/* * 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. * * Definitions for the IP module. * * Version: @(#)ip.h 1.0.2 05/07/93 * * Authors: Ross Biro * Fred N. van Kempen, * Alan Cox, * * Changes: * Mike McLagan : Routing by source * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _IP_H #define _IP_H #include #include #include #include #include #include #include #include #include #include #include #include #define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */ #define IPV4_MIN_MTU 68 /* RFC 791 */ struct sock; struct inet_skb_parm { int iif; struct ip_options opt; /* Compiled IP options */ u16 flags; #define IPSKB_FORWARDED BIT(0) #define IPSKB_XFRM_TUNNEL_SIZE BIT(1) #define IPSKB_XFRM_TRANSFORMED BIT(2) #define IPSKB_FRAG_COMPLETE BIT(3) #define IPSKB_REROUTED BIT(4) #define IPSKB_DOREDIRECT BIT(5) #define IPSKB_FRAG_PMTU BIT(6) #define IPSKB_L3SLAVE BIT(7) u16 frag_max_size; }; static inline bool ipv4_l3mdev_skb(u16 flags) { return !!(flags & IPSKB_L3SLAVE); } static inline unsigned int ip_hdrlen(const struct sk_buff *skb) { return ip_hdr(skb)->ihl * 4; } struct ipcm_cookie { struct sockcm_cookie sockc; __be32 addr; int oif; struct ip_options_rcu *opt; __u8 ttl; __s16 tos; char priority; __u16 gso_size; }; static inline void ipcm_init(struct ipcm_cookie *ipcm) { *ipcm = (struct ipcm_cookie) { .tos = -1 }; } static inline void ipcm_init_sk(struct ipcm_cookie *ipcm, const struct inet_sock *inet) { ipcm_init(ipcm); ipcm->sockc.tsflags = inet->sk.sk_tsflags; ipcm->oif = inet->sk.sk_bound_dev_if; ipcm->addr = inet->inet_saddr; } #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb)) /* return enslaved device index if relevant */ static inline int inet_sdif(struct sk_buff *skb) { #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) return IPCB(skb)->iif; #endif return 0; } /* Special input handler for packets caught by router alert option. They are selected only by protocol field, and then processed likely local ones; but only if someone wants them! Otherwise, router not running rsvpd will kill RSVP. It is user level problem, what it will make with them. I have no idea, how it will masquearde or NAT them (it is joke, joke :-)), but receiver should be enough clever f.e. to forward mtrace requests, sent to multicast group to reach destination designated router. */ struct ip_ra_chain { struct ip_ra_chain __rcu *next; struct sock *sk; union { void (*destructor)(struct sock *); struct sock *saved_sk; }; struct rcu_head rcu; }; /* IP flags. */ #define IP_CE 0x8000 /* Flag: "Congestion" */ #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ #define IP_MF 0x2000 /* Flag: "More Fragments" */ #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ struct msghdr; struct net_device; struct packet_type; struct rtable; struct sockaddr; int igmp_mc_init(void); /* * Functions provided by ip.c */ int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, __be32 saddr, __be32 daddr, struct ip_options_rcu *opt); int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev); void ip_list_rcv(struct list_head *head, struct packet_type *pt, struct net_device *orig_dev); int ip_local_deliver(struct sk_buff *skb); int ip_mr_input(struct sk_buff *skb); int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int (*output)(struct net *, struct sock *, struct sk_buff *)); void ip_send_check(struct iphdr *ip); int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, __u8 tos); void ip_init(void); 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 len, int protolen, struct ipcm_cookie *ipc, struct rtable **rt, unsigned int flags); int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, int offset, size_t size, int flags); struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, struct sk_buff_head *queue, struct inet_cork *cork); int ip_send_skb(struct net *net, struct sk_buff *skb); int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); void ip_flush_pending_frames(struct sock *sk); 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); static inline 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); } static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) { return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); } static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet) { return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos); } static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk) { return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk); } /* datagram.c */ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); void ip4_datagram_release_cb(struct sock *sk); struct ip_reply_arg { struct kvec iov[1]; int flags; __wsum csum; int csumoffset; /* u16 offset of csum in iov[0].iov_base */ /* -1 if not needed */ int bound_dev_if; u8 tos; kuid_t uid; }; #define IP_REPLY_ARG_NOSRCCHECK 1 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) { return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; } 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); #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field) #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field) #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct); unsigned long snmp_fold_field(void __percpu *mib, int offt); #if BITS_PER_LONG==32 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, size_t syncp_offset); u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off); #else static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, size_t syncp_offset) { return snmp_get_cpu_field(mib, cpu, offct); } static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off) { return snmp_fold_field(mib, offt); } #endif #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \ { \ int i, c; \ for_each_possible_cpu(c) { \ for (i = 0; stats_list[i].name; i++) \ buff64[i] += snmp_get_cpu_field64( \ mib_statistic, \ c, stats_list[i].entry, \ offset); \ } \ } #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \ { \ int i, c; \ for_each_possible_cpu(c) { \ for (i = 0; stats_list[i].name; i++) \ buff[i] += snmp_get_cpu_field( \ mib_statistic, \ c, stats_list[i].entry); \ } \ } void inet_get_local_port_range(struct net *net, int *low, int *high); #ifdef CONFIG_SYSCTL static inline int inet_is_local_reserved_port(struct net *net, int port) { if (!net->ipv4.sysctl_local_reserved_ports) return 0; return test_bit(port, net->ipv4.sysctl_local_reserved_ports); } static inline bool sysctl_dev_name_is_allowed(const char *name) { return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; } static inline int inet_prot_sock(struct net *net) { return net->ipv4.sysctl_ip_prot_sock; } #else static inline int inet_is_local_reserved_port(struct net *net, int port) { return 0; } static inline int inet_prot_sock(struct net *net) { return PROT_SOCK; } #endif __be32 inet_current_timestamp(void); /* From inetpeer.c */ extern int inet_peer_threshold; extern int inet_peer_minttl; extern int inet_peer_maxttl; void ipfrag_init(void); void ip_static_sysctl_init(void); #define IP4_REPLY_MARK(net, mark) \ ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0) static inline bool ip_is_fragment(const struct iphdr *iph) { return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; } #ifdef CONFIG_INET #include /* The function in 2.2 was invalid, producing wrong result for * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ static inline int ip_decrease_ttl(struct iphdr *iph) { u32 check = (__force u32)iph->check; check += (__force u32)htons(0x0100); iph->check = (__force __sum16)(check + (check>=0xFFFF)); return --iph->ttl; } static inline int ip_mtu_locked(const struct dst_entry *dst) { const struct rtable *rt = (const struct rtable *)dst; return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); } static inline int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) { u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); return pmtudisc == IP_PMTUDISC_DO || (pmtudisc == IP_PMTUDISC_WANT && !ip_mtu_locked(dst)); } static inline bool ip_sk_accept_pmtu(const struct sock *sk) { return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE && inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT; } static inline bool ip_sk_use_pmtu(const struct sock *sk) { return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE; } static inline bool ip_sk_ignore_df(const struct sock *sk) { return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO || inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT; } static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, bool forwarding) { struct net *net = dev_net(dst->dev); unsigned int mtu; if (net->ipv4.sysctl_ip_fwd_use_pmtu || ip_mtu_locked(dst) || !forwarding) return dst_mtu(dst); /* 'forwarding = true' case should always honour route mtu */ mtu = dst_metric_raw(dst, RTAX_MTU); if (!mtu) mtu = min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU); return mtu - lwtunnel_headroom(dst->lwtstate, mtu); } static inline unsigned int ip_skb_dst_mtu(struct sock *sk, const struct sk_buff *skb) { unsigned int mtu; if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); } mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU); return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); } int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len, u32 *metrics); u32 ip_idents_reserve(u32 hash, int segs); void __ip_select_ident(struct net *net, struct iphdr *iph, int segs); static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb, struct sock *sk, int segs) { struct iphdr *iph = ip_hdr(skb); /* We had many attacks based on IPID, use the private * generator as much as we can. */ if (sk && inet_sk(sk)->inet_daddr) { iph->id = htons(inet_sk(sk)->inet_id); inet_sk(sk)->inet_id += segs; return; } if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { iph->id = 0; } else { /* Unfortunately we need the big hammer to get a suitable IPID */ __ip_select_ident(net, iph, segs); } } static inline void ip_select_ident(struct net *net, struct sk_buff *skb, struct sock *sk) { ip_select_ident_segs(net, skb, sk, 1); } static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) { return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, skb->len, proto, 0); } /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store * Equivalent to : flow->v4addrs.src = iph->saddr; * flow->v4addrs.dst = iph->daddr; */ static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, const struct iphdr *iph) { BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != offsetof(typeof(flow->addrs), v4addrs.src) + sizeof(flow->addrs.v4addrs.src)); memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs)); flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; } static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto) { const struct iphdr *iph = skb_gro_network_header(skb); return csum_tcpudp_nofold(iph->saddr, iph->daddr, skb_gro_len(skb), proto, 0); } /* * Map a multicast IP onto multicast MAC for type ethernet. */ static inline void ip_eth_mc_map(__be32 naddr, char *buf) { __u32 addr=ntohl(naddr); buf[0]=0x01; buf[1]=0x00; buf[2]=0x5e; buf[5]=addr&0xFF; addr>>=8; buf[4]=addr&0xFF; addr>>=8; buf[3]=addr&0x7F; } /* * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. * Leave P_Key as 0 to be filled in by driver. */ static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) { __u32 addr; unsigned char scope = broadcast[5] & 0xF; buf[0] = 0; /* Reserved */ buf[1] = 0xff; /* Multicast QPN */ buf[2] = 0xff; buf[3] = 0xff; addr = ntohl(naddr); buf[4] = 0xff; buf[5] = 0x10 | scope; /* scope from broadcast address */ buf[6] = 0x40; /* IPv4 signature */ buf[7] = 0x1b; buf[8] = broadcast[8]; /* P_Key */ buf[9] = broadcast[9]; buf[10] = 0; buf[11] = 0; buf[12] = 0; buf[13] = 0; buf[14] = 0; buf[15] = 0; buf[19] = addr & 0xff; addr >>= 8; buf[18] = addr & 0xff; addr >>= 8; buf[17] = addr & 0xff; addr >>= 8; buf[16] = addr & 0x0f; } static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) { if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) memcpy(buf, broadcast, 4); else memcpy(buf, &naddr, sizeof(naddr)); } #if IS_ENABLED(CONFIG_IPV6) #include #endif static __inline__ void inet_reset_saddr(struct sock *sk) { inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; #if IS_ENABLED(CONFIG_IPV6) if (sk->sk_family == PF_INET6) { struct ipv6_pinfo *np = inet6_sk(sk); memset(&np->saddr, 0, sizeof(np->saddr)); memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); } #endif } #endif static inline unsigned int ipv4_addr_hash(__be32 ip) { return (__force unsigned int) ip; } static inline u32 ipv4_portaddr_hash(const struct net *net, __be32 saddr, unsigned int port) { return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; } bool ip_call_ra_chain(struct sk_buff *skb); /* * Functions provided by ip_fragment.c */ enum ip_defrag_users { IP_DEFRAG_LOCAL_DELIVER, IP_DEFRAG_CALL_RA_CHAIN, IP_DEFRAG_CONNTRACK_IN, __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, IP_DEFRAG_CONNTRACK_OUT, __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, IP_DEFRAG_CONNTRACK_BRIDGE_IN, __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, IP_DEFRAG_VS_IN, IP_DEFRAG_VS_OUT, IP_DEFRAG_VS_FWD, IP_DEFRAG_AF_PACKET, IP_DEFRAG_MACVLAN, }; /* Return true if the value of 'user' is between 'lower_bond' * and 'upper_bond' inclusively. */ static inline bool ip_defrag_user_in_between(u32 user, enum ip_defrag_users lower_bond, enum ip_defrag_users upper_bond) { return user >= lower_bond && user <= upper_bond; } int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); #ifdef CONFIG_INET struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); #else static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) { return skb; } #endif /* * Functions provided by ip_forward.c */ int ip_forward(struct sk_buff *skb); /* * Functions provided by ip_options.c */ void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); int __ip_options_echo(struct net *net, struct ip_options *dopt, struct sk_buff *skb, const struct ip_options *sopt); static inline int ip_options_echo(struct net *net, struct ip_options *dopt, struct sk_buff *skb) { return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); } void ip_options_fragment(struct sk_buff *skb); int __ip_options_compile(struct net *net, struct ip_options *opt, struct sk_buff *skb, __be32 *info); int ip_options_compile(struct net *net, struct ip_options *opt, struct sk_buff *skb); int ip_options_get(struct net *net, struct ip_options_rcu **optp, unsigned char *data, int optlen); int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, unsigned char __user *data, int optlen); void ip_options_undo(struct ip_options *opt); void ip_forward_options(struct sk_buff *skb); int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); /* * Functions provided by ip_sockglue.c */ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb); void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, struct sk_buff *skb, int tlen, int offset); int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc, bool allow_ipv6); int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); int compat_ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); int compat_ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, u32 info, u8 *payload); void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, u32 info); static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) { ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); } bool icmp_global_allow(void); extern int sysctl_icmp_msgs_per_sec; extern int sysctl_icmp_msgs_burst; #ifdef CONFIG_PROC_FS int ip_misc_proc_init(void); #endif int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, struct netlink_ext_ack *extack); static inline bool inetdev_valid_mtu(unsigned int mtu) { return likely(mtu >= IPV4_MIN_MTU); } #endif /* _IP_H */