blob: 19746b3fcbbe68db18d774c1f0178e2e5a418952 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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.
5 *
6 * Implementation of the Transmission Control Protocol(TCP).
7 *
Jesper Juhl02c30a82005-05-05 16:16:16 -07008 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * 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>
19 *
20 * Fixes:
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
25 * (tcp_err()).
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
36 * unknown sockets.
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
39 * syn rule wrong]
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
45 * escape still
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
49 * facilities
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
54 * bit to skb ops.
55 * Alan Cox : Tidied tcp_data to avoid a potential
56 * nasty.
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
68 * sockets.
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
72 * state ack error.
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
77 * fixes
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
83 * completely
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
91 * (not yet usable)
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
104 * all cases.
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
109 * works now.
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
111 * BSD api.
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
119 * fixed ports.
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
125 * socket close.
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
130 * accept.
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
141 * close.
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
147 * comments.
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
155 * resemble the RFC.
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
160 * generates them.
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
173 * but it's a start!
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
194 * improvement.
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.
207 *
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.
212 *
213 * Description of States:
214 *
215 * TCP_SYN_SENT sent a connection request, waiting for ack
216 *
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
219 *
220 * TCP_ESTABLISHED connection established
221 *
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
224 *
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
226 * to shutdown
227 *
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
230 *
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)
236 *
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)
240 *
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
244 *
245 * TCP_CLOSE socket is finished
246 */
247
Joe Perchesafd465032012-03-12 07:03:32 +0000248#define pr_fmt(fmt) "TCP: " fmt
249
Ilpo Järvinen172589c2007-08-28 15:50:33 -0700250#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251#include <linux/module.h>
252#include <linux/types.h>
253#include <linux/fcntl.h>
254#include <linux/poll.h>
Eric Dumazet6e9250f2015-04-28 16:23:49 -0700255#include <linux/inet_diag.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257#include <linux/fs.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800258#include <linux/skbuff.h>
Andrew Morton81b23b42008-07-03 03:22:02 -0700259#include <linux/scatterlist.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800260#include <linux/splice.h>
261#include <linux/net.h>
262#include <linux/socket.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263#include <linux/random.h>
264#include <linux/bootmem.h>
Miquel van Smoorenburg57413eb2008-06-27 17:23:57 -0700265#include <linux/highmem.h>
266#include <linux/swap.h>
David S. Millerb8059ea2006-03-25 01:36:56 -0800267#include <linux/cache.h>
Herbert Xuf4c50d92006-06-22 03:02:40 -0700268#include <linux/err.h>
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800269#include <linux/crypto.h>
William Allen Simpsonda5c78c2009-12-02 18:12:09 +0000270#include <linux/time.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +0900271#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273#include <net/icmp.h>
Yuchung Chengcf60af02012-07-19 06:43:09 +0000274#include <net/inet_common.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275#include <net/tcp.h>
276#include <net/xfrm.h>
277#include <net/ip.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800278#include <net/sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
280#include <asm/uaccess.h>
281#include <asm/ioctls.h>
Eric Dumazetff5d7492016-01-27 10:52:43 -0800282#include <asm/unaligned.h>
Eliezer Tamir076bb0c2013-07-10 17:13:17 +0300283#include <net/busy_poll.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
Brian Haleyab32ea52006-09-22 14:15:41 -0700285int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
Eric Dumazet95bd09e2013-08-27 05:46:32 -0700287int sysctl_tcp_min_tso_segs __read_mostly = 2;
288
Eric Dumazetf54b3112013-12-05 22:36:05 -0800289int sysctl_tcp_autocorking __read_mostly = 1;
290
Eric Dumazetdd24c002008-11-25 21:17:14 -0800291struct percpu_counter tcp_orphan_count;
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -0700292EXPORT_SYMBOL_GPL(tcp_orphan_count);
293
Eric W. Biedermana4fe34b2013-10-19 16:25:36 -0700294long sysctl_tcp_mem[3] __read_mostly;
David S. Millerb8059ea2006-03-25 01:36:56 -0800295int sysctl_tcp_wmem[3] __read_mostly;
296int sysctl_tcp_rmem[3] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
Eric W. Biedermana4fe34b2013-10-19 16:25:36 -0700298EXPORT_SYMBOL(sysctl_tcp_mem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299EXPORT_SYMBOL(sysctl_tcp_rmem);
300EXPORT_SYMBOL(sysctl_tcp_wmem);
301
Eric Dumazet8d987e52010-11-09 23:24:26 +0000302atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303EXPORT_SYMBOL(tcp_memory_allocated);
Eric Dumazet17483762008-11-25 21:16:35 -0800304
305/*
306 * Current number of TCP sockets.
307 */
308struct percpu_counter tcp_sockets_allocated;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309EXPORT_SYMBOL(tcp_sockets_allocated);
310
311/*
Jens Axboe9c55e012007-11-06 23:30:13 -0800312 * TCP splice context
313 */
314struct tcp_splice_state {
315 struct pipe_inode_info *pipe;
316 size_t len;
317 unsigned int flags;
318};
319
320/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 * Pressure flag: try to collapse.
322 * Technical note: it is used by multiple contexts non atomically.
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800323 * All the __sk_mem_schedule() is of this nature: accounting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 * is strict, actions are advisory and have some latency.
325 */
Eric Dumazet4103f8c2007-03-27 13:58:31 -0700326int tcp_memory_pressure __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327EXPORT_SYMBOL(tcp_memory_pressure);
328
Pavel Emelyanov5c52ba12008-07-16 20:28:10 -0700329void tcp_enter_memory_pressure(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330{
331 if (!tcp_memory_pressure) {
Pavel Emelyanov4e673442008-07-16 20:30:14 -0700332 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 tcp_memory_pressure = 1;
334 }
335}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336EXPORT_SYMBOL(tcp_enter_memory_pressure);
337
Julian Anastasovb103cf32009-10-19 10:10:40 +0000338/* Convert seconds to retransmits based on initial and max timeout */
339static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
340{
341 u8 res = 0;
342
343 if (seconds > 0) {
344 int period = timeout;
345
346 res = 1;
347 while (seconds > period && res < 255) {
348 res++;
349 timeout <<= 1;
350 if (timeout > rto_max)
351 timeout = rto_max;
352 period += timeout;
353 }
354 }
355 return res;
356}
357
358/* Convert retransmits to seconds based on initial and max timeout */
359static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
360{
361 int period = 0;
362
363 if (retrans > 0) {
364 period = timeout;
365 while (--retrans) {
366 timeout <<= 1;
367 if (timeout > rto_max)
368 timeout = rto_max;
369 period += timeout;
370 }
371 }
372 return period;
373}
374
Neal Cardwell900f65d2012-04-19 09:55:21 +0000375/* Address-family independent initialization for a tcp_sock.
376 *
377 * NOTE: A lot of things set to zero explicitly by call to
378 * sk_alloc() so need not be done here.
379 */
380void tcp_init_sock(struct sock *sk)
381{
382 struct inet_connection_sock *icsk = inet_csk(sk);
383 struct tcp_sock *tp = tcp_sk(sk);
384
Eric Dumazet996b1752014-01-06 09:36:12 -0800385 __skb_queue_head_init(&tp->out_of_order_queue);
Neal Cardwell900f65d2012-04-19 09:55:21 +0000386 tcp_init_xmit_timers(sk);
387 tcp_prequeue_init(tp);
Eric Dumazet46d3cea2012-07-11 05:50:31 +0000388 INIT_LIST_HEAD(&tp->tsq_node);
Neal Cardwell900f65d2012-04-19 09:55:21 +0000389
390 icsk->icsk_rto = TCP_TIMEOUT_INIT;
Eric Dumazet740b0f12014-02-26 14:02:48 -0800391 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
Yuchung Chengf6722582015-10-16 21:57:42 -0700392 tp->rtt_min[0].rtt = ~0U;
Neal Cardwell900f65d2012-04-19 09:55:21 +0000393
394 /* So many TCP implementations out there (incorrectly) count the
395 * initial SYN frame in their delayed-ACK and congestion control
396 * algorithms that we must have the following bandaid to talk
397 * efficiently to them. -DaveM
398 */
399 tp->snd_cwnd = TCP_INIT_CWND;
400
401 /* See draft-stevens-tcpca-spec-01 for discussion of the
402 * initialization of these values.
403 */
404 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
405 tp->snd_cwnd_clamp = ~0;
406 tp->mss_cache = TCP_MSS_DEFAULT;
Eric Dumazetd6549762015-05-21 21:51:19 -0700407 u64_stats_init(&tp->syncp);
Neal Cardwell900f65d2012-04-19 09:55:21 +0000408
409 tp->reordering = sysctl_tcp_reordering;
Yuchung Chengeed530b2012-05-02 13:30:03 +0000410 tcp_enable_early_retrans(tp);
Florian Westphal55d86942014-09-26 22:37:32 +0200411 tcp_assign_congestion_control(sk);
Neal Cardwell900f65d2012-04-19 09:55:21 +0000412
Andrey Vaginceaa1fe2013-02-11 05:50:17 +0000413 tp->tsoffset = 0;
414
Neal Cardwell900f65d2012-04-19 09:55:21 +0000415 sk->sk_state = TCP_CLOSE;
416
417 sk->sk_write_space = sk_stream_write_space;
418 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
419
420 icsk->icsk_sync_mss = tcp_sync_mss;
421
Neal Cardwell900f65d2012-04-19 09:55:21 +0000422 sk->sk_sndbuf = sysctl_tcp_wmem[1];
423 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
424
425 local_bh_disable();
Johannes Weiner3d596f72016-01-14 15:21:05 -0800426 if (mem_cgroup_sockets_enabled)
427 sock_update_memcg(sk);
Neal Cardwell900f65d2012-04-19 09:55:21 +0000428 sk_sockets_allocated_inc(sk);
429 local_bh_enable();
430}
431EXPORT_SYMBOL(tcp_init_sock);
432
Willem de Bruijnf066e2b2014-08-06 15:09:44 -0400433static void tcp_tx_timestamp(struct sock *sk, struct sk_buff *skb)
Willem de Bruijn4ed2d762014-08-04 22:11:49 -0400434{
Willem de Bruijnf066e2b2014-08-06 15:09:44 -0400435 if (sk->sk_tsflags) {
436 struct skb_shared_info *shinfo = skb_shinfo(skb);
Willem de Bruijn4ed2d762014-08-04 22:11:49 -0400437
Willem de Bruijnf066e2b2014-08-06 15:09:44 -0400438 sock_tx_timestamp(sk, &shinfo->tx_flags);
439 if (shinfo->tx_flags & SKBTX_ANY_TSTAMP)
440 shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
441 }
Willem de Bruijn4ed2d762014-08-04 22:11:49 -0400442}
443
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 * Wait for a TCP event.
446 *
447 * Note that we don't need to lock the socket, as the upper poll layers
448 * take care of normal races (between the test and the event) and we don't
449 * go look at any of the socket buffers directly.
450 */
451unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
452{
453 unsigned int mask;
454 struct sock *sk = sock->sk;
Eric Dumazetcf533ea2011-10-21 05:22:42 -0400455 const struct tcp_sock *tp = tcp_sk(sk);
Eric Dumazet00fd38d2015-11-12 08:43:18 -0800456 int state;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
David Majnemerc3f1dba2013-05-31 13:15:38 +0000458 sock_rps_record_flow(sk);
459
Eric Dumazetaa395142010-04-20 13:03:51 +0000460 sock_poll_wait(file, sk_sleep(sk), wait);
Eric Dumazet00fd38d2015-11-12 08:43:18 -0800461
462 state = sk_state_load(sk);
463 if (state == TCP_LISTEN)
Arnaldo Carvalho de Melodc40c7b2005-08-23 21:52:58 -0700464 return inet_csk_listen_poll(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
466 /* Socket is not locked. We are protected from async events
Will Newton70efce22008-07-16 20:13:43 -0700467 * by poll logic and correct handling of state changes
468 * made by other threads is impossible in any case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 */
470
471 mask = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
473 /*
474 * POLLHUP is certainly not done right. But poll() doesn't
475 * have a notion of HUP in just one direction, and for a
476 * socket the read side is more interesting.
477 *
478 * Some poll() documentation says that POLLHUP is incompatible
479 * with the POLLOUT/POLLWR flags, so somebody should check this
480 * all. But careful, it tends to be safer to return too many
481 * bits than too few, and you can easily break real applications
482 * if you don't tell them that something has hung up!
483 *
484 * Check-me.
485 *
486 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
487 * our fs/select.c). It means that after we received EOF,
488 * poll always returns immediately, making impossible poll() on write()
489 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
490 * if and only if shutdown has been made in both directions.
491 * Actually, it is interesting to look how Solaris and DUX
Will Newton70efce22008-07-16 20:13:43 -0700492 * solve this dilemma. I would prefer, if POLLHUP were maskable,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 * then we could set it on SND_SHUTDOWN. BTW examples given
494 * in Stevens' books assume exactly this behaviour, it explains
Will Newton70efce22008-07-16 20:13:43 -0700495 * why POLLHUP is incompatible with POLLOUT. --ANK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 *
497 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
498 * blocking on fresh not-connected or disconnected socket. --ANK
499 */
Eric Dumazet00fd38d2015-11-12 08:43:18 -0800500 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 mask |= POLLHUP;
502 if (sk->sk_shutdown & RCV_SHUTDOWN)
Davide Libenzif348d702006-03-25 03:07:39 -0800503 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
Jerry Chu83368862012-08-31 12:29:12 +0000505 /* Connected or passive Fast Open socket? */
Eric Dumazet00fd38d2015-11-12 08:43:18 -0800506 if (state != TCP_SYN_SENT &&
507 (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
David S. Millerc7004482008-10-06 10:43:54 -0700508 int target = sock_rcvlowat(sk, 0, INT_MAX);
509
510 if (tp->urg_seq == tp->copied_seq &&
511 !sock_flag(sk, SOCK_URGINLINE) &&
512 tp->urg_data)
Alexandra Kossovskyb634f872010-03-18 20:29:24 -0700513 target++;
David S. Millerc7004482008-10-06 10:43:54 -0700514
David S. Millerc7004482008-10-06 10:43:54 -0700515 if (tp->rcv_nxt - tp->copied_seq >= target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 mask |= POLLIN | POLLRDNORM;
517
518 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
Eric Dumazet64dc6132013-07-22 20:26:31 -0700519 if (sk_stream_is_writeable(sk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 mask |= POLLOUT | POLLWRNORM;
521 } else { /* send SIGIO later */
Eric Dumazet9cd3e072015-11-29 20:03:10 -0800522 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
524
525 /* Race breaker. If space is freed after
526 * wspace test but before the flags are set,
jbaron@akamai.com3c715122015-04-20 20:05:07 +0000527 * IO signal will be lost. Memory barrier
528 * pairs with the input side.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 */
jbaron@akamai.com3c715122015-04-20 20:05:07 +0000530 smp_mb__after_atomic();
Eric Dumazet64dc6132013-07-22 20:26:31 -0700531 if (sk_stream_is_writeable(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 mask |= POLLOUT | POLLWRNORM;
533 }
KOSAKI Motohirod84ba632010-08-24 16:05:48 +0000534 } else
535 mask |= POLLOUT | POLLWRNORM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536
537 if (tp->urg_data & TCP_URG_VALID)
538 mask |= POLLPRI;
539 }
Tom Marshalla4d25802010-09-20 15:42:05 -0700540 /* This barrier is coupled with smp_wmb() in tcp_reset() */
541 smp_rmb();
Willem de Bruijn4ed2d762014-08-04 22:11:49 -0400542 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
Tom Marshalla4d25802010-09-20 15:42:05 -0700543 mask |= POLLERR;
544
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 return mask;
546}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000547EXPORT_SYMBOL(tcp_poll);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
549int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
550{
551 struct tcp_sock *tp = tcp_sk(sk);
552 int answ;
Eric Dumazet0e71c552012-10-21 20:06:56 +0000553 bool slow;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
555 switch (cmd) {
556 case SIOCINQ:
557 if (sk->sk_state == TCP_LISTEN)
558 return -EINVAL;
559
Eric Dumazet0e71c552012-10-21 20:06:56 +0000560 slow = lock_sock_fast(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
562 answ = 0;
563 else if (sock_flag(sk, SOCK_URGINLINE) ||
564 !tp->urg_data ||
565 before(tp->urg_seq, tp->copied_seq) ||
566 !before(tp->urg_seq, tp->rcv_nxt)) {
David S. Miller91521942009-05-28 21:35:47 -0700567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 answ = tp->rcv_nxt - tp->copied_seq;
569
Eric Dumazeta3374c42012-10-18 09:14:12 +0000570 /* Subtract 1, if FIN was received */
571 if (answ && sock_flag(sk, SOCK_DONE))
572 answ--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 } else
574 answ = tp->urg_seq - tp->copied_seq;
Eric Dumazet0e71c552012-10-21 20:06:56 +0000575 unlock_sock_fast(sk, slow);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 break;
577 case SIOCATMARK:
578 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
579 break;
580 case SIOCOUTQ:
581 if (sk->sk_state == TCP_LISTEN)
582 return -EINVAL;
583
584 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
585 answ = 0;
586 else
587 answ = tp->write_seq - tp->snd_una;
588 break;
Mario Schuknecht2f4e1b32011-03-09 14:08:09 -0800589 case SIOCOUTQNSD:
590 if (sk->sk_state == TCP_LISTEN)
591 return -EINVAL;
592
593 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
594 answ = 0;
595 else
596 answ = tp->write_seq - tp->snd_nxt;
597 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 default:
599 return -ENOIOCTLCMD;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700600 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601
602 return put_user(answ, (int __user *)arg);
603}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000604EXPORT_SYMBOL(tcp_ioctl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
607{
Eric Dumazet4de075e2011-09-27 13:25:05 -0400608 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 tp->pushed_seq = tp->write_seq;
610}
611
Eric Dumazeta2a385d2012-05-16 23:15:34 +0000612static inline bool forced_push(const struct tcp_sock *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613{
614 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
615}
616
Eric Dumazetf4a775d2014-09-22 16:29:32 -0700617static void skb_entail(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700619 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo352d4802006-11-17 19:59:12 -0200620 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
621
622 skb->csum = 0;
623 tcb->seq = tcb->end_seq = tp->write_seq;
Eric Dumazet4de075e2011-09-27 13:25:05 -0400624 tcb->tcp_flags = TCPHDR_ACK;
Arnaldo Carvalho de Melo352d4802006-11-17 19:59:12 -0200625 tcb->sacked = 0;
Eric Dumazetf4a775d2014-09-22 16:29:32 -0700626 __skb_header_release(skb);
David S. Millerfe067e82007-03-07 12:12:44 -0800627 tcp_add_write_queue_tail(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800628 sk->sk_wmem_queued += skb->truesize;
629 sk_mem_charge(sk, skb->truesize);
David S. Miller89ebd192005-08-23 10:13:06 -0700630 if (tp->nonagle & TCP_NAGLE_PUSH)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900631 tp->nonagle &= ~TCP_NAGLE_PUSH;
Eric Dumazet6f021c62015-08-21 12:30:00 -0700632
633 tcp_slow_start_after_idle_check(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634}
635
Krishna Kumarafeca342009-12-10 07:16:52 +0000636static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637{
Ilpo Järvinen33f5f572008-10-07 14:43:06 -0700638 if (flags & MSG_OOB)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 tp->snd_up = tp->write_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640}
641
Eric Dumazetf54b3112013-12-05 22:36:05 -0800642/* If a not yet filled skb is pushed, do not send it if
Eric Dumazeta181ceb2013-12-17 09:58:30 -0800643 * we have data packets in Qdisc or NIC queues :
Eric Dumazetf54b3112013-12-05 22:36:05 -0800644 * Because TX completion will happen shortly, it gives a chance
645 * to coalesce future sendmsg() payload into this skb, without
646 * need for a timer, and with no latency trade off.
647 * As packets containing data payload have a bigger truesize
Eric Dumazeta181ceb2013-12-17 09:58:30 -0800648 * than pure acks (dataless) packets, the last checks prevent
649 * autocorking if we only have an ACK in Qdisc/NIC queues,
650 * or if TX completion was delayed after we processed ACK packet.
Eric Dumazetf54b3112013-12-05 22:36:05 -0800651 */
652static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
653 int size_goal)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654{
Eric Dumazetf54b3112013-12-05 22:36:05 -0800655 return skb->len < size_goal &&
656 sysctl_tcp_autocorking &&
Eric Dumazeta181ceb2013-12-17 09:58:30 -0800657 skb != tcp_write_queue_head(sk) &&
Eric Dumazetf54b3112013-12-05 22:36:05 -0800658 atomic_read(&sk->sk_wmem_alloc) > skb->truesize;
659}
Krishna Kumarafeca342009-12-10 07:16:52 +0000660
Eric Dumazetf54b3112013-12-05 22:36:05 -0800661static void tcp_push(struct sock *sk, int flags, int mss_now,
662 int nonagle, int size_goal)
663{
664 struct tcp_sock *tp = tcp_sk(sk);
665 struct sk_buff *skb;
Krishna Kumarafeca342009-12-10 07:16:52 +0000666
Eric Dumazetf54b3112013-12-05 22:36:05 -0800667 if (!tcp_send_head(sk))
668 return;
669
670 skb = tcp_write_queue_tail(sk);
671 if (!(flags & MSG_MORE) || forced_push(tp))
672 tcp_mark_push(tp, skb);
673
674 tcp_mark_urg(tp, flags);
675
676 if (tcp_should_autocork(sk, skb, size_goal)) {
677
678 /* avoid atomic op if TSQ_THROTTLED bit is already set */
679 if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) {
680 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
681 set_bit(TSQ_THROTTLED, &tp->tsq_flags);
682 }
Eric Dumazeta181ceb2013-12-17 09:58:30 -0800683 /* It is possible TX completion already happened
684 * before we set TSQ_THROTTLED.
685 */
686 if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize)
687 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 }
Eric Dumazetf54b3112013-12-05 22:36:05 -0800689
690 if (flags & MSG_MORE)
691 nonagle = TCP_NAGLE_CORK;
692
693 __tcp_push_pending_frames(sk, mss_now, nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694}
695
Adrian Bunk6ff77512007-11-06 23:32:26 -0800696static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
697 unsigned int offset, size_t len)
Jens Axboe9c55e012007-11-06 23:30:13 -0800698{
699 struct tcp_splice_state *tss = rd_desc->arg.data;
Willy Tarreau33966dd02009-01-13 16:04:36 -0800700 int ret;
Jens Axboe9c55e012007-11-06 23:30:13 -0800701
Hannes Frederic Sowaa60e3cc2015-05-21 17:00:00 +0200702 ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
703 min(rd_desc->count, len), tss->flags,
704 skb_socket_splice);
Willy Tarreau33966dd02009-01-13 16:04:36 -0800705 if (ret > 0)
706 rd_desc->count -= ret;
707 return ret;
Jens Axboe9c55e012007-11-06 23:30:13 -0800708}
709
710static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
711{
712 /* Store TCP splice context information in read_descriptor_t. */
713 read_descriptor_t rd_desc = {
714 .arg.data = tss,
Willy Tarreau33966dd02009-01-13 16:04:36 -0800715 .count = tss->len,
Jens Axboe9c55e012007-11-06 23:30:13 -0800716 };
717
718 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
719}
720
721/**
722 * tcp_splice_read - splice data from TCP socket to a pipe
723 * @sock: socket to splice from
724 * @ppos: position (not valid)
725 * @pipe: pipe to splice to
726 * @len: number of bytes to splice
727 * @flags: splice modifier flags
728 *
729 * Description:
730 * Will read pages from given socket and fill them into a pipe.
731 *
732 **/
733ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
734 struct pipe_inode_info *pipe, size_t len,
735 unsigned int flags)
736{
737 struct sock *sk = sock->sk;
738 struct tcp_splice_state tss = {
739 .pipe = pipe,
740 .len = len,
741 .flags = flags,
742 };
743 long timeo;
744 ssize_t spliced;
745 int ret;
746
Changli Gao3a047bf2010-07-12 21:00:12 +0000747 sock_rps_record_flow(sk);
Jens Axboe9c55e012007-11-06 23:30:13 -0800748 /*
749 * We can't seek on a socket input
750 */
751 if (unlikely(*ppos))
752 return -ESPIPE;
753
754 ret = spliced = 0;
755
756 lock_sock(sk);
757
Eric Dumazet42324c62009-10-01 15:26:00 -0700758 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
Jens Axboe9c55e012007-11-06 23:30:13 -0800759 while (tss.len) {
760 ret = __tcp_splice_read(sk, &tss);
761 if (ret < 0)
762 break;
763 else if (!ret) {
764 if (spliced)
765 break;
Jens Axboe9c55e012007-11-06 23:30:13 -0800766 if (sock_flag(sk, SOCK_DONE))
767 break;
768 if (sk->sk_err) {
769 ret = sock_error(sk);
770 break;
771 }
772 if (sk->sk_shutdown & RCV_SHUTDOWN)
773 break;
774 if (sk->sk_state == TCP_CLOSE) {
775 /*
776 * This occurs when user tries to read
777 * from never connected socket.
778 */
779 if (!sock_flag(sk, SOCK_DONE))
780 ret = -ENOTCONN;
781 break;
782 }
783 if (!timeo) {
784 ret = -EAGAIN;
785 break;
786 }
Sabrina Dubrocadfbafc92015-07-24 18:19:25 +0200787 sk_wait_data(sk, &timeo, NULL);
Jens Axboe9c55e012007-11-06 23:30:13 -0800788 if (signal_pending(current)) {
789 ret = sock_intr_errno(timeo);
790 break;
791 }
792 continue;
793 }
794 tss.len -= ret;
795 spliced += ret;
796
Willy Tarreau33966dd02009-01-13 16:04:36 -0800797 if (!timeo)
798 break;
Jens Axboe9c55e012007-11-06 23:30:13 -0800799 release_sock(sk);
800 lock_sock(sk);
801
802 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
Willy Tarreau33966dd02009-01-13 16:04:36 -0800803 (sk->sk_shutdown & RCV_SHUTDOWN) ||
Jens Axboe9c55e012007-11-06 23:30:13 -0800804 signal_pending(current))
805 break;
806 }
807
808 release_sock(sk);
809
810 if (spliced)
811 return spliced;
812
813 return ret;
814}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000815EXPORT_SYMBOL(tcp_splice_read);
Jens Axboe9c55e012007-11-06 23:30:13 -0800816
Eric Dumazeteb934472015-05-19 13:26:55 -0700817struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
818 bool force_schedule)
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100819{
820 struct sk_buff *skb;
821
822 /* The TCP header must be at least 32-bit aligned. */
823 size = ALIGN(size, 4);
824
Eric Dumazet8e4d9802015-05-15 12:39:28 -0700825 if (unlikely(tcp_under_memory_pressure(sk)))
826 sk_mem_reclaim_partial(sk);
827
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100828 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
Eric Dumazet8e4d9802015-05-15 12:39:28 -0700829 if (likely(skb)) {
Eric Dumazeteb934472015-05-19 13:26:55 -0700830 bool mem_scheduled;
Eric Dumazet8e4d9802015-05-15 12:39:28 -0700831
Eric Dumazeteb934472015-05-19 13:26:55 -0700832 if (force_schedule) {
833 mem_scheduled = true;
Eric Dumazet8e4d9802015-05-15 12:39:28 -0700834 sk_forced_mem_schedule(sk, skb->truesize);
835 } else {
Eric Dumazeteb934472015-05-19 13:26:55 -0700836 mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
Eric Dumazet8e4d9802015-05-15 12:39:28 -0700837 }
Eric Dumazeteb934472015-05-19 13:26:55 -0700838 if (likely(mem_scheduled)) {
Eric Dumazeta21d4572012-04-10 20:30:48 +0000839 skb_reserve(skb, sk->sk_prot->max_header);
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100840 /*
841 * Make sure that we have exactly size bytes
842 * available to the caller, no more, no less.
843 */
Eric Dumazet16fad692013-03-14 05:40:32 +0000844 skb->reserved_tailroom = skb->end - skb->tail - size;
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100845 return skb;
846 }
847 __kfree_skb(skb);
848 } else {
Pavel Emelyanov5c52ba12008-07-16 20:28:10 -0700849 sk->sk_prot->enter_memory_pressure(sk);
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100850 sk_stream_moderate_sndbuf(sk);
851 }
852 return NULL;
853}
854
Ilpo Järvinen0c54b852009-03-14 14:23:05 +0000855static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
856 int large_allowed)
857{
858 struct tcp_sock *tp = tcp_sk(sk);
Eric Dumazet6c09fa02015-03-05 08:03:06 -0800859 u32 new_size_goal, size_goal;
Ilpo Järvinen0c54b852009-03-14 14:23:05 +0000860
Eric Dumazet605ad7f2014-12-07 12:22:18 -0800861 if (!large_allowed || !sk_can_gso(sk))
862 return mss_now;
Ilpo Järvinen0c54b852009-03-14 14:23:05 +0000863
Eric Dumazet6c09fa02015-03-05 08:03:06 -0800864 /* Note : tcp_tso_autosize() will eventually split this later */
865 new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER;
Eric Dumazet605ad7f2014-12-07 12:22:18 -0800866 new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal);
Eric Dumazet95bd09e2013-08-27 05:46:32 -0700867
Eric Dumazet605ad7f2014-12-07 12:22:18 -0800868 /* We try hard to avoid divides here */
869 size_goal = tp->gso_segs * mss_now;
870 if (unlikely(new_size_goal < size_goal ||
871 new_size_goal >= size_goal + mss_now)) {
872 tp->gso_segs = min_t(u16, new_size_goal / mss_now,
873 sk->sk_gso_max_segs);
874 size_goal = tp->gso_segs * mss_now;
Ilpo Järvinen0c54b852009-03-14 14:23:05 +0000875 }
876
Eric Dumazet605ad7f2014-12-07 12:22:18 -0800877 return max(size_goal, mss_now);
Ilpo Järvinen0c54b852009-03-14 14:23:05 +0000878}
879
880static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
881{
882 int mss_now;
883
884 mss_now = tcp_current_mss(sk);
885 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
886
887 return mss_now;
888}
889
Eric Dumazet64022d02012-12-01 13:07:02 +0000890static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
891 size_t size, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892{
893 struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700894 int mss_now, size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 int err;
896 ssize_t copied;
897 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
898
Jerry Chu83368862012-08-31 12:29:12 +0000899 /* Wait for a connection to finish. One exception is TCP Fast Open
900 * (passive side) where data is allowed to be sent before a connection
901 * is fully established.
902 */
903 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
904 !tcp_passive_fastopen(sk)) {
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -0700905 err = sk_stream_wait_connect(sk, &timeo);
906 if (err != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 goto out_err;
Jerry Chu83368862012-08-31 12:29:12 +0000908 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909
Eric Dumazet9cd3e072015-11-29 20:03:10 -0800910 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911
Ilpo Järvinen0c54b852009-03-14 14:23:05 +0000912 mss_now = tcp_send_mss(sk, &size_goal, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 copied = 0;
914
915 err = -EPIPE;
916 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
Ilpo Järvinen0d6a7752009-02-28 04:44:41 +0000917 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918
Eric Dumazet64022d02012-12-01 13:07:02 +0000919 while (size > 0) {
David S. Millerfe067e82007-03-07 12:12:44 -0800920 struct sk_buff *skb = tcp_write_queue_tail(sk);
Eric Dumazet38ba0a62012-04-23 17:48:27 +0000921 int copy, i;
Eric Dumazet38ba0a62012-04-23 17:48:27 +0000922 bool can_coalesce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923
David S. Millerfe067e82007-03-07 12:12:44 -0800924 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925new_segment:
926 if (!sk_stream_memory_free(sk))
927 goto wait_for_sndbuf;
928
Eric Dumazeteb934472015-05-19 13:26:55 -0700929 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
930 skb_queue_empty(&sk->sk_write_queue));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 if (!skb)
932 goto wait_for_memory;
933
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700934 skb_entail(sk, skb);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700935 copy = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 }
937
938 if (copy > size)
939 copy = size;
940
941 i = skb_shinfo(skb)->nr_frags;
942 can_coalesce = skb_can_coalesce(skb, i, page, offset);
943 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
944 tcp_mark_push(tp, skb);
945 goto new_segment;
946 }
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800947 if (!sk_wmem_schedule(sk, copy))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 goto wait_for_memory;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900949
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 if (can_coalesce) {
Eric Dumazet9e903e02011-10-18 21:00:24 +0000951 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 } else {
953 get_page(page);
954 skb_fill_page_desc(skb, i, page, offset, copy);
955 }
Pravin B Shelarc9af6db2013-02-11 09:27:41 +0000956 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
Eric Dumazetcef401d2013-01-25 20:34:37 +0000957
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 skb->len += copy;
959 skb->data_len += copy;
960 skb->truesize += copy;
961 sk->sk_wmem_queued += copy;
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800962 sk_mem_charge(sk, copy);
Patrick McHardy84fa7932006-08-29 16:44:56 -0700963 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 tp->write_seq += copy;
965 TCP_SKB_CB(skb)->end_seq += copy;
Eric Dumazetcd7d8492014-09-24 04:11:22 -0700966 tcp_skb_pcount_set(skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
968 if (!copied)
Eric Dumazet4de075e2011-09-27 13:25:05 -0400969 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970
971 copied += copy;
Eric Dumazet64022d02012-12-01 13:07:02 +0000972 offset += copy;
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -0700973 size -= copy;
974 if (!size) {
Willem de Bruijn4ed2d762014-08-04 22:11:49 -0400975 tcp_tx_timestamp(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 goto out;
Willem de Bruijn4ed2d762014-08-04 22:11:49 -0400977 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
Herbert Xu69d15062008-03-22 15:47:05 -0700979 if (skb->len < size_goal || (flags & MSG_OOB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 continue;
981
982 if (forced_push(tp)) {
983 tcp_mark_push(tp, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700984 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
David S. Millerfe067e82007-03-07 12:12:44 -0800985 } else if (skb == tcp_send_head(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 tcp_push_one(sk, mss_now);
987 continue;
988
989wait_for_sndbuf:
990 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
991wait_for_memory:
Eric Dumazetf54b3112013-12-05 22:36:05 -0800992 tcp_push(sk, flags & ~MSG_MORE, mss_now,
993 TCP_NAGLE_PUSH, size_goal);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -0700995 err = sk_stream_wait_memory(sk, &timeo);
996 if (err != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 goto do_error;
998
Ilpo Järvinen0c54b852009-03-14 14:23:05 +0000999 mss_now = tcp_send_mss(sk, &size_goal, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 }
1001
1002out:
Eric Dumazet35f9c092012-04-05 03:05:35 +00001003 if (copied && !(flags & MSG_SENDPAGE_NOTLAST))
Eric Dumazetf54b3112013-12-05 22:36:05 -08001004 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 return copied;
1006
1007do_error:
1008 if (copied)
1009 goto out;
1010out_err:
Jason Baronce5ec442015-05-20 15:52:53 +00001011 /* make sure we wake any epoll edge trigger waiter */
1012 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
1013 sk->sk_write_space(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014 return sk_stream_error(sk, flags, err);
1015}
1016
Changli Gao7ba42912010-07-10 20:41:55 +00001017int tcp_sendpage(struct sock *sk, struct page *page, int offset,
1018 size_t size, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019{
1020 ssize_t res;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022 if (!(sk->sk_route_caps & NETIF_F_SG) ||
Tom Herbert9a498502015-12-14 11:19:45 -08001023 !sk_check_csum_caps(sk))
Changli Gao7ba42912010-07-10 20:41:55 +00001024 return sock_no_sendpage(sk->sk_socket, page, offset, size,
1025 flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 lock_sock(sk);
Eric Dumazet64022d02012-12-01 13:07:02 +00001028 res = do_tcp_sendpages(sk, page, offset, size, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 release_sock(sk);
1030 return res;
1031}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00001032EXPORT_SYMBOL(tcp_sendpage);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033
Eric Dumazet690e99c2011-11-28 00:27:47 +00001034static inline int select_size(const struct sock *sk, bool sg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035{
Eric Dumazetcf533ea2011-10-21 05:22:42 -04001036 const struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -07001037 int tmp = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038
Krishna Kumardef87cf2009-12-10 07:16:59 +00001039 if (sg) {
Eric Dumazetf07d9602011-11-28 22:41:47 +00001040 if (sk_can_gso(sk)) {
1041 /* Small frames wont use a full page:
1042 * Payload will immediately follow tcp header.
1043 */
1044 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
1045 } else {
David S. Millerb4e26f52005-07-05 15:20:27 -07001046 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
1047
1048 if (tmp >= pgbreak &&
1049 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
1050 tmp = pgbreak;
1051 }
1052 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 return tmp;
1055}
1056
Yuchung Chengcf60af02012-07-19 06:43:09 +00001057void tcp_free_fastopen_req(struct tcp_sock *tp)
1058{
Ian Morris00db4122015-04-03 09:17:27 +01001059 if (tp->fastopen_req) {
Yuchung Chengcf60af02012-07-19 06:43:09 +00001060 kfree(tp->fastopen_req);
1061 tp->fastopen_req = NULL;
1062 }
1063}
1064
Eric Dumazetf5ddcbb2014-02-20 10:09:18 -08001065static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
1066 int *copied, size_t size)
Yuchung Chengcf60af02012-07-19 06:43:09 +00001067{
1068 struct tcp_sock *tp = tcp_sk(sk);
1069 int err, flags;
1070
1071 if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE))
1072 return -EOPNOTSUPP;
Ian Morris00db4122015-04-03 09:17:27 +01001073 if (tp->fastopen_req)
Yuchung Chengcf60af02012-07-19 06:43:09 +00001074 return -EALREADY; /* Another Fast Open is in progress */
1075
1076 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
1077 sk->sk_allocation);
Ian Morris51456b22015-04-03 09:17:26 +01001078 if (unlikely(!tp->fastopen_req))
Yuchung Chengcf60af02012-07-19 06:43:09 +00001079 return -ENOBUFS;
1080 tp->fastopen_req->data = msg;
Eric Dumazetf5ddcbb2014-02-20 10:09:18 -08001081 tp->fastopen_req->size = size;
Yuchung Chengcf60af02012-07-19 06:43:09 +00001082
1083 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1084 err = __inet_stream_connect(sk->sk_socket, msg->msg_name,
1085 msg->msg_namelen, flags);
Eric Dumazetf5ddcbb2014-02-20 10:09:18 -08001086 *copied = tp->fastopen_req->copied;
Yuchung Chengcf60af02012-07-19 06:43:09 +00001087 tcp_free_fastopen_req(tp);
1088 return err;
1089}
1090
Ying Xue1b784142015-03-02 15:37:48 +08001091int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 struct tcp_sock *tp = tcp_sk(sk);
1094 struct sk_buff *skb;
Al Viro57be5bd2014-11-28 13:40:20 -05001095 int flags, err, copied = 0;
1096 int mss_now = 0, size_goal, copied_syn = 0;
Eric Dumazet690e99c2011-11-28 00:27:47 +00001097 bool sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 long timeo;
1099
1100 lock_sock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101
1102 flags = msg->msg_flags;
Yuchung Chengcf60af02012-07-19 06:43:09 +00001103 if (flags & MSG_FASTOPEN) {
Eric Dumazetf5ddcbb2014-02-20 10:09:18 -08001104 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
Yuchung Chengcf60af02012-07-19 06:43:09 +00001105 if (err == -EINPROGRESS && copied_syn > 0)
1106 goto out;
1107 else if (err)
1108 goto out_err;
Yuchung Chengcf60af02012-07-19 06:43:09 +00001109 }
1110
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1112
Jerry Chu83368862012-08-31 12:29:12 +00001113 /* Wait for a connection to finish. One exception is TCP Fast Open
1114 * (passive side) where data is allowed to be sent before a connection
1115 * is fully established.
1116 */
1117 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
1118 !tcp_passive_fastopen(sk)) {
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -07001119 err = sk_stream_wait_connect(sk, &timeo);
1120 if (err != 0)
Yuchung Chengcf60af02012-07-19 06:43:09 +00001121 goto do_error;
Jerry Chu83368862012-08-31 12:29:12 +00001122 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123
Pavel Emelyanovc0e88ff2012-04-19 03:41:01 +00001124 if (unlikely(tp->repair)) {
1125 if (tp->repair_queue == TCP_RECV_QUEUE) {
1126 copied = tcp_send_rcvq(sk, msg, size);
Christoph Paasch5924f172014-06-28 18:26:37 +02001127 goto out_nopush;
Pavel Emelyanovc0e88ff2012-04-19 03:41:01 +00001128 }
1129
1130 err = -EINVAL;
1131 if (tp->repair_queue == TCP_NO_QUEUE)
1132 goto out_err;
1133
1134 /* 'common' sending to sendq */
1135 }
1136
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 /* This should be in poll */
Eric Dumazet9cd3e072015-11-29 20:03:10 -08001138 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
Ilpo Järvinen0c54b852009-03-14 14:23:05 +00001140 mss_now = tcp_send_mss(sk, &size_goal, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141
1142 /* Ok commence sending. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 copied = 0;
1144
1145 err = -EPIPE;
1146 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
Ilpo Järvinen0d6a7752009-02-28 04:44:41 +00001147 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148
Eric Dumazet690e99c2011-11-28 00:27:47 +00001149 sg = !!(sk->sk_route_caps & NETIF_F_SG);
Krishna Kumardef87cf2009-12-10 07:16:59 +00001150
Al Viro01e97e62014-12-15 21:39:31 -05001151 while (msg_data_left(msg)) {
Al Viro57be5bd2014-11-28 13:40:20 -05001152 int copy = 0;
1153 int max = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154
Al Viro57be5bd2014-11-28 13:40:20 -05001155 skb = tcp_write_queue_tail(sk);
1156 if (tcp_send_head(sk)) {
1157 if (skb->ip_summed == CHECKSUM_NONE)
1158 max = mss_now;
1159 copy = max - skb->len;
Yuchung Chengcf60af02012-07-19 06:43:09 +00001160 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161
Al Viro57be5bd2014-11-28 13:40:20 -05001162 if (copy <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163new_segment:
Al Viro57be5bd2014-11-28 13:40:20 -05001164 /* Allocate new segment. If the interface is SG,
1165 * allocate skb fitting to single page.
1166 */
1167 if (!sk_stream_memory_free(sk))
1168 goto wait_for_sndbuf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169
Al Viro57be5bd2014-11-28 13:40:20 -05001170 skb = sk_stream_alloc_skb(sk,
1171 select_size(sk, sg),
Eric Dumazeteb934472015-05-19 13:26:55 -07001172 sk->sk_allocation,
1173 skb_queue_empty(&sk->sk_write_queue));
Al Viro57be5bd2014-11-28 13:40:20 -05001174 if (!skb)
1175 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176
Al Viro57be5bd2014-11-28 13:40:20 -05001177 /*
1178 * Check whether we can use HW checksum.
1179 */
Tom Herbert9a498502015-12-14 11:19:45 -08001180 if (sk_check_csum_caps(sk))
Al Viro57be5bd2014-11-28 13:40:20 -05001181 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182
Al Viro57be5bd2014-11-28 13:40:20 -05001183 skb_entail(sk, skb);
1184 copy = size_goal;
1185 max = size_goal;
Andrey Vagin9d186ca2014-08-13 16:03:10 +04001186
Al Viro57be5bd2014-11-28 13:40:20 -05001187 /* All packets are restored as if they have
1188 * already been sent. skb_mstamp isn't set to
1189 * avoid wrong rtt estimation.
1190 */
1191 if (tp->repair)
1192 TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
1193 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194
Al Viro57be5bd2014-11-28 13:40:20 -05001195 /* Try to append data to the end of skb. */
Al Viro01e97e62014-12-15 21:39:31 -05001196 if (copy > msg_data_left(msg))
1197 copy = msg_data_left(msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198
Al Viro57be5bd2014-11-28 13:40:20 -05001199 /* Where to copy to? */
1200 if (skb_availroom(skb) > 0) {
1201 /* We have some space in skb head. Superb! */
1202 copy = min_t(int, copy, skb_availroom(skb));
1203 err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy);
1204 if (err)
1205 goto do_fault;
1206 } else {
1207 bool merge = true;
1208 int i = skb_shinfo(skb)->nr_frags;
1209 struct page_frag *pfrag = sk_page_frag(sk);
Eric Dumazet761965e2011-12-04 07:05:17 +00001210
Al Viro57be5bd2014-11-28 13:40:20 -05001211 if (!sk_page_frag_refill(sk, pfrag))
1212 goto wait_for_memory;
Eric Dumazet761965e2011-12-04 07:05:17 +00001213
Al Viro57be5bd2014-11-28 13:40:20 -05001214 if (!skb_can_coalesce(skb, i, pfrag->page,
1215 pfrag->offset)) {
1216 if (i == MAX_SKB_FRAGS || !sg) {
1217 tcp_mark_push(tp, skb);
1218 goto new_segment;
Eric Dumazet5640f762012-09-23 23:04:42 +00001219 }
Al Viro57be5bd2014-11-28 13:40:20 -05001220 merge = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 }
1222
Al Viro57be5bd2014-11-28 13:40:20 -05001223 copy = min_t(int, copy, pfrag->size - pfrag->offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224
Al Viro57be5bd2014-11-28 13:40:20 -05001225 if (!sk_wmem_schedule(sk, copy))
1226 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227
Al Viro57be5bd2014-11-28 13:40:20 -05001228 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
1229 pfrag->page,
1230 pfrag->offset,
1231 copy);
1232 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 goto do_error;
1234
Al Viro57be5bd2014-11-28 13:40:20 -05001235 /* Update the skb. */
1236 if (merge) {
1237 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1238 } else {
1239 skb_fill_page_desc(skb, i, pfrag->page,
1240 pfrag->offset, copy);
1241 get_page(pfrag->page);
1242 }
1243 pfrag->offset += copy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 }
Al Viro57be5bd2014-11-28 13:40:20 -05001245
1246 if (!copied)
1247 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1248
1249 tp->write_seq += copy;
1250 TCP_SKB_CB(skb)->end_seq += copy;
1251 tcp_skb_pcount_set(skb, 0);
1252
1253 copied += copy;
Al Viro01e97e62014-12-15 21:39:31 -05001254 if (!msg_data_left(msg)) {
Al Viro57be5bd2014-11-28 13:40:20 -05001255 tcp_tx_timestamp(sk, skb);
1256 goto out;
1257 }
1258
1259 if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
1260 continue;
1261
1262 if (forced_push(tp)) {
1263 tcp_mark_push(tp, skb);
1264 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1265 } else if (skb == tcp_send_head(sk))
1266 tcp_push_one(sk, mss_now);
1267 continue;
1268
1269wait_for_sndbuf:
1270 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1271wait_for_memory:
1272 if (copied)
1273 tcp_push(sk, flags & ~MSG_MORE, mss_now,
1274 TCP_NAGLE_PUSH, size_goal);
1275
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -07001276 err = sk_stream_wait_memory(sk, &timeo);
1277 if (err != 0)
Al Viro57be5bd2014-11-28 13:40:20 -05001278 goto do_error;
1279
1280 mss_now = tcp_send_mss(sk, &size_goal, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 }
1282
1283out:
Andrew Vaginec342322012-11-15 04:03:17 +00001284 if (copied)
Eric Dumazetf54b3112013-12-05 22:36:05 -08001285 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
Christoph Paasch5924f172014-06-28 18:26:37 +02001286out_nopush:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 release_sock(sk);
Yuchung Chengcf60af02012-07-19 06:43:09 +00001288 return copied + copied_syn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289
1290do_fault:
1291 if (!skb->len) {
David S. Millerfe067e82007-03-07 12:12:44 -08001292 tcp_unlink_write_queue(skb, sk);
1293 /* It is the one place in all of TCP, except connection
1294 * reset, where we can be unlinking the send_head.
1295 */
1296 tcp_check_send_head(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001297 sk_wmem_free_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 }
1299
1300do_error:
Yuchung Chengcf60af02012-07-19 06:43:09 +00001301 if (copied + copied_syn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 goto out;
1303out_err:
1304 err = sk_stream_error(sk, flags, err);
Jason Baronce5ec442015-05-20 15:52:53 +00001305 /* make sure we wake any epoll edge trigger waiter */
1306 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
1307 sk->sk_write_space(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308 release_sock(sk);
1309 return err;
1310}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00001311EXPORT_SYMBOL(tcp_sendmsg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312
1313/*
1314 * Handle reading urgent data. BSD has very simple semantics for
1315 * this, no blocking and very strange errors 8)
1316 */
1317
Rami Rosen377f0a02009-03-31 14:43:17 -07001318static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319{
1320 struct tcp_sock *tp = tcp_sk(sk);
1321
1322 /* No URG data to read. */
1323 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1324 tp->urg_data == TCP_URG_READ)
1325 return -EINVAL; /* Yes this is right ! */
1326
1327 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1328 return -ENOTCONN;
1329
1330 if (tp->urg_data & TCP_URG_VALID) {
1331 int err = 0;
1332 char c = tp->urg_data;
1333
1334 if (!(flags & MSG_PEEK))
1335 tp->urg_data = TCP_URG_READ;
1336
1337 /* Read urgent data. */
1338 msg->msg_flags |= MSG_OOB;
1339
1340 if (len > 0) {
1341 if (!(flags & MSG_TRUNC))
Al Viro7eab8d92014-04-06 21:51:23 -04001342 err = memcpy_to_msg(msg, &c, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343 len = 1;
1344 } else
1345 msg->msg_flags |= MSG_TRUNC;
1346
1347 return err ? -EFAULT : len;
1348 }
1349
1350 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1351 return 0;
1352
1353 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1354 * the available implementations agree in this case:
1355 * this call should never block, independent of the
1356 * blocking state of the socket.
1357 * Mike <pall@rz.uni-karlsruhe.de>
1358 */
1359 return -EAGAIN;
1360}
1361
Pavel Emelyanovc0e88ff2012-04-19 03:41:01 +00001362static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
1363{
1364 struct sk_buff *skb;
1365 int copied = 0, err = 0;
1366
1367 /* XXX -- need to support SO_PEEK_OFF */
1368
1369 skb_queue_walk(&sk->sk_write_queue, skb) {
David S. Miller51f3d022014-11-05 16:46:40 -05001370 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
Pavel Emelyanovc0e88ff2012-04-19 03:41:01 +00001371 if (err)
1372 break;
1373
1374 copied += skb->len;
1375 }
1376
1377 return err ?: copied;
1378}
1379
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380/* Clean up the receive buffer for full frames taken by the user,
1381 * then send an ACK if necessary. COPIED is the number of bytes
1382 * tcp_recvmsg has given to the user so far, it speeds up the
1383 * calculation of whether or not we must ACK for the sake of
1384 * a window update.
1385 */
Dan Williams3f334072013-12-30 17:12:07 -08001386static void tcp_cleanup_rbuf(struct sock *sk, int copied)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387{
1388 struct tcp_sock *tp = tcp_sk(sk);
Eric Dumazeta2a385d2012-05-16 23:15:34 +00001389 bool time_to_ack = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001390
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1392
Ilpo Järvinend792c102009-11-13 13:56:33 -08001393 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
Joe Perches2af6fd82010-10-30 11:08:53 +00001394 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
Ilpo Järvinend792c102009-11-13 13:56:33 -08001395 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001396
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001397 if (inet_csk_ack_scheduled(sk)) {
1398 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001399 /* Delayed ACKs frequently hit locked sockets during bulk
1400 * receive. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001401 if (icsk->icsk_ack.blocked ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 /* Once-per-two-segments ACK was not sent by tcp_input.c */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001403 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 /*
1405 * If this read emptied read buffer, we send ACK, if
1406 * connection is not bidirectional, user drained
1407 * receive buffer and there was a small segment
1408 * in queue.
1409 */
Alexey Kuznetsov1ef96962006-09-19 12:52:50 -07001410 (copied > 0 &&
1411 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1412 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1413 !icsk->icsk_ack.pingpong)) &&
1414 !atomic_read(&sk->sk_rmem_alloc)))
Eric Dumazeta2a385d2012-05-16 23:15:34 +00001415 time_to_ack = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416 }
1417
1418 /* We send an ACK if we can now advertise a non-zero window
1419 * which has been raised "significantly".
1420 *
1421 * Even if window raised up to infinity, do not send window open ACK
1422 * in states, where we will not receive more. It is useless.
1423 */
1424 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1425 __u32 rcv_window_now = tcp_receive_window(tp);
1426
1427 /* Optimize, __tcp_select_window() is not cheap. */
1428 if (2*rcv_window_now <= tp->window_clamp) {
1429 __u32 new_window = __tcp_select_window(sk);
1430
1431 /* Send ACK now, if this read freed lots of space
1432 * in our buffer. Certainly, new_window is new window.
1433 * We can advertise it now, if it is not less than current one.
1434 * "Lots" means "at least twice" here.
1435 */
1436 if (new_window && new_window >= 2 * rcv_window_now)
Eric Dumazeta2a385d2012-05-16 23:15:34 +00001437 time_to_ack = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 }
1439 }
1440 if (time_to_ack)
1441 tcp_send_ack(sk);
1442}
1443
1444static void tcp_prequeue_process(struct sock *sk)
1445{
1446 struct sk_buff *skb;
1447 struct tcp_sock *tp = tcp_sk(sk);
1448
Pavel Emelyanov6f67c812008-07-16 20:31:39 -07001449 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450
1451 /* RX process wants to run with disabled BHs, though it is not
1452 * necessary */
1453 local_bh_disable();
1454 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
Peter Zijlstrac57943a2008-10-07 14:18:42 -07001455 sk_backlog_rcv(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456 local_bh_enable();
1457
1458 /* Clear memory counter. */
1459 tp->ucopy.memory = 0;
1460}
1461
Eric Dumazetf26845b2013-01-09 20:59:09 +00001462static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463{
1464 struct sk_buff *skb;
1465 u32 offset;
1466
Eric Dumazetf26845b2013-01-09 20:59:09 +00001467 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468 offset = seq - TCP_SKB_CB(skb)->seq;
Eric Dumazete11ecdd2014-09-15 04:19:51 -07001469 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001470 offset--;
Eric Dumazete11ecdd2014-09-15 04:19:51 -07001471 if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472 *off = offset;
1473 return skb;
1474 }
Eric Dumazetf26845b2013-01-09 20:59:09 +00001475 /* This looks weird, but this can happen if TCP collapsing
1476 * splitted a fat GRO packet, while we released socket lock
1477 * in skb_splice_bits()
1478 */
Dan Williams7bced392013-12-30 12:37:29 -08001479 sk_eat_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480 }
1481 return NULL;
1482}
1483
1484/*
1485 * This routine provides an alternative to tcp_recvmsg() for routines
1486 * that would like to handle copying from skbuffs directly in 'sendfile'
1487 * fashion.
1488 * Note:
1489 * - It is assumed that the socket was locked by the caller.
1490 * - The routine does not block.
1491 * - At present, there is no support for reading OOB data
1492 * or for 'peeking' the socket using this routine
1493 * (although both would be easy to implement).
1494 */
1495int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1496 sk_read_actor_t recv_actor)
1497{
1498 struct sk_buff *skb;
1499 struct tcp_sock *tp = tcp_sk(sk);
1500 u32 seq = tp->copied_seq;
1501 u32 offset;
1502 int copied = 0;
1503
1504 if (sk->sk_state == TCP_LISTEN)
1505 return -ENOTCONN;
1506 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1507 if (offset < skb->len) {
Octavian Purdila374e7b52008-07-03 03:31:21 -07001508 int used;
1509 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510
1511 len = skb->len - offset;
1512 /* Stop reading if we hit a patch of urgent data */
1513 if (tp->urg_data) {
1514 u32 urg_offset = tp->urg_seq - seq;
1515 if (urg_offset < len)
1516 len = urg_offset;
1517 if (!len)
1518 break;
1519 }
1520 used = recv_actor(desc, skb, offset, len);
Eric Dumazetff905b12013-01-10 07:06:10 +00001521 if (used <= 0) {
Jens Axboeddb61a52007-06-23 23:07:50 -07001522 if (!copied)
1523 copied = used;
1524 break;
1525 } else if (used <= len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 seq += used;
1527 copied += used;
1528 offset += used;
1529 }
Willy Tarreau02275a22012-12-02 11:49:27 +00001530 /* If recv_actor drops the lock (e.g. TCP splice
Octavian Purdila293ad602008-06-04 15:45:58 -07001531 * receive) the skb pointer might be invalid when
1532 * getting here: tcp_collapse might have deleted it
1533 * while aggregating skbs from the socket queue.
1534 */
Willy Tarreau02275a22012-12-02 11:49:27 +00001535 skb = tcp_recv_skb(sk, seq - 1, &offset);
1536 if (!skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537 break;
Willy Tarreau02275a22012-12-02 11:49:27 +00001538 /* TCP coalescing might have appended data to the skb.
1539 * Try to splice more frags
1540 */
1541 if (offset + 1 != skb->len)
1542 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001543 }
Eric Dumazete11ecdd2014-09-15 04:19:51 -07001544 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
Dan Williams7bced392013-12-30 12:37:29 -08001545 sk_eat_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546 ++seq;
1547 break;
1548 }
Dan Williams7bced392013-12-30 12:37:29 -08001549 sk_eat_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001550 if (!desc->count)
1551 break;
Steven J. Magnanibaff42a2010-03-30 13:56:01 -07001552 tp->copied_seq = seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553 }
1554 tp->copied_seq = seq;
1555
1556 tcp_rcv_space_adjust(sk);
1557
1558 /* Clean up data we have read: This will do ACK frames. */
Eric Dumazetf26845b2013-01-09 20:59:09 +00001559 if (copied > 0) {
1560 tcp_recv_skb(sk, seq, &offset);
Chris Leech0e4b4992006-05-23 18:00:16 -07001561 tcp_cleanup_rbuf(sk, copied);
Eric Dumazetf26845b2013-01-09 20:59:09 +00001562 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563 return copied;
1564}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00001565EXPORT_SYMBOL(tcp_read_sock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566
1567/*
1568 * This routine copies from a sock struct into the user buffer.
1569 *
1570 * Technical note: in 2.3 we work on _locked_ socket, so that
1571 * tricks with *seq access order and skb->users are not required.
1572 * Probably, code can be easily improved even more.
1573 */
1574
Ying Xue1b784142015-03-02 15:37:48 +08001575int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
1576 int flags, int *addr_len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001577{
1578 struct tcp_sock *tp = tcp_sk(sk);
1579 int copied = 0;
1580 u32 peek_seq;
1581 u32 *seq;
1582 unsigned long used;
1583 int err;
1584 int target; /* Read at least this many bytes */
1585 long timeo;
1586 struct task_struct *user_recv = NULL;
Sabrina Dubrocadfbafc92015-07-24 18:19:25 +02001587 struct sk_buff *skb, *last;
Ilpo Järvinen77527312009-05-10 20:32:34 +00001588 u32 urg_hole = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589
Willem de Bruijn4ed2d762014-08-04 22:11:49 -04001590 if (unlikely(flags & MSG_ERRQUEUE))
Willem de Bruijnf4713a32014-11-26 14:53:02 -05001591 return inet_recv_error(sk, msg, len, addr_len);
Willem de Bruijn4ed2d762014-08-04 22:11:49 -04001592
Eliezer Tamircbf55002013-07-08 16:20:34 +03001593 if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
1594 (sk->sk_state == TCP_ESTABLISHED))
1595 sk_busy_loop(sk, nonblock);
Eliezer Tamird30e3832013-06-10 11:40:10 +03001596
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 lock_sock(sk);
1598
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599 err = -ENOTCONN;
1600 if (sk->sk_state == TCP_LISTEN)
1601 goto out;
1602
1603 timeo = sock_rcvtimeo(sk, nonblock);
1604
1605 /* Urgent data needs to be handled specially. */
1606 if (flags & MSG_OOB)
1607 goto recv_urg;
1608
Pavel Emelyanovc0e88ff2012-04-19 03:41:01 +00001609 if (unlikely(tp->repair)) {
1610 err = -EPERM;
1611 if (!(flags & MSG_PEEK))
1612 goto out;
1613
1614 if (tp->repair_queue == TCP_SEND_QUEUE)
1615 goto recv_sndq;
1616
1617 err = -EINVAL;
1618 if (tp->repair_queue == TCP_NO_QUEUE)
1619 goto out;
1620
1621 /* 'common' recv queue MSG_PEEK-ing */
1622 }
1623
Linus Torvalds1da177e2005-04-16 15:20:36 -07001624 seq = &tp->copied_seq;
1625 if (flags & MSG_PEEK) {
1626 peek_seq = tp->copied_seq;
1627 seq = &peek_seq;
1628 }
1629
1630 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1631
1632 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 u32 offset;
1634
1635 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1636 if (tp->urg_data && tp->urg_seq == *seq) {
1637 if (copied)
1638 break;
1639 if (signal_pending(current)) {
1640 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1641 break;
1642 }
1643 }
1644
1645 /* Next get a buffer. */
1646
Sabrina Dubrocadfbafc92015-07-24 18:19:25 +02001647 last = skb_peek_tail(&sk->sk_receive_queue);
David S. Miller91521942009-05-28 21:35:47 -07001648 skb_queue_walk(&sk->sk_receive_queue, skb) {
Sabrina Dubrocadfbafc92015-07-24 18:19:25 +02001649 last = skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001650 /* Now that we have two receive queues this
1651 * shouldn't happen.
1652 */
Ilpo Järvinend792c102009-11-13 13:56:33 -08001653 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
Joe Perches2af6fd82010-10-30 11:08:53 +00001654 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1655 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1656 flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657 break;
Ilpo Järvinend792c102009-11-13 13:56:33 -08001658
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659 offset = *seq - TCP_SKB_CB(skb)->seq;
Eric Dumazete11ecdd2014-09-15 04:19:51 -07001660 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661 offset--;
1662 if (offset < skb->len)
1663 goto found_ok_skb;
Eric Dumazete11ecdd2014-09-15 04:19:51 -07001664 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665 goto found_fin_ok;
Joe Perches2af6fd82010-10-30 11:08:53 +00001666 WARN(!(flags & MSG_PEEK),
1667 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1668 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
David S. Miller91521942009-05-28 21:35:47 -07001669 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670
1671 /* Well, if we have backlog, try to process it now yet. */
1672
1673 if (copied >= target && !sk->sk_backlog.tail)
1674 break;
1675
1676 if (copied) {
1677 if (sk->sk_err ||
1678 sk->sk_state == TCP_CLOSE ||
1679 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1680 !timeo ||
David S. Miller518a09e2008-11-05 03:36:01 -08001681 signal_pending(current))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682 break;
1683 } else {
1684 if (sock_flag(sk, SOCK_DONE))
1685 break;
1686
1687 if (sk->sk_err) {
1688 copied = sock_error(sk);
1689 break;
1690 }
1691
1692 if (sk->sk_shutdown & RCV_SHUTDOWN)
1693 break;
1694
1695 if (sk->sk_state == TCP_CLOSE) {
1696 if (!sock_flag(sk, SOCK_DONE)) {
1697 /* This occurs when user tries to read
1698 * from never connected socket.
1699 */
1700 copied = -ENOTCONN;
1701 break;
1702 }
1703 break;
1704 }
1705
1706 if (!timeo) {
1707 copied = -EAGAIN;
1708 break;
1709 }
1710
1711 if (signal_pending(current)) {
1712 copied = sock_intr_errno(timeo);
1713 break;
1714 }
1715 }
1716
Chris Leech0e4b4992006-05-23 18:00:16 -07001717 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718
David S. Miller7df55122005-06-18 23:01:10 -07001719 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 /* Install new reader */
1721 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1722 user_recv = current;
1723 tp->ucopy.task = user_recv;
Al Virof4362a22014-11-24 13:26:06 -05001724 tp->ucopy.msg = msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 }
1726
1727 tp->ucopy.len = len;
1728
Ilpo Järvinen547b7922008-07-25 21:43:18 -07001729 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1730 !(flags & (MSG_PEEK | MSG_TRUNC)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731
1732 /* Ugly... If prequeue is not empty, we have to
1733 * process it before releasing socket, otherwise
1734 * order will be broken at second iteration.
1735 * More elegant solution is required!!!
1736 *
1737 * Look: we have the following (pseudo)queues:
1738 *
1739 * 1. packets in flight
1740 * 2. backlog
1741 * 3. prequeue
1742 * 4. receive_queue
1743 *
1744 * Each queue can be processed only if the next ones
1745 * are empty. At this point we have empty receive_queue.
1746 * But prequeue _can_ be not empty after 2nd iteration,
1747 * when we jumped to start of loop because backlog
1748 * processing added something to receive_queue.
1749 * We cannot release_sock(), because backlog contains
1750 * packets arrived _after_ prequeued ones.
1751 *
1752 * Shortly, algorithm is clear --- to process all
1753 * the queues in order. We could make it more directly,
1754 * requeueing packets from backlog to prequeue, if
1755 * is not empty. It is more elegant, but eats cycles,
1756 * unfortunately.
1757 */
David S. Millerb03efcf2005-07-08 14:57:23 -07001758 if (!skb_queue_empty(&tp->ucopy.prequeue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759 goto do_prequeue;
1760
1761 /* __ Set realtime policy in scheduler __ */
1762 }
1763
1764 if (copied >= target) {
1765 /* Do not sleep, just process backlog. */
1766 release_sock(sk);
1767 lock_sock(sk);
Sabrina Dubrocadfbafc92015-07-24 18:19:25 +02001768 } else {
1769 sk_wait_data(sk, &timeo, last);
1770 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771
1772 if (user_recv) {
1773 int chunk;
1774
1775 /* __ Restore normal policy in scheduler __ */
1776
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -07001777 chunk = len - tp->ucopy.len;
1778 if (chunk != 0) {
Pavel Emelyanoved880982008-07-16 20:32:45 -07001779 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001780 len -= chunk;
1781 copied += chunk;
1782 }
1783
1784 if (tp->rcv_nxt == tp->copied_seq &&
David S. Millerb03efcf2005-07-08 14:57:23 -07001785 !skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786do_prequeue:
1787 tcp_prequeue_process(sk);
1788
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -07001789 chunk = len - tp->ucopy.len;
1790 if (chunk != 0) {
Pavel Emelyanoved880982008-07-16 20:32:45 -07001791 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792 len -= chunk;
1793 copied += chunk;
1794 }
1795 }
1796 }
Ilpo Järvinen77527312009-05-10 20:32:34 +00001797 if ((flags & MSG_PEEK) &&
1798 (peek_seq - copied - urg_hole != tp->copied_seq)) {
Joe Perchese87cc472012-05-13 21:56:26 +00001799 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1800 current->comm,
1801 task_pid_nr(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802 peek_seq = tp->copied_seq;
1803 }
1804 continue;
1805
1806 found_ok_skb:
1807 /* Ok so how much can we use? */
1808 used = skb->len - offset;
1809 if (len < used)
1810 used = len;
1811
1812 /* Do we have urgent data here? */
1813 if (tp->urg_data) {
1814 u32 urg_offset = tp->urg_seq - *seq;
1815 if (urg_offset < used) {
1816 if (!urg_offset) {
1817 if (!sock_flag(sk, SOCK_URGINLINE)) {
1818 ++*seq;
Ilpo Järvinen77527312009-05-10 20:32:34 +00001819 urg_hole++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001820 offset++;
1821 used--;
1822 if (!used)
1823 goto skip_copy;
1824 }
1825 } else
1826 used = urg_offset;
1827 }
1828 }
1829
1830 if (!(flags & MSG_TRUNC)) {
David S. Miller51f3d022014-11-05 16:46:40 -05001831 err = skb_copy_datagram_msg(skb, offset, msg, used);
Dan Williams7bced392013-12-30 12:37:29 -08001832 if (err) {
1833 /* Exception. Bailout! */
1834 if (!copied)
1835 copied = -EFAULT;
1836 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001837 }
1838 }
1839
1840 *seq += used;
1841 copied += used;
1842 len -= used;
1843
1844 tcp_rcv_space_adjust(sk);
1845
1846skip_copy:
1847 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1848 tp->urg_data = 0;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001849 tcp_fast_path_check(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001850 }
1851 if (used + offset < skb->len)
1852 continue;
1853
Eric Dumazete11ecdd2014-09-15 04:19:51 -07001854 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 goto found_fin_ok;
Dan Williams7bced392013-12-30 12:37:29 -08001856 if (!(flags & MSG_PEEK))
1857 sk_eat_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858 continue;
1859
1860 found_fin_ok:
1861 /* Process the FIN. */
1862 ++*seq;
Dan Williams7bced392013-12-30 12:37:29 -08001863 if (!(flags & MSG_PEEK))
1864 sk_eat_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001865 break;
1866 } while (len > 0);
1867
1868 if (user_recv) {
David S. Millerb03efcf2005-07-08 14:57:23 -07001869 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870 int chunk;
1871
1872 tp->ucopy.len = copied > 0 ? len : 0;
1873
1874 tcp_prequeue_process(sk);
1875
1876 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
Pavel Emelyanoved880982008-07-16 20:32:45 -07001877 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878 len -= chunk;
1879 copied += chunk;
1880 }
1881 }
1882
1883 tp->ucopy.task = NULL;
1884 tp->ucopy.len = 0;
1885 }
1886
1887 /* According to UNIX98, msg_name/msg_namelen are ignored
1888 * on connected socket. I was just happy when found this 8) --ANK
1889 */
1890
1891 /* Clean up data we have read: This will do ACK frames. */
Chris Leech0e4b4992006-05-23 18:00:16 -07001892 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894 release_sock(sk);
1895 return copied;
1896
1897out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001898 release_sock(sk);
1899 return err;
1900
1901recv_urg:
Rami Rosen377f0a02009-03-31 14:43:17 -07001902 err = tcp_recv_urg(sk, msg, len, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001903 goto out;
Pavel Emelyanovc0e88ff2012-04-19 03:41:01 +00001904
1905recv_sndq:
1906 err = tcp_peek_sndq(sk, msg, len);
1907 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001908}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00001909EXPORT_SYMBOL(tcp_recvmsg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001910
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001911void tcp_set_state(struct sock *sk, int state)
1912{
1913 int oldstate = sk->sk_state;
1914
1915 switch (state) {
1916 case TCP_ESTABLISHED:
1917 if (oldstate != TCP_ESTABLISHED)
Pavel Emelyanov81cc8a72008-07-16 20:22:04 -07001918 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001919 break;
1920
1921 case TCP_CLOSE:
1922 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
Pavel Emelyanov81cc8a72008-07-16 20:22:04 -07001923 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001924
1925 sk->sk_prot->unhash(sk);
1926 if (inet_csk(sk)->icsk_bind_hash &&
1927 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001928 inet_put_port(sk);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001929 /* fall through */
1930 default:
Jianjun Kong5a5f3a82008-11-03 00:24:34 -08001931 if (oldstate == TCP_ESTABLISHED)
Pavel Emelyanov74688e42008-07-16 20:22:46 -07001932 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001933 }
1934
1935 /* Change state AFTER socket is unhashed to avoid closed
1936 * socket sitting in hash tables.
1937 */
Eric Dumazet00fd38d2015-11-12 08:43:18 -08001938 sk_state_store(sk, state);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001939
1940#ifdef STATE_TRACE
Jianjun Kong5a5f3a82008-11-03 00:24:34 -08001941 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001942#endif
1943}
1944EXPORT_SYMBOL_GPL(tcp_set_state);
1945
Linus Torvalds1da177e2005-04-16 15:20:36 -07001946/*
1947 * State processing on a close. This implements the state shift for
1948 * sending our FIN frame. Note that we only send a FIN for some
1949 * states. A shutdown() may have already sent the FIN, or we may be
1950 * closed.
1951 */
1952
Arjan van de Ven9b5b5cf2005-11-29 16:21:38 -08001953static const unsigned char new_state[16] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001954 /* current state: new state: action: */
Eric Dumazet0980c1e2015-03-24 15:58:53 -07001955 [0 /* (Invalid) */] = TCP_CLOSE,
1956 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1957 [TCP_SYN_SENT] = TCP_CLOSE,
1958 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1959 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
1960 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
1961 [TCP_TIME_WAIT] = TCP_CLOSE,
1962 [TCP_CLOSE] = TCP_CLOSE,
1963 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
1964 [TCP_LAST_ACK] = TCP_LAST_ACK,
1965 [TCP_LISTEN] = TCP_CLOSE,
1966 [TCP_CLOSING] = TCP_CLOSING,
1967 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968};
1969
1970static int tcp_close_state(struct sock *sk)
1971{
1972 int next = (int)new_state[sk->sk_state];
1973 int ns = next & TCP_STATE_MASK;
1974
1975 tcp_set_state(sk, ns);
1976
1977 return next & TCP_ACTION_FIN;
1978}
1979
1980/*
1981 * Shutdown the sending side of a connection. Much like close except
Satoru SATOH1f29b052008-04-21 02:27:58 -07001982 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001983 */
1984
1985void tcp_shutdown(struct sock *sk, int how)
1986{
1987 /* We need to grab some memory, and put together a FIN,
1988 * and then put it into the queue to be sent.
1989 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1990 */
1991 if (!(how & SEND_SHUTDOWN))
1992 return;
1993
1994 /* If we've already sent a FIN, or it's a closed state, skip this. */
1995 if ((1 << sk->sk_state) &
1996 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1997 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1998 /* Clear out any half completed packets. FIN if needed. */
1999 if (tcp_close_state(sk))
2000 tcp_send_fin(sk);
2001 }
2002}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00002003EXPORT_SYMBOL(tcp_shutdown);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004
Arun Sharmaefcdbf22012-01-30 14:16:06 -08002005bool tcp_check_oom(struct sock *sk, int shift)
2006{
2007 bool too_many_orphans, out_of_socket_memory;
2008
2009 too_many_orphans = tcp_too_many_orphans(sk, shift);
2010 out_of_socket_memory = tcp_out_of_memory(sk);
2011
Joe Perchese87cc472012-05-13 21:56:26 +00002012 if (too_many_orphans)
2013 net_info_ratelimited("too many orphaned sockets\n");
2014 if (out_of_socket_memory)
2015 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
Arun Sharmaefcdbf22012-01-30 14:16:06 -08002016 return too_many_orphans || out_of_socket_memory;
2017}
2018
Linus Torvalds1da177e2005-04-16 15:20:36 -07002019void tcp_close(struct sock *sk, long timeout)
2020{
2021 struct sk_buff *skb;
2022 int data_was_unread = 0;
Herbert Xu75c2d9072006-05-03 23:31:35 -07002023 int state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002024
2025 lock_sock(sk);
2026 sk->sk_shutdown = SHUTDOWN_MASK;
2027
2028 if (sk->sk_state == TCP_LISTEN) {
2029 tcp_set_state(sk, TCP_CLOSE);
2030
2031 /* Special case. */
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07002032 inet_csk_listen_stop(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033
2034 goto adjudge_to_death;
2035 }
2036
2037 /* We need to flush the recv. buffs. We do this only on the
2038 * descriptor close, not protocol-sourced closes, because the
2039 * reader process may not have drained the data yet!
2040 */
2041 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
Eric Dumazete11ecdd2014-09-15 04:19:51 -07002042 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq;
2043
2044 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2045 len--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046 data_was_unread += len;
2047 __kfree_skb(skb);
2048 }
2049
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002050 sk_mem_reclaim(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002051
Konstantin Khorenko565b7b22010-06-24 21:54:58 -07002052 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2053 if (sk->sk_state == TCP_CLOSE)
2054 goto adjudge_to_death;
2055
Gerrit Renker65bb7232007-04-28 21:21:46 -07002056 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2057 * data was lost. To witness the awful effects of the old behavior of
2058 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2059 * GET in an FTP client, suspend the process, wait for the client to
2060 * advertise a zero window, then kill -9 the FTP client, wheee...
2061 * Note: timeout is always zero in such a case.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002062 */
Pavel Emelyanovee995282012-04-19 03:40:39 +00002063 if (unlikely(tcp_sk(sk)->repair)) {
2064 sk->sk_prot->disconnect(sk, 0);
2065 } else if (data_was_unread) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002066 /* Unread data was tossed, zap the connection. */
Pavel Emelyanov6f67c812008-07-16 20:31:39 -07002067 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002068 tcp_set_state(sk, TCP_CLOSE);
Wu Fengguangaa133072009-09-02 23:45:45 -07002069 tcp_send_active_reset(sk, sk->sk_allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002070 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
2071 /* Check zero linger _after_ checking for unread data. */
2072 sk->sk_prot->disconnect(sk, 0);
Pavel Emelyanov6f67c812008-07-16 20:31:39 -07002073 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002074 } else if (tcp_close_state(sk)) {
2075 /* We FIN if the application ate all the data before
2076 * zapping the connection.
2077 */
2078
2079 /* RED-PEN. Formally speaking, we have broken TCP state
2080 * machine. State transitions:
2081 *
2082 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2083 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2084 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2085 *
2086 * are legal only when FIN has been sent (i.e. in window),
2087 * rather than queued out of window. Purists blame.
2088 *
2089 * F.e. "RFC state" is ESTABLISHED,
2090 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2091 *
2092 * The visible declinations are that sometimes
2093 * we enter time-wait state, when it is not required really
2094 * (harmless), do not send active resets, when they are
2095 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2096 * they look as CLOSING or LAST_ACK for Linux)
2097 * Probably, I missed some more holelets.
2098 * --ANK
Jerry Chu83368862012-08-31 12:29:12 +00002099 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2100 * in a single packet! (May consider it later but will
2101 * probably need API support or TCP_CORK SYN-ACK until
2102 * data is written and socket is closed.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002103 */
2104 tcp_send_fin(sk);
2105 }
2106
2107 sk_stream_wait_close(sk, timeout);
2108
2109adjudge_to_death:
Herbert Xu75c2d9072006-05-03 23:31:35 -07002110 state = sk->sk_state;
2111 sock_hold(sk);
2112 sock_orphan(sk);
Herbert Xu75c2d9072006-05-03 23:31:35 -07002113
Linus Torvalds1da177e2005-04-16 15:20:36 -07002114 /* It is the last release_sock in its life. It will remove backlog. */
2115 release_sock(sk);
2116
2117
2118 /* Now socket is owned by kernel and we acquire BH lock
2119 to finish close. No need to check for user refs.
2120 */
2121 local_bh_disable();
2122 bh_lock_sock(sk);
Ilpo Järvinen547b7922008-07-25 21:43:18 -07002123 WARN_ON(sock_owned_by_user(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002124
Herbert Xueb4dea52008-12-29 23:04:08 -08002125 percpu_counter_inc(sk->sk_prot->orphan_count);
2126
Herbert Xu75c2d9072006-05-03 23:31:35 -07002127 /* Have we already been destroyed by a softirq or backlog? */
2128 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
2129 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002130
2131 /* This is a (useful) BSD violating of the RFC. There is a
2132 * problem with TCP as specified in that the other end could
2133 * keep a socket open forever with no application left this end.
Jesper Juhlb10bd542014-02-09 23:30:32 +01002134 * We use a 1 minute timeout (about the same as BSD) then kill
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 * our end. If they send after that then tough - BUT: long enough
2136 * that we won't make the old 4*rto = almost no time - whoops
2137 * reset mistake.
2138 *
2139 * Nope, it was not mistake. It is really desired behaviour
2140 * f.e. on http servers, when such sockets are useless, but
2141 * consume significant resources. Let's do it with special
2142 * linger2 option. --ANK
2143 */
2144
2145 if (sk->sk_state == TCP_FIN_WAIT2) {
2146 struct tcp_sock *tp = tcp_sk(sk);
2147 if (tp->linger2 < 0) {
2148 tcp_set_state(sk, TCP_CLOSE);
2149 tcp_send_active_reset(sk, GFP_ATOMIC);
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07002150 NET_INC_STATS_BH(sock_net(sk),
2151 LINUX_MIB_TCPABORTONLINGER);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002153 const int tmo = tcp_fin_time(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002154
2155 if (tmo > TCP_TIMEWAIT_LEN) {
David S. Miller52499af2006-07-31 22:32:09 -07002156 inet_csk_reset_keepalive_timer(sk,
2157 tmo - TCP_TIMEWAIT_LEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002158 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002159 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2160 goto out;
2161 }
2162 }
2163 }
2164 if (sk->sk_state != TCP_CLOSE) {
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002165 sk_mem_reclaim(sk);
Arun Sharmaefcdbf22012-01-30 14:16:06 -08002166 if (tcp_check_oom(sk, 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002167 tcp_set_state(sk, TCP_CLOSE);
2168 tcp_send_active_reset(sk, GFP_ATOMIC);
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07002169 NET_INC_STATS_BH(sock_net(sk),
2170 LINUX_MIB_TCPABORTONMEMORY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002171 }
2172 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002173
Jerry Chu83368862012-08-31 12:29:12 +00002174 if (sk->sk_state == TCP_CLOSE) {
2175 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
2176 /* We could get here with a non-NULL req if the socket is
2177 * aborted (e.g., closed with unread data) before 3WHS
2178 * finishes.
2179 */
Ian Morris00db4122015-04-03 09:17:27 +01002180 if (req)
Jerry Chu83368862012-08-31 12:29:12 +00002181 reqsk_fastopen_remove(sk, req, false);
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07002182 inet_csk_destroy_sock(sk);
Jerry Chu83368862012-08-31 12:29:12 +00002183 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002184 /* Otherwise, socket is reprieved until protocol close. */
2185
2186out:
2187 bh_unlock_sock(sk);
2188 local_bh_enable();
2189 sock_put(sk);
2190}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00002191EXPORT_SYMBOL(tcp_close);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002192
2193/* These states need RST on ABORT according to RFC793 */
2194
Eric Dumazeta2a385d2012-05-16 23:15:34 +00002195static inline bool tcp_need_reset(int state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002196{
2197 return (1 << state) &
2198 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2199 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2200}
2201
2202int tcp_disconnect(struct sock *sk, int flags)
2203{
2204 struct inet_sock *inet = inet_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002205 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002206 struct tcp_sock *tp = tcp_sk(sk);
2207 int err = 0;
2208 int old_state = sk->sk_state;
2209
2210 if (old_state != TCP_CLOSE)
2211 tcp_set_state(sk, TCP_CLOSE);
2212
2213 /* ABORT function of RFC793 */
2214 if (old_state == TCP_LISTEN) {
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07002215 inet_csk_listen_stop(sk);
Pavel Emelyanovee995282012-04-19 03:40:39 +00002216 } else if (unlikely(tp->repair)) {
2217 sk->sk_err = ECONNABORTED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002218 } else if (tcp_need_reset(old_state) ||
2219 (tp->snd_nxt != tp->write_seq &&
2220 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -08002221 /* The last check adjusts for discrepancy of Linux wrt. RFC
Linus Torvalds1da177e2005-04-16 15:20:36 -07002222 * states
2223 */
2224 tcp_send_active_reset(sk, gfp_any());
2225 sk->sk_err = ECONNRESET;
2226 } else if (old_state == TCP_SYN_SENT)
2227 sk->sk_err = ECONNRESET;
2228
2229 tcp_clear_xmit_timers(sk);
2230 __skb_queue_purge(&sk->sk_receive_queue);
David S. Millerfe067e82007-03-07 12:12:44 -08002231 tcp_write_queue_purge(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002232 __skb_queue_purge(&tp->out_of_order_queue);
2233
Eric Dumazetc720c7e2009-10-15 06:30:45 +00002234 inet->inet_dport = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002235
2236 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2237 inet_reset_saddr(sk);
2238
2239 sk->sk_shutdown = 0;
2240 sock_reset_flag(sk, SOCK_DONE);
Eric Dumazet740b0f12014-02-26 14:02:48 -08002241 tp->srtt_us = 0;
Yuvaraja Mariappan686a5622015-10-06 10:53:29 -07002242 tp->write_seq += tp->max_window + 2;
2243 if (tp->write_seq == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002244 tp->write_seq = 1;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002245 icsk->icsk_backoff = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002246 tp->snd_cwnd = 2;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002247 icsk->icsk_probes_out = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002248 tp->packets_out = 0;
Ilpo Järvinen0b6a05c2009-09-15 01:30:10 -07002249 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002250 tp->snd_cwnd_cnt = 0;
Eric Dumazet1fdf4752009-11-30 12:53:30 -08002251 tp->window_clamp = 0;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002252 tcp_set_ca_state(sk, TCP_CA_Open);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002253 tcp_clear_retrans(tp);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002254 inet_csk_delack_init(sk);
David S. Millerfe067e82007-03-07 12:12:44 -08002255 tcp_init_send_head(sk);
Srinivas Ajib40b4f72007-05-03 17:32:28 -07002256 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002257 __sk_dst_reset(sk);
2258
Eric Dumazetc720c7e2009-10-15 06:30:45 +00002259 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002260
2261 sk->sk_error_report(sk);
2262 return err;
2263}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00002264EXPORT_SYMBOL(tcp_disconnect);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002265
Eric Dumazeta2a385d2012-05-16 23:15:34 +00002266static inline bool tcp_can_repair_sock(const struct sock *sk)
Pavel Emelyanovee995282012-04-19 03:40:39 +00002267{
Eric W. Biederman52e804c2012-11-16 03:03:05 +00002268 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
Pavel Emelyanovee995282012-04-19 03:40:39 +00002269 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED));
2270}
2271
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002272static int tcp_repair_options_est(struct tcp_sock *tp,
2273 struct tcp_repair_opt __user *optbuf, unsigned int len)
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002274{
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002275 struct tcp_repair_opt opt;
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002276
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002277 while (len >= sizeof(opt)) {
2278 if (copy_from_user(&opt, optbuf, sizeof(opt)))
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002279 return -EFAULT;
2280
2281 optbuf++;
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002282 len -= sizeof(opt);
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002283
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002284 switch (opt.opt_code) {
2285 case TCPOPT_MSS:
2286 tp->rx_opt.mss_clamp = opt.opt_val;
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002287 break;
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002288 case TCPOPT_WINDOW:
Andrey Vaginbc26ccd2012-09-19 09:40:00 +00002289 {
2290 u16 snd_wscale = opt.opt_val & 0xFFFF;
2291 u16 rcv_wscale = opt.opt_val >> 16;
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002292
Andrey Vaginbc26ccd2012-09-19 09:40:00 +00002293 if (snd_wscale > 14 || rcv_wscale > 14)
2294 return -EFBIG;
2295
2296 tp->rx_opt.snd_wscale = snd_wscale;
2297 tp->rx_opt.rcv_wscale = rcv_wscale;
2298 tp->rx_opt.wscale_ok = 1;
2299 }
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002300 break;
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002301 case TCPOPT_SACK_PERM:
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002302 if (opt.opt_val != 0)
2303 return -EINVAL;
2304
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002305 tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
2306 if (sysctl_tcp_fack)
2307 tcp_enable_fack(tp);
2308 break;
2309 case TCPOPT_TIMESTAMP:
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002310 if (opt.opt_val != 0)
2311 return -EINVAL;
2312
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002313 tp->rx_opt.tstamp_ok = 1;
2314 break;
2315 }
2316 }
2317
2318 return 0;
2319}
2320
Linus Torvalds1da177e2005-04-16 15:20:36 -07002321/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002322 * Socket option code for TCP.
2323 */
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002324static int do_tcp_setsockopt(struct sock *sk, int level,
David S. Millerb7058842009-09-30 16:12:20 -07002325 int optname, char __user *optval, unsigned int optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002326{
2327 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002328 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002329 int val;
2330 int err = 0;
2331
William Allen Simpsone56fb502009-12-02 18:19:30 +00002332 /* These are data/string values, all the others are ints */
2333 switch (optname) {
2334 case TCP_CONGESTION: {
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002335 char name[TCP_CA_NAME_MAX];
2336
2337 if (optlen < 1)
2338 return -EINVAL;
2339
2340 val = strncpy_from_user(name, optval,
Andrew Morton4fdb78d2009-10-01 15:02:20 -07002341 min_t(long, TCP_CA_NAME_MAX-1, optlen));
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002342 if (val < 0)
2343 return -EFAULT;
2344 name[val] = 0;
2345
2346 lock_sock(sk);
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002347 err = tcp_set_congestion_control(sk, name);
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002348 release_sock(sk);
2349 return err;
2350 }
William Allen Simpsone56fb502009-12-02 18:19:30 +00002351 default:
2352 /* fallthru */
2353 break;
Joe Perchesccbd6a52010-05-14 10:58:26 +00002354 }
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002355
Linus Torvalds1da177e2005-04-16 15:20:36 -07002356 if (optlen < sizeof(int))
2357 return -EINVAL;
2358
2359 if (get_user(val, (int __user *)optval))
2360 return -EFAULT;
2361
2362 lock_sock(sk);
2363
2364 switch (optname) {
2365 case TCP_MAXSEG:
2366 /* Values greater than interface MTU won't take effect. However
2367 * at the point when this call is done we typically don't yet
2368 * know which interface is going to be used */
David S. Millerc39508d2010-11-24 11:47:22 -08002369 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002370 err = -EINVAL;
2371 break;
2372 }
2373 tp->rx_opt.user_mss = val;
2374 break;
2375
2376 case TCP_NODELAY:
2377 if (val) {
2378 /* TCP_NODELAY is weaker than TCP_CORK, so that
2379 * this option on corked socket is remembered, but
2380 * it is not activated until cork is cleared.
2381 *
2382 * However, when TCP_NODELAY is set we make
2383 * an explicit push, which overrides even TCP_CORK
2384 * for currently queued segments.
2385 */
2386 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002387 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002388 } else {
2389 tp->nonagle &= ~TCP_NAGLE_OFF;
2390 }
2391 break;
2392
Andreas Petlund36e31b0a2010-02-18 02:47:01 +00002393 case TCP_THIN_LINEAR_TIMEOUTS:
2394 if (val < 0 || val > 1)
2395 err = -EINVAL;
2396 else
2397 tp->thin_lto = val;
2398 break;
2399
Andreas Petlund7e380172010-02-18 04:48:19 +00002400 case TCP_THIN_DUPACK:
2401 if (val < 0 || val > 1)
2402 err = -EINVAL;
Dave Jonese2e5c4c2013-09-05 13:43:34 -04002403 else {
Andreas Petlund7e380172010-02-18 04:48:19 +00002404 tp->thin_dupack = val;
Yuchung Chengeed530b2012-05-02 13:30:03 +00002405 if (tp->thin_dupack)
2406 tcp_disable_early_retrans(tp);
Dave Jonese2e5c4c2013-09-05 13:43:34 -04002407 }
Andreas Petlund7e380172010-02-18 04:48:19 +00002408 break;
2409
Pavel Emelyanovee995282012-04-19 03:40:39 +00002410 case TCP_REPAIR:
2411 if (!tcp_can_repair_sock(sk))
2412 err = -EPERM;
2413 else if (val == 1) {
2414 tp->repair = 1;
2415 sk->sk_reuse = SK_FORCE_REUSE;
2416 tp->repair_queue = TCP_NO_QUEUE;
2417 } else if (val == 0) {
2418 tp->repair = 0;
2419 sk->sk_reuse = SK_NO_REUSE;
2420 tcp_send_window_probe(sk);
2421 } else
2422 err = -EINVAL;
2423
2424 break;
2425
2426 case TCP_REPAIR_QUEUE:
2427 if (!tp->repair)
2428 err = -EPERM;
2429 else if (val < TCP_QUEUES_NR)
2430 tp->repair_queue = val;
2431 else
2432 err = -EINVAL;
2433 break;
2434
2435 case TCP_QUEUE_SEQ:
2436 if (sk->sk_state != TCP_CLOSE)
2437 err = -EPERM;
2438 else if (tp->repair_queue == TCP_SEND_QUEUE)
2439 tp->write_seq = val;
2440 else if (tp->repair_queue == TCP_RECV_QUEUE)
2441 tp->rcv_nxt = val;
2442 else
2443 err = -EINVAL;
2444 break;
2445
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002446 case TCP_REPAIR_OPTIONS:
2447 if (!tp->repair)
2448 err = -EINVAL;
2449 else if (sk->sk_state == TCP_ESTABLISHED)
Pavel Emelyanovde248a72012-04-25 23:43:04 +00002450 err = tcp_repair_options_est(tp,
2451 (struct tcp_repair_opt __user *)optval,
2452 optlen);
Pavel Emelyanovb139ba42012-04-19 03:41:57 +00002453 else
2454 err = -EPERM;
2455 break;
2456
Linus Torvalds1da177e2005-04-16 15:20:36 -07002457 case TCP_CORK:
2458 /* When set indicates to always queue non-full frames.
2459 * Later the user clears this option and we transmit
2460 * any pending partial frames in the queue. This is
2461 * meant to be used alongside sendfile() to get properly
2462 * filled frames when the user (for example) must write
2463 * out headers with a write() call first and then use
2464 * sendfile to send out the data parts.
2465 *
2466 * TCP_CORK can be set together with TCP_NODELAY and it is
2467 * stronger than TCP_NODELAY.
2468 */
2469 if (val) {
2470 tp->nonagle |= TCP_NAGLE_CORK;
2471 } else {
2472 tp->nonagle &= ~TCP_NAGLE_CORK;
2473 if (tp->nonagle&TCP_NAGLE_OFF)
2474 tp->nonagle |= TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002475 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002476 }
2477 break;
2478
2479 case TCP_KEEPIDLE:
2480 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2481 err = -EINVAL;
2482 else {
2483 tp->keepalive_time = val * HZ;
2484 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2485 !((1 << sk->sk_state) &
2486 (TCPF_CLOSE | TCPF_LISTEN))) {
Flavio Leitner6c37e5d2010-04-26 18:33:27 +00002487 u32 elapsed = keepalive_time_elapsed(tp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002488 if (tp->keepalive_time > elapsed)
2489 elapsed = tp->keepalive_time - elapsed;
2490 else
2491 elapsed = 0;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002492 inet_csk_reset_keepalive_timer(sk, elapsed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002493 }
2494 }
2495 break;
2496 case TCP_KEEPINTVL:
2497 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2498 err = -EINVAL;
2499 else
2500 tp->keepalive_intvl = val * HZ;
2501 break;
2502 case TCP_KEEPCNT:
2503 if (val < 1 || val > MAX_TCP_KEEPCNT)
2504 err = -EINVAL;
2505 else
2506 tp->keepalive_probes = val;
2507 break;
2508 case TCP_SYNCNT:
2509 if (val < 1 || val > MAX_TCP_SYNCNT)
2510 err = -EINVAL;
2511 else
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002512 icsk->icsk_syn_retries = val;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002513 break;
2514
Eric Dumazetcd8ae852015-05-03 21:34:46 -07002515 case TCP_SAVE_SYN:
2516 if (val < 0 || val > 1)
2517 err = -EINVAL;
2518 else
2519 tp->save_syn = val;
2520 break;
2521
Linus Torvalds1da177e2005-04-16 15:20:36 -07002522 case TCP_LINGER2:
2523 if (val < 0)
2524 tp->linger2 = -1;
2525 else if (val > sysctl_tcp_fin_timeout / HZ)
2526 tp->linger2 = 0;
2527 else
2528 tp->linger2 = val * HZ;
2529 break;
2530
2531 case TCP_DEFER_ACCEPT:
Julian Anastasovb103cf32009-10-19 10:10:40 +00002532 /* Translate value in seconds to number of retransmits */
2533 icsk->icsk_accept_queue.rskq_defer_accept =
2534 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2535 TCP_RTO_MAX / HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002536 break;
2537
2538 case TCP_WINDOW_CLAMP:
2539 if (!val) {
2540 if (sk->sk_state != TCP_CLOSE) {
2541 err = -EINVAL;
2542 break;
2543 }
2544 tp->window_clamp = 0;
2545 } else
2546 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2547 SOCK_MIN_RCVBUF / 2 : val;
2548 break;
2549
2550 case TCP_QUICKACK:
2551 if (!val) {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002552 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002553 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002554 icsk->icsk_ack.pingpong = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002555 if ((1 << sk->sk_state) &
2556 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002557 inet_csk_ack_scheduled(sk)) {
2558 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
Chris Leech0e4b4992006-05-23 18:00:16 -07002559 tcp_cleanup_rbuf(sk, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002560 if (!(val & 1))
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002561 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002562 }
2563 }
2564 break;
2565
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002566#ifdef CONFIG_TCP_MD5SIG
2567 case TCP_MD5SIG:
2568 /* Read the IP->Key mappings from userspace */
2569 err = tp->af_specific->md5_parse(sk, optval, optlen);
2570 break;
2571#endif
Jerry Chudca43c72010-08-27 19:13:28 +00002572 case TCP_USER_TIMEOUT:
Yuchung Chengb2482302014-09-29 13:20:38 -07002573 /* Cap the max time in ms TCP will retry or probe the window
Jerry Chudca43c72010-08-27 19:13:28 +00002574 * before giving up and aborting (ETIMEDOUT) a connection.
2575 */
Hangbin Liu42493572012-07-26 22:52:21 +00002576 if (val < 0)
2577 err = -EINVAL;
2578 else
2579 icsk->icsk_user_timeout = msecs_to_jiffies(val);
Jerry Chudca43c72010-08-27 19:13:28 +00002580 break;
Jerry Chu83368862012-08-31 12:29:12 +00002581
2582 case TCP_FASTOPEN:
2583 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
Christoph Paaschdfea2aa2015-06-18 09:15:34 -07002584 TCPF_LISTEN))) {
2585 tcp_fastopen_init_key_once(true);
2586
Eric Dumazet0536fcc2015-09-29 07:42:52 -07002587 fastopen_queue_tune(sk, val);
Christoph Paaschdfea2aa2015-06-18 09:15:34 -07002588 } else {
Jerry Chu83368862012-08-31 12:29:12 +00002589 err = -EINVAL;
Christoph Paaschdfea2aa2015-06-18 09:15:34 -07002590 }
Jerry Chu83368862012-08-31 12:29:12 +00002591 break;
Andrey Vagin93be6ce2013-02-11 05:50:18 +00002592 case TCP_TIMESTAMP:
2593 if (!tp->repair)
2594 err = -EPERM;
2595 else
2596 tp->tsoffset = val - tcp_time_stamp;
2597 break;
Eric Dumazetc9bee3b72013-07-22 20:27:07 -07002598 case TCP_NOTSENT_LOWAT:
2599 tp->notsent_lowat = val;
2600 sk->sk_write_space(sk);
2601 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002602 default:
2603 err = -ENOPROTOOPT;
2604 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002605 }
2606
Linus Torvalds1da177e2005-04-16 15:20:36 -07002607 release_sock(sk);
2608 return err;
2609}
2610
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002611int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
David S. Millerb7058842009-09-30 16:12:20 -07002612 unsigned int optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002613{
Eric Dumazetcf533ea2011-10-21 05:22:42 -04002614 const struct inet_connection_sock *icsk = inet_csk(sk);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002615
2616 if (level != SOL_TCP)
2617 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2618 optval, optlen);
2619 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2620}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00002621EXPORT_SYMBOL(tcp_setsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002622
2623#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002624int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
David S. Millerb7058842009-09-30 16:12:20 -07002625 char __user *optval, unsigned int optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002626{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002627 if (level != SOL_TCP)
2628 return inet_csk_compat_setsockopt(sk, level, optname,
2629 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002630 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2631}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002632EXPORT_SYMBOL(compat_tcp_setsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002633#endif
2634
Linus Torvalds1da177e2005-04-16 15:20:36 -07002635/* Return information about state of tcp endpoint in API format. */
Eric Dumazet0df48c22015-04-28 15:28:17 -07002636void tcp_get_info(struct sock *sk, struct tcp_info *info)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002637{
Craig Gallek35ac8382015-06-15 11:26:20 -04002638 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002639 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002640 u32 now = tcp_time_stamp;
Eric Dumazetd6549762015-05-21 21:51:19 -07002641 unsigned int start;
Eric Dumazetff5d7492016-01-27 10:52:43 -08002642 u64 rate64;
Eric Dumazetfad9dfe2015-04-16 16:12:28 -07002643 u32 rate;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002644
2645 memset(info, 0, sizeof(*info));
Craig Gallek35ac8382015-06-15 11:26:20 -04002646 if (sk->sk_type != SOCK_STREAM)
2647 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002648
Eric Dumazet00fd38d2015-11-12 08:43:18 -08002649 info->tcpi_state = sk_state_load(sk);
2650
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002651 info->tcpi_ca_state = icsk->icsk_ca_state;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002652 info->tcpi_retransmits = icsk->icsk_retransmits;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002653 info->tcpi_probes = icsk->icsk_probes_out;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002654 info->tcpi_backoff = icsk->icsk_backoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002655
2656 if (tp->rx_opt.tstamp_ok)
2657 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
Ilpo Järvinene60402d2007-08-09 15:14:46 +03002658 if (tcp_is_sack(tp))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002659 info->tcpi_options |= TCPI_OPT_SACK;
2660 if (tp->rx_opt.wscale_ok) {
2661 info->tcpi_options |= TCPI_OPT_WSCALE;
2662 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2663 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09002664 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002665
Eric Dumazetb5c56932011-10-03 14:01:21 -04002666 if (tp->ecn_flags & TCP_ECN_OK)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002667 info->tcpi_options |= TCPI_OPT_ECN;
Eric Dumazetb5c56932011-10-03 14:01:21 -04002668 if (tp->ecn_flags & TCP_ECN_SEEN)
2669 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Yuchung Cheng6f736012012-10-19 15:14:44 +00002670 if (tp->syn_data_acked)
2671 info->tcpi_options |= TCPI_OPT_SYN_DATA;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002672
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002673 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2674 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002675 info->tcpi_snd_mss = tp->mss_cache;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002676 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002677
Eric Dumazet00fd38d2015-11-12 08:43:18 -08002678 if (info->tcpi_state == TCP_LISTEN) {
Rick Jones5ee3afb2007-09-18 13:26:31 -07002679 info->tcpi_unacked = sk->sk_ack_backlog;
2680 info->tcpi_sacked = sk->sk_max_ack_backlog;
2681 } else {
2682 info->tcpi_unacked = tp->packets_out;
2683 info->tcpi_sacked = tp->sacked_out;
2684 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002685 info->tcpi_lost = tp->lost_out;
2686 info->tcpi_retrans = tp->retrans_out;
2687 info->tcpi_fackets = tp->fackets_out;
2688
2689 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002690 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002691 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2692
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08002693 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002694 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
Eric Dumazet740b0f12014-02-26 14:02:48 -08002695 info->tcpi_rtt = tp->srtt_us >> 3;
2696 info->tcpi_rttvar = tp->mdev_us >> 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002697 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2698 info->tcpi_snd_cwnd = tp->snd_cwnd;
2699 info->tcpi_advmss = tp->advmss;
2700 info->tcpi_reordering = tp->reordering;
2701
2702 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2703 info->tcpi_rcv_space = tp->rcvq_space.space;
2704
2705 info->tcpi_total_retrans = tp->total_retrans;
Eric Dumazet977cb0e2014-02-13 14:27:40 -08002706
Eric Dumazetfad9dfe2015-04-16 16:12:28 -07002707 rate = READ_ONCE(sk->sk_pacing_rate);
Eric Dumazetff5d7492016-01-27 10:52:43 -08002708 rate64 = rate != ~0U ? rate : ~0ULL;
2709 put_unaligned(rate64, &info->tcpi_pacing_rate);
Eric Dumazetfad9dfe2015-04-16 16:12:28 -07002710
2711 rate = READ_ONCE(sk->sk_max_pacing_rate);
Eric Dumazetff5d7492016-01-27 10:52:43 -08002712 rate64 = rate != ~0U ? rate : ~0ULL;
2713 put_unaligned(rate64, &info->tcpi_max_pacing_rate);
Eric Dumazet0df48c22015-04-28 15:28:17 -07002714
Eric Dumazetd6549762015-05-21 21:51:19 -07002715 do {
2716 start = u64_stats_fetch_begin_irq(&tp->syncp);
Eric Dumazetff5d7492016-01-27 10:52:43 -08002717 put_unaligned(tp->bytes_acked, &info->tcpi_bytes_acked);
2718 put_unaligned(tp->bytes_received, &info->tcpi_bytes_received);
Eric Dumazetd6549762015-05-21 21:51:19 -07002719 } while (u64_stats_fetch_retry_irq(&tp->syncp, start));
Marcelo Ricardo Leitner2efd0552015-05-20 16:35:41 -07002720 info->tcpi_segs_out = tp->segs_out;
2721 info->tcpi_segs_in = tp->segs_in;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002722}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002723EXPORT_SYMBOL_GPL(tcp_get_info);
2724
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002725static int do_tcp_getsockopt(struct sock *sk, int level,
2726 int optname, char __user *optval, int __user *optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002727{
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002728 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002729 struct tcp_sock *tp = tcp_sk(sk);
2730 int val, len;
2731
Linus Torvalds1da177e2005-04-16 15:20:36 -07002732 if (get_user(len, optlen))
2733 return -EFAULT;
2734
2735 len = min_t(unsigned int, len, sizeof(int));
2736
2737 if (len < 0)
2738 return -EINVAL;
2739
2740 switch (optname) {
2741 case TCP_MAXSEG:
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002742 val = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002743 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2744 val = tp->rx_opt.user_mss;
Pavel Emelyanov5e6a3ce2012-04-19 03:41:32 +00002745 if (tp->repair)
2746 val = tp->rx_opt.mss_clamp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002747 break;
2748 case TCP_NODELAY:
2749 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2750 break;
2751 case TCP_CORK:
2752 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2753 break;
2754 case TCP_KEEPIDLE:
Eric Dumazetdf19a622009-08-28 23:48:54 -07002755 val = keepalive_time_when(tp) / HZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002756 break;
2757 case TCP_KEEPINTVL:
Eric Dumazetdf19a622009-08-28 23:48:54 -07002758 val = keepalive_intvl_when(tp) / HZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002759 break;
2760 case TCP_KEEPCNT:
Eric Dumazetdf19a622009-08-28 23:48:54 -07002761 val = keepalive_probes(tp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002762 break;
2763 case TCP_SYNCNT:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002764 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002765 break;
2766 case TCP_LINGER2:
2767 val = tp->linger2;
2768 if (val >= 0)
2769 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2770 break;
2771 case TCP_DEFER_ACCEPT:
Julian Anastasovb103cf32009-10-19 10:10:40 +00002772 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2773 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002774 break;
2775 case TCP_WINDOW_CLAMP:
2776 val = tp->window_clamp;
2777 break;
2778 case TCP_INFO: {
2779 struct tcp_info info;
2780
2781 if (get_user(len, optlen))
2782 return -EFAULT;
2783
2784 tcp_get_info(sk, &info);
2785
2786 len = min_t(unsigned int, len, sizeof(info));
2787 if (put_user(len, optlen))
2788 return -EFAULT;
2789 if (copy_to_user(optval, &info, len))
2790 return -EFAULT;
2791 return 0;
2792 }
Eric Dumazet6e9250f2015-04-28 16:23:49 -07002793 case TCP_CC_INFO: {
2794 const struct tcp_congestion_ops *ca_ops;
2795 union tcp_cc_info info;
2796 size_t sz = 0;
2797 int attr;
2798
2799 if (get_user(len, optlen))
2800 return -EFAULT;
2801
2802 ca_ops = icsk->icsk_ca_ops;
2803 if (ca_ops && ca_ops->get_info)
2804 sz = ca_ops->get_info(sk, ~0U, &attr, &info);
2805
2806 len = min_t(unsigned int, len, sz);
2807 if (put_user(len, optlen))
2808 return -EFAULT;
2809 if (copy_to_user(optval, &info, len))
2810 return -EFAULT;
2811 return 0;
2812 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002813 case TCP_QUICKACK:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002814 val = !icsk->icsk_ack.pingpong;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002815 break;
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002816
2817 case TCP_CONGESTION:
2818 if (get_user(len, optlen))
2819 return -EFAULT;
2820 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2821 if (put_user(len, optlen))
2822 return -EFAULT;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002823 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002824 return -EFAULT;
2825 return 0;
William Allen Simpsone56fb502009-12-02 18:19:30 +00002826
Josh Hunt3c0fef02010-07-30 13:49:35 +00002827 case TCP_THIN_LINEAR_TIMEOUTS:
2828 val = tp->thin_lto;
2829 break;
2830 case TCP_THIN_DUPACK:
2831 val = tp->thin_dupack;
2832 break;
Jerry Chudca43c72010-08-27 19:13:28 +00002833
Pavel Emelyanovee995282012-04-19 03:40:39 +00002834 case TCP_REPAIR:
2835 val = tp->repair;
2836 break;
2837
2838 case TCP_REPAIR_QUEUE:
2839 if (tp->repair)
2840 val = tp->repair_queue;
2841 else
2842 return -EINVAL;
2843 break;
2844
2845 case TCP_QUEUE_SEQ:
2846 if (tp->repair_queue == TCP_SEND_QUEUE)
2847 val = tp->write_seq;
2848 else if (tp->repair_queue == TCP_RECV_QUEUE)
2849 val = tp->rcv_nxt;
2850 else
2851 return -EINVAL;
2852 break;
2853
Jerry Chudca43c72010-08-27 19:13:28 +00002854 case TCP_USER_TIMEOUT:
2855 val = jiffies_to_msecs(icsk->icsk_user_timeout);
2856 break;
Kenjiro Nakayama1536e282014-04-17 01:25:01 +09002857
2858 case TCP_FASTOPEN:
Eric Dumazet0536fcc2015-09-29 07:42:52 -07002859 val = icsk->icsk_accept_queue.fastopenq.max_qlen;
Kenjiro Nakayama1536e282014-04-17 01:25:01 +09002860 break;
2861
Andrey Vagin93be6ce2013-02-11 05:50:18 +00002862 case TCP_TIMESTAMP:
2863 val = tcp_time_stamp + tp->tsoffset;
2864 break;
Eric Dumazetc9bee3b72013-07-22 20:27:07 -07002865 case TCP_NOTSENT_LOWAT:
2866 val = tp->notsent_lowat;
2867 break;
Eric Dumazetcd8ae852015-05-03 21:34:46 -07002868 case TCP_SAVE_SYN:
2869 val = tp->save_syn;
2870 break;
2871 case TCP_SAVED_SYN: {
2872 if (get_user(len, optlen))
2873 return -EFAULT;
2874
2875 lock_sock(sk);
2876 if (tp->saved_syn) {
Eric B Munsonaea09292015-05-18 14:35:58 -04002877 if (len < tp->saved_syn[0]) {
2878 if (put_user(tp->saved_syn[0], optlen)) {
2879 release_sock(sk);
2880 return -EFAULT;
2881 }
2882 release_sock(sk);
2883 return -EINVAL;
2884 }
2885 len = tp->saved_syn[0];
Eric Dumazetcd8ae852015-05-03 21:34:46 -07002886 if (put_user(len, optlen)) {
2887 release_sock(sk);
2888 return -EFAULT;
2889 }
2890 if (copy_to_user(optval, tp->saved_syn + 1, len)) {
2891 release_sock(sk);
2892 return -EFAULT;
2893 }
2894 tcp_saved_syn_free(tp);
2895 release_sock(sk);
2896 } else {
2897 release_sock(sk);
2898 len = 0;
2899 if (put_user(len, optlen))
2900 return -EFAULT;
2901 }
2902 return 0;
2903 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002904 default:
2905 return -ENOPROTOOPT;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002906 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002907
2908 if (put_user(len, optlen))
2909 return -EFAULT;
2910 if (copy_to_user(optval, &val, len))
2911 return -EFAULT;
2912 return 0;
2913}
2914
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002915int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2916 int __user *optlen)
2917{
2918 struct inet_connection_sock *icsk = inet_csk(sk);
2919
2920 if (level != SOL_TCP)
2921 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2922 optval, optlen);
2923 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2924}
Eric Dumazet4bc2f182010-07-09 21:22:10 +00002925EXPORT_SYMBOL(tcp_getsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002926
2927#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002928int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2929 char __user *optval, int __user *optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002930{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002931 if (level != SOL_TCP)
2932 return inet_csk_compat_getsockopt(sk, level, optname,
2933 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002934 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2935}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002936EXPORT_SYMBOL(compat_tcp_getsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002937#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002938
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002939#ifdef CONFIG_TCP_MD5SIG
Eric Dumazet349ce992014-10-23 12:58:58 -07002940static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
Eric Dumazet71cea172013-05-20 06:52:26 +00002941static DEFINE_MUTEX(tcp_md5sig_mutex);
Eric Dumazet349ce992014-10-23 12:58:58 -07002942static bool tcp_md5sig_pool_populated = false;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002943
Eric Dumazet71cea172013-05-20 06:52:26 +00002944static void __tcp_alloc_md5sig_pool(void)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002945{
2946 int cpu;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002947
2948 for_each_possible_cpu(cpu) {
Eric Dumazet349ce992014-10-23 12:58:58 -07002949 if (!per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm) {
2950 struct crypto_hash *hash;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002951
Eric Dumazet349ce992014-10-23 12:58:58 -07002952 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2953 if (IS_ERR_OR_NULL(hash))
2954 return;
2955 per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm = hash;
2956 }
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002957 }
Eric Dumazet349ce992014-10-23 12:58:58 -07002958 /* before setting tcp_md5sig_pool_populated, we must commit all writes
2959 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
Eric Dumazet71cea172013-05-20 06:52:26 +00002960 */
2961 smp_wmb();
Eric Dumazet349ce992014-10-23 12:58:58 -07002962 tcp_md5sig_pool_populated = true;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002963}
2964
Eric Dumazet71cea172013-05-20 06:52:26 +00002965bool tcp_alloc_md5sig_pool(void)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002966{
Eric Dumazet349ce992014-10-23 12:58:58 -07002967 if (unlikely(!tcp_md5sig_pool_populated)) {
Eric Dumazet71cea172013-05-20 06:52:26 +00002968 mutex_lock(&tcp_md5sig_mutex);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002969
Eric Dumazet349ce992014-10-23 12:58:58 -07002970 if (!tcp_md5sig_pool_populated)
Eric Dumazet71cea172013-05-20 06:52:26 +00002971 __tcp_alloc_md5sig_pool();
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002972
Eric Dumazet71cea172013-05-20 06:52:26 +00002973 mutex_unlock(&tcp_md5sig_mutex);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002974 }
Eric Dumazet349ce992014-10-23 12:58:58 -07002975 return tcp_md5sig_pool_populated;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002976}
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002977EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2978
Eric Dumazet35790c02010-05-16 00:34:04 -07002979
2980/**
2981 * tcp_get_md5sig_pool - get md5sig_pool for this user
2982 *
2983 * We use percpu structure, so if we succeed, we exit with preemption
2984 * and BH disabled, to make sure another thread or softirq handling
2985 * wont try to get same context.
2986 */
2987struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002988{
Eric Dumazet35790c02010-05-16 00:34:04 -07002989 local_bh_disable();
Eric Dumazet35790c02010-05-16 00:34:04 -07002990
Eric Dumazet349ce992014-10-23 12:58:58 -07002991 if (tcp_md5sig_pool_populated) {
2992 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
2993 smp_rmb();
2994 return this_cpu_ptr(&tcp_md5sig_pool);
2995 }
Eric Dumazet35790c02010-05-16 00:34:04 -07002996 local_bh_enable();
2997 return NULL;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002998}
Eric Dumazet35790c02010-05-16 00:34:04 -07002999EXPORT_SYMBOL(tcp_get_md5sig_pool);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08003000
Adam Langley49a72df2008-07-19 00:01:42 -07003001int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
Eric Dumazetca35a0e2011-10-24 01:52:35 -04003002 const struct tcphdr *th)
Adam Langley49a72df2008-07-19 00:01:42 -07003003{
3004 struct scatterlist sg;
Eric Dumazetca35a0e2011-10-24 01:52:35 -04003005 struct tcphdr hdr;
Adam Langley49a72df2008-07-19 00:01:42 -07003006 int err;
3007
Eric Dumazetca35a0e2011-10-24 01:52:35 -04003008 /* We are not allowed to change tcphdr, make a local copy */
3009 memcpy(&hdr, th, sizeof(hdr));
3010 hdr.check = 0;
3011
Adam Langley49a72df2008-07-19 00:01:42 -07003012 /* options aren't included in the hash */
Eric Dumazetca35a0e2011-10-24 01:52:35 -04003013 sg_init_one(&sg, &hdr, sizeof(hdr));
3014 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr));
Adam Langley49a72df2008-07-19 00:01:42 -07003015 return err;
3016}
Adam Langley49a72df2008-07-19 00:01:42 -07003017EXPORT_SYMBOL(tcp_md5_hash_header);
3018
3019int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
Eric Dumazetcf533ea2011-10-21 05:22:42 -04003020 const struct sk_buff *skb, unsigned int header_len)
Adam Langley49a72df2008-07-19 00:01:42 -07003021{
3022 struct scatterlist sg;
3023 const struct tcphdr *tp = tcp_hdr(skb);
3024 struct hash_desc *desc = &hp->md5_desc;
Eric Dumazet95c96172012-04-15 05:58:06 +00003025 unsigned int i;
3026 const unsigned int head_data_len = skb_headlen(skb) > header_len ?
3027 skb_headlen(skb) - header_len : 0;
Adam Langley49a72df2008-07-19 00:01:42 -07003028 const struct skb_shared_info *shi = skb_shinfo(skb);
Eric Dumazetd7fd1b572010-05-17 20:40:51 +00003029 struct sk_buff *frag_iter;
Adam Langley49a72df2008-07-19 00:01:42 -07003030
3031 sg_init_table(&sg, 1);
3032
3033 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3034 if (crypto_hash_update(desc, &sg, head_data_len))
3035 return 1;
3036
3037 for (i = 0; i < shi->nr_frags; ++i) {
3038 const struct skb_frag_struct *f = &shi->frags[i];
Eric Dumazet54d27fc2013-05-13 21:25:52 +00003039 unsigned int offset = f->page_offset;
3040 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
3041
3042 sg_set_page(&sg, page, skb_frag_size(f),
3043 offset_in_page(offset));
Eric Dumazet9e903e02011-10-18 21:00:24 +00003044 if (crypto_hash_update(desc, &sg, skb_frag_size(f)))
Adam Langley49a72df2008-07-19 00:01:42 -07003045 return 1;
3046 }
3047
Eric Dumazetd7fd1b572010-05-17 20:40:51 +00003048 skb_walk_frags(skb, frag_iter)
3049 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3050 return 1;
3051
Adam Langley49a72df2008-07-19 00:01:42 -07003052 return 0;
3053}
Adam Langley49a72df2008-07-19 00:01:42 -07003054EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3055
Eric Dumazetcf533ea2011-10-21 05:22:42 -04003056int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
Adam Langley49a72df2008-07-19 00:01:42 -07003057{
3058 struct scatterlist sg;
3059
3060 sg_init_one(&sg, key->key, key->keylen);
3061 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
3062}
Adam Langley49a72df2008-07-19 00:01:42 -07003063EXPORT_SYMBOL(tcp_md5_hash_key);
3064
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08003065#endif
3066
Andi Kleen4ac02ba2007-04-20 17:11:46 -07003067void tcp_done(struct sock *sk)
3068{
Jerry Chu83368862012-08-31 12:29:12 +00003069 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
3070
Jianjun Kong5a5f3a82008-11-03 00:24:34 -08003071 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07003072 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
Andi Kleen4ac02ba2007-04-20 17:11:46 -07003073
3074 tcp_set_state(sk, TCP_CLOSE);
3075 tcp_clear_xmit_timers(sk);
Ian Morris00db4122015-04-03 09:17:27 +01003076 if (req)
Jerry Chu83368862012-08-31 12:29:12 +00003077 reqsk_fastopen_remove(sk, req, false);
Andi Kleen4ac02ba2007-04-20 17:11:46 -07003078
3079 sk->sk_shutdown = SHUTDOWN_MASK;
3080
3081 if (!sock_flag(sk, SOCK_DEAD))
3082 sk->sk_state_change(sk);
3083 else
3084 inet_csk_destroy_sock(sk);
3085}
3086EXPORT_SYMBOL_GPL(tcp_done);
3087
Lorenzo Colittic1e64e22015-12-16 12:30:05 +09003088int tcp_abort(struct sock *sk, int err)
3089{
3090 if (!sk_fullsock(sk)) {
Eric Dumazet07f6f4a2015-12-17 16:14:11 -08003091 if (sk->sk_state == TCP_NEW_SYN_RECV) {
3092 struct request_sock *req = inet_reqsk(sk);
3093
3094 local_bh_disable();
3095 inet_csk_reqsk_queue_drop_and_put(req->rsk_listener,
3096 req);
3097 local_bh_enable();
3098 return 0;
3099 }
Lorenzo Colittic1e64e22015-12-16 12:30:05 +09003100 sock_gen_put(sk);
3101 return -EOPNOTSUPP;
3102 }
3103
3104 /* Don't race with userspace socket closes such as tcp_close. */
3105 lock_sock(sk);
3106
Lorenzo Colitti2010b932015-12-22 00:03:44 +09003107 if (sk->sk_state == TCP_LISTEN) {
3108 tcp_set_state(sk, TCP_CLOSE);
3109 inet_csk_listen_stop(sk);
3110 }
3111
Lorenzo Colittic1e64e22015-12-16 12:30:05 +09003112 /* Don't race with BH socket closes such as inet_csk_listen_stop. */
3113 local_bh_disable();
3114 bh_lock_sock(sk);
3115
3116 if (!sock_flag(sk, SOCK_DEAD)) {
3117 sk->sk_err = err;
3118 /* This barrier is coupled with smp_rmb() in tcp_poll() */
3119 smp_wmb();
3120 sk->sk_error_report(sk);
3121 if (tcp_need_reset(sk->sk_state))
3122 tcp_send_active_reset(sk, GFP_ATOMIC);
3123 tcp_done(sk);
3124 }
3125
3126 bh_unlock_sock(sk);
3127 local_bh_enable();
3128 release_sock(sk);
3129 sock_put(sk);
3130 return 0;
3131}
3132EXPORT_SYMBOL_GPL(tcp_abort);
3133
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07003134extern struct tcp_congestion_ops tcp_reno;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003135
3136static __initdata unsigned long thash_entries;
3137static int __init set_thash_entries(char *str)
3138{
Eldad Zack413c27d2012-05-19 14:13:18 +00003139 ssize_t ret;
3140
Linus Torvalds1da177e2005-04-16 15:20:36 -07003141 if (!str)
3142 return 0;
Eldad Zack413c27d2012-05-19 14:13:18 +00003143
3144 ret = kstrtoul(str, 0, &thash_entries);
3145 if (ret)
3146 return 0;
3147
Linus Torvalds1da177e2005-04-16 15:20:36 -07003148 return 1;
3149}
3150__setup("thash_entries=", set_thash_entries);
3151
Fabian Frederick47d7a88c2014-10-01 18:27:50 +02003152static void __init tcp_init_mem(void)
Glauber Costa4acb4192012-01-30 01:20:17 +00003153{
Eric Dumazetb66e91c2015-05-15 12:39:30 -07003154 unsigned long limit = nr_free_buffer_pages() / 16;
3155
Glauber Costa4acb4192012-01-30 01:20:17 +00003156 limit = max(limit, 128UL);
Eric Dumazetb66e91c2015-05-15 12:39:30 -07003157 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */
3158 sysctl_tcp_mem[1] = limit; /* 6.25 % */
3159 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */
Glauber Costa4acb4192012-01-30 01:20:17 +00003160}
3161
Linus Torvalds1da177e2005-04-16 15:20:36 -07003162void __init tcp_init(void)
3163{
Eric Dumazetf03d78d2011-07-07 00:27:05 -07003164 unsigned long limit;
Eric Dumazetb49960a2012-05-02 02:28:41 +00003165 int max_rshare, max_wshare, cnt;
Dimitri Sivanich074b8512012-02-08 12:39:07 -08003166 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003167
Eyal Birgerb4772ef2015-03-01 14:58:29 +02003168 sock_skb_cb_check_size(sizeof(struct tcp_skb_cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003169
Tejun Heo908c7f12014-09-08 09:51:29 +09003170 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
3171 percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07003172 tcp_hashinfo.bind_bucket_cachep =
3173 kmem_cache_create("tcp_bind_bucket",
3174 sizeof(struct inet_bind_bucket), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09003175 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003176
Linus Torvalds1da177e2005-04-16 15:20:36 -07003177 /* Size and allocate the main established and bind bucket
3178 * hash tables.
3179 *
3180 * The methodology is similar to that of the buffer cache.
3181 */
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07003182 tcp_hashinfo.ehash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07003183 alloc_large_system_hash("TCP established",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07003184 sizeof(struct inet_ehash_bucket),
Linus Torvalds1da177e2005-04-16 15:20:36 -07003185 thash_entries,
Eric Dumazetfd90b292012-11-30 10:08:52 +00003186 17, /* one slot per 128 KB of memory */
John Heffner9e950ef2006-11-06 23:10:51 -08003187 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003188 NULL,
Eric Dumazetf373b532009-10-09 00:16:19 +00003189 &tcp_hashinfo.ehash_mask,
Tim Bird31fe62b2012-05-23 13:33:35 +00003190 0,
Jean Delvare0ccfe612007-10-30 00:59:25 -07003191 thash_entries ? 0 : 512 * 1024);
Eric Dumazet05dbc7b2013-10-03 00:22:02 -07003192 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08003193 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
Eric Dumazet05dbc7b2013-10-03 00:22:02 -07003194
Eric Dumazet230140c2007-11-07 02:40:20 -08003195 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3196 panic("TCP: failed to alloc ehash_locks");
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07003197 tcp_hashinfo.bhash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07003198 alloc_large_system_hash("TCP bind",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07003199 sizeof(struct inet_bind_hashbucket),
Eric Dumazetf373b532009-10-09 00:16:19 +00003200 tcp_hashinfo.ehash_mask + 1,
Eric Dumazetfd90b292012-11-30 10:08:52 +00003201 17, /* one slot per 128 KB of memory */
John Heffner9e950ef2006-11-06 23:10:51 -08003202 0,
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07003203 &tcp_hashinfo.bhash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003204 NULL,
Tim Bird31fe62b2012-05-23 13:33:35 +00003205 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003206 64 * 1024);
Dimitri Sivanich074b8512012-02-08 12:39:07 -08003207 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07003208 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3209 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3210 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003211 }
3212
Eric Dumazetc5ed63d2010-08-25 23:02:17 -07003213
3214 cnt = tcp_hashinfo.ehash_mask + 1;
3215
3216 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3217 sysctl_tcp_max_orphans = cnt / 2;
3218 sysctl_max_syn_backlog = max(128, cnt / 256);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003219
Eric W. Biedermana4fe34b2013-10-19 16:25:36 -07003220 tcp_init_mem();
Jason Wangc43b8742012-02-02 00:07:00 +00003221 /* Set per-socket limits to no more than 1/128 the pressure threshold */
Eric Dumazet5fb84b12012-04-10 00:56:42 +00003222 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
Eric Dumazetb49960a2012-05-02 02:28:41 +00003223 max_wshare = min(4UL*1024*1024, limit);
3224 max_rshare = min(6UL*1024*1024, limit);
John Heffner7b4f4b52006-03-25 01:34:07 -08003225
Hideo Aoki3ab224b2007-12-31 00:11:19 -08003226 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08003227 sysctl_tcp_wmem[1] = 16*1024;
Eric Dumazetb49960a2012-05-02 02:28:41 +00003228 sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
John Heffner7b4f4b52006-03-25 01:34:07 -08003229
Hideo Aoki3ab224b2007-12-31 00:11:19 -08003230 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08003231 sysctl_tcp_rmem[1] = 87380;
Eric Dumazetb49960a2012-05-02 02:28:41 +00003232 sysctl_tcp_rmem[2] = max(87380, max_rshare);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003233
Joe Perchesafd465032012-03-12 07:03:32 +00003234 pr_info("Hash tables configured (established %u bind %u)\n",
Joe Perches058bd4d2012-03-11 18:36:11 +00003235 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
Stephen Hemminger317a76f2005-06-23 12:19:55 -07003236
David S. Miller51c5d0c2012-07-10 00:49:14 -07003237 tcp_metrics_init();
Florian Westphal55d86942014-09-26 22:37:32 +02003238 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
Eric Dumazet46d3cea2012-07-11 05:50:31 +00003239 tcp_tasklet_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003240}