi_pacing_rate = rate64; + + rate = READ_ONCE(sk->sk_max_pacing_rate); + rate64 = (rate != ~0UL) ? rate : ~0ULL; + info->tcpi_max_pacing_rate = rate64; + + info->tcpi_reordering = tp->reordering; + info->tcpi_snd_cwnd = tp->snd_cwnd; + + if (info->tcpi_state == TCP_LISTEN) { + /* listeners aliased fields : + * tcpi_unacked -> Number of children ready for accept() + * tcpi_sacked -> max backlog + */ + info->tcpi_unacked = READ_ONCE(sk->sk_ack_backlog); + info->tcpi_sacked = READ_ONCE(sk->sk_max_ack_backlog); + return; + } + + slow = lock_sock_fast(sk); + + info->tcpi_ca_state = icsk->icsk_ca_state; + info->tcpi_retransmits = icsk->icsk_retransmits; + info->tcpi_probes = icsk->icsk_probes_out; + info->tcpi_backoff = icsk->icsk_backoff; + + if (tp->rx_opt.tstamp_ok) + info->tcpi_options |= TCPI_OPT_TIMESTAMPS; + if (tcp_is_sack(tp)) + info->tcpi_options |= TCPI_OPT_SACK; + if (tp->rx_opt.wscale_ok) { + info->tcpi_options |= TCPI_OPT_WSCALE; + info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; + info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; + } + + if (tp->ecn_flags & TCP_ECN_OK) + info->tcpi_options |= TCPI_OPT_ECN; + if (tp->ecn_flags & TCP_ECN_SEEN) + info->tcpi_options |= TCPI_OPT_ECN_SEEN; + if (tp->syn_data_acked) + info->tcpi_options |= TCPI_OPT_SYN_DATA; + + info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); + info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); + info->tcpi_snd_mss = tp->mss_cache; + info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; + + info->tcpi_unacked = tp->packets_out; + info->tcpi_sacked = tp->sacked_out; + + info->tcpi_lost = tp->lost_out; + info->tcpi_retrans = tp->retrans_out; + + now = tcp_jiffies32; + info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); + info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); + info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); + + info->tcpi_pmtu = icsk->icsk_pmtu_cookie; + info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; + info->tcpi_rtt = tp->srtt_us >> 3; + info->tcpi_rttvar = tp->mdev_us >> 2; + info->tcpi_snd_ssthresh = tp->snd_ssthresh; + info->tcpi_advmss = tp->advmss; + + info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3; + info->tcpi_rcv_space = tp->rcvq_space.space; + + info->tcpi_total_retrans = tp->total_retrans; + + info->tcpi_bytes_acked = tp->bytes_acked; + info->tcpi_bytes_received = tp->bytes_received; + info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt); + tcp_get_info_chrono_stats(tp, info); + + info->tcpi_segs_out = tp->segs_out; + info->tcpi_segs_in = tp->segs_in; + + info->tcpi_min_rtt = tcp_min_rtt(tp); + info->tcpi_data_segs_in = tp->data_segs_in; + info->tcpi_data_segs_out = tp->data_segs_out; + + info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0; + rate64 = tcp_compute_delivery_rate(tp); + if (rate64) + info->tcpi_delivery_rate = rate64; + info->tcpi_delivered = tp->delivered; + info->tcpi_delivered_ce = tp->delivered_ce; + info->tcpi_bytes_sent = tp->bytes_sent; + info->tcpi_bytes_retrans = tp->bytes_retrans; + info->tcpi_dsack_dups = tp->dsack_dups; + info->tcpi_reord_seen = tp->reord_seen; + info->tcpi_rcv_ooopack = tp->rcv_ooopack; + info->tcpi_snd_wnd = tp->snd_wnd; + info->tcpi_fastopen_client_fail = tp->fastopen_client_fail; + unlock_sock_fast(sk, slow); +} +EXPORT_SYMBOL_GPL(tcp_get_info); + +static size_t tcp_opt_stats_get_size(void) +{ + return + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BUSY */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_RWND_LIMITED */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_SNDBUF_LIMITED */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DATA_SEGS_OUT */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_TOTAL_RETRANS */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_PACING_RATE */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DELIVERY_RATE */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_CWND */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_REORDERING */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_MIN_RTT */ + nla_total_size(sizeof(u8)) + /* TCP_NLA_RECUR_RETRANS */ + nla_total_size(sizeof(u8)) + /* TCP_NLA_DELIVERY_RATE_APP_LMT */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_SNDQ_SIZE */ + nla_total_size(sizeof(u8)) + /* TCP_NLA_CA_STATE */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_SSTHRESH */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */ + nla_total_size(sizeof(u16)) + /* TCP_NLA_TIMEOUT_REHASH */ + nla_total_size(sizeof(u32)) + /* TCP_NLA_BYTES_NOTSENT */ + nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_EDT */ + 0; +} + +struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, + const struct sk_buff *orig_skb) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *stats; + struct tcp_info info; + unsigned long rate; + u64 rate64; + + stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC); + if (!stats) + return NULL; + + tcp_get_info_chrono_stats(tp, &info); + nla_put_u64_64bit(stats, TCP_NLA_BUSY, + info.tcpi_busy_time, TCP_NLA_PAD); + nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED, + info.tcpi_rwnd_limited, TCP_NLA_PAD); + nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED, + info.tcpi_sndbuf_limited, TCP_NLA_PAD); + nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT, + tp->data_segs_out, TCP_NLA_PAD); + nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS, + tp->total_retrans, TCP_NLA_PAD); + + rate = READ_ONCE(sk->sk_pacing_rate); + rate64 = (rate != ~0UL) ? rate : ~0ULL; + nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD); + + rate64 = tcp_compute_delivery_rate(tp); + nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD); + + nla_put_u32(stats, TCP_NLA_SND_CWND, tp->snd_cwnd); + nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering); + nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp)); + + nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits); + nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited); + nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh); + nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered); + nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce); + + nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una); + nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state); + + nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent, + TCP_NLA_PAD); + nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans, + TCP_NLA_PAD); + nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups); + nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen); + nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3); + nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash); + nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT, + max_t(int, 0, tp->write_seq - tp->snd_nxt)); + nla_put_u64_64bit(stats, TCP_NLA_EDT, orig_skb->skb_mstamp_ns, + TCP_NLA_PAD); + + return stats; +} + +static int do_tcp_getsockopt(struct sock *sk, int level, + int optname, char __user *optval, int __user *optlen) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + int val, len; + + if (get_user(len, optlen)) + return -EFAULT; + + len = min_t(unsigned int, len, sizeof(int)); + + if (len < 0) + return -EINVAL; + + switch (optname) { + case TCP_MAXSEG: + val = tp->mss_cache; + if (tp->rx_opt.user_mss && + ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) + val = tp->rx_opt.user_mss; + if (tp->repair) + val = tp->rx_opt.mss_clamp; + break; + case TCP_NODELAY: + val = !!(tp->nonagle&TCP_NAGLE_OFF); + break; + case TCP_CORK: + val = !!(tp->nonagle&TCP_NAGLE_CORK); + break; + case TCP_KEEPIDLE: + val = keepalive_time_when(tp) / HZ; + break; + case TCP_KEEPINTVL: + val = keepalive_intvl_when(tp) / HZ; + break; + case TCP_KEEPCNT: + val = keepalive_probes(tp); + break; + case TCP_SYNCNT: + val = READ_ONCE(icsk->icsk_syn_retries) ? : + READ_ONCE(net->ipv4.sysctl_tcp_syn_retries); + break; + case TCP_LINGER2: + val = READ_ONCE(tp->linger2); + if (val >= 0) + val = (val ? : READ_ONCE(net->ipv4.sysctl_tcp_fin_timeout)) / HZ; + break; + case TCP_DEFER_ACCEPT: + val = READ_ONCE(icsk->icsk_accept_queue.rskq_defer_accept); + val = retrans_to_secs(val, TCP_TIMEOUT_INIT / HZ, + TCP_RTO_MAX / HZ); + break; + case TCP_WINDOW_CLAMP: + val = tp->window_clamp; + break; + case TCP_INFO: { + struct tcp_info info; + + if (get_user(len, optlen)) + return -EFAULT; + + tcp_get_info(sk, &info); + + len = min_t(unsigned int, len, sizeof(info)); + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &info, len)) + return -EFAULT; + return 0; + } + case TCP_CC_INFO: { + const struct tcp_congestion_ops *ca_ops; + union tcp_cc_info info; + size_t sz = 0; + int attr; + + if (get_user(len, optlen)) + return -EFAULT; + + ca_ops = icsk->icsk_ca_ops; + if (ca_ops && ca_ops->get_info) + sz = ca_ops->get_info(sk, ~0U, &attr, &info); + + len = min_t(unsigned int, len, sz); + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &info, len)) + return -EFAULT; + return 0; + } + case TCP_QUICKACK: + val = !inet_csk_in_pingpong_mode(sk); + break; + + case TCP_CONGESTION: + if (get_user(len, optlen)) + return -EFAULT; + len = min_t(unsigned int, len, TCP_CA_NAME_MAX); + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) + return -EFAULT; + return 0; + + case TCP_ULP: + if (get_user(len, optlen)) + return -EFAULT; + len = min_t(unsigned int, len, TCP_ULP_NAME_MAX); + if (!icsk->icsk_ulp_ops) { + if (put_user(0, optlen)) + return -EFAULT; + return 0; + } + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len)) + return -EFAULT; + return 0; + + case TCP_FASTOPEN_KEY: { + u64 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u64)]; + unsigned int key_len; + + if (get_user(len, optlen)) + return -EFAULT; + + key_len = tcp_fastopen_get_cipher(net, icsk, key) * + TCP_FASTOPEN_KEY_LENGTH; + len = min_t(unsigned int, len, key_len); + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, key, len)) + return -EFAULT; + return 0; + } + case TCP_THIN_LINEAR_TIMEOUTS: + val = tp->thin_lto; + break; + + case TCP_THIN_DUPACK: + val = 0; + break; + + case TCP_REPAIR: + val = tp->repair; + break; + + case TCP_REPAIR_QUEUE: + if (tp->repair) + val = tp->repair_queue; + else + return -EINVAL; + break; + + case TCP_REPAIR_WINDOW: { + struct tcp_repair_window opt; + + if (get_user(len, optlen)) + return -EFAULT; + + if (len != sizeof(opt)) + return -EINVAL; + + if (!tp->repair) + return -EPERM; + + opt.snd_wl1 = tp->snd_wl1; + opt.snd_wnd = tp->snd_wnd; + opt.max_window = tp->max_window; + opt.rcv_wnd = tp->rcv_wnd; + opt.rcv_wup = tp->rcv_wup; + + if (copy_to_user(optval, &opt, len)) + return -EFAULT; + return 0; + } + case TCP_QUEUE_SEQ: + if (tp->repair_queue == TCP_SEND_QUEUE) + val = tp->write_seq; + else if (tp->repair_queue == TCP_RECV_QUEUE) + val = tp->rcv_nxt; + else + return -EINVAL; + break; + + case TCP_USER_TIMEOUT: + val = READ_ONCE(icsk->icsk_user_timeout); + break; + + case TCP_FASTOPEN: + val = READ_ONCE(icsk->icsk_accept_queue.fastopenq.max_qlen); + break; + + case TCP_FASTOPEN_CONNECT: + val = tp->fastopen_connect; + break; + + case TCP_FASTOPEN_NO_COOKIE: + val = tp->fastopen_no_cookie; + break; + + case TCP_TX_DELAY: + val = READ_ONCE(tp->tcp_tx_delay); + break; + + case TCP_TIMESTAMP: + val = tcp_time_stamp_raw() + tp->tsoffset; + break; + case TCP_NOTSENT_LOWAT: + val = READ_ONCE(tp->notsent_lowat); + break; + case TCP_INQ: + val = tp->recvmsg_inq; + break; + case TCP_SAVE_SYN: + val = tp->save_syn; + break; + case TCP_SAVED_SYN: { + if (get_user(len, optlen)) + return -EFAULT; + + lock_sock(sk); + if (tp->saved_syn) { + if (len < tcp_saved_syn_len(tp->saved_syn)) { + if (put_user(tcp_saved_syn_len(tp->saved_syn), + optlen)) { + release_sock(sk); + return -EFAULT; + } + release_sock(sk); + return -EINVAL; + } + len = tcp_saved_syn_len(tp->saved_syn); + if (put_user(len, optlen)) { + release_sock(sk); + return -EFAULT; + } + if (copy_to_user(optval, tp->saved_syn->data, len)) { + release_sock(sk); + return -EFAULT; + } + tcp_saved_syn_free(tp); + release_sock(sk); + } else { + release_sock(sk); + len = 0; + if (put_user(len, optlen)) + return -EFAULT; + } + return 0; + } +#ifdef CONFIG_MMU + case TCP_ZEROCOPY_RECEIVE: { + struct tcp_zerocopy_receive zc = {}; + int err; + + if (get_user(len, optlen)) + return -EFAULT; + if (len < 0 || + len < offsetofend(struct tcp_zerocopy_receive, length)) + return -EINVAL; + if (len > sizeof(zc)) { + len = sizeof(zc); + if (put_user(len, optlen)) + return -EFAULT; + } + if (copy_from_user(&zc, optval, len)) + return -EFAULT; + lock_sock(sk); + err = tcp_zerocopy_receive(sk, &zc); + err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname, + &zc, &len, err); + release_sock(sk); + if (len >= offsetofend(struct tcp_zerocopy_receive, err)) + goto zerocopy_rcv_sk_err; + switch (len) { + case offsetofend(struct tcp_zerocopy_receive, err): + goto zerocopy_rcv_sk_err; + case offsetofend(struct tcp_zerocopy_receive, inq): + goto zerocopy_rcv_inq; + case offsetofend(struct tcp_zerocopy_receive, length): + default: + goto zerocopy_rcv_out; + } +zerocopy_rcv_sk_err: + if (!err) + zc.err = sock_error(sk); +zerocopy_rcv_inq: + zc.inq = tcp_inq_hint(sk); +zerocopy_rcv_out: + if (!err && copy_to_user(optval, &zc, len)) + err = -EFAULT; + return err; + } +#endif + default: + return -ENOPROTOOPT; + } + + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &val, len)) + return -EFAULT; + return 0; +} + +bool tcp_bpf_bypass_getsockopt(int level, int optname) +{ + /* TCP do_tcp_getsockopt has optimized getsockopt implementation + * to avoid extra socket lock for TCP_ZEROCOPY_RECEIVE. + */ + if (level == SOL_TCP && optname == TCP_ZEROCOPY_RECEIVE) + return true; + + return false; +} +EXPORT_SYMBOL(tcp_bpf_bypass_getsockopt); + +int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, + int __user *optlen) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + if (level != SOL_TCP) + return icsk->icsk_af_ops->getsockopt(sk, level, optname, + optval, optlen); + return do_tcp_getsockopt(sk, level, optname, optval, optlen); +} +EXPORT_SYMBOL(tcp_getsockopt); + +#ifdef CONFIG_TCP_MD5SIG +static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool); +static DEFINE_MUTEX(tcp_md5sig_mutex); +static bool tcp_md5sig_pool_populated = false; + +static void __tcp_alloc_md5sig_pool(void) +{ + struct crypto_ahash *hash; + int cpu; + + hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hash)) + return; + + for_each_possible_cpu(cpu) { + void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch; + struct ahash_request *req; + + if (!scratch) { + scratch = kmalloc_node(sizeof(union tcp_md5sum_block) + + sizeof(struct tcphdr), + GFP_KERNEL, + cpu_to_node(cpu)); + if (!scratch) + return; + per_cpu(tcp_md5sig_pool, cpu).scratch = scratch; + } + if (per_cpu(tcp_md5sig_pool, cpu).md5_req) + continue; + + req = ahash_request_alloc(hash, GFP_KERNEL); + if (!req) + return; + + ahash_request_set_callback(req, 0, NULL, NULL); + + per_cpu(tcp_md5sig_pool, cpu).md5_req = req; + } + /* before setting tcp_md5sig_pool_populated, we must commit all writes + * to memory. See smp_rmb() in tcp_get_md5sig_pool() + */ + smp_wmb(); + /* Paired with READ_ONCE() from tcp_alloc_md5sig_pool() + * and tcp_get_md5sig_pool(). + */ + WRITE_ONCE(tcp_md5sig_pool_populated, true); +} + +bool tcp_alloc_md5sig_pool(void) +{ + /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */ + if (unlikely(!READ_ONCE(tcp_md5sig_pool_populated))) { + mutex_lock(&tcp_md5sig_mutex); + + if (!tcp_md5sig_pool_populated) { + __tcp_alloc_md5sig_pool(); + if (tcp_md5sig_pool_populated) + static_branch_inc(&tcp_md5_needed); + } + + mutex_unlock(&tcp_md5sig_mutex); + } + /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */ + return READ_ONCE(tcp_md5sig_pool_populated); +} +EXPORT_SYMBOL(tcp_alloc_md5sig_pool); + + +/** + * tcp_get_md5sig_pool - get md5sig_pool for this user + * + * We use percpu structure, so if we succeed, we exit with preemption + * and BH disabled, to make sure another thread or softirq handling + * wont try to get same context. + */ +struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) +{ + local_bh_disable(); + + /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */ + if (READ_ONCE(tcp_md5sig_pool_populated)) { + /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */ + smp_rmb(); + return this_cpu_ptr(&tcp_md5sig_pool); + } + local_bh_enable(); + return NULL; +} +EXPORT_SYMBOL(tcp_get_md5sig_pool); + +int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, + const struct sk_buff *skb, unsigned int header_len) +{ + struct scatterlist sg; + const struct tcphdr *tp = tcp_hdr(skb); + struct ahash_request *req = hp->md5_req; + unsigned int i; + const unsigned int head_data_len = skb_headlen(skb) > header_len ? + skb_headlen(skb) - header_len : 0; + const struct skb_shared_info *shi = skb_shinfo(skb); + struct sk_buff *frag_iter; + + sg_init_table(&sg, 1); + + sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); + ahash_request_set_crypt(req, &sg, NULL, head_data_len); + if (crypto_ahash_update(req)) + return 1; + + for (i = 0; i < shi->nr_frags; ++i) { + const skb_frag_t *f = &shi->frags[i]; + unsigned int offset = skb_frag_off(f); + struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); + + sg_set_page(&sg, page, skb_frag_size(f), + offset_in_page(offset)); + ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f)); + if (crypto_ahash_update(req)) + return 1; + } + + skb_walk_frags(skb, frag_iter) + if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) + return 1; + + return 0; +} +EXPORT_SYMBOL(tcp_md5_hash_skb_data); + +int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) +{ + u8 keylen = READ_ONCE(key->keylen); /* paired with WRITE_ONCE() in tcp_md5_do_add */ + struct scatterlist sg; + + sg_init_one(&sg, key->key, keylen); + ahash_request_set_crypt(hp->md5_req, &sg, NULL, keylen); + + /* We use data_race() because tcp_md5_do_add() might change key->key under us */ + return data_race(crypto_ahash_update(hp->md5_req)); +} +EXPORT_SYMBOL(tcp_md5_hash_key); + +#endif + +void tcp_done(struct sock *sk) +{ + struct request_sock *req; + + /* We might be called with a new socket, after + * inet_csk_prepare_forced_close() has been called + * so we can not use lockdep_sock_is_held(sk) + */ + req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, 1); + + if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) + TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); + + tcp_set_state(sk, TCP_CLOSE); + tcp_clear_xmit_timers(sk); + if (req) + reqsk_fastopen_remove(sk, req, false); + + WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK); + + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + else + inet_csk_destroy_sock(sk); +} +EXPORT_SYMBOL_GPL(tcp_done); + +int tcp_abort(struct sock *sk, int err) +{ + if (!sk_fullsock(sk)) { + if (sk->sk_state == TCP_NEW_SYN_RECV) { + struct request_sock *req = inet_reqsk(sk); + + local_bh_disable(); + inet_csk_reqsk_queue_drop(req->rsk_listener, req); + local_bh_enable(); + return 0; + } + return -EOPNOTSUPP; + } + + /* Don't race with userspace socket closes such as tcp_close. */ + lock_sock(sk); + + if (sk->sk_state == TCP_LISTEN) { + tcp_set_state(sk, TCP_CLOSE); + inet_csk_listen_stop(sk); + } + + /* Don't race with BH socket closes such as inet_csk_listen_stop. */ + local_bh_disable(); + bh_lock_sock(sk); + + if (!sock_flag(sk, SOCK_DEAD)) { + sk->sk_err = err; + /* This barrier is coupled with smp_rmb() in tcp_poll() */ + smp_wmb(); + sk->sk_error_report(sk); + if (tcp_need_reset(sk->sk_state)) + tcp_send_active_reset(sk, GFP_ATOMIC); + tcp_done(sk); + } + + bh_unlock_sock(sk); + local_bh_enable(); + tcp_write_queue_purge(sk); + release_sock(sk); + return 0; +} +EXPORT_SYMBOL_GPL(tcp_abort); + +extern struct tcp_congestion_ops tcp_reno; + +static __initdata unsigned long thash_entries; +static int __init set_thash_entries(char *str) +{ + ssize_t ret; + + if (!str) + return 0; + + ret = kstrtoul(str, 0, &thash_entries); + if (ret) + return 0; + + return 1; +} +__setup("thash_entries=", set_thash_entries); + +static void __init tcp_init_mem(void) +{ + unsigned long limit = nr_free_buffer_pages() / 16; + + limit = max(limit, 128UL); + sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */ + sysctl_tcp_mem[1] = limit; /* 6.25 % */ + sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */ +} + +void __init tcp_init(void) +{ + int max_rshare, max_wshare, cnt; + unsigned long limit; + unsigned int i; + + BUILD_BUG_ON(TCP_MIN_SND_MSS <= MAX_TCP_OPTION_SPACE); + BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > + sizeof_field(struct sk_buff, cb)); + + percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); + + timer_setup(&tcp_orphan_timer, tcp_orphan_update, TIMER_DEFERRABLE); + mod_timer(&tcp_orphan_timer, jiffies + TCP_ORPHAN_TIMER_PERIOD); + + inet_hashinfo_init(&tcp_hashinfo); + inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash", + thash_entries, 21, /* one slot per 2 MB*/ + 0, 64 * 1024); + tcp_hashinfo.bind_bucket_cachep = + kmem_cache_create("tcp_bind_bucket", + sizeof(struct inet_bind_bucket), 0, + SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + + /* Size and allocate the main established and bind bucket + * hash tables. + * + * The methodology is similar to that of the buffer cache. + */ + tcp_hashinfo.ehash = + alloc_large_system_hash("TCP established", + sizeof(struct inet_ehash_bucket), + thash_entries, + 17, /* one slot per 128 KB of memory */ + 0, + NULL, + &tcp_hashinfo.ehash_mask, + 0, + thash_entries ? 0 : 512 * 1024); + for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) + INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); + + if (inet_ehash_locks_alloc(&tcp_hashinfo)) + panic("TCP: failed to alloc ehash_locks"); + tcp_hashinfo.bhash = + alloc_large_system_hash("TCP bind", + sizeof(struct inet_bind_hashbucket), + tcp_hashinfo.ehash_mask + 1, + 17, /* one slot per 128 KB of memory */ + 0, + &tcp_hashinfo.bhash_size, + NULL, + 0, + 64 * 1024); + tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; + for (i = 0; i < tcp_hashinfo.bhash_size; i++) { + spin_lock_init(&tcp_hashinfo.bhash[i].lock); + INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); + } + + + cnt = tcp_hashinfo.ehash_mask + 1; + sysctl_tcp_max_orphans = cnt / 2; + + tcp_init_mem(); + /* Set per-socket limits to no more than 1/128 the pressure threshold */ + limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); + max_wshare = min(4UL*1024*1024, limit); + max_rshare = min(6UL*1024*1024, limit); + + init_net.ipv4.sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; + init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024; + init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare); + + init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; + init_net.ipv4.sysctl_tcp_rmem[1] = 131072; + init_net.ipv4.sysctl_tcp_rmem[2] = max(131072, max_rshare); + + pr_info("Hash tables configured (established %u bind %u)\n", + tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); + + tcp_v4_init(); + tcp_metrics_init(); + BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); + tcp_tasklet_init(); + mptcp_init(); +} diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c new file mode 100644 index 000000000..6274462b8 --- /dev/null +++ b/net/ipv4/tcp_bbr.c @@ -0,0 +1,1174 @@ +/* Bottleneck Bandwidth and RTT (BBR) congestion control + * + * BBR congestion control computes the sending rate based on the delivery + * rate (throughput) estimated from ACKs. In a nutshell: + * + * On each ACK, update our model of the network path: + * bottleneck_bandwidth = windowed_max(delivered / elapsed, 10 round trips) + * min_rtt = windowed_min(rtt, 10 seconds) + * pacing_rate = pacing_gain * bottleneck_bandwidth + * cwnd = max(cwnd_gain * bottleneck_bandwidth * min_rtt, 4) + * + * The core algorithm does not react directly to packet losses or delays, + * although BBR may adjust the size of next send per ACK when loss is + * observed, or adjust the sending rate if it estimates there is a + * traffic policer, in order to keep the drop rate reasonable. + * + * Here is a state transition diagram for BBR: + * + * | + * V + * +---> STARTUP ----+ + * | | | + * | V | + * | DRAIN ----+ + * | | | + * | V | + * +---> PROBE_BW ----+ + * | ^ | | + * | | | | + * | +----+ | + * | | + * +---- PROBE_RTT <--+ + * + * A BBR flow starts in STARTUP, and ramps up its sending rate quickly. + * When it estimates the pipe is full, it enters DRAIN to drain the queue. + * In steady state a BBR flow only uses PROBE_BW and PROBE_RTT. + * A long-lived BBR flow spends the vast majority of its time remaining + * (repeatedly) in PROBE_BW, fully probing and utilizing the pipe's bandwidth + * in a fair manner, with a small, bounded queue. *If* a flow has been + * continuously sending for the entire min_rtt window, and hasn't seen an RTT + * sample that matches or decreases its min_rtt estimate for 10 seconds, then + * it briefly enters PROBE_RTT to cut inflight to a minimum value to re-probe + * the path's two-way propagation delay (min_rtt). When exiting PROBE_RTT, if + * we estimated that we reached the full bw of the pipe then we enter PROBE_BW; + * otherwise we enter STARTUP to try to fill the pipe. + * + * BBR is described in detail in: + * "BBR: Congestion-Based Congestion Control", + * Neal Cardwell, Yuchung Cheng, C. Stephen Gunn, Soheil Hassas Yeganeh, + * Van Jacobson. ACM Queue, Vol. 14 No. 5, September-October 2016. + * + * There is a public e-mail list for discussing BBR development and testing: + * https://groups.google.com/forum/#!forum/bbr-dev + * + * NOTE: BBR might be used with the fq qdisc ("man tc-fq") with pacing enabled, + * otherwise TCP stack falls back to an internal pacing using one high + * resolution timer per TCP socket and may use more resources. + */ +#include <linux/module.h> +#include <net/tcp.h> +#include <linux/inet_diag.h> +#include <linux/inet.h> +#include <linux/random.h> +#include <linux/win_minmax.h> + +/* Scale factor for rate in pkt/uSec unit to avoid truncation in bandwidth + * estimation. The rate unit ~= (1500 bytes / 1 usec / 2^24) ~= 715 bps. + * This handles bandwidths from 0.06pps (715bps) to 256Mpps (3Tbps) in a u32. + * Since the minimum window is >=4 packets, the lower bound isn't + * an issue. The upper bound isn't an issue with existing technologies. + */ +#define BW_SCALE 24 +#define BW_UNIT (1 << BW_SCALE) + +#define BBR_SCALE 8 /* scaling factor for fractions in BBR (e.g. gains) */ +#define BBR_UNIT (1 << BBR_SCALE) + +/* BBR has the following modes for deciding how fast to send: */ +enum bbr_mode { + BBR_STARTUP, /* ramp up sending rate rapidly to fill pipe */ + BBR_DRAIN, /* drain any queue created during startup */ + BBR_PROBE_BW, /* discover, share bw: pace around estimated bw */ + BBR_PROBE_RTT, /* cut inflight to min to probe min_rtt */ +}; + +/* BBR congestion control block */ +struct bbr { + u32 min_rtt_us; /* min RTT in min_rtt_win_sec window */ + u32 min_rtt_stamp; /* timestamp of min_rtt_us */ + u32 probe_rtt_done_stamp; /* end time for BBR_PROBE_RTT mode */ + struct minmax bw; /* Max recent delivery rate in pkts/uS << 24 */ + u32 rtt_cnt; /* count of packet-timed rounds elapsed */ + u32 next_rtt_delivered; /* scb->tx.delivered at end of round */ + u64 cycle_mstamp; /* time of this cycle phase start */ + u32 mode:3, /* current bbr_mode in state machine */ + prev_ca_state:3, /* CA state on previous ACK */ + packet_conservation:1, /* use packet conservation? */ + round_start:1, /* start of packet-timed tx->ack round? */ + idle_restart:1, /* restarting after idle? */ + probe_rtt_round_done:1, /* a BBR_PROBE_RTT round at 4 pkts? */ + unused:13, + lt_is_sampling:1, /* taking long-term ("LT") samples now? */ + lt_rtt_cnt:7, /* round trips in long-term interval */ + lt_use_bw:1; /* use lt_bw as our bw estimate? */ + u32 lt_bw; /* LT est delivery rate in pkts/uS << 24 */ + u32 lt_last_delivered; /* LT intvl start: tp->delivered */ + u32 lt_last_stamp; /* LT intvl start: tp->delivered_mstamp */ + u32 lt_last_lost; /* LT intvl start: tp->lost */ + u32 pacing_gain:10, /* current gain for setting pacing rate */ + cwnd_gain:10, /* current gain for setting cwnd */ + full_bw_reached:1, /* reached full bw in Startup? */ + full_bw_cnt:2, /* number of rounds without large bw gains */ + cycle_idx:3, /* current index in pacing_gain cycle array */ + has_seen_rtt:1, /* have we seen an RTT sample yet? */ + unused_b:5; + u32 prior_cwnd; /* prior cwnd upon entering loss recovery */ + u32 full_bw; /* recent bw, to estimate if pipe is full */ + + /* For tracking ACK aggregation: */ + u64 ack_epoch_mstamp; /* start of ACK sampling epoch */ + u16 extra_acked[2]; /* max excess data ACKed in epoch */ + u32 ack_epoch_acked:20, /* packets (S)ACKed in sampling epoch */ + extra_acked_win_rtts:5, /* age of extra_acked, in round trips */ + extra_acked_win_idx:1, /* current index in extra_acked array */ + unused_c:6; +}; + +#define CYCLE_LEN 8 /* number of phases in a pacing gain cycle */ + +/* Window length of bw filter (in rounds): */ +static const int bbr_bw_rtts = CYCLE_LEN + 2; +/* Window length of min_rtt filter (in sec): */ +static const u32 bbr_min_rtt_win_sec = 10; +/* Minimum time (in ms) spent at bbr_cwnd_min_target in BBR_PROBE_RTT mode: */ +static const u32 bbr_probe_rtt_mode_ms = 200; +/* Skip TSO below the following bandwidth (bits/sec): */ +static const int bbr_min_tso_rate = 1200000; + +/* Pace at ~1% below estimated bw, on average, to reduce queue at bottleneck. + * In order to help drive the network toward lower queues and low latency while + * maintaining high utilization, the average pacing rate aims to be slightly + * lower than the estimated bandwidth. This is an important aspect of the + * design. + */ +static const int bbr_pacing_margin_percent = 1; + +/* We use a high_gain value of 2/ln(2) because it's the smallest pacing gain + * that will allow a smoothly increasing pacing rate that will double each RTT + * and send the same number of packets per RTT that an un-paced, slow-starting + * Reno or CUBIC flow would: + */ +static const int bbr_high_gain = BBR_UNIT * 2885 / 1000 + 1; +/* The pacing gain of 1/high_gain in BBR_DRAIN is calculated to typically drain + * the queue created in BBR_STARTUP in a single round: + */ +static const int bbr_drain_gain = BBR_UNIT * 1000 / 2885; +/* The gain for deriving steady-state cwnd tolerates delayed/stretched ACKs: */ +static const int bbr_cwnd_gain = BBR_UNIT * 2; +/* The pacing_gain values for the PROBE_BW gain cycle, to discover/share bw: */ +static const int bbr_pacing_gain[] = { + BBR_UNIT * 5 / 4, /* probe for more available bw */ + BBR_UNIT * 3 / 4, /* drain queue and/or yield bw to other flows */ + BBR_UNIT, BBR_UNIT, BBR_UNIT, /* cruise at 1.0*bw to utilize pipe, */ + BBR_UNIT, BBR_UNIT, BBR_UNIT /* without creating excess queue... */ +}; +/* Randomize the starting gain cycling phase over N phases: */ +static const u32 bbr_cycle_rand = 7; + +/* Try to keep at least this many packets in flight, if things go smoothly. For + * smooth functioning, a sliding window protocol ACKing every other packet + * needs at least 4 packets in flight: + */ +static const u32 bbr_cwnd_min_target = 4; + +/* To estimate if BBR_STARTUP mode (i.e. high_gain) has filled pipe... */ +/* If bw has increased significantly (1.25x), there may be more bw available: */ +static const u32 bbr_full_bw_thresh = BBR_UNIT * 5 / 4; +/* But after 3 rounds w/o significant bw growth, estimate pipe is full: */ +static const u32 bbr_full_bw_cnt = 3; + +/* "long-term" ("LT") bandwidth estimator parameters... */ +/* The minimum number of rounds in an LT bw sampling interval: */ +static const u32 bbr_lt_intvl_min_rtts = 4; +/* If lost/delivered ratio > 20%, interval is "lossy" and we may be policed: */ +static const u32 bbr_lt_loss_thresh = 50; +/* If 2 intervals have a bw ratio <= 1/8, their bw is "consistent": */ +static const u32 bbr_lt_bw_ratio = BBR_UNIT / 8; +/* If 2 intervals have a bw diff <= 4 Kbit/sec their bw is "consistent": */ +static const u32 bbr_lt_bw_diff = 4000 / 8; +/* If we estimate we're policed, use lt_bw for this many round trips: */ +static const u32 bbr_lt_bw_max_rtts = 48; + +/* Gain factor for adding extra_acked to target cwnd: */ +static const int bbr_extra_acked_gain = BBR_UNIT; +/* Window length of extra_acked window. */ +static const u32 bbr_extra_acked_win_rtts = 5; +/* Max allowed val for ack_epoch_acked, after which sampling epoch is reset */ +static const u32 bbr_ack_epoch_acked_reset_thresh = 1U << 20; +/* Time period for clamping cwnd increment due to ack aggregation */ +static const u32 bbr_extra_acked_max_us = 100 * 1000; + +static void bbr_check_probe_rtt_done(struct sock *sk); + +/* Do we estimate that STARTUP filled the pipe? */ +static bool bbr_full_bw_reached(const struct sock *sk) +{ + const struct bbr *bbr = inet_csk_ca(sk); + + return bbr->full_bw_reached; +} + +/* Return the windowed max recent bandwidth sample, in pkts/uS << BW_SCALE. */ +static u32 bbr_max_bw(const struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + return minmax_get(&bbr->bw); +} + +/* Return the estimated bandwidth of the path, in pkts/uS << BW_SCALE. */ +static u32 bbr_bw(const struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + return bbr->lt_use_bw ? bbr->lt_bw : bbr_max_bw(sk); +} + +/* Return maximum extra acked in past k-2k round trips, + * where k = bbr_extra_acked_win_rtts. + */ +static u16 bbr_extra_acked(const struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + return max(bbr->extra_acked[0], bbr->extra_acked[1]); +} + +/* Return rate in bytes per second, optionally with a gain. + * The order here is chosen carefully to avoid overflow of u64. This should + * work for input rates of up to 2.9Tbit/sec and gain of 2.89x. + */ +static u64 bbr_rate_bytes_per_sec(struct sock *sk, u64 rate, int gain) +{ + unsigned int mss = tcp_sk(sk)->mss_cache; + + rate *= mss; + rate *= gain; + rate >>= BBR_SCALE; + rate *= USEC_PER_SEC / 100 * (100 - bbr_pacing_margin_percent); + return rate >> BW_SCALE; +} + +/* Convert a BBR bw and gain factor to a pacing rate in bytes per second. */ +static unsigned long bbr_bw_to_pacing_rate(struct sock *sk, u32 bw, int gain) +{ + u64 rate = bw; + + rate = bbr_rate_bytes_per_sec(sk, rate, gain); + rate = min_t(u64, rate, sk->sk_max_pacing_rate); + return rate; +} + +/* Initialize pacing rate to: high_gain * init_cwnd / RTT. */ +static void bbr_init_pacing_rate_from_rtt(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u64 bw; + u32 rtt_us; + + if (tp->srtt_us) { /* any RTT sample yet? */ + rtt_us = max(tp->srtt_us >> 3, 1U); + bbr->has_seen_rtt = 1; + } else { /* no RTT sample yet */ + rtt_us = USEC_PER_MSEC; /* use nominal default RTT */ + } + bw = (u64)tp->snd_cwnd * BW_UNIT; + do_div(bw, rtt_us); + sk->sk_pacing_rate = bbr_bw_to_pacing_rate(sk, bw, bbr_high_gain); +} + +/* Pace using current bw estimate and a gain factor. */ +static void bbr_set_pacing_rate(struct sock *sk, u32 bw, int gain) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + unsigned long rate = bbr_bw_to_pacing_rate(sk, bw, gain); + + if (unlikely(!bbr->has_seen_rtt && tp->srtt_us)) + bbr_init_pacing_rate_from_rtt(sk); + if (bbr_full_bw_reached(sk) || rate > sk->sk_pacing_rate) + sk->sk_pacing_rate = rate; +} + +/* override sysctl_tcp_min_tso_segs */ +static u32 bbr_min_tso_segs(struct sock *sk) +{ + return sk->sk_pacing_rate < (bbr_min_tso_rate >> 3) ? 1 : 2; +} + +static u32 bbr_tso_segs_goal(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 segs, bytes; + + /* Sort of tcp_tso_autosize() but ignoring + * driver provided sk_gso_max_size. + */ + bytes = min_t(unsigned long, + sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift), + GSO_MAX_SIZE - 1 - MAX_TCP_HEADER); + segs = max_t(u32, bytes / tp->mss_cache, bbr_min_tso_segs(sk)); + + return min(segs, 0x7FU); +} + +/* Save "last known good" cwnd so we can restore it after losses or PROBE_RTT */ +static void bbr_save_cwnd(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + if (bbr->prev_ca_state < TCP_CA_Recovery && bbr->mode != BBR_PROBE_RTT) + bbr->prior_cwnd = tp->snd_cwnd; /* this cwnd is good enough */ + else /* loss recovery or BBR_PROBE_RTT have temporarily cut cwnd */ + bbr->prior_cwnd = max(bbr->prior_cwnd, tp->snd_cwnd); +} + +static void bbr_cwnd_event(struct sock *sk, enum tcp_ca_event event) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + if (event == CA_EVENT_TX_START && tp->app_limited) { + bbr->idle_restart = 1; + bbr->ack_epoch_mstamp = tp->tcp_mstamp; + bbr->ack_epoch_acked = 0; + /* Avoid pointless buffer overflows: pace at est. bw if we don't + * need more speed (we're restarting from idle and app-limited). + */ + if (bbr->mode == BBR_PROBE_BW) + bbr_set_pacing_rate(sk, bbr_bw(sk), BBR_UNIT); + else if (bbr->mode == BBR_PROBE_RTT) + bbr_check_probe_rtt_done(sk); + } +} + +/* Calculate bdp based on min RTT and the estimated bottleneck bandwidth: + * + * bdp = ceil(bw * min_rtt * gain) + * + * The key factor, gain, controls the amount of queue. While a small gain + * builds a smaller queue, it becomes more vulnerable to noise in RTT + * measurements (e.g., delayed ACKs or other ACK compression effects). This + * noise may cause BBR to under-estimate the rate. + */ +static u32 bbr_bdp(struct sock *sk, u32 bw, int gain) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 bdp; + u64 w; + + /* If we've never had a valid RTT sample, cap cwnd at the initial + * default. This should only happen when the connection is not using TCP + * timestamps and has retransmitted all of the SYN/SYNACK/data packets + * ACKed so far. In this case, an RTO can cut cwnd to 1, in which + * case we need to slow-start up toward something safe: TCP_INIT_CWND. + */ + if (unlikely(bbr->min_rtt_us == ~0U)) /* no valid RTT samples yet? */ + return TCP_INIT_CWND; /* be safe: cap at default initial cwnd*/ + + w = (u64)bw * bbr->min_rtt_us; + + /* Apply a gain to the given value, remove the BW_SCALE shift, and + * round the value up to avoid a negative feedback loop. + */ + bdp = (((w * gain) >> BBR_SCALE) + BW_UNIT - 1) / BW_UNIT; + + return bdp; +} + +/* To achieve full performance in high-speed paths, we budget enough cwnd to + * fit full-sized skbs in-flight on both end hosts to fully utilize the path: + * - one skb in sending host Qdisc, + * - one skb in sending host TSO/GSO engine + * - one skb being received by receiver host LRO/GRO/delayed-ACK engine + * Don't worry, at low rates (bbr_min_tso_rate) this won't bloat cwnd because + * in such cases tso_segs_goal is 1. The minimum cwnd is 4 packets, + * which allows 2 outstanding 2-packet sequences, to try to keep pipe + * full even with ACK-every-other-packet delayed ACKs. + */ +static u32 bbr_quantization_budget(struct sock *sk, u32 cwnd) +{ + struct bbr *bbr = inet_csk_ca(sk); + + /* Allow enough full-sized skbs in flight to utilize end systems. */ + cwnd += 3 * bbr_tso_segs_goal(sk); + + /* Reduce delayed ACKs by rounding up cwnd to the next even number. */ + cwnd = (cwnd + 1) & ~1U; + + /* Ensure gain cycling gets inflight above BDP even for small BDPs. */ + if (bbr->mode == BBR_PROBE_BW && bbr->cycle_idx == 0) + cwnd += 2; + + return cwnd; +} + +/* Find inflight based on min RTT and the estimated bottleneck bandwidth. */ +static u32 bbr_inflight(struct sock *sk, u32 bw, int gain) +{ + u32 inflight; + + inflight = bbr_bdp(sk, bw, gain); + inflight = bbr_quantization_budget(sk, inflight); + + return inflight; +} + +/* With pacing at lower layers, there's often less data "in the network" than + * "in flight". With TSQ and departure time pacing at lower layers (e.g. fq), + * we often have several skbs queued in the pacing layer with a pre-scheduled + * earliest departure time (EDT). BBR adapts its pacing rate based on the + * inflight level that it estimates has already been "baked in" by previous + * departure time decisions. We calculate a rough estimate of the number of our + * packets that might be in the network at the earliest departure time for the + * next skb scheduled: + * in_network_at_edt = inflight_at_edt - (EDT - now) * bw + * If we're increasing inflight, then we want to know if the transmit of the + * EDT skb will push inflight above the target, so inflight_at_edt includes + * bbr_tso_segs_goal() from the skb departing at EDT. If decreasing inflight, + * then estimate if inflight will sink too low just before the EDT transmit. + */ +static u32 bbr_packets_in_net_at_edt(struct sock *sk, u32 inflight_now) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u64 now_ns, edt_ns, interval_us; + u32 interval_delivered, inflight_at_edt; + + now_ns = tp->tcp_clock_cache; + edt_ns = max(tp->tcp_wstamp_ns, now_ns); + interval_us = div_u64(edt_ns - now_ns, NSEC_PER_USEC); + interval_delivered = (u64)bbr_bw(sk) * interval_us >> BW_SCALE; + inflight_at_edt = inflight_now; + if (bbr->pacing_gain > BBR_UNIT) /* increasing inflight */ + inflight_at_edt += bbr_tso_segs_goal(sk); /* include EDT skb */ + if (interval_delivered >= inflight_at_edt) + return 0; + return inflight_at_edt - interval_delivered; +} + +/* Find the cwnd increment based on estimate of ack aggregation */ +static u32 bbr_ack_aggregation_cwnd(struct sock *sk) +{ + u32 max_aggr_cwnd, aggr_cwnd = 0; + + if (bbr_extra_acked_gain && bbr_full_bw_reached(sk)) { + max_aggr_cwnd = ((u64)bbr_bw(sk) * bbr_extra_acked_max_us) + / BW_UNIT; + aggr_cwnd = (bbr_extra_acked_gain * bbr_extra_acked(sk)) + >> BBR_SCALE; + aggr_cwnd = min(aggr_cwnd, max_aggr_cwnd); + } + + return aggr_cwnd; +} + +/* An optimization in BBR to reduce losses: On the first round of recovery, we + * follow the packet conservation principle: send P packets per P packets acked. + * After that, we slow-start and send at most 2*P packets per P packets acked. + * After recovery finishes, or upon undo, we restore the cwnd we had when + * recovery started (capped by the target cwnd based on estimated BDP). + * + * TODO(ycheng/ncardwell): implement a rate-based approach. + */ +static bool bbr_set_cwnd_to_recover_or_restore( + struct sock *sk, const struct rate_sample *rs, u32 acked, u32 *new_cwnd) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u8 prev_state = bbr->prev_ca_state, state = inet_csk(sk)->icsk_ca_state; + u32 cwnd = tp->snd_cwnd; + + /* An ACK for P pkts should release at most 2*P packets. We do this + * in two steps. First, here we deduct the number of lost packets. + * Then, in bbr_set_cwnd() we slow start up toward the target cwnd. + */ + if (rs->losses > 0) + cwnd = max_t(s32, cwnd - rs->losses, 1); + + if (state == TCP_CA_Recovery && prev_state != TCP_CA_Recovery) { + /* Starting 1st round of Recovery, so do packet conservation. */ + bbr->packet_conservation = 1; + bbr->next_rtt_delivered = tp->delivered; /* start round now */ + /* Cut unused cwnd from app behavior, TSQ, or TSO deferral: */ + cwnd = tcp_packets_in_flight(tp) + acked; + } else if (prev_state >= TCP_CA_Recovery && state < TCP_CA_Recovery) { + /* Exiting loss recovery; restore cwnd saved before recovery. */ + cwnd = max(cwnd, bbr->prior_cwnd); + bbr->packet_conservation = 0; + } + bbr->prev_ca_state = state; + + if (bbr->packet_conservation) { + *new_cwnd = max(cwnd, tcp_packets_in_flight(tp) + acked); + return true; /* yes, using packet conservation */ + } + *new_cwnd = cwnd; + return false; +} + +/* Slow-start up toward target cwnd (if bw estimate is growing, or packet loss + * has drawn us down below target), or snap down to target if we're above it. + */ +static void bbr_set_cwnd(struct sock *sk, const struct rate_sample *rs, + u32 acked, u32 bw, int gain) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u32 cwnd = tp->snd_cwnd, target_cwnd = 0; + + if (!acked) + goto done; /* no packet fully ACKed; just apply caps */ + + if (bbr_set_cwnd_to_recover_or_restore(sk, rs, acked, &cwnd)) + goto done; + + target_cwnd = bbr_bdp(sk, bw, gain); + + /* Increment the cwnd to account for excess ACKed data that seems + * due to aggregation (of data and/or ACKs) visible in the ACK stream. + */ + target_cwnd += bbr_ack_aggregation_cwnd(sk); + target_cwnd = bbr_quantization_budget(sk, target_cwnd); + + /* If we're below target cwnd, slow start cwnd toward target cwnd. */ + if (bbr_full_bw_reached(sk)) /* only cut cwnd if we filled the pipe */ + cwnd = min(cwnd + acked, target_cwnd); + else if (cwnd < target_cwnd || tp->delivered < TCP_INIT_CWND) + cwnd = cwnd + acked; + cwnd = max(cwnd, bbr_cwnd_min_target); + +done: + tp->snd_cwnd = min(cwnd, tp->snd_cwnd_clamp); /* apply global cap */ + if (bbr->mode == BBR_PROBE_RTT) /* drain queue, refresh min_rtt */ + tp->snd_cwnd = min(tp->snd_cwnd, bbr_cwnd_min_target); +} + +/* End cycle phase if it's time and/or we hit the phase's in-flight target. */ +static bool bbr_is_next_cycle_phase(struct sock *sk, + const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + bool is_full_length = + tcp_stamp_us_delta(tp->delivered_mstamp, bbr->cycle_mstamp) > + bbr->min_rtt_us; + u32 inflight, bw; + + /* The pacing_gain of 1.0 paces at the estimated bw to try to fully + * use the pipe without increasing the queue. + */ + if (bbr->pacing_gain == BBR_UNIT) + return is_full_length; /* just use wall clock time */ + + inflight = bbr_packets_in_net_at_edt(sk, rs->prior_in_flight); + bw = bbr_max_bw(sk); + + /* A pacing_gain > 1.0 probes for bw by trying to raise inflight to at + * least pacing_gain*BDP; this may take more than min_rtt if min_rtt is + * small (e.g. on a LAN). We do not persist if packets are lost, since + * a path with small buffers may not hold that much. + */ + if (bbr->pacing_gain > BBR_UNIT) + return is_full_length && + (rs->losses || /* perhaps pacing_gain*BDP won't fit */ + inflight >= bbr_inflight(sk, bw, bbr->pacing_gain)); + + /* A pacing_gain < 1.0 tries to drain extra queue we added if bw + * probing didn't find more bw. If inflight falls to match BDP then we + * estimate queue is drained; persisting would underutilize the pipe. + */ + return is_full_length || + inflight <= bbr_inflight(sk, bw, BBR_UNIT); +} + +static void bbr_advance_cycle_phase(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + bbr->cycle_idx = (bbr->cycle_idx + 1) & (CYCLE_LEN - 1); + bbr->cycle_mstamp = tp->delivered_mstamp; +} + +/* Gain cycling: cycle pacing gain to converge to fair share of available bw. */ +static void bbr_update_cycle_phase(struct sock *sk, + const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + + if (bbr->mode == BBR_PROBE_BW && bbr_is_next_cycle_phase(sk, rs)) + bbr_advance_cycle_phase(sk); +} + +static void bbr_reset_startup_mode(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + bbr->mode = BBR_STARTUP; +} + +static void bbr_reset_probe_bw_mode(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + bbr->mode = BBR_PROBE_BW; + bbr->cycle_idx = CYCLE_LEN - 1 - prandom_u32_max(bbr_cycle_rand); + bbr_advance_cycle_phase(sk); /* flip to next phase of gain cycle */ +} + +static void bbr_reset_mode(struct sock *sk) +{ + if (!bbr_full_bw_reached(sk)) + bbr_reset_startup_mode(sk); + else + bbr_reset_probe_bw_mode(sk); +} + +/* Start a new long-term sampling interval. */ +static void bbr_reset_lt_bw_sampling_interval(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + bbr->lt_last_stamp = div_u64(tp->delivered_mstamp, USEC_PER_MSEC); + bbr->lt_last_delivered = tp->delivered; + bbr->lt_last_lost = tp->lost; + bbr->lt_rtt_cnt = 0; +} + +/* Completely reset long-term bandwidth sampling. */ +static void bbr_reset_lt_bw_sampling(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + bbr->lt_bw = 0; + bbr->lt_use_bw = 0; + bbr->lt_is_sampling = false; + bbr_reset_lt_bw_sampling_interval(sk); +} + +/* Long-term bw sampling interval is done. Estimate whether we're policed. */ +static void bbr_lt_bw_interval_done(struct sock *sk, u32 bw) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 diff; + + if (bbr->lt_bw) { /* do we have bw from a previous interval? */ + /* Is new bw close to the lt_bw from the previous interval? */ + diff = abs(bw - bbr->lt_bw); + if ((diff * BBR_UNIT <= bbr_lt_bw_ratio * bbr->lt_bw) || + (bbr_rate_bytes_per_sec(sk, diff, BBR_UNIT) <= + bbr_lt_bw_diff)) { + /* All criteria are met; estimate we're policed. */ + bbr->lt_bw = (bw + bbr->lt_bw) >> 1; /* avg 2 intvls */ + bbr->lt_use_bw = 1; + bbr->pacing_gain = BBR_UNIT; /* try to avoid drops */ + bbr->lt_rtt_cnt = 0; + return; + } + } + bbr->lt_bw = bw; + bbr_reset_lt_bw_sampling_interval(sk); +} + +/* Token-bucket traffic policers are common (see "An Internet-Wide Analysis of + * Traffic Policing", SIGCOMM 2016). BBR detects token-bucket policers and + * explicitly models their policed rate, to reduce unnecessary losses. We + * estimate that we're policed if we see 2 consecutive sampling intervals with + * consistent throughput and high packet loss. If we think we're being policed, + * set lt_bw to the "long-term" average delivery rate from those 2 intervals. + */ +static void bbr_lt_bw_sampling(struct sock *sk, const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u32 lost, delivered; + u64 bw; + u32 t; + + if (bbr->lt_use_bw) { /* already using long-term rate, lt_bw? */ + if (bbr->mode == BBR_PROBE_BW && bbr->round_start && + ++bbr->lt_rtt_cnt >= bbr_lt_bw_max_rtts) { + bbr_reset_lt_bw_sampling(sk); /* stop using lt_bw */ + bbr_reset_probe_bw_mode(sk); /* restart gain cycling */ + } + return; + } + + /* Wait for the first loss before sampling, to let the policer exhaust + * its tokens and estimate the steady-state rate allowed by the policer. + * Starting samples earlier includes bursts that over-estimate the bw. + */ + if (!bbr->lt_is_sampling) { + if (!rs->losses) + return; + bbr_reset_lt_bw_sampling_interval(sk); + bbr->lt_is_sampling = true; + } + + /* To avoid underestimates, reset sampling if we run out of data. */ + if (rs->is_app_limited) { + bbr_reset_lt_bw_sampling(sk); + return; + } + + if (bbr->round_start) + bbr->lt_rtt_cnt++; /* count round trips in this interval */ + if (bbr->lt_rtt_cnt < bbr_lt_intvl_min_rtts) + return; /* sampling interval needs to be longer */ + if (bbr->lt_rtt_cnt > 4 * bbr_lt_intvl_min_rtts) { + bbr_reset_lt_bw_sampling(sk); /* interval is too long */ + return; + } + + /* End sampling interval when a packet is lost, so we estimate the + * policer tokens were exhausted. Stopping the sampling before the + * tokens are exhausted under-estimates the policed rate. + */ + if (!rs->losses) + return; + + /* Calculate packets lost and delivered in sampling interval. */ + lost = tp->lost - bbr->lt_last_lost; + delivered = tp->delivered - bbr->lt_last_delivered; + /* Is loss rate (lost/delivered) >= lt_loss_thresh? If not, wait. */ + if (!delivered || (lost << BBR_SCALE) < bbr_lt_loss_thresh * delivered) + return; + + /* Find average delivery rate in this sampling interval. */ + t = div_u64(tp->delivered_mstamp, USEC_PER_MSEC) - bbr->lt_last_stamp; + if ((s32)t < 1) + return; /* interval is less than one ms, so wait */ + /* Check if can multiply without overflow */ + if (t >= ~0U / USEC_PER_MSEC) { + bbr_reset_lt_bw_sampling(sk); /* interval too long; reset */ + return; + } + t *= USEC_PER_MSEC; + bw = (u64)delivered * BW_UNIT; + do_div(bw, t); + bbr_lt_bw_interval_done(sk, bw); +} + +/* Estimate the bandwidth based on how fast packets are delivered */ +static void bbr_update_bw(struct sock *sk, const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u64 bw; + + bbr->round_start = 0; + if (rs->delivered < 0 || rs->interval_us <= 0) + return; /* Not a valid observation */ + + /* See if we've reached the next RTT */ + if (!before(rs->prior_delivered, bbr->next_rtt_delivered)) { + bbr->next_rtt_delivered = tp->delivered; + bbr->rtt_cnt++; + bbr->round_start = 1; + bbr->packet_conservation = 0; + } + + bbr_lt_bw_sampling(sk, rs); + + /* Divide delivered by the interval to find a (lower bound) bottleneck + * bandwidth sample. Delivered is in packets and interval_us in uS and + * ratio will be <<1 for most connections. So delivered is first scaled. + */ + bw = div64_long((u64)rs->delivered * BW_UNIT, rs->interval_us); + + /* If this sample is application-limited, it is likely to have a very + * low delivered count that represents application behavior rather than + * the available network rate. Such a sample could drag down estimated + * bw, causing needless slow-down. Thus, to continue to send at the + * last measured network rate, we filter out app-limited samples unless + * they describe the path bw at least as well as our bw model. + * + * So the goal during app-limited phase is to proceed with the best + * network rate no matter how long. We automatically leave this + * phase when app writes faster than the network can deliver :) + */ + if (!rs->is_app_limited || bw >= bbr_max_bw(sk)) { + /* Incorporate new sample into our max bw filter. */ + minmax_running_max(&bbr->bw, bbr_bw_rtts, bbr->rtt_cnt, bw); + } +} + +/* Estimates the windowed max degree of ack aggregation. + * This is used to provision extra in-flight data to keep sending during + * inter-ACK silences. + * + * Degree of ack aggregation is estimated as extra data acked beyond expected. + * + * max_extra_acked = "maximum recent excess data ACKed beyond max_bw * interval" + * cwnd += max_extra_acked + * + * Max extra_acked is clamped by cwnd and bw * bbr_extra_acked_max_us (100 ms). + * Max filter is an approximate sliding window of 5-10 (packet timed) round + * trips. + */ +static void bbr_update_ack_aggregation(struct sock *sk, + const struct rate_sample *rs) +{ + u32 epoch_us, expected_acked, extra_acked; + struct bbr *bbr = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + if (!bbr_extra_acked_gain || rs->acked_sacked <= 0 || + rs->delivered < 0 || rs->interval_us <= 0) + return; + + if (bbr->round_start) { + bbr->extra_acked_win_rtts = min(0x1F, + bbr->extra_acked_win_rtts + 1); + if (bbr->extra_acked_win_rtts >= bbr_extra_acked_win_rtts) { + bbr->extra_acked_win_rtts = 0; + bbr->extra_acked_win_idx = bbr->extra_acked_win_idx ? + 0 : 1; + bbr->extra_acked[bbr->extra_acked_win_idx] = 0; + } + } + + /* Compute how many packets we expected to be delivered over epoch. */ + epoch_us = tcp_stamp_us_delta(tp->delivered_mstamp, + bbr->ack_epoch_mstamp); + expected_acked = ((u64)bbr_bw(sk) * epoch_us) / BW_UNIT; + + /* Reset the aggregation epoch if ACK rate is below expected rate or + * significantly large no. of ack received since epoch (potentially + * quite old epoch). + */ + if (bbr->ack_epoch_acked <= expected_acked || + (bbr->ack_epoch_acked + rs->acked_sacked >= + bbr_ack_epoch_acked_reset_thresh)) { + bbr->ack_epoch_acked = 0; + bbr->ack_epoch_mstamp = tp->delivered_mstamp; + expected_acked = 0; + } + + /* Compute excess data delivered, beyond what was expected. */ + bbr->ack_epoch_acked = min_t(u32, 0xFFFFF, + bbr->ack_epoch_acked + rs->acked_sacked); + extra_acked = bbr->ack_epoch_acked - expected_acked; + extra_acked = min(extra_acked, tp->snd_cwnd); + if (extra_acked > bbr->extra_acked[bbr->extra_acked_win_idx]) + bbr->extra_acked[bbr->extra_acked_win_idx] = extra_acked; +} + +/* Estimate when the pipe is full, using the change in delivery rate: BBR + * estimates that STARTUP filled the pipe if the estimated bw hasn't changed by + * at least bbr_full_bw_thresh (25%) after bbr_full_bw_cnt (3) non-app-limited + * rounds. Why 3 rounds: 1: rwin autotuning grows the rwin, 2: we fill the + * higher rwin, 3: we get higher delivery rate samples. Or transient + * cross-traffic or radio noise can go away. CUBIC Hystart shares a similar + * design goal, but uses delay and inter-ACK spacing instead of bandwidth. + */ +static void bbr_check_full_bw_reached(struct sock *sk, + const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 bw_thresh; + + if (bbr_full_bw_reached(sk) || !bbr->round_start || rs->is_app_limited) + return; + + bw_thresh = (u64)bbr->full_bw * bbr_full_bw_thresh >> BBR_SCALE; + if (bbr_max_bw(sk) >= bw_thresh) { + bbr->full_bw = bbr_max_bw(sk); + bbr->full_bw_cnt = 0; + return; + } + ++bbr->full_bw_cnt; + bbr->full_bw_reached = bbr->full_bw_cnt >= bbr_full_bw_cnt; +} + +/* If pipe is probably full, drain the queue and then enter steady-state. */ +static void bbr_check_drain(struct sock *sk, const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + + if (bbr->mode == BBR_STARTUP && bbr_full_bw_reached(sk)) { + bbr->mode = BBR_DRAIN; /* drain queue we created */ + tcp_sk(sk)->snd_ssthresh = + bbr_inflight(sk, bbr_max_bw(sk), BBR_UNIT); + } /* fall through to check if in-flight is already small: */ + if (bbr->mode == BBR_DRAIN && + bbr_packets_in_net_at_edt(sk, tcp_packets_in_flight(tcp_sk(sk))) <= + bbr_inflight(sk, bbr_max_bw(sk), BBR_UNIT)) + bbr_reset_probe_bw_mode(sk); /* we estimate queue is drained */ +} + +static void bbr_check_probe_rtt_done(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + if (!(bbr->probe_rtt_done_stamp && + after(tcp_jiffies32, bbr->probe_rtt_done_stamp))) + return; + + bbr->min_rtt_stamp = tcp_jiffies32; /* wait a while until PROBE_RTT */ + tp->snd_cwnd = max(tp->snd_cwnd, bbr->prior_cwnd); + bbr_reset_mode(sk); +} + +/* The goal of PROBE_RTT mode is to have BBR flows cooperatively and + * periodically drain the bottleneck queue, to converge to measure the true + * min_rtt (unloaded propagation delay). This allows the flows to keep queues + * small (reducing queuing delay and packet loss) and achieve fairness among + * BBR flows. + * + * The min_rtt filter window is 10 seconds. When the min_rtt estimate expires, + * we enter PROBE_RTT mode and cap the cwnd at bbr_cwnd_min_target=4 packets. + * After at least bbr_probe_rtt_mode_ms=200ms and at least one packet-timed + * round trip elapsed with that flight size <= 4, we leave PROBE_RTT mode and + * re-enter the previous mode. BBR uses 200ms to approximately bound the + * performance penalty of PROBE_RTT's cwnd capping to roughly 2% (200ms/10s). + * + * Note that flows need only pay 2% if they are busy sending over the last 10 + * seconds. Interactive applications (e.g., Web, RPCs, video chunks) often have + * natural silences or low-rate periods within 10 seconds where the rate is low + * enough for long enough to drain its queue in the bottleneck. We pick up + * these min RTT measurements opportunistically with our min_rtt filter. :-) + */ +static void bbr_update_min_rtt(struct sock *sk, const struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + bool filter_expired; + + /* Track min RTT seen in the min_rtt_win_sec filter window: */ + filter_expired = after(tcp_jiffies32, + bbr->min_rtt_stamp + bbr_min_rtt_win_sec * HZ); + if (rs->rtt_us >= 0 && + (rs->rtt_us < bbr->min_rtt_us || + (filter_expired && !rs->is_ack_delayed))) { + bbr->min_rtt_us = rs->rtt_us; + bbr->min_rtt_stamp = tcp_jiffies32; + } + + if (bbr_probe_rtt_mode_ms > 0 && filter_expired && + !bbr->idle_restart && bbr->mode != BBR_PROBE_RTT) { + bbr->mode = BBR_PROBE_RTT; /* dip, drain queue */ + bbr_save_cwnd(sk); /* note cwnd so we can restore it */ + bbr->probe_rtt_done_stamp = 0; + } + + if (bbr->mode == BBR_PROBE_RTT) { + /* Ignore low rate samples during this mode. */ + tp->app_limited = + (tp->delivered + tcp_packets_in_flight(tp)) ? : 1; + /* Maintain min packets in flight for max(200 ms, 1 round). */ + if (!bbr->probe_rtt_done_stamp && + tcp_packets_in_flight(tp) <= bbr_cwnd_min_target) { + bbr->probe_rtt_done_stamp = tcp_jiffies32 + + msecs_to_jiffies(bbr_probe_rtt_mode_ms); + bbr->probe_rtt_round_done = 0; + bbr->next_rtt_delivered = tp->delivered; + } else if (bbr->probe_rtt_done_stamp) { + if (bbr->round_start) + bbr->probe_rtt_round_done = 1; + if (bbr->probe_rtt_round_done) + bbr_check_probe_rtt_done(sk); + } + } + /* Restart after idle ends only once we process a new S/ACK for data */ + if (rs->delivered > 0) + bbr->idle_restart = 0; +} + +static void bbr_update_gains(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + switch (bbr->mode) { + case BBR_STARTUP: + bbr->pacing_gain = bbr_high_gain; + bbr->cwnd_gain = bbr_high_gain; + break; + case BBR_DRAIN: + bbr->pacing_gain = bbr_drain_gain; /* slow, to drain */ + bbr->cwnd_gain = bbr_high_gain; /* keep cwnd */ + break; + case BBR_PROBE_BW: + bbr->pacing_gain = (bbr->lt_use_bw ? + BBR_UNIT : + bbr_pacing_gain[bbr->cycle_idx]); + bbr->cwnd_gain = bbr_cwnd_gain; + break; + case BBR_PROBE_RTT: + bbr->pacing_gain = BBR_UNIT; + bbr->cwnd_gain = BBR_UNIT; + break; + default: + WARN_ONCE(1, "BBR bad mode: %u\n", bbr->mode); + break; + } +} + +static void bbr_update_model(struct sock *sk, const struct rate_sample *rs) +{ + bbr_update_bw(sk, rs); + bbr_update_ack_aggregation(sk, rs); + bbr_update_cycle_phase(sk, rs); + bbr_check_full_bw_reached(sk, rs); + bbr_check_drain(sk, rs); + bbr_update_min_rtt(sk, rs); + bbr_update_gains(sk); +} + +static void bbr_main(struct sock *sk, const struct rate_sample *rs) +{ + struct bbr *bbr = inet_csk_ca(sk); + u32 bw; + + bbr_update_model(sk, rs); + + bw = bbr_bw(sk); + bbr_set_pacing_rate(sk, bw, bbr->pacing_gain); + bbr_set_cwnd(sk, rs, rs->acked_sacked, bw, bbr->cwnd_gain); +} + +static void bbr_init(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + + bbr->prior_cwnd = 0; + tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; + bbr->rtt_cnt = 0; + bbr->next_rtt_delivered = tp->delivered; + bbr->prev_ca_state = TCP_CA_Open; + bbr->packet_conservation = 0; + + bbr->probe_rtt_done_stamp = 0; + bbr->probe_rtt_round_done = 0; + bbr->min_rtt_us = tcp_min_rtt(tp); + bbr->min_rtt_stamp = tcp_jiffies32; + + minmax_reset(&bbr->bw, bbr->rtt_cnt, 0); /* init max bw to 0 */ + + bbr->has_seen_rtt = 0; + bbr_init_pacing_rate_from_rtt(sk); + + bbr->round_start = 0; + bbr->idle_restart = 0; + bbr->full_bw_reached = 0; + bbr->full_bw = 0; + bbr->full_bw_cnt = 0; + bbr->cycle_mstamp = 0; + bbr->cycle_idx = 0; + bbr_reset_lt_bw_sampling(sk); + bbr_reset_startup_mode(sk); + + bbr->ack_epoch_mstamp = tp->tcp_mstamp; + bbr->ack_epoch_acked = 0; + bbr->extra_acked_win_rtts = 0; + bbr->extra_acked_win_idx = 0; + bbr->extra_acked[0] = 0; + bbr->extra_acked[1] = 0; + + cmpxchg(&sk->sk_pacing_status, SK_PACING_NONE, SK_PACING_NEEDED); +} + +static u32 bbr_sndbuf_expand(struct sock *sk) +{ + /* Provision 3 * cwnd since BBR may slow-start even during recovery. */ + return 3; +} + +/* In theory BBR does not need to undo the cwnd since it does not + * always reduce cwnd on losses (see bbr_main()). Keep it for now. + */ +static u32 bbr_undo_cwnd(struct sock *sk) +{ + struct bbr *bbr = inet_csk_ca(sk); + + bbr->full_bw = 0; /* spurious slow-down; reset full pipe detection */ + bbr->full_bw_cnt = 0; + bbr_reset_lt_bw_sampling(sk); + return tcp_sk(sk)->snd_cwnd; +} + +/* Entering loss recovery, so save cwnd for when we exit or undo recovery. */ +static u32 bbr_ssthresh(struct sock *sk) +{ + bbr_save_cwnd(sk); + return tcp_sk(sk)->snd_ssthresh; +} + +static size_t bbr_get_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info) +{ + if (ext & (1 << (INET_DIAG_BBRINFO - 1)) || + ext & (1 << (INET_DIAG_VEGASINFO - 1))) { + struct tcp_sock *tp = tcp_sk(sk); + struct bbr *bbr = inet_csk_ca(sk); + u64 bw = bbr_bw(sk); + + bw = bw * tp->mss_cache * USEC_PER_SEC >> BW_SCALE; + memset(&info->bbr, 0, sizeof(info->bbr)); + info->bbr.bbr_bw_lo = (u32)bw; + info->bbr.bbr_bw_hi = (u32)(bw >> 32); + info->bbr.bbr_min_rtt = bbr->min_rtt_us; + info->bbr.bbr_pacing_gain = bbr->pacing_gain; + info->bbr.bbr_cwnd_gain = bbr->cwnd_gain; + *attr = INET_DIAG_BBRINFO; + return sizeof(info->bbr); + } + return 0; +} + +static void bbr_set_state(struct sock *sk, u8 new_state) +{ + struct bbr *bbr = inet_csk_ca(sk); + + if (new_state == TCP_CA_Loss) { + struct rate_sample rs = { .losses = 1 }; + + bbr->prev_ca_state = TCP_CA_Loss; + bbr->full_bw = 0; + bbr->round_start = 1; /* treat RTO like end of a round */ + bbr_lt_bw_sampling(sk, &rs); + } +} + +static struct tcp_congestion_ops tcp_bbr_cong_ops __read_mostly = { + .flags = TCP_CONG_NON_RESTRICTED, + .name = "bbr", + .owner = THIS_MODULE, + .init = bbr_init, + .cong_control = bbr_main, + .sndbuf_expand = bbr_sndbuf_expand, + .undo_cwnd = bbr_undo_cwnd, + .cwnd_event = bbr_cwnd_event, + .ssthresh = bbr_ssthresh, + .min_tso_segs = bbr_min_tso_segs, + .get_info = bbr_get_info, + .set_state = bbr_set_state, +}; + +static int __init bbr_register(void) +{ + BUILD_BUG_ON(sizeof(struct bbr) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&tcp_bbr_cong_ops); +} + +static void __exit bbr_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_bbr_cong_ops); +} + +module_init(bbr_register); +module_exit(bbr_unregister); + +MODULE_AUTHOR("Van Jacobson <vanj@google.com>"); +MODULE_AUTHOR("Neal Cardwell <ncardwell@google.com>"); +MODULE_AUTHOR("Yuchung Cheng <ycheng@google.com>"); +MODULE_AUTHOR("Soheil Hassas Yeganeh <soheil@google.com>"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_DESCRIPTION("TCP BBR (Bottleneck Bandwidth and RTT)"); diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c new file mode 100644 index 000000000..f5f588b1f --- /dev/null +++ b/net/ipv4/tcp_bic.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Binary Increase Congestion control for TCP + * Home page: + * http://netsrv.csc.ncsu.edu/twiki/bin/view/Main/BIC + * This is from the implementation of BICTCP in + * Lison-Xu, Kahaled Harfoush, and Injong Rhee. + * "Binary Increase Congestion Control for Fast, Long Distance + * Networks" in InfoComm 2004 + * Available from: + * http://netsrv.csc.ncsu.edu/export/bitcp.pdf + * + * Unless BIC is enabled and congestion window is large + * this behaves the same as the original Reno. + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <net/tcp.h> + +#define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation + * max_cwnd = snd_cwnd * beta + */ +#define BICTCP_B 4 /* + * In binary search, + * go to point (max+min)/N + */ + +static int fast_convergence = 1; +static int max_increment = 16; +static int low_window = 14; +static int beta = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */ +static int initial_ssthresh; +static int smooth_part = 20; + +module_param(fast_convergence, int, 0644); +MODULE_PARM_DESC(fast_convergence, "turn on/off fast convergence"); +module_param(max_increment, int, 0644); +MODULE_PARM_DESC(max_increment, "Limit on increment allowed during binary search"); +module_param(low_window, int, 0644); +MODULE_PARM_DESC(low_window, "lower bound on congestion window (for TCP friendliness)"); +module_param(beta, int, 0644); +MODULE_PARM_DESC(beta, "beta for multiplicative increase"); +module_param(initial_ssthresh, int, 0644); +MODULE_PARM_DESC(initial_ssthresh, "initial value of slow start threshold"); +module_param(smooth_part, int, 0644); +MODULE_PARM_DESC(smooth_part, "log(B/(B*Smin))/log(B/(B-1))+B, # of RTT from Wmax-B to Wmax"); + +/* BIC TCP Parameters */ +struct bictcp { + u32 cnt; /* increase cwnd by 1 after ACKs */ + u32 last_max_cwnd; /* last maximum snd_cwnd */ + u32 last_cwnd; /* the last snd_cwnd */ + u32 last_time; /* time when updated last_cwnd */ + u32 epoch_start; /* beginning of an epoch */ +#define ACK_RATIO_SHIFT 4 + u32 delayed_ack; /* estimate the ratio of Packets/ACKs << 4 */ +}; + +static inline void bictcp_reset(struct bictcp *ca) +{ + ca->cnt = 0; + ca->last_max_cwnd = 0; + ca->last_cwnd = 0; + ca->last_time = 0; + ca->epoch_start = 0; + ca->delayed_ack = 2 << ACK_RATIO_SHIFT; +} + +static void bictcp_init(struct sock *sk) +{ + struct bictcp *ca = inet_csk_ca(sk); + + bictcp_reset(ca); + + if (initial_ssthresh) + tcp_sk(sk)->snd_ssthresh = initial_ssthresh; +} + +/* + * Compute congestion window to use. + */ +static inline void bictcp_update(struct bictcp *ca, u32 cwnd) +{ + if (ca->last_cwnd == cwnd && + (s32)(tcp_jiffies32 - ca->last_time) <= HZ / 32) + return; + + ca->last_cwnd = cwnd; + ca->last_time = tcp_jiffies32; + + if (ca->epoch_start == 0) /* record the beginning of an epoch */ + ca->epoch_start = tcp_jiffies32; + + /* start off normal */ + if (cwnd <= low_window) { + ca->cnt = cwnd; + return; + } + + /* binary increase */ + if (cwnd < ca->last_max_cwnd) { + __u32 dist = (ca->last_max_cwnd - cwnd) + / BICTCP_B; + + if (dist > max_increment) + /* linear increase */ + ca->cnt = cwnd / max_increment; + else if (dist <= 1U) + /* binary search increase */ + ca->cnt = (cwnd * smooth_part) / BICTCP_B; + else + /* binary search increase */ + ca->cnt = cwnd / dist; + } else { + /* slow start AMD linear increase */ + if (cwnd < ca->last_max_cwnd + BICTCP_B) + /* slow start */ + ca->cnt = (cwnd * smooth_part) / BICTCP_B; + else if (cwnd < ca->last_max_cwnd + max_increment*(BICTCP_B-1)) + /* slow start */ + ca->cnt = (cwnd * (BICTCP_B-1)) + / (cwnd - ca->last_max_cwnd); + else + /* linear increase */ + ca->cnt = cwnd / max_increment; + } + + /* if in slow start or link utilization is very low */ + if (ca->last_max_cwnd == 0) { + if (ca->cnt > 20) /* increase cwnd 5% per RTT */ + ca->cnt = 20; + } + + ca->cnt = (ca->cnt << ACK_RATIO_SHIFT) / ca->delayed_ack; + if (ca->cnt == 0) /* cannot be zero */ + ca->cnt = 1; +} + +static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bictcp *ca = inet_csk_ca(sk); + + if (!tcp_is_cwnd_limited(sk)) + return; + + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + return; + } + bictcp_update(ca, tp->snd_cwnd); + tcp_cong_avoid_ai(tp, ca->cnt, acked); +} + +/* + * behave like Reno until low_window is reached, + * then increase congestion window slowly + */ +static u32 bictcp_recalc_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct bictcp *ca = inet_csk_ca(sk); + + ca->epoch_start = 0; /* end of epoch */ + + /* Wmax and fast convergence */ + if (tp->snd_cwnd < ca->last_max_cwnd && fast_convergence) + ca->last_max_cwnd = (tp->snd_cwnd * (BICTCP_BETA_SCALE + beta)) + / (2 * BICTCP_BETA_SCALE); + else + ca->last_max_cwnd = tp->snd_cwnd; + + if (tp->snd_cwnd <= low_window) + return max(tp->snd_cwnd >> 1U, 2U); + else + return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U); +} + +static void bictcp_state(struct sock *sk, u8 new_state) +{ + if (new_state == TCP_CA_Loss) + bictcp_reset(inet_csk_ca(sk)); +} + +/* Track delayed acknowledgment ratio using sliding window + * ratio = (15*ratio + sample) / 16 + */ +static void bictcp_acked(struct sock *sk, const struct ack_sample *sample) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ca_state == TCP_CA_Open) { + struct bictcp *ca = inet_csk_ca(sk); + + ca->delayed_ack += sample->pkts_acked - + (ca->delayed_ack >> ACK_RATIO_SHIFT); + } +} + +static struct tcp_congestion_ops bictcp __read_mostly = { + .init = bictcp_init, + .ssthresh = bictcp_recalc_ssthresh, + .cong_avoid = bictcp_cong_avoid, + .set_state = bictcp_state, + .undo_cwnd = tcp_reno_undo_cwnd, + .pkts_acked = bictcp_acked, + .owner = THIS_MODULE, + .name = "bic", +}; + +static int __init bictcp_register(void) +{ + BUILD_BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&bictcp); +} + +static void __exit bictcp_unregister(void) +{ + tcp_unregister_congestion_control(&bictcp); +} + +module_init(bictcp_register); +module_exit(bictcp_unregister); + +MODULE_AUTHOR("Stephen Hemminger"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("BIC TCP"); diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c new file mode 100644 index 000000000..d0ca1fc32 --- /dev/null +++ b/net/ipv4/tcp_bpf.c @@ -0,0 +1,651 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ + +#include <linux/skmsg.h> +#include <linux/filter.h> +#include <linux/bpf.h> +#include <linux/init.h> +#include <linux/wait.h> +#include <linux/util_macros.h> + +#include <net/inet_common.h> +#include <net/tls.h> + +int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock, + struct msghdr *msg, int len, int flags) +{ + struct iov_iter *iter = &msg->msg_iter; + int peek = flags & MSG_PEEK; + struct sk_msg *msg_rx; + int i, copied = 0; + + msg_rx = list_first_entry_or_null(&psock->ingress_msg, + struct sk_msg, list); + + while (copied != len) { + struct scatterlist *sge; + + if (unlikely(!msg_rx)) + break; + + i = msg_rx->sg.start; + do { + struct page *page; + int copy; + + sge = sk_msg_elem(msg_rx, i); + copy = sge->length; + page = sg_page(sge); + if (copied + copy > len) + copy = len - copied; + copy = copy_page_to_iter(page, sge->offset, copy, iter); + if (!copy) + return copied ? copied : -EFAULT; + + copied += copy; + if (likely(!peek)) { + sge->offset += copy; + sge->length -= copy; + if (!msg_rx->skb) + sk_mem_uncharge(sk, copy); + msg_rx->sg.size -= copy; + + if (!sge->length) { + sk_msg_iter_var_next(i); + if (!msg_rx->skb) + put_page(page); + } + } else { + /* Lets not optimize peek case if copy_page_to_iter + * didn't copy the entire length lets just break. + */ + if (copy != sge->length) + return copied; + sk_msg_iter_var_next(i); + } + + if (copied == len) + break; + } while (i != msg_rx->sg.end); + + if (unlikely(peek)) { + if (msg_rx == list_last_entry(&psock->ingress_msg, + struct sk_msg, list)) + break; + msg_rx = list_next_entry(msg_rx, list); + continue; + } + + msg_rx->sg.start = i; + if (!sge->length && msg_rx->sg.start == msg_rx->sg.end) { + list_del(&msg_rx->list); + if (msg_rx->skb) + consume_skb(msg_rx->skb); + kfree(msg_rx); + } + msg_rx = list_first_entry_or_null(&psock->ingress_msg, + struct sk_msg, list); + } + + return copied; +} +EXPORT_SYMBOL_GPL(__tcp_bpf_recvmsg); + +static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock, + struct sk_msg *msg, u32 apply_bytes, int flags) +{ + bool apply = apply_bytes; + struct scatterlist *sge; + u32 size, copied = 0; + struct sk_msg *tmp; + int i, ret = 0; + + tmp = kzalloc(sizeof(*tmp), __GFP_NOWARN | GFP_KERNEL); + if (unlikely(!tmp)) + return -ENOMEM; + + lock_sock(sk); + tmp->sg.start = msg->sg.start; + i = msg->sg.start; + do { + sge = sk_msg_elem(msg, i); + size = (apply && apply_bytes < sge->length) ? + apply_bytes : sge->length; + if (!sk_wmem_schedule(sk, size)) { + if (!copied) + ret = -ENOMEM; + break; + } + + sk_mem_charge(sk, size); + sk_msg_xfer(tmp, msg, i, size); + copied += size; + if (sge->length) + get_page(sk_msg_page(tmp, i)); + sk_msg_iter_var_next(i); + tmp->sg.end = i; + if (apply) { + apply_bytes -= size; + if (!apply_bytes) { + if (sge->length) + sk_msg_iter_var_prev(i); + break; + } + } + } while (i != msg->sg.end); + + if (!ret) { + msg->sg.start = i; + sk_psock_queue_msg(psock, tmp); + sk_psock_data_ready(sk, psock); + } else { + sk_msg_free(sk, tmp); + kfree(tmp); + } + + release_sock(sk); + return ret; +} + +static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes, + int flags, bool uncharge) +{ + bool apply = apply_bytes; + struct scatterlist *sge; + struct page *page; + int size, ret = 0; + u32 off; + + while (1) { + bool has_tx_ulp; + + sge = sk_msg_elem(msg, msg->sg.start); + size = (apply && apply_bytes < sge->length) ? + apply_bytes : sge->length; + off = sge->offset; + page = sg_page(sge); + + tcp_rate_check_app_limited(sk); +retry: + has_tx_ulp = tls_sw_has_ctx_tx(sk); + if (has_tx_ulp) { + flags |= MSG_SENDPAGE_NOPOLICY; + ret = kernel_sendpage_locked(sk, + page, off, size, flags); + } else { + ret = do_tcp_sendpages(sk, page, off, size, flags); + } + + if (ret <= 0) + return ret; + if (apply) + apply_bytes -= ret; + msg->sg.size -= ret; + sge->offset += ret; + sge->length -= ret; + if (uncharge) + sk_mem_uncharge(sk, ret); + if (ret != size) { + size -= ret; + off += ret; + goto retry; + } + if (!sge->length) { + put_page(page); + sk_msg_iter_next(msg, start); + sg_init_table(sge, 1); + if (msg->sg.start == msg->sg.end) + break; + } + if (apply && !apply_bytes) + break; + } + + return 0; +} + +static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg, + u32 apply_bytes, int flags, bool uncharge) +{ + int ret; + + lock_sock(sk); + ret = tcp_bpf_push(sk, msg, apply_bytes, flags, uncharge); + release_sock(sk); + return ret; +} + +int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, + u32 bytes, int flags) +{ + bool ingress = sk_msg_to_ingress(msg); + struct sk_psock *psock = sk_psock_get(sk); + int ret; + + if (unlikely(!psock)) + return -EPIPE; + + ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) : + tcp_bpf_push_locked(sk, msg, bytes, flags, false); + sk_psock_put(sk, psock); + return ret; +} +EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir); + +#ifdef CONFIG_BPF_STREAM_PARSER +static bool tcp_bpf_stream_read(const struct sock *sk) +{ + struct sk_psock *psock; + bool empty = true; + + rcu_read_lock(); + psock = sk_psock(sk); + if (likely(psock)) + empty = list_empty(&psock->ingress_msg); + rcu_read_unlock(); + return !empty; +} + +static int tcp_bpf_wait_data(struct sock *sk, struct sk_psock *psock, + int flags, long timeo, int *err) +{ + DEFINE_WAIT_FUNC(wait, woken_wake_function); + int ret = 0; + + if (sk->sk_shutdown & RCV_SHUTDOWN) + return 1; + + if (!timeo) + return ret; + + add_wait_queue(sk_sleep(sk), &wait); + sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); + ret = sk_wait_event(sk, &timeo, + !list_empty(&psock->ingress_msg) || + !skb_queue_empty_lockless(&sk->sk_receive_queue), &wait); + sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); + remove_wait_queue(sk_sleep(sk), &wait); + return ret; +} + +static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int nonblock, int flags, int *addr_len) +{ + struct sk_psock *psock; + int copied, ret; + + if (unlikely(flags & MSG_ERRQUEUE)) + return inet_recv_error(sk, msg, len, addr_len); + + psock = sk_psock_get(sk); + if (unlikely(!psock)) + return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + if (!skb_queue_empty(&sk->sk_receive_queue) && + sk_psock_queue_empty(psock)) { + sk_psock_put(sk, psock); + return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + } + lock_sock(sk); +msg_bytes_ready: + copied = __tcp_bpf_recvmsg(sk, psock, msg, len, flags); + if (!copied) { + int data, err = 0; + long timeo; + + timeo = sock_rcvtimeo(sk, nonblock); + data = tcp_bpf_wait_data(sk, psock, flags, timeo, &err); + if (data) { + if (!sk_psock_queue_empty(psock)) + goto msg_bytes_ready; + release_sock(sk); + sk_psock_put(sk, psock); + return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + } + if (err) { + ret = err; + goto out; + } + copied = -EAGAIN; + } + ret = copied; +out: + release_sock(sk); + sk_psock_put(sk, psock); + return ret; +} + +static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock, + struct sk_msg *msg, int *copied, int flags) +{ + bool cork = false, enospc = sk_msg_full(msg); + struct sock *sk_redir; + u32 tosend, origsize, sent, delta = 0; + u32 eval; + int ret; + +more_data: + if (psock->eval == __SK_NONE) { + /* Track delta in msg size to add/subtract it on SK_DROP from + * returned to user copied size. This ensures user doesn't + * get a positive return code with msg_cut_data and SK_DROP + * verdict. + */ + delta = msg->sg.size; + psock->eval = sk_psock_msg_verdict(sk, psock, msg); + delta -= msg->sg.size; + } + + if (msg->cork_bytes && + msg->cork_bytes > msg->sg.size && !enospc) { + psock->cork_bytes = msg->cork_bytes - msg->sg.size; + if (!psock->cork) { + psock->cork = kzalloc(sizeof(*psock->cork), + GFP_ATOMIC | __GFP_NOWARN); + if (!psock->cork) + return -ENOMEM; + } + memcpy(psock->cork, msg, sizeof(*msg)); + return 0; + } + + tosend = msg->sg.size; + if (psock->apply_bytes && psock->apply_bytes < tosend) + tosend = psock->apply_bytes; + eval = __SK_NONE; + + switch (psock->eval) { + case __SK_PASS: + ret = tcp_bpf_push(sk, msg, tosend, flags, true); + if (unlikely(ret)) { + *copied -= sk_msg_free(sk, msg); + break; + } + sk_msg_apply_bytes(psock, tosend); + break; + case __SK_REDIRECT: + sk_redir = psock->sk_redir; + sk_msg_apply_bytes(psock, tosend); + if (!psock->apply_bytes) { + /* Clean up before releasing the sock lock. */ + eval = psock->eval; + psock->eval = __SK_NONE; + psock->sk_redir = NULL; + } + if (psock->cork) { + cork = true; + psock->cork = NULL; + } + sk_msg_return(sk, msg, tosend); + release_sock(sk); + + origsize = msg->sg.size; + ret = tcp_bpf_sendmsg_redir(sk_redir, msg, tosend, flags); + sent = origsize - msg->sg.size; + + if (eval == __SK_REDIRECT) + sock_put(sk_redir); + + lock_sock(sk); + if (unlikely(ret < 0)) { + int free = sk_msg_free_nocharge(sk, msg); + + if (!cork) + *copied -= free; + } + if (cork) { + sk_msg_free(sk, msg); + kfree(msg); + msg = NULL; + ret = 0; + } + break; + case __SK_DROP: + default: + sk_msg_free_partial(sk, msg, tosend); + sk_msg_apply_bytes(psock, tosend); + *copied -= (tosend + delta); + return -EACCES; + } + + if (likely(!ret)) { + if (!psock->apply_bytes) { + psock->eval = __SK_NONE; + if (psock->sk_redir) { + sock_put(psock->sk_redir); + psock->sk_redir = NULL; + } + } + if (msg && + msg->sg.data[msg->sg.start].page_link && + msg->sg.data[msg->sg.start].length) { + if (eval == __SK_REDIRECT) + sk_mem_charge(sk, tosend - sent); + goto more_data; + } + } + return ret; +} + +static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) +{ + struct sk_msg tmp, *msg_tx = NULL; + int copied = 0, err = 0; + struct sk_psock *psock; + long timeo; + int flags; + + /* Don't let internal do_tcp_sendpages() flags through */ + flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED); + flags |= MSG_NO_SHARED_FRAGS; + + psock = sk_psock_get(sk); + if (unlikely(!psock)) + return tcp_sendmsg(sk, msg, size); + + lock_sock(sk); + timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); + while (msg_data_left(msg)) { + bool enospc = false; + u32 copy, osize; + + if (sk->sk_err) { + err = -sk->sk_err; + goto out_err; + } + + copy = msg_data_left(msg); + if (!sk_stream_memory_free(sk)) + goto wait_for_sndbuf; + if (psock->cork) { + msg_tx = psock->cork; + } else { + msg_tx = &tmp; + sk_msg_init(msg_tx); + } + + osize = msg_tx->sg.size; + err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1); + if (err) { + if (err != -ENOSPC) + goto wait_for_memory; + enospc = true; + copy = msg_tx->sg.size - osize; + } + + err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx, + copy); + if (err < 0) { + sk_msg_trim(sk, msg_tx, osize); + goto out_err; + } + + copied += copy; + if (psock->cork_bytes) { + if (size > psock->cork_bytes) + psock->cork_bytes = 0; + else + psock->cork_bytes -= size; + if (psock->cork_bytes && !enospc) + goto out_err; + /* All cork bytes are accounted, rerun the prog. */ + psock->eval = __SK_NONE; + psock->cork_bytes = 0; + } + + err = tcp_bpf_send_verdict(sk, psock, msg_tx, &copied, flags); + if (unlikely(err < 0)) + goto out_err; + continue; +wait_for_sndbuf: + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); +wait_for_memory: + err = sk_stream_wait_memory(sk, &timeo); + if (err) { + if (msg_tx && msg_tx != psock->cork) + sk_msg_free(sk, msg_tx); + goto out_err; + } + } +out_err: + if (err < 0) + err = sk_stream_error(sk, msg->msg_flags, err); + release_sock(sk); + sk_psock_put(sk, psock); + return copied ? copied : err; +} + +static int tcp_bpf_sendpage(struct sock *sk, struct page *page, int offset, + size_t size, int flags) +{ + struct sk_msg tmp, *msg = NULL; + int err = 0, copied = 0; + struct sk_psock *psock; + bool enospc = false; + + psock = sk_psock_get(sk); + if (unlikely(!psock)) + return tcp_sendpage(sk, page, offset, size, flags); + + lock_sock(sk); + if (psock->cork) { + msg = psock->cork; + } else { + msg = &tmp; + sk_msg_init(msg); + } + + /* Catch case where ring is full and sendpage is stalled. */ + if (unlikely(sk_msg_full(msg))) + goto out_err; + + sk_msg_page_add(msg, page, size, offset); + sk_mem_charge(sk, size); + copied = size; + if (sk_msg_full(msg)) + enospc = true; + if (psock->cork_bytes) { + if (size > psock->cork_bytes) + psock->cork_bytes = 0; + else + psock->cork_bytes -= size; + if (psock->cork_bytes && !enospc) + goto out_err; + /* All cork bytes are accounted, rerun the prog. */ + psock->eval = __SK_NONE; + psock->cork_bytes = 0; + } + + err = tcp_bpf_send_verdict(sk, psock, msg, &copied, flags); +out_err: + release_sock(sk); + sk_psock_put(sk, psock); + return copied ? copied : err; +} + +enum { + TCP_BPF_IPV4, + TCP_BPF_IPV6, + TCP_BPF_NUM_PROTS, +}; + +enum { + TCP_BPF_BASE, + TCP_BPF_TX, + TCP_BPF_NUM_CFGS, +}; + +static struct proto *tcpv6_prot_saved __read_mostly; +static DEFINE_SPINLOCK(tcpv6_prot_lock); +static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS]; + +static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS], + struct proto *base) +{ + prot[TCP_BPF_BASE] = *base; + prot[TCP_BPF_BASE].close = sock_map_close; + prot[TCP_BPF_BASE].recvmsg = tcp_bpf_recvmsg; + prot[TCP_BPF_BASE].stream_memory_read = tcp_bpf_stream_read; + + prot[TCP_BPF_TX] = prot[TCP_BPF_BASE]; + prot[TCP_BPF_TX].sendmsg = tcp_bpf_sendmsg; + prot[TCP_BPF_TX].sendpage = tcp_bpf_sendpage; +} + +static void tcp_bpf_check_v6_needs_rebuild(struct proto *ops) +{ + if (unlikely(ops != smp_load_acquire(&tcpv6_prot_saved))) { + spin_lock_bh(&tcpv6_prot_lock); + if (likely(ops != tcpv6_prot_saved)) { + tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV6], ops); + smp_store_release(&tcpv6_prot_saved, ops); + } + spin_unlock_bh(&tcpv6_prot_lock); + } +} + +static int __init tcp_bpf_v4_build_proto(void) +{ + tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot); + return 0; +} +late_initcall(tcp_bpf_v4_build_proto); + +static int tcp_bpf_assert_proto_ops(struct proto *ops) +{ + /* In order to avoid retpoline, we make assumptions when we call + * into ops if e.g. a psock is not present. Make sure they are + * indeed valid assumptions. + */ + return ops->recvmsg == tcp_recvmsg && + ops->sendmsg == tcp_sendmsg && + ops->sendpage == tcp_sendpage ? 0 : -ENOTSUPP; +} + +struct proto *tcp_bpf_get_proto(struct sock *sk, struct sk_psock *psock) +{ + int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4; + int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE; + + if (sk->sk_family == AF_INET6) { + if (tcp_bpf_assert_proto_ops(psock->sk_proto)) + return ERR_PTR(-EINVAL); + + tcp_bpf_check_v6_needs_rebuild(psock->sk_proto); + } + + return &tcp_bpf_prots[family][config]; +} + +/* If a child got cloned from a listening socket that had tcp_bpf + * protocol callbacks installed, we need to restore the callbacks to + * the default ones because the child does not inherit the psock state + * that tcp_bpf callbacks expect. + */ +void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) +{ + struct proto *prot = newsk->sk_prot; + + if (is_insidevar(prot, tcp_bpf_prots)) + newsk->sk_prot = sk->sk_prot_creator; +} +#endif /* CONFIG_BPF_STREAM_PARSER */ diff --git a/net/ipv4/tcp_cdg.c b/net/ipv4/tcp_cdg.c new file mode 100644 index 000000000..56dede4b5 --- /dev/null +++ b/net/ipv4/tcp_cdg.c @@ -0,0 +1,428 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CAIA Delay-Gradient (CDG) congestion control + * + * This implementation is based on the paper: + * D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using + * delay gradients." In IFIP Networking, pages 328-341. Springer, 2011. + * + * Scavenger traffic (Less-than-Best-Effort) should disable coexistence + * heuristics using parameters use_shadow=0 and use_ineff=0. + * + * Parameters window, backoff_beta, and backoff_factor are crucial for + * throughput and delay. Future work is needed to determine better defaults, + * and to provide guidelines for use in different environments/contexts. + * + * Except for window, knobs are configured via /sys/module/tcp_cdg/parameters/. + * Parameter window is only configurable when loading tcp_cdg as a module. + * + * Notable differences from paper/FreeBSD: + * o Using Hybrid Slow start and Proportional Rate Reduction. + * o Add toggle for shadow window mechanism. Suggested by David Hayes. + * o Add toggle for non-congestion loss tolerance. + * o Scaling parameter G is changed to a backoff factor; + * conversion is given by: backoff_factor = 1000/(G * window). + * o Limit shadow window to 2 * cwnd, or to cwnd when application limited. + * o More accurate e^-x. + */ +#include <linux/kernel.h> +#include <linux/random.h> +#include <linux/module.h> +#include <linux/sched/clock.h> + +#include <net/tcp.h> + +#define HYSTART_ACK_TRAIN 1 +#define HYSTART_DELAY 2 + +static int window __read_mostly = 8; +static unsigned int backoff_beta __read_mostly = 0.7071 * 1024; /* sqrt 0.5 */ +static unsigned int backoff_factor __read_mostly = 42; +static unsigned int hystart_detect __read_mostly = 3; +static unsigned int use_ineff __read_mostly = 5; +static bool use_shadow __read_mostly = true; +static bool use_tolerance __read_mostly; + +module_param(window, int, 0444); +MODULE_PARM_DESC(window, "gradient window size (power of two <= 256)"); +module_param(backoff_beta, uint, 0644); +MODULE_PARM_DESC(backoff_beta, "backoff beta (0-1024)"); +module_param(backoff_factor, uint, 0644); +MODULE_PARM_DESC(backoff_factor, "backoff probability scale factor"); +module_param(hystart_detect, uint, 0644); +MODULE_PARM_DESC(hystart_detect, "use Hybrid Slow start " + "(0: disabled, 1: ACK train, 2: delay threshold, 3: both)"); +module_param(use_ineff, uint, 0644); +MODULE_PARM_DESC(use_ineff, "use ineffectual backoff detection (threshold)"); +module_param(use_shadow, bool, 0644); +MODULE_PARM_DESC(use_shadow, "use shadow window heuristic"); +module_param(use_tolerance, bool, 0644); +MODULE_PARM_DESC(use_tolerance, "use loss tolerance heuristic"); + +struct cdg_minmax { + union { + struct { + s32 min; + s32 max; + }; + u64 v64; + }; +}; + +enum cdg_state { + CDG_UNKNOWN = 0, + CDG_NONFULL = 1, + CDG_FULL = 2, + CDG_BACKOFF = 3, +}; + +struct cdg { + struct cdg_minmax rtt; + struct cdg_minmax rtt_prev; + struct cdg_minmax *gradients; + struct cdg_minmax gsum; + bool gfilled; + u8 tail; + u8 state; + u8 delack; + u32 rtt_seq; + u32 shadow_wnd; + u16 backoff_cnt; + u16 sample_cnt; + s32 delay_min; + u32 last_ack; + u32 round_start; +}; + +/** + * nexp_u32 - negative base-e exponential + * @ux: x in units of micro + * + * Returns exp(ux * -1e-6) * U32_MAX. + */ +static u32 __pure nexp_u32(u32 ux) +{ + static const u16 v[] = { + /* exp(-x)*65536-1 for x = 0, 0.000256, 0.000512, ... */ + 65535, + 65518, 65501, 65468, 65401, 65267, 65001, 64470, 63422, + 61378, 57484, 50423, 38795, 22965, 8047, 987, 14, + }; + u32 msb = ux >> 8; + u32 res; + int i; + + /* Cut off when ux >= 2^24 (actual result is <= 222/U32_MAX). */ + if (msb > U16_MAX) + return 0; + + /* Scale first eight bits linearly: */ + res = U32_MAX - (ux & 0xff) * (U32_MAX / 1000000); + + /* Obtain e^(x + y + ...) by computing e^x * e^y * ...: */ + for (i = 1; msb; i++, msb >>= 1) { + u32 y = v[i & -(msb & 1)] + U32_C(1); + + res = ((u64)res * y) >> 16; + } + + return res; +} + +/* Based on the HyStart algorithm (by Ha et al.) that is implemented in + * tcp_cubic. Differences/experimental changes: + * o Using Hayes' delayed ACK filter. + * o Using a usec clock for the ACK train. + * o Reset ACK train when application limited. + * o Invoked at any cwnd (i.e. also when cwnd < 16). + * o Invoked only when cwnd < ssthresh (i.e. not when cwnd == ssthresh). + */ +static void tcp_cdg_hystart_update(struct sock *sk) +{ + struct cdg *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + ca->delay_min = min_not_zero(ca->delay_min, ca->rtt.min); + if (ca->delay_min == 0) + return; + + if (hystart_detect & HYSTART_ACK_TRAIN) { + u32 now_us = tp->tcp_mstamp; + + if (ca->last_ack == 0 || !tcp_is_cwnd_limited(sk)) { + ca->last_ack = now_us; + ca->round_start = now_us; + } else if (before(now_us, ca->last_ack + 3000)) { + u32 base_owd = max(ca->delay_min / 2U, 125U); + + ca->last_ack = now_us; + if (after(now_us, ca->round_start + base_owd)) { + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTTRAINDETECT); + NET_ADD_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTTRAINCWND, + tp->snd_cwnd); + tp->snd_ssthresh = tp->snd_cwnd; + return; + } + } + } + + if (hystart_detect & HYSTART_DELAY) { + if (ca->sample_cnt < 8) { + ca->sample_cnt++; + } else { + s32 thresh = max(ca->delay_min + ca->delay_min / 8U, + 125U); + + if (ca->rtt.min > thresh) { + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTDELAYDETECT); + NET_ADD_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTDELAYCWND, + tp->snd_cwnd); + tp->snd_ssthresh = tp->snd_cwnd; + } + } + } +} + +static s32 tcp_cdg_grad(struct cdg *ca) +{ + s32 gmin = ca->rtt.min - ca->rtt_prev.min; + s32 gmax = ca->rtt.max - ca->rtt_prev.max; + s32 grad; + + if (ca->gradients) { + ca->gsum.min += gmin - ca->gradients[ca->tail].min; + ca->gsum.max += gmax - ca->gradients[ca->tail].max; + ca->gradients[ca->tail].min = gmin; + ca->gradients[ca->tail].max = gmax; + ca->tail = (ca->tail + 1) & (window - 1); + gmin = ca->gsum.min; + gmax = ca->gsum.max; + } + + /* We keep sums to ignore gradients during cwnd reductions; + * the paper's smoothed gradients otherwise simplify to: + * (rtt_latest - rtt_oldest) / window. + * + * We also drop division by window here. + */ + grad = gmin > 0 ? gmin : gmax; + + /* Extrapolate missing values in gradient window: */ + if (!ca->gfilled) { + if (!ca->gradients && window > 1) + grad *= window; /* Memory allocation failed. */ + else if (ca->tail == 0) + ca->gfilled = true; + else + grad = (grad * window) / (int)ca->tail; + } + + /* Backoff was effectual: */ + if (gmin <= -32 || gmax <= -32) + ca->backoff_cnt = 0; + + if (use_tolerance) { + /* Reduce small variations to zero: */ + gmin = DIV_ROUND_CLOSEST(gmin, 64); + gmax = DIV_ROUND_CLOSEST(gmax, 64); + + if (gmin > 0 && gmax <= 0) + ca->state = CDG_FULL; + else if ((gmin > 0 && gmax > 0) || gmax < 0) + ca->state = CDG_NONFULL; + } + return grad; +} + +static bool tcp_cdg_backoff(struct sock *sk, u32 grad) +{ + struct cdg *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + if (prandom_u32() <= nexp_u32(grad * backoff_factor)) + return false; + + if (use_ineff) { + ca->backoff_cnt++; + if (ca->backoff_cnt > use_ineff) + return false; + } + + ca->shadow_wnd = max(ca->shadow_wnd, tp->snd_cwnd); + ca->state = CDG_BACKOFF; + tcp_enter_cwr(sk); + return true; +} + +/* Not called in CWR or Recovery state. */ +static void tcp_cdg_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct cdg *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + u32 prior_snd_cwnd; + u32 incr; + + if (tcp_in_slow_start(tp) && hystart_detect) + tcp_cdg_hystart_update(sk); + + if (after(ack, ca->rtt_seq) && ca->rtt.v64) { + s32 grad = 0; + + if (ca->rtt_prev.v64) + grad = tcp_cdg_grad(ca); + ca->rtt_seq = tp->snd_nxt; + ca->rtt_prev = ca->rtt; + ca->rtt.v64 = 0; + ca->last_ack = 0; + ca->sample_cnt = 0; + + if (grad > 0 && tcp_cdg_backoff(sk, grad)) + return; + } + + if (!tcp_is_cwnd_limited(sk)) { + ca->shadow_wnd = min(ca->shadow_wnd, tp->snd_cwnd); + return; + } + + prior_snd_cwnd = tp->snd_cwnd; + tcp_reno_cong_avoid(sk, ack, acked); + + incr = tp->snd_cwnd - prior_snd_cwnd; + ca->shadow_wnd = max(ca->shadow_wnd, ca->shadow_wnd + incr); +} + +static void tcp_cdg_acked(struct sock *sk, const struct ack_sample *sample) +{ + struct cdg *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + if (sample->rtt_us <= 0) + return; + + /* A heuristic for filtering delayed ACKs, adapted from: + * D.A. Hayes. "Timing enhancements to the FreeBSD kernel to support + * delay and rate based TCP mechanisms." TR 100219A. CAIA, 2010. + */ + if (tp->sacked_out == 0) { + if (sample->pkts_acked == 1 && ca->delack) { + /* A delayed ACK is only used for the minimum if it is + * provenly lower than an existing non-zero minimum. + */ + ca->rtt.min = min(ca->rtt.min, sample->rtt_us); + ca->delack--; + return; + } else if (sample->pkts_acked > 1 && ca->delack < 5) { + ca->delack++; + } + } + + ca->rtt.min = min_not_zero(ca->rtt.min, sample->rtt_us); + ca->rtt.max = max(ca->rtt.max, sample->rtt_us); +} + +static u32 tcp_cdg_ssthresh(struct sock *sk) +{ + struct cdg *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + if (ca->state == CDG_BACKOFF) + return max(2U, (tp->snd_cwnd * min(1024U, backoff_beta)) >> 10); + + if (ca->state == CDG_NONFULL && use_tolerance) + return tp->snd_cwnd; + + ca->shadow_wnd = min(ca->shadow_wnd >> 1, tp->snd_cwnd); + if (use_shadow) + return max3(2U, ca->shadow_wnd, tp->snd_cwnd >> 1); + return max(2U, tp->snd_cwnd >> 1); +} + +static void tcp_cdg_cwnd_event(struct sock *sk, const enum tcp_ca_event ev) +{ + struct cdg *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct cdg_minmax *gradients; + + switch (ev) { + case CA_EVENT_CWND_RESTART: + gradients = ca->gradients; + if (gradients) + memset(gradients, 0, window * sizeof(gradients[0])); + memset(ca, 0, sizeof(*ca)); + + ca->gradients = gradients; + ca->rtt_seq = tp->snd_nxt; + ca->shadow_wnd = tp->snd_cwnd; + break; + case CA_EVENT_COMPLETE_CWR: + ca->state = CDG_UNKNOWN; + ca->rtt_seq = tp->snd_nxt; + ca->rtt_prev = ca->rtt; + ca->rtt.v64 = 0; + break; + default: + break; + } +} + +static void tcp_cdg_init(struct sock *sk) +{ + struct cdg *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + ca->gradients = NULL; + /* We silently fall back to window = 1 if allocation fails. */ + if (window > 1) + ca->gradients = kcalloc(window, sizeof(ca->gradients[0]), + GFP_NOWAIT | __GFP_NOWARN); + ca->rtt_seq = tp->snd_nxt; + ca->shadow_wnd = tp->snd_cwnd; +} + +static void tcp_cdg_release(struct sock *sk) +{ + struct cdg *ca = inet_csk_ca(sk); + + kfree(ca->gradients); + ca->gradients = NULL; +} + +static struct tcp_congestion_ops tcp_cdg __read_mostly = { + .cong_avoid = tcp_cdg_cong_avoid, + .cwnd_event = tcp_cdg_cwnd_event, + .pkts_acked = tcp_cdg_acked, + .undo_cwnd = tcp_reno_undo_cwnd, + .ssthresh = tcp_cdg_ssthresh, + .release = tcp_cdg_release, + .init = tcp_cdg_init, + .owner = THIS_MODULE, + .name = "cdg", +}; + +static int __init tcp_cdg_register(void) +{ + if (backoff_beta > 1024 || window < 1 || window > 256) + return -ERANGE; + if (!is_power_of_2(window)) + return -EINVAL; + + BUILD_BUG_ON(sizeof(struct cdg) > ICSK_CA_PRIV_SIZE); + tcp_register_congestion_control(&tcp_cdg); + return 0; +} + +static void __exit tcp_cdg_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_cdg); +} + +module_init(tcp_cdg_register); +module_exit(tcp_cdg_unregister); +MODULE_AUTHOR("Kenneth Klette Jonassen"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP CDG"); diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c new file mode 100644 index 000000000..db5831e6c --- /dev/null +++ b/net/ipv4/tcp_cong.c @@ -0,0 +1,478 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Pluggable TCP congestion control support and newReno + * congestion control. + * Based on ideas from I/O scheduler support and Web100. + * + * Copyright (C) 2005 Stephen Hemminger <shemminger@osdl.org> + */ + +#define pr_fmt(fmt) "TCP: " fmt + +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/gfp.h> +#include <linux/jhash.h> +#include <net/tcp.h> + +static DEFINE_SPINLOCK(tcp_cong_list_lock); +static LIST_HEAD(tcp_cong_list); + +/* Simple linear search, don't expect many entries! */ +struct tcp_congestion_ops *tcp_ca_find(const char *name) +{ + struct tcp_congestion_ops *e; + + list_for_each_entry_rcu(e, &tcp_cong_list, list) { + if (strcmp(e->name, name) == 0) + return e; + } + + return NULL; +} + +/* Must be called with rcu lock held */ +static struct tcp_congestion_ops *tcp_ca_find_autoload(struct net *net, + const char *name) +{ + struct tcp_congestion_ops *ca = tcp_ca_find(name); + +#ifdef CONFIG_MODULES + if (!ca && capable(CAP_NET_ADMIN)) { + rcu_read_unlock(); + request_module("tcp_%s", name); + rcu_read_lock(); + ca = tcp_ca_find(name); + } +#endif + return ca; +} + +/* Simple linear search, not much in here. */ +struct tcp_congestion_ops *tcp_ca_find_key(u32 key) +{ + struct tcp_congestion_ops *e; + + list_for_each_entry_rcu(e, &tcp_cong_list, list) { + if (e->key == key) + return e; + } + + return NULL; +} + +/* + * Attach new congestion control algorithm to the list + * of available options. + */ +int tcp_register_congestion_control(struct tcp_congestion_ops *ca) +{ + int ret = 0; + + /* all algorithms must implement these */ + if (!ca->ssthresh || !ca->undo_cwnd || + !(ca->cong_avoid || ca->cong_control)) { + pr_err("%s does not implement required ops\n", ca->name); + return -EINVAL; + } + + ca->key = jhash(ca->name, sizeof(ca->name), strlen(ca->name)); + + spin_lock(&tcp_cong_list_lock); + if (ca->key == TCP_CA_UNSPEC || tcp_ca_find_key(ca->key)) { + pr_notice("%s already registered or non-unique key\n", + ca->name); + ret = -EEXIST; + } else { + list_add_tail_rcu(&ca->list, &tcp_cong_list); + pr_debug("%s registered\n", ca->name); + } + spin_unlock(&tcp_cong_list_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(tcp_register_congestion_control); + +/* + * Remove congestion control algorithm, called from + * the module's remove function. Module ref counts are used + * to ensure that this can't be done till all sockets using + * that method are closed. + */ +void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca) +{ + spin_lock(&tcp_cong_list_lock); + list_del_rcu(&ca->list); + spin_unlock(&tcp_cong_list_lock); + + /* Wait for outstanding readers to complete before the + * module gets removed entirely. + * + * A try_module_get() should fail by now as our module is + * in "going" state since no refs are held anymore and + * module_exit() handler being called. + */ + synchronize_rcu(); +} +EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control); + +u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca) +{ + const struct tcp_congestion_ops *ca; + u32 key = TCP_CA_UNSPEC; + + might_sleep(); + + rcu_read_lock(); + ca = tcp_ca_find_autoload(net, name); + if (ca) { + key = ca->key; + *ecn_ca = ca->flags & TCP_CONG_NEEDS_ECN; + } + rcu_read_unlock(); + + return key; +} +EXPORT_SYMBOL_GPL(tcp_ca_get_key_by_name); + +char *tcp_ca_get_name_by_key(u32 key, char *buffer) +{ + const struct tcp_congestion_ops *ca; + char *ret = NULL; + + rcu_read_lock(); + ca = tcp_ca_find_key(key); + if (ca) + ret = strncpy(buffer, ca->name, + TCP_CA_NAME_MAX); + rcu_read_unlock(); + + return ret; +} +EXPORT_SYMBOL_GPL(tcp_ca_get_name_by_key); + +/* Assign choice of congestion control. */ +void tcp_assign_congestion_control(struct sock *sk) +{ + struct net *net = sock_net(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + const struct tcp_congestion_ops *ca; + + rcu_read_lock(); + ca = rcu_dereference(net->ipv4.tcp_congestion_control); + if (unlikely(!bpf_try_module_get(ca, ca->owner))) + ca = &tcp_reno; + icsk->icsk_ca_ops = ca; + rcu_read_unlock(); + + memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv)); + if (ca->flags & TCP_CONG_NEEDS_ECN) + INET_ECN_xmit(sk); + else + INET_ECN_dontxmit(sk); +} + +void tcp_init_congestion_control(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + tcp_sk(sk)->prior_ssthresh = 0; + if (icsk->icsk_ca_ops->init) + icsk->icsk_ca_ops->init(sk); + if (tcp_ca_needs_ecn(sk)) + INET_ECN_xmit(sk); + else + INET_ECN_dontxmit(sk); + icsk->icsk_ca_initialized = 1; +} + +static void tcp_reinit_congestion_control(struct sock *sk, + const struct tcp_congestion_ops *ca) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + tcp_cleanup_congestion_control(sk); + icsk->icsk_ca_ops = ca; + icsk->icsk_ca_setsockopt = 1; + memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv)); + + if (ca->flags & TCP_CONG_NEEDS_ECN) + INET_ECN_xmit(sk); + else + INET_ECN_dontxmit(sk); + + if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) + tcp_init_congestion_control(sk); +} + +/* Manage refcounts on socket close. */ +void tcp_cleanup_congestion_control(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ca_ops->release) + icsk->icsk_ca_ops->release(sk); + bpf_module_put(icsk->icsk_ca_ops, icsk->icsk_ca_ops->owner); +} + +/* Used by sysctl to change default congestion control */ +int tcp_set_default_congestion_control(struct net *net, const char *name) +{ + struct tcp_congestion_ops *ca; + const struct tcp_congestion_ops *prev; + int ret; + + rcu_read_lock(); + ca = tcp_ca_find_autoload(net, name); + if (!ca) { + ret = -ENOENT; + } else if (!bpf_try_module_get(ca, ca->owner)) { + ret = -EBUSY; + } else if (!net_eq(net, &init_net) && + !(ca->flags & TCP_CONG_NON_RESTRICTED)) { + /* Only init netns can set default to a restricted algorithm */ + ret = -EPERM; + } else { + prev = xchg(&net->ipv4.tcp_congestion_control, ca); + if (prev) + bpf_module_put(prev, prev->owner); + + ca->flags |= TCP_CONG_NON_RESTRICTED; + ret = 0; + } + rcu_read_unlock(); + + return ret; +} + +/* Set default value from kernel configuration at bootup */ +static int __init tcp_congestion_default(void) +{ + return tcp_set_default_congestion_control(&init_net, + CONFIG_DEFAULT_TCP_CONG); +} +late_initcall(tcp_congestion_default); + +/* Build string with list of available congestion control values */ +void tcp_get_available_congestion_control(char *buf, size_t maxlen) +{ + struct tcp_congestion_ops *ca; + size_t offs = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(ca, &tcp_cong_list, list) { + offs += snprintf(buf + offs, maxlen - offs, + "%s%s", + offs == 0 ? "" : " ", ca->name); + + if (WARN_ON_ONCE(offs >= maxlen)) + break; + } + rcu_read_unlock(); +} + +/* Get current default congestion control */ +void tcp_get_default_congestion_control(struct net *net, char *name) +{ + const struct tcp_congestion_ops *ca; + + rcu_read_lock(); + ca = rcu_dereference(net->ipv4.tcp_congestion_control); + strncpy(name, ca->name, TCP_CA_NAME_MAX); + rcu_read_unlock(); +} + +/* Built list of non-restricted congestion control values */ +void tcp_get_allowed_congestion_control(char *buf, size_t maxlen) +{ + struct tcp_congestion_ops *ca; + size_t offs = 0; + + *buf = '\0'; + rcu_read_lock(); + list_for_each_entry_rcu(ca, &tcp_cong_list, list) { + if (!(ca->flags & TCP_CONG_NON_RESTRICTED)) + continue; + offs += snprintf(buf + offs, maxlen - offs, + "%s%s", + offs == 0 ? "" : " ", ca->name); + + if (WARN_ON_ONCE(offs >= maxlen)) + break; + } + rcu_read_unlock(); +} + +/* Change list of non-restricted congestion control */ +int tcp_set_allowed_congestion_control(char *val) +{ + struct tcp_congestion_ops *ca; + char *saved_clone, *clone, *name; + int ret = 0; + + saved_clone = clone = kstrdup(val, GFP_USER); + if (!clone) + return -ENOMEM; + + spin_lock(&tcp_cong_list_lock); + /* pass 1 check for bad entries */ + while ((name = strsep(&clone, " ")) && *name) { + ca = tcp_ca_find(name); + if (!ca) { + ret = -ENOENT; + goto out; + } + } + + /* pass 2 clear old values */ + list_for_each_entry_rcu(ca, &tcp_cong_list, list) + ca->flags &= ~TCP_CONG_NON_RESTRICTED; + + /* pass 3 mark as allowed */ + while ((name = strsep(&val, " ")) && *name) { + ca = tcp_ca_find(name); + WARN_ON(!ca); + if (ca) + ca->flags |= TCP_CONG_NON_RESTRICTED; + } +out: + spin_unlock(&tcp_cong_list_lock); + kfree(saved_clone); + + return ret; +} + +/* Change congestion control for socket. If load is false, then it is the + * responsibility of the caller to call tcp_init_congestion_control or + * tcp_reinit_congestion_control (if the current congestion control was + * already initialized. + */ +int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, + bool cap_net_admin) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + const struct tcp_congestion_ops *ca; + int err = 0; + + if (icsk->icsk_ca_dst_locked) + return -EPERM; + + rcu_read_lock(); + if (!load) + ca = tcp_ca_find(name); + else + ca = tcp_ca_find_autoload(sock_net(sk), name); + + /* No change asking for existing value */ + if (ca == icsk->icsk_ca_ops) { + icsk->icsk_ca_setsockopt = 1; + goto out; + } + + if (!ca) + err = -ENOENT; + else if (!((ca->flags & TCP_CONG_NON_RESTRICTED) || cap_net_admin)) + err = -EPERM; + else if (!bpf_try_module_get(ca, ca->owner)) + err = -EBUSY; + else + tcp_reinit_congestion_control(sk, ca); + out: + rcu_read_unlock(); + return err; +} + +/* Slow start is used when congestion window is no greater than the slow start + * threshold. We base on RFC2581 and also handle stretch ACKs properly. + * We do not implement RFC3465 Appropriate Byte Counting (ABC) per se but + * something better;) a packet is only considered (s)acked in its entirety to + * defend the ACK attacks described in the RFC. Slow start processes a stretch + * ACK of degree N as if N acks of degree 1 are received back to back except + * ABC caps N to 2. Slow start exits when cwnd grows over ssthresh and + * returns the leftover acks to adjust cwnd in congestion avoidance mode. + */ +u32 tcp_slow_start(struct tcp_sock *tp, u32 acked) +{ + u32 cwnd = min(tp->snd_cwnd + acked, tp->snd_ssthresh); + + acked -= cwnd - tp->snd_cwnd; + tp->snd_cwnd = min(cwnd, tp->snd_cwnd_clamp); + + return acked; +} +EXPORT_SYMBOL_GPL(tcp_slow_start); + +/* In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd (or alternative w), + * for every packet that was ACKed. + */ +void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked) +{ + /* If credits accumulated at a higher w, apply them gently now. */ + if (tp->snd_cwnd_cnt >= w) { + tp->snd_cwnd_cnt = 0; + tp->snd_cwnd++; + } + + tp->snd_cwnd_cnt += acked; + if (tp->snd_cwnd_cnt >= w) { + u32 delta = tp->snd_cwnd_cnt / w; + + tp->snd_cwnd_cnt -= delta * w; + tp->snd_cwnd += delta; + } + tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_cwnd_clamp); +} +EXPORT_SYMBOL_GPL(tcp_cong_avoid_ai); + +/* + * TCP Reno congestion control + * This is special case used for fallback as well. + */ +/* This is Jacobson's slow start and congestion avoidance. + * SIGCOMM '88, p. 328. + */ +void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (!tcp_is_cwnd_limited(sk)) + return; + + /* In "safe" area, increase. */ + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + return; + } + /* In dangerous area, increase slowly. */ + tcp_cong_avoid_ai(tp, tp->snd_cwnd, acked); +} +EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid); + +/* Slow start threshold is half the congestion window (min 2) */ +u32 tcp_reno_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + return max(tp->snd_cwnd >> 1U, 2U); +} +EXPORT_SYMBOL_GPL(tcp_reno_ssthresh); + +u32 tcp_reno_undo_cwnd(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + return max(tp->snd_cwnd, tp->prior_cwnd); +} +EXPORT_SYMBOL_GPL(tcp_reno_undo_cwnd); + +struct tcp_congestion_ops tcp_reno = { + .flags = TCP_CONG_NON_RESTRICTED, + .name = "reno", + .owner = THIS_MODULE, + .ssthresh = tcp_reno_ssthresh, + .cong_avoid = tcp_reno_cong_avoid, + .undo_cwnd = tcp_reno_undo_cwnd, +}; diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c new file mode 100644 index 000000000..fffa011a0 --- /dev/null +++ b/net/ipv4/tcp_cubic.c @@ -0,0 +1,541 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP CUBIC: Binary Increase Congestion control for TCP v2.3 + * Home page: + * http://netsrv.csc.ncsu.edu/twiki/bin/view/Main/BIC + * This is from the implementation of CUBIC TCP in + * Sangtae Ha, Injong Rhee and Lisong Xu, + * "CUBIC: A New TCP-Friendly High-Speed TCP Variant" + * in ACM SIGOPS Operating System Review, July 2008. + * Available from: + * http://netsrv.csc.ncsu.edu/export/cubic_a_new_tcp_2008.pdf + * + * CUBIC integrates a new slow start algorithm, called HyStart. + * The details of HyStart are presented in + * Sangtae Ha and Injong Rhee, + * "Taming the Elephants: New TCP Slow Start", NCSU TechReport 2008. + * Available from: + * http://netsrv.csc.ncsu.edu/export/hystart_techreport_2008.pdf + * + * All testing results are available from: + * http://netsrv.csc.ncsu.edu/wiki/index.php/TCP_Testing + * + * Unless CUBIC is enabled and congestion window is large + * this behaves the same as the original Reno. + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/math64.h> +#include <net/tcp.h> + +#define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation + * max_cwnd = snd_cwnd * beta + */ +#define BICTCP_HZ 10 /* BIC HZ 2^10 = 1024 */ + +/* Two methods of hybrid slow start */ +#define HYSTART_ACK_TRAIN 0x1 +#define HYSTART_DELAY 0x2 + +/* Number of delay samples for detecting the increase of delay */ +#define HYSTART_MIN_SAMPLES 8 +#define HYSTART_DELAY_MIN (4000U) /* 4 ms */ +#define HYSTART_DELAY_MAX (16000U) /* 16 ms */ +#define HYSTART_DELAY_THRESH(x) clamp(x, HYSTART_DELAY_MIN, HYSTART_DELAY_MAX) + +static int fast_convergence __read_mostly = 1; +static int beta __read_mostly = 717; /* = 717/1024 (BICTCP_BETA_SCALE) */ +static int initial_ssthresh __read_mostly; +static int bic_scale __read_mostly = 41; +static int tcp_friendliness __read_mostly = 1; + +static int hystart __read_mostly = 1; +static int hystart_detect __read_mostly = HYSTART_ACK_TRAIN | HYSTART_DELAY; +static int hystart_low_window __read_mostly = 16; +static int hystart_ack_delta_us __read_mostly = 2000; + +static u32 cube_rtt_scale __read_mostly; +static u32 beta_scale __read_mostly; +static u64 cube_factor __read_mostly; + +/* Note parameters that are used for precomputing scale factors are read-only */ +module_param(fast_convergence, int, 0644); +MODULE_PARM_DESC(fast_convergence, "turn on/off fast convergence"); +module_param(beta, int, 0644); +MODULE_PARM_DESC(beta, "beta for multiplicative increase"); +module_param(initial_ssthresh, int, 0644); +MODULE_PARM_DESC(initial_ssthresh, "initial value of slow start threshold"); +module_param(bic_scale, int, 0444); +MODULE_PARM_DESC(bic_scale, "scale (scaled by 1024) value for bic function (bic_scale/1024)"); +module_param(tcp_friendliness, int, 0644); +MODULE_PARM_DESC(tcp_friendliness, "turn on/off tcp friendliness"); +module_param(hystart, int, 0644); +MODULE_PARM_DESC(hystart, "turn on/off hybrid slow start algorithm"); +module_param(hystart_detect, int, 0644); +MODULE_PARM_DESC(hystart_detect, "hybrid slow start detection mechanisms" + " 1: packet-train 2: delay 3: both packet-train and delay"); +module_param(hystart_low_window, int, 0644); +MODULE_PARM_DESC(hystart_low_window, "lower bound cwnd for hybrid slow start"); +module_param(hystart_ack_delta_us, int, 0644); +MODULE_PARM_DESC(hystart_ack_delta_us, "spacing between ack's indicating train (usecs)"); + +/* BIC TCP Parameters */ +struct bictcp { + u32 cnt; /* increase cwnd by 1 after ACKs */ + u32 last_max_cwnd; /* last maximum snd_cwnd */ + u32 last_cwnd; /* the last snd_cwnd */ + u32 last_time; /* time when updated last_cwnd */ + u32 bic_origin_point;/* origin point of bic function */ + u32 bic_K; /* time to origin point + from the beginning of the current epoch */ + u32 delay_min; /* min delay (usec) */ + u32 epoch_start; /* beginning of an epoch */ + u32 ack_cnt; /* number of acks */ + u32 tcp_cwnd; /* estimated tcp cwnd */ + u16 unused; + u8 sample_cnt; /* number of samples to decide curr_rtt */ + u8 found; /* the exit point is found? */ + u32 round_start; /* beginning of each round */ + u32 end_seq; /* end_seq of the round */ + u32 last_ack; /* last time when the ACK spacing is close */ + u32 curr_rtt; /* the minimum rtt of current round */ +}; + +static inline void bictcp_reset(struct bictcp *ca) +{ + ca->cnt = 0; + ca->last_max_cwnd = 0; + ca->last_cwnd = 0; + ca->last_time = 0; + ca->bic_origin_point = 0; + ca->bic_K = 0; + ca->delay_min = 0; + ca->epoch_start = 0; + ca->ack_cnt = 0; + ca->tcp_cwnd = 0; + ca->found = 0; +} + +static inline u32 bictcp_clock_us(const struct sock *sk) +{ + return tcp_sk(sk)->tcp_mstamp; +} + +static inline void bictcp_hystart_reset(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bictcp *ca = inet_csk_ca(sk); + + ca->round_start = ca->last_ack = bictcp_clock_us(sk); + ca->end_seq = tp->snd_nxt; + ca->curr_rtt = ~0U; + ca->sample_cnt = 0; +} + +static void bictcp_init(struct sock *sk) +{ + struct bictcp *ca = inet_csk_ca(sk); + + bictcp_reset(ca); + + if (hystart) + bictcp_hystart_reset(sk); + + if (!hystart && initial_ssthresh) + tcp_sk(sk)->snd_ssthresh = initial_ssthresh; +} + +static void bictcp_cwnd_event(struct sock *sk, enum tcp_ca_event event) +{ + if (event == CA_EVENT_TX_START) { + struct bictcp *ca = inet_csk_ca(sk); + u32 now = tcp_jiffies32; + s32 delta; + + delta = now - tcp_sk(sk)->lsndtime; + + /* We were application limited (idle) for a while. + * Shift epoch_start to keep cwnd growth to cubic curve. + */ + if (ca->epoch_start && delta > 0) { + ca->epoch_start += delta; + if (after(ca->epoch_start, now)) + ca->epoch_start = now; + } + return; + } +} + +/* calculate the cubic root of x using a table lookup followed by one + * Newton-Raphson iteration. + * Avg err ~= 0.195% + */ +static u32 cubic_root(u64 a) +{ + u32 x, b, shift; + /* + * cbrt(x) MSB values for x MSB values in [0..63]. + * Precomputed then refined by hand - Willy Tarreau + * + * For x in [0..63], + * v = cbrt(x << 18) - 1 + * cbrt(x) = (v[x] + 10) >> 6 + */ + static const u8 v[] = { + /* 0x00 */ 0, 54, 54, 54, 118, 118, 118, 118, + /* 0x08 */ 123, 129, 134, 138, 143, 147, 151, 156, + /* 0x10 */ 157, 161, 164, 168, 170, 173, 176, 179, + /* 0x18 */ 181, 185, 187, 190, 192, 194, 197, 199, + /* 0x20 */ 200, 202, 204, 206, 209, 211, 213, 215, + /* 0x28 */ 217, 219, 221, 222, 224, 225, 227, 229, + /* 0x30 */ 231, 232, 234, 236, 237, 239, 240, 242, + /* 0x38 */ 244, 245, 246, 248, 250, 251, 252, 254, + }; + + b = fls64(a); + if (b < 7) { + /* a in [0..63] */ + return ((u32)v[(u32)a] + 35) >> 6; + } + + b = ((b * 84) >> 8) - 1; + shift = (a >> (b * 3)); + + x = ((u32)(((u32)v[shift] + 10) << b)) >> 6; + + /* + * Newton-Raphson iteration + * 2 + * x = ( 2 * x + a / x ) / 3 + * k+1 k k + */ + x = (2 * x + (u32)div64_u64(a, (u64)x * (u64)(x - 1))); + x = ((x * 341) >> 10); + return x; +} + +/* + * Compute congestion window to use. + */ +static inline void bictcp_update(struct bictcp *ca, u32 cwnd, u32 acked) +{ + u32 delta, bic_target, max_cnt; + u64 offs, t; + + ca->ack_cnt += acked; /* count the number of ACKed packets */ + + if (ca->last_cwnd == cwnd && + (s32)(tcp_jiffies32 - ca->last_time) <= HZ / 32) + return; + + /* The CUBIC function can update ca->cnt at most once per jiffy. + * On all cwnd reduction events, ca->epoch_start is set to 0, + * which will force a recalculation of ca->cnt. + */ + if (ca->epoch_start && tcp_jiffies32 == ca->last_time) + goto tcp_friendliness; + + ca->last_cwnd = cwnd; + ca->last_time = tcp_jiffies32; + + if (ca->epoch_start == 0) { + ca->epoch_start = tcp_jiffies32; /* record beginning */ + ca->ack_cnt = acked; /* start counting */ + ca->tcp_cwnd = cwnd; /* syn with cubic */ + + if (ca->last_max_cwnd <= cwnd) { + ca->bic_K = 0; + ca->bic_origin_point = cwnd; + } else { + /* Compute new K based on + * (wmax-cwnd) * (srtt>>3 / HZ) / c * 2^(3*bictcp_HZ) + */ + ca->bic_K = cubic_root(cube_factor + * (ca->last_max_cwnd - cwnd)); + ca->bic_origin_point = ca->last_max_cwnd; + } + } + + /* cubic function - calc*/ + /* calculate c * time^3 / rtt, + * while considering overflow in calculation of time^3 + * (so time^3 is done by using 64 bit) + * and without the support of division of 64bit numbers + * (so all divisions are done by using 32 bit) + * also NOTE the unit of those veriables + * time = (t - K) / 2^bictcp_HZ + * c = bic_scale >> 10 + * rtt = (srtt >> 3) / HZ + * !!! The following code does not have overflow problems, + * if the cwnd < 1 million packets !!! + */ + + t = (s32)(tcp_jiffies32 - ca->epoch_start); + t += usecs_to_jiffies(ca->delay_min); + /* change the unit from HZ to bictcp_HZ */ + t <<= BICTCP_HZ; + do_div(t, HZ); + + if (t < ca->bic_K) /* t - K */ + offs = ca->bic_K - t; + else + offs = t - ca->bic_K; + + /* c/rtt * (t-K)^3 */ + delta = (cube_rtt_scale * offs * offs * offs) >> (10+3*BICTCP_HZ); + if (t < ca->bic_K) /* below origin*/ + bic_target = ca->bic_origin_point - delta; + else /* above origin*/ + bic_target = ca->bic_origin_point + delta; + + /* cubic function - calc bictcp_cnt*/ + if (bic_target > cwnd) { + ca->cnt = cwnd / (bic_target - cwnd); + } else { + ca->cnt = 100 * cwnd; /* very small increment*/ + } + + /* + * The initial growth of cubic function may be too conservative + * when the available bandwidth is still unknown. + */ + if (ca->last_max_cwnd == 0 && ca->cnt > 20) + ca->cnt = 20; /* increase cwnd 5% per RTT */ + +tcp_friendliness: + /* TCP Friendly */ + if (tcp_friendliness) { + u32 scale = beta_scale; + + delta = (cwnd * scale) >> 3; + while (ca->ack_cnt > delta) { /* update tcp cwnd */ + ca->ack_cnt -= delta; + ca->tcp_cwnd++; + } + + if (ca->tcp_cwnd > cwnd) { /* if bic is slower than tcp */ + delta = ca->tcp_cwnd - cwnd; + max_cnt = cwnd / delta; + if (ca->cnt > max_cnt) + ca->cnt = max_cnt; + } + } + + /* The maximum rate of cwnd increase CUBIC allows is 1 packet per + * 2 packets ACKed, meaning cwnd grows at 1.5x per RTT. + */ + ca->cnt = max(ca->cnt, 2U); +} + +static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bictcp *ca = inet_csk_ca(sk); + + if (!tcp_is_cwnd_limited(sk)) + return; + + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + return; + } + bictcp_update(ca, tp->snd_cwnd, acked); + tcp_cong_avoid_ai(tp, ca->cnt, acked); +} + +static u32 bictcp_recalc_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct bictcp *ca = inet_csk_ca(sk); + + ca->epoch_start = 0; /* end of epoch */ + + /* Wmax and fast convergence */ + if (tp->snd_cwnd < ca->last_max_cwnd && fast_convergence) + ca->last_max_cwnd = (tp->snd_cwnd * (BICTCP_BETA_SCALE + beta)) + / (2 * BICTCP_BETA_SCALE); + else + ca->last_max_cwnd = tp->snd_cwnd; + + return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U); +} + +static void bictcp_state(struct sock *sk, u8 new_state) +{ + if (new_state == TCP_CA_Loss) { + bictcp_reset(inet_csk_ca(sk)); + bictcp_hystart_reset(sk); + } +} + +/* Account for TSO/GRO delays. + * Otherwise short RTT flows could get too small ssthresh, since during + * slow start we begin with small TSO packets and ca->delay_min would + * not account for long aggregation delay when TSO packets get bigger. + * Ideally even with a very small RTT we would like to have at least one + * TSO packet being sent and received by GRO, and another one in qdisc layer. + * We apply another 100% factor because @rate is doubled at this point. + * We cap the cushion to 1ms. + */ +static u32 hystart_ack_delay(struct sock *sk) +{ + unsigned long rate; + + rate = READ_ONCE(sk->sk_pacing_rate); + if (!rate) + return 0; + return min_t(u64, USEC_PER_MSEC, + div64_ul((u64)GSO_MAX_SIZE * 4 * USEC_PER_SEC, rate)); +} + +static void hystart_update(struct sock *sk, u32 delay) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct bictcp *ca = inet_csk_ca(sk); + u32 threshold; + + if (after(tp->snd_una, ca->end_seq)) + bictcp_hystart_reset(sk); + + if (hystart_detect & HYSTART_ACK_TRAIN) { + u32 now = bictcp_clock_us(sk); + + /* first detection parameter - ack-train detection */ + if ((s32)(now - ca->last_ack) <= hystart_ack_delta_us) { + ca->last_ack = now; + + threshold = ca->delay_min + hystart_ack_delay(sk); + + /* Hystart ack train triggers if we get ack past + * ca->delay_min/2. + * Pacing might have delayed packets up to RTT/2 + * during slow start. + */ + if (sk->sk_pacing_status == SK_PACING_NONE) + threshold >>= 1; + + if ((s32)(now - ca->round_start) > threshold) { + ca->found = 1; + pr_debug("hystart_ack_train (%u > %u) delay_min %u (+ ack_delay %u) cwnd %u\n", + now - ca->round_start, threshold, + ca->delay_min, hystart_ack_delay(sk), tp->snd_cwnd); + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTTRAINDETECT); + NET_ADD_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTTRAINCWND, + tp->snd_cwnd); + tp->snd_ssthresh = tp->snd_cwnd; + } + } + } + + if (hystart_detect & HYSTART_DELAY) { + /* obtain the minimum delay of more than sampling packets */ + if (ca->curr_rtt > delay) + ca->curr_rtt = delay; + if (ca->sample_cnt < HYSTART_MIN_SAMPLES) { + ca->sample_cnt++; + } else { + if (ca->curr_rtt > ca->delay_min + + HYSTART_DELAY_THRESH(ca->delay_min >> 3)) { + ca->found = 1; + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTDELAYDETECT); + NET_ADD_STATS(sock_net(sk), + LINUX_MIB_TCPHYSTARTDELAYCWND, + tp->snd_cwnd); + tp->snd_ssthresh = tp->snd_cwnd; + } + } + } +} + +static void bictcp_acked(struct sock *sk, const struct ack_sample *sample) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct bictcp *ca = inet_csk_ca(sk); + u32 delay; + + /* Some calls are for duplicates without timetamps */ + if (sample->rtt_us < 0) + return; + + /* Discard delay samples right after fast recovery */ + if (ca->epoch_start && (s32)(tcp_jiffies32 - ca->epoch_start) < HZ) + return; + + delay = sample->rtt_us; + if (delay == 0) + delay = 1; + + /* first time call or link delay decreases */ + if (ca->delay_min == 0 || ca->delay_min > delay) + ca->delay_min = delay; + + /* hystart triggers when cwnd is larger than some threshold */ + if (!ca->found && tcp_in_slow_start(tp) && hystart && + tp->snd_cwnd >= hystart_low_window) + hystart_update(sk, delay); +} + +static struct tcp_congestion_ops cubictcp __read_mostly = { + .init = bictcp_init, + .ssthresh = bictcp_recalc_ssthresh, + .cong_avoid = bictcp_cong_avoid, + .set_state = bictcp_state, + .undo_cwnd = tcp_reno_undo_cwnd, + .cwnd_event = bictcp_cwnd_event, + .pkts_acked = bictcp_acked, + .owner = THIS_MODULE, + .name = "cubic", +}; + +static int __init cubictcp_register(void) +{ + BUILD_BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE); + + /* Precompute a bunch of the scaling factors that are used per-packet + * based on SRTT of 100ms + */ + + beta_scale = 8*(BICTCP_BETA_SCALE+beta) / 3 + / (BICTCP_BETA_SCALE - beta); + + cube_rtt_scale = (bic_scale * 10); /* 1024*c/rtt */ + + /* calculate the "K" for (wmax-cwnd) = c/rtt * K^3 + * so K = cubic_root( (wmax-cwnd)*rtt/c ) + * the unit of K is bictcp_HZ=2^10, not HZ + * + * c = bic_scale >> 10 + * rtt = 100ms + * + * the following code has been designed and tested for + * cwnd < 1 million packets + * RTT < 100 seconds + * HZ < 1,000,00 (corresponding to 10 nano-second) + */ + + /* 1/c * 2^2*bictcp_HZ * srtt */ + cube_factor = 1ull << (10+3*BICTCP_HZ); /* 2^40 */ + + /* divide by bic_scale and by constant Srtt (100ms) */ + do_div(cube_factor, bic_scale * 10); + + return tcp_register_congestion_control(&cubictcp); +} + +static void __exit cubictcp_unregister(void) +{ + tcp_unregister_congestion_control(&cubictcp); +} + +module_init(cubictcp_register); +module_exit(cubictcp_unregister); + +MODULE_AUTHOR("Sangtae Ha, Stephen Hemminger"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("CUBIC TCP"); +MODULE_VERSION("2.3"); diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c new file mode 100644 index 000000000..79f705450 --- /dev/null +++ b/net/ipv4/tcp_dctcp.c @@ -0,0 +1,258 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* DataCenter TCP (DCTCP) congestion control. + * + * http://simula.stanford.edu/~alizade/Site/DCTCP.html + * + * This is an implementation of DCTCP over Reno, an enhancement to the + * TCP congestion control algorithm designed for data centers. DCTCP + * leverages Explicit Congestion Notification (ECN) in the network to + * provide multi-bit feedback to the end hosts. DCTCP's goal is to meet + * the following three data center transport requirements: + * + * - High burst tolerance (incast due to partition/aggregate) + * - Low latency (short flows, queries) + * - High throughput (continuous data updates, large file transfers) + * with commodity shallow buffered switches + * + * The algorithm is described in detail in the following two papers: + * + * 1) Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye, + * Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan: + * "Data Center TCP (DCTCP)", Data Center Networks session + * Proc. ACM SIGCOMM, New Delhi, 2010. + * http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf + * + * 2) Mohammad Alizadeh, Adel Javanmard, and Balaji Prabhakar: + * "Analysis of DCTCP: Stability, Convergence, and Fairness" + * Proc. ACM SIGMETRICS, San Jose, 2011. + * http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf + * + * Initial prototype from Abdul Kabbani, Masato Yasuda and Mohammad Alizadeh. + * + * Authors: + * + * Daniel Borkmann <dborkman@redhat.com> + * Florian Westphal <fw@strlen.de> + * Glenn Judd <glenn.judd@morganstanley.com> + */ + +#include <linux/module.h> +#include <linux/mm.h> +#include <net/tcp.h> +#include <linux/inet_diag.h> +#include "tcp_dctcp.h" + +#define DCTCP_MAX_ALPHA 1024U + +struct dctcp { + u32 old_delivered; + u32 old_delivered_ce; + u32 prior_rcv_nxt; + u32 dctcp_alpha; + u32 next_seq; + u32 ce_state; + u32 loss_cwnd; +}; + +static unsigned int dctcp_shift_g __read_mostly = 4; /* g = 1/2^4 */ +module_param(dctcp_shift_g, uint, 0644); +MODULE_PARM_DESC(dctcp_shift_g, "parameter g for updating dctcp_alpha"); + +static unsigned int dctcp_alpha_on_init __read_mostly = DCTCP_MAX_ALPHA; +module_param(dctcp_alpha_on_init, uint, 0644); +MODULE_PARM_DESC(dctcp_alpha_on_init, "parameter for initial alpha value"); + +static struct tcp_congestion_ops dctcp_reno; + +static void dctcp_reset(const struct tcp_sock *tp, struct dctcp *ca) +{ + ca->next_seq = tp->snd_nxt; + + ca->old_delivered = tp->delivered; + ca->old_delivered_ce = tp->delivered_ce; +} + +static void dctcp_init(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + if ((tp->ecn_flags & TCP_ECN_OK) || + (sk->sk_state == TCP_LISTEN || + sk->sk_state == TCP_CLOSE)) { + struct dctcp *ca = inet_csk_ca(sk); + + ca->prior_rcv_nxt = tp->rcv_nxt; + + ca->dctcp_alpha = min(dctcp_alpha_on_init, DCTCP_MAX_ALPHA); + + ca->loss_cwnd = 0; + ca->ce_state = 0; + + dctcp_reset(tp, ca); + return; + } + + /* No ECN support? Fall back to Reno. Also need to clear + * ECT from sk since it is set during 3WHS for DCTCP. + */ + inet_csk(sk)->icsk_ca_ops = &dctcp_reno; + INET_ECN_dontxmit(sk); +} + +static u32 dctcp_ssthresh(struct sock *sk) +{ + struct dctcp *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + ca->loss_cwnd = tp->snd_cwnd; + return max(tp->snd_cwnd - ((tp->snd_cwnd * ca->dctcp_alpha) >> 11U), 2U); +} + +static void dctcp_update_alpha(struct sock *sk, u32 flags) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct dctcp *ca = inet_csk_ca(sk); + + /* Expired RTT */ + if (!before(tp->snd_una, ca->next_seq)) { + u32 delivered_ce = tp->delivered_ce - ca->old_delivered_ce; + u32 alpha = ca->dctcp_alpha; + + /* alpha = (1 - g) * alpha + g * F */ + + alpha -= min_not_zero(alpha, alpha >> dctcp_shift_g); + if (delivered_ce) { + u32 delivered = tp->delivered - ca->old_delivered; + + /* If dctcp_shift_g == 1, a 32bit value would overflow + * after 8 M packets. + */ + delivered_ce <<= (10 - dctcp_shift_g); + delivered_ce /= max(1U, delivered); + + alpha = min(alpha + delivered_ce, DCTCP_MAX_ALPHA); + } + /* dctcp_alpha can be read from dctcp_get_info() without + * synchro, so we ask compiler to not use dctcp_alpha + * as a temporary variable in prior operations. + */ + WRITE_ONCE(ca->dctcp_alpha, alpha); + dctcp_reset(tp, ca); + } +} + +static void dctcp_react_to_loss(struct sock *sk) +{ + struct dctcp *ca = inet_csk_ca(sk); + struct tcp_sock *tp = tcp_sk(sk); + + ca->loss_cwnd = tp->snd_cwnd; + tp->snd_ssthresh = max(tp->snd_cwnd >> 1U, 2U); +} + +static void dctcp_state(struct sock *sk, u8 new_state) +{ + if (new_state == TCP_CA_Recovery && + new_state != inet_csk(sk)->icsk_ca_state) + dctcp_react_to_loss(sk); + /* We handle RTO in dctcp_cwnd_event to ensure that we perform only + * one loss-adjustment per RTT. + */ +} + +static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev) +{ + struct dctcp *ca = inet_csk_ca(sk); + + switch (ev) { + case CA_EVENT_ECN_IS_CE: + case CA_EVENT_ECN_NO_CE: + dctcp_ece_ack_update(sk, ev, &ca->prior_rcv_nxt, &ca->ce_state); + break; + case CA_EVENT_LOSS: + dctcp_react_to_loss(sk); + break; + default: + /* Don't care for the rest. */ + break; + } +} + +static size_t dctcp_get_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info) +{ + const struct dctcp *ca = inet_csk_ca(sk); + const struct tcp_sock *tp = tcp_sk(sk); + + /* Fill it also in case of VEGASINFO due to req struct limits. + * We can still correctly retrieve it later. + */ + if (ext & (1 << (INET_DIAG_DCTCPINFO - 1)) || + ext & (1 << (INET_DIAG_VEGASINFO - 1))) { + memset(&info->dctcp, 0, sizeof(info->dctcp)); + if (inet_csk(sk)->icsk_ca_ops != &dctcp_reno) { + info->dctcp.dctcp_enabled = 1; + info->dctcp.dctcp_ce_state = (u16) ca->ce_state; + info->dctcp.dctcp_alpha = ca->dctcp_alpha; + info->dctcp.dctcp_ab_ecn = tp->mss_cache * + (tp->delivered_ce - ca->old_delivered_ce); + info->dctcp.dctcp_ab_tot = tp->mss_cache * + (tp->delivered - ca->old_delivered); + } + + *attr = INET_DIAG_DCTCPINFO; + return sizeof(info->dctcp); + } + return 0; +} + +static u32 dctcp_cwnd_undo(struct sock *sk) +{ + const struct dctcp *ca = inet_csk_ca(sk); + + return max(tcp_sk(sk)->snd_cwnd, ca->loss_cwnd); +} + +static struct tcp_congestion_ops dctcp __read_mostly = { + .init = dctcp_init, + .in_ack_event = dctcp_update_alpha, + .cwnd_event = dctcp_cwnd_event, + .ssthresh = dctcp_ssthresh, + .cong_avoid = tcp_reno_cong_avoid, + .undo_cwnd = dctcp_cwnd_undo, + .set_state = dctcp_state, + .get_info = dctcp_get_info, + .flags = TCP_CONG_NEEDS_ECN, + .owner = THIS_MODULE, + .name = "dctcp", +}; + +static struct tcp_congestion_ops dctcp_reno __read_mostly = { + .ssthresh = tcp_reno_ssthresh, + .cong_avoid = tcp_reno_cong_avoid, + .undo_cwnd = tcp_reno_undo_cwnd, + .get_info = dctcp_get_info, + .owner = THIS_MODULE, + .name = "dctcp-reno", +}; + +static int __init dctcp_register(void) +{ + BUILD_BUG_ON(sizeof(struct dctcp) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&dctcp); +} + +static void __exit dctcp_unregister(void) +{ + tcp_unregister_congestion_control(&dctcp); +} + +module_init(dctcp_register); +module_exit(dctcp_unregister); + +MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>"); +MODULE_AUTHOR("Florian Westphal <fw@strlen.de>"); +MODULE_AUTHOR("Glenn Judd <glenn.judd@morganstanley.com>"); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("DataCenter TCP (DCTCP)"); diff --git a/net/ipv4/tcp_dctcp.h b/net/ipv4/tcp_dctcp.h new file mode 100644 index 000000000..d69a77cbd --- /dev/null +++ b/net/ipv4/tcp_dctcp.h @@ -0,0 +1,40 @@ +#ifndef _TCP_DCTCP_H +#define _TCP_DCTCP_H + +static inline void dctcp_ece_ack_cwr(struct sock *sk, u32 ce_state) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (ce_state == 1) + tp->ecn_flags |= TCP_ECN_DEMAND_CWR; + else + tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR; +} + +/* Minimal DCTP CE state machine: + * + * S: 0 <- last pkt was non-CE + * 1 <- last pkt was CE + */ +static inline void dctcp_ece_ack_update(struct sock *sk, enum tcp_ca_event evt, + u32 *prior_rcv_nxt, u32 *ce_state) +{ + u32 new_ce_state = (evt == CA_EVENT_ECN_IS_CE) ? 1 : 0; + + if (*ce_state != new_ce_state) { + /* CE state has changed, force an immediate ACK to + * reflect the new CE state. If an ACK was delayed, + * send that first to reflect the prior CE state. + */ + if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) { + dctcp_ece_ack_cwr(sk, *ce_state); + __tcp_send_ack(sk, *prior_rcv_nxt); + } + inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW; + } + *prior_rcv_nxt = tcp_sk(sk)->rcv_nxt; + *ce_state = new_ce_state; + dctcp_ece_ack_cwr(sk, new_ce_state); +} + +#endif diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c new file mode 100644 index 000000000..75a1c985f --- /dev/null +++ b/net/ipv4/tcp_diag.c @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * tcp_diag.c Module for monitoring TCP transport protocols sockets. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + */ + +#include <linux/module.h> +#include <linux/net.h> +#include <linux/sock_diag.h> +#include <linux/inet_diag.h> + +#include <linux/tcp.h> + +#include <net/netlink.h> +#include <net/tcp.h> + +static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, + void *_info) +{ + struct tcp_info *info = _info; + + if (inet_sk_state_load(sk) == TCP_LISTEN) { + r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog); + r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog); + } else if (sk->sk_type == SOCK_STREAM) { + const struct tcp_sock *tp = tcp_sk(sk); + + r->idiag_rqueue = max_t(int, READ_ONCE(tp->rcv_nxt) - + READ_ONCE(tp->copied_seq), 0); + r->idiag_wqueue = READ_ONCE(tp->write_seq) - tp->snd_una; + } + if (info) + tcp_get_info(sk, info); +} + +#ifdef CONFIG_TCP_MD5SIG +static void tcp_diag_md5sig_fill(struct tcp_diag_md5sig *info, + const struct tcp_md5sig_key *key) +{ + info->tcpm_family = key->family; + info->tcpm_prefixlen = key->prefixlen; + info->tcpm_keylen = key->keylen; + memcpy(info->tcpm_key, key->key, key->keylen); + + if (key->family == AF_INET) + info->tcpm_addr[0] = key->addr.a4.s_addr; + #if IS_ENABLED(CONFIG_IPV6) + else if (key->family == AF_INET6) + memcpy(&info->tcpm_addr, &key->addr.a6, + sizeof(info->tcpm_addr)); + #endif +} + +static int tcp_diag_put_md5sig(struct sk_buff *skb, + const struct tcp_md5sig_info *md5sig) +{ + const struct tcp_md5sig_key *key; + struct tcp_diag_md5sig *info; + struct nlattr *attr; + int md5sig_count = 0; + + hlist_for_each_entry_rcu(key, &md5sig->head, node) + md5sig_count++; + if (md5sig_count == 0) + return 0; + + attr = nla_reserve(skb, INET_DIAG_MD5SIG, + md5sig_count * sizeof(struct tcp_diag_md5sig)); + if (!attr) + return -EMSGSIZE; + + info = nla_data(attr); + memset(info, 0, md5sig_count * sizeof(struct tcp_diag_md5sig)); + hlist_for_each_entry_rcu(key, &md5sig->head, node) { + tcp_diag_md5sig_fill(info++, key); + if (--md5sig_count == 0) + break; + } + + return 0; +} +#endif + +static int tcp_diag_put_ulp(struct sk_buff *skb, struct sock *sk, + const struct tcp_ulp_ops *ulp_ops) +{ + struct nlattr *nest; + int err; + + nest = nla_nest_start_noflag(skb, INET_DIAG_ULP_INFO); + if (!nest) + return -EMSGSIZE; + + err = nla_put_string(skb, INET_ULP_INFO_NAME, ulp_ops->name); + if (err) + goto nla_failure; + + if (ulp_ops->get_info) + err = ulp_ops->get_info(sk, skb); + if (err) + goto nla_failure; + + nla_nest_end(skb, nest); + return 0; + +nla_failure: + nla_nest_cancel(skb, nest); + return err; +} + +static int tcp_diag_get_aux(struct sock *sk, bool net_admin, + struct sk_buff *skb) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + int err = 0; + +#ifdef CONFIG_TCP_MD5SIG + if (net_admin) { + struct tcp_md5sig_info *md5sig; + + rcu_read_lock(); + md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); + if (md5sig) + err = tcp_diag_put_md5sig(skb, md5sig); + rcu_read_unlock(); + if (err < 0) + return err; + } +#endif + + if (net_admin) { + const struct tcp_ulp_ops *ulp_ops; + + ulp_ops = icsk->icsk_ulp_ops; + if (ulp_ops) + err = tcp_diag_put_ulp(skb, sk, ulp_ops); + if (err) + return err; + } + return 0; +} + +static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + size_t size = 0; + +#ifdef CONFIG_TCP_MD5SIG + if (net_admin && sk_fullsock(sk)) { + const struct tcp_md5sig_info *md5sig; + const struct tcp_md5sig_key *key; + size_t md5sig_count = 0; + + rcu_read_lock(); + md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); + if (md5sig) { + hlist_for_each_entry_rcu(key, &md5sig->head, node) + md5sig_count++; + } + rcu_read_unlock(); + size += nla_total_size(md5sig_count * + sizeof(struct tcp_diag_md5sig)); + } +#endif + + if (net_admin && sk_fullsock(sk)) { + const struct tcp_ulp_ops *ulp_ops; + + ulp_ops = icsk->icsk_ulp_ops; + if (ulp_ops) { + size += nla_total_size(0) + + nla_total_size(TCP_ULP_NAME_MAX); + if (ulp_ops->get_info_size) + size += ulp_ops->get_info_size(sk); + } + } + return size; +} + +static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r); +} + +static int tcp_diag_dump_one(struct netlink_callback *cb, + const struct inet_diag_req_v2 *req) +{ + return inet_diag_dump_one_icsk(&tcp_hashinfo, cb, req); +} + +#ifdef CONFIG_INET_DIAG_DESTROY +static int tcp_diag_destroy(struct sk_buff *in_skb, + const struct inet_diag_req_v2 *req) +{ + struct net *net = sock_net(in_skb->sk); + struct sock *sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req); + int err; + + if (IS_ERR(sk)) + return PTR_ERR(sk); + + err = sock_diag_destroy(sk, ECONNABORTED); + + sock_gen_put(sk); + + return err; +} +#endif + +static const struct inet_diag_handler tcp_diag_handler = { + .dump = tcp_diag_dump, + .dump_one = tcp_diag_dump_one, + .idiag_get_info = tcp_diag_get_info, + .idiag_get_aux = tcp_diag_get_aux, + .idiag_get_aux_size = tcp_diag_get_aux_size, + .idiag_type = IPPROTO_TCP, + .idiag_info_size = sizeof(struct tcp_info), +#ifdef CONFIG_INET_DIAG_DESTROY + .destroy = tcp_diag_destroy, +#endif +}; + +static int __init tcp_diag_init(void) +{ + return inet_diag_register(&tcp_diag_handler); +} + +static void __exit tcp_diag_exit(void) +{ + inet_diag_unregister(&tcp_diag_handler); +} + +module_init(tcp_diag_init); +module_exit(tcp_diag_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */); diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c new file mode 100644 index 000000000..92d63cf3e --- /dev/null +++ b/net/ipv4/tcp_fastopen.c @@ -0,0 +1,611 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/crypto.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/tcp.h> +#include <linux/rcupdate.h> +#include <linux/rculist.h> +#include <net/inetpeer.h> +#include <net/tcp.h> + +void tcp_fastopen_init_key_once(struct net *net) +{ + u8 key[TCP_FASTOPEN_KEY_LENGTH]; + struct tcp_fastopen_context *ctxt; + + rcu_read_lock(); + ctxt = rcu_dereference(net->ipv4.tcp_fastopen_ctx); + if (ctxt) { + rcu_read_unlock(); + return; + } + rcu_read_unlock(); + + /* tcp_fastopen_reset_cipher publishes the new context + * atomically, so we allow this race happening here. + * + * All call sites of tcp_fastopen_cookie_gen also check + * for a valid cookie, so this is an acceptable risk. + */ + get_random_bytes(key, sizeof(key)); + tcp_fastopen_reset_cipher(net, NULL, key, NULL); +} + +static void tcp_fastopen_ctx_free(struct rcu_head *head) +{ + struct tcp_fastopen_context *ctx = + container_of(head, struct tcp_fastopen_context, rcu); + + kfree_sensitive(ctx); +} + +void tcp_fastopen_destroy_cipher(struct sock *sk) +{ + struct tcp_fastopen_context *ctx; + + ctx = rcu_dereference_protected( + inet_csk(sk)->icsk_accept_queue.fastopenq.ctx, 1); + if (ctx) + call_rcu(&ctx->rcu, tcp_fastopen_ctx_free); +} + +void tcp_fastopen_ctx_destroy(struct net *net) +{ + struct tcp_fastopen_context *ctxt; + + spin_lock(&net->ipv4.tcp_fastopen_ctx_lock); + + ctxt = rcu_dereference_protected(net->ipv4.tcp_fastopen_ctx, + lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock)); + rcu_assign_pointer(net->ipv4.tcp_fastopen_ctx, NULL); + spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock); + + if (ctxt) + call_rcu(&ctxt->rcu, tcp_fastopen_ctx_free); +} + +int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, + void *primary_key, void *backup_key) +{ + struct tcp_fastopen_context *ctx, *octx; + struct fastopen_queue *q; + int err = 0; + + ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) { + err = -ENOMEM; + goto out; + } + + ctx->key[0].key[0] = get_unaligned_le64(primary_key); + ctx->key[0].key[1] = get_unaligned_le64(primary_key + 8); + if (backup_key) { + ctx->key[1].key[0] = get_unaligned_le64(backup_key); + ctx->key[1].key[1] = get_unaligned_le64(backup_key + 8); + ctx->num = 2; + } else { + ctx->num = 1; + } + + spin_lock(&net->ipv4.tcp_fastopen_ctx_lock); + if (sk) { + q = &inet_csk(sk)->icsk_accept_queue.fastopenq; + octx = rcu_dereference_protected(q->ctx, + lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock)); + rcu_assign_pointer(q->ctx, ctx); + } else { + octx = rcu_dereference_protected(net->ipv4.tcp_fastopen_ctx, + lockdep_is_held(&net->ipv4.tcp_fastopen_ctx_lock)); + rcu_assign_pointer(net->ipv4.tcp_fastopen_ctx, ctx); + } + spin_unlock(&net->ipv4.tcp_fastopen_ctx_lock); + + if (octx) + call_rcu(&octx->rcu, tcp_fastopen_ctx_free); +out: + return err; +} + +int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, + u64 *key) +{ + struct tcp_fastopen_context *ctx; + int n_keys = 0, i; + + rcu_read_lock(); + if (icsk) + ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx); + else + ctx = rcu_dereference(net->ipv4.tcp_fastopen_ctx); + if (ctx) { + n_keys = tcp_fastopen_context_len(ctx); + for (i = 0; i < n_keys; i++) { + put_unaligned_le64(ctx->key[i].key[0], key + (i * 2)); + put_unaligned_le64(ctx->key[i].key[1], key + (i * 2) + 1); + } + } + rcu_read_unlock(); + + return n_keys; +} + +static bool __tcp_fastopen_cookie_gen_cipher(struct request_sock *req, + struct sk_buff *syn, + const siphash_key_t *key, + struct tcp_fastopen_cookie *foc) +{ + BUILD_BUG_ON(TCP_FASTOPEN_COOKIE_SIZE != sizeof(u64)); + + if (req->rsk_ops->family == AF_INET) { + const struct iphdr *iph = ip_hdr(syn); + + foc->val[0] = cpu_to_le64(siphash(&iph->saddr, + sizeof(iph->saddr) + + sizeof(iph->daddr), + key)); + foc->len = TCP_FASTOPEN_COOKIE_SIZE; + return true; + } +#if IS_ENABLED(CONFIG_IPV6) + if (req->rsk_ops->family == AF_INET6) { + const struct ipv6hdr *ip6h = ipv6_hdr(syn); + + foc->val[0] = cpu_to_le64(siphash(&ip6h->saddr, + sizeof(ip6h->saddr) + + sizeof(ip6h->daddr), + key)); + foc->len = TCP_FASTOPEN_COOKIE_SIZE; + return true; + } +#endif + return false; +} + +/* Generate the fastopen cookie by applying SipHash to both the source and + * destination addresses. + */ +static void tcp_fastopen_cookie_gen(struct sock *sk, + struct request_sock *req, + struct sk_buff *syn, + struct tcp_fastopen_cookie *foc) +{ + struct tcp_fastopen_context *ctx; + + rcu_read_lock(); + ctx = tcp_fastopen_get_ctx(sk); + if (ctx) + __tcp_fastopen_cookie_gen_cipher(req, syn, &ctx->key[0], foc); + rcu_read_unlock(); +} + +/* If an incoming SYN or SYNACK frame contains a payload and/or FIN, + * queue this additional data / FIN. + */ +void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (TCP_SKB_CB(skb)->end_seq == tp->rcv_nxt) + return; + + skb = skb_clone(skb, GFP_ATOMIC); + if (!skb) + return; + + skb_dst_drop(skb); + /* segs_in has been initialized to 1 in tcp_create_openreq_child(). + * Hence, reset segs_in to 0 before calling tcp_segs_in() + * to avoid double counting. Also, tcp_segs_in() expects + * skb->len to include the tcp_hdrlen. Hence, it should + * be called before __skb_pull(). + */ + tp->segs_in = 0; + tcp_segs_in(tp, skb); + __skb_pull(skb, tcp_hdrlen(skb)); + sk_forced_mem_schedule(sk, skb->truesize); + skb_set_owner_r(skb, sk); + + TCP_SKB_CB(skb)->seq++; + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_SYN; + + tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq; + __skb_queue_tail(&sk->sk_receive_queue, skb); + tp->syn_data_acked = 1; + + /* u64_stats_update_begin(&tp->syncp) not needed here, + * as we certainly are not changing upper 32bit value (0) + */ + tp->bytes_received = skb->len; + + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) + tcp_fin(sk); +} + +/* returns 0 - no key match, 1 for primary, 2 for backup */ +static int tcp_fastopen_cookie_gen_check(struct sock *sk, + struct request_sock *req, + struct sk_buff *syn, + struct tcp_fastopen_cookie *orig, + struct tcp_fastopen_cookie *valid_foc) +{ + struct tcp_fastopen_cookie search_foc = { .len = -1 }; + struct tcp_fastopen_cookie *foc = valid_foc; + struct tcp_fastopen_context *ctx; + int i, ret = 0; + + rcu_read_lock(); + ctx = tcp_fastopen_get_ctx(sk); + if (!ctx) + goto out; + for (i = 0; i < tcp_fastopen_context_len(ctx); i++) { + __tcp_fastopen_cookie_gen_cipher(req, syn, &ctx->key[i], foc); + if (tcp_fastopen_cookie_match(foc, orig)) { + ret = i + 1; + goto out; + } + foc = &search_foc; + } +out: + rcu_read_unlock(); + return ret; +} + +static struct sock *tcp_fastopen_create_child(struct sock *sk, + struct sk_buff *skb, + struct request_sock *req) +{ + struct tcp_sock *tp; + struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; + struct sock *child; + bool own_req; + + child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL, + NULL, &own_req); + if (!child) + return NULL; + + spin_lock(&queue->fastopenq.lock); + queue->fastopenq.qlen++; + spin_unlock(&queue->fastopenq.lock); + + /* Initialize the child socket. Have to fix some values to take + * into account the child is a Fast Open socket and is created + * only out of the bits carried in the SYN packet. + */ + tp = tcp_sk(child); + + rcu_assign_pointer(tp->fastopen_rsk, req); + tcp_rsk(req)->tfo_listener = true; + + /* RFC1323: The window in SYN & SYN/ACK segments is never + * scaled. So correct it appropriately. + */ + tp->snd_wnd = ntohs(tcp_hdr(skb)->window); + tp->max_window = tp->snd_wnd; + + /* Activate the retrans timer so that SYNACK can be retransmitted. + * The request socket is not added to the ehash + * because it's been added to the accept queue directly. + */ + inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS, + TCP_TIMEOUT_INIT, TCP_RTO_MAX); + + refcount_set(&req->rsk_refcnt, 2); + + /* Now finish processing the fastopen child socket. */ + tcp_init_transfer(child, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, skb); + + tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1; + + tcp_fastopen_add_skb(child, skb); + + tcp_rsk(req)->rcv_nxt = tp->rcv_nxt; + tp->rcv_wup = tp->rcv_nxt; + /* tcp_conn_request() is sending the SYNACK, + * and queues the child into listener accept queue. + */ + return child; +} + +static bool tcp_fastopen_queue_check(struct sock *sk) +{ + struct fastopen_queue *fastopenq; + int max_qlen; + + /* Make sure the listener has enabled fastopen, and we don't + * exceed the max # of pending TFO requests allowed before trying + * to validating the cookie in order to avoid burning CPU cycles + * unnecessarily. + * + * XXX (TFO) - The implication of checking the max_qlen before + * processing a cookie request is that clients can't differentiate + * between qlen overflow causing Fast Open to be disabled + * temporarily vs a server not supporting Fast Open at all. + */ + fastopenq = &inet_csk(sk)->icsk_accept_queue.fastopenq; + max_qlen = READ_ONCE(fastopenq->max_qlen); + if (max_qlen == 0) + return false; + + if (fastopenq->qlen >= max_qlen) { + struct request_sock *req1; + spin_lock(&fastopenq->lock); + req1 = fastopenq->rskq_rst_head; + if (!req1 || time_after(req1->rsk_timer.expires, jiffies)) { + __NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPFASTOPENLISTENOVERFLOW); + spin_unlock(&fastopenq->lock); + return false; + } + fastopenq->rskq_rst_head = req1->dl_next; + fastopenq->qlen--; + spin_unlock(&fastopenq->lock); + reqsk_put(req1); + } + return true; +} + +static bool tcp_fastopen_no_cookie(const struct sock *sk, + const struct dst_entry *dst, + int flag) +{ + return (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen) & flag) || + tcp_sk(sk)->fastopen_no_cookie || + (dst && dst_metric(dst, RTAX_FASTOPEN_NO_COOKIE)); +} + +/* Returns true if we should perform Fast Open on the SYN. The cookie (foc) + * may be updated and return the client in the SYN-ACK later. E.g., Fast Open + * cookie request (foc->len == 0). + */ +struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + const struct dst_entry *dst) +{ + bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1; + int tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen); + struct tcp_fastopen_cookie valid_foc = { .len = -1 }; + struct sock *child; + int ret = 0; + + if (foc->len == 0) /* Client requests a cookie */ + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENCOOKIEREQD); + + if (!((tcp_fastopen & TFO_SERVER_ENABLE) && + (syn_data || foc->len >= 0) && + tcp_fastopen_queue_check(sk))) { + foc->len = -1; + return NULL; + } + + if (tcp_fastopen_no_cookie(sk, dst, TFO_SERVER_COOKIE_NOT_REQD)) + goto fastopen; + + if (foc->len == 0) { + /* Client requests a cookie. */ + tcp_fastopen_cookie_gen(sk, req, skb, &valid_foc); + } else if (foc->len > 0) { + ret = tcp_fastopen_cookie_gen_check(sk, req, skb, foc, + &valid_foc); + if (!ret) { + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPFASTOPENPASSIVEFAIL); + } else { + /* Cookie is valid. Create a (full) child socket to + * accept the data in SYN before returning a SYN-ACK to + * ack the data. If we fail to create the socket, fall + * back and ack the ISN only but includes the same + * cookie. + * + * Note: Data-less SYN with valid cookie is allowed to + * send data in SYN_RECV state. + */ +fastopen: + child = tcp_fastopen_create_child(sk, skb, req); + if (child) { + if (ret == 2) { + valid_foc.exp = foc->exp; + *foc = valid_foc; + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPFASTOPENPASSIVEALTKEY); + } else { + foc->len = -1; + } + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPFASTOPENPASSIVE); + return child; + } + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPFASTOPENPASSIVEFAIL); + } + } + valid_foc.exp = foc->exp; + *foc = valid_foc; + return NULL; +} + +bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, + struct tcp_fastopen_cookie *cookie) +{ + const struct dst_entry *dst; + + tcp_fastopen_cache_get(sk, mss, cookie); + + /* Firewall blackhole issue check */ + if (tcp_fastopen_active_should_disable(sk)) { + cookie->len = -1; + return false; + } + + dst = __sk_dst_get(sk); + + if (tcp_fastopen_no_cookie(sk, dst, TFO_CLIENT_NO_COOKIE)) { + cookie->len = -1; + return true; + } + if (cookie->len > 0) + return true; + tcp_sk(sk)->fastopen_client_fail = TFO_COOKIE_UNAVAILABLE; + return false; +} + +/* This function checks if we want to defer sending SYN until the first + * write(). We defer under the following conditions: + * 1. fastopen_connect sockopt is set + * 2. we have a valid cookie + * Return value: return true if we want to defer until application writes data + * return false if we want to send out SYN immediately + */ +bool tcp_fastopen_defer_connect(struct sock *sk, int *err) +{ + struct tcp_fastopen_cookie cookie = { .len = 0 }; + struct tcp_sock *tp = tcp_sk(sk); + u16 mss; + + if (tp->fastopen_connect && !tp->fastopen_req) { + if (tcp_fastopen_cookie_check(sk, &mss, &cookie)) { + inet_sk(sk)->defer_connect = 1; + return true; + } + + /* Alloc fastopen_req in order for FO option to be included + * in SYN + */ + tp->fastopen_req = kzalloc(sizeof(*tp->fastopen_req), + sk->sk_allocation); + if (tp->fastopen_req) + tp->fastopen_req->cookie = cookie; + else + *err = -ENOBUFS; + } + return false; +} +EXPORT_SYMBOL(tcp_fastopen_defer_connect); + +/* + * The following code block is to deal with middle box issues with TFO: + * Middlebox firewall issues can potentially cause server's data being + * blackholed after a successful 3WHS using TFO. + * The proposed solution is to disable active TFO globally under the + * following circumstances: + * 1. client side TFO socket receives out of order FIN + * 2. client side TFO socket receives out of order RST + * 3. client side TFO socket has timed out three times consecutively during + * or after handshake + * We disable active side TFO globally for 1hr at first. Then if it + * happens again, we disable it for 2h, then 4h, 8h, ... + * And we reset the timeout back to 1hr when we see a successful active + * TFO connection with data exchanges. + */ + +/* Disable active TFO and record current jiffies and + * tfo_active_disable_times + */ +void tcp_fastopen_active_disable(struct sock *sk) +{ + struct net *net = sock_net(sk); + + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout)) + return; + + /* Paired with READ_ONCE() in tcp_fastopen_active_should_disable() */ + WRITE_ONCE(net->ipv4.tfo_active_disable_stamp, jiffies); + + /* Paired with smp_rmb() in tcp_fastopen_active_should_disable(). + * We want net->ipv4.tfo_active_disable_stamp to be updated first. + */ + smp_mb__before_atomic(); + atomic_inc(&net->ipv4.tfo_active_disable_times); + + NET_INC_STATS(net, LINUX_MIB_TCPFASTOPENBLACKHOLE); +} + +/* Calculate timeout for tfo active disable + * Return true if we are still in the active TFO disable period + * Return false if timeout already expired and we should use active TFO + */ +bool tcp_fastopen_active_should_disable(struct sock *sk) +{ + unsigned int tfo_bh_timeout = + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout); + unsigned long timeout; + int tfo_da_times; + int multiplier; + + if (!tfo_bh_timeout) + return false; + + tfo_da_times = atomic_read(&sock_net(sk)->ipv4.tfo_active_disable_times); + if (!tfo_da_times) + return false; + + /* Paired with smp_mb__before_atomic() in tcp_fastopen_active_disable() */ + smp_rmb(); + + /* Limit timout to max: 2^6 * initial timeout */ + multiplier = 1 << min(tfo_da_times - 1, 6); + + /* Paired with the WRITE_ONCE() in tcp_fastopen_active_disable(). */ + timeout = READ_ONCE(sock_net(sk)->ipv4.tfo_active_disable_stamp) + + multiplier * tfo_bh_timeout * HZ; + if (time_before(jiffies, timeout)) + return true; + + /* Mark check bit so we can check for successful active TFO + * condition and reset tfo_active_disable_times + */ + tcp_sk(sk)->syn_fastopen_ch = 1; + return false; +} + +/* Disable active TFO if FIN is the only packet in the ofo queue + * and no data is received. + * Also check if we can reset tfo_active_disable_times if data is + * received successfully on a marked active TFO sockets opened on + * a non-loopback interface + */ +void tcp_fastopen_active_disable_ofo_check(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct dst_entry *dst; + struct sk_buff *skb; + + if (!tp->syn_fastopen) + return; + + if (!tp->data_segs_in) { + skb = skb_rb_first(&tp->out_of_order_queue); + if (skb && !skb_rb_next(skb)) { + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) { + tcp_fastopen_active_disable(sk); + return; + } + } + } else if (tp->syn_fastopen_ch && + atomic_read(&sock_net(sk)->ipv4.tfo_active_disable_times)) { + dst = sk_dst_get(sk); + if (!(dst && dst->dev && (dst->dev->flags & IFF_LOOPBACK))) + atomic_set(&sock_net(sk)->ipv4.tfo_active_disable_times, 0); + dst_release(dst); + } +} + +void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired) +{ + u32 timeouts = inet_csk(sk)->icsk_retransmits; + struct tcp_sock *tp = tcp_sk(sk); + + /* Broken middle-boxes may black-hole Fast Open connection during or + * even after the handshake. Be extremely conservative and pause + * Fast Open globally after hitting the third consecutive timeout or + * exceeding the configured timeout limit. + */ + if ((tp->syn_fastopen || tp->syn_data || tp->syn_data_acked) && + (timeouts == 2 || (timeouts < 2 && expired))) { + tcp_fastopen_active_disable(sk); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVEFAIL); + } +} diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c new file mode 100644 index 000000000..349069d6c --- /dev/null +++ b/net/ipv4/tcp_highspeed.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Sally Floyd's High Speed TCP (RFC 3649) congestion control + * + * See https://www.icir.org/floyd/hstcp.html + * + * John Heffner <jheffner@psc.edu> + */ + +#include <linux/module.h> +#include <net/tcp.h> + +/* From AIMD tables from RFC 3649 appendix B, + * with fixed-point MD scaled <<8. + */ +static const struct hstcp_aimd_val { + unsigned int cwnd; + unsigned int md; +} hstcp_aimd_vals[] = { + { 38, 128, /* 0.50 */ }, + { 118, 112, /* 0.44 */ }, + { 221, 104, /* 0.41 */ }, + { 347, 98, /* 0.38 */ }, + { 495, 93, /* 0.37 */ }, + { 663, 89, /* 0.35 */ }, + { 851, 86, /* 0.34 */ }, + { 1058, 83, /* 0.33 */ }, + { 1284, 81, /* 0.32 */ }, + { 1529, 78, /* 0.31 */ }, + { 1793, 76, /* 0.30 */ }, + { 2076, 74, /* 0.29 */ }, + { 2378, 72, /* 0.28 */ }, + { 2699, 71, /* 0.28 */ }, + { 3039, 69, /* 0.27 */ }, + { 3399, 68, /* 0.27 */ }, + { 3778, 66, /* 0.26 */ }, + { 4177, 65, /* 0.26 */ }, + { 4596, 64, /* 0.25 */ }, + { 5036, 62, /* 0.25 */ }, + { 5497, 61, /* 0.24 */ }, + { 5979, 60, /* 0.24 */ }, + { 6483, 59, /* 0.23 */ }, + { 7009, 58, /* 0.23 */ }, + { 7558, 57, /* 0.22 */ }, + { 8130, 56, /* 0.22 */ }, + { 8726, 55, /* 0.22 */ }, + { 9346, 54, /* 0.21 */ }, + { 9991, 53, /* 0.21 */ }, + { 10661, 52, /* 0.21 */ }, + { 11358, 52, /* 0.20 */ }, + { 12082, 51, /* 0.20 */ }, + { 12834, 50, /* 0.20 */ }, + { 13614, 49, /* 0.19 */ }, + { 14424, 48, /* 0.19 */ }, + { 15265, 48, /* 0.19 */ }, + { 16137, 47, /* 0.19 */ }, + { 17042, 46, /* 0.18 */ }, + { 17981, 45, /* 0.18 */ }, + { 18955, 45, /* 0.18 */ }, + { 19965, 44, /* 0.17 */ }, + { 21013, 43, /* 0.17 */ }, + { 22101, 43, /* 0.17 */ }, + { 23230, 42, /* 0.17 */ }, + { 24402, 41, /* 0.16 */ }, + { 25618, 41, /* 0.16 */ }, + { 26881, 40, /* 0.16 */ }, + { 28193, 39, /* 0.16 */ }, + { 29557, 39, /* 0.15 */ }, + { 30975, 38, /* 0.15 */ }, + { 32450, 38, /* 0.15 */ }, + { 33986, 37, /* 0.15 */ }, + { 35586, 36, /* 0.14 */ }, + { 37253, 36, /* 0.14 */ }, + { 38992, 35, /* 0.14 */ }, + { 40808, 35, /* 0.14 */ }, + { 42707, 34, /* 0.13 */ }, + { 44694, 33, /* 0.13 */ }, + { 46776, 33, /* 0.13 */ }, + { 48961, 32, /* 0.13 */ }, + { 51258, 32, /* 0.13 */ }, + { 53677, 31, /* 0.12 */ }, + { 56230, 30, /* 0.12 */ }, + { 58932, 30, /* 0.12 */ }, + { 61799, 29, /* 0.12 */ }, + { 64851, 28, /* 0.11 */ }, + { 68113, 28, /* 0.11 */ }, + { 71617, 27, /* 0.11 */ }, + { 75401, 26, /* 0.10 */ }, + { 79517, 26, /* 0.10 */ }, + { 84035, 25, /* 0.10 */ }, + { 89053, 24, /* 0.10 */ }, +}; + +#define HSTCP_AIMD_MAX ARRAY_SIZE(hstcp_aimd_vals) + +struct hstcp { + u32 ai; +}; + +static void hstcp_init(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct hstcp *ca = inet_csk_ca(sk); + + ca->ai = 0; + + /* Ensure the MD arithmetic works. This is somewhat pedantic, + * since I don't think we will see a cwnd this large. :) */ + tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128); +} + +static void hstcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct hstcp *ca = inet_csk_ca(sk); + + if (!tcp_is_cwnd_limited(sk)) + return; + + if (tcp_in_slow_start(tp)) + tcp_slow_start(tp, acked); + else { + /* Update AIMD parameters. + * + * We want to guarantee that: + * hstcp_aimd_vals[ca->ai-1].cwnd < + * snd_cwnd <= + * hstcp_aimd_vals[ca->ai].cwnd + */ + if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) { + while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd && + ca->ai < HSTCP_AIMD_MAX - 1) + ca->ai++; + } else if (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd) { + while (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd) + ca->ai--; + } + + /* Do additive increase */ + if (tp->snd_cwnd < tp->snd_cwnd_clamp) { + /* cwnd = cwnd + a(w) / cwnd */ + tp->snd_cwnd_cnt += ca->ai + 1; + if (tp->snd_cwnd_cnt >= tp->snd_cwnd) { + tp->snd_cwnd_cnt -= tp->snd_cwnd; + tp->snd_cwnd++; + } + } + } +} + +static u32 hstcp_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct hstcp *ca = inet_csk_ca(sk); + + /* Do multiplicative decrease */ + return max(tp->snd_cwnd - ((tp->snd_cwnd * hstcp_aimd_vals[ca->ai].md) >> 8), 2U); +} + +static struct tcp_congestion_ops tcp_highspeed __read_mostly = { + .init = hstcp_init, + .ssthresh = hstcp_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = hstcp_cong_avoid, + + .owner = THIS_MODULE, + .name = "highspeed" +}; + +static int __init hstcp_register(void) +{ + BUILD_BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&tcp_highspeed); +} + +static void __exit hstcp_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_highspeed); +} + +module_init(hstcp_register); +module_exit(hstcp_unregister); + +MODULE_AUTHOR("John Heffner"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("High Speed TCP"); diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c new file mode 100644 index 000000000..55adcfcf9 --- /dev/null +++ b/net/ipv4/tcp_htcp.c @@ -0,0 +1,317 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * H-TCP congestion control. The algorithm is detailed in: + * R.N.Shorten, D.J.Leith: + * "H-TCP: TCP for high-speed and long-distance networks" + * Proc. PFLDnet, Argonne, 2004. + * https://www.hamilton.ie/net/htcp3.pdf + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <net/tcp.h> + +#define ALPHA_BASE (1<<7) /* 1.0 with shift << 7 */ +#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */ +#define BETA_MAX 102 /* 0.8 with shift << 7 */ + +static int use_rtt_scaling __read_mostly = 1; +module_param(use_rtt_scaling, int, 0644); +MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling"); + +static int use_bandwidth_switch __read_mostly = 1; +module_param(use_bandwidth_switch, int, 0644); +MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher"); + +struct htcp { + u32 alpha; /* Fixed point arith, << 7 */ + u8 beta; /* Fixed point arith, << 7 */ + u8 modeswitch; /* Delay modeswitch + until we had at least one congestion event */ + u16 pkts_acked; + u32 packetcount; + u32 minRTT; + u32 maxRTT; + u32 last_cong; /* Time since last congestion event end */ + u32 undo_last_cong; + + u32 undo_maxRTT; + u32 undo_old_maxB; + + /* Bandwidth estimation */ + u32 minB; + u32 maxB; + u32 old_maxB; + u32 Bi; + u32 lasttime; +}; + +static inline u32 htcp_cong_time(const struct htcp *ca) +{ + return jiffies - ca->last_cong; +} + +static inline u32 htcp_ccount(const struct htcp *ca) +{ + return htcp_cong_time(ca) / ca->minRTT; +} + +static inline void htcp_reset(struct htcp *ca) +{ + ca->undo_last_cong = ca->last_cong; + ca->undo_maxRTT = ca->maxRTT; + ca->undo_old_maxB = ca->old_maxB; + + ca->last_cong = jiffies; +} + +static u32 htcp_cwnd_undo(struct sock *sk) +{ + struct htcp *ca = inet_csk_ca(sk); + + if (ca->undo_last_cong) { + ca->last_cong = ca->undo_last_cong; + ca->maxRTT = ca->undo_maxRTT; + ca->old_maxB = ca->undo_old_maxB; + ca->undo_last_cong = 0; + } + + return tcp_reno_undo_cwnd(sk); +} + +static inline void measure_rtt(struct sock *sk, u32 srtt) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct htcp *ca = inet_csk_ca(sk); + + /* keep track of minimum RTT seen so far, minRTT is zero at first */ + if (ca->minRTT > srtt || !ca->minRTT) + ca->minRTT = srtt; + + /* max RTT */ + if (icsk->icsk_ca_state == TCP_CA_Open) { + if (ca->maxRTT < ca->minRTT) + ca->maxRTT = ca->minRTT; + if (ca->maxRTT < srtt && + srtt <= ca->maxRTT + msecs_to_jiffies(20)) + ca->maxRTT = srtt; + } +} + +static void measure_achieved_throughput(struct sock *sk, + const struct ack_sample *sample) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + const struct tcp_sock *tp = tcp_sk(sk); + struct htcp *ca = inet_csk_ca(sk); + u32 now = tcp_jiffies32; + + if (icsk->icsk_ca_state == TCP_CA_Open) + ca->pkts_acked = sample->pkts_acked; + + if (sample->rtt_us > 0) + measure_rtt(sk, usecs_to_jiffies(sample->rtt_us)); + + if (!use_bandwidth_switch) + return; + + /* achieved throughput calculations */ + if (!((1 << icsk->icsk_ca_state) & (TCPF_CA_Open | TCPF_CA_Disorder))) { + ca->packetcount = 0; + ca->lasttime = now; + return; + } + + ca->packetcount += sample->pkts_acked; + + if (ca->packetcount >= tp->snd_cwnd - (ca->alpha >> 7 ? : 1) && + now - ca->lasttime >= ca->minRTT && + ca->minRTT > 0) { + __u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime); + + if (htcp_ccount(ca) <= 3) { + /* just after backoff */ + ca->minB = ca->maxB = ca->Bi = cur_Bi; + } else { + ca->Bi = (3 * ca->Bi + cur_Bi) / 4; + if (ca->Bi > ca->maxB) + ca->maxB = ca->Bi; + if (ca->minB > ca->maxB) + ca->minB = ca->maxB; + } + ca->packetcount = 0; + ca->lasttime = now; + } +} + +static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT) +{ + if (use_bandwidth_switch) { + u32 maxB = ca->maxB; + u32 old_maxB = ca->old_maxB; + + ca->old_maxB = ca->maxB; + if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) { + ca->beta = BETA_MIN; + ca->modeswitch = 0; + return; + } + } + + if (ca->modeswitch && minRTT > msecs_to_jiffies(10) && maxRTT) { + ca->beta = (minRTT << 7) / maxRTT; + if (ca->beta < BETA_MIN) + ca->beta = BETA_MIN; + else if (ca->beta > BETA_MAX) + ca->beta = BETA_MAX; + } else { + ca->beta = BETA_MIN; + ca->modeswitch = 1; + } +} + +static inline void htcp_alpha_update(struct htcp *ca) +{ + u32 minRTT = ca->minRTT; + u32 factor = 1; + u32 diff = htcp_cong_time(ca); + + if (diff > HZ) { + diff -= HZ; + factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / HZ)) / HZ; + } + + if (use_rtt_scaling && minRTT) { + u32 scale = (HZ << 3) / (10 * minRTT); + + /* clamping ratio to interval [0.5,10]<<3 */ + scale = min(max(scale, 1U << 2), 10U << 3); + factor = (factor << 3) / scale; + if (!factor) + factor = 1; + } + + ca->alpha = 2 * factor * ((1 << 7) - ca->beta); + if (!ca->alpha) + ca->alpha = ALPHA_BASE; +} + +/* + * After we have the rtt data to calculate beta, we'd still prefer to wait one + * rtt before we adjust our beta to ensure we are working from a consistent + * data. + * + * This function should be called when we hit a congestion event since only at + * that point do we really have a real sense of maxRTT (the queues en route + * were getting just too full now). + */ +static void htcp_param_update(struct sock *sk) +{ + struct htcp *ca = inet_csk_ca(sk); + u32 minRTT = ca->minRTT; + u32 maxRTT = ca->maxRTT; + + htcp_beta_update(ca, minRTT, maxRTT); + htcp_alpha_update(ca); + + /* add slowly fading memory for maxRTT to accommodate routing changes */ + if (minRTT > 0 && maxRTT > minRTT) + ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100; +} + +static u32 htcp_recalc_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const struct htcp *ca = inet_csk_ca(sk); + + htcp_param_update(sk); + return max((tp->snd_cwnd * ca->beta) >> 7, 2U); +} + +static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct htcp *ca = inet_csk_ca(sk); + + if (!tcp_is_cwnd_limited(sk)) + return; + + if (tcp_in_slow_start(tp)) + tcp_slow_start(tp, acked); + else { + /* In dangerous area, increase slowly. + * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd + */ + if ((tp->snd_cwnd_cnt * ca->alpha)>>7 >= tp->snd_cwnd) { + if (tp->snd_cwnd < tp->snd_cwnd_clamp) + tp->snd_cwnd++; + tp->snd_cwnd_cnt = 0; + htcp_alpha_update(ca); + } else + tp->snd_cwnd_cnt += ca->pkts_acked; + + ca->pkts_acked = 1; + } +} + +static void htcp_init(struct sock *sk) +{ + struct htcp *ca = inet_csk_ca(sk); + + memset(ca, 0, sizeof(struct htcp)); + ca->alpha = ALPHA_BASE; + ca->beta = BETA_MIN; + ca->pkts_acked = 1; + ca->last_cong = jiffies; +} + +static void htcp_state(struct sock *sk, u8 new_state) +{ + switch (new_state) { + case TCP_CA_Open: + { + struct htcp *ca = inet_csk_ca(sk); + + if (ca->undo_last_cong) { + ca->last_cong = jiffies; + ca->undo_last_cong = 0; + } + } + break; + case TCP_CA_CWR: + case TCP_CA_Recovery: + case TCP_CA_Loss: + htcp_reset(inet_csk_ca(sk)); + break; + } +} + +static struct tcp_congestion_ops htcp __read_mostly = { + .init = htcp_init, + .ssthresh = htcp_recalc_ssthresh, + .cong_avoid = htcp_cong_avoid, + .set_state = htcp_state, + .undo_cwnd = htcp_cwnd_undo, + .pkts_acked = measure_achieved_throughput, + .owner = THIS_MODULE, + .name = "htcp", +}; + +static int __init htcp_register(void) +{ + BUILD_BUG_ON(sizeof(struct htcp) > ICSK_CA_PRIV_SIZE); + BUILD_BUG_ON(BETA_MIN >= BETA_MAX); + return tcp_register_congestion_control(&htcp); +} + +static void __exit htcp_unregister(void) +{ + tcp_unregister_congestion_control(&htcp); +} + +module_init(htcp_register); +module_exit(htcp_unregister); + +MODULE_AUTHOR("Baruch Even"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("H-TCP"); diff --git a/net/ipv4/tcp_hybla.c b/net/ipv4/tcp_hybla.c new file mode 100644 index 000000000..be39327e0 --- /dev/null +++ b/net/ipv4/tcp_hybla.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP HYBLA + * + * TCP-HYBLA Congestion control algorithm, based on: + * C.Caini, R.Firrincieli, "TCP-Hybla: A TCP Enhancement + * for Heterogeneous Networks", + * International Journal on satellite Communications, + * September 2004 + * Daniele Lacamera + * root at danielinux.net + */ + +#include <linux/module.h> +#include <net/tcp.h> + +/* Tcp Hybla structure. */ +struct hybla { + bool hybla_en; + u32 snd_cwnd_cents; /* Keeps increment values when it is <1, <<7 */ + u32 rho; /* Rho parameter, integer part */ + u32 rho2; /* Rho * Rho, integer part */ + u32 rho_3ls; /* Rho parameter, <<3 */ + u32 rho2_7ls; /* Rho^2, <<7 */ + u32 minrtt_us; /* Minimum smoothed round trip time value seen */ +}; + +/* Hybla reference round trip time (default= 1/40 sec = 25 ms), in ms */ +static int rtt0 = 25; +module_param(rtt0, int, 0644); +MODULE_PARM_DESC(rtt0, "reference rout trip time (ms)"); + +/* This is called to refresh values for hybla parameters */ +static inline void hybla_recalc_param (struct sock *sk) +{ + struct hybla *ca = inet_csk_ca(sk); + + ca->rho_3ls = max_t(u32, + tcp_sk(sk)->srtt_us / (rtt0 * USEC_PER_MSEC), + 8U); + ca->rho = ca->rho_3ls >> 3; + ca->rho2_7ls = (ca->rho_3ls * ca->rho_3ls) << 1; + ca->rho2 = ca->rho2_7ls >> 7; +} + +static void hybla_init(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct hybla *ca = inet_csk_ca(sk); + + ca->rho = 0; + ca->rho2 = 0; + ca->rho_3ls = 0; + ca->rho2_7ls = 0; + ca->snd_cwnd_cents = 0; + ca->hybla_en = true; + tp->snd_cwnd = 2; + tp->snd_cwnd_clamp = 65535; + + /* 1st Rho measurement based on initial srtt */ + hybla_recalc_param(sk); + + /* set minimum rtt as this is the 1st ever seen */ + ca->minrtt_us = tp->srtt_us; + tp->snd_cwnd = ca->rho; +} + +static void hybla_state(struct sock *sk, u8 ca_state) +{ + struct hybla *ca = inet_csk_ca(sk); + + ca->hybla_en = (ca_state == TCP_CA_Open); +} + +static inline u32 hybla_fraction(u32 odds) +{ + static const u32 fractions[] = { + 128, 139, 152, 165, 181, 197, 215, 234, + }; + + return (odds < ARRAY_SIZE(fractions)) ? fractions[odds] : 128; +} + +/* TCP Hybla main routine. + * This is the algorithm behavior: + * o Recalc Hybla parameters if min_rtt has changed + * o Give cwnd a new value based on the model proposed + * o remember increments <1 + */ +static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct hybla *ca = inet_csk_ca(sk); + u32 increment, odd, rho_fractions; + int is_slowstart = 0; + + /* Recalculate rho only if this srtt is the lowest */ + if (tp->srtt_us < ca->minrtt_us) { + hybla_recalc_param(sk); + ca->minrtt_us = tp->srtt_us; + } + + if (!tcp_is_cwnd_limited(sk)) + return; + + if (!ca->hybla_en) { + tcp_reno_cong_avoid(sk, ack, acked); + return; + } + + if (ca->rho == 0) + hybla_recalc_param(sk); + + rho_fractions = ca->rho_3ls - (ca->rho << 3); + + if (tcp_in_slow_start(tp)) { + /* + * slow start + * INC = 2^RHO - 1 + * This is done by splitting the rho parameter + * into 2 parts: an integer part and a fraction part. + * Inrement<<7 is estimated by doing: + * [2^(int+fract)]<<7 + * that is equal to: + * (2^int) * [(2^fract) <<7] + * 2^int is straightly computed as 1<<int, + * while we will use hybla_slowstart_fraction_increment() to + * calculate 2^fract in a <<7 value. + */ + is_slowstart = 1; + increment = ((1 << min(ca->rho, 16U)) * + hybla_fraction(rho_fractions)) - 128; + } else { + /* + * congestion avoidance + * INC = RHO^2 / W + * as long as increment is estimated as (rho<<7)/window + * it already is <<7 and we can easily count its fractions. + */ + increment = ca->rho2_7ls / tp->snd_cwnd; + if (increment < 128) + tp->snd_cwnd_cnt++; + } + + odd = increment % 128; + tp->snd_cwnd += increment >> 7; + ca->snd_cwnd_cents += odd; + + /* check when fractions goes >=128 and increase cwnd by 1. */ + while (ca->snd_cwnd_cents >= 128) { + tp->snd_cwnd++; + ca->snd_cwnd_cents -= 128; + tp->snd_cwnd_cnt = 0; + } + /* check when cwnd has not been incremented for a while */ + if (increment == 0 && odd == 0 && tp->snd_cwnd_cnt >= tp->snd_cwnd) { + tp->snd_cwnd++; + tp->snd_cwnd_cnt = 0; + } + /* clamp down slowstart cwnd to ssthresh value. */ + if (is_slowstart) + tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh); + + tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp); +} + +static struct tcp_congestion_ops tcp_hybla __read_mostly = { + .init = hybla_init, + .ssthresh = tcp_reno_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = hybla_cong_avoid, + .set_state = hybla_state, + + .owner = THIS_MODULE, + .name = "hybla" +}; + +static int __init hybla_register(void) +{ + BUILD_BUG_ON(sizeof(struct hybla) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&tcp_hybla); +} + +static void __exit hybla_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_hybla); +} + +module_init(hybla_register); +module_exit(hybla_unregister); + +MODULE_AUTHOR("Daniele Lacamera"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP Hybla"); diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c new file mode 100644 index 000000000..00e548732 --- /dev/null +++ b/net/ipv4/tcp_illinois.c @@ -0,0 +1,358 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP Illinois congestion control. + * Home page: + * http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html + * + * The algorithm is described in: + * "TCP-Illinois: A Loss and Delay-Based Congestion Control Algorithm + * for High-Speed Networks" + * http://tamerbasar.csl.illinois.edu/LiuBasarSrikantPerfEvalArtJun2008.pdf + * + * Implemented from description in paper and ns-2 simulation. + * Copyright (C) 2007 Stephen Hemminger <shemminger@linux-foundation.org> + */ + +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/inet_diag.h> +#include <asm/div64.h> +#include <net/tcp.h> + +#define ALPHA_SHIFT 7 +#define ALPHA_SCALE (1u<<ALPHA_SHIFT) +#define ALPHA_MIN ((3*ALPHA_SCALE)/10) /* ~0.3 */ +#define ALPHA_MAX (10*ALPHA_SCALE) /* 10.0 */ +#define ALPHA_BASE ALPHA_SCALE /* 1.0 */ +#define RTT_MAX (U32_MAX / ALPHA_MAX) /* 3.3 secs */ + +#define BETA_SHIFT 6 +#define BETA_SCALE (1u<<BETA_SHIFT) +#define BETA_MIN (BETA_SCALE/8) /* 0.125 */ +#define BETA_MAX (BETA_SCALE/2) /* 0.5 */ +#define BETA_BASE BETA_MAX + +static int win_thresh __read_mostly = 15; +module_param(win_thresh, int, 0); +MODULE_PARM_DESC(win_thresh, "Window threshold for starting adaptive sizing"); + +static int theta __read_mostly = 5; +module_param(theta, int, 0); +MODULE_PARM_DESC(theta, "# of fast RTT's before full growth"); + +/* TCP Illinois Parameters */ +struct illinois { + u64 sum_rtt; /* sum of rtt's measured within last rtt */ + u16 cnt_rtt; /* # of rtts measured within last rtt */ + u32 base_rtt; /* min of all rtt in usec */ + u32 max_rtt; /* max of all rtt in usec */ + u32 end_seq; /* right edge of current RTT */ + u32 alpha; /* Additive increase */ + u32 beta; /* Muliplicative decrease */ + u16 acked; /* # packets acked by current ACK */ + u8 rtt_above; /* average rtt has gone above threshold */ + u8 rtt_low; /* # of rtts measurements below threshold */ +}; + +static void rtt_reset(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct illinois *ca = inet_csk_ca(sk); + + ca->end_seq = tp->snd_nxt; + ca->cnt_rtt = 0; + ca->sum_rtt = 0; + + /* TODO: age max_rtt? */ +} + +static void tcp_illinois_init(struct sock *sk) +{ + struct illinois *ca = inet_csk_ca(sk); + + ca->alpha = ALPHA_MAX; + ca->beta = BETA_BASE; + ca->base_rtt = 0x7fffffff; + ca->max_rtt = 0; + + ca->acked = 0; + ca->rtt_low = 0; + ca->rtt_above = 0; + + rtt_reset(sk); +} + +/* Measure RTT for each ack. */ +static void tcp_illinois_acked(struct sock *sk, const struct ack_sample *sample) +{ + struct illinois *ca = inet_csk_ca(sk); + s32 rtt_us = sample->rtt_us; + + ca->acked = sample->pkts_acked; + + /* dup ack, no rtt sample */ + if (rtt_us < 0) + return; + + /* ignore bogus values, this prevents wraparound in alpha math */ + if (rtt_us > RTT_MAX) + rtt_us = RTT_MAX; + + /* keep track of minimum RTT seen so far */ + if (ca->base_rtt > rtt_us) + ca->base_rtt = rtt_us; + + /* and max */ + if (ca->max_rtt < rtt_us) + ca->max_rtt = rtt_us; + + ++ca->cnt_rtt; + ca->sum_rtt += rtt_us; +} + +/* Maximum queuing delay */ +static inline u32 max_delay(const struct illinois *ca) +{ + return ca->max_rtt - ca->base_rtt; +} + +/* Average queuing delay */ +static inline u32 avg_delay(const struct illinois *ca) +{ + u64 t = ca->sum_rtt; + + do_div(t, ca->cnt_rtt); + return t - ca->base_rtt; +} + +/* + * Compute value of alpha used for additive increase. + * If small window then use 1.0, equivalent to Reno. + * + * For larger windows, adjust based on average delay. + * A. If average delay is at minimum (we are uncongested), + * then use large alpha (10.0) to increase faster. + * B. If average delay is at maximum (getting congested) + * then use small alpha (0.3) + * + * The result is a convex window growth curve. + */ +static u32 alpha(struct illinois *ca, u32 da, u32 dm) +{ + u32 d1 = dm / 100; /* Low threshold */ + + if (da <= d1) { + /* If never got out of low delay zone, then use max */ + if (!ca->rtt_above) + return ALPHA_MAX; + + /* Wait for 5 good RTT's before allowing alpha to go alpha max. + * This prevents one good RTT from causing sudden window increase. + */ + if (++ca->rtt_low < theta) + return ca->alpha; + + ca->rtt_low = 0; + ca->rtt_above = 0; + return ALPHA_MAX; + } + + ca->rtt_above = 1; + + /* + * Based on: + * + * (dm - d1) amin amax + * k1 = ------------------- + * amax - amin + * + * (dm - d1) amin + * k2 = ---------------- - d1 + * amax - amin + * + * k1 + * alpha = ---------- + * k2 + da + */ + + dm -= d1; + da -= d1; + return (dm * ALPHA_MAX) / + (dm + (da * (ALPHA_MAX - ALPHA_MIN)) / ALPHA_MIN); +} + +/* + * Beta used for multiplicative decrease. + * For small window sizes returns same value as Reno (0.5) + * + * If delay is small (10% of max) then beta = 1/8 + * If delay is up to 80% of max then beta = 1/2 + * In between is a linear function + */ +static u32 beta(u32 da, u32 dm) +{ + u32 d2, d3; + + d2 = dm / 10; + if (da <= d2) + return BETA_MIN; + + d3 = (8 * dm) / 10; + if (da >= d3 || d3 <= d2) + return BETA_MAX; + + /* + * Based on: + * + * bmin d3 - bmax d2 + * k3 = ------------------- + * d3 - d2 + * + * bmax - bmin + * k4 = ------------- + * d3 - d2 + * + * b = k3 + k4 da + */ + return (BETA_MIN * d3 - BETA_MAX * d2 + (BETA_MAX - BETA_MIN) * da) + / (d3 - d2); +} + +/* Update alpha and beta values once per RTT */ +static void update_params(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct illinois *ca = inet_csk_ca(sk); + + if (tp->snd_cwnd < win_thresh) { + ca->alpha = ALPHA_BASE; + ca->beta = BETA_BASE; + } else if (ca->cnt_rtt > 0) { + u32 dm = max_delay(ca); + u32 da = avg_delay(ca); + + ca->alpha = alpha(ca, da, dm); + ca->beta = beta(da, dm); + } + + rtt_reset(sk); +} + +/* + * In case of loss, reset to default values + */ +static void tcp_illinois_state(struct sock *sk, u8 new_state) +{ + struct illinois *ca = inet_csk_ca(sk); + + if (new_state == TCP_CA_Loss) { + ca->alpha = ALPHA_BASE; + ca->beta = BETA_BASE; + ca->rtt_low = 0; + ca->rtt_above = 0; + rtt_reset(sk); + } +} + +/* + * Increase window in response to successful acknowledgment. + */ +static void tcp_illinois_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct illinois *ca = inet_csk_ca(sk); + + if (after(ack, ca->end_seq)) + update_params(sk); + + /* RFC2861 only increase cwnd if fully utilized */ + if (!tcp_is_cwnd_limited(sk)) + return; + + /* In slow start */ + if (tcp_in_slow_start(tp)) + tcp_slow_start(tp, acked); + + else { + u32 delta; + + /* snd_cwnd_cnt is # of packets since last cwnd increment */ + tp->snd_cwnd_cnt += ca->acked; + ca->acked = 1; + + /* This is close approximation of: + * tp->snd_cwnd += alpha/tp->snd_cwnd + */ + delta = (tp->snd_cwnd_cnt * ca->alpha) >> ALPHA_SHIFT; + if (delta >= tp->snd_cwnd) { + tp->snd_cwnd = min(tp->snd_cwnd + delta / tp->snd_cwnd, + (u32)tp->snd_cwnd_clamp); + tp->snd_cwnd_cnt = 0; + } + } +} + +static u32 tcp_illinois_ssthresh(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct illinois *ca = inet_csk_ca(sk); + + /* Multiplicative decrease */ + return max(tp->snd_cwnd - ((tp->snd_cwnd * ca->beta) >> BETA_SHIFT), 2U); +} + +/* Extract info for Tcp socket info provided via netlink. */ +static size_t tcp_illinois_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info) +{ + const struct illinois *ca = inet_csk_ca(sk); + + if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) { + info->vegas.tcpv_enabled = 1; + info->vegas.tcpv_rttcnt = ca->cnt_rtt; + info->vegas.tcpv_minrtt = ca->base_rtt; + info->vegas.tcpv_rtt = 0; + + if (info->vegas.tcpv_rttcnt > 0) { + u64 t = ca->sum_rtt; + + do_div(t, info->vegas.tcpv_rttcnt); + info->vegas.tcpv_rtt = t; + } + *attr = INET_DIAG_VEGASINFO; + return sizeof(struct tcpvegas_info); + } + return 0; +} + +static struct tcp_congestion_ops tcp_illinois __read_mostly = { + .init = tcp_illinois_init, + .ssthresh = tcp_illinois_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = tcp_illinois_cong_avoid, + .set_state = tcp_illinois_state, + .get_info = tcp_illinois_info, + .pkts_acked = tcp_illinois_acked, + + .owner = THIS_MODULE, + .name = "illinois", +}; + +static int __init tcp_illinois_register(void) +{ + BUILD_BUG_ON(sizeof(struct illinois) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&tcp_illinois); +} + +static void __exit tcp_illinois_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_illinois); +} + +module_init(tcp_illinois_register); +module_exit(tcp_illinois_unregister); + +MODULE_AUTHOR("Stephen Hemminger, Shao Liu"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP Illinois"); +MODULE_VERSION("1.0"); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c new file mode 100644 index 000000000..0f9fe5eda --- /dev/null +++ b/net/ipv4/tcp_input.c @@ -0,0 +1,6989 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Implementation of the Transmission Control Protocol(TCP). + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * Corey Minyard <wf-rch!minyard@relay.EU.net> + * Florian La Roche, <flla@stud.uni-sb.de> + * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> + * Linus Torvalds, <torvalds@cs.helsinki.fi> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Matthew Dillon, <dillon@apollo.west.oic.com> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Jorge Cwik, <jorge@laser.satlink.net> + */ + +/* + * Changes: + * Pedro Roque : Fast Retransmit/Recovery. + * Two receive queues. + * Retransmit queue handled by TCP. + * Better retransmit timer handling. + * New congestion avoidance. + * Header prediction. + * Variable renaming. + * + * Eric : Fast Retransmit. + * Randy Scott : MSS option defines. + * Eric Schenk : Fixes to slow start algorithm. + * Eric Schenk : Yet another double ACK bug. + * Eric Schenk : Delayed ACK bug fixes. + * Eric Schenk : Floyd style fast retrans war avoidance. + * David S. Miller : Don't allow zero congestion window. + * Eric Schenk : Fix retransmitter so that it sends + * next packet on ack of previous packet. + * Andi Kleen : Moved open_request checking here + * and process RSTs for open_requests. + * Andi Kleen : Better prune_queue, and other fixes. + * Andrey Savochkin: Fix RTT measurements in the presence of + * timestamps. + * Andrey Savochkin: Check sequence numbers correctly when + * removing SACKs due to in sequence incoming + * data segments. + * Andi Kleen: Make sure we never ack data there is not + * enough room for. Also make this condition + * a fatal error if it might still happen. + * Andi Kleen: Add tcp_measure_rcv_mss to make + * connections with MSS<min(MTU,ann. MSS) + * work without delayed acks. + * Andi Kleen: Process packets with PSH set in the + * fast path. + * J Hadi Salim: ECN support + * Andrei Gurtov, + * Pasi Sarolahti, + * Panu Kuhlberg: Experimental audit of TCP (re)transmission + * engine. Lots of bugs are found. + * Pasi Sarolahti: F-RTO for dealing with spurious RTOs + */ + +#define pr_fmt(fmt) "TCP: " fmt + +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/sysctl.h> +#include <linux/kernel.h> +#include <linux/prefetch.h> +#include <net/dst.h> +#include <net/tcp.h> +#include <net/inet_common.h> +#include <linux/ipsec.h> +#include <asm/unaligned.h> +#include <linux/errqueue.h> +#include <trace/events/tcp.h> +#include <linux/jump_label_ratelimit.h> +#include <net/busy_poll.h> +#include <net/mptcp.h> + +int sysctl_tcp_max_orphans __read_mostly = NR_FILE; + +#define FLAG_DATA 0x01 /* Incoming frame contained data. */ +#define FLAG_WIN_UPDATE 0x02 /* Incoming ACK was a window update. */ +#define FLAG_DATA_ACKED 0x04 /* This ACK acknowledged new data. */ +#define FLAG_RETRANS_DATA_ACKED 0x08 /* "" "" some of which was retransmitted. */ +#define FLAG_SYN_ACKED 0x10 /* This ACK acknowledged SYN. */ +#define FLAG_DATA_SACKED 0x20 /* New SACK. */ +#define FLAG_ECE 0x40 /* ECE in this ACK */ +#define FLAG_LOST_RETRANS 0x80 /* This ACK marks some retransmission lost */ +#define FLAG_SLOWPATH 0x100 /* Do not skip RFC checks for window update.*/ +#define FLAG_ORIG_SACK_ACKED 0x200 /* Never retransmitted data are (s)acked */ +#define FLAG_SND_UNA_ADVANCED 0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */ +#define FLAG_DSACKING_ACK 0x800 /* SACK blocks contained D-SACK info */ +#define FLAG_SET_XMIT_TIMER 0x1000 /* Set TLP or RTO timer */ +#define FLAG_SACK_RENEGING 0x2000 /* snd_una advanced to a sacked seq */ +#define FLAG_UPDATE_TS_RECENT 0x4000 /* tcp_replace_ts_recent() */ +#define FLAG_NO_CHALLENGE_ACK 0x8000 /* do not call tcp_send_challenge_ack() */ +#define FLAG_ACK_MAYBE_DELAYED 0x10000 /* Likely a delayed ACK */ + +#define FLAG_ACKED (FLAG_DATA_ACKED|FLAG_SYN_ACKED) +#define FLAG_NOT_DUP (FLAG_DATA|FLAG_WIN_UPDATE|FLAG_ACKED) +#define FLAG_CA_ALERT (FLAG_DATA_SACKED|FLAG_ECE|FLAG_DSACKING_ACK) +#define FLAG_FORWARD_PROGRESS (FLAG_ACKED|FLAG_DATA_SACKED) + +#define TCP_REMNANT (TCP_FLAG_FIN|TCP_FLAG_URG|TCP_FLAG_SYN|TCP_FLAG_PSH) +#define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH)) + +#define REXMIT_NONE 0 /* no loss recovery to do */ +#define REXMIT_LOST 1 /* retransmit packets marked lost */ +#define REXMIT_NEW 2 /* FRTO-style transmit of unsent/new packets */ + +#if IS_ENABLED(CONFIG_TLS_DEVICE) +static DEFINE_STATIC_KEY_DEFERRED_FALSE(clean_acked_data_enabled, HZ); + +void clean_acked_data_enable(struct inet_connection_sock *icsk, + void (*cad)(struct sock *sk, u32 ack_seq)) +{ + icsk->icsk_clean_acked = cad; + static_branch_deferred_inc(&clean_acked_data_enabled); +} +EXPORT_SYMBOL_GPL(clean_acked_data_enable); + +void clean_acked_data_disable(struct inet_connection_sock *icsk) +{ + static_branch_slow_dec_deferred(&clean_acked_data_enabled); + icsk->icsk_clean_acked = NULL; +} +EXPORT_SYMBOL_GPL(clean_acked_data_disable); + +void clean_acked_data_flush(void) +{ + static_key_deferred_flush(&clean_acked_data_enabled); +} +EXPORT_SYMBOL_GPL(clean_acked_data_flush); +#endif + +#ifdef CONFIG_CGROUP_BPF +static void bpf_skops_parse_hdr(struct sock *sk, struct sk_buff *skb) +{ + bool unknown_opt = tcp_sk(sk)->rx_opt.saw_unknown && + BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), + BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG); + bool parse_all_opt = BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), + BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG); + struct bpf_sock_ops_kern sock_ops; + + if (likely(!unknown_opt && !parse_all_opt)) + return; + + /* The skb will be handled in the + * bpf_skops_established() or + * bpf_skops_write_hdr_opt(). + */ + switch (sk->sk_state) { + case TCP_SYN_RECV: + case TCP_SYN_SENT: + case TCP_LISTEN: + return; + } + + sock_owned_by_me(sk); + + memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); + sock_ops.op = BPF_SOCK_OPS_PARSE_HDR_OPT_CB; + sock_ops.is_fullsock = 1; + sock_ops.sk = sk; + bpf_skops_init_skb(&sock_ops, skb, tcp_hdrlen(skb)); + + BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); +} + +static void bpf_skops_established(struct sock *sk, int bpf_op, + struct sk_buff *skb) +{ + struct bpf_sock_ops_kern sock_ops; + + sock_owned_by_me(sk); + + memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); + sock_ops.op = bpf_op; + sock_ops.is_fullsock = 1; + sock_ops.sk = sk; + /* sk with TCP_REPAIR_ON does not have skb in tcp_finish_connect */ + if (skb) + bpf_skops_init_skb(&sock_ops, skb, tcp_hdrlen(skb)); + + BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); +} +#else +static void bpf_skops_parse_hdr(struct sock *sk, struct sk_buff *skb) +{ +} + +static void bpf_skops_established(struct sock *sk, int bpf_op, + struct sk_buff *skb) +{ +} +#endif + +static void tcp_gro_dev_warn(struct sock *sk, const struct sk_buff *skb, + unsigned int len) +{ + static bool __once __read_mostly; + + if (!__once) { + struct net_device *dev; + + __once = true; + + rcu_read_lock(); + dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif); + if (!dev || len >= dev->mtu) + pr_warn("%s: Driver has suspect GRO implementation, TCP performance may be compromised.\n", + dev ? dev->name : "Unknown driver"); + rcu_read_unlock(); + } +} + +/* Adapt the MSS value used to make delayed ack decision to the + * real world. + */ +static void tcp_measure_rcv_mss(struct sock *sk, const struct sk_buff *skb) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + const unsigned int lss = icsk->icsk_ack.last_seg_size; + unsigned int len; + + icsk->icsk_ack.last_seg_size = 0; + + /* skb->len may jitter because of SACKs, even if peer + * sends good full-sized frames. + */ + len = skb_shinfo(skb)->gso_size ? : skb->len; + if (len >= icsk->icsk_ack.rcv_mss) { + icsk->icsk_ack.rcv_mss = min_t(unsigned int, len, + tcp_sk(sk)->advmss); + /* Account for possibly-removed options */ + if (unlikely(len > icsk->icsk_ack.rcv_mss + + MAX_TCP_OPTION_SPACE)) + tcp_gro_dev_warn(sk, skb, len); + /* If the skb has a len of exactly 1*MSS and has the PSH bit + * set then it is likely the end of an application write. So + * more data may not be arriving soon, and yet the data sender + * may be waiting for an ACK if cwnd-bound or using TX zero + * copy. So we set ICSK_ACK_PUSHED here so that + * tcp_cleanup_rbuf() will send an ACK immediately if the app + * reads all of the data and is not ping-pong. If len > MSS + * then this logic does not matter (and does not hurt) because + * tcp_cleanup_rbuf() will always ACK immediately if the app + * reads data and there is more than an MSS of unACKed data. + */ + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_PSH) + icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; + } else { + /* Otherwise, we make more careful check taking into account, + * that SACKs block is variable. + * + * "len" is invariant segment length, including TCP header. + */ + len += skb->data - skb_transport_header(skb); + if (len >= TCP_MSS_DEFAULT + sizeof(struct tcphdr) || + /* If PSH is not set, packet should be + * full sized, provided peer TCP is not badly broken. + * This observation (if it is correct 8)) allows + * to handle super-low mtu links fairly. + */ + (len >= TCP_MIN_MSS + sizeof(struct tcphdr) && + !(tcp_flag_word(tcp_hdr(skb)) & TCP_REMNANT))) { + /* Subtract also invariant (if peer is RFC compliant), + * tcp header plus fixed timestamp option length. + * Resulting "len" is MSS free of SACK jitter. + */ + len -= tcp_sk(sk)->tcp_header_len; + icsk->icsk_ack.last_seg_size = len; + if (len == lss) { + icsk->icsk_ack.rcv_mss = len; + return; + } + } + if (icsk->icsk_ack.pending & ICSK_ACK_PUSHED) + icsk->icsk_ack.pending |= ICSK_ACK_PUSHED2; + icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; + } +} + +static void tcp_incr_quickack(struct sock *sk, unsigned int max_quickacks) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + unsigned int quickacks = tcp_sk(sk)->rcv_wnd / (2 * icsk->icsk_ack.rcv_mss); + + if (quickacks == 0) + quickacks = 2; + quickacks = min(quickacks, max_quickacks); + if (quickacks > icsk->icsk_ack.quick) + icsk->icsk_ack.quick = quickacks; +} + +static void tcp_enter_quickack_mode(struct sock *sk, unsigned int max_quickacks) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + tcp_incr_quickack(sk, max_quickacks); + inet_csk_exit_pingpong_mode(sk); + icsk->icsk_ack.ato = TCP_ATO_MIN; +} + +/* Send ACKs quickly, if "quick" count is not exhausted + * and the session is not interactive. + */ + +static bool tcp_in_quickack_mode(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + const struct dst_entry *dst = __sk_dst_get(sk); + + return (dst && dst_metric(dst, RTAX_QUICKACK)) || + (icsk->icsk_ack.quick && !inet_csk_in_pingpong_mode(sk)); +} + +static void tcp_ecn_queue_cwr(struct tcp_sock *tp) +{ + if (tp->ecn_flags & TCP_ECN_OK) + tp->ecn_flags |= TCP_ECN_QUEUE_CWR; +} + +static void tcp_ecn_accept_cwr(struct sock *sk, const struct sk_buff *skb) +{ + if (tcp_hdr(skb)->cwr) { + tcp_sk(sk)->ecn_flags &= ~TCP_ECN_DEMAND_CWR; + + /* If the sender is telling us it has entered CWR, then its + * cwnd may be very low (even just 1 packet), so we should ACK + * immediately. + */ + if (TCP_SKB_CB(skb)->seq != TCP_SKB_CB(skb)->end_seq) + inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW; + } +} + +static void tcp_ecn_withdraw_cwr(struct tcp_sock *tp) +{ + tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR; +} + +static void __tcp_ecn_check_ce(struct sock *sk, const struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + switch (TCP_SKB_CB(skb)->ip_dsfield & INET_ECN_MASK) { + case INET_ECN_NOT_ECT: + /* Funny extension: if ECT is not set on a segment, + * and we already seen ECT on a previous segment, + * it is probably a retransmit. + */ + if (tp->ecn_flags & TCP_ECN_SEEN) + tcp_enter_quickack_mode(sk, 2); + break; + case INET_ECN_CE: + if (tcp_ca_needs_ecn(sk)) + tcp_ca_event(sk, CA_EVENT_ECN_IS_CE); + + if (!(tp->ecn_flags & TCP_ECN_DEMAND_CWR)) { + /* Better not delay acks, sender can have a very low cwnd */ + tcp_enter_quickack_mode(sk, 2); + tp->ecn_flags |= TCP_ECN_DEMAND_CWR; + } + tp->ecn_flags |= TCP_ECN_SEEN; + break; + default: + if (tcp_ca_needs_ecn(sk)) + tcp_ca_event(sk, CA_EVENT_ECN_NO_CE); + tp->ecn_flags |= TCP_ECN_SEEN; + break; + } +} + +static void tcp_ecn_check_ce(struct sock *sk, const struct sk_buff *skb) +{ + if (tcp_sk(sk)->ecn_flags & TCP_ECN_OK) + __tcp_ecn_check_ce(sk, skb); +} + +static void tcp_ecn_rcv_synack(struct tcp_sock *tp, const struct tcphdr *th) +{ + if ((tp->ecn_flags & TCP_ECN_OK) && (!th->ece || th->cwr)) + tp->ecn_flags &= ~TCP_ECN_OK; +} + +static void tcp_ecn_rcv_syn(struct tcp_sock *tp, const struct tcphdr *th) +{ + if ((tp->ecn_flags & TCP_ECN_OK) && (!th->ece || !th->cwr)) + tp->ecn_flags &= ~TCP_ECN_OK; +} + +static bool tcp_ecn_rcv_ecn_echo(const struct tcp_sock *tp, const struct tcphdr *th) +{ + if (th->ece && !th->syn && (tp->ecn_flags & TCP_ECN_OK)) + return true; + return false; +} + +/* Buffer size and advertised window tuning. + * + * 1. Tuning sk->sk_sndbuf, when connection enters established state. + */ + +static void tcp_sndbuf_expand(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; + int sndmem, per_mss; + u32 nr_segs; + + /* Worst case is non GSO/TSO : each frame consumes one skb + * and skb->head is kmalloced using power of two area of memory + */ + per_mss = max_t(u32, tp->rx_opt.mss_clamp, tp->mss_cache) + + MAX_TCP_HEADER + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + + per_mss = roundup_pow_of_two(per_mss) + + SKB_DATA_ALIGN(sizeof(struct sk_buff)); + + nr_segs = max_t(u32, TCP_INIT_CWND, tp->snd_cwnd); + nr_segs = max_t(u32, nr_segs, tp->reordering + 1); + + /* Fast Recovery (RFC 5681 3.2) : + * Cubic needs 1.7 factor, rounded to 2 to include + * extra cushion (application might react slowly to EPOLLOUT) + */ + sndmem = ca_ops->sndbuf_expand ? ca_ops->sndbuf_expand(sk) : 2; + sndmem *= nr_segs * per_mss; + + if (sk->sk_sndbuf < sndmem) + WRITE_ONCE(sk->sk_sndbuf, + min(sndmem, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[2]))); +} + +/* 2. Tuning advertised window (window_clamp, rcv_ssthresh) + * + * All tcp_full_space() is split to two parts: "network" buffer, allocated + * forward and advertised in receiver window (tp->rcv_wnd) and + * "application buffer", required to isolate scheduling/application + * latencies from network. + * window_clamp is maximal advertised window. It can be less than + * tcp_full_space(), in this case tcp_full_space() - window_clamp + * is reserved for "application" buffer. The less window_clamp is + * the smoother our behaviour from viewpoint of network, but the lower + * throughput and the higher sensitivity of the connection to losses. 8) + * + * rcv_ssthresh is more strict window_clamp used at "slow start" + * phase to predict further behaviour of this connection. + * It is used for two goals: + * - to enforce header prediction at sender, even when application + * requires some significant "application buffer". It is check #1. + * - to prevent pruning of receive queue because of misprediction + * of receiver window. Check #2. + * + * The scheme does not work when sender sends good segments opening + * window and then starts to feed us spaghetti. But it should work + * in common situations. Otherwise, we have to rely on queue collapsing. + */ + +/* Slow part of check#2. */ +static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb, + unsigned int skbtruesize) +{ + struct tcp_sock *tp = tcp_sk(sk); + /* Optimize this! */ + int truesize = tcp_win_from_space(sk, skbtruesize) >> 1; + int window = tcp_win_from_space(sk, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2])) >> 1; + + while (tp->rcv_ssthresh <= window) { + if (truesize <= skb->len) + return 2 * inet_csk(sk)->icsk_ack.rcv_mss; + + truesize >>= 1; + window >>= 1; + } + return 0; +} + +/* Even if skb appears to have a bad len/truesize ratio, TCP coalescing + * can play nice with us, as sk_buff and skb->head might be either + * freed or shared with up to MAX_SKB_FRAGS segments. + * Only give a boost to drivers using page frag(s) to hold the frame(s), + * and if no payload was pulled in skb->head before reaching us. + */ +static u32 truesize_adjust(bool adjust, const struct sk_buff *skb) +{ + u32 truesize = skb->truesize; + + if (adjust && !skb_headlen(skb)) { + truesize -= SKB_TRUESIZE(skb_end_offset(skb)); + /* paranoid check, some drivers might be buggy */ + if (unlikely((int)truesize < (int)skb->len)) + truesize = skb->truesize; + } + return truesize; +} + +static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb, + bool adjust) +{ + struct tcp_sock *tp = tcp_sk(sk); + int room; + + room = min_t(int, tp->window_clamp, tcp_space(sk)) - tp->rcv_ssthresh; + + /* Check #1 */ + if (room > 0 && !tcp_under_memory_pressure(sk)) { + unsigned int truesize = truesize_adjust(adjust, skb); + int incr; + + /* Check #2. Increase window, if skb with such overhead + * will fit to rcvbuf in future. + */ + if (tcp_win_from_space(sk, truesize) <= skb->len) + incr = 2 * tp->advmss; + else + incr = __tcp_grow_window(sk, skb, truesize); + + if (incr) { + incr = max_t(int, incr, 2 * skb->len); + tp->rcv_ssthresh += min(room, incr); + inet_csk(sk)->icsk_ack.quick |= 1; + } + } +} + +/* 3. Try to fixup all. It is made immediately after connection enters + * established state. + */ +static void tcp_init_buffer_space(struct sock *sk) +{ + int tcp_app_win = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_app_win); + struct tcp_sock *tp = tcp_sk(sk); + int maxwin; + + if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) + tcp_sndbuf_expand(sk); + + tcp_mstamp_refresh(tp); + tp->rcvq_space.time = tp->tcp_mstamp; + tp->rcvq_space.seq = tp->copied_seq; + + maxwin = tcp_full_space(sk); + + if (tp->window_clamp >= maxwin) { + tp->window_clamp = maxwin; + + if (tcp_app_win && maxwin > 4 * tp->advmss) + tp->window_clamp = max(maxwin - + (maxwin >> tcp_app_win), + 4 * tp->advmss); + } + + /* Force reservation of one segment. */ + if (tcp_app_win && + tp->window_clamp > 2 * tp->advmss && + tp->window_clamp + tp->advmss > maxwin) + tp->window_clamp = max(2 * tp->advmss, maxwin - tp->advmss); + + tp->rcv_ssthresh = min(tp->rcv_ssthresh, tp->window_clamp); + tp->snd_cwnd_stamp = tcp_jiffies32; + tp->rcvq_space.space = min3(tp->rcv_ssthresh, tp->rcv_wnd, + (u32)TCP_INIT_CWND * tp->advmss); +} + +/* 4. Recalculate window clamp after socket hit its memory bounds. */ +static void tcp_clamp_window(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + struct net *net = sock_net(sk); + int rmem2; + + icsk->icsk_ack.quick = 0; + rmem2 = READ_ONCE(net->ipv4.sysctl_tcp_rmem[2]); + + if (sk->sk_rcvbuf < rmem2 && + !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) && + !tcp_under_memory_pressure(sk) && + sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) { + WRITE_ONCE(sk->sk_rcvbuf, + min(atomic_read(&sk->sk_rmem_alloc), rmem2)); + } + if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) + tp->rcv_ssthresh = min(tp->window_clamp, 2U * tp->advmss); +} + +/* Initialize RCV_MSS value. + * RCV_MSS is an our guess about MSS used by the peer. + * We haven't any direct information about the MSS. + * It's better to underestimate the RCV_MSS rather than overestimate. + * Overestimations make us ACKing less frequently than needed. + * Underestimations are more easy to detect and fix by tcp_measure_rcv_mss(). + */ +void tcp_initialize_rcv_mss(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + unsigned int hint = min_t(unsigned int, tp->advmss, tp->mss_cache); + + hint = min(hint, tp->rcv_wnd / 2); + hint = min(hint, TCP_MSS_DEFAULT); + hint = max(hint, TCP_MIN_MSS); + + inet_csk(sk)->icsk_ack.rcv_mss = hint; +} +EXPORT_SYMBOL(tcp_initialize_rcv_mss); + +/* Receiver "autotuning" code. + * + * The algorithm for RTT estimation w/o timestamps is based on + * Dynamic Right-Sizing (DRS) by Wu Feng and Mike Fisk of LANL. + * <https://public.lanl.gov/radiant/pubs.html#DRS> + * + * More detail on this code can be found at + * <http://staff.psc.edu/jheffner/>, + * though this reference is out of date. A new paper + * is pending. + */ +static void tcp_rcv_rtt_update(struct tcp_sock *tp, u32 sample, int win_dep) +{ + u32 new_sample = tp->rcv_rtt_est.rtt_us; + long m = sample; + + if (new_sample != 0) { + /* If we sample in larger samples in the non-timestamp + * case, we could grossly overestimate the RTT especially + * with chatty applications or bulk transfer apps which + * are stalled on filesystem I/O. + * + * Also, since we are only going for a minimum in the + * non-timestamp case, we do not smooth things out + * else with timestamps disabled convergence takes too + * long. + */ + if (!win_dep) { + m -= (new_sample >> 3); + new_sample += m; + } else { + m <<= 3; + if (m < new_sample) + new_sample = m; + } + } else { + /* No previous measure. */ + new_sample = m << 3; + } + + tp->rcv_rtt_est.rtt_us = new_sample; +} + +static inline void tcp_rcv_rtt_measure(struct tcp_sock *tp) +{ + u32 delta_us; + + if (tp->rcv_rtt_est.time == 0) + goto new_measure; + if (before(tp->rcv_nxt, tp->rcv_rtt_est.seq)) + return; + delta_us = tcp_stamp_us_delta(tp->tcp_mstamp, tp->rcv_rtt_est.time); + if (!delta_us) + delta_us = 1; + tcp_rcv_rtt_update(tp, delta_us, 1); + +new_measure: + tp->rcv_rtt_est.seq = tp->rcv_nxt + tp->rcv_wnd; + tp->rcv_rtt_est.time = tp->tcp_mstamp; +} + +static inline void tcp_rcv_rtt_measure_ts(struct sock *sk, + const struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->rx_opt.rcv_tsecr == tp->rcv_rtt_last_tsecr) + return; + tp->rcv_rtt_last_tsecr = tp->rx_opt.rcv_tsecr; + + if (TCP_SKB_CB(skb)->end_seq - + TCP_SKB_CB(skb)->seq >= inet_csk(sk)->icsk_ack.rcv_mss) { + u32 delta = tcp_time_stamp(tp) - tp->rx_opt.rcv_tsecr; + u32 delta_us; + + if (likely(delta < INT_MAX / (USEC_PER_SEC / TCP_TS_HZ))) { + if (!delta) + delta = 1; + delta_us = delta * (USEC_PER_SEC / TCP_TS_HZ); + tcp_rcv_rtt_update(tp, delta_us, 0); + } + } +} + +/* + * This function should be called every time data is copied to user space. + * It calculates the appropriate TCP receive buffer space. + */ +void tcp_rcv_space_adjust(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 copied; + int time; + + trace_tcp_rcv_space_adjust(sk); + + tcp_mstamp_refresh(tp); + time = tcp_stamp_us_delta(tp->tcp_mstamp, tp->rcvq_space.time); + if (time < (tp->rcv_rtt_est.rtt_us >> 3) || tp->rcv_rtt_est.rtt_us == 0) + return; + + /* Number of bytes copied to user in last RTT */ + copied = tp->copied_seq - tp->rcvq_space.seq; + if (copied <= tp->rcvq_space.space) + goto new_measure; + + /* A bit of theory : + * copied = bytes received in previous RTT, our base window + * To cope with packet losses, we need a 2x factor + * To cope with slow start, and sender growing its cwin by 100 % + * every RTT, we need a 4x factor, because the ACK we are sending + * now is for the next RTT, not the current one : + * <prev RTT . ><current RTT .. ><next RTT .... > + */ + + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf) && + !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) { + int rcvmem, rcvbuf; + u64 rcvwin, grow; + + /* minimal window to cope with packet losses, assuming + * steady state. Add some cushion because of small variations. + */ + rcvwin = ((u64)copied << 1) + 16 * tp->advmss; + + /* Accommodate for sender rate increase (eg. slow start) */ + grow = rcvwin * (copied - tp->rcvq_space.space); + do_div(grow, tp->rcvq_space.space); + rcvwin += (grow << 1); + + rcvmem = SKB_TRUESIZE(tp->advmss + MAX_TCP_HEADER); + while (tcp_win_from_space(sk, rcvmem) < tp->advmss) + rcvmem += 128; + + do_div(rcvwin, tp->advmss); + rcvbuf = min_t(u64, rcvwin * rcvmem, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2])); + if (rcvbuf > sk->sk_rcvbuf) { + WRITE_ONCE(sk->sk_rcvbuf, rcvbuf); + + /* Make the window clamp follow along. */ + tp->window_clamp = tcp_win_from_space(sk, rcvbuf); + } + } + tp->rcvq_space.space = copied; + +new_measure: + tp->rcvq_space.seq = tp->copied_seq; + tp->rcvq_space.time = tp->tcp_mstamp; +} + +/* There is something which you must keep in mind when you analyze the + * behavior of the tp->ato delayed ack timeout interval. When a + * connection starts up, we want to ack as quickly as possible. The + * problem is that "good" TCP's do slow start at the beginning of data + * transmission. The means that until we send the first few ACK's the + * sender will sit on his end and only queue most of his data, because + * he can only send snd_cwnd unacked packets at any given time. For + * each ACK we send, he increments snd_cwnd and transmits more of his + * queue. -DaveM + */ +static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + u32 now; + + inet_csk_schedule_ack(sk); + + tcp_measure_rcv_mss(sk, skb); + + tcp_rcv_rtt_measure(tp); + + now = tcp_jiffies32; + + if (!icsk->icsk_ack.ato) { + /* The _first_ data packet received, initialize + * delayed ACK engine. + */ + tcp_incr_quickack(sk, TCP_MAX_QUICKACKS); + icsk->icsk_ack.ato = TCP_ATO_MIN; + } else { + int m = now - icsk->icsk_ack.lrcvtime; + + if (m <= TCP_ATO_MIN / 2) { + /* The fastest case is the first. */ + icsk->icsk_ack.ato = (icsk->icsk_ack.ato >> 1) + TCP_ATO_MIN / 2; + } else if (m < icsk->icsk_ack.ato) { + icsk->icsk_ack.ato = (icsk->icsk_ack.ato >> 1) + m; + if (icsk->icsk_ack.ato > icsk->icsk_rto) + icsk->icsk_ack.ato = icsk->icsk_rto; + } else if (m > icsk->icsk_rto) { + /* Too long gap. Apparently sender failed to + * restart window, so that we send ACKs quickly. + */ + tcp_incr_quickack(sk, TCP_MAX_QUICKACKS); + sk_mem_reclaim(sk); + } + } + icsk->icsk_ack.lrcvtime = now; + + tcp_ecn_check_ce(sk, skb); + + if (skb->len >= 128) + tcp_grow_window(sk, skb, true); +} + +/* Called to compute a smoothed rtt estimate. The data fed to this + * routine either comes from timestamps, or from segments that were + * known _not_ to have been retransmitted [see Karn/Partridge + * Proceedings SIGCOMM 87]. The algorithm is from the SIGCOMM 88 + * piece by Van Jacobson. + * NOTE: the next three routines used to be one big routine. + * To save cycles in the RFC 1323 implementation it was better to break + * it up into three procedures. -- erics + */ +static void tcp_rtt_estimator(struct sock *sk, long mrtt_us) +{ + struct tcp_sock *tp = tcp_sk(sk); + long m = mrtt_us; /* RTT */ + u32 srtt = tp->srtt_us; + + /* The following amusing code comes from Jacobson's + * article in SIGCOMM '88. Note that rtt and mdev + * are scaled versions of rtt and mean deviation. + * This is designed to be as fast as possible + * m stands for "measurement". + * + * On a 1990 paper the rto value is changed to: + * RTO = rtt + 4 * mdev + * + * Funny. This algorithm seems to be very broken. + * These formulae increase RTO, when it should be decreased, increase + * too slowly, when it should be increased quickly, decrease too quickly + * etc. I guess in BSD RTO takes ONE value, so that it is absolutely + * does not matter how to _calculate_ it. Seems, it was trap + * that VJ failed to avoid. 8) + */ + if (srtt != 0) { + m -= (srtt >> 3); /* m is now error in rtt est */ + srtt += m; /* rtt = 7/8 rtt + 1/8 new */ + if (m < 0) { + m = -m; /* m is now abs(error) */ + m -= (tp->mdev_us >> 2); /* similar update on mdev */ + /* This is similar to one of Eifel findings. + * Eifel blocks mdev updates when rtt decreases. + * This solution is a bit different: we use finer gain + * for mdev in this case (alpha*beta). + * Like Eifel it also prevents growth of rto, + * but also it limits too fast rto decreases, + * happening in pure Eifel. + */ + if (m > 0) + m >>= 3; + } else { + m -= (tp->mdev_us >> 2); /* similar update on mdev */ + } + tp->mdev_us += m; /* mdev = 3/4 mdev + 1/4 new */ + if (tp->mdev_us > tp->mdev_max_us) { + tp->mdev_max_us = tp->mdev_us; + if (tp->mdev_max_us > tp->rttvar_us) + tp->rttvar_us = tp->mdev_max_us; + } + if (after(tp->snd_una, tp->rtt_seq)) { + if (tp->mdev_max_us < tp->rttvar_us) + tp->rttvar_us -= (tp->rttvar_us - tp->mdev_max_us) >> 2; + tp->rtt_seq = tp->snd_nxt; + tp->mdev_max_us = tcp_rto_min_us(sk); + + tcp_bpf_rtt(sk); + } + } else { + /* no previous measure. */ + srtt = m << 3; /* take the measured time to be rtt */ + tp->mdev_us = m << 1; /* make sure rto = 3*rtt */ + tp->rttvar_us = max(tp->mdev_us, tcp_rto_min_us(sk)); + tp->mdev_max_us = tp->rttvar_us; + tp->rtt_seq = tp->snd_nxt; + + tcp_bpf_rtt(sk); + } + tp->srtt_us = max(1U, srtt); +} + +static void tcp_update_pacing_rate(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + u64 rate; + + /* set sk_pacing_rate to 200 % of current rate (mss * cwnd / srtt) */ + rate = (u64)tp->mss_cache * ((USEC_PER_SEC / 100) << 3); + + /* current rate is (cwnd * mss) / srtt + * In Slow Start [1], set sk_pacing_rate to 200 % the current rate. + * In Congestion Avoidance phase, set it to 120 % the current rate. + * + * [1] : Normal Slow Start condition is (tp->snd_cwnd < tp->snd_ssthresh) + * If snd_cwnd >= (tp->snd_ssthresh / 2), we are approaching + * end of slow start and should slow down. + */ + if (tp->snd_cwnd < tp->snd_ssthresh / 2) + rate *= sock_net(sk)->ipv4.sysctl_tcp_pacing_ss_ratio; + else + rate *= sock_net(sk)->ipv4.sysctl_tcp_pacing_ca_ratio; + + rate *= max(tp->snd_cwnd, tp->packets_out); + + if (likely(tp->srtt_us)) + do_div(rate, tp->srtt_us); + + /* WRITE_ONCE() is needed because sch_fq fetches sk_pacing_rate + * without any lock. We want to make sure compiler wont store + * intermediate values in this location. + */ + WRITE_ONCE(sk->sk_pacing_rate, min_t(u64, rate, + sk->sk_max_pacing_rate)); +} + +/* Calculate rto without backoff. This is the second half of Van Jacobson's + * routine referred to above. + */ +static void tcp_set_rto(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + /* Old crap is replaced with new one. 8) + * + * More seriously: + * 1. If rtt variance happened to be less 50msec, it is hallucination. + * It cannot be less due to utterly erratic ACK generation made + * at least by solaris and freebsd. "Erratic ACKs" has _nothing_ + * to do with delayed acks, because at cwnd>2 true delack timeout + * is invisible. Actually, Linux-2.4 also generates erratic + * ACKs in some circumstances. + */ + inet_csk(sk)->icsk_rto = __tcp_set_rto(tp); + + /* 2. Fixups made earlier cannot be right. + * If we do not estimate RTO correctly without them, + * all the algo is pure shit and should be replaced + * with correct one. It is exactly, which we pretend to do. + */ + + /* NOTE: clamping at TCP_RTO_MIN is not required, current algo + * guarantees that rto is higher. + */ + tcp_bound_rto(sk); +} + +__u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst) +{ + __u32 cwnd = (dst ? dst_metric(dst, RTAX_INITCWND) : 0); + + if (!cwnd) + cwnd = TCP_INIT_CWND; + return min_t(__u32, cwnd, tp->snd_cwnd_clamp); +} + +struct tcp_sacktag_state { + /* Timestamps for earliest and latest never-retransmitted segment + * that was SACKed. RTO needs the earliest RTT to stay conservative, + * but congestion control should still get an accurate delay signal. + */ + u64 first_sackt; + u64 last_sackt; + u32 reord; + u32 sack_delivered; + int flag; + unsigned int mss_now; + struct rate_sample *rate; +}; + +/* Take a notice that peer is sending D-SACKs. Skip update of data delivery + * and spurious retransmission information if this DSACK is unlikely caused by + * sender's action: + * - DSACKed sequence range is larger than maximum receiver's window. + * - Total no. of DSACKed segments exceed the total no. of retransmitted segs. + */ +static u32 tcp_dsack_seen(struct tcp_sock *tp, u32 start_seq, + u32 end_seq, struct tcp_sacktag_state *state) +{ + u32 seq_len, dup_segs = 1; + + if (!before(start_seq, end_seq)) + return 0; + + seq_len = end_seq - start_seq; + /* Dubious DSACK: DSACKed range greater than maximum advertised rwnd */ + if (seq_len > tp->max_window) + return 0; + if (seq_len > tp->mss_cache) + dup_segs = DIV_ROUND_UP(seq_len, tp->mss_cache); + + tp->dsack_dups += dup_segs; + /* Skip the DSACK if dup segs weren't retransmitted by sender */ + if (tp->dsack_dups > tp->total_retrans) + return 0; + + tp->rx_opt.sack_ok |= TCP_DSACK_SEEN; + tp->rack.dsack_seen = 1; + + state->flag |= FLAG_DSACKING_ACK; + /* A spurious retransmission is delivered */ + state->sack_delivered += dup_segs; + + return dup_segs; +} + +/* It's reordering when higher sequence was delivered (i.e. sacked) before + * some lower never-retransmitted sequence ("low_seq"). The maximum reordering + * distance is approximated in full-mss packet distance ("reordering"). + */ +static void tcp_check_sack_reordering(struct sock *sk, const u32 low_seq, + const int ts) +{ + struct tcp_sock *tp = tcp_sk(sk); + const u32 mss = tp->mss_cache; + u32 fack, metric; + + fack = tcp_highest_sack_seq(tp); + if (!before(low_seq, fack)) + return; + + metric = fack - low_seq; + if ((metric > tp->reordering * mss) && mss) { +#if FASTRETRANS_DEBUG > 1 + pr_debug("Disorder%d %d %u f%u s%u rr%d\n", + tp->rx_opt.sack_ok, inet_csk(sk)->icsk_ca_state, + tp->reordering, + 0, + tp->sacked_out, + tp->undo_marker ? tp->undo_retrans : 0); +#endif + tp->reordering = min_t(u32, (metric + mss - 1) / mss, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering)); + } + + /* This exciting event is worth to be remembered. 8) */ + tp->reord_seen++; + NET_INC_STATS(sock_net(sk), + ts ? LINUX_MIB_TCPTSREORDER : LINUX_MIB_TCPSACKREORDER); +} + + /* This must be called before lost_out or retrans_out are updated + * on a new loss, because we want to know if all skbs previously + * known to be lost have already been retransmitted, indicating + * that this newly lost skb is our next skb to retransmit. + */ +static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb) +{ + if ((!tp->retransmit_skb_hint && tp->retrans_out >= tp->lost_out) || + (tp->retransmit_skb_hint && + before(TCP_SKB_CB(skb)->seq, + TCP_SKB_CB(tp->retransmit_skb_hint)->seq))) + tp->retransmit_skb_hint = skb; +} + +/* Sum the number of packets on the wire we have marked as lost, and + * notify the congestion control module that the given skb was marked lost. + */ +static void tcp_notify_skb_loss_event(struct tcp_sock *tp, const struct sk_buff *skb) +{ + tp->lost += tcp_skb_pcount(skb); +} + +void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb) +{ + __u8 sacked = TCP_SKB_CB(skb)->sacked; + struct tcp_sock *tp = tcp_sk(sk); + + if (sacked & TCPCB_SACKED_ACKED) + return; + + tcp_verify_retransmit_hint(tp, skb); + if (sacked & TCPCB_LOST) { + if (sacked & TCPCB_SACKED_RETRANS) { + /* Account for retransmits that are lost again */ + TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; + tp->retrans_out -= tcp_skb_pcount(skb); + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT, + tcp_skb_pcount(skb)); + tcp_notify_skb_loss_event(tp, skb); + } + } else { + tp->lost_out += tcp_skb_pcount(skb); + TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; + tcp_notify_skb_loss_event(tp, skb); + } +} + +/* Updates the delivered and delivered_ce counts */ +static void tcp_count_delivered(struct tcp_sock *tp, u32 delivered, + bool ece_ack) +{ + tp->delivered += delivered; + if (ece_ack) + tp->delivered_ce += delivered; +} + +/* This procedure tags the retransmission queue when SACKs arrive. + * + * We have three tag bits: SACKED(S), RETRANS(R) and LOST(L). + * Packets in queue with these bits set are counted in variables + * sacked_out, retrans_out and lost_out, correspondingly. + * + * Valid combinations are: + * Tag InFlight Description + * 0 1 - orig segment is in flight. + * S 0 - nothing flies, orig reached receiver. + * L 0 - nothing flies, orig lost by net. + * R 2 - both orig and retransmit are in flight. + * L|R 1 - orig is lost, retransmit is in flight. + * S|R 1 - orig reached receiver, retrans is still in flight. + * (L|S|R is logically valid, it could occur when L|R is sacked, + * but it is equivalent to plain S and code short-curcuits it to S. + * L|S is logically invalid, it would mean -1 packet in flight 8)) + * + * These 6 states form finite state machine, controlled by the following events: + * 1. New ACK (+SACK) arrives. (tcp_sacktag_write_queue()) + * 2. Retransmission. (tcp_retransmit_skb(), tcp_xmit_retransmit_queue()) + * 3. Loss detection event of two flavors: + * A. Scoreboard estimator decided the packet is lost. + * A'. Reno "three dupacks" marks head of queue lost. + * B. SACK arrives sacking SND.NXT at the moment, when the + * segment was retransmitted. + * 4. D-SACK added new rule: D-SACK changes any tag to S. + * + * It is pleasant to note, that state diagram turns out to be commutative, + * so that we are allowed not to be bothered by order of our actions, + * when multiple events arrive simultaneously. (see the function below). + * + * Reordering detection. + * -------------------- + * Reordering metric is maximal distance, which a packet can be displaced + * in packet stream. With SACKs we can estimate it: + * + * 1. SACK fills old hole and the corresponding segment was not + * ever retransmitted -> reordering. Alas, we cannot use it + * when segment was retransmitted. + * 2. The last flaw is solved with D-SACK. D-SACK arrives + * for retransmitted and already SACKed segment -> reordering.. + * Both of these heuristics are not used in Loss state, when we cannot + * account for retransmits accurately. + * + * SACK block validation. + * ---------------------- + * + * SACK block range validation checks that the received SACK block fits to + * the expected sequence limits, i.e., it is between SND.UNA and SND.NXT. + * Note that SND.UNA is not included to the range though being valid because + * it means that the receiver is rather inconsistent with itself reporting + * SACK reneging when it should advance SND.UNA. Such SACK block this is + * perfectly valid, however, in light of RFC2018 which explicitly states + * that "SACK block MUST reflect the newest segment. Even if the newest + * segment is going to be discarded ...", not that it looks very clever + * in case of head skb. Due to potentional receiver driven attacks, we + * choose to avoid immediate execution of a walk in write queue due to + * reneging and defer head skb's loss recovery to standard loss recovery + * procedure that will eventually trigger (nothing forbids us doing this). + * + * Implements also blockage to start_seq wrap-around. Problem lies in the + * fact that though start_seq (s) is before end_seq (i.e., not reversed), + * there's no guarantee that it will be before snd_nxt (n). The problem + * happens when start_seq resides between end_seq wrap (e_w) and snd_nxt + * wrap (s_w): + * + * <- outs wnd -> <- wrapzone -> + * u e n u_w e_w s n_w + * | | | | | | | + * |<------------+------+----- TCP seqno space --------------+---------->| + * ...-- <2^31 ->| |<--------... + * ...---- >2^31 ------>| |<--------... + * + * Current code wouldn't be vulnerable but it's better still to discard such + * crazy SACK blocks. Doing this check for start_seq alone closes somewhat + * similar case (end_seq after snd_nxt wrap) as earlier reversed check in + * snd_nxt wrap -> snd_una region will then become "well defined", i.e., + * equal to the ideal case (infinite seqno space without wrap caused issues). + * + * With D-SACK the lower bound is extended to cover sequence space below + * SND.UNA down to undo_marker, which is the last point of interest. Yet + * again, D-SACK block must not to go across snd_una (for the same reason as + * for the normal SACK blocks, explained above). But there all simplicity + * ends, TCP might receive valid D-SACKs below that. As long as they reside + * fully below undo_marker they do not affect behavior in anyway and can + * therefore be safely ignored. In rare cases (which are more or less + * theoretical ones), the D-SACK will nicely cross that boundary due to skb + * fragmentation and packet reordering past skb's retransmission. To consider + * them correctly, the acceptable range must be extended even more though + * the exact amount is rather hard to quantify. However, tp->max_window can + * be used as an exaggerated estimate. + */ +static bool tcp_is_sackblock_valid(struct tcp_sock *tp, bool is_dsack, + u32 start_seq, u32 end_seq) +{ + /* Too far in future, or reversed (interpretation is ambiguous) */ + if (after(end_seq, tp->snd_nxt) || !before(start_seq, end_seq)) + return false; + + /* Nasty start_seq wrap-around check (see comments above) */ + if (!before(start_seq, tp->snd_nxt)) + return false; + + /* In outstanding window? ...This is valid exit for D-SACKs too. + * start_seq == snd_una is non-sensical (see comments above) + */ + if (after(start_seq, tp->snd_una)) + return true; + + if (!is_dsack || !tp->undo_marker) + return false; + + /* ...Then it's D-SACK, and must reside below snd_una completely */ + if (after(end_seq, tp->snd_una)) + return false; + + if (!before(start_seq, tp->undo_marker)) + return true; + + /* Too old */ + if (!after(end_seq, tp->undo_marker)) + return false; + + /* Undo_marker boundary crossing (overestimates a lot). Known already: + * start_seq < undo_marker and end_seq >= undo_marker. + */ + return !before(start_seq, end_seq - tp->max_window); +} + +static bool tcp_check_dsack(struct sock *sk, const struct sk_buff *ack_skb, + struct tcp_sack_block_wire *sp, int num_sacks, + u32 prior_snd_una, struct tcp_sacktag_state *state) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 start_seq_0 = get_unaligned_be32(&sp[0].start_seq); + u32 end_seq_0 = get_unaligned_be32(&sp[0].end_seq); + u32 dup_segs; + + if (before(start_seq_0, TCP_SKB_CB(ack_skb)->ack_seq)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPDSACKRECV); + } else if (num_sacks > 1) { + u32 end_seq_1 = get_unaligned_be32(&sp[1].end_seq); + u32 start_seq_1 = get_unaligned_be32(&sp[1].start_seq); + + if (after(end_seq_0, end_seq_1) || before(start_seq_0, start_seq_1)) + return false; + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPDSACKOFORECV); + } else { + return false; + } + + dup_segs = tcp_dsack_seen(tp, start_seq_0, end_seq_0, state); + if (!dup_segs) { /* Skip dubious DSACK */ + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPDSACKIGNOREDDUBIOUS); + return false; + } + + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDSACKRECVSEGS, dup_segs); + + /* D-SACK for already forgotten data... Do dumb counting. */ + if (tp->undo_marker && tp->undo_retrans > 0 && + !after(end_seq_0, prior_snd_una) && + after(end_seq_0, tp->undo_marker)) + tp->undo_retrans = max_t(int, 0, tp->undo_retrans - dup_segs); + + return true; +} + +/* Check if skb is fully within the SACK block. In presence of GSO skbs, + * the incoming SACK may not exactly match but we can find smaller MSS + * aligned portion of it that matches. Therefore we might need to fragment + * which may fail and creates some hassle (caller must handle error case + * returns). + * + * FIXME: this could be merged to shift decision code + */ +static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb, + u32 start_seq, u32 end_seq) +{ + int err; + bool in_sack; + unsigned int pkt_len; + unsigned int mss; + + in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq) && + !before(end_seq, TCP_SKB_CB(skb)->end_seq); + + if (tcp_skb_pcount(skb) > 1 && !in_sack && + after(TCP_SKB_CB(skb)->end_seq, start_seq)) { + mss = tcp_skb_mss(skb); + in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq); + + if (!in_sack) { + pkt_len = start_seq - TCP_SKB_CB(skb)->seq; + if (pkt_len < mss) + pkt_len = mss; + } else { + pkt_len = end_seq - TCP_SKB_CB(skb)->seq; + if (pkt_len < mss) + return -EINVAL; + } + + /* Round if necessary so that SACKs cover only full MSSes + * and/or the remaining small portion (if present) + */ + if (pkt_len > mss) { + unsigned int new_len = (pkt_len / mss) * mss; + if (!in_sack && new_len < pkt_len) + new_len += mss; + pkt_len = new_len; + } + + if (pkt_len >= skb->len && !in_sack) + return 0; + + err = tcp_fragment(sk, TCP_FRAG_IN_RTX_QUEUE, skb, + pkt_len, mss, GFP_ATOMIC); + if (err < 0) + return err; + } + + return in_sack; +} + +/* Mark the given newly-SACKed range as such, adjusting counters and hints. */ +static u8 tcp_sacktag_one(struct sock *sk, + struct tcp_sacktag_state *state, u8 sacked, + u32 start_seq, u32 end_seq, + int dup_sack, int pcount, + u64 xmit_time) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* Account D-SACK for retransmitted packet. */ + if (dup_sack && (sacked & TCPCB_RETRANS)) { + if (tp->undo_marker && tp->undo_retrans > 0 && + after(end_seq, tp->undo_marker)) + tp->undo_retrans = max_t(int, 0, tp->undo_retrans - pcount); + if ((sacked & TCPCB_SACKED_ACKED) && + before(start_seq, state->reord)) + state->reord = start_seq; + } + + /* Nothing to do; acked frame is about to be dropped (was ACKed). */ + if (!after(end_seq, tp->snd_una)) + return sacked; + + if (!(sacked & TCPCB_SACKED_ACKED)) { + tcp_rack_advance(tp, sacked, end_seq, xmit_time); + + if (sacked & TCPCB_SACKED_RETRANS) { + /* If the segment is not tagged as lost, + * we do not clear RETRANS, believing + * that retransmission is still in flight. + */ + if (sacked & TCPCB_LOST) { + sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS); + tp->lost_out -= pcount; + tp->retrans_out -= pcount; + } + } else { + if (!(sacked & TCPCB_RETRANS)) { + /* New sack for not retransmitted frame, + * which was in hole. It is reordering. + */ + if (before(start_seq, + tcp_highest_sack_seq(tp)) && + before(start_seq, state->reord)) + state->reord = start_seq; + + if (!after(end_seq, tp->high_seq)) + state->flag |= FLAG_ORIG_SACK_ACKED; + if (state->first_sackt == 0) + state->first_sackt = xmit_time; + state->last_sackt = xmit_time; + } + + if (sacked & TCPCB_LOST) { + sacked &= ~TCPCB_LOST; + tp->lost_out -= pcount; + } + } + + sacked |= TCPCB_SACKED_ACKED; + state->flag |= FLAG_DATA_SACKED; + tp->sacked_out += pcount; + /* Out-of-order packets delivered */ + state->sack_delivered += pcount; + + /* Lost marker hint past SACKed? Tweak RFC3517 cnt */ + if (tp->lost_skb_hint && + before(start_seq, TCP_SKB_CB(tp->lost_skb_hint)->seq)) + tp->lost_cnt_hint += pcount; + } + + /* D-SACK. We can detect redundant retransmission in S|R and plain R + * frames and clear it. undo_retrans is decreased above, L|R frames + * are accounted above as well. + */ + if (dup_sack && (sacked & TCPCB_SACKED_RETRANS)) { + sacked &= ~TCPCB_SACKED_RETRANS; + tp->retrans_out -= pcount; + } + + return sacked; +} + +/* Shift newly-SACKed bytes from this skb to the immediately previous + * already-SACKed sk_buff. Mark the newly-SACKed bytes as such. + */ +static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *prev, + struct sk_buff *skb, + struct tcp_sacktag_state *state, + unsigned int pcount, int shifted, int mss, + bool dup_sack) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 start_seq = TCP_SKB_CB(skb)->seq; /* start of newly-SACKed */ + u32 end_seq = start_seq + shifted; /* end of newly-SACKed */ + + BUG_ON(!pcount); + + /* Adjust counters and hints for the newly sacked sequence + * range but discard the return value since prev is already + * marked. We must tag the range first because the seq + * advancement below implicitly advances + * tcp_highest_sack_seq() when skb is highest_sack. + */ + tcp_sacktag_one(sk, state, TCP_SKB_CB(skb)->sacked, + start_seq, end_seq, dup_sack, pcount, + tcp_skb_timestamp_us(skb)); + tcp_rate_skb_delivered(sk, skb, state->rate); + + if (skb == tp->lost_skb_hint) + tp->lost_cnt_hint += pcount; + + TCP_SKB_CB(prev)->end_seq += shifted; + TCP_SKB_CB(skb)->seq += shifted; + + tcp_skb_pcount_add(prev, pcount); + WARN_ON_ONCE(tcp_skb_pcount(skb) < pcount); + tcp_skb_pcount_add(skb, -pcount); + + /* When we're adding to gso_segs == 1, gso_size will be zero, + * in theory this shouldn't be necessary but as long as DSACK + * code can come after this skb later on it's better to keep + * setting gso_size to something. + */ + if (!TCP_SKB_CB(prev)->tcp_gso_size) + TCP_SKB_CB(prev)->tcp_gso_size = mss; + + /* CHECKME: To clear or not to clear? Mimics normal skb currently */ + if (tcp_skb_pcount(skb) <= 1) + TCP_SKB_CB(skb)->tcp_gso_size = 0; + + /* Difference in this won't matter, both ACKed by the same cumul. ACK */ + TCP_SKB_CB(prev)->sacked |= (TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS); + + if (skb->len > 0) { + BUG_ON(!tcp_skb_pcount(skb)); + NET_INC_STATS(sock_net(sk), LINUX_MIB_SACKSHIFTED); + return false; + } + + /* Whole SKB was eaten :-) */ + + if (skb == tp->retransmit_skb_hint) + tp->retransmit_skb_hint = prev; + if (skb == tp->lost_skb_hint) { + tp->lost_skb_hint = prev; + tp->lost_cnt_hint -= tcp_skb_pcount(prev); + } + + TCP_SKB_CB(prev)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; + TCP_SKB_CB(prev)->eor = TCP_SKB_CB(skb)->eor; + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) + TCP_SKB_CB(prev)->end_seq++; + + if (skb == tcp_highest_sack(sk)) + tcp_advance_highest_sack(sk, skb); + + tcp_skb_collapse_tstamp(prev, skb); + if (unlikely(TCP_SKB_CB(prev)->tx.delivered_mstamp)) + TCP_SKB_CB(prev)->tx.delivered_mstamp = 0; + + tcp_rtx_queue_unlink_and_free(skb, sk); + + NET_INC_STATS(sock_net(sk), LINUX_MIB_SACKMERGED); + + return true; +} + +/* I wish gso_size would have a bit more sane initialization than + * something-or-zero which complicates things + */ +static int tcp_skb_seglen(const struct sk_buff *skb) +{ + return tcp_skb_pcount(skb) == 1 ? skb->len : tcp_skb_mss(skb); +} + +/* Shifting pages past head area doesn't work */ +static int skb_can_shift(const struct sk_buff *skb) +{ + return !skb_headlen(skb) && skb_is_nonlinear(skb); +} + +int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, + int pcount, int shiftlen) +{ + /* TCP min gso_size is 8 bytes (TCP_MIN_GSO_SIZE) + * Since TCP_SKB_CB(skb)->tcp_gso_segs is 16 bits, we need + * to make sure not storing more than 65535 * 8 bytes per skb, + * even if current MSS is bigger. + */ + if (unlikely(to->len + shiftlen >= 65535 * TCP_MIN_GSO_SIZE)) + return 0; + if (unlikely(tcp_skb_pcount(to) + pcount > 65535)) + return 0; + return skb_shift(to, from, shiftlen); +} + +/* Try collapsing SACK blocks spanning across multiple skbs to a single + * skb. + */ +static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb, + struct tcp_sacktag_state *state, + u32 start_seq, u32 end_seq, + bool dup_sack) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *prev; + int mss; + int pcount = 0; + int len; + int in_sack; + + /* Normally R but no L won't result in plain S */ + if (!dup_sack && + (TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_RETRANS)) == TCPCB_SACKED_RETRANS) + goto fallback; + if (!skb_can_shift(skb)) + goto fallback; + /* This frame is about to be dropped (was ACKed). */ + if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una)) + goto fallback; + + /* Can only happen with delayed DSACK + discard craziness */ + prev = skb_rb_prev(skb); + if (!prev) + goto fallback; + + if ((TCP_SKB_CB(prev)->sacked & TCPCB_TAGBITS) != TCPCB_SACKED_ACKED) + goto fallback; + + if (!tcp_skb_can_collapse(prev, skb)) + goto fallback; + + in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq) && + !before(end_seq, TCP_SKB_CB(skb)->end_seq); + + if (in_sack) { + len = skb->len; + pcount = tcp_skb_pcount(skb); + mss = tcp_skb_seglen(skb); + + /* TODO: Fix DSACKs to not fragment already SACKed and we can + * drop this restriction as unnecessary + */ + if (mss != tcp_skb_seglen(prev)) + goto fallback; + } else { + if (!after(TCP_SKB_CB(skb)->end_seq, start_seq)) + goto noop; + /* CHECKME: This is non-MSS split case only?, this will + * cause skipped skbs due to advancing loop btw, original + * has that feature too + */ + if (tcp_skb_pcount(skb) <= 1) + goto noop; + + in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq); + if (!in_sack) { + /* TODO: head merge to next could be attempted here + * if (!after(TCP_SKB_CB(skb)->end_seq, end_seq)), + * though it might not be worth of the additional hassle + * + * ...we can probably just fallback to what was done + * previously. We could try merging non-SACKed ones + * as well but it probably isn't going to buy off + * because later SACKs might again split them, and + * it would make skb timestamp tracking considerably + * harder problem. + */ + goto fallback; + } + + len = end_seq - TCP_SKB_CB(skb)->seq; + BUG_ON(len < 0); + BUG_ON(len > skb->len); + + /* MSS boundaries should be honoured or else pcount will + * severely break even though it makes things bit trickier. + * Optimize common case to avoid most of the divides + */ + mss = tcp_skb_mss(skb); + + /* TODO: Fix DSACKs to not fragment already SACKed and we can + * drop this restriction as unnecessary + */ + if (mss != tcp_skb_seglen(prev)) + goto fallback; + + if (len == mss) { + pcount = 1; + } else if (len < mss) { + goto noop; + } else { + pcount = len / mss; + len = pcount * mss; + } + } + + /* tcp_sacktag_one() won't SACK-tag ranges below snd_una */ + if (!after(TCP_SKB_CB(skb)->seq + len, tp->snd_una)) + goto fallback; + + if (!tcp_skb_shift(prev, skb, pcount, len)) + goto fallback; + if (!tcp_shifted_skb(sk, prev, skb, state, pcount, len, mss, dup_sack)) + goto out; + + /* Hole filled allows collapsing with the next as well, this is very + * useful when hole on every nth skb pattern happens + */ + skb = skb_rb_next(prev); + if (!skb) + goto out; + + if (!skb_can_shift(skb) || + ((TCP_SKB_CB(skb)->sacked & TCPCB_TAGBITS) != TCPCB_SACKED_ACKED) || + (mss != tcp_skb_seglen(skb))) + goto out; + + if (!tcp_skb_can_collapse(prev, skb)) + goto out; + len = skb->len; + pcount = tcp_skb_pcount(skb); + if (tcp_skb_shift(prev, skb, pcount, len)) + tcp_shifted_skb(sk, prev, skb, state, pcount, + len, mss, 0); + +out: + return prev; + +noop: + return skb; + +fallback: + NET_INC_STATS(sock_net(sk), LINUX_MIB_SACKSHIFTFALLBACK); + return NULL; +} + +static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk, + struct tcp_sack_block *next_dup, + struct tcp_sacktag_state *state, + u32 start_seq, u32 end_seq, + bool dup_sack_in) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *tmp; + + skb_rbtree_walk_from(skb) { + int in_sack = 0; + bool dup_sack = dup_sack_in; + + /* queue is in-order => we can short-circuit the walk early */ + if (!before(TCP_SKB_CB(skb)->seq, end_seq)) + break; + + if (next_dup && + before(TCP_SKB_CB(skb)->seq, next_dup->end_seq)) { + in_sack = tcp_match_skb_to_sack(sk, skb, + next_dup->start_seq, + next_dup->end_seq); + if (in_sack > 0) + dup_sack = true; + } + + /* skb reference here is a bit tricky to get right, since + * shifting can eat and free both this skb and the next, + * so not even _safe variant of the loop is enough. + */ + if (in_sack <= 0) { + tmp = tcp_shift_skb_data(sk, skb, state, + start_seq, end_seq, dup_sack); + if (tmp) { + if (tmp != skb) { + skb = tmp; + continue; + } + + in_sack = 0; + } else { + in_sack = tcp_match_skb_to_sack(sk, skb, + start_seq, + end_seq); + } + } + + if (unlikely(in_sack < 0)) + break; + + if (in_sack) { + TCP_SKB_CB(skb)->sacked = + tcp_sacktag_one(sk, + state, + TCP_SKB_CB(skb)->sacked, + TCP_SKB_CB(skb)->seq, + TCP_SKB_CB(skb)->end_seq, + dup_sack, + tcp_skb_pcount(skb), + tcp_skb_timestamp_us(skb)); + tcp_rate_skb_delivered(sk, skb, state->rate); + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) + list_del_init(&skb->tcp_tsorted_anchor); + + if (!before(TCP_SKB_CB(skb)->seq, + tcp_highest_sack_seq(tp))) + tcp_advance_highest_sack(sk, skb); + } + } + return skb; +} + +static struct sk_buff *tcp_sacktag_bsearch(struct sock *sk, u32 seq) +{ + struct rb_node *parent, **p = &sk->tcp_rtx_queue.rb_node; + struct sk_buff *skb; + + while (*p) { + parent = *p; + skb = rb_to_skb(parent); + if (before(seq, TCP_SKB_CB(skb)->seq)) { + p = &parent->rb_left; + continue; + } + if (!before(seq, TCP_SKB_CB(skb)->end_seq)) { + p = &parent->rb_right; + continue; + } + return skb; + } + return NULL; +} + +static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk, + u32 skip_to_seq) +{ + if (skb && after(TCP_SKB_CB(skb)->seq, skip_to_seq)) + return skb; + + return tcp_sacktag_bsearch(sk, skip_to_seq); +} + +static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb, + struct sock *sk, + struct tcp_sack_block *next_dup, + struct tcp_sacktag_state *state, + u32 skip_to_seq) +{ + if (!next_dup) + return skb; + + if (before(next_dup->start_seq, skip_to_seq)) { + skb = tcp_sacktag_skip(skb, sk, next_dup->start_seq); + skb = tcp_sacktag_walk(skb, sk, NULL, state, + next_dup->start_seq, next_dup->end_seq, + 1); + } + + return skb; +} + +static int tcp_sack_cache_ok(const struct tcp_sock *tp, const struct tcp_sack_block *cache) +{ + return cache < tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache); +} + +static int +tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb, + u32 prior_snd_una, struct tcp_sacktag_state *state) +{ + struct tcp_sock *tp = tcp_sk(sk); + const unsigned char *ptr = (skb_transport_header(ack_skb) + + TCP_SKB_CB(ack_skb)->sacked); + struct tcp_sack_block_wire *sp_wire = (struct tcp_sack_block_wire *)(ptr+2); + struct tcp_sack_block sp[TCP_NUM_SACKS]; + struct tcp_sack_block *cache; + struct sk_buff *skb; + int num_sacks = min(TCP_NUM_SACKS, (ptr[1] - TCPOLEN_SACK_BASE) >> 3); + int used_sacks; + bool found_dup_sack = false; + int i, j; + int first_sack_index; + + state->flag = 0; + state->reord = tp->snd_nxt; + + if (!tp->sacked_out) + tcp_highest_sack_reset(sk); + + found_dup_sack = tcp_check_dsack(sk, ack_skb, sp_wire, + num_sacks, prior_snd_una, state); + + /* Eliminate too old ACKs, but take into + * account more or less fresh ones, they can + * contain valid SACK info. + */ + if (before(TCP_SKB_CB(ack_skb)->ack_seq, prior_snd_una - tp->max_window)) + return 0; + + if (!tp->packets_out) + goto out; + + used_sacks = 0; + first_sack_index = 0; + for (i = 0; i < num_sacks; i++) { + bool dup_sack = !i && found_dup_sack; + + sp[used_sacks].start_seq = get_unaligned_be32(&sp_wire[i].start_seq); + sp[used_sacks].end_seq = get_unaligned_be32(&sp_wire[i].end_seq); + + if (!tcp_is_sackblock_valid(tp, dup_sack, + sp[used_sacks].start_seq, + sp[used_sacks].end_seq)) { + int mib_idx; + + if (dup_sack) { + if (!tp->undo_marker) + mib_idx = LINUX_MIB_TCPDSACKIGNOREDNOUNDO; + else + mib_idx = LINUX_MIB_TCPDSACKIGNOREDOLD; + } else { + /* Don't count olds caused by ACK reordering */ + if ((TCP_SKB_CB(ack_skb)->ack_seq != tp->snd_una) && + !after(sp[used_sacks].end_seq, tp->snd_una)) + continue; + mib_idx = LINUX_MIB_TCPSACKDISCARD; + } + + NET_INC_STATS(sock_net(sk), mib_idx); + if (i == 0) + first_sack_index = -1; + continue; + } + + /* Ignore very old stuff early */ + if (!after(sp[used_sacks].end_seq, prior_snd_una)) { + if (i == 0) + first_sack_index = -1; + continue; + } + + used_sacks++; + } + + /* order SACK blocks to allow in order walk of the retrans queue */ + for (i = used_sacks - 1; i > 0; i--) { + for (j = 0; j < i; j++) { + if (after(sp[j].start_seq, sp[j + 1].start_seq)) { + swap(sp[j], sp[j + 1]); + + /* Track where the first SACK block goes to */ + if (j == first_sack_index) + first_sack_index = j + 1; + } + } + } + + state->mss_now = tcp_current_mss(sk); + skb = NULL; + i = 0; + + if (!tp->sacked_out) { + /* It's already past, so skip checking against it */ + cache = tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache); + } else { + cache = tp->recv_sack_cache; + /* Skip empty blocks in at head of the cache */ + while (tcp_sack_cache_ok(tp, cache) && !cache->start_seq && + !cache->end_seq) + cache++; + } + + while (i < used_sacks) { + u32 start_seq = sp[i].start_seq; + u32 end_seq = sp[i].end_seq; + bool dup_sack = (found_dup_sack && (i == first_sack_index)); + struct tcp_sack_block *next_dup = NULL; + + if (found_dup_sack && ((i + 1) == first_sack_index)) + next_dup = &sp[i + 1]; + + /* Skip too early cached blocks */ + while (tcp_sack_cache_ok(tp, cache) && + !before(start_seq, cache->end_seq)) + cache++; + + /* Can skip some work by looking recv_sack_cache? */ + if (tcp_sack_cache_ok(tp, cache) && !dup_sack && + after(end_seq, cache->start_seq)) { + + /* Head todo? */ + if (before(start_seq, cache->start_seq)) { + skb = tcp_sacktag_skip(skb, sk, start_seq); + skb = tcp_sacktag_walk(skb, sk, next_dup, + state, + start_seq, + cache->start_seq, + dup_sack); + } + + /* Rest of the block already fully processed? */ + if (!after(end_seq, cache->end_seq)) + goto advance_sp; + + skb = tcp_maybe_skipping_dsack(skb, sk, next_dup, + state, + cache->end_seq); + + /* ...tail remains todo... */ + if (tcp_highest_sack_seq(tp) == cache->end_seq) { + /* ...but better entrypoint exists! */ + skb = tcp_highest_sack(sk); + if (!skb) + break; + cache++; + goto walk; + } + + skb = tcp_sacktag_skip(skb, sk, cache->end_seq); + /* Check overlap against next cached too (past this one already) */ + cache++; + continue; + } + + if (!before(start_seq, tcp_highest_sack_seq(tp))) { + skb = tcp_highest_sack(sk); + if (!skb) + break; + } + skb = tcp_sacktag_skip(skb, sk, start_seq); + +walk: + skb = tcp_sacktag_walk(skb, sk, next_dup, state, + start_seq, end_seq, dup_sack); + +advance_sp: + i++; + } + + /* Clear the head of the cache sack blocks so we can skip it next time */ + for (i = 0; i < ARRAY_SIZE(tp->recv_sack_cache) - used_sacks; i++) { + tp->recv_sack_cache[i].start_seq = 0; + tp->recv_sack_cache[i].end_seq = 0; + } + for (j = 0; j < used_sacks; j++) + tp->recv_sack_cache[i++] = sp[j]; + + if (inet_csk(sk)->icsk_ca_state != TCP_CA_Loss || tp->undo_marker) + tcp_check_sack_reordering(sk, state->reord, 0); + + tcp_verify_left_out(tp); +out: + +#if FASTRETRANS_DEBUG > 0 + WARN_ON((int)tp->sacked_out < 0); + WARN_ON((int)tp->lost_out < 0); + WARN_ON((int)tp->retrans_out < 0); + WARN_ON((int)tcp_packets_in_flight(tp) < 0); +#endif + return state->flag; +} + +/* Limits sacked_out so that sum with lost_out isn't ever larger than + * packets_out. Returns false if sacked_out adjustement wasn't necessary. + */ +static bool tcp_limit_reno_sacked(struct tcp_sock *tp) +{ + u32 holes; + + holes = max(tp->lost_out, 1U); + holes = min(holes, tp->packets_out); + + if ((tp->sacked_out + holes) > tp->packets_out) { + tp->sacked_out = tp->packets_out - holes; + return true; + } + return false; +} + +/* If we receive more dupacks than we expected counting segments + * in assumption of absent reordering, interpret this as reordering. + * The only another reason could be bug in receiver TCP. + */ +static void tcp_check_reno_reordering(struct sock *sk, const int addend) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (!tcp_limit_reno_sacked(tp)) + return; + + tp->reordering = min_t(u32, tp->packets_out + addend, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering)); + tp->reord_seen++; + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRENOREORDER); +} + +/* Emulate SACKs for SACKless connection: account for a new dupack. */ + +static void tcp_add_reno_sack(struct sock *sk, int num_dupack, bool ece_ack) +{ + if (num_dupack) { + struct tcp_sock *tp = tcp_sk(sk); + u32 prior_sacked = tp->sacked_out; + s32 delivered; + + tp->sacked_out += num_dupack; + tcp_check_reno_reordering(sk, 0); + delivered = tp->sacked_out - prior_sacked; + if (delivered > 0) + tcp_count_delivered(tp, delivered, ece_ack); + tcp_verify_left_out(tp); + } +} + +/* Account for ACK, ACKing some data in Reno Recovery phase. */ + +static void tcp_remove_reno_sacks(struct sock *sk, int acked, bool ece_ack) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (acked > 0) { + /* One ACK acked hole. The rest eat duplicate ACKs. */ + tcp_count_delivered(tp, max_t(int, acked - tp->sacked_out, 1), + ece_ack); + if (acked - 1 >= tp->sacked_out) + tp->sacked_out = 0; + else + tp->sacked_out -= acked - 1; + } + tcp_check_reno_reordering(sk, acked); + tcp_verify_left_out(tp); +} + +static inline void tcp_reset_reno_sack(struct tcp_sock *tp) +{ + tp->sacked_out = 0; +} + +void tcp_clear_retrans(struct tcp_sock *tp) +{ + tp->retrans_out = 0; + tp->lost_out = 0; + tp->undo_marker = 0; + tp->undo_retrans = -1; + tp->sacked_out = 0; +} + +static inline void tcp_init_undo(struct tcp_sock *tp) +{ + tp->undo_marker = tp->snd_una; + /* Retransmission still in flight may cause DSACKs later. */ + tp->undo_retrans = tp->retrans_out ? : -1; +} + +static bool tcp_is_rack(const struct sock *sk) +{ + return READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_LOSS_DETECTION; +} + +/* If we detect SACK reneging, forget all SACK information + * and reset tags completely, otherwise preserve SACKs. If receiver + * dropped its ofo queue, we will know this due to reneging detection. + */ +static void tcp_timeout_mark_lost(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb, *head; + bool is_reneg; /* is receiver reneging on SACKs? */ + + head = tcp_rtx_queue_head(sk); + is_reneg = head && (TCP_SKB_CB(head)->sacked & TCPCB_SACKED_ACKED); + if (is_reneg) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSACKRENEGING); + tp->sacked_out = 0; + /* Mark SACK reneging until we recover from this loss event. */ + tp->is_sack_reneg = 1; + } else if (tcp_is_reno(tp)) { + tcp_reset_reno_sack(tp); + } + + skb = head; + skb_rbtree_walk_from(skb) { + if (is_reneg) + TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED; + else if (tcp_is_rack(sk) && skb != head && + tcp_rack_skb_timeout(tp, skb, 0) > 0) + continue; /* Don't mark recently sent ones lost yet */ + tcp_mark_skb_lost(sk, skb); + } + tcp_verify_left_out(tp); + tcp_clear_all_retrans_hints(tp); +} + +/* Enter Loss state. */ +void tcp_enter_loss(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + bool new_recovery = icsk->icsk_ca_state < TCP_CA_Recovery; + u8 reordering; + + tcp_timeout_mark_lost(sk); + + /* Reduce ssthresh if it has not yet been made inside this window. */ + if (icsk->icsk_ca_state <= TCP_CA_Disorder || + !after(tp->high_seq, tp->snd_una) || + (icsk->icsk_ca_state == TCP_CA_Loss && !icsk->icsk_retransmits)) { + tp->prior_ssthresh = tcp_current_ssthresh(sk); + tp->prior_cwnd = tp->snd_cwnd; + tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk); + tcp_ca_event(sk, CA_EVENT_LOSS); + tcp_init_undo(tp); + } + tp->snd_cwnd = tcp_packets_in_flight(tp) + 1; + tp->snd_cwnd_cnt = 0; + tp->snd_cwnd_stamp = tcp_jiffies32; + + /* Timeout in disordered state after receiving substantial DUPACKs + * suggests that the degree of reordering is over-estimated. + */ + reordering = READ_ONCE(net->ipv4.sysctl_tcp_reordering); + if (icsk->icsk_ca_state <= TCP_CA_Disorder && + tp->sacked_out >= reordering) + tp->reordering = min_t(unsigned int, tp->reordering, + reordering); + + tcp_set_ca_state(sk, TCP_CA_Loss); + tp->high_seq = tp->snd_nxt; + tcp_ecn_queue_cwr(tp); + + /* F-RTO RFC5682 sec 3.1 step 1: retransmit SND.UNA if no previous + * loss recovery is underway except recurring timeout(s) on + * the same SND.UNA (sec 3.2). Disable F-RTO on path MTU probing + */ + tp->frto = READ_ONCE(net->ipv4.sysctl_tcp_frto) && + (new_recovery || icsk->icsk_retransmits) && + !inet_csk(sk)->icsk_mtup.probe_size; +} + +/* If ACK arrived pointing to a remembered SACK, it means that our + * remembered SACKs do not reflect real state of receiver i.e. + * receiver _host_ is heavily congested (or buggy). + * + * To avoid big spurious retransmission bursts due to transient SACK + * scoreboard oddities that look like reneging, we give the receiver a + * little time (max(RTT/2, 10ms)) to send us some more ACKs that will + * restore sanity to the SACK scoreboard. If the apparent reneging + * persists until this RTO then we'll clear the SACK scoreboard. + */ +static bool tcp_check_sack_reneging(struct sock *sk, int *ack_flag) +{ + if (*ack_flag & FLAG_SACK_RENEGING && + *ack_flag & FLAG_SND_UNA_ADVANCED) { + struct tcp_sock *tp = tcp_sk(sk); + unsigned long delay = max(usecs_to_jiffies(tp->srtt_us >> 4), + msecs_to_jiffies(10)); + + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + delay, TCP_RTO_MAX); + *ack_flag &= ~FLAG_SET_XMIT_TIMER; + return true; + } + return false; +} + +/* Heurestics to calculate number of duplicate ACKs. There's no dupACKs + * counter when SACK is enabled (without SACK, sacked_out is used for + * that purpose). + * + * With reordering, holes may still be in flight, so RFC3517 recovery + * uses pure sacked_out (total number of SACKed segments) even though + * it violates the RFC that uses duplicate ACKs, often these are equal + * but when e.g. out-of-window ACKs or packet duplication occurs, + * they differ. Since neither occurs due to loss, TCP should really + * ignore them. + */ +static inline int tcp_dupack_heuristics(const struct tcp_sock *tp) +{ + return tp->sacked_out + 1; +} + +/* Linux NewReno/SACK/ECN state machine. + * -------------------------------------- + * + * "Open" Normal state, no dubious events, fast path. + * "Disorder" In all the respects it is "Open", + * but requires a bit more attention. It is entered when + * we see some SACKs or dupacks. It is split of "Open" + * mainly to move some processing from fast path to slow one. + * "CWR" CWND was reduced due to some Congestion Notification event. + * It can be ECN, ICMP source quench, local device congestion. + * "Recovery" CWND was reduced, we are fast-retransmitting. + * "Loss" CWND was reduced due to RTO timeout or SACK reneging. + * + * tcp_fastretrans_alert() is entered: + * - each incoming ACK, if state is not "Open" + * - when arrived ACK is unusual, namely: + * * SACK + * * Duplicate ACK. + * * ECN ECE. + * + * Counting packets in flight is pretty simple. + * + * in_flight = packets_out - left_out + retrans_out + * + * packets_out is SND.NXT-SND.UNA counted in packets. + * + * retrans_out is number of retransmitted segments. + * + * left_out is number of segments left network, but not ACKed yet. + * + * left_out = sacked_out + lost_out + * + * sacked_out: Packets, which arrived to receiver out of order + * and hence not ACKed. With SACKs this number is simply + * amount of SACKed data. Even without SACKs + * it is easy to give pretty reliable estimate of this number, + * counting duplicate ACKs. + * + * lost_out: Packets lost by network. TCP has no explicit + * "loss notification" feedback from network (for now). + * It means that this number can be only _guessed_. + * Actually, it is the heuristics to predict lossage that + * distinguishes different algorithms. + * + * F.e. after RTO, when all the queue is considered as lost, + * lost_out = packets_out and in_flight = retrans_out. + * + * Essentially, we have now a few algorithms detecting + * lost packets. + * + * If the receiver supports SACK: + * + * RFC6675/3517: It is the conventional algorithm. A packet is + * considered lost if the number of higher sequence packets + * SACKed is greater than or equal the DUPACK thoreshold + * (reordering). This is implemented in tcp_mark_head_lost and + * tcp_update_scoreboard. + * + * RACK (draft-ietf-tcpm-rack-01): it is a newer algorithm + * (2017-) that checks timing instead of counting DUPACKs. + * Essentially a packet is considered lost if it's not S/ACKed + * after RTT + reordering_window, where both metrics are + * dynamically measured and adjusted. This is implemented in + * tcp_rack_mark_lost. + * + * If the receiver does not support SACK: + * + * NewReno (RFC6582): in Recovery we assume that one segment + * is lost (classic Reno). While we are in Recovery and + * a partial ACK arrives, we assume that one more packet + * is lost (NewReno). This heuristics are the same in NewReno + * and SACK. + * + * Really tricky (and requiring careful tuning) part of algorithm + * is hidden in functions tcp_time_to_recover() and tcp_xmit_retransmit_queue(). + * The first determines the moment _when_ we should reduce CWND and, + * hence, slow down forward transmission. In fact, it determines the moment + * when we decide that hole is caused by loss, rather than by a reorder. + * + * tcp_xmit_retransmit_queue() decides, _what_ we should retransmit to fill + * holes, caused by lost packets. + * + * And the most logically complicated part of algorithm is undo + * heuristics. We detect false retransmits due to both too early + * fast retransmit (reordering) and underestimated RTO, analyzing + * timestamps and D-SACKs. When we detect that some segments were + * retransmitted by mistake and CWND reduction was wrong, we undo + * window reduction and abort recovery phase. This logic is hidden + * inside several functions named tcp_try_undo_<something>. + */ + +/* This function decides, when we should leave Disordered state + * and enter Recovery phase, reducing congestion window. + * + * Main question: may we further continue forward transmission + * with the same cwnd? + */ +static bool tcp_time_to_recover(struct sock *sk, int flag) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* Trick#1: The loss is proven. */ + if (tp->lost_out) + return true; + + /* Not-A-Trick#2 : Classic rule... */ + if (!tcp_is_rack(sk) && tcp_dupack_heuristics(tp) > tp->reordering) + return true; + + return false; +} + +/* Detect loss in event "A" above by marking head of queue up as lost. + * For RFC3517 SACK, a segment is considered lost if it + * has at least tp->reordering SACKed seqments above it; "packets" refers to + * the maximum SACKed segments to pass before reaching this limit. + */ +static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + int cnt; + /* Use SACK to deduce losses of new sequences sent during recovery */ + const u32 loss_high = tp->snd_nxt; + + WARN_ON(packets > tp->packets_out); + skb = tp->lost_skb_hint; + if (skb) { + /* Head already handled? */ + if (mark_head && after(TCP_SKB_CB(skb)->seq, tp->snd_una)) + return; + cnt = tp->lost_cnt_hint; + } else { + skb = tcp_rtx_queue_head(sk); + cnt = 0; + } + + skb_rbtree_walk_from(skb) { + /* TODO: do this better */ + /* this is not the most efficient way to do this... */ + tp->lost_skb_hint = skb; + tp->lost_cnt_hint = cnt; + + if (after(TCP_SKB_CB(skb)->end_seq, loss_high)) + break; + + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) + cnt += tcp_skb_pcount(skb); + + if (cnt > packets) + break; + + if (!(TCP_SKB_CB(skb)->sacked & TCPCB_LOST)) + tcp_mark_skb_lost(sk, skb); + + if (mark_head) + break; + } + tcp_verify_left_out(tp); +} + +/* Account newly detected lost packet(s) */ + +static void tcp_update_scoreboard(struct sock *sk, int fast_rexmit) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tcp_is_sack(tp)) { + int sacked_upto = tp->sacked_out - tp->reordering; + if (sacked_upto >= 0) + tcp_mark_head_lost(sk, sacked_upto, 0); + else if (fast_rexmit) + tcp_mark_head_lost(sk, 1, 1); + } +} + +static bool tcp_tsopt_ecr_before(const struct tcp_sock *tp, u32 when) +{ + return tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr && + before(tp->rx_opt.rcv_tsecr, when); +} + +/* skb is spurious retransmitted if the returned timestamp echo + * reply is prior to the skb transmission time + */ +static bool tcp_skb_spurious_retrans(const struct tcp_sock *tp, + const struct sk_buff *skb) +{ + return (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS) && + tcp_tsopt_ecr_before(tp, tcp_skb_timestamp(skb)); +} + +/* Nothing was retransmitted or returned timestamp is less + * than timestamp of the first retransmission. + */ +static inline bool tcp_packet_delayed(const struct tcp_sock *tp) +{ + return tp->retrans_stamp && + tcp_tsopt_ecr_before(tp, tp->retrans_stamp); +} + +/* Undo procedures. */ + +/* We can clear retrans_stamp when there are no retransmissions in the + * window. It would seem that it is trivially available for us in + * tp->retrans_out, however, that kind of assumptions doesn't consider + * what will happen if errors occur when sending retransmission for the + * second time. ...It could the that such segment has only + * TCPCB_EVER_RETRANS set at the present time. It seems that checking + * the head skb is enough except for some reneging corner cases that + * are not worth the effort. + * + * Main reason for all this complexity is the fact that connection dying + * time now depends on the validity of the retrans_stamp, in particular, + * that successive retransmissions of a segment must not advance + * retrans_stamp under any conditions. + */ +static bool tcp_any_retrans_done(const struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + + if (tp->retrans_out) + return true; + + skb = tcp_rtx_queue_head(sk); + if (unlikely(skb && TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS)) + return true; + + return false; +} + +static void DBGUNDO(struct sock *sk, const char *msg) +{ +#if FASTRETRANS_DEBUG > 1 + struct tcp_sock *tp = tcp_sk(sk); + struct inet_sock *inet = inet_sk(sk); + + if (sk->sk_family == AF_INET) { + pr_debug("Undo %s %pI4/%u c%u l%u ss%u/%u p%u\n", + msg, + &inet->inet_daddr, ntohs(inet->inet_dport), + tp->snd_cwnd, tcp_left_out(tp), + tp->snd_ssthresh, tp->prior_ssthresh, + tp->packets_out); + } +#if IS_ENABLED(CONFIG_IPV6) + else if (sk->sk_family == AF_INET6) { + pr_debug("Undo %s %pI6/%u c%u l%u ss%u/%u p%u\n", + msg, + &sk->sk_v6_daddr, ntohs(inet->inet_dport), + tp->snd_cwnd, tcp_left_out(tp), + tp->snd_ssthresh, tp->prior_ssthresh, + tp->packets_out); + } +#endif +#endif +} + +static void tcp_undo_cwnd_reduction(struct sock *sk, bool unmark_loss) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (unmark_loss) { + struct sk_buff *skb; + + skb_rbtree_walk(skb, &sk->tcp_rtx_queue) { + TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST; + } + tp->lost_out = 0; + tcp_clear_all_retrans_hints(tp); + } + + if (tp->prior_ssthresh) { + const struct inet_connection_sock *icsk = inet_csk(sk); + + tp->snd_cwnd = icsk->icsk_ca_ops->undo_cwnd(sk); + + if (tp->prior_ssthresh > tp->snd_ssthresh) { + tp->snd_ssthresh = tp->prior_ssthresh; + tcp_ecn_withdraw_cwr(tp); + } + } + tp->snd_cwnd_stamp = tcp_jiffies32; + tp->undo_marker = 0; + tp->rack.advanced = 1; /* Force RACK to re-exam losses */ +} + +static inline bool tcp_may_undo(const struct tcp_sock *tp) +{ + return tp->undo_marker && (!tp->undo_retrans || tcp_packet_delayed(tp)); +} + +static bool tcp_is_non_sack_preventing_reopen(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->snd_una == tp->high_seq && tcp_is_reno(tp)) { + /* Hold old state until something *above* high_seq + * is ACKed. For Reno it is MUST to prevent false + * fast retransmits (RFC2582). SACK TCP is safe. */ + if (!tcp_any_retrans_done(sk)) + tp->retrans_stamp = 0; + return true; + } + return false; +} + +/* People celebrate: "We love our President!" */ +static bool tcp_try_undo_recovery(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tcp_may_undo(tp)) { + int mib_idx; + + /* Happy end! We did not retransmit anything + * or our original transmission succeeded. + */ + DBGUNDO(sk, inet_csk(sk)->icsk_ca_state == TCP_CA_Loss ? "loss" : "retrans"); + tcp_undo_cwnd_reduction(sk, false); + if (inet_csk(sk)->icsk_ca_state == TCP_CA_Loss) + mib_idx = LINUX_MIB_TCPLOSSUNDO; + else + mib_idx = LINUX_MIB_TCPFULLUNDO; + + NET_INC_STATS(sock_net(sk), mib_idx); + } else if (tp->rack.reo_wnd_persist) { + tp->rack.reo_wnd_persist--; + } + if (tcp_is_non_sack_preventing_reopen(sk)) + return true; + tcp_set_ca_state(sk, TCP_CA_Open); + tp->is_sack_reneg = 0; + return false; +} + +/* Try to undo cwnd reduction, because D-SACKs acked all retransmitted data */ +static bool tcp_try_undo_dsack(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->undo_marker && !tp->undo_retrans) { + tp->rack.reo_wnd_persist = min(TCP_RACK_RECOVERY_THRESH, + tp->rack.reo_wnd_persist + 1); + DBGUNDO(sk, "D-SACK"); + tcp_undo_cwnd_reduction(sk, false); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPDSACKUNDO); + return true; + } + return false; +} + +/* Undo during loss recovery after partial ACK or using F-RTO. */ +static bool tcp_try_undo_loss(struct sock *sk, bool frto_undo) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (frto_undo || tcp_may_undo(tp)) { + tcp_undo_cwnd_reduction(sk, true); + + DBGUNDO(sk, "partial loss"); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPLOSSUNDO); + if (frto_undo) + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPSPURIOUSRTOS); + inet_csk(sk)->icsk_retransmits = 0; + if (tcp_is_non_sack_preventing_reopen(sk)) + return true; + if (frto_undo || tcp_is_sack(tp)) { + tcp_set_ca_state(sk, TCP_CA_Open); + tp->is_sack_reneg = 0; + } + return true; + } + return false; +} + +/* The cwnd reduction in CWR and Recovery uses the PRR algorithm in RFC 6937. + * It computes the number of packets to send (sndcnt) based on packets newly + * delivered: + * 1) If the packets in flight is larger than ssthresh, PRR spreads the + * cwnd reductions across a full RTT. + * 2) Otherwise PRR uses packet conservation to send as much as delivered. + * But when the retransmits are acked without further losses, PRR + * slow starts cwnd up to ssthresh to speed up the recovery. + */ +static void tcp_init_cwnd_reduction(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + tp->high_seq = tp->snd_nxt; + tp->tlp_high_seq = 0; + tp->snd_cwnd_cnt = 0; + tp->prior_cwnd = tp->snd_cwnd; + tp->prr_delivered = 0; + tp->prr_out = 0; + tp->snd_ssthresh = inet_csk(sk)->icsk_ca_ops->ssthresh(sk); + tcp_ecn_queue_cwr(tp); +} + +void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int flag) +{ + struct tcp_sock *tp = tcp_sk(sk); + int sndcnt = 0; + int delta = tp->snd_ssthresh - tcp_packets_in_flight(tp); + + if (newly_acked_sacked <= 0 || WARN_ON_ONCE(!tp->prior_cwnd)) + return; + + tp->prr_delivered += newly_acked_sacked; + if (delta < 0) { + u64 dividend = (u64)tp->snd_ssthresh * tp->prr_delivered + + tp->prior_cwnd - 1; + sndcnt = div_u64(dividend, tp->prior_cwnd) - tp->prr_out; + } else if ((flag & (FLAG_RETRANS_DATA_ACKED | FLAG_LOST_RETRANS)) == + FLAG_RETRANS_DATA_ACKED) { + sndcnt = min_t(int, delta, + max_t(int, tp->prr_delivered - tp->prr_out, + newly_acked_sacked) + 1); + } else { + sndcnt = min(delta, newly_acked_sacked); + } + /* Force a fast retransmit upon entering fast recovery */ + sndcnt = max(sndcnt, (tp->prr_out ? 0 : 1)); + tp->snd_cwnd = tcp_packets_in_flight(tp) + sndcnt; +} + +static inline void tcp_end_cwnd_reduction(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (inet_csk(sk)->icsk_ca_ops->cong_control) + return; + + /* Reset cwnd to ssthresh in CWR or Recovery (unless it's undone) */ + if (tp->snd_ssthresh < TCP_INFINITE_SSTHRESH && + (inet_csk(sk)->icsk_ca_state == TCP_CA_CWR || tp->undo_marker)) { + tp->snd_cwnd = tp->snd_ssthresh; + tp->snd_cwnd_stamp = tcp_jiffies32; + } + tcp_ca_event(sk, CA_EVENT_COMPLETE_CWR); +} + +/* Enter CWR state. Disable cwnd undo since congestion is proven with ECN */ +void tcp_enter_cwr(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + tp->prior_ssthresh = 0; + if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) { + tp->undo_marker = 0; + tcp_init_cwnd_reduction(sk); + tcp_set_ca_state(sk, TCP_CA_CWR); + } +} +EXPORT_SYMBOL(tcp_enter_cwr); + +static void tcp_try_keep_open(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + int state = TCP_CA_Open; + + if (tcp_left_out(tp) || tcp_any_retrans_done(sk)) + state = TCP_CA_Disorder; + + if (inet_csk(sk)->icsk_ca_state != state) { + tcp_set_ca_state(sk, state); + tp->high_seq = tp->snd_nxt; + } +} + +static void tcp_try_to_open(struct sock *sk, int flag) +{ + struct tcp_sock *tp = tcp_sk(sk); + + tcp_verify_left_out(tp); + + if (!tcp_any_retrans_done(sk)) + tp->retrans_stamp = 0; + + if (flag & FLAG_ECE) + tcp_enter_cwr(sk); + + if (inet_csk(sk)->icsk_ca_state != TCP_CA_CWR) { + tcp_try_keep_open(sk); + } +} + +static void tcp_mtup_probe_failed(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + icsk->icsk_mtup.search_high = icsk->icsk_mtup.probe_size - 1; + icsk->icsk_mtup.probe_size = 0; + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMTUPFAIL); +} + +static void tcp_mtup_probe_success(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + u64 val; + + tp->prior_ssthresh = tcp_current_ssthresh(sk); + + val = (u64)tp->snd_cwnd * tcp_mss_to_mtu(sk, tp->mss_cache); + do_div(val, icsk->icsk_mtup.probe_size); + WARN_ON_ONCE((u32)val != val); + tp->snd_cwnd = max_t(u32, 1U, val); + + tp->snd_cwnd_cnt = 0; + tp->snd_cwnd_stamp = tcp_jiffies32; + tp->snd_ssthresh = tcp_current_ssthresh(sk); + + icsk->icsk_mtup.search_low = icsk->icsk_mtup.probe_size; + icsk->icsk_mtup.probe_size = 0; + tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMTUPSUCCESS); +} + +/* Do a simple retransmit without using the backoff mechanisms in + * tcp_timer. This is used for path mtu discovery. + * The socket is already locked here. + */ +void tcp_simple_retransmit(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + unsigned int mss = tcp_current_mss(sk); + + skb_rbtree_walk(skb, &sk->tcp_rtx_queue) { + if (tcp_skb_seglen(skb) > mss) + tcp_mark_skb_lost(sk, skb); + } + + tcp_clear_retrans_hints_partial(tp); + + if (!tp->lost_out) + return; + + if (tcp_is_reno(tp)) + tcp_limit_reno_sacked(tp); + + tcp_verify_left_out(tp); + + /* Don't muck with the congestion window here. + * Reason is that we do not increase amount of _data_ + * in network, but units changed and effective + * cwnd/ssthresh really reduced now. + */ + if (icsk->icsk_ca_state != TCP_CA_Loss) { + tp->high_seq = tp->snd_nxt; + tp->snd_ssthresh = tcp_current_ssthresh(sk); + tp->prior_ssthresh = 0; + tp->undo_marker = 0; + tcp_set_ca_state(sk, TCP_CA_Loss); + } + tcp_xmit_retransmit_queue(sk); +} +EXPORT_SYMBOL(tcp_simple_retransmit); + +void tcp_enter_recovery(struct sock *sk, bool ece_ack) +{ + struct tcp_sock *tp = tcp_sk(sk); + int mib_idx; + + if (tcp_is_reno(tp)) + mib_idx = LINUX_MIB_TCPRENORECOVERY; + else + mib_idx = LINUX_MIB_TCPSACKRECOVERY; + + NET_INC_STATS(sock_net(sk), mib_idx); + + tp->prior_ssthresh = 0; + tcp_init_undo(tp); + + if (!tcp_in_cwnd_reduction(sk)) { + if (!ece_ack) + tp->prior_ssthresh = tcp_current_ssthresh(sk); + tcp_init_cwnd_reduction(sk); + } + tcp_set_ca_state(sk, TCP_CA_Recovery); +} + +/* Process an ACK in CA_Loss state. Move to CA_Open if lost data are + * recovered or spurious. Otherwise retransmits more on partial ACKs. + */ +static void tcp_process_loss(struct sock *sk, int flag, int num_dupack, + int *rexmit) +{ + struct tcp_sock *tp = tcp_sk(sk); + bool recovered = !before(tp->snd_una, tp->high_seq); + + if ((flag & FLAG_SND_UNA_ADVANCED || rcu_access_pointer(tp->fastopen_rsk)) && + tcp_try_undo_loss(sk, false)) + return; + + if (tp->frto) { /* F-RTO RFC5682 sec 3.1 (sack enhanced version). */ + /* Step 3.b. A timeout is spurious if not all data are + * lost, i.e., never-retransmitted data are (s)acked. + */ + if ((flag & FLAG_ORIG_SACK_ACKED) && + tcp_try_undo_loss(sk, true)) + return; + + if (after(tp->snd_nxt, tp->high_seq)) { + if (flag & FLAG_DATA_SACKED || num_dupack) + tp->frto = 0; /* Step 3.a. loss was real */ + } else if (flag & FLAG_SND_UNA_ADVANCED && !recovered) { + tp->high_seq = tp->snd_nxt; + /* Step 2.b. Try send new data (but deferred until cwnd + * is updated in tcp_ack()). Otherwise fall back to + * the conventional recovery. + */ + if (!tcp_write_queue_empty(sk) && + after(tcp_wnd_end(tp), tp->snd_nxt)) { + *rexmit = REXMIT_NEW; + return; + } + tp->frto = 0; + } + } + + if (recovered) { + /* F-RTO RFC5682 sec 3.1 step 2.a and 1st part of step 3.a */ + tcp_try_undo_recovery(sk); + return; + } + if (tcp_is_reno(tp)) { + /* A Reno DUPACK means new data in F-RTO step 2.b above are + * delivered. Lower inflight to clock out (re)tranmissions. + */ + if (after(tp->snd_nxt, tp->high_seq) && num_dupack) + tcp_add_reno_sack(sk, num_dupack, flag & FLAG_ECE); + else if (flag & FLAG_SND_UNA_ADVANCED) + tcp_reset_reno_sack(tp); + } + *rexmit = REXMIT_LOST; +} + +static bool tcp_force_fast_retransmit(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + return after(tcp_highest_sack_seq(tp), + tp->snd_una + tp->reordering * tp->mss_cache); +} + +/* Undo during fast recovery after partial ACK. */ +static bool tcp_try_undo_partial(struct sock *sk, u32 prior_snd_una, + bool *do_lost) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->undo_marker && tcp_packet_delayed(tp)) { + /* Plain luck! Hole if filled with delayed + * packet, rather than with a retransmit. Check reordering. + */ + tcp_check_sack_reordering(sk, prior_snd_una, 1); + + /* We are getting evidence that the reordering degree is higher + * than we realized. If there are no retransmits out then we + * can undo. Otherwise we clock out new packets but do not + * mark more packets lost or retransmit more. + */ + if (tp->retrans_out) + return true; + + if (!tcp_any_retrans_done(sk)) + tp->retrans_stamp = 0; + + DBGUNDO(sk, "partial recovery"); + tcp_undo_cwnd_reduction(sk, true); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPARTIALUNDO); + tcp_try_keep_open(sk); + } else { + /* Partial ACK arrived. Force fast retransmit. */ + *do_lost = tcp_force_fast_retransmit(sk); + } + return false; +} + +static void tcp_identify_packet_loss(struct sock *sk, int *ack_flag) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tcp_rtx_queue_empty(sk)) + return; + + if (unlikely(tcp_is_reno(tp))) { + tcp_newreno_mark_lost(sk, *ack_flag & FLAG_SND_UNA_ADVANCED); + } else if (tcp_is_rack(sk)) { + u32 prior_retrans = tp->retrans_out; + + if (tcp_rack_mark_lost(sk)) + *ack_flag &= ~FLAG_SET_XMIT_TIMER; + if (prior_retrans > tp->retrans_out) + *ack_flag |= FLAG_LOST_RETRANS; + } +} + +/* Process an event, which can update packets-in-flight not trivially. + * Main goal of this function is to calculate new estimate for left_out, + * taking into account both packets sitting in receiver's buffer and + * packets lost by network. + * + * Besides that it updates the congestion state when packet loss or ECN + * is detected. But it does not reduce the cwnd, it is done by the + * congestion control later. + * + * It does _not_ decide what to send, it is made in function + * tcp_xmit_retransmit_queue(). + */ +static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una, + int num_dupack, int *ack_flag, int *rexmit) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + int fast_rexmit = 0, flag = *ack_flag; + bool ece_ack = flag & FLAG_ECE; + bool do_lost = num_dupack || ((flag & FLAG_DATA_SACKED) && + tcp_force_fast_retransmit(sk)); + + if (!tp->packets_out && tp->sacked_out) + tp->sacked_out = 0; + + /* Now state machine starts. + * A. ECE, hence prohibit cwnd undoing, the reduction is required. */ + if (ece_ack) + tp->prior_ssthresh = 0; + + /* B. In all the states check for reneging SACKs. */ + if (tcp_check_sack_reneging(sk, ack_flag)) + return; + + /* C. Check consistency of the current state. */ + tcp_verify_left_out(tp); + + /* D. Check state exit conditions. State can be terminated + * when high_seq is ACKed. */ + if (icsk->icsk_ca_state == TCP_CA_Open) { + WARN_ON(tp->retrans_out != 0); + tp->retrans_stamp = 0; + } else if (!before(tp->snd_una, tp->high_seq)) { + switch (icsk->icsk_ca_state) { + case TCP_CA_CWR: + /* CWR is to be held something *above* high_seq + * is ACKed for CWR bit to reach receiver. */ + if (tp->snd_una != tp->high_seq) { + tcp_end_cwnd_reduction(sk); + tcp_set_ca_state(sk, TCP_CA_Open); + } + break; + + case TCP_CA_Recovery: + if (tcp_is_reno(tp)) + tcp_reset_reno_sack(tp); + if (tcp_try_undo_recovery(sk)) + return; + tcp_end_cwnd_reduction(sk); + break; + } + } + + /* E. Process state. */ + switch (icsk->icsk_ca_state) { + case TCP_CA_Recovery: + if (!(flag & FLAG_SND_UNA_ADVANCED)) { + if (tcp_is_reno(tp)) + tcp_add_reno_sack(sk, num_dupack, ece_ack); + } else if (tcp_try_undo_partial(sk, prior_snd_una, &do_lost)) + return; + + if (tcp_try_undo_dsack(sk)) + tcp_try_keep_open(sk); + + tcp_identify_packet_loss(sk, ack_flag); + if (icsk->icsk_ca_state != TCP_CA_Recovery) { + if (!tcp_time_to_recover(sk, flag)) + return; + /* Undo reverts the recovery state. If loss is evident, + * starts a new recovery (e.g. reordering then loss); + */ + tcp_enter_recovery(sk, ece_ack); + } + break; + case TCP_CA_Loss: + tcp_process_loss(sk, flag, num_dupack, rexmit); + tcp_identify_packet_loss(sk, ack_flag); + if (!(icsk->icsk_ca_state == TCP_CA_Open || + (*ack_flag & FLAG_LOST_RETRANS))) + return; + /* Change state if cwnd is undone or retransmits are lost */ + fallthrough; + default: + if (tcp_is_reno(tp)) { + if (flag & FLAG_SND_UNA_ADVANCED) + tcp_reset_reno_sack(tp); + tcp_add_reno_sack(sk, num_dupack, ece_ack); + } + + if (icsk->icsk_ca_state <= TCP_CA_Disorder) + tcp_try_undo_dsack(sk); + + tcp_identify_packet_loss(sk, ack_flag); + if (!tcp_time_to_recover(sk, flag)) { + tcp_try_to_open(sk, flag); + return; + } + + /* MTU probe failure: don't reduce cwnd */ + if (icsk->icsk_ca_state < TCP_CA_CWR && + icsk->icsk_mtup.probe_size && + tp->snd_una == tp->mtu_probe.probe_seq_start) { + tcp_mtup_probe_failed(sk); + /* Restores the reduction we did in tcp_mtup_probe() */ + tp->snd_cwnd++; + tcp_simple_retransmit(sk); + return; + } + + /* Otherwise enter Recovery state */ + tcp_enter_recovery(sk, ece_ack); + fast_rexmit = 1; + } + + if (!tcp_is_rack(sk) && do_lost) + tcp_update_scoreboard(sk, fast_rexmit); + *rexmit = REXMIT_LOST; +} + +static void tcp_update_rtt_min(struct sock *sk, u32 rtt_us, const int flag) +{ + u32 wlen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_min_rtt_wlen) * HZ; + struct tcp_sock *tp = tcp_sk(sk); + + if ((flag & FLAG_ACK_MAYBE_DELAYED) && rtt_us > tcp_min_rtt(tp)) { + /* If the remote keeps returning delayed ACKs, eventually + * the min filter would pick it up and overestimate the + * prop. delay when it expires. Skip suspected delayed ACKs. + */ + return; + } + minmax_running_min(&tp->rtt_min, wlen, tcp_jiffies32, + rtt_us ? : jiffies_to_usecs(1)); +} + +static bool tcp_ack_update_rtt(struct sock *sk, const int flag, + long seq_rtt_us, long sack_rtt_us, + long ca_rtt_us, struct rate_sample *rs) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + /* Prefer RTT measured from ACK's timing to TS-ECR. This is because + * broken middle-boxes or peers may corrupt TS-ECR fields. But + * Karn's algorithm forbids taking RTT if some retransmitted data + * is acked (RFC6298). + */ + if (seq_rtt_us < 0) + seq_rtt_us = sack_rtt_us; + + /* RTTM Rule: A TSecr value received in a segment is used to + * update the averaged RTT measurement only if the segment + * acknowledges some new data, i.e., only if it advances the + * left edge of the send window. + * See draft-ietf-tcplw-high-performance-00, section 3.3. + */ + if (seq_rtt_us < 0 && tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr && + flag & FLAG_ACKED) { + u32 delta = tcp_time_stamp(tp) - tp->rx_opt.rcv_tsecr; + + if (likely(delta < INT_MAX / (USEC_PER_SEC / TCP_TS_HZ))) { + if (!delta) + delta = 1; + seq_rtt_us = delta * (USEC_PER_SEC / TCP_TS_HZ); + ca_rtt_us = seq_rtt_us; + } + } + rs->rtt_us = ca_rtt_us; /* RTT of last (S)ACKed packet (or -1) */ + if (seq_rtt_us < 0) + return false; + + /* ca_rtt_us >= 0 is counting on the invariant that ca_rtt_us is + * always taken together with ACK, SACK, or TS-opts. Any negative + * values will be skipped with the seq_rtt_us < 0 check above. + */ + tcp_update_rtt_min(sk, ca_rtt_us, flag); + tcp_rtt_estimator(sk, seq_rtt_us); + tcp_set_rto(sk); + + /* RFC6298: only reset backoff on valid RTT measurement. */ + inet_csk(sk)->icsk_backoff = 0; + return true; +} + +/* Compute time elapsed between (last) SYNACK and the ACK completing 3WHS. */ +void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req) +{ + struct rate_sample rs; + long rtt_us = -1L; + + if (req && !req->num_retrans && tcp_rsk(req)->snt_synack) + rtt_us = tcp_stamp_us_delta(tcp_clock_us(), tcp_rsk(req)->snt_synack); + + tcp_ack_update_rtt(sk, FLAG_SYN_ACKED, rtt_us, -1L, rtt_us, &rs); +} + + +static void tcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + icsk->icsk_ca_ops->cong_avoid(sk, ack, acked); + tcp_sk(sk)->snd_cwnd_stamp = tcp_jiffies32; +} + +/* Restart timer after forward progress on connection. + * RFC2988 recommends to restart timer to now+rto. + */ +void tcp_rearm_rto(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + + /* If the retrans timer is currently being used by Fast Open + * for SYN-ACK retrans purpose, stay put. + */ + if (rcu_access_pointer(tp->fastopen_rsk)) + return; + + if (!tp->packets_out) { + inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); + } else { + u32 rto = inet_csk(sk)->icsk_rto; + /* Offset the time elapsed after installing regular RTO */ + if (icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || + icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { + s64 delta_us = tcp_rto_delta_us(sk); + /* delta_us may not be positive if the socket is locked + * when the retrans timer fires and is rescheduled. + */ + rto = usecs_to_jiffies(max_t(int, delta_us, 1)); + } + tcp_reset_xmit_timer(sk, ICSK_TIME_RETRANS, rto, + TCP_RTO_MAX); + } +} + +/* Try to schedule a loss probe; if that doesn't work, then schedule an RTO. */ +static void tcp_set_xmit_timer(struct sock *sk) +{ + if (!tcp_schedule_loss_probe(sk, true)) + tcp_rearm_rto(sk); +} + +/* If we get here, the whole TSO packet has not been acked. */ +static u32 tcp_tso_acked(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 packets_acked; + + BUG_ON(!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una)); + + packets_acked = tcp_skb_pcount(skb); + if (tcp_trim_head(sk, skb, tp->snd_una - TCP_SKB_CB(skb)->seq)) + return 0; + packets_acked -= tcp_skb_pcount(skb); + + if (packets_acked) { + BUG_ON(tcp_skb_pcount(skb) == 0); + BUG_ON(!before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq)); + } + + return packets_acked; +} + +static void tcp_ack_tstamp(struct sock *sk, struct sk_buff *skb, + u32 prior_snd_una) +{ + const struct skb_shared_info *shinfo; + + /* Avoid cache line misses to get skb_shinfo() and shinfo->tx_flags */ + if (likely(!TCP_SKB_CB(skb)->txstamp_ack)) + return; + + shinfo = skb_shinfo(skb); + if (!before(shinfo->tskey, prior_snd_una) && + before(shinfo->tskey, tcp_sk(sk)->snd_una)) { + tcp_skb_tsorted_save(skb) { + __skb_tstamp_tx(skb, NULL, sk, SCM_TSTAMP_ACK); + } tcp_skb_tsorted_restore(skb); + } +} + +/* Remove acknowledged frames from the retransmission queue. If our packet + * is before the ack sequence we can discard it as it's confirmed to have + * arrived at the other end. + */ +static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack, + u32 prior_snd_una, + struct tcp_sacktag_state *sack, bool ece_ack) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + u64 first_ackt, last_ackt; + struct tcp_sock *tp = tcp_sk(sk); + u32 prior_sacked = tp->sacked_out; + u32 reord = tp->snd_nxt; /* lowest acked un-retx un-sacked seq */ + struct sk_buff *skb, *next; + bool fully_acked = true; + long sack_rtt_us = -1L; + long seq_rtt_us = -1L; + long ca_rtt_us = -1L; + u32 pkts_acked = 0; + u32 last_in_flight = 0; + bool rtt_update; + int flag = 0; + + first_ackt = 0; + + for (skb = skb_rb_first(&sk->tcp_rtx_queue); skb; skb = next) { + struct tcp_skb_cb *scb = TCP_SKB_CB(skb); + const u32 start_seq = scb->seq; + u8 sacked = scb->sacked; + u32 acked_pcount; + + /* Determine how many packets and what bytes were acked, tso and else */ + if (after(scb->end_seq, tp->snd_una)) { + if (tcp_skb_pcount(skb) == 1 || + !after(tp->snd_una, scb->seq)) + break; + + acked_pcount = tcp_tso_acked(sk, skb); + if (!acked_pcount) + break; + fully_acked = false; + } else { + acked_pcount = tcp_skb_pcount(skb); + } + + if (unlikely(sacked & TCPCB_RETRANS)) { + if (sacked & TCPCB_SACKED_RETRANS) + tp->retrans_out -= acked_pcount; + flag |= FLAG_RETRANS_DATA_ACKED; + } else if (!(sacked & TCPCB_SACKED_ACKED)) { + last_ackt = tcp_skb_timestamp_us(skb); + WARN_ON_ONCE(last_ackt == 0); + if (!first_ackt) + first_ackt = last_ackt; + + last_in_flight = TCP_SKB_CB(skb)->tx.in_flight; + if (before(start_seq, reord)) + reord = start_seq; + if (!after(scb->end_seq, tp->high_seq)) + flag |= FLAG_ORIG_SACK_ACKED; + } + + if (sacked & TCPCB_SACKED_ACKED) { + tp->sacked_out -= acked_pcount; + } else if (tcp_is_sack(tp)) { + tcp_count_delivered(tp, acked_pcount, ece_ack); + if (!tcp_skb_spurious_retrans(tp, skb)) + tcp_rack_advance(tp, sacked, scb->end_seq, + tcp_skb_timestamp_us(skb)); + } + if (sacked & TCPCB_LOST) + tp->lost_out -= acked_pcount; + + tp->packets_out -= acked_pcount; + pkts_acked += acked_pcount; + tcp_rate_skb_delivered(sk, skb, sack->rate); + + /* Initial outgoing SYN's get put onto the write_queue + * just like anything else we transmit. It is not + * true data, and if we misinform our callers that + * this ACK acks real data, we will erroneously exit + * connection startup slow start one packet too + * quickly. This is severely frowned upon behavior. + */ + if (likely(!(scb->tcp_flags & TCPHDR_SYN))) { + flag |= FLAG_DATA_ACKED; + } else { + flag |= FLAG_SYN_ACKED; + tp->retrans_stamp = 0; + } + + if (!fully_acked) + break; + + tcp_ack_tstamp(sk, skb, prior_snd_una); + + next = skb_rb_next(skb); + if (unlikely(skb == tp->retransmit_skb_hint)) + tp->retransmit_skb_hint = NULL; + if (unlikely(skb == tp->lost_skb_hint)) + tp->lost_skb_hint = NULL; + tcp_highest_sack_replace(sk, skb, next); + tcp_rtx_queue_unlink_and_free(skb, sk); + } + + if (!skb) + tcp_chrono_stop(sk, TCP_CHRONO_BUSY); + + if (likely(between(tp->snd_up, prior_snd_una, tp->snd_una))) + tp->snd_up = tp->snd_una; + + if (skb) { + tcp_ack_tstamp(sk, skb, prior_snd_una); + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) + flag |= FLAG_SACK_RENEGING; + } + + if (likely(first_ackt) && !(flag & FLAG_RETRANS_DATA_ACKED)) { + seq_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, first_ackt); + ca_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, last_ackt); + + if (pkts_acked == 1 && last_in_flight < tp->mss_cache && + last_in_flight && !prior_sacked && fully_acked && + sack->rate->prior_delivered + 1 == tp->delivered && + !(flag & (FLAG_CA_ALERT | FLAG_SYN_ACKED))) { + /* Conservatively mark a delayed ACK. It's typically + * from a lone runt packet over the round trip to + * a receiver w/o out-of-order or CE events. + */ + flag |= FLAG_ACK_MAYBE_DELAYED; + } + } + if (sack->first_sackt) { + sack_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, sack->first_sackt); + ca_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, sack->last_sackt); + } + rtt_update = tcp_ack_update_rtt(sk, flag, seq_rtt_us, sack_rtt_us, + ca_rtt_us, sack->rate); + + if (flag & FLAG_ACKED) { + flag |= FLAG_SET_XMIT_TIMER; /* set TLP or RTO timer */ + if (unlikely(icsk->icsk_mtup.probe_size && + !after(tp->mtu_probe.probe_seq_end, tp->snd_una))) { + tcp_mtup_probe_success(sk); + } + + if (tcp_is_reno(tp)) { + tcp_remove_reno_sacks(sk, pkts_acked, ece_ack); + + /* If any of the cumulatively ACKed segments was + * retransmitted, non-SACK case cannot confirm that + * progress was due to original transmission due to + * lack of TCPCB_SACKED_ACKED bits even if some of + * the packets may have been never retransmitted. + */ + if (flag & FLAG_RETRANS_DATA_ACKED) + flag &= ~FLAG_ORIG_SACK_ACKED; + } else { + int delta; + + /* Non-retransmitted hole got filled? That's reordering */ + if (before(reord, prior_fack)) + tcp_check_sack_reordering(sk, reord, 0); + + delta = prior_sacked - tp->sacked_out; + tp->lost_cnt_hint -= min(tp->lost_cnt_hint, delta); + } + } else if (skb && rtt_update && sack_rtt_us >= 0 && + sack_rtt_us > tcp_stamp_us_delta(tp->tcp_mstamp, + tcp_skb_timestamp_us(skb))) { + /* Do not re-arm RTO if the sack RTT is measured from data sent + * after when the head was last (re)transmitted. Otherwise the + * timeout may continue to extend in loss recovery. + */ + flag |= FLAG_SET_XMIT_TIMER; /* set TLP or RTO timer */ + } + + if (icsk->icsk_ca_ops->pkts_acked) { + struct ack_sample sample = { .pkts_acked = pkts_acked, + .rtt_us = sack->rate->rtt_us, + .in_flight = last_in_flight }; + + icsk->icsk_ca_ops->pkts_acked(sk, &sample); + } + +#if FASTRETRANS_DEBUG > 0 + WARN_ON((int)tp->sacked_out < 0); + WARN_ON((int)tp->lost_out < 0); + WARN_ON((int)tp->retrans_out < 0); + if (!tp->packets_out && tcp_is_sack(tp)) { + icsk = inet_csk(sk); + if (tp->lost_out) { + pr_debug("Leak l=%u %d\n", + tp->lost_out, icsk->icsk_ca_state); + tp->lost_out = 0; + } + if (tp->sacked_out) { + pr_debug("Leak s=%u %d\n", + tp->sacked_out, icsk->icsk_ca_state); + tp->sacked_out = 0; + } + if (tp->retrans_out) { + pr_debug("Leak r=%u %d\n", + tp->retrans_out, icsk->icsk_ca_state); + tp->retrans_out = 0; + } + } +#endif + return flag; +} + +static void tcp_ack_probe(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct sk_buff *head = tcp_send_head(sk); + const struct tcp_sock *tp = tcp_sk(sk); + + /* Was it a usable window open? */ + if (!head) + return; + if (!after(TCP_SKB_CB(head)->end_seq, tcp_wnd_end(tp))) { + icsk->icsk_backoff = 0; + icsk->icsk_probes_tstamp = 0; + inet_csk_clear_xmit_timer(sk, ICSK_TIME_PROBE0); + /* Socket must be waked up by subsequent tcp_data_snd_check(). + * This function is not for random using! + */ + } else { + unsigned long when = tcp_probe0_when(sk, TCP_RTO_MAX); + + when = tcp_clamp_probe0_to_user_timeout(sk, when); + tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, when, TCP_RTO_MAX); + } +} + +static inline bool tcp_ack_is_dubious(const struct sock *sk, const int flag) +{ + return !(flag & FLAG_NOT_DUP) || (flag & FLAG_CA_ALERT) || + inet_csk(sk)->icsk_ca_state != TCP_CA_Open; +} + +/* Decide wheather to run the increase function of congestion control. */ +static inline bool tcp_may_raise_cwnd(const struct sock *sk, const int flag) +{ + /* If reordering is high then always grow cwnd whenever data is + * delivered regardless of its ordering. Otherwise stay conservative + * and only grow cwnd on in-order delivery (RFC5681). A stretched ACK w/ + * new SACK or ECE mark may first advance cwnd here and later reduce + * cwnd in tcp_fastretrans_alert() based on more states. + */ + if (tcp_sk(sk)->reordering > + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reordering)) + return flag & FLAG_FORWARD_PROGRESS; + + return flag & FLAG_DATA_ACKED; +} + +/* The "ultimate" congestion control function that aims to replace the rigid + * cwnd increase and decrease control (tcp_cong_avoid,tcp_*cwnd_reduction). + * It's called toward the end of processing an ACK with precise rate + * information. All transmission or retransmission are delayed afterwards. + */ +static void tcp_cong_control(struct sock *sk, u32 ack, u32 acked_sacked, + int flag, const struct rate_sample *rs) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ca_ops->cong_control) { + icsk->icsk_ca_ops->cong_control(sk, rs); + return; + } + + if (tcp_in_cwnd_reduction(sk)) { + /* Reduce cwnd if state mandates */ + tcp_cwnd_reduction(sk, acked_sacked, flag); + } else if (tcp_may_raise_cwnd(sk, flag)) { + /* Advance cwnd if state allows */ + tcp_cong_avoid(sk, ack, acked_sacked); + } + tcp_update_pacing_rate(sk); +} + +/* Check that window update is acceptable. + * The function assumes that snd_una<=ack<=snd_next. + */ +static inline bool tcp_may_update_window(const struct tcp_sock *tp, + const u32 ack, const u32 ack_seq, + const u32 nwin) +{ + return after(ack, tp->snd_una) || + after(ack_seq, tp->snd_wl1) || + (ack_seq == tp->snd_wl1 && nwin > tp->snd_wnd); +} + +/* If we update tp->snd_una, also update tp->bytes_acked */ +static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack) +{ + u32 delta = ack - tp->snd_una; + + sock_owned_by_me((struct sock *)tp); + tp->bytes_acked += delta; + tp->snd_una = ack; +} + +/* If we update tp->rcv_nxt, also update tp->bytes_received */ +static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq) +{ + u32 delta = seq - tp->rcv_nxt; + + sock_owned_by_me((struct sock *)tp); + tp->bytes_received += delta; + WRITE_ONCE(tp->rcv_nxt, seq); +} + +/* Update our send window. + * + * Window update algorithm, described in RFC793/RFC1122 (used in linux-2.2 + * and in FreeBSD. NetBSD's one is even worse.) is wrong. + */ +static int tcp_ack_update_window(struct sock *sk, const struct sk_buff *skb, u32 ack, + u32 ack_seq) +{ + struct tcp_sock *tp = tcp_sk(sk); + int flag = 0; + u32 nwin = ntohs(tcp_hdr(skb)->window); + + if (likely(!tcp_hdr(skb)->syn)) + nwin <<= tp->rx_opt.snd_wscale; + + if (tcp_may_update_window(tp, ack, ack_seq, nwin)) { + flag |= FLAG_WIN_UPDATE; + tcp_update_wl(tp, ack_seq); + + if (tp->snd_wnd != nwin) { + tp->snd_wnd = nwin; + + /* Note, it is the only place, where + * fast path is recovered for sending TCP. + */ + tp->pred_flags = 0; + tcp_fast_path_check(sk); + + if (!tcp_write_queue_empty(sk)) + tcp_slow_start_after_idle_check(sk); + + if (nwin > tp->max_window) { + tp->max_window = nwin; + tcp_sync_mss(sk, inet_csk(sk)->icsk_pmtu_cookie); + } + } + } + + tcp_snd_una_update(tp, ack); + + return flag; +} + +static bool __tcp_oow_rate_limited(struct net *net, int mib_idx, + u32 *last_oow_ack_time) +{ + /* Paired with the WRITE_ONCE() in this function. */ + u32 val = READ_ONCE(*last_oow_ack_time); + + if (val) { + s32 elapsed = (s32)(tcp_jiffies32 - val); + + if (0 <= elapsed && + elapsed < READ_ONCE(net->ipv4.sysctl_tcp_invalid_ratelimit)) { + NET_INC_STATS(net, mib_idx); + return true; /* rate-limited: don't send yet! */ + } + } + + /* Paired with the prior READ_ONCE() and with itself, + * as we might be lockless. + */ + WRITE_ONCE(*last_oow_ack_time, tcp_jiffies32); + + return false; /* not rate-limited: go ahead, send dupack now! */ +} + +/* Return true if we're currently rate-limiting out-of-window ACKs and + * thus shouldn't send a dupack right now. We rate-limit dupacks in + * response to out-of-window SYNs or ACKs to mitigate ACK loops or DoS + * attacks that send repeated SYNs or ACKs for the same connection. To + * do this, we do not send a duplicate SYNACK or ACK if the remote + * endpoint is sending out-of-window SYNs or pure ACKs at a high rate. + */ +bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, + int mib_idx, u32 *last_oow_ack_time) +{ + /* Data packets without SYNs are not likely part of an ACK loop. */ + if ((TCP_SKB_CB(skb)->seq != TCP_SKB_CB(skb)->end_seq) && + !tcp_hdr(skb)->syn) + return false; + + return __tcp_oow_rate_limited(net, mib_idx, last_oow_ack_time); +} + +/* RFC 5961 7 [ACK Throttling] */ +static void tcp_send_challenge_ack(struct sock *sk, const struct sk_buff *skb) +{ + /* unprotected vars, we dont care of overwrites */ + static u32 challenge_timestamp; + static unsigned int challenge_count; + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + u32 count, now; + + /* First check our per-socket dupack rate limit. */ + if (__tcp_oow_rate_limited(net, + LINUX_MIB_TCPACKSKIPPEDCHALLENGE, + &tp->last_oow_ack_time)) + return; + + /* Then check host-wide RFC 5961 rate limit. */ + now = jiffies / HZ; + if (now != READ_ONCE(challenge_timestamp)) { + u32 ack_limit = READ_ONCE(net->ipv4.sysctl_tcp_challenge_ack_limit); + u32 half = (ack_limit + 1) >> 1; + + WRITE_ONCE(challenge_timestamp, now); + WRITE_ONCE(challenge_count, half + prandom_u32_max(ack_limit)); + } + count = READ_ONCE(challenge_count); + if (count > 0) { + WRITE_ONCE(challenge_count, count - 1); + NET_INC_STATS(net, LINUX_MIB_TCPCHALLENGEACK); + tcp_send_ack(sk); + } +} + +static void tcp_store_ts_recent(struct tcp_sock *tp) +{ + tp->rx_opt.ts_recent = tp->rx_opt.rcv_tsval; + tp->rx_opt.ts_recent_stamp = ktime_get_seconds(); +} + +static void tcp_replace_ts_recent(struct tcp_sock *tp, u32 seq) +{ + if (tp->rx_opt.saw_tstamp && !after(seq, tp->rcv_wup)) { + /* PAWS bug workaround wrt. ACK frames, the PAWS discard + * extra check below makes sure this can only happen + * for pure ACK frames. -DaveM + * + * Not only, also it occurs for expired timestamps. + */ + + if (tcp_paws_check(&tp->rx_opt, 0)) + tcp_store_ts_recent(tp); + } +} + +/* This routine deals with acks during a TLP episode and ends an episode by + * resetting tlp_high_seq. Ref: TLP algorithm in draft-ietf-tcpm-rack + */ +static void tcp_process_tlp_ack(struct sock *sk, u32 ack, int flag) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (before(ack, tp->tlp_high_seq)) + return; + + if (!tp->tlp_retrans) { + /* TLP of new data has been acknowledged */ + tp->tlp_high_seq = 0; + } else if (flag & FLAG_DSACKING_ACK) { + /* This DSACK means original and TLP probe arrived; no loss */ + tp->tlp_high_seq = 0; + } else if (after(ack, tp->tlp_high_seq)) { + /* ACK advances: there was a loss, so reduce cwnd. Reset + * tlp_high_seq in tcp_init_cwnd_reduction() + */ + tcp_init_cwnd_reduction(sk); + tcp_set_ca_state(sk, TCP_CA_CWR); + tcp_end_cwnd_reduction(sk); + tcp_try_keep_open(sk); + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPLOSSPROBERECOVERY); + } else if (!(flag & (FLAG_SND_UNA_ADVANCED | + FLAG_NOT_DUP | FLAG_DATA_SACKED))) { + /* Pure dupack: original and TLP probe arrived; no loss */ + tp->tlp_high_seq = 0; + } +} + +static inline void tcp_in_ack_event(struct sock *sk, u32 flags) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ca_ops->in_ack_event) + icsk->icsk_ca_ops->in_ack_event(sk, flags); +} + +/* Congestion control has updated the cwnd already. So if we're in + * loss recovery then now we do any new sends (for FRTO) or + * retransmits (for CA_Loss or CA_recovery) that make sense. + */ +static void tcp_xmit_recovery(struct sock *sk, int rexmit) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (rexmit == REXMIT_NONE || sk->sk_state == TCP_SYN_SENT) + return; + + if (unlikely(rexmit == REXMIT_NEW)) { + __tcp_push_pending_frames(sk, tcp_current_mss(sk), + TCP_NAGLE_OFF); + if (after(tp->snd_nxt, tp->high_seq)) + return; + tp->frto = 0; + } + tcp_xmit_retransmit_queue(sk); +} + +/* Returns the number of packets newly acked or sacked by the current ACK */ +static u32 tcp_newly_delivered(struct sock *sk, u32 prior_delivered, int flag) +{ + const struct net *net = sock_net(sk); + struct tcp_sock *tp = tcp_sk(sk); + u32 delivered; + + delivered = tp->delivered - prior_delivered; + NET_ADD_STATS(net, LINUX_MIB_TCPDELIVERED, delivered); + if (flag & FLAG_ECE) + NET_ADD_STATS(net, LINUX_MIB_TCPDELIVEREDCE, delivered); + + return delivered; +} + +/* This routine deals with incoming acks, but not outgoing ones. */ +static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_sacktag_state sack_state; + struct rate_sample rs = { .prior_delivered = 0 }; + u32 prior_snd_una = tp->snd_una; + bool is_sack_reneg = tp->is_sack_reneg; + u32 ack_seq = TCP_SKB_CB(skb)->seq; + u32 ack = TCP_SKB_CB(skb)->ack_seq; + int num_dupack = 0; + int prior_packets = tp->packets_out; + u32 delivered = tp->delivered; + u32 lost = tp->lost; + int rexmit = REXMIT_NONE; /* Flag to (re)transmit to recover losses */ + u32 prior_fack; + + sack_state.first_sackt = 0; + sack_state.rate = &rs; + sack_state.sack_delivered = 0; + + /* We very likely will need to access rtx queue. */ + prefetch(sk->tcp_rtx_queue.rb_node); + + /* If the ack is older than previous acks + * then we can probably ignore it. + */ + if (before(ack, prior_snd_una)) { + u32 max_window; + + /* do not accept ACK for bytes we never sent. */ + max_window = min_t(u64, tp->max_window, tp->bytes_acked); + /* RFC 5961 5.2 [Blind Data Injection Attack].[Mitigation] */ + if (before(ack, prior_snd_una - max_window)) { + if (!(flag & FLAG_NO_CHALLENGE_ACK)) + tcp_send_challenge_ack(sk, skb); + return -1; + } + goto old_ack; + } + + /* If the ack includes data we haven't sent yet, discard + * this segment (RFC793 Section 3.9). + */ + if (after(ack, tp->snd_nxt)) + return -1; + + if (after(ack, prior_snd_una)) { + flag |= FLAG_SND_UNA_ADVANCED; + icsk->icsk_retransmits = 0; + +#if IS_ENABLED(CONFIG_TLS_DEVICE) + if (static_branch_unlikely(&clean_acked_data_enabled.key)) + if (icsk->icsk_clean_acked) + icsk->icsk_clean_acked(sk, ack); +#endif + } + + prior_fack = tcp_is_sack(tp) ? tcp_highest_sack_seq(tp) : tp->snd_una; + rs.prior_in_flight = tcp_packets_in_flight(tp); + + /* ts_recent update must be made after we are sure that the packet + * is in window. + */ + if (flag & FLAG_UPDATE_TS_RECENT) + tcp_replace_ts_recent(tp, TCP_SKB_CB(skb)->seq); + + if ((flag & (FLAG_SLOWPATH | FLAG_SND_UNA_ADVANCED)) == + FLAG_SND_UNA_ADVANCED) { + /* Window is constant, pure forward advance. + * No more checks are required. + * Note, we use the fact that SND.UNA>=SND.WL2. + */ + tcp_update_wl(tp, ack_seq); + tcp_snd_una_update(tp, ack); + flag |= FLAG_WIN_UPDATE; + + tcp_in_ack_event(sk, CA_ACK_WIN_UPDATE); + + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHPACKS); + } else { + u32 ack_ev_flags = CA_ACK_SLOWPATH; + + if (ack_seq != TCP_SKB_CB(skb)->end_seq) + flag |= FLAG_DATA; + else + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPUREACKS); + + flag |= tcp_ack_update_window(sk, skb, ack, ack_seq); + + if (TCP_SKB_CB(skb)->sacked) + flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una, + &sack_state); + + if (tcp_ecn_rcv_ecn_echo(tp, tcp_hdr(skb))) { + flag |= FLAG_ECE; + ack_ev_flags |= CA_ACK_ECE; + } + + if (sack_state.sack_delivered) + tcp_count_delivered(tp, sack_state.sack_delivered, + flag & FLAG_ECE); + + if (flag & FLAG_WIN_UPDATE) + ack_ev_flags |= CA_ACK_WIN_UPDATE; + + tcp_in_ack_event(sk, ack_ev_flags); + } + + /* This is a deviation from RFC3168 since it states that: + * "When the TCP data sender is ready to set the CWR bit after reducing + * the congestion window, it SHOULD set the CWR bit only on the first + * new data packet that it transmits." + * We accept CWR on pure ACKs to be more robust + * with widely-deployed TCP implementations that do this. + */ + tcp_ecn_accept_cwr(sk, skb); + + /* We passed data and got it acked, remove any soft error + * log. Something worked... + */ + sk->sk_err_soft = 0; + icsk->icsk_probes_out = 0; + tp->rcv_tstamp = tcp_jiffies32; + if (!prior_packets) + goto no_queue; + + /* See if we can take anything off of the retransmit queue. */ + flag |= tcp_clean_rtx_queue(sk, prior_fack, prior_snd_una, &sack_state, + flag & FLAG_ECE); + + tcp_rack_update_reo_wnd(sk, &rs); + + if (tp->tlp_high_seq) + tcp_process_tlp_ack(sk, ack, flag); + + if (tcp_ack_is_dubious(sk, flag)) { + if (!(flag & (FLAG_SND_UNA_ADVANCED | + FLAG_NOT_DUP | FLAG_DSACKING_ACK))) { + num_dupack = 1; + /* Consider if pure acks were aggregated in tcp_add_backlog() */ + if (!(flag & FLAG_DATA)) + num_dupack = max_t(u16, 1, skb_shinfo(skb)->gso_segs); + } + tcp_fastretrans_alert(sk, prior_snd_una, num_dupack, &flag, + &rexmit); + } + + /* If needed, reset TLP/RTO timer when RACK doesn't set. */ + if (flag & FLAG_SET_XMIT_TIMER) + tcp_set_xmit_timer(sk); + + if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP)) + sk_dst_confirm(sk); + + delivered = tcp_newly_delivered(sk, delivered, flag); + lost = tp->lost - lost; /* freshly marked lost */ + rs.is_ack_delayed = !!(flag & FLAG_ACK_MAYBE_DELAYED); + tcp_rate_gen(sk, delivered, lost, is_sack_reneg, sack_state.rate); + tcp_cong_control(sk, ack, delivered, flag, sack_state.rate); + tcp_xmit_recovery(sk, rexmit); + return 1; + +no_queue: + /* If data was DSACKed, see if we can undo a cwnd reduction. */ + if (flag & FLAG_DSACKING_ACK) { + tcp_fastretrans_alert(sk, prior_snd_una, num_dupack, &flag, + &rexmit); + tcp_newly_delivered(sk, delivered, flag); + } + /* If this ack opens up a zero window, clear backoff. It was + * being used to time the probes, and is probably far higher than + * it needs to be for normal retransmission. + */ + tcp_ack_probe(sk); + + if (tp->tlp_high_seq) + tcp_process_tlp_ack(sk, ack, flag); + return 1; + +old_ack: + /* If data was SACKed, tag it and see if we should send more data. + * If data was DSACKed, see if we can undo a cwnd reduction. + */ + if (TCP_SKB_CB(skb)->sacked) { + flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una, + &sack_state); + tcp_fastretrans_alert(sk, prior_snd_una, num_dupack, &flag, + &rexmit); + tcp_newly_delivered(sk, delivered, flag); + tcp_xmit_recovery(sk, rexmit); + } + + return 0; +} + +static void tcp_parse_fastopen_option(int len, const unsigned char *cookie, + bool syn, struct tcp_fastopen_cookie *foc, + bool exp_opt) +{ + /* Valid only in SYN or SYN-ACK with an even length. */ + if (!foc || !syn || len < 0 || (len & 1)) + return; + + if (len >= TCP_FASTOPEN_COOKIE_MIN && + len <= TCP_FASTOPEN_COOKIE_MAX) + memcpy(foc->val, cookie, len); + else if (len != 0) + len = -1; + foc->len = len; + foc->exp = exp_opt; +} + +static bool smc_parse_options(const struct tcphdr *th, + struct tcp_options_received *opt_rx, + const unsigned char *ptr, + int opsize) +{ +#if IS_ENABLED(CONFIG_SMC) + if (static_branch_unlikely(&tcp_have_smc)) { + if (th->syn && !(opsize & 1) && + opsize >= TCPOLEN_EXP_SMC_BASE && + get_unaligned_be32(ptr) == TCPOPT_SMC_MAGIC) { + opt_rx->smc_ok = 1; + return true; + } + } +#endif + return false; +} + +/* Try to parse the MSS option from the TCP header. Return 0 on failure, clamped + * value on success. + */ +static u16 tcp_parse_mss_option(const struct tcphdr *th, u16 user_mss) +{ + const unsigned char *ptr = (const unsigned char *)(th + 1); + int length = (th->doff * 4) - sizeof(struct tcphdr); + u16 mss = 0; + + while (length > 0) { + int opcode = *ptr++; + int opsize; + + switch (opcode) { + case TCPOPT_EOL: + return mss; + case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ + length--; + continue; + default: + if (length < 2) + return mss; + opsize = *ptr++; + if (opsize < 2) /* "silly options" */ + return mss; + if (opsize > length) + return mss; /* fail on partial options */ + if (opcode == TCPOPT_MSS && opsize == TCPOLEN_MSS) { + u16 in_mss = get_unaligned_be16(ptr); + + if (in_mss) { + if (user_mss && user_mss < in_mss) + in_mss = user_mss; + mss = in_mss; + } + } + ptr += opsize - 2; + length -= opsize; + } + } + return mss; +} + +/* Look for tcp options. Normally only called on SYN and SYNACK packets. + * But, this can also be called on packets in the established flow when + * the fast version below fails. + */ +void tcp_parse_options(const struct net *net, + const struct sk_buff *skb, + struct tcp_options_received *opt_rx, int estab, + struct tcp_fastopen_cookie *foc) +{ + const unsigned char *ptr; + const struct tcphdr *th = tcp_hdr(skb); + int length = (th->doff * 4) - sizeof(struct tcphdr); + + ptr = (const unsigned char *)(th + 1); + opt_rx->saw_tstamp = 0; + opt_rx->saw_unknown = 0; + + while (length > 0) { + int opcode = *ptr++; + int opsize; + + switch (opcode) { + case TCPOPT_EOL: + return; + case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ + length--; + continue; + default: + if (length < 2) + return; + opsize = *ptr++; + if (opsize < 2) /* "silly options" */ + return; + if (opsize > length) + return; /* don't parse partial options */ + switch (opcode) { + case TCPOPT_MSS: + if (opsize == TCPOLEN_MSS && th->syn && !estab) { + u16 in_mss = get_unaligned_be16(ptr); + if (in_mss) { + if (opt_rx->user_mss && + opt_rx->user_mss < in_mss) + in_mss = opt_rx->user_mss; + opt_rx->mss_clamp = in_mss; + } + } + break; + case TCPOPT_WINDOW: + if (opsize == TCPOLEN_WINDOW && th->syn && + !estab && READ_ONCE(net->ipv4.sysctl_tcp_window_scaling)) { + __u8 snd_wscale = *(__u8 *)ptr; + opt_rx->wscale_ok = 1; + if (snd_wscale > TCP_MAX_WSCALE) { + net_info_ratelimited("%s: Illegal window scaling value %d > %u received\n", + __func__, + snd_wscale, + TCP_MAX_WSCALE); + snd_wscale = TCP_MAX_WSCALE; + } + opt_rx->snd_wscale = snd_wscale; + } + break; + case TCPOPT_TIMESTAMP: + if ((opsize == TCPOLEN_TIMESTAMP) && + ((estab && opt_rx->tstamp_ok) || + (!estab && READ_ONCE(net->ipv4.sysctl_tcp_timestamps)))) { + opt_rx->saw_tstamp = 1; + opt_rx->rcv_tsval = get_unaligned_be32(ptr); + opt_rx->rcv_tsecr = get_unaligned_be32(ptr + 4); + } + break; + case TCPOPT_SACK_PERM: + if (opsize == TCPOLEN_SACK_PERM && th->syn && + !estab && READ_ONCE(net->ipv4.sysctl_tcp_sack)) { + opt_rx->sack_ok = TCP_SACK_SEEN; + tcp_sack_reset(opt_rx); + } + break; + + case TCPOPT_SACK: + if ((opsize >= (TCPOLEN_SACK_BASE + TCPOLEN_SACK_PERBLOCK)) && + !((opsize - TCPOLEN_SACK_BASE) % TCPOLEN_SACK_PERBLOCK) && + opt_rx->sack_ok) { + TCP_SKB_CB(skb)->sacked = (ptr - 2) - (unsigned char *)th; + } + break; +#ifdef CONFIG_TCP_MD5SIG + case TCPOPT_MD5SIG: + /* + * The MD5 Hash has already been + * checked (see tcp_v{4,6}_do_rcv()). + */ + break; +#endif + case TCPOPT_FASTOPEN: + tcp_parse_fastopen_option( + opsize - TCPOLEN_FASTOPEN_BASE, + ptr, th->syn, foc, false); + break; + + case TCPOPT_EXP: + /* Fast Open option shares code 254 using a + * 16 bits magic number. + */ + if (opsize >= TCPOLEN_EXP_FASTOPEN_BASE && + get_unaligned_be16(ptr) == + TCPOPT_FASTOPEN_MAGIC) { + tcp_parse_fastopen_option(opsize - + TCPOLEN_EXP_FASTOPEN_BASE, + ptr + 2, th->syn, foc, true); + break; + } + + if (smc_parse_options(th, opt_rx, ptr, opsize)) + break; + + opt_rx->saw_unknown = 1; + break; + + default: + opt_rx->saw_unknown = 1; + } + ptr += opsize-2; + length -= opsize; + } + } +} +EXPORT_SYMBOL(tcp_parse_options); + +static bool tcp_parse_aligned_timestamp(struct tcp_sock *tp, const struct tcphdr *th) +{ + const __be32 *ptr = (const __be32 *)(th + 1); + + if (*ptr == htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) + | (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)) { + tp->rx_opt.saw_tstamp = 1; + ++ptr; + tp->rx_opt.rcv_tsval = ntohl(*ptr); + ++ptr; + if (*ptr) + tp->rx_opt.rcv_tsecr = ntohl(*ptr) - tp->tsoffset; + else + tp->rx_opt.rcv_tsecr = 0; + return true; + } + return false; +} + +/* Fast parse options. This hopes to only see timestamps. + * If it is wrong it falls back on tcp_parse_options(). + */ +static bool tcp_fast_parse_options(const struct net *net, + const struct sk_buff *skb, + const struct tcphdr *th, struct tcp_sock *tp) +{ + /* In the spirit of fast parsing, compare doff directly to constant + * values. Because equality is used, short doff can be ignored here. + */ + if (th->doff == (sizeof(*th) / 4)) { + tp->rx_opt.saw_tstamp = 0; + return false; + } else if (tp->rx_opt.tstamp_ok && + th->doff == ((sizeof(*th) + TCPOLEN_TSTAMP_ALIGNED) / 4)) { + if (tcp_parse_aligned_timestamp(tp, th)) + return true; + } + + tcp_parse_options(net, skb, &tp->rx_opt, 1, NULL); + if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr) + tp->rx_opt.rcv_tsecr -= tp->tsoffset; + + return true; +} + +#ifdef CONFIG_TCP_MD5SIG +/* + * Parse MD5 Signature option + */ +const u8 *tcp_parse_md5sig_option(const struct tcphdr *th) +{ + int length = (th->doff << 2) - sizeof(*th); + const u8 *ptr = (const u8 *)(th + 1); + + /* If not enough data remaining, we can short cut */ + while (length >= TCPOLEN_MD5SIG) { + int opcode = *ptr++; + int opsize; + + switch (opcode) { + case TCPOPT_EOL: + return NULL; + case TCPOPT_NOP: + length--; + continue; + default: + opsize = *ptr++; + if (opsize < 2 || opsize > length) + return NULL; + if (opcode == TCPOPT_MD5SIG) + return opsize == TCPOLEN_MD5SIG ? ptr : NULL; + } + ptr += opsize - 2; + length -= opsize; + } + return NULL; +} +EXPORT_SYMBOL(tcp_parse_md5sig_option); +#endif + +/* Sorry, PAWS as specified is broken wrt. pure-ACKs -DaveM + * + * It is not fatal. If this ACK does _not_ change critical state (seqs, window) + * it can pass through stack. So, the following predicate verifies that + * this segment is not used for anything but congestion avoidance or + * fast retransmit. Moreover, we even are able to eliminate most of such + * second order effects, if we apply some small "replay" window (~RTO) + * to timestamp space. + * + * All these measures still do not guarantee that we reject wrapped ACKs + * on networks with high bandwidth, when sequence space is recycled fastly, + * but it guarantees that such events will be very rare and do not affect + * connection seriously. This doesn't look nice, but alas, PAWS is really + * buggy extension. + * + * [ Later note. Even worse! It is buggy for segments _with_ data. RFC + * states that events when retransmit arrives after original data are rare. + * It is a blatant lie. VJ forgot about fast retransmit! 8)8) It is + * the biggest problem on large power networks even with minor reordering. + * OK, let's give it small replay window. If peer clock is even 1hz, it is safe + * up to bandwidth of 18Gigabit/sec. 8) ] + */ + +static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const struct tcphdr *th = tcp_hdr(skb); + u32 seq = TCP_SKB_CB(skb)->seq; + u32 ack = TCP_SKB_CB(skb)->ack_seq; + + return (/* 1. Pure ACK with correct sequence number. */ + (th->ack && seq == TCP_SKB_CB(skb)->end_seq && seq == tp->rcv_nxt) && + + /* 2. ... and duplicate ACK. */ + ack == tp->snd_una && + + /* 3. ... and does not update window. */ + !tcp_may_update_window(tp, ack, seq, ntohs(th->window) << tp->rx_opt.snd_wscale) && + + /* 4. ... and sits in replay window. */ + (s32)(tp->rx_opt.ts_recent - tp->rx_opt.rcv_tsval) <= (inet_csk(sk)->icsk_rto * 1024) / HZ); +} + +static inline bool tcp_paws_discard(const struct sock *sk, + const struct sk_buff *skb) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + return !tcp_paws_check(&tp->rx_opt, TCP_PAWS_WINDOW) && + !tcp_disordered_ack(sk, skb); +} + +/* Check segment sequence number for validity. + * + * Segment controls are considered valid, if the segment + * fits to the window after truncation to the window. Acceptability + * of data (and SYN, FIN, of course) is checked separately. + * See tcp_data_queue(), for example. + * + * Also, controls (RST is main one) are accepted using RCV.WUP instead + * of RCV.NXT. Peer still did not advance his SND.UNA when we + * delayed ACK, so that hisSND.UNA<=ourRCV.WUP. + * (borrowed from freebsd) + */ + +static inline bool tcp_sequence(const struct tcp_sock *tp, u32 seq, u32 end_seq) +{ + return !before(end_seq, tp->rcv_wup) && + !after(seq, tp->rcv_nxt + tcp_receive_window(tp)); +} + +/* When we get a reset we do this. */ +void tcp_reset(struct sock *sk) +{ + trace_tcp_receive_reset(sk); + + /* We want the right error as BSD sees it (and indeed as we do). */ + switch (sk->sk_state) { + case TCP_SYN_SENT: + sk->sk_err = ECONNREFUSED; + break; + case TCP_CLOSE_WAIT: + sk->sk_err = EPIPE; + break; + case TCP_CLOSE: + return; + default: + sk->sk_err = ECONNRESET; + } + /* This barrier is coupled with smp_rmb() in tcp_poll() */ + smp_wmb(); + + tcp_write_queue_purge(sk); + tcp_done(sk); + + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_error_report(sk); +} + +/* + * Process the FIN bit. This now behaves as it is supposed to work + * and the FIN takes effect when it is validly part of sequence + * space. Not before when we get holes. + * + * If we are ESTABLISHED, a received fin moves us to CLOSE-WAIT + * (and thence onto LAST-ACK and finally, CLOSE, we never enter + * TIME-WAIT) + * + * If we are in FINWAIT-1, a received FIN indicates simultaneous + * close and we go into CLOSING (and later onto TIME-WAIT) + * + * If we are in FINWAIT-2, a received FIN moves us to TIME-WAIT. + */ +void tcp_fin(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + inet_csk_schedule_ack(sk); + + WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | RCV_SHUTDOWN); + sock_set_flag(sk, SOCK_DONE); + + switch (sk->sk_state) { + case TCP_SYN_RECV: + case TCP_ESTABLISHED: + /* Move to CLOSE_WAIT */ + tcp_set_state(sk, TCP_CLOSE_WAIT); + inet_csk_enter_pingpong_mode(sk); + break; + + case TCP_CLOSE_WAIT: + case TCP_CLOSING: + /* Received a retransmission of the FIN, do + * nothing. + */ + break; + case TCP_LAST_ACK: + /* RFC793: Remain in the LAST-ACK state. */ + break; + + case TCP_FIN_WAIT1: + /* This case occurs when a simultaneous close + * happens, we must ack the received FIN and + * enter the CLOSING state. + */ + tcp_send_ack(sk); + tcp_set_state(sk, TCP_CLOSING); + break; + case TCP_FIN_WAIT2: + /* Received a FIN -- send ACK and enter TIME_WAIT. */ + tcp_send_ack(sk); + tcp_time_wait(sk, TCP_TIME_WAIT, 0); + break; + default: + /* Only TCP_LISTEN and TCP_CLOSE are left, in these + * cases we should never reach this piece of code. + */ + pr_err("%s: Impossible, sk->sk_state=%d\n", + __func__, sk->sk_state); + break; + } + + /* It _is_ possible, that we have something out-of-order _after_ FIN. + * Probably, we should reset in this case. For now drop them. + */ + skb_rbtree_purge(&tp->out_of_order_queue); + if (tcp_is_sack(tp)) + tcp_sack_reset(&tp->rx_opt); + sk_mem_reclaim(sk); + + if (!sock_flag(sk, SOCK_DEAD)) { + sk->sk_state_change(sk); + + /* Do not send POLL_HUP for half duplex close. */ + if (sk->sk_shutdown == SHUTDOWN_MASK || + sk->sk_state == TCP_CLOSE) + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); + else + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); + } +} + +static inline bool tcp_sack_extend(struct tcp_sack_block *sp, u32 seq, + u32 end_seq) +{ + if (!after(seq, sp->end_seq) && !after(sp->start_seq, end_seq)) { + if (before(seq, sp->start_seq)) + sp->start_seq = seq; + if (after(end_seq, sp->end_seq)) + sp->end_seq = end_seq; + return true; + } + return false; +} + +static void tcp_dsack_set(struct sock *sk, u32 seq, u32 end_seq) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tcp_is_sack(tp) && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_dsack)) { + int mib_idx; + + if (before(seq, tp->rcv_nxt)) + mib_idx = LINUX_MIB_TCPDSACKOLDSENT; + else + mib_idx = LINUX_MIB_TCPDSACKOFOSENT; + + NET_INC_STATS(sock_net(sk), mib_idx); + + tp->rx_opt.dsack = 1; + tp->duplicate_sack[0].start_seq = seq; + tp->duplicate_sack[0].end_seq = end_seq; + } +} + +static void tcp_dsack_extend(struct sock *sk, u32 seq, u32 end_seq) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (!tp->rx_opt.dsack) + tcp_dsack_set(sk, seq, end_seq); + else + tcp_sack_extend(tp->duplicate_sack, seq, end_seq); +} + +static void tcp_rcv_spurious_retrans(struct sock *sk, const struct sk_buff *skb) +{ + /* When the ACK path fails or drops most ACKs, the sender would + * timeout and spuriously retransmit the same segment repeatedly. + * The receiver remembers and reflects via DSACKs. Leverage the + * DSACK state and change the txhash to re-route speculatively. + */ + if (TCP_SKB_CB(skb)->seq == tcp_sk(sk)->duplicate_sack[0].start_seq && + sk_rethink_txhash(sk)) + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPDUPLICATEDATAREHASH); +} + +static void tcp_send_dupack(struct sock *sk, const struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq && + before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOST); + tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS); + + if (tcp_is_sack(tp) && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_dsack)) { + u32 end_seq = TCP_SKB_CB(skb)->end_seq; + + tcp_rcv_spurious_retrans(sk, skb); + if (after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) + end_seq = tp->rcv_nxt; + tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, end_seq); + } + } + + tcp_send_ack(sk); +} + +/* These routines update the SACK block as out-of-order packets arrive or + * in-order packets close up the sequence space. + */ +static void tcp_sack_maybe_coalesce(struct tcp_sock *tp) +{ + int this_sack; + struct tcp_sack_block *sp = &tp->selective_acks[0]; + struct tcp_sack_block *swalk = sp + 1; + + /* See if the recent change to the first SACK eats into + * or hits the sequence space of other SACK blocks, if so coalesce. + */ + for (this_sack = 1; this_sack < tp->rx_opt.num_sacks;) { + if (tcp_sack_extend(sp, swalk->start_seq, swalk->end_seq)) { + int i; + + /* Zap SWALK, by moving every further SACK up by one slot. + * Decrease num_sacks. + */ + tp->rx_opt.num_sacks--; + for (i = this_sack; i < tp->rx_opt.num_sacks; i++) + sp[i] = sp[i + 1]; + continue; + } + this_sack++; + swalk++; + } +} + +static void tcp_sack_compress_send_ack(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (!tp->compressed_ack) + return; + + if (hrtimer_try_to_cancel(&tp->compressed_ack_timer) == 1) + __sock_put(sk); + + /* Since we have to send one ack finally, + * substract one from tp->compressed_ack to keep + * LINUX_MIB_TCPACKCOMPRESSED accurate. + */ + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPACKCOMPRESSED, + tp->compressed_ack - 1); + + tp->compressed_ack = 0; + tcp_send_ack(sk); +} + +/* Reasonable amount of sack blocks included in TCP SACK option + * The max is 4, but this becomes 3 if TCP timestamps are there. + * Given that SACK packets might be lost, be conservative and use 2. + */ +#define TCP_SACK_BLOCKS_EXPECTED 2 + +static void tcp_sack_new_ofo_skb(struct sock *sk, u32 seq, u32 end_seq) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_sack_block *sp = &tp->selective_acks[0]; + int cur_sacks = tp->rx_opt.num_sacks; + int this_sack; + + if (!cur_sacks) + goto new_sack; + + for (this_sack = 0; this_sack < cur_sacks; this_sack++, sp++) { + if (tcp_sack_extend(sp, seq, end_seq)) { + if (this_sack >= TCP_SACK_BLOCKS_EXPECTED) + tcp_sack_compress_send_ack(sk); + /* Rotate this_sack to the first one. */ + for (; this_sack > 0; this_sack--, sp--) + swap(*sp, *(sp - 1)); + if (cur_sacks > 1) + tcp_sack_maybe_coalesce(tp); + return; + } + } + + if (this_sack >= TCP_SACK_BLOCKS_EXPECTED) + tcp_sack_compress_send_ack(sk); + + /* Could not find an adjacent existing SACK, build a new one, + * put it at the front, and shift everyone else down. We + * always know there is at least one SACK present already here. + * + * If the sack array is full, forget about the last one. + */ + if (this_sack >= TCP_NUM_SACKS) { + this_sack--; + tp->rx_opt.num_sacks--; + sp--; + } + for (; this_sack > 0; this_sack--, sp--) + *sp = *(sp - 1); + +new_sack: + /* Build the new head SACK, and we're done. */ + sp->start_seq = seq; + sp->end_seq = end_seq; + tp->rx_opt.num_sacks++; +} + +/* RCV.NXT advances, some SACKs should be eaten. */ + +static void tcp_sack_remove(struct tcp_sock *tp) +{ + struct tcp_sack_block *sp = &tp->selective_acks[0]; + int num_sacks = tp->rx_opt.num_sacks; + int this_sack; + + /* Empty ofo queue, hence, all the SACKs are eaten. Clear. */ + if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) { + tp->rx_opt.num_sacks = 0; + return; + } + + for (this_sack = 0; this_sack < num_sacks;) { + /* Check if the start of the sack is covered by RCV.NXT. */ + if (!before(tp->rcv_nxt, sp->start_seq)) { + int i; + + /* RCV.NXT must cover all the block! */ + WARN_ON(before(tp->rcv_nxt, sp->end_seq)); + + /* Zap this SACK, by moving forward any other SACKS. */ + for (i = this_sack+1; i < num_sacks; i++) + tp->selective_acks[i-1] = tp->selective_acks[i]; + num_sacks--; + continue; + } + this_sack++; + sp++; + } + tp->rx_opt.num_sacks = num_sacks; +} + +/** + * tcp_try_coalesce - try to merge skb to prior one + * @sk: socket + * @to: prior buffer + * @from: buffer to add in queue + * @fragstolen: pointer to boolean + * + * Before queueing skb @from after @to, try to merge them + * to reduce overall memory use and queue lengths, if cost is small. + * Packets in ofo or receive queues can stay a long time. + * Better try to coalesce them right now to avoid future collapses. + * Returns true if caller should free @from instead of queueing it + */ +static bool tcp_try_coalesce(struct sock *sk, + struct sk_buff *to, + struct sk_buff *from, + bool *fragstolen) +{ + int delta; + + *fragstolen = false; + + /* Its possible this segment overlaps with prior segment in queue */ + if (TCP_SKB_CB(from)->seq != TCP_SKB_CB(to)->end_seq) + return false; + + if (!mptcp_skb_can_collapse(to, from)) + return false; + +#ifdef CONFIG_TLS_DEVICE + if (from->decrypted != to->decrypted) + return false; +#endif + + if (!skb_try_coalesce(to, from, fragstolen, &delta)) + return false; + + atomic_add(delta, &sk->sk_rmem_alloc); + sk_mem_charge(sk, delta); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVCOALESCE); + TCP_SKB_CB(to)->end_seq = TCP_SKB_CB(from)->end_seq; + TCP_SKB_CB(to)->ack_seq = TCP_SKB_CB(from)->ack_seq; + TCP_SKB_CB(to)->tcp_flags |= TCP_SKB_CB(from)->tcp_flags; + + if (TCP_SKB_CB(from)->has_rxtstamp) { + TCP_SKB_CB(to)->has_rxtstamp = true; + to->tstamp = from->tstamp; + skb_hwtstamps(to)->hwtstamp = skb_hwtstamps(from)->hwtstamp; + } + + return true; +} + +static bool tcp_ooo_try_coalesce(struct sock *sk, + struct sk_buff *to, + struct sk_buff *from, + bool *fragstolen) +{ + bool res = tcp_try_coalesce(sk, to, from, fragstolen); + + /* In case tcp_drop() is called later, update to->gso_segs */ + if (res) { + u32 gso_segs = max_t(u16, 1, skb_shinfo(to)->gso_segs) + + max_t(u16, 1, skb_shinfo(from)->gso_segs); + + skb_shinfo(to)->gso_segs = min_t(u32, gso_segs, 0xFFFF); + } + return res; +} + +static void tcp_drop(struct sock *sk, struct sk_buff *skb) +{ + sk_drops_add(sk, skb); + __kfree_skb(skb); +} + +/* This one checks to see if we can put data from the + * out_of_order queue into the receive_queue. + */ +static void tcp_ofo_queue(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + __u32 dsack_high = tp->rcv_nxt; + bool fin, fragstolen, eaten; + struct sk_buff *skb, *tail; + struct rb_node *p; + + p = rb_first(&tp->out_of_order_queue); + while (p) { + skb = rb_to_skb(p); + if (after(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) + break; + + if (before(TCP_SKB_CB(skb)->seq, dsack_high)) { + __u32 dsack = dsack_high; + if (before(TCP_SKB_CB(skb)->end_seq, dsack_high)) + dsack_high = TCP_SKB_CB(skb)->end_seq; + tcp_dsack_extend(sk, TCP_SKB_CB(skb)->seq, dsack); + } + p = rb_next(p); + rb_erase(&skb->rbnode, &tp->out_of_order_queue); + + if (unlikely(!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))) { + tcp_drop(sk, skb); + continue; + } + + tail = skb_peek_tail(&sk->sk_receive_queue); + eaten = tail && tcp_try_coalesce(sk, tail, skb, &fragstolen); + tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq); + fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; + if (!eaten) + __skb_queue_tail(&sk->sk_receive_queue, skb); + else + kfree_skb_partial(skb, fragstolen); + + if (unlikely(fin)) { + tcp_fin(sk); + /* tcp_fin() purges tp->out_of_order_queue, + * so we must end this loop right now. + */ + break; + } + } +} + +static bool tcp_prune_ofo_queue(struct sock *sk); +static int tcp_prune_queue(struct sock *sk); + +static int tcp_try_rmem_schedule(struct sock *sk, struct sk_buff *skb, + unsigned int size) +{ + if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || + !sk_rmem_schedule(sk, skb, size)) { + + if (tcp_prune_queue(sk) < 0) + return -1; + + while (!sk_rmem_schedule(sk, skb, size)) { + if (!tcp_prune_ofo_queue(sk)) + return -1; + } + } + return 0; +} + +static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct rb_node **p, *parent; + struct sk_buff *skb1; + u32 seq, end_seq; + bool fragstolen; + + tcp_ecn_check_ce(sk, skb); + + if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFODROP); + sk->sk_data_ready(sk); + tcp_drop(sk, skb); + return; + } + + /* Disable header prediction. */ + tp->pred_flags = 0; + inet_csk_schedule_ack(sk); + + tp->rcv_ooopack += max_t(u16, 1, skb_shinfo(skb)->gso_segs); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOQUEUE); + seq = TCP_SKB_CB(skb)->seq; + end_seq = TCP_SKB_CB(skb)->end_seq; + + p = &tp->out_of_order_queue.rb_node; + if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) { + /* Initial out of order segment, build 1 SACK. */ + if (tcp_is_sack(tp)) { + tp->rx_opt.num_sacks = 1; + tp->selective_acks[0].start_seq = seq; + tp->selective_acks[0].end_seq = end_seq; + } + rb_link_node(&skb->rbnode, NULL, p); + rb_insert_color(&skb->rbnode, &tp->out_of_order_queue); + tp->ooo_last_skb = skb; + goto end; + } + + /* In the typical case, we are adding an skb to the end of the list. + * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup. + */ + if (tcp_ooo_try_coalesce(sk, tp->ooo_last_skb, + skb, &fragstolen)) { +coalesce_done: + /* For non sack flows, do not grow window to force DUPACK + * and trigger fast retransmit. + */ + if (tcp_is_sack(tp)) + tcp_grow_window(sk, skb, true); + kfree_skb_partial(skb, fragstolen); + skb = NULL; + goto add_sack; + } + /* Can avoid an rbtree lookup if we are adding skb after ooo_last_skb */ + if (!before(seq, TCP_SKB_CB(tp->ooo_last_skb)->end_seq)) { + parent = &tp->ooo_last_skb->rbnode; + p = &parent->rb_right; + goto insert; + } + + /* Find place to insert this segment. Handle overlaps on the way. */ + parent = NULL; + while (*p) { + parent = *p; + skb1 = rb_to_skb(parent); + if (before(seq, TCP_SKB_CB(skb1)->seq)) { + p = &parent->rb_left; + continue; + } + if (before(seq, TCP_SKB_CB(skb1)->end_seq)) { + if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) { + /* All the bits are present. Drop. */ + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPOFOMERGE); + tcp_drop(sk, skb); + skb = NULL; + tcp_dsack_set(sk, seq, end_seq); + goto add_sack; + } + if (after(seq, TCP_SKB_CB(skb1)->seq)) { + /* Partial overlap. */ + tcp_dsack_set(sk, seq, TCP_SKB_CB(skb1)->end_seq); + } else { + /* skb's seq == skb1's seq and skb covers skb1. + * Replace skb1 with skb. + */ + rb_replace_node(&skb1->rbnode, &skb->rbnode, + &tp->out_of_order_queue); + tcp_dsack_extend(sk, + TCP_SKB_CB(skb1)->seq, + TCP_SKB_CB(skb1)->end_seq); + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPOFOMERGE); + tcp_drop(sk, skb1); + goto merge_right; + } + } else if (tcp_ooo_try_coalesce(sk, skb1, + skb, &fragstolen)) { + goto coalesce_done; + } + p = &parent->rb_right; + } +insert: + /* Insert segment into RB tree. */ + rb_link_node(&skb->rbnode, parent, p); + rb_insert_color(&skb->rbnode, &tp->out_of_order_queue); + +merge_right: + /* Remove other segments covered by skb. */ + while ((skb1 = skb_rb_next(skb)) != NULL) { + if (!after(end_seq, TCP_SKB_CB(skb1)->seq)) + break; + if (before(end_seq, TCP_SKB_CB(skb1)->end_seq)) { + tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq, + end_seq); + break; + } + rb_erase(&skb1->rbnode, &tp->out_of_order_queue); + tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq, + TCP_SKB_CB(skb1)->end_seq); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE); + tcp_drop(sk, skb1); + } + /* If there is no skb after us, we are the last_skb ! */ + if (!skb1) + tp->ooo_last_skb = skb; + +add_sack: + if (tcp_is_sack(tp)) + tcp_sack_new_ofo_skb(sk, seq, end_seq); +end: + if (skb) { + /* For non sack flows, do not grow window to force DUPACK + * and trigger fast retransmit. + */ + if (tcp_is_sack(tp)) + tcp_grow_window(sk, skb, false); + skb_condense(skb); + skb_set_owner_r(skb, sk); + } +} + +static int __must_check tcp_queue_rcv(struct sock *sk, struct sk_buff *skb, + bool *fragstolen) +{ + int eaten; + struct sk_buff *tail = skb_peek_tail(&sk->sk_receive_queue); + + eaten = (tail && + tcp_try_coalesce(sk, tail, + skb, fragstolen)) ? 1 : 0; + tcp_rcv_nxt_update(tcp_sk(sk), TCP_SKB_CB(skb)->end_seq); + if (!eaten) { + __skb_queue_tail(&sk->sk_receive_queue, skb); + skb_set_owner_r(skb, sk); + } + return eaten; +} + +int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size) +{ + struct sk_buff *skb; + int err = -ENOMEM; + int data_len = 0; + bool fragstolen; + + if (size == 0) + return 0; + + if (size > PAGE_SIZE) { + int npages = min_t(size_t, size >> PAGE_SHIFT, MAX_SKB_FRAGS); + + data_len = npages << PAGE_SHIFT; + size = data_len + (size & ~PAGE_MASK); + } + skb = alloc_skb_with_frags(size - data_len, data_len, + PAGE_ALLOC_COSTLY_ORDER, + &err, sk->sk_allocation); + if (!skb) + goto err; + + skb_put(skb, size - data_len); + skb->data_len = data_len; + skb->len = size; + + if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP); + goto err_free; + } + + err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); + if (err) + goto err_free; + + TCP_SKB_CB(skb)->seq = tcp_sk(sk)->rcv_nxt; + TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + size; + TCP_SKB_CB(skb)->ack_seq = tcp_sk(sk)->snd_una - 1; + + if (tcp_queue_rcv(sk, skb, &fragstolen)) { + WARN_ON_ONCE(fragstolen); /* should not happen */ + __kfree_skb(skb); + } + return size; + +err_free: + kfree_skb(skb); +err: + return err; + +} + +void tcp_data_ready(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + int avail = tp->rcv_nxt - tp->copied_seq; + + if (avail < sk->sk_rcvlowat && !tcp_rmem_pressure(sk) && + !sock_flag(sk, SOCK_DONE) && + tcp_receive_window(tp) > inet_csk(sk)->icsk_ack.rcv_mss) + return; + + sk->sk_data_ready(sk); +} + +static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + bool fragstolen; + int eaten; + + if (sk_is_mptcp(sk)) + mptcp_incoming_options(sk, skb); + + if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { + __kfree_skb(skb); + return; + } + skb_dst_drop(skb); + __skb_pull(skb, tcp_hdr(skb)->doff * 4); + + tp->rx_opt.dsack = 0; + + /* Queue data for delivery to the user. + * Packets in sequence go to the receive queue. + * Out of sequence packets to the out_of_order_queue. + */ + if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt) { + if (tcp_receive_window(tp) == 0) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP); + goto out_of_window; + } + + /* Ok. In sequence. In window. */ +queue_and_out: + if (skb_queue_len(&sk->sk_receive_queue) == 0) + sk_forced_mem_schedule(sk, skb->truesize); + else if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP); + sk->sk_data_ready(sk); + goto drop; + } + + eaten = tcp_queue_rcv(sk, skb, &fragstolen); + if (skb->len) + tcp_event_data_recv(sk, skb); + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) + tcp_fin(sk); + + if (!RB_EMPTY_ROOT(&tp->out_of_order_queue)) { + tcp_ofo_queue(sk); + + /* RFC5681. 4.2. SHOULD send immediate ACK, when + * gap in queue is filled. + */ + if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) + inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW; + } + + if (tp->rx_opt.num_sacks) + tcp_sack_remove(tp); + + tcp_fast_path_check(sk); + + if (eaten > 0) + kfree_skb_partial(skb, fragstolen); + if (!sock_flag(sk, SOCK_DEAD)) + tcp_data_ready(sk); + return; + } + + if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) { + tcp_rcv_spurious_retrans(sk, skb); + /* A retransmit, 2nd most common case. Force an immediate ack. */ + NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOST); + tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq); + +out_of_window: + tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS); + inet_csk_schedule_ack(sk); +drop: + tcp_drop(sk, skb); + return; + } + + /* Out of window. F.e. zero window probe. */ + if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt + tcp_receive_window(tp))) + goto out_of_window; + + if (before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) { + /* Partial packet, seq < rcv_next < end_seq */ + tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, tp->rcv_nxt); + + /* If window is closed, drop tail of packet. But after + * remembering D-SACK for its head made in previous line. + */ + if (!tcp_receive_window(tp)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP); + goto out_of_window; + } + goto queue_and_out; + } + + tcp_data_queue_ofo(sk, skb); +} + +static struct sk_buff *tcp_skb_next(struct sk_buff *skb, struct sk_buff_head *list) +{ + if (list) + return !skb_queue_is_last(list, skb) ? skb->next : NULL; + + return skb_rb_next(skb); +} + +static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb, + struct sk_buff_head *list, + struct rb_root *root) +{ + struct sk_buff *next = tcp_skb_next(skb, list); + + if (list) + __skb_unlink(skb, list); + else + rb_erase(&skb->rbnode, root); + + __kfree_skb(skb); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVCOLLAPSED); + + return next; +} + +/* Insert skb into rb tree, ordered by TCP_SKB_CB(skb)->seq */ +void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb) +{ + struct rb_node **p = &root->rb_node; + struct rb_node *parent = NULL; + struct sk_buff *skb1; + + while (*p) { + parent = *p; + skb1 = rb_to_skb(parent); + if (before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb1)->seq)) + p = &parent->rb_left; + else + p = &parent->rb_right; + } + rb_link_node(&skb->rbnode, parent, p); + rb_insert_color(&skb->rbnode, root); +} + +/* Collapse contiguous sequence of skbs head..tail with + * sequence numbers start..end. + * + * If tail is NULL, this means until the end of the queue. + * + * Segments with FIN/SYN are not collapsed (only because this + * simplifies code) + */ +static void +tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, + struct sk_buff *head, struct sk_buff *tail, u32 start, u32 end) +{ + struct sk_buff *skb = head, *n; + struct sk_buff_head tmp; + bool end_of_skbs; + + /* First, check that queue is collapsible and find + * the point where collapsing can be useful. + */ +restart: + for (end_of_skbs = true; skb != NULL && skb != tail; skb = n) { + n = tcp_skb_next(skb, list); + + /* No new bits? It is possible on ofo queue. */ + if (!before(start, TCP_SKB_CB(skb)->end_seq)) { + skb = tcp_collapse_one(sk, skb, list, root); + if (!skb) + break; + goto restart; + } + + /* The first skb to collapse is: + * - not SYN/FIN and + * - bloated or contains data before "start" or + * overlaps to the next one and mptcp allow collapsing. + */ + if (!(TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)) && + (tcp_win_from_space(sk, skb->truesize) > skb->len || + before(TCP_SKB_CB(skb)->seq, start))) { + end_of_skbs = false; + break; + } + + if (n && n != tail && mptcp_skb_can_collapse(skb, n) && + TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(n)->seq) { + end_of_skbs = false; + break; + } + + /* Decided to skip this, advance start seq. */ + start = TCP_SKB_CB(skb)->end_seq; + } + if (end_of_skbs || + (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN))) + return; + + __skb_queue_head_init(&tmp); + + while (before(start, end)) { + int copy = min_t(int, SKB_MAX_ORDER(0, 0), end - start); + struct sk_buff *nskb; + + nskb = alloc_skb(copy, GFP_ATOMIC); + if (!nskb) + break; + + memcpy(nskb->cb, skb->cb, sizeof(skb->cb)); +#ifdef CONFIG_TLS_DEVICE + nskb->decrypted = skb->decrypted; +#endif + TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start; + if (list) + __skb_queue_before(list, skb, nskb); + else + __skb_queue_tail(&tmp, nskb); /* defer rbtree insertion */ + skb_set_owner_r(nskb, sk); + mptcp_skb_ext_move(nskb, skb); + + /* Copy data, releasing collapsed skbs. */ + while (copy > 0) { + int offset = start - TCP_SKB_CB(skb)->seq; + int size = TCP_SKB_CB(skb)->end_seq - start; + + BUG_ON(offset < 0); + if (size > 0) { + size = min(copy, size); + if (skb_copy_bits(skb, offset, skb_put(nskb, size), size)) + BUG(); + TCP_SKB_CB(nskb)->end_seq += size; + copy -= size; + start += size; + } + if (!before(start, TCP_SKB_CB(skb)->end_seq)) { + skb = tcp_collapse_one(sk, skb, list, root); + if (!skb || + skb == tail || + !mptcp_skb_can_collapse(nskb, skb) || + (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN))) + goto end; +#ifdef CONFIG_TLS_DEVICE + if (skb->decrypted != nskb->decrypted) + goto end; +#endif + } + } + } +end: + skb_queue_walk_safe(&tmp, skb, n) + tcp_rbtree_insert(root, skb); +} + +/* Collapse ofo queue. Algorithm: select contiguous sequence of skbs + * and tcp_collapse() them until all the queue is collapsed. + */ +static void tcp_collapse_ofo_queue(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 range_truesize, sum_tiny = 0; + struct sk_buff *skb, *head; + u32 start, end; + + skb = skb_rb_first(&tp->out_of_order_queue); +new_range: + if (!skb) { + tp->ooo_last_skb = skb_rb_last(&tp->out_of_order_queue); + return; + } + start = TCP_SKB_CB(skb)->seq; + end = TCP_SKB_CB(skb)->end_seq; + range_truesize = skb->truesize; + + for (head = skb;;) { + skb = skb_rb_next(skb); + + /* Range is terminated when we see a gap or when + * we are at the queue end. + */ + if (!skb || + after(TCP_SKB_CB(skb)->seq, end) || + before(TCP_SKB_CB(skb)->end_seq, start)) { + /* Do not attempt collapsing tiny skbs */ + if (range_truesize != head->truesize || + end - start >= SKB_WITH_OVERHEAD(SK_MEM_QUANTUM)) { + tcp_collapse(sk, NULL, &tp->out_of_order_queue, + head, skb, start, end); + } else { + sum_tiny += range_truesize; + if (sum_tiny > sk->sk_rcvbuf >> 3) + return; + } + goto new_range; + } + + range_truesize += skb->truesize; + if (unlikely(before(TCP_SKB_CB(skb)->seq, start))) + start = TCP_SKB_CB(skb)->seq; + if (after(TCP_SKB_CB(skb)->end_seq, end)) + end = TCP_SKB_CB(skb)->end_seq; + } +} + +/* + * Clean the out-of-order queue to make room. + * We drop high sequences packets to : + * 1) Let a chance for holes to be filled. + * 2) not add too big latencies if thousands of packets sit there. + * (But if application shrinks SO_RCVBUF, we could still end up + * freeing whole queue here) + * 3) Drop at least 12.5 % of sk_rcvbuf to avoid malicious attacks. + * + * Return true if queue has shrunk. + */ +static bool tcp_prune_ofo_queue(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct rb_node *node, *prev; + int goal; + + if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) + return false; + + NET_INC_STATS(sock_net(sk), LINUX_MIB_OFOPRUNED); + goal = sk->sk_rcvbuf >> 3; + node = &tp->ooo_last_skb->rbnode; + do { + prev = rb_prev(node); + rb_erase(node, &tp->out_of_order_queue); + goal -= rb_to_skb(node)->truesize; + tcp_drop(sk, rb_to_skb(node)); + if (!prev || goal <= 0) { + sk_mem_reclaim(sk); + if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && + !tcp_under_memory_pressure(sk)) + break; + goal = sk->sk_rcvbuf >> 3; + } + node = prev; + } while (node); + tp->ooo_last_skb = rb_to_skb(prev); + + /* Reset SACK state. A conforming SACK implementation will + * do the same at a timeout based retransmit. When a connection + * is in a sad state like this, we care only about integrity + * of the connection not performance. + */ + if (tp->rx_opt.sack_ok) + tcp_sack_reset(&tp->rx_opt); + return true; +} + +/* Reduce allocated memory if we can, trying to get + * the socket within its memory limits again. + * + * Return less than zero if we should start dropping frames + * until the socket owning process reads some of the data + * to stabilize the situation. + */ +static int tcp_prune_queue(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + NET_INC_STATS(sock_net(sk), LINUX_MIB_PRUNECALLED); + + if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) + tcp_clamp_window(sk); + else if (tcp_under_memory_pressure(sk)) + tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss); + + if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) + return 0; + + tcp_collapse_ofo_queue(sk); + if (!skb_queue_empty(&sk->sk_receive_queue)) + tcp_collapse(sk, &sk->sk_receive_queue, NULL, + skb_peek(&sk->sk_receive_queue), + NULL, + tp->copied_seq, tp->rcv_nxt); + sk_mem_reclaim(sk); + + if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) + return 0; + + /* Collapsing did not help, destructive actions follow. + * This must not ever occur. */ + + tcp_prune_ofo_queue(sk); + + if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) + return 0; + + /* If we are really being abused, tell the caller to silently + * drop receive data on the floor. It will get retransmitted + * and hopefully then we'll have sufficient space. + */ + NET_INC_STATS(sock_net(sk), LINUX_MIB_RCVPRUNED); + + /* Massive buffer overcommit. */ + tp->pred_flags = 0; + return -1; +} + +static bool tcp_should_expand_sndbuf(const struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + /* If the user specified a specific send buffer setting, do + * not modify it. + */ + if (sk->sk_userlocks & SOCK_SNDBUF_LOCK) + return false; + + /* If we are under global TCP memory pressure, do not expand. */ + if (tcp_under_memory_pressure(sk)) + return false; + + /* If we are under soft global TCP memory pressure, do not expand. */ + if (sk_memory_allocated(sk) >= sk_prot_mem_limits(sk, 0)) + return false; + + /* If we filled the congestion window, do not expand. */ + if (tcp_packets_in_flight(tp) >= tp->snd_cwnd) + return false; + + return true; +} + +static void tcp_new_space(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tcp_should_expand_sndbuf(sk)) { + tcp_sndbuf_expand(sk); + tp->snd_cwnd_stamp = tcp_jiffies32; + } + + sk->sk_write_space(sk); +} + +/* Caller made space either from: + * 1) Freeing skbs in rtx queues (after tp->snd_una has advanced) + * 2) Sent skbs from output queue (and thus advancing tp->snd_nxt) + * + * We might be able to generate EPOLLOUT to the application if: + * 1) Space consumed in output/rtx queues is below sk->sk_sndbuf/2 + * 2) notsent amount (tp->write_seq - tp->snd_nxt) became + * small enough that tcp_stream_memory_free() decides it + * is time to generate EPOLLOUT. + */ +void tcp_check_space(struct sock *sk) +{ + /* pairs with tcp_poll() */ + smp_mb(); + if (sk->sk_socket && + test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { + tcp_new_space(sk); + if (!test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) + tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); + } +} + +static inline void tcp_data_snd_check(struct sock *sk) +{ + tcp_push_pending_frames(sk); + tcp_check_space(sk); +} + +/* + * Check if sending an ack is needed. + */ +static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible) +{ + struct tcp_sock *tp = tcp_sk(sk); + unsigned long rtt, delay; + + /* More than one full frame received... */ + if (((tp->rcv_nxt - tp->rcv_wup) > inet_csk(sk)->icsk_ack.rcv_mss && + /* ... and right edge of window advances far enough. + * (tcp_recvmsg() will send ACK otherwise). + * If application uses SO_RCVLOWAT, we want send ack now if + * we have not received enough bytes to satisfy the condition. + */ + (tp->rcv_nxt - tp->copied_seq < sk->sk_rcvlowat || + __tcp_select_window(sk) >= tp->rcv_wnd)) || + /* We ACK each frame or... */ + tcp_in_quickack_mode(sk) || + /* Protocol state mandates a one-time immediate ACK */ + inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOW) { +send_now: + tcp_send_ack(sk); + return; + } + + if (!ofo_possible || RB_EMPTY_ROOT(&tp->out_of_order_queue)) { + tcp_send_delayed_ack(sk); + return; + } + + if (!tcp_is_sack(tp) || + tp->compressed_ack >= READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr)) + goto send_now; + + if (tp->compressed_ack_rcv_nxt != tp->rcv_nxt) { + tp->compressed_ack_rcv_nxt = tp->rcv_nxt; + tp->dup_ack_counter = 0; + } + if (tp->dup_ack_counter < TCP_FASTRETRANS_THRESH) { + tp->dup_ack_counter++; + goto send_now; + } + tp->compressed_ack++; + if (hrtimer_is_queued(&tp->compressed_ack_timer)) + return; + + /* compress ack timer : 5 % of rtt, but no more than tcp_comp_sack_delay_ns */ + + rtt = tp->rcv_rtt_est.rtt_us; + if (tp->srtt_us && tp->srtt_us < rtt) + rtt = tp->srtt_us; + + delay = min_t(unsigned long, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_delay_ns), + rtt * (NSEC_PER_USEC >> 3)/20); + sock_hold(sk); + hrtimer_start_range_ns(&tp->compressed_ack_timer, ns_to_ktime(delay), + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_slack_ns), + HRTIMER_MODE_REL_PINNED_SOFT); +} + +static inline void tcp_ack_snd_check(struct sock *sk) +{ + if (!inet_csk_ack_scheduled(sk)) { + /* We sent a data segment already. */ + return; + } + __tcp_ack_snd_check(sk, 1); +} + +/* + * This routine is only called when we have urgent data + * signaled. Its the 'slow' part of tcp_urg. It could be + * moved inline now as tcp_urg is only called from one + * place. We handle URGent data wrong. We have to - as + * BSD still doesn't use the correction from RFC961. + * For 1003.1g we should support a new option TCP_STDURG to permit + * either form (or just set the sysctl tcp_stdurg). + */ + +static void tcp_check_urg(struct sock *sk, const struct tcphdr *th) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 ptr = ntohs(th->urg_ptr); + + if (ptr && !READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_stdurg)) + ptr--; + ptr += ntohl(th->seq); + + /* Ignore urgent data that we've already seen and read. */ + if (after(tp->copied_seq, ptr)) + return; + + /* Do not replay urg ptr. + * + * NOTE: interesting situation not covered by specs. + * Misbehaving sender may send urg ptr, pointing to segment, + * which we already have in ofo queue. We are not able to fetch + * such data and will stay in TCP_URG_NOTYET until will be eaten + * by recvmsg(). Seems, we are not obliged to handle such wicked + * situations. But it is worth to think about possibility of some + * DoSes using some hypothetical application level deadlock. + */ + if (before(ptr, tp->rcv_nxt)) + return; + + /* Do we already have a newer (or duplicate) urgent pointer? */ + if (tp->urg_data && !after(ptr, tp->urg_seq)) + return; + + /* Tell the world about our new urgent pointer. */ + sk_send_sigurg(sk); + + /* We may be adding urgent data when the last byte read was + * urgent. To do this requires some care. We cannot just ignore + * tp->copied_seq since we would read the last urgent byte again + * as data, nor can we alter copied_seq until this data arrives + * or we break the semantics of SIOCATMARK (and thus sockatmark()) + * + * NOTE. Double Dutch. Rendering to plain English: author of comment + * above did something sort of send("A", MSG_OOB); send("B", MSG_OOB); + * and expect that both A and B disappear from stream. This is _wrong_. + * Though this happens in BSD with high probability, this is occasional. + * Any application relying on this is buggy. Note also, that fix "works" + * only in this artificial test. Insert some normal data between A and B and we will + * decline of BSD again. Verdict: it is better to remove to trap + * buggy users. + */ + if (tp->urg_seq == tp->copied_seq && tp->urg_data && + !sock_flag(sk, SOCK_URGINLINE) && tp->copied_seq != tp->rcv_nxt) { + struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); + tp->copied_seq++; + if (skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)) { + __skb_unlink(skb, &sk->sk_receive_queue); + __kfree_skb(skb); + } + } + + tp->urg_data = TCP_URG_NOTYET; + WRITE_ONCE(tp->urg_seq, ptr); + + /* Disable header prediction. */ + tp->pred_flags = 0; +} + +/* This is the 'fast' part of urgent handling. */ +static void tcp_urg(struct sock *sk, struct sk_buff *skb, const struct tcphdr *th) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* Check if we get a new urgent pointer - normally not. */ + if (th->urg) + tcp_check_urg(sk, th); + + /* Do we wait for any urgent data? - normally not... */ + if (tp->urg_data == TCP_URG_NOTYET) { + u32 ptr = tp->urg_seq - ntohl(th->seq) + (th->doff * 4) - + th->syn; + + /* Is the urgent pointer pointing into this packet? */ + if (ptr < skb->len) { + u8 tmp; + if (skb_copy_bits(skb, ptr, &tmp, 1)) + BUG(); + tp->urg_data = TCP_URG_VALID | tmp; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_data_ready(sk); + } + } +} + +/* Accept RST for rcv_nxt - 1 after a FIN. + * When tcp connections are abruptly terminated from Mac OSX (via ^C), a + * FIN is sent followed by a RST packet. The RST is sent with the same + * sequence number as the FIN, and thus according to RFC 5961 a challenge + * ACK should be sent. However, Mac OSX rate limits replies to challenge + * ACKs on the closed socket. In addition middleboxes can drop either the + * challenge ACK or a subsequent RST. + */ +static bool tcp_reset_check(const struct sock *sk, const struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + return unlikely(TCP_SKB_CB(skb)->seq == (tp->rcv_nxt - 1) && + (1 << sk->sk_state) & (TCPF_CLOSE_WAIT | TCPF_LAST_ACK | + TCPF_CLOSING)); +} + +/* Does PAWS and seqno based validation of an incoming segment, flags will + * play significant role here. + */ +static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb, + const struct tcphdr *th, int syn_inerr) +{ + struct tcp_sock *tp = tcp_sk(sk); + bool rst_seq_match = false; + + /* RFC1323: H1. Apply PAWS check first. */ + if (tcp_fast_parse_options(sock_net(sk), skb, th, tp) && + tp->rx_opt.saw_tstamp && + tcp_paws_discard(sk, skb)) { + if (!th->rst) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED); + if (!tcp_oow_rate_limited(sock_net(sk), skb, + LINUX_MIB_TCPACKSKIPPEDPAWS, + &tp->last_oow_ack_time)) + tcp_send_dupack(sk, skb); + goto discard; + } + /* Reset is accepted even if it did not pass PAWS. */ + } + + /* Step 1: check sequence number */ + if (!tcp_sequence(tp, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq)) { + /* RFC793, page 37: "In all states except SYN-SENT, all reset + * (RST) segments are validated by checking their SEQ-fields." + * And page 69: "If an incoming segment is not acceptable, + * an acknowledgment should be sent in reply (unless the RST + * bit is set, if so drop the segment and return)". + */ + if (!th->rst) { + if (th->syn) + goto syn_challenge; + if (!tcp_oow_rate_limited(sock_net(sk), skb, + LINUX_MIB_TCPACKSKIPPEDSEQ, + &tp->last_oow_ack_time)) + tcp_send_dupack(sk, skb); + } else if (tcp_reset_check(sk, skb)) { + tcp_reset(sk); + } + goto discard; + } + + /* Step 2: check RST bit */ + if (th->rst) { + /* RFC 5961 3.2 (extend to match against (RCV.NXT - 1) after a + * FIN and SACK too if available): + * If seq num matches RCV.NXT or (RCV.NXT - 1) after a FIN, or + * the right-most SACK block, + * then + * RESET the connection + * else + * Send a challenge ACK + */ + if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt || + tcp_reset_check(sk, skb)) { + rst_seq_match = true; + } else if (tcp_is_sack(tp) && tp->rx_opt.num_sacks > 0) { + struct tcp_sack_block *sp = &tp->selective_acks[0]; + int max_sack = sp[0].end_seq; + int this_sack; + + for (this_sack = 1; this_sack < tp->rx_opt.num_sacks; + ++this_sack) { + max_sack = after(sp[this_sack].end_seq, + max_sack) ? + sp[this_sack].end_seq : max_sack; + } + + if (TCP_SKB_CB(skb)->seq == max_sack) + rst_seq_match = true; + } + + if (rst_seq_match) + tcp_reset(sk); + else { + /* Disable TFO if RST is out-of-order + * and no data has been received + * for current active TFO socket + */ + if (tp->syn_fastopen && !tp->data_segs_in && + sk->sk_state == TCP_ESTABLISHED) + tcp_fastopen_active_disable(sk); + tcp_send_challenge_ack(sk, skb); + } + goto discard; + } + + /* step 3: check security and precedence [ignored] */ + + /* step 4: Check for a SYN + * RFC 5961 4.2 : Send a challenge ack + */ + if (th->syn) { +syn_challenge: + if (syn_inerr) + TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNCHALLENGE); + tcp_send_challenge_ack(sk, skb); + goto discard; + } + + bpf_skops_parse_hdr(sk, skb); + + return true; + +discard: + tcp_drop(sk, skb); + return false; +} + +/* + * TCP receive function for the ESTABLISHED state. + * + * It is split into a fast path and a slow path. The fast path is + * disabled when: + * - A zero window was announced from us - zero window probing + * is only handled properly in the slow path. + * - Out of order segments arrived. + * - Urgent data is expected. + * - There is no buffer space left + * - Unexpected TCP flags/window values/header lengths are received + * (detected by checking the TCP header against pred_flags) + * - Data is sent in both directions. Fast path only supports pure senders + * or pure receivers (this means either the sequence number or the ack + * value must stay constant) + * - Unexpected TCP option. + * + * When these conditions are not satisfied it drops into a standard + * receive procedure patterned after RFC793 to handle all cases. + * The first three cases are guaranteed by proper pred_flags setting, + * the rest is checked inline. Fast processing is turned on in + * tcp_data_queue when everything is OK. + */ +void tcp_rcv_established(struct sock *sk, struct sk_buff *skb) +{ + const struct tcphdr *th = (const struct tcphdr *)skb->data; + struct tcp_sock *tp = tcp_sk(sk); + unsigned int len = skb->len; + + /* TCP congestion window tracking */ + trace_tcp_probe(sk, skb); + + tcp_mstamp_refresh(tp); + if (unlikely(!rcu_access_pointer(sk->sk_rx_dst))) + inet_csk(sk)->icsk_af_ops->sk_rx_dst_set(sk, skb); + /* + * Header prediction. + * The code loosely follows the one in the famous + * "30 instruction TCP receive" Van Jacobson mail. + * + * Van's trick is to deposit buffers into socket queue + * on a device interrupt, to call tcp_recv function + * on the receive process context and checksum and copy + * the buffer to user space. smart... + * + * Our current scheme is not silly either but we take the + * extra cost of the net_bh soft interrupt processing... + * We do checksum and copy also but from device to kernel. + */ + + tp->rx_opt.saw_tstamp = 0; + + /* pred_flags is 0xS?10 << 16 + snd_wnd + * if header_prediction is to be made + * 'S' will always be tp->tcp_header_len >> 2 + * '?' will be 0 for the fast path, otherwise pred_flags is 0 to + * turn it off (when there are holes in the receive + * space for instance) + * PSH flag is ignored. + */ + + if ((tcp_flag_word(th) & TCP_HP_BITS) == tp->pred_flags && + TCP_SKB_CB(skb)->seq == tp->rcv_nxt && + !after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) { + int tcp_header_len = tp->tcp_header_len; + + /* Timestamp header prediction: tcp_header_len + * is automatically equal to th->doff*4 due to pred_flags + * match. + */ + + /* Check timestamp */ + if (tcp_header_len == sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) { + /* No? Slow path! */ + if (!tcp_parse_aligned_timestamp(tp, th)) + goto slow_path; + + /* If PAWS failed, check it more carefully in slow path */ + if ((s32)(tp->rx_opt.rcv_tsval - tp->rx_opt.ts_recent) < 0) + goto slow_path; + + /* DO NOT update ts_recent here, if checksum fails + * and timestamp was corrupted part, it will result + * in a hung connection since we will drop all + * future packets due to the PAWS test. + */ + } + + if (len <= tcp_header_len) { + /* Bulk data transfer: sender */ + if (len == tcp_header_len) { + /* Predicted packet is in window by definition. + * seq == rcv_nxt and rcv_wup <= rcv_nxt. + * Hence, check seq<=rcv_wup reduces to: + */ + if (tcp_header_len == + (sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) && + tp->rcv_nxt == tp->rcv_wup) + tcp_store_ts_recent(tp); + + /* We know that such packets are checksummed + * on entry. + */ + tcp_ack(sk, skb, 0); + __kfree_skb(skb); + tcp_data_snd_check(sk); + /* When receiving pure ack in fast path, update + * last ts ecr directly instead of calling + * tcp_rcv_rtt_measure_ts() + */ + tp->rcv_rtt_last_tsecr = tp->rx_opt.rcv_tsecr; + return; + } else { /* Header too small */ + TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); + goto discard; + } + } else { + int eaten = 0; + bool fragstolen = false; + + if (tcp_checksum_complete(skb)) + goto csum_error; + + if ((int)skb->truesize > sk->sk_forward_alloc) + goto step5; + + /* Predicted packet is in window by definition. + * seq == rcv_nxt and rcv_wup <= rcv_nxt. + * Hence, check seq<=rcv_wup reduces to: + */ + if (tcp_header_len == + (sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) && + tp->rcv_nxt == tp->rcv_wup) + tcp_store_ts_recent(tp); + + tcp_rcv_rtt_measure_ts(sk, skb); + + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHPHITS); + + /* Bulk data transfer: receiver */ + __skb_pull(skb, tcp_header_len); + eaten = tcp_queue_rcv(sk, skb, &fragstolen); + + tcp_event_data_recv(sk, skb); + + if (TCP_SKB_CB(skb)->ack_seq != tp->snd_una) { + /* Well, only one small jumplet in fast path... */ + tcp_ack(sk, skb, FLAG_DATA); + tcp_data_snd_check(sk); + if (!inet_csk_ack_scheduled(sk)) + goto no_ack; + } else { + tcp_update_wl(tp, TCP_SKB_CB(skb)->seq); + } + + __tcp_ack_snd_check(sk, 0); +no_ack: + if (eaten) + kfree_skb_partial(skb, fragstolen); + tcp_data_ready(sk); + return; + } + } + +slow_path: + if (len < (th->doff << 2) || tcp_checksum_complete(skb)) + goto csum_error; + + if (!th->ack && !th->rst && !th->syn) + goto discard; + + /* + * Standard slow path. + */ + + if (!tcp_validate_incoming(sk, skb, th, 1)) + return; + +step5: + if (tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT) < 0) + goto discard; + + tcp_rcv_rtt_measure_ts(sk, skb); + + /* Process urgent data. */ + tcp_urg(sk, skb, th); + + /* step 7: process the segment text */ + tcp_data_queue(sk, skb); + + tcp_data_snd_check(sk); + tcp_ack_snd_check(sk); + return; + +csum_error: + TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); + TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); + +discard: + tcp_drop(sk, skb); +} +EXPORT_SYMBOL(tcp_rcv_established); + +void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + + tcp_mtup_init(sk); + icsk->icsk_af_ops->rebuild_header(sk); + tcp_init_metrics(sk); + + /* Initialize the congestion window to start the transfer. + * Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been + * retransmitted. In light of RFC6298 more aggressive 1sec + * initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK + * retransmission has occurred. + */ + if (tp->total_retrans > 1 && tp->undo_marker) + tp->snd_cwnd = 1; + else + tp->snd_cwnd = tcp_init_cwnd(tp, __sk_dst_get(sk)); + tp->snd_cwnd_stamp = tcp_jiffies32; + + bpf_skops_established(sk, bpf_op, skb); + /* Initialize congestion control unless BPF initialized it already: */ + if (!icsk->icsk_ca_initialized) + tcp_init_congestion_control(sk); + tcp_init_buffer_space(sk); +} + +void tcp_finish_connect(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + + tcp_set_state(sk, TCP_ESTABLISHED); + icsk->icsk_ack.lrcvtime = tcp_jiffies32; + + if (skb) { + icsk->icsk_af_ops->sk_rx_dst_set(sk, skb); + security_inet_conn_established(sk, skb); + sk_mark_napi_id(sk, skb); + } + + tcp_init_transfer(sk, BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, skb); + + /* Prevent spurious tcp_cwnd_restart() on first data + * packet. + */ + tp->lsndtime = tcp_jiffies32; + + if (sock_flag(sk, SOCK_KEEPOPEN)) + inet_csk_reset_keepalive_timer(sk, keepalive_time_when(tp)); + + if (!tp->rx_opt.snd_wscale) + __tcp_fast_path_on(tp, tp->snd_wnd); + else + tp->pred_flags = 0; +} + +static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, + struct tcp_fastopen_cookie *cookie) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *data = tp->syn_data ? tcp_rtx_queue_head(sk) : NULL; + u16 mss = tp->rx_opt.mss_clamp, try_exp = 0; + bool syn_drop = false; + + if (mss == tp->rx_opt.user_mss) { + struct tcp_options_received opt; + + /* Get original SYNACK MSS value if user MSS sets mss_clamp */ + tcp_clear_options(&opt); + opt.user_mss = opt.mss_clamp = 0; + tcp_parse_options(sock_net(sk), synack, &opt, 0, NULL); + mss = opt.mss_clamp; + } + + if (!tp->syn_fastopen) { + /* Ignore an unsolicited cookie */ + cookie->len = -1; + } else if (tp->total_retrans) { + /* SYN timed out and the SYN-ACK neither has a cookie nor + * acknowledges data. Presumably the remote received only + * the retransmitted (regular) SYNs: either the original + * SYN-data or the corresponding SYN-ACK was dropped. + */ + syn_drop = (cookie->len < 0 && data); + } else if (cookie->len < 0 && !tp->syn_data) { + /* We requested a cookie but didn't get it. If we did not use + * the (old) exp opt format then try so next time (try_exp=1). + * Otherwise we go back to use the RFC7413 opt (try_exp=2). + */ + try_exp = tp->syn_fastopen_exp ? 2 : 1; + } + + tcp_fastopen_cache_set(sk, mss, cookie, syn_drop, try_exp); + + if (data) { /* Retransmit unacked data in SYN */ + if (tp->total_retrans) + tp->fastopen_client_fail = TFO_SYN_RETRANSMITTED; + else + tp->fastopen_client_fail = TFO_DATA_NOT_ACKED; + skb_rbtree_walk_from(data) { + if (__tcp_retransmit_skb(sk, data, 1)) + break; + } + tcp_rearm_rto(sk); + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPFASTOPENACTIVEFAIL); + return true; + } + tp->syn_data_acked = tp->syn_data; + if (tp->syn_data_acked) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVE); + /* SYN-data is counted as two separate packets in tcp_ack() */ + if (tp->delivered > 1) + --tp->delivered; + } + + tcp_fastopen_add_skb(sk, synack); + + return false; +} + +static void smc_check_reset_syn(struct tcp_sock *tp) +{ +#if IS_ENABLED(CONFIG_SMC) + if (static_branch_unlikely(&tcp_have_smc)) { + if (tp->syn_smc && !tp->rx_opt.smc_ok) + tp->syn_smc = 0; + } +#endif +} + +static void tcp_try_undo_spurious_syn(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 syn_stamp; + + /* undo_marker is set when SYN or SYNACK times out. The timeout is + * spurious if the ACK's timestamp option echo value matches the + * original SYN timestamp. + */ + syn_stamp = tp->retrans_stamp; + if (tp->undo_marker && syn_stamp && tp->rx_opt.saw_tstamp && + syn_stamp == tp->rx_opt.rcv_tsecr) + tp->undo_marker = 0; +} + +static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, + const struct tcphdr *th) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_fastopen_cookie foc = { .len = -1 }; + int saved_clamp = tp->rx_opt.mss_clamp; + bool fastopen_fail; + + tcp_parse_options(sock_net(sk), skb, &tp->rx_opt, 0, &foc); + if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr) + tp->rx_opt.rcv_tsecr -= tp->tsoffset; + + if (th->ack) { + /* rfc793: + * "If the state is SYN-SENT then + * first check the ACK bit + * If the ACK bit is set + * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send + * a reset (unless the RST bit is set, if so drop + * the segment and return)" + */ + if (!after(TCP_SKB_CB(skb)->ack_seq, tp->snd_una) || + after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) { + /* Previous FIN/ACK or RST/ACK might be ignored. */ + if (icsk->icsk_retransmits == 0) + inet_csk_reset_xmit_timer(sk, + ICSK_TIME_RETRANS, + TCP_TIMEOUT_MIN, TCP_RTO_MAX); + goto reset_and_undo; + } + + if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr && + !between(tp->rx_opt.rcv_tsecr, tp->retrans_stamp, + tcp_time_stamp(tp))) { + NET_INC_STATS(sock_net(sk), + LINUX_MIB_PAWSACTIVEREJECTED); + goto reset_and_undo; + } + + /* Now ACK is acceptable. + * + * "If the RST bit is set + * If the ACK was acceptable then signal the user "error: + * connection reset", drop the segment, enter CLOSED state, + * delete TCB, and return." + */ + + if (th->rst) { + tcp_reset(sk); + goto discard; + } + + /* rfc793: + * "fifth, if neither of the SYN or RST bits is set then + * drop the segment and return." + * + * See note below! + * --ANK(990513) + */ + if (!th->syn) + goto discard_and_undo; + + /* rfc793: + * "If the SYN bit is on ... + * are acceptable then ... + * (our SYN has been ACKed), change the connection + * state to ESTABLISHED..." + */ + + tcp_ecn_rcv_synack(tp, th); + + tcp_init_wl(tp, TCP_SKB_CB(skb)->seq); + tcp_try_undo_spurious_syn(sk); + tcp_ack(sk, skb, FLAG_SLOWPATH); + + /* Ok.. it's good. Set up sequence numbers and + * move to established. + */ + WRITE_ONCE(tp->rcv_nxt, TCP_SKB_CB(skb)->seq + 1); + tp->rcv_wup = TCP_SKB_CB(skb)->seq + 1; + + /* RFC1323: The window in SYN & SYN/ACK segments is + * never scaled. + */ + tp->snd_wnd = ntohs(th->window); + + if (!tp->rx_opt.wscale_ok) { + tp->rx_opt.snd_wscale = tp->rx_opt.rcv_wscale = 0; + tp->window_clamp = min(tp->window_clamp, 65535U); + } + + if (tp->rx_opt.saw_tstamp) { + tp->rx_opt.tstamp_ok = 1; + tp->tcp_header_len = + sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED; + tp->advmss -= TCPOLEN_TSTAMP_ALIGNED; + tcp_store_ts_recent(tp); + } else { + tp->tcp_header_len = sizeof(struct tcphdr); + } + + tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); + tcp_initialize_rcv_mss(sk); + + /* Remember, tcp_poll() does not lock socket! + * Change state from SYN-SENT only after copied_seq + * is initialized. */ + WRITE_ONCE(tp->copied_seq, tp->rcv_nxt); + + smc_check_reset_syn(tp); + + smp_mb(); + + tcp_finish_connect(sk, skb); + + fastopen_fail = (tp->syn_fastopen || tp->syn_data) && + tcp_rcv_fastopen_synack(sk, skb, &foc); + + if (!sock_flag(sk, SOCK_DEAD)) { + sk->sk_state_change(sk); + sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT); + } + if (fastopen_fail) + return -1; + if (sk->sk_write_pending || + icsk->icsk_accept_queue.rskq_defer_accept || + inet_csk_in_pingpong_mode(sk)) { + /* Save one ACK. Data will be ready after + * several ticks, if write_pending is set. + * + * It may be deleted, but with this feature tcpdumps + * look so _wonderfully_ clever, that I was not able + * to stand against the temptation 8) --ANK + */ + inet_csk_schedule_ack(sk); + tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, + TCP_DELACK_MAX, TCP_RTO_MAX); + +discard: + tcp_drop(sk, skb); + return 0; + } else { + tcp_send_ack(sk); + } + return -1; + } + + /* No ACK in the segment */ + + if (th->rst) { + /* rfc793: + * "If the RST bit is set + * + * Otherwise (no ACK) drop the segment and return." + */ + + goto discard_and_undo; + } + + /* PAWS check. */ + if (tp->rx_opt.ts_recent_stamp && tp->rx_opt.saw_tstamp && + tcp_paws_reject(&tp->rx_opt, 0)) + goto discard_and_undo; + + if (th->syn) { + /* We see SYN without ACK. It is attempt of + * simultaneous connect with crossed SYNs. + * Particularly, it can be connect to self. + */ + tcp_set_state(sk, TCP_SYN_RECV); + + if (tp->rx_opt.saw_tstamp) { + tp->rx_opt.tstamp_ok = 1; + tcp_store_ts_recent(tp); + tp->tcp_header_len = + sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED; + } else { + tp->tcp_header_len = sizeof(struct tcphdr); + } + + WRITE_ONCE(tp->rcv_nxt, TCP_SKB_CB(skb)->seq + 1); + WRITE_ONCE(tp->copied_seq, tp->rcv_nxt); + tp->rcv_wup = TCP_SKB_CB(skb)->seq + 1; + + /* RFC1323: The window in SYN & SYN/ACK segments is + * never scaled. + */ + tp->snd_wnd = ntohs(th->window); + tp->snd_wl1 = TCP_SKB_CB(skb)->seq; + tp->max_window = tp->snd_wnd; + + tcp_ecn_rcv_syn(tp, th); + + tcp_mtup_init(sk); + tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); + tcp_initialize_rcv_mss(sk); + + tcp_send_synack(sk); +#if 0 + /* Note, we could accept data and URG from this segment. + * There are no obstacles to make this (except that we must + * either change tcp_recvmsg() to prevent it from returning data + * before 3WHS completes per RFC793, or employ TCP Fast Open). + * + * However, if we ignore data in ACKless segments sometimes, + * we have no reasons to accept it sometimes. + * Also, seems the code doing it in step6 of tcp_rcv_state_process + * is not flawless. So, discard packet for sanity. + * Uncomment this return to process the data. + */ + return -1; +#else + goto discard; +#endif + } + /* "fifth, if neither of the SYN or RST bits is set then + * drop the segment and return." + */ + +discard_and_undo: + tcp_clear_options(&tp->rx_opt); + tp->rx_opt.mss_clamp = saved_clamp; + goto discard; + +reset_and_undo: + tcp_clear_options(&tp->rx_opt); + tp->rx_opt.mss_clamp = saved_clamp; + return 1; +} + +static void tcp_rcv_synrecv_state_fastopen(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct request_sock *req; + + /* If we are still handling the SYNACK RTO, see if timestamp ECR allows + * undo. If peer SACKs triggered fast recovery, we can't undo here. + */ + if (inet_csk(sk)->icsk_ca_state == TCP_CA_Loss && !tp->packets_out) + tcp_try_undo_recovery(sk); + + /* Reset rtx states to prevent spurious retransmits_timed_out() */ + tp->retrans_stamp = 0; + inet_csk(sk)->icsk_retransmits = 0; + + /* Once we leave TCP_SYN_RECV or TCP_FIN_WAIT_1, + * we no longer need req so release it. + */ + req = rcu_dereference_protected(tp->fastopen_rsk, + lockdep_sock_is_held(sk)); + reqsk_fastopen_remove(sk, req, false); + + /* Re-arm the timer because data may have been sent out. + * This is similar to the regular data transmission case + * when new data has just been ack'ed. + * + * (TFO) - we could try to be more aggressive and + * retransmitting any data sooner based on when they + * are sent out. + */ + tcp_rearm_rto(sk); +} + +/* + * This function implements the receiving procedure of RFC 793 for + * all states except ESTABLISHED and TIME_WAIT. + * It's called from both tcp_v4_rcv and tcp_v6_rcv and should be + * address independent. + */ + +int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + const struct tcphdr *th = tcp_hdr(skb); + struct request_sock *req; + int queued = 0; + bool acceptable; + + switch (sk->sk_state) { + case TCP_CLOSE: + goto discard; + + case TCP_LISTEN: + if (th->ack) + return 1; + + if (th->rst) + goto discard; + + if (th->syn) { + if (th->fin) + goto discard; + /* It is possible that we process SYN packets from backlog, + * so we need to make sure to disable BH and RCU right there. + */ + rcu_read_lock(); + local_bh_disable(); + acceptable = icsk->icsk_af_ops->conn_request(sk, skb) >= 0; + local_bh_enable(); + rcu_read_unlock(); + + if (!acceptable) + return 1; + consume_skb(skb); + return 0; + } + goto discard; + + case TCP_SYN_SENT: + tp->rx_opt.saw_tstamp = 0; + tcp_mstamp_refresh(tp); + queued = tcp_rcv_synsent_state_process(sk, skb, th); + if (queued >= 0) + return queued; + + /* Do step6 onward by hand. */ + tcp_urg(sk, skb, th); + __kfree_skb(skb); + tcp_data_snd_check(sk); + return 0; + } + + tcp_mstamp_refresh(tp); + tp->rx_opt.saw_tstamp = 0; + req = rcu_dereference_protected(tp->fastopen_rsk, + lockdep_sock_is_held(sk)); + if (req) { + bool req_stolen; + + WARN_ON_ONCE(sk->sk_state != TCP_SYN_RECV && + sk->sk_state != TCP_FIN_WAIT1); + + if (!tcp_check_req(sk, skb, req, true, &req_stolen)) + goto discard; + } + + if (!th->ack && !th->rst && !th->syn) + goto discard; + + if (!tcp_validate_incoming(sk, skb, th, 0)) + return 0; + + /* step 5: check the ACK field */ + acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH | + FLAG_UPDATE_TS_RECENT | + FLAG_NO_CHALLENGE_ACK) > 0; + + if (!acceptable) { + if (sk->sk_state == TCP_SYN_RECV) + return 1; /* send one RST */ + tcp_send_challenge_ack(sk, skb); + goto discard; + } + switch (sk->sk_state) { + case TCP_SYN_RECV: + tp->delivered++; /* SYN-ACK delivery isn't tracked in tcp_ack */ + if (!tp->srtt_us) + tcp_synack_rtt_meas(sk, req); + + if (req) { + tcp_rcv_synrecv_state_fastopen(sk); + } else { + tcp_try_undo_spurious_syn(sk); + tp->retrans_stamp = 0; + tcp_init_transfer(sk, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, + skb); + WRITE_ONCE(tp->copied_seq, tp->rcv_nxt); + } + smp_mb(); + tcp_set_state(sk, TCP_ESTABLISHED); + sk->sk_state_change(sk); + + /* Note, that this wakeup is only for marginal crossed SYN case. + * Passively open sockets are not waked up, because + * sk->sk_sleep == NULL and sk->sk_socket == NULL. + */ + if (sk->sk_socket) + sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT); + + tp->snd_una = TCP_SKB_CB(skb)->ack_seq; + tp->snd_wnd = ntohs(th->window) << tp->rx_opt.snd_wscale; + tcp_init_wl(tp, TCP_SKB_CB(skb)->seq); + + if (tp->rx_opt.tstamp_ok) + tp->advmss -= TCPOLEN_TSTAMP_ALIGNED; + + if (!inet_csk(sk)->icsk_ca_ops->cong_control) + tcp_update_pacing_rate(sk); + + /* Prevent spurious tcp_cwnd_restart() on first data packet */ + tp->lsndtime = tcp_jiffies32; + + tcp_initialize_rcv_mss(sk); + tcp_fast_path_on(tp); + break; + + case TCP_FIN_WAIT1: { + int tmo; + + if (req) + tcp_rcv_synrecv_state_fastopen(sk); + + if (tp->snd_una != tp->write_seq) + break; + + tcp_set_state(sk, TCP_FIN_WAIT2); + WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | SEND_SHUTDOWN); + + sk_dst_confirm(sk); + + if (!sock_flag(sk, SOCK_DEAD)) { + /* Wake up lingering close() */ + sk->sk_state_change(sk); + break; + } + + if (tp->linger2 < 0) { + tcp_done(sk); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); + return 1; + } + if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq && + after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) { + /* Receive out of order FIN after close() */ + if (tp->syn_fastopen && th->fin) + tcp_fastopen_active_disable(sk); + tcp_done(sk); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); + return 1; + } + + tmo = tcp_fin_time(sk); + if (tmo > TCP_TIMEWAIT_LEN) { + inet_csk_reset_keepalive_timer(sk, tmo - TCP_TIMEWAIT_LEN); + } else if (th->fin || sock_owned_by_user(sk)) { + /* Bad case. We could lose such FIN otherwise. + * It is not a big problem, but it looks confusing + * and not so rare event. We still can lose it now, + * if it spins in bh_lock_sock(), but it is really + * marginal case. + */ + inet_csk_reset_keepalive_timer(sk, tmo); + } else { + tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); + goto discard; + } + break; + } + + case TCP_CLOSING: + if (tp->snd_una == tp->write_seq) { + tcp_time_wait(sk, TCP_TIME_WAIT, 0); + goto discard; + } + break; + + case TCP_LAST_ACK: + if (tp->snd_una == tp->write_seq) { + tcp_update_metrics(sk); + tcp_done(sk); + goto discard; + } + break; + } + + /* step 6: check the URG bit */ + tcp_urg(sk, skb, th); + + /* step 7: process the segment text */ + switch (sk->sk_state) { + case TCP_CLOSE_WAIT: + case TCP_CLOSING: + case TCP_LAST_ACK: + if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) { + if (sk_is_mptcp(sk)) + mptcp_incoming_options(sk, skb); + break; + } + fallthrough; + case TCP_FIN_WAIT1: + case TCP_FIN_WAIT2: + /* RFC 793 says to queue data in these states, + * RFC 1122 says we MUST send a reset. + * BSD 4.4 also does reset. + */ + if (sk->sk_shutdown & RCV_SHUTDOWN) { + if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq && + after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); + tcp_reset(sk); + return 1; + } + } + fallthrough; + case TCP_ESTABLISHED: + tcp_data_queue(sk, skb); + queued = 1; + break; + } + + /* tcp_data could move socket to TIME-WAIT */ + if (sk->sk_state != TCP_CLOSE) { + tcp_data_snd_check(sk); + tcp_ack_snd_check(sk); + } + + if (!queued) { +discard: + tcp_drop(sk, skb); + } + return 0; +} +EXPORT_SYMBOL(tcp_rcv_state_process); + +static inline void pr_drop_req(struct request_sock *req, __u16 port, int family) +{ + struct inet_request_sock *ireq = inet_rsk(req); + + if (family == AF_INET) + net_dbg_ratelimited("drop open request from %pI4/%u\n", + &ireq->ir_rmt_addr, port); +#if IS_ENABLED(CONFIG_IPV6) + else if (family == AF_INET6) + net_dbg_ratelimited("drop open request from %pI6/%u\n", + &ireq->ir_v6_rmt_addr, port); +#endif +} + +/* RFC3168 : 6.1.1 SYN packets must not have ECT/ECN bits set + * + * If we receive a SYN packet with these bits set, it means a + * network is playing bad games with TOS bits. In order to + * avoid possible false congestion notifications, we disable + * TCP ECN negotiation. + * + * Exception: tcp_ca wants ECN. This is required for DCTCP + * congestion control: Linux DCTCP asserts ECT on all packets, + * including SYN, which is most optimal solution; however, + * others, such as FreeBSD do not. + * + * Exception: At least one of the reserved bits of the TCP header (th->res1) is + * set, indicating the use of a future TCP extension (such as AccECN). See + * RFC8311 §4.3 which updates RFC3168 to allow the development of such + * extensions. + */ +static void tcp_ecn_create_request(struct request_sock *req, + const struct sk_buff *skb, + const struct sock *listen_sk, + const struct dst_entry *dst) +{ + const struct tcphdr *th = tcp_hdr(skb); + const struct net *net = sock_net(listen_sk); + bool th_ecn = th->ece && th->cwr; + bool ect, ecn_ok; + u32 ecn_ok_dst; + + if (!th_ecn) + return; + + ect = !INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield); + ecn_ok_dst = dst_feature(dst, DST_FEATURE_ECN_MASK); + ecn_ok = net->ipv4.sysctl_tcp_ecn || ecn_ok_dst; + + if (((!ect || th->res1) && ecn_ok) || tcp_ca_needs_ecn(listen_sk) || + (ecn_ok_dst & DST_FEATURE_ECN_CA) || + tcp_bpf_ca_needs_ecn((struct sock *)req)) + inet_rsk(req)->ecn_ok = 1; +} + +static void tcp_openreq_init(struct request_sock *req, + const struct tcp_options_received *rx_opt, + struct sk_buff *skb, const struct sock *sk) +{ + struct inet_request_sock *ireq = inet_rsk(req); + + req->rsk_rcv_wnd = 0; /* So that tcp_send_synack() knows! */ + tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; + tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->seq + 1; + tcp_rsk(req)->snt_synack = 0; + tcp_rsk(req)->last_oow_ack_time = 0; + req->mss = rx_opt->mss_clamp; + req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0; + ireq->tstamp_ok = rx_opt->tstamp_ok; + ireq->sack_ok = rx_opt->sack_ok; + ireq->snd_wscale = rx_opt->snd_wscale; + ireq->wscale_ok = rx_opt->wscale_ok; + ireq->acked = 0; + ireq->ecn_ok = 0; + ireq->ir_rmt_port = tcp_hdr(skb)->source; + ireq->ir_num = ntohs(tcp_hdr(skb)->dest); + ireq->ir_mark = inet_request_mark(sk, skb); +#if IS_ENABLED(CONFIG_SMC) + ireq->smc_ok = rx_opt->smc_ok; +#endif +} + +struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops, + struct sock *sk_listener, + bool attach_listener) +{ + struct request_sock *req = reqsk_alloc(ops, sk_listener, + attach_listener); + + if (req) { + struct inet_request_sock *ireq = inet_rsk(req); + + ireq->ireq_opt = NULL; +#if IS_ENABLED(CONFIG_IPV6) + ireq->pktopts = NULL; +#endif + atomic64_set(&ireq->ir_cookie, 0); + ireq->ireq_state = TCP_NEW_SYN_RECV; + write_pnet(&ireq->ireq_net, sock_net(sk_listener)); + ireq->ireq_family = sk_listener->sk_family; + } + + return req; +} +EXPORT_SYMBOL(inet_reqsk_alloc); + +/* + * Return true if a syncookie should be sent + */ +static bool tcp_syn_flood_action(const struct sock *sk, const char *proto) +{ + struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; + const char *msg = "Dropping request"; + struct net *net = sock_net(sk); + bool want_cookie = false; + u8 syncookies; + + syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies); + +#ifdef CONFIG_SYN_COOKIES + if (syncookies) { + msg = "Sending cookies"; + want_cookie = true; + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPREQQFULLDOCOOKIES); + } else +#endif + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP); + + if (!queue->synflood_warned && syncookies != 2 && + xchg(&queue->synflood_warned, 1) == 0) + net_info_ratelimited("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n", + proto, sk->sk_num, msg); + + return want_cookie; +} + +static void tcp_reqsk_record_syn(const struct sock *sk, + struct request_sock *req, + const struct sk_buff *skb) +{ + if (tcp_sk(sk)->save_syn) { + u32 len = skb_network_header_len(skb) + tcp_hdrlen(skb); + struct saved_syn *saved_syn; + u32 mac_hdrlen; + void *base; + + if (tcp_sk(sk)->save_syn == 2) { /* Save full header. */ + base = skb_mac_header(skb); + mac_hdrlen = skb_mac_header_len(skb); + len += mac_hdrlen; + } else { + base = skb_network_header(skb); + mac_hdrlen = 0; + } + + saved_syn = kmalloc(struct_size(saved_syn, data, len), + GFP_ATOMIC); + if (saved_syn) { + saved_syn->mac_hdrlen = mac_hdrlen; + saved_syn->network_hdrlen = skb_network_header_len(skb); + saved_syn->tcp_hdrlen = tcp_hdrlen(skb); + memcpy(saved_syn->data, base, len); + req->saved_syn = saved_syn; + } + } +} + +/* If a SYN cookie is required and supported, returns a clamped MSS value to be + * used for SYN cookie generation. + */ +u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, + const struct tcp_request_sock_ops *af_ops, + struct sock *sk, struct tcphdr *th) +{ + struct tcp_sock *tp = tcp_sk(sk); + u16 mss; + + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) != 2 && + !inet_csk_reqsk_queue_is_full(sk)) + return 0; + + if (!tcp_syn_flood_action(sk, rsk_ops->slab_name)) + return 0; + + if (sk_acceptq_is_full(sk)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); + return 0; + } + + mss = tcp_parse_mss_option(th, tp->rx_opt.user_mss); + if (!mss) + mss = af_ops->mss_clamp; + + return mss; +} +EXPORT_SYMBOL_GPL(tcp_get_syncookie_mss); + +int tcp_conn_request(struct request_sock_ops *rsk_ops, + const struct tcp_request_sock_ops *af_ops, + struct sock *sk, struct sk_buff *skb) +{ + struct tcp_fastopen_cookie foc = { .len = -1 }; + __u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn; + struct tcp_options_received tmp_opt; + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + struct sock *fastopen_sk = NULL; + struct request_sock *req; + bool want_cookie = false; + struct dst_entry *dst; + struct flowi fl; + u8 syncookies; + + syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies); + + /* TW buckets are converted to open requests without + * limitations, they conserve resources and peer is + * evidently real one. + */ + if ((syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) && !isn) { + want_cookie = tcp_syn_flood_action(sk, rsk_ops->slab_name); + if (!want_cookie) + goto drop; + } + + if (sk_acceptq_is_full(sk)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); + goto drop; + } + + req = inet_reqsk_alloc(rsk_ops, sk, !want_cookie); + if (!req) + goto drop; + + req->syncookie = want_cookie; + tcp_rsk(req)->af_specific = af_ops; + tcp_rsk(req)->ts_off = 0; +#if IS_ENABLED(CONFIG_MPTCP) + tcp_rsk(req)->is_mptcp = 0; +#endif + + tcp_clear_options(&tmp_opt); + tmp_opt.mss_clamp = af_ops->mss_clamp; + tmp_opt.user_mss = tp->rx_opt.user_mss; + tcp_parse_options(sock_net(sk), skb, &tmp_opt, 0, + want_cookie ? NULL : &foc); + + if (want_cookie && !tmp_opt.saw_tstamp) + tcp_clear_options(&tmp_opt); + + if (IS_ENABLED(CONFIG_SMC) && want_cookie) + tmp_opt.smc_ok = 0; + + tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; + tcp_openreq_init(req, &tmp_opt, skb, sk); + inet_rsk(req)->no_srccheck = inet_sk(sk)->transparent; + + /* Note: tcp_v6_init_req() might override ir_iif for link locals */ + inet_rsk(req)->ir_iif = inet_request_bound_dev_if(sk, skb); + + af_ops->init_req(req, sk, skb); + + if (security_inet_conn_request(sk, skb, req)) + goto drop_and_free; + + if (tmp_opt.tstamp_ok) + tcp_rsk(req)->ts_off = af_ops->init_ts_off(net, skb); + + dst = af_ops->route_req(sk, &fl, req); + if (!dst) + goto drop_and_free; + + if (!want_cookie && !isn) { + int max_syn_backlog = READ_ONCE(net->ipv4.sysctl_max_syn_backlog); + + /* Kill the following clause, if you dislike this way. */ + if (!syncookies && + (max_syn_backlog - inet_csk_reqsk_queue_len(sk) < + (max_syn_backlog >> 2)) && + !tcp_peer_is_proven(req, dst)) { + /* Without syncookies last quarter of + * backlog is filled with destinations, + * proven to be alive. + * It means that we continue to communicate + * to destinations, already remembered + * to the moment of synflood. + */ + pr_drop_req(req, ntohs(tcp_hdr(skb)->source), + rsk_ops->family); + goto drop_and_release; + } + + isn = af_ops->init_seq(skb); + } + + tcp_ecn_create_request(req, skb, sk, dst); + + if (want_cookie) { + isn = cookie_init_sequence(af_ops, sk, skb, &req->mss); + if (!tmp_opt.tstamp_ok) + inet_rsk(req)->ecn_ok = 0; + } + + tcp_rsk(req)->snt_isn = isn; + tcp_rsk(req)->txhash = net_tx_rndhash(); + tcp_rsk(req)->syn_tos = TCP_SKB_CB(skb)->ip_dsfield; + tcp_openreq_init_rwin(req, sk, dst); + sk_rx_queue_set(req_to_sk(req), skb); + if (!want_cookie) { + tcp_reqsk_record_syn(sk, req, skb); + fastopen_sk = tcp_try_fastopen(sk, skb, req, &foc, dst); + } + if (fastopen_sk) { + af_ops->send_synack(fastopen_sk, dst, &fl, req, + &foc, TCP_SYNACK_FASTOPEN, skb); + /* Add the child socket directly into the accept queue */ + if (!inet_csk_reqsk_queue_add(sk, req, fastopen_sk)) { + reqsk_fastopen_remove(fastopen_sk, req, false); + bh_unlock_sock(fastopen_sk); + sock_put(fastopen_sk); + goto drop_and_free; + } + sk->sk_data_ready(sk); + bh_unlock_sock(fastopen_sk); + sock_put(fastopen_sk); + } else { + tcp_rsk(req)->tfo_listener = false; + if (!want_cookie) + inet_csk_reqsk_queue_hash_add(sk, req, + tcp_timeout_init((struct sock *)req)); + af_ops->send_synack(sk, dst, &fl, req, &foc, + !want_cookie ? TCP_SYNACK_NORMAL : + TCP_SYNACK_COOKIE, + skb); + if (want_cookie) { + reqsk_free(req); + return 0; + } + } + reqsk_put(req); + return 0; + +drop_and_release: + dst_release(dst); +drop_and_free: + __reqsk_free(req); +drop: + tcp_listendrop(sk); + return 0; +} +EXPORT_SYMBOL(tcp_conn_request); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c new file mode 100644 index 000000000..7a94acbd9 --- /dev/null +++ b/net/ipv4/tcp_ipv4.c @@ -0,0 +1,3034 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Implementation of the Transmission Control Protocol(TCP). + * + * IPv4 specific functions + * + * code split from: + * linux/ipv4/tcp.c + * linux/ipv4/tcp_input.c + * linux/ipv4/tcp_output.c + * + * See tcp.c for author information + */ + +/* + * Changes: + * David S. Miller : New socket lookup architecture. + * This code is dedicated to John Dyson. + * David S. Miller : Change semantics of established hash, + * half is devoted to TIME_WAIT sockets + * and the rest go in the other half. + * Andi Kleen : Add support for syncookies and fixed + * some bugs: ip options weren't passed to + * the TCP layer, missed a check for an + * ACK bit. + * Andi Kleen : Implemented fast path mtu discovery. + * Fixed many serious bugs in the + * request_sock handling and moved + * most of it into the af independent code. + * Added tail drop and some other bugfixes. + * Added new listen semantics. + * Mike McLagan : Routing by source + * Juan Jose Ciarlante: ip_dynaddr bits + * Andi Kleen: various fixes. + * Vitaly E. Lavrov : Transparent proxy revived after year + * coma. + * Andi Kleen : Fix new listen. + * Andi Kleen : Fix accept error reporting. + * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which + * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind + * a single port at the same time. + */ + +#define pr_fmt(fmt) "TCP: " fmt + +#include <linux/bottom_half.h> +#include <linux/types.h> +#include <linux/fcntl.h> +#include <linux/module.h> +#include <linux/random.h> +#include <linux/cache.h> +#include <linux/jhash.h> +#include <linux/init.h> +#include <linux/times.h> +#include <linux/slab.h> + +#include <net/net_namespace.h> +#include <net/icmp.h> +#include <net/inet_hashtables.h> +#include <net/tcp.h> +#include <net/transp_v6.h> +#include <net/ipv6.h> +#include <net/inet_common.h> +#include <net/timewait_sock.h> +#include <net/xfrm.h> +#include <net/secure_seq.h> +#include <net/busy_poll.h> + +#include <linux/inet.h> +#include <linux/ipv6.h> +#include <linux/stddef.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/inetdevice.h> +#include <linux/btf_ids.h> + +#include <crypto/hash.h> +#include <linux/scatterlist.h> + +#include <trace/events/tcp.h> + +#ifdef CONFIG_TCP_MD5SIG +static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, + __be32 daddr, __be32 saddr, const struct tcphdr *th); +#endif + +struct inet_hashinfo tcp_hashinfo; +EXPORT_SYMBOL(tcp_hashinfo); + +static DEFINE_PER_CPU(struct sock *, ipv4_tcp_sk); + +static u32 tcp_v4_init_seq(const struct sk_buff *skb) +{ + return secure_tcp_seq(ip_hdr(skb)->daddr, + ip_hdr(skb)->saddr, + tcp_hdr(skb)->dest, + tcp_hdr(skb)->source); +} + +static u32 tcp_v4_init_ts_off(const struct net *net, const struct sk_buff *skb) +{ + return secure_tcp_ts_off(net, ip_hdr(skb)->daddr, ip_hdr(skb)->saddr); +} + +int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) +{ + int reuse = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tw_reuse); + const struct inet_timewait_sock *tw = inet_twsk(sktw); + const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); + struct tcp_sock *tp = tcp_sk(sk); + + if (reuse == 2) { + /* Still does not detect *everything* that goes through + * lo, since we require a loopback src or dst address + * or direct binding to 'lo' interface. + */ + bool loopback = false; + if (tw->tw_bound_dev_if == LOOPBACK_IFINDEX) + loopback = true; +#if IS_ENABLED(CONFIG_IPV6) + if (tw->tw_family == AF_INET6) { + if (ipv6_addr_loopback(&tw->tw_v6_daddr) || + ipv6_addr_v4mapped_loopback(&tw->tw_v6_daddr) || + ipv6_addr_loopback(&tw->tw_v6_rcv_saddr) || + ipv6_addr_v4mapped_loopback(&tw->tw_v6_rcv_saddr)) + loopback = true; + } else +#endif + { + if (ipv4_is_loopback(tw->tw_daddr) || + ipv4_is_loopback(tw->tw_rcv_saddr)) + loopback = true; + } + if (!loopback) + reuse = 0; + } + + /* With PAWS, it is safe from the viewpoint + of data integrity. Even without PAWS it is safe provided sequence + spaces do not overlap i.e. at data rates <= 80Mbit/sec. + + Actually, the idea is close to VJ's one, only timestamp cache is + held not per host, but per port pair and TW bucket is used as state + holder. + + If TW bucket has been already destroyed we fall back to VJ's scheme + and use initial timestamp retrieved from peer table. + */ + if (tcptw->tw_ts_recent_stamp && + (!twp || (reuse && time_after32(ktime_get_seconds(), + tcptw->tw_ts_recent_stamp)))) { + /* In case of repair and re-using TIME-WAIT sockets we still + * want to be sure that it is safe as above but honor the + * sequence numbers and time stamps set as part of the repair + * process. + * + * Without this check re-using a TIME-WAIT socket with TCP + * repair would accumulate a -1 on the repair assigned + * sequence number. The first time it is reused the sequence + * is -1, the second time -2, etc. This fixes that issue + * without appearing to create any others. + */ + if (likely(!tp->repair)) { + u32 seq = tcptw->tw_snd_nxt + 65535 + 2; + + if (!seq) + seq = 1; + WRITE_ONCE(tp->write_seq, seq); + tp->rx_opt.ts_recent = tcptw->tw_ts_recent; + tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; + } + sock_hold(sktw); + return 1; + } + + return 0; +} +EXPORT_SYMBOL_GPL(tcp_twsk_unique); + +static int tcp_v4_pre_connect(struct sock *sk, struct sockaddr *uaddr, + int addr_len) +{ + /* This check is replicated from tcp_v4_connect() and intended to + * prevent BPF program called below from accessing bytes that are out + * of the bound specified by user in addr_len. + */ + if (addr_len < sizeof(struct sockaddr_in)) + return -EINVAL; + + sock_owned_by_me(sk); + + return BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr); +} + +/* This will initiate an outgoing connection. */ +int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; + struct inet_sock *inet = inet_sk(sk); + struct tcp_sock *tp = tcp_sk(sk); + __be16 orig_sport, orig_dport; + __be32 daddr, nexthop; + struct flowi4 *fl4; + struct rtable *rt; + int err; + struct ip_options_rcu *inet_opt; + struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; + + if (addr_len < sizeof(struct sockaddr_in)) + return -EINVAL; + + if (usin->sin_family != AF_INET) + return -EAFNOSUPPORT; + + nexthop = daddr = usin->sin_addr.s_addr; + inet_opt = rcu_dereference_protected(inet->inet_opt, + lockdep_sock_is_held(sk)); + if (inet_opt && inet_opt->opt.srr) { + if (!daddr) + return -EINVAL; + nexthop = inet_opt->opt.faddr; + } + + orig_sport = inet->inet_sport; + orig_dport = usin->sin_port; + fl4 = &inet->cork.fl.u.ip4; + rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, + RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, + IPPROTO_TCP, + orig_sport, orig_dport, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + if (err == -ENETUNREACH) + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); + return err; + } + + if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { + ip_rt_put(rt); + return -ENETUNREACH; + } + + if (!inet_opt || !inet_opt->opt.srr) + daddr = fl4->daddr; + + if (!inet->inet_saddr) + inet->inet_saddr = fl4->saddr; + sk_rcv_saddr_set(sk, inet->inet_saddr); + + if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { + /* Reset inherited state */ + tp->rx_opt.ts_recent = 0; + tp->rx_opt.ts_recent_stamp = 0; + if (likely(!tp->repair)) + WRITE_ONCE(tp->write_seq, 0); + } + + inet->inet_dport = usin->sin_port; + sk_daddr_set(sk, daddr); + + inet_csk(sk)->icsk_ext_hdr_len = 0; + if (inet_opt) + inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; + + tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; + + /* Socket identity is still unknown (sport may be zero). + * However we set state to SYN-SENT and not releasing socket + * lock select source port, enter ourselves into the hash tables and + * complete initialization after this. + */ + tcp_set_state(sk, TCP_SYN_SENT); + err = inet_hash_connect(tcp_death_row, sk); + if (err) + goto failure; + + sk_set_txhash(sk); + + rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, + inet->inet_sport, inet->inet_dport, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + rt = NULL; + goto failure; + } + /* OK, now commit destination to socket. */ + sk->sk_gso_type = SKB_GSO_TCPV4; + sk_setup_caps(sk, &rt->dst); + rt = NULL; + + if (likely(!tp->repair)) { + if (!tp->write_seq) + WRITE_ONCE(tp->write_seq, + secure_tcp_seq(inet->inet_saddr, + inet->inet_daddr, + inet->inet_sport, + usin->sin_port)); + tp->tsoffset = secure_tcp_ts_off(sock_net(sk), + inet->inet_saddr, + inet->inet_daddr); + } + + inet->inet_id = prandom_u32(); + + if (tcp_fastopen_defer_connect(sk, &err)) + return err; + if (err) + goto failure; + + err = tcp_connect(sk); + + if (err) + goto failure; + + return 0; + +failure: + /* + * This unhashes the socket and releases the local port, + * if necessary. + */ + tcp_set_state(sk, TCP_CLOSE); + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + inet_reset_saddr(sk); + ip_rt_put(rt); + sk->sk_route_caps = 0; + inet->inet_dport = 0; + return err; +} +EXPORT_SYMBOL(tcp_v4_connect); + +/* + * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191. + * It can be called through tcp_release_cb() if socket was owned by user + * at the time tcp_v4_err() was called to handle ICMP message. + */ +void tcp_v4_mtu_reduced(struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + struct dst_entry *dst; + u32 mtu; + + if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) + return; + mtu = READ_ONCE(tcp_sk(sk)->mtu_info); + dst = inet_csk_update_pmtu(sk, mtu); + if (!dst) + return; + + /* Something is about to be wrong... Remember soft error + * for the case, if this connection will not able to recover. + */ + if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) + sk->sk_err_soft = EMSGSIZE; + + mtu = dst_mtu(dst); + + if (inet->pmtudisc != IP_PMTUDISC_DONT && + ip_sk_accept_pmtu(sk) && + inet_csk(sk)->icsk_pmtu_cookie > mtu) { + tcp_sync_mss(sk, mtu); + + /* Resend the TCP packet because it's + * clear that the old packet has been + * dropped. This is the new "fast" path mtu + * discovery. + */ + tcp_simple_retransmit(sk); + } /* else let the usual retransmit timer handle it */ +} +EXPORT_SYMBOL(tcp_v4_mtu_reduced); + +static void do_redirect(struct sk_buff *skb, struct sock *sk) +{ + struct dst_entry *dst = __sk_dst_check(sk, 0); + + if (dst) + dst->ops->redirect(dst, sk, skb); +} + + +/* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */ +void tcp_req_err(struct sock *sk, u32 seq, bool abort) +{ + struct request_sock *req = inet_reqsk(sk); + struct net *net = sock_net(sk); + + /* ICMPs are not backlogged, hence we cannot get + * an established socket here. + */ + if (seq != tcp_rsk(req)->snt_isn) { + __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); + } else if (abort) { + /* + * Still in SYN_RECV, just remove it silently. + * There is no good way to pass the error to the newly + * created socket, and POSIX does not want network + * errors returned from accept(). + */ + inet_csk_reqsk_queue_drop(req->rsk_listener, req); + tcp_listendrop(req->rsk_listener); + } + reqsk_put(req); +} +EXPORT_SYMBOL(tcp_req_err); + +/* TCP-LD (RFC 6069) logic */ +void tcp_ld_RTO_revert(struct sock *sk, u32 seq) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + s32 remaining; + u32 delta_us; + + if (sock_owned_by_user(sk)) + return; + + if (seq != tp->snd_una || !icsk->icsk_retransmits || + !icsk->icsk_backoff) + return; + + skb = tcp_rtx_queue_head(sk); + if (WARN_ON_ONCE(!skb)) + return; + + icsk->icsk_backoff--; + icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) : TCP_TIMEOUT_INIT; + icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX); + + tcp_mstamp_refresh(tp); + delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb)); + remaining = icsk->icsk_rto - usecs_to_jiffies(delta_us); + + if (remaining > 0) { + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + remaining, TCP_RTO_MAX); + } else { + /* RTO revert clocked out retransmission. + * Will retransmit now. + */ + tcp_retransmit_timer(sk); + } +} +EXPORT_SYMBOL(tcp_ld_RTO_revert); + +/* + * This routine is called by the ICMP module when it gets some + * sort of error condition. If err < 0 then the socket should + * be closed and the error returned to the user. If err > 0 + * it's just the icmp type << 8 | icmp code. After adjustment + * header points to the first 8 bytes of the tcp header. We need + * to find the appropriate port. + * + * The locking strategy used here is very "optimistic". When + * someone else accesses the socket the ICMP is just dropped + * and for some paths there is no check at all. + * A more general error queue to queue errors for later handling + * is probably better. + * + */ + +int tcp_v4_err(struct sk_buff *skb, u32 info) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2)); + struct tcp_sock *tp; + struct inet_sock *inet; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + struct sock *sk; + struct request_sock *fastopen; + u32 seq, snd_una; + int err; + struct net *net = dev_net(skb->dev); + + sk = __inet_lookup_established(net, &tcp_hashinfo, iph->daddr, + th->dest, iph->saddr, ntohs(th->source), + inet_iif(skb), 0); + if (!sk) { + __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); + return -ENOENT; + } + if (sk->sk_state == TCP_TIME_WAIT) { + inet_twsk_put(inet_twsk(sk)); + return 0; + } + seq = ntohl(th->seq); + if (sk->sk_state == TCP_NEW_SYN_RECV) { + tcp_req_err(sk, seq, type == ICMP_PARAMETERPROB || + type == ICMP_TIME_EXCEEDED || + (type == ICMP_DEST_UNREACH && + (code == ICMP_NET_UNREACH || + code == ICMP_HOST_UNREACH))); + return 0; + } + + bh_lock_sock(sk); + /* If too many ICMPs get dropped on busy + * servers this needs to be solved differently. + * We do take care of PMTU discovery (RFC1191) special case : + * we can receive locally generated ICMP messages while socket is held. + */ + if (sock_owned_by_user(sk)) { + if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)) + __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); + } + if (sk->sk_state == TCP_CLOSE) + goto out; + + if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { + __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); + goto out; + } + + tp = tcp_sk(sk); + /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ + fastopen = rcu_dereference(tp->fastopen_rsk); + snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; + if (sk->sk_state != TCP_LISTEN && + !between(seq, snd_una, tp->snd_nxt)) { + __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); + goto out; + } + + switch (type) { + case ICMP_REDIRECT: + if (!sock_owned_by_user(sk)) + do_redirect(skb, sk); + goto out; + case ICMP_SOURCE_QUENCH: + /* Just silently ignore these. */ + goto out; + case ICMP_PARAMETERPROB: + err = EPROTO; + break; + case ICMP_DEST_UNREACH: + if (code > NR_ICMP_UNREACH) + goto out; + + if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ + /* We are not interested in TCP_LISTEN and open_requests + * (SYN-ACKs send out by Linux are always <576bytes so + * they should go through unfragmented). + */ + if (sk->sk_state == TCP_LISTEN) + goto out; + + WRITE_ONCE(tp->mtu_info, info); + if (!sock_owned_by_user(sk)) { + tcp_v4_mtu_reduced(sk); + } else { + if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &sk->sk_tsq_flags)) + sock_hold(sk); + } + goto out; + } + + err = icmp_err_convert[code].errno; + /* check if this ICMP message allows revert of backoff. + * (see RFC 6069) + */ + if (!fastopen && + (code == ICMP_NET_UNREACH || code == ICMP_HOST_UNREACH)) + tcp_ld_RTO_revert(sk, seq); + break; + case ICMP_TIME_EXCEEDED: + err = EHOSTUNREACH; + break; + default: + goto out; + } + + switch (sk->sk_state) { + case TCP_SYN_SENT: + case TCP_SYN_RECV: + /* Only in fast or simultaneous open. If a fast open socket is + * already accepted it is treated as a connected one below. + */ + if (fastopen && !fastopen->sk) + break; + + ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th); + + if (!sock_owned_by_user(sk)) { + sk->sk_err = err; + + sk->sk_error_report(sk); + + tcp_done(sk); + } else { + sk->sk_err_soft = err; + } + goto out; + } + + /* If we've already connected we will keep trying + * until we time out, or the user gives up. + * + * rfc1122 4.2.3.9 allows to consider as hard errors + * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, + * but it is obsoleted by pmtu discovery). + * + * Note, that in modern internet, where routing is unreliable + * and in each dark corner broken firewalls sit, sending random + * errors ordered by their masters even this two messages finally lose + * their original sense (even Linux sends invalid PORT_UNREACHs) + * + * Now we are in compliance with RFCs. + * --ANK (980905) + */ + + inet = inet_sk(sk); + if (!sock_owned_by_user(sk) && inet->recverr) { + sk->sk_err = err; + sk->sk_error_report(sk); + } else { /* Only an error on timeout */ + sk->sk_err_soft = err; + } + +out: + bh_unlock_sock(sk); + sock_put(sk); + return 0; +} + +void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr) +{ + struct tcphdr *th = tcp_hdr(skb); + + th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0); + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct tcphdr, check); +} + +/* This routine computes an IPv4 TCP checksum. */ +void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) +{ + const struct inet_sock *inet = inet_sk(sk); + + __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr); +} +EXPORT_SYMBOL(tcp_v4_send_check); + +/* + * This routine will send an RST to the other tcp. + * + * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) + * for reset. + * Answer: if a packet caused RST, it is not for a socket + * existing in our system, if it is matched to a socket, + * it is just duplicate segment or bug in other side's TCP. + * So that we build reply only basing on parameters + * arrived with segment. + * Exception: precedence violation. We do not implement it in any case. + */ + +static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) +{ + const struct tcphdr *th = tcp_hdr(skb); + struct { + struct tcphdr th; +#ifdef CONFIG_TCP_MD5SIG + __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)]; +#endif + } rep; + struct ip_reply_arg arg; +#ifdef CONFIG_TCP_MD5SIG + struct tcp_md5sig_key *key = NULL; + const __u8 *hash_location = NULL; + unsigned char newhash[16]; + int genhash; + struct sock *sk1 = NULL; +#endif + u64 transmit_time = 0; + struct sock *ctl_sk; + struct net *net; + + /* Never send a reset in response to a reset. */ + if (th->rst) + return; + + /* If sk not NULL, it means we did a successful lookup and incoming + * route had to be correct. prequeue might have dropped our dst. + */ + if (!sk && skb_rtable(skb)->rt_type != RTN_LOCAL) + return; + + /* Swap the send and the receive. */ + memset(&rep, 0, sizeof(rep)); + rep.th.dest = th->source; + rep.th.source = th->dest; + rep.th.doff = sizeof(struct tcphdr) / 4; + rep.th.rst = 1; + + if (th->ack) { + rep.th.seq = th->ack_seq; + } else { + rep.th.ack = 1; + rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + + skb->len - (th->doff << 2)); + } + + memset(&arg, 0, sizeof(arg)); + arg.iov[0].iov_base = (unsigned char *)&rep; + arg.iov[0].iov_len = sizeof(rep.th); + + net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); +#ifdef CONFIG_TCP_MD5SIG + rcu_read_lock(); + hash_location = tcp_parse_md5sig_option(th); + if (sk && sk_fullsock(sk)) { + const union tcp_md5_addr *addr; + int l3index; + + /* sdif set, means packet ingressed via a device + * in an L3 domain and inet_iif is set to it. + */ + l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; + addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; + key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); + } else if (hash_location) { + const union tcp_md5_addr *addr; + int sdif = tcp_v4_sdif(skb); + int dif = inet_iif(skb); + int l3index; + + /* + * active side is lost. Try to find listening socket through + * source port, and then find md5 key through listening socket. + * we are not loose security here: + * Incoming packet is checked with md5 hash with finding key, + * no RST generated if md5 hash doesn't match. + */ + sk1 = __inet_lookup_listener(net, &tcp_hashinfo, NULL, 0, + ip_hdr(skb)->saddr, + th->source, ip_hdr(skb)->daddr, + ntohs(th->source), dif, sdif); + /* don't send rst if it can't find key */ + if (!sk1) + goto out; + + /* sdif set, means packet ingressed via a device + * in an L3 domain and dif is set to it. + */ + l3index = sdif ? dif : 0; + addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; + key = tcp_md5_do_lookup(sk1, l3index, addr, AF_INET); + if (!key) + goto out; + + + genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb); + if (genhash || memcmp(hash_location, newhash, 16) != 0) + goto out; + + } + + if (key) { + rep.opt[0] = htonl((TCPOPT_NOP << 24) | + (TCPOPT_NOP << 16) | + (TCPOPT_MD5SIG << 8) | + TCPOLEN_MD5SIG); + /* Update length and the length the header thinks exists */ + arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; + rep.th.doff = arg.iov[0].iov_len / 4; + + tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1], + key, ip_hdr(skb)->saddr, + ip_hdr(skb)->daddr, &rep.th); + } +#endif + arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, + ip_hdr(skb)->saddr, /* XXX */ + arg.iov[0].iov_len, IPPROTO_TCP, 0); + arg.csumoffset = offsetof(struct tcphdr, check) / 2; + arg.flags = (sk && inet_sk_transparent(sk)) ? IP_REPLY_ARG_NOSRCCHECK : 0; + + /* When socket is gone, all binding information is lost. + * routing might fail in this case. No choice here, if we choose to force + * input interface, we will misroute in case of asymmetric route. + */ + if (sk) { + arg.bound_dev_if = sk->sk_bound_dev_if; + if (sk_fullsock(sk)) + trace_tcp_send_reset(sk, skb); + } + + BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) != + offsetof(struct inet_timewait_sock, tw_bound_dev_if)); + + arg.tos = ip_hdr(skb)->tos; + arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); + local_bh_disable(); + ctl_sk = this_cpu_read(ipv4_tcp_sk); + sock_net_set(ctl_sk, net); + if (sk) { + ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? + inet_twsk(sk)->tw_mark : sk->sk_mark; + ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? + inet_twsk(sk)->tw_priority : sk->sk_priority; + transmit_time = tcp_transmit_time(sk); + xfrm_sk_clone_policy(ctl_sk, sk); + } else { + ctl_sk->sk_mark = 0; + ctl_sk->sk_priority = 0; + } + ip_send_unicast_reply(ctl_sk, + skb, &TCP_SKB_CB(skb)->header.h4.opt, + ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, + &arg, arg.iov[0].iov_len, + transmit_time); + + xfrm_sk_free_policy(ctl_sk); + sock_net_set(ctl_sk, &init_net); + __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); + __TCP_INC_STATS(net, TCP_MIB_OUTRSTS); + local_bh_enable(); + +#ifdef CONFIG_TCP_MD5SIG +out: + rcu_read_unlock(); +#endif +} + +/* The code following below sending ACKs in SYN-RECV and TIME-WAIT states + outside socket context is ugly, certainly. What can I do? + */ + +static void tcp_v4_send_ack(const struct sock *sk, + struct sk_buff *skb, u32 seq, u32 ack, + u32 win, u32 tsval, u32 tsecr, int oif, + struct tcp_md5sig_key *key, + int reply_flags, u8 tos) +{ + const struct tcphdr *th = tcp_hdr(skb); + struct { + struct tcphdr th; + __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) +#ifdef CONFIG_TCP_MD5SIG + + (TCPOLEN_MD5SIG_ALIGNED >> 2) +#endif + ]; + } rep; + struct net *net = sock_net(sk); + struct ip_reply_arg arg; + struct sock *ctl_sk; + u64 transmit_time; + + memset(&rep.th, 0, sizeof(struct tcphdr)); + memset(&arg, 0, sizeof(arg)); + + arg.iov[0].iov_base = (unsigned char *)&rep; + arg.iov[0].iov_len = sizeof(rep.th); + if (tsecr) { + rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | + (TCPOPT_TIMESTAMP << 8) | + TCPOLEN_TIMESTAMP); + rep.opt[1] = htonl(tsval); + rep.opt[2] = htonl(tsecr); + arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; + } + + /* Swap the send and the receive. */ + rep.th.dest = th->source; + rep.th.source = th->dest; + rep.th.doff = arg.iov[0].iov_len / 4; + rep.th.seq = htonl(seq); + rep.th.ack_seq = htonl(ack); + rep.th.ack = 1; + rep.th.window = htons(win); + +#ifdef CONFIG_TCP_MD5SIG + if (key) { + int offset = (tsecr) ? 3 : 0; + + rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | + (TCPOPT_NOP << 16) | + (TCPOPT_MD5SIG << 8) | + TCPOLEN_MD5SIG); + arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; + rep.th.doff = arg.iov[0].iov_len/4; + + tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], + key, ip_hdr(skb)->saddr, + ip_hdr(skb)->daddr, &rep.th); + } +#endif + arg.flags = reply_flags; + arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, + ip_hdr(skb)->saddr, /* XXX */ + arg.iov[0].iov_len, IPPROTO_TCP, 0); + arg.csumoffset = offsetof(struct tcphdr, check) / 2; + if (oif) + arg.bound_dev_if = oif; + arg.tos = tos; + arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL); + local_bh_disable(); + ctl_sk = this_cpu_read(ipv4_tcp_sk); + sock_net_set(ctl_sk, net); + ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? + inet_twsk(sk)->tw_mark : sk->sk_mark; + ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? + inet_twsk(sk)->tw_priority : sk->sk_priority; + transmit_time = tcp_transmit_time(sk); + ip_send_unicast_reply(ctl_sk, + skb, &TCP_SKB_CB(skb)->header.h4.opt, + ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, + &arg, arg.iov[0].iov_len, + transmit_time); + + sock_net_set(ctl_sk, &init_net); + __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); + local_bh_enable(); +} + +static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) +{ + struct inet_timewait_sock *tw = inet_twsk(sk); + struct tcp_timewait_sock *tcptw = tcp_twsk(sk); + + tcp_v4_send_ack(sk, skb, + tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, + tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, + tcp_time_stamp_raw() + tcptw->tw_ts_offset, + tcptw->tw_ts_recent, + tw->tw_bound_dev_if, + tcp_twsk_md5_key(tcptw), + tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, + tw->tw_tos + ); + + inet_twsk_put(tw); +} + +static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + const union tcp_md5_addr *addr; + int l3index; + + /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV + * sk->sk_state == TCP_SYN_RECV -> for Fast Open. + */ + u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 : + tcp_sk(sk)->snd_nxt; + + /* RFC 7323 2.3 + * The window field (SEG.WND) of every outgoing segment, with the + * exception of <SYN> segments, MUST be right-shifted by + * Rcv.Wind.Shift bits: + */ + addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; + l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; + tcp_v4_send_ack(sk, skb, seq, + tcp_rsk(req)->rcv_nxt, + req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, + tcp_time_stamp_raw() + tcp_rsk(req)->ts_off, + READ_ONCE(req->ts_recent), + 0, + tcp_md5_do_lookup(sk, l3index, addr, AF_INET), + inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, + ip_hdr(skb)->tos); +} + +/* + * Send a SYN-ACK after having received a SYN. + * This still operates on a request_sock only, not on a big + * socket. + */ +static int tcp_v4_send_synack(const struct sock *sk, struct dst_entry *dst, + struct flowi *fl, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + enum tcp_synack_type synack_type, + struct sk_buff *syn_skb) +{ + const struct inet_request_sock *ireq = inet_rsk(req); + struct flowi4 fl4; + int err = -1; + struct sk_buff *skb; + u8 tos; + + /* First, grab a route. */ + if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) + return -1; + + skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); + + if (skb) { + __tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr); + + tos = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ? + (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | + (inet_sk(sk)->tos & INET_ECN_MASK) : + inet_sk(sk)->tos; + + if (!INET_ECN_is_capable(tos) && + tcp_bpf_ca_needs_ecn((struct sock *)req)) + tos |= INET_ECN_ECT_0; + + rcu_read_lock(); + err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, + ireq->ir_rmt_addr, + rcu_dereference(ireq->ireq_opt), + tos); + rcu_read_unlock(); + err = net_xmit_eval(err); + } + + return err; +} + +/* + * IPv4 request_sock destructor. + */ +static void tcp_v4_reqsk_destructor(struct request_sock *req) +{ + kfree(rcu_dereference_protected(inet_rsk(req)->ireq_opt, 1)); +} + +#ifdef CONFIG_TCP_MD5SIG +/* + * RFC2385 MD5 checksumming requires a mapping of + * IP address->MD5 Key. + * We need to maintain these in the sk structure. + */ + +DEFINE_STATIC_KEY_FALSE(tcp_md5_needed); +EXPORT_SYMBOL(tcp_md5_needed); + +static bool better_md5_match(struct tcp_md5sig_key *old, struct tcp_md5sig_key *new) +{ + if (!old) + return true; + + /* l3index always overrides non-l3index */ + if (old->l3index && new->l3index == 0) + return false; + if (old->l3index == 0 && new->l3index) + return true; + + return old->prefixlen < new->prefixlen; +} + +/* Find the Key structure for an address. */ +struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, + const union tcp_md5_addr *addr, + int family) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct tcp_md5sig_key *key; + const struct tcp_md5sig_info *md5sig; + __be32 mask; + struct tcp_md5sig_key *best_match = NULL; + bool match; + + /* caller either holds rcu_read_lock() or socket lock */ + md5sig = rcu_dereference_check(tp->md5sig_info, + lockdep_sock_is_held(sk)); + if (!md5sig) + return NULL; + + hlist_for_each_entry_rcu(key, &md5sig->head, node, + lockdep_sock_is_held(sk)) { + if (key->family != family) + continue; + if (key->l3index && key->l3index != l3index) + continue; + if (family == AF_INET) { + mask = inet_make_mask(key->prefixlen); + match = (key->addr.a4.s_addr & mask) == + (addr->a4.s_addr & mask); +#if IS_ENABLED(CONFIG_IPV6) + } else if (family == AF_INET6) { + match = ipv6_prefix_equal(&key->addr.a6, &addr->a6, + key->prefixlen); +#endif + } else { + match = false; + } + + if (match && better_md5_match(best_match, key)) + best_match = key; + } + return best_match; +} +EXPORT_SYMBOL(__tcp_md5_do_lookup); + +static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk, + const union tcp_md5_addr *addr, + int family, u8 prefixlen, + int l3index) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct tcp_md5sig_key *key; + unsigned int size = sizeof(struct in_addr); + const struct tcp_md5sig_info *md5sig; + + /* caller either holds rcu_read_lock() or socket lock */ + md5sig = rcu_dereference_check(tp->md5sig_info, + lockdep_sock_is_held(sk)); + if (!md5sig) + return NULL; +#if IS_ENABLED(CONFIG_IPV6) + if (family == AF_INET6) + size = sizeof(struct in6_addr); +#endif + hlist_for_each_entry_rcu(key, &md5sig->head, node, + lockdep_sock_is_held(sk)) { + if (key->family != family) + continue; + if (key->l3index != l3index) + continue; + if (!memcmp(&key->addr, addr, size) && + key->prefixlen == prefixlen) + return key; + } + return NULL; +} + +struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, + const struct sock *addr_sk) +{ + const union tcp_md5_addr *addr; + int l3index; + + l3index = l3mdev_master_ifindex_by_index(sock_net(sk), + addr_sk->sk_bound_dev_if); + addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr; + return tcp_md5_do_lookup(sk, l3index, addr, AF_INET); +} +EXPORT_SYMBOL(tcp_v4_md5_lookup); + +/* This can be called on a newly created socket, from other files */ +int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, + int family, u8 prefixlen, int l3index, + const u8 *newkey, u8 newkeylen, gfp_t gfp) +{ + /* Add Key to the list */ + struct tcp_md5sig_key *key; + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_md5sig_info *md5sig; + + key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index); + if (key) { + /* Pre-existing entry - just update that one. + * Note that the key might be used concurrently. + * data_race() is telling kcsan that we do not care of + * key mismatches, since changing MD5 key on live flows + * can lead to packet drops. + */ + data_race(memcpy(key->key, newkey, newkeylen)); + + /* Pairs with READ_ONCE() in tcp_md5_hash_key(). + * Also note that a reader could catch new key->keylen value + * but old key->key[], this is the reason we use __GFP_ZERO + * at sock_kmalloc() time below these lines. + */ + WRITE_ONCE(key->keylen, newkeylen); + + return 0; + } + + md5sig = rcu_dereference_protected(tp->md5sig_info, + lockdep_sock_is_held(sk)); + if (!md5sig) { + md5sig = kmalloc(sizeof(*md5sig), gfp); + if (!md5sig) + return -ENOMEM; + + sk_nocaps_add(sk, NETIF_F_GSO_MASK); + INIT_HLIST_HEAD(&md5sig->head); + rcu_assign_pointer(tp->md5sig_info, md5sig); + } + + key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO); + if (!key) + return -ENOMEM; + if (!tcp_alloc_md5sig_pool()) { + sock_kfree_s(sk, key, sizeof(*key)); + return -ENOMEM; + } + + memcpy(key->key, newkey, newkeylen); + key->keylen = newkeylen; + key->family = family; + key->prefixlen = prefixlen; + key->l3index = l3index; + memcpy(&key->addr, addr, + (family == AF_INET6) ? sizeof(struct in6_addr) : + sizeof(struct in_addr)); + hlist_add_head_rcu(&key->node, &md5sig->head); + return 0; +} +EXPORT_SYMBOL(tcp_md5_do_add); + +int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family, + u8 prefixlen, int l3index) +{ + struct tcp_md5sig_key *key; + + key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index); + if (!key) + return -ENOENT; + hlist_del_rcu(&key->node); + atomic_sub(sizeof(*key), &sk->sk_omem_alloc); + kfree_rcu(key, rcu); + return 0; +} +EXPORT_SYMBOL(tcp_md5_do_del); + +static void tcp_clear_md5_list(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_md5sig_key *key; + struct hlist_node *n; + struct tcp_md5sig_info *md5sig; + + md5sig = rcu_dereference_protected(tp->md5sig_info, 1); + + hlist_for_each_entry_safe(key, n, &md5sig->head, node) { + hlist_del_rcu(&key->node); + atomic_sub(sizeof(*key), &sk->sk_omem_alloc); + kfree_rcu(key, rcu); + } +} + +static int tcp_v4_parse_md5_keys(struct sock *sk, int optname, + sockptr_t optval, int optlen) +{ + struct tcp_md5sig cmd; + struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; + const union tcp_md5_addr *addr; + u8 prefixlen = 32; + int l3index = 0; + + if (optlen < sizeof(cmd)) + return -EINVAL; + + if (copy_from_sockptr(&cmd, optval, sizeof(cmd))) + return -EFAULT; + + if (sin->sin_family != AF_INET) + return -EINVAL; + + if (optname == TCP_MD5SIG_EXT && + cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { + prefixlen = cmd.tcpm_prefixlen; + if (prefixlen > 32) + return -EINVAL; + } + + if (optname == TCP_MD5SIG_EXT && + cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) { + struct net_device *dev; + + rcu_read_lock(); + dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex); + if (dev && netif_is_l3_master(dev)) + l3index = dev->ifindex; + + rcu_read_unlock(); + + /* ok to reference set/not set outside of rcu; + * right now device MUST be an L3 master + */ + if (!dev || !l3index) + return -EINVAL; + } + + addr = (union tcp_md5_addr *)&sin->sin_addr.s_addr; + + if (!cmd.tcpm_keylen) + return tcp_md5_do_del(sk, addr, AF_INET, prefixlen, l3index); + + if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) + return -EINVAL; + + return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, + cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); +} + +static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp, + __be32 daddr, __be32 saddr, + const struct tcphdr *th, int nbytes) +{ + struct tcp4_pseudohdr *bp; + struct scatterlist sg; + struct tcphdr *_th; + + bp = hp->scratch; + bp->saddr = saddr; + bp->daddr = daddr; + bp->pad = 0; + bp->protocol = IPPROTO_TCP; + bp->len = cpu_to_be16(nbytes); + + _th = (struct tcphdr *)(bp + 1); + memcpy(_th, th, sizeof(*th)); + _th->check = 0; + + sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); + ahash_request_set_crypt(hp->md5_req, &sg, NULL, + sizeof(*bp) + sizeof(*th)); + return crypto_ahash_update(hp->md5_req); +} + +static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, + __be32 daddr, __be32 saddr, const struct tcphdr *th) +{ + struct tcp_md5sig_pool *hp; + struct ahash_request *req; + + hp = tcp_get_md5sig_pool(); + if (!hp) + goto clear_hash_noput; + req = hp->md5_req; + + if (crypto_ahash_init(req)) + goto clear_hash; + if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2)) + goto clear_hash; + if (tcp_md5_hash_key(hp, key)) + goto clear_hash; + ahash_request_set_crypt(req, NULL, md5_hash, 0); + if (crypto_ahash_final(req)) + goto clear_hash; + + tcp_put_md5sig_pool(); + return 0; + +clear_hash: + tcp_put_md5sig_pool(); +clear_hash_noput: + memset(md5_hash, 0, 16); + return 1; +} + +int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, + const struct sock *sk, + const struct sk_buff *skb) +{ + struct tcp_md5sig_pool *hp; + struct ahash_request *req; + const struct tcphdr *th = tcp_hdr(skb); + __be32 saddr, daddr; + + if (sk) { /* valid for establish/request sockets */ + saddr = sk->sk_rcv_saddr; + daddr = sk->sk_daddr; + } else { + const struct iphdr *iph = ip_hdr(skb); + saddr = iph->saddr; + daddr = iph->daddr; + } + + hp = tcp_get_md5sig_pool(); + if (!hp) + goto clear_hash_noput; + req = hp->md5_req; + + if (crypto_ahash_init(req)) + goto clear_hash; + + if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, skb->len)) + goto clear_hash; + if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) + goto clear_hash; + if (tcp_md5_hash_key(hp, key)) + goto clear_hash; + ahash_request_set_crypt(req, NULL, md5_hash, 0); + if (crypto_ahash_final(req)) + goto clear_hash; + + tcp_put_md5sig_pool(); + return 0; + +clear_hash: + tcp_put_md5sig_pool(); +clear_hash_noput: + memset(md5_hash, 0, 16); + return 1; +} +EXPORT_SYMBOL(tcp_v4_md5_hash_skb); + +#endif + +/* Called with rcu_read_lock() */ +static bool tcp_v4_inbound_md5_hash(const struct sock *sk, + const struct sk_buff *skb, + int dif, int sdif) +{ +#ifdef CONFIG_TCP_MD5SIG + /* + * This gets called for each TCP segment that arrives + * so we want to be efficient. + * We have 3 drop cases: + * o No MD5 hash and one expected. + * o MD5 hash and we're not expecting one. + * o MD5 hash and its wrong. + */ + const __u8 *hash_location = NULL; + struct tcp_md5sig_key *hash_expected; + const struct iphdr *iph = ip_hdr(skb); + const struct tcphdr *th = tcp_hdr(skb); + const union tcp_md5_addr *addr; + unsigned char newhash[16]; + int genhash, l3index; + + /* sdif set, means packet ingressed via a device + * in an L3 domain and dif is set to the l3mdev + */ + l3index = sdif ? dif : 0; + + addr = (union tcp_md5_addr *)&iph->saddr; + hash_expected = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); + hash_location = tcp_parse_md5sig_option(th); + + /* We've parsed the options - do we have a hash? */ + if (!hash_expected && !hash_location) + return false; + + if (hash_expected && !hash_location) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); + return true; + } + + if (!hash_expected && hash_location) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); + return true; + } + + /* Okay, so this is hash_expected and hash_location - + * so we need to calculate the checksum. + */ + genhash = tcp_v4_md5_hash_skb(newhash, + hash_expected, + NULL, skb); + + if (genhash || memcmp(hash_location, newhash, 16) != 0) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE); + net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n", + &iph->saddr, ntohs(th->source), + &iph->daddr, ntohs(th->dest), + genhash ? " tcp_v4_calc_md5_hash failed" + : "", l3index); + return true; + } + return false; +#endif + return false; +} + +static void tcp_v4_init_req(struct request_sock *req, + const struct sock *sk_listener, + struct sk_buff *skb) +{ + struct inet_request_sock *ireq = inet_rsk(req); + struct net *net = sock_net(sk_listener); + + sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); + sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); + RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(net, skb)); +} + +static struct dst_entry *tcp_v4_route_req(const struct sock *sk, + struct flowi *fl, + const struct request_sock *req) +{ + return inet_csk_route_req(sk, &fl->u.ip4, req); +} + +struct request_sock_ops tcp_request_sock_ops __read_mostly = { + .family = PF_INET, + .obj_size = sizeof(struct tcp_request_sock), + .rtx_syn_ack = tcp_rtx_synack, + .send_ack = tcp_v4_reqsk_send_ack, + .destructor = tcp_v4_reqsk_destructor, + .send_reset = tcp_v4_send_reset, + .syn_ack_timeout = tcp_syn_ack_timeout, +}; + +const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { + .mss_clamp = TCP_MSS_DEFAULT, +#ifdef CONFIG_TCP_MD5SIG + .req_md5_lookup = tcp_v4_md5_lookup, + .calc_md5_hash = tcp_v4_md5_hash_skb, +#endif + .init_req = tcp_v4_init_req, +#ifdef CONFIG_SYN_COOKIES + .cookie_init_seq = cookie_v4_init_sequence, +#endif + .route_req = tcp_v4_route_req, + .init_seq = tcp_v4_init_seq, + .init_ts_off = tcp_v4_init_ts_off, + .send_synack = tcp_v4_send_synack, +}; + +int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) +{ + /* Never answer to SYNs send to broadcast or multicast */ + if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) + goto drop; + + return tcp_conn_request(&tcp_request_sock_ops, + &tcp_request_sock_ipv4_ops, sk, skb); + +drop: + tcp_listendrop(sk); + return 0; +} +EXPORT_SYMBOL(tcp_v4_conn_request); + + +/* + * The three way handshake has completed - we got a valid synack - + * now create the new socket. + */ +struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst, + struct request_sock *req_unhash, + bool *own_req) +{ + struct inet_request_sock *ireq; + bool found_dup_sk = false; + struct inet_sock *newinet; + struct tcp_sock *newtp; + struct sock *newsk; +#ifdef CONFIG_TCP_MD5SIG + const union tcp_md5_addr *addr; + struct tcp_md5sig_key *key; + int l3index; +#endif + struct ip_options_rcu *inet_opt; + + if (sk_acceptq_is_full(sk)) + goto exit_overflow; + + newsk = tcp_create_openreq_child(sk, req, skb); + if (!newsk) + goto exit_nonewsk; + + newsk->sk_gso_type = SKB_GSO_TCPV4; + inet_sk_rx_dst_set(newsk, skb); + + newtp = tcp_sk(newsk); + newinet = inet_sk(newsk); + ireq = inet_rsk(req); + sk_daddr_set(newsk, ireq->ir_rmt_addr); + sk_rcv_saddr_set(newsk, ireq->ir_loc_addr); + newsk->sk_bound_dev_if = ireq->ir_iif; + newinet->inet_saddr = ireq->ir_loc_addr; + inet_opt = rcu_dereference(ireq->ireq_opt); + RCU_INIT_POINTER(newinet->inet_opt, inet_opt); + newinet->mc_index = inet_iif(skb); + newinet->mc_ttl = ip_hdr(skb)->ttl; + newinet->rcv_tos = ip_hdr(skb)->tos; + inet_csk(newsk)->icsk_ext_hdr_len = 0; + if (inet_opt) + inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; + newinet->inet_id = prandom_u32(); + + /* Set ToS of the new socket based upon the value of incoming SYN. + * ECT bits are set later in tcp_init_transfer(). + */ + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) + newinet->tos = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; + + if (!dst) { + dst = inet_csk_route_child_sock(sk, newsk, req); + if (!dst) + goto put_and_exit; + } else { + /* syncookie case : see end of cookie_v4_check() */ + } + sk_setup_caps(newsk, dst); + + tcp_ca_openreq_child(newsk, dst); + + tcp_sync_mss(newsk, dst_mtu(dst)); + newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); + + tcp_initialize_rcv_mss(newsk); + +#ifdef CONFIG_TCP_MD5SIG + l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif); + /* Copy over the MD5 key from the original socket */ + addr = (union tcp_md5_addr *)&newinet->inet_daddr; + key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); + if (key) { + /* + * We're using one, so create a matching key + * on the newsk structure. If we fail to get + * memory, then we end up not copying the key + * across. Shucks. + */ + tcp_md5_do_add(newsk, addr, AF_INET, 32, l3index, + key->key, key->keylen, GFP_ATOMIC); + sk_nocaps_add(newsk, NETIF_F_GSO_MASK); + } +#endif + + if (__inet_inherit_port(sk, newsk) < 0) + goto put_and_exit; + *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), + &found_dup_sk); + if (likely(*own_req)) { + tcp_move_syn(newtp, req); + ireq->ireq_opt = NULL; + } else { + newinet->inet_opt = NULL; + + if (!req_unhash && found_dup_sk) { + /* This code path should only be executed in the + * syncookie case only + */ + bh_unlock_sock(newsk); + sock_put(newsk); + newsk = NULL; + } + } + return newsk; + +exit_overflow: + NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); +exit_nonewsk: + dst_release(dst); +exit: + tcp_listendrop(sk); + return NULL; +put_and_exit: + newinet->inet_opt = NULL; + inet_csk_prepare_forced_close(newsk); + tcp_done(newsk); + goto exit; +} +EXPORT_SYMBOL(tcp_v4_syn_recv_sock); + +static struct sock *tcp_v4_cookie_check(struct sock *sk, struct sk_buff *skb) +{ +#ifdef CONFIG_SYN_COOKIES + const struct tcphdr *th = tcp_hdr(skb); + + if (!th->syn) + sk = cookie_v4_check(sk, skb); +#endif + return sk; +} + +u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, + struct tcphdr *th, u32 *cookie) +{ + u16 mss = 0; +#ifdef CONFIG_SYN_COOKIES + mss = tcp_get_syncookie_mss(&tcp_request_sock_ops, + &tcp_request_sock_ipv4_ops, sk, th); + if (mss) { + *cookie = __cookie_v4_init_sequence(iph, th, &mss); + tcp_synq_overflow(sk); + } +#endif + return mss; +} + +/* The socket must have it's spinlock held when we get + * here, unless it is a TCP_LISTEN socket. + * + * We have a potential double-lock case here, so even when + * doing backlog processing we use the BH locking scheme. + * This is because we cannot sleep with the original spinlock + * held. + */ +int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct sock *rsk; + + if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ + struct dst_entry *dst; + + dst = rcu_dereference_protected(sk->sk_rx_dst, + lockdep_sock_is_held(sk)); + + sock_rps_save_rxhash(sk, skb); + sk_mark_napi_id(sk, skb); + if (dst) { + if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif || + !dst->ops->check(dst, 0)) { + RCU_INIT_POINTER(sk->sk_rx_dst, NULL); + dst_release(dst); + } + } + tcp_rcv_established(sk, skb); + return 0; + } + + if (tcp_checksum_complete(skb)) + goto csum_err; + + if (sk->sk_state == TCP_LISTEN) { + struct sock *nsk = tcp_v4_cookie_check(sk, skb); + + if (!nsk) + goto discard; + if (nsk != sk) { + if (tcp_child_process(sk, nsk, skb)) { + rsk = nsk; + goto reset; + } + return 0; + } + } else + sock_rps_save_rxhash(sk, skb); + + if (tcp_rcv_state_process(sk, skb)) { + rsk = sk; + goto reset; + } + return 0; + +reset: + tcp_v4_send_reset(rsk, skb); +discard: + kfree_skb(skb); + /* Be careful here. If this function gets more complicated and + * gcc suffers from register pressure on the x86, sk (in %ebx) + * might be destroyed here. This current version compiles correctly, + * but you have been warned. + */ + return 0; + +csum_err: + TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); + TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); + goto discard; +} +EXPORT_SYMBOL(tcp_v4_do_rcv); + +int tcp_v4_early_demux(struct sk_buff *skb) +{ + const struct iphdr *iph; + const struct tcphdr *th; + struct sock *sk; + + if (skb->pkt_type != PACKET_HOST) + return 0; + + if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) + return 0; + + iph = ip_hdr(skb); + th = tcp_hdr(skb); + + if (th->doff < sizeof(struct tcphdr) / 4) + return 0; + + sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo, + iph->saddr, th->source, + iph->daddr, ntohs(th->dest), + skb->skb_iif, inet_sdif(skb)); + if (sk) { + skb->sk = sk; + skb->destructor = sock_edemux; + if (sk_fullsock(sk)) { + struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst); + + if (dst) + dst = dst_check(dst, 0); + if (dst && + inet_sk(sk)->rx_dst_ifindex == skb->skb_iif) + skb_dst_set_noref(skb, dst); + } + } + return 0; +} + +bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb) +{ + u32 limit, tail_gso_size, tail_gso_segs; + struct skb_shared_info *shinfo; + const struct tcphdr *th; + struct tcphdr *thtail; + struct sk_buff *tail; + unsigned int hdrlen; + bool fragstolen; + u32 gso_segs; + u32 gso_size; + int delta; + + /* In case all data was pulled from skb frags (in __pskb_pull_tail()), + * we can fix skb->truesize to its real value to avoid future drops. + * This is valid because skb is not yet charged to the socket. + * It has been noticed pure SACK packets were sometimes dropped + * (if cooked by drivers without copybreak feature). + */ + skb_condense(skb); + + skb_dst_drop(skb); + + if (unlikely(tcp_checksum_complete(skb))) { + bh_unlock_sock(sk); + __TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); + __TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); + return true; + } + + /* Attempt coalescing to last skb in backlog, even if we are + * above the limits. + * This is okay because skb capacity is limited to MAX_SKB_FRAGS. + */ + th = (const struct tcphdr *)skb->data; + hdrlen = th->doff * 4; + + tail = sk->sk_backlog.tail; + if (!tail) + goto no_coalesce; + thtail = (struct tcphdr *)tail->data; + + if (TCP_SKB_CB(tail)->end_seq != TCP_SKB_CB(skb)->seq || + TCP_SKB_CB(tail)->ip_dsfield != TCP_SKB_CB(skb)->ip_dsfield || + ((TCP_SKB_CB(tail)->tcp_flags | + TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_SYN | TCPHDR_RST | TCPHDR_URG)) || + !((TCP_SKB_CB(tail)->tcp_flags & + TCP_SKB_CB(skb)->tcp_flags) & TCPHDR_ACK) || + ((TCP_SKB_CB(tail)->tcp_flags ^ + TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || +#ifdef CONFIG_TLS_DEVICE + tail->decrypted != skb->decrypted || +#endif + !mptcp_skb_can_collapse(tail, skb) || + thtail->doff != th->doff || + memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th))) + goto no_coalesce; + + __skb_pull(skb, hdrlen); + + shinfo = skb_shinfo(skb); + gso_size = shinfo->gso_size ?: skb->len; + gso_segs = shinfo->gso_segs ?: 1; + + shinfo = skb_shinfo(tail); + tail_gso_size = shinfo->gso_size ?: (tail->len - hdrlen); + tail_gso_segs = shinfo->gso_segs ?: 1; + + if (skb_try_coalesce(tail, skb, &fragstolen, &delta)) { + TCP_SKB_CB(tail)->end_seq = TCP_SKB_CB(skb)->end_seq; + + if (likely(!before(TCP_SKB_CB(skb)->ack_seq, TCP_SKB_CB(tail)->ack_seq))) { + TCP_SKB_CB(tail)->ack_seq = TCP_SKB_CB(skb)->ack_seq; + thtail->window = th->window; + } + + /* We have to update both TCP_SKB_CB(tail)->tcp_flags and + * thtail->fin, so that the fast path in tcp_rcv_established() + * is not entered if we append a packet with a FIN. + * SYN, RST, URG are not present. + * ACK is set on both packets. + * PSH : we do not really care in TCP stack, + * at least for 'GRO' packets. + */ + thtail->fin |= th->fin; + TCP_SKB_CB(tail)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; + + if (TCP_SKB_CB(skb)->has_rxtstamp) { + TCP_SKB_CB(tail)->has_rxtstamp = true; + tail->tstamp = skb->tstamp; + skb_hwtstamps(tail)->hwtstamp = skb_hwtstamps(skb)->hwtstamp; + } + + /* Not as strict as GRO. We only need to carry mss max value */ + shinfo->gso_size = max(gso_size, tail_gso_size); + shinfo->gso_segs = min_t(u32, gso_segs + tail_gso_segs, 0xFFFF); + + sk->sk_backlog.len += delta; + __NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPBACKLOGCOALESCE); + kfree_skb_partial(skb, fragstolen); + return false; + } + __skb_push(skb, hdrlen); + +no_coalesce: + limit = (u32)READ_ONCE(sk->sk_rcvbuf) + (u32)(READ_ONCE(sk->sk_sndbuf) >> 1); + + /* Only socket owner can try to collapse/prune rx queues + * to reduce memory overhead, so add a little headroom here. + * Few sockets backlog are possibly concurrently non empty. + */ + limit += 64 * 1024; + + if (unlikely(sk_add_backlog(sk, skb, limit))) { + bh_unlock_sock(sk); + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP); + return true; + } + return false; +} +EXPORT_SYMBOL(tcp_add_backlog); + +int tcp_filter(struct sock *sk, struct sk_buff *skb) +{ + struct tcphdr *th = (struct tcphdr *)skb->data; + + return sk_filter_trim_cap(sk, skb, th->doff * 4); +} +EXPORT_SYMBOL(tcp_filter); + +static void tcp_v4_restore_cb(struct sk_buff *skb) +{ + memmove(IPCB(skb), &TCP_SKB_CB(skb)->header.h4, + sizeof(struct inet_skb_parm)); +} + +static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph, + const struct tcphdr *th) +{ + /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB() + * barrier() makes sure compiler wont play fool^Waliasing games. + */ + memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb), + sizeof(struct inet_skb_parm)); + barrier(); + + TCP_SKB_CB(skb)->seq = ntohl(th->seq); + TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + + skb->len - th->doff * 4); + TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); + TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); + TCP_SKB_CB(skb)->tcp_tw_isn = 0; + TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph); + TCP_SKB_CB(skb)->sacked = 0; + TCP_SKB_CB(skb)->has_rxtstamp = + skb->tstamp || skb_hwtstamps(skb)->hwtstamp; +} + +/* + * From tcp_input.c + */ + +int tcp_v4_rcv(struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + struct sk_buff *skb_to_free; + int sdif = inet_sdif(skb); + int dif = inet_iif(skb); + const struct iphdr *iph; + const struct tcphdr *th; + bool refcounted; + struct sock *sk; + int ret; + + if (skb->pkt_type != PACKET_HOST) + goto discard_it; + + /* Count it even if it's bad */ + __TCP_INC_STATS(net, TCP_MIB_INSEGS); + + if (!pskb_may_pull(skb, sizeof(struct tcphdr))) + goto discard_it; + + th = (const struct tcphdr *)skb->data; + + if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) + goto bad_packet; + if (!pskb_may_pull(skb, th->doff * 4)) + goto discard_it; + + /* An explanation is required here, I think. + * Packet length and doff are validated by header prediction, + * provided case of th->doff==0 is eliminated. + * So, we defer the checks. */ + + if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo)) + goto csum_error; + + th = (const struct tcphdr *)skb->data; + iph = ip_hdr(skb); +lookup: + sk = __inet_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), th->source, + th->dest, sdif, &refcounted); + if (!sk) + goto no_tcp_socket; + +process: + if (sk->sk_state == TCP_TIME_WAIT) + goto do_time_wait; + + if (sk->sk_state == TCP_NEW_SYN_RECV) { + struct request_sock *req = inet_reqsk(sk); + bool req_stolen = false; + struct sock *nsk; + + sk = req->rsk_listener; + if (unlikely(!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb) || + tcp_v4_inbound_md5_hash(sk, skb, dif, sdif))) { + sk_drops_add(sk, skb); + reqsk_put(req); + goto discard_it; + } + if (tcp_checksum_complete(skb)) { + reqsk_put(req); + goto csum_error; + } + if (unlikely(sk->sk_state != TCP_LISTEN)) { + inet_csk_reqsk_queue_drop_and_put(sk, req); + goto lookup; + } + /* We own a reference on the listener, increase it again + * as we might lose it too soon. + */ + sock_hold(sk); + refcounted = true; + nsk = NULL; + if (!tcp_filter(sk, skb)) { + th = (const struct tcphdr *)skb->data; + iph = ip_hdr(skb); + tcp_v4_fill_cb(skb, iph, th); + nsk = tcp_check_req(sk, skb, req, false, &req_stolen); + } + if (!nsk) { + reqsk_put(req); + if (req_stolen) { + /* Another cpu got exclusive access to req + * and created a full blown socket. + * Try to feed this packet to this socket + * instead of discarding it. + */ + tcp_v4_restore_cb(skb); + sock_put(sk); + goto lookup; + } + goto discard_and_relse; + } + nf_reset_ct(skb); + if (nsk == sk) { + reqsk_put(req); + tcp_v4_restore_cb(skb); + } else if (tcp_child_process(sk, nsk, skb)) { + tcp_v4_send_reset(nsk, skb); + goto discard_and_relse; + } else { + sock_put(sk); + return 0; + } + } + if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { + __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); + goto discard_and_relse; + } + + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) + goto discard_and_relse; + + if (tcp_v4_inbound_md5_hash(sk, skb, dif, sdif)) + goto discard_and_relse; + + nf_reset_ct(skb); + + if (tcp_filter(sk, skb)) + goto discard_and_relse; + th = (const struct tcphdr *)skb->data; + iph = ip_hdr(skb); + tcp_v4_fill_cb(skb, iph, th); + + skb->dev = NULL; + + if (sk->sk_state == TCP_LISTEN) { + ret = tcp_v4_do_rcv(sk, skb); + goto put_and_return; + } + + sk_incoming_cpu_update(sk); + + bh_lock_sock_nested(sk); + tcp_segs_in(tcp_sk(sk), skb); + ret = 0; + if (!sock_owned_by_user(sk)) { + skb_to_free = sk->sk_rx_skb_cache; + sk->sk_rx_skb_cache = NULL; + ret = tcp_v4_do_rcv(sk, skb); + } else { + if (tcp_add_backlog(sk, skb)) + goto discard_and_relse; + skb_to_free = NULL; + } + bh_unlock_sock(sk); + if (skb_to_free) + __kfree_skb(skb_to_free); + +put_and_return: + if (refcounted) + sock_put(sk); + + return ret; + +no_tcp_socket: + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto discard_it; + + tcp_v4_fill_cb(skb, iph, th); + + if (tcp_checksum_complete(skb)) { +csum_error: + __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); +bad_packet: + __TCP_INC_STATS(net, TCP_MIB_INERRS); + } else { + tcp_v4_send_reset(NULL, skb); + } + +discard_it: + /* Discard frame. */ + kfree_skb(skb); + return 0; + +discard_and_relse: + sk_drops_add(sk, skb); + if (refcounted) + sock_put(sk); + goto discard_it; + +do_time_wait: + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { + inet_twsk_put(inet_twsk(sk)); + goto discard_it; + } + + tcp_v4_fill_cb(skb, iph, th); + + if (tcp_checksum_complete(skb)) { + inet_twsk_put(inet_twsk(sk)); + goto csum_error; + } + switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { + case TCP_TW_SYN: { + struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), + &tcp_hashinfo, skb, + __tcp_hdrlen(th), + iph->saddr, th->source, + iph->daddr, th->dest, + inet_iif(skb), + sdif); + if (sk2) { + inet_twsk_deschedule_put(inet_twsk(sk)); + sk = sk2; + tcp_v4_restore_cb(skb); + refcounted = false; + goto process; + } + } + /* to ACK */ + fallthrough; + case TCP_TW_ACK: + tcp_v4_timewait_ack(sk, skb); + break; + case TCP_TW_RST: + tcp_v4_send_reset(sk, skb); + inet_twsk_deschedule_put(inet_twsk(sk)); + goto discard_it; + case TCP_TW_SUCCESS:; + } + goto discard_it; +} + +static struct timewait_sock_ops tcp_timewait_sock_ops = { + .twsk_obj_size = sizeof(struct tcp_timewait_sock), + .twsk_unique = tcp_twsk_unique, + .twsk_destructor= tcp_twsk_destructor, +}; + +void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + + if (dst && dst_hold_safe(dst)) { + rcu_assign_pointer(sk->sk_rx_dst, dst); + inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; + } +} +EXPORT_SYMBOL(inet_sk_rx_dst_set); + +const struct inet_connection_sock_af_ops ipv4_specific = { + .queue_xmit = ip_queue_xmit, + .send_check = tcp_v4_send_check, + .rebuild_header = inet_sk_rebuild_header, + .sk_rx_dst_set = inet_sk_rx_dst_set, + .conn_request = tcp_v4_conn_request, + .syn_recv_sock = tcp_v4_syn_recv_sock, + .net_header_len = sizeof(struct iphdr), + .setsockopt = ip_setsockopt, + .getsockopt = ip_getsockopt, + .addr2sockaddr = inet_csk_addr2sockaddr, + .sockaddr_len = sizeof(struct sockaddr_in), + .mtu_reduced = tcp_v4_mtu_reduced, +}; +EXPORT_SYMBOL(ipv4_specific); + +#ifdef CONFIG_TCP_MD5SIG +static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { + .md5_lookup = tcp_v4_md5_lookup, + .calc_md5_hash = tcp_v4_md5_hash_skb, + .md5_parse = tcp_v4_parse_md5_keys, +}; +#endif + +/* NOTE: A lot of things set to zero explicitly by call to + * sk_alloc() so need not be done here. + */ +static int tcp_v4_init_sock(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + tcp_init_sock(sk); + + icsk->icsk_af_ops = &ipv4_specific; + +#ifdef CONFIG_TCP_MD5SIG + tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; +#endif + + return 0; +} + +void tcp_v4_destroy_sock(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + trace_tcp_destroy_sock(sk); + + tcp_clear_xmit_timers(sk); + + tcp_cleanup_congestion_control(sk); + + tcp_cleanup_ulp(sk); + + /* Cleanup up the write buffer. */ + tcp_write_queue_purge(sk); + + /* Check if we want to disable active TFO */ + tcp_fastopen_active_disable_ofo_check(sk); + + /* Cleans up our, hopefully empty, out_of_order_queue. */ + skb_rbtree_purge(&tp->out_of_order_queue); + +#ifdef CONFIG_TCP_MD5SIG + /* Clean up the MD5 key list, if any */ + if (tp->md5sig_info) { + tcp_clear_md5_list(sk); + kfree_rcu(rcu_dereference_protected(tp->md5sig_info, 1), rcu); + tp->md5sig_info = NULL; + } +#endif + + /* Clean up a referenced TCP bind bucket. */ + if (inet_csk(sk)->icsk_bind_hash) + inet_put_port(sk); + + BUG_ON(rcu_access_pointer(tp->fastopen_rsk)); + + /* If socket is aborted during connect operation */ + tcp_free_fastopen_req(tp); + tcp_fastopen_destroy_cipher(sk); + tcp_saved_syn_free(tp); + + sk_sockets_allocated_dec(sk); +} +EXPORT_SYMBOL(tcp_v4_destroy_sock); + +#ifdef CONFIG_PROC_FS +/* Proc filesystem TCP sock list dumping. */ + +/* + * Get next listener socket follow cur. If cur is NULL, get first socket + * starting from bucket given in st->bucket; when st->bucket is zero the + * very first socket in the hash table is returned. + */ +static void *listening_get_next(struct seq_file *seq, void *cur) +{ + struct tcp_seq_afinfo *afinfo; + struct tcp_iter_state *st = seq->private; + struct net *net = seq_file_net(seq); + struct inet_listen_hashbucket *ilb; + struct hlist_nulls_node *node; + struct sock *sk = cur; + + if (st->bpf_seq_afinfo) + afinfo = st->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + if (!sk) { +get_head: + ilb = &tcp_hashinfo.listening_hash[st->bucket]; + spin_lock(&ilb->lock); + sk = sk_nulls_head(&ilb->nulls_head); + st->offset = 0; + goto get_sk; + } + ilb = &tcp_hashinfo.listening_hash[st->bucket]; + ++st->num; + ++st->offset; + + sk = sk_nulls_next(sk); +get_sk: + sk_nulls_for_each_from(sk, node) { + if (!net_eq(sock_net(sk), net)) + continue; + if (afinfo->family == AF_UNSPEC || + sk->sk_family == afinfo->family) + return sk; + } + spin_unlock(&ilb->lock); + st->offset = 0; + if (++st->bucket < INET_LHTABLE_SIZE) + goto get_head; + return NULL; +} + +static void *listening_get_idx(struct seq_file *seq, loff_t *pos) +{ + struct tcp_iter_state *st = seq->private; + void *rc; + + st->bucket = 0; + st->offset = 0; + rc = listening_get_next(seq, NULL); + + while (rc && *pos) { + rc = listening_get_next(seq, rc); + --*pos; + } + return rc; +} + +static inline bool empty_bucket(const struct tcp_iter_state *st) +{ + return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain); +} + +/* + * Get first established socket starting from bucket given in st->bucket. + * If st->bucket is zero, the very first socket in the hash is returned. + */ +static void *established_get_first(struct seq_file *seq) +{ + struct tcp_seq_afinfo *afinfo; + struct tcp_iter_state *st = seq->private; + struct net *net = seq_file_net(seq); + void *rc = NULL; + + if (st->bpf_seq_afinfo) + afinfo = st->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + st->offset = 0; + for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) { + struct sock *sk; + struct hlist_nulls_node *node; + spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket); + + /* Lockless fast path for the common case of empty buckets */ + if (empty_bucket(st)) + continue; + + spin_lock_bh(lock); + sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { + if ((afinfo->family != AF_UNSPEC && + sk->sk_family != afinfo->family) || + !net_eq(sock_net(sk), net)) { + continue; + } + rc = sk; + goto out; + } + spin_unlock_bh(lock); + } +out: + return rc; +} + +static void *established_get_next(struct seq_file *seq, void *cur) +{ + struct tcp_seq_afinfo *afinfo; + struct sock *sk = cur; + struct hlist_nulls_node *node; + struct tcp_iter_state *st = seq->private; + struct net *net = seq_file_net(seq); + + if (st->bpf_seq_afinfo) + afinfo = st->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + ++st->num; + ++st->offset; + + sk = sk_nulls_next(sk); + + sk_nulls_for_each_from(sk, node) { + if ((afinfo->family == AF_UNSPEC || + sk->sk_family == afinfo->family) && + net_eq(sock_net(sk), net)) + return sk; + } + + spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); + ++st->bucket; + return established_get_first(seq); +} + +static void *established_get_idx(struct seq_file *seq, loff_t pos) +{ + struct tcp_iter_state *st = seq->private; + void *rc; + + st->bucket = 0; + rc = established_get_first(seq); + + while (rc && pos) { + rc = established_get_next(seq, rc); + --pos; + } + return rc; +} + +static void *tcp_get_idx(struct seq_file *seq, loff_t pos) +{ + void *rc; + struct tcp_iter_state *st = seq->private; + + st->state = TCP_SEQ_STATE_LISTENING; + rc = listening_get_idx(seq, &pos); + + if (!rc) { + st->state = TCP_SEQ_STATE_ESTABLISHED; + rc = established_get_idx(seq, pos); + } + + return rc; +} + +static void *tcp_seek_last_pos(struct seq_file *seq) +{ + struct tcp_iter_state *st = seq->private; + int bucket = st->bucket; + int offset = st->offset; + int orig_num = st->num; + void *rc = NULL; + + switch (st->state) { + case TCP_SEQ_STATE_LISTENING: + if (st->bucket >= INET_LHTABLE_SIZE) + break; + st->state = TCP_SEQ_STATE_LISTENING; + rc = listening_get_next(seq, NULL); + while (offset-- && rc && bucket == st->bucket) + rc = listening_get_next(seq, rc); + if (rc) + break; + st->bucket = 0; + st->state = TCP_SEQ_STATE_ESTABLISHED; + fallthrough; + case TCP_SEQ_STATE_ESTABLISHED: + if (st->bucket > tcp_hashinfo.ehash_mask) + break; + rc = established_get_first(seq); + while (offset-- && rc && bucket == st->bucket) + rc = established_get_next(seq, rc); + } + + st->num = orig_num; + + return rc; +} + +void *tcp_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct tcp_iter_state *st = seq->private; + void *rc; + + if (*pos && *pos == st->last_pos) { + rc = tcp_seek_last_pos(seq); + if (rc) + goto out; + } + + st->state = TCP_SEQ_STATE_LISTENING; + st->num = 0; + st->bucket = 0; + st->offset = 0; + rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; + +out: + st->last_pos = *pos; + return rc; +} +EXPORT_SYMBOL(tcp_seq_start); + +void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct tcp_iter_state *st = seq->private; + void *rc = NULL; + + if (v == SEQ_START_TOKEN) { + rc = tcp_get_idx(seq, 0); + goto out; + } + + switch (st->state) { + case TCP_SEQ_STATE_LISTENING: + rc = listening_get_next(seq, v); + if (!rc) { + st->state = TCP_SEQ_STATE_ESTABLISHED; + st->bucket = 0; + st->offset = 0; + rc = established_get_first(seq); + } + break; + case TCP_SEQ_STATE_ESTABLISHED: + rc = established_get_next(seq, v); + break; + } +out: + ++*pos; + st->last_pos = *pos; + return rc; +} +EXPORT_SYMBOL(tcp_seq_next); + +void tcp_seq_stop(struct seq_file *seq, void *v) +{ + struct tcp_iter_state *st = seq->private; + + switch (st->state) { + case TCP_SEQ_STATE_LISTENING: + if (v != SEQ_START_TOKEN) + spin_unlock(&tcp_hashinfo.listening_hash[st->bucket].lock); + break; + case TCP_SEQ_STATE_ESTABLISHED: + if (v) + spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); + break; + } +} +EXPORT_SYMBOL(tcp_seq_stop); + +static void get_openreq4(const struct request_sock *req, + struct seq_file *f, int i) +{ + const struct inet_request_sock *ireq = inet_rsk(req); + long delta = req->rsk_timer.expires - jiffies; + + seq_printf(f, "%4d: %08X:%04X %08X:%04X" + " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK", + i, + ireq->ir_loc_addr, + ireq->ir_num, + ireq->ir_rmt_addr, + ntohs(ireq->ir_rmt_port), + TCP_SYN_RECV, + 0, 0, /* could print option size, but that is af dependent. */ + 1, /* timers active (only the expire timer) */ + jiffies_delta_to_clock_t(delta), + req->num_timeout, + from_kuid_munged(seq_user_ns(f), + sock_i_uid(req->rsk_listener)), + 0, /* non standard timer */ + 0, /* open_requests have no inode */ + 0, + req); +} + +static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) +{ + int timer_active; + unsigned long timer_expires; + const struct tcp_sock *tp = tcp_sk(sk); + const struct inet_connection_sock *icsk = inet_csk(sk); + const struct inet_sock *inet = inet_sk(sk); + const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; + __be32 dest = inet->inet_daddr; + __be32 src = inet->inet_rcv_saddr; + __u16 destp = ntohs(inet->inet_dport); + __u16 srcp = ntohs(inet->inet_sport); + int rx_queue; + int state; + + if (icsk->icsk_pending == ICSK_TIME_RETRANS || + icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || + icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { + timer_active = 1; + timer_expires = icsk->icsk_timeout; + } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { + timer_active = 4; + timer_expires = icsk->icsk_timeout; + } else if (timer_pending(&sk->sk_timer)) { + timer_active = 2; + timer_expires = sk->sk_timer.expires; + } else { + timer_active = 0; + timer_expires = jiffies; + } + + state = inet_sk_state_load(sk); + if (state == TCP_LISTEN) + rx_queue = READ_ONCE(sk->sk_ack_backlog); + else + /* Because we don't lock the socket, + * we might find a transient negative value. + */ + rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - + READ_ONCE(tp->copied_seq), 0); + + seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " + "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d", + i, src, srcp, dest, destp, state, + READ_ONCE(tp->write_seq) - tp->snd_una, + rx_queue, + timer_active, + jiffies_delta_to_clock_t(timer_expires - jiffies), + icsk->icsk_retransmits, + from_kuid_munged(seq_user_ns(f), sock_i_uid(sk)), + icsk->icsk_probes_out, + sock_i_ino(sk), + refcount_read(&sk->sk_refcnt), sk, + jiffies_to_clock_t(icsk->icsk_rto), + jiffies_to_clock_t(icsk->icsk_ack.ato), + (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sk), + tp->snd_cwnd, + state == TCP_LISTEN ? + fastopenq->max_qlen : + (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)); +} + +static void get_timewait4_sock(const struct inet_timewait_sock *tw, + struct seq_file *f, int i) +{ + long delta = tw->tw_timer.expires - jiffies; + __be32 dest, src; + __u16 destp, srcp; + + dest = tw->tw_daddr; + src = tw->tw_rcv_saddr; + destp = ntohs(tw->tw_dport); + srcp = ntohs(tw->tw_sport); + + seq_printf(f, "%4d: %08X:%04X %08X:%04X" + " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK", + i, src, srcp, dest, destp, tw->tw_substate, 0, 0, + 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, + refcount_read(&tw->tw_refcnt), tw); +} + +#define TMPSZ 150 + +static int tcp4_seq_show(struct seq_file *seq, void *v) +{ + struct tcp_iter_state *st; + struct sock *sk = v; + + seq_setwidth(seq, TMPSZ - 1); + if (v == SEQ_START_TOKEN) { + seq_puts(seq, " sl local_address rem_address st tx_queue " + "rx_queue tr tm->when retrnsmt uid timeout " + "inode"); + goto out; + } + st = seq->private; + + if (sk->sk_state == TCP_TIME_WAIT) + get_timewait4_sock(v, seq, st->num); + else if (sk->sk_state == TCP_NEW_SYN_RECV) + get_openreq4(v, seq, st->num); + else + get_tcp4_sock(v, seq, st->num); +out: + seq_pad(seq, '\n'); + return 0; +} + +#ifdef CONFIG_BPF_SYSCALL +struct bpf_iter__tcp { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct sock_common *, sk_common); + uid_t uid __aligned(8); +}; + +static int tcp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, + struct sock_common *sk_common, uid_t uid) +{ + struct bpf_iter__tcp ctx; + + meta->seq_num--; /* skip SEQ_START_TOKEN */ + ctx.meta = meta; + ctx.sk_common = sk_common; + ctx.uid = uid; + return bpf_iter_run_prog(prog, &ctx); +} + +static int bpf_iter_tcp_seq_show(struct seq_file *seq, void *v) +{ + struct bpf_iter_meta meta; + struct bpf_prog *prog; + struct sock *sk = v; + uid_t uid; + + if (v == SEQ_START_TOKEN) + return 0; + + if (sk->sk_state == TCP_TIME_WAIT) { + uid = 0; + } else if (sk->sk_state == TCP_NEW_SYN_RECV) { + const struct request_sock *req = v; + + uid = from_kuid_munged(seq_user_ns(seq), + sock_i_uid(req->rsk_listener)); + } else { + uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); + } + + meta.seq = seq; + prog = bpf_iter_get_info(&meta, false); + return tcp_prog_seq_show(prog, &meta, v, uid); +} + +static void bpf_iter_tcp_seq_stop(struct seq_file *seq, void *v) +{ + struct bpf_iter_meta meta; + struct bpf_prog *prog; + + if (!v) { + meta.seq = seq; + prog = bpf_iter_get_info(&meta, true); + if (prog) + (void)tcp_prog_seq_show(prog, &meta, v, 0); + } + + tcp_seq_stop(seq, v); +} + +static const struct seq_operations bpf_iter_tcp_seq_ops = { + .show = bpf_iter_tcp_seq_show, + .start = tcp_seq_start, + .next = tcp_seq_next, + .stop = bpf_iter_tcp_seq_stop, +}; +#endif + +static const struct seq_operations tcp4_seq_ops = { + .show = tcp4_seq_show, + .start = tcp_seq_start, + .next = tcp_seq_next, + .stop = tcp_seq_stop, +}; + +static struct tcp_seq_afinfo tcp4_seq_afinfo = { + .family = AF_INET, +}; + +static int __net_init tcp4_proc_init_net(struct net *net) +{ + if (!proc_create_net_data("tcp", 0444, net->proc_net, &tcp4_seq_ops, + sizeof(struct tcp_iter_state), &tcp4_seq_afinfo)) + return -ENOMEM; + return 0; +} + +static void __net_exit tcp4_proc_exit_net(struct net *net) +{ + remove_proc_entry("tcp", net->proc_net); +} + +static struct pernet_operations tcp4_net_ops = { + .init = tcp4_proc_init_net, + .exit = tcp4_proc_exit_net, +}; + +int __init tcp4_proc_init(void) +{ + return register_pernet_subsys(&tcp4_net_ops); +} + +void tcp4_proc_exit(void) +{ + unregister_pernet_subsys(&tcp4_net_ops); +} +#endif /* CONFIG_PROC_FS */ + +struct proto tcp_prot = { + .name = "TCP", + .owner = THIS_MODULE, + .close = tcp_close, + .pre_connect = tcp_v4_pre_connect, + .connect = tcp_v4_connect, + .disconnect = tcp_disconnect, + .accept = inet_csk_accept, + .ioctl = tcp_ioctl, + .init = tcp_v4_init_sock, + .destroy = tcp_v4_destroy_sock, + .shutdown = tcp_shutdown, + .setsockopt = tcp_setsockopt, + .getsockopt = tcp_getsockopt, + .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, + .keepalive = tcp_set_keepalive, + .recvmsg = tcp_recvmsg, + .sendmsg = tcp_sendmsg, + .sendpage = tcp_sendpage, + .backlog_rcv = tcp_v4_do_rcv, + .release_cb = tcp_release_cb, + .hash = inet_hash, + .unhash = inet_unhash, + .get_port = inet_csk_get_port, + .enter_memory_pressure = tcp_enter_memory_pressure, + .leave_memory_pressure = tcp_leave_memory_pressure, + .stream_memory_free = tcp_stream_memory_free, + .sockets_allocated = &tcp_sockets_allocated, + .orphan_count = &tcp_orphan_count, + .memory_allocated = &tcp_memory_allocated, + .memory_pressure = &tcp_memory_pressure, + .sysctl_mem = sysctl_tcp_mem, + .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), + .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), + .max_header = MAX_TCP_HEADER, + .obj_size = sizeof(struct tcp_sock), + .slab_flags = SLAB_TYPESAFE_BY_RCU, + .twsk_prot = &tcp_timewait_sock_ops, + .rsk_prot = &tcp_request_sock_ops, + .h.hashinfo = &tcp_hashinfo, + .no_autobind = true, + .diag_destroy = tcp_abort, +}; +EXPORT_SYMBOL(tcp_prot); + +static void __net_exit tcp_sk_exit(struct net *net) +{ + if (net->ipv4.tcp_congestion_control) + bpf_module_put(net->ipv4.tcp_congestion_control, + net->ipv4.tcp_congestion_control->owner); +} + +static int __net_init tcp_sk_init(struct net *net) +{ + int cnt; + + net->ipv4.sysctl_tcp_ecn = 2; + net->ipv4.sysctl_tcp_ecn_fallback = 1; + + net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS; + net->ipv4.sysctl_tcp_min_snd_mss = TCP_MIN_SND_MSS; + net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD; + net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL; + net->ipv4.sysctl_tcp_mtu_probe_floor = TCP_MIN_SND_MSS; + + net->ipv4.sysctl_tcp_keepalive_time = TCP_KEEPALIVE_TIME; + net->ipv4.sysctl_tcp_keepalive_probes = TCP_KEEPALIVE_PROBES; + net->ipv4.sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL; + + net->ipv4.sysctl_tcp_syn_retries = TCP_SYN_RETRIES; + net->ipv4.sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES; + net->ipv4.sysctl_tcp_syncookies = 1; + net->ipv4.sysctl_tcp_reordering = TCP_FASTRETRANS_THRESH; + net->ipv4.sysctl_tcp_retries1 = TCP_RETR1; + net->ipv4.sysctl_tcp_retries2 = TCP_RETR2; + net->ipv4.sysctl_tcp_orphan_retries = 0; + net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT; + net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX; + net->ipv4.sysctl_tcp_tw_reuse = 2; + net->ipv4.sysctl_tcp_no_ssthresh_metrics_save = 1; + + cnt = tcp_hashinfo.ehash_mask + 1; + net->ipv4.tcp_death_row.sysctl_max_tw_buckets = cnt / 2; + net->ipv4.tcp_death_row.hashinfo = &tcp_hashinfo; + + net->ipv4.sysctl_max_syn_backlog = max(128, cnt / 128); + net->ipv4.sysctl_tcp_sack = 1; + net->ipv4.sysctl_tcp_window_scaling = 1; + net->ipv4.sysctl_tcp_timestamps = 1; + net->ipv4.sysctl_tcp_early_retrans = 3; + net->ipv4.sysctl_tcp_recovery = TCP_RACK_LOSS_DETECTION; + net->ipv4.sysctl_tcp_slow_start_after_idle = 1; /* By default, RFC2861 behavior. */ + net->ipv4.sysctl_tcp_retrans_collapse = 1; + net->ipv4.sysctl_tcp_max_reordering = 300; + net->ipv4.sysctl_tcp_dsack = 1; + net->ipv4.sysctl_tcp_app_win = 31; + net->ipv4.sysctl_tcp_adv_win_scale = 1; + net->ipv4.sysctl_tcp_frto = 2; + net->ipv4.sysctl_tcp_moderate_rcvbuf = 1; + /* This limits the percentage of the congestion window which we + * will allow a single TSO frame to consume. Building TSO frames + * which are too large can cause TCP streams to be bursty. + */ + net->ipv4.sysctl_tcp_tso_win_divisor = 3; + /* Default TSQ limit of 16 TSO segments */ + net->ipv4.sysctl_tcp_limit_output_bytes = 16 * 65536; + /* rfc5961 challenge ack rate limiting */ + net->ipv4.sysctl_tcp_challenge_ack_limit = 1000; + net->ipv4.sysctl_tcp_min_tso_segs = 2; + net->ipv4.sysctl_tcp_min_rtt_wlen = 300; + net->ipv4.sysctl_tcp_autocorking = 1; + net->ipv4.sysctl_tcp_invalid_ratelimit = HZ/2; + net->ipv4.sysctl_tcp_pacing_ss_ratio = 200; + net->ipv4.sysctl_tcp_pacing_ca_ratio = 120; + if (net != &init_net) { + memcpy(net->ipv4.sysctl_tcp_rmem, + init_net.ipv4.sysctl_tcp_rmem, + sizeof(init_net.ipv4.sysctl_tcp_rmem)); + memcpy(net->ipv4.sysctl_tcp_wmem, + init_net.ipv4.sysctl_tcp_wmem, + sizeof(init_net.ipv4.sysctl_tcp_wmem)); + } + net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC; + net->ipv4.sysctl_tcp_comp_sack_slack_ns = 100 * NSEC_PER_USEC; + net->ipv4.sysctl_tcp_comp_sack_nr = 44; + net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE; + spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock); + net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 0; + atomic_set(&net->ipv4.tfo_active_disable_times, 0); + + /* Reno is always built in */ + if (!net_eq(net, &init_net) && + bpf_try_module_get(init_net.ipv4.tcp_congestion_control, + init_net.ipv4.tcp_congestion_control->owner)) + net->ipv4.tcp_congestion_control = init_net.ipv4.tcp_congestion_control; + else + net->ipv4.tcp_congestion_control = &tcp_reno; + + return 0; +} + +static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) +{ + struct net *net; + + inet_twsk_purge(&tcp_hashinfo, AF_INET); + + list_for_each_entry(net, net_exit_list, exit_list) + tcp_fastopen_ctx_destroy(net); +} + +static struct pernet_operations __net_initdata tcp_sk_ops = { + .init = tcp_sk_init, + .exit = tcp_sk_exit, + .exit_batch = tcp_sk_exit_batch, +}; + +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) +DEFINE_BPF_ITER_FUNC(tcp, struct bpf_iter_meta *meta, + struct sock_common *sk_common, uid_t uid) + +static int bpf_iter_init_tcp(void *priv_data, struct bpf_iter_aux_info *aux) +{ + struct tcp_iter_state *st = priv_data; + struct tcp_seq_afinfo *afinfo; + int ret; + + afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN); + if (!afinfo) + return -ENOMEM; + + afinfo->family = AF_UNSPEC; + st->bpf_seq_afinfo = afinfo; + ret = bpf_iter_init_seq_net(priv_data, aux); + if (ret) + kfree(afinfo); + return ret; +} + +static void bpf_iter_fini_tcp(void *priv_data) +{ + struct tcp_iter_state *st = priv_data; + + kfree(st->bpf_seq_afinfo); + bpf_iter_fini_seq_net(priv_data); +} + +static const struct bpf_iter_seq_info tcp_seq_info = { + .seq_ops = &bpf_iter_tcp_seq_ops, + .init_seq_private = bpf_iter_init_tcp, + .fini_seq_private = bpf_iter_fini_tcp, + .seq_priv_size = sizeof(struct tcp_iter_state), +}; + +static struct bpf_iter_reg tcp_reg_info = { + .target = "tcp", + .ctx_arg_info_size = 1, + .ctx_arg_info = { + { offsetof(struct bpf_iter__tcp, sk_common), + PTR_TO_BTF_ID_OR_NULL }, + }, + .seq_info = &tcp_seq_info, +}; + +static void __init bpf_iter_register(void) +{ + tcp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON]; + if (bpf_iter_reg_target(&tcp_reg_info)) + pr_warn("Warning: could not register bpf iterator tcp\n"); +} + +#endif + +void __init tcp_v4_init(void) +{ + int cpu, res; + + for_each_possible_cpu(cpu) { + struct sock *sk; + + res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW, + IPPROTO_TCP, &init_net); + if (res) + panic("Failed to create the TCP control socket.\n"); + sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); + + /* Please enforce IP_DF and IPID==0 for RST and + * ACK sent in SYN-RECV and TIME-WAIT state. + */ + inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO; + + per_cpu(ipv4_tcp_sk, cpu) = sk; + } + if (register_pernet_subsys(&tcp_sk_ops)) + panic("Failed to create the TCP control socket.\n"); + +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) + bpf_iter_register(); +#endif +} diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c new file mode 100644 index 000000000..8c643a4ff --- /dev/null +++ b/net/ipv4/tcp_lp.c @@ -0,0 +1,347 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP Low Priority (TCP-LP) + * + * TCP Low Priority is a distributed algorithm whose goal is to utilize only + * the excess network bandwidth as compared to the ``fair share`` of + * bandwidth as targeted by TCP. + * + * As of 2.6.13, Linux supports pluggable congestion control algorithms. + * Due to the limitation of the API, we take the following changes from + * the original TCP-LP implementation: + * o We use newReno in most core CA handling. Only add some checking + * within cong_avoid. + * o Error correcting in remote HZ, therefore remote HZ will be keeped + * on checking and updating. + * o Handling calculation of One-Way-Delay (OWD) within rtt_sample, since + * OWD have a similar meaning as RTT. Also correct the buggy formular. + * o Handle reaction for Early Congestion Indication (ECI) within + * pkts_acked, as mentioned within pseudo code. + * o OWD is handled in relative format, where local time stamp will in + * tcp_time_stamp format. + * + * Original Author: + * Aleksandar Kuzmanovic <akuzma@northwestern.edu> + * Available from: + * http://www.ece.rice.edu/~akuzma/Doc/akuzma/TCP-LP.pdf + * Original implementation for 2.4.19: + * http://www-ece.rice.edu/networks/TCP-LP/ + * + * 2.6.x module Authors: + * Wong Hoi Sing, Edison <hswong3i@gmail.com> + * Hung Hing Lun, Mike <hlhung3i@gmail.com> + * SourceForge project page: + * http://tcp-lp-mod.sourceforge.net/ + */ + +#include <linux/module.h> +#include <net/tcp.h> + +/* resolution of owd */ +#define LP_RESOL TCP_TS_HZ + +/** + * enum tcp_lp_state + * @LP_VALID_RHZ: is remote HZ valid? + * @LP_VALID_OWD: is OWD valid? + * @LP_WITHIN_THR: are we within threshold? + * @LP_WITHIN_INF: are we within inference? + * + * TCP-LP's state flags. + * We create this set of state flag mainly for debugging. + */ +enum tcp_lp_state { + LP_VALID_RHZ = (1 << 0), + LP_VALID_OWD = (1 << 1), + LP_WITHIN_THR = (1 << 3), + LP_WITHIN_INF = (1 << 4), +}; + +/** + * struct lp + * @flag: TCP-LP state flag + * @sowd: smoothed OWD << 3 + * @owd_min: min OWD + * @owd_max: max OWD + * @owd_max_rsv: resrved max owd + * @remote_hz: estimated remote HZ + * @remote_ref_time: remote reference time + * @local_ref_time: local reference time + * @last_drop: time for last active drop + * @inference: current inference + * + * TCP-LP's private struct. + * We get the idea from original TCP-LP implementation where only left those we + * found are really useful. + */ +struct lp { + u32 flag; + u32 sowd; + u32 owd_min; + u32 owd_max; + u32 owd_max_rsv; + u32 remote_hz; + u32 remote_ref_time; + u32 local_ref_time; + u32 last_drop; + u32 inference; +}; + +/** + * tcp_lp_init + * + * Init all required variables. + * Clone the handling from Vegas module implementation. + */ +static void tcp_lp_init(struct sock *sk) +{ + struct lp *lp = inet_csk_ca(sk); + + lp->flag = 0; + lp->sowd = 0; + lp->owd_min = 0xffffffff; + lp->owd_max = 0; + lp->owd_max_rsv = 0; + lp->remote_hz = 0; + lp->remote_ref_time = 0; + lp->local_ref_time = 0; + lp->last_drop = 0; + lp->inference = 0; +} + +/** + * tcp_lp_cong_avoid + * + * Implementation of cong_avoid. + * Will only call newReno CA when away from inference. + * From TCP-LP's paper, this will be handled in additive increasement. + */ +static void tcp_lp_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct lp *lp = inet_csk_ca(sk); + + if (!(lp->flag & LP_WITHIN_INF)) + tcp_reno_cong_avoid(sk, ack, acked); +} + +/** + * tcp_lp_remote_hz_estimator + * + * Estimate remote HZ. + * We keep on updating the estimated value, where original TCP-LP + * implementation only guest it for once and use forever. + */ +static u32 tcp_lp_remote_hz_estimator(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct lp *lp = inet_csk_ca(sk); + s64 rhz = lp->remote_hz << 6; /* remote HZ << 6 */ + s64 m = 0; + + /* not yet record reference time + * go away!! record it before come back!! */ + if (lp->remote_ref_time == 0 || lp->local_ref_time == 0) + goto out; + + /* we can't calc remote HZ with no different!! */ + if (tp->rx_opt.rcv_tsval == lp->remote_ref_time || + tp->rx_opt.rcv_tsecr == lp->local_ref_time) + goto out; + + m = TCP_TS_HZ * + (tp->rx_opt.rcv_tsval - lp->remote_ref_time) / + (tp->rx_opt.rcv_tsecr - lp->local_ref_time); + if (m < 0) + m = -m; + + if (rhz > 0) { + m -= rhz >> 6; /* m is now error in remote HZ est */ + rhz += m; /* 63/64 old + 1/64 new */ + } else + rhz = m << 6; + + out: + /* record time for successful remote HZ calc */ + if ((rhz >> 6) > 0) + lp->flag |= LP_VALID_RHZ; + else + lp->flag &= ~LP_VALID_RHZ; + + /* record reference time stamp */ + lp->remote_ref_time = tp->rx_opt.rcv_tsval; + lp->local_ref_time = tp->rx_opt.rcv_tsecr; + + return rhz >> 6; +} + +/** + * tcp_lp_owd_calculator + * + * Calculate one way delay (in relative format). + * Original implement OWD as minus of remote time difference to local time + * difference directly. As this time difference just simply equal to RTT, when + * the network status is stable, remote RTT will equal to local RTT, and result + * OWD into zero. + * It seems to be a bug and so we fixed it. + */ +static u32 tcp_lp_owd_calculator(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct lp *lp = inet_csk_ca(sk); + s64 owd = 0; + + lp->remote_hz = tcp_lp_remote_hz_estimator(sk); + + if (lp->flag & LP_VALID_RHZ) { + owd = + tp->rx_opt.rcv_tsval * (LP_RESOL / lp->remote_hz) - + tp->rx_opt.rcv_tsecr * (LP_RESOL / TCP_TS_HZ); + if (owd < 0) + owd = -owd; + } + + if (owd > 0) + lp->flag |= LP_VALID_OWD; + else + lp->flag &= ~LP_VALID_OWD; + + return owd; +} + +/** + * tcp_lp_rtt_sample + * + * Implementation or rtt_sample. + * Will take the following action, + * 1. calc OWD, + * 2. record the min/max OWD, + * 3. calc smoothed OWD (SOWD). + * Most ideas come from the original TCP-LP implementation. + */ +static void tcp_lp_rtt_sample(struct sock *sk, u32 rtt) +{ + struct lp *lp = inet_csk_ca(sk); + s64 mowd = tcp_lp_owd_calculator(sk); + + /* sorry that we don't have valid data */ + if (!(lp->flag & LP_VALID_RHZ) || !(lp->flag & LP_VALID_OWD)) + return; + + /* record the next min owd */ + if (mowd < lp->owd_min) + lp->owd_min = mowd; + + /* always forget the max of the max + * we just set owd_max as one below it */ + if (mowd > lp->owd_max) { + if (mowd > lp->owd_max_rsv) { + if (lp->owd_max_rsv == 0) + lp->owd_max = mowd; + else + lp->owd_max = lp->owd_max_rsv; + lp->owd_max_rsv = mowd; + } else + lp->owd_max = mowd; + } + + /* calc for smoothed owd */ + if (lp->sowd != 0) { + mowd -= lp->sowd >> 3; /* m is now error in owd est */ + lp->sowd += mowd; /* owd = 7/8 owd + 1/8 new */ + } else + lp->sowd = mowd << 3; /* take the measured time be owd */ +} + +/** + * tcp_lp_pkts_acked + * + * Implementation of pkts_acked. + * Deal with active drop under Early Congestion Indication. + * Only drop to half and 1 will be handle, because we hope to use back + * newReno in increase case. + * We work it out by following the idea from TCP-LP's paper directly + */ +static void tcp_lp_pkts_acked(struct sock *sk, const struct ack_sample *sample) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct lp *lp = inet_csk_ca(sk); + u32 now = tcp_time_stamp(tp); + u32 delta; + + if (sample->rtt_us > 0) + tcp_lp_rtt_sample(sk, sample->rtt_us); + + /* calc inference */ + delta = now - tp->rx_opt.rcv_tsecr; + if ((s32)delta > 0) + lp->inference = 3 * delta; + + /* test if within inference */ + if (lp->last_drop && (now - lp->last_drop < lp->inference)) + lp->flag |= LP_WITHIN_INF; + else + lp->flag &= ~LP_WITHIN_INF; + + /* test if within threshold */ + if (lp->sowd >> 3 < + lp->owd_min + 15 * (lp->owd_max - lp->owd_min) / 100) + lp->flag |= LP_WITHIN_THR; + else + lp->flag &= ~LP_WITHIN_THR; + + pr_debug("TCP-LP: %05o|%5u|%5u|%15u|%15u|%15u\n", lp->flag, + tp->snd_cwnd, lp->remote_hz, lp->owd_min, lp->owd_max, + lp->sowd >> 3); + + if (lp->flag & LP_WITHIN_THR) + return; + + /* FIXME: try to reset owd_min and owd_max here + * so decrease the chance the min/max is no longer suitable + * and will usually within threshold when whithin inference */ + lp->owd_min = lp->sowd >> 3; + lp->owd_max = lp->sowd >> 2; + lp->owd_max_rsv = lp->sowd >> 2; + + /* happened within inference + * drop snd_cwnd into 1 */ + if (lp->flag & LP_WITHIN_INF) + tp->snd_cwnd = 1U; + + /* happened after inference + * cut snd_cwnd into half */ + else + tp->snd_cwnd = max(tp->snd_cwnd >> 1U, 1U); + + /* record this drop time */ + lp->last_drop = now; +} + +static struct tcp_congestion_ops tcp_lp __read_mostly = { + .init = tcp_lp_init, + .ssthresh = tcp_reno_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = tcp_lp_cong_avoid, + .pkts_acked = tcp_lp_pkts_acked, + + .owner = THIS_MODULE, + .name = "lp" +}; + +static int __init tcp_lp_register(void) +{ + BUILD_BUG_ON(sizeof(struct lp) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&tcp_lp); +} + +static void __exit tcp_lp_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_lp); +} + +module_init(tcp_lp_register); +module_exit(tcp_lp_unregister); + +MODULE_AUTHOR("Wong Hoi Sing Edison, Hung Hing Lun Mike"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP Low Priority"); diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c new file mode 100644 index 000000000..f823a15b9 --- /dev/null +++ b/net/ipv4/tcp_metrics.c @@ -0,0 +1,1054 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/rcupdate.h> +#include <linux/spinlock.h> +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/cache.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/tcp.h> +#include <linux/hash.h> +#include <linux/tcp_metrics.h> +#include <linux/vmalloc.h> + +#include <net/inet_connection_sock.h> +#include <net/net_namespace.h> +#include <net/request_sock.h> +#include <net/inetpeer.h> +#include <net/sock.h> +#include <net/ipv6.h> +#include <net/dst.h> +#include <net/tcp.h> +#include <net/genetlink.h> + +static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr, + const struct inetpeer_addr *daddr, + struct net *net, unsigned int hash); + +struct tcp_fastopen_metrics { + u16 mss; + u16 syn_loss:10, /* Recurring Fast Open SYN losses */ + try_exp:2; /* Request w/ exp. option (once) */ + unsigned long last_syn_loss; /* Last Fast Open SYN loss */ + struct tcp_fastopen_cookie cookie; +}; + +/* TCP_METRIC_MAX includes 2 extra fields for userspace compatibility + * Kernel only stores RTT and RTTVAR in usec resolution + */ +#define TCP_METRIC_MAX_KERNEL (TCP_METRIC_MAX - 2) + +struct tcp_metrics_block { + struct tcp_metrics_block __rcu *tcpm_next; + struct net *tcpm_net; + struct inetpeer_addr tcpm_saddr; + struct inetpeer_addr tcpm_daddr; + unsigned long tcpm_stamp; + u32 tcpm_lock; + u32 tcpm_vals[TCP_METRIC_MAX_KERNEL + 1]; + struct tcp_fastopen_metrics tcpm_fastopen; + + struct rcu_head rcu_head; +}; + +static inline struct net *tm_net(const struct tcp_metrics_block *tm) +{ + /* Paired with the WRITE_ONCE() in tcpm_new() */ + return READ_ONCE(tm->tcpm_net); +} + +static bool tcp_metric_locked(struct tcp_metrics_block *tm, + enum tcp_metric_index idx) +{ + /* Paired with WRITE_ONCE() in tcpm_suck_dst() */ + return READ_ONCE(tm->tcpm_lock) & (1 << idx); +} + +static u32 tcp_metric_get(const struct tcp_metrics_block *tm, + enum tcp_metric_index idx) +{ + /* Paired with WRITE_ONCE() in tcp_metric_set() */ + return READ_ONCE(tm->tcpm_vals[idx]); +} + +static void tcp_metric_set(struct tcp_metrics_block *tm, + enum tcp_metric_index idx, + u32 val) +{ + /* Paired with READ_ONCE() in tcp_metric_get() */ + WRITE_ONCE(tm->tcpm_vals[idx], val); +} + +static bool addr_same(const struct inetpeer_addr *a, + const struct inetpeer_addr *b) +{ + return (a->family == b->family) && !inetpeer_addr_cmp(a, b); +} + +struct tcpm_hash_bucket { + struct tcp_metrics_block __rcu *chain; +}; + +static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly; +static unsigned int tcp_metrics_hash_log __read_mostly; + +static DEFINE_SPINLOCK(tcp_metrics_lock); +static DEFINE_SEQLOCK(fastopen_seqlock); + +static void tcpm_suck_dst(struct tcp_metrics_block *tm, + const struct dst_entry *dst, + bool fastopen_clear) +{ + u32 msval; + u32 val; + + WRITE_ONCE(tm->tcpm_stamp, jiffies); + + val = 0; + if (dst_metric_locked(dst, RTAX_RTT)) + val |= 1 << TCP_METRIC_RTT; + if (dst_metric_locked(dst, RTAX_RTTVAR)) + val |= 1 << TCP_METRIC_RTTVAR; + if (dst_metric_locked(dst, RTAX_SSTHRESH)) + val |= 1 << TCP_METRIC_SSTHRESH; + if (dst_metric_locked(dst, RTAX_CWND)) + val |= 1 << TCP_METRIC_CWND; + if (dst_metric_locked(dst, RTAX_REORDERING)) + val |= 1 << TCP_METRIC_REORDERING; + /* Paired with READ_ONCE() in tcp_metric_locked() */ + WRITE_ONCE(tm->tcpm_lock, val); + + msval = dst_metric_raw(dst, RTAX_RTT); + tcp_metric_set(tm, TCP_METRIC_RTT, msval * USEC_PER_MSEC); + + msval = dst_metric_raw(dst, RTAX_RTTVAR); + tcp_metric_set(tm, TCP_METRIC_RTTVAR, msval * USEC_PER_MSEC); + tcp_metric_set(tm, TCP_METRIC_SSTHRESH, + dst_metric_raw(dst, RTAX_SSTHRESH)); + tcp_metric_set(tm, TCP_METRIC_CWND, + dst_metric_raw(dst, RTAX_CWND)); + tcp_metric_set(tm, TCP_METRIC_REORDERING, + dst_metric_raw(dst, RTAX_REORDERING)); + if (fastopen_clear) { + write_seqlock(&fastopen_seqlock); + tm->tcpm_fastopen.mss = 0; + tm->tcpm_fastopen.syn_loss = 0; + tm->tcpm_fastopen.try_exp = 0; + tm->tcpm_fastopen.cookie.exp = false; + tm->tcpm_fastopen.cookie.len = 0; + write_sequnlock(&fastopen_seqlock); + } +} + +#define TCP_METRICS_TIMEOUT (60 * 60 * HZ) + +static void tcpm_check_stamp(struct tcp_metrics_block *tm, + const struct dst_entry *dst) +{ + unsigned long limit; + + if (!tm) + return; + limit = READ_ONCE(tm->tcpm_stamp) + TCP_METRICS_TIMEOUT; + if (unlikely(time_after(jiffies, limit))) + tcpm_suck_dst(tm, dst, false); +} + +#define TCP_METRICS_RECLAIM_DEPTH 5 +#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL + +#define deref_locked(p) \ + rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock)) + +static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, + struct inetpeer_addr *saddr, + struct inetpeer_addr *daddr, + unsigned int hash) +{ + struct tcp_metrics_block *tm; + struct net *net; + bool reclaim = false; + + spin_lock_bh(&tcp_metrics_lock); + net = dev_net(dst->dev); + + /* While waiting for the spin-lock the cache might have been populated + * with this entry and so we have to check again. + */ + tm = __tcp_get_metrics(saddr, daddr, net, hash); + if (tm == TCP_METRICS_RECLAIM_PTR) { + reclaim = true; + tm = NULL; + } + if (tm) { + tcpm_check_stamp(tm, dst); + goto out_unlock; + } + + if (unlikely(reclaim)) { + struct tcp_metrics_block *oldest; + + oldest = deref_locked(tcp_metrics_hash[hash].chain); + for (tm = deref_locked(oldest->tcpm_next); tm; + tm = deref_locked(tm->tcpm_next)) { + if (time_before(READ_ONCE(tm->tcpm_stamp), + READ_ONCE(oldest->tcpm_stamp))) + oldest = tm; + } + tm = oldest; + } else { + tm = kzalloc(sizeof(*tm), GFP_ATOMIC); + if (!tm) + goto out_unlock; + } + /* Paired with the READ_ONCE() in tm_net() */ + WRITE_ONCE(tm->tcpm_net, net); + + tm->tcpm_saddr = *saddr; + tm->tcpm_daddr = *daddr; + + tcpm_suck_dst(tm, dst, reclaim); + + if (likely(!reclaim)) { + tm->tcpm_next = tcp_metrics_hash[hash].chain; + rcu_assign_pointer(tcp_metrics_hash[hash].chain, tm); + } + +out_unlock: + spin_unlock_bh(&tcp_metrics_lock); + return tm; +} + +static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth) +{ + if (tm) + return tm; + if (depth > TCP_METRICS_RECLAIM_DEPTH) + return TCP_METRICS_RECLAIM_PTR; + return NULL; +} + +static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr, + const struct inetpeer_addr *daddr, + struct net *net, unsigned int hash) +{ + struct tcp_metrics_block *tm; + int depth = 0; + + for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; + tm = rcu_dereference(tm->tcpm_next)) { + if (addr_same(&tm->tcpm_saddr, saddr) && + addr_same(&tm->tcpm_daddr, daddr) && + net_eq(tm_net(tm), net)) + break; + depth++; + } + return tcp_get_encode(tm, depth); +} + +static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req, + struct dst_entry *dst) +{ + struct tcp_metrics_block *tm; + struct inetpeer_addr saddr, daddr; + unsigned int hash; + struct net *net; + + saddr.family = req->rsk_ops->family; + daddr.family = req->rsk_ops->family; + switch (daddr.family) { + case AF_INET: + inetpeer_set_addr_v4(&saddr, inet_rsk(req)->ir_loc_addr); + inetpeer_set_addr_v4(&daddr, inet_rsk(req)->ir_rmt_addr); + hash = ipv4_addr_hash(inet_rsk(req)->ir_rmt_addr); + break; +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: + inetpeer_set_addr_v6(&saddr, &inet_rsk(req)->ir_v6_loc_addr); + inetpeer_set_addr_v6(&daddr, &inet_rsk(req)->ir_v6_rmt_addr); + hash = ipv6_addr_hash(&inet_rsk(req)->ir_v6_rmt_addr); + break; +#endif + default: + return NULL; + } + + net = dev_net(dst->dev); + hash ^= net_hash_mix(net); + hash = hash_32(hash, tcp_metrics_hash_log); + + for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; + tm = rcu_dereference(tm->tcpm_next)) { + if (addr_same(&tm->tcpm_saddr, &saddr) && + addr_same(&tm->tcpm_daddr, &daddr) && + net_eq(tm_net(tm), net)) + break; + } + tcpm_check_stamp(tm, dst); + return tm; +} + +static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk, + struct dst_entry *dst, + bool create) +{ + struct tcp_metrics_block *tm; + struct inetpeer_addr saddr, daddr; + unsigned int hash; + struct net *net; + + if (sk->sk_family == AF_INET) { + inetpeer_set_addr_v4(&saddr, inet_sk(sk)->inet_saddr); + inetpeer_set_addr_v4(&daddr, inet_sk(sk)->inet_daddr); + hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr); + } +#if IS_ENABLED(CONFIG_IPV6) + else if (sk->sk_family == AF_INET6) { + if (ipv6_addr_v4mapped(&sk->sk_v6_daddr)) { + inetpeer_set_addr_v4(&saddr, inet_sk(sk)->inet_saddr); + inetpeer_set_addr_v4(&daddr, inet_sk(sk)->inet_daddr); + hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr); + } else { + inetpeer_set_addr_v6(&saddr, &sk->sk_v6_rcv_saddr); + inetpeer_set_addr_v6(&daddr, &sk->sk_v6_daddr); + hash = ipv6_addr_hash(&sk->sk_v6_daddr); + } + } +#endif + else + return NULL; + + net = dev_net(dst->dev); + hash ^= net_hash_mix(net); + hash = hash_32(hash, tcp_metrics_hash_log); + + tm = __tcp_get_metrics(&saddr, &daddr, net, hash); + if (tm == TCP_METRICS_RECLAIM_PTR) + tm = NULL; + if (!tm && create) + tm = tcpm_new(dst, &saddr, &daddr, hash); + else + tcpm_check_stamp(tm, dst); + + return tm; +} + +/* Save metrics learned by this TCP session. This function is called + * only, when TCP finishes successfully i.e. when it enters TIME-WAIT + * or goes from LAST-ACK to CLOSE. + */ +void tcp_update_metrics(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct dst_entry *dst = __sk_dst_get(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + struct tcp_metrics_block *tm; + unsigned long rtt; + u32 val; + int m; + + sk_dst_confirm(sk); + if (READ_ONCE(net->ipv4.sysctl_tcp_nometrics_save) || !dst) + return; + + rcu_read_lock(); + if (icsk->icsk_backoff || !tp->srtt_us) { + /* This session failed to estimate rtt. Why? + * Probably, no packets returned in time. Reset our + * results. + */ + tm = tcp_get_metrics(sk, dst, false); + if (tm && !tcp_metric_locked(tm, TCP_METRIC_RTT)) + tcp_metric_set(tm, TCP_METRIC_RTT, 0); + goto out_unlock; + } else + tm = tcp_get_metrics(sk, dst, true); + + if (!tm) + goto out_unlock; + + rtt = tcp_metric_get(tm, TCP_METRIC_RTT); + m = rtt - tp->srtt_us; + + /* If newly calculated rtt larger than stored one, store new + * one. Otherwise, use EWMA. Remember, rtt overestimation is + * always better than underestimation. + */ + if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) { + if (m <= 0) + rtt = tp->srtt_us; + else + rtt -= (m >> 3); + tcp_metric_set(tm, TCP_METRIC_RTT, rtt); + } + + if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) { + unsigned long var; + + if (m < 0) + m = -m; + + /* Scale deviation to rttvar fixed point */ + m >>= 1; + if (m < tp->mdev_us) + m = tp->mdev_us; + + var = tcp_metric_get(tm, TCP_METRIC_RTTVAR); + if (m >= var) + var = m; + else + var -= (var - m) >> 2; + + tcp_metric_set(tm, TCP_METRIC_RTTVAR, var); + } + + if (tcp_in_initial_slowstart(tp)) { + /* Slow start still did not finish. */ + if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && + !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { + val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); + if (val && (tp->snd_cwnd >> 1) > val) + tcp_metric_set(tm, TCP_METRIC_SSTHRESH, + tp->snd_cwnd >> 1); + } + if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { + val = tcp_metric_get(tm, TCP_METRIC_CWND); + if (tp->snd_cwnd > val) + tcp_metric_set(tm, TCP_METRIC_CWND, + tp->snd_cwnd); + } + } else if (!tcp_in_slow_start(tp) && + icsk->icsk_ca_state == TCP_CA_Open) { + /* Cong. avoidance phase, cwnd is reliable. */ + if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && + !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) + tcp_metric_set(tm, TCP_METRIC_SSTHRESH, + max(tp->snd_cwnd >> 1, tp->snd_ssthresh)); + if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { + val = tcp_metric_get(tm, TCP_METRIC_CWND); + tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1); + } + } else { + /* Else slow start did not finish, cwnd is non-sense, + * ssthresh may be also invalid. + */ + if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { + val = tcp_metric_get(tm, TCP_METRIC_CWND); + tcp_metric_set(tm, TCP_METRIC_CWND, + (val + tp->snd_ssthresh) >> 1); + } + if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && + !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { + val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); + if (val && tp->snd_ssthresh > val) + tcp_metric_set(tm, TCP_METRIC_SSTHRESH, + tp->snd_ssthresh); + } + if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) { + val = tcp_metric_get(tm, TCP_METRIC_REORDERING); + if (val < tp->reordering && + tp->reordering != + READ_ONCE(net->ipv4.sysctl_tcp_reordering)) + tcp_metric_set(tm, TCP_METRIC_REORDERING, + tp->reordering); + } + } + WRITE_ONCE(tm->tcpm_stamp, jiffies); +out_unlock: + rcu_read_unlock(); +} + +/* Initialize metrics on socket. */ + +void tcp_init_metrics(struct sock *sk) +{ + struct dst_entry *dst = __sk_dst_get(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + struct tcp_metrics_block *tm; + u32 val, crtt = 0; /* cached RTT scaled by 8 */ + + sk_dst_confirm(sk); + /* ssthresh may have been reduced unnecessarily during. + * 3WHS. Restore it back to its initial default. + */ + tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; + if (!dst) + goto reset; + + rcu_read_lock(); + tm = tcp_get_metrics(sk, dst, false); + if (!tm) { + rcu_read_unlock(); + goto reset; + } + + if (tcp_metric_locked(tm, TCP_METRIC_CWND)) + tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND); + + val = READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) ? + 0 : tcp_metric_get(tm, TCP_METRIC_SSTHRESH); + if (val) { + tp->snd_ssthresh = val; + if (tp->snd_ssthresh > tp->snd_cwnd_clamp) + tp->snd_ssthresh = tp->snd_cwnd_clamp; + } + val = tcp_metric_get(tm, TCP_METRIC_REORDERING); + if (val && tp->reordering != val) + tp->reordering = val; + + crtt = tcp_metric_get(tm, TCP_METRIC_RTT); + rcu_read_unlock(); +reset: + /* The initial RTT measurement from the SYN/SYN-ACK is not ideal + * to seed the RTO for later data packets because SYN packets are + * small. Use the per-dst cached values to seed the RTO but keep + * the RTT estimator variables intact (e.g., srtt, mdev, rttvar). + * Later the RTO will be updated immediately upon obtaining the first + * data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only + * influences the first RTO but not later RTT estimation. + * + * But if RTT is not available from the SYN (due to retransmits or + * syn cookies) or the cache, force a conservative 3secs timeout. + * + * A bit of theory. RTT is time passed after "normal" sized packet + * is sent until it is ACKed. In normal circumstances sending small + * packets force peer to delay ACKs and calculation is correct too. + * The algorithm is adaptive and, provided we follow specs, it + * NEVER underestimate RTT. BUT! If peer tries to make some clever + * tricks sort of "quick acks" for time long enough to decrease RTT + * to low value, and then abruptly stops to do it and starts to delay + * ACKs, wait for troubles. + */ + if (crtt > tp->srtt_us) { + /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */ + crtt /= 8 * USEC_PER_SEC / HZ; + inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk)); + } else if (tp->srtt_us == 0) { + /* RFC6298: 5.7 We've failed to get a valid RTT sample from + * 3WHS. This is most likely due to retransmission, + * including spurious one. Reset the RTO back to 3secs + * from the more aggressive 1sec to avoid more spurious + * retransmission. + */ + tp->rttvar_us = jiffies_to_usecs(TCP_TIMEOUT_FALLBACK); + tp->mdev_us = tp->mdev_max_us = tp->rttvar_us; + + inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK; + } +} + +bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst) +{ + struct tcp_metrics_block *tm; + bool ret; + + if (!dst) + return false; + + rcu_read_lock(); + tm = __tcp_get_metrics_req(req, dst); + if (tm && tcp_metric_get(tm, TCP_METRIC_RTT)) + ret = true; + else + ret = false; + rcu_read_unlock(); + + return ret; +} + +void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, + struct tcp_fastopen_cookie *cookie) +{ + struct tcp_metrics_block *tm; + + rcu_read_lock(); + tm = tcp_get_metrics(sk, __sk_dst_get(sk), false); + if (tm) { + struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; + unsigned int seq; + + do { + seq = read_seqbegin(&fastopen_seqlock); + if (tfom->mss) + *mss = tfom->mss; + *cookie = tfom->cookie; + if (cookie->len <= 0 && tfom->try_exp == 1) + cookie->exp = true; + } while (read_seqretry(&fastopen_seqlock, seq)); + } + rcu_read_unlock(); +} + +void tcp_fastopen_cache_set(struct sock *sk, u16 mss, + struct tcp_fastopen_cookie *cookie, bool syn_lost, + u16 try_exp) +{ + struct dst_entry *dst = __sk_dst_get(sk); + struct tcp_metrics_block *tm; + + if (!dst) + return; + rcu_read_lock(); + tm = tcp_get_metrics(sk, dst, true); + if (tm) { + struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; + + write_seqlock_bh(&fastopen_seqlock); + if (mss) + tfom->mss = mss; + if (cookie && cookie->len > 0) + tfom->cookie = *cookie; + else if (try_exp > tfom->try_exp && + tfom->cookie.len <= 0 && !tfom->cookie.exp) + tfom->try_exp = try_exp; + if (syn_lost) { + ++tfom->syn_loss; + tfom->last_syn_loss = jiffies; + } else + tfom->syn_loss = 0; + write_sequnlock_bh(&fastopen_seqlock); + } + rcu_read_unlock(); +} + +static struct genl_family tcp_metrics_nl_family; + +static const struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = { + [TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, }, + [TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY, + .len = sizeof(struct in6_addr), }, + /* Following attributes are not received for GET/DEL, + * we keep them for reference + */ +#if 0 + [TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, }, + [TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, }, + [TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, }, + [TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, }, + [TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, }, + [TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, }, + [TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, }, + [TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY, + .len = TCP_FASTOPEN_COOKIE_MAX, }, +#endif +}; + +/* Add attributes, caller cancels its header on failure */ +static int tcp_metrics_fill_info(struct sk_buff *msg, + struct tcp_metrics_block *tm) +{ + struct nlattr *nest; + int i; + + switch (tm->tcpm_daddr.family) { + case AF_INET: + if (nla_put_in_addr(msg, TCP_METRICS_ATTR_ADDR_IPV4, + inetpeer_get_addr_v4(&tm->tcpm_daddr)) < 0) + goto nla_put_failure; + if (nla_put_in_addr(msg, TCP_METRICS_ATTR_SADDR_IPV4, + inetpeer_get_addr_v4(&tm->tcpm_saddr)) < 0) + goto nla_put_failure; + break; + case AF_INET6: + if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_ADDR_IPV6, + inetpeer_get_addr_v6(&tm->tcpm_daddr)) < 0) + goto nla_put_failure; + if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_SADDR_IPV6, + inetpeer_get_addr_v6(&tm->tcpm_saddr)) < 0) + goto nla_put_failure; + break; + default: + return -EAFNOSUPPORT; + } + + if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE, + jiffies - READ_ONCE(tm->tcpm_stamp), + TCP_METRICS_ATTR_PAD) < 0) + goto nla_put_failure; + + { + int n = 0; + + nest = nla_nest_start_noflag(msg, TCP_METRICS_ATTR_VALS); + if (!nest) + goto nla_put_failure; + for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) { + u32 val = tcp_metric_get(tm, i); + + if (!val) + continue; + if (i == TCP_METRIC_RTT) { + if (nla_put_u32(msg, TCP_METRIC_RTT_US + 1, + val) < 0) + goto nla_put_failure; + n++; + val = max(val / 1000, 1U); + } + if (i == TCP_METRIC_RTTVAR) { + if (nla_put_u32(msg, TCP_METRIC_RTTVAR_US + 1, + val) < 0) + goto nla_put_failure; + n++; + val = max(val / 1000, 1U); + } + if (nla_put_u32(msg, i + 1, val) < 0) + goto nla_put_failure; + n++; + } + if (n) + nla_nest_end(msg, nest); + else + nla_nest_cancel(msg, nest); + } + + { + struct tcp_fastopen_metrics tfom_copy[1], *tfom; + unsigned int seq; + + do { + seq = read_seqbegin(&fastopen_seqlock); + tfom_copy[0] = tm->tcpm_fastopen; + } while (read_seqretry(&fastopen_seqlock, seq)); + + tfom = tfom_copy; + if (tfom->mss && + nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS, + tfom->mss) < 0) + goto nla_put_failure; + if (tfom->syn_loss && + (nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS, + tfom->syn_loss) < 0 || + nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS, + jiffies - tfom->last_syn_loss, + TCP_METRICS_ATTR_PAD) < 0)) + goto nla_put_failure; + if (tfom->cookie.len > 0 && + nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE, + tfom->cookie.len, tfom->cookie.val) < 0) + goto nla_put_failure; + } + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int tcp_metrics_dump_info(struct sk_buff *skb, + struct netlink_callback *cb, + struct tcp_metrics_block *tm) +{ + void *hdr; + + hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, + &tcp_metrics_nl_family, NLM_F_MULTI, + TCP_METRICS_CMD_GET); + if (!hdr) + return -EMSGSIZE; + + if (tcp_metrics_fill_info(skb, tm) < 0) + goto nla_put_failure; + + genlmsg_end(skb, hdr); + return 0; + +nla_put_failure: + genlmsg_cancel(skb, hdr); + return -EMSGSIZE; +} + +static int tcp_metrics_nl_dump(struct sk_buff *skb, + struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + unsigned int max_rows = 1U << tcp_metrics_hash_log; + unsigned int row, s_row = cb->args[0]; + int s_col = cb->args[1], col = s_col; + + for (row = s_row; row < max_rows; row++, s_col = 0) { + struct tcp_metrics_block *tm; + struct tcpm_hash_bucket *hb = tcp_metrics_hash + row; + + rcu_read_lock(); + for (col = 0, tm = rcu_dereference(hb->chain); tm; + tm = rcu_dereference(tm->tcpm_next), col++) { + if (!net_eq(tm_net(tm), net)) + continue; + if (col < s_col) + continue; + if (tcp_metrics_dump_info(skb, cb, tm) < 0) { + rcu_read_unlock(); + goto done; + } + } + rcu_read_unlock(); + } + +done: + cb->args[0] = row; + cb->args[1] = col; + return skb->len; +} + +static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, + unsigned int *hash, int optional, int v4, int v6) +{ + struct nlattr *a; + + a = info->attrs[v4]; + if (a) { + inetpeer_set_addr_v4(addr, nla_get_in_addr(a)); + if (hash) + *hash = ipv4_addr_hash(inetpeer_get_addr_v4(addr)); + return 0; + } + a = info->attrs[v6]; + if (a) { + struct in6_addr in6; + + if (nla_len(a) != sizeof(struct in6_addr)) + return -EINVAL; + in6 = nla_get_in6_addr(a); + inetpeer_set_addr_v6(addr, &in6); + if (hash) + *hash = ipv6_addr_hash(inetpeer_get_addr_v6(addr)); + return 0; + } + return optional ? 1 : -EAFNOSUPPORT; +} + +static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, + unsigned int *hash, int optional) +{ + return __parse_nl_addr(info, addr, hash, optional, + TCP_METRICS_ATTR_ADDR_IPV4, + TCP_METRICS_ATTR_ADDR_IPV6); +} + +static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr) +{ + return __parse_nl_addr(info, addr, NULL, 0, + TCP_METRICS_ATTR_SADDR_IPV4, + TCP_METRICS_ATTR_SADDR_IPV6); +} + +static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info) +{ + struct tcp_metrics_block *tm; + struct inetpeer_addr saddr, daddr; + unsigned int hash; + struct sk_buff *msg; + struct net *net = genl_info_net(info); + void *reply; + int ret; + bool src = true; + + ret = parse_nl_addr(info, &daddr, &hash, 0); + if (ret < 0) + return ret; + + ret = parse_nl_saddr(info, &saddr); + if (ret < 0) + src = false; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0, + info->genlhdr->cmd); + if (!reply) + goto nla_put_failure; + + hash ^= net_hash_mix(net); + hash = hash_32(hash, tcp_metrics_hash_log); + ret = -ESRCH; + rcu_read_lock(); + for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; + tm = rcu_dereference(tm->tcpm_next)) { + if (addr_same(&tm->tcpm_daddr, &daddr) && + (!src || addr_same(&tm->tcpm_saddr, &saddr)) && + net_eq(tm_net(tm), net)) { + ret = tcp_metrics_fill_info(msg, tm); + break; + } + } + rcu_read_unlock(); + if (ret < 0) + goto out_free; + + genlmsg_end(msg, reply); + return genlmsg_reply(msg, info); + +nla_put_failure: + ret = -EMSGSIZE; + +out_free: + nlmsg_free(msg); + return ret; +} + +static void tcp_metrics_flush_all(struct net *net) +{ + unsigned int max_rows = 1U << tcp_metrics_hash_log; + struct tcpm_hash_bucket *hb = tcp_metrics_hash; + struct tcp_metrics_block *tm; + unsigned int row; + + for (row = 0; row < max_rows; row++, hb++) { + struct tcp_metrics_block __rcu **pp; + bool match; + + spin_lock_bh(&tcp_metrics_lock); + pp = &hb->chain; + for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { + match = net ? net_eq(tm_net(tm), net) : + !refcount_read(&tm_net(tm)->count); + if (match) { + rcu_assign_pointer(*pp, tm->tcpm_next); + kfree_rcu(tm, rcu_head); + } else { + pp = &tm->tcpm_next; + } + } + spin_unlock_bh(&tcp_metrics_lock); + } +} + +static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info) +{ + struct tcpm_hash_bucket *hb; + struct tcp_metrics_block *tm; + struct tcp_metrics_block __rcu **pp; + struct inetpeer_addr saddr, daddr; + unsigned int hash; + struct net *net = genl_info_net(info); + int ret; + bool src = true, found = false; + + ret = parse_nl_addr(info, &daddr, &hash, 1); + if (ret < 0) + return ret; + if (ret > 0) { + tcp_metrics_flush_all(net); + return 0; + } + ret = parse_nl_saddr(info, &saddr); + if (ret < 0) + src = false; + + hash ^= net_hash_mix(net); + hash = hash_32(hash, tcp_metrics_hash_log); + hb = tcp_metrics_hash + hash; + pp = &hb->chain; + spin_lock_bh(&tcp_metrics_lock); + for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { + if (addr_same(&tm->tcpm_daddr, &daddr) && + (!src || addr_same(&tm->tcpm_saddr, &saddr)) && + net_eq(tm_net(tm), net)) { + rcu_assign_pointer(*pp, tm->tcpm_next); + kfree_rcu(tm, rcu_head); + found = true; + } else { + pp = &tm->tcpm_next; + } + } + spin_unlock_bh(&tcp_metrics_lock); + if (!found) + return -ESRCH; + return 0; +} + +static const struct genl_small_ops tcp_metrics_nl_ops[] = { + { + .cmd = TCP_METRICS_CMD_GET, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = tcp_metrics_nl_cmd_get, + .dumpit = tcp_metrics_nl_dump, + }, + { + .cmd = TCP_METRICS_CMD_DEL, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .doit = tcp_metrics_nl_cmd_del, + .flags = GENL_ADMIN_PERM, + }, +}; + +static struct genl_family tcp_metrics_nl_family __ro_after_init = { + .hdrsize = 0, + .name = TCP_METRICS_GENL_NAME, + .version = TCP_METRICS_GENL_VERSION, + .maxattr = TCP_METRICS_ATTR_MAX, + .policy = tcp_metrics_nl_policy, + .netnsok = true, + .module = THIS_MODULE, + .small_ops = tcp_metrics_nl_ops, + .n_small_ops = ARRAY_SIZE(tcp_metrics_nl_ops), +}; + +static unsigned int tcpmhash_entries; +static int __init set_tcpmhash_entries(char *str) +{ + ssize_t ret; + + if (!str) + return 0; + + ret = kstrtouint(str, 0, &tcpmhash_entries); + if (ret) + return 0; + + return 1; +} +__setup("tcpmhash_entries=", set_tcpmhash_entries); + +static int __net_init tcp_net_metrics_init(struct net *net) +{ + size_t size; + unsigned int slots; + + if (!net_eq(net, &init_net)) + return 0; + + slots = tcpmhash_entries; + if (!slots) { + if (totalram_pages() >= 128 * 1024) + slots = 16 * 1024; + else + slots = 8 * 1024; + } + + tcp_metrics_hash_log = order_base_2(slots); + size = sizeof(struct tcpm_hash_bucket) << tcp_metrics_hash_log; + + tcp_metrics_hash = kvzalloc(size, GFP_KERNEL); + if (!tcp_metrics_hash) + return -ENOMEM; + + return 0; +} + +static void __net_exit tcp_net_metrics_exit_batch(struct list_head *net_exit_list) +{ + tcp_metrics_flush_all(NULL); +} + +static __net_initdata struct pernet_operations tcp_net_metrics_ops = { + .init = tcp_net_metrics_init, + .exit_batch = tcp_net_metrics_exit_batch, +}; + +void __init tcp_metrics_init(void) +{ + int ret; + + ret = register_pernet_subsys(&tcp_net_metrics_ops); + if (ret < 0) + panic("Could not allocate the tcp_metrics hash table\n"); + + ret = genl_register_family(&tcp_metrics_nl_family); + if (ret < 0) + panic("Could not register tcp_metrics generic netlink\n"); +} diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c new file mode 100644 index 000000000..01e27620b --- /dev/null +++ b/net/ipv4/tcp_minisocks.c @@ -0,0 +1,863 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Implementation of the Transmission Control Protocol(TCP). + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * Corey Minyard <wf-rch!minyard@relay.EU.net> + * Florian La Roche, <flla@stud.uni-sb.de> + * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> + * Linus Torvalds, <torvalds@cs.helsinki.fi> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Matthew Dillon, <dillon@apollo.west.oic.com> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Jorge Cwik, <jorge@laser.satlink.net> + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/sysctl.h> +#include <linux/workqueue.h> +#include <linux/static_key.h> +#include <net/tcp.h> +#include <net/inet_common.h> +#include <net/xfrm.h> +#include <net/busy_poll.h> + +static bool tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win) +{ + if (seq == s_win) + return true; + if (after(end_seq, s_win) && before(seq, e_win)) + return true; + return seq == e_win && seq == end_seq; +} + +static enum tcp_tw_status +tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw, + const struct sk_buff *skb, int mib_idx) +{ + struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw); + + if (!tcp_oow_rate_limited(twsk_net(tw), skb, mib_idx, + &tcptw->tw_last_oow_ack_time)) { + /* Send ACK. Note, we do not put the bucket, + * it will be released by caller. + */ + return TCP_TW_ACK; + } + + /* We are rate-limiting, so just release the tw sock and drop skb. */ + inet_twsk_put(tw); + return TCP_TW_SUCCESS; +} + +/* + * * Main purpose of TIME-WAIT state is to close connection gracefully, + * when one of ends sits in LAST-ACK or CLOSING retransmitting FIN + * (and, probably, tail of data) and one or more our ACKs are lost. + * * What is TIME-WAIT timeout? It is associated with maximal packet + * lifetime in the internet, which results in wrong conclusion, that + * it is set to catch "old duplicate segments" wandering out of their path. + * It is not quite correct. This timeout is calculated so that it exceeds + * maximal retransmission timeout enough to allow to lose one (or more) + * segments sent by peer and our ACKs. This time may be calculated from RTO. + * * When TIME-WAIT socket receives RST, it means that another end + * finally closed and we are allowed to kill TIME-WAIT too. + * * Second purpose of TIME-WAIT is catching old duplicate segments. + * Well, certainly it is pure paranoia, but if we load TIME-WAIT + * with this semantics, we MUST NOT kill TIME-WAIT state with RSTs. + * * If we invented some more clever way to catch duplicates + * (f.e. based on PAWS), we could truncate TIME-WAIT to several RTOs. + * + * The algorithm below is based on FORMAL INTERPRETATION of RFCs. + * When you compare it to RFCs, please, read section SEGMENT ARRIVES + * from the very beginning. + * + * NOTE. With recycling (and later with fin-wait-2) TW bucket + * is _not_ stateless. It means, that strictly speaking we must + * spinlock it. I do not want! Well, probability of misbehaviour + * is ridiculously low and, seems, we could use some mb() tricks + * to avoid misread sequence numbers, states etc. --ANK + * + * We don't need to initialize tmp_out.sack_ok as we don't use the results + */ +enum tcp_tw_status +tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, + const struct tcphdr *th) +{ + struct tcp_options_received tmp_opt; + struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw); + bool paws_reject = false; + + tmp_opt.saw_tstamp = 0; + if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) { + tcp_parse_options(twsk_net(tw), skb, &tmp_opt, 0, NULL); + + if (tmp_opt.saw_tstamp) { + if (tmp_opt.rcv_tsecr) + tmp_opt.rcv_tsecr -= tcptw->tw_ts_offset; + tmp_opt.ts_recent = tcptw->tw_ts_recent; + tmp_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; + paws_reject = tcp_paws_reject(&tmp_opt, th->rst); + } + } + + if (tw->tw_substate == TCP_FIN_WAIT2) { + /* Just repeat all the checks of tcp_rcv_state_process() */ + + /* Out of window, send ACK */ + if (paws_reject || + !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq, + tcptw->tw_rcv_nxt, + tcptw->tw_rcv_nxt + tcptw->tw_rcv_wnd)) + return tcp_timewait_check_oow_rate_limit( + tw, skb, LINUX_MIB_TCPACKSKIPPEDFINWAIT2); + + if (th->rst) + goto kill; + + if (th->syn && !before(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt)) + return TCP_TW_RST; + + /* Dup ACK? */ + if (!th->ack || + !after(TCP_SKB_CB(skb)->end_seq, tcptw->tw_rcv_nxt) || + TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq) { + inet_twsk_put(tw); + return TCP_TW_SUCCESS; + } + + /* New data or FIN. If new data arrive after half-duplex close, + * reset. + */ + if (!th->fin || + TCP_SKB_CB(skb)->end_seq != tcptw->tw_rcv_nxt + 1) + return TCP_TW_RST; + + /* FIN arrived, enter true time-wait state. */ + tw->tw_substate = TCP_TIME_WAIT; + tcptw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq; + if (tmp_opt.saw_tstamp) { + tcptw->tw_ts_recent_stamp = ktime_get_seconds(); + tcptw->tw_ts_recent = tmp_opt.rcv_tsval; + } + + inet_twsk_reschedule(tw, TCP_TIMEWAIT_LEN); + return TCP_TW_ACK; + } + + /* + * Now real TIME-WAIT state. + * + * RFC 1122: + * "When a connection is [...] on TIME-WAIT state [...] + * [a TCP] MAY accept a new SYN from the remote TCP to + * reopen the connection directly, if it: + * + * (1) assigns its initial sequence number for the new + * connection to be larger than the largest sequence + * number it used on the previous connection incarnation, + * and + * + * (2) returns to TIME-WAIT state if the SYN turns out + * to be an old duplicate". + */ + + if (!paws_reject && + (TCP_SKB_CB(skb)->seq == tcptw->tw_rcv_nxt && + (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq || th->rst))) { + /* In window segment, it may be only reset or bare ack. */ + + if (th->rst) { + /* This is TIME_WAIT assassination, in two flavors. + * Oh well... nobody has a sufficient solution to this + * protocol bug yet. + */ + if (!READ_ONCE(twsk_net(tw)->ipv4.sysctl_tcp_rfc1337)) { +kill: + inet_twsk_deschedule_put(tw); + return TCP_TW_SUCCESS; + } + } else { + inet_twsk_reschedule(tw, TCP_TIMEWAIT_LEN); + } + + if (tmp_opt.saw_tstamp) { + tcptw->tw_ts_recent = tmp_opt.rcv_tsval; + tcptw->tw_ts_recent_stamp = ktime_get_seconds(); + } + + inet_twsk_put(tw); + return TCP_TW_SUCCESS; + } + + /* Out of window segment. + + All the segments are ACKed immediately. + + The only exception is new SYN. We accept it, if it is + not old duplicate and we are not in danger to be killed + by delayed old duplicates. RFC check is that it has + newer sequence number works at rates <40Mbit/sec. + However, if paws works, it is reliable AND even more, + we even may relax silly seq space cutoff. + + RED-PEN: we violate main RFC requirement, if this SYN will appear + old duplicate (i.e. we receive RST in reply to SYN-ACK), + we must return socket to time-wait state. It is not good, + but not fatal yet. + */ + + if (th->syn && !th->rst && !th->ack && !paws_reject && + (after(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt) || + (tmp_opt.saw_tstamp && + (s32)(tcptw->tw_ts_recent - tmp_opt.rcv_tsval) < 0))) { + u32 isn = tcptw->tw_snd_nxt + 65535 + 2; + if (isn == 0) + isn++; + TCP_SKB_CB(skb)->tcp_tw_isn = isn; + return TCP_TW_SYN; + } + + if (paws_reject) + __NET_INC_STATS(twsk_net(tw), LINUX_MIB_PAWSESTABREJECTED); + + if (!th->rst) { + /* In this case we must reset the TIMEWAIT timer. + * + * If it is ACKless SYN it may be both old duplicate + * and new good SYN with random sequence number <rcv_nxt. + * Do not reschedule in the last case. + */ + if (paws_reject || th->ack) + inet_twsk_reschedule(tw, TCP_TIMEWAIT_LEN); + + return tcp_timewait_check_oow_rate_limit( + tw, skb, LINUX_MIB_TCPACKSKIPPEDTIMEWAIT); + } + inet_twsk_put(tw); + return TCP_TW_SUCCESS; +} +EXPORT_SYMBOL(tcp_timewait_state_process); + +/* + * Move a socket to time-wait or dead fin-wait-2 state. + */ +void tcp_time_wait(struct sock *sk, int state, int timeo) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + const struct tcp_sock *tp = tcp_sk(sk); + struct inet_timewait_sock *tw; + struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; + + tw = inet_twsk_alloc(sk, tcp_death_row, state); + + if (tw) { + struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw); + const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1); + struct inet_sock *inet = inet_sk(sk); + + tw->tw_transparent = inet->transparent; + tw->tw_mark = sk->sk_mark; + tw->tw_priority = sk->sk_priority; + tw->tw_rcv_wscale = tp->rx_opt.rcv_wscale; + tcptw->tw_rcv_nxt = tp->rcv_nxt; + tcptw->tw_snd_nxt = tp->snd_nxt; + tcptw->tw_rcv_wnd = tcp_receive_window(tp); + tcptw->tw_ts_recent = tp->rx_opt.ts_recent; + tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp; + tcptw->tw_ts_offset = tp->tsoffset; + tcptw->tw_last_oow_ack_time = 0; + tcptw->tw_tx_delay = tp->tcp_tx_delay; +#if IS_ENABLED(CONFIG_IPV6) + if (tw->tw_family == PF_INET6) { + struct ipv6_pinfo *np = inet6_sk(sk); + + tw->tw_v6_daddr = sk->sk_v6_daddr; + tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr; + tw->tw_tclass = np->tclass; + tw->tw_flowlabel = be32_to_cpu(np->flow_label & IPV6_FLOWLABEL_MASK); + tw->tw_txhash = sk->sk_txhash; + tw->tw_ipv6only = sk->sk_ipv6only; + } +#endif + +#ifdef CONFIG_TCP_MD5SIG + /* + * The timewait bucket does not have the key DB from the + * sock structure. We just make a quick copy of the + * md5 key being used (if indeed we are using one) + * so the timewait ack generating code has the key. + */ + do { + tcptw->tw_md5_key = NULL; + if (static_branch_unlikely(&tcp_md5_needed)) { + struct tcp_md5sig_key *key; + + key = tp->af_specific->md5_lookup(sk, sk); + if (key) { + tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC); + BUG_ON(tcptw->tw_md5_key && !tcp_alloc_md5sig_pool()); + } + } + } while (0); +#endif + + /* Get the TIME_WAIT timeout firing. */ + if (timeo < rto) + timeo = rto; + + if (state == TCP_TIME_WAIT) + timeo = TCP_TIMEWAIT_LEN; + + /* tw_timer is pinned, so we need to make sure BH are disabled + * in following section, otherwise timer handler could run before + * we complete the initialization. + */ + local_bh_disable(); + inet_twsk_schedule(tw, timeo); + /* Linkage updates. + * Note that access to tw after this point is illegal. + */ + inet_twsk_hashdance(tw, sk, &tcp_hashinfo); + local_bh_enable(); + } else { + /* Sorry, if we're out of memory, just CLOSE this + * socket up. We've got bigger problems than + * non-graceful socket closings. + */ + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPTIMEWAITOVERFLOW); + } + + tcp_update_metrics(sk); + tcp_done(sk); +} +EXPORT_SYMBOL(tcp_time_wait); + +void tcp_twsk_destructor(struct sock *sk) +{ +#ifdef CONFIG_TCP_MD5SIG + if (static_branch_unlikely(&tcp_md5_needed)) { + struct tcp_timewait_sock *twsk = tcp_twsk(sk); + + if (twsk->tw_md5_key) + kfree_rcu(twsk->tw_md5_key, rcu); + } +#endif +} +EXPORT_SYMBOL_GPL(tcp_twsk_destructor); + +/* Warning : This function is called without sk_listener being locked. + * Be sure to read socket fields once, as their value could change under us. + */ +void tcp_openreq_init_rwin(struct request_sock *req, + const struct sock *sk_listener, + const struct dst_entry *dst) +{ + struct inet_request_sock *ireq = inet_rsk(req); + const struct tcp_sock *tp = tcp_sk(sk_listener); + int full_space = tcp_full_space(sk_listener); + u32 window_clamp; + __u8 rcv_wscale; + u32 rcv_wnd; + int mss; + + mss = tcp_mss_clamp(tp, dst_metric_advmss(dst)); + window_clamp = READ_ONCE(tp->window_clamp); + /* Set this up on the first call only */ + req->rsk_window_clamp = window_clamp ? : dst_metric(dst, RTAX_WINDOW); + + /* limit the window selection if the user enforce a smaller rx buffer */ + if (sk_listener->sk_userlocks & SOCK_RCVBUF_LOCK && + (req->rsk_window_clamp > full_space || req->rsk_window_clamp == 0)) + req->rsk_window_clamp = full_space; + + rcv_wnd = tcp_rwnd_init_bpf((struct sock *)req); + if (rcv_wnd == 0) + rcv_wnd = dst_metric(dst, RTAX_INITRWND); + else if (full_space < rcv_wnd * mss) + full_space = rcv_wnd * mss; + + /* tcp_full_space because it is guaranteed to be the first packet */ + tcp_select_initial_window(sk_listener, full_space, + mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0), + &req->rsk_rcv_wnd, + &req->rsk_window_clamp, + ireq->wscale_ok, + &rcv_wscale, + rcv_wnd); + ireq->rcv_wscale = rcv_wscale; +} +EXPORT_SYMBOL(tcp_openreq_init_rwin); + +static void tcp_ecn_openreq_child(struct tcp_sock *tp, + const struct request_sock *req) +{ + tp->ecn_flags = inet_rsk(req)->ecn_ok ? TCP_ECN_OK : 0; +} + +void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + u32 ca_key = dst_metric(dst, RTAX_CC_ALGO); + bool ca_got_dst = false; + + if (ca_key != TCP_CA_UNSPEC) { + const struct tcp_congestion_ops *ca; + + rcu_read_lock(); + ca = tcp_ca_find_key(ca_key); + if (likely(ca && bpf_try_module_get(ca, ca->owner))) { + icsk->icsk_ca_dst_locked = tcp_ca_dst_locked(dst); + icsk->icsk_ca_ops = ca; + ca_got_dst = true; + } + rcu_read_unlock(); + } + + /* If no valid choice made yet, assign current system default ca. */ + if (!ca_got_dst && + (!icsk->icsk_ca_setsockopt || + !bpf_try_module_get(icsk->icsk_ca_ops, icsk->icsk_ca_ops->owner))) + tcp_assign_congestion_control(sk); + + tcp_set_ca_state(sk, TCP_CA_Open); +} +EXPORT_SYMBOL_GPL(tcp_ca_openreq_child); + +static void smc_check_reset_syn_req(struct tcp_sock *oldtp, + struct request_sock *req, + struct tcp_sock *newtp) +{ +#if IS_ENABLED(CONFIG_SMC) + struct inet_request_sock *ireq; + + if (static_branch_unlikely(&tcp_have_smc)) { + ireq = inet_rsk(req); + if (oldtp->syn_smc && !ireq->smc_ok) + newtp->syn_smc = 0; + } +#endif +} + +/* This is not only more efficient than what we used to do, it eliminates + * a lot of code duplication between IPv4/IPv6 SYN recv processing. -DaveM + * + * Actually, we could lots of memory writes here. tp of listening + * socket contains all necessary default parameters. + */ +struct sock *tcp_create_openreq_child(const struct sock *sk, + struct request_sock *req, + struct sk_buff *skb) +{ + struct sock *newsk = inet_csk_clone_lock(sk, req, GFP_ATOMIC); + const struct inet_request_sock *ireq = inet_rsk(req); + struct tcp_request_sock *treq = tcp_rsk(req); + struct inet_connection_sock *newicsk; + struct tcp_sock *oldtp, *newtp; + u32 seq; + + if (!newsk) + return NULL; + + newicsk = inet_csk(newsk); + newtp = tcp_sk(newsk); + oldtp = tcp_sk(sk); + + smc_check_reset_syn_req(oldtp, req, newtp); + + /* Now setup tcp_sock */ + newtp->pred_flags = 0; + + seq = treq->rcv_isn + 1; + newtp->rcv_wup = seq; + WRITE_ONCE(newtp->copied_seq, seq); + WRITE_ONCE(newtp->rcv_nxt, seq); + newtp->segs_in = 1; + + seq = treq->snt_isn + 1; + newtp->snd_sml = newtp->snd_una = seq; + WRITE_ONCE(newtp->snd_nxt, seq); + newtp->snd_up = seq; + + INIT_LIST_HEAD(&newtp->tsq_node); + INIT_LIST_HEAD(&newtp->tsorted_sent_queue); + + tcp_init_wl(newtp, treq->rcv_isn); + + minmax_reset(&newtp->rtt_min, tcp_jiffies32, ~0U); + newicsk->icsk_ack.lrcvtime = tcp_jiffies32; + + newtp->lsndtime = tcp_jiffies32; + newsk->sk_txhash = treq->txhash; + newtp->total_retrans = req->num_retrans; + + tcp_init_xmit_timers(newsk); + WRITE_ONCE(newtp->write_seq, newtp->pushed_seq = treq->snt_isn + 1); + + if (sock_flag(newsk, SOCK_KEEPOPEN)) + inet_csk_reset_keepalive_timer(newsk, + keepalive_time_when(newtp)); + + newtp->rx_opt.tstamp_ok = ireq->tstamp_ok; + newtp->rx_opt.sack_ok = ireq->sack_ok; + newtp->window_clamp = req->rsk_window_clamp; + newtp->rcv_ssthresh = req->rsk_rcv_wnd; + newtp->rcv_wnd = req->rsk_rcv_wnd; + newtp->rx_opt.wscale_ok = ireq->wscale_ok; + if (newtp->rx_opt.wscale_ok) { + newtp->rx_opt.snd_wscale = ireq->snd_wscale; + newtp->rx_opt.rcv_wscale = ireq->rcv_wscale; + } else { + newtp->rx_opt.snd_wscale = newtp->rx_opt.rcv_wscale = 0; + newtp->window_clamp = min(newtp->window_clamp, 65535U); + } + newtp->snd_wnd = ntohs(tcp_hdr(skb)->window) << newtp->rx_opt.snd_wscale; + newtp->max_window = newtp->snd_wnd; + + if (newtp->rx_opt.tstamp_ok) { + newtp->rx_opt.ts_recent = READ_ONCE(req->ts_recent); + newtp->rx_opt.ts_recent_stamp = ktime_get_seconds(); + newtp->tcp_header_len = sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED; + } else { + newtp->rx_opt.ts_recent_stamp = 0; + newtp->tcp_header_len = sizeof(struct tcphdr); + } + if (req->num_timeout) { + newtp->undo_marker = treq->snt_isn; + newtp->retrans_stamp = div_u64(treq->snt_synack, + USEC_PER_SEC / TCP_TS_HZ); + } + newtp->tsoffset = treq->ts_off; +#ifdef CONFIG_TCP_MD5SIG + newtp->md5sig_info = NULL; /*XXX*/ + if (treq->af_specific->req_md5_lookup(sk, req_to_sk(req))) + newtp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED; +#endif + if (skb->len >= TCP_MSS_DEFAULT + newtp->tcp_header_len) + newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len; + newtp->rx_opt.mss_clamp = req->mss; + tcp_ecn_openreq_child(newtp, req); + newtp->fastopen_req = NULL; + RCU_INIT_POINTER(newtp->fastopen_rsk, NULL); + + tcp_bpf_clone(sk, newsk); + + __TCP_INC_STATS(sock_net(sk), TCP_MIB_PASSIVEOPENS); + + return newsk; +} +EXPORT_SYMBOL(tcp_create_openreq_child); + +/* + * Process an incoming packet for SYN_RECV sockets represented as a + * request_sock. Normally sk is the listener socket but for TFO it + * points to the child socket. + * + * XXX (TFO) - The current impl contains a special check for ack + * validation and inside tcp_v4_reqsk_send_ack(). Can we do better? + * + * We don't need to initialize tmp_opt.sack_ok as we don't use the results + * + * Note: If @fastopen is true, this can be called from process context. + * Otherwise, this is from BH context. + */ + +struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + bool fastopen, bool *req_stolen) +{ + struct tcp_options_received tmp_opt; + struct sock *child; + const struct tcphdr *th = tcp_hdr(skb); + __be32 flg = tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_SYN|TCP_FLAG_ACK); + bool paws_reject = false; + bool own_req; + + tmp_opt.saw_tstamp = 0; + if (th->doff > (sizeof(struct tcphdr)>>2)) { + tcp_parse_options(sock_net(sk), skb, &tmp_opt, 0, NULL); + + if (tmp_opt.saw_tstamp) { + tmp_opt.ts_recent = READ_ONCE(req->ts_recent); + if (tmp_opt.rcv_tsecr) + tmp_opt.rcv_tsecr -= tcp_rsk(req)->ts_off; + /* We do not store true stamp, but it is not required, + * it can be estimated (approximately) + * from another data. + */ + tmp_opt.ts_recent_stamp = ktime_get_seconds() - ((TCP_TIMEOUT_INIT/HZ)<<req->num_timeout); + paws_reject = tcp_paws_reject(&tmp_opt, th->rst); + } + } + + /* Check for pure retransmitted SYN. */ + if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn && + flg == TCP_FLAG_SYN && + !paws_reject) { + /* + * RFC793 draws (Incorrectly! It was fixed in RFC1122) + * this case on figure 6 and figure 8, but formal + * protocol description says NOTHING. + * To be more exact, it says that we should send ACK, + * because this segment (at least, if it has no data) + * is out of window. + * + * CONCLUSION: RFC793 (even with RFC1122) DOES NOT + * describe SYN-RECV state. All the description + * is wrong, we cannot believe to it and should + * rely only on common sense and implementation + * experience. + * + * Enforce "SYN-ACK" according to figure 8, figure 6 + * of RFC793, fixed by RFC1122. + * + * Note that even if there is new data in the SYN packet + * they will be thrown away too. + * + * Reset timer after retransmitting SYNACK, similar to + * the idea of fast retransmit in recovery. + */ + if (!tcp_oow_rate_limited(sock_net(sk), skb, + LINUX_MIB_TCPACKSKIPPEDSYNRECV, + &tcp_rsk(req)->last_oow_ack_time) && + + !inet_rtx_syn_ack(sk, req)) { + unsigned long expires = jiffies; + + expires += min(TCP_TIMEOUT_INIT << req->num_timeout, + TCP_RTO_MAX); + if (!fastopen) + mod_timer_pending(&req->rsk_timer, expires); + else + req->rsk_timer.expires = expires; + } + return NULL; + } + + /* Further reproduces section "SEGMENT ARRIVES" + for state SYN-RECEIVED of RFC793. + It is broken, however, it does not work only + when SYNs are crossed. + + You would think that SYN crossing is impossible here, since + we should have a SYN_SENT socket (from connect()) on our end, + but this is not true if the crossed SYNs were sent to both + ends by a malicious third party. We must defend against this, + and to do that we first verify the ACK (as per RFC793, page + 36) and reset if it is invalid. Is this a true full defense? + To convince ourselves, let us consider a way in which the ACK + test can still pass in this 'malicious crossed SYNs' case. + Malicious sender sends identical SYNs (and thus identical sequence + numbers) to both A and B: + + A: gets SYN, seq=7 + B: gets SYN, seq=7 + + By our good fortune, both A and B select the same initial + send sequence number of seven :-) + + A: sends SYN|ACK, seq=7, ack_seq=8 + B: sends SYN|ACK, seq=7, ack_seq=8 + + So we are now A eating this SYN|ACK, ACK test passes. So + does sequence test, SYN is truncated, and thus we consider + it a bare ACK. + + If icsk->icsk_accept_queue.rskq_defer_accept, we silently drop this + bare ACK. Otherwise, we create an established connection. Both + ends (listening sockets) accept the new incoming connection and try + to talk to each other. 8-) + + Note: This case is both harmless, and rare. Possibility is about the + same as us discovering intelligent life on another plant tomorrow. + + But generally, we should (RFC lies!) to accept ACK + from SYNACK both here and in tcp_rcv_state_process(). + tcp_rcv_state_process() does not, hence, we do not too. + + Note that the case is absolutely generic: + we cannot optimize anything here without + violating protocol. All the checks must be made + before attempt to create socket. + */ + + /* RFC793 page 36: "If the connection is in any non-synchronized state ... + * and the incoming segment acknowledges something not yet + * sent (the segment carries an unacceptable ACK) ... + * a reset is sent." + * + * Invalid ACK: reset will be sent by listening socket. + * Note that the ACK validity check for a Fast Open socket is done + * elsewhere and is checked directly against the child socket rather + * than req because user data may have been sent out. + */ + if ((flg & TCP_FLAG_ACK) && !fastopen && + (TCP_SKB_CB(skb)->ack_seq != + tcp_rsk(req)->snt_isn + 1)) + return sk; + + /* Also, it would be not so bad idea to check rcv_tsecr, which + * is essentially ACK extension and too early or too late values + * should cause reset in unsynchronized states. + */ + + /* RFC793: "first check sequence number". */ + + if (paws_reject || !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq, + tcp_rsk(req)->rcv_nxt, tcp_rsk(req)->rcv_nxt + req->rsk_rcv_wnd)) { + /* Out of window: send ACK and drop. */ + if (!(flg & TCP_FLAG_RST) && + !tcp_oow_rate_limited(sock_net(sk), skb, + LINUX_MIB_TCPACKSKIPPEDSYNRECV, + &tcp_rsk(req)->last_oow_ack_time)) + req->rsk_ops->send_ack(sk, skb, req); + if (paws_reject) + NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED); + return NULL; + } + + /* In sequence, PAWS is OK. */ + + /* TODO: We probably should defer ts_recent change once + * we take ownership of @req. + */ + if (tmp_opt.saw_tstamp && !after(TCP_SKB_CB(skb)->seq, tcp_rsk(req)->rcv_nxt)) + WRITE_ONCE(req->ts_recent, tmp_opt.rcv_tsval); + + if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn) { + /* Truncate SYN, it is out of window starting + at tcp_rsk(req)->rcv_isn + 1. */ + flg &= ~TCP_FLAG_SYN; + } + + /* RFC793: "second check the RST bit" and + * "fourth, check the SYN bit" + */ + if (flg & (TCP_FLAG_RST|TCP_FLAG_SYN)) { + TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); + goto embryonic_reset; + } + + /* ACK sequence verified above, just make sure ACK is + * set. If ACK not set, just silently drop the packet. + * + * XXX (TFO) - if we ever allow "data after SYN", the + * following check needs to be removed. + */ + if (!(flg & TCP_FLAG_ACK)) + return NULL; + + /* For Fast Open no more processing is needed (sk is the + * child socket). + */ + if (fastopen) + return sk; + + /* While TCP_DEFER_ACCEPT is active, drop bare ACK. */ + if (req->num_timeout < inet_csk(sk)->icsk_accept_queue.rskq_defer_accept && + TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) { + inet_rsk(req)->acked = 1; + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPDEFERACCEPTDROP); + return NULL; + } + + /* OK, ACK is valid, create big socket and + * feed this segment to it. It will repeat all + * the tests. THIS SEGMENT MUST MOVE SOCKET TO + * ESTABLISHED STATE. If it will be dropped after + * socket is created, wait for troubles. + */ + child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL, + req, &own_req); + if (!child) + goto listen_overflow; + + if (own_req && rsk_drop_req(req)) { + reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req); + inet_csk_reqsk_queue_drop_and_put(sk, req); + return child; + } + + sock_rps_save_rxhash(child, skb); + tcp_synack_rtt_meas(child, req); + *req_stolen = !own_req; + return inet_csk_complete_hashdance(sk, child, req, own_req); + +listen_overflow: + if (!sock_net(sk)->ipv4.sysctl_tcp_abort_on_overflow) { + inet_rsk(req)->acked = 1; + return NULL; + } + +embryonic_reset: + if (!(flg & TCP_FLAG_RST)) { + /* Received a bad SYN pkt - for TFO We try not to reset + * the local connection unless it's really necessary to + * avoid becoming vulnerable to outside attack aiming at + * resetting legit local connections. + */ + req->rsk_ops->send_reset(sk, skb); + } else if (fastopen) { /* received a valid RST pkt */ + reqsk_fastopen_remove(sk, req, true); + tcp_reset(sk); + } + if (!fastopen) { + bool unlinked = inet_csk_reqsk_queue_drop(sk, req); + + if (unlinked) + __NET_INC_STATS(sock_net(sk), LINUX_MIB_EMBRYONICRSTS); + *req_stolen = !unlinked; + } + return NULL; +} +EXPORT_SYMBOL(tcp_check_req); + +/* + * Queue segment on the new socket if the new socket is active, + * otherwise we just shortcircuit this and continue with + * the new socket. + * + * For the vast majority of cases child->sk_state will be TCP_SYN_RECV + * when entering. But other states are possible due to a race condition + * where after __inet_lookup_established() fails but before the listener + * locked is obtained, other packets cause the same connection to + * be created. + */ + +int tcp_child_process(struct sock *parent, struct sock *child, + struct sk_buff *skb) + __releases(&((child)->sk_lock.slock)) +{ + int ret = 0; + int state = child->sk_state; + + /* record NAPI ID of child */ + sk_mark_napi_id(child, skb); + + tcp_segs_in(tcp_sk(child), skb); + if (!sock_owned_by_user(child)) { + ret = tcp_rcv_state_process(child, skb); + /* Wakeup parent, send SIGIO */ + if (state == TCP_SYN_RECV && child->sk_state != state) + parent->sk_data_ready(parent); + } else { + /* Alas, it is possible again, because we do lookup + * in main socket hash table and lock on listening + * socket does not protect us more. + */ + __sk_add_backlog(child, skb); + } + + bh_unlock_sock(child); + sock_put(child); + return ret; +} +EXPORT_SYMBOL(tcp_child_process); diff --git a/net/ipv4/tcp_nv.c b/net/ipv4/tcp_nv.c new file mode 100644 index 000000000..95db7a11b --- /dev/null +++ b/net/ipv4/tcp_nv.c @@ -0,0 +1,502 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP NV: TCP with Congestion Avoidance + * + * TCP-NV is a successor of TCP-Vegas that has been developed to + * deal with the issues that occur in modern networks. + * Like TCP-Vegas, TCP-NV supports true congestion avoidance, + * the ability to detect congestion before packet losses occur. + * When congestion (queue buildup) starts to occur, TCP-NV + * predicts what the cwnd size should be for the current + * throughput and it reduces the cwnd proportionally to + * the difference between the current cwnd and the predicted cwnd. + * + * NV is only recommeneded for traffic within a data center, and when + * all the flows are NV (at least those within the data center). This + * is due to the inherent unfairness between flows using losses to + * detect congestion (congestion control) and those that use queue + * buildup to detect congestion (congestion avoidance). + * + * Note: High NIC coalescence values may lower the performance of NV + * due to the increased noise in RTT values. In particular, we have + * seen issues with rx-frames values greater than 8. + * + * TODO: + * 1) Add mechanism to deal with reverse congestion. + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/math64.h> +#include <net/tcp.h> +#include <linux/inet_diag.h> + +/* TCP NV parameters + * + * nv_pad Max number of queued packets allowed in network + * nv_pad_buffer Do not grow cwnd if this closed to nv_pad + * nv_reset_period How often (in) seconds)to reset min_rtt + * nv_min_cwnd Don't decrease cwnd below this if there are no losses + * nv_cong_dec_mult Decrease cwnd by X% (30%) of congestion when detected + * nv_ssthresh_factor On congestion set ssthresh to this * <desired cwnd> / 8 + * nv_rtt_factor RTT averaging factor + * nv_loss_dec_factor Decrease cwnd to this (80%) when losses occur + * nv_dec_eval_min_calls Wait this many RTT measurements before dec cwnd + * nv_inc_eval_min_calls Wait this many RTT measurements before inc cwnd + * nv_ssthresh_eval_min_calls Wait this many RTT measurements before stopping + * slow-start due to congestion + * nv_stop_rtt_cnt Only grow cwnd for this many RTTs after non-congestion + * nv_rtt_min_cnt Wait these many RTTs before making congesion decision + * nv_cwnd_growth_rate_neg + * nv_cwnd_growth_rate_pos + * How quickly to double growth rate (not rate) of cwnd when not + * congested. One value (nv_cwnd_growth_rate_neg) for when + * rate < 1 pkt/RTT (after losses). The other (nv_cwnd_growth_rate_pos) + * otherwise. + */ + +static int nv_pad __read_mostly = 10; +static int nv_pad_buffer __read_mostly = 2; +static int nv_reset_period __read_mostly = 5; /* in seconds */ +static int nv_min_cwnd __read_mostly = 2; +static int nv_cong_dec_mult __read_mostly = 30 * 128 / 100; /* = 30% */ +static int nv_ssthresh_factor __read_mostly = 8; /* = 1 */ +static int nv_rtt_factor __read_mostly = 128; /* = 1/2*old + 1/2*new */ +static int nv_loss_dec_factor __read_mostly = 819; /* => 80% */ +static int nv_cwnd_growth_rate_neg __read_mostly = 8; +static int nv_cwnd_growth_rate_pos __read_mostly; /* 0 => fixed like Reno */ +static int nv_dec_eval_min_calls __read_mostly = 60; +static int nv_inc_eval_min_calls __read_mostly = 20; +static int nv_ssthresh_eval_min_calls __read_mostly = 30; +static int nv_stop_rtt_cnt __read_mostly = 10; +static int nv_rtt_min_cnt __read_mostly = 2; + +module_param(nv_pad, int, 0644); +MODULE_PARM_DESC(nv_pad, "max queued packets allowed in network"); +module_param(nv_reset_period, int, 0644); +MODULE_PARM_DESC(nv_reset_period, "nv_min_rtt reset period (secs)"); +module_param(nv_min_cwnd, int, 0644); +MODULE_PARM_DESC(nv_min_cwnd, "NV will not decrease cwnd below this value" + " without losses"); + +/* TCP NV Parameters */ +struct tcpnv { + unsigned long nv_min_rtt_reset_jiffies; /* when to switch to + * nv_min_rtt_new */ + s8 cwnd_growth_factor; /* Current cwnd growth factor, + * < 0 => less than 1 packet/RTT */ + u8 available8; + u16 available16; + u8 nv_allow_cwnd_growth:1, /* whether cwnd can grow */ + nv_reset:1, /* whether to reset values */ + nv_catchup:1; /* whether we are growing because + * of temporary cwnd decrease */ + u8 nv_eval_call_cnt; /* call count since last eval */ + u8 nv_min_cwnd; /* nv won't make a ca decision if cwnd is + * smaller than this. It may grow to handle + * TSO, LRO and interrupt coalescence because + * with these a small cwnd cannot saturate + * the link. Note that this is different from + * the file local nv_min_cwnd */ + u8 nv_rtt_cnt; /* RTTs without making ca decision */; + u32 nv_last_rtt; /* last rtt */ + u32 nv_min_rtt; /* active min rtt. Used to determine slope */ + u32 nv_min_rtt_new; /* min rtt for future use */ + u32 nv_base_rtt; /* If non-zero it represents the threshold for + * congestion */ + u32 nv_lower_bound_rtt; /* Used in conjunction with nv_base_rtt. It is + * set to 80% of nv_base_rtt. It helps reduce + * unfairness between flows */ + u32 nv_rtt_max_rate; /* max rate seen during current RTT */ + u32 nv_rtt_start_seq; /* current RTT ends when packet arrives + * acking beyond nv_rtt_start_seq */ + u32 nv_last_snd_una; /* Previous value of tp->snd_una. It is + * used to determine bytes acked since last + * call to bictcp_acked */ + u32 nv_no_cong_cnt; /* Consecutive no congestion decisions */ +}; + +#define NV_INIT_RTT U32_MAX +#define NV_MIN_CWND 4 +#define NV_MIN_CWND_GROW 2 +#define NV_TSO_CWND_BOUND 80 + +static inline void tcpnv_reset(struct tcpnv *ca, struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + ca->nv_reset = 0; + ca->nv_no_cong_cnt = 0; + ca->nv_rtt_cnt = 0; + ca->nv_last_rtt = 0; + ca->nv_rtt_max_rate = 0; + ca->nv_rtt_start_seq = tp->snd_una; + ca->nv_eval_call_cnt = 0; + ca->nv_last_snd_una = tp->snd_una; +} + +static void tcpnv_init(struct sock *sk) +{ + struct tcpnv *ca = inet_csk_ca(sk); + int base_rtt; + + tcpnv_reset(ca, sk); + + /* See if base_rtt is available from socket_ops bpf program. + * It is meant to be used in environments, such as communication + * within a datacenter, where we have reasonable estimates of + * RTTs + */ + base_rtt = tcp_call_bpf(sk, BPF_SOCK_OPS_BASE_RTT, 0, NULL); + if (base_rtt > 0) { + ca->nv_base_rtt = base_rtt; + ca->nv_lower_bound_rtt = (base_rtt * 205) >> 8; /* 80% */ + } else { + ca->nv_base_rtt = 0; + ca->nv_lower_bound_rtt = 0; + } + + ca->nv_allow_cwnd_growth = 1; + ca->nv_min_rtt_reset_jiffies = jiffies + 2 * HZ; + ca->nv_min_rtt = NV_INIT_RTT; + ca->nv_min_rtt_new = NV_INIT_RTT; + ca->nv_min_cwnd = NV_MIN_CWND; + ca->nv_catchup = 0; + ca->cwnd_growth_factor = 0; +} + +/* If provided, apply upper (base_rtt) and lower (lower_bound_rtt) + * bounds to RTT. + */ +inline u32 nv_get_bounded_rtt(struct tcpnv *ca, u32 val) +{ + if (ca->nv_lower_bound_rtt > 0 && val < ca->nv_lower_bound_rtt) + return ca->nv_lower_bound_rtt; + else if (ca->nv_base_rtt > 0 && val > ca->nv_base_rtt) + return ca->nv_base_rtt; + else + return val; +} + +static void tcpnv_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcpnv *ca = inet_csk_ca(sk); + u32 cnt; + + if (!tcp_is_cwnd_limited(sk)) + return; + + /* Only grow cwnd if NV has not detected congestion */ + if (!ca->nv_allow_cwnd_growth) + return; + + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + return; + } + + if (ca->cwnd_growth_factor < 0) { + cnt = tp->snd_cwnd << -ca->cwnd_growth_factor; + tcp_cong_avoid_ai(tp, cnt, acked); + } else { + cnt = max(4U, tp->snd_cwnd >> ca->cwnd_growth_factor); + tcp_cong_avoid_ai(tp, cnt, acked); + } +} + +static u32 tcpnv_recalc_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + return max((tp->snd_cwnd * nv_loss_dec_factor) >> 10, 2U); +} + +static void tcpnv_state(struct sock *sk, u8 new_state) +{ + struct tcpnv *ca = inet_csk_ca(sk); + + if (new_state == TCP_CA_Open && ca->nv_reset) { + tcpnv_reset(ca, sk); + } else if (new_state == TCP_CA_Loss || new_state == TCP_CA_CWR || + new_state == TCP_CA_Recovery) { + ca->nv_reset = 1; + ca->nv_allow_cwnd_growth = 0; + if (new_state == TCP_CA_Loss) { + /* Reset cwnd growth factor to Reno value */ + if (ca->cwnd_growth_factor > 0) + ca->cwnd_growth_factor = 0; + /* Decrease growth rate if allowed */ + if (nv_cwnd_growth_rate_neg > 0 && + ca->cwnd_growth_factor > -8) + ca->cwnd_growth_factor--; + } + } +} + +/* Do congestion avoidance calculations for TCP-NV + */ +static void tcpnv_acked(struct sock *sk, const struct ack_sample *sample) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct tcpnv *ca = inet_csk_ca(sk); + unsigned long now = jiffies; + u64 rate64; + u32 rate, max_win, cwnd_by_slope; + u32 avg_rtt; + u32 bytes_acked = 0; + + /* Some calls are for duplicates without timetamps */ + if (sample->rtt_us < 0) + return; + + /* If not in TCP_CA_Open or TCP_CA_Disorder states, skip. */ + if (icsk->icsk_ca_state != TCP_CA_Open && + icsk->icsk_ca_state != TCP_CA_Disorder) + return; + + /* Stop cwnd growth if we were in catch up mode */ + if (ca->nv_catchup && tp->snd_cwnd >= nv_min_cwnd) { + ca->nv_catchup = 0; + ca->nv_allow_cwnd_growth = 0; + } + + bytes_acked = tp->snd_una - ca->nv_last_snd_una; + ca->nv_last_snd_una = tp->snd_una; + + if (sample->in_flight == 0) + return; + + /* Calculate moving average of RTT */ + if (nv_rtt_factor > 0) { + if (ca->nv_last_rtt > 0) { + avg_rtt = (((u64)sample->rtt_us) * nv_rtt_factor + + ((u64)ca->nv_last_rtt) + * (256 - nv_rtt_factor)) >> 8; + } else { + avg_rtt = sample->rtt_us; + ca->nv_min_rtt = avg_rtt << 1; + } + ca->nv_last_rtt = avg_rtt; + } else { + avg_rtt = sample->rtt_us; + } + + /* rate in 100's bits per second */ + rate64 = ((u64)sample->in_flight) * 80000; + do_div(rate64, avg_rtt ?: 1); + rate = (u32)rate64; + + /* Remember the maximum rate seen during this RTT + * Note: It may be more than one RTT. This function should be + * called at least nv_dec_eval_min_calls times. + */ + if (ca->nv_rtt_max_rate < rate) + ca->nv_rtt_max_rate = rate; + + /* We have valid information, increment counter */ + if (ca->nv_eval_call_cnt < 255) + ca->nv_eval_call_cnt++; + + /* Apply bounds to rtt. Only used to update min_rtt */ + avg_rtt = nv_get_bounded_rtt(ca, avg_rtt); + + /* update min rtt if necessary */ + if (avg_rtt < ca->nv_min_rtt) + ca->nv_min_rtt = avg_rtt; + + /* update future min_rtt if necessary */ + if (avg_rtt < ca->nv_min_rtt_new) + ca->nv_min_rtt_new = avg_rtt; + + /* nv_min_rtt is updated with the minimum (possibley averaged) rtt + * seen in the last sysctl_tcp_nv_reset_period seconds (i.e. a + * warm reset). This new nv_min_rtt will be continued to be updated + * and be used for another sysctl_tcp_nv_reset_period seconds, + * when it will be updated again. + * In practice we introduce some randomness, so the actual period used + * is chosen randomly from the range: + * [sysctl_tcp_nv_reset_period*3/4, sysctl_tcp_nv_reset_period*5/4) + */ + if (time_after_eq(now, ca->nv_min_rtt_reset_jiffies)) { + unsigned char rand; + + ca->nv_min_rtt = ca->nv_min_rtt_new; + ca->nv_min_rtt_new = NV_INIT_RTT; + get_random_bytes(&rand, 1); + ca->nv_min_rtt_reset_jiffies = + now + ((nv_reset_period * (384 + rand) * HZ) >> 9); + /* Every so often we decrease ca->nv_min_cwnd in case previous + * value is no longer accurate. + */ + ca->nv_min_cwnd = max(ca->nv_min_cwnd / 2, NV_MIN_CWND); + } + + /* Once per RTT check if we need to do congestion avoidance */ + if (before(ca->nv_rtt_start_seq, tp->snd_una)) { + ca->nv_rtt_start_seq = tp->snd_nxt; + if (ca->nv_rtt_cnt < 0xff) + /* Increase counter for RTTs without CA decision */ + ca->nv_rtt_cnt++; + + /* If this function is only called once within an RTT + * the cwnd is probably too small (in some cases due to + * tso, lro or interrupt coalescence), so we increase + * ca->nv_min_cwnd. + */ + if (ca->nv_eval_call_cnt == 1 && + bytes_acked >= (ca->nv_min_cwnd - 1) * tp->mss_cache && + ca->nv_min_cwnd < (NV_TSO_CWND_BOUND + 1)) { + ca->nv_min_cwnd = min(ca->nv_min_cwnd + + NV_MIN_CWND_GROW, + NV_TSO_CWND_BOUND + 1); + ca->nv_rtt_start_seq = tp->snd_nxt + + ca->nv_min_cwnd * tp->mss_cache; + ca->nv_eval_call_cnt = 0; + ca->nv_allow_cwnd_growth = 1; + return; + } + + /* Find the ideal cwnd for current rate from slope + * slope = 80000.0 * mss / nv_min_rtt + * cwnd_by_slope = nv_rtt_max_rate / slope + */ + cwnd_by_slope = (u32) + div64_u64(((u64)ca->nv_rtt_max_rate) * ca->nv_min_rtt, + 80000ULL * tp->mss_cache); + max_win = cwnd_by_slope + nv_pad; + + /* If cwnd > max_win, decrease cwnd + * if cwnd < max_win, grow cwnd + * else leave the same + */ + if (tp->snd_cwnd > max_win) { + /* there is congestion, check that it is ok + * to make a CA decision + * 1. We should have at least nv_dec_eval_min_calls + * data points before making a CA decision + * 2. We only make a congesion decision after + * nv_rtt_min_cnt RTTs + */ + if (ca->nv_rtt_cnt < nv_rtt_min_cnt) { + return; + } else if (tp->snd_ssthresh == TCP_INFINITE_SSTHRESH) { + if (ca->nv_eval_call_cnt < + nv_ssthresh_eval_min_calls) + return; + /* otherwise we will decrease cwnd */ + } else if (ca->nv_eval_call_cnt < + nv_dec_eval_min_calls) { + if (ca->nv_allow_cwnd_growth && + ca->nv_rtt_cnt > nv_stop_rtt_cnt) + ca->nv_allow_cwnd_growth = 0; + return; + } + + /* We have enough data to determine we are congested */ + ca->nv_allow_cwnd_growth = 0; + tp->snd_ssthresh = + (nv_ssthresh_factor * max_win) >> 3; + if (tp->snd_cwnd - max_win > 2) { + /* gap > 2, we do exponential cwnd decrease */ + int dec; + + dec = max(2U, ((tp->snd_cwnd - max_win) * + nv_cong_dec_mult) >> 7); + tp->snd_cwnd -= dec; + } else if (nv_cong_dec_mult > 0) { + tp->snd_cwnd = max_win; + } + if (ca->cwnd_growth_factor > 0) + ca->cwnd_growth_factor = 0; + ca->nv_no_cong_cnt = 0; + } else if (tp->snd_cwnd <= max_win - nv_pad_buffer) { + /* There is no congestion, grow cwnd if allowed*/ + if (ca->nv_eval_call_cnt < nv_inc_eval_min_calls) + return; + + ca->nv_allow_cwnd_growth = 1; + ca->nv_no_cong_cnt++; + if (ca->cwnd_growth_factor < 0 && + nv_cwnd_growth_rate_neg > 0 && + ca->nv_no_cong_cnt > nv_cwnd_growth_rate_neg) { + ca->cwnd_growth_factor++; + ca->nv_no_cong_cnt = 0; + } else if (ca->cwnd_growth_factor >= 0 && + nv_cwnd_growth_rate_pos > 0 && + ca->nv_no_cong_cnt > + nv_cwnd_growth_rate_pos) { + ca->cwnd_growth_factor++; + ca->nv_no_cong_cnt = 0; + } + } else { + /* cwnd is in-between, so do nothing */ + return; + } + + /* update state */ + ca->nv_eval_call_cnt = 0; + ca->nv_rtt_cnt = 0; + ca->nv_rtt_max_rate = 0; + + /* Don't want to make cwnd < nv_min_cwnd + * (it wasn't before, if it is now is because nv + * decreased it). + */ + if (tp->snd_cwnd < nv_min_cwnd) + tp->snd_cwnd = nv_min_cwnd; + } +} + +/* Extract info for Tcp socket info provided via netlink */ +static size_t tcpnv_get_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info) +{ + const struct tcpnv *ca = inet_csk_ca(sk); + + if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) { + info->vegas.tcpv_enabled = 1; + info->vegas.tcpv_rttcnt = ca->nv_rtt_cnt; + info->vegas.tcpv_rtt = ca->nv_last_rtt; + info->vegas.tcpv_minrtt = ca->nv_min_rtt; + + *attr = INET_DIAG_VEGASINFO; + return sizeof(struct tcpvegas_info); + } + return 0; +} + +static struct tcp_congestion_ops tcpnv __read_mostly = { + .init = tcpnv_init, + .ssthresh = tcpnv_recalc_ssthresh, + .cong_avoid = tcpnv_cong_avoid, + .set_state = tcpnv_state, + .undo_cwnd = tcp_reno_undo_cwnd, + .pkts_acked = tcpnv_acked, + .get_info = tcpnv_get_info, + + .owner = THIS_MODULE, + .name = "nv", +}; + +static int __init tcpnv_register(void) +{ + BUILD_BUG_ON(sizeof(struct tcpnv) > ICSK_CA_PRIV_SIZE); + + return tcp_register_congestion_control(&tcpnv); +} + +static void __exit tcpnv_unregister(void) +{ + tcp_unregister_congestion_control(&tcpnv); +} + +module_init(tcpnv_register); +module_exit(tcpnv_unregister); + +MODULE_AUTHOR("Lawrence Brakmo"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP NV"); +MODULE_VERSION("1.0"); diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c new file mode 100644 index 000000000..fc61cd3fe --- /dev/null +++ b/net/ipv4/tcp_offload.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IPV4 GSO/GRO offload support + * Linux INET implementation + * + * TCPv4 GSO/GRO support + */ + +#include <linux/indirect_call_wrapper.h> +#include <linux/skbuff.h> +#include <net/tcp.h> +#include <net/protocol.h> + +static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq, + unsigned int seq, unsigned int mss) +{ + while (skb) { + if (before(ts_seq, seq + mss)) { + skb_shinfo(skb)->tx_flags |= SKBTX_SW_TSTAMP; + skb_shinfo(skb)->tskey = ts_seq; + return; + } + + skb = skb->next; + seq += mss; + } +} + +static struct sk_buff *tcp4_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)) + return ERR_PTR(-EINVAL); + + if (!pskb_may_pull(skb, sizeof(struct tcphdr))) + return ERR_PTR(-EINVAL); + + if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) { + const struct iphdr *iph = ip_hdr(skb); + struct tcphdr *th = tcp_hdr(skb); + + /* Set up checksum pseudo header, usually expect stack to + * have done this already. + */ + + th->check = 0; + skb->ip_summed = CHECKSUM_PARTIAL; + __tcp_v4_send_check(skb, iph->saddr, iph->daddr); + } + + return tcp_gso_segment(skb, features); +} + +struct sk_buff *tcp_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + unsigned int sum_truesize = 0; + struct tcphdr *th; + unsigned int thlen; + unsigned int seq; + __be32 delta; + unsigned int oldlen; + unsigned int mss; + struct sk_buff *gso_skb = skb; + __sum16 newcheck; + bool ooo_okay, copy_destructor; + + th = tcp_hdr(skb); + thlen = th->doff * 4; + if (thlen < sizeof(*th)) + goto out; + + if (!pskb_may_pull(skb, thlen)) + goto out; + + oldlen = (u16)~skb->len; + __skb_pull(skb, thlen); + + mss = skb_shinfo(skb)->gso_size; + if (unlikely(skb->len <= mss)) + goto out; + + if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { + /* Packet is from an untrusted source, reset gso_segs. */ + + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); + + segs = NULL; + goto out; + } + + copy_destructor = gso_skb->destructor == tcp_wfree; + ooo_okay = gso_skb->ooo_okay; + /* All segments but the first should have ooo_okay cleared */ + skb->ooo_okay = 0; + + segs = skb_segment(skb, features); + if (IS_ERR(segs)) + goto out; + + /* Only first segment might have ooo_okay set */ + segs->ooo_okay = ooo_okay; + + /* GSO partial and frag_list segmentation only requires splitting + * the frame into an MSS multiple and possibly a remainder, both + * cases return a GSO skb. So update the mss now. + */ + if (skb_is_gso(segs)) + mss *= skb_shinfo(segs)->gso_segs; + + delta = htonl(oldlen + (thlen + mss)); + + skb = segs; + th = tcp_hdr(skb); + seq = ntohl(th->seq); + + if (unlikely(skb_shinfo(gso_skb)->tx_flags & SKBTX_SW_TSTAMP)) + tcp_gso_tstamp(segs, skb_shinfo(gso_skb)->tskey, seq, mss); + + newcheck = ~csum_fold((__force __wsum)((__force u32)th->check + + (__force u32)delta)); + + while (skb->next) { + th->fin = th->psh = 0; + th->check = newcheck; + + if (skb->ip_summed == CHECKSUM_PARTIAL) + gso_reset_checksum(skb, ~th->check); + else + th->check = gso_make_checksum(skb, ~th->check); + + seq += mss; + if (copy_destructor) { + skb->destructor = gso_skb->destructor; + skb->sk = gso_skb->sk; + sum_truesize += skb->truesize; + } + skb = skb->next; + th = tcp_hdr(skb); + + th->seq = htonl(seq); + th->cwr = 0; + } + + /* Following permits TCP Small Queues to work well with GSO : + * The callback to TCP stack will be called at the time last frag + * is freed at TX completion, and not right now when gso_skb + * is freed by GSO engine + */ + if (copy_destructor) { + int delta; + + swap(gso_skb->sk, skb->sk); + swap(gso_skb->destructor, skb->destructor); + sum_truesize += skb->truesize; + delta = sum_truesize - gso_skb->truesize; + /* In some pathological cases, delta can be negative. + * We need to either use refcount_add() or refcount_sub_and_test() + */ + if (likely(delta >= 0)) + refcount_add(delta, &skb->sk->sk_wmem_alloc); + else + WARN_ON_ONCE(refcount_sub_and_test(-delta, &skb->sk->sk_wmem_alloc)); + } + + delta = htonl(oldlen + (skb_tail_pointer(skb) - + skb_transport_header(skb)) + + skb->data_len); + th->check = ~csum_fold((__force __wsum)((__force u32)th->check + + (__force u32)delta)); + if (skb->ip_summed == CHECKSUM_PARTIAL) + gso_reset_checksum(skb, ~th->check); + else + th->check = gso_make_checksum(skb, ~th->check); +out: + return segs; +} + +struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) +{ + struct sk_buff *pp = NULL; + struct sk_buff *p; + struct tcphdr *th; + struct tcphdr *th2; + unsigned int len; + unsigned int thlen; + __be32 flags; + unsigned int mss = 1; + unsigned int hlen; + unsigned int off; + int flush = 1; + int i; + + off = skb_gro_offset(skb); + hlen = off + sizeof(*th); + th = skb_gro_header_fast(skb, off); + if (skb_gro_header_hard(skb, hlen)) { + th = skb_gro_header_slow(skb, hlen, off); + if (unlikely(!th)) + goto out; + } + + thlen = th->doff * 4; + if (thlen < sizeof(*th)) + goto out; + + hlen = off + thlen; + if (skb_gro_header_hard(skb, hlen)) { + th = skb_gro_header_slow(skb, hlen, off); + if (unlikely(!th)) + goto out; + } + + skb_gro_pull(skb, thlen); + + len = skb_gro_len(skb); + flags = tcp_flag_word(th); + + list_for_each_entry(p, head, list) { + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + th2 = tcp_hdr(p); + + if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + + goto found; + } + p = NULL; + goto out_check_final; + +found: + /* Include the IP ID check below from the inner most IP hdr */ + flush = NAPI_GRO_CB(p)->flush; + flush |= (__force int)(flags & TCP_FLAG_CWR); + flush |= (__force int)((flags ^ tcp_flag_word(th2)) & + ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); + flush |= (__force int)(th->ack_seq ^ th2->ack_seq); + for (i = sizeof(*th); i < thlen; i += 4) + flush |= *(u32 *)((u8 *)th + i) ^ + *(u32 *)((u8 *)th2 + i); + + /* When we receive our second frame we can made a decision on if we + * continue this flow as an atomic flow with a fixed ID or if we use + * an incrementing ID. + */ + if (NAPI_GRO_CB(p)->flush_id != 1 || + NAPI_GRO_CB(p)->count != 1 || + !NAPI_GRO_CB(p)->is_atomic) + flush |= NAPI_GRO_CB(p)->flush_id; + else + NAPI_GRO_CB(p)->is_atomic = false; + + mss = skb_shinfo(p)->gso_size; + + flush |= (len - 1) >= mss; + flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); +#ifdef CONFIG_TLS_DEVICE + flush |= p->decrypted ^ skb->decrypted; +#endif + + if (flush || skb_gro_receive(p, skb)) { + mss = 1; + goto out_check_final; + } + + tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); + +out_check_final: + flush = len < mss; + flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | + TCP_FLAG_RST | TCP_FLAG_SYN | + TCP_FLAG_FIN)); + + if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) + pp = p; + +out: + NAPI_GRO_CB(skb)->flush |= (flush != 0); + + return pp; +} + +int tcp_gro_complete(struct sk_buff *skb) +{ + struct tcphdr *th = tcp_hdr(skb); + + skb->csum_start = (unsigned char *)th - skb->head; + skb->csum_offset = offsetof(struct tcphdr, check); + skb->ip_summed = CHECKSUM_PARTIAL; + + skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; + + if (th->cwr) + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; + + if (skb->encapsulation) + skb->inner_transport_header = skb->transport_header; + + return 0; +} +EXPORT_SYMBOL(tcp_gro_complete); + +INDIRECT_CALLABLE_SCOPE +struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb) +{ + /* Don't bother verifying checksum if we're going to flush anyway. */ + if (!NAPI_GRO_CB(skb)->flush && + skb_gro_checksum_validate(skb, IPPROTO_TCP, + inet_gro_compute_pseudo)) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + + return tcp_gro_receive(head, skb); +} + +INDIRECT_CALLABLE_SCOPE int tcp4_gro_complete(struct sk_buff *skb, int thoff) +{ + const struct iphdr *iph = ip_hdr(skb); + struct tcphdr *th = tcp_hdr(skb); + + th->check = ~tcp_v4_check(skb->len - thoff, iph->saddr, + iph->daddr, 0); + skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4; + + if (NAPI_GRO_CB(skb)->is_atomic) + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_FIXEDID; + + return tcp_gro_complete(skb); +} + +static const struct net_offload tcpv4_offload = { + .callbacks = { + .gso_segment = tcp4_gso_segment, + .gro_receive = tcp4_gro_receive, + .gro_complete = tcp4_gro_complete, + }, +}; + +int __init tcpv4_offload_init(void) +{ + return inet_add_offload(&tcpv4_offload, IPPROTO_TCP); +} diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c new file mode 100644 index 000000000..f0df14782 --- /dev/null +++ b/net/ipv4/tcp_output.c @@ -0,0 +1,4157 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Implementation of the Transmission Control Protocol(TCP). + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * Corey Minyard <wf-rch!minyard@relay.EU.net> + * Florian La Roche, <flla@stud.uni-sb.de> + * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> + * Linus Torvalds, <torvalds@cs.helsinki.fi> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Matthew Dillon, <dillon@apollo.west.oic.com> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Jorge Cwik, <jorge@laser.satlink.net> + */ + +/* + * Changes: Pedro Roque : Retransmit queue handled by TCP. + * : Fragmentation on mtu decrease + * : Segment collapse on retransmit + * : AF independence + * + * Linus Torvalds : send_delayed_ack + * David S. Miller : Charge memory using the right skb + * during syn/ack processing. + * David S. Miller : Output engine completely rewritten. + * Andrea Arcangeli: SYNACK carry ts_recent in tsecr. + * Cacophonix Gaul : draft-minshall-nagle-01 + * J Hadi Salim : ECN support + * + */ + +#define pr_fmt(fmt) "TCP: " fmt + +#include <net/tcp.h> +#include <net/mptcp.h> + +#include <linux/compiler.h> +#include <linux/gfp.h> +#include <linux/module.h> +#include <linux/static_key.h> + +#include <trace/events/tcp.h> + +/* Refresh clocks of a TCP socket, + * ensuring monotically increasing values. + */ +void tcp_mstamp_refresh(struct tcp_sock *tp) +{ + u64 val = tcp_clock_ns(); + + tp->tcp_clock_cache = val; + tp->tcp_mstamp = div_u64(val, NSEC_PER_USEC); +} + +static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, + int push_one, gfp_t gfp); + +/* Account for new data that has been sent to the network. */ +static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + unsigned int prior_packets = tp->packets_out; + + WRITE_ONCE(tp->snd_nxt, TCP_SKB_CB(skb)->end_seq); + + __skb_unlink(skb, &sk->sk_write_queue); + tcp_rbtree_insert(&sk->tcp_rtx_queue, skb); + + if (tp->highest_sack == NULL) + tp->highest_sack = skb; + + tp->packets_out += tcp_skb_pcount(skb); + if (!prior_packets || icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) + tcp_rearm_rto(sk); + + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPORIGDATASENT, + tcp_skb_pcount(skb)); + tcp_check_space(sk); +} + +/* SND.NXT, if window was not shrunk or the amount of shrunk was less than one + * window scaling factor due to loss of precision. + * If window has been shrunk, what should we make? It is not clear at all. + * Using SND.UNA we will fail to open window, SND.NXT is out of window. :-( + * Anything in between SND.UNA...SND.UNA+SND.WND also can be already + * invalid. OK, let's make this for now: + */ +static inline __u32 tcp_acceptable_seq(const struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + if (!before(tcp_wnd_end(tp), tp->snd_nxt) || + (tp->rx_opt.wscale_ok && + ((tp->snd_nxt - tcp_wnd_end(tp)) < (1 << tp->rx_opt.rcv_wscale)))) + return tp->snd_nxt; + else + return tcp_wnd_end(tp); +} + +/* Calculate mss to advertise in SYN segment. + * RFC1122, RFC1063, draft-ietf-tcpimpl-pmtud-01 state that: + * + * 1. It is independent of path mtu. + * 2. Ideally, it is maximal possible segment size i.e. 65535-40. + * 3. For IPv4 it is reasonable to calculate it from maximal MTU of + * attached devices, because some buggy hosts are confused by + * large MSS. + * 4. We do not make 3, we advertise MSS, calculated from first + * hop device mtu, but allow to raise it to ip_rt_min_advmss. + * This may be overridden via information stored in routing table. + * 5. Value 65535 for MSS is valid in IPv6 and means "as large as possible, + * probably even Jumbo". + */ +static __u16 tcp_advertise_mss(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + const struct dst_entry *dst = __sk_dst_get(sk); + int mss = tp->advmss; + + if (dst) { + unsigned int metric = dst_metric_advmss(dst); + + if (metric < mss) { + mss = metric; + tp->advmss = mss; + } + } + + return (__u16)mss; +} + +/* RFC2861. Reset CWND after idle period longer RTO to "restart window". + * This is the first part of cwnd validation mechanism. + */ +void tcp_cwnd_restart(struct sock *sk, s32 delta) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 restart_cwnd = tcp_init_cwnd(tp, __sk_dst_get(sk)); + u32 cwnd = tp->snd_cwnd; + + tcp_ca_event(sk, CA_EVENT_CWND_RESTART); + + tp->snd_ssthresh = tcp_current_ssthresh(sk); + restart_cwnd = min(restart_cwnd, cwnd); + + while ((delta -= inet_csk(sk)->icsk_rto) > 0 && cwnd > restart_cwnd) + cwnd >>= 1; + tp->snd_cwnd = max(cwnd, restart_cwnd); + tp->snd_cwnd_stamp = tcp_jiffies32; + tp->snd_cwnd_used = 0; +} + +/* Congestion state accounting after a packet has been sent. */ +static void tcp_event_data_sent(struct tcp_sock *tp, + struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + const u32 now = tcp_jiffies32; + + if (tcp_packets_in_flight(tp) == 0) + tcp_ca_event(sk, CA_EVENT_TX_START); + + tp->lsndtime = now; + + /* If it is a reply for ato after last received + * packet, enter pingpong mode. + */ + if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato) + inet_csk_enter_pingpong_mode(sk); +} + +/* Account for an ACK we sent. */ +static inline void tcp_event_ack_sent(struct sock *sk, u32 rcv_nxt) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (unlikely(tp->compressed_ack)) { + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPACKCOMPRESSED, + tp->compressed_ack); + tp->compressed_ack = 0; + if (hrtimer_try_to_cancel(&tp->compressed_ack_timer) == 1) + __sock_put(sk); + } + + if (unlikely(rcv_nxt != tp->rcv_nxt)) + return; /* Special ACK sent by DCTCP to reflect ECN */ + tcp_dec_quickack_mode(sk); + inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); +} + +/* Determine a window scaling and initial window to offer. + * Based on the assumption that the given amount of space + * will be offered. Store the results in the tp structure. + * NOTE: for smooth operation initial space offering should + * be a multiple of mss if possible. We assume here that mss >= 1. + * This MUST be enforced by all callers. + */ +void tcp_select_initial_window(const struct sock *sk, int __space, __u32 mss, + __u32 *rcv_wnd, __u32 *window_clamp, + int wscale_ok, __u8 *rcv_wscale, + __u32 init_rcv_wnd) +{ + unsigned int space = (__space < 0 ? 0 : __space); + + /* If no clamp set the clamp to the max possible scaled window */ + if (*window_clamp == 0) + (*window_clamp) = (U16_MAX << TCP_MAX_WSCALE); + space = min(*window_clamp, space); + + /* Quantize space offering to a multiple of mss if possible. */ + if (space > mss) + space = rounddown(space, mss); + + /* NOTE: offering an initial window larger than 32767 + * will break some buggy TCP stacks. If the admin tells us + * it is likely we could be speaking with such a buggy stack + * we will truncate our initial window offering to 32K-1 + * unless the remote has sent us a window scaling option, + * which we interpret as a sign the remote TCP is not + * misinterpreting the window field as a signed quantity. + */ + if (sock_net(sk)->ipv4.sysctl_tcp_workaround_signed_windows) + (*rcv_wnd) = min(space, MAX_TCP_WINDOW); + else + (*rcv_wnd) = min_t(u32, space, U16_MAX); + + if (init_rcv_wnd) + *rcv_wnd = min(*rcv_wnd, init_rcv_wnd * mss); + + *rcv_wscale = 0; + if (wscale_ok) { + /* Set window scaling on max possible window */ + space = max_t(u32, space, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2])); + space = max_t(u32, space, READ_ONCE(sysctl_rmem_max)); + space = min_t(u32, space, *window_clamp); + *rcv_wscale = clamp_t(int, ilog2(space) - 15, + 0, TCP_MAX_WSCALE); + } + /* Set the clamp no higher than max representable value */ + (*window_clamp) = min_t(__u32, U16_MAX << (*rcv_wscale), *window_clamp); +} +EXPORT_SYMBOL(tcp_select_initial_window); + +/* Chose a new window to advertise, update state in tcp_sock for the + * socket, and return result with RFC1323 scaling applied. The return + * value can be stuffed directly into th->window for an outgoing + * frame. + */ +static u16 tcp_select_window(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 old_win = tp->rcv_wnd; + u32 cur_win = tcp_receive_window(tp); + u32 new_win = __tcp_select_window(sk); + + /* Never shrink the offered window */ + if (new_win < cur_win) { + /* Danger Will Robinson! + * Don't update rcv_wup/rcv_wnd here or else + * we will not be able to advertise a zero + * window in time. --DaveM + * + * Relax Will Robinson. + */ + if (new_win == 0) + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPWANTZEROWINDOWADV); + new_win = ALIGN(cur_win, 1 << tp->rx_opt.rcv_wscale); + } + tp->rcv_wnd = new_win; + tp->rcv_wup = tp->rcv_nxt; + + /* Make sure we do not exceed the maximum possible + * scaled window. + */ + if (!tp->rx_opt.rcv_wscale && + sock_net(sk)->ipv4.sysctl_tcp_workaround_signed_windows) + new_win = min(new_win, MAX_TCP_WINDOW); + else + new_win = min(new_win, (65535U << tp->rx_opt.rcv_wscale)); + + /* RFC1323 scaling applied */ + new_win >>= tp->rx_opt.rcv_wscale; + + /* If we advertise zero window, disable fast path. */ + if (new_win == 0) { + tp->pred_flags = 0; + if (old_win) + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPTOZEROWINDOWADV); + } else if (old_win == 0) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFROMZEROWINDOWADV); + } + + return new_win; +} + +/* Packet ECN state for a SYN-ACK */ +static void tcp_ecn_send_synack(struct sock *sk, struct sk_buff *skb) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_CWR; + if (!(tp->ecn_flags & TCP_ECN_OK)) + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_ECE; + else if (tcp_ca_needs_ecn(sk) || + tcp_bpf_ca_needs_ecn(sk)) + INET_ECN_xmit(sk); +} + +/* Packet ECN state for a SYN. */ +static void tcp_ecn_send_syn(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + bool bpf_needs_ecn = tcp_bpf_ca_needs_ecn(sk); + bool use_ecn = sock_net(sk)->ipv4.sysctl_tcp_ecn == 1 || + tcp_ca_needs_ecn(sk) || bpf_needs_ecn; + + if (!use_ecn) { + const struct dst_entry *dst = __sk_dst_get(sk); + + if (dst && dst_feature(dst, RTAX_FEATURE_ECN)) + use_ecn = true; + } + + tp->ecn_flags = 0; + + if (use_ecn) { + TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_ECE | TCPHDR_CWR; + tp->ecn_flags = TCP_ECN_OK; + if (tcp_ca_needs_ecn(sk) || bpf_needs_ecn) + INET_ECN_xmit(sk); + } +} + +static void tcp_ecn_clear_syn(struct sock *sk, struct sk_buff *skb) +{ + if (sock_net(sk)->ipv4.sysctl_tcp_ecn_fallback) + /* tp->ecn_flags are cleared at a later point in time when + * SYN ACK is ultimatively being received. + */ + TCP_SKB_CB(skb)->tcp_flags &= ~(TCPHDR_ECE | TCPHDR_CWR); +} + +static void +tcp_ecn_make_synack(const struct request_sock *req, struct tcphdr *th) +{ + if (inet_rsk(req)->ecn_ok) + th->ece = 1; +} + +/* Set up ECN state for a packet on a ESTABLISHED socket that is about to + * be sent. + */ +static void tcp_ecn_send(struct sock *sk, struct sk_buff *skb, + struct tcphdr *th, int tcp_header_len) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->ecn_flags & TCP_ECN_OK) { + /* Not-retransmitted data segment: set ECT and inject CWR. */ + if (skb->len != tcp_header_len && + !before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) { + INET_ECN_xmit(sk); + if (tp->ecn_flags & TCP_ECN_QUEUE_CWR) { + tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR; + th->cwr = 1; + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; + } + } else if (!tcp_ca_needs_ecn(sk)) { + /* ACK or retransmitted segment: clear ECT|CE */ + INET_ECN_dontxmit(sk); + } + if (tp->ecn_flags & TCP_ECN_DEMAND_CWR) + th->ece = 1; + } +} + +/* Constructs common control bits of non-data skb. If SYN/FIN is present, + * auto increment end seqno. + */ +static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags) +{ + skb->ip_summed = CHECKSUM_PARTIAL; + + TCP_SKB_CB(skb)->tcp_flags = flags; + TCP_SKB_CB(skb)->sacked = 0; + + tcp_skb_pcount_set(skb, 1); + + TCP_SKB_CB(skb)->seq = seq; + if (flags & (TCPHDR_SYN | TCPHDR_FIN)) + seq++; + TCP_SKB_CB(skb)->end_seq = seq; +} + +static inline bool tcp_urg_mode(const struct tcp_sock *tp) +{ + return tp->snd_una != tp->snd_up; +} + +#define OPTION_SACK_ADVERTISE (1 << 0) +#define OPTION_TS (1 << 1) +#define OPTION_MD5 (1 << 2) +#define OPTION_WSCALE (1 << 3) +#define OPTION_FAST_OPEN_COOKIE (1 << 8) +#define OPTION_SMC (1 << 9) +#define OPTION_MPTCP (1 << 10) + +static void smc_options_write(__be32 *ptr, u16 *options) +{ +#if IS_ENABLED(CONFIG_SMC) + if (static_branch_unlikely(&tcp_have_smc)) { + if (unlikely(OPTION_SMC & *options)) { + *ptr++ = htonl((TCPOPT_NOP << 24) | + (TCPOPT_NOP << 16) | + (TCPOPT_EXP << 8) | + (TCPOLEN_EXP_SMC_BASE)); + *ptr++ = htonl(TCPOPT_SMC_MAGIC); + } + } +#endif +} + +struct tcp_out_options { + u16 options; /* bit field of OPTION_* */ + u16 mss; /* 0 to disable */ + u8 ws; /* window scale, 0 to disable */ + u8 num_sack_blocks; /* number of SACK blocks to include */ + u8 hash_size; /* bytes in hash_location */ + u8 bpf_opt_len; /* length of BPF hdr option */ + __u8 *hash_location; /* temporary pointer, overloaded */ + __u32 tsval, tsecr; /* need to include OPTION_TS */ + struct tcp_fastopen_cookie *fastopen_cookie; /* Fast open cookie */ + struct mptcp_out_options mptcp; +}; + +static void mptcp_options_write(__be32 *ptr, struct tcp_out_options *opts) +{ +#if IS_ENABLED(CONFIG_MPTCP) + if (unlikely(OPTION_MPTCP & opts->options)) + mptcp_write_options(ptr, &opts->mptcp); +#endif +} + +#ifdef CONFIG_CGROUP_BPF +static int bpf_skops_write_hdr_opt_arg0(struct sk_buff *skb, + enum tcp_synack_type synack_type) +{ + if (unlikely(!skb)) + return BPF_WRITE_HDR_TCP_CURRENT_MSS; + + if (unlikely(synack_type == TCP_SYNACK_COOKIE)) + return BPF_WRITE_HDR_TCP_SYNACK_COOKIE; + + return 0; +} + +/* req, syn_skb and synack_type are used when writing synack */ +static void bpf_skops_hdr_opt_len(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct sk_buff *syn_skb, + enum tcp_synack_type synack_type, + struct tcp_out_options *opts, + unsigned int *remaining) +{ + struct bpf_sock_ops_kern sock_ops; + int err; + + if (likely(!BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), + BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG)) || + !*remaining) + return; + + /* *remaining has already been aligned to 4 bytes, so *remaining >= 4 */ + + /* init sock_ops */ + memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); + + sock_ops.op = BPF_SOCK_OPS_HDR_OPT_LEN_CB; + + if (req) { + /* The listen "sk" cannot be passed here because + * it is not locked. It would not make too much + * sense to do bpf_setsockopt(listen_sk) based + * on individual connection request also. + * + * Thus, "req" is passed here and the cgroup-bpf-progs + * of the listen "sk" will be run. + * + * "req" is also used here for fastopen even the "sk" here is + * a fullsock "child" sk. It is to keep the behavior + * consistent between fastopen and non-fastopen on + * the bpf programming side. + */ + sock_ops.sk = (struct sock *)req; + sock_ops.syn_skb = syn_skb; + } else { + sock_owned_by_me(sk); + + sock_ops.is_fullsock = 1; + sock_ops.sk = sk; + } + + sock_ops.args[0] = bpf_skops_write_hdr_opt_arg0(skb, synack_type); + sock_ops.remaining_opt_len = *remaining; + /* tcp_current_mss() does not pass a skb */ + if (skb) + bpf_skops_init_skb(&sock_ops, skb, 0); + + err = BPF_CGROUP_RUN_PROG_SOCK_OPS_SK(&sock_ops, sk); + + if (err || sock_ops.remaining_opt_len == *remaining) + return; + + opts->bpf_opt_len = *remaining - sock_ops.remaining_opt_len; + /* round up to 4 bytes */ + opts->bpf_opt_len = (opts->bpf_opt_len + 3) & ~3; + + *remaining -= opts->bpf_opt_len; +} + +static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct sk_buff *syn_skb, + enum tcp_synack_type synack_type, + struct tcp_out_options *opts) +{ + u8 first_opt_off, nr_written, max_opt_len = opts->bpf_opt_len; + struct bpf_sock_ops_kern sock_ops; + int err; + + if (likely(!max_opt_len)) + return; + + memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); + + sock_ops.op = BPF_SOCK_OPS_WRITE_HDR_OPT_CB; + + if (req) { + sock_ops.sk = (struct sock *)req; + sock_ops.syn_skb = syn_skb; + } else { + sock_owned_by_me(sk); + + sock_ops.is_fullsock = 1; + sock_ops.sk = sk; + } + + sock_ops.args[0] = bpf_skops_write_hdr_opt_arg0(skb, synack_type); + sock_ops.remaining_opt_len = max_opt_len; + first_opt_off = tcp_hdrlen(skb) - max_opt_len; + bpf_skops_init_skb(&sock_ops, skb, first_opt_off); + + err = BPF_CGROUP_RUN_PROG_SOCK_OPS_SK(&sock_ops, sk); + + if (err) + nr_written = 0; + else + nr_written = max_opt_len - sock_ops.remaining_opt_len; + + if (nr_written < max_opt_len) + memset(skb->data + first_opt_off + nr_written, TCPOPT_NOP, + max_opt_len - nr_written); +} +#else +static void bpf_skops_hdr_opt_len(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct sk_buff *syn_skb, + enum tcp_synack_type synack_type, + struct tcp_out_options *opts, + unsigned int *remaining) +{ +} + +static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct sk_buff *syn_skb, + enum tcp_synack_type synack_type, + struct tcp_out_options *opts) +{ +} +#endif + +/* Write previously computed TCP options to the packet. + * + * Beware: Something in the Internet is very sensitive to the ordering of + * TCP options, we learned this through the hard way, so be careful here. + * Luckily we can at least blame others for their non-compliance but from + * inter-operability perspective it seems that we're somewhat stuck with + * the ordering which we have been using if we want to keep working with + * those broken things (not that it currently hurts anybody as there isn't + * particular reason why the ordering would need to be changed). + * + * At least SACK_PERM as the first option is known to lead to a disaster + * (but it may well be that other scenarios fail similarly). + */ +static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp, + struct tcp_out_options *opts) +{ + u16 options = opts->options; /* mungable copy */ + + if (unlikely(OPTION_MD5 & options)) { + *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | + (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); + /* overload cookie hash location */ + opts->hash_location = (__u8 *)ptr; + ptr += 4; + } + + if (unlikely(opts->mss)) { + *ptr++ = htonl((TCPOPT_MSS << 24) | + (TCPOLEN_MSS << 16) | + opts->mss); + } + + if (likely(OPTION_TS & options)) { + if (unlikely(OPTION_SACK_ADVERTISE & options)) { + *ptr++ = htonl((TCPOPT_SACK_PERM << 24) | + (TCPOLEN_SACK_PERM << 16) | + (TCPOPT_TIMESTAMP << 8) | + TCPOLEN_TIMESTAMP); + options &= ~OPTION_SACK_ADVERTISE; + } else { + *ptr++ = htonl((TCPOPT_NOP << 24) | + (TCPOPT_NOP << 16) | + (TCPOPT_TIMESTAMP << 8) | + TCPOLEN_TIMESTAMP); + } + *ptr++ = htonl(opts->tsval); + *ptr++ = htonl(opts->tsecr); + } + + if (unlikely(OPTION_SACK_ADVERTISE & options)) { + *ptr++ = htonl((TCPOPT_NOP << 24) | + (TCPOPT_NOP << 16) | + (TCPOPT_SACK_PERM << 8) | + TCPOLEN_SACK_PERM); + } + + if (unlikely(OPTION_WSCALE & options)) { + *ptr++ = htonl((TCPOPT_NOP << 24) | + (TCPOPT_WINDOW << 16) | + (TCPOLEN_WINDOW << 8) | + opts->ws); + } + + if (unlikely(opts->num_sack_blocks)) { + struct tcp_sack_block *sp = tp->rx_opt.dsack ? + tp->duplicate_sack : tp->selective_acks; + int this_sack; + + *ptr++ = htonl((TCPOPT_NOP << 24) | + (TCPOPT_NOP << 16) | + (TCPOPT_SACK << 8) | + (TCPOLEN_SACK_BASE + (opts->num_sack_blocks * + TCPOLEN_SACK_PERBLOCK))); + + for (this_sack = 0; this_sack < opts->num_sack_blocks; + ++this_sack) { + *ptr++ = htonl(sp[this_sack].start_seq); + *ptr++ = htonl(sp[this_sack].end_seq); + } + + tp->rx_opt.dsack = 0; + } + + if (unlikely(OPTION_FAST_OPEN_COOKIE & options)) { + struct tcp_fastopen_cookie *foc = opts->fastopen_cookie; + u8 *p = (u8 *)ptr; + u32 len; /* Fast Open option length */ + + if (foc->exp) { + len = TCPOLEN_EXP_FASTOPEN_BASE + foc->len; + *ptr = htonl((TCPOPT_EXP << 24) | (len << 16) | + TCPOPT_FASTOPEN_MAGIC); + p += TCPOLEN_EXP_FASTOPEN_BASE; + } else { + len = TCPOLEN_FASTOPEN_BASE + foc->len; + *p++ = TCPOPT_FASTOPEN; + *p++ = len; + } + + memcpy(p, foc->val, foc->len); + if ((len & 3) == 2) { + p[foc->len] = TCPOPT_NOP; + p[foc->len + 1] = TCPOPT_NOP; + } + ptr += (len + 3) >> 2; + } + + smc_options_write(ptr, &options); + + mptcp_options_write(ptr, opts); +} + +static void smc_set_option(const struct tcp_sock *tp, + struct tcp_out_options *opts, + unsigned int *remaining) +{ +#if IS_ENABLED(CONFIG_SMC) + if (static_branch_unlikely(&tcp_have_smc)) { + if (tp->syn_smc) { + if (*remaining >= TCPOLEN_EXP_SMC_BASE_ALIGNED) { + opts->options |= OPTION_SMC; + *remaining -= TCPOLEN_EXP_SMC_BASE_ALIGNED; + } + } + } +#endif +} + +static void smc_set_option_cond(const struct tcp_sock *tp, + const struct inet_request_sock *ireq, + struct tcp_out_options *opts, + unsigned int *remaining) +{ +#if IS_ENABLED(CONFIG_SMC) + if (static_branch_unlikely(&tcp_have_smc)) { + if (tp->syn_smc && ireq->smc_ok) { + if (*remaining >= TCPOLEN_EXP_SMC_BASE_ALIGNED) { + opts->options |= OPTION_SMC; + *remaining -= TCPOLEN_EXP_SMC_BASE_ALIGNED; + } + } + } +#endif +} + +static void mptcp_set_option_cond(const struct request_sock *req, + struct tcp_out_options *opts, + unsigned int *remaining) +{ + if (rsk_is_mptcp(req)) { + unsigned int size; + + if (mptcp_synack_options(req, &size, &opts->mptcp)) { + if (*remaining >= size) { + opts->options |= OPTION_MPTCP; + *remaining -= size; + } + } + } +} + +/* Compute TCP options for SYN packets. This is not the final + * network wire format yet. + */ +static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb, + struct tcp_out_options *opts, + struct tcp_md5sig_key **md5) +{ + struct tcp_sock *tp = tcp_sk(sk); + unsigned int remaining = MAX_TCP_OPTION_SPACE; + struct tcp_fastopen_request *fastopen = tp->fastopen_req; + + *md5 = NULL; +#ifdef CONFIG_TCP_MD5SIG + if (static_branch_unlikely(&tcp_md5_needed) && + rcu_access_pointer(tp->md5sig_info)) { + *md5 = tp->af_specific->md5_lookup(sk, sk); + if (*md5) { + opts->options |= OPTION_MD5; + remaining -= TCPOLEN_MD5SIG_ALIGNED; + } + } +#endif + + /* We always get an MSS option. The option bytes which will be seen in + * normal data packets should timestamps be used, must be in the MSS + * advertised. But we subtract them from tp->mss_cache so that + * calculations in tcp_sendmsg are simpler etc. So account for this + * fact here if necessary. If we don't do this correctly, as a + * receiver we won't recognize data packets as being full sized when we + * should, and thus we won't abide by the delayed ACK rules correctly. + * SACKs don't matter, we never delay an ACK when we have any of those + * going out. */ + opts->mss = tcp_advertise_mss(sk); + remaining -= TCPOLEN_MSS_ALIGNED; + + if (likely(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_timestamps) && !*md5)) { + opts->options |= OPTION_TS; + opts->tsval = tcp_skb_timestamp(skb) + tp->tsoffset; + opts->tsecr = tp->rx_opt.ts_recent; + remaining -= TCPOLEN_TSTAMP_ALIGNED; + } + if (likely(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_window_scaling))) { + opts->ws = tp->rx_opt.rcv_wscale; + opts->options |= OPTION_WSCALE; + remaining -= TCPOLEN_WSCALE_ALIGNED; + } + if (likely(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_sack))) { + opts->options |= OPTION_SACK_ADVERTISE; + if (unlikely(!(OPTION_TS & opts->options))) + remaining -= TCPOLEN_SACKPERM_ALIGNED; + } + + if (fastopen && fastopen->cookie.len >= 0) { + u32 need = fastopen->cookie.len; + + need += fastopen->cookie.exp ? TCPOLEN_EXP_FASTOPEN_BASE : + TCPOLEN_FASTOPEN_BASE; + need = (need + 3) & ~3U; /* Align to 32 bits */ + if (remaining >= need) { + opts->options |= OPTION_FAST_OPEN_COOKIE; + opts->fastopen_cookie = &fastopen->cookie; + remaining -= need; + tp->syn_fastopen = 1; + tp->syn_fastopen_exp = fastopen->cookie.exp ? 1 : 0; + } + } + + smc_set_option(tp, opts, &remaining); + + if (sk_is_mptcp(sk)) { + unsigned int size; + + if (mptcp_syn_options(sk, skb, &size, &opts->mptcp)) { + opts->options |= OPTION_MPTCP; + remaining -= size; + } + } + + bpf_skops_hdr_opt_len(sk, skb, NULL, NULL, 0, opts, &remaining); + + return MAX_TCP_OPTION_SPACE - remaining; +} + +/* Set up TCP options for SYN-ACKs. */ +static unsigned int tcp_synack_options(const struct sock *sk, + struct request_sock *req, + unsigned int mss, struct sk_buff *skb, + struct tcp_out_options *opts, + const struct tcp_md5sig_key *md5, + struct tcp_fastopen_cookie *foc, + enum tcp_synack_type synack_type, + struct sk_buff *syn_skb) +{ + struct inet_request_sock *ireq = inet_rsk(req); + unsigned int remaining = MAX_TCP_OPTION_SPACE; + +#ifdef CONFIG_TCP_MD5SIG + if (md5) { + opts->options |= OPTION_MD5; + remaining -= TCPOLEN_MD5SIG_ALIGNED; + + /* We can't fit any SACK blocks in a packet with MD5 + TS + * options. There was discussion about disabling SACK + * rather than TS in order to fit in better with old, + * buggy kernels, but that was deemed to be unnecessary. + */ + if (synack_type != TCP_SYNACK_COOKIE) + ireq->tstamp_ok &= !ireq->sack_ok; + } +#endif + + /* We always send an MSS option. */ + opts->mss = mss; + remaining -= TCPOLEN_MSS_ALIGNED; + + if (likely(ireq->wscale_ok)) { + opts->ws = ireq->rcv_wscale; + opts->options |= OPTION_WSCALE; + remaining -= TCPOLEN_WSCALE_ALIGNED; + } + if (likely(ireq->tstamp_ok)) { + opts->options |= OPTION_TS; + opts->tsval = tcp_skb_timestamp(skb) + tcp_rsk(req)->ts_off; + opts->tsecr = READ_ONCE(req->ts_recent); + remaining -= TCPOLEN_TSTAMP_ALIGNED; + } + if (likely(ireq->sack_ok)) { + opts->options |= OPTION_SACK_ADVERTISE; + if (unlikely(!ireq->tstamp_ok)) + remaining -= TCPOLEN_SACKPERM_ALIGNED; + } + if (foc != NULL && foc->len >= 0) { + u32 need = foc->len; + + need += foc->exp ? TCPOLEN_EXP_FASTOPEN_BASE : + TCPOLEN_FASTOPEN_BASE; + need = (need + 3) & ~3U; /* Align to 32 bits */ + if (remaining >= need) { + opts->options |= OPTION_FAST_OPEN_COOKIE; + opts->fastopen_cookie = foc; + remaining -= need; + } + } + + mptcp_set_option_cond(req, opts, &remaining); + + smc_set_option_cond(tcp_sk(sk), ireq, opts, &remaining); + + bpf_skops_hdr_opt_len((struct sock *)sk, skb, req, syn_skb, + synack_type, opts, &remaining); + + return MAX_TCP_OPTION_SPACE - remaining; +} + +/* Compute TCP options for ESTABLISHED sockets. This is not the + * final wire format yet. + */ +static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb, + struct tcp_out_options *opts, + struct tcp_md5sig_key **md5) +{ + struct tcp_sock *tp = tcp_sk(sk); + unsigned int size = 0; + unsigned int eff_sacks; + + opts->options = 0; + + *md5 = NULL; +#ifdef CONFIG_TCP_MD5SIG + if (static_branch_unlikely(&tcp_md5_needed) && + rcu_access_pointer(tp->md5sig_info)) { + *md5 = tp->af_specific->md5_lookup(sk, sk); + if (*md5) { + opts->options |= OPTION_MD5; + size += TCPOLEN_MD5SIG_ALIGNED; + } + } +#endif + + if (likely(tp->rx_opt.tstamp_ok)) { + opts->options |= OPTION_TS; + opts->tsval = skb ? tcp_skb_timestamp(skb) + tp->tsoffset : 0; + opts->tsecr = tp->rx_opt.ts_recent; + size += TCPOLEN_TSTAMP_ALIGNED; + } + + /* MPTCP options have precedence over SACK for the limited TCP + * option space because a MPTCP connection would be forced to + * fall back to regular TCP if a required multipath option is + * missing. SACK still gets a chance to use whatever space is + * left. + */ + if (sk_is_mptcp(sk)) { + unsigned int remaining = MAX_TCP_OPTION_SPACE - size; + unsigned int opt_size = 0; + + if (mptcp_established_options(sk, skb, &opt_size, remaining, + &opts->mptcp)) { + opts->options |= OPTION_MPTCP; + size += opt_size; + } + } + + eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack; + if (unlikely(eff_sacks)) { + const unsigned int remaining = MAX_TCP_OPTION_SPACE - size; + if (unlikely(remaining < TCPOLEN_SACK_BASE_ALIGNED + + TCPOLEN_SACK_PERBLOCK)) + return size; + + opts->num_sack_blocks = + min_t(unsigned int, eff_sacks, + (remaining - TCPOLEN_SACK_BASE_ALIGNED) / + TCPOLEN_SACK_PERBLOCK); + + size += TCPOLEN_SACK_BASE_ALIGNED + + opts->num_sack_blocks * TCPOLEN_SACK_PERBLOCK; + } + + if (unlikely(BPF_SOCK_OPS_TEST_FLAG(tp, + BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG))) { + unsigned int remaining = MAX_TCP_OPTION_SPACE - size; + + bpf_skops_hdr_opt_len(sk, skb, NULL, NULL, 0, opts, &remaining); + + size = MAX_TCP_OPTION_SPACE - remaining; + } + + return size; +} + + +/* TCP SMALL QUEUES (TSQ) + * + * TSQ goal is to keep small amount of skbs per tcp flow in tx queues (qdisc+dev) + * to reduce RTT and bufferbloat. + * We do this using a special skb destructor (tcp_wfree). + * + * Its important tcp_wfree() can be replaced by sock_wfree() in the event skb + * needs to be reallocated in a driver. + * The invariant being skb->truesize subtracted from sk->sk_wmem_alloc + * + * Since transmit from skb destructor is forbidden, we use a tasklet + * to process all sockets that eventually need to send more skbs. + * We use one tasklet per cpu, with its own queue of sockets. + */ +struct tsq_tasklet { + struct tasklet_struct tasklet; + struct list_head head; /* queue of tcp sockets */ +}; +static DEFINE_PER_CPU(struct tsq_tasklet, tsq_tasklet); + +static void tcp_tsq_write(struct sock *sk) +{ + if ((1 << sk->sk_state) & + (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_CLOSING | + TCPF_CLOSE_WAIT | TCPF_LAST_ACK)) { + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->lost_out > tp->retrans_out && + tp->snd_cwnd > tcp_packets_in_flight(tp)) { + tcp_mstamp_refresh(tp); + tcp_xmit_retransmit_queue(sk); + } + + tcp_write_xmit(sk, tcp_current_mss(sk), tp->nonagle, + 0, GFP_ATOMIC); + } +} + +static void tcp_tsq_handler(struct sock *sk) +{ + bh_lock_sock(sk); + if (!sock_owned_by_user(sk)) + tcp_tsq_write(sk); + else if (!test_and_set_bit(TCP_TSQ_DEFERRED, &sk->sk_tsq_flags)) + sock_hold(sk); + bh_unlock_sock(sk); +} +/* + * One tasklet per cpu tries to send more skbs. + * We run in tasklet context but need to disable irqs when + * transferring tsq->head because tcp_wfree() might + * interrupt us (non NAPI drivers) + */ +static void tcp_tasklet_func(unsigned long data) +{ + struct tsq_tasklet *tsq = (struct tsq_tasklet *)data; + LIST_HEAD(list); + unsigned long flags; + struct list_head *q, *n; + struct tcp_sock *tp; + struct sock *sk; + + local_irq_save(flags); + list_splice_init(&tsq->head, &list); + local_irq_restore(flags); + + list_for_each_safe(q, n, &list) { + tp = list_entry(q, struct tcp_sock, tsq_node); + list_del(&tp->tsq_node); + + sk = (struct sock *)tp; + smp_mb__before_atomic(); + clear_bit(TSQ_QUEUED, &sk->sk_tsq_flags); + + tcp_tsq_handler(sk); + sk_free(sk); + } +} + +#define TCP_DEFERRED_ALL (TCPF_TSQ_DEFERRED | \ + TCPF_WRITE_TIMER_DEFERRED | \ + TCPF_DELACK_TIMER_DEFERRED | \ + TCPF_MTU_REDUCED_DEFERRED) +/** + * tcp_release_cb - tcp release_sock() callback + * @sk: socket + * + * called from release_sock() to perform protocol dependent + * actions before socket release. + */ +void tcp_release_cb(struct sock *sk) +{ + unsigned long flags, nflags; + + /* perform an atomic operation only if at least one flag is set */ + do { + flags = sk->sk_tsq_flags; + if (!(flags & TCP_DEFERRED_ALL)) + return; + nflags = flags & ~TCP_DEFERRED_ALL; + } while (cmpxchg(&sk->sk_tsq_flags, flags, nflags) != flags); + + if (flags & TCPF_TSQ_DEFERRED) { + tcp_tsq_write(sk); + __sock_put(sk); + } + /* Here begins the tricky part : + * We are called from release_sock() with : + * 1) BH disabled + * 2) sk_lock.slock spinlock held + * 3) socket owned by us (sk->sk_lock.owned == 1) + * + * But following code is meant to be called from BH handlers, + * so we should keep BH disabled, but early release socket ownership + */ + sock_release_ownership(sk); + + if (flags & TCPF_WRITE_TIMER_DEFERRED) { + tcp_write_timer_handler(sk); + __sock_put(sk); + } + if (flags & TCPF_DELACK_TIMER_DEFERRED) { + tcp_delack_timer_handler(sk); + __sock_put(sk); + } + if (flags & TCPF_MTU_REDUCED_DEFERRED) { + inet_csk(sk)->icsk_af_ops->mtu_reduced(sk); + __sock_put(sk); + } +} +EXPORT_SYMBOL(tcp_release_cb); + +void __init tcp_tasklet_init(void) +{ + int i; + + for_each_possible_cpu(i) { + struct tsq_tasklet *tsq = &per_cpu(tsq_tasklet, i); + + INIT_LIST_HEAD(&tsq->head); + tasklet_init(&tsq->tasklet, + tcp_tasklet_func, + (unsigned long)tsq); + } +} + +/* + * Write buffer destructor automatically called from kfree_skb. + * We can't xmit new skbs from this context, as we might already + * hold qdisc lock. + */ +void tcp_wfree(struct sk_buff *skb) +{ + struct sock *sk = skb->sk; + struct tcp_sock *tp = tcp_sk(sk); + unsigned long flags, nval, oval; + + /* Keep one reference on sk_wmem_alloc. + * Will be released by sk_free() from here or tcp_tasklet_func() + */ + WARN_ON(refcount_sub_and_test(skb->truesize - 1, &sk->sk_wmem_alloc)); + + /* If this softirq is serviced by ksoftirqd, we are likely under stress. + * Wait until our queues (qdisc + devices) are drained. + * This gives : + * - less callbacks to tcp_write_xmit(), reducing stress (batches) + * - chance for incoming ACK (processed by another cpu maybe) + * to migrate this flow (skb->ooo_okay will be eventually set) + */ + if (refcount_read(&sk->sk_wmem_alloc) >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current) + goto out; + + for (oval = READ_ONCE(sk->sk_tsq_flags);; oval = nval) { + struct tsq_tasklet *tsq; + bool empty; + + if (!(oval & TSQF_THROTTLED) || (oval & TSQF_QUEUED)) + goto out; + + nval = (oval & ~TSQF_THROTTLED) | TSQF_QUEUED; + nval = cmpxchg(&sk->sk_tsq_flags, oval, nval); + if (nval != oval) + continue; + + /* queue this socket to tasklet queue */ + local_irq_save(flags); + tsq = this_cpu_ptr(&tsq_tasklet); + empty = list_empty(&tsq->head); + list_add(&tp->tsq_node, &tsq->head); + if (empty) + tasklet_schedule(&tsq->tasklet); + local_irq_restore(flags); + return; + } +out: + sk_free(sk); +} + +/* Note: Called under soft irq. + * We can call TCP stack right away, unless socket is owned by user. + */ +enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer) +{ + struct tcp_sock *tp = container_of(timer, struct tcp_sock, pacing_timer); + struct sock *sk = (struct sock *)tp; + + tcp_tsq_handler(sk); + sock_put(sk); + + return HRTIMER_NORESTART; +} + +static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb, + u64 prior_wstamp) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (sk->sk_pacing_status != SK_PACING_NONE) { + unsigned long rate = sk->sk_pacing_rate; + + /* Original sch_fq does not pace first 10 MSS + * Note that tp->data_segs_out overflows after 2^32 packets, + * this is a minor annoyance. + */ + if (rate != ~0UL && rate && tp->data_segs_out >= 10) { + u64 len_ns = div64_ul((u64)skb->len * NSEC_PER_SEC, rate); + u64 credit = tp->tcp_wstamp_ns - prior_wstamp; + + /* take into account OS jitter */ + len_ns -= min_t(u64, len_ns / 2, credit); + tp->tcp_wstamp_ns += len_ns; + } + } + list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue); +} + +INDIRECT_CALLABLE_DECLARE(int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)); +INDIRECT_CALLABLE_DECLARE(int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)); +INDIRECT_CALLABLE_DECLARE(void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)); + +/* This routine actually transmits TCP packets queued in by + * tcp_do_sendmsg(). This is used by both the initial + * transmission and possible later retransmissions. + * All SKB's seen here are completely headerless. It is our + * job to build the TCP header, and pass the packet down to + * IP so it can do the same plus pass the packet off to the + * device. + * + * We are working here with either a clone of the original + * SKB, or a fresh unique copy made by the retransmit engine. + */ +static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, + int clone_it, gfp_t gfp_mask, u32 rcv_nxt) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_sock *inet; + struct tcp_sock *tp; + struct tcp_skb_cb *tcb; + struct tcp_out_options opts; + unsigned int tcp_options_size, tcp_header_size; + struct sk_buff *oskb = NULL; + struct tcp_md5sig_key *md5; + struct tcphdr *th; + u64 prior_wstamp; + int err; + + BUG_ON(!skb || !tcp_skb_pcount(skb)); + tp = tcp_sk(sk); + prior_wstamp = tp->tcp_wstamp_ns; + tp->tcp_wstamp_ns = max(tp->tcp_wstamp_ns, tp->tcp_clock_cache); + skb->skb_mstamp_ns = tp->tcp_wstamp_ns; + if (clone_it) { + TCP_SKB_CB(skb)->tx.in_flight = TCP_SKB_CB(skb)->end_seq + - tp->snd_una; + oskb = skb; + + tcp_skb_tsorted_save(oskb) { + if (unlikely(skb_cloned(oskb))) + skb = pskb_copy(oskb, gfp_mask); + else + skb = skb_clone(oskb, gfp_mask); + } tcp_skb_tsorted_restore(oskb); + + if (unlikely(!skb)) + return -ENOBUFS; + /* retransmit skbs might have a non zero value in skb->dev + * because skb->dev is aliased with skb->rbnode.rb_left + */ + skb->dev = NULL; + } + + inet = inet_sk(sk); + tcb = TCP_SKB_CB(skb); + memset(&opts, 0, sizeof(opts)); + + if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) { + tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5); + } else { + tcp_options_size = tcp_established_options(sk, skb, &opts, + &md5); + /* Force a PSH flag on all (GSO) packets to expedite GRO flush + * at receiver : This slightly improve GRO performance. + * Note that we do not force the PSH flag for non GSO packets, + * because they might be sent under high congestion events, + * and in this case it is better to delay the delivery of 1-MSS + * packets and thus the corresponding ACK packet that would + * release the following packet. + */ + if (tcp_skb_pcount(skb) > 1) + tcb->tcp_flags |= TCPHDR_PSH; + } + tcp_header_size = tcp_options_size + sizeof(struct tcphdr); + + /* if no packet is in qdisc/device queue, then allow XPS to select + * another queue. We can be called from tcp_tsq_handler() + * which holds one reference to sk. + * + * TODO: Ideally, in-flight pure ACK packets should not matter here. + * One way to get this would be to set skb->truesize = 2 on them. + */ + skb->ooo_okay = sk_wmem_alloc_get(sk) < SKB_TRUESIZE(1); + + /* If we had to use memory reserve to allocate this skb, + * this might cause drops if packet is looped back : + * Other socket might not have SOCK_MEMALLOC. + * Packets not looped back do not care about pfmemalloc. + */ + skb->pfmemalloc = 0; + + skb_push(skb, tcp_header_size); + skb_reset_transport_header(skb); + + skb_orphan(skb); + skb->sk = sk; + skb->destructor = skb_is_tcp_pure_ack(skb) ? __sock_wfree : tcp_wfree; + skb_set_hash_from_sk(skb, sk); + refcount_add(skb->truesize, &sk->sk_wmem_alloc); + + skb_set_dst_pending_confirm(skb, READ_ONCE(sk->sk_dst_pending_confirm)); + + /* Build TCP header and checksum it. */ + th = (struct tcphdr *)skb->data; + th->source = inet->inet_sport; + th->dest = inet->inet_dport; + th->seq = htonl(tcb->seq); + th->ack_seq = htonl(rcv_nxt); + *(((__be16 *)th) + 6) = htons(((tcp_header_size >> 2) << 12) | + tcb->tcp_flags); + + th->check = 0; + th->urg_ptr = 0; + + /* The urg_mode check is necessary during a below snd_una win probe */ + if (unlikely(tcp_urg_mode(tp) && before(tcb->seq, tp->snd_up))) { + if (before(tp->snd_up, tcb->seq + 0x10000)) { + th->urg_ptr = htons(tp->snd_up - tcb->seq); + th->urg = 1; + } else if (after(tcb->seq + 0xFFFF, tp->snd_nxt)) { + th->urg_ptr = htons(0xFFFF); + th->urg = 1; + } + } + + tcp_options_write((__be32 *)(th + 1), tp, &opts); + skb_shinfo(skb)->gso_type = sk->sk_gso_type; + if (likely(!(tcb->tcp_flags & TCPHDR_SYN))) { + th->window = htons(tcp_select_window(sk)); + tcp_ecn_send(sk, skb, th, tcp_header_size); + } else { + /* RFC1323: The window in SYN & SYN/ACK segments + * is never scaled. + */ + th->window = htons(min(tp->rcv_wnd, 65535U)); + } +#ifdef CONFIG_TCP_MD5SIG + /* Calculate the MD5 hash, as we have all we need now */ + if (md5) { + sk_nocaps_add(sk, NETIF_F_GSO_MASK); + tp->af_specific->calc_md5_hash(opts.hash_location, + md5, sk, skb); + } +#endif + + /* BPF prog is the last one writing header option */ + bpf_skops_write_hdr_opt(sk, skb, NULL, NULL, 0, &opts); + + INDIRECT_CALL_INET(icsk->icsk_af_ops->send_check, + tcp_v6_send_check, tcp_v4_send_check, + sk, skb); + + if (likely(tcb->tcp_flags & TCPHDR_ACK)) + tcp_event_ack_sent(sk, rcv_nxt); + + if (skb->len != tcp_header_size) { + tcp_event_data_sent(tp, sk); + tp->data_segs_out += tcp_skb_pcount(skb); + tp->bytes_sent += skb->len - tcp_header_size; + } + + if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq) + TCP_ADD_STATS(sock_net(sk), TCP_MIB_OUTSEGS, + tcp_skb_pcount(skb)); + + tp->segs_out += tcp_skb_pcount(skb); + /* OK, its time to fill skb_shinfo(skb)->gso_{segs|size} */ + skb_shinfo(skb)->gso_segs = tcp_skb_pcount(skb); + skb_shinfo(skb)->gso_size = tcp_skb_mss(skb); + + /* Leave earliest departure time in skb->tstamp (skb->skb_mstamp_ns) */ + + /* Cleanup our debris for IP stacks */ + memset(skb->cb, 0, max(sizeof(struct inet_skb_parm), + sizeof(struct inet6_skb_parm))); + + tcp_add_tx_delay(skb, tp); + + err = INDIRECT_CALL_INET(icsk->icsk_af_ops->queue_xmit, + inet6_csk_xmit, ip_queue_xmit, + sk, skb, &inet->cork.fl); + + if (unlikely(err > 0)) { + tcp_enter_cwr(sk); + err = net_xmit_eval(err); + } + if (!err && oskb) { + tcp_update_skb_after_send(sk, oskb, prior_wstamp); + tcp_rate_skb_sent(sk, oskb); + } + return err; +} + +static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, + gfp_t gfp_mask) +{ + return __tcp_transmit_skb(sk, skb, clone_it, gfp_mask, + tcp_sk(sk)->rcv_nxt); +} + +/* This routine just queues the buffer for sending. + * + * NOTE: probe0 timer is not checked, do not forget tcp_push_pending_frames, + * otherwise socket can stall. + */ +static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* Advance write_seq and place onto the write_queue. */ + WRITE_ONCE(tp->write_seq, TCP_SKB_CB(skb)->end_seq); + __skb_header_release(skb); + tcp_add_write_queue_tail(sk, skb); + sk_wmem_queued_add(sk, skb->truesize); + sk_mem_charge(sk, skb->truesize); +} + +/* Initialize TSO segments for a packet. */ +static void tcp_set_skb_tso_segs(struct sk_buff *skb, unsigned int mss_now) +{ + if (skb->len <= mss_now) { + /* Avoid the costly divide in the normal + * non-TSO case. + */ + tcp_skb_pcount_set(skb, 1); + TCP_SKB_CB(skb)->tcp_gso_size = 0; + } else { + tcp_skb_pcount_set(skb, DIV_ROUND_UP(skb->len, mss_now)); + TCP_SKB_CB(skb)->tcp_gso_size = mss_now; + } +} + +/* Pcount in the middle of the write queue got changed, we need to do various + * tweaks to fix counters + */ +static void tcp_adjust_pcount(struct sock *sk, const struct sk_buff *skb, int decr) +{ + struct tcp_sock *tp = tcp_sk(sk); + + tp->packets_out -= decr; + + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) + tp->sacked_out -= decr; + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) + tp->retrans_out -= decr; + if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) + tp->lost_out -= decr; + + /* Reno case is special. Sigh... */ + if (tcp_is_reno(tp) && decr > 0) + tp->sacked_out -= min_t(u32, tp->sacked_out, decr); + + if (tp->lost_skb_hint && + before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(tp->lost_skb_hint)->seq) && + (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) + tp->lost_cnt_hint -= decr; + + tcp_verify_left_out(tp); +} + +static bool tcp_has_tx_tstamp(const struct sk_buff *skb) +{ + return TCP_SKB_CB(skb)->txstamp_ack || + (skb_shinfo(skb)->tx_flags & SKBTX_ANY_TSTAMP); +} + +static void tcp_fragment_tstamp(struct sk_buff *skb, struct sk_buff *skb2) +{ + struct skb_shared_info *shinfo = skb_shinfo(skb); + + if (unlikely(tcp_has_tx_tstamp(skb)) && + !before(shinfo->tskey, TCP_SKB_CB(skb2)->seq)) { + struct skb_shared_info *shinfo2 = skb_shinfo(skb2); + u8 tsflags = shinfo->tx_flags & SKBTX_ANY_TSTAMP; + + shinfo->tx_flags &= ~tsflags; + shinfo2->tx_flags |= tsflags; + swap(shinfo->tskey, shinfo2->tskey); + TCP_SKB_CB(skb2)->txstamp_ack = TCP_SKB_CB(skb)->txstamp_ack; + TCP_SKB_CB(skb)->txstamp_ack = 0; + } +} + +static void tcp_skb_fragment_eor(struct sk_buff *skb, struct sk_buff *skb2) +{ + TCP_SKB_CB(skb2)->eor = TCP_SKB_CB(skb)->eor; + TCP_SKB_CB(skb)->eor = 0; +} + +/* Insert buff after skb on the write or rtx queue of sk. */ +static void tcp_insert_write_queue_after(struct sk_buff *skb, + struct sk_buff *buff, + struct sock *sk, + enum tcp_queue tcp_queue) +{ + if (tcp_queue == TCP_FRAG_IN_WRITE_QUEUE) + __skb_queue_after(&sk->sk_write_queue, skb, buff); + else + tcp_rbtree_insert(&sk->tcp_rtx_queue, buff); +} + +/* Function to create two new TCP segments. Shrinks the given segment + * to the specified size and appends a new segment with the rest of the + * packet to the list. This won't be called frequently, I hope. + * Remember, these are still headerless SKBs at this point. + */ +int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, + struct sk_buff *skb, u32 len, + unsigned int mss_now, gfp_t gfp) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *buff; + int nsize, old_factor; + long limit; + int nlen; + u8 flags; + + if (WARN_ON(len > skb->len)) + return -EINVAL; + + nsize = skb_headlen(skb) - len; + if (nsize < 0) + nsize = 0; + + /* tcp_sendmsg() can overshoot sk_wmem_queued by one full size skb. + * We need some allowance to not penalize applications setting small + * SO_SNDBUF values. + * Also allow first and last skb in retransmit queue to be split. + */ + limit = sk->sk_sndbuf + 2 * SKB_TRUESIZE(GSO_MAX_SIZE); + if (unlikely((sk->sk_wmem_queued >> 1) > limit && + tcp_queue != TCP_FRAG_IN_WRITE_QUEUE && + skb != tcp_rtx_queue_head(sk) && + skb != tcp_rtx_queue_tail(sk))) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPWQUEUETOOBIG); + return -ENOMEM; + } + + if (skb_unclone(skb, gfp)) + return -ENOMEM; + + /* Get a new skb... force flag on. */ + buff = sk_stream_alloc_skb(sk, nsize, gfp, true); + if (!buff) + return -ENOMEM; /* We'll just try again later. */ + skb_copy_decrypted(buff, skb); + + sk_wmem_queued_add(sk, buff->truesize); + sk_mem_charge(sk, buff->truesize); + nlen = skb->len - len - nsize; + buff->truesize += nlen; + skb->truesize -= nlen; + + /* Correct the sequence numbers. */ + TCP_SKB_CB(buff)->seq = TCP_SKB_CB(skb)->seq + len; + TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq; + TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq; + + /* PSH and FIN should only be set in the second packet. */ + flags = TCP_SKB_CB(skb)->tcp_flags; + TCP_SKB_CB(skb)->tcp_flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH); + TCP_SKB_CB(buff)->tcp_flags = flags; + TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked; + tcp_skb_fragment_eor(skb, buff); + + skb_split(skb, buff, len); + + buff->ip_summed = CHECKSUM_PARTIAL; + + buff->tstamp = skb->tstamp; + tcp_fragment_tstamp(skb, buff); + + old_factor = tcp_skb_pcount(skb); + + /* Fix up tso_factor for both original and new SKB. */ + tcp_set_skb_tso_segs(skb, mss_now); + tcp_set_skb_tso_segs(buff, mss_now); + + /* Update delivered info for the new segment */ + TCP_SKB_CB(buff)->tx = TCP_SKB_CB(skb)->tx; + + /* If this packet has been sent out already, we must + * adjust the various packet counters. + */ + if (!before(tp->snd_nxt, TCP_SKB_CB(buff)->end_seq)) { + int diff = old_factor - tcp_skb_pcount(skb) - + tcp_skb_pcount(buff); + + if (diff) + tcp_adjust_pcount(sk, skb, diff); + } + + /* Link BUFF into the send queue. */ + __skb_header_release(buff); + tcp_insert_write_queue_after(skb, buff, sk, tcp_queue); + if (tcp_queue == TCP_FRAG_IN_RTX_QUEUE) + list_add(&buff->tcp_tsorted_anchor, &skb->tcp_tsorted_anchor); + + return 0; +} + +/* This is similar to __pskb_pull_tail(). The difference is that pulled + * data is not copied, but immediately discarded. + */ +static int __pskb_trim_head(struct sk_buff *skb, int len) +{ + struct skb_shared_info *shinfo; + int i, k, eat; + + eat = min_t(int, len, skb_headlen(skb)); + if (eat) { + __skb_pull(skb, eat); + len -= eat; + if (!len) + return 0; + } + eat = len; + k = 0; + shinfo = skb_shinfo(skb); + for (i = 0; i < shinfo->nr_frags; i++) { + int size = skb_frag_size(&shinfo->frags[i]); + + if (size <= eat) { + skb_frag_unref(skb, i); + eat -= size; + } else { + shinfo->frags[k] = shinfo->frags[i]; + if (eat) { + skb_frag_off_add(&shinfo->frags[k], eat); + skb_frag_size_sub(&shinfo->frags[k], eat); + eat = 0; + } + k++; + } + } + shinfo->nr_frags = k; + + skb->data_len -= len; + skb->len = skb->data_len; + return len; +} + +/* Remove acked data from a packet in the transmit queue. */ +int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len) +{ + u32 delta_truesize; + + if (skb_unclone(skb, GFP_ATOMIC)) + return -ENOMEM; + + delta_truesize = __pskb_trim_head(skb, len); + + TCP_SKB_CB(skb)->seq += len; + skb->ip_summed = CHECKSUM_PARTIAL; + + if (delta_truesize) { + skb->truesize -= delta_truesize; + sk_wmem_queued_add(sk, -delta_truesize); + sk_mem_uncharge(sk, delta_truesize); + } + + /* Any change of skb->len requires recalculation of tso factor. */ + if (tcp_skb_pcount(skb) > 1) + tcp_set_skb_tso_segs(skb, tcp_skb_mss(skb)); + + return 0; +} + +/* Calculate MSS not accounting any TCP options. */ +static inline int __tcp_mtu_to_mss(struct sock *sk, int pmtu) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const struct inet_connection_sock *icsk = inet_csk(sk); + int mss_now; + + /* Calculate base mss without TCP options: + It is MMS_S - sizeof(tcphdr) of rfc1122 + */ + mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr); + + /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */ + if (icsk->icsk_af_ops->net_frag_header_len) { + const struct dst_entry *dst = __sk_dst_get(sk); + + if (dst && dst_allfrag(dst)) + mss_now -= icsk->icsk_af_ops->net_frag_header_len; + } + + /* Clamp it (mss_clamp does not include tcp options) */ + if (mss_now > tp->rx_opt.mss_clamp) + mss_now = tp->rx_opt.mss_clamp; + + /* Now subtract optional transport overhead */ + mss_now -= icsk->icsk_ext_hdr_len; + + /* Then reserve room for full set of TCP options and 8 bytes of data */ + mss_now = max(mss_now, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_min_snd_mss)); + return mss_now; +} + +/* Calculate MSS. Not accounting for SACKs here. */ +int tcp_mtu_to_mss(struct sock *sk, int pmtu) +{ + /* Subtract TCP options size, not including SACKs */ + return __tcp_mtu_to_mss(sk, pmtu) - + (tcp_sk(sk)->tcp_header_len - sizeof(struct tcphdr)); +} +EXPORT_SYMBOL(tcp_mtu_to_mss); + +/* Inverse of above */ +int tcp_mss_to_mtu(struct sock *sk, int mss) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const struct inet_connection_sock *icsk = inet_csk(sk); + int mtu; + + mtu = mss + + tp->tcp_header_len + + icsk->icsk_ext_hdr_len + + icsk->icsk_af_ops->net_header_len; + + /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */ + if (icsk->icsk_af_ops->net_frag_header_len) { + const struct dst_entry *dst = __sk_dst_get(sk); + + if (dst && dst_allfrag(dst)) + mtu += icsk->icsk_af_ops->net_frag_header_len; + } + return mtu; +} +EXPORT_SYMBOL(tcp_mss_to_mtu); + +/* MTU probing init per socket */ +void tcp_mtup_init(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + struct net *net = sock_net(sk); + + icsk->icsk_mtup.enabled = READ_ONCE(net->ipv4.sysctl_tcp_mtu_probing) > 1; + icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) + + icsk->icsk_af_ops->net_header_len; + icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, READ_ONCE(net->ipv4.sysctl_tcp_base_mss)); + icsk->icsk_mtup.probe_size = 0; + if (icsk->icsk_mtup.enabled) + icsk->icsk_mtup.probe_timestamp = tcp_jiffies32; +} +EXPORT_SYMBOL(tcp_mtup_init); + +/* This function synchronize snd mss to current pmtu/exthdr set. + + tp->rx_opt.user_mss is mss set by user by TCP_MAXSEG. It does NOT counts + for TCP options, but includes only bare TCP header. + + tp->rx_opt.mss_clamp is mss negotiated at connection setup. + It is minimum of user_mss and mss received with SYN. + It also does not include TCP options. + + inet_csk(sk)->icsk_pmtu_cookie is last pmtu, seen by this function. + + tp->mss_cache is current effective sending mss, including + all tcp options except for SACKs. It is evaluated, + taking into account current pmtu, but never exceeds + tp->rx_opt.mss_clamp. + + NOTE1. rfc1122 clearly states that advertised MSS + DOES NOT include either tcp or ip options. + + NOTE2. inet_csk(sk)->icsk_pmtu_cookie and tp->mss_cache + are READ ONLY outside this function. --ANK (980731) + */ +unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + int mss_now; + + if (icsk->icsk_mtup.search_high > pmtu) + icsk->icsk_mtup.search_high = pmtu; + + mss_now = tcp_mtu_to_mss(sk, pmtu); + mss_now = tcp_bound_to_half_wnd(tp, mss_now); + + /* And store cached results */ + icsk->icsk_pmtu_cookie = pmtu; + if (icsk->icsk_mtup.enabled) + mss_now = min(mss_now, tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low)); + tp->mss_cache = mss_now; + + return mss_now; +} +EXPORT_SYMBOL(tcp_sync_mss); + +/* Compute the current effective MSS, taking SACKs and IP options, + * and even PMTU discovery events into account. + */ +unsigned int tcp_current_mss(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const struct dst_entry *dst = __sk_dst_get(sk); + u32 mss_now; + unsigned int header_len; + struct tcp_out_options opts; + struct tcp_md5sig_key *md5; + + mss_now = tp->mss_cache; + + if (dst) { + u32 mtu = dst_mtu(dst); + if (mtu != inet_csk(sk)->icsk_pmtu_cookie) + mss_now = tcp_sync_mss(sk, mtu); + } + + header_len = tcp_established_options(sk, NULL, &opts, &md5) + + sizeof(struct tcphdr); + /* The mss_cache is sized based on tp->tcp_header_len, which assumes + * some common options. If this is an odd packet (because we have SACK + * blocks etc) then our calculated header_len will be different, and + * we have to adjust mss_now correspondingly */ + if (header_len != tp->tcp_header_len) { + int delta = (int) header_len - tp->tcp_header_len; + mss_now -= delta; + } + + return mss_now; +} + +/* RFC2861, slow part. Adjust cwnd, after it was not full during one rto. + * As additional protections, we do not touch cwnd in retransmission phases, + * and if application hit its sndbuf limit recently. + */ +static void tcp_cwnd_application_limited(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (inet_csk(sk)->icsk_ca_state == TCP_CA_Open && + sk->sk_socket && !test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { + /* Limited by application or receiver window. */ + u32 init_win = tcp_init_cwnd(tp, __sk_dst_get(sk)); + u32 win_used = max(tp->snd_cwnd_used, init_win); + if (win_used < tp->snd_cwnd) { + tp->snd_ssthresh = tcp_current_ssthresh(sk); + tp->snd_cwnd = (tp->snd_cwnd + win_used) >> 1; + } + tp->snd_cwnd_used = 0; + } + tp->snd_cwnd_stamp = tcp_jiffies32; +} + +static void tcp_cwnd_validate(struct sock *sk, bool is_cwnd_limited) +{ + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; + struct tcp_sock *tp = tcp_sk(sk); + + /* Track the strongest available signal of the degree to which the cwnd + * is fully utilized. If cwnd-limited then remember that fact for the + * current window. If not cwnd-limited then track the maximum number of + * outstanding packets in the current window. (If cwnd-limited then we + * chose to not update tp->max_packets_out to avoid an extra else + * clause with no functional impact.) + */ + if (!before(tp->snd_una, tp->cwnd_usage_seq) || + is_cwnd_limited || + (!tp->is_cwnd_limited && + tp->packets_out > tp->max_packets_out)) { + tp->is_cwnd_limited = is_cwnd_limited; + tp->max_packets_out = tp->packets_out; + tp->cwnd_usage_seq = tp->snd_nxt; + } + + if (tcp_is_cwnd_limited(sk)) { + /* Network is feed fully. */ + tp->snd_cwnd_used = 0; + tp->snd_cwnd_stamp = tcp_jiffies32; + } else { + /* Network starves. */ + if (tp->packets_out > tp->snd_cwnd_used) + tp->snd_cwnd_used = tp->packets_out; + + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) && + (s32)(tcp_jiffies32 - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto && + !ca_ops->cong_control) + tcp_cwnd_application_limited(sk); + + /* The following conditions together indicate the starvation + * is caused by insufficient sender buffer: + * 1) just sent some data (see tcp_write_xmit) + * 2) not cwnd limited (this else condition) + * 3) no more data to send (tcp_write_queue_empty()) + * 4) application is hitting buffer limit (SOCK_NOSPACE) + */ + if (tcp_write_queue_empty(sk) && sk->sk_socket && + test_bit(SOCK_NOSPACE, &sk->sk_socket->flags) && + (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) + tcp_chrono_start(sk, TCP_CHRONO_SNDBUF_LIMITED); + } +} + +/* Minshall's variant of the Nagle send check. */ +static bool tcp_minshall_check(const struct tcp_sock *tp) +{ + return after(tp->snd_sml, tp->snd_una) && + !after(tp->snd_sml, tp->snd_nxt); +} + +/* Update snd_sml if this skb is under mss + * Note that a TSO packet might end with a sub-mss segment + * The test is really : + * if ((skb->len % mss) != 0) + * tp->snd_sml = TCP_SKB_CB(skb)->end_seq; + * But we can avoid doing the divide again given we already have + * skb_pcount = skb->len / mss_now + */ +static void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss_now, + const struct sk_buff *skb) +{ + if (skb->len < tcp_skb_pcount(skb) * mss_now) + tp->snd_sml = TCP_SKB_CB(skb)->end_seq; +} + +/* Return false, if packet can be sent now without violation Nagle's rules: + * 1. It is full sized. (provided by caller in %partial bool) + * 2. Or it contains FIN. (already checked by caller) + * 3. Or TCP_CORK is not set, and TCP_NODELAY is set. + * 4. Or TCP_CORK is not set, and all sent packets are ACKed. + * With Minshall's modification: all sent small packets are ACKed. + */ +static bool tcp_nagle_check(bool partial, const struct tcp_sock *tp, + int nonagle) +{ + return partial && + ((nonagle & TCP_NAGLE_CORK) || + (!nonagle && tp->packets_out && tcp_minshall_check(tp))); +} + +/* Return how many segs we'd like on a TSO packet, + * to send one TSO packet per ms + */ +static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, + int min_tso_segs) +{ + u32 bytes, segs; + + bytes = min_t(unsigned long, + sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift), + sk->sk_gso_max_size - 1 - MAX_TCP_HEADER); + + /* Goal is to send at least one packet per ms, + * not one big TSO packet every 100 ms. + * This preserves ACK clocking and is consistent + * with tcp_tso_should_defer() heuristic. + */ + segs = max_t(u32, bytes / mss_now, min_tso_segs); + + return segs; +} + +/* Return the number of segments we want in the skb we are transmitting. + * See if congestion control module wants to decide; otherwise, autosize. + */ +static u32 tcp_tso_segs(struct sock *sk, unsigned int mss_now) +{ + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; + u32 min_tso, tso_segs; + + min_tso = ca_ops->min_tso_segs ? + ca_ops->min_tso_segs(sk) : + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs); + + tso_segs = tcp_tso_autosize(sk, mss_now, min_tso); + return min_t(u32, tso_segs, sk->sk_gso_max_segs); +} + +/* Returns the portion of skb which can be sent right away */ +static unsigned int tcp_mss_split_point(const struct sock *sk, + const struct sk_buff *skb, + unsigned int mss_now, + unsigned int max_segs, + int nonagle) +{ + const struct tcp_sock *tp = tcp_sk(sk); + u32 partial, needed, window, max_len; + + window = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq; + max_len = mss_now * max_segs; + + if (likely(max_len <= window && skb != tcp_write_queue_tail(sk))) + return max_len; + + needed = min(skb->len, window); + + if (max_len <= needed) + return max_len; + + partial = needed % mss_now; + /* If last segment is not a full MSS, check if Nagle rules allow us + * to include this last segment in this skb. + * Otherwise, we'll split the skb at last MSS boundary + */ + if (tcp_nagle_check(partial != 0, tp, nonagle)) + return needed - partial; + + return needed; +} + +/* Can at least one segment of SKB be sent right now, according to the + * congestion window rules? If so, return how many segments are allowed. + */ +static inline unsigned int tcp_cwnd_test(const struct tcp_sock *tp, + const struct sk_buff *skb) +{ + u32 in_flight, cwnd, halfcwnd; + + /* Don't be strict about the congestion window for the final FIN. */ + if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) && + tcp_skb_pcount(skb) == 1) + return 1; + + in_flight = tcp_packets_in_flight(tp); + cwnd = tp->snd_cwnd; + if (in_flight >= cwnd) + return 0; + + /* For better scheduling, ensure we have at least + * 2 GSO packets in flight. + */ + halfcwnd = max(cwnd >> 1, 1U); + return min(halfcwnd, cwnd - in_flight); +} + +/* Initialize TSO state of a skb. + * This must be invoked the first time we consider transmitting + * SKB onto the wire. + */ +static int tcp_init_tso_segs(struct sk_buff *skb, unsigned int mss_now) +{ + int tso_segs = tcp_skb_pcount(skb); + + if (!tso_segs || (tso_segs > 1 && tcp_skb_mss(skb) != mss_now)) { + tcp_set_skb_tso_segs(skb, mss_now); + tso_segs = tcp_skb_pcount(skb); + } + return tso_segs; +} + + +/* Return true if the Nagle test allows this packet to be + * sent now. + */ +static inline bool tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buff *skb, + unsigned int cur_mss, int nonagle) +{ + /* Nagle rule does not apply to frames, which sit in the middle of the + * write_queue (they have no chances to get new data). + * + * This is implemented in the callers, where they modify the 'nonagle' + * argument based upon the location of SKB in the send queue. + */ + if (nonagle & TCP_NAGLE_PUSH) + return true; + + /* Don't use the nagle rule for urgent data (or for the final FIN). */ + if (tcp_urg_mode(tp) || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) + return true; + + if (!tcp_nagle_check(skb->len < cur_mss, tp, nonagle)) + return true; + + return false; +} + +/* Does at least the first segment of SKB fit into the send window? */ +static bool tcp_snd_wnd_test(const struct tcp_sock *tp, + const struct sk_buff *skb, + unsigned int cur_mss) +{ + u32 end_seq = TCP_SKB_CB(skb)->end_seq; + + if (skb->len > cur_mss) + end_seq = TCP_SKB_CB(skb)->seq + cur_mss; + + return !after(end_seq, tcp_wnd_end(tp)); +} + +/* Trim TSO SKB to LEN bytes, put the remaining data into a new packet + * which is put after SKB on the list. It is very much like + * tcp_fragment() except that it may make several kinds of assumptions + * in order to speed up the splitting operation. In particular, we + * know that all the data is in scatter-gather pages, and that the + * packet has never been sent out before (and thus is not cloned). + */ +static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len, + unsigned int mss_now, gfp_t gfp) +{ + int nlen = skb->len - len; + struct sk_buff *buff; + u8 flags; + + /* All of a TSO frame must be composed of paged data. */ + if (skb->len != skb->data_len) + return tcp_fragment(sk, TCP_FRAG_IN_WRITE_QUEUE, + skb, len, mss_now, gfp); + + buff = sk_stream_alloc_skb(sk, 0, gfp, true); + if (unlikely(!buff)) + return -ENOMEM; + skb_copy_decrypted(buff, skb); + + sk_wmem_queued_add(sk, buff->truesize); + sk_mem_charge(sk, buff->truesize); + buff->truesize += nlen; + skb->truesize -= nlen; + + /* Correct the sequence numbers. */ + TCP_SKB_CB(buff)->seq = TCP_SKB_CB(skb)->seq + len; + TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq; + TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq; + + /* PSH and FIN should only be set in the second packet. */ + flags = TCP_SKB_CB(skb)->tcp_flags; + TCP_SKB_CB(skb)->tcp_flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH); + TCP_SKB_CB(buff)->tcp_flags = flags; + + /* This packet was never sent out yet, so no SACK bits. */ + TCP_SKB_CB(buff)->sacked = 0; + + tcp_skb_fragment_eor(skb, buff); + + buff->ip_summed = CHECKSUM_PARTIAL; + skb_split(skb, buff, len); + tcp_fragment_tstamp(skb, buff); + + /* Fix up tso_factor for both original and new SKB. */ + tcp_set_skb_tso_segs(skb, mss_now); + tcp_set_skb_tso_segs(buff, mss_now); + + /* Link BUFF into the send queue. */ + __skb_header_release(buff); + tcp_insert_write_queue_after(skb, buff, sk, TCP_FRAG_IN_WRITE_QUEUE); + + return 0; +} + +/* Try to defer sending, if possible, in order to minimize the amount + * of TSO splitting we do. View it as a kind of TSO Nagle test. + * + * This algorithm is from John Heffner. + */ +static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, + bool *is_cwnd_limited, + bool *is_rwnd_limited, + u32 max_segs) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + u32 send_win, cong_win, limit, in_flight; + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *head; + int win_divisor; + s64 delta; + + if (icsk->icsk_ca_state >= TCP_CA_Recovery) + goto send_now; + + /* Avoid bursty behavior by allowing defer + * only if the last write was recent (1 ms). + * Note that tp->tcp_wstamp_ns can be in the future if we have + * packets waiting in a qdisc or device for EDT delivery. + */ + delta = tp->tcp_clock_cache - tp->tcp_wstamp_ns - NSEC_PER_MSEC; + if (delta > 0) + goto send_now; + + in_flight = tcp_packets_in_flight(tp); + + BUG_ON(tcp_skb_pcount(skb) <= 1); + BUG_ON(tp->snd_cwnd <= in_flight); + + send_win = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq; + + /* From in_flight test above, we know that cwnd > in_flight. */ + cong_win = (tp->snd_cwnd - in_flight) * tp->mss_cache; + + limit = min(send_win, cong_win); + + /* If a full-sized TSO skb can be sent, do it. */ + if (limit >= max_segs * tp->mss_cache) + goto send_now; + + /* Middle in queue won't get any more data, full sendable already? */ + if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len)) + goto send_now; + + win_divisor = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tso_win_divisor); + if (win_divisor) { + u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache); + + /* If at least some fraction of a window is available, + * just use it. + */ + chunk /= win_divisor; + if (limit >= chunk) + goto send_now; + } else { + /* Different approach, try not to defer past a single + * ACK. Receiver should ACK every other full sized + * frame, so if we have space for more than 3 frames + * then send now. + */ + if (limit > tcp_max_tso_deferred_mss(tp) * tp->mss_cache) + goto send_now; + } + + /* TODO : use tsorted_sent_queue ? */ + head = tcp_rtx_queue_head(sk); + if (!head) + goto send_now; + delta = tp->tcp_clock_cache - head->tstamp; + /* If next ACK is likely to come too late (half srtt), do not defer */ + if ((s64)(delta - (u64)NSEC_PER_USEC * (tp->srtt_us >> 4)) < 0) + goto send_now; + + /* Ok, it looks like it is advisable to defer. + * Three cases are tracked : + * 1) We are cwnd-limited + * 2) We are rwnd-limited + * 3) We are application limited. + */ + if (cong_win < send_win) { + if (cong_win <= skb->len) { + *is_cwnd_limited = true; + return true; + } + } else { + if (send_win <= skb->len) { + *is_rwnd_limited = true; + return true; + } + } + + /* If this packet won't get more data, do not wait. */ + if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) || + TCP_SKB_CB(skb)->eor) + goto send_now; + + return true; + +send_now: + return false; +} + +static inline void tcp_mtu_check_reprobe(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + u32 interval; + s32 delta; + + interval = READ_ONCE(net->ipv4.sysctl_tcp_probe_interval); + delta = tcp_jiffies32 - icsk->icsk_mtup.probe_timestamp; + if (unlikely(delta >= interval * HZ)) { + int mss = tcp_current_mss(sk); + + /* Update current search range */ + icsk->icsk_mtup.probe_size = 0; + icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + + sizeof(struct tcphdr) + + icsk->icsk_af_ops->net_header_len; + icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss); + + /* Update probe time stamp */ + icsk->icsk_mtup.probe_timestamp = tcp_jiffies32; + } +} + +static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len) +{ + struct sk_buff *skb, *next; + + skb = tcp_send_head(sk); + tcp_for_write_queue_from_safe(skb, next, sk) { + if (len <= skb->len) + break; + + if (unlikely(TCP_SKB_CB(skb)->eor) || tcp_has_tx_tstamp(skb)) + return false; + + len -= skb->len; + } + + return true; +} + +/* Create a new MTU probe if we are ready. + * MTU probe is regularly attempting to increase the path MTU by + * deliberately sending larger packets. This discovers routing + * changes resulting in larger path MTUs. + * + * Returns 0 if we should wait to probe (no cwnd available), + * 1 if a probe was sent, + * -1 otherwise + */ +static int tcp_mtu_probe(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb, *nskb, *next; + struct net *net = sock_net(sk); + int probe_size; + int size_needed; + int copy, len; + int mss_now; + int interval; + + /* Not currently probing/verifying, + * not in recovery, + * have enough cwnd, and + * not SACKing (the variable headers throw things off) + */ + if (likely(!icsk->icsk_mtup.enabled || + icsk->icsk_mtup.probe_size || + inet_csk(sk)->icsk_ca_state != TCP_CA_Open || + tp->snd_cwnd < 11 || + tp->rx_opt.num_sacks || tp->rx_opt.dsack)) + return -1; + + /* Use binary search for probe_size between tcp_mss_base, + * and current mss_clamp. if (search_high - search_low) + * smaller than a threshold, backoff from probing. + */ + mss_now = tcp_current_mss(sk); + probe_size = tcp_mtu_to_mss(sk, (icsk->icsk_mtup.search_high + + icsk->icsk_mtup.search_low) >> 1); + size_needed = probe_size + (tp->reordering + 1) * tp->mss_cache; + interval = icsk->icsk_mtup.search_high - icsk->icsk_mtup.search_low; + /* When misfortune happens, we are reprobing actively, + * and then reprobe timer has expired. We stick with current + * probing process by not resetting search range to its orignal. + */ + if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high) || + interval < READ_ONCE(net->ipv4.sysctl_tcp_probe_threshold)) { + /* Check whether enough time has elaplased for + * another round of probing. + */ + tcp_mtu_check_reprobe(sk); + return -1; + } + + /* Have enough data in the send queue to probe? */ + if (tp->write_seq - tp->snd_nxt < size_needed) + return -1; + + if (tp->snd_wnd < size_needed) + return -1; + if (after(tp->snd_nxt + size_needed, tcp_wnd_end(tp))) + return 0; + + /* Do we need to wait to drain cwnd? With none in flight, don't stall */ + if (tcp_packets_in_flight(tp) + 2 > tp->snd_cwnd) { + if (!tcp_packets_in_flight(tp)) + return -1; + else + return 0; + } + + if (!tcp_can_coalesce_send_queue_head(sk, probe_size)) + return -1; + + /* We're allowed to probe. Build it now. */ + nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC, false); + if (!nskb) + return -1; + sk_wmem_queued_add(sk, nskb->truesize); + sk_mem_charge(sk, nskb->truesize); + + skb = tcp_send_head(sk); + skb_copy_decrypted(nskb, skb); + + TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq; + TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size; + TCP_SKB_CB(nskb)->tcp_flags = TCPHDR_ACK; + TCP_SKB_CB(nskb)->sacked = 0; + nskb->csum = 0; + nskb->ip_summed = CHECKSUM_PARTIAL; + + tcp_insert_write_queue_before(nskb, skb, sk); + tcp_highest_sack_replace(sk, skb, nskb); + + len = 0; + tcp_for_write_queue_from_safe(skb, next, sk) { + copy = min_t(int, skb->len, probe_size - len); + skb_copy_bits(skb, 0, skb_put(nskb, copy), copy); + + if (skb->len <= copy) { + /* We've eaten all the data from this skb. + * Throw it away. */ + TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; + /* If this is the last SKB we copy and eor is set + * we need to propagate it to the new skb. + */ + TCP_SKB_CB(nskb)->eor = TCP_SKB_CB(skb)->eor; + tcp_skb_collapse_tstamp(nskb, skb); + tcp_unlink_write_queue(skb, sk); + sk_wmem_free_skb(sk, skb); + } else { + TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags & + ~(TCPHDR_FIN|TCPHDR_PSH); + if (!skb_shinfo(skb)->nr_frags) { + skb_pull(skb, copy); + } else { + __pskb_trim_head(skb, copy); + tcp_set_skb_tso_segs(skb, mss_now); + } + TCP_SKB_CB(skb)->seq += copy; + } + + len += copy; + + if (len >= probe_size) + break; + } + tcp_init_tso_segs(nskb, nskb->len); + + /* We're ready to send. If this fails, the probe will + * be resegmented into mss-sized pieces by tcp_write_xmit(). + */ + if (!tcp_transmit_skb(sk, nskb, 1, GFP_ATOMIC)) { + /* Decrement cwnd here because we are sending + * effectively two packets. */ + tp->snd_cwnd--; + tcp_event_new_data_sent(sk, nskb); + + icsk->icsk_mtup.probe_size = tcp_mss_to_mtu(sk, nskb->len); + tp->mtu_probe.probe_seq_start = TCP_SKB_CB(nskb)->seq; + tp->mtu_probe.probe_seq_end = TCP_SKB_CB(nskb)->end_seq; + + return 1; + } + + return -1; +} + +static bool tcp_pacing_check(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (!tcp_needs_internal_pacing(sk)) + return false; + + if (tp->tcp_wstamp_ns <= tp->tcp_clock_cache) + return false; + + if (!hrtimer_is_queued(&tp->pacing_timer)) { + hrtimer_start(&tp->pacing_timer, + ns_to_ktime(tp->tcp_wstamp_ns), + HRTIMER_MODE_ABS_PINNED_SOFT); + sock_hold(sk); + } + return true; +} + +static bool tcp_rtx_queue_empty_or_single_skb(const struct sock *sk) +{ + const struct rb_node *node = sk->tcp_rtx_queue.rb_node; + + /* No skb in the rtx queue. */ + if (!node) + return true; + + /* Only one skb in rtx queue. */ + return !node->rb_left && !node->rb_right; +} + +/* TCP Small Queues : + * Control number of packets in qdisc/devices to two packets / or ~1 ms. + * (These limits are doubled for retransmits) + * This allows for : + * - better RTT estimation and ACK scheduling + * - faster recovery + * - high rates + * Alas, some drivers / subsystems require a fair amount + * of queued bytes to ensure line rate. + * One example is wifi aggregation (802.11 AMPDU) + */ +static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb, + unsigned int factor) +{ + unsigned long limit; + + limit = max_t(unsigned long, + 2 * skb->truesize, + sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift)); + if (sk->sk_pacing_status == SK_PACING_NONE) + limit = min_t(unsigned long, limit, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_limit_output_bytes)); + limit <<= factor; + + if (static_branch_unlikely(&tcp_tx_delay_enabled) && + tcp_sk(sk)->tcp_tx_delay) { + u64 extra_bytes = (u64)sk->sk_pacing_rate * tcp_sk(sk)->tcp_tx_delay; + + /* TSQ is based on skb truesize sum (sk_wmem_alloc), so we + * approximate our needs assuming an ~100% skb->truesize overhead. + * USEC_PER_SEC is approximated by 2^20. + * do_div(extra_bytes, USEC_PER_SEC/2) is replaced by a right shift. + */ + extra_bytes >>= (20 - 1); + limit += extra_bytes; + } + if (refcount_read(&sk->sk_wmem_alloc) > limit) { + /* Always send skb if rtx queue is empty or has one skb. + * No need to wait for TX completion to call us back, + * after softirq/tasklet schedule. + * This helps when TX completions are delayed too much. + */ + if (tcp_rtx_queue_empty_or_single_skb(sk)) + return false; + + set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags); + /* It is possible TX completion already happened + * before we set TSQ_THROTTLED, so we must + * test again the condition. + */ + smp_mb__after_atomic(); + if (refcount_read(&sk->sk_wmem_alloc) > limit) + return true; + } + return false; +} + +static void tcp_chrono_set(struct tcp_sock *tp, const enum tcp_chrono new) +{ + const u32 now = tcp_jiffies32; + enum tcp_chrono old = tp->chrono_type; + + if (old > TCP_CHRONO_UNSPEC) + tp->chrono_stat[old - 1] += now - tp->chrono_start; + tp->chrono_start = now; + tp->chrono_type = new; +} + +void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* If there are multiple conditions worthy of tracking in a + * chronograph then the highest priority enum takes precedence + * over the other conditions. So that if something "more interesting" + * starts happening, stop the previous chrono and start a new one. + */ + if (type > tp->chrono_type) + tcp_chrono_set(tp, type); +} + +void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type) +{ + struct tcp_sock *tp = tcp_sk(sk); + + + /* There are multiple conditions worthy of tracking in a + * chronograph, so that the highest priority enum takes + * precedence over the other conditions (see tcp_chrono_start). + * If a condition stops, we only stop chrono tracking if + * it's the "most interesting" or current chrono we are + * tracking and starts busy chrono if we have pending data. + */ + if (tcp_rtx_and_write_queues_empty(sk)) + tcp_chrono_set(tp, TCP_CHRONO_UNSPEC); + else if (type == tp->chrono_type) + tcp_chrono_set(tp, TCP_CHRONO_BUSY); +} + +/* This routine writes packets to the network. It advances the + * send_head. This happens as incoming acks open up the remote + * window for us. + * + * LARGESEND note: !tcp_urg_mode is overkill, only frames between + * snd_up-64k-mss .. snd_up cannot be large. However, taking into + * account rare use of URG, this is not a big flaw. + * + * Send at most one packet when push_one > 0. Temporarily ignore + * cwnd limit to force at most one packet out when push_one == 2. + + * Returns true, if no segments are in flight and we have queued segments, + * but cannot send anything now because of SWS or another problem. + */ +static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, + int push_one, gfp_t gfp) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + unsigned int tso_segs, sent_pkts; + int cwnd_quota; + int result; + bool is_cwnd_limited = false, is_rwnd_limited = false; + u32 max_segs; + + sent_pkts = 0; + + tcp_mstamp_refresh(tp); + if (!push_one) { + /* Do MTU probing. */ + result = tcp_mtu_probe(sk); + if (!result) { + return false; + } else if (result > 0) { + sent_pkts = 1; + } + } + + max_segs = tcp_tso_segs(sk, mss_now); + while ((skb = tcp_send_head(sk))) { + unsigned int limit; + + if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) { + /* "skb_mstamp_ns" is used as a start point for the retransmit timer */ + skb->skb_mstamp_ns = tp->tcp_wstamp_ns = tp->tcp_clock_cache; + list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue); + tcp_init_tso_segs(skb, mss_now); + goto repair; /* Skip network transmission */ + } + + if (tcp_pacing_check(sk)) + break; + + tso_segs = tcp_init_tso_segs(skb, mss_now); + BUG_ON(!tso_segs); + + cwnd_quota = tcp_cwnd_test(tp, skb); + if (!cwnd_quota) { + if (push_one == 2) + /* Force out a loss probe pkt. */ + cwnd_quota = 1; + else + break; + } + + if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now))) { + is_rwnd_limited = true; + break; + } + + if (tso_segs == 1) { + if (unlikely(!tcp_nagle_test(tp, skb, mss_now, + (tcp_skb_is_last(sk, skb) ? + nonagle : TCP_NAGLE_PUSH)))) + break; + } else { + if (!push_one && + tcp_tso_should_defer(sk, skb, &is_cwnd_limited, + &is_rwnd_limited, max_segs)) + break; + } + + limit = mss_now; + if (tso_segs > 1 && !tcp_urg_mode(tp)) + limit = tcp_mss_split_point(sk, skb, mss_now, + min_t(unsigned int, + cwnd_quota, + max_segs), + nonagle); + + if (skb->len > limit && + unlikely(tso_fragment(sk, skb, limit, mss_now, gfp))) + break; + + if (tcp_small_queue_check(sk, skb, 0)) + break; + + /* Argh, we hit an empty skb(), presumably a thread + * is sleeping in sendmsg()/sk_stream_wait_memory(). + * We do not want to send a pure-ack packet and have + * a strange looking rtx queue with empty packet(s). + */ + if (TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq) + break; + + if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp))) + break; + +repair: + /* Advance the send_head. This one is sent out. + * This call will increment packets_out. + */ + tcp_event_new_data_sent(sk, skb); + + tcp_minshall_update(tp, mss_now, skb); + sent_pkts += tcp_skb_pcount(skb); + + if (push_one) + break; + } + + if (is_rwnd_limited) + tcp_chrono_start(sk, TCP_CHRONO_RWND_LIMITED); + else + tcp_chrono_stop(sk, TCP_CHRONO_RWND_LIMITED); + + is_cwnd_limited |= (tcp_packets_in_flight(tp) >= tp->snd_cwnd); + if (likely(sent_pkts || is_cwnd_limited)) + tcp_cwnd_validate(sk, is_cwnd_limited); + + if (likely(sent_pkts)) { + if (tcp_in_cwnd_reduction(sk)) + tp->prr_out += sent_pkts; + + /* Send one loss probe per tail loss episode. */ + if (push_one != 2) + tcp_schedule_loss_probe(sk, false); + return false; + } + return !tp->packets_out && !tcp_write_queue_empty(sk); +} + +bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + u32 timeout, timeout_us, rto_delta_us; + int early_retrans; + + /* Don't do any loss probe on a Fast Open connection before 3WHS + * finishes. + */ + if (rcu_access_pointer(tp->fastopen_rsk)) + return false; + + early_retrans = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_early_retrans); + /* Schedule a loss probe in 2*RTT for SACK capable connections + * not in loss recovery, that are either limited by cwnd or application. + */ + if ((early_retrans != 3 && early_retrans != 4) || + !tp->packets_out || !tcp_is_sack(tp) || + (icsk->icsk_ca_state != TCP_CA_Open && + icsk->icsk_ca_state != TCP_CA_CWR)) + return false; + + /* Probe timeout is 2*rtt. Add minimum RTO to account + * for delayed ack when there's one outstanding packet. If no RTT + * sample is available then probe after TCP_TIMEOUT_INIT. + */ + if (tp->srtt_us) { + timeout_us = tp->srtt_us >> 2; + if (tp->packets_out == 1) + timeout_us += tcp_rto_min_us(sk); + else + timeout_us += TCP_TIMEOUT_MIN_US; + timeout = usecs_to_jiffies(timeout_us); + } else { + timeout = TCP_TIMEOUT_INIT; + } + + /* If the RTO formula yields an earlier time, then use that time. */ + rto_delta_us = advancing_rto ? + jiffies_to_usecs(inet_csk(sk)->icsk_rto) : + tcp_rto_delta_us(sk); /* How far in future is RTO? */ + if (rto_delta_us > 0) + timeout = min_t(u32, timeout, usecs_to_jiffies(rto_delta_us)); + + tcp_reset_xmit_timer(sk, ICSK_TIME_LOSS_PROBE, timeout, TCP_RTO_MAX); + return true; +} + +/* Thanks to skb fast clones, we can detect if a prior transmit of + * a packet is still in a qdisc or driver queue. + * In this case, there is very little point doing a retransmit ! + */ +static bool skb_still_in_host_queue(const struct sock *sk, + const struct sk_buff *skb) +{ + if (unlikely(skb_fclone_busy(sk, skb))) { + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES); + return true; + } + return false; +} + +/* When probe timeout (PTO) fires, try send a new segment if possible, else + * retransmit the last segment. + */ +void tcp_send_loss_probe(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + int pcount; + int mss = tcp_current_mss(sk); + + /* At most one outstanding TLP */ + if (tp->tlp_high_seq) + goto rearm_timer; + + tp->tlp_retrans = 0; + skb = tcp_send_head(sk); + if (skb && tcp_snd_wnd_test(tp, skb, mss)) { + pcount = tp->packets_out; + tcp_write_xmit(sk, mss, TCP_NAGLE_OFF, 2, GFP_ATOMIC); + if (tp->packets_out > pcount) + goto probe_sent; + goto rearm_timer; + } + skb = skb_rb_last(&sk->tcp_rtx_queue); + if (unlikely(!skb)) { + WARN_ONCE(tp->packets_out, + "invalid inflight: %u state %u cwnd %u mss %d\n", + tp->packets_out, sk->sk_state, tp->snd_cwnd, mss); + inet_csk(sk)->icsk_pending = 0; + return; + } + + if (skb_still_in_host_queue(sk, skb)) + goto rearm_timer; + + pcount = tcp_skb_pcount(skb); + if (WARN_ON(!pcount)) + goto rearm_timer; + + if ((pcount > 1) && (skb->len > (pcount - 1) * mss)) { + if (unlikely(tcp_fragment(sk, TCP_FRAG_IN_RTX_QUEUE, skb, + (pcount - 1) * mss, mss, + GFP_ATOMIC))) + goto rearm_timer; + skb = skb_rb_next(skb); + } + + if (WARN_ON(!skb || !tcp_skb_pcount(skb))) + goto rearm_timer; + + if (__tcp_retransmit_skb(sk, skb, 1)) + goto rearm_timer; + + tp->tlp_retrans = 1; + +probe_sent: + /* Record snd_nxt for loss detection. */ + tp->tlp_high_seq = tp->snd_nxt; + + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPLOSSPROBES); + /* Reset s.t. tcp_rearm_rto will restart timer from now */ + inet_csk(sk)->icsk_pending = 0; +rearm_timer: + tcp_rearm_rto(sk); +} + +/* Push out any pending frames which were held back due to + * TCP_CORK or attempt at coalescing tiny packets. + * The socket must be locked by the caller. + */ +void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, + int nonagle) +{ + /* If we are closed, the bytes will have to remain here. + * In time closedown will finish, we empty the write queue and + * all will be happy. + */ + if (unlikely(sk->sk_state == TCP_CLOSE)) + return; + + if (tcp_write_xmit(sk, cur_mss, nonagle, 0, + sk_gfp_mask(sk, GFP_ATOMIC))) + tcp_check_probe_timer(sk); +} + +/* Send _single_ skb sitting at the send head. This function requires + * true push pending frames to setup probe timer etc. + */ +void tcp_push_one(struct sock *sk, unsigned int mss_now) +{ + struct sk_buff *skb = tcp_send_head(sk); + + BUG_ON(!skb || skb->len < mss_now); + + tcp_write_xmit(sk, mss_now, TCP_NAGLE_PUSH, 1, sk->sk_allocation); +} + +/* This function returns the amount that we can raise the + * usable window based on the following constraints + * + * 1. The window can never be shrunk once it is offered (RFC 793) + * 2. We limit memory per socket + * + * RFC 1122: + * "the suggested [SWS] avoidance algorithm for the receiver is to keep + * RECV.NEXT + RCV.WIN fixed until: + * RCV.BUFF - RCV.USER - RCV.WINDOW >= min(1/2 RCV.BUFF, MSS)" + * + * i.e. don't raise the right edge of the window until you can raise + * it at least MSS bytes. + * + * Unfortunately, the recommended algorithm breaks header prediction, + * since header prediction assumes th->window stays fixed. + * + * Strictly speaking, keeping th->window fixed violates the receiver + * side SWS prevention criteria. The problem is that under this rule + * a stream of single byte packets will cause the right side of the + * window to always advance by a single byte. + * + * Of course, if the sender implements sender side SWS prevention + * then this will not be a problem. + * + * BSD seems to make the following compromise: + * + * If the free space is less than the 1/4 of the maximum + * space available and the free space is less than 1/2 mss, + * then set the window to 0. + * [ Actually, bsd uses MSS and 1/4 of maximal _window_ ] + * Otherwise, just prevent the window from shrinking + * and from being larger than the largest representable value. + * + * This prevents incremental opening of the window in the regime + * where TCP is limited by the speed of the reader side taking + * data out of the TCP receive queue. It does nothing about + * those cases where the window is constrained on the sender side + * because the pipeline is full. + * + * BSD also seems to "accidentally" limit itself to windows that are a + * multiple of MSS, at least until the free space gets quite small. + * This would appear to be a side effect of the mbuf implementation. + * Combining these two algorithms results in the observed behavior + * of having a fixed window size at almost all times. + * + * Below we obtain similar behavior by forcing the offered window to + * a multiple of the mss when it is feasible to do so. + * + * Note, we don't "adjust" for TIMESTAMP or SACK option bytes. + * Regular options like TIMESTAMP are taken into account. + */ +u32 __tcp_select_window(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + /* MSS for the peer's data. Previous versions used mss_clamp + * here. I don't know if the value based on our guesses + * of peer's MSS is better for the performance. It's more correct + * but may be worse for the performance because of rcv_mss + * fluctuations. --SAW 1998/11/1 + */ + int mss = icsk->icsk_ack.rcv_mss; + int free_space = tcp_space(sk); + int allowed_space = tcp_full_space(sk); + int full_space, window; + + if (sk_is_mptcp(sk)) + mptcp_space(sk, &free_space, &allowed_space); + + full_space = min_t(int, tp->window_clamp, allowed_space); + + if (unlikely(mss > full_space)) { + mss = full_space; + if (mss <= 0) + return 0; + } + if (free_space < (full_space >> 1)) { + icsk->icsk_ack.quick = 0; + + if (tcp_under_memory_pressure(sk)) + tp->rcv_ssthresh = min(tp->rcv_ssthresh, + 4U * tp->advmss); + + /* free_space might become our new window, make sure we don't + * increase it due to wscale. + */ + free_space = round_down(free_space, 1 << tp->rx_opt.rcv_wscale); + + /* if free space is less than mss estimate, or is below 1/16th + * of the maximum allowed, try to move to zero-window, else + * tcp_clamp_window() will grow rcv buf up to tcp_rmem[2], and + * new incoming data is dropped due to memory limits. + * With large window, mss test triggers way too late in order + * to announce zero window in time before rmem limit kicks in. + */ + if (free_space < (allowed_space >> 4) || free_space < mss) + return 0; + } + + if (free_space > tp->rcv_ssthresh) + free_space = tp->rcv_ssthresh; + + /* Don't do rounding if we are using window scaling, since the + * scaled window will not line up with the MSS boundary anyway. + */ + if (tp->rx_opt.rcv_wscale) { + window = free_space; + + /* Advertise enough space so that it won't get scaled away. + * Import case: prevent zero window announcement if + * 1<<rcv_wscale > mss. + */ + window = ALIGN(window, (1 << tp->rx_opt.rcv_wscale)); + } else { + window = tp->rcv_wnd; + /* Get the largest window that is a nice multiple of mss. + * Window clamp already applied above. + * If our current window offering is within 1 mss of the + * free space we just keep it. This prevents the divide + * and multiply from happening most of the time. + * We also don't do any window rounding when the free space + * is too small. + */ + if (window <= free_space - mss || window > free_space) + window = rounddown(free_space, mss); + else if (mss == full_space && + free_space > window + (full_space >> 1)) + window = free_space; + } + + return window; +} + +void tcp_skb_collapse_tstamp(struct sk_buff *skb, + const struct sk_buff *next_skb) +{ + if (unlikely(tcp_has_tx_tstamp(next_skb))) { + const struct skb_shared_info *next_shinfo = + skb_shinfo(next_skb); + struct skb_shared_info *shinfo = skb_shinfo(skb); + + shinfo->tx_flags |= next_shinfo->tx_flags & SKBTX_ANY_TSTAMP; + shinfo->tskey = next_shinfo->tskey; + TCP_SKB_CB(skb)->txstamp_ack |= + TCP_SKB_CB(next_skb)->txstamp_ack; + } +} + +/* Collapses two adjacent SKB's during retransmission. */ +static bool tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *next_skb = skb_rb_next(skb); + int next_skb_size; + + next_skb_size = next_skb->len; + + BUG_ON(tcp_skb_pcount(skb) != 1 || tcp_skb_pcount(next_skb) != 1); + + if (next_skb_size) { + if (next_skb_size <= skb_availroom(skb)) + skb_copy_bits(next_skb, 0, skb_put(skb, next_skb_size), + next_skb_size); + else if (!tcp_skb_shift(skb, next_skb, 1, next_skb_size)) + return false; + } + tcp_highest_sack_replace(sk, next_skb, skb); + + /* Update sequence range on original skb. */ + TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq; + + /* Merge over control information. This moves PSH/FIN etc. over */ + TCP_SKB_CB(skb)->tcp_flags |= TCP_SKB_CB(next_skb)->tcp_flags; + + /* All done, get rid of second SKB and account for it so + * packet counting does not break. + */ + TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS; + TCP_SKB_CB(skb)->eor = TCP_SKB_CB(next_skb)->eor; + + /* changed transmit queue under us so clear hints */ + tcp_clear_retrans_hints_partial(tp); + if (next_skb == tp->retransmit_skb_hint) + tp->retransmit_skb_hint = skb; + + tcp_adjust_pcount(sk, next_skb, tcp_skb_pcount(next_skb)); + + tcp_skb_collapse_tstamp(skb, next_skb); + + tcp_rtx_queue_unlink_and_free(next_skb, sk); + return true; +} + +/* Check if coalescing SKBs is legal. */ +static bool tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb) +{ + if (tcp_skb_pcount(skb) > 1) + return false; + if (skb_cloned(skb)) + return false; + /* Some heuristics for collapsing over SACK'd could be invented */ + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) + return false; + + return true; +} + +/* Collapse packets in the retransmit queue to make to create + * less packets on the wire. This is only done on retransmission. + */ +static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, + int space) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb = to, *tmp; + bool first = true; + + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retrans_collapse)) + return; + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) + return; + + skb_rbtree_walk_from_safe(skb, tmp) { + if (!tcp_can_collapse(sk, skb)) + break; + + if (!tcp_skb_can_collapse(to, skb)) + break; + + space -= skb->len; + + if (first) { + first = false; + continue; + } + + if (space < 0) + break; + + if (after(TCP_SKB_CB(skb)->end_seq, tcp_wnd_end(tp))) + break; + + if (!tcp_collapse_retrans(sk, to)) + break; + } +} + +/* This retransmits one SKB. Policy decisions and retransmit queue + * state updates are done by the caller. Returns non-zero if an + * error occurred which prevented the send. + */ +int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + unsigned int cur_mss; + int diff, len, err; + int avail_wnd; + + /* Inconclusive MTU probe */ + if (icsk->icsk_mtup.probe_size) + icsk->icsk_mtup.probe_size = 0; + + /* Do not sent more than we queued. 1/4 is reserved for possible + * copying overhead: fragmentation, tunneling, mangling etc. + */ + if (refcount_read(&sk->sk_wmem_alloc) > + min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), + sk->sk_sndbuf)) + return -EAGAIN; + + if (skb_still_in_host_queue(sk, skb)) + return -EBUSY; + +start: + if (before(TCP_SKB_CB(skb)->seq, tp->snd_una)) { + if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_SYN; + TCP_SKB_CB(skb)->seq++; + goto start; + } + if (unlikely(before(TCP_SKB_CB(skb)->end_seq, tp->snd_una))) { + WARN_ON_ONCE(1); + return -EINVAL; + } + if (tcp_trim_head(sk, skb, tp->snd_una - TCP_SKB_CB(skb)->seq)) + return -ENOMEM; + } + + if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk)) + return -EHOSTUNREACH; /* Routing failure or similar. */ + + cur_mss = tcp_current_mss(sk); + avail_wnd = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq; + + /* If receiver has shrunk his window, and skb is out of + * new window, do not retransmit it. The exception is the + * case, when window is shrunk to zero. In this case + * our retransmit of one segment serves as a zero window probe. + */ + if (avail_wnd <= 0) { + if (TCP_SKB_CB(skb)->seq != tp->snd_una) + return -EAGAIN; + avail_wnd = cur_mss; + } + + len = cur_mss * segs; + if (len > avail_wnd) { + len = rounddown(avail_wnd, cur_mss); + if (!len) + len = avail_wnd; + } + if (skb->len > len) { + if (tcp_fragment(sk, TCP_FRAG_IN_RTX_QUEUE, skb, len, + cur_mss, GFP_ATOMIC)) + return -ENOMEM; /* We'll try again later. */ + } else { + if (skb_unclone(skb, GFP_ATOMIC)) + return -ENOMEM; + + diff = tcp_skb_pcount(skb); + tcp_set_skb_tso_segs(skb, cur_mss); + diff -= tcp_skb_pcount(skb); + if (diff) + tcp_adjust_pcount(sk, skb, diff); + avail_wnd = min_t(int, avail_wnd, cur_mss); + if (skb->len < avail_wnd) + tcp_retrans_try_collapse(sk, skb, avail_wnd); + } + + /* RFC3168, section 6.1.1.1. ECN fallback */ + if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN_ECN) == TCPHDR_SYN_ECN) + tcp_ecn_clear_syn(sk, skb); + + /* Update global and local TCP statistics. */ + segs = tcp_skb_pcount(skb); + TCP_ADD_STATS(sock_net(sk), TCP_MIB_RETRANSSEGS, segs); + if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); + tp->total_retrans += segs; + tp->bytes_retrans += skb->len; + + /* make sure skb->data is aligned on arches that require it + * and check if ack-trimming & collapsing extended the headroom + * beyond what csum_start can cover. + */ + if (unlikely((NET_IP_ALIGN && ((unsigned long)skb->data & 3)) || + skb_headroom(skb) >= 0xFFFF)) { + struct sk_buff *nskb; + + tcp_skb_tsorted_save(skb) { + nskb = __pskb_copy(skb, MAX_TCP_HEADER, GFP_ATOMIC); + if (nskb) { + nskb->dev = NULL; + err = tcp_transmit_skb(sk, nskb, 0, GFP_ATOMIC); + } else { + err = -ENOBUFS; + } + } tcp_skb_tsorted_restore(skb); + + if (!err) { + tcp_update_skb_after_send(sk, skb, tp->tcp_wstamp_ns); + tcp_rate_skb_sent(sk, skb); + } + } else { + err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); + } + + /* To avoid taking spuriously low RTT samples based on a timestamp + * for a transmit that never happened, always mark EVER_RETRANS + */ + TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS; + + if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RETRANS_CB_FLAG)) + tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RETRANS_CB, + TCP_SKB_CB(skb)->seq, segs, err); + + if (likely(!err)) { + trace_tcp_retransmit_skb(sk, skb); + } else if (err != -EBUSY) { + NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL, segs); + } + return err; +} + +int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) +{ + struct tcp_sock *tp = tcp_sk(sk); + int err = __tcp_retransmit_skb(sk, skb, segs); + + if (err == 0) { +#if FASTRETRANS_DEBUG > 0 + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) { + net_dbg_ratelimited("retrans_out leaked\n"); + } +#endif + TCP_SKB_CB(skb)->sacked |= TCPCB_RETRANS; + tp->retrans_out += tcp_skb_pcount(skb); + } + + /* Save stamp of the first (attempted) retransmit. */ + if (!tp->retrans_stamp) + tp->retrans_stamp = tcp_skb_timestamp(skb); + + if (tp->undo_retrans < 0) + tp->undo_retrans = 0; + tp->undo_retrans += tcp_skb_pcount(skb); + return err; +} + +/* This gets called after a retransmit timeout, and the initially + * retransmitted data is acknowledged. It tries to continue + * resending the rest of the retransmit queue, until either + * we've sent it all or the congestion window limit is reached. + */ +void tcp_xmit_retransmit_queue(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct sk_buff *skb, *rtx_head, *hole = NULL; + struct tcp_sock *tp = tcp_sk(sk); + bool rearm_timer = false; + u32 max_segs; + int mib_idx; + + if (!tp->packets_out) + return; + + rtx_head = tcp_rtx_queue_head(sk); + skb = tp->retransmit_skb_hint ?: rtx_head; + max_segs = tcp_tso_segs(sk, tcp_current_mss(sk)); + skb_rbtree_walk_from(skb) { + __u8 sacked; + int segs; + + if (tcp_pacing_check(sk)) + break; + + /* we could do better than to assign each time */ + if (!hole) + tp->retransmit_skb_hint = skb; + + segs = tp->snd_cwnd - tcp_packets_in_flight(tp); + if (segs <= 0) + break; + sacked = TCP_SKB_CB(skb)->sacked; + /* In case tcp_shift_skb_data() have aggregated large skbs, + * we need to make sure not sending too bigs TSO packets + */ + segs = min_t(int, segs, max_segs); + + if (tp->retrans_out >= tp->lost_out) { + break; + } else if (!(sacked & TCPCB_LOST)) { + if (!hole && !(sacked & (TCPCB_SACKED_RETRANS|TCPCB_SACKED_ACKED))) + hole = skb; + continue; + + } else { + if (icsk->icsk_ca_state != TCP_CA_Loss) + mib_idx = LINUX_MIB_TCPFASTRETRANS; + else + mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS; + } + + if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS)) + continue; + + if (tcp_small_queue_check(sk, skb, 1)) + break; + + if (tcp_retransmit_skb(sk, skb, segs)) + break; + + NET_ADD_STATS(sock_net(sk), mib_idx, tcp_skb_pcount(skb)); + + if (tcp_in_cwnd_reduction(sk)) + tp->prr_out += tcp_skb_pcount(skb); + + if (skb == rtx_head && + icsk->icsk_pending != ICSK_TIME_REO_TIMEOUT) + rearm_timer = true; + + } + if (rearm_timer) + tcp_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + inet_csk(sk)->icsk_rto, + TCP_RTO_MAX); +} + +/* We allow to exceed memory limits for FIN packets to expedite + * connection tear down and (memory) recovery. + * Otherwise tcp_send_fin() could be tempted to either delay FIN + * or even be forced to close flow without any FIN. + * In general, we want to allow one skb per socket to avoid hangs + * with edge trigger epoll() + */ +void sk_forced_mem_schedule(struct sock *sk, int size) +{ + int delta, amt; + + delta = size - sk->sk_forward_alloc; + if (delta <= 0) + return; + amt = sk_mem_pages(delta); + sk->sk_forward_alloc += amt * SK_MEM_QUANTUM; + sk_memory_allocated_add(sk, amt); + + if (mem_cgroup_sockets_enabled && sk->sk_memcg) + mem_cgroup_charge_skmem(sk->sk_memcg, amt); +} + +/* Send a FIN. The caller locks the socket for us. + * We should try to send a FIN packet really hard, but eventually give up. + */ +void tcp_send_fin(struct sock *sk) +{ + struct sk_buff *skb, *tskb, *tail = tcp_write_queue_tail(sk); + struct tcp_sock *tp = tcp_sk(sk); + + /* Optimization, tack on the FIN if we have one skb in write queue and + * this skb was not yet sent, or we are under memory pressure. + * Note: in the latter case, FIN packet will be sent after a timeout, + * as TCP stack thinks it has already been transmitted. + */ + tskb = tail; + if (!tskb && tcp_under_memory_pressure(sk)) + tskb = skb_rb_last(&sk->tcp_rtx_queue); + + if (tskb) { + TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN; + TCP_SKB_CB(tskb)->end_seq++; + tp->write_seq++; + if (!tail) { + /* This means tskb was already sent. + * Pretend we included the FIN on previous transmit. + * We need to set tp->snd_nxt to the value it would have + * if FIN had been sent. This is because retransmit path + * does not change tp->snd_nxt. + */ + WRITE_ONCE(tp->snd_nxt, tp->snd_nxt + 1); + return; + } + } else { + skb = alloc_skb_fclone(MAX_TCP_HEADER, sk->sk_allocation); + if (unlikely(!skb)) + return; + + INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); + skb_reserve(skb, MAX_TCP_HEADER); + sk_forced_mem_schedule(sk, skb->truesize); + /* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */ + tcp_init_nondata_skb(skb, tp->write_seq, + TCPHDR_ACK | TCPHDR_FIN); + tcp_queue_skb(sk, skb); + } + __tcp_push_pending_frames(sk, tcp_current_mss(sk), TCP_NAGLE_OFF); +} + +/* We get here when a process closes a file descriptor (either due to + * an explicit close() or as a byproduct of exit()'ing) and there + * was unread data in the receive queue. This behavior is recommended + * by RFC 2525, section 2.17. -DaveM + */ +void tcp_send_active_reset(struct sock *sk, gfp_t priority) +{ + struct sk_buff *skb; + + TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTRSTS); + + /* NOTE: No TCP options attached and we never retransmit this. */ + skb = alloc_skb(MAX_TCP_HEADER, priority); + if (!skb) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED); + return; + } + + /* Reserve space for headers and prepare control bits. */ + skb_reserve(skb, MAX_TCP_HEADER); + tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk), + TCPHDR_ACK | TCPHDR_RST); + tcp_mstamp_refresh(tcp_sk(sk)); + /* Send it off. */ + if (tcp_transmit_skb(sk, skb, 0, priority)) + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED); + + /* skb of trace_tcp_send_reset() keeps the skb that caused RST, + * skb here is different to the troublesome skb, so use NULL + */ + trace_tcp_send_reset(sk, NULL); +} + +/* Send a crossed SYN-ACK during socket establishment. + * WARNING: This routine must only be called when we have already sent + * a SYN packet that crossed the incoming SYN that caused this routine + * to get called. If this assumption fails then the initial rcv_wnd + * and rcv_wscale values will not be correct. + */ +int tcp_send_synack(struct sock *sk) +{ + struct sk_buff *skb; + + skb = tcp_rtx_queue_head(sk); + if (!skb || !(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { + pr_err("%s: wrong queue state\n", __func__); + return -EFAULT; + } + if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK)) { + if (skb_cloned(skb)) { + struct sk_buff *nskb; + + tcp_skb_tsorted_save(skb) { + nskb = skb_copy(skb, GFP_ATOMIC); + } tcp_skb_tsorted_restore(skb); + if (!nskb) + return -ENOMEM; + INIT_LIST_HEAD(&nskb->tcp_tsorted_anchor); + tcp_highest_sack_replace(sk, skb, nskb); + tcp_rtx_queue_unlink_and_free(skb, sk); + __skb_header_release(nskb); + tcp_rbtree_insert(&sk->tcp_rtx_queue, nskb); + sk_wmem_queued_add(sk, nskb->truesize); + sk_mem_charge(sk, nskb->truesize); + skb = nskb; + } + + TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_ACK; + tcp_ecn_send_synack(sk, skb); + } + return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); +} + +/** + * tcp_make_synack - Allocate one skb and build a SYNACK packet. + * @sk: listener socket + * @dst: dst entry attached to the SYNACK. It is consumed and caller + * should not use it again. + * @req: request_sock pointer + * @foc: cookie for tcp fast open + * @synack_type: Type of synack to prepare + * @syn_skb: SYN packet just received. It could be NULL for rtx case. + */ +struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + enum tcp_synack_type synack_type, + struct sk_buff *syn_skb) +{ + struct inet_request_sock *ireq = inet_rsk(req); + const struct tcp_sock *tp = tcp_sk(sk); + struct tcp_md5sig_key *md5 = NULL; + struct tcp_out_options opts; + struct sk_buff *skb; + int tcp_header_size; + struct tcphdr *th; + int mss; + u64 now; + + skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC); + if (unlikely(!skb)) { + dst_release(dst); + return NULL; + } + /* Reserve space for headers. */ + skb_reserve(skb, MAX_TCP_HEADER); + + switch (synack_type) { + case TCP_SYNACK_NORMAL: + skb_set_owner_w(skb, req_to_sk(req)); + break; + case TCP_SYNACK_COOKIE: + /* Under synflood, we do not attach skb to a socket, + * to avoid false sharing. + */ + break; + case TCP_SYNACK_FASTOPEN: + /* sk is a const pointer, because we want to express multiple + * cpu might call us concurrently. + * sk->sk_wmem_alloc in an atomic, we can promote to rw. + */ + skb_set_owner_w(skb, (struct sock *)sk); + break; + } + skb_dst_set(skb, dst); + + mss = tcp_mss_clamp(tp, dst_metric_advmss(dst)); + + memset(&opts, 0, sizeof(opts)); + now = tcp_clock_ns(); +#ifdef CONFIG_SYN_COOKIES + if (unlikely(synack_type == TCP_SYNACK_COOKIE && ireq->tstamp_ok)) + skb->skb_mstamp_ns = cookie_init_timestamp(req, now); + else +#endif + { + skb->skb_mstamp_ns = now; + if (!tcp_rsk(req)->snt_synack) /* Timestamp first SYNACK */ + tcp_rsk(req)->snt_synack = tcp_skb_timestamp_us(skb); + } + +#ifdef CONFIG_TCP_MD5SIG + rcu_read_lock(); + md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req)); +#endif + skb_set_hash(skb, tcp_rsk(req)->txhash, PKT_HASH_TYPE_L4); + /* bpf program will be interested in the tcp_flags */ + TCP_SKB_CB(skb)->tcp_flags = TCPHDR_SYN | TCPHDR_ACK; + tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5, + foc, synack_type, + syn_skb) + sizeof(*th); + + skb_push(skb, tcp_header_size); + skb_reset_transport_header(skb); + + th = (struct tcphdr *)skb->data; + memset(th, 0, sizeof(struct tcphdr)); + th->syn = 1; + th->ack = 1; + tcp_ecn_make_synack(req, th); + th->source = htons(ireq->ir_num); + th->dest = ireq->ir_rmt_port; + skb->mark = ireq->ir_mark; + skb->ip_summed = CHECKSUM_PARTIAL; + th->seq = htonl(tcp_rsk(req)->snt_isn); + /* XXX data is queued and acked as is. No buffer/window check */ + th->ack_seq = htonl(tcp_rsk(req)->rcv_nxt); + + /* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */ + th->window = htons(min(req->rsk_rcv_wnd, 65535U)); + tcp_options_write((__be32 *)(th + 1), NULL, &opts); + th->doff = (tcp_header_size >> 2); + TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS); + +#ifdef CONFIG_TCP_MD5SIG + /* Okay, we have all we need - do the md5 hash if needed */ + if (md5) + tcp_rsk(req)->af_specific->calc_md5_hash(opts.hash_location, + md5, req_to_sk(req), skb); + rcu_read_unlock(); +#endif + + bpf_skops_write_hdr_opt((struct sock *)sk, skb, req, syn_skb, + synack_type, &opts); + + skb->skb_mstamp_ns = now; + tcp_add_tx_delay(skb, tp); + + return skb; +} +EXPORT_SYMBOL(tcp_make_synack); + +static void tcp_ca_dst_init(struct sock *sk, const struct dst_entry *dst) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + const struct tcp_congestion_ops *ca; + u32 ca_key = dst_metric(dst, RTAX_CC_ALGO); + + if (ca_key == TCP_CA_UNSPEC) + return; + + rcu_read_lock(); + ca = tcp_ca_find_key(ca_key); + if (likely(ca && bpf_try_module_get(ca, ca->owner))) { + bpf_module_put(icsk->icsk_ca_ops, icsk->icsk_ca_ops->owner); + icsk->icsk_ca_dst_locked = tcp_ca_dst_locked(dst); + icsk->icsk_ca_ops = ca; + } + rcu_read_unlock(); +} + +/* Do all connect socket setups that can be done AF independent. */ +static void tcp_connect_init(struct sock *sk) +{ + const struct dst_entry *dst = __sk_dst_get(sk); + struct tcp_sock *tp = tcp_sk(sk); + __u8 rcv_wscale; + u32 rcv_wnd; + + /* We'll fix this up when we get a response from the other end. + * See tcp_input.c:tcp_rcv_state_process case TCP_SYN_SENT. + */ + tp->tcp_header_len = sizeof(struct tcphdr); + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_timestamps)) + tp->tcp_header_len += TCPOLEN_TSTAMP_ALIGNED; + +#ifdef CONFIG_TCP_MD5SIG + if (tp->af_specific->md5_lookup(sk, sk)) + tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED; +#endif + + /* If user gave his TCP_MAXSEG, record it to clamp */ + if (tp->rx_opt.user_mss) + tp->rx_opt.mss_clamp = tp->rx_opt.user_mss; + tp->max_window = 0; + tcp_mtup_init(sk); + tcp_sync_mss(sk, dst_mtu(dst)); + + tcp_ca_dst_init(sk, dst); + + if (!tp->window_clamp) + tp->window_clamp = dst_metric(dst, RTAX_WINDOW); + tp->advmss = tcp_mss_clamp(tp, dst_metric_advmss(dst)); + + tcp_initialize_rcv_mss(sk); + + /* limit the window selection if the user enforce a smaller rx buffer */ + if (sk->sk_userlocks & SOCK_RCVBUF_LOCK && + (tp->window_clamp > tcp_full_space(sk) || tp->window_clamp == 0)) + tp->window_clamp = tcp_full_space(sk); + + rcv_wnd = tcp_rwnd_init_bpf(sk); + if (rcv_wnd == 0) + rcv_wnd = dst_metric(dst, RTAX_INITRWND); + + tcp_select_initial_window(sk, tcp_full_space(sk), + tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0), + &tp->rcv_wnd, + &tp->window_clamp, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_window_scaling), + &rcv_wscale, + rcv_wnd); + + tp->rx_opt.rcv_wscale = rcv_wscale; + tp->rcv_ssthresh = tp->rcv_wnd; + + sk->sk_err = 0; + sock_reset_flag(sk, SOCK_DONE); + tp->snd_wnd = 0; + tcp_init_wl(tp, 0); + tcp_write_queue_purge(sk); + tp->snd_una = tp->write_seq; + tp->snd_sml = tp->write_seq; + tp->snd_up = tp->write_seq; + WRITE_ONCE(tp->snd_nxt, tp->write_seq); + + if (likely(!tp->repair)) + tp->rcv_nxt = 0; + else + tp->rcv_tstamp = tcp_jiffies32; + tp->rcv_wup = tp->rcv_nxt; + WRITE_ONCE(tp->copied_seq, tp->rcv_nxt); + + inet_csk(sk)->icsk_rto = tcp_timeout_init(sk); + inet_csk(sk)->icsk_retransmits = 0; + tcp_clear_retrans(tp); +} + +static void tcp_connect_queue_skb(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); + + tcb->end_seq += skb->len; + __skb_header_release(skb); + sk_wmem_queued_add(sk, skb->truesize); + sk_mem_charge(sk, skb->truesize); + WRITE_ONCE(tp->write_seq, tcb->end_seq); + tp->packets_out += tcp_skb_pcount(skb); +} + +/* Build and send a SYN with data and (cached) Fast Open cookie. However, + * queue a data-only packet after the regular SYN, such that regular SYNs + * are retransmitted on timeouts. Also if the remote SYN-ACK acknowledges + * only the SYN sequence, the data are retransmitted in the first ACK. + * If cookie is not cached or other error occurs, falls back to send a + * regular SYN with Fast Open cookie request option. + */ +static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_fastopen_request *fo = tp->fastopen_req; + int space, err = 0; + struct sk_buff *syn_data; + + tp->rx_opt.mss_clamp = tp->advmss; /* If MSS is not cached */ + if (!tcp_fastopen_cookie_check(sk, &tp->rx_opt.mss_clamp, &fo->cookie)) + goto fallback; + + /* MSS for SYN-data is based on cached MSS and bounded by PMTU and + * user-MSS. Reserve maximum option space for middleboxes that add + * private TCP options. The cost is reduced data space in SYN :( + */ + tp->rx_opt.mss_clamp = tcp_mss_clamp(tp, tp->rx_opt.mss_clamp); + /* Sync mss_cache after updating the mss_clamp */ + tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); + + space = __tcp_mtu_to_mss(sk, icsk->icsk_pmtu_cookie) - + MAX_TCP_OPTION_SPACE; + + space = min_t(size_t, space, fo->size); + + /* limit to order-0 allocations */ + space = min_t(size_t, space, SKB_MAX_HEAD(MAX_TCP_HEADER)); + + syn_data = sk_stream_alloc_skb(sk, space, sk->sk_allocation, false); + if (!syn_data) + goto fallback; + syn_data->ip_summed = CHECKSUM_PARTIAL; + memcpy(syn_data->cb, syn->cb, sizeof(syn->cb)); + if (space) { + int copied = copy_from_iter(skb_put(syn_data, space), space, + &fo->data->msg_iter); + if (unlikely(!copied)) { + tcp_skb_tsorted_anchor_cleanup(syn_data); + kfree_skb(syn_data); + goto fallback; + } + if (copied != space) { + skb_trim(syn_data, copied); + space = copied; + } + skb_zcopy_set(syn_data, fo->uarg, NULL); + } + /* No more data pending in inet_wait_for_connect() */ + if (space == fo->size) + fo->data = NULL; + fo->copied = space; + + tcp_connect_queue_skb(sk, syn_data); + if (syn_data->len) + tcp_chrono_start(sk, TCP_CHRONO_BUSY); + + err = tcp_transmit_skb(sk, syn_data, 1, sk->sk_allocation); + + syn->skb_mstamp_ns = syn_data->skb_mstamp_ns; + + /* Now full SYN+DATA was cloned and sent (or not), + * remove the SYN from the original skb (syn_data) + * we keep in write queue in case of a retransmit, as we + * also have the SYN packet (with no data) in the same queue. + */ + TCP_SKB_CB(syn_data)->seq++; + TCP_SKB_CB(syn_data)->tcp_flags = TCPHDR_ACK | TCPHDR_PSH; + if (!err) { + tp->syn_data = (fo->copied > 0); + tcp_rbtree_insert(&sk->tcp_rtx_queue, syn_data); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPORIGDATASENT); + goto done; + } + + /* data was not sent, put it in write_queue */ + __skb_queue_tail(&sk->sk_write_queue, syn_data); + tp->packets_out -= tcp_skb_pcount(syn_data); + +fallback: + /* Send a regular SYN with Fast Open cookie request option */ + if (fo->cookie.len > 0) + fo->cookie.len = 0; + err = tcp_transmit_skb(sk, syn, 1, sk->sk_allocation); + if (err) + tp->syn_fastopen = 0; +done: + fo->cookie.len = -1; /* Exclude Fast Open option for SYN retries */ + return err; +} + +/* Build a SYN and send it off. */ +int tcp_connect(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *buff; + int err; + + tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB, 0, NULL); + + if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk)) + return -EHOSTUNREACH; /* Routing failure or similar. */ + + tcp_connect_init(sk); + + if (unlikely(tp->repair)) { + tcp_finish_connect(sk, NULL); + return 0; + } + + buff = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, true); + if (unlikely(!buff)) + return -ENOBUFS; + + tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN); + tcp_mstamp_refresh(tp); + tp->retrans_stamp = tcp_time_stamp(tp); + tcp_connect_queue_skb(sk, buff); + tcp_ecn_send_syn(sk, buff); + tcp_rbtree_insert(&sk->tcp_rtx_queue, buff); + + /* Send off SYN; include data in Fast Open. */ + err = tp->fastopen_req ? tcp_send_syn_data(sk, buff) : + tcp_transmit_skb(sk, buff, 1, sk->sk_allocation); + if (err == -ECONNREFUSED) + return err; + + /* We change tp->snd_nxt after the tcp_transmit_skb() call + * in order to make this packet get counted in tcpOutSegs. + */ + WRITE_ONCE(tp->snd_nxt, tp->write_seq); + tp->pushed_seq = tp->write_seq; + buff = tcp_send_head(sk); + if (unlikely(buff)) { + WRITE_ONCE(tp->snd_nxt, TCP_SKB_CB(buff)->seq); + tp->pushed_seq = TCP_SKB_CB(buff)->seq; + } + TCP_INC_STATS(sock_net(sk), TCP_MIB_ACTIVEOPENS); + + /* Timer for repeating the SYN until an answer. */ + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + inet_csk(sk)->icsk_rto, TCP_RTO_MAX); + return 0; +} +EXPORT_SYMBOL(tcp_connect); + +/* Send out a delayed ack, the caller does the policy checking + * to see if we should even be here. See tcp_input.c:tcp_ack_snd_check() + * for details. + */ +void tcp_send_delayed_ack(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + int ato = icsk->icsk_ack.ato; + unsigned long timeout; + + if (ato > TCP_DELACK_MIN) { + const struct tcp_sock *tp = tcp_sk(sk); + int max_ato = HZ / 2; + + if (inet_csk_in_pingpong_mode(sk) || + (icsk->icsk_ack.pending & ICSK_ACK_PUSHED)) + max_ato = TCP_DELACK_MAX; + + /* Slow path, intersegment interval is "high". */ + + /* If some rtt estimate is known, use it to bound delayed ack. + * Do not use inet_csk(sk)->icsk_rto here, use results of rtt measurements + * directly. + */ + if (tp->srtt_us) { + int rtt = max_t(int, usecs_to_jiffies(tp->srtt_us >> 3), + TCP_DELACK_MIN); + + if (rtt < max_ato) + max_ato = rtt; + } + + ato = min(ato, max_ato); + } + + ato = min_t(u32, ato, inet_csk(sk)->icsk_delack_max); + + /* Stay within the limit we were given */ + timeout = jiffies + ato; + + /* Use new timeout only if there wasn't a older one earlier. */ + if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { + /* If delack timer is about to expire, send ACK now. */ + if (time_before_eq(icsk->icsk_ack.timeout, jiffies + (ato >> 2))) { + tcp_send_ack(sk); + return; + } + + if (!time_before(timeout, icsk->icsk_ack.timeout)) + timeout = icsk->icsk_ack.timeout; + } + icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; + icsk->icsk_ack.timeout = timeout; + sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); +} + +/* This routine sends an ack and also updates the window. */ +void __tcp_send_ack(struct sock *sk, u32 rcv_nxt) +{ + struct sk_buff *buff; + + /* If we have been reset, we may not send again. */ + if (sk->sk_state == TCP_CLOSE) + return; + + /* We are not putting this on the write queue, so + * tcp_transmit_skb() will set the ownership to this + * sock. + */ + buff = alloc_skb(MAX_TCP_HEADER, + sk_gfp_mask(sk, GFP_ATOMIC | __GFP_NOWARN)); + if (unlikely(!buff)) { + struct inet_connection_sock *icsk = inet_csk(sk); + unsigned long delay; + + delay = TCP_DELACK_MAX << icsk->icsk_ack.retry; + if (delay < TCP_RTO_MAX) + icsk->icsk_ack.retry++; + inet_csk_schedule_ack(sk); + icsk->icsk_ack.ato = TCP_ATO_MIN; + inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, delay, TCP_RTO_MAX); + return; + } + + /* Reserve space for headers and prepare control bits. */ + skb_reserve(buff, MAX_TCP_HEADER); + tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPHDR_ACK); + + /* We do not want pure acks influencing TCP Small Queues or fq/pacing + * too much. + * SKB_TRUESIZE(max(1 .. 66, MAX_TCP_HEADER)) is unfortunately ~784 + */ + skb_set_tcp_pure_ack(buff); + + /* Send it off, this clears delayed acks for us. */ + __tcp_transmit_skb(sk, buff, 0, (__force gfp_t)0, rcv_nxt); +} +EXPORT_SYMBOL_GPL(__tcp_send_ack); + +void tcp_send_ack(struct sock *sk) +{ + __tcp_send_ack(sk, tcp_sk(sk)->rcv_nxt); +} + +/* This routine sends a packet with an out of date sequence + * number. It assumes the other end will try to ack it. + * + * Question: what should we make while urgent mode? + * 4.4BSD forces sending single byte of data. We cannot send + * out of window data, because we have SND.NXT==SND.MAX... + * + * Current solution: to send TWO zero-length segments in urgent mode: + * one is with SEG.SEQ=SND.UNA to deliver urgent pointer, another is + * out-of-date with SND.UNA-1 to probe window. + */ +static int tcp_xmit_probe_skb(struct sock *sk, int urgent, int mib) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + + /* We don't queue it, tcp_transmit_skb() sets ownership. */ + skb = alloc_skb(MAX_TCP_HEADER, + sk_gfp_mask(sk, GFP_ATOMIC | __GFP_NOWARN)); + if (!skb) + return -1; + + /* Reserve space for headers and set control bits. */ + skb_reserve(skb, MAX_TCP_HEADER); + /* Use a previous sequence. This should cause the other + * end to send an ack. Don't queue or clone SKB, just + * send it. + */ + tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK); + NET_INC_STATS(sock_net(sk), mib); + return tcp_transmit_skb(sk, skb, 0, (__force gfp_t)0); +} + +/* Called from setsockopt( ... TCP_REPAIR ) */ +void tcp_send_window_probe(struct sock *sk) +{ + if (sk->sk_state == TCP_ESTABLISHED) { + tcp_sk(sk)->snd_wl1 = tcp_sk(sk)->rcv_nxt - 1; + tcp_mstamp_refresh(tcp_sk(sk)); + tcp_xmit_probe_skb(sk, 0, LINUX_MIB_TCPWINPROBE); + } +} + +/* Initiate keepalive or window probe from timer. */ +int tcp_write_wakeup(struct sock *sk, int mib) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb; + + if (sk->sk_state == TCP_CLOSE) + return -1; + + skb = tcp_send_head(sk); + if (skb && before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp))) { + int err; + unsigned int mss = tcp_current_mss(sk); + unsigned int seg_size = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq; + + if (before(tp->pushed_seq, TCP_SKB_CB(skb)->end_seq)) + tp->pushed_seq = TCP_SKB_CB(skb)->end_seq; + + /* We are probing the opening of a window + * but the window size is != 0 + * must have been a result SWS avoidance ( sender ) + */ + if (seg_size < TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq || + skb->len > mss) { + seg_size = min(seg_size, mss); + TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; + if (tcp_fragment(sk, TCP_FRAG_IN_WRITE_QUEUE, + skb, seg_size, mss, GFP_ATOMIC)) + return -1; + } else if (!tcp_skb_pcount(skb)) + tcp_set_skb_tso_segs(skb, mss); + + TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; + err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); + if (!err) + tcp_event_new_data_sent(sk, skb); + return err; + } else { + if (between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF)) + tcp_xmit_probe_skb(sk, 1, mib); + return tcp_xmit_probe_skb(sk, 0, mib); + } +} + +/* A window probe timeout has occurred. If window is not closed send + * a partial packet else a zero probe. + */ +void tcp_send_probe0(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + unsigned long timeout; + int err; + + err = tcp_write_wakeup(sk, LINUX_MIB_TCPWINPROBE); + + if (tp->packets_out || tcp_write_queue_empty(sk)) { + /* Cancel probe timer, if it is not required. */ + icsk->icsk_probes_out = 0; + icsk->icsk_backoff = 0; + icsk->icsk_probes_tstamp = 0; + return; + } + + icsk->icsk_probes_out++; + if (err <= 0) { + if (icsk->icsk_backoff < READ_ONCE(net->ipv4.sysctl_tcp_retries2)) + icsk->icsk_backoff++; + timeout = tcp_probe0_when(sk, TCP_RTO_MAX); + } else { + /* If packet was not sent due to local congestion, + * Let senders fight for local resources conservatively. + */ + timeout = TCP_RESOURCE_PROBE_INTERVAL; + } + + timeout = tcp_clamp_probe0_to_user_timeout(sk, timeout); + tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, timeout, TCP_RTO_MAX); +} + +int tcp_rtx_synack(const struct sock *sk, struct request_sock *req) +{ + const struct tcp_request_sock_ops *af_ops = tcp_rsk(req)->af_specific; + struct flowi fl; + int res; + + tcp_rsk(req)->txhash = net_tx_rndhash(); + res = af_ops->send_synack(sk, NULL, &fl, req, NULL, TCP_SYNACK_NORMAL, + NULL); + if (!res) { + TCP_INC_STATS(sock_net(sk), TCP_MIB_RETRANSSEGS); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); + if (unlikely(tcp_passive_fastopen(sk))) + tcp_sk(sk)->total_retrans++; + trace_tcp_retransmit_synack(sk, req); + } + return res; +} +EXPORT_SYMBOL(tcp_rtx_synack); diff --git a/net/ipv4/tcp_rate.c b/net/ipv4/tcp_rate.c new file mode 100644 index 000000000..6ab197928 --- /dev/null +++ b/net/ipv4/tcp_rate.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <net/tcp.h> + +/* The bandwidth estimator estimates the rate at which the network + * can currently deliver outbound data packets for this flow. At a high + * level, it operates by taking a delivery rate sample for each ACK. + * + * A rate sample records the rate at which the network delivered packets + * for this flow, calculated over the time interval between the transmission + * of a data packet and the acknowledgment of that packet. + * + * Specifically, over the interval between each transmit and corresponding ACK, + * the estimator generates a delivery rate sample. Typically it uses the rate + * at which packets were acknowledged. However, the approach of using only the + * acknowledgment rate faces a challenge under the prevalent ACK decimation or + * compression: packets can temporarily appear to be delivered much quicker + * than the bottleneck rate. Since it is physically impossible to do that in a + * sustained fashion, when the estimator notices that the ACK rate is faster + * than the transmit rate, it uses the latter: + * + * send_rate = #pkts_delivered/(last_snd_time - first_snd_time) + * ack_rate = #pkts_delivered/(last_ack_time - first_ack_time) + * bw = min(send_rate, ack_rate) + * + * Notice the estimator essentially estimates the goodput, not always the + * network bottleneck link rate when the sending or receiving is limited by + * other factors like applications or receiver window limits. The estimator + * deliberately avoids using the inter-packet spacing approach because that + * approach requires a large number of samples and sophisticated filtering. + * + * TCP flows can often be application-limited in request/response workloads. + * The estimator marks a bandwidth sample as application-limited if there + * was some moment during the sampled window of packets when there was no data + * ready to send in the write queue. + */ + +/* Snapshot the current delivery information in the skb, to generate + * a rate sample later when the skb is (s)acked in tcp_rate_skb_delivered(). + */ +void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* In general we need to start delivery rate samples from the + * time we received the most recent ACK, to ensure we include + * the full time the network needs to deliver all in-flight + * packets. If there are no packets in flight yet, then we + * know that any ACKs after now indicate that the network was + * able to deliver those packets completely in the sampling + * interval between now and the next ACK. + * + * Note that we use packets_out instead of tcp_packets_in_flight(tp) + * because the latter is a guess based on RTO and loss-marking + * heuristics. We don't want spurious RTOs or loss markings to cause + * a spuriously small time interval, causing a spuriously high + * bandwidth estimate. + */ + if (!tp->packets_out) { + u64 tstamp_us = tcp_skb_timestamp_us(skb); + + tp->first_tx_mstamp = tstamp_us; + tp->delivered_mstamp = tstamp_us; + } + + TCP_SKB_CB(skb)->tx.first_tx_mstamp = tp->first_tx_mstamp; + TCP_SKB_CB(skb)->tx.delivered_mstamp = tp->delivered_mstamp; + TCP_SKB_CB(skb)->tx.delivered = tp->delivered; + TCP_SKB_CB(skb)->tx.is_app_limited = tp->app_limited ? 1 : 0; +} + +/* When an skb is sacked or acked, we fill in the rate sample with the (prior) + * delivery information when the skb was last transmitted. + * + * If an ACK (s)acks multiple skbs (e.g., stretched-acks), this function is + * called multiple times. We favor the information from the most recently + * sent skb, i.e., the skb with the most recently sent time and the highest + * sequence. + */ +void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, + struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_skb_cb *scb = TCP_SKB_CB(skb); + u64 tx_tstamp; + + if (!scb->tx.delivered_mstamp) + return; + + tx_tstamp = tcp_skb_timestamp_us(skb); + if (!rs->prior_delivered || + tcp_skb_sent_after(tx_tstamp, tp->first_tx_mstamp, + scb->end_seq, rs->last_end_seq)) { + rs->prior_delivered = scb->tx.delivered; + rs->prior_mstamp = scb->tx.delivered_mstamp; + rs->is_app_limited = scb->tx.is_app_limited; + rs->is_retrans = scb->sacked & TCPCB_RETRANS; + rs->last_end_seq = scb->end_seq; + + /* Record send time of most recently ACKed packet: */ + tp->first_tx_mstamp = tx_tstamp; + /* Find the duration of the "send phase" of this window: */ + rs->interval_us = tcp_stamp_us_delta(tp->first_tx_mstamp, + scb->tx.first_tx_mstamp); + + } + /* Mark off the skb delivered once it's sacked to avoid being + * used again when it's cumulatively acked. For acked packets + * we don't need to reset since it'll be freed soon. + */ + if (scb->sacked & TCPCB_SACKED_ACKED) + scb->tx.delivered_mstamp = 0; +} + +/* Update the connection delivery information and generate a rate sample. */ +void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, + bool is_sack_reneg, struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 snd_us, ack_us; + + /* Clear app limited if bubble is acked and gone. */ + if (tp->app_limited && after(tp->delivered, tp->app_limited)) + tp->app_limited = 0; + + /* TODO: there are multiple places throughout tcp_ack() to get + * current time. Refactor the code using a new "tcp_acktag_state" + * to carry current time, flags, stats like "tcp_sacktag_state". + */ + if (delivered) + tp->delivered_mstamp = tp->tcp_mstamp; + + rs->acked_sacked = delivered; /* freshly ACKed or SACKed */ + rs->losses = lost; /* freshly marked lost */ + /* Return an invalid sample if no timing information is available or + * in recovery from loss with SACK reneging. Rate samples taken during + * a SACK reneging event may overestimate bw by including packets that + * were SACKed before the reneg. + */ + if (!rs->prior_mstamp || is_sack_reneg) { + rs->delivered = -1; + rs->interval_us = -1; + return; + } + rs->delivered = tp->delivered - rs->prior_delivered; + + /* Model sending data and receiving ACKs as separate pipeline phases + * for a window. Usually the ACK phase is longer, but with ACK + * compression the send phase can be longer. To be safe we use the + * longer phase. + */ + snd_us = rs->interval_us; /* send phase */ + ack_us = tcp_stamp_us_delta(tp->tcp_mstamp, + rs->prior_mstamp); /* ack phase */ + rs->interval_us = max(snd_us, ack_us); + + /* Record both segment send and ack receive intervals */ + rs->snd_interval_us = snd_us; + rs->rcv_interval_us = ack_us; + + /* Normally we expect interval_us >= min-rtt. + * Note that rate may still be over-estimated when a spuriously + * retransmistted skb was first (s)acked because "interval_us" + * is under-estimated (up to an RTT). However continuously + * measuring the delivery rate during loss recovery is crucial + * for connections suffer heavy or prolonged losses. + */ + if (unlikely(rs->interval_us < tcp_min_rtt(tp))) { + if (!rs->is_retrans) + pr_debug("tcp rate: %ld %d %u %u %u\n", + rs->interval_us, rs->delivered, + inet_csk(sk)->icsk_ca_state, + tp->rx_opt.sack_ok, tcp_min_rtt(tp)); + rs->interval_us = -1; + return; + } + + /* Record the last non-app-limited or the highest app-limited bw */ + if (!rs->is_app_limited || + ((u64)rs->delivered * tp->rate_interval_us >= + (u64)tp->rate_delivered * rs->interval_us)) { + tp->rate_delivered = rs->delivered; + tp->rate_interval_us = rs->interval_us; + tp->rate_app_limited = rs->is_app_limited; + } +} + +/* If a gap is detected between sends, mark the socket application-limited. */ +void tcp_rate_check_app_limited(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (/* We have less than one packet to send. */ + tp->write_seq - tp->snd_nxt < tp->mss_cache && + /* Nothing in sending host's qdisc queues or NIC tx queue. */ + sk_wmem_alloc_get(sk) < SKB_TRUESIZE(1) && + /* We are not limited by CWND. */ + tcp_packets_in_flight(tp) < tp->snd_cwnd && + /* All lost packets have been retransmitted. */ + tp->lost_out <= tp->retrans_out) + tp->app_limited = + (tp->delivered + tcp_packets_in_flight(tp)) ? : 1; +} +EXPORT_SYMBOL_GPL(tcp_rate_check_app_limited); diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c new file mode 100644 index 000000000..f84c5804e --- /dev/null +++ b/net/ipv4/tcp_recovery.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/tcp.h> +#include <net/tcp.h> + +static bool tcp_rack_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) +{ + return t1 > t2 || (t1 == t2 && after(seq1, seq2)); +} + +static u32 tcp_rack_reo_wnd(const struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (!tp->reord_seen) { + /* If reordering has not been observed, be aggressive during + * the recovery or starting the recovery by DUPACK threshold. + */ + if (inet_csk(sk)->icsk_ca_state >= TCP_CA_Recovery) + return 0; + + if (tp->sacked_out >= tp->reordering && + !(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_NO_DUPTHRESH)) + return 0; + } + + /* To be more reordering resilient, allow min_rtt/4 settling delay. + * Use min_rtt instead of the smoothed RTT because reordering is + * often a path property and less related to queuing or delayed ACKs. + * Upon receiving DSACKs, linearly increase the window up to the + * smoothed RTT. + */ + return min((tcp_min_rtt(tp) >> 2) * tp->rack.reo_wnd_steps, + tp->srtt_us >> 3); +} + +s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, u32 reo_wnd) +{ + return tp->rack.rtt_us + reo_wnd - + tcp_stamp_us_delta(tp->tcp_mstamp, tcp_skb_timestamp_us(skb)); +} + +/* RACK loss detection (IETF draft draft-ietf-tcpm-rack-01): + * + * Marks a packet lost, if some packet sent later has been (s)acked. + * The underlying idea is similar to the traditional dupthresh and FACK + * but they look at different metrics: + * + * dupthresh: 3 OOO packets delivered (packet count) + * FACK: sequence delta to highest sacked sequence (sequence space) + * RACK: sent time delta to the latest delivered packet (time domain) + * + * The advantage of RACK is it applies to both original and retransmitted + * packet and therefore is robust against tail losses. Another advantage + * is being more resilient to reordering by simply allowing some + * "settling delay", instead of tweaking the dupthresh. + * + * When tcp_rack_detect_loss() detects some packets are lost and we + * are not already in the CA_Recovery state, either tcp_rack_reo_timeout() + * or tcp_time_to_recover()'s "Trick#1: the loss is proven" code path will + * make us enter the CA_Recovery state. + */ +static void tcp_rack_detect_loss(struct sock *sk, u32 *reo_timeout) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct sk_buff *skb, *n; + u32 reo_wnd; + + *reo_timeout = 0; + reo_wnd = tcp_rack_reo_wnd(sk); + list_for_each_entry_safe(skb, n, &tp->tsorted_sent_queue, + tcp_tsorted_anchor) { + struct tcp_skb_cb *scb = TCP_SKB_CB(skb); + s32 remaining; + + /* Skip ones marked lost but not yet retransmitted */ + if ((scb->sacked & TCPCB_LOST) && + !(scb->sacked & TCPCB_SACKED_RETRANS)) + continue; + + if (!tcp_rack_sent_after(tp->rack.mstamp, + tcp_skb_timestamp_us(skb), + tp->rack.end_seq, scb->end_seq)) + break; + + /* A packet is lost if it has not been s/acked beyond + * the recent RTT plus the reordering window. + */ + remaining = tcp_rack_skb_timeout(tp, skb, reo_wnd); + if (remaining <= 0) { + tcp_mark_skb_lost(sk, skb); + list_del_init(&skb->tcp_tsorted_anchor); + } else { + /* Record maximum wait time */ + *reo_timeout = max_t(u32, *reo_timeout, remaining); + } + } +} + +bool tcp_rack_mark_lost(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 timeout; + + if (!tp->rack.advanced) + return false; + + /* Reset the advanced flag to avoid unnecessary queue scanning */ + tp->rack.advanced = 0; + tcp_rack_detect_loss(sk, &timeout); + if (timeout) { + timeout = usecs_to_jiffies(timeout + TCP_TIMEOUT_MIN_US); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_REO_TIMEOUT, + timeout, inet_csk(sk)->icsk_rto); + } + return !!timeout; +} + +/* Record the most recently (re)sent time among the (s)acked packets + * This is "Step 3: Advance RACK.xmit_time and update RACK.RTT" from + * draft-cheng-tcpm-rack-00.txt + */ +void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, + u64 xmit_time) +{ + u32 rtt_us; + + rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, xmit_time); + if (rtt_us < tcp_min_rtt(tp) && (sacked & TCPCB_RETRANS)) { + /* If the sacked packet was retransmitted, it's ambiguous + * whether the retransmission or the original (or the prior + * retransmission) was sacked. + * + * If the original is lost, there is no ambiguity. Otherwise + * we assume the original can be delayed up to aRTT + min_rtt. + * the aRTT term is bounded by the fast recovery or timeout, + * so it's at least one RTT (i.e., retransmission is at least + * an RTT later). + */ + return; + } + tp->rack.advanced = 1; + tp->rack.rtt_us = rtt_us; + if (tcp_rack_sent_after(xmit_time, tp->rack.mstamp, + end_seq, tp->rack.end_seq)) { + tp->rack.mstamp = xmit_time; + tp->rack.end_seq = end_seq; + } +} + +/* We have waited long enough to accommodate reordering. Mark the expired + * packets lost and retransmit them. + */ +void tcp_rack_reo_timeout(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + u32 timeout, prior_inflight; + + prior_inflight = tcp_packets_in_flight(tp); + tcp_rack_detect_loss(sk, &timeout); + if (prior_inflight != tcp_packets_in_flight(tp)) { + if (inet_csk(sk)->icsk_ca_state != TCP_CA_Recovery) { + tcp_enter_recovery(sk, false); + if (!inet_csk(sk)->icsk_ca_ops->cong_control) + tcp_cwnd_reduction(sk, 1, 0); + } + tcp_xmit_retransmit_queue(sk); + } + if (inet_csk(sk)->icsk_pending != ICSK_TIME_RETRANS) + tcp_rearm_rto(sk); +} + +/* Updates the RACK's reo_wnd based on DSACK and no. of recoveries. + * + * If DSACK is received, increment reo_wnd by min_rtt/4 (upper bounded + * by srtt), since there is possibility that spurious retransmission was + * due to reordering delay longer than reo_wnd. + * + * Persist the current reo_wnd value for TCP_RACK_RECOVERY_THRESH (16) + * no. of successful recoveries (accounts for full DSACK-based loss + * recovery undo). After that, reset it to default (min_rtt/4). + * + * At max, reo_wnd is incremented only once per rtt. So that the new + * DSACK on which we are reacting, is due to the spurious retx (approx) + * after the reo_wnd has been updated last time. + * + * reo_wnd is tracked in terms of steps (of min_rtt/4), rather than + * absolute value to account for change in rtt. + */ +void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if ((READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_STATIC_REO_WND) || + !rs->prior_delivered) + return; + + /* Disregard DSACK if a rtt has not passed since we adjusted reo_wnd */ + if (before(rs->prior_delivered, tp->rack.last_delivered)) + tp->rack.dsack_seen = 0; + + /* Adjust the reo_wnd if update is pending */ + if (tp->rack.dsack_seen) { + tp->rack.reo_wnd_steps = min_t(u32, 0xFF, + tp->rack.reo_wnd_steps + 1); + tp->rack.dsack_seen = 0; + tp->rack.last_delivered = tp->delivered; + tp->rack.reo_wnd_persist = TCP_RACK_RECOVERY_THRESH; + } else if (!tp->rack.reo_wnd_persist) { + tp->rack.reo_wnd_steps = 1; + } +} + +/* RFC6582 NewReno recovery for non-SACK connection. It simply retransmits + * the next unacked packet upon receiving + * a) three or more DUPACKs to start the fast recovery + * b) an ACK acknowledging new data during the fast recovery. + */ +void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced) +{ + const u8 state = inet_csk(sk)->icsk_ca_state; + struct tcp_sock *tp = tcp_sk(sk); + + if ((state < TCP_CA_Recovery && tp->sacked_out >= tp->reordering) || + (state == TCP_CA_Recovery && snd_una_advanced)) { + struct sk_buff *skb = tcp_rtx_queue_head(sk); + u32 mss; + + if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) + return; + + mss = tcp_skb_mss(skb); + if (tcp_skb_pcount(skb) > 1 && skb->len > mss) + tcp_fragment(sk, TCP_FRAG_IN_RTX_QUEUE, skb, + mss, mss, GFP_ATOMIC); + + tcp_mark_skb_lost(sk, skb); + } +} diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c new file mode 100644 index 000000000..5842081bc --- /dev/null +++ b/net/ipv4/tcp_scalable.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Tom Kelly's Scalable TCP + * + * See http://www.deneholme.net/tom/scalable/ + * + * John Heffner <jheffner@sc.edu> + */ + +#include <linux/module.h> +#include <net/tcp.h> + +/* These factors derived from the recommended values in the aer: + * .01 and 7/8. + */ +#define TCP_SCALABLE_AI_CNT 100U +#define TCP_SCALABLE_MD_SCALE 3 + +static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (!tcp_is_cwnd_limited(sk)) + return; + + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + return; + } + tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT), + acked); +} + +static u32 tcp_scalable_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + + return max(tp->snd_cwnd - (tp->snd_cwnd>>TCP_SCALABLE_MD_SCALE), 2U); +} + +static struct tcp_congestion_ops tcp_scalable __read_mostly = { + .ssthresh = tcp_scalable_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = tcp_scalable_cong_avoid, + + .owner = THIS_MODULE, + .name = "scalable", +}; + +static int __init tcp_scalable_register(void) +{ + return tcp_register_congestion_control(&tcp_scalable); +} + +static void __exit tcp_scalable_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_scalable); +} + +module_init(tcp_scalable_register); +module_exit(tcp_scalable_unregister); + +MODULE_AUTHOR("John Heffner"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Scalable TCP"); diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c new file mode 100644 index 000000000..5c7e10939 --- /dev/null +++ b/net/ipv4/tcp_timer.c @@ -0,0 +1,820 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Implementation of the Transmission Control Protocol(TCP). + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * Corey Minyard <wf-rch!minyard@relay.EU.net> + * Florian La Roche, <flla@stud.uni-sb.de> + * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> + * Linus Torvalds, <torvalds@cs.helsinki.fi> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Matthew Dillon, <dillon@apollo.west.oic.com> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Jorge Cwik, <jorge@laser.satlink.net> + */ + +#include <linux/module.h> +#include <linux/gfp.h> +#include <net/tcp.h> + +static u32 tcp_clamp_rto_to_user_timeout(const struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + u32 elapsed, start_ts; + s32 remaining; + + start_ts = tcp_sk(sk)->retrans_stamp; + if (!icsk->icsk_user_timeout) + return icsk->icsk_rto; + elapsed = tcp_time_stamp(tcp_sk(sk)) - start_ts; + remaining = icsk->icsk_user_timeout - elapsed; + if (remaining <= 0) + return 1; /* user timeout has passed; fire ASAP */ + + return min_t(u32, icsk->icsk_rto, msecs_to_jiffies(remaining)); +} + +u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + u32 remaining; + s32 elapsed; + + if (!icsk->icsk_user_timeout || !icsk->icsk_probes_tstamp) + return when; + + elapsed = tcp_jiffies32 - icsk->icsk_probes_tstamp; + if (unlikely(elapsed < 0)) + elapsed = 0; + remaining = msecs_to_jiffies(icsk->icsk_user_timeout) - elapsed; + remaining = max_t(u32, remaining, TCP_TIMEOUT_MIN); + + return min_t(u32, remaining, when); +} + +/** + * tcp_write_err() - close socket and save error info + * @sk: The socket the error has appeared on. + * + * Returns: Nothing (void) + */ + +static void tcp_write_err(struct sock *sk) +{ + sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT; + sk->sk_error_report(sk); + + tcp_write_queue_purge(sk); + tcp_done(sk); + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONTIMEOUT); +} + +/** + * tcp_out_of_resources() - Close socket if out of resources + * @sk: pointer to current socket + * @do_reset: send a last packet with reset flag + * + * Do not allow orphaned sockets to eat all our resources. + * This is direct violation of TCP specs, but it is required + * to prevent DoS attacks. It is called when a retransmission timeout + * or zero probe timeout occurs on orphaned socket. + * + * Also close if our net namespace is exiting; in that case there is no + * hope of ever communicating again since all netns interfaces are already + * down (or about to be down), and we need to release our dst references, + * which have been moved to the netns loopback interface, so the namespace + * can finish exiting. This condition is only possible if we are a kernel + * socket, as those do not hold references to the namespace. + * + * Criteria is still not confirmed experimentally and may change. + * We kill the socket, if: + * 1. If number of orphaned sockets exceeds an administratively configured + * limit. + * 2. If we have strong memory pressure. + * 3. If our net namespace is exiting. + */ +static int tcp_out_of_resources(struct sock *sk, bool do_reset) +{ + struct tcp_sock *tp = tcp_sk(sk); + int shift = 0; + + /* If peer does not open window for long time, or did not transmit + * anything for long time, penalize it. */ + if ((s32)(tcp_jiffies32 - tp->lsndtime) > 2*TCP_RTO_MAX || !do_reset) + shift++; + + /* If some dubious ICMP arrived, penalize even more. */ + if (sk->sk_err_soft) + shift++; + + if (tcp_check_oom(sk, shift)) { + /* Catch exceptional cases, when connection requires reset. + * 1. Last segment was sent recently. */ + if ((s32)(tcp_jiffies32 - tp->lsndtime) <= TCP_TIMEWAIT_LEN || + /* 2. Window is closed. */ + (!tp->snd_wnd && !tp->packets_out)) + do_reset = true; + if (do_reset) + tcp_send_active_reset(sk, GFP_ATOMIC); + tcp_done(sk); + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONMEMORY); + return 1; + } + + if (!check_net(sock_net(sk))) { + /* Not possible to send reset; just close */ + tcp_done(sk); + return 1; + } + + return 0; +} + +/** + * tcp_orphan_retries() - Returns maximal number of retries on an orphaned socket + * @sk: Pointer to the current socket. + * @alive: bool, socket alive state + */ +static int tcp_orphan_retries(struct sock *sk, bool alive) +{ + int retries = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_orphan_retries); /* May be zero. */ + + /* We know from an ICMP that something is wrong. */ + if (sk->sk_err_soft && !alive) + retries = 0; + + /* However, if socket sent something recently, select some safe + * number of retries. 8 corresponds to >100 seconds with minimal + * RTO of 200msec. */ + if (retries == 0 && alive) + retries = 8; + return retries; +} + +static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk) +{ + const struct net *net = sock_net(sk); + int mss; + + /* Black hole detection */ + if (!READ_ONCE(net->ipv4.sysctl_tcp_mtu_probing)) + return; + + if (!icsk->icsk_mtup.enabled) { + icsk->icsk_mtup.enabled = 1; + icsk->icsk_mtup.probe_timestamp = tcp_jiffies32; + } else { + mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1; + mss = min(READ_ONCE(net->ipv4.sysctl_tcp_base_mss), mss); + mss = max(mss, READ_ONCE(net->ipv4.sysctl_tcp_mtu_probe_floor)); + mss = max(mss, READ_ONCE(net->ipv4.sysctl_tcp_min_snd_mss)); + icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss); + } + tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); +} + +static unsigned int tcp_model_timeout(struct sock *sk, + unsigned int boundary, + unsigned int rto_base) +{ + unsigned int linear_backoff_thresh, timeout; + + linear_backoff_thresh = ilog2(TCP_RTO_MAX / rto_base); + if (boundary <= linear_backoff_thresh) + timeout = ((2 << boundary) - 1) * rto_base; + else + timeout = ((2 << linear_backoff_thresh) - 1) * rto_base + + (boundary - linear_backoff_thresh) * TCP_RTO_MAX; + return jiffies_to_msecs(timeout); +} +/** + * retransmits_timed_out() - returns true if this connection has timed out + * @sk: The current socket + * @boundary: max number of retransmissions + * @timeout: A custom timeout value. + * If set to 0 the default timeout is calculated and used. + * Using TCP_RTO_MIN and the number of unsuccessful retransmits. + * + * The default "timeout" value this function can calculate and use + * is equivalent to the timeout of a TCP Connection + * after "boundary" unsuccessful, exponentially backed-off + * retransmissions with an initial RTO of TCP_RTO_MIN. + */ +static bool retransmits_timed_out(struct sock *sk, + unsigned int boundary, + unsigned int timeout) +{ + unsigned int start_ts; + + if (!inet_csk(sk)->icsk_retransmits) + return false; + + start_ts = tcp_sk(sk)->retrans_stamp; + if (likely(timeout == 0)) { + unsigned int rto_base = TCP_RTO_MIN; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) + rto_base = tcp_timeout_init(sk); + timeout = tcp_model_timeout(sk, boundary, rto_base); + } + + return (s32)(tcp_time_stamp(tcp_sk(sk)) - start_ts - timeout) >= 0; +} + +/* A write timeout has occurred. Process the after effects. */ +static int tcp_write_timeout(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + bool expired = false, do_reset; + int retry_until; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { + if (icsk->icsk_retransmits) + __dst_negative_advice(sk); + retry_until = icsk->icsk_syn_retries ? : + READ_ONCE(net->ipv4.sysctl_tcp_syn_retries); + expired = icsk->icsk_retransmits >= retry_until; + } else { + if (retransmits_timed_out(sk, READ_ONCE(net->ipv4.sysctl_tcp_retries1), 0)) { + /* Black hole detection */ + tcp_mtu_probing(icsk, sk); + + __dst_negative_advice(sk); + } + + retry_until = READ_ONCE(net->ipv4.sysctl_tcp_retries2); + if (sock_flag(sk, SOCK_DEAD)) { + const bool alive = icsk->icsk_rto < TCP_RTO_MAX; + + retry_until = tcp_orphan_retries(sk, alive); + do_reset = alive || + !retransmits_timed_out(sk, retry_until, 0); + + if (tcp_out_of_resources(sk, do_reset)) + return 1; + } + } + if (!expired) + expired = retransmits_timed_out(sk, retry_until, + icsk->icsk_user_timeout); + tcp_fastopen_active_detect_blackhole(sk, expired); + + if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RTO_CB_FLAG)) + tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RTO_CB, + icsk->icsk_retransmits, + icsk->icsk_rto, (int)expired); + + if (expired) { + /* Has it gone just too far? */ + tcp_write_err(sk); + return 1; + } + + if (sk_rethink_txhash(sk)) { + tp->timeout_rehash++; + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPTIMEOUTREHASH); + } + + return 0; +} + +/* Called with BH disabled */ +void tcp_delack_timer_handler(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + sk_mem_reclaim_partial(sk); + + if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) || + !(icsk->icsk_ack.pending & ICSK_ACK_TIMER)) + goto out; + + if (time_after(icsk->icsk_ack.timeout, jiffies)) { + sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); + goto out; + } + icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER; + + if (inet_csk_ack_scheduled(sk)) { + if (!inet_csk_in_pingpong_mode(sk)) { + /* Delayed ACK missed: inflate ATO. */ + icsk->icsk_ack.ato = min(icsk->icsk_ack.ato << 1, icsk->icsk_rto); + } else { + /* Delayed ACK missed: leave pingpong mode and + * deflate ATO. + */ + inet_csk_exit_pingpong_mode(sk); + icsk->icsk_ack.ato = TCP_ATO_MIN; + } + tcp_mstamp_refresh(tcp_sk(sk)); + tcp_send_ack(sk); + __NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKS); + } + +out: + if (tcp_under_memory_pressure(sk)) + sk_mem_reclaim(sk); +} + + +/** + * tcp_delack_timer() - The TCP delayed ACK timeout handler + * @t: Pointer to the timer. (gets casted to struct sock *) + * + * This function gets (indirectly) called when the kernel timer for a TCP packet + * of this socket expires. Calls tcp_delack_timer_handler() to do the actual work. + * + * Returns: Nothing (void) + */ +static void tcp_delack_timer(struct timer_list *t) +{ + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_delack_timer); + struct sock *sk = &icsk->icsk_inet.sk; + + bh_lock_sock(sk); + if (!sock_owned_by_user(sk)) { + tcp_delack_timer_handler(sk); + } else { + __NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED); + /* deleguate our work to tcp_release_cb() */ + if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, &sk->sk_tsq_flags)) + sock_hold(sk); + } + bh_unlock_sock(sk); + sock_put(sk); +} + +static void tcp_probe_timer(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct sk_buff *skb = tcp_send_head(sk); + struct tcp_sock *tp = tcp_sk(sk); + int max_probes; + + if (tp->packets_out || !skb) { + icsk->icsk_probes_out = 0; + icsk->icsk_probes_tstamp = 0; + return; + } + + /* RFC 1122 4.2.2.17 requires the sender to stay open indefinitely as + * long as the receiver continues to respond probes. We support this by + * default and reset icsk_probes_out with incoming ACKs. But if the + * socket is orphaned or the user specifies TCP_USER_TIMEOUT, we + * kill the socket when the retry count and the time exceeds the + * corresponding system limit. We also implement similar policy when + * we use RTO to probe window in tcp_retransmit_timer(). + */ + if (!icsk->icsk_probes_tstamp) + icsk->icsk_probes_tstamp = tcp_jiffies32; + else if (icsk->icsk_user_timeout && + (s32)(tcp_jiffies32 - icsk->icsk_probes_tstamp) >= + msecs_to_jiffies(icsk->icsk_user_timeout)) + goto abort; + + max_probes = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retries2); + if (sock_flag(sk, SOCK_DEAD)) { + const bool alive = inet_csk_rto_backoff(icsk, TCP_RTO_MAX) < TCP_RTO_MAX; + + max_probes = tcp_orphan_retries(sk, alive); + if (!alive && icsk->icsk_backoff >= max_probes) + goto abort; + if (tcp_out_of_resources(sk, true)) + return; + } + + if (icsk->icsk_probes_out >= max_probes) { +abort: tcp_write_err(sk); + } else { + /* Only send another probe if we didn't close things up. */ + tcp_send_probe0(sk); + } +} + +/* + * Timer for Fast Open socket to retransmit SYNACK. Note that the + * sk here is the child socket, not the parent (listener) socket. + */ +static void tcp_fastopen_synack_timer(struct sock *sk, struct request_sock *req) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + int max_retries; + + req->rsk_ops->syn_ack_timeout(req); + + /* add one more retry for fastopen */ + max_retries = icsk->icsk_syn_retries ? : + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_synack_retries) + 1; + + if (req->num_timeout >= max_retries) { + tcp_write_err(sk); + return; + } + /* Lower cwnd after certain SYNACK timeout like tcp_init_transfer() */ + if (icsk->icsk_retransmits == 1) + tcp_enter_loss(sk); + /* XXX (TFO) - Unlike regular SYN-ACK retransmit, we ignore error + * returned from rtx_syn_ack() to make it more persistent like + * regular retransmit because if the child socket has been accepted + * it's not good to give up too easily. + */ + inet_rtx_syn_ack(sk, req); + req->num_timeout++; + icsk->icsk_retransmits++; + if (!tp->retrans_stamp) + tp->retrans_stamp = tcp_time_stamp(tp); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); +} + +static bool tcp_rtx_probe0_timed_out(const struct sock *sk, + const struct sk_buff *skb) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const int timeout = TCP_RTO_MAX * 2; + u32 rcv_delta, rtx_delta; + + rcv_delta = inet_csk(sk)->icsk_timeout - tp->rcv_tstamp; + if (rcv_delta <= timeout) + return false; + + rtx_delta = (u32)msecs_to_jiffies(tcp_time_stamp(tp) - + (tp->retrans_stamp ?: tcp_skb_timestamp(skb))); + + return rtx_delta > timeout; +} + +/** + * tcp_retransmit_timer() - The TCP retransmit timeout handler + * @sk: Pointer to the current socket. + * + * This function gets called when the kernel timer for a TCP packet + * of this socket expires. + * + * It handles retransmission, timer adjustment and other necesarry measures. + * + * Returns: Nothing (void) + */ +void tcp_retransmit_timer(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + struct request_sock *req; + struct sk_buff *skb; + + req = rcu_dereference_protected(tp->fastopen_rsk, + lockdep_sock_is_held(sk)); + if (req) { + WARN_ON_ONCE(sk->sk_state != TCP_SYN_RECV && + sk->sk_state != TCP_FIN_WAIT1); + tcp_fastopen_synack_timer(sk, req); + /* Before we receive ACK to our SYN-ACK don't retransmit + * anything else (e.g., data or FIN segments). + */ + return; + } + + if (!tp->packets_out) + return; + + skb = tcp_rtx_queue_head(sk); + if (WARN_ON_ONCE(!skb)) + return; + + tp->tlp_high_seq = 0; + + if (!tp->snd_wnd && !sock_flag(sk, SOCK_DEAD) && + !((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))) { + /* Receiver dastardly shrinks window. Our retransmits + * become zero probes, but we should not timeout this + * connection. If the socket is an orphan, time it out, + * we cannot allow such beasts to hang infinitely. + */ + struct inet_sock *inet = inet_sk(sk); + if (sk->sk_family == AF_INET) { + net_dbg_ratelimited("Peer %pI4:%u/%u unexpectedly shrunk window %u:%u (repaired)\n", + &inet->inet_daddr, + ntohs(inet->inet_dport), + inet->inet_num, + tp->snd_una, tp->snd_nxt); + } +#if IS_ENABLED(CONFIG_IPV6) + else if (sk->sk_family == AF_INET6) { + net_dbg_ratelimited("Peer %pI6:%u/%u unexpectedly shrunk window %u:%u (repaired)\n", + &sk->sk_v6_daddr, + ntohs(inet->inet_dport), + inet->inet_num, + tp->snd_una, tp->snd_nxt); + } +#endif + if (tcp_rtx_probe0_timed_out(sk, skb)) { + tcp_write_err(sk); + goto out; + } + tcp_enter_loss(sk); + tcp_retransmit_skb(sk, skb, 1); + __sk_dst_reset(sk); + goto out_reset_timer; + } + + __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPTIMEOUTS); + if (tcp_write_timeout(sk)) + goto out; + + if (icsk->icsk_retransmits == 0) { + int mib_idx = 0; + + if (icsk->icsk_ca_state == TCP_CA_Recovery) { + if (tcp_is_sack(tp)) + mib_idx = LINUX_MIB_TCPSACKRECOVERYFAIL; + else + mib_idx = LINUX_MIB_TCPRENORECOVERYFAIL; + } else if (icsk->icsk_ca_state == TCP_CA_Loss) { + mib_idx = LINUX_MIB_TCPLOSSFAILURES; + } else if ((icsk->icsk_ca_state == TCP_CA_Disorder) || + tp->sacked_out) { + if (tcp_is_sack(tp)) + mib_idx = LINUX_MIB_TCPSACKFAILURES; + else + mib_idx = LINUX_MIB_TCPRENOFAILURES; + } + if (mib_idx) + __NET_INC_STATS(sock_net(sk), mib_idx); + } + + tcp_enter_loss(sk); + + icsk->icsk_retransmits++; + if (tcp_retransmit_skb(sk, tcp_rtx_queue_head(sk), 1) > 0) { + /* Retransmission failed because of local congestion, + * Let senders fight for local resources conservatively. + */ + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + TCP_RESOURCE_PROBE_INTERVAL, + TCP_RTO_MAX); + goto out; + } + + /* Increase the timeout each time we retransmit. Note that + * we do not increase the rtt estimate. rto is initialized + * from rtt, but increases here. Jacobson (SIGCOMM 88) suggests + * that doubling rto each time is the least we can get away with. + * In KA9Q, Karn uses this for the first few times, and then + * goes to quadratic. netBSD doubles, but only goes up to *64, + * and clamps at 1 to 64 sec afterwards. Note that 120 sec is + * defined in the protocol as the maximum possible RTT. I guess + * we'll have to use something other than TCP to talk to the + * University of Mars. + * + * PAWS allows us longer timeouts and large windows, so once + * implemented ftp to mars will work nicely. We will have to fix + * the 120 second clamps though! + */ + icsk->icsk_backoff++; + +out_reset_timer: + /* If stream is thin, use linear timeouts. Since 'icsk_backoff' is + * used to reset timer, set to 0. Recalculate 'icsk_rto' as this + * might be increased if the stream oscillates between thin and thick, + * thus the old value might already be too high compared to the value + * set by 'tcp_set_rto' in tcp_input.c which resets the rto without + * backoff. Limit to TCP_THIN_LINEAR_RETRIES before initiating + * exponential backoff behaviour to avoid continue hammering + * linear-timeout retransmissions into a black hole + */ + if (sk->sk_state == TCP_ESTABLISHED && + (tp->thin_lto || READ_ONCE(net->ipv4.sysctl_tcp_thin_linear_timeouts)) && + tcp_stream_is_thin(tp) && + icsk->icsk_retransmits <= TCP_THIN_LINEAR_RETRIES) { + icsk->icsk_backoff = 0; + icsk->icsk_rto = clamp(__tcp_set_rto(tp), + tcp_rto_min(sk), + TCP_RTO_MAX); + } else { + /* Use normal (exponential) backoff */ + icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX); + } + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + tcp_clamp_rto_to_user_timeout(sk), TCP_RTO_MAX); + if (retransmits_timed_out(sk, READ_ONCE(net->ipv4.sysctl_tcp_retries1) + 1, 0)) + __sk_dst_reset(sk); + +out:; +} + +/* Called with bottom-half processing disabled. + Called by tcp_write_timer() */ +void tcp_write_timer_handler(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + int event; + + if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) || + !icsk->icsk_pending) + goto out; + + if (time_after(icsk->icsk_timeout, jiffies)) { + sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); + goto out; + } + + tcp_mstamp_refresh(tcp_sk(sk)); + event = icsk->icsk_pending; + + switch (event) { + case ICSK_TIME_REO_TIMEOUT: + tcp_rack_reo_timeout(sk); + break; + case ICSK_TIME_LOSS_PROBE: + tcp_send_loss_probe(sk); + break; + case ICSK_TIME_RETRANS: + icsk->icsk_pending = 0; + tcp_retransmit_timer(sk); + break; + case ICSK_TIME_PROBE0: + icsk->icsk_pending = 0; + tcp_probe_timer(sk); + break; + } + +out: + sk_mem_reclaim(sk); +} + +static void tcp_write_timer(struct timer_list *t) +{ + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_retransmit_timer); + struct sock *sk = &icsk->icsk_inet.sk; + + bh_lock_sock(sk); + if (!sock_owned_by_user(sk)) { + tcp_write_timer_handler(sk); + } else { + /* delegate our work to tcp_release_cb() */ + if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &sk->sk_tsq_flags)) + sock_hold(sk); + } + bh_unlock_sock(sk); + sock_put(sk); +} + +void tcp_syn_ack_timeout(const struct request_sock *req) +{ + struct net *net = read_pnet(&inet_rsk(req)->ireq_net); + + __NET_INC_STATS(net, LINUX_MIB_TCPTIMEOUTS); +} +EXPORT_SYMBOL(tcp_syn_ack_timeout); + +void tcp_set_keepalive(struct sock *sk, int val) +{ + if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) + return; + + if (val && !sock_flag(sk, SOCK_KEEPOPEN)) + inet_csk_reset_keepalive_timer(sk, keepalive_time_when(tcp_sk(sk))); + else if (!val) + inet_csk_delete_keepalive_timer(sk); +} +EXPORT_SYMBOL_GPL(tcp_set_keepalive); + + +static void tcp_keepalive_timer (struct timer_list *t) +{ + struct sock *sk = from_timer(sk, t, sk_timer); + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + u32 elapsed; + + /* Only process if socket is not in use. */ + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + /* Try again later. */ + inet_csk_reset_keepalive_timer (sk, HZ/20); + goto out; + } + + if (sk->sk_state == TCP_LISTEN) { + pr_err("Hmm... keepalive on a LISTEN ???\n"); + goto out; + } + + tcp_mstamp_refresh(tp); + if (sk->sk_state == TCP_FIN_WAIT2 && sock_flag(sk, SOCK_DEAD)) { + if (tp->linger2 >= 0) { + const int tmo = tcp_fin_time(sk) - TCP_TIMEWAIT_LEN; + + if (tmo > 0) { + tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); + goto out; + } + } + tcp_send_active_reset(sk, GFP_ATOMIC); + goto death; + } + + if (!sock_flag(sk, SOCK_KEEPOPEN) || + ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT))) + goto out; + + elapsed = keepalive_time_when(tp); + + /* It is alive without keepalive 8) */ + if (tp->packets_out || !tcp_write_queue_empty(sk)) + goto resched; + + elapsed = keepalive_time_elapsed(tp); + + if (elapsed >= keepalive_time_when(tp)) { + /* If the TCP_USER_TIMEOUT option is enabled, use that + * to determine when to timeout instead. + */ + if ((icsk->icsk_user_timeout != 0 && + elapsed >= msecs_to_jiffies(icsk->icsk_user_timeout) && + icsk->icsk_probes_out > 0) || + (icsk->icsk_user_timeout == 0 && + icsk->icsk_probes_out >= keepalive_probes(tp))) { + tcp_send_active_reset(sk, GFP_ATOMIC); + tcp_write_err(sk); + goto out; + } + if (tcp_write_wakeup(sk, LINUX_MIB_TCPKEEPALIVE) <= 0) { + icsk->icsk_probes_out++; + elapsed = keepalive_intvl_when(tp); + } else { + /* If keepalive was lost due to local congestion, + * try harder. + */ + elapsed = TCP_RESOURCE_PROBE_INTERVAL; + } + } else { + /* It is tp->rcv_tstamp + keepalive_time_when(tp) */ + elapsed = keepalive_time_when(tp) - elapsed; + } + + sk_mem_reclaim(sk); + +resched: + inet_csk_reset_keepalive_timer (sk, elapsed); + goto out; + +death: + tcp_done(sk); + +out: + bh_unlock_sock(sk); + sock_put(sk); +} + +static enum hrtimer_restart tcp_compressed_ack_kick(struct hrtimer *timer) +{ + struct tcp_sock *tp = container_of(timer, struct tcp_sock, compressed_ack_timer); + struct sock *sk = (struct sock *)tp; + + bh_lock_sock(sk); + if (!sock_owned_by_user(sk)) { + if (tp->compressed_ack) { + /* Since we have to send one ack finally, + * substract one from tp->compressed_ack to keep + * LINUX_MIB_TCPACKCOMPRESSED accurate. + */ + tp->compressed_ack--; + tcp_send_ack(sk); + } + } else { + if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, + &sk->sk_tsq_flags)) + sock_hold(sk); + } + bh_unlock_sock(sk); + + sock_put(sk); + + return HRTIMER_NORESTART; +} + +void tcp_init_xmit_timers(struct sock *sk) +{ + inet_csk_init_xmit_timers(sk, &tcp_write_timer, &tcp_delack_timer, + &tcp_keepalive_timer); + hrtimer_init(&tcp_sk(sk)->pacing_timer, CLOCK_MONOTONIC, + HRTIMER_MODE_ABS_PINNED_SOFT); + tcp_sk(sk)->pacing_timer.function = tcp_pace_kick; + + hrtimer_init(&tcp_sk(sk)->compressed_ack_timer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_PINNED_SOFT); + tcp_sk(sk)->compressed_ack_timer.function = tcp_compressed_ack_kick; +} diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c new file mode 100644 index 000000000..8e135af0d --- /dev/null +++ b/net/ipv4/tcp_ulp.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Pluggable TCP upper layer protocol support. + * + * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved. + * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved. + * + */ + +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/gfp.h> +#include <net/tcp.h> + +static DEFINE_SPINLOCK(tcp_ulp_list_lock); +static LIST_HEAD(tcp_ulp_list); + +/* Simple linear search, don't expect many entries! */ +static struct tcp_ulp_ops *tcp_ulp_find(const char *name) +{ + struct tcp_ulp_ops *e; + + list_for_each_entry_rcu(e, &tcp_ulp_list, list, + lockdep_is_held(&tcp_ulp_list_lock)) { + if (strcmp(e->name, name) == 0) + return e; + } + + return NULL; +} + +static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name) +{ + const struct tcp_ulp_ops *ulp = NULL; + + rcu_read_lock(); + ulp = tcp_ulp_find(name); + +#ifdef CONFIG_MODULES + if (!ulp && capable(CAP_NET_ADMIN)) { + rcu_read_unlock(); + request_module("tcp-ulp-%s", name); + rcu_read_lock(); + ulp = tcp_ulp_find(name); + } +#endif + if (!ulp || !try_module_get(ulp->owner)) + ulp = NULL; + + rcu_read_unlock(); + return ulp; +} + +/* Attach new upper layer protocol to the list + * of available protocols. + */ +int tcp_register_ulp(struct tcp_ulp_ops *ulp) +{ + int ret = 0; + + spin_lock(&tcp_ulp_list_lock); + if (tcp_ulp_find(ulp->name)) + ret = -EEXIST; + else + list_add_tail_rcu(&ulp->list, &tcp_ulp_list); + spin_unlock(&tcp_ulp_list_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(tcp_register_ulp); + +void tcp_unregister_ulp(struct tcp_ulp_ops *ulp) +{ + spin_lock(&tcp_ulp_list_lock); + list_del_rcu(&ulp->list); + spin_unlock(&tcp_ulp_list_lock); + + synchronize_rcu(); +} +EXPORT_SYMBOL_GPL(tcp_unregister_ulp); + +/* Build string with list of available upper layer protocl values */ +void tcp_get_available_ulp(char *buf, size_t maxlen) +{ + struct tcp_ulp_ops *ulp_ops; + size_t offs = 0; + + *buf = '\0'; + rcu_read_lock(); + list_for_each_entry_rcu(ulp_ops, &tcp_ulp_list, list) { + offs += snprintf(buf + offs, maxlen - offs, + "%s%s", + offs == 0 ? "" : " ", ulp_ops->name); + + if (WARN_ON_ONCE(offs >= maxlen)) + break; + } + rcu_read_unlock(); +} + +void tcp_update_ulp(struct sock *sk, struct proto *proto, + void (*write_space)(struct sock *sk)) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ulp_ops->update) + icsk->icsk_ulp_ops->update(sk, proto, write_space); +} + +void tcp_cleanup_ulp(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + /* No sock_owned_by_me() check here as at the time the + * stack calls this function, the socket is dead and + * about to be destroyed. + */ + if (!icsk->icsk_ulp_ops) + return; + + if (icsk->icsk_ulp_ops->release) + icsk->icsk_ulp_ops->release(sk); + module_put(icsk->icsk_ulp_ops->owner); + + icsk->icsk_ulp_ops = NULL; +} + +static int __tcp_set_ulp(struct sock *sk, const struct tcp_ulp_ops *ulp_ops) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + int err; + + err = -EEXIST; + if (icsk->icsk_ulp_ops) + goto out_err; + + err = -ENOTCONN; + if (!ulp_ops->clone && sk->sk_state == TCP_LISTEN) + goto out_err; + + err = ulp_ops->init(sk); + if (err) + goto out_err; + + icsk->icsk_ulp_ops = ulp_ops; + return 0; +out_err: + module_put(ulp_ops->owner); + return err; +} + +int tcp_set_ulp(struct sock *sk, const char *name) +{ + const struct tcp_ulp_ops *ulp_ops; + + sock_owned_by_me(sk); + + ulp_ops = __tcp_ulp_find_autoload(name); + if (!ulp_ops) + return -ENOENT; + + return __tcp_set_ulp(sk, ulp_ops); +} diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c new file mode 100644 index 000000000..c8003c8aa --- /dev/null +++ b/net/ipv4/tcp_vegas.c @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP Vegas congestion control + * + * This is based on the congestion detection/avoidance scheme described in + * Lawrence S. Brakmo and Larry L. Peterson. + * "TCP Vegas: End to end congestion avoidance on a global internet." + * IEEE Journal on Selected Areas in Communication, 13(8):1465--1480, + * October 1995. Available from: + * ftp://ftp.cs.arizona.edu/xkernel/Papers/jsac.ps + * + * See http://www.cs.arizona.edu/xkernel/ for their implementation. + * The main aspects that distinguish this implementation from the + * Arizona Vegas implementation are: + * o We do not change the loss detection or recovery mechanisms of + * Linux in any way. Linux already recovers from losses quite well, + * using fine-grained timers, NewReno, and FACK. + * o To avoid the performance penalty imposed by increasing cwnd + * only every-other RTT during slow start, we increase during + * every RTT during slow start, just like Reno. + * o Largely to allow continuous cwnd growth during slow start, + * we use the rate at which ACKs come back as the "actual" + * rate, rather than the rate at which data is sent. + * o To speed convergence to the right rate, we set the cwnd + * to achieve the right ("actual") rate when we exit slow start. + * o To filter out the noise caused by delayed ACKs, we use the + * minimum RTT sample observed during the last RTT to calculate + * the actual rate. + * o When the sender re-starts from idle, it waits until it has + * received ACKs for an entire flight of new data before making + * a cwnd adjustment decision. The original Vegas implementation + * assumed senders never went idle. + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/inet_diag.h> + +#include <net/tcp.h> + +#include "tcp_vegas.h" + +static int alpha = 2; +static int beta = 4; +static int gamma = 1; + +module_param(alpha, int, 0644); +MODULE_PARM_DESC(alpha, "lower bound of packets in network"); +module_param(beta, int, 0644); +MODULE_PARM_DESC(beta, "upper bound of packets in network"); +module_param(gamma, int, 0644); +MODULE_PARM_DESC(gamma, "limit on increase (scale by 2)"); + +/* There are several situations when we must "re-start" Vegas: + * + * o when a connection is established + * o after an RTO + * o after fast recovery + * o when we send a packet and there is no outstanding + * unacknowledged data (restarting an idle connection) + * + * In these circumstances we cannot do a Vegas calculation at the + * end of the first RTT, because any calculation we do is using + * stale info -- both the saved cwnd and congestion feedback are + * stale. + * + * Instead we must wait until the completion of an RTT during + * which we actually receive ACKs. + */ +static void vegas_enable(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct vegas *vegas = inet_csk_ca(sk); + + /* Begin taking Vegas samples next time we send something. */ + vegas->doing_vegas_now = 1; + + /* Set the beginning of the next send window. */ + vegas->beg_snd_nxt = tp->snd_nxt; + + vegas->cntRTT = 0; + vegas->minRTT = 0x7fffffff; +} + +/* Stop taking Vegas samples for now. */ +static inline void vegas_disable(struct sock *sk) +{ + struct vegas *vegas = inet_csk_ca(sk); + + vegas->doing_vegas_now = 0; +} + +void tcp_vegas_init(struct sock *sk) +{ + struct vegas *vegas = inet_csk_ca(sk); + + vegas->baseRTT = 0x7fffffff; + vegas_enable(sk); +} +EXPORT_SYMBOL_GPL(tcp_vegas_init); + +/* Do RTT sampling needed for Vegas. + * Basically we: + * o min-filter RTT samples from within an RTT to get the current + * propagation delay + queuing delay (we are min-filtering to try to + * avoid the effects of delayed ACKs) + * o min-filter RTT samples from a much longer window (forever for now) + * to find the propagation delay (baseRTT) + */ +void tcp_vegas_pkts_acked(struct sock *sk, const struct ack_sample *sample) +{ + struct vegas *vegas = inet_csk_ca(sk); + u32 vrtt; + + if (sample->rtt_us < 0) + return; + + /* Never allow zero rtt or baseRTT */ + vrtt = sample->rtt_us + 1; + + /* Filter to find propagation delay: */ + if (vrtt < vegas->baseRTT) + vegas->baseRTT = vrtt; + + /* Find the min RTT during the last RTT to find + * the current prop. delay + queuing delay: + */ + vegas->minRTT = min(vegas->minRTT, vrtt); + vegas->cntRTT++; +} +EXPORT_SYMBOL_GPL(tcp_vegas_pkts_acked); + +void tcp_vegas_state(struct sock *sk, u8 ca_state) +{ + if (ca_state == TCP_CA_Open) + vegas_enable(sk); + else + vegas_disable(sk); +} +EXPORT_SYMBOL_GPL(tcp_vegas_state); + +/* + * If the connection is idle and we are restarting, + * then we don't want to do any Vegas calculations + * until we get fresh RTT samples. So when we + * restart, we reset our Vegas state to a clean + * slate. After we get acks for this flight of + * packets, _then_ we can make Vegas calculations + * again. + */ +void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event) +{ + if (event == CA_EVENT_CWND_RESTART || + event == CA_EVENT_TX_START) + tcp_vegas_init(sk); +} +EXPORT_SYMBOL_GPL(tcp_vegas_cwnd_event); + +static inline u32 tcp_vegas_ssthresh(struct tcp_sock *tp) +{ + return min(tp->snd_ssthresh, tp->snd_cwnd); +} + +static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct vegas *vegas = inet_csk_ca(sk); + + if (!vegas->doing_vegas_now) { + tcp_reno_cong_avoid(sk, ack, acked); + return; + } + + if (after(ack, vegas->beg_snd_nxt)) { + /* Do the Vegas once-per-RTT cwnd adjustment. */ + + /* Save the extent of the current window so we can use this + * at the end of the next RTT. + */ + vegas->beg_snd_nxt = tp->snd_nxt; + + /* We do the Vegas calculations only if we got enough RTT + * samples that we can be reasonably sure that we got + * at least one RTT sample that wasn't from a delayed ACK. + * If we only had 2 samples total, + * then that means we're getting only 1 ACK per RTT, which + * means they're almost certainly delayed ACKs. + * If we have 3 samples, we should be OK. + */ + + if (vegas->cntRTT <= 2) { + /* We don't have enough RTT samples to do the Vegas + * calculation, so we'll behave like Reno. + */ + tcp_reno_cong_avoid(sk, ack, acked); + } else { + u32 rtt, diff; + u64 target_cwnd; + + /* We have enough RTT samples, so, using the Vegas + * algorithm, we determine if we should increase or + * decrease cwnd, and by how much. + */ + + /* Pluck out the RTT we are using for the Vegas + * calculations. This is the min RTT seen during the + * last RTT. Taking the min filters out the effects + * of delayed ACKs, at the cost of noticing congestion + * a bit later. + */ + rtt = vegas->minRTT; + + /* Calculate the cwnd we should have, if we weren't + * going too fast. + * + * This is: + * (actual rate in segments) * baseRTT + */ + target_cwnd = (u64)tp->snd_cwnd * vegas->baseRTT; + do_div(target_cwnd, rtt); + + /* Calculate the difference between the window we had, + * and the window we would like to have. This quantity + * is the "Diff" from the Arizona Vegas papers. + */ + diff = tp->snd_cwnd * (rtt-vegas->baseRTT) / vegas->baseRTT; + + if (diff > gamma && tcp_in_slow_start(tp)) { + /* Going too fast. Time to slow down + * and switch to congestion avoidance. + */ + + /* Set cwnd to match the actual rate + * exactly: + * cwnd = (actual rate) * baseRTT + * Then we add 1 because the integer + * truncation robs us of full link + * utilization. + */ + tp->snd_cwnd = min(tp->snd_cwnd, (u32)target_cwnd+1); + tp->snd_ssthresh = tcp_vegas_ssthresh(tp); + + } else if (tcp_in_slow_start(tp)) { + /* Slow start. */ + tcp_slow_start(tp, acked); + } else { + /* Congestion avoidance. */ + + /* Figure out where we would like cwnd + * to be. + */ + if (diff > beta) { + /* The old window was too fast, so + * we slow down. + */ + tp->snd_cwnd--; + tp->snd_ssthresh + = tcp_vegas_ssthresh(tp); + } else if (diff < alpha) { + /* We don't have enough extra packets + * in the network, so speed up. + */ + tp->snd_cwnd++; + } else { + /* Sending just as fast as we + * should be. + */ + } + } + + if (tp->snd_cwnd < 2) + tp->snd_cwnd = 2; + else if (tp->snd_cwnd > tp->snd_cwnd_clamp) + tp->snd_cwnd = tp->snd_cwnd_clamp; + + tp->snd_ssthresh = tcp_current_ssthresh(sk); + } + + /* Wipe the slate clean for the next RTT. */ + vegas->cntRTT = 0; + vegas->minRTT = 0x7fffffff; + } + /* Use normal slow start */ + else if (tcp_in_slow_start(tp)) + tcp_slow_start(tp, acked); +} + +/* Extract info for Tcp socket info provided via netlink. */ +size_t tcp_vegas_get_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info) +{ + const struct vegas *ca = inet_csk_ca(sk); + + if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) { + info->vegas.tcpv_enabled = ca->doing_vegas_now; + info->vegas.tcpv_rttcnt = ca->cntRTT; + info->vegas.tcpv_rtt = ca->baseRTT; + info->vegas.tcpv_minrtt = ca->minRTT; + + *attr = INET_DIAG_VEGASINFO; + return sizeof(struct tcpvegas_info); + } + return 0; +} +EXPORT_SYMBOL_GPL(tcp_vegas_get_info); + +static struct tcp_congestion_ops tcp_vegas __read_mostly = { + .init = tcp_vegas_init, + .ssthresh = tcp_reno_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = tcp_vegas_cong_avoid, + .pkts_acked = tcp_vegas_pkts_acked, + .set_state = tcp_vegas_state, + .cwnd_event = tcp_vegas_cwnd_event, + .get_info = tcp_vegas_get_info, + + .owner = THIS_MODULE, + .name = "vegas", +}; + +static int __init tcp_vegas_register(void) +{ + BUILD_BUG_ON(sizeof(struct vegas) > ICSK_CA_PRIV_SIZE); + tcp_register_congestion_control(&tcp_vegas); + return 0; +} + +static void __exit tcp_vegas_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_vegas); +} + +module_init(tcp_vegas_register); +module_exit(tcp_vegas_unregister); + +MODULE_AUTHOR("Stephen Hemminger"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP Vegas"); diff --git a/net/ipv4/tcp_vegas.h b/net/ipv4/tcp_vegas.h new file mode 100644 index 000000000..4f24d0e37 --- /dev/null +++ b/net/ipv4/tcp_vegas.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * TCP Vegas congestion control interface + */ +#ifndef __TCP_VEGAS_H +#define __TCP_VEGAS_H 1 + +/* Vegas variables */ +struct vegas { + u32 beg_snd_nxt; /* right edge during last RTT */ + u32 beg_snd_una; /* left edge during last RTT */ + u32 beg_snd_cwnd; /* saves the size of the cwnd */ + u8 doing_vegas_now;/* if true, do vegas for this RTT */ + u16 cntRTT; /* # of RTTs measured within last RTT */ + u32 minRTT; /* min of RTTs measured within last RTT (in usec) */ + u32 baseRTT; /* the min of all Vegas RTT measurements seen (in usec) */ +}; + +void tcp_vegas_init(struct sock *sk); +void tcp_vegas_state(struct sock *sk, u8 ca_state); +void tcp_vegas_pkts_acked(struct sock *sk, const struct ack_sample *sample); +void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event); +size_t tcp_vegas_get_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info); + +#endif /* __TCP_VEGAS_H */ diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c new file mode 100644 index 000000000..cd50a61c9 --- /dev/null +++ b/net/ipv4/tcp_veno.c @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP Veno congestion control + * + * This is based on the congestion detection/avoidance scheme described in + * C. P. Fu, S. C. Liew. + * "TCP Veno: TCP Enhancement for Transmission over Wireless Access Networks." + * IEEE Journal on Selected Areas in Communication, + * Feb. 2003. + * See https://www.ie.cuhk.edu.hk/fileadmin/staff_upload/soung/Journal/J3.pdf + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/inet_diag.h> + +#include <net/tcp.h> + +/* Default values of the Veno variables, in fixed-point representation + * with V_PARAM_SHIFT bits to the right of the binary point. + */ +#define V_PARAM_SHIFT 1 +static const int beta = 3 << V_PARAM_SHIFT; + +/* Veno variables */ +struct veno { + u8 doing_veno_now; /* if true, do veno for this rtt */ + u16 cntrtt; /* # of rtts measured within last rtt */ + u32 minrtt; /* min of rtts measured within last rtt (in usec) */ + u32 basertt; /* the min of all Veno rtt measurements seen (in usec) */ + u32 inc; /* decide whether to increase cwnd */ + u32 diff; /* calculate the diff rate */ +}; + +/* There are several situations when we must "re-start" Veno: + * + * o when a connection is established + * o after an RTO + * o after fast recovery + * o when we send a packet and there is no outstanding + * unacknowledged data (restarting an idle connection) + * + */ +static inline void veno_enable(struct sock *sk) +{ + struct veno *veno = inet_csk_ca(sk); + + /* turn on Veno */ + veno->doing_veno_now = 1; + + veno->minrtt = 0x7fffffff; +} + +static inline void veno_disable(struct sock *sk) +{ + struct veno *veno = inet_csk_ca(sk); + + /* turn off Veno */ + veno->doing_veno_now = 0; +} + +static void tcp_veno_init(struct sock *sk) +{ + struct veno *veno = inet_csk_ca(sk); + + veno->basertt = 0x7fffffff; + veno->inc = 1; + veno_enable(sk); +} + +/* Do rtt sampling needed for Veno. */ +static void tcp_veno_pkts_acked(struct sock *sk, + const struct ack_sample *sample) +{ + struct veno *veno = inet_csk_ca(sk); + u32 vrtt; + + if (sample->rtt_us < 0) + return; + + /* Never allow zero rtt or baseRTT */ + vrtt = sample->rtt_us + 1; + + /* Filter to find propagation delay: */ + if (vrtt < veno->basertt) + veno->basertt = vrtt; + + /* Find the min rtt during the last rtt to find + * the current prop. delay + queuing delay: + */ + veno->minrtt = min(veno->minrtt, vrtt); + veno->cntrtt++; +} + +static void tcp_veno_state(struct sock *sk, u8 ca_state) +{ + if (ca_state == TCP_CA_Open) + veno_enable(sk); + else + veno_disable(sk); +} + +/* + * If the connection is idle and we are restarting, + * then we don't want to do any Veno calculations + * until we get fresh rtt samples. So when we + * restart, we reset our Veno state to a clean + * state. After we get acks for this flight of + * packets, _then_ we can make Veno calculations + * again. + */ +static void tcp_veno_cwnd_event(struct sock *sk, enum tcp_ca_event event) +{ + if (event == CA_EVENT_CWND_RESTART || event == CA_EVENT_TX_START) + tcp_veno_init(sk); +} + +static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct veno *veno = inet_csk_ca(sk); + + if (!veno->doing_veno_now) { + tcp_reno_cong_avoid(sk, ack, acked); + return; + } + + /* limited by applications */ + if (!tcp_is_cwnd_limited(sk)) + return; + + /* We do the Veno calculations only if we got enough rtt samples */ + if (veno->cntrtt <= 2) { + /* We don't have enough rtt samples to do the Veno + * calculation, so we'll behave like Reno. + */ + tcp_reno_cong_avoid(sk, ack, acked); + } else { + u64 target_cwnd; + u32 rtt; + + /* We have enough rtt samples, so, using the Veno + * algorithm, we determine the state of the network. + */ + + rtt = veno->minrtt; + + target_cwnd = (u64)tp->snd_cwnd * veno->basertt; + target_cwnd <<= V_PARAM_SHIFT; + do_div(target_cwnd, rtt); + + veno->diff = (tp->snd_cwnd << V_PARAM_SHIFT) - target_cwnd; + + if (tcp_in_slow_start(tp)) { + /* Slow start. */ + acked = tcp_slow_start(tp, acked); + if (!acked) + goto done; + } + + /* Congestion avoidance. */ + if (veno->diff < beta) { + /* In the "non-congestive state", increase cwnd + * every rtt. + */ + tcp_cong_avoid_ai(tp, tp->snd_cwnd, acked); + } else { + /* In the "congestive state", increase cwnd + * every other rtt. + */ + if (tp->snd_cwnd_cnt >= tp->snd_cwnd) { + if (veno->inc && + tp->snd_cwnd < tp->snd_cwnd_clamp) { + tp->snd_cwnd++; + veno->inc = 0; + } else + veno->inc = 1; + tp->snd_cwnd_cnt = 0; + } else + tp->snd_cwnd_cnt += acked; + } +done: + if (tp->snd_cwnd < 2) + tp->snd_cwnd = 2; + else if (tp->snd_cwnd > tp->snd_cwnd_clamp) + tp->snd_cwnd = tp->snd_cwnd_clamp; + } + /* Wipe the slate clean for the next rtt. */ + /* veno->cntrtt = 0; */ + veno->minrtt = 0x7fffffff; +} + +/* Veno MD phase */ +static u32 tcp_veno_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct veno *veno = inet_csk_ca(sk); + + if (veno->diff < beta) + /* in "non-congestive state", cut cwnd by 1/5 */ + return max(tp->snd_cwnd * 4 / 5, 2U); + else + /* in "congestive state", cut cwnd by 1/2 */ + return max(tp->snd_cwnd >> 1U, 2U); +} + +static struct tcp_congestion_ops tcp_veno __read_mostly = { + .init = tcp_veno_init, + .ssthresh = tcp_veno_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = tcp_veno_cong_avoid, + .pkts_acked = tcp_veno_pkts_acked, + .set_state = tcp_veno_state, + .cwnd_event = tcp_veno_cwnd_event, + + .owner = THIS_MODULE, + .name = "veno", +}; + +static int __init tcp_veno_register(void) +{ + BUILD_BUG_ON(sizeof(struct veno) > ICSK_CA_PRIV_SIZE); + tcp_register_congestion_control(&tcp_veno); + return 0; +} + +static void __exit tcp_veno_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_veno); +} + +module_init(tcp_veno_register); +module_exit(tcp_veno_unregister); + +MODULE_AUTHOR("Bin Zhou, Cheng Peng Fu"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP Veno"); diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c new file mode 100644 index 000000000..b2e05c4ce --- /dev/null +++ b/net/ipv4/tcp_westwood.c @@ -0,0 +1,308 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TCP Westwood+: end-to-end bandwidth estimation for TCP + * + * Angelo Dell'Aera: author of the first version of TCP Westwood+ in Linux 2.4 + * + * Support at http://c3lab.poliba.it/index.php/Westwood + * Main references in literature: + * + * - Mascolo S, Casetti, M. Gerla et al. + * "TCP Westwood: bandwidth estimation for TCP" Proc. ACM Mobicom 2001 + * + * - A. Grieco, s. Mascolo + * "Performance evaluation of New Reno, Vegas, Westwood+ TCP" ACM Computer + * Comm. Review, 2004 + * + * - A. Dell'Aera, L. Grieco, S. Mascolo. + * "Linux 2.4 Implementation of Westwood+ TCP with Rate-Halving : + * A Performance Evaluation Over the Internet" (ICC 2004), Paris, June 2004 + * + * Westwood+ employs end-to-end bandwidth measurement to set cwnd and + * ssthresh after packet loss. The probing phase is as the original Reno. + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/inet_diag.h> +#include <net/tcp.h> + +/* TCP Westwood structure */ +struct westwood { + u32 bw_ns_est; /* first bandwidth estimation..not too smoothed 8) */ + u32 bw_est; /* bandwidth estimate */ + u32 rtt_win_sx; /* here starts a new evaluation... */ + u32 bk; + u32 snd_una; /* used for evaluating the number of acked bytes */ + u32 cumul_ack; + u32 accounted; + u32 rtt; + u32 rtt_min; /* minimum observed RTT */ + u8 first_ack; /* flag which infers that this is the first ack */ + u8 reset_rtt_min; /* Reset RTT min to next RTT sample*/ +}; + +/* TCP Westwood functions and constants */ +#define TCP_WESTWOOD_RTT_MIN (HZ/20) /* 50ms */ +#define TCP_WESTWOOD_INIT_RTT (20*HZ) /* maybe too conservative?! */ + +/* + * @tcp_westwood_create + * This function initializes fields used in TCP Westwood+, + * it is called after the initial SYN, so the sequence numbers + * are correct but new passive connections we have no + * information about RTTmin at this time so we simply set it to + * TCP_WESTWOOD_INIT_RTT. This value was chosen to be too conservative + * since in this way we're sure it will be updated in a consistent + * way as soon as possible. It will reasonably happen within the first + * RTT period of the connection lifetime. + */ +static void tcp_westwood_init(struct sock *sk) +{ + struct westwood *w = inet_csk_ca(sk); + + w->bk = 0; + w->bw_ns_est = 0; + w->bw_est = 0; + w->accounted = 0; + w->cumul_ack = 0; + w->reset_rtt_min = 1; + w->rtt_min = w->rtt = TCP_WESTWOOD_INIT_RTT; + w->rtt_win_sx = tcp_jiffies32; + w->snd_una = tcp_sk(sk)->snd_una; + w->first_ack = 1; +} + +/* + * @westwood_do_filter + * Low-pass filter. Implemented using constant coefficients. + */ +static inline u32 westwood_do_filter(u32 a, u32 b) +{ + return ((7 * a) + b) >> 3; +} + +static void westwood_filter(struct westwood *w, u32 delta) +{ + /* If the filter is empty fill it with the first sample of bandwidth */ + if (w->bw_ns_est == 0 && w->bw_est == 0) { + w->bw_ns_est = w->bk / delta; + w->bw_est = w->bw_ns_est; + } else { + w->bw_ns_est = westwood_do_filter(w->bw_ns_est, w->bk / delta); + w->bw_est = westwood_do_filter(w->bw_est, w->bw_ns_est); + } +} + +/* + * @westwood_pkts_acked + * Called after processing group of packets. + * but all westwood needs is the last sample of srtt. + */ +static void tcp_westwood_pkts_acked(struct sock *sk, + const struct ack_sample *sample) +{ + struct westwood *w = inet_csk_ca(sk); + + if (sample->rtt_us > 0) + w->rtt = usecs_to_jiffies(sample->rtt_us); +} + +/* + * @westwood_update_window + * It updates RTT evaluation window if it is the right moment to do + * it. If so it calls filter for evaluating bandwidth. + */ +static void westwood_update_window(struct sock *sk) +{ + struct westwood *w = inet_csk_ca(sk); + s32 delta = tcp_jiffies32 - w->rtt_win_sx; + + /* Initialize w->snd_una with the first acked sequence number in order + * to fix mismatch between tp->snd_una and w->snd_una for the first + * bandwidth sample + */ + if (w->first_ack) { + w->snd_una = tcp_sk(sk)->snd_una; + w->first_ack = 0; + } + + /* + * See if a RTT-window has passed. + * Be careful since if RTT is less than + * 50ms we don't filter but we continue 'building the sample'. + * This minimum limit was chosen since an estimation on small + * time intervals is better to avoid... + * Obviously on a LAN we reasonably will always have + * right_bound = left_bound + WESTWOOD_RTT_MIN + */ + if (w->rtt && delta > max_t(u32, w->rtt, TCP_WESTWOOD_RTT_MIN)) { + westwood_filter(w, delta); + + w->bk = 0; + w->rtt_win_sx = tcp_jiffies32; + } +} + +static inline void update_rtt_min(struct westwood *w) +{ + if (w->reset_rtt_min) { + w->rtt_min = w->rtt; + w->reset_rtt_min = 0; + } else + w->rtt_min = min(w->rtt, w->rtt_min); +} + +/* + * @westwood_fast_bw + * It is called when we are in fast path. In particular it is called when + * header prediction is successful. In such case in fact update is + * straight forward and doesn't need any particular care. + */ +static inline void westwood_fast_bw(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct westwood *w = inet_csk_ca(sk); + + westwood_update_window(sk); + + w->bk += tp->snd_una - w->snd_una; + w->snd_una = tp->snd_una; + update_rtt_min(w); +} + +/* + * @westwood_acked_count + * This function evaluates cumul_ack for evaluating bk in case of + * delayed or partial acks. + */ +static inline u32 westwood_acked_count(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct westwood *w = inet_csk_ca(sk); + + w->cumul_ack = tp->snd_una - w->snd_una; + + /* If cumul_ack is 0 this is a dupack since it's not moving + * tp->snd_una. + */ + if (!w->cumul_ack) { + w->accounted += tp->mss_cache; + w->cumul_ack = tp->mss_cache; + } + + if (w->cumul_ack > tp->mss_cache) { + /* Partial or delayed ack */ + if (w->accounted >= w->cumul_ack) { + w->accounted -= w->cumul_ack; + w->cumul_ack = tp->mss_cache; + } else { + w->cumul_ack -= w->accounted; + w->accounted = 0; + } + } + + w->snd_una = tp->snd_una; + + return w->cumul_ack; +} + +/* + * TCP Westwood + * Here limit is evaluated as Bw estimation*RTTmin (for obtaining it + * in packets we use mss_cache). Rttmin is guaranteed to be >= 2 + * so avoids ever returning 0. + */ +static u32 tcp_westwood_bw_rttmin(const struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + const struct westwood *w = inet_csk_ca(sk); + + return max_t(u32, (w->bw_est * w->rtt_min) / tp->mss_cache, 2); +} + +static void tcp_westwood_ack(struct sock *sk, u32 ack_flags) +{ + if (ack_flags & CA_ACK_SLOWPATH) { + struct westwood *w = inet_csk_ca(sk); + + westwood_update_window(sk); + w->bk += westwood_acked_count(sk); + + update_rtt_min(w); + return; + } + + westwood_fast_bw(sk); +} + +static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct westwood *w = inet_csk_ca(sk); + + switch (event) { + case CA_EVENT_COMPLETE_CWR: + tp->snd_cwnd = tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk); + break; + case CA_EVENT_LOSS: + tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk); + /* Update RTT_min when next ack arrives */ + w->reset_rtt_min = 1; + break; + default: + /* don't care */ + break; + } +} + +/* Extract info for Tcp socket info provided via netlink. */ +static size_t tcp_westwood_info(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info) +{ + const struct westwood *ca = inet_csk_ca(sk); + + if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) { + info->vegas.tcpv_enabled = 1; + info->vegas.tcpv_rttcnt = 0; + info->vegas.tcpv_rtt = jiffies_to_usecs(ca->rtt); + info->vegas.tcpv_minrtt = jiffies_to_usecs(ca->rtt_min); + + *attr = INET_DIAG_VEGASINFO; + return sizeof(struct tcpvegas_info); + } + return 0; +} + +static struct tcp_congestion_ops tcp_westwood __read_mostly = { + .init = tcp_westwood_init, + .ssthresh = tcp_reno_ssthresh, + .cong_avoid = tcp_reno_cong_avoid, + .undo_cwnd = tcp_reno_undo_cwnd, + .cwnd_event = tcp_westwood_event, + .in_ack_event = tcp_westwood_ack, + .get_info = tcp_westwood_info, + .pkts_acked = tcp_westwood_pkts_acked, + + .owner = THIS_MODULE, + .name = "westwood" +}; + +static int __init tcp_westwood_register(void) +{ + BUILD_BUG_ON(sizeof(struct westwood) > ICSK_CA_PRIV_SIZE); + return tcp_register_congestion_control(&tcp_westwood); +} + +static void __exit tcp_westwood_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_westwood); +} + +module_init(tcp_westwood_register); +module_exit(tcp_westwood_unregister); + +MODULE_AUTHOR("Stephen Hemminger, Angelo Dell'Aera"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP Westwood+"); diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c new file mode 100644 index 000000000..3bb448761 --- /dev/null +++ b/net/ipv4/tcp_yeah.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * YeAH TCP + * + * For further details look at: + * https://web.archive.org/web/20080316215752/http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf + * + */ +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/inet_diag.h> + +#include <net/tcp.h> + +#include "tcp_vegas.h" + +#define TCP_YEAH_ALPHA 80 /* number of packets queued at the bottleneck */ +#define TCP_YEAH_GAMMA 1 /* fraction of queue to be removed per rtt */ +#define TCP_YEAH_DELTA 3 /* log minimum fraction of cwnd to be removed on loss */ +#define TCP_YEAH_EPSILON 1 /* log maximum fraction to be removed on early decongestion */ +#define TCP_YEAH_PHY 8 /* maximum delta from base */ +#define TCP_YEAH_RHO 16 /* minimum number of consecutive rtt to consider competition on loss */ +#define TCP_YEAH_ZETA 50 /* minimum number of state switches to reset reno_count */ + +#define TCP_SCALABLE_AI_CNT 100U + +/* YeAH variables */ +struct yeah { + struct vegas vegas; /* must be first */ + + /* YeAH */ + u32 lastQ; + u32 doing_reno_now; + + u32 reno_count; + u32 fast_count; +}; + +static void tcp_yeah_init(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct yeah *yeah = inet_csk_ca(sk); + + tcp_vegas_init(sk); + + yeah->doing_reno_now = 0; + yeah->lastQ = 0; + + yeah->reno_count = 2; + + /* Ensure the MD arithmetic works. This is somewhat pedantic, + * since I don't think we will see a cwnd this large. :) */ + tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128); +} + +static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct yeah *yeah = inet_csk_ca(sk); + + if (!tcp_is_cwnd_limited(sk)) + return; + + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + goto do_vegas; + } + + if (!yeah->doing_reno_now) { + /* Scalable */ + tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT), + acked); + } else { + /* Reno */ + tcp_cong_avoid_ai(tp, tp->snd_cwnd, acked); + } + + /* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt. + * + * These are so named because they represent the approximate values + * of snd_una and snd_nxt at the beginning of the current RTT. More + * precisely, they represent the amount of data sent during the RTT. + * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt, + * we will calculate that (v_beg_snd_nxt - v_vegas.beg_snd_una) outstanding + * bytes of data have been ACKed during the course of the RTT, giving + * an "actual" rate of: + * + * (v_beg_snd_nxt - v_vegas.beg_snd_una) / (rtt duration) + * + * Unfortunately, v_vegas.beg_snd_una is not exactly equal to snd_una, + * because delayed ACKs can cover more than one segment, so they + * don't line up yeahly with the boundaries of RTTs. + * + * Another unfortunate fact of life is that delayed ACKs delay the + * advance of the left edge of our send window, so that the number + * of bytes we send in an RTT is often less than our cwnd will allow. + * So we keep track of our cwnd separately, in v_beg_snd_cwnd. + */ +do_vegas: + if (after(ack, yeah->vegas.beg_snd_nxt)) { + /* We do the Vegas calculations only if we got enough RTT + * samples that we can be reasonably sure that we got + * at least one RTT sample that wasn't from a delayed ACK. + * If we only had 2 samples total, + * then that means we're getting only 1 ACK per RTT, which + * means they're almost certainly delayed ACKs. + * If we have 3 samples, we should be OK. + */ + + if (yeah->vegas.cntRTT > 2) { + u32 rtt, queue; + u64 bw; + + /* We have enough RTT samples, so, using the Vegas + * algorithm, we determine if we should increase or + * decrease cwnd, and by how much. + */ + + /* Pluck out the RTT we are using for the Vegas + * calculations. This is the min RTT seen during the + * last RTT. Taking the min filters out the effects + * of delayed ACKs, at the cost of noticing congestion + * a bit later. + */ + rtt = yeah->vegas.minRTT; + + /* Compute excess number of packets above bandwidth + * Avoid doing full 64 bit divide. + */ + bw = tp->snd_cwnd; + bw *= rtt - yeah->vegas.baseRTT; + do_div(bw, rtt); + queue = bw; + + if (queue > TCP_YEAH_ALPHA || + rtt - yeah->vegas.baseRTT > (yeah->vegas.baseRTT / TCP_YEAH_PHY)) { + if (queue > TCP_YEAH_ALPHA && + tp->snd_cwnd > yeah->reno_count) { + u32 reduction = min(queue / TCP_YEAH_GAMMA , + tp->snd_cwnd >> TCP_YEAH_EPSILON); + + tp->snd_cwnd -= reduction; + + tp->snd_cwnd = max(tp->snd_cwnd, + yeah->reno_count); + + tp->snd_ssthresh = tp->snd_cwnd; + } + + if (yeah->reno_count <= 2) + yeah->reno_count = max(tp->snd_cwnd>>1, 2U); + else + yeah->reno_count++; + + yeah->doing_reno_now = min(yeah->doing_reno_now + 1, + 0xffffffU); + } else { + yeah->fast_count++; + + if (yeah->fast_count > TCP_YEAH_ZETA) { + yeah->reno_count = 2; + yeah->fast_count = 0; + } + + yeah->doing_reno_now = 0; + } + + yeah->lastQ = queue; + } + + /* Save the extent of the current window so we can use this + * at the end of the next RTT. + */ + yeah->vegas.beg_snd_una = yeah->vegas.beg_snd_nxt; + yeah->vegas.beg_snd_nxt = tp->snd_nxt; + yeah->vegas.beg_snd_cwnd = tp->snd_cwnd; + + /* Wipe the slate clean for the next RTT. */ + yeah->vegas.cntRTT = 0; + yeah->vegas.minRTT = 0x7fffffff; + } +} + +static u32 tcp_yeah_ssthresh(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + struct yeah *yeah = inet_csk_ca(sk); + u32 reduction; + + if (yeah->doing_reno_now < TCP_YEAH_RHO) { + reduction = yeah->lastQ; + + reduction = min(reduction, max(tp->snd_cwnd>>1, 2U)); + + reduction = max(reduction, tp->snd_cwnd >> TCP_YEAH_DELTA); + } else + reduction = max(tp->snd_cwnd>>1, 2U); + + yeah->fast_count = 0; + yeah->reno_count = max(yeah->reno_count>>1, 2U); + + return max_t(int, tp->snd_cwnd - reduction, 2); +} + +static struct tcp_congestion_ops tcp_yeah __read_mostly = { + .init = tcp_yeah_init, + .ssthresh = tcp_yeah_ssthresh, + .undo_cwnd = tcp_reno_undo_cwnd, + .cong_avoid = tcp_yeah_cong_avoid, + .set_state = tcp_vegas_state, + .cwnd_event = tcp_vegas_cwnd_event, + .get_info = tcp_vegas_get_info, + .pkts_acked = tcp_vegas_pkts_acked, + + .owner = THIS_MODULE, + .name = "yeah", +}; + +static int __init tcp_yeah_register(void) +{ + BUG_ON(sizeof(struct yeah) > ICSK_CA_PRIV_SIZE); + tcp_register_congestion_control(&tcp_yeah); + return 0; +} + +static void __exit tcp_yeah_unregister(void) +{ + tcp_unregister_congestion_control(&tcp_yeah); +} + +module_init(tcp_yeah_register); +module_exit(tcp_yeah_unregister); + +MODULE_AUTHOR("Angelo P. Castellani"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("YeAH TCP"); diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c new file mode 100644 index 000000000..e44aaf41a --- /dev/null +++ b/net/ipv4/tunnel4.c @@ -0,0 +1,300 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* tunnel4.c: Generic IP tunnel transformer. + * + * Copyright (C) 2003 David S. Miller (davem@redhat.com) + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/mpls.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <net/icmp.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/xfrm.h> + +static struct xfrm_tunnel __rcu *tunnel4_handlers __read_mostly; +static struct xfrm_tunnel __rcu *tunnel64_handlers __read_mostly; +static struct xfrm_tunnel __rcu *tunnelmpls4_handlers __read_mostly; +static DEFINE_MUTEX(tunnel4_mutex); + +static inline struct xfrm_tunnel __rcu **fam_handlers(unsigned short family) +{ + return (family == AF_INET) ? &tunnel4_handlers : + (family == AF_INET6) ? &tunnel64_handlers : + &tunnelmpls4_handlers; +} + +int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family) +{ + struct xfrm_tunnel __rcu **pprev; + struct xfrm_tunnel *t; + + int ret = -EEXIST; + int priority = handler->priority; + + mutex_lock(&tunnel4_mutex); + + for (pprev = fam_handlers(family); + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&tunnel4_mutex))) != NULL; + pprev = &t->next) { + if (t->priority > priority) + break; + if (t->priority == priority) + goto err; + } + + handler->next = *pprev; + rcu_assign_pointer(*pprev, handler); + + ret = 0; + +err: + mutex_unlock(&tunnel4_mutex); + + return ret; +} +EXPORT_SYMBOL(xfrm4_tunnel_register); + +int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family) +{ + struct xfrm_tunnel __rcu **pprev; + struct xfrm_tunnel *t; + int ret = -ENOENT; + + mutex_lock(&tunnel4_mutex); + + for (pprev = fam_handlers(family); + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&tunnel4_mutex))) != NULL; + pprev = &t->next) { + if (t == handler) { + *pprev = handler->next; + ret = 0; + break; + } + } + + mutex_unlock(&tunnel4_mutex); + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(xfrm4_tunnel_deregister); + +#define for_each_tunnel_rcu(head, handler) \ + for (handler = rcu_dereference(head); \ + handler != NULL; \ + handler = rcu_dereference(handler->next)) \ + +static int tunnel4_rcv(struct sk_buff *skb) +{ + struct xfrm_tunnel *handler; + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + goto drop; + + for_each_tunnel_rcu(tunnel4_handlers, handler) + if (!handler->handler(skb)) + return 0; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + +drop: + kfree_skb(skb); + return 0; +} + +#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL) +static int tunnel4_rcv_cb(struct sk_buff *skb, u8 proto, int err) +{ + struct xfrm_tunnel __rcu *head; + struct xfrm_tunnel *handler; + int ret; + + head = (proto == IPPROTO_IPIP) ? tunnel4_handlers : tunnel64_handlers; + + for_each_tunnel_rcu(head, handler) { + if (handler->cb_handler) { + ret = handler->cb_handler(skb, err); + if (ret <= 0) + return ret; + } + } + + return 0; +} + +static const struct xfrm_input_afinfo tunnel4_input_afinfo = { + .family = AF_INET, + .is_ipip = true, + .callback = tunnel4_rcv_cb, +}; +#endif + +#if IS_ENABLED(CONFIG_IPV6) +static int tunnel64_rcv(struct sk_buff *skb) +{ + struct xfrm_tunnel *handler; + + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) + goto drop; + + for_each_tunnel_rcu(tunnel64_handlers, handler) + if (!handler->handler(skb)) + return 0; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + +drop: + kfree_skb(skb); + return 0; +} +#endif + +#if IS_ENABLED(CONFIG_MPLS) +static int tunnelmpls4_rcv(struct sk_buff *skb) +{ + struct xfrm_tunnel *handler; + + if (!pskb_may_pull(skb, sizeof(struct mpls_label))) + goto drop; + + for_each_tunnel_rcu(tunnelmpls4_handlers, handler) + if (!handler->handler(skb)) + return 0; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + +drop: + kfree_skb(skb); + return 0; +} +#endif + +static int tunnel4_err(struct sk_buff *skb, u32 info) +{ + struct xfrm_tunnel *handler; + + for_each_tunnel_rcu(tunnel4_handlers, handler) + if (!handler->err_handler(skb, info)) + return 0; + + return -ENOENT; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int tunnel64_err(struct sk_buff *skb, u32 info) +{ + struct xfrm_tunnel *handler; + + for_each_tunnel_rcu(tunnel64_handlers, handler) + if (!handler->err_handler(skb, info)) + return 0; + + return -ENOENT; +} +#endif + +#if IS_ENABLED(CONFIG_MPLS) +static int tunnelmpls4_err(struct sk_buff *skb, u32 info) +{ + struct xfrm_tunnel *handler; + + for_each_tunnel_rcu(tunnelmpls4_handlers, handler) + if (!handler->err_handler(skb, info)) + return 0; + + return -ENOENT; +} +#endif + +static const struct net_protocol tunnel4_protocol = { + .handler = tunnel4_rcv, + .err_handler = tunnel4_err, + .no_policy = 1, + .netns_ok = 1, +}; + +#if IS_ENABLED(CONFIG_IPV6) +static const struct net_protocol tunnel64_protocol = { + .handler = tunnel64_rcv, + .err_handler = tunnel64_err, + .no_policy = 1, + .netns_ok = 1, +}; +#endif + +#if IS_ENABLED(CONFIG_MPLS) +static const struct net_protocol tunnelmpls4_protocol = { + .handler = tunnelmpls4_rcv, + .err_handler = tunnelmpls4_err, + .no_policy = 1, + .netns_ok = 1, +}; +#endif + +static int __init tunnel4_init(void) +{ + if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) + goto err; +#if IS_ENABLED(CONFIG_IPV6) + if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) { + inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); + goto err; + } +#endif +#if IS_ENABLED(CONFIG_MPLS) + if (inet_add_protocol(&tunnelmpls4_protocol, IPPROTO_MPLS)) { + inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); +#if IS_ENABLED(CONFIG_IPV6) + inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6); +#endif + goto err; + } +#endif +#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL) + if (xfrm_input_register_afinfo(&tunnel4_input_afinfo)) { + inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); +#if IS_ENABLED(CONFIG_IPV6) + inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6); +#endif +#if IS_ENABLED(CONFIG_MPLS) + inet_del_protocol(&tunnelmpls4_protocol, IPPROTO_MPLS); +#endif + goto err; + } +#endif + return 0; + +err: + pr_err("%s: can't add protocol\n", __func__); + return -EAGAIN; +} + +static void __exit tunnel4_fini(void) +{ +#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL) + if (xfrm_input_unregister_afinfo(&tunnel4_input_afinfo)) + pr_err("tunnel4 close: can't remove input afinfo\n"); +#endif +#if IS_ENABLED(CONFIG_MPLS) + if (inet_del_protocol(&tunnelmpls4_protocol, IPPROTO_MPLS)) + pr_err("tunnelmpls4 close: can't remove protocol\n"); +#endif +#if IS_ENABLED(CONFIG_IPV6) + if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6)) + pr_err("tunnel64 close: can't remove protocol\n"); +#endif + if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP)) + pr_err("tunnel4 close: can't remove protocol\n"); +} + +module_init(tunnel4_init); +module_exit(tunnel4_fini); +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c new file mode 100644 index 000000000..476f79f15 --- /dev/null +++ b/net/ipv4/udp.c @@ -0,0 +1,3304 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The User Datagram Protocol (UDP). + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Alan Cox, <alan@lxorguk.ukuu.org.uk> + * Hirokazu Takahashi, <taka@valinux.co.jp> + * + * Fixes: + * Alan Cox : verify_area() calls + * Alan Cox : stopped close while in use off icmp + * messages. Not a fix but a botch that + * for udp at least is 'valid'. + * Alan Cox : Fixed icmp handling properly + * Alan Cox : Correct error for oversized datagrams + * Alan Cox : Tidied select() semantics. + * Alan Cox : udp_err() fixed properly, also now + * select and read wake correctly on errors + * Alan Cox : udp_send verify_area moved to avoid mem leak + * Alan Cox : UDP can count its memory + * Alan Cox : send to an unknown connection causes + * an ECONNREFUSED off the icmp, but + * does NOT close. + * Alan Cox : Switched to new sk_buff handlers. No more backlog! + * Alan Cox : Using generic datagram code. Even smaller and the PEEK + * bug no longer crashes it. + * Fred Van Kempen : Net2e support for sk->broadcast. + * Alan Cox : Uses skb_free_datagram + * Alan Cox : Added get/set sockopt support. + * Alan Cox : Broadcasting without option set returns EACCES. + * Alan Cox : No wakeup calls. Instead we now use the callbacks. + * Alan Cox : Use ip_tos and ip_ttl + * Alan Cox : SNMP Mibs + * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. + * Matt Dillon : UDP length checks. + * Alan Cox : Smarter af_inet used properly. + * Alan Cox : Use new kernel side addressing. + * Alan Cox : Incorrect return on truncated datagram receive. + * Arnt Gulbrandsen : New udp_send and stuff + * Alan Cox : Cache last socket + * Alan Cox : Route cache + * Jon Peatfield : Minor efficiency fix to sendto(). + * Mike Shaver : RFC1122 checks. + * Alan Cox : Nonblocking error fix. + * Willy Konynenberg : Transparent proxying support. + * Mike McLagan : Routing by source + * David S. Miller : New socket lookup architecture. + * Last socket cache retained as it + * does have a high hit rate. + * Olaf Kirch : Don't linearise iovec on sendmsg. + * Andi Kleen : Some cleanups, cache destination entry + * for connect. + * Vitaly E. Lavrov : Transparent proxy revived after year coma. + * Melvin Smith : Check msg_name not msg_namelen in sendto(), + * return ENOTCONN for unconnected sockets (POSIX) + * Janos Farkas : don't deliver multi/broadcasts to a different + * bound-to-device socket + * Hirokazu Takahashi : HW checksumming for outgoing UDP + * datagrams. + * Hirokazu Takahashi : sendfile() on UDP works now. + * Arnaldo C. Melo : convert /proc/net/udp to seq_file + * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which + * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind + * a single port at the same time. + * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support + * James Chapman : Add L2TP encapsulation type. + */ + +#define pr_fmt(fmt) "UDP: " fmt + +#include <linux/uaccess.h> +#include <asm/ioctls.h> +#include <linux/memblock.h> +#include <linux/highmem.h> +#include <linux/swap.h> +#include <linux/types.h> +#include <linux/fcntl.h> +#include <linux/module.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/igmp.h> +#include <linux/inetdevice.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/slab.h> +#include <net/tcp_states.h> +#include <linux/skbuff.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <net/net_namespace.h> +#include <net/icmp.h> +#include <net/inet_hashtables.h> +#include <net/ip_tunnels.h> +#include <net/route.h> +#include <net/checksum.h> +#include <net/xfrm.h> +#include <trace/events/udp.h> +#include <linux/static_key.h> +#include <linux/btf_ids.h> +#include <trace/events/skb.h> +#include <net/busy_poll.h> +#include "udp_impl.h" +#include <net/sock_reuseport.h> +#include <net/addrconf.h> +#include <net/udp_tunnel.h> +#if IS_ENABLED(CONFIG_IPV6) +#include <net/ipv6_stubs.h> +#endif + +struct udp_table udp_table __read_mostly; +EXPORT_SYMBOL(udp_table); + +long sysctl_udp_mem[3] __read_mostly; +EXPORT_SYMBOL(sysctl_udp_mem); + +atomic_long_t udp_memory_allocated; +EXPORT_SYMBOL(udp_memory_allocated); + +#define MAX_UDP_PORTS 65536 +#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) + +static int udp_lib_lport_inuse(struct net *net, __u16 num, + const struct udp_hslot *hslot, + unsigned long *bitmap, + struct sock *sk, unsigned int log) +{ + struct sock *sk2; + kuid_t uid = sock_i_uid(sk); + + sk_for_each(sk2, &hslot->head) { + if (net_eq(sock_net(sk2), net) && + sk2 != sk && + (bitmap || udp_sk(sk2)->udp_port_hash == num) && + (!sk2->sk_reuse || !sk->sk_reuse) && + (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || + sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && + inet_rcv_saddr_equal(sk, sk2, true)) { + if (sk2->sk_reuseport && sk->sk_reuseport && + !rcu_access_pointer(sk->sk_reuseport_cb) && + uid_eq(uid, sock_i_uid(sk2))) { + if (!bitmap) + return 0; + } else { + if (!bitmap) + return 1; + __set_bit(udp_sk(sk2)->udp_port_hash >> log, + bitmap); + } + } + } + return 0; +} + +/* + * Note: we still hold spinlock of primary hash chain, so no other writer + * can insert/delete a socket with local_port == num + */ +static int udp_lib_lport_inuse2(struct net *net, __u16 num, + struct udp_hslot *hslot2, + struct sock *sk) +{ + struct sock *sk2; + kuid_t uid = sock_i_uid(sk); + int res = 0; + + spin_lock(&hslot2->lock); + udp_portaddr_for_each_entry(sk2, &hslot2->head) { + if (net_eq(sock_net(sk2), net) && + sk2 != sk && + (udp_sk(sk2)->udp_port_hash == num) && + (!sk2->sk_reuse || !sk->sk_reuse) && + (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || + sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && + inet_rcv_saddr_equal(sk, sk2, true)) { + if (sk2->sk_reuseport && sk->sk_reuseport && + !rcu_access_pointer(sk->sk_reuseport_cb) && + uid_eq(uid, sock_i_uid(sk2))) { + res = 0; + } else { + res = 1; + } + break; + } + } + spin_unlock(&hslot2->lock); + return res; +} + +static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot) +{ + struct net *net = sock_net(sk); + kuid_t uid = sock_i_uid(sk); + struct sock *sk2; + + sk_for_each(sk2, &hslot->head) { + if (net_eq(sock_net(sk2), net) && + sk2 != sk && + sk2->sk_family == sk->sk_family && + ipv6_only_sock(sk2) == ipv6_only_sock(sk) && + (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) && + (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && + sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && + inet_rcv_saddr_equal(sk, sk2, false)) { + return reuseport_add_sock(sk, sk2, + inet_rcv_saddr_any(sk)); + } + } + + return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); +} + +/** + * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 + * + * @sk: socket struct in question + * @snum: port number to look up + * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, + * with NULL address + */ +int udp_lib_get_port(struct sock *sk, unsigned short snum, + unsigned int hash2_nulladdr) +{ + struct udp_hslot *hslot, *hslot2; + struct udp_table *udptable = sk->sk_prot->h.udp_table; + int error = 1; + struct net *net = sock_net(sk); + + if (!snum) { + int low, high, remaining; + unsigned int rand; + unsigned short first, last; + DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); + + inet_get_local_port_range(net, &low, &high); + remaining = (high - low) + 1; + + rand = prandom_u32(); + first = reciprocal_scale(rand, remaining) + low; + /* + * force rand to be an odd multiple of UDP_HTABLE_SIZE + */ + rand = (rand | 1) * (udptable->mask + 1); + last = first + udptable->mask + 1; + do { + hslot = udp_hashslot(udptable, net, first); + bitmap_zero(bitmap, PORTS_PER_CHAIN); + spin_lock_bh(&hslot->lock); + udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, + udptable->log); + + snum = first; + /* + * Iterate on all possible values of snum for this hash. + * Using steps of an odd multiple of UDP_HTABLE_SIZE + * give us randomization and full range coverage. + */ + do { + if (low <= snum && snum <= high && + !test_bit(snum >> udptable->log, bitmap) && + !inet_is_local_reserved_port(net, snum)) + goto found; + snum += rand; + } while (snum != first); + spin_unlock_bh(&hslot->lock); + cond_resched(); + } while (++first != last); + goto fail; + } else { + hslot = udp_hashslot(udptable, net, snum); + spin_lock_bh(&hslot->lock); + if (hslot->count > 10) { + int exist; + unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; + + slot2 &= udptable->mask; + hash2_nulladdr &= udptable->mask; + + hslot2 = udp_hashslot2(udptable, slot2); + if (hslot->count < hslot2->count) + goto scan_primary_hash; + + exist = udp_lib_lport_inuse2(net, snum, hslot2, sk); + if (!exist && (hash2_nulladdr != slot2)) { + hslot2 = udp_hashslot2(udptable, hash2_nulladdr); + exist = udp_lib_lport_inuse2(net, snum, hslot2, + sk); + } + if (exist) + goto fail_unlock; + else + goto found; + } +scan_primary_hash: + if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0)) + goto fail_unlock; + } +found: + inet_sk(sk)->inet_num = snum; + udp_sk(sk)->udp_port_hash = snum; + udp_sk(sk)->udp_portaddr_hash ^= snum; + if (sk_unhashed(sk)) { + if (sk->sk_reuseport && + udp_reuseport_add_sock(sk, hslot)) { + inet_sk(sk)->inet_num = 0; + udp_sk(sk)->udp_port_hash = 0; + udp_sk(sk)->udp_portaddr_hash ^= snum; + goto fail_unlock; + } + + sk_add_node_rcu(sk, &hslot->head); + hslot->count++; + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); + + hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); + spin_lock(&hslot2->lock); + if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && + sk->sk_family == AF_INET6) + hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node, + &hslot2->head); + else + hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, + &hslot2->head); + hslot2->count++; + spin_unlock(&hslot2->lock); + } + sock_set_flag(sk, SOCK_RCU_FREE); + error = 0; +fail_unlock: + spin_unlock_bh(&hslot->lock); +fail: + return error; +} +EXPORT_SYMBOL(udp_lib_get_port); + +int udp_v4_get_port(struct sock *sk, unsigned short snum) +{ + unsigned int hash2_nulladdr = + ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); + unsigned int hash2_partial = + ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); + + /* precompute partial secondary hash */ + udp_sk(sk)->udp_portaddr_hash = hash2_partial; + return udp_lib_get_port(sk, snum, hash2_nulladdr); +} + +static int compute_score(struct sock *sk, struct net *net, + __be32 saddr, __be16 sport, + __be32 daddr, unsigned short hnum, + int dif, int sdif) +{ + int score; + struct inet_sock *inet; + bool dev_match; + + if (!net_eq(sock_net(sk), net) || + udp_sk(sk)->udp_port_hash != hnum || + ipv6_only_sock(sk)) + return -1; + + if (sk->sk_rcv_saddr != daddr) + return -1; + + score = (sk->sk_family == PF_INET) ? 2 : 1; + + inet = inet_sk(sk); + if (inet->inet_daddr) { + if (inet->inet_daddr != saddr) + return -1; + score += 4; + } + + if (inet->inet_dport) { + if (inet->inet_dport != sport) + return -1; + score += 4; + } + + dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, + dif, sdif); + if (!dev_match) + return -1; + if (sk->sk_bound_dev_if) + score += 4; + + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) + score++; + return score; +} + +static u32 udp_ehashfn(const struct net *net, const __be32 laddr, + const __u16 lport, const __be32 faddr, + const __be16 fport) +{ + static u32 udp_ehash_secret __read_mostly; + + net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); + + return __inet_ehashfn(laddr, lport, faddr, fport, + udp_ehash_secret + net_hash_mix(net)); +} + +static struct sock *lookup_reuseport(struct net *net, struct sock *sk, + struct sk_buff *skb, + __be32 saddr, __be16 sport, + __be32 daddr, unsigned short hnum) +{ + struct sock *reuse_sk = NULL; + u32 hash; + + if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) { + hash = udp_ehashfn(net, daddr, hnum, saddr, sport); + reuse_sk = reuseport_select_sock(sk, hash, skb, + sizeof(struct udphdr)); + } + return reuse_sk; +} + +/* called with rcu_read_lock() */ +static struct sock *udp4_lib_lookup2(struct net *net, + __be32 saddr, __be16 sport, + __be32 daddr, unsigned int hnum, + int dif, int sdif, + struct udp_hslot *hslot2, + struct sk_buff *skb) +{ + struct sock *sk, *result; + int score, badness; + + result = NULL; + badness = 0; + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { + score = compute_score(sk, net, saddr, sport, + daddr, hnum, dif, sdif); + if (score > badness) { + badness = score; + result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (!result) { + result = sk; + continue; + } + + /* Fall back to scoring if group has connections */ + if (!reuseport_has_conns(sk)) + return result; + + /* Reuseport logic returned an error, keep original score. */ + if (IS_ERR(result)) + continue; + + badness = compute_score(result, net, saddr, sport, + daddr, hnum, dif, sdif); + + } + } + return result; +} + +static struct sock *udp4_lookup_run_bpf(struct net *net, + struct udp_table *udptable, + struct sk_buff *skb, + __be32 saddr, __be16 sport, + __be32 daddr, u16 hnum) +{ + struct sock *sk, *reuse_sk; + bool no_reuseport; + + if (udptable != &udp_table) + return NULL; /* only UDP is supported */ + + no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP, + saddr, sport, daddr, hnum, &sk); + if (no_reuseport || IS_ERR_OR_NULL(sk)) + return sk; + + reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (reuse_sk) + sk = reuse_sk; + return sk; +} + +/* UDP is nearly always wildcards out the wazoo, it makes no sense to try + * harder than this. -DaveM + */ +struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, + __be16 sport, __be32 daddr, __be16 dport, int dif, + int sdif, struct udp_table *udptable, struct sk_buff *skb) +{ + unsigned short hnum = ntohs(dport); + unsigned int hash2, slot2; + struct udp_hslot *hslot2; + struct sock *result, *sk; + + hash2 = ipv4_portaddr_hash(net, daddr, hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + /* Lookup connected or non-wildcard socket */ + result = udp4_lib_lookup2(net, saddr, sport, + daddr, hnum, dif, sdif, + hslot2, skb); + if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED) + goto done; + + /* Lookup redirect from BPF */ + if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { + sk = udp4_lookup_run_bpf(net, udptable, skb, + saddr, sport, daddr, hnum); + if (sk) { + result = sk; + goto done; + } + } + + /* Got non-wildcard socket or error on first lookup */ + if (result) + goto done; + + /* Lookup wildcard sockets */ + hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + result = udp4_lib_lookup2(net, saddr, sport, + htonl(INADDR_ANY), hnum, dif, sdif, + hslot2, skb); +done: + if (IS_ERR(result)) + return NULL; + return result; +} +EXPORT_SYMBOL_GPL(__udp4_lib_lookup); + +static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, + __be16 sport, __be16 dport, + struct udp_table *udptable) +{ + const struct iphdr *iph = ip_hdr(skb); + + return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, + iph->daddr, dport, inet_iif(skb), + inet_sdif(skb), udptable, skb); +} + +struct sock *udp4_lib_lookup_skb(struct sk_buff *skb, + __be16 sport, __be16 dport) +{ + const struct iphdr *iph = ip_hdr(skb); + + return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, + iph->daddr, dport, inet_iif(skb), + inet_sdif(skb), &udp_table, NULL); +} +EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb); + +/* Must be called under rcu_read_lock(). + * Does increment socket refcount. + */ +#if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4) +struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, + __be32 daddr, __be16 dport, int dif) +{ + struct sock *sk; + + sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, + dif, 0, &udp_table, NULL); + if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + return sk; +} +EXPORT_SYMBOL_GPL(udp4_lib_lookup); +#endif + +static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, + __be16 loc_port, __be32 loc_addr, + __be16 rmt_port, __be32 rmt_addr, + int dif, int sdif, unsigned short hnum) +{ + struct inet_sock *inet = inet_sk(sk); + + if (!net_eq(sock_net(sk), net) || + udp_sk(sk)->udp_port_hash != hnum || + (inet->inet_daddr && inet->inet_daddr != rmt_addr) || + (inet->inet_dport != rmt_port && inet->inet_dport) || + (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || + ipv6_only_sock(sk) || + !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) + return false; + if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif)) + return false; + return true; +} + +DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key); +void udp_encap_enable(void) +{ + static_branch_inc(&udp_encap_needed_key); +} +EXPORT_SYMBOL(udp_encap_enable); + +void udp_encap_disable(void) +{ + static_branch_dec(&udp_encap_needed_key); +} +EXPORT_SYMBOL(udp_encap_disable); + +/* Handler for tunnels with arbitrary destination ports: no socket lookup, go + * through error handlers in encapsulations looking for a match. + */ +static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info) +{ + int i; + + for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { + int (*handler)(struct sk_buff *skb, u32 info); + const struct ip_tunnel_encap_ops *encap; + + encap = rcu_dereference(iptun_encaps[i]); + if (!encap) + continue; + handler = encap->err_handler; + if (handler && !handler(skb, info)) + return 0; + } + + return -ENOENT; +} + +/* Try to match ICMP errors to UDP tunnels by looking up a socket without + * reversing source and destination port: this will match tunnels that force the + * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that + * lwtunnels might actually break this assumption by being configured with + * different destination ports on endpoints, in this case we won't be able to + * trace ICMP messages back to them. + * + * If this doesn't match any socket, probe tunnels with arbitrary destination + * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port + * we've sent packets to won't necessarily match the local destination port. + * + * Then ask the tunnel implementation to match the error against a valid + * association. + * + * Return an error if we can't find a match, the socket if we need further + * processing, zero otherwise. + */ +static struct sock *__udp4_lib_err_encap(struct net *net, + const struct iphdr *iph, + struct udphdr *uh, + struct udp_table *udptable, + struct sk_buff *skb, u32 info) +{ + int network_offset, transport_offset; + struct sock *sk; + + network_offset = skb_network_offset(skb); + transport_offset = skb_transport_offset(skb); + + /* Network header needs to point to the outer IPv4 header inside ICMP */ + skb_reset_network_header(skb); + + /* Transport header needs to point to the UDP header */ + skb_set_transport_header(skb, iph->ihl << 2); + + sk = __udp4_lib_lookup(net, iph->daddr, uh->source, + iph->saddr, uh->dest, skb->dev->ifindex, 0, + udptable, NULL); + if (sk) { + int (*lookup)(struct sock *sk, struct sk_buff *skb); + struct udp_sock *up = udp_sk(sk); + + lookup = READ_ONCE(up->encap_err_lookup); + if (!lookup || lookup(sk, skb)) + sk = NULL; + } + + if (!sk) + sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info)); + + skb_set_transport_header(skb, transport_offset); + skb_set_network_header(skb, network_offset); + + return sk; +} + +/* + * This routine is called by the ICMP module when it gets some + * sort of error condition. If err < 0 then the socket should + * be closed and the error returned to the user. If err > 0 + * it's just the icmp type << 8 | icmp code. + * Header points to the ip header of the error packet. We move + * on past this. Then (as it used to claim before adjustment) + * header points to the first 8 bytes of the udp header. We need + * to find the appropriate port. + */ + +int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) +{ + struct inet_sock *inet; + const struct iphdr *iph = (const struct iphdr *)skb->data; + struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + bool tunnel = false; + struct sock *sk; + int harderr; + int err; + struct net *net = dev_net(skb->dev); + + sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, + iph->saddr, uh->source, skb->dev->ifindex, + inet_sdif(skb), udptable, NULL); + if (!sk) { + /* No socket for error: try tunnels before discarding */ + sk = ERR_PTR(-ENOENT); + if (static_branch_unlikely(&udp_encap_needed_key)) { + sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb, + info); + if (!sk) + return 0; + } + + if (IS_ERR(sk)) { + __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); + return PTR_ERR(sk); + } + + tunnel = true; + } + + err = 0; + harderr = 0; + inet = inet_sk(sk); + + switch (type) { + default: + case ICMP_TIME_EXCEEDED: + err = EHOSTUNREACH; + break; + case ICMP_SOURCE_QUENCH: + goto out; + case ICMP_PARAMETERPROB: + err = EPROTO; + harderr = 1; + break; + case ICMP_DEST_UNREACH: + if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ + ipv4_sk_update_pmtu(skb, sk, info); + if (inet->pmtudisc != IP_PMTUDISC_DONT) { + err = EMSGSIZE; + harderr = 1; + break; + } + goto out; + } + err = EHOSTUNREACH; + if (code <= NR_ICMP_UNREACH) { + harderr = icmp_err_convert[code].fatal; + err = icmp_err_convert[code].errno; + } + break; + case ICMP_REDIRECT: + ipv4_sk_redirect(skb, sk); + goto out; + } + + /* + * RFC1122: OK. Passes ICMP errors back to application, as per + * 4.1.3.3. + */ + if (tunnel) { + /* ...not for tunnels though: we don't have a sending socket */ + goto out; + } + if (!inet->recverr) { + if (!harderr || sk->sk_state != TCP_ESTABLISHED) + goto out; + } else + ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); + + sk->sk_err = err; + sk->sk_error_report(sk); +out: + return 0; +} + +int udp_err(struct sk_buff *skb, u32 info) +{ + return __udp4_lib_err(skb, info, &udp_table); +} + +/* + * Throw away all pending data and cancel the corking. Socket is locked. + */ +void udp_flush_pending_frames(struct sock *sk) +{ + struct udp_sock *up = udp_sk(sk); + + if (up->pending) { + up->len = 0; + up->pending = 0; + ip_flush_pending_frames(sk); + } +} +EXPORT_SYMBOL(udp_flush_pending_frames); + +/** + * udp4_hwcsum - handle outgoing HW checksumming + * @skb: sk_buff containing the filled-in UDP header + * (checksum field must be zeroed out) + * @src: source IP address + * @dst: destination IP address + */ +void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) +{ + struct udphdr *uh = udp_hdr(skb); + int offset = skb_transport_offset(skb); + int len = skb->len - offset; + int hlen = len; + __wsum csum = 0; + + if (!skb_has_frag_list(skb)) { + /* + * Only one fragment on the socket. + */ + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + uh->check = ~csum_tcpudp_magic(src, dst, len, + IPPROTO_UDP, 0); + } else { + struct sk_buff *frags; + + /* + * HW-checksum won't work as there are two or more + * fragments on the socket so that all csums of sk_buffs + * should be together + */ + skb_walk_frags(skb, frags) { + csum = csum_add(csum, frags->csum); + hlen -= frags->len; + } + + csum = skb_checksum(skb, offset, hlen, csum); + skb->ip_summed = CHECKSUM_NONE; + + uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + } +} +EXPORT_SYMBOL_GPL(udp4_hwcsum); + +/* Function to set UDP checksum for an IPv4 UDP packet. This is intended + * for the simple case like when setting the checksum for a UDP tunnel. + */ +void udp_set_csum(bool nocheck, struct sk_buff *skb, + __be32 saddr, __be32 daddr, int len) +{ + struct udphdr *uh = udp_hdr(skb); + + if (nocheck) { + uh->check = 0; + } else if (skb_is_gso(skb)) { + uh->check = ~udp_v4_check(len, saddr, daddr, 0); + } else if (skb->ip_summed == CHECKSUM_PARTIAL) { + uh->check = 0; + uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb)); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + } else { + skb->ip_summed = CHECKSUM_PARTIAL; + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + uh->check = ~udp_v4_check(len, saddr, daddr, 0); + } +} +EXPORT_SYMBOL(udp_set_csum); + +static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4, + struct inet_cork *cork) +{ + struct sock *sk = skb->sk; + struct inet_sock *inet = inet_sk(sk); + struct udphdr *uh; + int err = 0; + int is_udplite = IS_UDPLITE(sk); + int offset = skb_transport_offset(skb); + int len = skb->len - offset; + int datalen = len - sizeof(*uh); + __wsum csum = 0; + + /* + * Create a UDP header + */ + uh = udp_hdr(skb); + uh->source = inet->inet_sport; + uh->dest = fl4->fl4_dport; + uh->len = htons(len); + uh->check = 0; + + if (cork->gso_size) { + const int hlen = skb_network_header_len(skb) + + sizeof(struct udphdr); + + if (hlen + cork->gso_size > cork->fragsize) { + kfree_skb(skb); + return -EINVAL; + } + if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) { + kfree_skb(skb); + return -EINVAL; + } + if (sk->sk_no_check_tx) { + kfree_skb(skb); + return -EINVAL; + } + if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || + dst_xfrm(skb_dst(skb))) { + kfree_skb(skb); + return -EIO; + } + + if (datalen > cork->gso_size) { + skb_shinfo(skb)->gso_size = cork->gso_size; + skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, + cork->gso_size); + } + goto csum_partial; + } + + if (is_udplite) /* UDP-Lite */ + csum = udplite_csum(skb); + + else if (sk->sk_no_check_tx) { /* UDP csum off */ + + skb->ip_summed = CHECKSUM_NONE; + goto send; + + } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ +csum_partial: + + udp4_hwcsum(skb, fl4->saddr, fl4->daddr); + goto send; + + } else + csum = udp_csum(skb); + + /* add protocol-dependent pseudo-header */ + uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, + sk->sk_protocol, csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + +send: + err = ip_send_skb(sock_net(sk), skb); + if (err) { + if (err == -ENOBUFS && !inet->recverr) { + UDP_INC_STATS(sock_net(sk), + UDP_MIB_SNDBUFERRORS, is_udplite); + err = 0; + } + } else + UDP_INC_STATS(sock_net(sk), + UDP_MIB_OUTDATAGRAMS, is_udplite); + return err; +} + +/* + * Push out all pending data as one UDP datagram. Socket is locked. + */ +int udp_push_pending_frames(struct sock *sk) +{ + struct udp_sock *up = udp_sk(sk); + struct inet_sock *inet = inet_sk(sk); + struct flowi4 *fl4 = &inet->cork.fl.u.ip4; + struct sk_buff *skb; + int err = 0; + + skb = ip_finish_skb(sk, fl4); + if (!skb) + goto out; + + err = udp_send_skb(skb, fl4, &inet->cork.base); + +out: + up->len = 0; + up->pending = 0; + return err; +} +EXPORT_SYMBOL(udp_push_pending_frames); + +static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size) +{ + switch (cmsg->cmsg_type) { + case UDP_SEGMENT: + if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16))) + return -EINVAL; + *gso_size = *(__u16 *)CMSG_DATA(cmsg); + return 0; + default: + return -EINVAL; + } +} + +int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size) +{ + struct cmsghdr *cmsg; + bool need_ip = false; + int err; + + for_each_cmsghdr(cmsg, msg) { + if (!CMSG_OK(msg, cmsg)) + return -EINVAL; + + if (cmsg->cmsg_level != SOL_UDP) { + need_ip = true; + continue; + } + + err = __udp_cmsg_send(cmsg, gso_size); + if (err) + return err; + } + + return need_ip; +} +EXPORT_SYMBOL_GPL(udp_cmsg_send); + +int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct inet_sock *inet = inet_sk(sk); + struct udp_sock *up = udp_sk(sk); + DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); + struct flowi4 fl4_stack; + struct flowi4 *fl4; + int ulen = len; + struct ipcm_cookie ipc; + struct rtable *rt = NULL; + int free = 0; + int connected = 0; + __be32 daddr, faddr, saddr; + __be16 dport; + u8 tos; + int err, is_udplite = IS_UDPLITE(sk); + int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE; + int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); + struct sk_buff *skb; + struct ip_options_data opt_copy; + + if (len > 0xFFFF) + return -EMSGSIZE; + + /* + * Check the flags. + */ + + if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ + return -EOPNOTSUPP; + + getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; + + fl4 = &inet->cork.fl.u.ip4; + if (up->pending) { + /* + * There are pending frames. + * The socket lock must be held while it's corked. + */ + lock_sock(sk); + if (likely(up->pending)) { + if (unlikely(up->pending != AF_INET)) { + release_sock(sk); + return -EINVAL; + } + goto do_append_data; + } + release_sock(sk); + } + ulen += sizeof(struct udphdr); + + /* + * Get and verify the address. + */ + if (usin) { + if (msg->msg_namelen < sizeof(*usin)) + return -EINVAL; + if (usin->sin_family != AF_INET) { + if (usin->sin_family != AF_UNSPEC) + return -EAFNOSUPPORT; + } + + daddr = usin->sin_addr.s_addr; + dport = usin->sin_port; + if (dport == 0) + return -EINVAL; + } else { + if (sk->sk_state != TCP_ESTABLISHED) + return -EDESTADDRREQ; + daddr = inet->inet_daddr; + dport = inet->inet_dport; + /* Open fast path for connected socket. + Route will not be used, if at least one option is set. + */ + connected = 1; + } + + ipcm_init_sk(&ipc, inet); + ipc.gso_size = READ_ONCE(up->gso_size); + + if (msg->msg_controllen) { + err = udp_cmsg_send(sk, msg, &ipc.gso_size); + if (err > 0) + err = ip_cmsg_send(sk, msg, &ipc, + sk->sk_family == AF_INET6); + if (unlikely(err < 0)) { + kfree(ipc.opt); + return err; + } + if (ipc.opt) + free = 1; + connected = 0; + } + if (!ipc.opt) { + struct ip_options_rcu *inet_opt; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) { + memcpy(&opt_copy, inet_opt, + sizeof(*inet_opt) + inet_opt->opt.optlen); + ipc.opt = &opt_copy.opt; + } + rcu_read_unlock(); + } + + if (cgroup_bpf_enabled && !connected) { + err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, + (struct sockaddr *)usin, &ipc.addr); + if (err) + goto out_free; + if (usin) { + if (usin->sin_port == 0) { + /* BPF program set invalid port. Reject it. */ + err = -EINVAL; + goto out_free; + } + daddr = usin->sin_addr.s_addr; + dport = usin->sin_port; + } + } + + saddr = ipc.addr; + ipc.addr = faddr = daddr; + + if (ipc.opt && ipc.opt->opt.srr) { + if (!daddr) { + err = -EINVAL; + goto out_free; + } + faddr = ipc.opt->opt.faddr; + connected = 0; + } + tos = get_rttos(&ipc, inet); + if (sock_flag(sk, SOCK_LOCALROUTE) || + (msg->msg_flags & MSG_DONTROUTE) || + (ipc.opt && ipc.opt->opt.is_strictroute)) { + tos |= RTO_ONLINK; + connected = 0; + } + + if (ipv4_is_multicast(daddr)) { + if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) + ipc.oif = inet->mc_index; + if (!saddr) + saddr = inet->mc_addr; + connected = 0; + } else if (!ipc.oif) { + ipc.oif = inet->uc_index; + } else if (ipv4_is_lbcast(daddr) && inet->uc_index) { + /* oif is set, packet is to local broadcast and + * uc_index is set. oif is most likely set + * by sk_bound_dev_if. If uc_index != oif check if the + * oif is an L3 master and uc_index is an L3 slave. + * If so, we want to allow the send using the uc_index. + */ + if (ipc.oif != inet->uc_index && + ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk), + inet->uc_index)) { + ipc.oif = inet->uc_index; + } + } + + if (connected) + rt = (struct rtable *)sk_dst_check(sk, 0); + + if (!rt) { + struct net *net = sock_net(sk); + __u8 flow_flags = inet_sk_flowi_flags(sk); + + fl4 = &fl4_stack; + + flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos, + RT_SCOPE_UNIVERSE, sk->sk_protocol, + flow_flags, + faddr, saddr, dport, inet->inet_sport, + sk->sk_uid); + + security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); + rt = ip_route_output_flow(net, fl4, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + rt = NULL; + if (err == -ENETUNREACH) + IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); + goto out; + } + + err = -EACCES; + if ((rt->rt_flags & RTCF_BROADCAST) && + !sock_flag(sk, SOCK_BROADCAST)) + goto out; + if (connected) + sk_dst_set(sk, dst_clone(&rt->dst)); + } + + if (msg->msg_flags&MSG_CONFIRM) + goto do_confirm; +back_from_confirm: + + saddr = fl4->saddr; + if (!ipc.addr) + daddr = ipc.addr = fl4->daddr; + + /* Lockless fast path for the non-corking case. */ + if (!corkreq) { + struct inet_cork cork; + + skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, + sizeof(struct udphdr), &ipc, &rt, + &cork, msg->msg_flags); + err = PTR_ERR(skb); + if (!IS_ERR_OR_NULL(skb)) + err = udp_send_skb(skb, fl4, &cork); + goto out; + } + + lock_sock(sk); + if (unlikely(up->pending)) { + /* The socket is already corked while preparing it. */ + /* ... which is an evident application bug. --ANK */ + release_sock(sk); + + net_dbg_ratelimited("socket already corked\n"); + err = -EINVAL; + goto out; + } + /* + * Now cork the socket to pend data. + */ + fl4 = &inet->cork.fl.u.ip4; + fl4->daddr = daddr; + fl4->saddr = saddr; + fl4->fl4_dport = dport; + fl4->fl4_sport = inet->inet_sport; + up->pending = AF_INET; + +do_append_data: + up->len += ulen; + err = ip_append_data(sk, fl4, getfrag, msg, ulen, + sizeof(struct udphdr), &ipc, &rt, + corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); + if (err) + udp_flush_pending_frames(sk); + else if (!corkreq) + err = udp_push_pending_frames(sk); + else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) + up->pending = 0; + release_sock(sk); + +out: + ip_rt_put(rt); +out_free: + if (free) + kfree(ipc.opt); + if (!err) + return len; + /* + * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting + * ENOBUFS might not be good (it's not tunable per se), but otherwise + * we don't have a good statistic (IpOutDiscards but it can be too many + * things). We could add another new stat but at least for now that + * seems like overkill. + */ + if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { + UDP_INC_STATS(sock_net(sk), + UDP_MIB_SNDBUFERRORS, is_udplite); + } + return err; + +do_confirm: + if (msg->msg_flags & MSG_PROBE) + dst_confirm_neigh(&rt->dst, &fl4->daddr); + if (!(msg->msg_flags&MSG_PROBE) || len) + goto back_from_confirm; + err = 0; + goto out; +} +EXPORT_SYMBOL(udp_sendmsg); + +int udp_sendpage(struct sock *sk, struct page *page, int offset, + size_t size, int flags) +{ + struct inet_sock *inet = inet_sk(sk); + struct udp_sock *up = udp_sk(sk); + int ret; + + if (flags & MSG_SENDPAGE_NOTLAST) + flags |= MSG_MORE; + + if (!up->pending) { + struct msghdr msg = { .msg_flags = flags|MSG_MORE }; + + /* Call udp_sendmsg to specify destination address which + * sendpage interface can't pass. + * This will succeed only when the socket is connected. + */ + ret = udp_sendmsg(sk, &msg, 0); + if (ret < 0) + return ret; + } + + lock_sock(sk); + + if (unlikely(!up->pending)) { + release_sock(sk); + + net_dbg_ratelimited("cork failed\n"); + return -EINVAL; + } + + ret = ip_append_page(sk, &inet->cork.fl.u.ip4, + page, offset, size, flags); + if (ret == -EOPNOTSUPP) { + release_sock(sk); + return sock_no_sendpage(sk->sk_socket, page, offset, + size, flags); + } + if (ret < 0) { + udp_flush_pending_frames(sk); + goto out; + } + + up->len += size; + if (!(READ_ONCE(up->corkflag) || (flags&MSG_MORE))) + ret = udp_push_pending_frames(sk); + if (!ret) + ret = size; +out: + release_sock(sk); + return ret; +} + +#define UDP_SKB_IS_STATELESS 0x80000000 + +/* all head states (dst, sk, nf conntrack) except skb extensions are + * cleared by udp_rcv(). + * + * We need to preserve secpath, if present, to eventually process + * IP_CMSG_PASSSEC at recvmsg() time. + * + * Other extensions can be cleared. + */ +static bool udp_try_make_stateless(struct sk_buff *skb) +{ + if (!skb_has_extensions(skb)) + return true; + + if (!secpath_exists(skb)) { + skb_ext_reset(skb); + return true; + } + + return false; +} + +static void udp_set_dev_scratch(struct sk_buff *skb) +{ + struct udp_dev_scratch *scratch = udp_skb_scratch(skb); + + BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long)); + scratch->_tsize_state = skb->truesize; +#if BITS_PER_LONG == 64 + scratch->len = skb->len; + scratch->csum_unnecessary = !!skb_csum_unnecessary(skb); + scratch->is_linear = !skb_is_nonlinear(skb); +#endif + if (udp_try_make_stateless(skb)) + scratch->_tsize_state |= UDP_SKB_IS_STATELESS; +} + +static void udp_skb_csum_unnecessary_set(struct sk_buff *skb) +{ + /* We come here after udp_lib_checksum_complete() returned 0. + * This means that __skb_checksum_complete() might have + * set skb->csum_valid to 1. + * On 64bit platforms, we can set csum_unnecessary + * to true, but only if the skb is not shared. + */ +#if BITS_PER_LONG == 64 + if (!skb_shared(skb)) + udp_skb_scratch(skb)->csum_unnecessary = true; +#endif +} + +static int udp_skb_truesize(struct sk_buff *skb) +{ + return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS; +} + +static bool udp_skb_has_head_state(struct sk_buff *skb) +{ + return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS); +} + +/* fully reclaim rmem/fwd memory allocated for skb */ +static void udp_rmem_release(struct sock *sk, int size, int partial, + bool rx_queue_lock_held) +{ + struct udp_sock *up = udp_sk(sk); + struct sk_buff_head *sk_queue; + int amt; + + if (likely(partial)) { + up->forward_deficit += size; + size = up->forward_deficit; + if (size < (sk->sk_rcvbuf >> 2) && + !skb_queue_empty(&up->reader_queue)) + return; + } else { + size += up->forward_deficit; + } + up->forward_deficit = 0; + + /* acquire the sk_receive_queue for fwd allocated memory scheduling, + * if the called don't held it already + */ + sk_queue = &sk->sk_receive_queue; + if (!rx_queue_lock_held) + spin_lock(&sk_queue->lock); + + + sk->sk_forward_alloc += size; + amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); + sk->sk_forward_alloc -= amt; + + if (amt) + __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); + + atomic_sub(size, &sk->sk_rmem_alloc); + + /* this can save us from acquiring the rx queue lock on next receive */ + skb_queue_splice_tail_init(sk_queue, &up->reader_queue); + + if (!rx_queue_lock_held) + spin_unlock(&sk_queue->lock); +} + +/* Note: called with reader_queue.lock held. + * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch + * This avoids a cache line miss while receive_queue lock is held. + * Look at __udp_enqueue_schedule_skb() to find where this copy is done. + */ +void udp_skb_destructor(struct sock *sk, struct sk_buff *skb) +{ + prefetch(&skb->data); + udp_rmem_release(sk, udp_skb_truesize(skb), 1, false); +} +EXPORT_SYMBOL(udp_skb_destructor); + +/* as above, but the caller held the rx queue lock, too */ +static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb) +{ + prefetch(&skb->data); + udp_rmem_release(sk, udp_skb_truesize(skb), 1, true); +} + +/* Idea of busylocks is to let producers grab an extra spinlock + * to relieve pressure on the receive_queue spinlock shared by consumer. + * Under flood, this means that only one producer can be in line + * trying to acquire the receive_queue spinlock. + * These busylock can be allocated on a per cpu manner, instead of a + * per socket one (that would consume a cache line per socket) + */ +static int udp_busylocks_log __read_mostly; +static spinlock_t *udp_busylocks __read_mostly; + +static spinlock_t *busylock_acquire(void *ptr) +{ + spinlock_t *busy; + + busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log); + spin_lock(busy); + return busy; +} + +static void busylock_release(spinlock_t *busy) +{ + if (busy) + spin_unlock(busy); +} + +int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff_head *list = &sk->sk_receive_queue; + int rmem, delta, amt, err = -ENOMEM; + spinlock_t *busy = NULL; + int size; + + /* try to avoid the costly atomic add/sub pair when the receive + * queue is full; always allow at least a packet + */ + rmem = atomic_read(&sk->sk_rmem_alloc); + if (rmem > sk->sk_rcvbuf) + goto drop; + + /* Under mem pressure, it might be helpful to help udp_recvmsg() + * having linear skbs : + * - Reduce memory overhead and thus increase receive queue capacity + * - Less cache line misses at copyout() time + * - Less work at consume_skb() (less alien page frag freeing) + */ + if (rmem > (sk->sk_rcvbuf >> 1)) { + skb_condense(skb); + + busy = busylock_acquire(sk); + } + size = skb->truesize; + udp_set_dev_scratch(skb); + + /* we drop only if the receive buf is full and the receive + * queue contains some other skb + */ + rmem = atomic_add_return(size, &sk->sk_rmem_alloc); + if (rmem > (size + (unsigned int)sk->sk_rcvbuf)) + goto uncharge_drop; + + spin_lock(&list->lock); + if (size >= sk->sk_forward_alloc) { + amt = sk_mem_pages(size); + delta = amt << SK_MEM_QUANTUM_SHIFT; + if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { + err = -ENOBUFS; + spin_unlock(&list->lock); + goto uncharge_drop; + } + + sk->sk_forward_alloc += delta; + } + + sk->sk_forward_alloc -= size; + + /* no need to setup a destructor, we will explicitly release the + * forward allocated memory on dequeue + */ + sock_skb_set_dropcount(sk, skb); + + __skb_queue_tail(list, skb); + spin_unlock(&list->lock); + + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_data_ready(sk); + + busylock_release(busy); + return 0; + +uncharge_drop: + atomic_sub(skb->truesize, &sk->sk_rmem_alloc); + +drop: + atomic_inc(&sk->sk_drops); + busylock_release(busy); + return err; +} +EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); + +void udp_destruct_common(struct sock *sk) +{ + /* reclaim completely the forward allocated memory */ + struct udp_sock *up = udp_sk(sk); + unsigned int total = 0; + struct sk_buff *skb; + + skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue); + while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) { + total += skb->truesize; + kfree_skb(skb); + } + udp_rmem_release(sk, total, 0, true); +} +EXPORT_SYMBOL_GPL(udp_destruct_common); + +static void udp_destruct_sock(struct sock *sk) +{ + udp_destruct_common(sk); + inet_sock_destruct(sk); +} + +int udp_init_sock(struct sock *sk) +{ + skb_queue_head_init(&udp_sk(sk)->reader_queue); + sk->sk_destruct = udp_destruct_sock; + return 0; +} + +void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) +{ + if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { + bool slow = lock_sock_fast(sk); + + sk_peek_offset_bwd(sk, len); + unlock_sock_fast(sk, slow); + } + + if (!skb_unref(skb)) + return; + + /* In the more common cases we cleared the head states previously, + * see __udp_queue_rcv_skb(). + */ + if (unlikely(udp_skb_has_head_state(skb))) + skb_release_head_state(skb); + __consume_stateless_skb(skb); +} +EXPORT_SYMBOL_GPL(skb_consume_udp); + +static struct sk_buff *__first_packet_length(struct sock *sk, + struct sk_buff_head *rcvq, + int *total) +{ + struct sk_buff *skb; + + while ((skb = skb_peek(rcvq)) != NULL) { + if (udp_lib_checksum_complete(skb)) { + __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, + IS_UDPLITE(sk)); + __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, + IS_UDPLITE(sk)); + atomic_inc(&sk->sk_drops); + __skb_unlink(skb, rcvq); + *total += skb->truesize; + kfree_skb(skb); + } else { + udp_skb_csum_unnecessary_set(skb); + break; + } + } + return skb; +} + +/** + * first_packet_length - return length of first packet in receive queue + * @sk: socket + * + * Drops all bad checksum frames, until a valid one is found. + * Returns the length of found skb, or -1 if none is found. + */ +static int first_packet_length(struct sock *sk) +{ + struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue; + struct sk_buff_head *sk_queue = &sk->sk_receive_queue; + struct sk_buff *skb; + int total = 0; + int res; + + spin_lock_bh(&rcvq->lock); + skb = __first_packet_length(sk, rcvq, &total); + if (!skb && !skb_queue_empty_lockless(sk_queue)) { + spin_lock(&sk_queue->lock); + skb_queue_splice_tail_init(sk_queue, rcvq); + spin_unlock(&sk_queue->lock); + + skb = __first_packet_length(sk, rcvq, &total); + } + res = skb ? skb->len : -1; + if (total) + udp_rmem_release(sk, total, 1, false); + spin_unlock_bh(&rcvq->lock); + return res; +} + +/* + * IOCTL requests applicable to the UDP protocol + */ + +int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + switch (cmd) { + case SIOCOUTQ: + { + int amount = sk_wmem_alloc_get(sk); + + return put_user(amount, (int __user *)arg); + } + + case SIOCINQ: + { + int amount = max_t(int, 0, first_packet_length(sk)); + + return put_user(amount, (int __user *)arg); + } + + default: + return -ENOIOCTLCMD; + } + + return 0; +} +EXPORT_SYMBOL(udp_ioctl); + +struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, + int noblock, int *off, int *err) +{ + struct sk_buff_head *sk_queue = &sk->sk_receive_queue; + struct sk_buff_head *queue; + struct sk_buff *last; + long timeo; + int error; + + queue = &udp_sk(sk)->reader_queue; + flags |= noblock ? MSG_DONTWAIT : 0; + timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); + do { + struct sk_buff *skb; + + error = sock_error(sk); + if (error) + break; + + error = -EAGAIN; + do { + spin_lock_bh(&queue->lock); + skb = __skb_try_recv_from_queue(sk, queue, flags, off, + err, &last); + if (skb) { + if (!(flags & MSG_PEEK)) + udp_skb_destructor(sk, skb); + spin_unlock_bh(&queue->lock); + return skb; + } + + if (skb_queue_empty_lockless(sk_queue)) { + spin_unlock_bh(&queue->lock); + goto busy_check; + } + + /* refill the reader queue and walk it again + * keep both queues locked to avoid re-acquiring + * the sk_receive_queue lock if fwd memory scheduling + * is needed. + */ + spin_lock(&sk_queue->lock); + skb_queue_splice_tail_init(sk_queue, queue); + + skb = __skb_try_recv_from_queue(sk, queue, flags, off, + err, &last); + if (skb && !(flags & MSG_PEEK)) + udp_skb_dtor_locked(sk, skb); + spin_unlock(&sk_queue->lock); + spin_unlock_bh(&queue->lock); + if (skb) + return skb; + +busy_check: + if (!sk_can_busy_loop(sk)) + break; + + sk_busy_loop(sk, flags & MSG_DONTWAIT); + } while (!skb_queue_empty_lockless(sk_queue)); + + /* sk_queue is empty, reader_queue may contain peeked packets */ + } while (timeo && + !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue, + &error, &timeo, + (struct sk_buff *)sk_queue)); + + *err = error; + return NULL; +} +EXPORT_SYMBOL(__skb_recv_udp); + +/* + * This should be easy, if there is something there we + * return it, otherwise we block. + */ + +int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, + int flags, int *addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); + struct sk_buff *skb; + unsigned int ulen, copied; + int off, err, peeking = flags & MSG_PEEK; + int is_udplite = IS_UDPLITE(sk); + bool checksum_valid = false; + + if (flags & MSG_ERRQUEUE) + return ip_recv_error(sk, msg, len, addr_len); + +try_again: + off = sk_peek_offset(sk, flags); + skb = __skb_recv_udp(sk, flags, noblock, &off, &err); + if (!skb) + return err; + + ulen = udp_skb_len(skb); + copied = len; + if (copied > ulen - off) + copied = ulen - off; + else if (copied < ulen) + msg->msg_flags |= MSG_TRUNC; + + /* + * If checksum is needed at all, try to do it while copying the + * data. If the data is truncated, or if we only want a partial + * coverage checksum (UDP-Lite), do it before the copy. + */ + + if (copied < ulen || peeking || + (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { + checksum_valid = udp_skb_csum_unnecessary(skb) || + !__udp_lib_checksum_complete(skb); + if (!checksum_valid) + goto csum_copy_err; + } + + if (checksum_valid || udp_skb_csum_unnecessary(skb)) { + if (udp_skb_is_linear(skb)) + err = copy_linear_skb(skb, copied, off, &msg->msg_iter); + else + err = skb_copy_datagram_msg(skb, off, msg, copied); + } else { + err = skb_copy_and_csum_datagram_msg(skb, off, msg); + + if (err == -EINVAL) + goto csum_copy_err; + } + + if (unlikely(err)) { + if (!peeking) { + atomic_inc(&sk->sk_drops); + UDP_INC_STATS(sock_net(sk), + UDP_MIB_INERRORS, is_udplite); + } + kfree_skb(skb); + return err; + } + + if (!peeking) + UDP_INC_STATS(sock_net(sk), + UDP_MIB_INDATAGRAMS, is_udplite); + + sock_recv_ts_and_drops(msg, sk, skb); + + /* Copy the address. */ + if (sin) { + sin->sin_family = AF_INET; + sin->sin_port = udp_hdr(skb)->source; + sin->sin_addr.s_addr = ip_hdr(skb)->saddr; + memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); + + if (cgroup_bpf_enabled) + BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, + (struct sockaddr *)sin); + } + + if (udp_sk(sk)->gro_enabled) + udp_cmsg_recv(msg, sk, skb); + + if (inet->cmsg_flags) + ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); + + err = copied; + if (flags & MSG_TRUNC) + err = ulen; + + skb_consume_udp(sk, skb, peeking ? -err : err); + return err; + +csum_copy_err: + if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, + udp_skb_destructor)) { + UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); + UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + } + kfree_skb(skb); + + /* starting over for a new packet, but check if we need to yield */ + cond_resched(); + msg->msg_flags &= ~MSG_TRUNC; + goto try_again; +} + +int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + /* This check is replicated from __ip4_datagram_connect() and + * intended to prevent BPF program called below from accessing bytes + * that are out of the bound specified by user in addr_len. + */ + if (addr_len < sizeof(struct sockaddr_in)) + return -EINVAL; + + return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr); +} +EXPORT_SYMBOL(udp_pre_connect); + +int __udp_disconnect(struct sock *sk, int flags) +{ + struct inet_sock *inet = inet_sk(sk); + /* + * 1003.1g - break association. + */ + + sk->sk_state = TCP_CLOSE; + inet->inet_daddr = 0; + inet->inet_dport = 0; + sock_rps_reset_rxhash(sk); + sk->sk_bound_dev_if = 0; + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) { + inet_reset_saddr(sk); + if (sk->sk_prot->rehash && + (sk->sk_userlocks & SOCK_BINDPORT_LOCK)) + sk->sk_prot->rehash(sk); + } + + if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { + sk->sk_prot->unhash(sk); + inet->inet_sport = 0; + } + sk_dst_reset(sk); + return 0; +} +EXPORT_SYMBOL(__udp_disconnect); + +int udp_disconnect(struct sock *sk, int flags) +{ + lock_sock(sk); + __udp_disconnect(sk, flags); + release_sock(sk); + return 0; +} +EXPORT_SYMBOL(udp_disconnect); + +void udp_lib_unhash(struct sock *sk) +{ + if (sk_hashed(sk)) { + struct udp_table *udptable = sk->sk_prot->h.udp_table; + struct udp_hslot *hslot, *hslot2; + + hslot = udp_hashslot(udptable, sock_net(sk), + udp_sk(sk)->udp_port_hash); + hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); + + spin_lock_bh(&hslot->lock); + if (rcu_access_pointer(sk->sk_reuseport_cb)) + reuseport_detach_sock(sk); + if (sk_del_node_init_rcu(sk)) { + hslot->count--; + inet_sk(sk)->inet_num = 0; + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + + spin_lock(&hslot2->lock); + hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); + hslot2->count--; + spin_unlock(&hslot2->lock); + } + spin_unlock_bh(&hslot->lock); + } +} +EXPORT_SYMBOL(udp_lib_unhash); + +/* + * inet_rcv_saddr was changed, we must rehash secondary hash + */ +void udp_lib_rehash(struct sock *sk, u16 newhash) +{ + if (sk_hashed(sk)) { + struct udp_table *udptable = sk->sk_prot->h.udp_table; + struct udp_hslot *hslot, *hslot2, *nhslot2; + + hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); + nhslot2 = udp_hashslot2(udptable, newhash); + udp_sk(sk)->udp_portaddr_hash = newhash; + + if (hslot2 != nhslot2 || + rcu_access_pointer(sk->sk_reuseport_cb)) { + hslot = udp_hashslot(udptable, sock_net(sk), + udp_sk(sk)->udp_port_hash); + /* we must lock primary chain too */ + spin_lock_bh(&hslot->lock); + if (rcu_access_pointer(sk->sk_reuseport_cb)) + reuseport_detach_sock(sk); + + if (hslot2 != nhslot2) { + spin_lock(&hslot2->lock); + hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); + hslot2->count--; + spin_unlock(&hslot2->lock); + + spin_lock(&nhslot2->lock); + hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, + &nhslot2->head); + nhslot2->count++; + spin_unlock(&nhslot2->lock); + } + + spin_unlock_bh(&hslot->lock); + } + } +} +EXPORT_SYMBOL(udp_lib_rehash); + +void udp_v4_rehash(struct sock *sk) +{ + u16 new_hash = ipv4_portaddr_hash(sock_net(sk), + inet_sk(sk)->inet_rcv_saddr, + inet_sk(sk)->inet_num); + udp_lib_rehash(sk, new_hash); +} + +static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + int rc; + + if (inet_sk(sk)->inet_daddr) { + sock_rps_save_rxhash(sk, skb); + sk_mark_napi_id(sk, skb); + sk_incoming_cpu_update(sk); + } else { + sk_mark_napi_id_once(sk, skb); + } + + rc = __udp_enqueue_schedule_skb(sk, skb); + if (rc < 0) { + int is_udplite = IS_UDPLITE(sk); + + /* Note that an ENOMEM error is charged twice */ + if (rc == -ENOMEM) + UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, + is_udplite); + UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + kfree_skb(skb); + trace_udp_fail_queue_rcv_skb(rc, sk); + return -1; + } + + return 0; +} + +/* returns: + * -1: error + * 0: success + * >0: "udp encap" protocol resubmission + * + * Note that in the success and error cases, the skb is assumed to + * have either been requeued or freed. + */ +static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) +{ + struct udp_sock *up = udp_sk(sk); + int is_udplite = IS_UDPLITE(sk); + + /* + * Charge it to the socket, dropping if the queue is full. + */ + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) + goto drop; + nf_reset_ct(skb); + + if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) { + int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); + + /* + * This is an encapsulation socket so pass the skb to + * the socket's udp_encap_rcv() hook. Otherwise, just + * fall through and pass this up the UDP socket. + * up->encap_rcv() returns the following value: + * =0 if skb was successfully passed to the encap + * handler or was discarded by it. + * >0 if skb should be passed on to UDP. + * <0 if skb should be resubmitted as proto -N + */ + + /* if we're overly short, let UDP handle it */ + encap_rcv = READ_ONCE(up->encap_rcv); + if (encap_rcv) { + int ret; + + /* Verify checksum before giving to encap */ + if (udp_lib_checksum_complete(skb)) + goto csum_error; + + ret = encap_rcv(sk, skb); + if (ret <= 0) { + __UDP_INC_STATS(sock_net(sk), + UDP_MIB_INDATAGRAMS, + is_udplite); + return -ret; + } + } + + /* FALLTHROUGH -- it's a UDP Packet */ + } + + /* + * UDP-Lite specific tests, ignored on UDP sockets + */ + if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { + + /* + * MIB statistics other than incrementing the error count are + * disabled for the following two types of errors: these depend + * on the application settings, not on the functioning of the + * protocol stack as such. + * + * RFC 3828 here recommends (sec 3.3): "There should also be a + * way ... to ... at least let the receiving application block + * delivery of packets with coverage values less than a value + * provided by the application." + */ + if (up->pcrlen == 0) { /* full coverage was set */ + net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", + UDP_SKB_CB(skb)->cscov, skb->len); + goto drop; + } + /* The next case involves violating the min. coverage requested + * by the receiver. This is subtle: if receiver wants x and x is + * greater than the buffersize/MTU then receiver will complain + * that it wants x while sender emits packets of smaller size y. + * Therefore the above ...()->partial_cov statement is essential. + */ + if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { + net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", + UDP_SKB_CB(skb)->cscov, up->pcrlen); + goto drop; + } + } + + prefetch(&sk->sk_rmem_alloc); + if (rcu_access_pointer(sk->sk_filter) && + udp_lib_checksum_complete(skb)) + goto csum_error; + + if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) + goto drop; + + udp_csum_pull_header(skb); + + ipv4_pktinfo_prepare(sk, skb); + return __udp_queue_rcv_skb(sk, skb); + +csum_error: + __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); +drop: + __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + atomic_inc(&sk->sk_drops); + kfree_skb(skb); + return -1; +} + +static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff *next, *segs; + int ret; + + if (likely(!udp_unexpected_gso(sk, skb))) + return udp_queue_rcv_one_skb(sk, skb); + + BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET); + __skb_push(skb, -skb_mac_offset(skb)); + segs = udp_rcv_segment(sk, skb, true); + skb_list_walk_safe(segs, skb, next) { + __skb_pull(skb, skb_transport_offset(skb)); + ret = udp_queue_rcv_one_skb(sk, skb); + if (ret > 0) + ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret); + } + return 0; +} + +/* For TCP sockets, sk_rx_dst is protected by socket lock + * For UDP, we use xchg() to guard against concurrent changes. + */ +bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) +{ + struct dst_entry *old; + + if (dst_hold_safe(dst)) { + old = xchg((__force struct dst_entry **)&sk->sk_rx_dst, dst); + dst_release(old); + return old != dst; + } + return false; +} +EXPORT_SYMBOL(udp_sk_rx_dst_set); + +/* + * Multicasts and broadcasts go to each listener. + * + * Note: called only from the BH handler context. + */ +static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, + struct udphdr *uh, + __be32 saddr, __be32 daddr, + struct udp_table *udptable, + int proto) +{ + struct sock *sk, *first = NULL; + unsigned short hnum = ntohs(uh->dest); + struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); + unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); + unsigned int offset = offsetof(typeof(*sk), sk_node); + int dif = skb->dev->ifindex; + int sdif = inet_sdif(skb); + struct hlist_node *node; + struct sk_buff *nskb; + + if (use_hash2) { + hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & + udptable->mask; + hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask; +start_lookup: + hslot = &udptable->hash2[hash2]; + offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); + } + + sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { + if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr, + uh->source, saddr, dif, sdif, hnum)) + continue; + + if (!first) { + first = sk; + continue; + } + nskb = skb_clone(skb, GFP_ATOMIC); + + if (unlikely(!nskb)) { + atomic_inc(&sk->sk_drops); + __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS, + IS_UDPLITE(sk)); + __UDP_INC_STATS(net, UDP_MIB_INERRORS, + IS_UDPLITE(sk)); + continue; + } + if (udp_queue_rcv_skb(sk, nskb) > 0) + consume_skb(nskb); + } + + /* Also lookup *:port if we are using hash2 and haven't done so yet. */ + if (use_hash2 && hash2 != hash2_any) { + hash2 = hash2_any; + goto start_lookup; + } + + if (first) { + if (udp_queue_rcv_skb(first, skb) > 0) + consume_skb(skb); + } else { + kfree_skb(skb); + __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI, + proto == IPPROTO_UDPLITE); + } + return 0; +} + +/* Initialize UDP checksum. If exited with zero value (success), + * CHECKSUM_UNNECESSARY means, that no more checks are required. + * Otherwise, csum completion requires checksumming packet body, + * including udp header and folding it to skb->csum. + */ +static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, + int proto) +{ + int err; + + UDP_SKB_CB(skb)->partial_cov = 0; + UDP_SKB_CB(skb)->cscov = skb->len; + + if (proto == IPPROTO_UDPLITE) { + err = udplite_checksum_init(skb, uh); + if (err) + return err; + + if (UDP_SKB_CB(skb)->partial_cov) { + skb->csum = inet_compute_pseudo(skb, proto); + return 0; + } + } + + /* Note, we are only interested in != 0 or == 0, thus the + * force to int. + */ + err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check, + inet_compute_pseudo); + if (err) + return err; + + if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) { + /* If SW calculated the value, we know it's bad */ + if (skb->csum_complete_sw) + return 1; + + /* HW says the value is bad. Let's validate that. + * skb->csum is no longer the full packet checksum, + * so don't treat it as such. + */ + skb_checksum_complete_unset(skb); + } + + return 0; +} + +/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and + * return code conversion for ip layer consumption + */ +static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, + struct udphdr *uh) +{ + int ret; + + if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) + skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo); + + ret = udp_queue_rcv_skb(sk, skb); + + /* a return value > 0 means to resubmit the input, but + * it wants the return to be -protocol, or 0 + */ + if (ret > 0) + return -ret; + return 0; +} + +/* + * All we need to do is get the socket, and then do a checksum. + */ + +int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, + int proto) +{ + struct sock *sk; + struct udphdr *uh; + unsigned short ulen; + struct rtable *rt = skb_rtable(skb); + __be32 saddr, daddr; + struct net *net = dev_net(skb->dev); + bool refcounted; + + /* + * Validate the packet. + */ + if (!pskb_may_pull(skb, sizeof(struct udphdr))) + goto drop; /* No space for header. */ + + uh = udp_hdr(skb); + ulen = ntohs(uh->len); + saddr = ip_hdr(skb)->saddr; + daddr = ip_hdr(skb)->daddr; + + if (ulen > skb->len) + goto short_packet; + + if (proto == IPPROTO_UDP) { + /* UDP validates ulen. */ + if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) + goto short_packet; + uh = udp_hdr(skb); + } + + if (udp4_csum_init(skb, uh, proto)) + goto csum_error; + + sk = skb_steal_sock(skb, &refcounted); + if (sk) { + struct dst_entry *dst = skb_dst(skb); + int ret; + + if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst)) + udp_sk_rx_dst_set(sk, dst); + + ret = udp_unicast_rcv_skb(sk, skb, uh); + if (refcounted) + sock_put(sk); + return ret; + } + + if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) + return __udp4_lib_mcast_deliver(net, skb, uh, + saddr, daddr, udptable, proto); + + sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); + if (sk) + return udp_unicast_rcv_skb(sk, skb, uh); + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto drop; + nf_reset_ct(skb); + + /* No socket. Drop packet silently, if checksum is wrong */ + if (udp_lib_checksum_complete(skb)) + goto csum_error; + + __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + + /* + * Hmm. We got an UDP packet to a port to which we + * don't wanna listen. Ignore it. + */ + kfree_skb(skb); + return 0; + +short_packet: + net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", + proto == IPPROTO_UDPLITE ? "Lite" : "", + &saddr, ntohs(uh->source), + ulen, skb->len, + &daddr, ntohs(uh->dest)); + goto drop; + +csum_error: + /* + * RFC1122: OK. Discards the bad packet silently (as far as + * the network is concerned, anyway) as per 4.1.3.4 (MUST). + */ + net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", + proto == IPPROTO_UDPLITE ? "Lite" : "", + &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), + ulen); + __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); +drop: + __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); + kfree_skb(skb); + return 0; +} + +/* We can only early demux multicast if there is a single matching socket. + * If more than one socket found returns NULL + */ +static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, + __be16 loc_port, __be32 loc_addr, + __be16 rmt_port, __be32 rmt_addr, + int dif, int sdif) +{ + struct sock *sk, *result; + unsigned short hnum = ntohs(loc_port); + unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); + struct udp_hslot *hslot = &udp_table.hash[slot]; + + /* Do not bother scanning a too big list */ + if (hslot->count > 10) + return NULL; + + result = NULL; + sk_for_each_rcu(sk, &hslot->head) { + if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, + rmt_port, rmt_addr, dif, sdif, hnum)) { + if (result) + return NULL; + result = sk; + } + } + + return result; +} + +/* For unicast we should only early demux connected sockets or we can + * break forwarding setups. The chains here can be long so only check + * if the first socket is an exact match and if not move on. + */ +static struct sock *__udp4_lib_demux_lookup(struct net *net, + __be16 loc_port, __be32 loc_addr, + __be16 rmt_port, __be32 rmt_addr, + int dif, int sdif) +{ + unsigned short hnum = ntohs(loc_port); + unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum); + unsigned int slot2 = hash2 & udp_table.mask; + struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; + INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); + const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); + struct sock *sk; + + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { + if (INET_MATCH(net, sk, acookie, ports, dif, sdif)) + return sk; + /* Only check first socket in chain */ + break; + } + return NULL; +} + +int udp_v4_early_demux(struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + struct in_device *in_dev = NULL; + const struct iphdr *iph; + const struct udphdr *uh; + struct sock *sk = NULL; + struct dst_entry *dst; + int dif = skb->dev->ifindex; + int sdif = inet_sdif(skb); + int ours; + + /* validate the packet */ + if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) + return 0; + + iph = ip_hdr(skb); + uh = udp_hdr(skb); + + if (skb->pkt_type == PACKET_MULTICAST) { + in_dev = __in_dev_get_rcu(skb->dev); + + if (!in_dev) + return 0; + + ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, + iph->protocol); + if (!ours) + return 0; + + sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, + uh->source, iph->saddr, + dif, sdif); + } else if (skb->pkt_type == PACKET_HOST) { + sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, + uh->source, iph->saddr, dif, sdif); + } + + if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) + return 0; + + skb->sk = sk; + skb->destructor = sock_efree; + dst = rcu_dereference(sk->sk_rx_dst); + + if (dst) + dst = dst_check(dst, 0); + if (dst) { + u32 itag = 0; + + /* set noref for now. + * any place which wants to hold dst has to call + * dst_hold_safe() + */ + skb_dst_set_noref(skb, dst); + + /* for unconnected multicast sockets we need to validate + * the source on each packet + */ + if (!inet_sk(sk)->inet_daddr && in_dev) + return ip_mc_validate_source(skb, iph->daddr, + iph->saddr, + iph->tos & IPTOS_RT_MASK, + skb->dev, in_dev, &itag); + } + return 0; +} + +int udp_rcv(struct sk_buff *skb) +{ + return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); +} + +void udp_destroy_sock(struct sock *sk) +{ + struct udp_sock *up = udp_sk(sk); + bool slow = lock_sock_fast(sk); + + /* protects from races with udp_abort() */ + sock_set_flag(sk, SOCK_DEAD); + udp_flush_pending_frames(sk); + unlock_sock_fast(sk, slow); + if (static_branch_unlikely(&udp_encap_needed_key)) { + if (up->encap_type) { + void (*encap_destroy)(struct sock *sk); + encap_destroy = READ_ONCE(up->encap_destroy); + if (encap_destroy) + encap_destroy(sk); + } + if (up->encap_enabled) + static_branch_dec(&udp_encap_needed_key); + } +} + +/* + * Socket option code for UDP + */ +int udp_lib_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen, + int (*push_pending_frames)(struct sock *)) +{ + struct udp_sock *up = udp_sk(sk); + int val, valbool; + int err = 0; + int is_udplite = IS_UDPLITE(sk); + + if (optlen < sizeof(int)) + return -EINVAL; + + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + valbool = val ? 1 : 0; + + switch (optname) { + case UDP_CORK: + if (val != 0) { + WRITE_ONCE(up->corkflag, 1); + } else { + WRITE_ONCE(up->corkflag, 0); + lock_sock(sk); + push_pending_frames(sk); + release_sock(sk); + } + break; + + case UDP_ENCAP: + switch (val) { + case 0: +#ifdef CONFIG_XFRM + case UDP_ENCAP_ESPINUDP: + case UDP_ENCAP_ESPINUDP_NON_IKE: +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + WRITE_ONCE(up->encap_rcv, + ipv6_stub->xfrm6_udp_encap_rcv); + else +#endif + WRITE_ONCE(up->encap_rcv, + xfrm4_udp_encap_rcv); +#endif + fallthrough; + case UDP_ENCAP_L2TPINUDP: + up->encap_type = val; + lock_sock(sk); + udp_tunnel_encap_enable(sk->sk_socket); + release_sock(sk); + break; + default: + err = -ENOPROTOOPT; + break; + } + break; + + case UDP_NO_CHECK6_TX: + up->no_check6_tx = valbool; + break; + + case UDP_NO_CHECK6_RX: + up->no_check6_rx = valbool; + break; + + case UDP_SEGMENT: + if (val < 0 || val > USHRT_MAX) + return -EINVAL; + WRITE_ONCE(up->gso_size, val); + break; + + case UDP_GRO: + lock_sock(sk); + + /* when enabling GRO, accept the related GSO packet type */ + if (valbool) + udp_tunnel_encap_enable(sk->sk_socket); + up->gro_enabled = valbool; + up->accept_udp_l4 = valbool; + release_sock(sk); + break; + + /* + * UDP-Lite's partial checksum coverage (RFC 3828). + */ + /* The sender sets actual checksum coverage length via this option. + * The case coverage > packet length is handled by send module. */ + case UDPLITE_SEND_CSCOV: + if (!is_udplite) /* Disable the option on UDP sockets */ + return -ENOPROTOOPT; + if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ + val = 8; + else if (val > USHRT_MAX) + val = USHRT_MAX; + up->pcslen = val; + up->pcflag |= UDPLITE_SEND_CC; + break; + + /* The receiver specifies a minimum checksum coverage value. To make + * sense, this should be set to at least 8 (as done below). If zero is + * used, this again means full checksum coverage. */ + case UDPLITE_RECV_CSCOV: + if (!is_udplite) /* Disable the option on UDP sockets */ + return -ENOPROTOOPT; + if (val != 0 && val < 8) /* Avoid silly minimal values. */ + val = 8; + else if (val > USHRT_MAX) + val = USHRT_MAX; + up->pcrlen = val; + up->pcflag |= UDPLITE_RECV_CC; + break; + + default: + err = -ENOPROTOOPT; + break; + } + + return err; +} +EXPORT_SYMBOL(udp_lib_setsockopt); + +int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, + unsigned int optlen) +{ + if (level == SOL_UDP || level == SOL_UDPLITE) + return udp_lib_setsockopt(sk, level, optname, + optval, optlen, + udp_push_pending_frames); + return ip_setsockopt(sk, level, optname, optval, optlen); +} + +int udp_lib_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct udp_sock *up = udp_sk(sk); + int val, len; + + if (get_user(len, optlen)) + return -EFAULT; + + len = min_t(unsigned int, len, sizeof(int)); + + if (len < 0) + return -EINVAL; + + switch (optname) { + case UDP_CORK: + val = READ_ONCE(up->corkflag); + break; + + case UDP_ENCAP: + val = up->encap_type; + break; + + case UDP_NO_CHECK6_TX: + val = up->no_check6_tx; + break; + + case UDP_NO_CHECK6_RX: + val = up->no_check6_rx; + break; + + case UDP_SEGMENT: + val = READ_ONCE(up->gso_size); + break; + + case UDP_GRO: + val = up->gro_enabled; + break; + + /* The following two cannot be changed on UDP sockets, the return is + * always 0 (which corresponds to the full checksum coverage of UDP). */ + case UDPLITE_SEND_CSCOV: + val = up->pcslen; + break; + + case UDPLITE_RECV_CSCOV: + val = up->pcrlen; + break; + + default: + return -ENOPROTOOPT; + } + + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &val, len)) + return -EFAULT; + return 0; +} +EXPORT_SYMBOL(udp_lib_getsockopt); + +int udp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + if (level == SOL_UDP || level == SOL_UDPLITE) + return udp_lib_getsockopt(sk, level, optname, optval, optlen); + return ip_getsockopt(sk, level, optname, optval, optlen); +} + +/** + * udp_poll - wait for a UDP event. + * @file: - file struct + * @sock: - socket + * @wait: - poll table + * + * This is same as datagram poll, except for the special case of + * blocking sockets. If application is using a blocking fd + * and a packet with checksum error is in the queue; + * then it could get return from select indicating data available + * but then block when reading it. Add special case code + * to work around these arguably broken applications. + */ +__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait) +{ + __poll_t mask = datagram_poll(file, sock, wait); + struct sock *sk = sock->sk; + + if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue)) + mask |= EPOLLIN | EPOLLRDNORM; + + /* Check for false positives due to checksum errors */ + if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) && + !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) + mask &= ~(EPOLLIN | EPOLLRDNORM); + + return mask; + +} +EXPORT_SYMBOL(udp_poll); + +int udp_abort(struct sock *sk, int err) +{ + lock_sock(sk); + + /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing + * with close() + */ + if (sock_flag(sk, SOCK_DEAD)) + goto out; + + sk->sk_err = err; + sk->sk_error_report(sk); + __udp_disconnect(sk, 0); + +out: + release_sock(sk); + + return 0; +} +EXPORT_SYMBOL_GPL(udp_abort); + +struct proto udp_prot = { + .name = "UDP", + .owner = THIS_MODULE, + .close = udp_lib_close, + .pre_connect = udp_pre_connect, + .connect = ip4_datagram_connect, + .disconnect = udp_disconnect, + .ioctl = udp_ioctl, + .init = udp_init_sock, + .destroy = udp_destroy_sock, + .setsockopt = udp_setsockopt, + .getsockopt = udp_getsockopt, + .sendmsg = udp_sendmsg, + .recvmsg = udp_recvmsg, + .sendpage = udp_sendpage, + .release_cb = ip4_datagram_release_cb, + .hash = udp_lib_hash, + .unhash = udp_lib_unhash, + .rehash = udp_v4_rehash, + .get_port = udp_v4_get_port, + .memory_allocated = &udp_memory_allocated, + .sysctl_mem = sysctl_udp_mem, + .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), + .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), + .obj_size = sizeof(struct udp_sock), + .h.udp_table = &udp_table, + .diag_destroy = udp_abort, +}; +EXPORT_SYMBOL(udp_prot); + +/* ------------------------------------------------------------------------ */ +#ifdef CONFIG_PROC_FS + +static struct sock *udp_get_first(struct seq_file *seq, int start) +{ + struct sock *sk; + struct udp_seq_afinfo *afinfo; + struct udp_iter_state *state = seq->private; + struct net *net = seq_file_net(seq); + + if (state->bpf_seq_afinfo) + afinfo = state->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + for (state->bucket = start; state->bucket <= afinfo->udp_table->mask; + ++state->bucket) { + struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket]; + + if (hlist_empty(&hslot->head)) + continue; + + spin_lock_bh(&hslot->lock); + sk_for_each(sk, &hslot->head) { + if (!net_eq(sock_net(sk), net)) + continue; + if (afinfo->family == AF_UNSPEC || + sk->sk_family == afinfo->family) + goto found; + } + spin_unlock_bh(&hslot->lock); + } + sk = NULL; +found: + return sk; +} + +static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) +{ + struct udp_seq_afinfo *afinfo; + struct udp_iter_state *state = seq->private; + struct net *net = seq_file_net(seq); + + if (state->bpf_seq_afinfo) + afinfo = state->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + do { + sk = sk_next(sk); + } while (sk && (!net_eq(sock_net(sk), net) || + (afinfo->family != AF_UNSPEC && + sk->sk_family != afinfo->family))); + + if (!sk) { + if (state->bucket <= afinfo->udp_table->mask) + spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); + return udp_get_first(seq, state->bucket + 1); + } + return sk; +} + +static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) +{ + struct sock *sk = udp_get_first(seq, 0); + + if (sk) + while (pos && (sk = udp_get_next(seq, sk)) != NULL) + --pos; + return pos ? NULL : sk; +} + +void *udp_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct udp_iter_state *state = seq->private; + state->bucket = MAX_UDP_PORTS; + + return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; +} +EXPORT_SYMBOL(udp_seq_start); + +void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct sock *sk; + + if (v == SEQ_START_TOKEN) + sk = udp_get_idx(seq, 0); + else + sk = udp_get_next(seq, v); + + ++*pos; + return sk; +} +EXPORT_SYMBOL(udp_seq_next); + +void udp_seq_stop(struct seq_file *seq, void *v) +{ + struct udp_seq_afinfo *afinfo; + struct udp_iter_state *state = seq->private; + + if (state->bpf_seq_afinfo) + afinfo = state->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + if (state->bucket <= afinfo->udp_table->mask) + spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); +} +EXPORT_SYMBOL(udp_seq_stop); + +/* ------------------------------------------------------------------------ */ +static void udp4_format_sock(struct sock *sp, struct seq_file *f, + int bucket) +{ + struct inet_sock *inet = inet_sk(sp); + __be32 dest = inet->inet_daddr; + __be32 src = inet->inet_rcv_saddr; + __u16 destp = ntohs(inet->inet_dport); + __u16 srcp = ntohs(inet->inet_sport); + + seq_printf(f, "%5d: %08X:%04X %08X:%04X" + " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", + bucket, src, srcp, dest, destp, sp->sk_state, + sk_wmem_alloc_get(sp), + udp_rqueue_get(sp), + 0, 0L, 0, + from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), + 0, sock_i_ino(sp), + refcount_read(&sp->sk_refcnt), sp, + atomic_read(&sp->sk_drops)); +} + +int udp4_seq_show(struct seq_file *seq, void *v) +{ + seq_setwidth(seq, 127); + if (v == SEQ_START_TOKEN) + seq_puts(seq, " sl local_address rem_address st tx_queue " + "rx_queue tr tm->when retrnsmt uid timeout " + "inode ref pointer drops"); + else { + struct udp_iter_state *state = seq->private; + + udp4_format_sock(v, seq, state->bucket); + } + seq_pad(seq, '\n'); + return 0; +} + +#ifdef CONFIG_BPF_SYSCALL +struct bpf_iter__udp { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct udp_sock *, udp_sk); + uid_t uid __aligned(8); + int bucket __aligned(8); +}; + +static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, + struct udp_sock *udp_sk, uid_t uid, int bucket) +{ + struct bpf_iter__udp ctx; + + meta->seq_num--; /* skip SEQ_START_TOKEN */ + ctx.meta = meta; + ctx.udp_sk = udp_sk; + ctx.uid = uid; + ctx.bucket = bucket; + return bpf_iter_run_prog(prog, &ctx); +} + +static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v) +{ + struct udp_iter_state *state = seq->private; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + struct sock *sk = v; + uid_t uid; + + if (v == SEQ_START_TOKEN) + return 0; + + uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); + meta.seq = seq; + prog = bpf_iter_get_info(&meta, false); + return udp_prog_seq_show(prog, &meta, v, uid, state->bucket); +} + +static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v) +{ + struct bpf_iter_meta meta; + struct bpf_prog *prog; + + if (!v) { + meta.seq = seq; + prog = bpf_iter_get_info(&meta, true); + if (prog) + (void)udp_prog_seq_show(prog, &meta, v, 0, 0); + } + + udp_seq_stop(seq, v); +} + +static const struct seq_operations bpf_iter_udp_seq_ops = { + .start = udp_seq_start, + .next = udp_seq_next, + .stop = bpf_iter_udp_seq_stop, + .show = bpf_iter_udp_seq_show, +}; +#endif + +const struct seq_operations udp_seq_ops = { + .start = udp_seq_start, + .next = udp_seq_next, + .stop = udp_seq_stop, + .show = udp4_seq_show, +}; +EXPORT_SYMBOL(udp_seq_ops); + +static struct udp_seq_afinfo udp4_seq_afinfo = { + .family = AF_INET, + .udp_table = &udp_table, +}; + +static int __net_init udp4_proc_init_net(struct net *net) +{ + if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops, + sizeof(struct udp_iter_state), &udp4_seq_afinfo)) + return -ENOMEM; + return 0; +} + +static void __net_exit udp4_proc_exit_net(struct net *net) +{ + remove_proc_entry("udp", net->proc_net); +} + +static struct pernet_operations udp4_net_ops = { + .init = udp4_proc_init_net, + .exit = udp4_proc_exit_net, +}; + +int __init udp4_proc_init(void) +{ + return register_pernet_subsys(&udp4_net_ops); +} + +void udp4_proc_exit(void) +{ + unregister_pernet_subsys(&udp4_net_ops); +} +#endif /* CONFIG_PROC_FS */ + +static __initdata unsigned long uhash_entries; +static int __init set_uhash_entries(char *str) +{ + ssize_t ret; + + if (!str) + return 0; + + ret = kstrtoul(str, 0, &uhash_entries); + if (ret) + return 0; + + if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) + uhash_entries = UDP_HTABLE_SIZE_MIN; + return 1; +} +__setup("uhash_entries=", set_uhash_entries); + +void __init udp_table_init(struct udp_table *table, const char *name) +{ + unsigned int i; + + table->hash = alloc_large_system_hash(name, + 2 * sizeof(struct udp_hslot), + uhash_entries, + 21, /* one slot per 2 MB */ + 0, + &table->log, + &table->mask, + UDP_HTABLE_SIZE_MIN, + 64 * 1024); + + table->hash2 = table->hash + (table->mask + 1); + for (i = 0; i <= table->mask; i++) { + INIT_HLIST_HEAD(&table->hash[i].head); + table->hash[i].count = 0; + spin_lock_init(&table->hash[i].lock); + } + for (i = 0; i <= table->mask; i++) { + INIT_HLIST_HEAD(&table->hash2[i].head); + table->hash2[i].count = 0; + spin_lock_init(&table->hash2[i].lock); + } +} + +u32 udp_flow_hashrnd(void) +{ + static u32 hashrnd __read_mostly; + + net_get_random_once(&hashrnd, sizeof(hashrnd)); + + return hashrnd; +} +EXPORT_SYMBOL(udp_flow_hashrnd); + +static void __udp_sysctl_init(struct net *net) +{ + net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM; + net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM; + +#ifdef CONFIG_NET_L3_MASTER_DEV + net->ipv4.sysctl_udp_l3mdev_accept = 0; +#endif +} + +static int __net_init udp_sysctl_init(struct net *net) +{ + __udp_sysctl_init(net); + return 0; +} + +static struct pernet_operations __net_initdata udp_sysctl_ops = { + .init = udp_sysctl_init, +}; + +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) +DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta, + struct udp_sock *udp_sk, uid_t uid, int bucket) + +static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux) +{ + struct udp_iter_state *st = priv_data; + struct udp_seq_afinfo *afinfo; + int ret; + + afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN); + if (!afinfo) + return -ENOMEM; + + afinfo->family = AF_UNSPEC; + afinfo->udp_table = &udp_table; + st->bpf_seq_afinfo = afinfo; + ret = bpf_iter_init_seq_net(priv_data, aux); + if (ret) + kfree(afinfo); + return ret; +} + +static void bpf_iter_fini_udp(void *priv_data) +{ + struct udp_iter_state *st = priv_data; + + kfree(st->bpf_seq_afinfo); + bpf_iter_fini_seq_net(priv_data); +} + +static const struct bpf_iter_seq_info udp_seq_info = { + .seq_ops = &bpf_iter_udp_seq_ops, + .init_seq_private = bpf_iter_init_udp, + .fini_seq_private = bpf_iter_fini_udp, + .seq_priv_size = sizeof(struct udp_iter_state), +}; + +static struct bpf_iter_reg udp_reg_info = { + .target = "udp", + .ctx_arg_info_size = 1, + .ctx_arg_info = { + { offsetof(struct bpf_iter__udp, udp_sk), + PTR_TO_BTF_ID_OR_NULL }, + }, + .seq_info = &udp_seq_info, +}; + +static void __init bpf_iter_register(void) +{ + udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP]; + if (bpf_iter_reg_target(&udp_reg_info)) + pr_warn("Warning: could not register bpf iterator udp\n"); +} +#endif + +void __init udp_init(void) +{ + unsigned long limit; + unsigned int i; + + udp_table_init(&udp_table, "UDP"); + limit = nr_free_buffer_pages() / 8; + limit = max(limit, 128UL); + sysctl_udp_mem[0] = limit / 4 * 3; + sysctl_udp_mem[1] = limit; + sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; + + __udp_sysctl_init(&init_net); + + /* 16 spinlocks per cpu */ + udp_busylocks_log = ilog2(nr_cpu_ids) + 4; + udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log, + GFP_KERNEL); + if (!udp_busylocks) + panic("UDP: failed to alloc udp_busylocks\n"); + for (i = 0; i < (1U << udp_busylocks_log); i++) + spin_lock_init(udp_busylocks + i); + + if (register_pernet_subsys(&udp_sysctl_ops)) + panic("UDP: failed to init sysctl parameters.\n"); + +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) + bpf_iter_register(); +#endif +} diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c new file mode 100644 index 000000000..69c9663f9 --- /dev/null +++ b/net/ipv4/udp_bpf.c @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */ + +#include <linux/skmsg.h> +#include <net/sock.h> +#include <net/udp.h> + +enum { + UDP_BPF_IPV4, + UDP_BPF_IPV6, + UDP_BPF_NUM_PROTS, +}; + +static struct proto *udpv6_prot_saved __read_mostly; +static DEFINE_SPINLOCK(udpv6_prot_lock); +static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS]; + +static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base) +{ + *prot = *base; + prot->unhash = sock_map_unhash; + prot->close = sock_map_close; +} + +static void udp_bpf_check_v6_needs_rebuild(struct proto *ops) +{ + if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) { + spin_lock_bh(&udpv6_prot_lock); + if (likely(ops != udpv6_prot_saved)) { + udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops); + smp_store_release(&udpv6_prot_saved, ops); + } + spin_unlock_bh(&udpv6_prot_lock); + } +} + +static int __init udp_bpf_v4_build_proto(void) +{ + udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot); + return 0; +} +late_initcall(udp_bpf_v4_build_proto); + +struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock) +{ + int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6; + + if (sk->sk_family == AF_INET6) + udp_bpf_check_v6_needs_rebuild(psock->sk_proto); + + return &udp_bpf_prots[family]; +} diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c new file mode 100644 index 000000000..1dbece344 --- /dev/null +++ b/net/ipv4/udp_diag.c @@ -0,0 +1,302 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * udp_diag.c Module for monitoring UDP transport protocols sockets. + * + * Authors: Pavel Emelyanov, <xemul@parallels.com> + */ + + +#include <linux/module.h> +#include <linux/inet_diag.h> +#include <linux/udp.h> +#include <net/udp.h> +#include <net/udplite.h> +#include <linux/sock_diag.h> + +static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *req, + struct nlattr *bc, bool net_admin) +{ + if (!inet_diag_bc_sk(bc, sk)) + return 0; + + return inet_sk_diag_fill(sk, NULL, skb, cb, req, NLM_F_MULTI, + net_admin); +} + +static int udp_dump_one(struct udp_table *tbl, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *req) +{ + struct sk_buff *in_skb = cb->skb; + int err = -EINVAL; + struct sock *sk = NULL; + struct sk_buff *rep; + struct net *net = sock_net(in_skb->sk); + + rcu_read_lock(); + if (req->sdiag_family == AF_INET) + /* src and dst are swapped for historical reasons */ + sk = __udp4_lib_lookup(net, + req->id.idiag_src[0], req->id.idiag_sport, + req->id.idiag_dst[0], req->id.idiag_dport, + req->id.idiag_if, 0, tbl, NULL); +#if IS_ENABLED(CONFIG_IPV6) + else if (req->sdiag_family == AF_INET6) + sk = __udp6_lib_lookup(net, + (struct in6_addr *)req->id.idiag_src, + req->id.idiag_sport, + (struct in6_addr *)req->id.idiag_dst, + req->id.idiag_dport, + req->id.idiag_if, 0, tbl, NULL); +#endif + if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + rcu_read_unlock(); + err = -ENOENT; + if (!sk) + goto out_nosk; + + err = sock_diag_check_cookie(sk, req->id.idiag_cookie); + if (err) + goto out; + + err = -ENOMEM; + rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) + + inet_diag_msg_attrs_size() + + nla_total_size(sizeof(struct inet_diag_meminfo)) + 64, + GFP_KERNEL); + if (!rep) + goto out; + + err = inet_sk_diag_fill(sk, NULL, rep, cb, req, 0, + netlink_net_capable(in_skb, CAP_NET_ADMIN)); + if (err < 0) { + WARN_ON(err == -EMSGSIZE); + kfree_skb(rep); + goto out; + } + err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid, + MSG_DONTWAIT); + if (err > 0) + err = 0; +out: + if (sk) + sock_put(sk); +out_nosk: + return err; +} + +static void udp_dump(struct udp_table *table, struct sk_buff *skb, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN); + struct net *net = sock_net(skb->sk); + struct inet_diag_dump_data *cb_data; + int num, s_num, slot, s_slot; + struct nlattr *bc; + + cb_data = cb->data; + bc = cb_data->inet_diag_nla_bc; + s_slot = cb->args[0]; + num = s_num = cb->args[1]; + + for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) { + struct udp_hslot *hslot = &table->hash[slot]; + struct sock *sk; + + num = 0; + + if (hlist_empty(&hslot->head)) + continue; + + spin_lock_bh(&hslot->lock); + sk_for_each(sk, &hslot->head) { + struct inet_sock *inet = inet_sk(sk); + + if (!net_eq(sock_net(sk), net)) + continue; + if (num < s_num) + goto next; + if (!(r->idiag_states & (1 << sk->sk_state))) + goto next; + if (r->sdiag_family != AF_UNSPEC && + sk->sk_family != r->sdiag_family) + goto next; + if (r->id.idiag_sport != inet->inet_sport && + r->id.idiag_sport) + goto next; + if (r->id.idiag_dport != inet->inet_dport && + r->id.idiag_dport) + goto next; + + if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) { + spin_unlock_bh(&hslot->lock); + goto done; + } +next: + num++; + } + spin_unlock_bh(&hslot->lock); + } +done: + cb->args[0] = slot; + cb->args[1] = num; +} + +static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + udp_dump(&udp_table, skb, cb, r); +} + +static int udp_diag_dump_one(struct netlink_callback *cb, + const struct inet_diag_req_v2 *req) +{ + return udp_dump_one(&udp_table, cb, req); +} + +static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, + void *info) +{ + r->idiag_rqueue = udp_rqueue_get(sk); + r->idiag_wqueue = sk_wmem_alloc_get(sk); +} + +#ifdef CONFIG_INET_DIAG_DESTROY +static int __udp_diag_destroy(struct sk_buff *in_skb, + const struct inet_diag_req_v2 *req, + struct udp_table *tbl) +{ + struct net *net = sock_net(in_skb->sk); + struct sock *sk; + int err; + + rcu_read_lock(); + + if (req->sdiag_family == AF_INET) + sk = __udp4_lib_lookup(net, + req->id.idiag_dst[0], req->id.idiag_dport, + req->id.idiag_src[0], req->id.idiag_sport, + req->id.idiag_if, 0, tbl, NULL); +#if IS_ENABLED(CONFIG_IPV6) + else if (req->sdiag_family == AF_INET6) { + if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) && + ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src)) + sk = __udp4_lib_lookup(net, + req->id.idiag_dst[3], req->id.idiag_dport, + req->id.idiag_src[3], req->id.idiag_sport, + req->id.idiag_if, 0, tbl, NULL); + + else + sk = __udp6_lib_lookup(net, + (struct in6_addr *)req->id.idiag_dst, + req->id.idiag_dport, + (struct in6_addr *)req->id.idiag_src, + req->id.idiag_sport, + req->id.idiag_if, 0, tbl, NULL); + } +#endif + else { + rcu_read_unlock(); + return -EINVAL; + } + + if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + + rcu_read_unlock(); + + if (!sk) + return -ENOENT; + + if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) { + sock_put(sk); + return -ENOENT; + } + + err = sock_diag_destroy(sk, ECONNABORTED); + + sock_put(sk); + + return err; +} + +static int udp_diag_destroy(struct sk_buff *in_skb, + const struct inet_diag_req_v2 *req) +{ + return __udp_diag_destroy(in_skb, req, &udp_table); +} + +static int udplite_diag_destroy(struct sk_buff *in_skb, + const struct inet_diag_req_v2 *req) +{ + return __udp_diag_destroy(in_skb, req, &udplite_table); +} + +#endif + +static const struct inet_diag_handler udp_diag_handler = { + .dump = udp_diag_dump, + .dump_one = udp_diag_dump_one, + .idiag_get_info = udp_diag_get_info, + .idiag_type = IPPROTO_UDP, + .idiag_info_size = 0, +#ifdef CONFIG_INET_DIAG_DESTROY + .destroy = udp_diag_destroy, +#endif +}; + +static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + udp_dump(&udplite_table, skb, cb, r); +} + +static int udplite_diag_dump_one(struct netlink_callback *cb, + const struct inet_diag_req_v2 *req) +{ + return udp_dump_one(&udplite_table, cb, req); +} + +static const struct inet_diag_handler udplite_diag_handler = { + .dump = udplite_diag_dump, + .dump_one = udplite_diag_dump_one, + .idiag_get_info = udp_diag_get_info, + .idiag_type = IPPROTO_UDPLITE, + .idiag_info_size = 0, +#ifdef CONFIG_INET_DIAG_DESTROY + .destroy = udplite_diag_destroy, +#endif +}; + +static int __init udp_diag_init(void) +{ + int err; + + err = inet_diag_register(&udp_diag_handler); + if (err) + goto out; + err = inet_diag_register(&udplite_diag_handler); + if (err) + goto out_lite; +out: + return err; +out_lite: + inet_diag_unregister(&udp_diag_handler); + goto out; +} + +static void __exit udp_diag_exit(void) +{ + inet_diag_unregister(&udplite_diag_handler); + inet_diag_unregister(&udp_diag_handler); +} + +module_init(udp_diag_init); +module_exit(udp_diag_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */); diff --git a/net/ipv4/udp_impl.h b/net/ipv4/udp_impl.h new file mode 100644 index 000000000..2878d8285 --- /dev/null +++ b/net/ipv4/udp_impl.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _UDP4_IMPL_H +#define _UDP4_IMPL_H +#include <net/udp.h> +#include <net/udplite.h> +#include <net/protocol.h> +#include <net/inet_common.h> + +int __udp4_lib_rcv(struct sk_buff *, struct udp_table *, int); +int __udp4_lib_err(struct sk_buff *, u32, struct udp_table *); + +int udp_v4_get_port(struct sock *sk, unsigned short snum); +void udp_v4_rehash(struct sock *sk); + +int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, + unsigned int optlen); +int udp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen); + +int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, + int flags, int *addr_len); +int udp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, + int flags); +void udp_destroy_sock(struct sock *sk); + +#ifdef CONFIG_PROC_FS +int udp4_seq_show(struct seq_file *seq, void *v); +#endif +#endif /* _UDP4_IMPL_H */ diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c new file mode 100644 index 000000000..f4b8e5606 --- /dev/null +++ b/net/ipv4/udp_offload.c @@ -0,0 +1,700 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IPV4 GSO/GRO offload support + * Linux INET implementation + * + * UDPv4 GSO support + */ + +#include <linux/skbuff.h> +#include <net/udp.h> +#include <net/protocol.h> +#include <net/inet_common.h> + +static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, + netdev_features_t features, + struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, + netdev_features_t features), + __be16 new_protocol, bool is_ipv6) +{ + int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); + bool remcsum, need_csum, offload_csum, gso_partial; + struct sk_buff *segs = ERR_PTR(-EINVAL); + struct udphdr *uh = udp_hdr(skb); + u16 mac_offset = skb->mac_header; + __be16 protocol = skb->protocol; + u16 mac_len = skb->mac_len; + int udp_offset, outer_hlen; + __wsum partial; + bool need_ipsec; + + if (unlikely(!pskb_may_pull(skb, tnl_hlen))) + goto out; + + /* Adjust partial header checksum to negate old length. + * We cannot rely on the value contained in uh->len as it is + * possible that the actual value exceeds the boundaries of the + * 16 bit length field due to the header being added outside of an + * IP or IPv6 frame that was already limited to 64K - 1. + */ + if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) + partial = (__force __wsum)uh->len; + else + partial = (__force __wsum)htonl(skb->len); + partial = csum_sub(csum_unfold(uh->check), partial); + + /* setup inner skb. */ + skb->encapsulation = 0; + SKB_GSO_CB(skb)->encap_level = 0; + __skb_pull(skb, tnl_hlen); + skb_reset_mac_header(skb); + skb_set_network_header(skb, skb_inner_network_offset(skb)); + skb->mac_len = skb_inner_network_offset(skb); + skb->protocol = new_protocol; + + need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); + skb->encap_hdr_csum = need_csum; + + remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); + skb->remcsum_offload = remcsum; + + need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb)); + /* Try to offload checksum if possible */ + offload_csum = !!(need_csum && + !need_ipsec && + (skb->dev->features & + (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) : + (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)))); + + features &= skb->dev->hw_enc_features; + + /* The only checksum offload we care about from here on out is the + * outer one so strip the existing checksum feature flags and + * instead set the flag based on our outer checksum offload value. + */ + if (remcsum) { + features &= ~NETIF_F_CSUM_MASK; + if (!need_csum || offload_csum) + features |= NETIF_F_HW_CSUM; + } + + /* segment inner packet. */ + segs = gso_inner_segment(skb, features); + if (IS_ERR_OR_NULL(segs)) { + skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, + mac_len); + goto out; + } + + gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); + + outer_hlen = skb_tnl_header_len(skb); + udp_offset = outer_hlen - tnl_hlen; + skb = segs; + do { + unsigned int len; + + if (remcsum) + skb->ip_summed = CHECKSUM_NONE; + + /* Set up inner headers if we are offloading inner checksum */ + if (skb->ip_summed == CHECKSUM_PARTIAL) { + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + } + + skb->mac_len = mac_len; + skb->protocol = protocol; + + __skb_push(skb, outer_hlen); + skb_reset_mac_header(skb); + skb_set_network_header(skb, mac_len); + skb_set_transport_header(skb, udp_offset); + len = skb->len - udp_offset; + uh = udp_hdr(skb); + + /* If we are only performing partial GSO the inner header + * will be using a length value equal to only one MSS sized + * segment instead of the entire frame. + */ + if (gso_partial && skb_is_gso(skb)) { + uh->len = htons(skb_shinfo(skb)->gso_size + + SKB_GSO_CB(skb)->data_offset + + skb->head - (unsigned char *)uh); + } else { + uh->len = htons(len); + } + + if (!need_csum) + continue; + + uh->check = ~csum_fold(csum_add(partial, + (__force __wsum)htonl(len))); + + if (skb->encapsulation || !offload_csum) { + uh->check = gso_make_checksum(skb, ~uh->check); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + } else { + skb->ip_summed = CHECKSUM_PARTIAL; + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + } + } while ((skb = skb->next)); +out: + return segs; +} + +struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, + netdev_features_t features, + bool is_ipv6) +{ + __be16 protocol = skb->protocol; + const struct net_offload **offloads; + const struct net_offload *ops; + struct sk_buff *segs = ERR_PTR(-EINVAL); + struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, + netdev_features_t features); + + rcu_read_lock(); + + switch (skb->inner_protocol_type) { + case ENCAP_TYPE_ETHER: + protocol = skb->inner_protocol; + gso_inner_segment = skb_mac_gso_segment; + break; + case ENCAP_TYPE_IPPROTO: + offloads = is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[skb->inner_ipproto]); + if (!ops || !ops->callbacks.gso_segment) + goto out_unlock; + gso_inner_segment = ops->callbacks.gso_segment; + break; + default: + goto out_unlock; + } + + segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, + protocol, is_ipv6); + +out_unlock: + rcu_read_unlock(); + + return segs; +} +EXPORT_SYMBOL(skb_udp_tunnel_segment); + +static void __udpv4_gso_segment_csum(struct sk_buff *seg, + __be32 *oldip, __be32 *newip, + __be16 *oldport, __be16 *newport) +{ + struct udphdr *uh; + struct iphdr *iph; + + if (*oldip == *newip && *oldport == *newport) + return; + + uh = udp_hdr(seg); + iph = ip_hdr(seg); + + if (uh->check) { + inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip, + true); + inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport, + false); + if (!uh->check) + uh->check = CSUM_MANGLED_0; + } + *oldport = *newport; + + csum_replace4(&iph->check, *oldip, *newip); + *oldip = *newip; +} + +static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs) +{ + struct sk_buff *seg; + struct udphdr *uh, *uh2; + struct iphdr *iph, *iph2; + + seg = segs; + uh = udp_hdr(seg); + iph = ip_hdr(seg); + + if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) && + (udp_hdr(seg)->source == udp_hdr(seg->next)->source) && + (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) && + (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr)) + return segs; + + while ((seg = seg->next)) { + uh2 = udp_hdr(seg); + iph2 = ip_hdr(seg); + + __udpv4_gso_segment_csum(seg, + &iph2->saddr, &iph->saddr, + &uh2->source, &uh->source); + __udpv4_gso_segment_csum(seg, + &iph2->daddr, &iph->daddr, + &uh2->dest, &uh->dest); + } + + return segs; +} + +static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb, + netdev_features_t features, + bool is_ipv6) +{ + unsigned int mss = skb_shinfo(skb)->gso_size; + + skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); + if (IS_ERR(skb)) + return skb; + + udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss); + + return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb); +} + +struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, + netdev_features_t features, bool is_ipv6) +{ + struct sock *sk = gso_skb->sk; + unsigned int sum_truesize = 0; + struct sk_buff *segs, *seg; + struct udphdr *uh; + unsigned int mss; + bool copy_dtor; + __sum16 check; + __be16 newlen; + + if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) + return __udp_gso_segment_list(gso_skb, features, is_ipv6); + + mss = skb_shinfo(gso_skb)->gso_size; + if (gso_skb->len <= sizeof(*uh) + mss) + return ERR_PTR(-EINVAL); + + skb_pull(gso_skb, sizeof(*uh)); + + /* clear destructor to avoid skb_segment assigning it to tail */ + copy_dtor = gso_skb->destructor == sock_wfree; + if (copy_dtor) + gso_skb->destructor = NULL; + + segs = skb_segment(gso_skb, features); + if (IS_ERR_OR_NULL(segs)) { + if (copy_dtor) + gso_skb->destructor = sock_wfree; + return segs; + } + + /* GSO partial and frag_list segmentation only requires splitting + * the frame into an MSS multiple and possibly a remainder, both + * cases return a GSO skb. So update the mss now. + */ + if (skb_is_gso(segs)) + mss *= skb_shinfo(segs)->gso_segs; + + seg = segs; + uh = udp_hdr(seg); + + /* preserve TX timestamp flags and TS key for first segment */ + skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; + skb_shinfo(seg)->tx_flags |= + (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); + + /* compute checksum adjustment based on old length versus new */ + newlen = htons(sizeof(*uh) + mss); + check = csum16_add(csum16_sub(uh->check, uh->len), newlen); + + for (;;) { + if (copy_dtor) { + seg->destructor = sock_wfree; + seg->sk = sk; + sum_truesize += seg->truesize; + } + + if (!seg->next) + break; + + uh->len = newlen; + uh->check = check; + + if (seg->ip_summed == CHECKSUM_PARTIAL) + gso_reset_checksum(seg, ~check); + else + uh->check = gso_make_checksum(seg, ~check) ? : + CSUM_MANGLED_0; + + seg = seg->next; + uh = udp_hdr(seg); + } + + /* last packet can be partial gso_size, account for that in checksum */ + newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + + seg->data_len); + check = csum16_add(csum16_sub(uh->check, uh->len), newlen); + + uh->len = newlen; + uh->check = check; + + if (seg->ip_summed == CHECKSUM_PARTIAL) + gso_reset_checksum(seg, ~check); + else + uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; + + /* update refcount for the packet */ + if (copy_dtor) { + int delta = sum_truesize - gso_skb->truesize; + + /* In some pathological cases, delta can be negative. + * We need to either use refcount_add() or refcount_sub_and_test() + */ + if (likely(delta >= 0)) + refcount_add(delta, &sk->sk_wmem_alloc); + else + WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); + } + return segs; +} +EXPORT_SYMBOL_GPL(__udp_gso_segment); + +static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + unsigned int mss; + __wsum csum; + struct udphdr *uh; + struct iphdr *iph; + + if (skb->encapsulation && + (skb_shinfo(skb)->gso_type & + (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { + segs = skb_udp_tunnel_segment(skb, features, false); + goto out; + } + + if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) + goto out; + + if (!pskb_may_pull(skb, sizeof(struct udphdr))) + goto out; + + if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) + return __udp_gso_segment(skb, features, false); + + mss = skb_shinfo(skb)->gso_size; + if (unlikely(skb->len <= mss)) + goto out; + + /* Do software UFO. Complete and fill in the UDP checksum as + * HW cannot do checksum of UDP packets sent as multiple + * IP fragments. + */ + + uh = udp_hdr(skb); + iph = ip_hdr(skb); + + uh->check = 0; + csum = skb_checksum(skb, 0, skb->len, 0); + uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + + skb->ip_summed = CHECKSUM_UNNECESSARY; + + /* If there is no outer header we can fake a checksum offload + * due to the fact that we have already done the checksum in + * software prior to segmenting the frame. + */ + if (!skb->encap_hdr_csum) + features |= NETIF_F_HW_CSUM; + + /* Fragment the skb. IP headers of the fragments are updated in + * inet_gso_segment() + */ + segs = skb_segment(skb, features); +out: + return segs; +} + +#define UDP_GRO_CNT_MAX 64 +static struct sk_buff *udp_gro_receive_segment(struct list_head *head, + struct sk_buff *skb) +{ + struct udphdr *uh = udp_gro_udphdr(skb); + struct sk_buff *pp = NULL; + struct udphdr *uh2; + struct sk_buff *p; + unsigned int ulen; + int ret = 0; + + /* requires non zero csum, for symmetry with GSO */ + if (!uh->check) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + + /* Do not deal with padded or malicious packets, sorry ! */ + ulen = ntohs(uh->len); + if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + /* pull encapsulating udp header */ + skb_gro_pull(skb, sizeof(struct udphdr)); + + list_for_each_entry(p, head, list) { + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + uh2 = udp_hdr(p); + + /* Match ports only, as csum is always non zero */ + if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + + if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { + NAPI_GRO_CB(skb)->flush = 1; + return p; + } + + /* Terminate the flow on len mismatch or if it grow "too much". + * Under small packet flood GRO count could elsewhere grow a lot + * leading to excessive truesize values. + * On len mismatch merge the first packet shorter than gso_size, + * otherwise complete the GRO packet. + */ + if (ulen > ntohs(uh2->len)) { + pp = p; + } else { + if (NAPI_GRO_CB(skb)->is_flist) { + if (!pskb_may_pull(skb, skb_gro_offset(skb))) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + if ((skb->ip_summed != p->ip_summed) || + (skb->csum_level != p->csum_level)) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + ret = skb_gro_receive_list(p, skb); + } else { + skb_gro_postpull_rcsum(skb, uh, + sizeof(struct udphdr)); + + ret = skb_gro_receive(p, skb); + } + } + + if (ret || ulen != ntohs(uh2->len) || + NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) + pp = p; + + return pp; + } + + /* mismatch, but we never need to flush */ + return NULL; +} + +struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, + struct udphdr *uh, struct sock *sk) +{ + struct sk_buff *pp = NULL; + struct sk_buff *p; + struct udphdr *uh2; + unsigned int off = skb_gro_offset(skb); + int flush = 1; + + NAPI_GRO_CB(skb)->is_flist = 0; + if (skb->dev->features & NETIF_F_GRO_FRAGLIST) + NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1; + + if ((sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) { + pp = call_gro_receive(udp_gro_receive_segment, head, skb); + return pp; + } + + if (!sk || NAPI_GRO_CB(skb)->encap_mark || + (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && + NAPI_GRO_CB(skb)->csum_cnt == 0 && + !NAPI_GRO_CB(skb)->csum_valid) || + !udp_sk(sk)->gro_receive) + goto out; + + /* mark that this skb passed once through the tunnel gro layer */ + NAPI_GRO_CB(skb)->encap_mark = 1; + + flush = 0; + + list_for_each_entry(p, head, list) { + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + uh2 = (struct udphdr *)(p->data + off); + + /* Match ports and either checksums are either both zero + * or nonzero. + */ + if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || + (!uh->check ^ !uh2->check)) { + NAPI_GRO_CB(p)->same_flow = 0; + continue; + } + } + + skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ + skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); + pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); + +out: + skb_gro_flush_final(skb, pp, flush); + return pp; +} +EXPORT_SYMBOL(udp_gro_receive); + +static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, + __be16 dport) +{ + const struct iphdr *iph = skb_gro_network_header(skb); + + return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, + iph->daddr, dport, inet_iif(skb), + inet_sdif(skb), &udp_table, NULL); +} + +INDIRECT_CALLABLE_SCOPE +struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) +{ + struct udphdr *uh = udp_gro_udphdr(skb); + struct sock *sk = NULL; + struct sk_buff *pp; + + if (unlikely(!uh)) + goto flush; + + /* Don't bother verifying checksum if we're going to flush anyway. */ + if (NAPI_GRO_CB(skb)->flush) + goto skip; + + if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, + inet_gro_compute_pseudo)) + goto flush; + else if (uh->check) + skb_gro_checksum_try_convert(skb, IPPROTO_UDP, + inet_gro_compute_pseudo); +skip: + NAPI_GRO_CB(skb)->is_ipv6 = 0; + rcu_read_lock(); + + if (static_branch_unlikely(&udp_encap_needed_key)) + sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); + + pp = udp_gro_receive(head, skb, uh, sk); + rcu_read_unlock(); + return pp; + +flush: + NAPI_GRO_CB(skb)->flush = 1; + return NULL; +} + +static int udp_gro_complete_segment(struct sk_buff *skb) +{ + struct udphdr *uh = udp_hdr(skb); + + skb->csum_start = (unsigned char *)uh - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + skb->ip_summed = CHECKSUM_PARTIAL; + + skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; + skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; + + if (skb->encapsulation) + skb->inner_transport_header = skb->transport_header; + + return 0; +} + +int udp_gro_complete(struct sk_buff *skb, int nhoff, + udp_lookup_t lookup) +{ + __be16 newlen = htons(skb->len - nhoff); + struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); + int err = -ENOSYS; + struct sock *sk; + + uh->len = newlen; + + rcu_read_lock(); + sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, + udp4_lib_lookup_skb, skb, uh->source, uh->dest); + if (sk && udp_sk(sk)->gro_complete) { + skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM + : SKB_GSO_UDP_TUNNEL; + + /* Set encapsulation before calling into inner gro_complete() + * functions to make them set up the inner offsets. + */ + skb->encapsulation = 1; + err = udp_sk(sk)->gro_complete(sk, skb, + nhoff + sizeof(struct udphdr)); + } else { + err = udp_gro_complete_segment(skb); + } + rcu_read_unlock(); + + if (skb->remcsum_offload) + skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; + + return err; +} +EXPORT_SYMBOL(udp_gro_complete); + +INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) +{ + const struct iphdr *iph = ip_hdr(skb); + struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); + + if (NAPI_GRO_CB(skb)->is_flist) { + uh->len = htons(skb->len - nhoff); + + skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); + skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; + + if (skb->ip_summed == CHECKSUM_UNNECESSARY) { + if (skb->csum_level < SKB_MAX_CSUM_LEVEL) + skb->csum_level++; + } else { + skb->ip_summed = CHECKSUM_UNNECESSARY; + skb->csum_level = 0; + } + + return 0; + } + + if (uh->check) + uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, + iph->daddr, 0); + + return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); +} + +static const struct net_offload udpv4_offload = { + .callbacks = { + .gso_segment = udp4_ufo_fragment, + .gro_receive = udp4_gro_receive, + .gro_complete = udp4_gro_complete, + }, +}; + +int __init udpv4_offload_init(void) +{ + return inet_add_offload(&udpv4_offload, IPPROTO_UDP); +} diff --git a/net/ipv4/udp_tunnel_core.c b/net/ipv4/udp_tunnel_core.c new file mode 100644 index 000000000..d70f683d3 --- /dev/null +++ b/net/ipv4/udp_tunnel_core.c @@ -0,0 +1,225 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/socket.h> +#include <linux/udp.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <net/dst_metadata.h> +#include <net/net_namespace.h> +#include <net/udp.h> +#include <net/udp_tunnel.h> + +int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg, + struct socket **sockp) +{ + int err; + struct socket *sock = NULL; + struct sockaddr_in udp_addr; + + err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock); + if (err < 0) + goto error; + + if (cfg->bind_ifindex) { + err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true); + if (err < 0) + goto error; + } + + udp_addr.sin_family = AF_INET; + udp_addr.sin_addr = cfg->local_ip; + udp_addr.sin_port = cfg->local_udp_port; + err = kernel_bind(sock, (struct sockaddr *)&udp_addr, + sizeof(udp_addr)); + if (err < 0) + goto error; + + if (cfg->peer_udp_port) { + udp_addr.sin_family = AF_INET; + udp_addr.sin_addr = cfg->peer_ip; + udp_addr.sin_port = cfg->peer_udp_port; + err = kernel_connect(sock, (struct sockaddr *)&udp_addr, + sizeof(udp_addr), 0); + if (err < 0) + goto error; + } + + sock->sk->sk_no_check_tx = !cfg->use_udp_checksums; + + *sockp = sock; + return 0; + +error: + if (sock) { + kernel_sock_shutdown(sock, SHUT_RDWR); + sock_release(sock); + } + *sockp = NULL; + return err; +} +EXPORT_SYMBOL(udp_sock_create4); + +void setup_udp_tunnel_sock(struct net *net, struct socket *sock, + struct udp_tunnel_sock_cfg *cfg) +{ + struct sock *sk = sock->sk; + + /* Disable multicast loopback */ + inet_sk(sk)->mc_loop = 0; + + /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */ + inet_inc_convert_csum(sk); + + rcu_assign_sk_user_data(sk, cfg->sk_user_data); + + udp_sk(sk)->encap_type = cfg->encap_type; + udp_sk(sk)->encap_rcv = cfg->encap_rcv; + udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup; + udp_sk(sk)->encap_destroy = cfg->encap_destroy; + udp_sk(sk)->gro_receive = cfg->gro_receive; + udp_sk(sk)->gro_complete = cfg->gro_complete; + + udp_tunnel_encap_enable(sock); +} +EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock); + +void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock, + unsigned short type) +{ + struct sock *sk = sock->sk; + struct udp_tunnel_info ti; + + if (!dev->netdev_ops->ndo_udp_tunnel_add || + !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT)) + return; + + ti.type = type; + ti.sa_family = sk->sk_family; + ti.port = inet_sk(sk)->inet_sport; + + dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti); +} +EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port); + +void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock, + unsigned short type) +{ + struct sock *sk = sock->sk; + struct udp_tunnel_info ti; + + if (!dev->netdev_ops->ndo_udp_tunnel_del || + !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT)) + return; + + ti.type = type; + ti.sa_family = sk->sk_family; + ti.port = inet_sk(sk)->inet_sport; + + dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti); +} +EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port); + +/* Notify netdevs that UDP port started listening */ +void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type) +{ + struct sock *sk = sock->sk; + struct net *net = sock_net(sk); + struct udp_tunnel_info ti; + struct net_device *dev; + + ti.type = type; + ti.sa_family = sk->sk_family; + ti.port = inet_sk(sk)->inet_sport; + + rcu_read_lock(); + for_each_netdev_rcu(net, dev) { + if (!dev->netdev_ops->ndo_udp_tunnel_add) + continue; + if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT)) + continue; + dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti); + } + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port); + +/* Notify netdevs that UDP port is no more listening */ +void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type) +{ + struct sock *sk = sock->sk; + struct net *net = sock_net(sk); + struct udp_tunnel_info ti; + struct net_device *dev; + + ti.type = type; + ti.sa_family = sk->sk_family; + ti.port = inet_sk(sk)->inet_sport; + + rcu_read_lock(); + for_each_netdev_rcu(net, dev) { + if (!dev->netdev_ops->ndo_udp_tunnel_del) + continue; + if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT)) + continue; + dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti); + } + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port); + +void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb, + __be32 src, __be32 dst, __u8 tos, __u8 ttl, + __be16 df, __be16 src_port, __be16 dst_port, + bool xnet, bool nocheck) +{ + struct udphdr *uh; + + __skb_push(skb, sizeof(*uh)); + skb_reset_transport_header(skb); + uh = udp_hdr(skb); + + uh->dest = dst_port; + uh->source = src_port; + uh->len = htons(skb->len); + + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + + udp_set_csum(nocheck, skb, src, dst, skb->len); + + iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet); +} +EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb); + +void udp_tunnel_sock_release(struct socket *sock) +{ + rcu_assign_sk_user_data(sock->sk, NULL); + synchronize_rcu(); + kernel_sock_shutdown(sock, SHUT_RDWR); + sock_release(sock); +} +EXPORT_SYMBOL_GPL(udp_tunnel_sock_release); + +struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family, + __be16 flags, __be64 tunnel_id, int md_size) +{ + struct metadata_dst *tun_dst; + struct ip_tunnel_info *info; + + if (family == AF_INET) + tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size); + else + tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size); + if (!tun_dst) + return NULL; + + info = &tun_dst->u.tun_info; + info->key.tp_src = udp_hdr(skb)->source; + info->key.tp_dst = udp_hdr(skb)->dest; + if (udp_hdr(skb)->check) + info->key.tun_flags |= TUNNEL_CSUM; + return tun_dst; +} +EXPORT_SYMBOL_GPL(udp_tun_rx_dst); + +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/udp_tunnel_nic.c b/net/ipv4/udp_tunnel_nic.c new file mode 100644 index 000000000..bc3a043a5 --- /dev/null +++ b/net/ipv4/udp_tunnel_nic.c @@ -0,0 +1,973 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) 2020 Facebook Inc. + +#include <linux/ethtool_netlink.h> +#include <linux/netdevice.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/workqueue.h> +#include <net/udp_tunnel.h> +#include <net/vxlan.h> + +enum udp_tunnel_nic_table_entry_flags { + UDP_TUNNEL_NIC_ENTRY_ADD = BIT(0), + UDP_TUNNEL_NIC_ENTRY_DEL = BIT(1), + UDP_TUNNEL_NIC_ENTRY_OP_FAIL = BIT(2), + UDP_TUNNEL_NIC_ENTRY_FROZEN = BIT(3), +}; + +struct udp_tunnel_nic_table_entry { + __be16 port; + u8 type; + u8 flags; + u16 use_cnt; +#define UDP_TUNNEL_NIC_USE_CNT_MAX U16_MAX + u8 hw_priv; +}; + +/** + * struct udp_tunnel_nic - UDP tunnel port offload state + * @work: async work for talking to hardware from process context + * @dev: netdev pointer + * @need_sync: at least one port start changed + * @need_replay: space was freed, we need a replay of all ports + * @work_pending: @work is currently scheduled + * @n_tables: number of tables under @entries + * @missed: bitmap of tables which overflown + * @entries: table of tables of ports currently offloaded + */ +struct udp_tunnel_nic { + struct work_struct work; + + struct net_device *dev; + + u8 need_sync:1; + u8 need_replay:1; + u8 work_pending:1; + + unsigned int n_tables; + unsigned long missed; + struct udp_tunnel_nic_table_entry **entries; +}; + +/* We ensure all work structs are done using driver state, but not the code. + * We need a workqueue we can flush before module gets removed. + */ +static struct workqueue_struct *udp_tunnel_nic_workqueue; + +static const char *udp_tunnel_nic_tunnel_type_name(unsigned int type) +{ + switch (type) { + case UDP_TUNNEL_TYPE_VXLAN: + return "vxlan"; + case UDP_TUNNEL_TYPE_GENEVE: + return "geneve"; + case UDP_TUNNEL_TYPE_VXLAN_GPE: + return "vxlan-gpe"; + default: + return "unknown"; + } +} + +static bool +udp_tunnel_nic_entry_is_free(struct udp_tunnel_nic_table_entry *entry) +{ + return entry->use_cnt == 0 && !entry->flags; +} + +static bool +udp_tunnel_nic_entry_is_present(struct udp_tunnel_nic_table_entry *entry) +{ + return entry->use_cnt && !(entry->flags & ~UDP_TUNNEL_NIC_ENTRY_FROZEN); +} + +static bool +udp_tunnel_nic_entry_is_frozen(struct udp_tunnel_nic_table_entry *entry) +{ + return entry->flags & UDP_TUNNEL_NIC_ENTRY_FROZEN; +} + +static void +udp_tunnel_nic_entry_freeze_used(struct udp_tunnel_nic_table_entry *entry) +{ + if (!udp_tunnel_nic_entry_is_free(entry)) + entry->flags |= UDP_TUNNEL_NIC_ENTRY_FROZEN; +} + +static void +udp_tunnel_nic_entry_unfreeze(struct udp_tunnel_nic_table_entry *entry) +{ + entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_FROZEN; +} + +static bool +udp_tunnel_nic_entry_is_queued(struct udp_tunnel_nic_table_entry *entry) +{ + return entry->flags & (UDP_TUNNEL_NIC_ENTRY_ADD | + UDP_TUNNEL_NIC_ENTRY_DEL); +} + +static void +udp_tunnel_nic_entry_queue(struct udp_tunnel_nic *utn, + struct udp_tunnel_nic_table_entry *entry, + unsigned int flag) +{ + entry->flags |= flag; + utn->need_sync = 1; +} + +static void +udp_tunnel_nic_ti_from_entry(struct udp_tunnel_nic_table_entry *entry, + struct udp_tunnel_info *ti) +{ + memset(ti, 0, sizeof(*ti)); + ti->port = entry->port; + ti->type = entry->type; + ti->hw_priv = entry->hw_priv; +} + +static bool +udp_tunnel_nic_is_empty(struct net_device *dev, struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + unsigned int i, j; + + for (i = 0; i < utn->n_tables; i++) + for (j = 0; j < info->tables[i].n_entries; j++) + if (!udp_tunnel_nic_entry_is_free(&utn->entries[i][j])) + return false; + return true; +} + +static bool +udp_tunnel_nic_should_replay(struct net_device *dev, struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_table_info *table; + unsigned int i, j; + + if (!utn->missed) + return false; + + for (i = 0; i < utn->n_tables; i++) { + table = &dev->udp_tunnel_nic_info->tables[i]; + if (!test_bit(i, &utn->missed)) + continue; + + for (j = 0; j < table->n_entries; j++) + if (udp_tunnel_nic_entry_is_free(&utn->entries[i][j])) + return true; + } + + return false; +} + +static void +__udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table, + unsigned int idx, struct udp_tunnel_info *ti) +{ + struct udp_tunnel_nic_table_entry *entry; + struct udp_tunnel_nic *utn; + + utn = dev->udp_tunnel_nic; + entry = &utn->entries[table][idx]; + + if (entry->use_cnt) + udp_tunnel_nic_ti_from_entry(entry, ti); +} + +static void +__udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table, + unsigned int idx, u8 priv) +{ + dev->udp_tunnel_nic->entries[table][idx].hw_priv = priv; +} + +static void +udp_tunnel_nic_entry_update_done(struct udp_tunnel_nic_table_entry *entry, + int err) +{ + bool dodgy = entry->flags & UDP_TUNNEL_NIC_ENTRY_OP_FAIL; + + WARN_ON_ONCE(entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD && + entry->flags & UDP_TUNNEL_NIC_ENTRY_DEL); + + if (entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD && + (!err || (err == -EEXIST && dodgy))) + entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_ADD; + + if (entry->flags & UDP_TUNNEL_NIC_ENTRY_DEL && + (!err || (err == -ENOENT && dodgy))) + entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_DEL; + + if (!err) + entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_OP_FAIL; + else + entry->flags |= UDP_TUNNEL_NIC_ENTRY_OP_FAIL; +} + +static void +udp_tunnel_nic_device_sync_one(struct net_device *dev, + struct udp_tunnel_nic *utn, + unsigned int table, unsigned int idx) +{ + struct udp_tunnel_nic_table_entry *entry; + struct udp_tunnel_info ti; + int err; + + entry = &utn->entries[table][idx]; + if (!udp_tunnel_nic_entry_is_queued(entry)) + return; + + udp_tunnel_nic_ti_from_entry(entry, &ti); + if (entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD) + err = dev->udp_tunnel_nic_info->set_port(dev, table, idx, &ti); + else + err = dev->udp_tunnel_nic_info->unset_port(dev, table, idx, + &ti); + udp_tunnel_nic_entry_update_done(entry, err); + + if (err) + netdev_warn(dev, + "UDP tunnel port sync failed port %d type %s: %d\n", + be16_to_cpu(entry->port), + udp_tunnel_nic_tunnel_type_name(entry->type), + err); +} + +static void +udp_tunnel_nic_device_sync_by_port(struct net_device *dev, + struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + unsigned int i, j; + + for (i = 0; i < utn->n_tables; i++) + for (j = 0; j < info->tables[i].n_entries; j++) + udp_tunnel_nic_device_sync_one(dev, utn, i, j); +} + +static void +udp_tunnel_nic_device_sync_by_table(struct net_device *dev, + struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + unsigned int i, j; + int err; + + for (i = 0; i < utn->n_tables; i++) { + /* Find something that needs sync in this table */ + for (j = 0; j < info->tables[i].n_entries; j++) + if (udp_tunnel_nic_entry_is_queued(&utn->entries[i][j])) + break; + if (j == info->tables[i].n_entries) + continue; + + err = info->sync_table(dev, i); + if (err) + netdev_warn(dev, "UDP tunnel port sync failed for table %d: %d\n", + i, err); + + for (j = 0; j < info->tables[i].n_entries; j++) { + struct udp_tunnel_nic_table_entry *entry; + + entry = &utn->entries[i][j]; + if (udp_tunnel_nic_entry_is_queued(entry)) + udp_tunnel_nic_entry_update_done(entry, err); + } + } +} + +static void +__udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn) +{ + if (!utn->need_sync) + return; + + if (dev->udp_tunnel_nic_info->sync_table) + udp_tunnel_nic_device_sync_by_table(dev, utn); + else + udp_tunnel_nic_device_sync_by_port(dev, utn); + + utn->need_sync = 0; + /* Can't replay directly here, in case we come from the tunnel driver's + * notification - trying to replay may deadlock inside tunnel driver. + */ + utn->need_replay = udp_tunnel_nic_should_replay(dev, utn); +} + +static void +udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + bool may_sleep; + + if (!utn->need_sync) + return; + + /* Drivers which sleep in the callback need to update from + * the workqueue, if we come from the tunnel driver's notification. + */ + may_sleep = info->flags & UDP_TUNNEL_NIC_INFO_MAY_SLEEP; + if (!may_sleep) + __udp_tunnel_nic_device_sync(dev, utn); + if (may_sleep || utn->need_replay) { + queue_work(udp_tunnel_nic_workqueue, &utn->work); + utn->work_pending = 1; + } +} + +static bool +udp_tunnel_nic_table_is_capable(const struct udp_tunnel_nic_table_info *table, + struct udp_tunnel_info *ti) +{ + return table->tunnel_types & ti->type; +} + +static bool +udp_tunnel_nic_is_capable(struct net_device *dev, struct udp_tunnel_nic *utn, + struct udp_tunnel_info *ti) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + unsigned int i; + + /* Special case IPv4-only NICs */ + if (info->flags & UDP_TUNNEL_NIC_INFO_IPV4_ONLY && + ti->sa_family != AF_INET) + return false; + + for (i = 0; i < utn->n_tables; i++) + if (udp_tunnel_nic_table_is_capable(&info->tables[i], ti)) + return true; + return false; +} + +static int +udp_tunnel_nic_has_collision(struct net_device *dev, struct udp_tunnel_nic *utn, + struct udp_tunnel_info *ti) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + struct udp_tunnel_nic_table_entry *entry; + unsigned int i, j; + + for (i = 0; i < utn->n_tables; i++) + for (j = 0; j < info->tables[i].n_entries; j++) { + entry = &utn->entries[i][j]; + + if (!udp_tunnel_nic_entry_is_free(entry) && + entry->port == ti->port && + entry->type != ti->type) { + __set_bit(i, &utn->missed); + return true; + } + } + return false; +} + +static void +udp_tunnel_nic_entry_adj(struct udp_tunnel_nic *utn, + unsigned int table, unsigned int idx, int use_cnt_adj) +{ + struct udp_tunnel_nic_table_entry *entry = &utn->entries[table][idx]; + bool dodgy = entry->flags & UDP_TUNNEL_NIC_ENTRY_OP_FAIL; + unsigned int from, to; + + WARN_ON(entry->use_cnt + (u32)use_cnt_adj > U16_MAX); + + /* If not going from used to unused or vice versa - all done. + * For dodgy entries make sure we try to sync again (queue the entry). + */ + entry->use_cnt += use_cnt_adj; + if (!dodgy && !entry->use_cnt == !(entry->use_cnt - use_cnt_adj)) + return; + + /* Cancel the op before it was sent to the device, if possible, + * otherwise we'd need to take special care to issue commands + * in the same order the ports arrived. + */ + if (use_cnt_adj < 0) { + from = UDP_TUNNEL_NIC_ENTRY_ADD; + to = UDP_TUNNEL_NIC_ENTRY_DEL; + } else { + from = UDP_TUNNEL_NIC_ENTRY_DEL; + to = UDP_TUNNEL_NIC_ENTRY_ADD; + } + + if (entry->flags & from) { + entry->flags &= ~from; + if (!dodgy) + return; + } + + udp_tunnel_nic_entry_queue(utn, entry, to); +} + +static bool +udp_tunnel_nic_entry_try_adj(struct udp_tunnel_nic *utn, + unsigned int table, unsigned int idx, + struct udp_tunnel_info *ti, int use_cnt_adj) +{ + struct udp_tunnel_nic_table_entry *entry = &utn->entries[table][idx]; + + if (udp_tunnel_nic_entry_is_free(entry) || + entry->port != ti->port || + entry->type != ti->type) + return false; + + if (udp_tunnel_nic_entry_is_frozen(entry)) + return true; + + udp_tunnel_nic_entry_adj(utn, table, idx, use_cnt_adj); + return true; +} + +/* Try to find existing matching entry and adjust its use count, instead of + * adding a new one. Returns true if entry was found. In case of delete the + * entry may have gotten removed in the process, in which case it will be + * queued for removal. + */ +static bool +udp_tunnel_nic_try_existing(struct net_device *dev, struct udp_tunnel_nic *utn, + struct udp_tunnel_info *ti, int use_cnt_adj) +{ + const struct udp_tunnel_nic_table_info *table; + unsigned int i, j; + + for (i = 0; i < utn->n_tables; i++) { + table = &dev->udp_tunnel_nic_info->tables[i]; + if (!udp_tunnel_nic_table_is_capable(table, ti)) + continue; + + for (j = 0; j < table->n_entries; j++) + if (udp_tunnel_nic_entry_try_adj(utn, i, j, ti, + use_cnt_adj)) + return true; + } + + return false; +} + +static bool +udp_tunnel_nic_add_existing(struct net_device *dev, struct udp_tunnel_nic *utn, + struct udp_tunnel_info *ti) +{ + return udp_tunnel_nic_try_existing(dev, utn, ti, +1); +} + +static bool +udp_tunnel_nic_del_existing(struct net_device *dev, struct udp_tunnel_nic *utn, + struct udp_tunnel_info *ti) +{ + return udp_tunnel_nic_try_existing(dev, utn, ti, -1); +} + +static bool +udp_tunnel_nic_add_new(struct net_device *dev, struct udp_tunnel_nic *utn, + struct udp_tunnel_info *ti) +{ + const struct udp_tunnel_nic_table_info *table; + unsigned int i, j; + + for (i = 0; i < utn->n_tables; i++) { + table = &dev->udp_tunnel_nic_info->tables[i]; + if (!udp_tunnel_nic_table_is_capable(table, ti)) + continue; + + for (j = 0; j < table->n_entries; j++) { + struct udp_tunnel_nic_table_entry *entry; + + entry = &utn->entries[i][j]; + if (!udp_tunnel_nic_entry_is_free(entry)) + continue; + + entry->port = ti->port; + entry->type = ti->type; + entry->use_cnt = 1; + udp_tunnel_nic_entry_queue(utn, entry, + UDP_TUNNEL_NIC_ENTRY_ADD); + return true; + } + + /* The different table may still fit this port in, but there + * are no devices currently which have multiple tables accepting + * the same tunnel type, and false positives are okay. + */ + __set_bit(i, &utn->missed); + } + + return false; +} + +static void +__udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + struct udp_tunnel_nic *utn; + + utn = dev->udp_tunnel_nic; + if (!utn) + return; + if (!netif_running(dev) && info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY) + return; + if (info->flags & UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN && + ti->port == htons(IANA_VXLAN_UDP_PORT)) { + if (ti->type != UDP_TUNNEL_TYPE_VXLAN) + netdev_warn(dev, "device assumes port 4789 will be used by vxlan tunnels\n"); + return; + } + + if (!udp_tunnel_nic_is_capable(dev, utn, ti)) + return; + + /* It may happen that a tunnel of one type is removed and different + * tunnel type tries to reuse its port before the device was informed. + * Rely on utn->missed to re-add this port later. + */ + if (udp_tunnel_nic_has_collision(dev, utn, ti)) + return; + + if (!udp_tunnel_nic_add_existing(dev, utn, ti)) + udp_tunnel_nic_add_new(dev, utn, ti); + + udp_tunnel_nic_device_sync(dev, utn); +} + +static void +__udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti) +{ + struct udp_tunnel_nic *utn; + + utn = dev->udp_tunnel_nic; + if (!utn) + return; + + if (!udp_tunnel_nic_is_capable(dev, utn, ti)) + return; + + udp_tunnel_nic_del_existing(dev, utn, ti); + + udp_tunnel_nic_device_sync(dev, utn); +} + +static void __udp_tunnel_nic_reset_ntf(struct net_device *dev) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + struct udp_tunnel_nic *utn; + unsigned int i, j; + + ASSERT_RTNL(); + + utn = dev->udp_tunnel_nic; + if (!utn) + return; + + utn->need_sync = false; + for (i = 0; i < utn->n_tables; i++) + for (j = 0; j < info->tables[i].n_entries; j++) { + struct udp_tunnel_nic_table_entry *entry; + + entry = &utn->entries[i][j]; + + entry->flags &= ~(UDP_TUNNEL_NIC_ENTRY_DEL | + UDP_TUNNEL_NIC_ENTRY_OP_FAIL); + /* We don't release rtnl across ops */ + WARN_ON(entry->flags & UDP_TUNNEL_NIC_ENTRY_FROZEN); + if (!entry->use_cnt) + continue; + + udp_tunnel_nic_entry_queue(utn, entry, + UDP_TUNNEL_NIC_ENTRY_ADD); + } + + __udp_tunnel_nic_device_sync(dev, utn); +} + +static size_t +__udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + struct udp_tunnel_nic *utn; + unsigned int j; + size_t size; + + utn = dev->udp_tunnel_nic; + if (!utn) + return 0; + + size = 0; + for (j = 0; j < info->tables[table].n_entries; j++) { + if (!udp_tunnel_nic_entry_is_present(&utn->entries[table][j])) + continue; + + size += nla_total_size(0) + /* _TABLE_ENTRY */ + nla_total_size(sizeof(__be16)) + /* _ENTRY_PORT */ + nla_total_size(sizeof(u32)); /* _ENTRY_TYPE */ + } + + return size; +} + +static int +__udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table, + struct sk_buff *skb) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + struct udp_tunnel_nic *utn; + struct nlattr *nest; + unsigned int j; + + utn = dev->udp_tunnel_nic; + if (!utn) + return 0; + + for (j = 0; j < info->tables[table].n_entries; j++) { + if (!udp_tunnel_nic_entry_is_present(&utn->entries[table][j])) + continue; + + nest = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY); + + if (nla_put_be16(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT, + utn->entries[table][j].port) || + nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE, + ilog2(utn->entries[table][j].type))) + goto err_cancel; + + nla_nest_end(skb, nest); + } + + return 0; + +err_cancel: + nla_nest_cancel(skb, nest); + return -EMSGSIZE; +} + +static const struct udp_tunnel_nic_ops __udp_tunnel_nic_ops = { + .get_port = __udp_tunnel_nic_get_port, + .set_port_priv = __udp_tunnel_nic_set_port_priv, + .add_port = __udp_tunnel_nic_add_port, + .del_port = __udp_tunnel_nic_del_port, + .reset_ntf = __udp_tunnel_nic_reset_ntf, + .dump_size = __udp_tunnel_nic_dump_size, + .dump_write = __udp_tunnel_nic_dump_write, +}; + +static void +udp_tunnel_nic_flush(struct net_device *dev, struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + unsigned int i, j; + + for (i = 0; i < utn->n_tables; i++) + for (j = 0; j < info->tables[i].n_entries; j++) { + int adj_cnt = -utn->entries[i][j].use_cnt; + + if (adj_cnt) + udp_tunnel_nic_entry_adj(utn, i, j, adj_cnt); + } + + __udp_tunnel_nic_device_sync(dev, utn); + + for (i = 0; i < utn->n_tables; i++) + memset(utn->entries[i], 0, array_size(info->tables[i].n_entries, + sizeof(**utn->entries))); + WARN_ON(utn->need_sync); + utn->need_replay = 0; +} + +static void +udp_tunnel_nic_replay(struct net_device *dev, struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + struct udp_tunnel_nic_shared_node *node; + unsigned int i, j; + + /* Freeze all the ports we are already tracking so that the replay + * does not double up the refcount. + */ + for (i = 0; i < utn->n_tables; i++) + for (j = 0; j < info->tables[i].n_entries; j++) + udp_tunnel_nic_entry_freeze_used(&utn->entries[i][j]); + utn->missed = 0; + utn->need_replay = 0; + + if (!info->shared) { + udp_tunnel_get_rx_info(dev); + } else { + list_for_each_entry(node, &info->shared->devices, list) + udp_tunnel_get_rx_info(node->dev); + } + + for (i = 0; i < utn->n_tables; i++) + for (j = 0; j < info->tables[i].n_entries; j++) + udp_tunnel_nic_entry_unfreeze(&utn->entries[i][j]); +} + +static void udp_tunnel_nic_device_sync_work(struct work_struct *work) +{ + struct udp_tunnel_nic *utn = + container_of(work, struct udp_tunnel_nic, work); + + rtnl_lock(); + utn->work_pending = 0; + __udp_tunnel_nic_device_sync(utn->dev, utn); + + if (utn->need_replay) + udp_tunnel_nic_replay(utn->dev, utn); + rtnl_unlock(); +} + +static struct udp_tunnel_nic * +udp_tunnel_nic_alloc(const struct udp_tunnel_nic_info *info, + unsigned int n_tables) +{ + struct udp_tunnel_nic *utn; + unsigned int i; + + utn = kzalloc(sizeof(*utn), GFP_KERNEL); + if (!utn) + return NULL; + utn->n_tables = n_tables; + INIT_WORK(&utn->work, udp_tunnel_nic_device_sync_work); + + utn->entries = kmalloc_array(n_tables, sizeof(void *), GFP_KERNEL); + if (!utn->entries) + goto err_free_utn; + + for (i = 0; i < n_tables; i++) { + utn->entries[i] = kcalloc(info->tables[i].n_entries, + sizeof(*utn->entries[i]), GFP_KERNEL); + if (!utn->entries[i]) + goto err_free_prev_entries; + } + + return utn; + +err_free_prev_entries: + while (i--) + kfree(utn->entries[i]); + kfree(utn->entries); +err_free_utn: + kfree(utn); + return NULL; +} + +static void udp_tunnel_nic_free(struct udp_tunnel_nic *utn) +{ + unsigned int i; + + for (i = 0; i < utn->n_tables; i++) + kfree(utn->entries[i]); + kfree(utn->entries); + kfree(utn); +} + +static int udp_tunnel_nic_register(struct net_device *dev) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + struct udp_tunnel_nic_shared_node *node = NULL; + struct udp_tunnel_nic *utn; + unsigned int n_tables, i; + + BUILD_BUG_ON(sizeof(utn->missed) * BITS_PER_BYTE < + UDP_TUNNEL_NIC_MAX_TABLES); + /* Expect use count of at most 2 (IPv4, IPv6) per device */ + BUILD_BUG_ON(UDP_TUNNEL_NIC_USE_CNT_MAX < + UDP_TUNNEL_NIC_MAX_SHARING_DEVICES * 2); + + /* Check that the driver info is sane */ + if (WARN_ON(!info->set_port != !info->unset_port) || + WARN_ON(!info->set_port == !info->sync_table) || + WARN_ON(!info->tables[0].n_entries)) + return -EINVAL; + + if (WARN_ON(info->shared && + info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY)) + return -EINVAL; + + n_tables = 1; + for (i = 1; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) { + if (!info->tables[i].n_entries) + continue; + + n_tables++; + if (WARN_ON(!info->tables[i - 1].n_entries)) + return -EINVAL; + } + + /* Create UDP tunnel state structures */ + if (info->shared) { + node = kzalloc(sizeof(*node), GFP_KERNEL); + if (!node) + return -ENOMEM; + + node->dev = dev; + } + + if (info->shared && info->shared->udp_tunnel_nic_info) { + utn = info->shared->udp_tunnel_nic_info; + } else { + utn = udp_tunnel_nic_alloc(info, n_tables); + if (!utn) { + kfree(node); + return -ENOMEM; + } + } + + if (info->shared) { + if (!info->shared->udp_tunnel_nic_info) { + INIT_LIST_HEAD(&info->shared->devices); + info->shared->udp_tunnel_nic_info = utn; + } + + list_add_tail(&node->list, &info->shared->devices); + } + + utn->dev = dev; + dev_hold(dev); + dev->udp_tunnel_nic = utn; + + if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY)) + udp_tunnel_get_rx_info(dev); + + return 0; +} + +static void +udp_tunnel_nic_unregister(struct net_device *dev, struct udp_tunnel_nic *utn) +{ + const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info; + + /* For a shared table remove this dev from the list of sharing devices + * and if there are other devices just detach. + */ + if (info->shared) { + struct udp_tunnel_nic_shared_node *node, *first; + + list_for_each_entry(node, &info->shared->devices, list) + if (node->dev == dev) + break; + if (list_entry_is_head(node, &info->shared->devices, list)) + return; + + list_del(&node->list); + kfree(node); + + first = list_first_entry_or_null(&info->shared->devices, + typeof(*first), list); + if (first) { + udp_tunnel_drop_rx_info(dev); + utn->dev = first->dev; + goto release_dev; + } + + info->shared->udp_tunnel_nic_info = NULL; + } + + /* Flush before we check work, so we don't waste time adding entries + * from the work which we will boot immediately. + */ + udp_tunnel_nic_flush(dev, utn); + + /* Wait for the work to be done using the state, netdev core will + * retry unregister until we give up our reference on this device. + */ + if (utn->work_pending) + return; + + udp_tunnel_nic_free(utn); +release_dev: + dev->udp_tunnel_nic = NULL; + dev_put(dev); +} + +static int +udp_tunnel_nic_netdevice_event(struct notifier_block *unused, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + const struct udp_tunnel_nic_info *info; + struct udp_tunnel_nic *utn; + + info = dev->udp_tunnel_nic_info; + if (!info) + return NOTIFY_DONE; + + if (event == NETDEV_REGISTER) { + int err; + + err = udp_tunnel_nic_register(dev); + if (err) + netdev_WARN(dev, "failed to register for UDP tunnel offloads: %d", err); + return notifier_from_errno(err); + } + /* All other events will need the udp_tunnel_nic state */ + utn = dev->udp_tunnel_nic; + if (!utn) + return NOTIFY_DONE; + + if (event == NETDEV_UNREGISTER) { + udp_tunnel_nic_unregister(dev, utn); + return NOTIFY_OK; + } + + /* All other events only matter if NIC has to be programmed open */ + if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY)) + return NOTIFY_DONE; + + if (event == NETDEV_UP) { + WARN_ON(!udp_tunnel_nic_is_empty(dev, utn)); + udp_tunnel_get_rx_info(dev); + return NOTIFY_OK; + } + if (event == NETDEV_GOING_DOWN) { + udp_tunnel_nic_flush(dev, utn); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static struct notifier_block udp_tunnel_nic_notifier_block __read_mostly = { + .notifier_call = udp_tunnel_nic_netdevice_event, +}; + +static int __init udp_tunnel_nic_init_module(void) +{ + int err; + + udp_tunnel_nic_workqueue = alloc_ordered_workqueue("udp_tunnel_nic", 0); + if (!udp_tunnel_nic_workqueue) + return -ENOMEM; + + rtnl_lock(); + udp_tunnel_nic_ops = &__udp_tunnel_nic_ops; + rtnl_unlock(); + + err = register_netdevice_notifier(&udp_tunnel_nic_notifier_block); + if (err) + goto err_unset_ops; + + return 0; + +err_unset_ops: + rtnl_lock(); + udp_tunnel_nic_ops = NULL; + rtnl_unlock(); + destroy_workqueue(udp_tunnel_nic_workqueue); + return err; +} +late_initcall(udp_tunnel_nic_init_module); + +static void __exit udp_tunnel_nic_cleanup_module(void) +{ + unregister_netdevice_notifier(&udp_tunnel_nic_notifier_block); + + rtnl_lock(); + udp_tunnel_nic_ops = NULL; + rtnl_unlock(); + + destroy_workqueue(udp_tunnel_nic_workqueue); +} +module_exit(udp_tunnel_nic_cleanup_module); + +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/udp_tunnel_stub.c b/net/ipv4/udp_tunnel_stub.c new file mode 100644 index 000000000..c4b2888f5 --- /dev/null +++ b/net/ipv4/udp_tunnel_stub.c @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) 2020 Facebook Inc. + +#include <net/udp_tunnel.h> + +const struct udp_tunnel_nic_ops *udp_tunnel_nic_ops; +EXPORT_SYMBOL_GPL(udp_tunnel_nic_ops); diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c new file mode 100644 index 000000000..edf82a400 --- /dev/null +++ b/net/ipv4/udplite.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * UDPLITE An implementation of the UDP-Lite protocol (RFC 3828). + * + * Authors: Gerrit Renker <gerrit@erg.abdn.ac.uk> + * + * Changes: + * Fixes: + */ + +#define pr_fmt(fmt) "UDPLite: " fmt + +#include <linux/export.h> +#include <linux/proc_fs.h> +#include "udp_impl.h" + +struct udp_table udplite_table __read_mostly; +EXPORT_SYMBOL(udplite_table); + +/* Designate sk as UDP-Lite socket */ +static int udplite_sk_init(struct sock *sk) +{ + udp_init_sock(sk); + udp_sk(sk)->pcflag = UDPLITE_BIT; + return 0; +} + +static int udplite_rcv(struct sk_buff *skb) +{ + return __udp4_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE); +} + +static int udplite_err(struct sk_buff *skb, u32 info) +{ + return __udp4_lib_err(skb, info, &udplite_table); +} + +static const struct net_protocol udplite_protocol = { + .handler = udplite_rcv, + .err_handler = udplite_err, + .no_policy = 1, + .netns_ok = 1, +}; + +struct proto udplite_prot = { + .name = "UDP-Lite", + .owner = THIS_MODULE, + .close = udp_lib_close, + .connect = ip4_datagram_connect, + .disconnect = udp_disconnect, + .ioctl = udp_ioctl, + .init = udplite_sk_init, + .destroy = udp_destroy_sock, + .setsockopt = udp_setsockopt, + .getsockopt = udp_getsockopt, + .sendmsg = udp_sendmsg, + .recvmsg = udp_recvmsg, + .sendpage = udp_sendpage, + .hash = udp_lib_hash, + .unhash = udp_lib_unhash, + .rehash = udp_v4_rehash, + .get_port = udp_v4_get_port, + .memory_allocated = &udp_memory_allocated, + .sysctl_mem = sysctl_udp_mem, + .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), + .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), + .obj_size = sizeof(struct udp_sock), + .h.udp_table = &udplite_table, +}; +EXPORT_SYMBOL(udplite_prot); + +static struct inet_protosw udplite4_protosw = { + .type = SOCK_DGRAM, + .protocol = IPPROTO_UDPLITE, + .prot = &udplite_prot, + .ops = &inet_dgram_ops, + .flags = INET_PROTOSW_PERMANENT, +}; + +#ifdef CONFIG_PROC_FS +static struct udp_seq_afinfo udplite4_seq_afinfo = { + .family = AF_INET, + .udp_table = &udplite_table, +}; + +static int __net_init udplite4_proc_init_net(struct net *net) +{ + if (!proc_create_net_data("udplite", 0444, net->proc_net, &udp_seq_ops, + sizeof(struct udp_iter_state), &udplite4_seq_afinfo)) + return -ENOMEM; + return 0; +} + +static void __net_exit udplite4_proc_exit_net(struct net *net) +{ + remove_proc_entry("udplite", net->proc_net); +} + +static struct pernet_operations udplite4_net_ops = { + .init = udplite4_proc_init_net, + .exit = udplite4_proc_exit_net, +}; + +static __init int udplite4_proc_init(void) +{ + return register_pernet_subsys(&udplite4_net_ops); +} +#else +static inline int udplite4_proc_init(void) +{ + return 0; +} +#endif + +void __init udplite4_register(void) +{ + udp_table_init(&udplite_table, "UDP-Lite"); + if (proto_register(&udplite_prot, 1)) + goto out_register_err; + + if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0) + goto out_unregister_proto; + + inet_register_protosw(&udplite4_protosw); + + if (udplite4_proc_init()) + pr_err("%s: Cannot register /proc!\n", __func__); + return; + +out_unregister_proto: + proto_unregister(&udplite_prot); +out_register_err: + pr_crit("%s: Cannot add UDP-Lite protocol\n", __func__); +} diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c new file mode 100644 index 000000000..eac206a29 --- /dev/null +++ b/net/ipv4/xfrm4_input.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * xfrm4_input.c + * + * Changes: + * YOSHIFUJI Hideaki @USAGI + * Split up af-specific portion + * Derek Atkins <derek@ihtfp.com> + * Add Encapsulation support + * + */ + +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> +#include <net/ip.h> +#include <net/xfrm.h> + +static int xfrm4_rcv_encap_finish2(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + return dst_input(skb); +} + +static inline int xfrm4_rcv_encap_finish(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + if (!skb_dst(skb)) { + const struct iphdr *iph = ip_hdr(skb); + + if (ip_route_input_noref(skb, iph->daddr, iph->saddr, + iph->tos, skb->dev)) + goto drop; + } + + if (xfrm_trans_queue(skb, xfrm4_rcv_encap_finish2)) + goto drop; + + return 0; +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +int xfrm4_transport_finish(struct sk_buff *skb, int async) +{ + struct xfrm_offload *xo = xfrm_offload(skb); + struct iphdr *iph = ip_hdr(skb); + + iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol; + +#ifndef CONFIG_NETFILTER + if (!async) + return -iph->protocol; +#endif + + __skb_push(skb, skb->data - skb_network_header(skb)); + iph->tot_len = htons(skb->len); + ip_send_check(iph); + + if (xo && (xo->flags & XFRM_GRO)) { + skb_mac_header_rebuild(skb); + skb_reset_transport_header(skb); + return 0; + } + + NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, + dev_net(skb->dev), NULL, skb, skb->dev, NULL, + xfrm4_rcv_encap_finish); + return 0; +} + +/* If it's a keepalive packet, then just eat it. + * If it's an encapsulated packet, then pass it to the + * IPsec xfrm input. + * Returns 0 if skb passed to xfrm or was dropped. + * Returns >0 if skb should be passed to UDP. + * Returns <0 if skb should be resubmitted (-ret is protocol) + */ +int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct udp_sock *up = udp_sk(sk); + struct udphdr *uh; + struct iphdr *iph; + int iphlen, len; + + __u8 *udpdata; + __be32 *udpdata32; + __u16 encap_type = up->encap_type; + + /* if this is not encapsulated socket, then just return now */ + if (!encap_type) + return 1; + + /* If this is a paged skb, make sure we pull up + * whatever data we need to look at. */ + len = skb->len - sizeof(struct udphdr); + if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8))) + return 1; + + /* Now we can get the pointers */ + uh = udp_hdr(skb); + udpdata = (__u8 *)uh + sizeof(struct udphdr); + udpdata32 = (__be32 *)udpdata; + + switch (encap_type) { + default: + case UDP_ENCAP_ESPINUDP: + /* Check if this is a keepalive packet. If so, eat it. */ + if (len == 1 && udpdata[0] == 0xff) { + goto drop; + } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) { + /* ESP Packet without Non-ESP header */ + len = sizeof(struct udphdr); + } else + /* Must be an IKE packet.. pass it through */ + return 1; + break; + case UDP_ENCAP_ESPINUDP_NON_IKE: + /* Check if this is a keepalive packet. If so, eat it. */ + if (len == 1 && udpdata[0] == 0xff) { + goto drop; + } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) && + udpdata32[0] == 0 && udpdata32[1] == 0) { + + /* ESP Packet with Non-IKE marker */ + len = sizeof(struct udphdr) + 2 * sizeof(u32); + } else + /* Must be an IKE packet.. pass it through */ + return 1; + break; + } + + /* At this point we are sure that this is an ESPinUDP packet, + * so we need to remove 'len' bytes from the packet (the UDP + * header and optional ESP marker bytes) and then modify the + * protocol to ESP, and then call into the transform receiver. + */ + if (skb_unclone(skb, GFP_ATOMIC)) + goto drop; + + /* Now we can update and verify the packet length... */ + iph = ip_hdr(skb); + iphlen = iph->ihl << 2; + iph->tot_len = htons(ntohs(iph->tot_len) - len); + if (skb->len < iphlen + len) { + /* packet is too small!?! */ + goto drop; + } + + /* pull the data buffer up to the ESP header and set the + * transport header to point to ESP. Keep UDP on the stack + * for later. + */ + __skb_pull(skb, len); + skb_reset_transport_header(skb); + + /* process ESP */ + return xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, encap_type); + +drop: + kfree_skb(skb); + return 0; +} +EXPORT_SYMBOL(xfrm4_udp_encap_rcv); + +int xfrm4_rcv(struct sk_buff *skb) +{ + return xfrm4_rcv_spi(skb, ip_hdr(skb)->protocol, 0); +} +EXPORT_SYMBOL(xfrm4_rcv); diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c new file mode 100644 index 000000000..3cff51ba7 --- /dev/null +++ b/net/ipv4/xfrm4_output.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * xfrm4_output.c - Common IPsec encapsulation code for IPv4. + * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au> + */ + +#include <linux/if_ether.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netfilter_ipv4.h> +#include <net/dst.h> +#include <net/ip.h> +#include <net/xfrm.h> +#include <net/icmp.h> + +static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ +#ifdef CONFIG_NETFILTER + struct xfrm_state *x = skb_dst(skb)->xfrm; + + if (!x) { + IPCB(skb)->flags |= IPSKB_REROUTED; + return dst_output(net, sk, skb); + } +#endif + + return xfrm_output(sk, skb); +} + +int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, + net, sk, skb, skb->dev, skb_dst(skb)->dev, + __xfrm4_output, + !(IPCB(skb)->flags & IPSKB_REROUTED)); +} + +void xfrm4_local_error(struct sk_buff *skb, u32 mtu) +{ + struct iphdr *hdr; + + hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb); + ip_local_error(skb->sk, EMSGSIZE, hdr->daddr, + inet_sk(skb->sk)->inet_dport, mtu); +} diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c new file mode 100644 index 000000000..9ebd54752 --- /dev/null +++ b/net/ipv4/xfrm4_policy.c @@ -0,0 +1,261 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * xfrm4_policy.c + * + * Changes: + * Kazunori MIYAZAWA @USAGI + * YOSHIFUJI Hideaki @USAGI + * Split up af-specific portion + * + */ + +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/inetdevice.h> +#include <net/dst.h> +#include <net/xfrm.h> +#include <net/ip.h> +#include <net/l3mdev.h> + +static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4, + int tos, int oif, + const xfrm_address_t *saddr, + const xfrm_address_t *daddr, + u32 mark) +{ + struct rtable *rt; + + memset(fl4, 0, sizeof(*fl4)); + fl4->daddr = daddr->a4; + fl4->flowi4_tos = tos; + fl4->flowi4_oif = l3mdev_master_ifindex_by_index(net, oif); + fl4->flowi4_mark = mark; + if (saddr) + fl4->saddr = saddr->a4; + + fl4->flowi4_flags = FLOWI_FLAG_SKIP_NH_OIF; + + rt = __ip_route_output_key(net, fl4); + if (!IS_ERR(rt)) + return &rt->dst; + + return ERR_CAST(rt); +} + +static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos, int oif, + const xfrm_address_t *saddr, + const xfrm_address_t *daddr, + u32 mark) +{ + struct flowi4 fl4; + + return __xfrm4_dst_lookup(net, &fl4, tos, oif, saddr, daddr, mark); +} + +static int xfrm4_get_saddr(struct net *net, int oif, + xfrm_address_t *saddr, xfrm_address_t *daddr, + u32 mark) +{ + struct dst_entry *dst; + struct flowi4 fl4; + + dst = __xfrm4_dst_lookup(net, &fl4, 0, oif, NULL, daddr, mark); + if (IS_ERR(dst)) + return -EHOSTUNREACH; + + saddr->a4 = fl4.saddr; + dst_release(dst); + return 0; +} + +static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, + const struct flowi *fl) +{ + struct rtable *rt = (struct rtable *)xdst->route; + const struct flowi4 *fl4 = &fl->u.ip4; + + xdst->u.rt.rt_iif = fl4->flowi4_iif; + + xdst->u.dst.dev = dev; + dev_hold(dev); + + /* Sheit... I remember I did this right. Apparently, + * it was magically lost, so this code needs audit */ + xdst->u.rt.rt_is_input = rt->rt_is_input; + xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | + RTCF_LOCAL); + xdst->u.rt.rt_type = rt->rt_type; + xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway; + xdst->u.rt.rt_gw_family = rt->rt_gw_family; + if (rt->rt_gw_family == AF_INET) + xdst->u.rt.rt_gw4 = rt->rt_gw4; + else if (rt->rt_gw_family == AF_INET6) + xdst->u.rt.rt_gw6 = rt->rt_gw6; + xdst->u.rt.rt_pmtu = rt->rt_pmtu; + xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked; + INIT_LIST_HEAD(&xdst->u.rt.rt_uncached); + rt_add_uncached_list(&xdst->u.rt); + + return 0; +} + +static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu, + bool confirm_neigh) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + struct dst_entry *path = xdst->route; + + path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh); +} + +static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + struct dst_entry *path = xdst->route; + + path->ops->redirect(path, sk, skb); +} + +static void xfrm4_dst_destroy(struct dst_entry *dst) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + + dst_destroy_metrics_generic(dst); + if (xdst->u.rt.rt_uncached_list) + rt_del_uncached_list(&xdst->u.rt); + xfrm_dst_destroy(xdst); +} + +static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, + int unregister) +{ + if (!unregister) + return; + + xfrm_dst_ifdown(dst, dev); +} + +static struct dst_ops xfrm4_dst_ops_template = { + .family = AF_INET, + .update_pmtu = xfrm4_update_pmtu, + .redirect = xfrm4_redirect, + .cow_metrics = dst_cow_metrics_generic, + .destroy = xfrm4_dst_destroy, + .ifdown = xfrm4_dst_ifdown, + .local_out = __ip_local_out, + .gc_thresh = 32768, +}; + +static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = { + .dst_ops = &xfrm4_dst_ops_template, + .dst_lookup = xfrm4_dst_lookup, + .get_saddr = xfrm4_get_saddr, + .fill_dst = xfrm4_fill_dst, + .blackhole_route = ipv4_blackhole_route, +}; + +#ifdef CONFIG_SYSCTL +static struct ctl_table xfrm4_policy_table[] = { + { + .procname = "xfrm4_gc_thresh", + .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static __net_init int xfrm4_net_sysctl_init(struct net *net) +{ + struct ctl_table *table; + struct ctl_table_header *hdr; + + table = xfrm4_policy_table; + if (!net_eq(net, &init_net)) { + table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); + if (!table) + goto err_alloc; + + table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; + } + + hdr = register_net_sysctl(net, "net/ipv4", table); + if (!hdr) + goto err_reg; + + net->ipv4.xfrm4_hdr = hdr; + return 0; + +err_reg: + if (!net_eq(net, &init_net)) + kfree(table); +err_alloc: + return -ENOMEM; +} + +static __net_exit void xfrm4_net_sysctl_exit(struct net *net) +{ + struct ctl_table *table; + + if (!net->ipv4.xfrm4_hdr) + return; + + table = net->ipv4.xfrm4_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); + if (!net_eq(net, &init_net)) + kfree(table); +} +#else /* CONFIG_SYSCTL */ +static inline int xfrm4_net_sysctl_init(struct net *net) +{ + return 0; +} + +static inline void xfrm4_net_sysctl_exit(struct net *net) +{ +} +#endif + +static int __net_init xfrm4_net_init(struct net *net) +{ + int ret; + + memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template, + sizeof(xfrm4_dst_ops_template)); + ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops); + if (ret) + return ret; + + ret = xfrm4_net_sysctl_init(net); + if (ret) + dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); + + return ret; +} + +static void __net_exit xfrm4_net_exit(struct net *net) +{ + xfrm4_net_sysctl_exit(net); + dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); +} + +static struct pernet_operations __net_initdata xfrm4_net_ops = { + .init = xfrm4_net_init, + .exit = xfrm4_net_exit, +}; + +static void __init xfrm4_policy_init(void) +{ + xfrm_policy_register_afinfo(&xfrm4_policy_afinfo, AF_INET); +} + +void __init xfrm4_init(void) +{ + xfrm4_state_init(); + xfrm4_policy_init(); + xfrm4_protocol_init(); + register_pernet_subsys(&xfrm4_net_ops); +} diff --git a/net/ipv4/xfrm4_protocol.c b/net/ipv4/xfrm4_protocol.c new file mode 100644 index 000000000..cfd46222e --- /dev/null +++ b/net/ipv4/xfrm4_protocol.c @@ -0,0 +1,309 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* xfrm4_protocol.c - Generic xfrm protocol multiplexer. + * + * Copyright (C) 2013 secunet Security Networks AG + * + * Author: + * Steffen Klassert <steffen.klassert@secunet.com> + * + * Based on: + * net/ipv4/tunnel4.c + */ + +#include <linux/init.h> +#include <linux/mutex.h> +#include <linux/skbuff.h> +#include <net/icmp.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/xfrm.h> + +static struct xfrm4_protocol __rcu *esp4_handlers __read_mostly; +static struct xfrm4_protocol __rcu *ah4_handlers __read_mostly; +static struct xfrm4_protocol __rcu *ipcomp4_handlers __read_mostly; +static DEFINE_MUTEX(xfrm4_protocol_mutex); + +static inline struct xfrm4_protocol __rcu **proto_handlers(u8 protocol) +{ + switch (protocol) { + case IPPROTO_ESP: + return &esp4_handlers; + case IPPROTO_AH: + return &ah4_handlers; + case IPPROTO_COMP: + return &ipcomp4_handlers; + } + + return NULL; +} + +#define for_each_protocol_rcu(head, handler) \ + for (handler = rcu_dereference(head); \ + handler != NULL; \ + handler = rcu_dereference(handler->next)) \ + +static int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err) +{ + int ret; + struct xfrm4_protocol *handler; + struct xfrm4_protocol __rcu **head = proto_handlers(protocol); + + if (!head) + return 0; + + for_each_protocol_rcu(*head, handler) + if ((ret = handler->cb_handler(skb, err)) <= 0) + return ret; + + return 0; +} + +int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi, + int encap_type) +{ + int ret; + struct xfrm4_protocol *handler; + struct xfrm4_protocol __rcu **head = proto_handlers(nexthdr); + + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; + XFRM_SPI_SKB_CB(skb)->family = AF_INET; + XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr); + + if (!head) + goto out; + + if (!skb_dst(skb)) { + const struct iphdr *iph = ip_hdr(skb); + + if (ip_route_input_noref(skb, iph->daddr, iph->saddr, + iph->tos, skb->dev)) + goto drop; + } + + for_each_protocol_rcu(*head, handler) + if ((ret = handler->input_handler(skb, nexthdr, spi, encap_type)) != -EINVAL) + return ret; + +out: + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + +drop: + kfree_skb(skb); + return 0; +} +EXPORT_SYMBOL(xfrm4_rcv_encap); + +static int xfrm4_esp_rcv(struct sk_buff *skb) +{ + int ret; + struct xfrm4_protocol *handler; + + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; + + for_each_protocol_rcu(esp4_handlers, handler) + if ((ret = handler->handler(skb)) != -EINVAL) + return ret; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + + kfree_skb(skb); + return 0; +} + +static int xfrm4_esp_err(struct sk_buff *skb, u32 info) +{ + struct xfrm4_protocol *handler; + + for_each_protocol_rcu(esp4_handlers, handler) + if (!handler->err_handler(skb, info)) + return 0; + + return -ENOENT; +} + +static int xfrm4_ah_rcv(struct sk_buff *skb) +{ + int ret; + struct xfrm4_protocol *handler; + + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; + + for_each_protocol_rcu(ah4_handlers, handler) + if ((ret = handler->handler(skb)) != -EINVAL) + return ret; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + + kfree_skb(skb); + return 0; +} + +static int xfrm4_ah_err(struct sk_buff *skb, u32 info) +{ + struct xfrm4_protocol *handler; + + for_each_protocol_rcu(ah4_handlers, handler) + if (!handler->err_handler(skb, info)) + return 0; + + return -ENOENT; +} + +static int xfrm4_ipcomp_rcv(struct sk_buff *skb) +{ + int ret; + struct xfrm4_protocol *handler; + + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; + + for_each_protocol_rcu(ipcomp4_handlers, handler) + if ((ret = handler->handler(skb)) != -EINVAL) + return ret; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + + kfree_skb(skb); + return 0; +} + +static int xfrm4_ipcomp_err(struct sk_buff *skb, u32 info) +{ + struct xfrm4_protocol *handler; + + for_each_protocol_rcu(ipcomp4_handlers, handler) + if (!handler->err_handler(skb, info)) + return 0; + + return -ENOENT; +} + +static const struct net_protocol esp4_protocol = { + .handler = xfrm4_esp_rcv, + .err_handler = xfrm4_esp_err, + .no_policy = 1, + .netns_ok = 1, +}; + +static const struct net_protocol ah4_protocol = { + .handler = xfrm4_ah_rcv, + .err_handler = xfrm4_ah_err, + .no_policy = 1, + .netns_ok = 1, +}; + +static const struct net_protocol ipcomp4_protocol = { + .handler = xfrm4_ipcomp_rcv, + .err_handler = xfrm4_ipcomp_err, + .no_policy = 1, + .netns_ok = 1, +}; + +static const struct xfrm_input_afinfo xfrm4_input_afinfo = { + .family = AF_INET, + .callback = xfrm4_rcv_cb, +}; + +static inline const struct net_protocol *netproto(unsigned char protocol) +{ + switch (protocol) { + case IPPROTO_ESP: + return &esp4_protocol; + case IPPROTO_AH: + return &ah4_protocol; + case IPPROTO_COMP: + return &ipcomp4_protocol; + } + + return NULL; +} + +int xfrm4_protocol_register(struct xfrm4_protocol *handler, + unsigned char protocol) +{ + struct xfrm4_protocol __rcu **pprev; + struct xfrm4_protocol *t; + bool add_netproto = false; + int ret = -EEXIST; + int priority = handler->priority; + + if (!proto_handlers(protocol) || !netproto(protocol)) + return -EINVAL; + + mutex_lock(&xfrm4_protocol_mutex); + + if (!rcu_dereference_protected(*proto_handlers(protocol), + lockdep_is_held(&xfrm4_protocol_mutex))) + add_netproto = true; + + for (pprev = proto_handlers(protocol); + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&xfrm4_protocol_mutex))) != NULL; + pprev = &t->next) { + if (t->priority < priority) + break; + if (t->priority == priority) + goto err; + } + + handler->next = *pprev; + rcu_assign_pointer(*pprev, handler); + + ret = 0; + +err: + mutex_unlock(&xfrm4_protocol_mutex); + + if (add_netproto) { + if (inet_add_protocol(netproto(protocol), protocol)) { + pr_err("%s: can't add protocol\n", __func__); + ret = -EAGAIN; + } + } + + return ret; +} +EXPORT_SYMBOL(xfrm4_protocol_register); + +int xfrm4_protocol_deregister(struct xfrm4_protocol *handler, + unsigned char protocol) +{ + struct xfrm4_protocol __rcu **pprev; + struct xfrm4_protocol *t; + int ret = -ENOENT; + + if (!proto_handlers(protocol) || !netproto(protocol)) + return -EINVAL; + + mutex_lock(&xfrm4_protocol_mutex); + + for (pprev = proto_handlers(protocol); + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&xfrm4_protocol_mutex))) != NULL; + pprev = &t->next) { + if (t == handler) { + *pprev = handler->next; + ret = 0; + break; + } + } + + if (!rcu_dereference_protected(*proto_handlers(protocol), + lockdep_is_held(&xfrm4_protocol_mutex))) { + if (inet_del_protocol(netproto(protocol), protocol) < 0) { + pr_err("%s: can't remove protocol\n", __func__); + ret = -EAGAIN; + } + } + + mutex_unlock(&xfrm4_protocol_mutex); + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(xfrm4_protocol_deregister); + +void __init xfrm4_protocol_init(void) +{ + xfrm_input_register_afinfo(&xfrm4_input_afinfo); +} diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c new file mode 100644 index 000000000..87d4db591 --- /dev/null +++ b/net/ipv4/xfrm4_state.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * xfrm4_state.c + * + * Changes: + * YOSHIFUJI Hideaki @USAGI + * Split up af-specific portion + * + */ + +#include <net/xfrm.h> + +static struct xfrm_state_afinfo xfrm4_state_afinfo = { + .family = AF_INET, + .proto = IPPROTO_IPIP, + .output = xfrm4_output, + .transport_finish = xfrm4_transport_finish, + .local_error = xfrm4_local_error, +}; + +void __init xfrm4_state_init(void) +{ + xfrm_state_register_afinfo(&xfrm4_state_afinfo); +} diff --git a/net/ipv4/xfrm4_tunnel.c b/net/ipv4/xfrm4_tunnel.c new file mode 100644 index 000000000..fb0648e7f --- /dev/null +++ b/net/ipv4/xfrm4_tunnel.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* xfrm4_tunnel.c: Generic IP tunnel transformer. + * + * Copyright (C) 2003 David S. Miller (davem@redhat.com) + */ + +#define pr_fmt(fmt) "IPsec: " fmt + +#include <linux/skbuff.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <net/xfrm.h> +#include <net/ip.h> +#include <net/protocol.h> + +static int ipip_output(struct xfrm_state *x, struct sk_buff *skb) +{ + skb_push(skb, -skb_network_offset(skb)); + return 0; +} + +static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb) +{ + return ip_hdr(skb)->protocol; +} + +static int ipip_init_state(struct xfrm_state *x) +{ + if (x->props.mode != XFRM_MODE_TUNNEL) + return -EINVAL; + + if (x->encap) + return -EINVAL; + + x->props.header_len = sizeof(struct iphdr); + + return 0; +} + +static void ipip_destroy(struct xfrm_state *x) +{ +} + +static const struct xfrm_type ipip_type = { + .description = "IPIP", + .owner = THIS_MODULE, + .proto = IPPROTO_IPIP, + .init_state = ipip_init_state, + .destructor = ipip_destroy, + .input = ipip_xfrm_rcv, + .output = ipip_output +}; + +static int xfrm_tunnel_rcv(struct sk_buff *skb) +{ + return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr); +} + +static int xfrm_tunnel_err(struct sk_buff *skb, u32 info) +{ + return -ENOENT; +} + +static struct xfrm_tunnel xfrm_tunnel_handler __read_mostly = { + .handler = xfrm_tunnel_rcv, + .err_handler = xfrm_tunnel_err, + .priority = 4, +}; + +#if IS_ENABLED(CONFIG_IPV6) +static struct xfrm_tunnel xfrm64_tunnel_handler __read_mostly = { + .handler = xfrm_tunnel_rcv, + .err_handler = xfrm_tunnel_err, + .priority = 3, +}; +#endif + +static int __init ipip_init(void) +{ + if (xfrm_register_type(&ipip_type, AF_INET) < 0) { + pr_info("%s: can't add xfrm type\n", __func__); + return -EAGAIN; + } + + if (xfrm4_tunnel_register(&xfrm_tunnel_handler, AF_INET)) { + pr_info("%s: can't add xfrm handler for AF_INET\n", __func__); + xfrm_unregister_type(&ipip_type, AF_INET); + return -EAGAIN; + } +#if IS_ENABLED(CONFIG_IPV6) + if (xfrm4_tunnel_register(&xfrm64_tunnel_handler, AF_INET6)) { + pr_info("%s: can't add xfrm handler for AF_INET6\n", __func__); + xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET); + xfrm_unregister_type(&ipip_type, AF_INET); + return -EAGAIN; + } +#endif + return 0; +} + +static void __exit ipip_fini(void) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (xfrm4_tunnel_deregister(&xfrm64_tunnel_handler, AF_INET6)) + pr_info("%s: can't remove xfrm handler for AF_INET6\n", + __func__); +#endif + if (xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET)) + pr_info("%s: can't remove xfrm handler for AF_INET\n", + __func__); + xfrm_unregister_type(&ipip_type, AF_INET); +} + +module_init(ipip_init); +module_exit(ipip_fini); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP); |