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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /net/ipv4/tcp.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c4864
1 files changed, 4864 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
new file mode 100644
index 000000000..90e24c3f6
--- /dev/null
+++ b/net/ipv4/tcp.c
@@ -0,0 +1,4864 @@
+// 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/cache.h>
+#include <linux/err.h>
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <linux/errqueue.h>
+#include <linux/static_key.h>
+#include <linux/btf.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>
+
+/* Track pending CMSGs. */
+enum {
+ TCP_CMSG_INQ = 1,
+ TCP_CMSG_TS = 2
+};
+
+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 ____cacheline_aligned_in_smp; /* Current allocated memory. */
+EXPORT_SYMBOL(tcp_memory_allocated);
+DEFINE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc);
+EXPORT_PER_CPU_SYMBOL_GPL(tcp_memory_per_cpu_fw_alloc);
+
+#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 ____cacheline_aligned_in_smp;
+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);
+
+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
+ */
+ tcp_snd_cwnd_set(tp, 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]));
+
+ set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
+ sk_sockets_allocated_inc(sk);
+}
+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 bool tcp_stream_is_readable(struct sock *sk, int target)
+{
+ if (tcp_epollin_ready(sk, target))
+ return true;
+ return sk_is_readable(sk);
+}
+
+/*
+ * 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);
+ u16 urg_data = READ_ONCE(tp->urg_data);
+
+ if (unlikely(urg_data) &&
+ READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq) &&
+ !sock_flag(sk, SOCK_URGINLINE))
+ target++;
+
+ if (tcp_stream_is_readable(sk, target))
+ 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 (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 = READ_ONCE(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);
+
+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));
+}
+
+void tcp_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);
+
+ tcb->seq = tcb->end_seq = tp->write_seq;
+ tcb->tcp_flags = TCPHDR_ACK;
+ __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 &&
+ tcp_skb_can_collapse_to(skb);
+}
+
+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);
+ smp_mb__after_atomic();
+ }
+ /* 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;
+ ret = sk_wait_data(sk, &timeo, NULL);
+ if (ret < 0)
+ break;
+ 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 *tcp_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
+ bool force_schedule)
+{
+ struct sk_buff *skb;
+
+ skb = alloc_skb_fclone(size + MAX_TCP_HEADER, gfp);
+ if (likely(skb)) {
+ bool mem_scheduled;
+
+ skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
+ 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, MAX_TCP_HEADER);
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ 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 = tcp_bound_to_half_wnd(tp, sk->sk_gso_max_size);
+
+ /* 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.
+ */
+void tcp_remove_empty_skb(struct sock *sk)
+{
+ struct sk_buff *skb = tcp_write_queue_tail(sk);
+
+ 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);
+ tcp_wmem_free_skb(sk, skb);
+ }
+}
+
+/* skb changing from pure zc to mixed, must charge zc */
+static int tcp_downgrade_zcopy_pure(struct sock *sk, struct sk_buff *skb)
+{
+ if (unlikely(skb_zcopy_pure(skb))) {
+ u32 extra = skb->truesize -
+ SKB_TRUESIZE(skb_end_offset(skb));
+
+ if (!sk_wmem_schedule(sk, extra))
+ return -ENOMEM;
+
+ sk_mem_charge(sk, extra);
+ skb_shinfo(skb)->flags &= ~SKBFL_PURE_ZEROCOPY;
+ }
+ return 0;
+}
+
+
+static int tcp_wmem_schedule(struct sock *sk, int copy)
+{
+ int left;
+
+ if (likely(sk_wmem_schedule(sk, copy)))
+ return copy;
+
+ /* We could be in trouble if we have nothing queued.
+ * Use whatever is left in sk->sk_forward_alloc and tcp_wmem[0]
+ * to guarantee some progress.
+ */
+ left = sock_net(sk)->ipv4.sysctl_tcp_wmem[0] - sk->sk_wmem_queued;
+ if (left > 0)
+ sk_forced_mem_schedule(sk, min(left, copy));
+ return min(copy, sk->sk_forward_alloc);
+}
+
+static struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags,
+ struct page *page, int offset, size_t *size)
+{
+ struct sk_buff *skb = tcp_write_queue_tail(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+ bool can_coalesce;
+ int copy, i;
+
+ if (!skb || (copy = size_goal - skb->len) <= 0 ||
+ !tcp_skb_can_collapse_to(skb)) {
+new_segment:
+ if (!sk_stream_memory_free(sk))
+ return NULL;
+
+ skb = tcp_stream_alloc_skb(sk, 0, sk->sk_allocation,
+ tcp_rtx_and_write_queues_empty(sk));
+ if (!skb)
+ return NULL;
+
+#ifdef CONFIG_TLS_DEVICE
+ skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED);
+#endif
+ tcp_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 >= READ_ONCE(sysctl_max_skb_frags)) {
+ tcp_mark_push(tp, skb);
+ goto new_segment;
+ }
+ if (tcp_downgrade_zcopy_pure(sk, skb))
+ return NULL;
+
+ copy = tcp_wmem_schedule(sk, copy);
+ if (!copy)
+ return NULL;
+
+ if (can_coalesce) {
+ skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
+ } else {
+ get_page(page);
+ skb_fill_page_desc_noacc(skb, i, page, offset, copy);
+ }
+
+ if (!(flags & MSG_NO_SHARED_FRAGS))
+ skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG;
+
+ skb->len += copy;
+ skb->data_len += copy;
+ skb->truesize += copy;
+ sk_wmem_queued_add(sk, copy);
+ sk_mem_charge(sk, copy);
+ WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
+ TCP_SKB_CB(skb)->end_seq += copy;
+ tcp_skb_pcount_set(skb, 0);
+
+ *size = copy;
+ return 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;
+ size_t copy = size;
+
+ skb = tcp_build_frag(sk, size_goal, flags, page, offset, &copy);
+ if (!skb)
+ goto wait_for_space;
+
+ 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);
+ 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;
+ }
+}
+
+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) {
+ skb = tcp_write_queue_tail(sk);
+
+ if (msg->msg_ubuf) {
+ uarg = msg->msg_ubuf;
+ net_zcopy_get(uarg);
+ zc = sk->sk_route_caps & NETIF_F_SG;
+ } else if (sock_flag(sk, SOCK_ZEROCOPY)) {
+ uarg = msg_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_to_msgzc(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 = tcp_stream_alloc_skb(sk, 0, sk->sk_allocation,
+ first_skb);
+ if (!skb)
+ goto wait_for_space;
+
+ process_backlog++;
+
+ tcp_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);
+
+ 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 >= READ_ONCE(sysctl_max_skb_frags)) {
+ tcp_mark_push(tp, skb);
+ goto new_segment;
+ }
+ merge = false;
+ }
+
+ copy = min_t(int, copy, pfrag->size - pfrag->offset);
+
+ if (unlikely(skb_zcopy_pure(skb) || skb_zcopy_managed(skb))) {
+ if (tcp_downgrade_zcopy_pure(sk, skb))
+ goto wait_for_space;
+ skb_zcopy_downgrade_managed(skb);
+ }
+
+ copy = tcp_wmem_schedule(sk, copy);
+ if (!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 {
+ /* First append to a fragless skb builds initial
+ * pure zerocopy skb
+ */
+ if (!skb->len)
+ skb_shinfo(skb)->flags |= SKBFL_PURE_ZEROCOPY;
+
+ if (!skb_zcopy_pure(skb)) {
+ copy = tcp_wmem_schedule(sk, copy);
+ if (!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:
+ net_zcopy_put(uarg);
+ return copied + copied_syn;
+
+do_error:
+ tcp_remove_empty_skb(sk);
+
+ if (copied + copied_syn)
+ goto out;
+out_err:
+ net_zcopy_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);
+
+void tcp_splice_eof(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct tcp_sock *tp = tcp_sk(sk);
+ int mss_now, size_goal;
+
+ if (!tcp_write_queue_tail(sk))
+ return;
+
+ lock_sock(sk);
+ mss_now = tcp_send_mss(sk, &size_goal, 0);
+ tcp_push(sk, 0, mss_now, tp->nonagle, size_goal);
+ release_sock(sk);
+}
+EXPORT_SYMBOL_GPL(tcp_splice_eof);
+
+/*
+ * 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))
+ WRITE_ONCE(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;
+
+ 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);
+}
+
+void tcp_cleanup_rbuf(struct sock *sk, int copied)
+{
+ struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ 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);
+ __tcp_cleanup_rbuf(sk, copied);
+}
+
+static void tcp_eat_recv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ __skb_unlink(skb, &sk->sk_receive_queue);
+ if (likely(skb->destructor == sock_rfree)) {
+ sock_rfree(skb);
+ skb->destructor = NULL;
+ skb->sk = NULL;
+ return skb_attempt_defer_free(skb);
+ }
+ __kfree_skb(skb);
+}
+
+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()
+ */
+ tcp_eat_recv_skb(sk, skb);
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(tcp_recv_skb);
+
+/*
+ * 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 (unlikely(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) {
+ tcp_eat_recv_skb(sk, skb);
+ ++seq;
+ break;
+ }
+ tcp_eat_recv_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_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
+{
+ struct sk_buff *skb;
+ int copied = 0;
+
+ if (sk->sk_state == TCP_LISTEN)
+ return -ENOTCONN;
+
+ while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
+ u8 tcp_flags;
+ int used;
+
+ __skb_unlink(skb, &sk->sk_receive_queue);
+ WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
+ tcp_flags = TCP_SKB_CB(skb)->tcp_flags;
+ used = recv_actor(sk, skb);
+ if (used < 0) {
+ if (!copied)
+ copied = used;
+ break;
+ }
+ copied += used;
+
+ if (tcp_flags & TCPHDR_FIN)
+ break;
+ }
+ return copied;
+}
+EXPORT_SYMBOL(tcp_read_skb);
+
+void tcp_read_done(struct sock *sk, size_t len)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ u32 seq = tp->copied_seq;
+ struct sk_buff *skb;
+ size_t left;
+ u32 offset;
+
+ if (sk->sk_state == TCP_LISTEN)
+ return;
+
+ left = len;
+ while (left && (skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
+ int used;
+
+ used = min_t(size_t, skb->len - offset, left);
+ seq += used;
+ left -= used;
+
+ if (skb->len > offset + used)
+ break;
+
+ if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
+ tcp_eat_recv_skb(sk, skb);
+ ++seq;
+ break;
+ }
+ tcp_eat_recv_skb(sk, skb);
+ }
+ WRITE_ONCE(tp->copied_seq, seq);
+
+ tcp_rcv_space_adjust(sk);
+
+ /* Clean up data we have read: This will do ACK frames. */
+ if (left != len)
+ tcp_cleanup_rbuf(sk, len - left);
+}
+EXPORT_SYMBOL(tcp_read_done);
+
+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);
+
+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};
+}
+
+#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 bool can_map_frag(const skb_frag_t *frag)
+{
+ return skb_frag_size(frag) == PAGE_SIZE && !skb_frag_off(frag);
+}
+
+static int find_next_mappable_frag(const skb_frag_t *frag,
+ int remaining_in_skb)
+{
+ int offset = 0;
+
+ if (likely(can_map_frag(frag)))
+ return 0;
+
+ while (offset < remaining_in_skb && !can_map_frag(frag)) {
+ offset += skb_frag_size(frag);
+ ++frag;
+ }
+ return offset;
+}
+
+static void tcp_zerocopy_set_hint_for_skb(struct sock *sk,
+ struct tcp_zerocopy_receive *zc,
+ struct sk_buff *skb, u32 offset)
+{
+ u32 frag_offset, partial_frag_remainder = 0;
+ int mappable_offset;
+ skb_frag_t *frag;
+
+ /* worst case: skip to next skb. try to improve on this case below */
+ zc->recv_skip_hint = skb->len - offset;
+
+ /* Find the frag containing this offset (and how far into that frag) */
+ frag = skb_advance_to_frag(skb, offset, &frag_offset);
+ if (!frag)
+ return;
+
+ if (frag_offset) {
+ struct skb_shared_info *info = skb_shinfo(skb);
+
+ /* We read part of the last frag, must recvmsg() rest of skb. */
+ if (frag == &info->frags[info->nr_frags - 1])
+ return;
+
+ /* Else, we must at least read the remainder in this frag. */
+ partial_frag_remainder = skb_frag_size(frag) - frag_offset;
+ zc->recv_skip_hint -= partial_frag_remainder;
+ ++frag;
+ }
+
+ /* partial_frag_remainder: If part way through a frag, must read rest.
+ * mappable_offset: Bytes till next mappable frag, *not* counting bytes
+ * in partial_frag_remainder.
+ */
+ mappable_offset = find_next_mappable_frag(frag, zc->recv_skip_hint);
+ zc->recv_skip_hint = mappable_offset + partial_frag_remainder;
+}
+
+static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
+ int flags, struct scm_timestamping_internal *tss,
+ int *cmsg_flags);
+static int receive_fallback_to_copy(struct sock *sk,
+ struct tcp_zerocopy_receive *zc, int inq,
+ struct scm_timestamping_internal *tss)
+{
+ unsigned long copy_address = (unsigned long)zc->copybuf_address;
+ struct msghdr msg = {};
+ struct iovec iov;
+ int err;
+
+ zc->length = 0;
+ zc->recv_skip_hint = 0;
+
+ if (copy_address != zc->copybuf_address)
+ return -EINVAL;
+
+ err = import_single_range(ITER_DEST, (void __user *)copy_address,
+ inq, &iov, &msg.msg_iter);
+ if (err)
+ return err;
+
+ err = tcp_recvmsg_locked(sk, &msg, inq, MSG_DONTWAIT,
+ tss, &zc->msg_flags);
+ if (err < 0)
+ return err;
+
+ zc->copybuf_len = err;
+ if (likely(zc->copybuf_len)) {
+ struct sk_buff *skb;
+ u32 offset;
+
+ skb = tcp_recv_skb(sk, tcp_sk(sk)->copied_seq, &offset);
+ if (skb)
+ tcp_zerocopy_set_hint_for_skb(sk, zc, skb, offset);
+ }
+ return 0;
+}
+
+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(ITER_DEST, (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_zc_handle_leftover(struct tcp_zerocopy_receive *zc,
+ struct sock *sk,
+ struct sk_buff *skb,
+ u32 *seq,
+ s32 copybuf_len,
+ struct scm_timestamping_internal *tss)
+{
+ 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);
+ if (TCP_SKB_CB(skb)->has_rxtstamp) {
+ tcp_update_recv_tstamps(skb, tss);
+ zc->msg_flags |= TCP_CMSG_TS;
+ }
+ }
+
+ 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_error(struct vm_area_struct *vma,
+ struct page **pending_pages,
+ unsigned long pages_remaining,
+ unsigned long *address,
+ u32 *length,
+ u32 *seq,
+ struct tcp_zerocopy_receive *zc,
+ u32 total_bytes_to_map,
+ int err)
+{
+ /* At least one page did not map. Try zapping if we skipped earlier. */
+ if (err == -EBUSY &&
+ zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT) {
+ u32 maybe_zap_len;
+
+ maybe_zap_len = total_bytes_to_map - /* All bytes to map */
+ *length + /* Mapped or pending */
+ (pages_remaining * PAGE_SIZE); /* Failed map. */
+ zap_page_range(vma, *address, maybe_zap_len);
+ err = 0;
+ }
+
+ if (!err) {
+ unsigned long leftover_pages = pages_remaining;
+ int bytes_mapped;
+
+ /* We called zap_page_range, try to reinsert. */
+ err = vm_insert_pages(vma, *address,
+ pending_pages,
+ &pages_remaining);
+ bytes_mapped = PAGE_SIZE * (leftover_pages - pages_remaining);
+ *seq += bytes_mapped;
+ *address += bytes_mapped;
+ }
+ if (err) {
+ /* Either we were unable to zap, OR we zapped, retried an
+ * insert, and still had an issue. Either ways, pages_remaining
+ * is the number of pages we were unable to map, and we unroll
+ * some state we speculatively touched before.
+ */
+ const int bytes_not_mapped = PAGE_SIZE * pages_remaining;
+
+ *length -= bytes_not_mapped;
+ zc->recv_skip_hint += bytes_not_mapped;
+ }
+ return err;
+}
+
+static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma,
+ struct page **pages,
+ unsigned int pages_to_map,
+ unsigned long *address,
+ u32 *length,
+ u32 *seq,
+ struct tcp_zerocopy_receive *zc,
+ u32 total_bytes_to_map)
+{
+ unsigned long pages_remaining = pages_to_map;
+ unsigned int pages_mapped;
+ unsigned int bytes_mapped;
+ int err;
+
+ err = vm_insert_pages(vma, *address, pages, &pages_remaining);
+ pages_mapped = pages_to_map - (unsigned int)pages_remaining;
+ bytes_mapped = PAGE_SIZE * pages_mapped;
+ /* Even if vm_insert_pages fails, it may have partially succeeded in
+ * mapping (some but not all of the pages).
+ */
+ *seq += bytes_mapped;
+ *address += bytes_mapped;
+
+ if (likely(!err))
+ return 0;
+
+ /* Error: maybe zap and retry + rollback state for failed inserts. */
+ return tcp_zerocopy_vm_insert_batch_error(vma, pages + pages_mapped,
+ pages_remaining, address, length, seq, zc, total_bytes_to_map,
+ err);
+}
+
+#define TCP_VALID_ZC_MSG_FLAGS (TCP_CMSG_TS)
+static void tcp_zc_finalize_rx_tstamp(struct sock *sk,
+ struct tcp_zerocopy_receive *zc,
+ struct scm_timestamping_internal *tss)
+{
+ unsigned long msg_control_addr;
+ struct msghdr cmsg_dummy;
+
+ msg_control_addr = (unsigned long)zc->msg_control;
+ cmsg_dummy.msg_control = (void *)msg_control_addr;
+ cmsg_dummy.msg_controllen =
+ (__kernel_size_t)zc->msg_controllen;
+ cmsg_dummy.msg_flags = in_compat_syscall()
+ ? MSG_CMSG_COMPAT : 0;
+ cmsg_dummy.msg_control_is_user = true;
+ zc->msg_flags = 0;
+ if (zc->msg_control == msg_control_addr &&
+ zc->msg_controllen == cmsg_dummy.msg_controllen) {
+ tcp_recv_timestamp(&cmsg_dummy, sk, tss);
+ zc->msg_control = (__u64)
+ ((uintptr_t)cmsg_dummy.msg_control);
+ zc->msg_controllen =
+ (__u64)cmsg_dummy.msg_controllen;
+ zc->msg_flags = (__u32)cmsg_dummy.msg_flags;
+ }
+}
+
+#define TCP_ZEROCOPY_PAGE_BATCH_SIZE 32
+static int tcp_zerocopy_receive(struct sock *sk,
+ struct tcp_zerocopy_receive *zc,
+ struct scm_timestamping_internal *tss)
+{
+ u32 length = 0, offset, vma_len, avail_len, copylen = 0;
+ unsigned long address = (unsigned long)zc->address;
+ struct page *pages[TCP_ZEROCOPY_PAGE_BATCH_SIZE];
+ s32 copybuf_len = zc->copybuf_len;
+ struct tcp_sock *tp = tcp_sk(sk);
+ const skb_frag_t *frags = NULL;
+ unsigned int pages_to_map = 0;
+ struct vm_area_struct *vma;
+ struct sk_buff *skb = NULL;
+ u32 seq = tp->copied_seq;
+ u32 total_bytes_to_map;
+ int inq = tcp_inq(sk);
+ int ret;
+
+ zc->copybuf_len = 0;
+ zc->msg_flags = 0;
+
+ if (address & (PAGE_SIZE - 1) || address != zc->address)
+ return -EINVAL;
+
+ if (sk->sk_state == TCP_LISTEN)
+ return -ENOTCONN;
+
+ sock_rps_record_flow(sk);
+
+ if (inq && inq <= copybuf_len)
+ return receive_fallback_to_copy(sk, zc, inq, tss);
+
+ if (inq < PAGE_SIZE) {
+ zc->length = 0;
+ zc->recv_skip_hint = inq;
+ if (!inq && sock_flag(sk, SOCK_DONE))
+ return -EIO;
+ return 0;
+ }
+
+ mmap_read_lock(current->mm);
+
+ vma = vma_lookup(current->mm, address);
+ if (!vma || 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);
+ total_bytes_to_map = avail_len & ~(PAGE_SIZE - 1);
+ if (total_bytes_to_map) {
+ if (!(zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT))
+ zap_page_range(vma, address, total_bytes_to_map);
+ zc->length = total_bytes_to_map;
+ zc->recv_skip_hint = 0;
+ } else {
+ zc->length = avail_len;
+ zc->recv_skip_hint = avail_len;
+ }
+ ret = 0;
+ while (length + PAGE_SIZE <= zc->length) {
+ int mappable_offset;
+ struct page *page;
+
+ if (zc->recv_skip_hint < PAGE_SIZE) {
+ u32 offset_frag;
+
+ 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);
+ }
+
+ if (TCP_SKB_CB(skb)->has_rxtstamp) {
+ tcp_update_recv_tstamps(skb, tss);
+ zc->msg_flags |= TCP_CMSG_TS;
+ }
+ zc->recv_skip_hint = skb->len - offset;
+ frags = skb_advance_to_frag(skb, offset, &offset_frag);
+ if (!frags || offset_frag)
+ break;
+ }
+
+ mappable_offset = find_next_mappable_frag(frags,
+ zc->recv_skip_hint);
+ if (mappable_offset) {
+ zc->recv_skip_hint = mappable_offset;
+ break;
+ }
+ page = skb_frag_page(frags);
+ prefetchw(page);
+ pages[pages_to_map++] = page;
+ length += PAGE_SIZE;
+ zc->recv_skip_hint -= PAGE_SIZE;
+ frags++;
+ if (pages_to_map == TCP_ZEROCOPY_PAGE_BATCH_SIZE ||
+ zc->recv_skip_hint < PAGE_SIZE) {
+ /* Either full batch, or we're about to go to next skb
+ * (and we cannot unroll failed ops across skbs).
+ */
+ ret = tcp_zerocopy_vm_insert_batch(vma, pages,
+ pages_to_map,
+ &address, &length,
+ &seq, zc,
+ total_bytes_to_map);
+ if (ret)
+ goto out;
+ pages_to_map = 0;
+ }
+ }
+ if (pages_to_map) {
+ ret = tcp_zerocopy_vm_insert_batch(vma, pages, pages_to_map,
+ &address, &length, &seq,
+ zc, total_bytes_to_map);
+ }
+out:
+ mmap_read_unlock(current->mm);
+ /* Try to copy straggler data. */
+ if (!ret)
+ copylen = tcp_zc_handle_leftover(zc, sk, skb, &seq, copybuf_len, tss);
+
+ 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
+
+/* Similar to __sock_recv_timestamp, but does not require an skb */
+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 (READ_ONCE(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 (READ_ONCE(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.
+ */
+
+static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
+ int flags, struct scm_timestamping_internal *tss,
+ int *cmsg_flags)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ int copied = 0;
+ u32 peek_seq;
+ u32 *seq;
+ unsigned long used;
+ int err;
+ int target; /* Read at least this many bytes */
+ long timeo;
+ struct sk_buff *skb, *last;
+ u32 urg_hole = 0;
+
+ err = -ENOTCONN;
+ if (sk->sk_state == TCP_LISTEN)
+ goto out;
+
+ if (tp->recvmsg_inq) {
+ *cmsg_flags = TCP_CMSG_INQ;
+ msg->msg_get_inq = 1;
+ }
+ timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+
+ /* 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 (unlikely(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 (!timeo ||
+ sk->sk_err ||
+ sk->sk_state == TCP_CLOSE ||
+ (sk->sk_shutdown & RCV_SHUTDOWN) ||
+ 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;
+ }
+ }
+
+ if (copied >= target) {
+ /* Do not sleep, just process backlog. */
+ __sk_flush_backlog(sk);
+ } else {
+ tcp_cleanup_rbuf(sk, copied);
+ err = sk_wait_data(sk, &timeo, last);
+ if (err < 0) {
+ err = copied ? : err;
+ goto out;
+ }
+ }
+
+ 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 (unlikely(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 (unlikely(tp->urg_data) && after(tp->copied_seq, tp->urg_seq)) {
+ WRITE_ONCE(tp->urg_data, 0);
+ tcp_fast_path_check(sk);
+ }
+
+ if (TCP_SKB_CB(skb)->has_rxtstamp) {
+ tcp_update_recv_tstamps(skb, tss);
+ *cmsg_flags |= TCP_CMSG_TS;
+ }
+
+ if (used + offset < skb->len)
+ continue;
+
+ if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
+ goto found_fin_ok;
+ if (!(flags & MSG_PEEK))
+ tcp_eat_recv_skb(sk, skb);
+ continue;
+
+found_fin_ok:
+ /* Process the FIN. */
+ WRITE_ONCE(*seq, *seq + 1);
+ if (!(flags & MSG_PEEK))
+ tcp_eat_recv_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);
+ return copied;
+
+out:
+ 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;
+}
+
+int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
+ int *addr_len)
+{
+ int cmsg_flags = 0, ret;
+ struct scm_timestamping_internal tss;
+
+ 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, flags & MSG_DONTWAIT);
+
+ lock_sock(sk);
+ ret = tcp_recvmsg_locked(sk, msg, len, flags, &tss, &cmsg_flags);
+ release_sock(sk);
+
+ if ((cmsg_flags || msg->msg_get_inq) && ret >= 0) {
+ if (cmsg_flags & TCP_CMSG_TS)
+ tcp_recv_timestamp(msg, sk, &tss);
+ if (msg->msg_get_inq) {
+ msg->msg_inq = tcp_inq_hint(sk);
+ if (cmsg_flags & TCP_CMSG_INQ)
+ put_cmsg(msg, SOL_TCP, TCP_CM_INQ,
+ sizeof(msg->msg_inq), &msg->msg_inq);
+ }
+ }
+ return ret;
+}
+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);
+
+ /* bpf uapi header bpf.h defines an anonymous enum with values
+ * BPF_TCP_* used by bpf programs. Currently gcc built vmlinux
+ * is able to emit this enum in DWARF due to the above BUILD_BUG_ON.
+ * But clang built vmlinux does not have this enum in DWARF
+ * since clang removes the above code before generating IR/debuginfo.
+ * Let us explicitly emit the type debuginfo to ensure the
+ * above-mentioned anonymous enum in the vmlinux DWARF and hence BTF
+ * regardless of which compiler is used.
+ */
+ BTF_TYPE_EMIT_ENUM(BPF_TCP_ESTABLISHED);
+
+ 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);
+ }
+
+ /* 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) {
+ 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);
+ tcp_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);
+ tcp_wmem_free_skb(sk, skb);
+ }
+ tcp_rtx_queue_purge(sk);
+ INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
+ 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;
+
+ 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);
+ WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
+ WRITE_ONCE(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;
+
+ inet_bhash2_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;
+ tcp_snd_cwnd_set(tp, 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_error_report(sk);
+ return 0;
+}
+EXPORT_SYMBOL(tcp_disconnect);
+
+static inline bool tcp_can_repair_sock(const struct sock *sk)
+{
+ return sockopt_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.
+ */
+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.
+ */
+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);
+
+int tcp_set_window_clamp(struct sock *sk, int val)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (!val) {
+ if (sk->sk_state != TCP_CLOSE)
+ return -EINVAL;
+ tp->window_clamp = 0;
+ } else {
+ u32 new_rcv_ssthresh, old_window_clamp = tp->window_clamp;
+ u32 new_window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
+ SOCK_MIN_RCVBUF / 2 : val;
+
+ if (new_window_clamp == old_window_clamp)
+ return 0;
+
+ tp->window_clamp = new_window_clamp;
+ if (new_window_clamp < old_window_clamp) {
+ /* need to apply the reserved mem provisioning only
+ * when shrinking the window clamp
+ */
+ __tcp_adjust_rcv_ssthresh(sk, tp->window_clamp);
+
+ } else {
+ new_rcv_ssthresh = min(tp->rcv_wnd, tp->window_clamp);
+ tp->rcv_ssthresh = max(new_rcv_ssthresh,
+ tp->rcv_ssthresh);
+ }
+ }
+ return 0;
+}
+
+/*
+ * Socket option code for TCP.
+ */
+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;
+
+ sockopt_lock_sock(sk);
+ err = tcp_set_congestion_control(sk, name, !has_current_bpf_ctx(),
+ sockopt_ns_capable(sock_net(sk)->user_ns,
+ CAP_NET_ADMIN));
+ sockopt_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;
+
+ sockopt_lock_sock(sk);
+ err = tcp_set_ulp(sk, name);
+ sockopt_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;
+
+ sockopt_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:
+ err = tcp_set_window_clamp(sk, 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
+ WRITE_ONCE(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;
+ }
+
+ sockopt_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)
+ /* Paired with WRITE_ONCE() in do_ipv6_setsockopt() and tcp_v6_connect() */
+ return READ_ONCE(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 = tcp_snd_cwnd(tp);
+
+ 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;
+
+ /* segs_in and data_segs_in can be updated from tcp_segs_in() from BH */
+ info->tcpi_segs_in = READ_ONCE(tp->segs_in);
+ info->tcpi_data_segs_in = READ_ONCE(tp->data_segs_in);
+
+ info->tcpi_min_rtt = tcp_min_rtt(tp);
+ 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 */
+ nla_total_size(sizeof(u8)) + /* TCP_NLA_TTL */
+ 0;
+}
+
+/* Returns TTL or hop limit of an incoming packet from skb. */
+static u8 tcp_skb_ttl_or_hop_limit(const struct sk_buff *skb)
+{
+ if (skb->protocol == htons(ETH_P_IP))
+ return ip_hdr(skb)->ttl;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ return ipv6_hdr(skb)->hop_limit;
+ else
+ return 0;
+}
+
+struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
+ const struct sk_buff *orig_skb,
+ const struct sk_buff *ack_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, tcp_snd_cwnd(tp));
+ 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);
+ if (ack_skb)
+ nla_put_u8(stats, TCP_NLA_TTL,
+ tcp_skb_ttl_or_hop_limit(ack_skb));
+
+ return stats;
+}
+
+int do_tcp_getsockopt(struct sock *sk, int level,
+ int optname, sockptr_t optval, sockptr_t 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 (copy_from_sockptr(&len, optlen, sizeof(int)))
+ 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 (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+
+ tcp_get_info(sk, &info);
+
+ len = min_t(unsigned int, len, sizeof(info));
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ if (copy_to_sockptr(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 (copy_from_sockptr(&len, optlen, sizeof(int)))
+ 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 (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ if (copy_to_sockptr(optval, &info, len))
+ return -EFAULT;
+ return 0;
+ }
+ case TCP_QUICKACK:
+ val = !inet_csk_in_pingpong_mode(sk);
+ break;
+
+ case TCP_CONGESTION:
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+ len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ if (copy_to_sockptr(optval, icsk->icsk_ca_ops->name, len))
+ return -EFAULT;
+ return 0;
+
+ case TCP_ULP:
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+ len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
+ if (!icsk->icsk_ulp_ops) {
+ len = 0;
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ return 0;
+ }
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ if (copy_to_sockptr(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 (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+
+ key_len = tcp_fastopen_get_cipher(net, icsk, key) *
+ TCP_FASTOPEN_KEY_LENGTH;
+ len = min_t(unsigned int, len, key_len);
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ if (copy_to_sockptr(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 (copy_from_sockptr(&len, optlen, sizeof(int)))
+ 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_sockptr(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() + READ_ONCE(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 (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+
+ sockopt_lock_sock(sk);
+ if (tp->saved_syn) {
+ if (len < tcp_saved_syn_len(tp->saved_syn)) {
+ len = tcp_saved_syn_len(tp->saved_syn);
+ if (copy_to_sockptr(optlen, &len, sizeof(int))) {
+ sockopt_release_sock(sk);
+ return -EFAULT;
+ }
+ sockopt_release_sock(sk);
+ return -EINVAL;
+ }
+ len = tcp_saved_syn_len(tp->saved_syn);
+ if (copy_to_sockptr(optlen, &len, sizeof(int))) {
+ sockopt_release_sock(sk);
+ return -EFAULT;
+ }
+ if (copy_to_sockptr(optval, tp->saved_syn->data, len)) {
+ sockopt_release_sock(sk);
+ return -EFAULT;
+ }
+ tcp_saved_syn_free(tp);
+ sockopt_release_sock(sk);
+ } else {
+ sockopt_release_sock(sk);
+ len = 0;
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ }
+ return 0;
+ }
+#ifdef CONFIG_MMU
+ case TCP_ZEROCOPY_RECEIVE: {
+ struct scm_timestamping_internal tss;
+ struct tcp_zerocopy_receive zc = {};
+ int err;
+
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+ if (len < 0 ||
+ len < offsetofend(struct tcp_zerocopy_receive, length))
+ return -EINVAL;
+ if (unlikely(len > sizeof(zc))) {
+ err = check_zeroed_sockptr(optval, sizeof(zc),
+ len - sizeof(zc));
+ if (err < 1)
+ return err == 0 ? -EINVAL : err;
+ len = sizeof(zc);
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ }
+ if (copy_from_sockptr(&zc, optval, len))
+ return -EFAULT;
+ if (zc.reserved)
+ return -EINVAL;
+ if (zc.msg_flags & ~(TCP_VALID_ZC_MSG_FLAGS))
+ return -EINVAL;
+ sockopt_lock_sock(sk);
+ err = tcp_zerocopy_receive(sk, &zc, &tss);
+ err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname,
+ &zc, &len, err);
+ sockopt_release_sock(sk);
+ if (len >= offsetofend(struct tcp_zerocopy_receive, msg_flags))
+ goto zerocopy_rcv_cmsg;
+ switch (len) {
+ case offsetofend(struct tcp_zerocopy_receive, msg_flags):
+ goto zerocopy_rcv_cmsg;
+ case offsetofend(struct tcp_zerocopy_receive, msg_controllen):
+ case offsetofend(struct tcp_zerocopy_receive, msg_control):
+ case offsetofend(struct tcp_zerocopy_receive, flags):
+ case offsetofend(struct tcp_zerocopy_receive, copybuf_len):
+ case offsetofend(struct tcp_zerocopy_receive, copybuf_address):
+ 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_cmsg:
+ if (zc.msg_flags & TCP_CMSG_TS)
+ tcp_zc_finalize_rx_tstamp(sk, &zc, &tss);
+ else
+ zc.msg_flags = 0;
+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_sockptr(optval, &zc, len))
+ err = -EFAULT;
+ return err;
+ }
+#endif
+ default:
+ return -ENOPROTOOPT;
+ }
+
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
+ return -EFAULT;
+ if (copy_to_sockptr(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)
+ /* Paired with WRITE_ONCE() in do_ipv6_setsockopt() and tcp_v6_connect() */
+ return READ_ONCE(icsk->icsk_af_ops)->getsockopt(sk, level, optname,
+ optval, optlen);
+ return do_tcp_getsockopt(sk, level, optname, USER_SOCKPTR(optval),
+ USER_SOCKPTR(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);
+
+/* Called with rcu_read_lock() */
+enum skb_drop_reason
+tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
+ const void *saddr, const void *daddr,
+ int family, int dif, int sdif)
+{
+ /*
+ * 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 tcphdr *th = tcp_hdr(skb);
+ struct tcp_sock *tp = tcp_sk(sk);
+ int genhash, l3index;
+ u8 newhash[16];
+
+ /* sdif set, means packet ingressed via a device
+ * in an L3 domain and dif is set to the l3mdev
+ */
+ l3index = sdif ? dif : 0;
+
+ hash_expected = tcp_md5_do_lookup(sk, l3index, saddr, family);
+ hash_location = tcp_parse_md5sig_option(th);
+
+ /* We've parsed the options - do we have a hash? */
+ if (!hash_expected && !hash_location)
+ return SKB_NOT_DROPPED_YET;
+
+ if (hash_expected && !hash_location) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
+ return SKB_DROP_REASON_TCP_MD5NOTFOUND;
+ }
+
+ if (!hash_expected && hash_location) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+ return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
+ }
+
+ /* Check the signature.
+ * To support dual stack listeners, we need to handle
+ * IPv4-mapped case.
+ */
+ if (family == AF_INET)
+ genhash = tcp_v4_md5_hash_skb(newhash,
+ hash_expected,
+ NULL, skb);
+ else
+ genhash = tp->af_specific->calc_md5_hash(newhash,
+ hash_expected,
+ NULL, skb);
+
+ if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
+ if (family == AF_INET) {
+ net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n",
+ saddr, ntohs(th->source),
+ daddr, ntohs(th->dest),
+ genhash ? " tcp_v4_calc_md5_hash failed"
+ : "", l3index);
+ } else {
+ net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
+ genhash ? "failed" : "mismatch",
+ saddr, ntohs(th->source),
+ daddr, ntohs(th->dest), l3index);
+ }
+ return SKB_DROP_REASON_TCP_MD5FAILURE;
+ }
+ return SKB_NOT_DROPPED_YET;
+}
+EXPORT_SYMBOL(tcp_inbound_md5_hash);
+
+#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)
+{
+ int state = inet_sk_state_load(sk);
+
+ if (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;
+ }
+ if (state == TCP_TIME_WAIT) {
+ struct inet_timewait_sock *tw = inet_twsk(sk);
+
+ refcount_inc(&tw->tw_refcnt);
+ local_bh_disable();
+ inet_twsk_deschedule_put(tw);
+ local_bh_enable();
+ return 0;
+ }
+
+ /* 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_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_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 |
+ SLAB_ACCOUNT,
+ NULL);
+ tcp_hashinfo.bind2_bucket_cachep =
+ kmem_cache_create("tcp_bind2_bucket",
+ sizeof(struct inet_bind2_bucket), 0,
+ SLAB_HWCACHE_ALIGN | SLAB_PANIC |
+ SLAB_ACCOUNT,
+ 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",
+ 2 * 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;
+ tcp_hashinfo.bhash2 = tcp_hashinfo.bhash + 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);
+ spin_lock_init(&tcp_hashinfo.bhash2[i].lock);
+ INIT_HLIST_HEAD(&tcp_hashinfo.bhash2[i].chain);
+ }
+
+ tcp_hashinfo.pernet = false;
+
+ 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] = PAGE_SIZE;
+ 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] = PAGE_SIZE;
+ 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();
+}