2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Implementation of the Transmission Control Protocol(TCP).
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Mark Evans, <evansmp@uhura.aston.ac.uk>
11 * Corey Minyard <wf-rch!minyard@relay.EU.net>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
14 * Linus Torvalds, <torvalds@cs.helsinki.fi>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Matthew Dillon, <dillon@apollo.west.oic.com>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Jorge Cwik, <jorge@laser.satlink.net>
21 * Alan Cox : Numerous verify_area() calls
22 * Alan Cox : Set the ACK bit on a reset
23 * Alan Cox : Stopped it crashing if it closed while
24 * sk->inuse=1 and was trying to connect
26 * Alan Cox : All icmp error handling was broken
27 * pointers passed where wrong and the
28 * socket was looked up backwards. Nobody
29 * tested any icmp error code obviously.
30 * Alan Cox : tcp_err() now handled properly. It
31 * wakes people on errors. poll
32 * behaves and the icmp error race
33 * has gone by moving it into sock.c
34 * Alan Cox : tcp_send_reset() fixed to work for
35 * everything not just packets for
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
40 * Herp Rosmanith : More reset fixes
41 * Alan Cox : No longer acks invalid rst frames.
42 * Acking any kind of RST is right out.
43 * Alan Cox : Sets an ignore me flag on an rst
44 * receive otherwise odd bits of prattle
46 * Alan Cox : Fixed another acking RST frame bug.
47 * Should stop LAN workplace lockups.
48 * Alan Cox : Some tidyups using the new skb list
50 * Alan Cox : sk->keepopen now seems to work
51 * Alan Cox : Pulls options out correctly on accepts
52 * Alan Cox : Fixed assorted sk->rqueue->next errors
53 * Alan Cox : PSH doesn't end a TCP read. Switched a
55 * Alan Cox : Tidied tcp_data to avoid a potential
57 * Alan Cox : Added some better commenting, as the
58 * tcp is hard to follow
59 * Alan Cox : Removed incorrect check for 20 * psh
60 * Michael O'Reilly : ack < copied bug fix.
61 * Johannes Stille : Misc tcp fixes (not all in yet).
62 * Alan Cox : FIN with no memory -> CRASH
63 * Alan Cox : Added socket option proto entries.
64 * Also added awareness of them to accept.
65 * Alan Cox : Added TCP options (SOL_TCP)
66 * Alan Cox : Switched wakeup calls to callbacks,
67 * so the kernel can layer network
69 * Alan Cox : Use ip_tos/ip_ttl settings.
70 * Alan Cox : Handle FIN (more) properly (we hope).
71 * Alan Cox : RST frames sent on unsynchronised
73 * Alan Cox : Put in missing check for SYN bit.
74 * Alan Cox : Added tcp_select_window() aka NET2E
75 * window non shrink trick.
76 * Alan Cox : Added a couple of small NET2E timer
78 * Charles Hedrick : TCP fixes
79 * Toomas Tamm : TCP window fixes
80 * Alan Cox : Small URG fix to rlogin ^C ack fight
81 * Charles Hedrick : Rewrote most of it to actually work
82 * Linus : Rewrote tcp_read() and URG handling
84 * Gerhard Koerting: Fixed some missing timer handling
85 * Matthew Dillon : Reworked TCP machine states as per RFC
86 * Gerhard Koerting: PC/TCP workarounds
87 * Adam Caldwell : Assorted timer/timing errors
88 * Matthew Dillon : Fixed another RST bug
89 * Alan Cox : Move to kernel side addressing changes.
90 * Alan Cox : Beginning work on TCP fastpathing
92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
93 * Alan Cox : TCP fast path debugging
94 * Alan Cox : Window clamping
95 * Michael Riepe : Bug in tcp_check()
96 * Matt Dillon : More TCP improvements and RST bug fixes
97 * Matt Dillon : Yet more small nasties remove from the
98 * TCP code (Be very nice to this man if
99 * tcp finally works 100%) 8)
100 * Alan Cox : BSD accept semantics.
101 * Alan Cox : Reset on closedown bug.
102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
103 * Michael Pall : Handle poll() after URG properly in
105 * Michael Pall : Undo the last fix in tcp_read_urg()
106 * (multi URG PUSH broke rlogin).
107 * Michael Pall : Fix the multi URG PUSH problem in
108 * tcp_readable(), poll() after URG
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
112 * Alan Cox : Changed the semantics of sk->socket to
113 * fix a race and a signal problem with
114 * accept() and async I/O.
115 * Alan Cox : Relaxed the rules on tcp_sendto().
116 * Yury Shevchuk : Really fixed accept() blocking problem.
117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
118 * clients/servers which listen in on
120 * Alan Cox : Cleaned the above up and shrank it to
121 * a sensible code size.
122 * Alan Cox : Self connect lockup fix.
123 * Alan Cox : No connect to multicast.
124 * Ross Biro : Close unaccepted children on master
126 * Alan Cox : Reset tracing code.
127 * Alan Cox : Spurious resets on shutdown.
128 * Alan Cox : Giant 15 minute/60 second timer error
129 * Alan Cox : Small whoops in polling before an
131 * Alan Cox : Kept the state trace facility since
132 * it's handy for debugging.
133 * Alan Cox : More reset handler fixes.
134 * Alan Cox : Started rewriting the code based on
135 * the RFC's for other useful protocol
136 * references see: Comer, KA9Q NOS, and
137 * for a reference on the difference
138 * between specifications and how BSD
139 * works see the 4.4lite source.
140 * A.N.Kuznetsov : Don't time wait on completion of tidy
142 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
143 * Linus Torvalds : Fixed BSD port reuse to work first syn
144 * Alan Cox : Reimplemented timers as per the RFC
145 * and using multiple timers for sanity.
146 * Alan Cox : Small bug fixes, and a lot of new
148 * Alan Cox : Fixed dual reader crash by locking
149 * the buffers (much like datagram.c)
150 * Alan Cox : Fixed stuck sockets in probe. A probe
151 * now gets fed up of retrying without
152 * (even a no space) answer.
153 * Alan Cox : Extracted closing code better
154 * Alan Cox : Fixed the closing state machine to
156 * Alan Cox : More 'per spec' fixes.
157 * Jorge Cwik : Even faster checksumming.
158 * Alan Cox : tcp_data() doesn't ack illegal PSH
159 * only frames. At least one pc tcp stack
161 * Alan Cox : Cache last socket.
162 * Alan Cox : Per route irtt.
163 * Matt Day : poll()->select() match BSD precisely on error
164 * Alan Cox : New buffers
165 * Marc Tamsky : Various sk->prot->retransmits and
166 * sk->retransmits misupdating fixed.
167 * Fixed tcp_write_timeout: stuck close,
168 * and TCP syn retries gets used now.
169 * Mark Yarvis : In tcp_read_wakeup(), don't send an
170 * ack if state is TCP_CLOSED.
171 * Alan Cox : Look up device on a retransmit - routes may
172 * change. Doesn't yet cope with MSS shrink right
174 * Marc Tamsky : Closing in closing fixes.
175 * Mike Shaver : RFC1122 verifications.
176 * Alan Cox : rcv_saddr errors.
177 * Alan Cox : Block double connect().
178 * Alan Cox : Small hooks for enSKIP.
179 * Alexey Kuznetsov: Path MTU discovery.
180 * Alan Cox : Support soft errors.
181 * Alan Cox : Fix MTU discovery pathological case
182 * when the remote claims no mtu!
183 * Marc Tamsky : TCP_CLOSE fix.
184 * Colin (G3TNE) : Send a reset on syn ack replies in
185 * window but wrong (fixes NT lpd problems)
186 * Pedro Roque : Better TCP window handling, delayed ack.
187 * Joerg Reuter : No modification of locked buffers in
188 * tcp_do_retransmit()
189 * Eric Schenk : Changed receiver side silly window
190 * avoidance algorithm to BSD style
191 * algorithm. This doubles throughput
192 * against machines running Solaris,
193 * and seems to result in general
195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
196 * Willy Konynenberg : Transparent proxying support.
197 * Mike McLagan : Routing by source
198 * Keith Owens : Do proper merging with partial SKB's in
199 * tcp_do_sendmsg to avoid burstiness.
200 * Eric Schenk : Fix fast close down bug with
201 * shutdown() followed by close().
202 * Andi Kleen : Make poll agree with SIGIO
203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
204 * lingertime == 0 (RFC 793 ABORT Call)
205 * Hirokazu Takahashi : Use copy_from_user() instead of
206 * csum_and_copy_from_user() if possible.
208 * This program is free software; you can redistribute it and/or
209 * modify it under the terms of the GNU General Public License
210 * as published by the Free Software Foundation; either version
211 * 2 of the License, or(at your option) any later version.
213 * Description of States:
215 * TCP_SYN_SENT sent a connection request, waiting for ack
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
220 * TCP_ESTABLISHED connection established
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
231 * TCP_TIME_WAIT timeout to catch resent junk before entering
232 * closed, can only be entered from FIN_WAIT2
233 * or CLOSING. Required because the other end
234 * may not have gotten our last ACK causing it
235 * to retransmit the data packet (which we ignore)
237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
238 * us to finish writing our data and to shutdown
239 * (we have to close() to move on to LAST_ACK)
241 * TCP_LAST_ACK out side has shutdown after remote has
242 * shutdown. There may still be data in our
243 * buffer that we have to finish sending
245 * TCP_CLOSE socket is finished
248 #define pr_fmt(fmt) "TCP: " fmt
250 #include <linux/kernel.h>
251 #include <linux/module.h>
252 #include <linux/types.h>
253 #include <linux/fcntl.h>
254 #include <linux/poll.h>
255 #include <linux/inet_diag.h>
256 #include <linux/init.h>
257 #include <linux/fs.h>
258 #include <linux/skbuff.h>
259 #include <linux/scatterlist.h>
260 #include <linux/splice.h>
261 #include <linux/net.h>
262 #include <linux/socket.h>
263 #include <linux/random.h>
264 #include <linux/bootmem.h>
265 #include <linux/highmem.h>
266 #include <linux/swap.h>
267 #include <linux/cache.h>
268 #include <linux/err.h>
269 #include <linux/crypto.h>
270 #include <linux/time.h>
271 #include <linux/slab.h>
273 #include <net/icmp.h>
274 #include <net/inet_common.h>
276 #include <net/xfrm.h>
278 #include <net/sock.h>
280 #include <asm/uaccess.h>
281 #include <asm/ioctls.h>
282 #include <net/busy_poll.h>
284 int sysctl_tcp_fin_timeout __read_mostly
= TCP_FIN_TIMEOUT
;
286 int sysctl_tcp_min_tso_segs __read_mostly
= 2;
288 int sysctl_tcp_autocorking __read_mostly
= 1;
290 struct percpu_counter tcp_orphan_count
;
291 EXPORT_SYMBOL_GPL(tcp_orphan_count
);
293 long sysctl_tcp_mem
[3] __read_mostly
;
294 int sysctl_tcp_wmem
[3] __read_mostly
;
295 int sysctl_tcp_rmem
[3] __read_mostly
;
297 EXPORT_SYMBOL(sysctl_tcp_mem
);
298 EXPORT_SYMBOL(sysctl_tcp_rmem
);
299 EXPORT_SYMBOL(sysctl_tcp_wmem
);
301 atomic_long_t tcp_memory_allocated
; /* Current allocated memory. */
302 EXPORT_SYMBOL(tcp_memory_allocated
);
305 * Current number of TCP sockets.
307 struct percpu_counter tcp_sockets_allocated
;
308 EXPORT_SYMBOL(tcp_sockets_allocated
);
313 struct tcp_splice_state
{
314 struct pipe_inode_info
*pipe
;
320 * Pressure flag: try to collapse.
321 * Technical note: it is used by multiple contexts non atomically.
322 * All the __sk_mem_schedule() is of this nature: accounting
323 * is strict, actions are advisory and have some latency.
325 int tcp_memory_pressure __read_mostly
;
326 EXPORT_SYMBOL(tcp_memory_pressure
);
328 void tcp_enter_memory_pressure(struct sock
*sk
)
330 if (!tcp_memory_pressure
) {
331 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMEMORYPRESSURES
);
332 tcp_memory_pressure
= 1;
335 EXPORT_SYMBOL(tcp_enter_memory_pressure
);
337 /* Convert seconds to retransmits based on initial and max timeout */
338 static u8
secs_to_retrans(int seconds
, int timeout
, int rto_max
)
343 int period
= timeout
;
346 while (seconds
> period
&& res
< 255) {
349 if (timeout
> rto_max
)
357 /* Convert retransmits to seconds based on initial and max timeout */
358 static int retrans_to_secs(u8 retrans
, int timeout
, int rto_max
)
366 if (timeout
> rto_max
)
374 /* Address-family independent initialization for a tcp_sock.
376 * NOTE: A lot of things set to zero explicitly by call to
377 * sk_alloc() so need not be done here.
379 void tcp_init_sock(struct sock
*sk
)
381 struct inet_connection_sock
*icsk
= inet_csk(sk
);
382 struct tcp_sock
*tp
= tcp_sk(sk
);
384 __skb_queue_head_init(&tp
->out_of_order_queue
);
385 tcp_init_xmit_timers(sk
);
386 tcp_prequeue_init(tp
);
387 INIT_LIST_HEAD(&tp
->tsq_node
);
389 icsk
->icsk_rto
= TCP_TIMEOUT_INIT
;
390 tp
->mdev_us
= jiffies_to_usecs(TCP_TIMEOUT_INIT
);
391 tp
->rtt_min
[0].rtt
= ~0U;
393 /* So many TCP implementations out there (incorrectly) count the
394 * initial SYN frame in their delayed-ACK and congestion control
395 * algorithms that we must have the following bandaid to talk
396 * efficiently to them. -DaveM
398 tp
->snd_cwnd
= TCP_INIT_CWND
;
400 /* See draft-stevens-tcpca-spec-01 for discussion of the
401 * initialization of these values.
403 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
404 tp
->snd_cwnd_clamp
= ~0;
405 tp
->mss_cache
= TCP_MSS_DEFAULT
;
406 u64_stats_init(&tp
->syncp
);
408 tp
->reordering
= sysctl_tcp_reordering
;
409 tcp_enable_early_retrans(tp
);
410 tcp_assign_congestion_control(sk
);
414 sk
->sk_state
= TCP_CLOSE
;
416 sk
->sk_write_space
= sk_stream_write_space
;
417 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
419 icsk
->icsk_sync_mss
= tcp_sync_mss
;
421 sk
->sk_sndbuf
= sysctl_tcp_wmem
[1];
422 sk
->sk_rcvbuf
= sysctl_tcp_rmem
[1];
425 sock_update_memcg(sk
);
426 sk_sockets_allocated_inc(sk
);
429 EXPORT_SYMBOL(tcp_init_sock
);
431 static void tcp_tx_timestamp(struct sock
*sk
, struct sk_buff
*skb
)
433 if (sk
->sk_tsflags
) {
434 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
436 sock_tx_timestamp(sk
, &shinfo
->tx_flags
);
437 if (shinfo
->tx_flags
& SKBTX_ANY_TSTAMP
)
438 shinfo
->tskey
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- 1;
443 * Wait for a TCP event.
445 * Note that we don't need to lock the socket, as the upper poll layers
446 * take care of normal races (between the test and the event) and we don't
447 * go look at any of the socket buffers directly.
449 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
452 struct sock
*sk
= sock
->sk
;
453 const struct tcp_sock
*tp
= tcp_sk(sk
);
456 sock_rps_record_flow(sk
);
458 sock_poll_wait(file
, sk_sleep(sk
), wait
);
460 state
= sk_state_load(sk
);
461 if (state
== TCP_LISTEN
)
462 return inet_csk_listen_poll(sk
);
464 /* Socket is not locked. We are protected from async events
465 * by poll logic and correct handling of state changes
466 * made by other threads is impossible in any case.
472 * POLLHUP is certainly not done right. But poll() doesn't
473 * have a notion of HUP in just one direction, and for a
474 * socket the read side is more interesting.
476 * Some poll() documentation says that POLLHUP is incompatible
477 * with the POLLOUT/POLLWR flags, so somebody should check this
478 * all. But careful, it tends to be safer to return too many
479 * bits than too few, and you can easily break real applications
480 * if you don't tell them that something has hung up!
484 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
485 * our fs/select.c). It means that after we received EOF,
486 * poll always returns immediately, making impossible poll() on write()
487 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
488 * if and only if shutdown has been made in both directions.
489 * Actually, it is interesting to look how Solaris and DUX
490 * solve this dilemma. I would prefer, if POLLHUP were maskable,
491 * then we could set it on SND_SHUTDOWN. BTW examples given
492 * in Stevens' books assume exactly this behaviour, it explains
493 * why POLLHUP is incompatible with POLLOUT. --ANK
495 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
496 * blocking on fresh not-connected or disconnected socket. --ANK
498 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| state
== TCP_CLOSE
)
500 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
501 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
503 /* Connected or passive Fast Open socket? */
504 if (state
!= TCP_SYN_SENT
&&
505 (state
!= TCP_SYN_RECV
|| tp
->fastopen_rsk
)) {
506 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
508 if (tp
->urg_seq
== tp
->copied_seq
&&
509 !sock_flag(sk
, SOCK_URGINLINE
) &&
513 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
514 mask
|= POLLIN
| POLLRDNORM
;
516 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
517 if (sk_stream_is_writeable(sk
)) {
518 mask
|= POLLOUT
| POLLWRNORM
;
519 } else { /* send SIGIO later */
520 sk_set_bit(SOCKWQ_ASYNC_NOSPACE
, sk
);
521 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
523 /* Race breaker. If space is freed after
524 * wspace test but before the flags are set,
525 * IO signal will be lost. Memory barrier
526 * pairs with the input side.
528 smp_mb__after_atomic();
529 if (sk_stream_is_writeable(sk
))
530 mask
|= POLLOUT
| POLLWRNORM
;
533 mask
|= POLLOUT
| POLLWRNORM
;
535 if (tp
->urg_data
& TCP_URG_VALID
)
538 /* This barrier is coupled with smp_wmb() in tcp_reset() */
540 if (sk
->sk_err
|| !skb_queue_empty(&sk
->sk_error_queue
))
545 EXPORT_SYMBOL(tcp_poll
);
547 int tcp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
549 struct tcp_sock
*tp
= tcp_sk(sk
);
555 if (sk
->sk_state
== TCP_LISTEN
)
558 slow
= lock_sock_fast(sk
);
559 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
561 else if (sock_flag(sk
, SOCK_URGINLINE
) ||
563 before(tp
->urg_seq
, tp
->copied_seq
) ||
564 !before(tp
->urg_seq
, tp
->rcv_nxt
)) {
566 answ
= tp
->rcv_nxt
- tp
->copied_seq
;
568 /* Subtract 1, if FIN was received */
569 if (answ
&& sock_flag(sk
, SOCK_DONE
))
572 answ
= tp
->urg_seq
- tp
->copied_seq
;
573 unlock_sock_fast(sk
, slow
);
576 answ
= tp
->urg_data
&& tp
->urg_seq
== tp
->copied_seq
;
579 if (sk
->sk_state
== TCP_LISTEN
)
582 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
585 answ
= tp
->write_seq
- tp
->snd_una
;
588 if (sk
->sk_state
== TCP_LISTEN
)
591 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
594 answ
= tp
->write_seq
- tp
->snd_nxt
;
600 return put_user(answ
, (int __user
*)arg
);
602 EXPORT_SYMBOL(tcp_ioctl
);
604 static inline void tcp_mark_push(struct tcp_sock
*tp
, struct sk_buff
*skb
)
606 TCP_SKB_CB(skb
)->tcp_flags
|= TCPHDR_PSH
;
607 tp
->pushed_seq
= tp
->write_seq
;
610 static inline bool forced_push(const struct tcp_sock
*tp
)
612 return after(tp
->write_seq
, tp
->pushed_seq
+ (tp
->max_window
>> 1));
615 static void skb_entail(struct sock
*sk
, struct sk_buff
*skb
)
617 struct tcp_sock
*tp
= tcp_sk(sk
);
618 struct tcp_skb_cb
*tcb
= TCP_SKB_CB(skb
);
621 tcb
->seq
= tcb
->end_seq
= tp
->write_seq
;
622 tcb
->tcp_flags
= TCPHDR_ACK
;
624 __skb_header_release(skb
);
625 tcp_add_write_queue_tail(sk
, skb
);
626 sk
->sk_wmem_queued
+= skb
->truesize
;
627 sk_mem_charge(sk
, skb
->truesize
);
628 if (tp
->nonagle
& TCP_NAGLE_PUSH
)
629 tp
->nonagle
&= ~TCP_NAGLE_PUSH
;
631 tcp_slow_start_after_idle_check(sk
);
634 static inline void tcp_mark_urg(struct tcp_sock
*tp
, int flags
)
637 tp
->snd_up
= tp
->write_seq
;
640 /* If a not yet filled skb is pushed, do not send it if
641 * we have data packets in Qdisc or NIC queues :
642 * Because TX completion will happen shortly, it gives a chance
643 * to coalesce future sendmsg() payload into this skb, without
644 * need for a timer, and with no latency trade off.
645 * As packets containing data payload have a bigger truesize
646 * than pure acks (dataless) packets, the last checks prevent
647 * autocorking if we only have an ACK in Qdisc/NIC queues,
648 * or if TX completion was delayed after we processed ACK packet.
650 static bool tcp_should_autocork(struct sock
*sk
, struct sk_buff
*skb
,
653 return skb
->len
< size_goal
&&
654 sysctl_tcp_autocorking
&&
655 skb
!= tcp_write_queue_head(sk
) &&
656 atomic_read(&sk
->sk_wmem_alloc
) > skb
->truesize
;
659 static void tcp_push(struct sock
*sk
, int flags
, int mss_now
,
660 int nonagle
, int size_goal
)
662 struct tcp_sock
*tp
= tcp_sk(sk
);
665 if (!tcp_send_head(sk
))
668 skb
= tcp_write_queue_tail(sk
);
669 if (!(flags
& MSG_MORE
) || forced_push(tp
))
670 tcp_mark_push(tp
, skb
);
672 tcp_mark_urg(tp
, flags
);
674 if (tcp_should_autocork(sk
, skb
, size_goal
)) {
676 /* avoid atomic op if TSQ_THROTTLED bit is already set */
677 if (!test_bit(TSQ_THROTTLED
, &tp
->tsq_flags
)) {
678 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPAUTOCORKING
);
679 set_bit(TSQ_THROTTLED
, &tp
->tsq_flags
);
681 /* It is possible TX completion already happened
682 * before we set TSQ_THROTTLED.
684 if (atomic_read(&sk
->sk_wmem_alloc
) > skb
->truesize
)
688 if (flags
& MSG_MORE
)
689 nonagle
= TCP_NAGLE_CORK
;
691 __tcp_push_pending_frames(sk
, mss_now
, nonagle
);
694 static int tcp_splice_data_recv(read_descriptor_t
*rd_desc
, struct sk_buff
*skb
,
695 unsigned int offset
, size_t len
)
697 struct tcp_splice_state
*tss
= rd_desc
->arg
.data
;
700 ret
= skb_splice_bits(skb
, skb
->sk
, offset
, tss
->pipe
,
701 min(rd_desc
->count
, len
), tss
->flags
,
704 rd_desc
->count
-= ret
;
708 static int __tcp_splice_read(struct sock
*sk
, struct tcp_splice_state
*tss
)
710 /* Store TCP splice context information in read_descriptor_t. */
711 read_descriptor_t rd_desc
= {
716 return tcp_read_sock(sk
, &rd_desc
, tcp_splice_data_recv
);
720 * tcp_splice_read - splice data from TCP socket to a pipe
721 * @sock: socket to splice from
722 * @ppos: position (not valid)
723 * @pipe: pipe to splice to
724 * @len: number of bytes to splice
725 * @flags: splice modifier flags
728 * Will read pages from given socket and fill them into a pipe.
731 ssize_t
tcp_splice_read(struct socket
*sock
, loff_t
*ppos
,
732 struct pipe_inode_info
*pipe
, size_t len
,
735 struct sock
*sk
= sock
->sk
;
736 struct tcp_splice_state tss
= {
745 sock_rps_record_flow(sk
);
747 * We can't seek on a socket input
756 timeo
= sock_rcvtimeo(sk
, sock
->file
->f_flags
& O_NONBLOCK
);
758 ret
= __tcp_splice_read(sk
, &tss
);
764 if (sock_flag(sk
, SOCK_DONE
))
767 ret
= sock_error(sk
);
770 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
772 if (sk
->sk_state
== TCP_CLOSE
) {
774 * This occurs when user tries to read
775 * from never connected socket.
777 if (!sock_flag(sk
, SOCK_DONE
))
785 sk_wait_data(sk
, &timeo
, NULL
);
786 if (signal_pending(current
)) {
787 ret
= sock_intr_errno(timeo
);
800 if (sk
->sk_err
|| sk
->sk_state
== TCP_CLOSE
||
801 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
802 signal_pending(current
))
813 EXPORT_SYMBOL(tcp_splice_read
);
815 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
,
820 /* The TCP header must be at least 32-bit aligned. */
821 size
= ALIGN(size
, 4);
823 if (unlikely(tcp_under_memory_pressure(sk
)))
824 sk_mem_reclaim_partial(sk
);
826 skb
= alloc_skb_fclone(size
+ sk
->sk_prot
->max_header
, gfp
);
830 if (force_schedule
) {
831 mem_scheduled
= true;
832 sk_forced_mem_schedule(sk
, skb
->truesize
);
834 mem_scheduled
= sk_wmem_schedule(sk
, skb
->truesize
);
836 if (likely(mem_scheduled
)) {
837 skb_reserve(skb
, sk
->sk_prot
->max_header
);
839 * Make sure that we have exactly size bytes
840 * available to the caller, no more, no less.
842 skb
->reserved_tailroom
= skb
->end
- skb
->tail
- size
;
847 sk
->sk_prot
->enter_memory_pressure(sk
);
848 sk_stream_moderate_sndbuf(sk
);
853 static unsigned int tcp_xmit_size_goal(struct sock
*sk
, u32 mss_now
,
856 struct tcp_sock
*tp
= tcp_sk(sk
);
857 u32 new_size_goal
, size_goal
;
859 if (!large_allowed
|| !sk_can_gso(sk
))
862 /* Note : tcp_tso_autosize() will eventually split this later */
863 new_size_goal
= sk
->sk_gso_max_size
- 1 - MAX_TCP_HEADER
;
864 new_size_goal
= tcp_bound_to_half_wnd(tp
, new_size_goal
);
866 /* We try hard to avoid divides here */
867 size_goal
= tp
->gso_segs
* mss_now
;
868 if (unlikely(new_size_goal
< size_goal
||
869 new_size_goal
>= size_goal
+ mss_now
)) {
870 tp
->gso_segs
= min_t(u16
, new_size_goal
/ mss_now
,
871 sk
->sk_gso_max_segs
);
872 size_goal
= tp
->gso_segs
* mss_now
;
875 return max(size_goal
, mss_now
);
878 static int tcp_send_mss(struct sock
*sk
, int *size_goal
, int flags
)
882 mss_now
= tcp_current_mss(sk
);
883 *size_goal
= tcp_xmit_size_goal(sk
, mss_now
, !(flags
& MSG_OOB
));
888 static ssize_t
do_tcp_sendpages(struct sock
*sk
, struct page
*page
, int offset
,
889 size_t size
, int flags
)
891 struct tcp_sock
*tp
= tcp_sk(sk
);
892 int mss_now
, size_goal
;
895 long timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
897 /* Wait for a connection to finish. One exception is TCP Fast Open
898 * (passive side) where data is allowed to be sent before a connection
899 * is fully established.
901 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
902 !tcp_passive_fastopen(sk
)) {
903 err
= sk_stream_wait_connect(sk
, &timeo
);
908 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE
, sk
);
910 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
914 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
918 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
922 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
924 if (!sk_stream_memory_free(sk
))
925 goto wait_for_sndbuf
;
927 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
,
928 skb_queue_empty(&sk
->sk_write_queue
));
930 goto wait_for_memory
;
939 i
= skb_shinfo(skb
)->nr_frags
;
940 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
941 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
942 tcp_mark_push(tp
, skb
);
945 if (!sk_wmem_schedule(sk
, copy
))
946 goto wait_for_memory
;
949 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
952 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
954 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
957 skb
->data_len
+= copy
;
958 skb
->truesize
+= copy
;
959 sk
->sk_wmem_queued
+= copy
;
960 sk_mem_charge(sk
, copy
);
961 skb
->ip_summed
= CHECKSUM_PARTIAL
;
962 tp
->write_seq
+= copy
;
963 TCP_SKB_CB(skb
)->end_seq
+= copy
;
964 tcp_skb_pcount_set(skb
, 0);
967 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
973 tcp_tx_timestamp(sk
, skb
);
977 if (skb
->len
< size_goal
|| (flags
& MSG_OOB
))
980 if (forced_push(tp
)) {
981 tcp_mark_push(tp
, skb
);
982 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
983 } else if (skb
== tcp_send_head(sk
))
984 tcp_push_one(sk
, mss_now
);
988 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
990 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
,
991 TCP_NAGLE_PUSH
, size_goal
);
993 err
= sk_stream_wait_memory(sk
, &timeo
);
997 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1001 if (copied
&& !(flags
& MSG_SENDPAGE_NOTLAST
))
1002 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
, size_goal
);
1009 /* make sure we wake any epoll edge trigger waiter */
1010 if (unlikely(skb_queue_len(&sk
->sk_write_queue
) == 0 && err
== -EAGAIN
))
1011 sk
->sk_write_space(sk
);
1012 return sk_stream_error(sk
, flags
, err
);
1015 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
1016 size_t size
, int flags
)
1020 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
1021 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
1022 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
1026 res
= do_tcp_sendpages(sk
, page
, offset
, size
, flags
);
1030 EXPORT_SYMBOL(tcp_sendpage
);
1032 static inline int select_size(const struct sock
*sk
, bool sg
)
1034 const struct tcp_sock
*tp
= tcp_sk(sk
);
1035 int tmp
= tp
->mss_cache
;
1038 if (sk_can_gso(sk
)) {
1039 /* Small frames wont use a full page:
1040 * Payload will immediately follow tcp header.
1042 tmp
= SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER
);
1044 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
1046 if (tmp
>= pgbreak
&&
1047 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
1055 void tcp_free_fastopen_req(struct tcp_sock
*tp
)
1057 if (tp
->fastopen_req
) {
1058 kfree(tp
->fastopen_req
);
1059 tp
->fastopen_req
= NULL
;
1063 static int tcp_sendmsg_fastopen(struct sock
*sk
, struct msghdr
*msg
,
1064 int *copied
, size_t size
)
1066 struct tcp_sock
*tp
= tcp_sk(sk
);
1069 if (!(sysctl_tcp_fastopen
& TFO_CLIENT_ENABLE
))
1071 if (tp
->fastopen_req
)
1072 return -EALREADY
; /* Another Fast Open is in progress */
1074 tp
->fastopen_req
= kzalloc(sizeof(struct tcp_fastopen_request
),
1076 if (unlikely(!tp
->fastopen_req
))
1078 tp
->fastopen_req
->data
= msg
;
1079 tp
->fastopen_req
->size
= size
;
1081 flags
= (msg
->msg_flags
& MSG_DONTWAIT
) ? O_NONBLOCK
: 0;
1082 err
= __inet_stream_connect(sk
->sk_socket
, msg
->msg_name
,
1083 msg
->msg_namelen
, flags
);
1084 *copied
= tp
->fastopen_req
->copied
;
1085 tcp_free_fastopen_req(tp
);
1089 int tcp_sendmsg(struct sock
*sk
, struct msghdr
*msg
, size_t size
)
1091 struct tcp_sock
*tp
= tcp_sk(sk
);
1092 struct sk_buff
*skb
;
1093 int flags
, err
, copied
= 0;
1094 int mss_now
= 0, size_goal
, copied_syn
= 0;
1100 flags
= msg
->msg_flags
;
1101 if (flags
& MSG_FASTOPEN
) {
1102 err
= tcp_sendmsg_fastopen(sk
, msg
, &copied_syn
, size
);
1103 if (err
== -EINPROGRESS
&& copied_syn
> 0)
1109 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
1111 /* Wait for a connection to finish. One exception is TCP Fast Open
1112 * (passive side) where data is allowed to be sent before a connection
1113 * is fully established.
1115 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
1116 !tcp_passive_fastopen(sk
)) {
1117 err
= sk_stream_wait_connect(sk
, &timeo
);
1122 if (unlikely(tp
->repair
)) {
1123 if (tp
->repair_queue
== TCP_RECV_QUEUE
) {
1124 copied
= tcp_send_rcvq(sk
, msg
, size
);
1129 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1132 /* 'common' sending to sendq */
1135 /* This should be in poll */
1136 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE
, sk
);
1138 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1140 /* Ok commence sending. */
1144 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
1147 sg
= !!(sk
->sk_route_caps
& NETIF_F_SG
);
1149 while (msg_data_left(msg
)) {
1151 int max
= size_goal
;
1153 skb
= tcp_write_queue_tail(sk
);
1154 if (tcp_send_head(sk
)) {
1155 if (skb
->ip_summed
== CHECKSUM_NONE
)
1157 copy
= max
- skb
->len
;
1162 /* Allocate new segment. If the interface is SG,
1163 * allocate skb fitting to single page.
1165 if (!sk_stream_memory_free(sk
))
1166 goto wait_for_sndbuf
;
1168 skb
= sk_stream_alloc_skb(sk
,
1169 select_size(sk
, sg
),
1171 skb_queue_empty(&sk
->sk_write_queue
));
1173 goto wait_for_memory
;
1176 * Check whether we can use HW checksum.
1178 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
1179 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1181 skb_entail(sk
, skb
);
1185 /* All packets are restored as if they have
1186 * already been sent. skb_mstamp isn't set to
1187 * avoid wrong rtt estimation.
1190 TCP_SKB_CB(skb
)->sacked
|= TCPCB_REPAIRED
;
1193 /* Try to append data to the end of skb. */
1194 if (copy
> msg_data_left(msg
))
1195 copy
= msg_data_left(msg
);
1197 /* Where to copy to? */
1198 if (skb_availroom(skb
) > 0) {
1199 /* We have some space in skb head. Superb! */
1200 copy
= min_t(int, copy
, skb_availroom(skb
));
1201 err
= skb_add_data_nocache(sk
, skb
, &msg
->msg_iter
, copy
);
1206 int i
= skb_shinfo(skb
)->nr_frags
;
1207 struct page_frag
*pfrag
= sk_page_frag(sk
);
1209 if (!sk_page_frag_refill(sk
, pfrag
))
1210 goto wait_for_memory
;
1212 if (!skb_can_coalesce(skb
, i
, pfrag
->page
,
1214 if (i
== MAX_SKB_FRAGS
|| !sg
) {
1215 tcp_mark_push(tp
, skb
);
1221 copy
= min_t(int, copy
, pfrag
->size
- pfrag
->offset
);
1223 if (!sk_wmem_schedule(sk
, copy
))
1224 goto wait_for_memory
;
1226 err
= skb_copy_to_page_nocache(sk
, &msg
->msg_iter
, skb
,
1233 /* Update the skb. */
1235 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
1237 skb_fill_page_desc(skb
, i
, pfrag
->page
,
1238 pfrag
->offset
, copy
);
1239 get_page(pfrag
->page
);
1241 pfrag
->offset
+= copy
;
1245 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
1247 tp
->write_seq
+= copy
;
1248 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1249 tcp_skb_pcount_set(skb
, 0);
1252 if (!msg_data_left(msg
)) {
1253 tcp_tx_timestamp(sk
, skb
);
1257 if (skb
->len
< max
|| (flags
& MSG_OOB
) || unlikely(tp
->repair
))
1260 if (forced_push(tp
)) {
1261 tcp_mark_push(tp
, skb
);
1262 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1263 } else if (skb
== tcp_send_head(sk
))
1264 tcp_push_one(sk
, mss_now
);
1268 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1271 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
,
1272 TCP_NAGLE_PUSH
, size_goal
);
1274 err
= sk_stream_wait_memory(sk
, &timeo
);
1278 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1283 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
, size_goal
);
1286 return copied
+ copied_syn
;
1290 tcp_unlink_write_queue(skb
, sk
);
1291 /* It is the one place in all of TCP, except connection
1292 * reset, where we can be unlinking the send_head.
1294 tcp_check_send_head(sk
, skb
);
1295 sk_wmem_free_skb(sk
, skb
);
1299 if (copied
+ copied_syn
)
1302 err
= sk_stream_error(sk
, flags
, err
);
1303 /* make sure we wake any epoll edge trigger waiter */
1304 if (unlikely(skb_queue_len(&sk
->sk_write_queue
) == 0 && err
== -EAGAIN
))
1305 sk
->sk_write_space(sk
);
1309 EXPORT_SYMBOL(tcp_sendmsg
);
1312 * Handle reading urgent data. BSD has very simple semantics for
1313 * this, no blocking and very strange errors 8)
1316 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1318 struct tcp_sock
*tp
= tcp_sk(sk
);
1320 /* No URG data to read. */
1321 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1322 tp
->urg_data
== TCP_URG_READ
)
1323 return -EINVAL
; /* Yes this is right ! */
1325 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1328 if (tp
->urg_data
& TCP_URG_VALID
) {
1330 char c
= tp
->urg_data
;
1332 if (!(flags
& MSG_PEEK
))
1333 tp
->urg_data
= TCP_URG_READ
;
1335 /* Read urgent data. */
1336 msg
->msg_flags
|= MSG_OOB
;
1339 if (!(flags
& MSG_TRUNC
))
1340 err
= memcpy_to_msg(msg
, &c
, 1);
1343 msg
->msg_flags
|= MSG_TRUNC
;
1345 return err
? -EFAULT
: len
;
1348 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1351 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1352 * the available implementations agree in this case:
1353 * this call should never block, independent of the
1354 * blocking state of the socket.
1355 * Mike <pall@rz.uni-karlsruhe.de>
1360 static int tcp_peek_sndq(struct sock
*sk
, struct msghdr
*msg
, int len
)
1362 struct sk_buff
*skb
;
1363 int copied
= 0, err
= 0;
1365 /* XXX -- need to support SO_PEEK_OFF */
1367 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
1368 err
= skb_copy_datagram_msg(skb
, 0, msg
, skb
->len
);
1375 return err
?: copied
;
1378 /* Clean up the receive buffer for full frames taken by the user,
1379 * then send an ACK if necessary. COPIED is the number of bytes
1380 * tcp_recvmsg has given to the user so far, it speeds up the
1381 * calculation of whether or not we must ACK for the sake of
1384 static void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1386 struct tcp_sock
*tp
= tcp_sk(sk
);
1387 bool time_to_ack
= false;
1389 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1391 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1392 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1393 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1395 if (inet_csk_ack_scheduled(sk
)) {
1396 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1397 /* Delayed ACKs frequently hit locked sockets during bulk
1399 if (icsk
->icsk_ack
.blocked
||
1400 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1401 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1403 * If this read emptied read buffer, we send ACK, if
1404 * connection is not bidirectional, user drained
1405 * receive buffer and there was a small segment
1409 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1410 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1411 !icsk
->icsk_ack
.pingpong
)) &&
1412 !atomic_read(&sk
->sk_rmem_alloc
)))
1416 /* We send an ACK if we can now advertise a non-zero window
1417 * which has been raised "significantly".
1419 * Even if window raised up to infinity, do not send window open ACK
1420 * in states, where we will not receive more. It is useless.
1422 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1423 __u32 rcv_window_now
= tcp_receive_window(tp
);
1425 /* Optimize, __tcp_select_window() is not cheap. */
1426 if (2*rcv_window_now
<= tp
->window_clamp
) {
1427 __u32 new_window
= __tcp_select_window(sk
);
1429 /* Send ACK now, if this read freed lots of space
1430 * in our buffer. Certainly, new_window is new window.
1431 * We can advertise it now, if it is not less than current one.
1432 * "Lots" means "at least twice" here.
1434 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1442 static void tcp_prequeue_process(struct sock
*sk
)
1444 struct sk_buff
*skb
;
1445 struct tcp_sock
*tp
= tcp_sk(sk
);
1447 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1449 /* RX process wants to run with disabled BHs, though it is not
1452 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1453 sk_backlog_rcv(sk
, skb
);
1456 /* Clear memory counter. */
1457 tp
->ucopy
.memory
= 0;
1460 static struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1462 struct sk_buff
*skb
;
1465 while ((skb
= skb_peek(&sk
->sk_receive_queue
)) != NULL
) {
1466 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1467 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_SYN
)
1469 if (offset
< skb
->len
|| (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)) {
1473 /* This looks weird, but this can happen if TCP collapsing
1474 * splitted a fat GRO packet, while we released socket lock
1475 * in skb_splice_bits()
1477 sk_eat_skb(sk
, skb
);
1483 * This routine provides an alternative to tcp_recvmsg() for routines
1484 * that would like to handle copying from skbuffs directly in 'sendfile'
1487 * - It is assumed that the socket was locked by the caller.
1488 * - The routine does not block.
1489 * - At present, there is no support for reading OOB data
1490 * or for 'peeking' the socket using this routine
1491 * (although both would be easy to implement).
1493 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1494 sk_read_actor_t recv_actor
)
1496 struct sk_buff
*skb
;
1497 struct tcp_sock
*tp
= tcp_sk(sk
);
1498 u32 seq
= tp
->copied_seq
;
1502 if (sk
->sk_state
== TCP_LISTEN
)
1504 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1505 if (offset
< skb
->len
) {
1509 len
= skb
->len
- offset
;
1510 /* Stop reading if we hit a patch of urgent data */
1512 u32 urg_offset
= tp
->urg_seq
- seq
;
1513 if (urg_offset
< len
)
1518 used
= recv_actor(desc
, skb
, offset
, len
);
1523 } else if (used
<= len
) {
1528 /* If recv_actor drops the lock (e.g. TCP splice
1529 * receive) the skb pointer might be invalid when
1530 * getting here: tcp_collapse might have deleted it
1531 * while aggregating skbs from the socket queue.
1533 skb
= tcp_recv_skb(sk
, seq
- 1, &offset
);
1536 /* TCP coalescing might have appended data to the skb.
1537 * Try to splice more frags
1539 if (offset
+ 1 != skb
->len
)
1542 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
) {
1543 sk_eat_skb(sk
, skb
);
1547 sk_eat_skb(sk
, skb
);
1550 tp
->copied_seq
= seq
;
1552 tp
->copied_seq
= seq
;
1554 tcp_rcv_space_adjust(sk
);
1556 /* Clean up data we have read: This will do ACK frames. */
1558 tcp_recv_skb(sk
, seq
, &offset
);
1559 tcp_cleanup_rbuf(sk
, copied
);
1563 EXPORT_SYMBOL(tcp_read_sock
);
1566 * This routine copies from a sock struct into the user buffer.
1568 * Technical note: in 2.3 we work on _locked_ socket, so that
1569 * tricks with *seq access order and skb->users are not required.
1570 * Probably, code can be easily improved even more.
1573 int tcp_recvmsg(struct sock
*sk
, struct msghdr
*msg
, size_t len
, int nonblock
,
1574 int flags
, int *addr_len
)
1576 struct tcp_sock
*tp
= tcp_sk(sk
);
1582 int target
; /* Read at least this many bytes */
1584 struct task_struct
*user_recv
= NULL
;
1585 struct sk_buff
*skb
, *last
;
1588 if (unlikely(flags
& MSG_ERRQUEUE
))
1589 return inet_recv_error(sk
, msg
, len
, addr_len
);
1591 if (sk_can_busy_loop(sk
) && skb_queue_empty(&sk
->sk_receive_queue
) &&
1592 (sk
->sk_state
== TCP_ESTABLISHED
))
1593 sk_busy_loop(sk
, nonblock
);
1598 if (sk
->sk_state
== TCP_LISTEN
)
1601 timeo
= sock_rcvtimeo(sk
, nonblock
);
1603 /* Urgent data needs to be handled specially. */
1604 if (flags
& MSG_OOB
)
1607 if (unlikely(tp
->repair
)) {
1609 if (!(flags
& MSG_PEEK
))
1612 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
1616 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1619 /* 'common' recv queue MSG_PEEK-ing */
1622 seq
= &tp
->copied_seq
;
1623 if (flags
& MSG_PEEK
) {
1624 peek_seq
= tp
->copied_seq
;
1628 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1633 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1634 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1637 if (signal_pending(current
)) {
1638 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1643 /* Next get a buffer. */
1645 last
= skb_peek_tail(&sk
->sk_receive_queue
);
1646 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1648 /* Now that we have two receive queues this
1651 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1652 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1653 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1657 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1658 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_SYN
)
1660 if (offset
< skb
->len
)
1662 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
1664 WARN(!(flags
& MSG_PEEK
),
1665 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1666 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
, flags
);
1669 /* Well, if we have backlog, try to process it now yet. */
1671 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1676 sk
->sk_state
== TCP_CLOSE
||
1677 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1679 signal_pending(current
))
1682 if (sock_flag(sk
, SOCK_DONE
))
1686 copied
= sock_error(sk
);
1690 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1693 if (sk
->sk_state
== TCP_CLOSE
) {
1694 if (!sock_flag(sk
, SOCK_DONE
)) {
1695 /* This occurs when user tries to read
1696 * from never connected socket.
1709 if (signal_pending(current
)) {
1710 copied
= sock_intr_errno(timeo
);
1715 tcp_cleanup_rbuf(sk
, copied
);
1717 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1718 /* Install new reader */
1719 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1720 user_recv
= current
;
1721 tp
->ucopy
.task
= user_recv
;
1722 tp
->ucopy
.msg
= msg
;
1725 tp
->ucopy
.len
= len
;
1727 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1728 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1730 /* Ugly... If prequeue is not empty, we have to
1731 * process it before releasing socket, otherwise
1732 * order will be broken at second iteration.
1733 * More elegant solution is required!!!
1735 * Look: we have the following (pseudo)queues:
1737 * 1. packets in flight
1742 * Each queue can be processed only if the next ones
1743 * are empty. At this point we have empty receive_queue.
1744 * But prequeue _can_ be not empty after 2nd iteration,
1745 * when we jumped to start of loop because backlog
1746 * processing added something to receive_queue.
1747 * We cannot release_sock(), because backlog contains
1748 * packets arrived _after_ prequeued ones.
1750 * Shortly, algorithm is clear --- to process all
1751 * the queues in order. We could make it more directly,
1752 * requeueing packets from backlog to prequeue, if
1753 * is not empty. It is more elegant, but eats cycles,
1756 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1759 /* __ Set realtime policy in scheduler __ */
1762 if (copied
>= target
) {
1763 /* Do not sleep, just process backlog. */
1767 sk_wait_data(sk
, &timeo
, last
);
1773 /* __ Restore normal policy in scheduler __ */
1775 chunk
= len
- tp
->ucopy
.len
;
1777 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1782 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1783 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1785 tcp_prequeue_process(sk
);
1787 chunk
= len
- tp
->ucopy
.len
;
1789 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1795 if ((flags
& MSG_PEEK
) &&
1796 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1797 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1799 task_pid_nr(current
));
1800 peek_seq
= tp
->copied_seq
;
1805 /* Ok so how much can we use? */
1806 used
= skb
->len
- offset
;
1810 /* Do we have urgent data here? */
1812 u32 urg_offset
= tp
->urg_seq
- *seq
;
1813 if (urg_offset
< used
) {
1815 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1828 if (!(flags
& MSG_TRUNC
)) {
1829 err
= skb_copy_datagram_msg(skb
, offset
, msg
, used
);
1831 /* Exception. Bailout! */
1842 tcp_rcv_space_adjust(sk
);
1845 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1847 tcp_fast_path_check(sk
);
1849 if (used
+ offset
< skb
->len
)
1852 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
1854 if (!(flags
& MSG_PEEK
))
1855 sk_eat_skb(sk
, skb
);
1859 /* Process the FIN. */
1861 if (!(flags
& MSG_PEEK
))
1862 sk_eat_skb(sk
, skb
);
1867 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1870 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1872 tcp_prequeue_process(sk
);
1874 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1875 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1881 tp
->ucopy
.task
= NULL
;
1885 /* According to UNIX98, msg_name/msg_namelen are ignored
1886 * on connected socket. I was just happy when found this 8) --ANK
1889 /* Clean up data we have read: This will do ACK frames. */
1890 tcp_cleanup_rbuf(sk
, copied
);
1900 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1904 err
= tcp_peek_sndq(sk
, msg
, len
);
1907 EXPORT_SYMBOL(tcp_recvmsg
);
1909 void tcp_set_state(struct sock
*sk
, int state
)
1911 int oldstate
= sk
->sk_state
;
1914 case TCP_ESTABLISHED
:
1915 if (oldstate
!= TCP_ESTABLISHED
)
1916 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1920 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1921 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1923 sk
->sk_prot
->unhash(sk
);
1924 if (inet_csk(sk
)->icsk_bind_hash
&&
1925 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1929 if (oldstate
== TCP_ESTABLISHED
)
1930 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1933 /* Change state AFTER socket is unhashed to avoid closed
1934 * socket sitting in hash tables.
1936 sk_state_store(sk
, state
);
1939 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
1942 EXPORT_SYMBOL_GPL(tcp_set_state
);
1945 * State processing on a close. This implements the state shift for
1946 * sending our FIN frame. Note that we only send a FIN for some
1947 * states. A shutdown() may have already sent the FIN, or we may be
1951 static const unsigned char new_state
[16] = {
1952 /* current state: new state: action: */
1953 [0 /* (Invalid) */] = TCP_CLOSE
,
1954 [TCP_ESTABLISHED
] = TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1955 [TCP_SYN_SENT
] = TCP_CLOSE
,
1956 [TCP_SYN_RECV
] = TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1957 [TCP_FIN_WAIT1
] = TCP_FIN_WAIT1
,
1958 [TCP_FIN_WAIT2
] = TCP_FIN_WAIT2
,
1959 [TCP_TIME_WAIT
] = TCP_CLOSE
,
1960 [TCP_CLOSE
] = TCP_CLOSE
,
1961 [TCP_CLOSE_WAIT
] = TCP_LAST_ACK
| TCP_ACTION_FIN
,
1962 [TCP_LAST_ACK
] = TCP_LAST_ACK
,
1963 [TCP_LISTEN
] = TCP_CLOSE
,
1964 [TCP_CLOSING
] = TCP_CLOSING
,
1965 [TCP_NEW_SYN_RECV
] = TCP_CLOSE
, /* should not happen ! */
1968 static int tcp_close_state(struct sock
*sk
)
1970 int next
= (int)new_state
[sk
->sk_state
];
1971 int ns
= next
& TCP_STATE_MASK
;
1973 tcp_set_state(sk
, ns
);
1975 return next
& TCP_ACTION_FIN
;
1979 * Shutdown the sending side of a connection. Much like close except
1980 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1983 void tcp_shutdown(struct sock
*sk
, int how
)
1985 /* We need to grab some memory, and put together a FIN,
1986 * and then put it into the queue to be sent.
1987 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1989 if (!(how
& SEND_SHUTDOWN
))
1992 /* If we've already sent a FIN, or it's a closed state, skip this. */
1993 if ((1 << sk
->sk_state
) &
1994 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
1995 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
1996 /* Clear out any half completed packets. FIN if needed. */
1997 if (tcp_close_state(sk
))
2001 EXPORT_SYMBOL(tcp_shutdown
);
2003 bool tcp_check_oom(struct sock
*sk
, int shift
)
2005 bool too_many_orphans
, out_of_socket_memory
;
2007 too_many_orphans
= tcp_too_many_orphans(sk
, shift
);
2008 out_of_socket_memory
= tcp_out_of_memory(sk
);
2010 if (too_many_orphans
)
2011 net_info_ratelimited("too many orphaned sockets\n");
2012 if (out_of_socket_memory
)
2013 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2014 return too_many_orphans
|| out_of_socket_memory
;
2017 void tcp_close(struct sock
*sk
, long timeout
)
2019 struct sk_buff
*skb
;
2020 int data_was_unread
= 0;
2024 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2026 if (sk
->sk_state
== TCP_LISTEN
) {
2027 tcp_set_state(sk
, TCP_CLOSE
);
2030 inet_csk_listen_stop(sk
);
2032 goto adjudge_to_death
;
2035 /* We need to flush the recv. buffs. We do this only on the
2036 * descriptor close, not protocol-sourced closes, because the
2037 * reader process may not have drained the data yet!
2039 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
2040 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
;
2042 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
2044 data_was_unread
+= len
;
2050 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2051 if (sk
->sk_state
== TCP_CLOSE
)
2052 goto adjudge_to_death
;
2054 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2055 * data was lost. To witness the awful effects of the old behavior of
2056 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2057 * GET in an FTP client, suspend the process, wait for the client to
2058 * advertise a zero window, then kill -9 the FTP client, wheee...
2059 * Note: timeout is always zero in such a case.
2061 if (unlikely(tcp_sk(sk
)->repair
)) {
2062 sk
->sk_prot
->disconnect(sk
, 0);
2063 } else if (data_was_unread
) {
2064 /* Unread data was tossed, zap the connection. */
2065 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
2066 tcp_set_state(sk
, TCP_CLOSE
);
2067 tcp_send_active_reset(sk
, sk
->sk_allocation
);
2068 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
2069 /* Check zero linger _after_ checking for unread data. */
2070 sk
->sk_prot
->disconnect(sk
, 0);
2071 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
2072 } else if (tcp_close_state(sk
)) {
2073 /* We FIN if the application ate all the data before
2074 * zapping the connection.
2077 /* RED-PEN. Formally speaking, we have broken TCP state
2078 * machine. State transitions:
2080 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2081 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2082 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2084 * are legal only when FIN has been sent (i.e. in window),
2085 * rather than queued out of window. Purists blame.
2087 * F.e. "RFC state" is ESTABLISHED,
2088 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2090 * The visible declinations are that sometimes
2091 * we enter time-wait state, when it is not required really
2092 * (harmless), do not send active resets, when they are
2093 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2094 * they look as CLOSING or LAST_ACK for Linux)
2095 * Probably, I missed some more holelets.
2097 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2098 * in a single packet! (May consider it later but will
2099 * probably need API support or TCP_CORK SYN-ACK until
2100 * data is written and socket is closed.)
2105 sk_stream_wait_close(sk
, timeout
);
2108 state
= sk
->sk_state
;
2112 /* It is the last release_sock in its life. It will remove backlog. */
2116 /* Now socket is owned by kernel and we acquire BH lock
2117 to finish close. No need to check for user refs.
2121 WARN_ON(sock_owned_by_user(sk
));
2123 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
2125 /* Have we already been destroyed by a softirq or backlog? */
2126 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
2129 /* This is a (useful) BSD violating of the RFC. There is a
2130 * problem with TCP as specified in that the other end could
2131 * keep a socket open forever with no application left this end.
2132 * We use a 1 minute timeout (about the same as BSD) then kill
2133 * our end. If they send after that then tough - BUT: long enough
2134 * that we won't make the old 4*rto = almost no time - whoops
2137 * Nope, it was not mistake. It is really desired behaviour
2138 * f.e. on http servers, when such sockets are useless, but
2139 * consume significant resources. Let's do it with special
2140 * linger2 option. --ANK
2143 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
2144 struct tcp_sock
*tp
= tcp_sk(sk
);
2145 if (tp
->linger2
< 0) {
2146 tcp_set_state(sk
, TCP_CLOSE
);
2147 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2148 NET_INC_STATS_BH(sock_net(sk
),
2149 LINUX_MIB_TCPABORTONLINGER
);
2151 const int tmo
= tcp_fin_time(sk
);
2153 if (tmo
> TCP_TIMEWAIT_LEN
) {
2154 inet_csk_reset_keepalive_timer(sk
,
2155 tmo
- TCP_TIMEWAIT_LEN
);
2157 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2162 if (sk
->sk_state
!= TCP_CLOSE
) {
2164 if (tcp_check_oom(sk
, 0)) {
2165 tcp_set_state(sk
, TCP_CLOSE
);
2166 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2167 NET_INC_STATS_BH(sock_net(sk
),
2168 LINUX_MIB_TCPABORTONMEMORY
);
2172 if (sk
->sk_state
== TCP_CLOSE
) {
2173 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
2174 /* We could get here with a non-NULL req if the socket is
2175 * aborted (e.g., closed with unread data) before 3WHS
2179 reqsk_fastopen_remove(sk
, req
, false);
2180 inet_csk_destroy_sock(sk
);
2182 /* Otherwise, socket is reprieved until protocol close. */
2189 EXPORT_SYMBOL(tcp_close
);
2191 /* These states need RST on ABORT according to RFC793 */
2193 static inline bool tcp_need_reset(int state
)
2195 return (1 << state
) &
2196 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2197 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2200 int tcp_disconnect(struct sock
*sk
, int flags
)
2202 struct inet_sock
*inet
= inet_sk(sk
);
2203 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2204 struct tcp_sock
*tp
= tcp_sk(sk
);
2206 int old_state
= sk
->sk_state
;
2208 if (old_state
!= TCP_CLOSE
)
2209 tcp_set_state(sk
, TCP_CLOSE
);
2211 /* ABORT function of RFC793 */
2212 if (old_state
== TCP_LISTEN
) {
2213 inet_csk_listen_stop(sk
);
2214 } else if (unlikely(tp
->repair
)) {
2215 sk
->sk_err
= ECONNABORTED
;
2216 } else if (tcp_need_reset(old_state
) ||
2217 (tp
->snd_nxt
!= tp
->write_seq
&&
2218 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2219 /* The last check adjusts for discrepancy of Linux wrt. RFC
2222 tcp_send_active_reset(sk
, gfp_any());
2223 sk
->sk_err
= ECONNRESET
;
2224 } else if (old_state
== TCP_SYN_SENT
)
2225 sk
->sk_err
= ECONNRESET
;
2227 tcp_clear_xmit_timers(sk
);
2228 __skb_queue_purge(&sk
->sk_receive_queue
);
2229 tcp_write_queue_purge(sk
);
2230 __skb_queue_purge(&tp
->out_of_order_queue
);
2232 inet
->inet_dport
= 0;
2234 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2235 inet_reset_saddr(sk
);
2237 sk
->sk_shutdown
= 0;
2238 sock_reset_flag(sk
, SOCK_DONE
);
2240 tp
->write_seq
+= tp
->max_window
+ 2;
2241 if (tp
->write_seq
== 0)
2243 icsk
->icsk_backoff
= 0;
2245 icsk
->icsk_probes_out
= 0;
2246 tp
->packets_out
= 0;
2247 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2248 tp
->snd_cwnd_cnt
= 0;
2249 tp
->window_clamp
= 0;
2250 tcp_set_ca_state(sk
, TCP_CA_Open
);
2251 tcp_clear_retrans(tp
);
2252 inet_csk_delack_init(sk
);
2253 tcp_init_send_head(sk
);
2254 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2257 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2259 sk
->sk_error_report(sk
);
2262 EXPORT_SYMBOL(tcp_disconnect
);
2264 static inline bool tcp_can_repair_sock(const struct sock
*sk
)
2266 return ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
) &&
2267 ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_ESTABLISHED
));
2270 static int tcp_repair_options_est(struct tcp_sock
*tp
,
2271 struct tcp_repair_opt __user
*optbuf
, unsigned int len
)
2273 struct tcp_repair_opt opt
;
2275 while (len
>= sizeof(opt
)) {
2276 if (copy_from_user(&opt
, optbuf
, sizeof(opt
)))
2282 switch (opt
.opt_code
) {
2284 tp
->rx_opt
.mss_clamp
= opt
.opt_val
;
2288 u16 snd_wscale
= opt
.opt_val
& 0xFFFF;
2289 u16 rcv_wscale
= opt
.opt_val
>> 16;
2291 if (snd_wscale
> 14 || rcv_wscale
> 14)
2294 tp
->rx_opt
.snd_wscale
= snd_wscale
;
2295 tp
->rx_opt
.rcv_wscale
= rcv_wscale
;
2296 tp
->rx_opt
.wscale_ok
= 1;
2299 case TCPOPT_SACK_PERM
:
2300 if (opt
.opt_val
!= 0)
2303 tp
->rx_opt
.sack_ok
|= TCP_SACK_SEEN
;
2304 if (sysctl_tcp_fack
)
2305 tcp_enable_fack(tp
);
2307 case TCPOPT_TIMESTAMP
:
2308 if (opt
.opt_val
!= 0)
2311 tp
->rx_opt
.tstamp_ok
= 1;
2320 * Socket option code for TCP.
2322 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2323 int optname
, char __user
*optval
, unsigned int optlen
)
2325 struct tcp_sock
*tp
= tcp_sk(sk
);
2326 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2330 /* These are data/string values, all the others are ints */
2332 case TCP_CONGESTION
: {
2333 char name
[TCP_CA_NAME_MAX
];
2338 val
= strncpy_from_user(name
, optval
,
2339 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2345 err
= tcp_set_congestion_control(sk
, name
);
2354 if (optlen
< sizeof(int))
2357 if (get_user(val
, (int __user
*)optval
))
2364 /* Values greater than interface MTU won't take effect. However
2365 * at the point when this call is done we typically don't yet
2366 * know which interface is going to be used */
2367 if (val
< TCP_MIN_MSS
|| val
> MAX_TCP_WINDOW
) {
2371 tp
->rx_opt
.user_mss
= val
;
2376 /* TCP_NODELAY is weaker than TCP_CORK, so that
2377 * this option on corked socket is remembered, but
2378 * it is not activated until cork is cleared.
2380 * However, when TCP_NODELAY is set we make
2381 * an explicit push, which overrides even TCP_CORK
2382 * for currently queued segments.
2384 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2385 tcp_push_pending_frames(sk
);
2387 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2391 case TCP_THIN_LINEAR_TIMEOUTS
:
2392 if (val
< 0 || val
> 1)
2398 case TCP_THIN_DUPACK
:
2399 if (val
< 0 || val
> 1)
2402 tp
->thin_dupack
= val
;
2403 if (tp
->thin_dupack
)
2404 tcp_disable_early_retrans(tp
);
2409 if (!tcp_can_repair_sock(sk
))
2411 else if (val
== 1) {
2413 sk
->sk_reuse
= SK_FORCE_REUSE
;
2414 tp
->repair_queue
= TCP_NO_QUEUE
;
2415 } else if (val
== 0) {
2417 sk
->sk_reuse
= SK_NO_REUSE
;
2418 tcp_send_window_probe(sk
);
2424 case TCP_REPAIR_QUEUE
:
2427 else if (val
< TCP_QUEUES_NR
)
2428 tp
->repair_queue
= val
;
2434 if (sk
->sk_state
!= TCP_CLOSE
)
2436 else if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2437 tp
->write_seq
= val
;
2438 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2444 case TCP_REPAIR_OPTIONS
:
2447 else if (sk
->sk_state
== TCP_ESTABLISHED
)
2448 err
= tcp_repair_options_est(tp
,
2449 (struct tcp_repair_opt __user
*)optval
,
2456 /* When set indicates to always queue non-full frames.
2457 * Later the user clears this option and we transmit
2458 * any pending partial frames in the queue. This is
2459 * meant to be used alongside sendfile() to get properly
2460 * filled frames when the user (for example) must write
2461 * out headers with a write() call first and then use
2462 * sendfile to send out the data parts.
2464 * TCP_CORK can be set together with TCP_NODELAY and it is
2465 * stronger than TCP_NODELAY.
2468 tp
->nonagle
|= TCP_NAGLE_CORK
;
2470 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2471 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2472 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2473 tcp_push_pending_frames(sk
);
2478 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2481 tp
->keepalive_time
= val
* HZ
;
2482 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2483 !((1 << sk
->sk_state
) &
2484 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2485 u32 elapsed
= keepalive_time_elapsed(tp
);
2486 if (tp
->keepalive_time
> elapsed
)
2487 elapsed
= tp
->keepalive_time
- elapsed
;
2490 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2495 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2498 tp
->keepalive_intvl
= val
* HZ
;
2501 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2504 tp
->keepalive_probes
= val
;
2507 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2510 icsk
->icsk_syn_retries
= val
;
2514 if (val
< 0 || val
> 1)
2523 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2526 tp
->linger2
= val
* HZ
;
2529 case TCP_DEFER_ACCEPT
:
2530 /* Translate value in seconds to number of retransmits */
2531 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2532 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2536 case TCP_WINDOW_CLAMP
:
2538 if (sk
->sk_state
!= TCP_CLOSE
) {
2542 tp
->window_clamp
= 0;
2544 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2545 SOCK_MIN_RCVBUF
/ 2 : val
;
2550 icsk
->icsk_ack
.pingpong
= 1;
2552 icsk
->icsk_ack
.pingpong
= 0;
2553 if ((1 << sk
->sk_state
) &
2554 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2555 inet_csk_ack_scheduled(sk
)) {
2556 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2557 tcp_cleanup_rbuf(sk
, 1);
2559 icsk
->icsk_ack
.pingpong
= 1;
2564 #ifdef CONFIG_TCP_MD5SIG
2566 /* Read the IP->Key mappings from userspace */
2567 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2570 case TCP_USER_TIMEOUT
:
2571 /* Cap the max time in ms TCP will retry or probe the window
2572 * before giving up and aborting (ETIMEDOUT) a connection.
2577 icsk
->icsk_user_timeout
= msecs_to_jiffies(val
);
2581 if (val
>= 0 && ((1 << sk
->sk_state
) & (TCPF_CLOSE
|
2583 tcp_fastopen_init_key_once(true);
2585 fastopen_queue_tune(sk
, val
);
2594 tp
->tsoffset
= val
- tcp_time_stamp
;
2596 case TCP_NOTSENT_LOWAT
:
2597 tp
->notsent_lowat
= val
;
2598 sk
->sk_write_space(sk
);
2609 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2610 unsigned int optlen
)
2612 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2614 if (level
!= SOL_TCP
)
2615 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2617 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2619 EXPORT_SYMBOL(tcp_setsockopt
);
2621 #ifdef CONFIG_COMPAT
2622 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2623 char __user
*optval
, unsigned int optlen
)
2625 if (level
!= SOL_TCP
)
2626 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2628 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2630 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2633 /* Return information about state of tcp endpoint in API format. */
2634 void tcp_get_info(struct sock
*sk
, struct tcp_info
*info
)
2636 const struct tcp_sock
*tp
= tcp_sk(sk
); /* iff sk_type == SOCK_STREAM */
2637 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2638 u32 now
= tcp_time_stamp
;
2642 memset(info
, 0, sizeof(*info
));
2643 if (sk
->sk_type
!= SOCK_STREAM
)
2646 info
->tcpi_state
= sk_state_load(sk
);
2648 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2649 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2650 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2651 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2653 if (tp
->rx_opt
.tstamp_ok
)
2654 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2655 if (tcp_is_sack(tp
))
2656 info
->tcpi_options
|= TCPI_OPT_SACK
;
2657 if (tp
->rx_opt
.wscale_ok
) {
2658 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2659 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2660 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2663 if (tp
->ecn_flags
& TCP_ECN_OK
)
2664 info
->tcpi_options
|= TCPI_OPT_ECN
;
2665 if (tp
->ecn_flags
& TCP_ECN_SEEN
)
2666 info
->tcpi_options
|= TCPI_OPT_ECN_SEEN
;
2667 if (tp
->syn_data_acked
)
2668 info
->tcpi_options
|= TCPI_OPT_SYN_DATA
;
2670 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2671 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2672 info
->tcpi_snd_mss
= tp
->mss_cache
;
2673 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2675 if (info
->tcpi_state
== TCP_LISTEN
) {
2676 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2677 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2679 info
->tcpi_unacked
= tp
->packets_out
;
2680 info
->tcpi_sacked
= tp
->sacked_out
;
2682 info
->tcpi_lost
= tp
->lost_out
;
2683 info
->tcpi_retrans
= tp
->retrans_out
;
2684 info
->tcpi_fackets
= tp
->fackets_out
;
2686 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2687 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2688 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2690 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2691 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2692 info
->tcpi_rtt
= tp
->srtt_us
>> 3;
2693 info
->tcpi_rttvar
= tp
->mdev_us
>> 2;
2694 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2695 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2696 info
->tcpi_advmss
= tp
->advmss
;
2697 info
->tcpi_reordering
= tp
->reordering
;
2699 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2700 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2702 info
->tcpi_total_retrans
= tp
->total_retrans
;
2704 rate
= READ_ONCE(sk
->sk_pacing_rate
);
2705 info
->tcpi_pacing_rate
= rate
!= ~0U ? rate
: ~0ULL;
2707 rate
= READ_ONCE(sk
->sk_max_pacing_rate
);
2708 info
->tcpi_max_pacing_rate
= rate
!= ~0U ? rate
: ~0ULL;
2711 start
= u64_stats_fetch_begin_irq(&tp
->syncp
);
2712 info
->tcpi_bytes_acked
= tp
->bytes_acked
;
2713 info
->tcpi_bytes_received
= tp
->bytes_received
;
2714 } while (u64_stats_fetch_retry_irq(&tp
->syncp
, start
));
2715 info
->tcpi_segs_out
= tp
->segs_out
;
2716 info
->tcpi_segs_in
= tp
->segs_in
;
2718 EXPORT_SYMBOL_GPL(tcp_get_info
);
2720 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2721 int optname
, char __user
*optval
, int __user
*optlen
)
2723 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2724 struct tcp_sock
*tp
= tcp_sk(sk
);
2727 if (get_user(len
, optlen
))
2730 len
= min_t(unsigned int, len
, sizeof(int));
2737 val
= tp
->mss_cache
;
2738 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2739 val
= tp
->rx_opt
.user_mss
;
2741 val
= tp
->rx_opt
.mss_clamp
;
2744 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2747 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2750 val
= keepalive_time_when(tp
) / HZ
;
2753 val
= keepalive_intvl_when(tp
) / HZ
;
2756 val
= keepalive_probes(tp
);
2759 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2764 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2766 case TCP_DEFER_ACCEPT
:
2767 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2768 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2770 case TCP_WINDOW_CLAMP
:
2771 val
= tp
->window_clamp
;
2774 struct tcp_info info
;
2776 if (get_user(len
, optlen
))
2779 tcp_get_info(sk
, &info
);
2781 len
= min_t(unsigned int, len
, sizeof(info
));
2782 if (put_user(len
, optlen
))
2784 if (copy_to_user(optval
, &info
, len
))
2789 const struct tcp_congestion_ops
*ca_ops
;
2790 union tcp_cc_info info
;
2794 if (get_user(len
, optlen
))
2797 ca_ops
= icsk
->icsk_ca_ops
;
2798 if (ca_ops
&& ca_ops
->get_info
)
2799 sz
= ca_ops
->get_info(sk
, ~0U, &attr
, &info
);
2801 len
= min_t(unsigned int, len
, sz
);
2802 if (put_user(len
, optlen
))
2804 if (copy_to_user(optval
, &info
, len
))
2809 val
= !icsk
->icsk_ack
.pingpong
;
2812 case TCP_CONGESTION
:
2813 if (get_user(len
, optlen
))
2815 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2816 if (put_user(len
, optlen
))
2818 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2822 case TCP_THIN_LINEAR_TIMEOUTS
:
2825 case TCP_THIN_DUPACK
:
2826 val
= tp
->thin_dupack
;
2833 case TCP_REPAIR_QUEUE
:
2835 val
= tp
->repair_queue
;
2841 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2842 val
= tp
->write_seq
;
2843 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2849 case TCP_USER_TIMEOUT
:
2850 val
= jiffies_to_msecs(icsk
->icsk_user_timeout
);
2854 val
= icsk
->icsk_accept_queue
.fastopenq
.max_qlen
;
2858 val
= tcp_time_stamp
+ tp
->tsoffset
;
2860 case TCP_NOTSENT_LOWAT
:
2861 val
= tp
->notsent_lowat
;
2866 case TCP_SAVED_SYN
: {
2867 if (get_user(len
, optlen
))
2871 if (tp
->saved_syn
) {
2872 if (len
< tp
->saved_syn
[0]) {
2873 if (put_user(tp
->saved_syn
[0], optlen
)) {
2880 len
= tp
->saved_syn
[0];
2881 if (put_user(len
, optlen
)) {
2885 if (copy_to_user(optval
, tp
->saved_syn
+ 1, len
)) {
2889 tcp_saved_syn_free(tp
);
2894 if (put_user(len
, optlen
))
2900 return -ENOPROTOOPT
;
2903 if (put_user(len
, optlen
))
2905 if (copy_to_user(optval
, &val
, len
))
2910 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2913 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2915 if (level
!= SOL_TCP
)
2916 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2918 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2920 EXPORT_SYMBOL(tcp_getsockopt
);
2922 #ifdef CONFIG_COMPAT
2923 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2924 char __user
*optval
, int __user
*optlen
)
2926 if (level
!= SOL_TCP
)
2927 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2929 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2931 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2934 #ifdef CONFIG_TCP_MD5SIG
2935 static DEFINE_PER_CPU(struct tcp_md5sig_pool
, tcp_md5sig_pool
);
2936 static DEFINE_MUTEX(tcp_md5sig_mutex
);
2937 static bool tcp_md5sig_pool_populated
= false;
2939 static void __tcp_alloc_md5sig_pool(void)
2943 for_each_possible_cpu(cpu
) {
2944 if (!per_cpu(tcp_md5sig_pool
, cpu
).md5_desc
.tfm
) {
2945 struct crypto_hash
*hash
;
2947 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
2948 if (IS_ERR_OR_NULL(hash
))
2950 per_cpu(tcp_md5sig_pool
, cpu
).md5_desc
.tfm
= hash
;
2953 /* before setting tcp_md5sig_pool_populated, we must commit all writes
2954 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
2957 tcp_md5sig_pool_populated
= true;
2960 bool tcp_alloc_md5sig_pool(void)
2962 if (unlikely(!tcp_md5sig_pool_populated
)) {
2963 mutex_lock(&tcp_md5sig_mutex
);
2965 if (!tcp_md5sig_pool_populated
)
2966 __tcp_alloc_md5sig_pool();
2968 mutex_unlock(&tcp_md5sig_mutex
);
2970 return tcp_md5sig_pool_populated
;
2972 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
2976 * tcp_get_md5sig_pool - get md5sig_pool for this user
2978 * We use percpu structure, so if we succeed, we exit with preemption
2979 * and BH disabled, to make sure another thread or softirq handling
2980 * wont try to get same context.
2982 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
2986 if (tcp_md5sig_pool_populated
) {
2987 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
2989 return this_cpu_ptr(&tcp_md5sig_pool
);
2994 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
2996 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
2997 const struct tcphdr
*th
)
2999 struct scatterlist sg
;
3003 /* We are not allowed to change tcphdr, make a local copy */
3004 memcpy(&hdr
, th
, sizeof(hdr
));
3007 /* options aren't included in the hash */
3008 sg_init_one(&sg
, &hdr
, sizeof(hdr
));
3009 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(hdr
));
3012 EXPORT_SYMBOL(tcp_md5_hash_header
);
3014 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
3015 const struct sk_buff
*skb
, unsigned int header_len
)
3017 struct scatterlist sg
;
3018 const struct tcphdr
*tp
= tcp_hdr(skb
);
3019 struct hash_desc
*desc
= &hp
->md5_desc
;
3021 const unsigned int head_data_len
= skb_headlen(skb
) > header_len
?
3022 skb_headlen(skb
) - header_len
: 0;
3023 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
3024 struct sk_buff
*frag_iter
;
3026 sg_init_table(&sg
, 1);
3028 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
3029 if (crypto_hash_update(desc
, &sg
, head_data_len
))
3032 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
3033 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
3034 unsigned int offset
= f
->page_offset
;
3035 struct page
*page
= skb_frag_page(f
) + (offset
>> PAGE_SHIFT
);
3037 sg_set_page(&sg
, page
, skb_frag_size(f
),
3038 offset_in_page(offset
));
3039 if (crypto_hash_update(desc
, &sg
, skb_frag_size(f
)))
3043 skb_walk_frags(skb
, frag_iter
)
3044 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3049 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3051 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, const struct tcp_md5sig_key
*key
)
3053 struct scatterlist sg
;
3055 sg_init_one(&sg
, key
->key
, key
->keylen
);
3056 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3058 EXPORT_SYMBOL(tcp_md5_hash_key
);
3062 void tcp_done(struct sock
*sk
)
3064 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
3066 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3067 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3069 tcp_set_state(sk
, TCP_CLOSE
);
3070 tcp_clear_xmit_timers(sk
);
3072 reqsk_fastopen_remove(sk
, req
, false);
3074 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3076 if (!sock_flag(sk
, SOCK_DEAD
))
3077 sk
->sk_state_change(sk
);
3079 inet_csk_destroy_sock(sk
);
3081 EXPORT_SYMBOL_GPL(tcp_done
);
3083 extern struct tcp_congestion_ops tcp_reno
;
3085 static __initdata
unsigned long thash_entries
;
3086 static int __init
set_thash_entries(char *str
)
3093 ret
= kstrtoul(str
, 0, &thash_entries
);
3099 __setup("thash_entries=", set_thash_entries
);
3101 static void __init
tcp_init_mem(void)
3103 unsigned long limit
= nr_free_buffer_pages() / 16;
3105 limit
= max(limit
, 128UL);
3106 sysctl_tcp_mem
[0] = limit
/ 4 * 3; /* 4.68 % */
3107 sysctl_tcp_mem
[1] = limit
; /* 6.25 % */
3108 sysctl_tcp_mem
[2] = sysctl_tcp_mem
[0] * 2; /* 9.37 % */
3111 void __init
tcp_init(void)
3113 unsigned long limit
;
3114 int max_rshare
, max_wshare
, cnt
;
3117 sock_skb_cb_check_size(sizeof(struct tcp_skb_cb
));
3119 percpu_counter_init(&tcp_sockets_allocated
, 0, GFP_KERNEL
);
3120 percpu_counter_init(&tcp_orphan_count
, 0, GFP_KERNEL
);
3121 tcp_hashinfo
.bind_bucket_cachep
=
3122 kmem_cache_create("tcp_bind_bucket",
3123 sizeof(struct inet_bind_bucket
), 0,
3124 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3126 /* Size and allocate the main established and bind bucket
3129 * The methodology is similar to that of the buffer cache.
3131 tcp_hashinfo
.ehash
=
3132 alloc_large_system_hash("TCP established",
3133 sizeof(struct inet_ehash_bucket
),
3135 17, /* one slot per 128 KB of memory */
3138 &tcp_hashinfo
.ehash_mask
,
3140 thash_entries
? 0 : 512 * 1024);
3141 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++)
3142 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3144 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3145 panic("TCP: failed to alloc ehash_locks");
3146 tcp_hashinfo
.bhash
=
3147 alloc_large_system_hash("TCP bind",
3148 sizeof(struct inet_bind_hashbucket
),
3149 tcp_hashinfo
.ehash_mask
+ 1,
3150 17, /* one slot per 128 KB of memory */
3152 &tcp_hashinfo
.bhash_size
,
3156 tcp_hashinfo
.bhash_size
= 1U << tcp_hashinfo
.bhash_size
;
3157 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3158 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3159 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3163 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
3165 tcp_death_row
.sysctl_max_tw_buckets
= cnt
/ 2;
3166 sysctl_tcp_max_orphans
= cnt
/ 2;
3167 sysctl_max_syn_backlog
= max(128, cnt
/ 256);
3170 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3171 limit
= nr_free_buffer_pages() << (PAGE_SHIFT
- 7);
3172 max_wshare
= min(4UL*1024*1024, limit
);
3173 max_rshare
= min(6UL*1024*1024, limit
);
3175 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3176 sysctl_tcp_wmem
[1] = 16*1024;
3177 sysctl_tcp_wmem
[2] = max(64*1024, max_wshare
);
3179 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3180 sysctl_tcp_rmem
[1] = 87380;
3181 sysctl_tcp_rmem
[2] = max(87380, max_rshare
);
3183 pr_info("Hash tables configured (established %u bind %u)\n",
3184 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3187 BUG_ON(tcp_register_congestion_control(&tcp_reno
) != 0);