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/init.h>
256 #include <linux/fs.h>
257 #include <linux/skbuff.h>
258 #include <linux/scatterlist.h>
259 #include <linux/splice.h>
260 #include <linux/net.h>
261 #include <linux/socket.h>
262 #include <linux/random.h>
263 #include <linux/bootmem.h>
264 #include <linux/highmem.h>
265 #include <linux/swap.h>
266 #include <linux/cache.h>
267 #include <linux/err.h>
268 #include <linux/crypto.h>
269 #include <linux/time.h>
270 #include <linux/slab.h>
272 #include <net/icmp.h>
273 #include <net/inet_common.h>
275 #include <net/xfrm.h>
277 #include <net/sock.h>
279 #include <asm/uaccess.h>
280 #include <asm/ioctls.h>
281 #include <net/busy_poll.h>
283 int sysctl_tcp_fin_timeout __read_mostly
= TCP_FIN_TIMEOUT
;
285 int sysctl_tcp_min_tso_segs __read_mostly
= 2;
287 int sysctl_tcp_autocorking __read_mostly
= 1;
289 struct percpu_counter tcp_orphan_count
;
290 EXPORT_SYMBOL_GPL(tcp_orphan_count
);
292 long sysctl_tcp_mem
[3] __read_mostly
;
293 int sysctl_tcp_wmem
[3] __read_mostly
;
294 int sysctl_tcp_rmem
[3] __read_mostly
;
296 EXPORT_SYMBOL(sysctl_tcp_mem
);
297 EXPORT_SYMBOL(sysctl_tcp_rmem
);
298 EXPORT_SYMBOL(sysctl_tcp_wmem
);
300 atomic_long_t tcp_memory_allocated
; /* Current allocated memory. */
301 EXPORT_SYMBOL(tcp_memory_allocated
);
304 * Current number of TCP sockets.
306 struct percpu_counter tcp_sockets_allocated
;
307 EXPORT_SYMBOL(tcp_sockets_allocated
);
312 struct tcp_splice_state
{
313 struct pipe_inode_info
*pipe
;
319 * Pressure flag: try to collapse.
320 * Technical note: it is used by multiple contexts non atomically.
321 * All the __sk_mem_schedule() is of this nature: accounting
322 * is strict, actions are advisory and have some latency.
324 int tcp_memory_pressure __read_mostly
;
325 EXPORT_SYMBOL(tcp_memory_pressure
);
327 void tcp_enter_memory_pressure(struct sock
*sk
)
329 if (!tcp_memory_pressure
) {
330 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMEMORYPRESSURES
);
331 tcp_memory_pressure
= 1;
334 EXPORT_SYMBOL(tcp_enter_memory_pressure
);
336 /* Convert seconds to retransmits based on initial and max timeout */
337 static u8
secs_to_retrans(int seconds
, int timeout
, int rto_max
)
342 int period
= timeout
;
345 while (seconds
> period
&& res
< 255) {
348 if (timeout
> rto_max
)
356 /* Convert retransmits to seconds based on initial and max timeout */
357 static int retrans_to_secs(u8 retrans
, int timeout
, int rto_max
)
365 if (timeout
> rto_max
)
373 /* Address-family independent initialization for a tcp_sock.
375 * NOTE: A lot of things set to zero explicitly by call to
376 * sk_alloc() so need not be done here.
378 void tcp_init_sock(struct sock
*sk
)
380 struct inet_connection_sock
*icsk
= inet_csk(sk
);
381 struct tcp_sock
*tp
= tcp_sk(sk
);
383 __skb_queue_head_init(&tp
->out_of_order_queue
);
384 tcp_init_xmit_timers(sk
);
385 tcp_prequeue_init(tp
);
386 INIT_LIST_HEAD(&tp
->tsq_node
);
388 icsk
->icsk_rto
= TCP_TIMEOUT_INIT
;
389 tp
->mdev_us
= jiffies_to_usecs(TCP_TIMEOUT_INIT
);
391 /* So many TCP implementations out there (incorrectly) count the
392 * initial SYN frame in their delayed-ACK and congestion control
393 * algorithms that we must have the following bandaid to talk
394 * efficiently to them. -DaveM
396 tp
->snd_cwnd
= TCP_INIT_CWND
;
398 /* See draft-stevens-tcpca-spec-01 for discussion of the
399 * initialization of these values.
401 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
402 tp
->snd_cwnd_clamp
= ~0;
403 tp
->mss_cache
= TCP_MSS_DEFAULT
;
405 tp
->reordering
= sysctl_tcp_reordering
;
406 tcp_enable_early_retrans(tp
);
407 tcp_assign_congestion_control(sk
);
411 sk
->sk_state
= TCP_CLOSE
;
413 sk
->sk_write_space
= sk_stream_write_space
;
414 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
416 icsk
->icsk_sync_mss
= tcp_sync_mss
;
418 sk
->sk_sndbuf
= sysctl_tcp_wmem
[1];
419 sk
->sk_rcvbuf
= sysctl_tcp_rmem
[1];
422 sock_update_memcg(sk
);
423 sk_sockets_allocated_inc(sk
);
426 EXPORT_SYMBOL(tcp_init_sock
);
428 static void tcp_tx_timestamp(struct sock
*sk
, struct sk_buff
*skb
)
430 if (sk
->sk_tsflags
) {
431 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
433 sock_tx_timestamp(sk
, &shinfo
->tx_flags
);
434 if (shinfo
->tx_flags
& SKBTX_ANY_TSTAMP
)
435 shinfo
->tskey
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- 1;
440 * Wait for a TCP event.
442 * Note that we don't need to lock the socket, as the upper poll layers
443 * take care of normal races (between the test and the event) and we don't
444 * go look at any of the socket buffers directly.
446 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
449 struct sock
*sk
= sock
->sk
;
450 const struct tcp_sock
*tp
= tcp_sk(sk
);
452 sock_rps_record_flow(sk
);
454 sock_poll_wait(file
, sk_sleep(sk
), wait
);
455 if (sk
->sk_state
== TCP_LISTEN
)
456 return inet_csk_listen_poll(sk
);
458 /* Socket is not locked. We are protected from async events
459 * by poll logic and correct handling of state changes
460 * made by other threads is impossible in any case.
466 * POLLHUP is certainly not done right. But poll() doesn't
467 * have a notion of HUP in just one direction, and for a
468 * socket the read side is more interesting.
470 * Some poll() documentation says that POLLHUP is incompatible
471 * with the POLLOUT/POLLWR flags, so somebody should check this
472 * all. But careful, it tends to be safer to return too many
473 * bits than too few, and you can easily break real applications
474 * if you don't tell them that something has hung up!
478 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
479 * our fs/select.c). It means that after we received EOF,
480 * poll always returns immediately, making impossible poll() on write()
481 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
482 * if and only if shutdown has been made in both directions.
483 * Actually, it is interesting to look how Solaris and DUX
484 * solve this dilemma. I would prefer, if POLLHUP were maskable,
485 * then we could set it on SND_SHUTDOWN. BTW examples given
486 * in Stevens' books assume exactly this behaviour, it explains
487 * why POLLHUP is incompatible with POLLOUT. --ANK
489 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
490 * blocking on fresh not-connected or disconnected socket. --ANK
492 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== TCP_CLOSE
)
494 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
495 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
497 /* Connected or passive Fast Open socket? */
498 if (sk
->sk_state
!= TCP_SYN_SENT
&&
499 (sk
->sk_state
!= TCP_SYN_RECV
|| tp
->fastopen_rsk
!= NULL
)) {
500 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
502 if (tp
->urg_seq
== tp
->copied_seq
&&
503 !sock_flag(sk
, SOCK_URGINLINE
) &&
507 /* Potential race condition. If read of tp below will
508 * escape above sk->sk_state, we can be illegally awaken
509 * in SYN_* states. */
510 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
511 mask
|= POLLIN
| POLLRDNORM
;
513 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
514 if (sk_stream_is_writeable(sk
)) {
515 mask
|= POLLOUT
| POLLWRNORM
;
516 } else { /* send SIGIO later */
517 set_bit(SOCK_ASYNC_NOSPACE
,
518 &sk
->sk_socket
->flags
);
519 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
521 /* Race breaker. If space is freed after
522 * wspace test but before the flags are set,
523 * IO signal will be lost.
525 if (sk_stream_is_writeable(sk
))
526 mask
|= POLLOUT
| POLLWRNORM
;
529 mask
|= POLLOUT
| POLLWRNORM
;
531 if (tp
->urg_data
& TCP_URG_VALID
)
534 /* This barrier is coupled with smp_wmb() in tcp_reset() */
536 if (sk
->sk_err
|| !skb_queue_empty(&sk
->sk_error_queue
))
541 EXPORT_SYMBOL(tcp_poll
);
543 int tcp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
545 struct tcp_sock
*tp
= tcp_sk(sk
);
551 if (sk
->sk_state
== TCP_LISTEN
)
554 slow
= lock_sock_fast(sk
);
555 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
557 else if (sock_flag(sk
, SOCK_URGINLINE
) ||
559 before(tp
->urg_seq
, tp
->copied_seq
) ||
560 !before(tp
->urg_seq
, tp
->rcv_nxt
)) {
562 answ
= tp
->rcv_nxt
- tp
->copied_seq
;
564 /* Subtract 1, if FIN was received */
565 if (answ
&& sock_flag(sk
, SOCK_DONE
))
568 answ
= tp
->urg_seq
- tp
->copied_seq
;
569 unlock_sock_fast(sk
, slow
);
572 answ
= tp
->urg_data
&& tp
->urg_seq
== tp
->copied_seq
;
575 if (sk
->sk_state
== TCP_LISTEN
)
578 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
581 answ
= tp
->write_seq
- tp
->snd_una
;
584 if (sk
->sk_state
== TCP_LISTEN
)
587 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
590 answ
= tp
->write_seq
- tp
->snd_nxt
;
596 return put_user(answ
, (int __user
*)arg
);
598 EXPORT_SYMBOL(tcp_ioctl
);
600 static inline void tcp_mark_push(struct tcp_sock
*tp
, struct sk_buff
*skb
)
602 TCP_SKB_CB(skb
)->tcp_flags
|= TCPHDR_PSH
;
603 tp
->pushed_seq
= tp
->write_seq
;
606 static inline bool forced_push(const struct tcp_sock
*tp
)
608 return after(tp
->write_seq
, tp
->pushed_seq
+ (tp
->max_window
>> 1));
611 static void skb_entail(struct sock
*sk
, struct sk_buff
*skb
)
613 struct tcp_sock
*tp
= tcp_sk(sk
);
614 struct tcp_skb_cb
*tcb
= TCP_SKB_CB(skb
);
617 tcb
->seq
= tcb
->end_seq
= tp
->write_seq
;
618 tcb
->tcp_flags
= TCPHDR_ACK
;
620 __skb_header_release(skb
);
621 tcp_add_write_queue_tail(sk
, skb
);
622 sk
->sk_wmem_queued
+= skb
->truesize
;
623 sk_mem_charge(sk
, skb
->truesize
);
624 if (tp
->nonagle
& TCP_NAGLE_PUSH
)
625 tp
->nonagle
&= ~TCP_NAGLE_PUSH
;
628 static inline void tcp_mark_urg(struct tcp_sock
*tp
, int flags
)
631 tp
->snd_up
= tp
->write_seq
;
634 /* If a not yet filled skb is pushed, do not send it if
635 * we have data packets in Qdisc or NIC queues :
636 * Because TX completion will happen shortly, it gives a chance
637 * to coalesce future sendmsg() payload into this skb, without
638 * need for a timer, and with no latency trade off.
639 * As packets containing data payload have a bigger truesize
640 * than pure acks (dataless) packets, the last checks prevent
641 * autocorking if we only have an ACK in Qdisc/NIC queues,
642 * or if TX completion was delayed after we processed ACK packet.
644 static bool tcp_should_autocork(struct sock
*sk
, struct sk_buff
*skb
,
647 return skb
->len
< size_goal
&&
648 sysctl_tcp_autocorking
&&
649 skb
!= tcp_write_queue_head(sk
) &&
650 atomic_read(&sk
->sk_wmem_alloc
) > skb
->truesize
;
653 static void tcp_push(struct sock
*sk
, int flags
, int mss_now
,
654 int nonagle
, int size_goal
)
656 struct tcp_sock
*tp
= tcp_sk(sk
);
659 if (!tcp_send_head(sk
))
662 skb
= tcp_write_queue_tail(sk
);
663 if (!(flags
& MSG_MORE
) || forced_push(tp
))
664 tcp_mark_push(tp
, skb
);
666 tcp_mark_urg(tp
, flags
);
668 if (tcp_should_autocork(sk
, skb
, size_goal
)) {
670 /* avoid atomic op if TSQ_THROTTLED bit is already set */
671 if (!test_bit(TSQ_THROTTLED
, &tp
->tsq_flags
)) {
672 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPAUTOCORKING
);
673 set_bit(TSQ_THROTTLED
, &tp
->tsq_flags
);
675 /* It is possible TX completion already happened
676 * before we set TSQ_THROTTLED.
678 if (atomic_read(&sk
->sk_wmem_alloc
) > skb
->truesize
)
682 if (flags
& MSG_MORE
)
683 nonagle
= TCP_NAGLE_CORK
;
685 __tcp_push_pending_frames(sk
, mss_now
, nonagle
);
688 static int tcp_splice_data_recv(read_descriptor_t
*rd_desc
, struct sk_buff
*skb
,
689 unsigned int offset
, size_t len
)
691 struct tcp_splice_state
*tss
= rd_desc
->arg
.data
;
694 ret
= skb_splice_bits(skb
, offset
, tss
->pipe
, min(rd_desc
->count
, len
),
697 rd_desc
->count
-= ret
;
701 static int __tcp_splice_read(struct sock
*sk
, struct tcp_splice_state
*tss
)
703 /* Store TCP splice context information in read_descriptor_t. */
704 read_descriptor_t rd_desc
= {
709 return tcp_read_sock(sk
, &rd_desc
, tcp_splice_data_recv
);
713 * tcp_splice_read - splice data from TCP socket to a pipe
714 * @sock: socket to splice from
715 * @ppos: position (not valid)
716 * @pipe: pipe to splice to
717 * @len: number of bytes to splice
718 * @flags: splice modifier flags
721 * Will read pages from given socket and fill them into a pipe.
724 ssize_t
tcp_splice_read(struct socket
*sock
, loff_t
*ppos
,
725 struct pipe_inode_info
*pipe
, size_t len
,
728 struct sock
*sk
= sock
->sk
;
729 struct tcp_splice_state tss
= {
738 sock_rps_record_flow(sk
);
740 * We can't seek on a socket input
749 timeo
= sock_rcvtimeo(sk
, sock
->file
->f_flags
& O_NONBLOCK
);
751 ret
= __tcp_splice_read(sk
, &tss
);
757 if (sock_flag(sk
, SOCK_DONE
))
760 ret
= sock_error(sk
);
763 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
765 if (sk
->sk_state
== TCP_CLOSE
) {
767 * This occurs when user tries to read
768 * from never connected socket.
770 if (!sock_flag(sk
, SOCK_DONE
))
778 sk_wait_data(sk
, &timeo
);
779 if (signal_pending(current
)) {
780 ret
= sock_intr_errno(timeo
);
793 if (sk
->sk_err
|| sk
->sk_state
== TCP_CLOSE
||
794 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
795 signal_pending(current
))
806 EXPORT_SYMBOL(tcp_splice_read
);
808 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
)
812 /* The TCP header must be at least 32-bit aligned. */
813 size
= ALIGN(size
, 4);
815 skb
= alloc_skb_fclone(size
+ sk
->sk_prot
->max_header
, gfp
);
817 if (sk_wmem_schedule(sk
, skb
->truesize
)) {
818 skb_reserve(skb
, sk
->sk_prot
->max_header
);
820 * Make sure that we have exactly size bytes
821 * available to the caller, no more, no less.
823 skb
->reserved_tailroom
= skb
->end
- skb
->tail
- size
;
828 sk
->sk_prot
->enter_memory_pressure(sk
);
829 sk_stream_moderate_sndbuf(sk
);
834 static unsigned int tcp_xmit_size_goal(struct sock
*sk
, u32 mss_now
,
837 struct tcp_sock
*tp
= tcp_sk(sk
);
838 u32 xmit_size_goal
, old_size_goal
;
840 xmit_size_goal
= mss_now
;
842 if (large_allowed
&& sk_can_gso(sk
)) {
845 /* Maybe we should/could use sk->sk_prot->max_header here ? */
846 hlen
= inet_csk(sk
)->icsk_af_ops
->net_header_len
+
847 inet_csk(sk
)->icsk_ext_hdr_len
+
850 /* Goal is to send at least one packet per ms,
851 * not one big TSO packet every 100 ms.
852 * This preserves ACK clocking and is consistent
853 * with tcp_tso_should_defer() heuristic.
855 gso_size
= sk
->sk_pacing_rate
/ (2 * MSEC_PER_SEC
);
856 gso_size
= max_t(u32
, gso_size
,
857 sysctl_tcp_min_tso_segs
* mss_now
);
859 xmit_size_goal
= min_t(u32
, gso_size
,
860 sk
->sk_gso_max_size
- 1 - hlen
);
862 xmit_size_goal
= tcp_bound_to_half_wnd(tp
, xmit_size_goal
);
864 /* We try hard to avoid divides here */
865 old_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
867 if (likely(old_size_goal
<= xmit_size_goal
&&
868 old_size_goal
+ mss_now
> xmit_size_goal
)) {
869 xmit_size_goal
= old_size_goal
;
871 tp
->xmit_size_goal_segs
=
872 min_t(u16
, xmit_size_goal
/ mss_now
,
873 sk
->sk_gso_max_segs
);
874 xmit_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
878 return max(xmit_size_goal
, mss_now
);
881 static int tcp_send_mss(struct sock
*sk
, int *size_goal
, int flags
)
885 mss_now
= tcp_current_mss(sk
);
886 *size_goal
= tcp_xmit_size_goal(sk
, mss_now
, !(flags
& MSG_OOB
));
891 static ssize_t
do_tcp_sendpages(struct sock
*sk
, struct page
*page
, int offset
,
892 size_t size
, int flags
)
894 struct tcp_sock
*tp
= tcp_sk(sk
);
895 int mss_now
, size_goal
;
898 long timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
900 /* Wait for a connection to finish. One exception is TCP Fast Open
901 * (passive side) where data is allowed to be sent before a connection
902 * is fully established.
904 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
905 !tcp_passive_fastopen(sk
)) {
906 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
910 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
912 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
916 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
920 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
924 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
926 if (!sk_stream_memory_free(sk
))
927 goto wait_for_sndbuf
;
929 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
);
931 goto wait_for_memory
;
940 i
= skb_shinfo(skb
)->nr_frags
;
941 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
942 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
943 tcp_mark_push(tp
, skb
);
946 if (!sk_wmem_schedule(sk
, copy
))
947 goto wait_for_memory
;
950 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
953 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
955 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
958 skb
->data_len
+= copy
;
959 skb
->truesize
+= copy
;
960 sk
->sk_wmem_queued
+= copy
;
961 sk_mem_charge(sk
, copy
);
962 skb
->ip_summed
= CHECKSUM_PARTIAL
;
963 tp
->write_seq
+= copy
;
964 TCP_SKB_CB(skb
)->end_seq
+= copy
;
965 tcp_skb_pcount_set(skb
, 0);
968 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
972 if (!(size
-= copy
)) {
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 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
996 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1000 if (copied
&& !(flags
& MSG_SENDPAGE_NOTLAST
))
1001 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
, size_goal
);
1008 return sk_stream_error(sk
, flags
, err
);
1011 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
1012 size_t size
, int flags
)
1016 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
1017 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
1018 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
1022 res
= do_tcp_sendpages(sk
, page
, offset
, size
, flags
);
1026 EXPORT_SYMBOL(tcp_sendpage
);
1028 static inline int select_size(const struct sock
*sk
, bool sg
)
1030 const struct tcp_sock
*tp
= tcp_sk(sk
);
1031 int tmp
= tp
->mss_cache
;
1034 if (sk_can_gso(sk
)) {
1035 /* Small frames wont use a full page:
1036 * Payload will immediately follow tcp header.
1038 tmp
= SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER
);
1040 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
1042 if (tmp
>= pgbreak
&&
1043 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
1051 void tcp_free_fastopen_req(struct tcp_sock
*tp
)
1053 if (tp
->fastopen_req
!= NULL
) {
1054 kfree(tp
->fastopen_req
);
1055 tp
->fastopen_req
= NULL
;
1059 static int tcp_sendmsg_fastopen(struct sock
*sk
, struct msghdr
*msg
,
1060 int *copied
, size_t size
)
1062 struct tcp_sock
*tp
= tcp_sk(sk
);
1065 if (!(sysctl_tcp_fastopen
& TFO_CLIENT_ENABLE
))
1067 if (tp
->fastopen_req
!= NULL
)
1068 return -EALREADY
; /* Another Fast Open is in progress */
1070 tp
->fastopen_req
= kzalloc(sizeof(struct tcp_fastopen_request
),
1072 if (unlikely(tp
->fastopen_req
== NULL
))
1074 tp
->fastopen_req
->data
= msg
;
1075 tp
->fastopen_req
->size
= size
;
1077 flags
= (msg
->msg_flags
& MSG_DONTWAIT
) ? O_NONBLOCK
: 0;
1078 err
= __inet_stream_connect(sk
->sk_socket
, msg
->msg_name
,
1079 msg
->msg_namelen
, flags
);
1080 *copied
= tp
->fastopen_req
->copied
;
1081 tcp_free_fastopen_req(tp
);
1085 int tcp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1089 struct tcp_sock
*tp
= tcp_sk(sk
);
1090 struct sk_buff
*skb
;
1091 int iovlen
, flags
, err
, copied
= 0;
1092 int mss_now
= 0, size_goal
, copied_syn
= 0, offset
= 0;
1098 flags
= msg
->msg_flags
;
1099 if (flags
& MSG_FASTOPEN
) {
1100 err
= tcp_sendmsg_fastopen(sk
, msg
, &copied_syn
, size
);
1101 if (err
== -EINPROGRESS
&& copied_syn
> 0)
1105 offset
= copied_syn
;
1108 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
1110 /* Wait for a connection to finish. One exception is TCP Fast Open
1111 * (passive side) where data is allowed to be sent before a connection
1112 * is fully established.
1114 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
1115 !tcp_passive_fastopen(sk
)) {
1116 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
1120 if (unlikely(tp
->repair
)) {
1121 if (tp
->repair_queue
== TCP_RECV_QUEUE
) {
1122 copied
= tcp_send_rcvq(sk
, msg
, size
);
1127 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1130 /* 'common' sending to sendq */
1133 /* This should be in poll */
1134 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
1136 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1138 /* Ok commence sending. */
1139 iovlen
= msg
->msg_iovlen
;
1144 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
1147 sg
= !!(sk
->sk_route_caps
& NETIF_F_SG
);
1149 while (--iovlen
>= 0) {
1150 size_t seglen
= iov
->iov_len
;
1151 unsigned char __user
*from
= iov
->iov_base
;
1154 if (unlikely(offset
> 0)) { /* Skip bytes copied in SYN */
1155 if (offset
>= seglen
) {
1164 while (seglen
> 0) {
1166 int max
= size_goal
;
1168 skb
= tcp_write_queue_tail(sk
);
1169 if (tcp_send_head(sk
)) {
1170 if (skb
->ip_summed
== CHECKSUM_NONE
)
1172 copy
= max
- skb
->len
;
1177 /* Allocate new segment. If the interface is SG,
1178 * allocate skb fitting to single page.
1180 if (!sk_stream_memory_free(sk
))
1181 goto wait_for_sndbuf
;
1183 skb
= sk_stream_alloc_skb(sk
,
1184 select_size(sk
, sg
),
1187 goto wait_for_memory
;
1190 * Check whether we can use HW checksum.
1192 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
1193 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1195 skb_entail(sk
, skb
);
1199 /* All packets are restored as if they have
1200 * already been sent. skb_mstamp isn't set to
1201 * avoid wrong rtt estimation.
1204 TCP_SKB_CB(skb
)->sacked
|= TCPCB_REPAIRED
;
1207 /* Try to append data to the end of skb. */
1211 /* Where to copy to? */
1212 if (skb_availroom(skb
) > 0) {
1213 /* We have some space in skb head. Superb! */
1214 copy
= min_t(int, copy
, skb_availroom(skb
));
1215 err
= skb_add_data_nocache(sk
, skb
, from
, copy
);
1220 int i
= skb_shinfo(skb
)->nr_frags
;
1221 struct page_frag
*pfrag
= sk_page_frag(sk
);
1223 if (!sk_page_frag_refill(sk
, pfrag
))
1224 goto wait_for_memory
;
1226 if (!skb_can_coalesce(skb
, i
, pfrag
->page
,
1228 if (i
== MAX_SKB_FRAGS
|| !sg
) {
1229 tcp_mark_push(tp
, skb
);
1235 copy
= min_t(int, copy
, pfrag
->size
- pfrag
->offset
);
1237 if (!sk_wmem_schedule(sk
, copy
))
1238 goto wait_for_memory
;
1240 err
= skb_copy_to_page_nocache(sk
, from
, skb
,
1247 /* Update the skb. */
1249 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
1251 skb_fill_page_desc(skb
, i
, pfrag
->page
,
1252 pfrag
->offset
, copy
);
1253 get_page(pfrag
->page
);
1255 pfrag
->offset
+= copy
;
1259 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
1261 tp
->write_seq
+= copy
;
1262 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1263 tcp_skb_pcount_set(skb
, 0);
1267 if ((seglen
-= copy
) == 0 && iovlen
== 0) {
1268 tcp_tx_timestamp(sk
, skb
);
1272 if (skb
->len
< max
|| (flags
& MSG_OOB
) || unlikely(tp
->repair
))
1275 if (forced_push(tp
)) {
1276 tcp_mark_push(tp
, skb
);
1277 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1278 } else if (skb
== tcp_send_head(sk
))
1279 tcp_push_one(sk
, mss_now
);
1283 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1286 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
,
1287 TCP_NAGLE_PUSH
, size_goal
);
1289 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1292 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1298 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
, size_goal
);
1301 return copied
+ copied_syn
;
1305 tcp_unlink_write_queue(skb
, sk
);
1306 /* It is the one place in all of TCP, except connection
1307 * reset, where we can be unlinking the send_head.
1309 tcp_check_send_head(sk
, skb
);
1310 sk_wmem_free_skb(sk
, skb
);
1314 if (copied
+ copied_syn
)
1317 err
= sk_stream_error(sk
, flags
, err
);
1321 EXPORT_SYMBOL(tcp_sendmsg
);
1324 * Handle reading urgent data. BSD has very simple semantics for
1325 * this, no blocking and very strange errors 8)
1328 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1330 struct tcp_sock
*tp
= tcp_sk(sk
);
1332 /* No URG data to read. */
1333 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1334 tp
->urg_data
== TCP_URG_READ
)
1335 return -EINVAL
; /* Yes this is right ! */
1337 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1340 if (tp
->urg_data
& TCP_URG_VALID
) {
1342 char c
= tp
->urg_data
;
1344 if (!(flags
& MSG_PEEK
))
1345 tp
->urg_data
= TCP_URG_READ
;
1347 /* Read urgent data. */
1348 msg
->msg_flags
|= MSG_OOB
;
1351 if (!(flags
& MSG_TRUNC
))
1352 err
= memcpy_toiovec(msg
->msg_iov
, &c
, 1);
1355 msg
->msg_flags
|= MSG_TRUNC
;
1357 return err
? -EFAULT
: len
;
1360 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1363 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1364 * the available implementations agree in this case:
1365 * this call should never block, independent of the
1366 * blocking state of the socket.
1367 * Mike <pall@rz.uni-karlsruhe.de>
1372 static int tcp_peek_sndq(struct sock
*sk
, struct msghdr
*msg
, int len
)
1374 struct sk_buff
*skb
;
1375 int copied
= 0, err
= 0;
1377 /* XXX -- need to support SO_PEEK_OFF */
1379 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
1380 err
= skb_copy_datagram_iovec(skb
, 0, msg
->msg_iov
, skb
->len
);
1387 return err
?: copied
;
1390 /* Clean up the receive buffer for full frames taken by the user,
1391 * then send an ACK if necessary. COPIED is the number of bytes
1392 * tcp_recvmsg has given to the user so far, it speeds up the
1393 * calculation of whether or not we must ACK for the sake of
1396 static void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1398 struct tcp_sock
*tp
= tcp_sk(sk
);
1399 bool time_to_ack
= false;
1401 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1403 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1404 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1405 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1407 if (inet_csk_ack_scheduled(sk
)) {
1408 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1409 /* Delayed ACKs frequently hit locked sockets during bulk
1411 if (icsk
->icsk_ack
.blocked
||
1412 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1413 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1415 * If this read emptied read buffer, we send ACK, if
1416 * connection is not bidirectional, user drained
1417 * receive buffer and there was a small segment
1421 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1422 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1423 !icsk
->icsk_ack
.pingpong
)) &&
1424 !atomic_read(&sk
->sk_rmem_alloc
)))
1428 /* We send an ACK if we can now advertise a non-zero window
1429 * which has been raised "significantly".
1431 * Even if window raised up to infinity, do not send window open ACK
1432 * in states, where we will not receive more. It is useless.
1434 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1435 __u32 rcv_window_now
= tcp_receive_window(tp
);
1437 /* Optimize, __tcp_select_window() is not cheap. */
1438 if (2*rcv_window_now
<= tp
->window_clamp
) {
1439 __u32 new_window
= __tcp_select_window(sk
);
1441 /* Send ACK now, if this read freed lots of space
1442 * in our buffer. Certainly, new_window is new window.
1443 * We can advertise it now, if it is not less than current one.
1444 * "Lots" means "at least twice" here.
1446 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1454 static void tcp_prequeue_process(struct sock
*sk
)
1456 struct sk_buff
*skb
;
1457 struct tcp_sock
*tp
= tcp_sk(sk
);
1459 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1461 /* RX process wants to run with disabled BHs, though it is not
1464 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1465 sk_backlog_rcv(sk
, skb
);
1468 /* Clear memory counter. */
1469 tp
->ucopy
.memory
= 0;
1472 static struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1474 struct sk_buff
*skb
;
1477 while ((skb
= skb_peek(&sk
->sk_receive_queue
)) != NULL
) {
1478 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1479 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_SYN
)
1481 if (offset
< skb
->len
|| (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)) {
1485 /* This looks weird, but this can happen if TCP collapsing
1486 * splitted a fat GRO packet, while we released socket lock
1487 * in skb_splice_bits()
1489 sk_eat_skb(sk
, skb
);
1495 * This routine provides an alternative to tcp_recvmsg() for routines
1496 * that would like to handle copying from skbuffs directly in 'sendfile'
1499 * - It is assumed that the socket was locked by the caller.
1500 * - The routine does not block.
1501 * - At present, there is no support for reading OOB data
1502 * or for 'peeking' the socket using this routine
1503 * (although both would be easy to implement).
1505 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1506 sk_read_actor_t recv_actor
)
1508 struct sk_buff
*skb
;
1509 struct tcp_sock
*tp
= tcp_sk(sk
);
1510 u32 seq
= tp
->copied_seq
;
1514 if (sk
->sk_state
== TCP_LISTEN
)
1516 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1517 if (offset
< skb
->len
) {
1521 len
= skb
->len
- offset
;
1522 /* Stop reading if we hit a patch of urgent data */
1524 u32 urg_offset
= tp
->urg_seq
- seq
;
1525 if (urg_offset
< len
)
1530 used
= recv_actor(desc
, skb
, offset
, len
);
1535 } else if (used
<= len
) {
1540 /* If recv_actor drops the lock (e.g. TCP splice
1541 * receive) the skb pointer might be invalid when
1542 * getting here: tcp_collapse might have deleted it
1543 * while aggregating skbs from the socket queue.
1545 skb
= tcp_recv_skb(sk
, seq
- 1, &offset
);
1548 /* TCP coalescing might have appended data to the skb.
1549 * Try to splice more frags
1551 if (offset
+ 1 != skb
->len
)
1554 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
) {
1555 sk_eat_skb(sk
, skb
);
1559 sk_eat_skb(sk
, skb
);
1562 tp
->copied_seq
= seq
;
1564 tp
->copied_seq
= seq
;
1566 tcp_rcv_space_adjust(sk
);
1568 /* Clean up data we have read: This will do ACK frames. */
1570 tcp_recv_skb(sk
, seq
, &offset
);
1571 tcp_cleanup_rbuf(sk
, copied
);
1575 EXPORT_SYMBOL(tcp_read_sock
);
1578 * This routine copies from a sock struct into the user buffer.
1580 * Technical note: in 2.3 we work on _locked_ socket, so that
1581 * tricks with *seq access order and skb->users are not required.
1582 * Probably, code can be easily improved even more.
1585 int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1586 size_t len
, int nonblock
, int flags
, int *addr_len
)
1588 struct tcp_sock
*tp
= tcp_sk(sk
);
1594 int target
; /* Read at least this many bytes */
1596 struct task_struct
*user_recv
= NULL
;
1597 struct sk_buff
*skb
;
1600 if (unlikely(flags
& MSG_ERRQUEUE
))
1601 return ip_recv_error(sk
, msg
, len
, addr_len
);
1603 if (sk_can_busy_loop(sk
) && skb_queue_empty(&sk
->sk_receive_queue
) &&
1604 (sk
->sk_state
== TCP_ESTABLISHED
))
1605 sk_busy_loop(sk
, nonblock
);
1610 if (sk
->sk_state
== TCP_LISTEN
)
1613 timeo
= sock_rcvtimeo(sk
, nonblock
);
1615 /* Urgent data needs to be handled specially. */
1616 if (flags
& MSG_OOB
)
1619 if (unlikely(tp
->repair
)) {
1621 if (!(flags
& MSG_PEEK
))
1624 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
1628 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1631 /* 'common' recv queue MSG_PEEK-ing */
1634 seq
= &tp
->copied_seq
;
1635 if (flags
& MSG_PEEK
) {
1636 peek_seq
= tp
->copied_seq
;
1640 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1645 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1646 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1649 if (signal_pending(current
)) {
1650 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1655 /* Next get a buffer. */
1657 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1658 /* Now that we have two receive queues this
1661 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1662 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1663 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1667 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1668 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_SYN
)
1670 if (offset
< skb
->len
)
1672 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
1674 WARN(!(flags
& MSG_PEEK
),
1675 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1676 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
, flags
);
1679 /* Well, if we have backlog, try to process it now yet. */
1681 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1686 sk
->sk_state
== TCP_CLOSE
||
1687 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1689 signal_pending(current
))
1692 if (sock_flag(sk
, SOCK_DONE
))
1696 copied
= sock_error(sk
);
1700 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1703 if (sk
->sk_state
== TCP_CLOSE
) {
1704 if (!sock_flag(sk
, SOCK_DONE
)) {
1705 /* This occurs when user tries to read
1706 * from never connected socket.
1719 if (signal_pending(current
)) {
1720 copied
= sock_intr_errno(timeo
);
1725 tcp_cleanup_rbuf(sk
, copied
);
1727 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1728 /* Install new reader */
1729 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1730 user_recv
= current
;
1731 tp
->ucopy
.task
= user_recv
;
1732 tp
->ucopy
.iov
= msg
->msg_iov
;
1735 tp
->ucopy
.len
= len
;
1737 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1738 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1740 /* Ugly... If prequeue is not empty, we have to
1741 * process it before releasing socket, otherwise
1742 * order will be broken at second iteration.
1743 * More elegant solution is required!!!
1745 * Look: we have the following (pseudo)queues:
1747 * 1. packets in flight
1752 * Each queue can be processed only if the next ones
1753 * are empty. At this point we have empty receive_queue.
1754 * But prequeue _can_ be not empty after 2nd iteration,
1755 * when we jumped to start of loop because backlog
1756 * processing added something to receive_queue.
1757 * We cannot release_sock(), because backlog contains
1758 * packets arrived _after_ prequeued ones.
1760 * Shortly, algorithm is clear --- to process all
1761 * the queues in order. We could make it more directly,
1762 * requeueing packets from backlog to prequeue, if
1763 * is not empty. It is more elegant, but eats cycles,
1766 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1769 /* __ Set realtime policy in scheduler __ */
1772 if (copied
>= target
) {
1773 /* Do not sleep, just process backlog. */
1777 sk_wait_data(sk
, &timeo
);
1782 /* __ Restore normal policy in scheduler __ */
1784 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1785 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1790 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1791 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1793 tcp_prequeue_process(sk
);
1795 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1796 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1802 if ((flags
& MSG_PEEK
) &&
1803 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1804 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1806 task_pid_nr(current
));
1807 peek_seq
= tp
->copied_seq
;
1812 /* Ok so how much can we use? */
1813 used
= skb
->len
- offset
;
1817 /* Do we have urgent data here? */
1819 u32 urg_offset
= tp
->urg_seq
- *seq
;
1820 if (urg_offset
< used
) {
1822 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1835 if (!(flags
& MSG_TRUNC
)) {
1836 err
= skb_copy_datagram_iovec(skb
, offset
,
1837 msg
->msg_iov
, used
);
1839 /* Exception. Bailout! */
1850 tcp_rcv_space_adjust(sk
);
1853 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1855 tcp_fast_path_check(sk
);
1857 if (used
+ offset
< skb
->len
)
1860 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
1862 if (!(flags
& MSG_PEEK
))
1863 sk_eat_skb(sk
, skb
);
1867 /* Process the FIN. */
1869 if (!(flags
& MSG_PEEK
))
1870 sk_eat_skb(sk
, skb
);
1875 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1878 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1880 tcp_prequeue_process(sk
);
1882 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1883 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1889 tp
->ucopy
.task
= NULL
;
1893 /* According to UNIX98, msg_name/msg_namelen are ignored
1894 * on connected socket. I was just happy when found this 8) --ANK
1897 /* Clean up data we have read: This will do ACK frames. */
1898 tcp_cleanup_rbuf(sk
, copied
);
1908 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1912 err
= tcp_peek_sndq(sk
, msg
, len
);
1915 EXPORT_SYMBOL(tcp_recvmsg
);
1917 void tcp_set_state(struct sock
*sk
, int state
)
1919 int oldstate
= sk
->sk_state
;
1922 case TCP_ESTABLISHED
:
1923 if (oldstate
!= TCP_ESTABLISHED
)
1924 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1928 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1929 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1931 sk
->sk_prot
->unhash(sk
);
1932 if (inet_csk(sk
)->icsk_bind_hash
&&
1933 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1937 if (oldstate
== TCP_ESTABLISHED
)
1938 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1941 /* Change state AFTER socket is unhashed to avoid closed
1942 * socket sitting in hash tables.
1944 sk
->sk_state
= state
;
1947 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
1950 EXPORT_SYMBOL_GPL(tcp_set_state
);
1953 * State processing on a close. This implements the state shift for
1954 * sending our FIN frame. Note that we only send a FIN for some
1955 * states. A shutdown() may have already sent the FIN, or we may be
1959 static const unsigned char new_state
[16] = {
1960 /* current state: new state: action: */
1961 /* (Invalid) */ TCP_CLOSE
,
1962 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1963 /* TCP_SYN_SENT */ TCP_CLOSE
,
1964 /* TCP_SYN_RECV */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1965 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1
,
1966 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2
,
1967 /* TCP_TIME_WAIT */ TCP_CLOSE
,
1968 /* TCP_CLOSE */ TCP_CLOSE
,
1969 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK
| TCP_ACTION_FIN
,
1970 /* TCP_LAST_ACK */ TCP_LAST_ACK
,
1971 /* TCP_LISTEN */ TCP_CLOSE
,
1972 /* TCP_CLOSING */ TCP_CLOSING
,
1975 static int tcp_close_state(struct sock
*sk
)
1977 int next
= (int)new_state
[sk
->sk_state
];
1978 int ns
= next
& TCP_STATE_MASK
;
1980 tcp_set_state(sk
, ns
);
1982 return next
& TCP_ACTION_FIN
;
1986 * Shutdown the sending side of a connection. Much like close except
1987 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1990 void tcp_shutdown(struct sock
*sk
, int how
)
1992 /* We need to grab some memory, and put together a FIN,
1993 * and then put it into the queue to be sent.
1994 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1996 if (!(how
& SEND_SHUTDOWN
))
1999 /* If we've already sent a FIN, or it's a closed state, skip this. */
2000 if ((1 << sk
->sk_state
) &
2001 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
2002 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
2003 /* Clear out any half completed packets. FIN if needed. */
2004 if (tcp_close_state(sk
))
2008 EXPORT_SYMBOL(tcp_shutdown
);
2010 bool tcp_check_oom(struct sock
*sk
, int shift
)
2012 bool too_many_orphans
, out_of_socket_memory
;
2014 too_many_orphans
= tcp_too_many_orphans(sk
, shift
);
2015 out_of_socket_memory
= tcp_out_of_memory(sk
);
2017 if (too_many_orphans
)
2018 net_info_ratelimited("too many orphaned sockets\n");
2019 if (out_of_socket_memory
)
2020 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2021 return too_many_orphans
|| out_of_socket_memory
;
2024 void tcp_close(struct sock
*sk
, long timeout
)
2026 struct sk_buff
*skb
;
2027 int data_was_unread
= 0;
2031 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2033 if (sk
->sk_state
== TCP_LISTEN
) {
2034 tcp_set_state(sk
, TCP_CLOSE
);
2037 inet_csk_listen_stop(sk
);
2039 goto adjudge_to_death
;
2042 /* We need to flush the recv. buffs. We do this only on the
2043 * descriptor close, not protocol-sourced closes, because the
2044 * reader process may not have drained the data yet!
2046 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
2047 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
;
2049 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
2051 data_was_unread
+= len
;
2057 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2058 if (sk
->sk_state
== TCP_CLOSE
)
2059 goto adjudge_to_death
;
2061 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2062 * data was lost. To witness the awful effects of the old behavior of
2063 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2064 * GET in an FTP client, suspend the process, wait for the client to
2065 * advertise a zero window, then kill -9 the FTP client, wheee...
2066 * Note: timeout is always zero in such a case.
2068 if (unlikely(tcp_sk(sk
)->repair
)) {
2069 sk
->sk_prot
->disconnect(sk
, 0);
2070 } else if (data_was_unread
) {
2071 /* Unread data was tossed, zap the connection. */
2072 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
2073 tcp_set_state(sk
, TCP_CLOSE
);
2074 tcp_send_active_reset(sk
, sk
->sk_allocation
);
2075 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
2076 /* Check zero linger _after_ checking for unread data. */
2077 sk
->sk_prot
->disconnect(sk
, 0);
2078 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
2079 } else if (tcp_close_state(sk
)) {
2080 /* We FIN if the application ate all the data before
2081 * zapping the connection.
2084 /* RED-PEN. Formally speaking, we have broken TCP state
2085 * machine. State transitions:
2087 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2088 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2089 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2091 * are legal only when FIN has been sent (i.e. in window),
2092 * rather than queued out of window. Purists blame.
2094 * F.e. "RFC state" is ESTABLISHED,
2095 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2097 * The visible declinations are that sometimes
2098 * we enter time-wait state, when it is not required really
2099 * (harmless), do not send active resets, when they are
2100 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2101 * they look as CLOSING or LAST_ACK for Linux)
2102 * Probably, I missed some more holelets.
2104 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2105 * in a single packet! (May consider it later but will
2106 * probably need API support or TCP_CORK SYN-ACK until
2107 * data is written and socket is closed.)
2112 sk_stream_wait_close(sk
, timeout
);
2115 state
= sk
->sk_state
;
2119 /* It is the last release_sock in its life. It will remove backlog. */
2123 /* Now socket is owned by kernel and we acquire BH lock
2124 to finish close. No need to check for user refs.
2128 WARN_ON(sock_owned_by_user(sk
));
2130 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
2132 /* Have we already been destroyed by a softirq or backlog? */
2133 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
2136 /* This is a (useful) BSD violating of the RFC. There is a
2137 * problem with TCP as specified in that the other end could
2138 * keep a socket open forever with no application left this end.
2139 * We use a 1 minute timeout (about the same as BSD) then kill
2140 * our end. If they send after that then tough - BUT: long enough
2141 * that we won't make the old 4*rto = almost no time - whoops
2144 * Nope, it was not mistake. It is really desired behaviour
2145 * f.e. on http servers, when such sockets are useless, but
2146 * consume significant resources. Let's do it with special
2147 * linger2 option. --ANK
2150 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
2151 struct tcp_sock
*tp
= tcp_sk(sk
);
2152 if (tp
->linger2
< 0) {
2153 tcp_set_state(sk
, TCP_CLOSE
);
2154 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2155 NET_INC_STATS_BH(sock_net(sk
),
2156 LINUX_MIB_TCPABORTONLINGER
);
2158 const int tmo
= tcp_fin_time(sk
);
2160 if (tmo
> TCP_TIMEWAIT_LEN
) {
2161 inet_csk_reset_keepalive_timer(sk
,
2162 tmo
- TCP_TIMEWAIT_LEN
);
2164 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2169 if (sk
->sk_state
!= TCP_CLOSE
) {
2171 if (tcp_check_oom(sk
, 0)) {
2172 tcp_set_state(sk
, TCP_CLOSE
);
2173 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2174 NET_INC_STATS_BH(sock_net(sk
),
2175 LINUX_MIB_TCPABORTONMEMORY
);
2179 if (sk
->sk_state
== TCP_CLOSE
) {
2180 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
2181 /* We could get here with a non-NULL req if the socket is
2182 * aborted (e.g., closed with unread data) before 3WHS
2186 reqsk_fastopen_remove(sk
, req
, false);
2187 inet_csk_destroy_sock(sk
);
2189 /* Otherwise, socket is reprieved until protocol close. */
2196 EXPORT_SYMBOL(tcp_close
);
2198 /* These states need RST on ABORT according to RFC793 */
2200 static inline bool tcp_need_reset(int state
)
2202 return (1 << state
) &
2203 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2204 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2207 int tcp_disconnect(struct sock
*sk
, int flags
)
2209 struct inet_sock
*inet
= inet_sk(sk
);
2210 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2211 struct tcp_sock
*tp
= tcp_sk(sk
);
2213 int old_state
= sk
->sk_state
;
2215 if (old_state
!= TCP_CLOSE
)
2216 tcp_set_state(sk
, TCP_CLOSE
);
2218 /* ABORT function of RFC793 */
2219 if (old_state
== TCP_LISTEN
) {
2220 inet_csk_listen_stop(sk
);
2221 } else if (unlikely(tp
->repair
)) {
2222 sk
->sk_err
= ECONNABORTED
;
2223 } else if (tcp_need_reset(old_state
) ||
2224 (tp
->snd_nxt
!= tp
->write_seq
&&
2225 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2226 /* The last check adjusts for discrepancy of Linux wrt. RFC
2229 tcp_send_active_reset(sk
, gfp_any());
2230 sk
->sk_err
= ECONNRESET
;
2231 } else if (old_state
== TCP_SYN_SENT
)
2232 sk
->sk_err
= ECONNRESET
;
2234 tcp_clear_xmit_timers(sk
);
2235 __skb_queue_purge(&sk
->sk_receive_queue
);
2236 tcp_write_queue_purge(sk
);
2237 __skb_queue_purge(&tp
->out_of_order_queue
);
2239 inet
->inet_dport
= 0;
2241 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2242 inet_reset_saddr(sk
);
2244 sk
->sk_shutdown
= 0;
2245 sock_reset_flag(sk
, SOCK_DONE
);
2247 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2249 icsk
->icsk_backoff
= 0;
2251 icsk
->icsk_probes_out
= 0;
2252 tp
->packets_out
= 0;
2253 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2254 tp
->snd_cwnd_cnt
= 0;
2255 tp
->window_clamp
= 0;
2256 tcp_set_ca_state(sk
, TCP_CA_Open
);
2257 tcp_clear_retrans(tp
);
2258 inet_csk_delack_init(sk
);
2259 tcp_init_send_head(sk
);
2260 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2263 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2265 sk
->sk_error_report(sk
);
2268 EXPORT_SYMBOL(tcp_disconnect
);
2270 void tcp_sock_destruct(struct sock
*sk
)
2272 inet_sock_destruct(sk
);
2274 kfree(inet_csk(sk
)->icsk_accept_queue
.fastopenq
);
2277 static inline bool tcp_can_repair_sock(const struct sock
*sk
)
2279 return ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
) &&
2280 ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_ESTABLISHED
));
2283 static int tcp_repair_options_est(struct tcp_sock
*tp
,
2284 struct tcp_repair_opt __user
*optbuf
, unsigned int len
)
2286 struct tcp_repair_opt opt
;
2288 while (len
>= sizeof(opt
)) {
2289 if (copy_from_user(&opt
, optbuf
, sizeof(opt
)))
2295 switch (opt
.opt_code
) {
2297 tp
->rx_opt
.mss_clamp
= opt
.opt_val
;
2301 u16 snd_wscale
= opt
.opt_val
& 0xFFFF;
2302 u16 rcv_wscale
= opt
.opt_val
>> 16;
2304 if (snd_wscale
> 14 || rcv_wscale
> 14)
2307 tp
->rx_opt
.snd_wscale
= snd_wscale
;
2308 tp
->rx_opt
.rcv_wscale
= rcv_wscale
;
2309 tp
->rx_opt
.wscale_ok
= 1;
2312 case TCPOPT_SACK_PERM
:
2313 if (opt
.opt_val
!= 0)
2316 tp
->rx_opt
.sack_ok
|= TCP_SACK_SEEN
;
2317 if (sysctl_tcp_fack
)
2318 tcp_enable_fack(tp
);
2320 case TCPOPT_TIMESTAMP
:
2321 if (opt
.opt_val
!= 0)
2324 tp
->rx_opt
.tstamp_ok
= 1;
2333 * Socket option code for TCP.
2335 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2336 int optname
, char __user
*optval
, unsigned int optlen
)
2338 struct tcp_sock
*tp
= tcp_sk(sk
);
2339 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2343 /* These are data/string values, all the others are ints */
2345 case TCP_CONGESTION
: {
2346 char name
[TCP_CA_NAME_MAX
];
2351 val
= strncpy_from_user(name
, optval
,
2352 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2358 err
= tcp_set_congestion_control(sk
, name
);
2367 if (optlen
< sizeof(int))
2370 if (get_user(val
, (int __user
*)optval
))
2377 /* Values greater than interface MTU won't take effect. However
2378 * at the point when this call is done we typically don't yet
2379 * know which interface is going to be used */
2380 if (val
< TCP_MIN_MSS
|| val
> MAX_TCP_WINDOW
) {
2384 tp
->rx_opt
.user_mss
= val
;
2389 /* TCP_NODELAY is weaker than TCP_CORK, so that
2390 * this option on corked socket is remembered, but
2391 * it is not activated until cork is cleared.
2393 * However, when TCP_NODELAY is set we make
2394 * an explicit push, which overrides even TCP_CORK
2395 * for currently queued segments.
2397 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2398 tcp_push_pending_frames(sk
);
2400 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2404 case TCP_THIN_LINEAR_TIMEOUTS
:
2405 if (val
< 0 || val
> 1)
2411 case TCP_THIN_DUPACK
:
2412 if (val
< 0 || val
> 1)
2415 tp
->thin_dupack
= val
;
2416 if (tp
->thin_dupack
)
2417 tcp_disable_early_retrans(tp
);
2422 if (!tcp_can_repair_sock(sk
))
2424 else if (val
== 1) {
2426 sk
->sk_reuse
= SK_FORCE_REUSE
;
2427 tp
->repair_queue
= TCP_NO_QUEUE
;
2428 } else if (val
== 0) {
2430 sk
->sk_reuse
= SK_NO_REUSE
;
2431 tcp_send_window_probe(sk
);
2437 case TCP_REPAIR_QUEUE
:
2440 else if (val
< TCP_QUEUES_NR
)
2441 tp
->repair_queue
= val
;
2447 if (sk
->sk_state
!= TCP_CLOSE
)
2449 else if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2450 tp
->write_seq
= val
;
2451 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2457 case TCP_REPAIR_OPTIONS
:
2460 else if (sk
->sk_state
== TCP_ESTABLISHED
)
2461 err
= tcp_repair_options_est(tp
,
2462 (struct tcp_repair_opt __user
*)optval
,
2469 /* When set indicates to always queue non-full frames.
2470 * Later the user clears this option and we transmit
2471 * any pending partial frames in the queue. This is
2472 * meant to be used alongside sendfile() to get properly
2473 * filled frames when the user (for example) must write
2474 * out headers with a write() call first and then use
2475 * sendfile to send out the data parts.
2477 * TCP_CORK can be set together with TCP_NODELAY and it is
2478 * stronger than TCP_NODELAY.
2481 tp
->nonagle
|= TCP_NAGLE_CORK
;
2483 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2484 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2485 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2486 tcp_push_pending_frames(sk
);
2491 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2494 tp
->keepalive_time
= val
* HZ
;
2495 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2496 !((1 << sk
->sk_state
) &
2497 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2498 u32 elapsed
= keepalive_time_elapsed(tp
);
2499 if (tp
->keepalive_time
> elapsed
)
2500 elapsed
= tp
->keepalive_time
- elapsed
;
2503 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2508 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2511 tp
->keepalive_intvl
= val
* HZ
;
2514 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2517 tp
->keepalive_probes
= val
;
2520 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2523 icsk
->icsk_syn_retries
= val
;
2529 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2532 tp
->linger2
= val
* HZ
;
2535 case TCP_DEFER_ACCEPT
:
2536 /* Translate value in seconds to number of retransmits */
2537 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2538 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2542 case TCP_WINDOW_CLAMP
:
2544 if (sk
->sk_state
!= TCP_CLOSE
) {
2548 tp
->window_clamp
= 0;
2550 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2551 SOCK_MIN_RCVBUF
/ 2 : val
;
2556 icsk
->icsk_ack
.pingpong
= 1;
2558 icsk
->icsk_ack
.pingpong
= 0;
2559 if ((1 << sk
->sk_state
) &
2560 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2561 inet_csk_ack_scheduled(sk
)) {
2562 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2563 tcp_cleanup_rbuf(sk
, 1);
2565 icsk
->icsk_ack
.pingpong
= 1;
2570 #ifdef CONFIG_TCP_MD5SIG
2572 /* Read the IP->Key mappings from userspace */
2573 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2576 case TCP_USER_TIMEOUT
:
2577 /* Cap the max time in ms TCP will retry or probe the window
2578 * before giving up and aborting (ETIMEDOUT) a connection.
2583 icsk
->icsk_user_timeout
= msecs_to_jiffies(val
);
2587 if (val
>= 0 && ((1 << sk
->sk_state
) & (TCPF_CLOSE
|
2589 err
= fastopen_init_queue(sk
, val
);
2597 tp
->tsoffset
= val
- tcp_time_stamp
;
2599 case TCP_NOTSENT_LOWAT
:
2600 tp
->notsent_lowat
= val
;
2601 sk
->sk_write_space(sk
);
2612 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2613 unsigned int optlen
)
2615 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2617 if (level
!= SOL_TCP
)
2618 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2620 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2622 EXPORT_SYMBOL(tcp_setsockopt
);
2624 #ifdef CONFIG_COMPAT
2625 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2626 char __user
*optval
, unsigned int optlen
)
2628 if (level
!= SOL_TCP
)
2629 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2631 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2633 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2636 /* Return information about state of tcp endpoint in API format. */
2637 void tcp_get_info(const struct sock
*sk
, struct tcp_info
*info
)
2639 const struct tcp_sock
*tp
= tcp_sk(sk
);
2640 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2641 u32 now
= tcp_time_stamp
;
2643 memset(info
, 0, sizeof(*info
));
2645 info
->tcpi_state
= sk
->sk_state
;
2646 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2647 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2648 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2649 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2651 if (tp
->rx_opt
.tstamp_ok
)
2652 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2653 if (tcp_is_sack(tp
))
2654 info
->tcpi_options
|= TCPI_OPT_SACK
;
2655 if (tp
->rx_opt
.wscale_ok
) {
2656 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2657 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2658 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2661 if (tp
->ecn_flags
& TCP_ECN_OK
)
2662 info
->tcpi_options
|= TCPI_OPT_ECN
;
2663 if (tp
->ecn_flags
& TCP_ECN_SEEN
)
2664 info
->tcpi_options
|= TCPI_OPT_ECN_SEEN
;
2665 if (tp
->syn_data_acked
)
2666 info
->tcpi_options
|= TCPI_OPT_SYN_DATA
;
2668 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2669 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2670 info
->tcpi_snd_mss
= tp
->mss_cache
;
2671 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2673 if (sk
->sk_state
== TCP_LISTEN
) {
2674 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2675 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2677 info
->tcpi_unacked
= tp
->packets_out
;
2678 info
->tcpi_sacked
= tp
->sacked_out
;
2680 info
->tcpi_lost
= tp
->lost_out
;
2681 info
->tcpi_retrans
= tp
->retrans_out
;
2682 info
->tcpi_fackets
= tp
->fackets_out
;
2684 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2685 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2686 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2688 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2689 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2690 info
->tcpi_rtt
= tp
->srtt_us
>> 3;
2691 info
->tcpi_rttvar
= tp
->mdev_us
>> 2;
2692 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2693 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2694 info
->tcpi_advmss
= tp
->advmss
;
2695 info
->tcpi_reordering
= tp
->reordering
;
2697 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2698 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2700 info
->tcpi_total_retrans
= tp
->total_retrans
;
2702 info
->tcpi_pacing_rate
= sk
->sk_pacing_rate
!= ~0U ?
2703 sk
->sk_pacing_rate
: ~0ULL;
2704 info
->tcpi_max_pacing_rate
= sk
->sk_max_pacing_rate
!= ~0U ?
2705 sk
->sk_max_pacing_rate
: ~0ULL;
2707 EXPORT_SYMBOL_GPL(tcp_get_info
);
2709 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2710 int optname
, char __user
*optval
, int __user
*optlen
)
2712 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2713 struct tcp_sock
*tp
= tcp_sk(sk
);
2716 if (get_user(len
, optlen
))
2719 len
= min_t(unsigned int, len
, sizeof(int));
2726 val
= tp
->mss_cache
;
2727 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2728 val
= tp
->rx_opt
.user_mss
;
2730 val
= tp
->rx_opt
.mss_clamp
;
2733 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2736 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2739 val
= keepalive_time_when(tp
) / HZ
;
2742 val
= keepalive_intvl_when(tp
) / HZ
;
2745 val
= keepalive_probes(tp
);
2748 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2753 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2755 case TCP_DEFER_ACCEPT
:
2756 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2757 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2759 case TCP_WINDOW_CLAMP
:
2760 val
= tp
->window_clamp
;
2763 struct tcp_info info
;
2765 if (get_user(len
, optlen
))
2768 tcp_get_info(sk
, &info
);
2770 len
= min_t(unsigned int, len
, sizeof(info
));
2771 if (put_user(len
, optlen
))
2773 if (copy_to_user(optval
, &info
, len
))
2778 val
= !icsk
->icsk_ack
.pingpong
;
2781 case TCP_CONGESTION
:
2782 if (get_user(len
, optlen
))
2784 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2785 if (put_user(len
, optlen
))
2787 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2791 case TCP_THIN_LINEAR_TIMEOUTS
:
2794 case TCP_THIN_DUPACK
:
2795 val
= tp
->thin_dupack
;
2802 case TCP_REPAIR_QUEUE
:
2804 val
= tp
->repair_queue
;
2810 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2811 val
= tp
->write_seq
;
2812 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2818 case TCP_USER_TIMEOUT
:
2819 val
= jiffies_to_msecs(icsk
->icsk_user_timeout
);
2823 if (icsk
->icsk_accept_queue
.fastopenq
!= NULL
)
2824 val
= icsk
->icsk_accept_queue
.fastopenq
->max_qlen
;
2830 val
= tcp_time_stamp
+ tp
->tsoffset
;
2832 case TCP_NOTSENT_LOWAT
:
2833 val
= tp
->notsent_lowat
;
2836 return -ENOPROTOOPT
;
2839 if (put_user(len
, optlen
))
2841 if (copy_to_user(optval
, &val
, len
))
2846 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2849 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2851 if (level
!= SOL_TCP
)
2852 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2854 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2856 EXPORT_SYMBOL(tcp_getsockopt
);
2858 #ifdef CONFIG_COMPAT
2859 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2860 char __user
*optval
, int __user
*optlen
)
2862 if (level
!= SOL_TCP
)
2863 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2865 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2867 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2870 #ifdef CONFIG_TCP_MD5SIG
2871 static struct tcp_md5sig_pool __percpu
*tcp_md5sig_pool __read_mostly
;
2872 static DEFINE_MUTEX(tcp_md5sig_mutex
);
2874 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu
*pool
)
2878 for_each_possible_cpu(cpu
) {
2879 struct tcp_md5sig_pool
*p
= per_cpu_ptr(pool
, cpu
);
2881 if (p
->md5_desc
.tfm
)
2882 crypto_free_hash(p
->md5_desc
.tfm
);
2887 static void __tcp_alloc_md5sig_pool(void)
2890 struct tcp_md5sig_pool __percpu
*pool
;
2892 pool
= alloc_percpu(struct tcp_md5sig_pool
);
2896 for_each_possible_cpu(cpu
) {
2897 struct crypto_hash
*hash
;
2899 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
2900 if (IS_ERR_OR_NULL(hash
))
2903 per_cpu_ptr(pool
, cpu
)->md5_desc
.tfm
= hash
;
2905 /* before setting tcp_md5sig_pool, we must commit all writes
2906 * to memory. See ACCESS_ONCE() in tcp_get_md5sig_pool()
2909 tcp_md5sig_pool
= pool
;
2912 __tcp_free_md5sig_pool(pool
);
2915 bool tcp_alloc_md5sig_pool(void)
2917 if (unlikely(!tcp_md5sig_pool
)) {
2918 mutex_lock(&tcp_md5sig_mutex
);
2920 if (!tcp_md5sig_pool
)
2921 __tcp_alloc_md5sig_pool();
2923 mutex_unlock(&tcp_md5sig_mutex
);
2925 return tcp_md5sig_pool
!= NULL
;
2927 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
2931 * tcp_get_md5sig_pool - get md5sig_pool for this user
2933 * We use percpu structure, so if we succeed, we exit with preemption
2934 * and BH disabled, to make sure another thread or softirq handling
2935 * wont try to get same context.
2937 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
2939 struct tcp_md5sig_pool __percpu
*p
;
2942 p
= ACCESS_ONCE(tcp_md5sig_pool
);
2944 return raw_cpu_ptr(p
);
2949 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
2951 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
2952 const struct tcphdr
*th
)
2954 struct scatterlist sg
;
2958 /* We are not allowed to change tcphdr, make a local copy */
2959 memcpy(&hdr
, th
, sizeof(hdr
));
2962 /* options aren't included in the hash */
2963 sg_init_one(&sg
, &hdr
, sizeof(hdr
));
2964 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(hdr
));
2967 EXPORT_SYMBOL(tcp_md5_hash_header
);
2969 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
2970 const struct sk_buff
*skb
, unsigned int header_len
)
2972 struct scatterlist sg
;
2973 const struct tcphdr
*tp
= tcp_hdr(skb
);
2974 struct hash_desc
*desc
= &hp
->md5_desc
;
2976 const unsigned int head_data_len
= skb_headlen(skb
) > header_len
?
2977 skb_headlen(skb
) - header_len
: 0;
2978 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
2979 struct sk_buff
*frag_iter
;
2981 sg_init_table(&sg
, 1);
2983 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
2984 if (crypto_hash_update(desc
, &sg
, head_data_len
))
2987 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
2988 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
2989 unsigned int offset
= f
->page_offset
;
2990 struct page
*page
= skb_frag_page(f
) + (offset
>> PAGE_SHIFT
);
2992 sg_set_page(&sg
, page
, skb_frag_size(f
),
2993 offset_in_page(offset
));
2994 if (crypto_hash_update(desc
, &sg
, skb_frag_size(f
)))
2998 skb_walk_frags(skb
, frag_iter
)
2999 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3004 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3006 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, const struct tcp_md5sig_key
*key
)
3008 struct scatterlist sg
;
3010 sg_init_one(&sg
, key
->key
, key
->keylen
);
3011 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3013 EXPORT_SYMBOL(tcp_md5_hash_key
);
3017 void tcp_done(struct sock
*sk
)
3019 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
3021 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3022 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3024 tcp_set_state(sk
, TCP_CLOSE
);
3025 tcp_clear_xmit_timers(sk
);
3027 reqsk_fastopen_remove(sk
, req
, false);
3029 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3031 if (!sock_flag(sk
, SOCK_DEAD
))
3032 sk
->sk_state_change(sk
);
3034 inet_csk_destroy_sock(sk
);
3036 EXPORT_SYMBOL_GPL(tcp_done
);
3038 extern struct tcp_congestion_ops tcp_reno
;
3040 static __initdata
unsigned long thash_entries
;
3041 static int __init
set_thash_entries(char *str
)
3048 ret
= kstrtoul(str
, 0, &thash_entries
);
3054 __setup("thash_entries=", set_thash_entries
);
3056 static void __init
tcp_init_mem(void)
3058 unsigned long limit
= nr_free_buffer_pages() / 8;
3059 limit
= max(limit
, 128UL);
3060 sysctl_tcp_mem
[0] = limit
/ 4 * 3;
3061 sysctl_tcp_mem
[1] = limit
;
3062 sysctl_tcp_mem
[2] = sysctl_tcp_mem
[0] * 2;
3065 void __init
tcp_init(void)
3067 struct sk_buff
*skb
= NULL
;
3068 unsigned long limit
;
3069 int max_rshare
, max_wshare
, cnt
;
3072 BUILD_BUG_ON(sizeof(struct tcp_skb_cb
) > sizeof(skb
->cb
));
3074 percpu_counter_init(&tcp_sockets_allocated
, 0, GFP_KERNEL
);
3075 percpu_counter_init(&tcp_orphan_count
, 0, GFP_KERNEL
);
3076 tcp_hashinfo
.bind_bucket_cachep
=
3077 kmem_cache_create("tcp_bind_bucket",
3078 sizeof(struct inet_bind_bucket
), 0,
3079 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3081 /* Size and allocate the main established and bind bucket
3084 * The methodology is similar to that of the buffer cache.
3086 tcp_hashinfo
.ehash
=
3087 alloc_large_system_hash("TCP established",
3088 sizeof(struct inet_ehash_bucket
),
3090 17, /* one slot per 128 KB of memory */
3093 &tcp_hashinfo
.ehash_mask
,
3095 thash_entries
? 0 : 512 * 1024);
3096 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++)
3097 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3099 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3100 panic("TCP: failed to alloc ehash_locks");
3101 tcp_hashinfo
.bhash
=
3102 alloc_large_system_hash("TCP bind",
3103 sizeof(struct inet_bind_hashbucket
),
3104 tcp_hashinfo
.ehash_mask
+ 1,
3105 17, /* one slot per 128 KB of memory */
3107 &tcp_hashinfo
.bhash_size
,
3111 tcp_hashinfo
.bhash_size
= 1U << tcp_hashinfo
.bhash_size
;
3112 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3113 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3114 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3118 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
3120 tcp_death_row
.sysctl_max_tw_buckets
= cnt
/ 2;
3121 sysctl_tcp_max_orphans
= cnt
/ 2;
3122 sysctl_max_syn_backlog
= max(128, cnt
/ 256);
3125 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3126 limit
= nr_free_buffer_pages() << (PAGE_SHIFT
- 7);
3127 max_wshare
= min(4UL*1024*1024, limit
);
3128 max_rshare
= min(6UL*1024*1024, limit
);
3130 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3131 sysctl_tcp_wmem
[1] = 16*1024;
3132 sysctl_tcp_wmem
[2] = max(64*1024, max_wshare
);
3134 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3135 sysctl_tcp_rmem
[1] = 87380;
3136 sysctl_tcp_rmem
[2] = max(87380, max_rshare
);
3138 pr_info("Hash tables configured (established %u bind %u)\n",
3139 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3142 BUG_ON(tcp_register_congestion_control(&tcp_reno
) != 0);