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
);
392 /* So many TCP implementations out there (incorrectly) count the
393 * initial SYN frame in their delayed-ACK and congestion control
394 * algorithms that we must have the following bandaid to talk
395 * efficiently to them. -DaveM
397 tp
->snd_cwnd
= TCP_INIT_CWND
;
399 /* See draft-stevens-tcpca-spec-01 for discussion of the
400 * initialization of these values.
402 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
403 tp
->snd_cwnd_clamp
= ~0;
404 tp
->mss_cache
= TCP_MSS_DEFAULT
;
405 u64_stats_init(&tp
->syncp
);
407 tp
->reordering
= sysctl_tcp_reordering
;
408 tcp_enable_early_retrans(tp
);
409 tcp_assign_congestion_control(sk
);
413 sk
->sk_state
= TCP_CLOSE
;
415 sk
->sk_write_space
= sk_stream_write_space
;
416 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
418 icsk
->icsk_sync_mss
= tcp_sync_mss
;
420 sk
->sk_sndbuf
= sysctl_tcp_wmem
[1];
421 sk
->sk_rcvbuf
= sysctl_tcp_rmem
[1];
424 sock_update_memcg(sk
);
425 sk_sockets_allocated_inc(sk
);
428 EXPORT_SYMBOL(tcp_init_sock
);
430 static void tcp_tx_timestamp(struct sock
*sk
, struct sk_buff
*skb
)
432 if (sk
->sk_tsflags
) {
433 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
435 sock_tx_timestamp(sk
, &shinfo
->tx_flags
);
436 if (shinfo
->tx_flags
& SKBTX_ANY_TSTAMP
)
437 shinfo
->tskey
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- 1;
442 * Wait for a TCP event.
444 * Note that we don't need to lock the socket, as the upper poll layers
445 * take care of normal races (between the test and the event) and we don't
446 * go look at any of the socket buffers directly.
448 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
451 struct sock
*sk
= sock
->sk
;
452 const struct tcp_sock
*tp
= tcp_sk(sk
);
454 sock_rps_record_flow(sk
);
456 sock_poll_wait(file
, sk_sleep(sk
), wait
);
457 if (sk
->sk_state
== TCP_LISTEN
)
458 return inet_csk_listen_poll(sk
);
460 /* Socket is not locked. We are protected from async events
461 * by poll logic and correct handling of state changes
462 * made by other threads is impossible in any case.
468 * POLLHUP is certainly not done right. But poll() doesn't
469 * have a notion of HUP in just one direction, and for a
470 * socket the read side is more interesting.
472 * Some poll() documentation says that POLLHUP is incompatible
473 * with the POLLOUT/POLLWR flags, so somebody should check this
474 * all. But careful, it tends to be safer to return too many
475 * bits than too few, and you can easily break real applications
476 * if you don't tell them that something has hung up!
480 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
481 * our fs/select.c). It means that after we received EOF,
482 * poll always returns immediately, making impossible poll() on write()
483 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
484 * if and only if shutdown has been made in both directions.
485 * Actually, it is interesting to look how Solaris and DUX
486 * solve this dilemma. I would prefer, if POLLHUP were maskable,
487 * then we could set it on SND_SHUTDOWN. BTW examples given
488 * in Stevens' books assume exactly this behaviour, it explains
489 * why POLLHUP is incompatible with POLLOUT. --ANK
491 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
492 * blocking on fresh not-connected or disconnected socket. --ANK
494 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== TCP_CLOSE
)
496 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
497 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
499 /* Connected or passive Fast Open socket? */
500 if (sk
->sk_state
!= TCP_SYN_SENT
&&
501 (sk
->sk_state
!= TCP_SYN_RECV
|| tp
->fastopen_rsk
)) {
502 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
504 if (tp
->urg_seq
== tp
->copied_seq
&&
505 !sock_flag(sk
, SOCK_URGINLINE
) &&
509 /* Potential race condition. If read of tp below will
510 * escape above sk->sk_state, we can be illegally awaken
511 * in SYN_* states. */
512 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
513 mask
|= POLLIN
| POLLRDNORM
;
515 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
516 if (sk_stream_is_writeable(sk
)) {
517 mask
|= POLLOUT
| POLLWRNORM
;
518 } else { /* send SIGIO later */
519 set_bit(SOCK_ASYNC_NOSPACE
,
520 &sk
->sk_socket
->flags
);
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 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
907 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
909 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
913 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
917 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
921 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
923 if (!sk_stream_memory_free(sk
))
924 goto wait_for_sndbuf
;
926 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
,
927 skb_queue_empty(&sk
->sk_write_queue
));
929 goto wait_for_memory
;
938 i
= skb_shinfo(skb
)->nr_frags
;
939 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
940 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
941 tcp_mark_push(tp
, skb
);
944 if (!sk_wmem_schedule(sk
, copy
))
945 goto wait_for_memory
;
948 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
951 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
953 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
956 skb
->data_len
+= copy
;
957 skb
->truesize
+= copy
;
958 sk
->sk_wmem_queued
+= copy
;
959 sk_mem_charge(sk
, copy
);
960 skb
->ip_summed
= CHECKSUM_PARTIAL
;
961 tp
->write_seq
+= copy
;
962 TCP_SKB_CB(skb
)->end_seq
+= copy
;
963 tcp_skb_pcount_set(skb
, 0);
966 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
970 if (!(size
-= copy
)) {
971 tcp_tx_timestamp(sk
, skb
);
975 if (skb
->len
< size_goal
|| (flags
& MSG_OOB
))
978 if (forced_push(tp
)) {
979 tcp_mark_push(tp
, skb
);
980 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
981 } else if (skb
== tcp_send_head(sk
))
982 tcp_push_one(sk
, mss_now
);
986 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
988 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
,
989 TCP_NAGLE_PUSH
, size_goal
);
991 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
994 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
998 if (copied
&& !(flags
& MSG_SENDPAGE_NOTLAST
))
999 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
, size_goal
);
1006 /* make sure we wake any epoll edge trigger waiter */
1007 if (unlikely(skb_queue_len(&sk
->sk_write_queue
) == 0 && err
== -EAGAIN
))
1008 sk
->sk_write_space(sk
);
1009 return sk_stream_error(sk
, flags
, err
);
1012 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
1013 size_t size
, int flags
)
1017 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
1018 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
1019 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
1023 res
= do_tcp_sendpages(sk
, page
, offset
, size
, flags
);
1027 EXPORT_SYMBOL(tcp_sendpage
);
1029 static inline int select_size(const struct sock
*sk
, bool sg
)
1031 const struct tcp_sock
*tp
= tcp_sk(sk
);
1032 int tmp
= tp
->mss_cache
;
1035 if (sk_can_gso(sk
)) {
1036 /* Small frames wont use a full page:
1037 * Payload will immediately follow tcp header.
1039 tmp
= SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER
);
1041 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
1043 if (tmp
>= pgbreak
&&
1044 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
1052 void tcp_free_fastopen_req(struct tcp_sock
*tp
)
1054 if (tp
->fastopen_req
) {
1055 kfree(tp
->fastopen_req
);
1056 tp
->fastopen_req
= NULL
;
1060 static int tcp_sendmsg_fastopen(struct sock
*sk
, struct msghdr
*msg
,
1061 int *copied
, size_t size
)
1063 struct tcp_sock
*tp
= tcp_sk(sk
);
1066 if (!(sysctl_tcp_fastopen
& TFO_CLIENT_ENABLE
))
1068 if (tp
->fastopen_req
)
1069 return -EALREADY
; /* Another Fast Open is in progress */
1071 tp
->fastopen_req
= kzalloc(sizeof(struct tcp_fastopen_request
),
1073 if (unlikely(!tp
->fastopen_req
))
1075 tp
->fastopen_req
->data
= msg
;
1076 tp
->fastopen_req
->size
= size
;
1078 flags
= (msg
->msg_flags
& MSG_DONTWAIT
) ? O_NONBLOCK
: 0;
1079 err
= __inet_stream_connect(sk
->sk_socket
, msg
->msg_name
,
1080 msg
->msg_namelen
, flags
);
1081 *copied
= tp
->fastopen_req
->copied
;
1082 tcp_free_fastopen_req(tp
);
1086 int tcp_sendmsg(struct sock
*sk
, struct msghdr
*msg
, size_t size
)
1088 struct tcp_sock
*tp
= tcp_sk(sk
);
1089 struct sk_buff
*skb
;
1090 int flags
, err
, copied
= 0;
1091 int mss_now
= 0, size_goal
, copied_syn
= 0;
1097 flags
= msg
->msg_flags
;
1098 if (flags
& MSG_FASTOPEN
) {
1099 err
= tcp_sendmsg_fastopen(sk
, msg
, &copied_syn
, size
);
1100 if (err
== -EINPROGRESS
&& copied_syn
> 0)
1106 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
1108 /* Wait for a connection to finish. One exception is TCP Fast Open
1109 * (passive side) where data is allowed to be sent before a connection
1110 * is fully established.
1112 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
1113 !tcp_passive_fastopen(sk
)) {
1114 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
1118 if (unlikely(tp
->repair
)) {
1119 if (tp
->repair_queue
== TCP_RECV_QUEUE
) {
1120 copied
= tcp_send_rcvq(sk
, msg
, size
);
1125 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1128 /* 'common' sending to sendq */
1131 /* This should be in poll */
1132 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
1134 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1136 /* Ok commence sending. */
1140 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
1143 sg
= !!(sk
->sk_route_caps
& NETIF_F_SG
);
1145 while (msg_data_left(msg
)) {
1147 int max
= size_goal
;
1149 skb
= tcp_write_queue_tail(sk
);
1150 if (tcp_send_head(sk
)) {
1151 if (skb
->ip_summed
== CHECKSUM_NONE
)
1153 copy
= max
- skb
->len
;
1158 /* Allocate new segment. If the interface is SG,
1159 * allocate skb fitting to single page.
1161 if (!sk_stream_memory_free(sk
))
1162 goto wait_for_sndbuf
;
1164 skb
= sk_stream_alloc_skb(sk
,
1165 select_size(sk
, sg
),
1167 skb_queue_empty(&sk
->sk_write_queue
));
1169 goto wait_for_memory
;
1172 * Check whether we can use HW checksum.
1174 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
1175 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1177 skb_entail(sk
, skb
);
1181 /* All packets are restored as if they have
1182 * already been sent. skb_mstamp isn't set to
1183 * avoid wrong rtt estimation.
1186 TCP_SKB_CB(skb
)->sacked
|= TCPCB_REPAIRED
;
1189 /* Try to append data to the end of skb. */
1190 if (copy
> msg_data_left(msg
))
1191 copy
= msg_data_left(msg
);
1193 /* Where to copy to? */
1194 if (skb_availroom(skb
) > 0) {
1195 /* We have some space in skb head. Superb! */
1196 copy
= min_t(int, copy
, skb_availroom(skb
));
1197 err
= skb_add_data_nocache(sk
, skb
, &msg
->msg_iter
, copy
);
1202 int i
= skb_shinfo(skb
)->nr_frags
;
1203 struct page_frag
*pfrag
= sk_page_frag(sk
);
1205 if (!sk_page_frag_refill(sk
, pfrag
))
1206 goto wait_for_memory
;
1208 if (!skb_can_coalesce(skb
, i
, pfrag
->page
,
1210 if (i
== MAX_SKB_FRAGS
|| !sg
) {
1211 tcp_mark_push(tp
, skb
);
1217 copy
= min_t(int, copy
, pfrag
->size
- pfrag
->offset
);
1219 if (!sk_wmem_schedule(sk
, copy
))
1220 goto wait_for_memory
;
1222 err
= skb_copy_to_page_nocache(sk
, &msg
->msg_iter
, skb
,
1229 /* Update the skb. */
1231 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
1233 skb_fill_page_desc(skb
, i
, pfrag
->page
,
1234 pfrag
->offset
, copy
);
1235 get_page(pfrag
->page
);
1237 pfrag
->offset
+= copy
;
1241 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
1243 tp
->write_seq
+= copy
;
1244 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1245 tcp_skb_pcount_set(skb
, 0);
1248 if (!msg_data_left(msg
)) {
1249 tcp_tx_timestamp(sk
, skb
);
1253 if (skb
->len
< max
|| (flags
& MSG_OOB
) || unlikely(tp
->repair
))
1256 if (forced_push(tp
)) {
1257 tcp_mark_push(tp
, skb
);
1258 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1259 } else if (skb
== tcp_send_head(sk
))
1260 tcp_push_one(sk
, mss_now
);
1264 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1267 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
,
1268 TCP_NAGLE_PUSH
, size_goal
);
1270 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1273 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1278 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
, size_goal
);
1281 return copied
+ copied_syn
;
1285 tcp_unlink_write_queue(skb
, sk
);
1286 /* It is the one place in all of TCP, except connection
1287 * reset, where we can be unlinking the send_head.
1289 tcp_check_send_head(sk
, skb
);
1290 sk_wmem_free_skb(sk
, skb
);
1294 if (copied
+ copied_syn
)
1297 err
= sk_stream_error(sk
, flags
, err
);
1298 /* make sure we wake any epoll edge trigger waiter */
1299 if (unlikely(skb_queue_len(&sk
->sk_write_queue
) == 0 && err
== -EAGAIN
))
1300 sk
->sk_write_space(sk
);
1304 EXPORT_SYMBOL(tcp_sendmsg
);
1307 * Handle reading urgent data. BSD has very simple semantics for
1308 * this, no blocking and very strange errors 8)
1311 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1313 struct tcp_sock
*tp
= tcp_sk(sk
);
1315 /* No URG data to read. */
1316 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1317 tp
->urg_data
== TCP_URG_READ
)
1318 return -EINVAL
; /* Yes this is right ! */
1320 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1323 if (tp
->urg_data
& TCP_URG_VALID
) {
1325 char c
= tp
->urg_data
;
1327 if (!(flags
& MSG_PEEK
))
1328 tp
->urg_data
= TCP_URG_READ
;
1330 /* Read urgent data. */
1331 msg
->msg_flags
|= MSG_OOB
;
1334 if (!(flags
& MSG_TRUNC
))
1335 err
= memcpy_to_msg(msg
, &c
, 1);
1338 msg
->msg_flags
|= MSG_TRUNC
;
1340 return err
? -EFAULT
: len
;
1343 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1346 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1347 * the available implementations agree in this case:
1348 * this call should never block, independent of the
1349 * blocking state of the socket.
1350 * Mike <pall@rz.uni-karlsruhe.de>
1355 static int tcp_peek_sndq(struct sock
*sk
, struct msghdr
*msg
, int len
)
1357 struct sk_buff
*skb
;
1358 int copied
= 0, err
= 0;
1360 /* XXX -- need to support SO_PEEK_OFF */
1362 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
1363 err
= skb_copy_datagram_msg(skb
, 0, msg
, skb
->len
);
1370 return err
?: copied
;
1373 /* Clean up the receive buffer for full frames taken by the user,
1374 * then send an ACK if necessary. COPIED is the number of bytes
1375 * tcp_recvmsg has given to the user so far, it speeds up the
1376 * calculation of whether or not we must ACK for the sake of
1379 static void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1381 struct tcp_sock
*tp
= tcp_sk(sk
);
1382 bool time_to_ack
= false;
1384 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1386 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1387 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1388 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1390 if (inet_csk_ack_scheduled(sk
)) {
1391 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1392 /* Delayed ACKs frequently hit locked sockets during bulk
1394 if (icsk
->icsk_ack
.blocked
||
1395 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1396 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1398 * If this read emptied read buffer, we send ACK, if
1399 * connection is not bidirectional, user drained
1400 * receive buffer and there was a small segment
1404 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1405 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1406 !icsk
->icsk_ack
.pingpong
)) &&
1407 !atomic_read(&sk
->sk_rmem_alloc
)))
1411 /* We send an ACK if we can now advertise a non-zero window
1412 * which has been raised "significantly".
1414 * Even if window raised up to infinity, do not send window open ACK
1415 * in states, where we will not receive more. It is useless.
1417 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1418 __u32 rcv_window_now
= tcp_receive_window(tp
);
1420 /* Optimize, __tcp_select_window() is not cheap. */
1421 if (2*rcv_window_now
<= tp
->window_clamp
) {
1422 __u32 new_window
= __tcp_select_window(sk
);
1424 /* Send ACK now, if this read freed lots of space
1425 * in our buffer. Certainly, new_window is new window.
1426 * We can advertise it now, if it is not less than current one.
1427 * "Lots" means "at least twice" here.
1429 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1437 static void tcp_prequeue_process(struct sock
*sk
)
1439 struct sk_buff
*skb
;
1440 struct tcp_sock
*tp
= tcp_sk(sk
);
1442 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1444 /* RX process wants to run with disabled BHs, though it is not
1447 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1448 sk_backlog_rcv(sk
, skb
);
1451 /* Clear memory counter. */
1452 tp
->ucopy
.memory
= 0;
1455 static struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1457 struct sk_buff
*skb
;
1460 while ((skb
= skb_peek(&sk
->sk_receive_queue
)) != NULL
) {
1461 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1462 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_SYN
)
1464 if (offset
< skb
->len
|| (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)) {
1468 /* This looks weird, but this can happen if TCP collapsing
1469 * splitted a fat GRO packet, while we released socket lock
1470 * in skb_splice_bits()
1472 sk_eat_skb(sk
, skb
);
1478 * This routine provides an alternative to tcp_recvmsg() for routines
1479 * that would like to handle copying from skbuffs directly in 'sendfile'
1482 * - It is assumed that the socket was locked by the caller.
1483 * - The routine does not block.
1484 * - At present, there is no support for reading OOB data
1485 * or for 'peeking' the socket using this routine
1486 * (although both would be easy to implement).
1488 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1489 sk_read_actor_t recv_actor
)
1491 struct sk_buff
*skb
;
1492 struct tcp_sock
*tp
= tcp_sk(sk
);
1493 u32 seq
= tp
->copied_seq
;
1497 if (sk
->sk_state
== TCP_LISTEN
)
1499 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1500 if (offset
< skb
->len
) {
1504 len
= skb
->len
- offset
;
1505 /* Stop reading if we hit a patch of urgent data */
1507 u32 urg_offset
= tp
->urg_seq
- seq
;
1508 if (urg_offset
< len
)
1513 used
= recv_actor(desc
, skb
, offset
, len
);
1518 } else if (used
<= len
) {
1523 /* If recv_actor drops the lock (e.g. TCP splice
1524 * receive) the skb pointer might be invalid when
1525 * getting here: tcp_collapse might have deleted it
1526 * while aggregating skbs from the socket queue.
1528 skb
= tcp_recv_skb(sk
, seq
- 1, &offset
);
1531 /* TCP coalescing might have appended data to the skb.
1532 * Try to splice more frags
1534 if (offset
+ 1 != skb
->len
)
1537 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
) {
1538 sk_eat_skb(sk
, skb
);
1542 sk_eat_skb(sk
, skb
);
1545 tp
->copied_seq
= seq
;
1547 tp
->copied_seq
= seq
;
1549 tcp_rcv_space_adjust(sk
);
1551 /* Clean up data we have read: This will do ACK frames. */
1553 tcp_recv_skb(sk
, seq
, &offset
);
1554 tcp_cleanup_rbuf(sk
, copied
);
1558 EXPORT_SYMBOL(tcp_read_sock
);
1561 * This routine copies from a sock struct into the user buffer.
1563 * Technical note: in 2.3 we work on _locked_ socket, so that
1564 * tricks with *seq access order and skb->users are not required.
1565 * Probably, code can be easily improved even more.
1568 int tcp_recvmsg(struct sock
*sk
, struct msghdr
*msg
, size_t len
, int nonblock
,
1569 int flags
, int *addr_len
)
1571 struct tcp_sock
*tp
= tcp_sk(sk
);
1577 int target
; /* Read at least this many bytes */
1579 struct task_struct
*user_recv
= NULL
;
1580 struct sk_buff
*skb
, *last
;
1583 if (unlikely(flags
& MSG_ERRQUEUE
))
1584 return inet_recv_error(sk
, msg
, len
, addr_len
);
1586 if (sk_can_busy_loop(sk
) && skb_queue_empty(&sk
->sk_receive_queue
) &&
1587 (sk
->sk_state
== TCP_ESTABLISHED
))
1588 sk_busy_loop(sk
, nonblock
);
1593 if (sk
->sk_state
== TCP_LISTEN
)
1596 timeo
= sock_rcvtimeo(sk
, nonblock
);
1598 /* Urgent data needs to be handled specially. */
1599 if (flags
& MSG_OOB
)
1602 if (unlikely(tp
->repair
)) {
1604 if (!(flags
& MSG_PEEK
))
1607 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
1611 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1614 /* 'common' recv queue MSG_PEEK-ing */
1617 seq
= &tp
->copied_seq
;
1618 if (flags
& MSG_PEEK
) {
1619 peek_seq
= tp
->copied_seq
;
1623 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1628 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1629 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1632 if (signal_pending(current
)) {
1633 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1638 /* Next get a buffer. */
1640 last
= skb_peek_tail(&sk
->sk_receive_queue
);
1641 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1643 /* Now that we have two receive queues this
1646 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1647 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1648 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1652 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1653 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_SYN
)
1655 if (offset
< skb
->len
)
1657 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
1659 WARN(!(flags
& MSG_PEEK
),
1660 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1661 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
, flags
);
1664 /* Well, if we have backlog, try to process it now yet. */
1666 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1671 sk
->sk_state
== TCP_CLOSE
||
1672 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1674 signal_pending(current
))
1677 if (sock_flag(sk
, SOCK_DONE
))
1681 copied
= sock_error(sk
);
1685 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1688 if (sk
->sk_state
== TCP_CLOSE
) {
1689 if (!sock_flag(sk
, SOCK_DONE
)) {
1690 /* This occurs when user tries to read
1691 * from never connected socket.
1704 if (signal_pending(current
)) {
1705 copied
= sock_intr_errno(timeo
);
1710 tcp_cleanup_rbuf(sk
, copied
);
1712 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1713 /* Install new reader */
1714 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1715 user_recv
= current
;
1716 tp
->ucopy
.task
= user_recv
;
1717 tp
->ucopy
.msg
= msg
;
1720 tp
->ucopy
.len
= len
;
1722 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1723 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1725 /* Ugly... If prequeue is not empty, we have to
1726 * process it before releasing socket, otherwise
1727 * order will be broken at second iteration.
1728 * More elegant solution is required!!!
1730 * Look: we have the following (pseudo)queues:
1732 * 1. packets in flight
1737 * Each queue can be processed only if the next ones
1738 * are empty. At this point we have empty receive_queue.
1739 * But prequeue _can_ be not empty after 2nd iteration,
1740 * when we jumped to start of loop because backlog
1741 * processing added something to receive_queue.
1742 * We cannot release_sock(), because backlog contains
1743 * packets arrived _after_ prequeued ones.
1745 * Shortly, algorithm is clear --- to process all
1746 * the queues in order. We could make it more directly,
1747 * requeueing packets from backlog to prequeue, if
1748 * is not empty. It is more elegant, but eats cycles,
1751 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1754 /* __ Set realtime policy in scheduler __ */
1757 if (copied
>= target
) {
1758 /* Do not sleep, just process backlog. */
1762 sk_wait_data(sk
, &timeo
, last
);
1768 /* __ Restore normal policy in scheduler __ */
1770 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1771 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1776 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1777 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1779 tcp_prequeue_process(sk
);
1781 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1782 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1788 if ((flags
& MSG_PEEK
) &&
1789 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1790 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1792 task_pid_nr(current
));
1793 peek_seq
= tp
->copied_seq
;
1798 /* Ok so how much can we use? */
1799 used
= skb
->len
- offset
;
1803 /* Do we have urgent data here? */
1805 u32 urg_offset
= tp
->urg_seq
- *seq
;
1806 if (urg_offset
< used
) {
1808 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1821 if (!(flags
& MSG_TRUNC
)) {
1822 err
= skb_copy_datagram_msg(skb
, offset
, msg
, used
);
1824 /* Exception. Bailout! */
1835 tcp_rcv_space_adjust(sk
);
1838 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1840 tcp_fast_path_check(sk
);
1842 if (used
+ offset
< skb
->len
)
1845 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
1847 if (!(flags
& MSG_PEEK
))
1848 sk_eat_skb(sk
, skb
);
1852 /* Process the FIN. */
1854 if (!(flags
& MSG_PEEK
))
1855 sk_eat_skb(sk
, skb
);
1860 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1863 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1865 tcp_prequeue_process(sk
);
1867 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1868 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1874 tp
->ucopy
.task
= NULL
;
1878 /* According to UNIX98, msg_name/msg_namelen are ignored
1879 * on connected socket. I was just happy when found this 8) --ANK
1882 /* Clean up data we have read: This will do ACK frames. */
1883 tcp_cleanup_rbuf(sk
, copied
);
1893 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1897 err
= tcp_peek_sndq(sk
, msg
, len
);
1900 EXPORT_SYMBOL(tcp_recvmsg
);
1902 void tcp_set_state(struct sock
*sk
, int state
)
1904 int oldstate
= sk
->sk_state
;
1907 case TCP_ESTABLISHED
:
1908 if (oldstate
!= TCP_ESTABLISHED
)
1909 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1913 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1914 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1916 sk
->sk_prot
->unhash(sk
);
1917 if (inet_csk(sk
)->icsk_bind_hash
&&
1918 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1922 if (oldstate
== TCP_ESTABLISHED
)
1923 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1926 /* Change state AFTER socket is unhashed to avoid closed
1927 * socket sitting in hash tables.
1929 sk
->sk_state
= state
;
1932 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
1935 EXPORT_SYMBOL_GPL(tcp_set_state
);
1938 * State processing on a close. This implements the state shift for
1939 * sending our FIN frame. Note that we only send a FIN for some
1940 * states. A shutdown() may have already sent the FIN, or we may be
1944 static const unsigned char new_state
[16] = {
1945 /* current state: new state: action: */
1946 [0 /* (Invalid) */] = TCP_CLOSE
,
1947 [TCP_ESTABLISHED
] = TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1948 [TCP_SYN_SENT
] = TCP_CLOSE
,
1949 [TCP_SYN_RECV
] = TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1950 [TCP_FIN_WAIT1
] = TCP_FIN_WAIT1
,
1951 [TCP_FIN_WAIT2
] = TCP_FIN_WAIT2
,
1952 [TCP_TIME_WAIT
] = TCP_CLOSE
,
1953 [TCP_CLOSE
] = TCP_CLOSE
,
1954 [TCP_CLOSE_WAIT
] = TCP_LAST_ACK
| TCP_ACTION_FIN
,
1955 [TCP_LAST_ACK
] = TCP_LAST_ACK
,
1956 [TCP_LISTEN
] = TCP_CLOSE
,
1957 [TCP_CLOSING
] = TCP_CLOSING
,
1958 [TCP_NEW_SYN_RECV
] = TCP_CLOSE
, /* should not happen ! */
1961 static int tcp_close_state(struct sock
*sk
)
1963 int next
= (int)new_state
[sk
->sk_state
];
1964 int ns
= next
& TCP_STATE_MASK
;
1966 tcp_set_state(sk
, ns
);
1968 return next
& TCP_ACTION_FIN
;
1972 * Shutdown the sending side of a connection. Much like close except
1973 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1976 void tcp_shutdown(struct sock
*sk
, int how
)
1978 /* We need to grab some memory, and put together a FIN,
1979 * and then put it into the queue to be sent.
1980 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1982 if (!(how
& SEND_SHUTDOWN
))
1985 /* If we've already sent a FIN, or it's a closed state, skip this. */
1986 if ((1 << sk
->sk_state
) &
1987 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
1988 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
1989 /* Clear out any half completed packets. FIN if needed. */
1990 if (tcp_close_state(sk
))
1994 EXPORT_SYMBOL(tcp_shutdown
);
1996 bool tcp_check_oom(struct sock
*sk
, int shift
)
1998 bool too_many_orphans
, out_of_socket_memory
;
2000 too_many_orphans
= tcp_too_many_orphans(sk
, shift
);
2001 out_of_socket_memory
= tcp_out_of_memory(sk
);
2003 if (too_many_orphans
)
2004 net_info_ratelimited("too many orphaned sockets\n");
2005 if (out_of_socket_memory
)
2006 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2007 return too_many_orphans
|| out_of_socket_memory
;
2010 void tcp_close(struct sock
*sk
, long timeout
)
2012 struct sk_buff
*skb
;
2013 int data_was_unread
= 0;
2017 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2019 if (sk
->sk_state
== TCP_LISTEN
) {
2020 tcp_set_state(sk
, TCP_CLOSE
);
2023 inet_csk_listen_stop(sk
);
2025 goto adjudge_to_death
;
2028 /* We need to flush the recv. buffs. We do this only on the
2029 * descriptor close, not protocol-sourced closes, because the
2030 * reader process may not have drained the data yet!
2032 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
2033 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
;
2035 if (TCP_SKB_CB(skb
)->tcp_flags
& TCPHDR_FIN
)
2037 data_was_unread
+= len
;
2043 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2044 if (sk
->sk_state
== TCP_CLOSE
)
2045 goto adjudge_to_death
;
2047 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2048 * data was lost. To witness the awful effects of the old behavior of
2049 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2050 * GET in an FTP client, suspend the process, wait for the client to
2051 * advertise a zero window, then kill -9 the FTP client, wheee...
2052 * Note: timeout is always zero in such a case.
2054 if (unlikely(tcp_sk(sk
)->repair
)) {
2055 sk
->sk_prot
->disconnect(sk
, 0);
2056 } else if (data_was_unread
) {
2057 /* Unread data was tossed, zap the connection. */
2058 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
2059 tcp_set_state(sk
, TCP_CLOSE
);
2060 tcp_send_active_reset(sk
, sk
->sk_allocation
);
2061 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
2062 /* Check zero linger _after_ checking for unread data. */
2063 sk
->sk_prot
->disconnect(sk
, 0);
2064 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
2065 } else if (tcp_close_state(sk
)) {
2066 /* We FIN if the application ate all the data before
2067 * zapping the connection.
2070 /* RED-PEN. Formally speaking, we have broken TCP state
2071 * machine. State transitions:
2073 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2074 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2075 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2077 * are legal only when FIN has been sent (i.e. in window),
2078 * rather than queued out of window. Purists blame.
2080 * F.e. "RFC state" is ESTABLISHED,
2081 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2083 * The visible declinations are that sometimes
2084 * we enter time-wait state, when it is not required really
2085 * (harmless), do not send active resets, when they are
2086 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2087 * they look as CLOSING or LAST_ACK for Linux)
2088 * Probably, I missed some more holelets.
2090 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2091 * in a single packet! (May consider it later but will
2092 * probably need API support or TCP_CORK SYN-ACK until
2093 * data is written and socket is closed.)
2098 sk_stream_wait_close(sk
, timeout
);
2101 state
= sk
->sk_state
;
2105 /* It is the last release_sock in its life. It will remove backlog. */
2109 /* Now socket is owned by kernel and we acquire BH lock
2110 to finish close. No need to check for user refs.
2114 WARN_ON(sock_owned_by_user(sk
));
2116 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
2118 /* Have we already been destroyed by a softirq or backlog? */
2119 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
2122 /* This is a (useful) BSD violating of the RFC. There is a
2123 * problem with TCP as specified in that the other end could
2124 * keep a socket open forever with no application left this end.
2125 * We use a 1 minute timeout (about the same as BSD) then kill
2126 * our end. If they send after that then tough - BUT: long enough
2127 * that we won't make the old 4*rto = almost no time - whoops
2130 * Nope, it was not mistake. It is really desired behaviour
2131 * f.e. on http servers, when such sockets are useless, but
2132 * consume significant resources. Let's do it with special
2133 * linger2 option. --ANK
2136 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
2137 struct tcp_sock
*tp
= tcp_sk(sk
);
2138 if (tp
->linger2
< 0) {
2139 tcp_set_state(sk
, TCP_CLOSE
);
2140 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2141 NET_INC_STATS_BH(sock_net(sk
),
2142 LINUX_MIB_TCPABORTONLINGER
);
2144 const int tmo
= tcp_fin_time(sk
);
2146 if (tmo
> TCP_TIMEWAIT_LEN
) {
2147 inet_csk_reset_keepalive_timer(sk
,
2148 tmo
- TCP_TIMEWAIT_LEN
);
2150 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2155 if (sk
->sk_state
!= TCP_CLOSE
) {
2157 if (tcp_check_oom(sk
, 0)) {
2158 tcp_set_state(sk
, TCP_CLOSE
);
2159 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2160 NET_INC_STATS_BH(sock_net(sk
),
2161 LINUX_MIB_TCPABORTONMEMORY
);
2165 if (sk
->sk_state
== TCP_CLOSE
) {
2166 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
2167 /* We could get here with a non-NULL req if the socket is
2168 * aborted (e.g., closed with unread data) before 3WHS
2172 reqsk_fastopen_remove(sk
, req
, false);
2173 inet_csk_destroy_sock(sk
);
2175 /* Otherwise, socket is reprieved until protocol close. */
2182 EXPORT_SYMBOL(tcp_close
);
2184 /* These states need RST on ABORT according to RFC793 */
2186 static inline bool tcp_need_reset(int state
)
2188 return (1 << state
) &
2189 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2190 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2193 int tcp_disconnect(struct sock
*sk
, int flags
)
2195 struct inet_sock
*inet
= inet_sk(sk
);
2196 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2197 struct tcp_sock
*tp
= tcp_sk(sk
);
2199 int old_state
= sk
->sk_state
;
2201 if (old_state
!= TCP_CLOSE
)
2202 tcp_set_state(sk
, TCP_CLOSE
);
2204 /* ABORT function of RFC793 */
2205 if (old_state
== TCP_LISTEN
) {
2206 inet_csk_listen_stop(sk
);
2207 } else if (unlikely(tp
->repair
)) {
2208 sk
->sk_err
= ECONNABORTED
;
2209 } else if (tcp_need_reset(old_state
) ||
2210 (tp
->snd_nxt
!= tp
->write_seq
&&
2211 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2212 /* The last check adjusts for discrepancy of Linux wrt. RFC
2215 tcp_send_active_reset(sk
, gfp_any());
2216 sk
->sk_err
= ECONNRESET
;
2217 } else if (old_state
== TCP_SYN_SENT
)
2218 sk
->sk_err
= ECONNRESET
;
2220 tcp_clear_xmit_timers(sk
);
2221 __skb_queue_purge(&sk
->sk_receive_queue
);
2222 tcp_write_queue_purge(sk
);
2223 __skb_queue_purge(&tp
->out_of_order_queue
);
2225 inet
->inet_dport
= 0;
2227 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2228 inet_reset_saddr(sk
);
2230 sk
->sk_shutdown
= 0;
2231 sock_reset_flag(sk
, SOCK_DONE
);
2233 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2235 icsk
->icsk_backoff
= 0;
2237 icsk
->icsk_probes_out
= 0;
2238 tp
->packets_out
= 0;
2239 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2240 tp
->snd_cwnd_cnt
= 0;
2241 tp
->window_clamp
= 0;
2242 tcp_set_ca_state(sk
, TCP_CA_Open
);
2243 tcp_clear_retrans(tp
);
2244 inet_csk_delack_init(sk
);
2245 tcp_init_send_head(sk
);
2246 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2249 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2251 sk
->sk_error_report(sk
);
2254 EXPORT_SYMBOL(tcp_disconnect
);
2256 void tcp_sock_destruct(struct sock
*sk
)
2258 inet_sock_destruct(sk
);
2260 kfree(inet_csk(sk
)->icsk_accept_queue
.fastopenq
);
2263 static inline bool tcp_can_repair_sock(const struct sock
*sk
)
2265 return ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
) &&
2266 ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_ESTABLISHED
));
2269 static int tcp_repair_options_est(struct tcp_sock
*tp
,
2270 struct tcp_repair_opt __user
*optbuf
, unsigned int len
)
2272 struct tcp_repair_opt opt
;
2274 while (len
>= sizeof(opt
)) {
2275 if (copy_from_user(&opt
, optbuf
, sizeof(opt
)))
2281 switch (opt
.opt_code
) {
2283 tp
->rx_opt
.mss_clamp
= opt
.opt_val
;
2287 u16 snd_wscale
= opt
.opt_val
& 0xFFFF;
2288 u16 rcv_wscale
= opt
.opt_val
>> 16;
2290 if (snd_wscale
> 14 || rcv_wscale
> 14)
2293 tp
->rx_opt
.snd_wscale
= snd_wscale
;
2294 tp
->rx_opt
.rcv_wscale
= rcv_wscale
;
2295 tp
->rx_opt
.wscale_ok
= 1;
2298 case TCPOPT_SACK_PERM
:
2299 if (opt
.opt_val
!= 0)
2302 tp
->rx_opt
.sack_ok
|= TCP_SACK_SEEN
;
2303 if (sysctl_tcp_fack
)
2304 tcp_enable_fack(tp
);
2306 case TCPOPT_TIMESTAMP
:
2307 if (opt
.opt_val
!= 0)
2310 tp
->rx_opt
.tstamp_ok
= 1;
2319 * Socket option code for TCP.
2321 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2322 int optname
, char __user
*optval
, unsigned int optlen
)
2324 struct tcp_sock
*tp
= tcp_sk(sk
);
2325 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2329 /* These are data/string values, all the others are ints */
2331 case TCP_CONGESTION
: {
2332 char name
[TCP_CA_NAME_MAX
];
2337 val
= strncpy_from_user(name
, optval
,
2338 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2344 err
= tcp_set_congestion_control(sk
, name
);
2353 if (optlen
< sizeof(int))
2356 if (get_user(val
, (int __user
*)optval
))
2363 /* Values greater than interface MTU won't take effect. However
2364 * at the point when this call is done we typically don't yet
2365 * know which interface is going to be used */
2366 if (val
< TCP_MIN_MSS
|| val
> MAX_TCP_WINDOW
) {
2370 tp
->rx_opt
.user_mss
= val
;
2375 /* TCP_NODELAY is weaker than TCP_CORK, so that
2376 * this option on corked socket is remembered, but
2377 * it is not activated until cork is cleared.
2379 * However, when TCP_NODELAY is set we make
2380 * an explicit push, which overrides even TCP_CORK
2381 * for currently queued segments.
2383 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2384 tcp_push_pending_frames(sk
);
2386 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2390 case TCP_THIN_LINEAR_TIMEOUTS
:
2391 if (val
< 0 || val
> 1)
2397 case TCP_THIN_DUPACK
:
2398 if (val
< 0 || val
> 1)
2401 tp
->thin_dupack
= val
;
2402 if (tp
->thin_dupack
)
2403 tcp_disable_early_retrans(tp
);
2408 if (!tcp_can_repair_sock(sk
))
2410 else if (val
== 1) {
2412 sk
->sk_reuse
= SK_FORCE_REUSE
;
2413 tp
->repair_queue
= TCP_NO_QUEUE
;
2414 } else if (val
== 0) {
2416 sk
->sk_reuse
= SK_NO_REUSE
;
2417 tcp_send_window_probe(sk
);
2423 case TCP_REPAIR_QUEUE
:
2426 else if (val
< TCP_QUEUES_NR
)
2427 tp
->repair_queue
= val
;
2433 if (sk
->sk_state
!= TCP_CLOSE
)
2435 else if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2436 tp
->write_seq
= val
;
2437 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2443 case TCP_REPAIR_OPTIONS
:
2446 else if (sk
->sk_state
== TCP_ESTABLISHED
)
2447 err
= tcp_repair_options_est(tp
,
2448 (struct tcp_repair_opt __user
*)optval
,
2455 /* When set indicates to always queue non-full frames.
2456 * Later the user clears this option and we transmit
2457 * any pending partial frames in the queue. This is
2458 * meant to be used alongside sendfile() to get properly
2459 * filled frames when the user (for example) must write
2460 * out headers with a write() call first and then use
2461 * sendfile to send out the data parts.
2463 * TCP_CORK can be set together with TCP_NODELAY and it is
2464 * stronger than TCP_NODELAY.
2467 tp
->nonagle
|= TCP_NAGLE_CORK
;
2469 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2470 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2471 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2472 tcp_push_pending_frames(sk
);
2477 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2480 tp
->keepalive_time
= val
* HZ
;
2481 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2482 !((1 << sk
->sk_state
) &
2483 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2484 u32 elapsed
= keepalive_time_elapsed(tp
);
2485 if (tp
->keepalive_time
> elapsed
)
2486 elapsed
= tp
->keepalive_time
- elapsed
;
2489 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2494 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2497 tp
->keepalive_intvl
= val
* HZ
;
2500 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2503 tp
->keepalive_probes
= val
;
2506 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2509 icsk
->icsk_syn_retries
= val
;
2513 if (val
< 0 || val
> 1)
2522 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2525 tp
->linger2
= val
* HZ
;
2528 case TCP_DEFER_ACCEPT
:
2529 /* Translate value in seconds to number of retransmits */
2530 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2531 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2535 case TCP_WINDOW_CLAMP
:
2537 if (sk
->sk_state
!= TCP_CLOSE
) {
2541 tp
->window_clamp
= 0;
2543 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2544 SOCK_MIN_RCVBUF
/ 2 : val
;
2549 icsk
->icsk_ack
.pingpong
= 1;
2551 icsk
->icsk_ack
.pingpong
= 0;
2552 if ((1 << sk
->sk_state
) &
2553 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2554 inet_csk_ack_scheduled(sk
)) {
2555 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2556 tcp_cleanup_rbuf(sk
, 1);
2558 icsk
->icsk_ack
.pingpong
= 1;
2563 #ifdef CONFIG_TCP_MD5SIG
2565 /* Read the IP->Key mappings from userspace */
2566 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2569 case TCP_USER_TIMEOUT
:
2570 /* Cap the max time in ms TCP will retry or probe the window
2571 * before giving up and aborting (ETIMEDOUT) a connection.
2576 icsk
->icsk_user_timeout
= msecs_to_jiffies(val
);
2580 if (val
>= 0 && ((1 << sk
->sk_state
) & (TCPF_CLOSE
|
2582 tcp_fastopen_init_key_once(true);
2584 err
= fastopen_init_queue(sk
, val
);
2593 tp
->tsoffset
= val
- tcp_time_stamp
;
2595 case TCP_NOTSENT_LOWAT
:
2596 tp
->notsent_lowat
= val
;
2597 sk
->sk_write_space(sk
);
2608 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2609 unsigned int optlen
)
2611 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2613 if (level
!= SOL_TCP
)
2614 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2616 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2618 EXPORT_SYMBOL(tcp_setsockopt
);
2620 #ifdef CONFIG_COMPAT
2621 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2622 char __user
*optval
, unsigned int optlen
)
2624 if (level
!= SOL_TCP
)
2625 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2627 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2629 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2632 /* Return information about state of tcp endpoint in API format. */
2633 void tcp_get_info(struct sock
*sk
, struct tcp_info
*info
)
2635 const struct tcp_sock
*tp
= tcp_sk(sk
); /* iff sk_type == SOCK_STREAM */
2636 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2637 u32 now
= tcp_time_stamp
;
2641 memset(info
, 0, sizeof(*info
));
2642 if (sk
->sk_type
!= SOCK_STREAM
)
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 rate
= READ_ONCE(sk
->sk_pacing_rate
);
2703 info
->tcpi_pacing_rate
= rate
!= ~0U ? rate
: ~0ULL;
2705 rate
= READ_ONCE(sk
->sk_max_pacing_rate
);
2706 info
->tcpi_max_pacing_rate
= rate
!= ~0U ? rate
: ~0ULL;
2709 start
= u64_stats_fetch_begin_irq(&tp
->syncp
);
2710 info
->tcpi_bytes_acked
= tp
->bytes_acked
;
2711 info
->tcpi_bytes_received
= tp
->bytes_received
;
2712 } while (u64_stats_fetch_retry_irq(&tp
->syncp
, start
));
2713 info
->tcpi_segs_out
= tp
->segs_out
;
2714 info
->tcpi_segs_in
= tp
->segs_in
;
2716 EXPORT_SYMBOL_GPL(tcp_get_info
);
2718 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2719 int optname
, char __user
*optval
, int __user
*optlen
)
2721 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2722 struct tcp_sock
*tp
= tcp_sk(sk
);
2725 if (get_user(len
, optlen
))
2728 len
= min_t(unsigned int, len
, sizeof(int));
2735 val
= tp
->mss_cache
;
2736 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2737 val
= tp
->rx_opt
.user_mss
;
2739 val
= tp
->rx_opt
.mss_clamp
;
2742 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2745 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2748 val
= keepalive_time_when(tp
) / HZ
;
2751 val
= keepalive_intvl_when(tp
) / HZ
;
2754 val
= keepalive_probes(tp
);
2757 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2762 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2764 case TCP_DEFER_ACCEPT
:
2765 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2766 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2768 case TCP_WINDOW_CLAMP
:
2769 val
= tp
->window_clamp
;
2772 struct tcp_info info
;
2774 if (get_user(len
, optlen
))
2777 tcp_get_info(sk
, &info
);
2779 len
= min_t(unsigned int, len
, sizeof(info
));
2780 if (put_user(len
, optlen
))
2782 if (copy_to_user(optval
, &info
, len
))
2787 const struct tcp_congestion_ops
*ca_ops
;
2788 union tcp_cc_info info
;
2792 if (get_user(len
, optlen
))
2795 ca_ops
= icsk
->icsk_ca_ops
;
2796 if (ca_ops
&& ca_ops
->get_info
)
2797 sz
= ca_ops
->get_info(sk
, ~0U, &attr
, &info
);
2799 len
= min_t(unsigned int, len
, sz
);
2800 if (put_user(len
, optlen
))
2802 if (copy_to_user(optval
, &info
, len
))
2807 val
= !icsk
->icsk_ack
.pingpong
;
2810 case TCP_CONGESTION
:
2811 if (get_user(len
, optlen
))
2813 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2814 if (put_user(len
, optlen
))
2816 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2820 case TCP_THIN_LINEAR_TIMEOUTS
:
2823 case TCP_THIN_DUPACK
:
2824 val
= tp
->thin_dupack
;
2831 case TCP_REPAIR_QUEUE
:
2833 val
= tp
->repair_queue
;
2839 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2840 val
= tp
->write_seq
;
2841 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2847 case TCP_USER_TIMEOUT
:
2848 val
= jiffies_to_msecs(icsk
->icsk_user_timeout
);
2852 if (icsk
->icsk_accept_queue
.fastopenq
)
2853 val
= icsk
->icsk_accept_queue
.fastopenq
->max_qlen
;
2859 val
= tcp_time_stamp
+ tp
->tsoffset
;
2861 case TCP_NOTSENT_LOWAT
:
2862 val
= tp
->notsent_lowat
;
2867 case TCP_SAVED_SYN
: {
2868 if (get_user(len
, optlen
))
2872 if (tp
->saved_syn
) {
2873 if (len
< tp
->saved_syn
[0]) {
2874 if (put_user(tp
->saved_syn
[0], optlen
)) {
2881 len
= tp
->saved_syn
[0];
2882 if (put_user(len
, optlen
)) {
2886 if (copy_to_user(optval
, tp
->saved_syn
+ 1, len
)) {
2890 tcp_saved_syn_free(tp
);
2895 if (put_user(len
, optlen
))
2901 return -ENOPROTOOPT
;
2904 if (put_user(len
, optlen
))
2906 if (copy_to_user(optval
, &val
, len
))
2911 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2914 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2916 if (level
!= SOL_TCP
)
2917 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2919 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2921 EXPORT_SYMBOL(tcp_getsockopt
);
2923 #ifdef CONFIG_COMPAT
2924 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2925 char __user
*optval
, int __user
*optlen
)
2927 if (level
!= SOL_TCP
)
2928 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2930 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2932 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2935 #ifdef CONFIG_TCP_MD5SIG
2936 static DEFINE_PER_CPU(struct tcp_md5sig_pool
, tcp_md5sig_pool
);
2937 static DEFINE_MUTEX(tcp_md5sig_mutex
);
2938 static bool tcp_md5sig_pool_populated
= false;
2940 static void __tcp_alloc_md5sig_pool(void)
2944 for_each_possible_cpu(cpu
) {
2945 if (!per_cpu(tcp_md5sig_pool
, cpu
).md5_desc
.tfm
) {
2946 struct crypto_hash
*hash
;
2948 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
2949 if (IS_ERR_OR_NULL(hash
))
2951 per_cpu(tcp_md5sig_pool
, cpu
).md5_desc
.tfm
= hash
;
2954 /* before setting tcp_md5sig_pool_populated, we must commit all writes
2955 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
2958 tcp_md5sig_pool_populated
= true;
2961 bool tcp_alloc_md5sig_pool(void)
2963 if (unlikely(!tcp_md5sig_pool_populated
)) {
2964 mutex_lock(&tcp_md5sig_mutex
);
2966 if (!tcp_md5sig_pool_populated
)
2967 __tcp_alloc_md5sig_pool();
2969 mutex_unlock(&tcp_md5sig_mutex
);
2971 return tcp_md5sig_pool_populated
;
2973 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
2977 * tcp_get_md5sig_pool - get md5sig_pool for this user
2979 * We use percpu structure, so if we succeed, we exit with preemption
2980 * and BH disabled, to make sure another thread or softirq handling
2981 * wont try to get same context.
2983 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
2987 if (tcp_md5sig_pool_populated
) {
2988 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
2990 return this_cpu_ptr(&tcp_md5sig_pool
);
2995 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
2997 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
2998 const struct tcphdr
*th
)
3000 struct scatterlist sg
;
3004 /* We are not allowed to change tcphdr, make a local copy */
3005 memcpy(&hdr
, th
, sizeof(hdr
));
3008 /* options aren't included in the hash */
3009 sg_init_one(&sg
, &hdr
, sizeof(hdr
));
3010 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(hdr
));
3013 EXPORT_SYMBOL(tcp_md5_hash_header
);
3015 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
3016 const struct sk_buff
*skb
, unsigned int header_len
)
3018 struct scatterlist sg
;
3019 const struct tcphdr
*tp
= tcp_hdr(skb
);
3020 struct hash_desc
*desc
= &hp
->md5_desc
;
3022 const unsigned int head_data_len
= skb_headlen(skb
) > header_len
?
3023 skb_headlen(skb
) - header_len
: 0;
3024 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
3025 struct sk_buff
*frag_iter
;
3027 sg_init_table(&sg
, 1);
3029 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
3030 if (crypto_hash_update(desc
, &sg
, head_data_len
))
3033 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
3034 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
3035 unsigned int offset
= f
->page_offset
;
3036 struct page
*page
= skb_frag_page(f
) + (offset
>> PAGE_SHIFT
);
3038 sg_set_page(&sg
, page
, skb_frag_size(f
),
3039 offset_in_page(offset
));
3040 if (crypto_hash_update(desc
, &sg
, skb_frag_size(f
)))
3044 skb_walk_frags(skb
, frag_iter
)
3045 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3050 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3052 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, const struct tcp_md5sig_key
*key
)
3054 struct scatterlist sg
;
3056 sg_init_one(&sg
, key
->key
, key
->keylen
);
3057 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3059 EXPORT_SYMBOL(tcp_md5_hash_key
);
3063 void tcp_done(struct sock
*sk
)
3065 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
3067 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3068 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3070 tcp_set_state(sk
, TCP_CLOSE
);
3071 tcp_clear_xmit_timers(sk
);
3073 reqsk_fastopen_remove(sk
, req
, false);
3075 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3077 if (!sock_flag(sk
, SOCK_DEAD
))
3078 sk
->sk_state_change(sk
);
3080 inet_csk_destroy_sock(sk
);
3082 EXPORT_SYMBOL_GPL(tcp_done
);
3084 extern struct tcp_congestion_ops tcp_reno
;
3086 static __initdata
unsigned long thash_entries
;
3087 static int __init
set_thash_entries(char *str
)
3094 ret
= kstrtoul(str
, 0, &thash_entries
);
3100 __setup("thash_entries=", set_thash_entries
);
3102 static void __init
tcp_init_mem(void)
3104 unsigned long limit
= nr_free_buffer_pages() / 16;
3106 limit
= max(limit
, 128UL);
3107 sysctl_tcp_mem
[0] = limit
/ 4 * 3; /* 4.68 % */
3108 sysctl_tcp_mem
[1] = limit
; /* 6.25 % */
3109 sysctl_tcp_mem
[2] = sysctl_tcp_mem
[0] * 2; /* 9.37 % */
3112 void __init
tcp_init(void)
3114 unsigned long limit
;
3115 int max_rshare
, max_wshare
, cnt
;
3118 sock_skb_cb_check_size(sizeof(struct tcp_skb_cb
));
3120 percpu_counter_init(&tcp_sockets_allocated
, 0, GFP_KERNEL
);
3121 percpu_counter_init(&tcp_orphan_count
, 0, GFP_KERNEL
);
3122 tcp_hashinfo
.bind_bucket_cachep
=
3123 kmem_cache_create("tcp_bind_bucket",
3124 sizeof(struct inet_bind_bucket
), 0,
3125 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3127 /* Size and allocate the main established and bind bucket
3130 * The methodology is similar to that of the buffer cache.
3132 tcp_hashinfo
.ehash
=
3133 alloc_large_system_hash("TCP established",
3134 sizeof(struct inet_ehash_bucket
),
3136 17, /* one slot per 128 KB of memory */
3139 &tcp_hashinfo
.ehash_mask
,
3141 thash_entries
? 0 : 512 * 1024);
3142 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++)
3143 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3145 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3146 panic("TCP: failed to alloc ehash_locks");
3147 tcp_hashinfo
.bhash
=
3148 alloc_large_system_hash("TCP bind",
3149 sizeof(struct inet_bind_hashbucket
),
3150 tcp_hashinfo
.ehash_mask
+ 1,
3151 17, /* one slot per 128 KB of memory */
3153 &tcp_hashinfo
.bhash_size
,
3157 tcp_hashinfo
.bhash_size
= 1U << tcp_hashinfo
.bhash_size
;
3158 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3159 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3160 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3164 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
3166 tcp_death_row
.sysctl_max_tw_buckets
= cnt
/ 2;
3167 sysctl_tcp_max_orphans
= cnt
/ 2;
3168 sysctl_max_syn_backlog
= max(128, cnt
/ 256);
3171 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3172 limit
= nr_free_buffer_pages() << (PAGE_SHIFT
- 7);
3173 max_wshare
= min(4UL*1024*1024, limit
);
3174 max_rshare
= min(6UL*1024*1024, limit
);
3176 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3177 sysctl_tcp_wmem
[1] = 16*1024;
3178 sysctl_tcp_wmem
[2] = max(64*1024, max_wshare
);
3180 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3181 sysctl_tcp_rmem
[1] = 87380;
3182 sysctl_tcp_rmem
[2] = max(87380, max_rshare
);
3184 pr_info("Hash tables configured (established %u bind %u)\n",
3185 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3188 BUG_ON(tcp_register_congestion_control(&tcp_reno
) != 0);