1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
7 * Implementation of the Transmission Control Protocol(TCP).
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Mark Evans, <evansmp@uhura.aston.ac.uk>
12 * Corey Minyard <wf-rch!minyard@relay.EU.net>
13 * Florian La Roche, <flla@stud.uni-sb.de>
14 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
15 * Linus Torvalds, <torvalds@cs.helsinki.fi>
16 * Alan Cox, <gw4pts@gw4pts.ampr.org>
17 * Matthew Dillon, <dillon@apollo.west.oic.com>
18 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
19 * Jorge Cwik, <jorge@laser.satlink.net>
22 * Alan Cox : Numerous verify_area() calls
23 * Alan Cox : Set the ACK bit on a reset
24 * Alan Cox : Stopped it crashing if it closed while
25 * sk->inuse=1 and was trying to connect
27 * Alan Cox : All icmp error handling was broken
28 * pointers passed where wrong and the
29 * socket was looked up backwards. Nobody
30 * tested any icmp error code obviously.
31 * Alan Cox : tcp_err() now handled properly. It
32 * wakes people on errors. poll
33 * behaves and the icmp error race
34 * has gone by moving it into sock.c
35 * Alan Cox : tcp_send_reset() fixed to work for
36 * everything not just packets for
38 * Alan Cox : tcp option processing.
39 * Alan Cox : Reset tweaked (still not 100%) [Had
41 * Herp Rosmanith : More reset fixes
42 * Alan Cox : No longer acks invalid rst frames.
43 * Acking any kind of RST is right out.
44 * Alan Cox : Sets an ignore me flag on an rst
45 * receive otherwise odd bits of prattle
47 * Alan Cox : Fixed another acking RST frame bug.
48 * Should stop LAN workplace lockups.
49 * Alan Cox : Some tidyups using the new skb list
51 * Alan Cox : sk->keepopen now seems to work
52 * Alan Cox : Pulls options out correctly on accepts
53 * Alan Cox : Fixed assorted sk->rqueue->next errors
54 * Alan Cox : PSH doesn't end a TCP read. Switched a
56 * Alan Cox : Tidied tcp_data to avoid a potential
58 * Alan Cox : Added some better commenting, as the
59 * tcp is hard to follow
60 * Alan Cox : Removed incorrect check for 20 * psh
61 * Michael O'Reilly : ack < copied bug fix.
62 * Johannes Stille : Misc tcp fixes (not all in yet).
63 * Alan Cox : FIN with no memory -> CRASH
64 * Alan Cox : Added socket option proto entries.
65 * Also added awareness of them to accept.
66 * Alan Cox : Added TCP options (SOL_TCP)
67 * Alan Cox : Switched wakeup calls to callbacks,
68 * so the kernel can layer network
70 * Alan Cox : Use ip_tos/ip_ttl settings.
71 * Alan Cox : Handle FIN (more) properly (we hope).
72 * Alan Cox : RST frames sent on unsynchronised
74 * Alan Cox : Put in missing check for SYN bit.
75 * Alan Cox : Added tcp_select_window() aka NET2E
76 * window non shrink trick.
77 * Alan Cox : Added a couple of small NET2E timer
79 * Charles Hedrick : TCP fixes
80 * Toomas Tamm : TCP window fixes
81 * Alan Cox : Small URG fix to rlogin ^C ack fight
82 * Charles Hedrick : Rewrote most of it to actually work
83 * Linus : Rewrote tcp_read() and URG handling
85 * Gerhard Koerting: Fixed some missing timer handling
86 * Matthew Dillon : Reworked TCP machine states as per RFC
87 * Gerhard Koerting: PC/TCP workarounds
88 * Adam Caldwell : Assorted timer/timing errors
89 * Matthew Dillon : Fixed another RST bug
90 * Alan Cox : Move to kernel side addressing changes.
91 * Alan Cox : Beginning work on TCP fastpathing
93 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
94 * Alan Cox : TCP fast path debugging
95 * Alan Cox : Window clamping
96 * Michael Riepe : Bug in tcp_check()
97 * Matt Dillon : More TCP improvements and RST bug fixes
98 * Matt Dillon : Yet more small nasties remove from the
99 * TCP code (Be very nice to this man if
100 * tcp finally works 100%) 8)
101 * Alan Cox : BSD accept semantics.
102 * Alan Cox : Reset on closedown bug.
103 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
104 * Michael Pall : Handle poll() after URG properly in
106 * Michael Pall : Undo the last fix in tcp_read_urg()
107 * (multi URG PUSH broke rlogin).
108 * Michael Pall : Fix the multi URG PUSH problem in
109 * tcp_readable(), poll() after URG
111 * Michael Pall : recv(...,MSG_OOB) never blocks in the
113 * Alan Cox : Changed the semantics of sk->socket to
114 * fix a race and a signal problem with
115 * accept() and async I/O.
116 * Alan Cox : Relaxed the rules on tcp_sendto().
117 * Yury Shevchuk : Really fixed accept() blocking problem.
118 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
119 * clients/servers which listen in on
121 * Alan Cox : Cleaned the above up and shrank it to
122 * a sensible code size.
123 * Alan Cox : Self connect lockup fix.
124 * Alan Cox : No connect to multicast.
125 * Ross Biro : Close unaccepted children on master
127 * Alan Cox : Reset tracing code.
128 * Alan Cox : Spurious resets on shutdown.
129 * Alan Cox : Giant 15 minute/60 second timer error
130 * Alan Cox : Small whoops in polling before an
132 * Alan Cox : Kept the state trace facility since
133 * it's handy for debugging.
134 * Alan Cox : More reset handler fixes.
135 * Alan Cox : Started rewriting the code based on
136 * the RFC's for other useful protocol
137 * references see: Comer, KA9Q NOS, and
138 * for a reference on the difference
139 * between specifications and how BSD
140 * works see the 4.4lite source.
141 * A.N.Kuznetsov : Don't time wait on completion of tidy
143 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
144 * Linus Torvalds : Fixed BSD port reuse to work first syn
145 * Alan Cox : Reimplemented timers as per the RFC
146 * and using multiple timers for sanity.
147 * Alan Cox : Small bug fixes, and a lot of new
149 * Alan Cox : Fixed dual reader crash by locking
150 * the buffers (much like datagram.c)
151 * Alan Cox : Fixed stuck sockets in probe. A probe
152 * now gets fed up of retrying without
153 * (even a no space) answer.
154 * Alan Cox : Extracted closing code better
155 * Alan Cox : Fixed the closing state machine to
157 * Alan Cox : More 'per spec' fixes.
158 * Jorge Cwik : Even faster checksumming.
159 * Alan Cox : tcp_data() doesn't ack illegal PSH
160 * only frames. At least one pc tcp stack
162 * Alan Cox : Cache last socket.
163 * Alan Cox : Per route irtt.
164 * Matt Day : poll()->select() match BSD precisely on error
165 * Alan Cox : New buffers
166 * Marc Tamsky : Various sk->prot->retransmits and
167 * sk->retransmits misupdating fixed.
168 * Fixed tcp_write_timeout: stuck close,
169 * and TCP syn retries gets used now.
170 * Mark Yarvis : In tcp_read_wakeup(), don't send an
171 * ack if state is TCP_CLOSED.
172 * Alan Cox : Look up device on a retransmit - routes may
173 * change. Doesn't yet cope with MSS shrink right
175 * Marc Tamsky : Closing in closing fixes.
176 * Mike Shaver : RFC1122 verifications.
177 * Alan Cox : rcv_saddr errors.
178 * Alan Cox : Block double connect().
179 * Alan Cox : Small hooks for enSKIP.
180 * Alexey Kuznetsov: Path MTU discovery.
181 * Alan Cox : Support soft errors.
182 * Alan Cox : Fix MTU discovery pathological case
183 * when the remote claims no mtu!
184 * Marc Tamsky : TCP_CLOSE fix.
185 * Colin (G3TNE) : Send a reset on syn ack replies in
186 * window but wrong (fixes NT lpd problems)
187 * Pedro Roque : Better TCP window handling, delayed ack.
188 * Joerg Reuter : No modification of locked buffers in
189 * tcp_do_retransmit()
190 * Eric Schenk : Changed receiver side silly window
191 * avoidance algorithm to BSD style
192 * algorithm. This doubles throughput
193 * against machines running Solaris,
194 * and seems to result in general
196 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
197 * Willy Konynenberg : Transparent proxying support.
198 * Mike McLagan : Routing by source
199 * Keith Owens : Do proper merging with partial SKB's in
200 * tcp_do_sendmsg to avoid burstiness.
201 * Eric Schenk : Fix fast close down bug with
202 * shutdown() followed by close().
203 * Andi Kleen : Make poll agree with SIGIO
204 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
205 * lingertime == 0 (RFC 793 ABORT Call)
206 * Hirokazu Takahashi : Use copy_from_user() instead of
207 * csum_and_copy_from_user() if possible.
209 * Description of States:
211 * TCP_SYN_SENT sent a connection request, waiting for ack
213 * TCP_SYN_RECV received a connection request, sent ack,
214 * waiting for final ack in three-way handshake.
216 * TCP_ESTABLISHED connection established
218 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
219 * transmission of remaining buffered data
221 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
224 * TCP_CLOSING both sides have shutdown but we still have
225 * data we have to finish sending
227 * TCP_TIME_WAIT timeout to catch resent junk before entering
228 * closed, can only be entered from FIN_WAIT2
229 * or CLOSING. Required because the other end
230 * may not have gotten our last ACK causing it
231 * to retransmit the data packet (which we ignore)
233 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
234 * us to finish writing our data and to shutdown
235 * (we have to close() to move on to LAST_ACK)
237 * TCP_LAST_ACK out side has shutdown after remote has
238 * shutdown. There may still be data in our
239 * buffer that we have to finish sending
241 * TCP_CLOSE socket is finished
244 #define pr_fmt(fmt) "TCP: " fmt
246 #include <crypto/hash.h>
247 #include <linux/kernel.h>
248 #include <linux/module.h>
249 #include <linux/types.h>
250 #include <linux/fcntl.h>
251 #include <linux/poll.h>
252 #include <linux/inet_diag.h>
253 #include <linux/init.h>
254 #include <linux/fs.h>
255 #include <linux/skbuff.h>
256 #include <linux/scatterlist.h>
257 #include <linux/splice.h>
258 #include <linux/net.h>
259 #include <linux/socket.h>
260 #include <linux/random.h>
261 #include <linux/memblock.h>
262 #include <linux/highmem.h>
263 #include <linux/swap.h>
264 #include <linux/cache.h>
265 #include <linux/err.h>
266 #include <linux/time.h>
267 #include <linux/slab.h>
268 #include <linux/errqueue.h>
269 #include <linux/static_key.h>
271 #include <net/icmp.h>
272 #include <net/inet_common.h>
274 #include <net/mptcp.h>
275 #include <net/xfrm.h>
277 #include <net/sock.h>
279 #include <linux/uaccess.h>
280 #include <asm/ioctls.h>
281 #include <net/busy_poll.h>
283 struct percpu_counter tcp_orphan_count;
284 EXPORT_SYMBOL_GPL(tcp_orphan_count);
286 long sysctl_tcp_mem[3] __read_mostly;
287 EXPORT_SYMBOL(sysctl_tcp_mem);
289 atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
290 EXPORT_SYMBOL(tcp_memory_allocated);
292 #if IS_ENABLED(CONFIG_SMC)
293 DEFINE_STATIC_KEY_FALSE(tcp_have_smc);
294 EXPORT_SYMBOL(tcp_have_smc);
298 * Current number of TCP sockets.
300 struct percpu_counter tcp_sockets_allocated;
301 EXPORT_SYMBOL(tcp_sockets_allocated);
306 struct tcp_splice_state {
307 struct pipe_inode_info *pipe;
313 * Pressure flag: try to collapse.
314 * Technical note: it is used by multiple contexts non atomically.
315 * All the __sk_mem_schedule() is of this nature: accounting
316 * is strict, actions are advisory and have some latency.
318 unsigned long tcp_memory_pressure __read_mostly;
319 EXPORT_SYMBOL_GPL(tcp_memory_pressure);
321 DEFINE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
322 EXPORT_SYMBOL(tcp_rx_skb_cache_key);
324 DEFINE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
326 void tcp_enter_memory_pressure(struct sock *sk)
330 if (READ_ONCE(tcp_memory_pressure))
336 if (!cmpxchg(&tcp_memory_pressure, 0, val))
337 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
339 EXPORT_SYMBOL_GPL(tcp_enter_memory_pressure);
341 void tcp_leave_memory_pressure(struct sock *sk)
345 if (!READ_ONCE(tcp_memory_pressure))
347 val = xchg(&tcp_memory_pressure, 0);
349 NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURESCHRONO,
350 jiffies_to_msecs(jiffies - val));
352 EXPORT_SYMBOL_GPL(tcp_leave_memory_pressure);
354 /* Convert seconds to retransmits based on initial and max timeout */
355 static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
360 int period = timeout;
363 while (seconds > period && res < 255) {
366 if (timeout > rto_max)
374 /* Convert retransmits to seconds based on initial and max timeout */
375 static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
383 if (timeout > rto_max)
391 static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp)
393 u32 rate = READ_ONCE(tp->rate_delivered);
394 u32 intv = READ_ONCE(tp->rate_interval_us);
398 rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC;
399 do_div(rate64, intv);
404 /* Address-family independent initialization for a tcp_sock.
406 * NOTE: A lot of things set to zero explicitly by call to
407 * sk_alloc() so need not be done here.
409 void tcp_init_sock(struct sock *sk)
411 struct inet_connection_sock *icsk = inet_csk(sk);
412 struct tcp_sock *tp = tcp_sk(sk);
414 tp->out_of_order_queue = RB_ROOT;
415 sk->tcp_rtx_queue = RB_ROOT;
416 tcp_init_xmit_timers(sk);
417 INIT_LIST_HEAD(&tp->tsq_node);
418 INIT_LIST_HEAD(&tp->tsorted_sent_queue);
420 icsk->icsk_rto = TCP_TIMEOUT_INIT;
421 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
422 minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U);
424 /* So many TCP implementations out there (incorrectly) count the
425 * initial SYN frame in their delayed-ACK and congestion control
426 * algorithms that we must have the following bandaid to talk
427 * efficiently to them. -DaveM
429 tp->snd_cwnd = TCP_INIT_CWND;
431 /* There's a bubble in the pipe until at least the first ACK. */
432 tp->app_limited = ~0U;
434 /* See draft-stevens-tcpca-spec-01 for discussion of the
435 * initialization of these values.
437 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
438 tp->snd_cwnd_clamp = ~0;
439 tp->mss_cache = TCP_MSS_DEFAULT;
441 tp->reordering = sock_net(sk)->ipv4.sysctl_tcp_reordering;
442 tcp_assign_congestion_control(sk);
445 tp->rack.reo_wnd_steps = 1;
447 sk->sk_write_space = sk_stream_write_space;
448 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
450 icsk->icsk_sync_mss = tcp_sync_mss;
452 WRITE_ONCE(sk->sk_sndbuf, sock_net(sk)->ipv4.sysctl_tcp_wmem[1]);
453 WRITE_ONCE(sk->sk_rcvbuf, sock_net(sk)->ipv4.sysctl_tcp_rmem[1]);
455 sk_sockets_allocated_inc(sk);
456 sk->sk_route_forced_caps = NETIF_F_GSO;
458 EXPORT_SYMBOL(tcp_init_sock);
460 static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
462 struct sk_buff *skb = tcp_write_queue_tail(sk);
464 if (tsflags && skb) {
465 struct skb_shared_info *shinfo = skb_shinfo(skb);
466 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
468 sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags);
469 if (tsflags & SOF_TIMESTAMPING_TX_ACK)
470 tcb->txstamp_ack = 1;
471 if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
472 shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
476 static inline bool tcp_stream_is_readable(const struct tcp_sock *tp,
477 int target, struct sock *sk)
479 int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq);
484 if (tcp_rmem_pressure(sk))
487 if (sk->sk_prot->stream_memory_read)
488 return sk->sk_prot->stream_memory_read(sk);
493 * Wait for a TCP event.
495 * Note that we don't need to lock the socket, as the upper poll layers
496 * take care of normal races (between the test and the event) and we don't
497 * go look at any of the socket buffers directly.
499 __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
502 struct sock *sk = sock->sk;
503 const struct tcp_sock *tp = tcp_sk(sk);
506 sock_poll_wait(file, sock, wait);
508 state = inet_sk_state_load(sk);
509 if (state == TCP_LISTEN)
510 return inet_csk_listen_poll(sk);
512 /* Socket is not locked. We are protected from async events
513 * by poll logic and correct handling of state changes
514 * made by other threads is impossible in any case.
520 * EPOLLHUP is certainly not done right. But poll() doesn't
521 * have a notion of HUP in just one direction, and for a
522 * socket the read side is more interesting.
524 * Some poll() documentation says that EPOLLHUP is incompatible
525 * with the EPOLLOUT/POLLWR flags, so somebody should check this
526 * all. But careful, it tends to be safer to return too many
527 * bits than too few, and you can easily break real applications
528 * if you don't tell them that something has hung up!
532 * Check number 1. EPOLLHUP is _UNMASKABLE_ event (see UNIX98 and
533 * our fs/select.c). It means that after we received EOF,
534 * poll always returns immediately, making impossible poll() on write()
535 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP
536 * if and only if shutdown has been made in both directions.
537 * Actually, it is interesting to look how Solaris and DUX
538 * solve this dilemma. I would prefer, if EPOLLHUP were maskable,
539 * then we could set it on SND_SHUTDOWN. BTW examples given
540 * in Stevens' books assume exactly this behaviour, it explains
541 * why EPOLLHUP is incompatible with EPOLLOUT. --ANK
543 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
544 * blocking on fresh not-connected or disconnected socket. --ANK
546 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
548 if (sk->sk_shutdown & RCV_SHUTDOWN)
549 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
551 /* Connected or passive Fast Open socket? */
552 if (state != TCP_SYN_SENT &&
553 (state != TCP_SYN_RECV || rcu_access_pointer(tp->fastopen_rsk))) {
554 int target = sock_rcvlowat(sk, 0, INT_MAX);
556 if (READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq) &&
557 !sock_flag(sk, SOCK_URGINLINE) &&
561 if (tcp_stream_is_readable(tp, target, sk))
562 mask |= EPOLLIN | EPOLLRDNORM;
564 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
565 if (sk_stream_is_writeable(sk)) {
566 mask |= EPOLLOUT | EPOLLWRNORM;
567 } else { /* send SIGIO later */
568 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
569 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
571 /* Race breaker. If space is freed after
572 * wspace test but before the flags are set,
573 * IO signal will be lost. Memory barrier
574 * pairs with the input side.
576 smp_mb__after_atomic();
577 if (sk_stream_is_writeable(sk))
578 mask |= EPOLLOUT | EPOLLWRNORM;
581 mask |= EPOLLOUT | EPOLLWRNORM;
583 if (tp->urg_data & TCP_URG_VALID)
585 } else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
586 /* Active TCP fastopen socket with defer_connect
587 * Return EPOLLOUT so application can call write()
588 * in order for kernel to generate SYN+data
590 mask |= EPOLLOUT | EPOLLWRNORM;
592 /* This barrier is coupled with smp_wmb() in tcp_reset() */
594 if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
599 EXPORT_SYMBOL(tcp_poll);
601 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
603 struct tcp_sock *tp = tcp_sk(sk);
609 if (sk->sk_state == TCP_LISTEN)
612 slow = lock_sock_fast(sk);
614 unlock_sock_fast(sk, slow);
617 answ = tp->urg_data &&
618 READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq);
621 if (sk->sk_state == TCP_LISTEN)
624 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
627 answ = READ_ONCE(tp->write_seq) - tp->snd_una;
630 if (sk->sk_state == TCP_LISTEN)
633 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
636 answ = READ_ONCE(tp->write_seq) -
637 READ_ONCE(tp->snd_nxt);
643 return put_user(answ, (int __user *)arg);
645 EXPORT_SYMBOL(tcp_ioctl);
647 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
649 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
650 tp->pushed_seq = tp->write_seq;
653 static inline bool forced_push(const struct tcp_sock *tp)
655 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
658 static void skb_entail(struct sock *sk, struct sk_buff *skb)
660 struct tcp_sock *tp = tcp_sk(sk);
661 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
664 tcb->seq = tcb->end_seq = tp->write_seq;
665 tcb->tcp_flags = TCPHDR_ACK;
667 __skb_header_release(skb);
668 tcp_add_write_queue_tail(sk, skb);
669 sk_wmem_queued_add(sk, skb->truesize);
670 sk_mem_charge(sk, skb->truesize);
671 if (tp->nonagle & TCP_NAGLE_PUSH)
672 tp->nonagle &= ~TCP_NAGLE_PUSH;
674 tcp_slow_start_after_idle_check(sk);
677 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
680 tp->snd_up = tp->write_seq;
683 /* If a not yet filled skb is pushed, do not send it if
684 * we have data packets in Qdisc or NIC queues :
685 * Because TX completion will happen shortly, it gives a chance
686 * to coalesce future sendmsg() payload into this skb, without
687 * need for a timer, and with no latency trade off.
688 * As packets containing data payload have a bigger truesize
689 * than pure acks (dataless) packets, the last checks prevent
690 * autocorking if we only have an ACK in Qdisc/NIC queues,
691 * or if TX completion was delayed after we processed ACK packet.
693 static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
696 return skb->len < size_goal &&
697 sock_net(sk)->ipv4.sysctl_tcp_autocorking &&
698 !tcp_rtx_queue_empty(sk) &&
699 refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
702 void tcp_push(struct sock *sk, int flags, int mss_now,
703 int nonagle, int size_goal)
705 struct tcp_sock *tp = tcp_sk(sk);
708 skb = tcp_write_queue_tail(sk);
711 if (!(flags & MSG_MORE) || forced_push(tp))
712 tcp_mark_push(tp, skb);
714 tcp_mark_urg(tp, flags);
716 if (tcp_should_autocork(sk, skb, size_goal)) {
718 /* avoid atomic op if TSQ_THROTTLED bit is already set */
719 if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
720 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
721 set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
723 /* It is possible TX completion already happened
724 * before we set TSQ_THROTTLED.
726 if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
730 if (flags & MSG_MORE)
731 nonagle = TCP_NAGLE_CORK;
733 __tcp_push_pending_frames(sk, mss_now, nonagle);
736 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
737 unsigned int offset, size_t len)
739 struct tcp_splice_state *tss = rd_desc->arg.data;
742 ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
743 min(rd_desc->count, len), tss->flags);
745 rd_desc->count -= ret;
749 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
751 /* Store TCP splice context information in read_descriptor_t. */
752 read_descriptor_t rd_desc = {
757 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
761 * tcp_splice_read - splice data from TCP socket to a pipe
762 * @sock: socket to splice from
763 * @ppos: position (not valid)
764 * @pipe: pipe to splice to
765 * @len: number of bytes to splice
766 * @flags: splice modifier flags
769 * Will read pages from given socket and fill them into a pipe.
772 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
773 struct pipe_inode_info *pipe, size_t len,
776 struct sock *sk = sock->sk;
777 struct tcp_splice_state tss = {
786 sock_rps_record_flow(sk);
788 * We can't seek on a socket input
797 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
799 ret = __tcp_splice_read(sk, &tss);
805 if (sock_flag(sk, SOCK_DONE))
808 ret = sock_error(sk);
811 if (sk->sk_shutdown & RCV_SHUTDOWN)
813 if (sk->sk_state == TCP_CLOSE) {
815 * This occurs when user tries to read
816 * from never connected socket.
825 /* if __tcp_splice_read() got nothing while we have
826 * an skb in receive queue, we do not want to loop.
827 * This might happen with URG data.
829 if (!skb_queue_empty(&sk->sk_receive_queue))
831 sk_wait_data(sk, &timeo, NULL);
832 if (signal_pending(current)) {
833 ret = sock_intr_errno(timeo);
846 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
847 (sk->sk_shutdown & RCV_SHUTDOWN) ||
848 signal_pending(current))
859 EXPORT_SYMBOL(tcp_splice_read);
861 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
867 skb = sk->sk_tx_skb_cache;
869 skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
870 sk->sk_tx_skb_cache = NULL;
872 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
873 skb_shinfo(skb)->tx_flags = 0;
874 memset(TCP_SKB_CB(skb), 0, sizeof(struct tcp_skb_cb));
878 /* The TCP header must be at least 32-bit aligned. */
879 size = ALIGN(size, 4);
881 if (unlikely(tcp_under_memory_pressure(sk)))
882 sk_mem_reclaim_partial(sk);
884 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
888 if (force_schedule) {
889 mem_scheduled = true;
890 sk_forced_mem_schedule(sk, skb->truesize);
892 mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
894 if (likely(mem_scheduled)) {
895 skb_reserve(skb, sk->sk_prot->max_header);
897 * Make sure that we have exactly size bytes
898 * available to the caller, no more, no less.
900 skb->reserved_tailroom = skb->end - skb->tail - size;
901 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
906 sk->sk_prot->enter_memory_pressure(sk);
907 sk_stream_moderate_sndbuf(sk);
912 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
915 struct tcp_sock *tp = tcp_sk(sk);
916 u32 new_size_goal, size_goal;
921 /* Note : tcp_tso_autosize() will eventually split this later */
922 new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER;
923 new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal);
925 /* We try hard to avoid divides here */
926 size_goal = tp->gso_segs * mss_now;
927 if (unlikely(new_size_goal < size_goal ||
928 new_size_goal >= size_goal + mss_now)) {
929 tp->gso_segs = min_t(u16, new_size_goal / mss_now,
930 sk->sk_gso_max_segs);
931 size_goal = tp->gso_segs * mss_now;
934 return max(size_goal, mss_now);
937 int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
941 mss_now = tcp_current_mss(sk);
942 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
947 /* In some cases, both sendpage() and sendmsg() could have added
948 * an skb to the write queue, but failed adding payload on it.
949 * We need to remove it to consume less memory, but more
950 * importantly be able to generate EPOLLOUT for Edge Trigger epoll()
953 static void tcp_remove_empty_skb(struct sock *sk, struct sk_buff *skb)
955 if (skb && !skb->len) {
956 tcp_unlink_write_queue(skb, sk);
957 if (tcp_write_queue_empty(sk))
958 tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
959 sk_wmem_free_skb(sk, skb);
963 ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
964 size_t size, int flags)
966 struct tcp_sock *tp = tcp_sk(sk);
967 int mss_now, size_goal;
970 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
972 if (IS_ENABLED(CONFIG_DEBUG_VM) &&
973 WARN_ONCE(PageSlab(page), "page must not be a Slab one"))
976 /* Wait for a connection to finish. One exception is TCP Fast Open
977 * (passive side) where data is allowed to be sent before a connection
978 * is fully established.
980 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
981 !tcp_passive_fastopen(sk)) {
982 err = sk_stream_wait_connect(sk, &timeo);
987 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
989 mss_now = tcp_send_mss(sk, &size_goal, flags);
993 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
997 struct sk_buff *skb = tcp_write_queue_tail(sk);
1001 if (!skb || (copy = size_goal - skb->len) <= 0 ||
1002 !tcp_skb_can_collapse_to(skb)) {
1004 if (!sk_stream_memory_free(sk))
1005 goto wait_for_sndbuf;
1007 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
1008 tcp_rtx_and_write_queues_empty(sk));
1010 goto wait_for_memory;
1012 #ifdef CONFIG_TLS_DEVICE
1013 skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED);
1015 skb_entail(sk, skb);
1022 i = skb_shinfo(skb)->nr_frags;
1023 can_coalesce = skb_can_coalesce(skb, i, page, offset);
1024 if (!can_coalesce && i >= sysctl_max_skb_frags) {
1025 tcp_mark_push(tp, skb);
1028 if (!sk_wmem_schedule(sk, copy))
1029 goto wait_for_memory;
1032 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1035 skb_fill_page_desc(skb, i, page, offset, copy);
1038 if (!(flags & MSG_NO_SHARED_FRAGS))
1039 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1042 skb->data_len += copy;
1043 skb->truesize += copy;
1044 sk_wmem_queued_add(sk, copy);
1045 sk_mem_charge(sk, copy);
1046 skb->ip_summed = CHECKSUM_PARTIAL;
1047 WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
1048 TCP_SKB_CB(skb)->end_seq += copy;
1049 tcp_skb_pcount_set(skb, 0);
1052 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1060 if (skb->len < size_goal || (flags & MSG_OOB))
1063 if (forced_push(tp)) {
1064 tcp_mark_push(tp, skb);
1065 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1066 } else if (skb == tcp_send_head(sk))
1067 tcp_push_one(sk, mss_now);
1071 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1073 tcp_push(sk, flags & ~MSG_MORE, mss_now,
1074 TCP_NAGLE_PUSH, size_goal);
1076 err = sk_stream_wait_memory(sk, &timeo);
1080 mss_now = tcp_send_mss(sk, &size_goal, flags);
1085 tcp_tx_timestamp(sk, sk->sk_tsflags);
1086 if (!(flags & MSG_SENDPAGE_NOTLAST))
1087 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1092 tcp_remove_empty_skb(sk, tcp_write_queue_tail(sk));
1096 /* make sure we wake any epoll edge trigger waiter */
1097 if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) {
1098 sk->sk_write_space(sk);
1099 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
1101 return sk_stream_error(sk, flags, err);
1103 EXPORT_SYMBOL_GPL(do_tcp_sendpages);
1105 int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
1106 size_t size, int flags)
1108 if (!(sk->sk_route_caps & NETIF_F_SG))
1109 return sock_no_sendpage_locked(sk, page, offset, size, flags);
1111 tcp_rate_check_app_limited(sk); /* is sending application-limited? */
1113 return do_tcp_sendpages(sk, page, offset, size, flags);
1115 EXPORT_SYMBOL_GPL(tcp_sendpage_locked);
1117 int tcp_sendpage(struct sock *sk, struct page *page, int offset,
1118 size_t size, int flags)
1123 ret = tcp_sendpage_locked(sk, page, offset, size, flags);
1128 EXPORT_SYMBOL(tcp_sendpage);
1130 void tcp_free_fastopen_req(struct tcp_sock *tp)
1132 if (tp->fastopen_req) {
1133 kfree(tp->fastopen_req);
1134 tp->fastopen_req = NULL;
1138 static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
1139 int *copied, size_t size,
1140 struct ubuf_info *uarg)
1142 struct tcp_sock *tp = tcp_sk(sk);
1143 struct inet_sock *inet = inet_sk(sk);
1144 struct sockaddr *uaddr = msg->msg_name;
1147 if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1148 (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
1149 uaddr->sa_family == AF_UNSPEC))
1151 if (tp->fastopen_req)
1152 return -EALREADY; /* Another Fast Open is in progress */
1154 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
1156 if (unlikely(!tp->fastopen_req))
1158 tp->fastopen_req->data = msg;
1159 tp->fastopen_req->size = size;
1160 tp->fastopen_req->uarg = uarg;
1162 if (inet->defer_connect) {
1163 err = tcp_connect(sk);
1164 /* Same failure procedure as in tcp_v4/6_connect */
1166 tcp_set_state(sk, TCP_CLOSE);
1167 inet->inet_dport = 0;
1168 sk->sk_route_caps = 0;
1171 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1172 err = __inet_stream_connect(sk->sk_socket, uaddr,
1173 msg->msg_namelen, flags, 1);
1174 /* fastopen_req could already be freed in __inet_stream_connect
1175 * if the connection times out or gets rst
1177 if (tp->fastopen_req) {
1178 *copied = tp->fastopen_req->copied;
1179 tcp_free_fastopen_req(tp);
1180 inet->defer_connect = 0;
1185 int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
1187 struct tcp_sock *tp = tcp_sk(sk);
1188 struct ubuf_info *uarg = NULL;
1189 struct sk_buff *skb;
1190 struct sockcm_cookie sockc;
1191 int flags, err, copied = 0;
1192 int mss_now = 0, size_goal, copied_syn = 0;
1193 int process_backlog = 0;
1197 flags = msg->msg_flags;
1199 if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) {
1200 skb = tcp_write_queue_tail(sk);
1201 uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb));
1207 zc = sk->sk_route_caps & NETIF_F_SG;
1212 if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) &&
1214 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size, uarg);
1215 if (err == -EINPROGRESS && copied_syn > 0)
1221 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1223 tcp_rate_check_app_limited(sk); /* is sending application-limited? */
1225 /* Wait for a connection to finish. One exception is TCP Fast Open
1226 * (passive side) where data is allowed to be sent before a connection
1227 * is fully established.
1229 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
1230 !tcp_passive_fastopen(sk)) {
1231 err = sk_stream_wait_connect(sk, &timeo);
1236 if (unlikely(tp->repair)) {
1237 if (tp->repair_queue == TCP_RECV_QUEUE) {
1238 copied = tcp_send_rcvq(sk, msg, size);
1243 if (tp->repair_queue == TCP_NO_QUEUE)
1246 /* 'common' sending to sendq */
1249 sockcm_init(&sockc, sk);
1250 if (msg->msg_controllen) {
1251 err = sock_cmsg_send(sk, msg, &sockc);
1252 if (unlikely(err)) {
1258 /* This should be in poll */
1259 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1261 /* Ok commence sending. */
1265 mss_now = tcp_send_mss(sk, &size_goal, flags);
1268 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1271 while (msg_data_left(msg)) {
1274 skb = tcp_write_queue_tail(sk);
1276 copy = size_goal - skb->len;
1278 if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1282 if (!sk_stream_memory_free(sk))
1283 goto wait_for_sndbuf;
1285 if (unlikely(process_backlog >= 16)) {
1286 process_backlog = 0;
1287 if (sk_flush_backlog(sk))
1290 first_skb = tcp_rtx_and_write_queues_empty(sk);
1291 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
1294 goto wait_for_memory;
1297 skb->ip_summed = CHECKSUM_PARTIAL;
1299 skb_entail(sk, skb);
1302 /* All packets are restored as if they have
1303 * already been sent. skb_mstamp_ns isn't set to
1304 * avoid wrong rtt estimation.
1307 TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
1310 /* Try to append data to the end of skb. */
1311 if (copy > msg_data_left(msg))
1312 copy = msg_data_left(msg);
1314 /* Where to copy to? */
1315 if (skb_availroom(skb) > 0 && !zc) {
1316 /* We have some space in skb head. Superb! */
1317 copy = min_t(int, copy, skb_availroom(skb));
1318 err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy);
1323 int i = skb_shinfo(skb)->nr_frags;
1324 struct page_frag *pfrag = sk_page_frag(sk);
1326 if (!sk_page_frag_refill(sk, pfrag))
1327 goto wait_for_memory;
1329 if (!skb_can_coalesce(skb, i, pfrag->page,
1331 if (i >= sysctl_max_skb_frags) {
1332 tcp_mark_push(tp, skb);
1338 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1340 if (!sk_wmem_schedule(sk, copy))
1341 goto wait_for_memory;
1343 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
1350 /* Update the skb. */
1352 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1354 skb_fill_page_desc(skb, i, pfrag->page,
1355 pfrag->offset, copy);
1356 page_ref_inc(pfrag->page);
1358 pfrag->offset += copy;
1360 err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
1361 if (err == -EMSGSIZE || err == -EEXIST) {
1362 tcp_mark_push(tp, skb);
1371 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1373 WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
1374 TCP_SKB_CB(skb)->end_seq += copy;
1375 tcp_skb_pcount_set(skb, 0);
1378 if (!msg_data_left(msg)) {
1379 if (unlikely(flags & MSG_EOR))
1380 TCP_SKB_CB(skb)->eor = 1;
1384 if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
1387 if (forced_push(tp)) {
1388 tcp_mark_push(tp, skb);
1389 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1390 } else if (skb == tcp_send_head(sk))
1391 tcp_push_one(sk, mss_now);
1395 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1398 tcp_push(sk, flags & ~MSG_MORE, mss_now,
1399 TCP_NAGLE_PUSH, size_goal);
1401 err = sk_stream_wait_memory(sk, &timeo);
1405 mss_now = tcp_send_mss(sk, &size_goal, flags);
1410 tcp_tx_timestamp(sk, sockc.tsflags);
1411 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1414 sock_zerocopy_put(uarg);
1415 return copied + copied_syn;
1418 skb = tcp_write_queue_tail(sk);
1420 tcp_remove_empty_skb(sk, skb);
1422 if (copied + copied_syn)
1425 sock_zerocopy_put_abort(uarg, true);
1426 err = sk_stream_error(sk, flags, err);
1427 /* make sure we wake any epoll edge trigger waiter */
1428 if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) {
1429 sk->sk_write_space(sk);
1430 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
1434 EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1436 int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
1441 ret = tcp_sendmsg_locked(sk, msg, size);
1446 EXPORT_SYMBOL(tcp_sendmsg);
1449 * Handle reading urgent data. BSD has very simple semantics for
1450 * this, no blocking and very strange errors 8)
1453 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1455 struct tcp_sock *tp = tcp_sk(sk);
1457 /* No URG data to read. */
1458 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1459 tp->urg_data == TCP_URG_READ)
1460 return -EINVAL; /* Yes this is right ! */
1462 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1465 if (tp->urg_data & TCP_URG_VALID) {
1467 char c = tp->urg_data;
1469 if (!(flags & MSG_PEEK))
1470 tp->urg_data = TCP_URG_READ;
1472 /* Read urgent data. */
1473 msg->msg_flags |= MSG_OOB;
1476 if (!(flags & MSG_TRUNC))
1477 err = memcpy_to_msg(msg, &c, 1);
1480 msg->msg_flags |= MSG_TRUNC;
1482 return err ? -EFAULT : len;
1485 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1488 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1489 * the available implementations agree in this case:
1490 * this call should never block, independent of the
1491 * blocking state of the socket.
1492 * Mike <pall@rz.uni-karlsruhe.de>
1497 static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
1499 struct sk_buff *skb;
1500 int copied = 0, err = 0;
1502 /* XXX -- need to support SO_PEEK_OFF */
1504 skb_rbtree_walk(skb, &sk->tcp_rtx_queue) {
1505 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
1511 skb_queue_walk(&sk->sk_write_queue, skb) {
1512 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
1519 return err ?: copied;
1522 /* Clean up the receive buffer for full frames taken by the user,
1523 * then send an ACK if necessary. COPIED is the number of bytes
1524 * tcp_recvmsg has given to the user so far, it speeds up the
1525 * calculation of whether or not we must ACK for the sake of
1528 static void tcp_cleanup_rbuf(struct sock *sk, int copied)
1530 struct tcp_sock *tp = tcp_sk(sk);
1531 bool time_to_ack = false;
1533 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1535 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1536 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1537 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1539 if (inet_csk_ack_scheduled(sk)) {
1540 const struct inet_connection_sock *icsk = inet_csk(sk);
1541 /* Delayed ACKs frequently hit locked sockets during bulk
1543 if (icsk->icsk_ack.blocked ||
1544 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1545 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1547 * If this read emptied read buffer, we send ACK, if
1548 * connection is not bidirectional, user drained
1549 * receive buffer and there was a small segment
1553 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1554 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1555 !inet_csk_in_pingpong_mode(sk))) &&
1556 !atomic_read(&sk->sk_rmem_alloc)))
1560 /* We send an ACK if we can now advertise a non-zero window
1561 * which has been raised "significantly".
1563 * Even if window raised up to infinity, do not send window open ACK
1564 * in states, where we will not receive more. It is useless.
1566 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1567 __u32 rcv_window_now = tcp_receive_window(tp);
1569 /* Optimize, __tcp_select_window() is not cheap. */
1570 if (2*rcv_window_now <= tp->window_clamp) {
1571 __u32 new_window = __tcp_select_window(sk);
1573 /* Send ACK now, if this read freed lots of space
1574 * in our buffer. Certainly, new_window is new window.
1575 * We can advertise it now, if it is not less than current one.
1576 * "Lots" means "at least twice" here.
1578 if (new_window && new_window >= 2 * rcv_window_now)
1586 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1588 struct sk_buff *skb;
1591 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1592 offset = seq - TCP_SKB_CB(skb)->seq;
1593 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
1594 pr_err_once("%s: found a SYN, please report !\n", __func__);
1597 if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
1601 /* This looks weird, but this can happen if TCP collapsing
1602 * splitted a fat GRO packet, while we released socket lock
1603 * in skb_splice_bits()
1605 sk_eat_skb(sk, skb);
1611 * This routine provides an alternative to tcp_recvmsg() for routines
1612 * that would like to handle copying from skbuffs directly in 'sendfile'
1615 * - It is assumed that the socket was locked by the caller.
1616 * - The routine does not block.
1617 * - At present, there is no support for reading OOB data
1618 * or for 'peeking' the socket using this routine
1619 * (although both would be easy to implement).
1621 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1622 sk_read_actor_t recv_actor)
1624 struct sk_buff *skb;
1625 struct tcp_sock *tp = tcp_sk(sk);
1626 u32 seq = tp->copied_seq;
1630 if (sk->sk_state == TCP_LISTEN)
1632 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1633 if (offset < skb->len) {
1637 len = skb->len - offset;
1638 /* Stop reading if we hit a patch of urgent data */
1640 u32 urg_offset = tp->urg_seq - seq;
1641 if (urg_offset < len)
1646 used = recv_actor(desc, skb, offset, len);
1651 } else if (used <= len) {
1656 /* If recv_actor drops the lock (e.g. TCP splice
1657 * receive) the skb pointer might be invalid when
1658 * getting here: tcp_collapse might have deleted it
1659 * while aggregating skbs from the socket queue.
1661 skb = tcp_recv_skb(sk, seq - 1, &offset);
1664 /* TCP coalescing might have appended data to the skb.
1665 * Try to splice more frags
1667 if (offset + 1 != skb->len)
1670 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
1671 sk_eat_skb(sk, skb);
1675 sk_eat_skb(sk, skb);
1678 WRITE_ONCE(tp->copied_seq, seq);
1680 WRITE_ONCE(tp->copied_seq, seq);
1682 tcp_rcv_space_adjust(sk);
1684 /* Clean up data we have read: This will do ACK frames. */
1686 tcp_recv_skb(sk, seq, &offset);
1687 tcp_cleanup_rbuf(sk, copied);
1691 EXPORT_SYMBOL(tcp_read_sock);
1693 int tcp_peek_len(struct socket *sock)
1695 return tcp_inq(sock->sk);
1697 EXPORT_SYMBOL(tcp_peek_len);
1699 /* Make sure sk_rcvbuf is big enough to satisfy SO_RCVLOWAT hint */
1700 int tcp_set_rcvlowat(struct sock *sk, int val)
1704 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
1705 cap = sk->sk_rcvbuf >> 1;
1707 cap = sock_net(sk)->ipv4.sysctl_tcp_rmem[2] >> 1;
1708 val = min(val, cap);
1709 WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1711 /* Check if we need to signal EPOLLIN right now */
1714 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
1718 if (val > sk->sk_rcvbuf) {
1719 WRITE_ONCE(sk->sk_rcvbuf, val);
1720 tcp_sk(sk)->window_clamp = tcp_win_from_space(sk, val);
1724 EXPORT_SYMBOL(tcp_set_rcvlowat);
1727 static const struct vm_operations_struct tcp_vm_ops = {
1730 int tcp_mmap(struct file *file, struct socket *sock,
1731 struct vm_area_struct *vma)
1733 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
1735 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
1737 /* Instruct vm_insert_page() to not mmap_read_lock(mm) */
1738 vma->vm_flags |= VM_MIXEDMAP;
1740 vma->vm_ops = &tcp_vm_ops;
1743 EXPORT_SYMBOL(tcp_mmap);
1745 static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma,
1746 struct page **pages,
1747 unsigned long pages_to_map,
1748 unsigned long *insert_addr,
1749 u32 *length_with_pending,
1751 struct tcp_zerocopy_receive *zc)
1753 unsigned long pages_remaining = pages_to_map;
1757 ret = vm_insert_pages(vma, *insert_addr, pages, &pages_remaining);
1758 bytes_mapped = PAGE_SIZE * (pages_to_map - pages_remaining);
1759 /* Even if vm_insert_pages fails, it may have partially succeeded in
1760 * mapping (some but not all of the pages).
1762 *seq += bytes_mapped;
1763 *insert_addr += bytes_mapped;
1765 /* But if vm_insert_pages did fail, we have to unroll some state
1766 * we speculatively touched before.
1768 const int bytes_not_mapped = PAGE_SIZE * pages_remaining;
1769 *length_with_pending -= bytes_not_mapped;
1770 zc->recv_skip_hint += bytes_not_mapped;
1775 static int tcp_zerocopy_receive(struct sock *sk,
1776 struct tcp_zerocopy_receive *zc)
1778 unsigned long address = (unsigned long)zc->address;
1779 u32 length = 0, seq, offset, zap_len;
1780 #define PAGE_BATCH_SIZE 8
1781 struct page *pages[PAGE_BATCH_SIZE];
1782 const skb_frag_t *frags = NULL;
1783 struct vm_area_struct *vma;
1784 struct sk_buff *skb = NULL;
1785 unsigned long pg_idx = 0;
1786 unsigned long curr_addr;
1787 struct tcp_sock *tp;
1791 if (address & (PAGE_SIZE - 1) || address != zc->address)
1794 if (sk->sk_state == TCP_LISTEN)
1797 sock_rps_record_flow(sk);
1801 mmap_read_lock(current->mm);
1803 vma = find_vma(current->mm, address);
1804 if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops) {
1805 mmap_read_unlock(current->mm);
1808 zc->length = min_t(unsigned long, zc->length, vma->vm_end - address);
1810 seq = tp->copied_seq;
1812 zc->length = min_t(u32, zc->length, inq);
1813 zap_len = zc->length & ~(PAGE_SIZE - 1);
1815 zap_page_range(vma, address, zap_len);
1816 zc->recv_skip_hint = 0;
1818 zc->recv_skip_hint = zc->length;
1821 curr_addr = address;
1822 while (length + PAGE_SIZE <= zc->length) {
1823 if (zc->recv_skip_hint < PAGE_SIZE) {
1824 /* If we're here, finish the current batch. */
1826 ret = tcp_zerocopy_vm_insert_batch(vma, pages,
1836 if (zc->recv_skip_hint > 0)
1839 offset = seq - TCP_SKB_CB(skb)->seq;
1841 skb = tcp_recv_skb(sk, seq, &offset);
1843 zc->recv_skip_hint = skb->len - offset;
1844 offset -= skb_headlen(skb);
1845 if ((int)offset < 0 || skb_has_frag_list(skb))
1847 frags = skb_shinfo(skb)->frags;
1849 if (skb_frag_size(frags) > offset)
1851 offset -= skb_frag_size(frags);
1855 if (skb_frag_size(frags) != PAGE_SIZE || skb_frag_off(frags)) {
1856 int remaining = zc->recv_skip_hint;
1858 while (remaining && (skb_frag_size(frags) != PAGE_SIZE ||
1859 skb_frag_off(frags))) {
1860 remaining -= skb_frag_size(frags);
1863 zc->recv_skip_hint -= remaining;
1866 pages[pg_idx] = skb_frag_page(frags);
1868 length += PAGE_SIZE;
1869 zc->recv_skip_hint -= PAGE_SIZE;
1871 if (pg_idx == PAGE_BATCH_SIZE) {
1872 ret = tcp_zerocopy_vm_insert_batch(vma, pages, pg_idx,
1873 &curr_addr, &length,
1881 ret = tcp_zerocopy_vm_insert_batch(vma, pages, pg_idx,
1882 &curr_addr, &length, &seq,
1886 mmap_read_unlock(current->mm);
1888 WRITE_ONCE(tp->copied_seq, seq);
1889 tcp_rcv_space_adjust(sk);
1891 /* Clean up data we have read: This will do ACK frames. */
1892 tcp_recv_skb(sk, seq, &offset);
1893 tcp_cleanup_rbuf(sk, length);
1895 if (length == zc->length)
1896 zc->recv_skip_hint = 0;
1898 if (!zc->recv_skip_hint && sock_flag(sk, SOCK_DONE))
1901 zc->length = length;
1906 static void tcp_update_recv_tstamps(struct sk_buff *skb,
1907 struct scm_timestamping_internal *tss)
1910 tss->ts[0] = ktime_to_timespec64(skb->tstamp);
1912 tss->ts[0] = (struct timespec64) {0};
1914 if (skb_hwtstamps(skb)->hwtstamp)
1915 tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp);
1917 tss->ts[2] = (struct timespec64) {0};
1920 /* Similar to __sock_recv_timestamp, but does not require an skb */
1921 static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
1922 struct scm_timestamping_internal *tss)
1924 int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
1925 bool has_timestamping = false;
1927 if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) {
1928 if (sock_flag(sk, SOCK_RCVTSTAMP)) {
1929 if (sock_flag(sk, SOCK_RCVTSTAMPNS)) {
1931 struct __kernel_timespec kts = {
1932 .tv_sec = tss->ts[0].tv_sec,
1933 .tv_nsec = tss->ts[0].tv_nsec,
1935 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
1938 struct __kernel_old_timespec ts_old = {
1939 .tv_sec = tss->ts[0].tv_sec,
1940 .tv_nsec = tss->ts[0].tv_nsec,
1942 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
1943 sizeof(ts_old), &ts_old);
1947 struct __kernel_sock_timeval stv = {
1948 .tv_sec = tss->ts[0].tv_sec,
1949 .tv_usec = tss->ts[0].tv_nsec / 1000,
1951 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
1954 struct __kernel_old_timeval tv = {
1955 .tv_sec = tss->ts[0].tv_sec,
1956 .tv_usec = tss->ts[0].tv_nsec / 1000,
1958 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
1964 if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE)
1965 has_timestamping = true;
1967 tss->ts[0] = (struct timespec64) {0};
1970 if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
1971 if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)
1972 has_timestamping = true;
1974 tss->ts[2] = (struct timespec64) {0};
1977 if (has_timestamping) {
1978 tss->ts[1] = (struct timespec64) {0};
1979 if (sock_flag(sk, SOCK_TSTAMP_NEW))
1980 put_cmsg_scm_timestamping64(msg, tss);
1982 put_cmsg_scm_timestamping(msg, tss);
1986 static int tcp_inq_hint(struct sock *sk)
1988 const struct tcp_sock *tp = tcp_sk(sk);
1989 u32 copied_seq = READ_ONCE(tp->copied_seq);
1990 u32 rcv_nxt = READ_ONCE(tp->rcv_nxt);
1993 inq = rcv_nxt - copied_seq;
1994 if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) {
1996 inq = tp->rcv_nxt - tp->copied_seq;
1999 /* After receiving a FIN, tell the user-space to continue reading
2000 * by returning a non-zero inq.
2002 if (inq == 0 && sock_flag(sk, SOCK_DONE))
2008 * This routine copies from a sock struct into the user buffer.
2010 * Technical note: in 2.3 we work on _locked_ socket, so that
2011 * tricks with *seq access order and skb->users are not required.
2012 * Probably, code can be easily improved even more.
2015 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
2016 int flags, int *addr_len)
2018 struct tcp_sock *tp = tcp_sk(sk);
2024 int target; /* Read at least this many bytes */
2026 struct sk_buff *skb, *last;
2028 struct scm_timestamping_internal tss;
2031 if (unlikely(flags & MSG_ERRQUEUE))
2032 return inet_recv_error(sk, msg, len, addr_len);
2034 if (sk_can_busy_loop(sk) && skb_queue_empty_lockless(&sk->sk_receive_queue) &&
2035 (sk->sk_state == TCP_ESTABLISHED))
2036 sk_busy_loop(sk, nonblock);
2041 if (sk->sk_state == TCP_LISTEN)
2044 cmsg_flags = tp->recvmsg_inq ? 1 : 0;
2045 timeo = sock_rcvtimeo(sk, nonblock);
2047 /* Urgent data needs to be handled specially. */
2048 if (flags & MSG_OOB)
2051 if (unlikely(tp->repair)) {
2053 if (!(flags & MSG_PEEK))
2056 if (tp->repair_queue == TCP_SEND_QUEUE)
2060 if (tp->repair_queue == TCP_NO_QUEUE)
2063 /* 'common' recv queue MSG_PEEK-ing */
2066 seq = &tp->copied_seq;
2067 if (flags & MSG_PEEK) {
2068 peek_seq = tp->copied_seq;
2072 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2077 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
2078 if (tp->urg_data && tp->urg_seq == *seq) {
2081 if (signal_pending(current)) {
2082 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
2087 /* Next get a buffer. */
2089 last = skb_peek_tail(&sk->sk_receive_queue);
2090 skb_queue_walk(&sk->sk_receive_queue, skb) {
2092 /* Now that we have two receive queues this
2095 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
2096 "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n",
2097 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
2101 offset = *seq - TCP_SKB_CB(skb)->seq;
2102 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
2103 pr_err_once("%s: found a SYN, please report !\n", __func__);
2106 if (offset < skb->len)
2108 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2110 WARN(!(flags & MSG_PEEK),
2111 "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n",
2112 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
2115 /* Well, if we have backlog, try to process it now yet. */
2117 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
2122 sk->sk_state == TCP_CLOSE ||
2123 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2125 signal_pending(current))
2128 if (sock_flag(sk, SOCK_DONE))
2132 copied = sock_error(sk);
2136 if (sk->sk_shutdown & RCV_SHUTDOWN)
2139 if (sk->sk_state == TCP_CLOSE) {
2140 /* This occurs when user tries to read
2141 * from never connected socket.
2152 if (signal_pending(current)) {
2153 copied = sock_intr_errno(timeo);
2158 tcp_cleanup_rbuf(sk, copied);
2160 if (copied >= target) {
2161 /* Do not sleep, just process backlog. */
2165 sk_wait_data(sk, &timeo, last);
2168 if ((flags & MSG_PEEK) &&
2169 (peek_seq - copied - urg_hole != tp->copied_seq)) {
2170 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
2172 task_pid_nr(current));
2173 peek_seq = tp->copied_seq;
2178 /* Ok so how much can we use? */
2179 used = skb->len - offset;
2183 /* Do we have urgent data here? */
2185 u32 urg_offset = tp->urg_seq - *seq;
2186 if (urg_offset < used) {
2188 if (!sock_flag(sk, SOCK_URGINLINE)) {
2189 WRITE_ONCE(*seq, *seq + 1);
2201 if (!(flags & MSG_TRUNC)) {
2202 err = skb_copy_datagram_msg(skb, offset, msg, used);
2204 /* Exception. Bailout! */
2211 WRITE_ONCE(*seq, *seq + used);
2215 tcp_rcv_space_adjust(sk);
2218 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
2220 tcp_fast_path_check(sk);
2223 if (TCP_SKB_CB(skb)->has_rxtstamp) {
2224 tcp_update_recv_tstamps(skb, &tss);
2228 if (used + offset < skb->len)
2231 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2233 if (!(flags & MSG_PEEK))
2234 sk_eat_skb(sk, skb);
2238 /* Process the FIN. */
2239 WRITE_ONCE(*seq, *seq + 1);
2240 if (!(flags & MSG_PEEK))
2241 sk_eat_skb(sk, skb);
2245 /* According to UNIX98, msg_name/msg_namelen are ignored
2246 * on connected socket. I was just happy when found this 8) --ANK
2249 /* Clean up data we have read: This will do ACK frames. */
2250 tcp_cleanup_rbuf(sk, copied);
2256 tcp_recv_timestamp(msg, sk, &tss);
2257 if (cmsg_flags & 1) {
2258 inq = tcp_inq_hint(sk);
2259 put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq);
2270 err = tcp_recv_urg(sk, msg, len, flags);
2274 err = tcp_peek_sndq(sk, msg, len);
2277 EXPORT_SYMBOL(tcp_recvmsg);
2279 void tcp_set_state(struct sock *sk, int state)
2281 int oldstate = sk->sk_state;
2283 /* We defined a new enum for TCP states that are exported in BPF
2284 * so as not force the internal TCP states to be frozen. The
2285 * following checks will detect if an internal state value ever
2286 * differs from the BPF value. If this ever happens, then we will
2287 * need to remap the internal value to the BPF value before calling
2288 * tcp_call_bpf_2arg.
2290 BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED);
2291 BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT);
2292 BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV);
2293 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1);
2294 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2);
2295 BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT);
2296 BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE);
2297 BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT);
2298 BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK);
2299 BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN);
2300 BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING);
2301 BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV);
2302 BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES);
2304 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG))
2305 tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state);
2308 case TCP_ESTABLISHED:
2309 if (oldstate != TCP_ESTABLISHED)
2310 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2314 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
2315 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
2317 sk->sk_prot->unhash(sk);
2318 if (inet_csk(sk)->icsk_bind_hash &&
2319 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2323 if (oldstate == TCP_ESTABLISHED)
2324 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2327 /* Change state AFTER socket is unhashed to avoid closed
2328 * socket sitting in hash tables.
2330 inet_sk_state_store(sk, state);
2332 EXPORT_SYMBOL_GPL(tcp_set_state);
2335 * State processing on a close. This implements the state shift for
2336 * sending our FIN frame. Note that we only send a FIN for some
2337 * states. A shutdown() may have already sent the FIN, or we may be
2341 static const unsigned char new_state[16] = {
2342 /* current state: new state: action: */
2343 [0 /* (Invalid) */] = TCP_CLOSE,
2344 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2345 [TCP_SYN_SENT] = TCP_CLOSE,
2346 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2347 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
2348 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
2349 [TCP_TIME_WAIT] = TCP_CLOSE,
2350 [TCP_CLOSE] = TCP_CLOSE,
2351 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
2352 [TCP_LAST_ACK] = TCP_LAST_ACK,
2353 [TCP_LISTEN] = TCP_CLOSE,
2354 [TCP_CLOSING] = TCP_CLOSING,
2355 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
2358 static int tcp_close_state(struct sock *sk)
2360 int next = (int)new_state[sk->sk_state];
2361 int ns = next & TCP_STATE_MASK;
2363 tcp_set_state(sk, ns);
2365 return next & TCP_ACTION_FIN;
2369 * Shutdown the sending side of a connection. Much like close except
2370 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
2373 void tcp_shutdown(struct sock *sk, int how)
2375 /* We need to grab some memory, and put together a FIN,
2376 * and then put it into the queue to be sent.
2377 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
2379 if (!(how & SEND_SHUTDOWN))
2382 /* If we've already sent a FIN, or it's a closed state, skip this. */
2383 if ((1 << sk->sk_state) &
2384 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
2385 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
2386 /* Clear out any half completed packets. FIN if needed. */
2387 if (tcp_close_state(sk))
2391 EXPORT_SYMBOL(tcp_shutdown);
2393 bool tcp_check_oom(struct sock *sk, int shift)
2395 bool too_many_orphans, out_of_socket_memory;
2397 too_many_orphans = tcp_too_many_orphans(sk, shift);
2398 out_of_socket_memory = tcp_out_of_memory(sk);
2400 if (too_many_orphans)
2401 net_info_ratelimited("too many orphaned sockets\n");
2402 if (out_of_socket_memory)
2403 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2404 return too_many_orphans || out_of_socket_memory;
2407 void tcp_close(struct sock *sk, long timeout)
2409 struct sk_buff *skb;
2410 int data_was_unread = 0;
2414 sk->sk_shutdown = SHUTDOWN_MASK;
2416 if (sk->sk_state == TCP_LISTEN) {
2417 tcp_set_state(sk, TCP_CLOSE);
2420 inet_csk_listen_stop(sk);
2422 goto adjudge_to_death;
2425 /* We need to flush the recv. buffs. We do this only on the
2426 * descriptor close, not protocol-sourced closes, because the
2427 * reader process may not have drained the data yet!
2429 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
2430 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq;
2432 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2434 data_was_unread += len;
2440 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2441 if (sk->sk_state == TCP_CLOSE)
2442 goto adjudge_to_death;
2444 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2445 * data was lost. To witness the awful effects of the old behavior of
2446 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2447 * GET in an FTP client, suspend the process, wait for the client to
2448 * advertise a zero window, then kill -9 the FTP client, wheee...
2449 * Note: timeout is always zero in such a case.
2451 if (unlikely(tcp_sk(sk)->repair)) {
2452 sk->sk_prot->disconnect(sk, 0);
2453 } else if (data_was_unread) {
2454 /* Unread data was tossed, zap the connection. */
2455 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
2456 tcp_set_state(sk, TCP_CLOSE);
2457 tcp_send_active_reset(sk, sk->sk_allocation);
2458 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
2459 /* Check zero linger _after_ checking for unread data. */
2460 sk->sk_prot->disconnect(sk, 0);
2461 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
2462 } else if (tcp_close_state(sk)) {
2463 /* We FIN if the application ate all the data before
2464 * zapping the connection.
2467 /* RED-PEN. Formally speaking, we have broken TCP state
2468 * machine. State transitions:
2470 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2471 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2472 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2474 * are legal only when FIN has been sent (i.e. in window),
2475 * rather than queued out of window. Purists blame.
2477 * F.e. "RFC state" is ESTABLISHED,
2478 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2480 * The visible declinations are that sometimes
2481 * we enter time-wait state, when it is not required really
2482 * (harmless), do not send active resets, when they are
2483 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2484 * they look as CLOSING or LAST_ACK for Linux)
2485 * Probably, I missed some more holelets.
2487 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2488 * in a single packet! (May consider it later but will
2489 * probably need API support or TCP_CORK SYN-ACK until
2490 * data is written and socket is closed.)
2495 sk_stream_wait_close(sk, timeout);
2498 state = sk->sk_state;
2504 /* remove backlog if any, without releasing ownership. */
2507 percpu_counter_inc(sk->sk_prot->orphan_count);
2509 /* Have we already been destroyed by a softirq or backlog? */
2510 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
2513 /* This is a (useful) BSD violating of the RFC. There is a
2514 * problem with TCP as specified in that the other end could
2515 * keep a socket open forever with no application left this end.
2516 * We use a 1 minute timeout (about the same as BSD) then kill
2517 * our end. If they send after that then tough - BUT: long enough
2518 * that we won't make the old 4*rto = almost no time - whoops
2521 * Nope, it was not mistake. It is really desired behaviour
2522 * f.e. on http servers, when such sockets are useless, but
2523 * consume significant resources. Let's do it with special
2524 * linger2 option. --ANK
2527 if (sk->sk_state == TCP_FIN_WAIT2) {
2528 struct tcp_sock *tp = tcp_sk(sk);
2529 if (tp->linger2 < 0) {
2530 tcp_set_state(sk, TCP_CLOSE);
2531 tcp_send_active_reset(sk, GFP_ATOMIC);
2532 __NET_INC_STATS(sock_net(sk),
2533 LINUX_MIB_TCPABORTONLINGER);
2535 const int tmo = tcp_fin_time(sk);
2537 if (tmo > TCP_TIMEWAIT_LEN) {
2538 inet_csk_reset_keepalive_timer(sk,
2539 tmo - TCP_TIMEWAIT_LEN);
2541 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2546 if (sk->sk_state != TCP_CLOSE) {
2548 if (tcp_check_oom(sk, 0)) {
2549 tcp_set_state(sk, TCP_CLOSE);
2550 tcp_send_active_reset(sk, GFP_ATOMIC);
2551 __NET_INC_STATS(sock_net(sk),
2552 LINUX_MIB_TCPABORTONMEMORY);
2553 } else if (!check_net(sock_net(sk))) {
2554 /* Not possible to send reset; just close */
2555 tcp_set_state(sk, TCP_CLOSE);
2559 if (sk->sk_state == TCP_CLOSE) {
2560 struct request_sock *req;
2562 req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk,
2563 lockdep_sock_is_held(sk));
2564 /* We could get here with a non-NULL req if the socket is
2565 * aborted (e.g., closed with unread data) before 3WHS
2569 reqsk_fastopen_remove(sk, req, false);
2570 inet_csk_destroy_sock(sk);
2572 /* Otherwise, socket is reprieved until protocol close. */
2580 EXPORT_SYMBOL(tcp_close);
2582 /* These states need RST on ABORT according to RFC793 */
2584 static inline bool tcp_need_reset(int state)
2586 return (1 << state) &
2587 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2588 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2591 static void tcp_rtx_queue_purge(struct sock *sk)
2593 struct rb_node *p = rb_first(&sk->tcp_rtx_queue);
2595 tcp_sk(sk)->highest_sack = NULL;
2597 struct sk_buff *skb = rb_to_skb(p);
2600 /* Since we are deleting whole queue, no need to
2601 * list_del(&skb->tcp_tsorted_anchor)
2603 tcp_rtx_queue_unlink(skb, sk);
2604 sk_wmem_free_skb(sk, skb);
2608 void tcp_write_queue_purge(struct sock *sk)
2610 struct sk_buff *skb;
2612 tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
2613 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
2614 tcp_skb_tsorted_anchor_cleanup(skb);
2615 sk_wmem_free_skb(sk, skb);
2617 tcp_rtx_queue_purge(sk);
2618 skb = sk->sk_tx_skb_cache;
2621 sk->sk_tx_skb_cache = NULL;
2623 INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
2625 tcp_clear_all_retrans_hints(tcp_sk(sk));
2626 tcp_sk(sk)->packets_out = 0;
2627 inet_csk(sk)->icsk_backoff = 0;
2630 int tcp_disconnect(struct sock *sk, int flags)
2632 struct inet_sock *inet = inet_sk(sk);
2633 struct inet_connection_sock *icsk = inet_csk(sk);
2634 struct tcp_sock *tp = tcp_sk(sk);
2635 int old_state = sk->sk_state;
2638 if (old_state != TCP_CLOSE)
2639 tcp_set_state(sk, TCP_CLOSE);
2641 /* ABORT function of RFC793 */
2642 if (old_state == TCP_LISTEN) {
2643 inet_csk_listen_stop(sk);
2644 } else if (unlikely(tp->repair)) {
2645 sk->sk_err = ECONNABORTED;
2646 } else if (tcp_need_reset(old_state) ||
2647 (tp->snd_nxt != tp->write_seq &&
2648 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2649 /* The last check adjusts for discrepancy of Linux wrt. RFC
2652 tcp_send_active_reset(sk, gfp_any());
2653 sk->sk_err = ECONNRESET;
2654 } else if (old_state == TCP_SYN_SENT)
2655 sk->sk_err = ECONNRESET;
2657 tcp_clear_xmit_timers(sk);
2658 __skb_queue_purge(&sk->sk_receive_queue);
2659 if (sk->sk_rx_skb_cache) {
2660 __kfree_skb(sk->sk_rx_skb_cache);
2661 sk->sk_rx_skb_cache = NULL;
2663 WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
2665 tcp_write_queue_purge(sk);
2666 tcp_fastopen_active_disable_ofo_check(sk);
2667 skb_rbtree_purge(&tp->out_of_order_queue);
2669 inet->inet_dport = 0;
2671 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2672 inet_reset_saddr(sk);
2674 sk->sk_shutdown = 0;
2675 sock_reset_flag(sk, SOCK_DONE);
2677 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
2678 tp->rcv_rtt_last_tsecr = 0;
2680 seq = tp->write_seq + tp->max_window + 2;
2683 WRITE_ONCE(tp->write_seq, seq);
2685 icsk->icsk_backoff = 0;
2686 icsk->icsk_probes_out = 0;
2687 icsk->icsk_rto = TCP_TIMEOUT_INIT;
2688 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2689 tp->snd_cwnd = TCP_INIT_CWND;
2690 tp->snd_cwnd_cnt = 0;
2691 tp->window_clamp = 0;
2693 tp->delivered_ce = 0;
2694 if (icsk->icsk_ca_ops->release)
2695 icsk->icsk_ca_ops->release(sk);
2696 memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
2697 tcp_set_ca_state(sk, TCP_CA_Open);
2698 tp->is_sack_reneg = 0;
2699 tcp_clear_retrans(tp);
2700 tp->total_retrans = 0;
2701 inet_csk_delack_init(sk);
2702 /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0
2703 * issue in __tcp_select_window()
2705 icsk->icsk_ack.rcv_mss = TCP_MIN_MSS;
2706 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2708 dst_release(sk->sk_rx_dst);
2709 sk->sk_rx_dst = NULL;
2710 tcp_saved_syn_free(tp);
2711 tp->compressed_ack = 0;
2715 tp->bytes_acked = 0;
2716 tp->bytes_received = 0;
2717 tp->bytes_retrans = 0;
2718 tp->data_segs_in = 0;
2719 tp->data_segs_out = 0;
2720 tp->duplicate_sack[0].start_seq = 0;
2721 tp->duplicate_sack[0].end_seq = 0;
2724 tp->retrans_out = 0;
2726 tp->tlp_high_seq = 0;
2727 tp->last_oow_ack_time = 0;
2728 /* There's a bubble in the pipe until at least the first ACK. */
2729 tp->app_limited = ~0U;
2730 tp->rack.mstamp = 0;
2731 tp->rack.advanced = 0;
2732 tp->rack.reo_wnd_steps = 1;
2733 tp->rack.last_delivered = 0;
2734 tp->rack.reo_wnd_persist = 0;
2735 tp->rack.dsack_seen = 0;
2736 tp->syn_data_acked = 0;
2737 tp->rx_opt.saw_tstamp = 0;
2738 tp->rx_opt.dsack = 0;
2739 tp->rx_opt.num_sacks = 0;
2740 tp->rcv_ooopack = 0;
2743 /* Clean up fastopen related fields */
2744 tcp_free_fastopen_req(tp);
2745 inet->defer_connect = 0;
2746 tp->fastopen_client_fail = 0;
2748 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2750 if (sk->sk_frag.page) {
2751 put_page(sk->sk_frag.page);
2752 sk->sk_frag.page = NULL;
2753 sk->sk_frag.offset = 0;
2756 sk->sk_error_report(sk);
2759 EXPORT_SYMBOL(tcp_disconnect);
2761 static inline bool tcp_can_repair_sock(const struct sock *sk)
2763 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2764 (sk->sk_state != TCP_LISTEN);
2767 static int tcp_repair_set_window(struct tcp_sock *tp, sockptr_t optbuf, int len)
2769 struct tcp_repair_window opt;
2774 if (len != sizeof(opt))
2777 if (copy_from_sockptr(&opt, optbuf, sizeof(opt)))
2780 if (opt.max_window < opt.snd_wnd)
2783 if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd))
2786 if (after(opt.rcv_wup, tp->rcv_nxt))
2789 tp->snd_wl1 = opt.snd_wl1;
2790 tp->snd_wnd = opt.snd_wnd;
2791 tp->max_window = opt.max_window;
2793 tp->rcv_wnd = opt.rcv_wnd;
2794 tp->rcv_wup = opt.rcv_wup;
2799 static int tcp_repair_options_est(struct sock *sk, sockptr_t optbuf,
2802 struct tcp_sock *tp = tcp_sk(sk);
2803 struct tcp_repair_opt opt;
2806 while (len >= sizeof(opt)) {
2807 if (copy_from_sockptr_offset(&opt, optbuf, offset, sizeof(opt)))
2810 offset += sizeof(opt);
2813 switch (opt.opt_code) {
2815 tp->rx_opt.mss_clamp = opt.opt_val;
2820 u16 snd_wscale = opt.opt_val & 0xFFFF;
2821 u16 rcv_wscale = opt.opt_val >> 16;
2823 if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2826 tp->rx_opt.snd_wscale = snd_wscale;
2827 tp->rx_opt.rcv_wscale = rcv_wscale;
2828 tp->rx_opt.wscale_ok = 1;
2831 case TCPOPT_SACK_PERM:
2832 if (opt.opt_val != 0)
2835 tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
2837 case TCPOPT_TIMESTAMP:
2838 if (opt.opt_val != 0)
2841 tp->rx_opt.tstamp_ok = 1;
2849 DEFINE_STATIC_KEY_FALSE(tcp_tx_delay_enabled);
2850 EXPORT_SYMBOL(tcp_tx_delay_enabled);
2852 static void tcp_enable_tx_delay(void)
2854 if (!static_branch_unlikely(&tcp_tx_delay_enabled)) {
2855 static int __tcp_tx_delay_enabled = 0;
2857 if (cmpxchg(&__tcp_tx_delay_enabled, 0, 1) == 0) {
2858 static_branch_enable(&tcp_tx_delay_enabled);
2859 pr_info("TCP_TX_DELAY enabled\n");
2864 /* When set indicates to always queue non-full frames. Later the user clears
2865 * this option and we transmit any pending partial frames in the queue. This is
2866 * meant to be used alongside sendfile() to get properly filled frames when the
2867 * user (for example) must write out headers with a write() call first and then
2868 * use sendfile to send out the data parts.
2870 * TCP_CORK can be set together with TCP_NODELAY and it is stronger than
2873 static void __tcp_sock_set_cork(struct sock *sk, bool on)
2875 struct tcp_sock *tp = tcp_sk(sk);
2878 tp->nonagle |= TCP_NAGLE_CORK;
2880 tp->nonagle &= ~TCP_NAGLE_CORK;
2881 if (tp->nonagle & TCP_NAGLE_OFF)
2882 tp->nonagle |= TCP_NAGLE_PUSH;
2883 tcp_push_pending_frames(sk);
2887 void tcp_sock_set_cork(struct sock *sk, bool on)
2890 __tcp_sock_set_cork(sk, on);
2893 EXPORT_SYMBOL(tcp_sock_set_cork);
2895 /* TCP_NODELAY is weaker than TCP_CORK, so that this option on corked socket is
2896 * remembered, but it is not activated until cork is cleared.
2898 * However, when TCP_NODELAY is set we make an explicit push, which overrides
2899 * even TCP_CORK for currently queued segments.
2901 static void __tcp_sock_set_nodelay(struct sock *sk, bool on)
2904 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2905 tcp_push_pending_frames(sk);
2907 tcp_sk(sk)->nonagle &= ~TCP_NAGLE_OFF;
2911 void tcp_sock_set_nodelay(struct sock *sk)
2914 __tcp_sock_set_nodelay(sk, true);
2917 EXPORT_SYMBOL(tcp_sock_set_nodelay);
2919 static void __tcp_sock_set_quickack(struct sock *sk, int val)
2922 inet_csk_enter_pingpong_mode(sk);
2926 inet_csk_exit_pingpong_mode(sk);
2927 if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2928 inet_csk_ack_scheduled(sk)) {
2929 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_PUSHED;
2930 tcp_cleanup_rbuf(sk, 1);
2932 inet_csk_enter_pingpong_mode(sk);
2936 void tcp_sock_set_quickack(struct sock *sk, int val)
2939 __tcp_sock_set_quickack(sk, val);
2942 EXPORT_SYMBOL(tcp_sock_set_quickack);
2944 int tcp_sock_set_syncnt(struct sock *sk, int val)
2946 if (val < 1 || val > MAX_TCP_SYNCNT)
2950 inet_csk(sk)->icsk_syn_retries = val;
2954 EXPORT_SYMBOL(tcp_sock_set_syncnt);
2956 void tcp_sock_set_user_timeout(struct sock *sk, u32 val)
2959 inet_csk(sk)->icsk_user_timeout = val;
2962 EXPORT_SYMBOL(tcp_sock_set_user_timeout);
2964 int tcp_sock_set_keepidle_locked(struct sock *sk, int val)
2966 struct tcp_sock *tp = tcp_sk(sk);
2968 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2971 tp->keepalive_time = val * HZ;
2972 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2973 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
2974 u32 elapsed = keepalive_time_elapsed(tp);
2976 if (tp->keepalive_time > elapsed)
2977 elapsed = tp->keepalive_time - elapsed;
2980 inet_csk_reset_keepalive_timer(sk, elapsed);
2986 int tcp_sock_set_keepidle(struct sock *sk, int val)
2991 err = tcp_sock_set_keepidle_locked(sk, val);
2995 EXPORT_SYMBOL(tcp_sock_set_keepidle);
2997 int tcp_sock_set_keepintvl(struct sock *sk, int val)
2999 if (val < 1 || val > MAX_TCP_KEEPINTVL)
3003 tcp_sk(sk)->keepalive_intvl = val * HZ;
3007 EXPORT_SYMBOL(tcp_sock_set_keepintvl);
3009 int tcp_sock_set_keepcnt(struct sock *sk, int val)
3011 if (val < 1 || val > MAX_TCP_KEEPCNT)
3015 tcp_sk(sk)->keepalive_probes = val;
3019 EXPORT_SYMBOL(tcp_sock_set_keepcnt);
3022 * Socket option code for TCP.
3024 static int do_tcp_setsockopt(struct sock *sk, int level, int optname,
3025 sockptr_t optval, unsigned int optlen)
3027 struct tcp_sock *tp = tcp_sk(sk);
3028 struct inet_connection_sock *icsk = inet_csk(sk);
3029 struct net *net = sock_net(sk);
3033 /* These are data/string values, all the others are ints */
3035 case TCP_CONGESTION: {
3036 char name[TCP_CA_NAME_MAX];
3041 val = strncpy_from_sockptr(name, optval,
3042 min_t(long, TCP_CA_NAME_MAX-1, optlen));
3048 err = tcp_set_congestion_control(sk, name, true, true,
3049 ns_capable(sock_net(sk)->user_ns,
3055 char name[TCP_ULP_NAME_MAX];
3060 val = strncpy_from_sockptr(name, optval,
3061 min_t(long, TCP_ULP_NAME_MAX - 1,
3068 err = tcp_set_ulp(sk, name);
3072 case TCP_FASTOPEN_KEY: {
3073 __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH];
3074 __u8 *backup_key = NULL;
3076 /* Allow a backup key as well to facilitate key rotation
3077 * First key is the active one.
3079 if (optlen != TCP_FASTOPEN_KEY_LENGTH &&
3080 optlen != TCP_FASTOPEN_KEY_BUF_LENGTH)
3083 if (copy_from_sockptr(key, optval, optlen))
3086 if (optlen == TCP_FASTOPEN_KEY_BUF_LENGTH)
3087 backup_key = key + TCP_FASTOPEN_KEY_LENGTH;
3089 return tcp_fastopen_reset_cipher(net, sk, key, backup_key);
3096 if (optlen < sizeof(int))
3099 if (copy_from_sockptr(&val, optval, sizeof(val)))
3106 /* Values greater than interface MTU won't take effect. However
3107 * at the point when this call is done we typically don't yet
3108 * know which interface is going to be used
3110 if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
3114 tp->rx_opt.user_mss = val;
3118 __tcp_sock_set_nodelay(sk, val);
3121 case TCP_THIN_LINEAR_TIMEOUTS:
3122 if (val < 0 || val > 1)
3128 case TCP_THIN_DUPACK:
3129 if (val < 0 || val > 1)
3134 if (!tcp_can_repair_sock(sk))
3136 else if (val == TCP_REPAIR_ON) {
3138 sk->sk_reuse = SK_FORCE_REUSE;
3139 tp->repair_queue = TCP_NO_QUEUE;
3140 } else if (val == TCP_REPAIR_OFF) {
3142 sk->sk_reuse = SK_NO_REUSE;
3143 tcp_send_window_probe(sk);
3144 } else if (val == TCP_REPAIR_OFF_NO_WP) {
3146 sk->sk_reuse = SK_NO_REUSE;
3152 case TCP_REPAIR_QUEUE:
3155 else if ((unsigned int)val < TCP_QUEUES_NR)
3156 tp->repair_queue = val;
3162 if (sk->sk_state != TCP_CLOSE)
3164 else if (tp->repair_queue == TCP_SEND_QUEUE)
3165 WRITE_ONCE(tp->write_seq, val);
3166 else if (tp->repair_queue == TCP_RECV_QUEUE) {
3167 WRITE_ONCE(tp->rcv_nxt, val);
3168 WRITE_ONCE(tp->copied_seq, val);
3174 case TCP_REPAIR_OPTIONS:
3177 else if (sk->sk_state == TCP_ESTABLISHED)
3178 err = tcp_repair_options_est(sk, optval, optlen);
3184 __tcp_sock_set_cork(sk, val);
3188 err = tcp_sock_set_keepidle_locked(sk, val);
3191 if (val < 1 || val > MAX_TCP_KEEPINTVL)
3194 tp->keepalive_intvl = val * HZ;
3197 if (val < 1 || val > MAX_TCP_KEEPCNT)
3200 tp->keepalive_probes = val;
3203 if (val < 1 || val > MAX_TCP_SYNCNT)
3206 icsk->icsk_syn_retries = val;
3210 if (val < 0 || val > 1)
3219 else if (val > TCP_FIN_TIMEOUT_MAX / HZ)
3220 tp->linger2 = TCP_FIN_TIMEOUT_MAX;
3222 tp->linger2 = val * HZ;
3225 case TCP_DEFER_ACCEPT:
3226 /* Translate value in seconds to number of retransmits */
3227 icsk->icsk_accept_queue.rskq_defer_accept =
3228 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
3232 case TCP_WINDOW_CLAMP:
3234 if (sk->sk_state != TCP_CLOSE) {
3238 tp->window_clamp = 0;
3240 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
3241 SOCK_MIN_RCVBUF / 2 : val;
3245 __tcp_sock_set_quickack(sk, val);
3248 #ifdef CONFIG_TCP_MD5SIG
3250 case TCP_MD5SIG_EXT:
3251 err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
3254 case TCP_USER_TIMEOUT:
3255 /* Cap the max time in ms TCP will retry or probe the window
3256 * before giving up and aborting (ETIMEDOUT) a connection.
3261 icsk->icsk_user_timeout = val;
3265 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
3267 tcp_fastopen_init_key_once(net);
3269 fastopen_queue_tune(sk, val);
3274 case TCP_FASTOPEN_CONNECT:
3275 if (val > 1 || val < 0) {
3277 } else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
3278 if (sk->sk_state == TCP_CLOSE)
3279 tp->fastopen_connect = val;
3286 case TCP_FASTOPEN_NO_COOKIE:
3287 if (val > 1 || val < 0)
3289 else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
3292 tp->fastopen_no_cookie = val;
3298 tp->tsoffset = val - tcp_time_stamp_raw();
3300 case TCP_REPAIR_WINDOW:
3301 err = tcp_repair_set_window(tp, optval, optlen);
3303 case TCP_NOTSENT_LOWAT:
3304 tp->notsent_lowat = val;
3305 sk->sk_write_space(sk);
3308 if (val > 1 || val < 0)
3311 tp->recvmsg_inq = val;
3315 tcp_enable_tx_delay();
3316 tp->tcp_tx_delay = val;
3327 int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
3328 unsigned int optlen)
3330 const struct inet_connection_sock *icsk = inet_csk(sk);
3332 if (level != SOL_TCP)
3333 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
3335 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
3337 EXPORT_SYMBOL(tcp_setsockopt);
3339 static void tcp_get_info_chrono_stats(const struct tcp_sock *tp,
3340 struct tcp_info *info)
3342 u64 stats[__TCP_CHRONO_MAX], total = 0;
3345 for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) {
3346 stats[i] = tp->chrono_stat[i - 1];
3347 if (i == tp->chrono_type)
3348 stats[i] += tcp_jiffies32 - tp->chrono_start;
3349 stats[i] *= USEC_PER_SEC / HZ;
3353 info->tcpi_busy_time = total;
3354 info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED];
3355 info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED];
3358 /* Return information about state of tcp endpoint in API format. */
3359 void tcp_get_info(struct sock *sk, struct tcp_info *info)
3361 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
3362 const struct inet_connection_sock *icsk = inet_csk(sk);
3368 memset(info, 0, sizeof(*info));
3369 if (sk->sk_type != SOCK_STREAM)
3372 info->tcpi_state = inet_sk_state_load(sk);
3374 /* Report meaningful fields for all TCP states, including listeners */
3375 rate = READ_ONCE(sk->sk_pacing_rate);
3376 rate64 = (rate != ~0UL) ? rate : ~0ULL;
3377 info->tcpi_pacing_rate = rate64;
3379 rate = READ_ONCE(sk->sk_max_pacing_rate);
3380 rate64 = (rate != ~0UL) ? rate : ~0ULL;
3381 info->tcpi_max_pacing_rate = rate64;
3383 info->tcpi_reordering = tp->reordering;
3384 info->tcpi_snd_cwnd = tp->snd_cwnd;
3386 if (info->tcpi_state == TCP_LISTEN) {
3387 /* listeners aliased fields :
3388 * tcpi_unacked -> Number of children ready for accept()
3389 * tcpi_sacked -> max backlog
3391 info->tcpi_unacked = READ_ONCE(sk->sk_ack_backlog);
3392 info->tcpi_sacked = READ_ONCE(sk->sk_max_ack_backlog);
3396 slow = lock_sock_fast(sk);
3398 info->tcpi_ca_state = icsk->icsk_ca_state;
3399 info->tcpi_retransmits = icsk->icsk_retransmits;
3400 info->tcpi_probes = icsk->icsk_probes_out;
3401 info->tcpi_backoff = icsk->icsk_backoff;
3403 if (tp->rx_opt.tstamp_ok)
3404 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
3405 if (tcp_is_sack(tp))
3406 info->tcpi_options |= TCPI_OPT_SACK;
3407 if (tp->rx_opt.wscale_ok) {
3408 info->tcpi_options |= TCPI_OPT_WSCALE;
3409 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
3410 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
3413 if (tp->ecn_flags & TCP_ECN_OK)
3414 info->tcpi_options |= TCPI_OPT_ECN;
3415 if (tp->ecn_flags & TCP_ECN_SEEN)
3416 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
3417 if (tp->syn_data_acked)
3418 info->tcpi_options |= TCPI_OPT_SYN_DATA;
3420 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
3421 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
3422 info->tcpi_snd_mss = tp->mss_cache;
3423 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
3425 info->tcpi_unacked = tp->packets_out;
3426 info->tcpi_sacked = tp->sacked_out;
3428 info->tcpi_lost = tp->lost_out;
3429 info->tcpi_retrans = tp->retrans_out;
3431 now = tcp_jiffies32;
3432 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
3433 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
3434 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
3436 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
3437 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
3438 info->tcpi_rtt = tp->srtt_us >> 3;
3439 info->tcpi_rttvar = tp->mdev_us >> 2;
3440 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
3441 info->tcpi_advmss = tp->advmss;
3443 info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
3444 info->tcpi_rcv_space = tp->rcvq_space.space;
3446 info->tcpi_total_retrans = tp->total_retrans;
3448 info->tcpi_bytes_acked = tp->bytes_acked;
3449 info->tcpi_bytes_received = tp->bytes_received;
3450 info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
3451 tcp_get_info_chrono_stats(tp, info);
3453 info->tcpi_segs_out = tp->segs_out;
3454 info->tcpi_segs_in = tp->segs_in;
3456 info->tcpi_min_rtt = tcp_min_rtt(tp);
3457 info->tcpi_data_segs_in = tp->data_segs_in;
3458 info->tcpi_data_segs_out = tp->data_segs_out;
3460 info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
3461 rate64 = tcp_compute_delivery_rate(tp);
3463 info->tcpi_delivery_rate = rate64;
3464 info->tcpi_delivered = tp->delivered;
3465 info->tcpi_delivered_ce = tp->delivered_ce;
3466 info->tcpi_bytes_sent = tp->bytes_sent;
3467 info->tcpi_bytes_retrans = tp->bytes_retrans;
3468 info->tcpi_dsack_dups = tp->dsack_dups;
3469 info->tcpi_reord_seen = tp->reord_seen;
3470 info->tcpi_rcv_ooopack = tp->rcv_ooopack;
3471 info->tcpi_snd_wnd = tp->snd_wnd;
3472 info->tcpi_fastopen_client_fail = tp->fastopen_client_fail;
3473 unlock_sock_fast(sk, slow);
3475 EXPORT_SYMBOL_GPL(tcp_get_info);
3477 static size_t tcp_opt_stats_get_size(void)
3480 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BUSY */
3481 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_RWND_LIMITED */
3482 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_SNDBUF_LIMITED */
3483 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DATA_SEGS_OUT */
3484 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_TOTAL_RETRANS */
3485 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_PACING_RATE */
3486 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DELIVERY_RATE */
3487 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_CWND */
3488 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORDERING */
3489 nla_total_size(sizeof(u32)) + /* TCP_NLA_MIN_RTT */
3490 nla_total_size(sizeof(u8)) + /* TCP_NLA_RECUR_RETRANS */
3491 nla_total_size(sizeof(u8)) + /* TCP_NLA_DELIVERY_RATE_APP_LMT */
3492 nla_total_size(sizeof(u32)) + /* TCP_NLA_SNDQ_SIZE */
3493 nla_total_size(sizeof(u8)) + /* TCP_NLA_CA_STATE */
3494 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_SSTHRESH */
3495 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED */
3496 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */
3497 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */
3498 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */
3499 nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */
3500 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */
3501 nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */
3502 nla_total_size(sizeof(u16)) + /* TCP_NLA_TIMEOUT_REHASH */
3503 nla_total_size(sizeof(u32)) + /* TCP_NLA_BYTES_NOTSENT */
3504 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_EDT */
3508 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
3509 const struct sk_buff *orig_skb)
3511 const struct tcp_sock *tp = tcp_sk(sk);
3512 struct sk_buff *stats;
3513 struct tcp_info info;
3517 stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC);
3521 tcp_get_info_chrono_stats(tp, &info);
3522 nla_put_u64_64bit(stats, TCP_NLA_BUSY,
3523 info.tcpi_busy_time, TCP_NLA_PAD);
3524 nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED,
3525 info.tcpi_rwnd_limited, TCP_NLA_PAD);
3526 nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED,
3527 info.tcpi_sndbuf_limited, TCP_NLA_PAD);
3528 nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT,
3529 tp->data_segs_out, TCP_NLA_PAD);
3530 nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS,
3531 tp->total_retrans, TCP_NLA_PAD);
3533 rate = READ_ONCE(sk->sk_pacing_rate);
3534 rate64 = (rate != ~0UL) ? rate : ~0ULL;
3535 nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD);
3537 rate64 = tcp_compute_delivery_rate(tp);
3538 nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD);
3540 nla_put_u32(stats, TCP_NLA_SND_CWND, tp->snd_cwnd);
3541 nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering);
3542 nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp));
3544 nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits);
3545 nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited);
3546 nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh);
3547 nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered);
3548 nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce);
3550 nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
3551 nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state);
3553 nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent,
3555 nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans,
3557 nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups);
3558 nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen);
3559 nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3);
3560 nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash);
3561 nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT,
3562 max_t(int, 0, tp->write_seq - tp->snd_nxt));
3563 nla_put_u64_64bit(stats, TCP_NLA_EDT, orig_skb->skb_mstamp_ns,
3569 static int do_tcp_getsockopt(struct sock *sk, int level,
3570 int optname, char __user *optval, int __user *optlen)
3572 struct inet_connection_sock *icsk = inet_csk(sk);
3573 struct tcp_sock *tp = tcp_sk(sk);
3574 struct net *net = sock_net(sk);
3577 if (get_user(len, optlen))
3580 len = min_t(unsigned int, len, sizeof(int));
3587 val = tp->mss_cache;
3588 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
3589 val = tp->rx_opt.user_mss;
3591 val = tp->rx_opt.mss_clamp;
3594 val = !!(tp->nonagle&TCP_NAGLE_OFF);
3597 val = !!(tp->nonagle&TCP_NAGLE_CORK);
3600 val = keepalive_time_when(tp) / HZ;
3603 val = keepalive_intvl_when(tp) / HZ;
3606 val = keepalive_probes(tp);
3609 val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
3614 val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
3616 case TCP_DEFER_ACCEPT:
3617 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
3618 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
3620 case TCP_WINDOW_CLAMP:
3621 val = tp->window_clamp;
3624 struct tcp_info info;
3626 if (get_user(len, optlen))
3629 tcp_get_info(sk, &info);
3631 len = min_t(unsigned int, len, sizeof(info));
3632 if (put_user(len, optlen))
3634 if (copy_to_user(optval, &info, len))
3639 const struct tcp_congestion_ops *ca_ops;
3640 union tcp_cc_info info;
3644 if (get_user(len, optlen))
3647 ca_ops = icsk->icsk_ca_ops;
3648 if (ca_ops && ca_ops->get_info)
3649 sz = ca_ops->get_info(sk, ~0U, &attr, &info);
3651 len = min_t(unsigned int, len, sz);
3652 if (put_user(len, optlen))
3654 if (copy_to_user(optval, &info, len))
3659 val = !inet_csk_in_pingpong_mode(sk);
3662 case TCP_CONGESTION:
3663 if (get_user(len, optlen))
3665 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
3666 if (put_user(len, optlen))
3668 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3673 if (get_user(len, optlen))
3675 len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3676 if (!icsk->icsk_ulp_ops) {
3677 if (put_user(0, optlen))
3681 if (put_user(len, optlen))
3683 if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
3687 case TCP_FASTOPEN_KEY: {
3688 __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH];
3689 struct tcp_fastopen_context *ctx;
3690 unsigned int key_len = 0;
3692 if (get_user(len, optlen))
3696 ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx);
3698 key_len = tcp_fastopen_context_len(ctx) *
3699 TCP_FASTOPEN_KEY_LENGTH;
3700 memcpy(&key[0], &ctx->key[0], key_len);
3704 len = min_t(unsigned int, len, key_len);
3705 if (put_user(len, optlen))
3707 if (copy_to_user(optval, key, len))
3711 case TCP_THIN_LINEAR_TIMEOUTS:
3715 case TCP_THIN_DUPACK:
3723 case TCP_REPAIR_QUEUE:
3725 val = tp->repair_queue;
3730 case TCP_REPAIR_WINDOW: {
3731 struct tcp_repair_window opt;
3733 if (get_user(len, optlen))
3736 if (len != sizeof(opt))
3742 opt.snd_wl1 = tp->snd_wl1;
3743 opt.snd_wnd = tp->snd_wnd;
3744 opt.max_window = tp->max_window;
3745 opt.rcv_wnd = tp->rcv_wnd;
3746 opt.rcv_wup = tp->rcv_wup;
3748 if (copy_to_user(optval, &opt, len))
3753 if (tp->repair_queue == TCP_SEND_QUEUE)
3754 val = tp->write_seq;
3755 else if (tp->repair_queue == TCP_RECV_QUEUE)
3761 case TCP_USER_TIMEOUT:
3762 val = icsk->icsk_user_timeout;
3766 val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3769 case TCP_FASTOPEN_CONNECT:
3770 val = tp->fastopen_connect;
3773 case TCP_FASTOPEN_NO_COOKIE:
3774 val = tp->fastopen_no_cookie;
3778 val = tp->tcp_tx_delay;
3782 val = tcp_time_stamp_raw() + tp->tsoffset;
3784 case TCP_NOTSENT_LOWAT:
3785 val = tp->notsent_lowat;
3788 val = tp->recvmsg_inq;
3793 case TCP_SAVED_SYN: {
3794 if (get_user(len, optlen))
3798 if (tp->saved_syn) {
3799 if (len < tp->saved_syn[0]) {
3800 if (put_user(tp->saved_syn[0], optlen)) {
3807 len = tp->saved_syn[0];
3808 if (put_user(len, optlen)) {
3812 if (copy_to_user(optval, tp->saved_syn + 1, len)) {
3816 tcp_saved_syn_free(tp);
3821 if (put_user(len, optlen))
3827 case TCP_ZEROCOPY_RECEIVE: {
3828 struct tcp_zerocopy_receive zc;
3831 if (get_user(len, optlen))
3833 if (len < offsetofend(struct tcp_zerocopy_receive, length))
3835 if (len > sizeof(zc)) {
3837 if (put_user(len, optlen))
3840 if (copy_from_user(&zc, optval, len))
3843 err = tcp_zerocopy_receive(sk, &zc);
3845 if (len == sizeof(zc))
3846 goto zerocopy_rcv_sk_err;
3848 case offsetofend(struct tcp_zerocopy_receive, err):
3849 goto zerocopy_rcv_sk_err;
3850 case offsetofend(struct tcp_zerocopy_receive, inq):
3851 goto zerocopy_rcv_inq;
3852 case offsetofend(struct tcp_zerocopy_receive, length):
3854 goto zerocopy_rcv_out;
3856 zerocopy_rcv_sk_err:
3858 zc.err = sock_error(sk);
3860 zc.inq = tcp_inq_hint(sk);
3862 if (!err && copy_to_user(optval, &zc, len))
3868 return -ENOPROTOOPT;
3871 if (put_user(len, optlen))
3873 if (copy_to_user(optval, &val, len))
3878 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
3881 struct inet_connection_sock *icsk = inet_csk(sk);
3883 if (level != SOL_TCP)
3884 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
3886 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
3888 EXPORT_SYMBOL(tcp_getsockopt);
3890 #ifdef CONFIG_TCP_MD5SIG
3891 static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3892 static DEFINE_MUTEX(tcp_md5sig_mutex);
3893 static bool tcp_md5sig_pool_populated = false;
3895 static void __tcp_alloc_md5sig_pool(void)
3897 struct crypto_ahash *hash;
3900 hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3904 for_each_possible_cpu(cpu) {
3905 void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
3906 struct ahash_request *req;
3909 scratch = kmalloc_node(sizeof(union tcp_md5sum_block) +
3910 sizeof(struct tcphdr),
3915 per_cpu(tcp_md5sig_pool, cpu).scratch = scratch;
3917 if (per_cpu(tcp_md5sig_pool, cpu).md5_req)
3920 req = ahash_request_alloc(hash, GFP_KERNEL);
3924 ahash_request_set_callback(req, 0, NULL, NULL);
3926 per_cpu(tcp_md5sig_pool, cpu).md5_req = req;
3928 /* before setting tcp_md5sig_pool_populated, we must commit all writes
3929 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3932 tcp_md5sig_pool_populated = true;
3935 bool tcp_alloc_md5sig_pool(void)
3937 if (unlikely(!tcp_md5sig_pool_populated)) {
3938 mutex_lock(&tcp_md5sig_mutex);
3940 if (!tcp_md5sig_pool_populated) {
3941 __tcp_alloc_md5sig_pool();
3942 if (tcp_md5sig_pool_populated)
3943 static_branch_inc(&tcp_md5_needed);
3946 mutex_unlock(&tcp_md5sig_mutex);
3948 return tcp_md5sig_pool_populated;
3950 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
3954 * tcp_get_md5sig_pool - get md5sig_pool for this user
3956 * We use percpu structure, so if we succeed, we exit with preemption
3957 * and BH disabled, to make sure another thread or softirq handling
3958 * wont try to get same context.
3960 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
3964 if (tcp_md5sig_pool_populated) {
3965 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
3967 return this_cpu_ptr(&tcp_md5sig_pool);
3972 EXPORT_SYMBOL(tcp_get_md5sig_pool);
3974 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3975 const struct sk_buff *skb, unsigned int header_len)
3977 struct scatterlist sg;
3978 const struct tcphdr *tp = tcp_hdr(skb);
3979 struct ahash_request *req = hp->md5_req;
3981 const unsigned int head_data_len = skb_headlen(skb) > header_len ?
3982 skb_headlen(skb) - header_len : 0;
3983 const struct skb_shared_info *shi = skb_shinfo(skb);
3984 struct sk_buff *frag_iter;
3986 sg_init_table(&sg, 1);
3988 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3989 ahash_request_set_crypt(req, &sg, NULL, head_data_len);
3990 if (crypto_ahash_update(req))
3993 for (i = 0; i < shi->nr_frags; ++i) {
3994 const skb_frag_t *f = &shi->frags[i];
3995 unsigned int offset = skb_frag_off(f);
3996 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
3998 sg_set_page(&sg, page, skb_frag_size(f),
3999 offset_in_page(offset));
4000 ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
4001 if (crypto_ahash_update(req))
4005 skb_walk_frags(skb, frag_iter)
4006 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
4011 EXPORT_SYMBOL(tcp_md5_hash_skb_data);
4013 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
4015 u8 keylen = READ_ONCE(key->keylen); /* paired with WRITE_ONCE() in tcp_md5_do_add */
4016 struct scatterlist sg;
4018 sg_init_one(&sg, key->key, keylen);
4019 ahash_request_set_crypt(hp->md5_req, &sg, NULL, keylen);
4021 /* We use data_race() because tcp_md5_do_add() might change key->key under us */
4022 return data_race(crypto_ahash_update(hp->md5_req));
4024 EXPORT_SYMBOL(tcp_md5_hash_key);
4028 void tcp_done(struct sock *sk)
4030 struct request_sock *req;
4032 /* We might be called with a new socket, after
4033 * inet_csk_prepare_forced_close() has been called
4034 * so we can not use lockdep_sock_is_held(sk)
4036 req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, 1);
4038 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
4039 TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
4041 tcp_set_state(sk, TCP_CLOSE);
4042 tcp_clear_xmit_timers(sk);
4044 reqsk_fastopen_remove(sk, req, false);
4046 sk->sk_shutdown = SHUTDOWN_MASK;
4048 if (!sock_flag(sk, SOCK_DEAD))
4049 sk->sk_state_change(sk);
4051 inet_csk_destroy_sock(sk);
4053 EXPORT_SYMBOL_GPL(tcp_done);
4055 int tcp_abort(struct sock *sk, int err)
4057 if (!sk_fullsock(sk)) {
4058 if (sk->sk_state == TCP_NEW_SYN_RECV) {
4059 struct request_sock *req = inet_reqsk(sk);
4062 inet_csk_reqsk_queue_drop(req->rsk_listener, req);
4069 /* Don't race with userspace socket closes such as tcp_close. */
4072 if (sk->sk_state == TCP_LISTEN) {
4073 tcp_set_state(sk, TCP_CLOSE);
4074 inet_csk_listen_stop(sk);
4077 /* Don't race with BH socket closes such as inet_csk_listen_stop. */
4081 if (!sock_flag(sk, SOCK_DEAD)) {
4083 /* This barrier is coupled with smp_rmb() in tcp_poll() */
4085 sk->sk_error_report(sk);
4086 if (tcp_need_reset(sk->sk_state))
4087 tcp_send_active_reset(sk, GFP_ATOMIC);
4093 tcp_write_queue_purge(sk);
4097 EXPORT_SYMBOL_GPL(tcp_abort);
4099 extern struct tcp_congestion_ops tcp_reno;
4101 static __initdata unsigned long thash_entries;
4102 static int __init set_thash_entries(char *str)
4109 ret = kstrtoul(str, 0, &thash_entries);
4115 __setup("thash_entries=", set_thash_entries);
4117 static void __init tcp_init_mem(void)
4119 unsigned long limit = nr_free_buffer_pages() / 16;
4121 limit = max(limit, 128UL);
4122 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */
4123 sysctl_tcp_mem[1] = limit; /* 6.25 % */
4124 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */
4127 void __init tcp_init(void)
4129 int max_rshare, max_wshare, cnt;
4130 unsigned long limit;
4133 BUILD_BUG_ON(TCP_MIN_SND_MSS <= MAX_TCP_OPTION_SPACE);
4134 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
4135 sizeof_field(struct sk_buff, cb));
4137 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
4138 percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
4139 inet_hashinfo_init(&tcp_hashinfo);
4140 inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash",
4141 thash_entries, 21, /* one slot per 2 MB*/
4143 tcp_hashinfo.bind_bucket_cachep =
4144 kmem_cache_create("tcp_bind_bucket",
4145 sizeof(struct inet_bind_bucket), 0,
4146 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
4148 /* Size and allocate the main established and bind bucket
4151 * The methodology is similar to that of the buffer cache.
4153 tcp_hashinfo.ehash =
4154 alloc_large_system_hash("TCP established",
4155 sizeof(struct inet_ehash_bucket),
4157 17, /* one slot per 128 KB of memory */
4160 &tcp_hashinfo.ehash_mask,
4162 thash_entries ? 0 : 512 * 1024);
4163 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
4164 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
4166 if (inet_ehash_locks_alloc(&tcp_hashinfo))
4167 panic("TCP: failed to alloc ehash_locks");
4168 tcp_hashinfo.bhash =
4169 alloc_large_system_hash("TCP bind",
4170 sizeof(struct inet_bind_hashbucket),
4171 tcp_hashinfo.ehash_mask + 1,
4172 17, /* one slot per 128 KB of memory */
4174 &tcp_hashinfo.bhash_size,
4178 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
4179 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
4180 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
4181 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
4185 cnt = tcp_hashinfo.ehash_mask + 1;
4186 sysctl_tcp_max_orphans = cnt / 2;
4189 /* Set per-socket limits to no more than 1/128 the pressure threshold */
4190 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
4191 max_wshare = min(4UL*1024*1024, limit);
4192 max_rshare = min(6UL*1024*1024, limit);
4194 init_net.ipv4.sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
4195 init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024;
4196 init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
4198 init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
4199 init_net.ipv4.sysctl_tcp_rmem[1] = 131072;
4200 init_net.ipv4.sysctl_tcp_rmem[2] = max(131072, max_rshare);
4202 pr_info("Hash tables configured (established %u bind %u)\n",
4203 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
4207 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
projects / linux-2.6-microblaze.git / blob