blob: 9e0e45c378061a17fa6a5bcecd729322c1e8bcbe [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
Ilpo Järvinen172589c2007-08-28 15:50:33 -0700248#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249#include <linux/module.h>
250#include <linux/types.h>
251#include <linux/fcntl.h>
252#include <linux/poll.h>
253#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254#include <linux/fs.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800255#include <linux/skbuff.h>
Andrew Morton81b23b42008-07-03 03:22:02 -0700256#include <linux/scatterlist.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800257#include <linux/splice.h>
258#include <linux/net.h>
259#include <linux/socket.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260#include <linux/random.h>
261#include <linux/bootmem.h>
Miquel van Smoorenburg57413eb2008-06-27 17:23:57 -0700262#include <linux/highmem.h>
263#include <linux/swap.h>
David S. Millerb8059ea2006-03-25 01:36:56 -0800264#include <linux/cache.h>
Herbert Xuf4c50d92006-06-22 03:02:40 -0700265#include <linux/err.h>
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800266#include <linux/crypto.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
268#include <net/icmp.h>
269#include <net/tcp.h>
270#include <net/xfrm.h>
271#include <net/ip.h>
Chris Leech1a2449a2006-05-23 18:05:53 -0700272#include <net/netdma.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800273#include <net/sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275#include <asm/uaccess.h>
276#include <asm/ioctls.h>
277
Brian Haleyab32ea52006-09-22 14:15:41 -0700278int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
Eric Dumazetba899662005-08-26 12:05:31 -0700280DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics) __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282atomic_t tcp_orphan_count = ATOMIC_INIT(0);
283
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -0700284EXPORT_SYMBOL_GPL(tcp_orphan_count);
285
David S. Millerb8059ea2006-03-25 01:36:56 -0800286int sysctl_tcp_mem[3] __read_mostly;
287int sysctl_tcp_wmem[3] __read_mostly;
288int sysctl_tcp_rmem[3] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
290EXPORT_SYMBOL(sysctl_tcp_mem);
291EXPORT_SYMBOL(sysctl_tcp_rmem);
292EXPORT_SYMBOL(sysctl_tcp_wmem);
293
294atomic_t tcp_memory_allocated; /* Current allocated memory. */
295atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */
296
297EXPORT_SYMBOL(tcp_memory_allocated);
298EXPORT_SYMBOL(tcp_sockets_allocated);
299
300/*
Jens Axboe9c55e012007-11-06 23:30:13 -0800301 * TCP splice context
302 */
303struct tcp_splice_state {
304 struct pipe_inode_info *pipe;
305 size_t len;
306 unsigned int flags;
307};
308
309/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 * Pressure flag: try to collapse.
311 * Technical note: it is used by multiple contexts non atomically.
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800312 * All the __sk_mem_schedule() is of this nature: accounting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 * is strict, actions are advisory and have some latency.
314 */
Eric Dumazet4103f8c2007-03-27 13:58:31 -0700315int tcp_memory_pressure __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
317EXPORT_SYMBOL(tcp_memory_pressure);
318
Pavel Emelyanov5c52ba12008-07-16 20:28:10 -0700319void tcp_enter_memory_pressure(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320{
321 if (!tcp_memory_pressure) {
Pavel Emelyanov4e673442008-07-16 20:30:14 -0700322 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 tcp_memory_pressure = 1;
324 }
325}
326
327EXPORT_SYMBOL(tcp_enter_memory_pressure);
328
329/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 * Wait for a TCP event.
331 *
332 * Note that we don't need to lock the socket, as the upper poll layers
333 * take care of normal races (between the test and the event) and we don't
334 * go look at any of the socket buffers directly.
335 */
336unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
337{
338 unsigned int mask;
339 struct sock *sk = sock->sk;
340 struct tcp_sock *tp = tcp_sk(sk);
341
342 poll_wait(file, sk->sk_sleep, wait);
343 if (sk->sk_state == TCP_LISTEN)
Arnaldo Carvalho de Melodc40c7b2005-08-23 21:52:58 -0700344 return inet_csk_listen_poll(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 /* Socket is not locked. We are protected from async events
Will Newton70efce22008-07-16 20:13:43 -0700347 * by poll logic and correct handling of state changes
348 * made by other threads is impossible in any case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 */
350
351 mask = 0;
352 if (sk->sk_err)
353 mask = POLLERR;
354
355 /*
356 * POLLHUP is certainly not done right. But poll() doesn't
357 * have a notion of HUP in just one direction, and for a
358 * socket the read side is more interesting.
359 *
360 * Some poll() documentation says that POLLHUP is incompatible
361 * with the POLLOUT/POLLWR flags, so somebody should check this
362 * all. But careful, it tends to be safer to return too many
363 * bits than too few, and you can easily break real applications
364 * if you don't tell them that something has hung up!
365 *
366 * Check-me.
367 *
368 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
369 * our fs/select.c). It means that after we received EOF,
370 * poll always returns immediately, making impossible poll() on write()
371 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
372 * if and only if shutdown has been made in both directions.
373 * Actually, it is interesting to look how Solaris and DUX
Will Newton70efce22008-07-16 20:13:43 -0700374 * solve this dilemma. I would prefer, if POLLHUP were maskable,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 * then we could set it on SND_SHUTDOWN. BTW examples given
376 * in Stevens' books assume exactly this behaviour, it explains
Will Newton70efce22008-07-16 20:13:43 -0700377 * why POLLHUP is incompatible with POLLOUT. --ANK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 *
379 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
380 * blocking on fresh not-connected or disconnected socket. --ANK
381 */
382 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
383 mask |= POLLHUP;
384 if (sk->sk_shutdown & RCV_SHUTDOWN)
Davide Libenzif348d702006-03-25 03:07:39 -0800385 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387 /* Connected? */
388 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
389 /* Potential race condition. If read of tp below will
390 * escape above sk->sk_state, we can be illegally awaken
391 * in SYN_* states. */
392 if ((tp->rcv_nxt != tp->copied_seq) &&
393 (tp->urg_seq != tp->copied_seq ||
394 tp->rcv_nxt != tp->copied_seq + 1 ||
395 sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data))
396 mask |= POLLIN | POLLRDNORM;
397
398 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
399 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
400 mask |= POLLOUT | POLLWRNORM;
401 } else { /* send SIGIO later */
402 set_bit(SOCK_ASYNC_NOSPACE,
403 &sk->sk_socket->flags);
404 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
405
406 /* Race breaker. If space is freed after
407 * wspace test but before the flags are set,
408 * IO signal will be lost.
409 */
410 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
411 mask |= POLLOUT | POLLWRNORM;
412 }
413 }
414
415 if (tp->urg_data & TCP_URG_VALID)
416 mask |= POLLPRI;
417 }
418 return mask;
419}
420
421int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
422{
423 struct tcp_sock *tp = tcp_sk(sk);
424 int answ;
425
426 switch (cmd) {
427 case SIOCINQ:
428 if (sk->sk_state == TCP_LISTEN)
429 return -EINVAL;
430
431 lock_sock(sk);
432 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
433 answ = 0;
434 else if (sock_flag(sk, SOCK_URGINLINE) ||
435 !tp->urg_data ||
436 before(tp->urg_seq, tp->copied_seq) ||
437 !before(tp->urg_seq, tp->rcv_nxt)) {
438 answ = tp->rcv_nxt - tp->copied_seq;
439
440 /* Subtract 1, if FIN is in queue. */
441 if (answ && !skb_queue_empty(&sk->sk_receive_queue))
442 answ -=
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700443 tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 } else
445 answ = tp->urg_seq - tp->copied_seq;
446 release_sock(sk);
447 break;
448 case SIOCATMARK:
449 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
450 break;
451 case SIOCOUTQ:
452 if (sk->sk_state == TCP_LISTEN)
453 return -EINVAL;
454
455 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
456 answ = 0;
457 else
458 answ = tp->write_seq - tp->snd_una;
459 break;
460 default:
461 return -ENOIOCTLCMD;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700462 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463
464 return put_user(answ, (int __user *)arg);
465}
466
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
468{
469 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
470 tp->pushed_seq = tp->write_seq;
471}
472
473static inline int forced_push(struct tcp_sock *tp)
474{
475 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
476}
477
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700478static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700480 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo352d4802006-11-17 19:59:12 -0200481 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
482
483 skb->csum = 0;
484 tcb->seq = tcb->end_seq = tp->write_seq;
485 tcb->flags = TCPCB_FLAG_ACK;
486 tcb->sacked = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 skb_header_release(skb);
David S. Millerfe067e82007-03-07 12:12:44 -0800488 tcp_add_write_queue_tail(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800489 sk->sk_wmem_queued += skb->truesize;
490 sk_mem_charge(sk, skb->truesize);
David S. Miller89ebd192005-08-23 10:13:06 -0700491 if (tp->nonagle & TCP_NAGLE_PUSH)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900492 tp->nonagle &= ~TCP_NAGLE_PUSH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493}
494
495static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
496 struct sk_buff *skb)
497{
498 if (flags & MSG_OOB) {
499 tp->urg_mode = 1;
500 tp->snd_up = tp->write_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 }
502}
503
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700504static inline void tcp_push(struct sock *sk, int flags, int mss_now,
505 int nonagle)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700507 struct tcp_sock *tp = tcp_sk(sk);
508
David S. Millerfe067e82007-03-07 12:12:44 -0800509 if (tcp_send_head(sk)) {
510 struct sk_buff *skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 if (!(flags & MSG_MORE) || forced_push(tp))
512 tcp_mark_push(tp, skb);
513 tcp_mark_urg(tp, flags, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700514 __tcp_push_pending_frames(sk, mss_now,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
516 }
517}
518
Adrian Bunk6ff77512007-11-06 23:32:26 -0800519static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
520 unsigned int offset, size_t len)
Jens Axboe9c55e012007-11-06 23:30:13 -0800521{
522 struct tcp_splice_state *tss = rd_desc->arg.data;
523
524 return skb_splice_bits(skb, offset, tss->pipe, tss->len, tss->flags);
525}
526
527static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
528{
529 /* Store TCP splice context information in read_descriptor_t. */
530 read_descriptor_t rd_desc = {
531 .arg.data = tss,
532 };
533
534 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
535}
536
537/**
538 * tcp_splice_read - splice data from TCP socket to a pipe
539 * @sock: socket to splice from
540 * @ppos: position (not valid)
541 * @pipe: pipe to splice to
542 * @len: number of bytes to splice
543 * @flags: splice modifier flags
544 *
545 * Description:
546 * Will read pages from given socket and fill them into a pipe.
547 *
548 **/
549ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
550 struct pipe_inode_info *pipe, size_t len,
551 unsigned int flags)
552{
553 struct sock *sk = sock->sk;
554 struct tcp_splice_state tss = {
555 .pipe = pipe,
556 .len = len,
557 .flags = flags,
558 };
559 long timeo;
560 ssize_t spliced;
561 int ret;
562
563 /*
564 * We can't seek on a socket input
565 */
566 if (unlikely(*ppos))
567 return -ESPIPE;
568
569 ret = spliced = 0;
570
571 lock_sock(sk);
572
573 timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
574 while (tss.len) {
575 ret = __tcp_splice_read(sk, &tss);
576 if (ret < 0)
577 break;
578 else if (!ret) {
579 if (spliced)
580 break;
581 if (flags & SPLICE_F_NONBLOCK) {
582 ret = -EAGAIN;
583 break;
584 }
585 if (sock_flag(sk, SOCK_DONE))
586 break;
587 if (sk->sk_err) {
588 ret = sock_error(sk);
589 break;
590 }
591 if (sk->sk_shutdown & RCV_SHUTDOWN)
592 break;
593 if (sk->sk_state == TCP_CLOSE) {
594 /*
595 * This occurs when user tries to read
596 * from never connected socket.
597 */
598 if (!sock_flag(sk, SOCK_DONE))
599 ret = -ENOTCONN;
600 break;
601 }
602 if (!timeo) {
603 ret = -EAGAIN;
604 break;
605 }
606 sk_wait_data(sk, &timeo);
607 if (signal_pending(current)) {
608 ret = sock_intr_errno(timeo);
609 break;
610 }
611 continue;
612 }
613 tss.len -= ret;
614 spliced += ret;
615
616 release_sock(sk);
617 lock_sock(sk);
618
619 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
620 (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo ||
621 signal_pending(current))
622 break;
623 }
624
625 release_sock(sk);
626
627 if (spliced)
628 return spliced;
629
630 return ret;
631}
632
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100633struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100634{
635 struct sk_buff *skb;
636
637 /* The TCP header must be at least 32-bit aligned. */
638 size = ALIGN(size, 4);
639
640 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
641 if (skb) {
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800642 if (sk_wmem_schedule(sk, skb->truesize)) {
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100643 /*
644 * Make sure that we have exactly size bytes
645 * available to the caller, no more, no less.
646 */
647 skb_reserve(skb, skb_tailroom(skb) - size);
648 return skb;
649 }
650 __kfree_skb(skb);
651 } else {
Pavel Emelyanov5c52ba12008-07-16 20:28:10 -0700652 sk->sk_prot->enter_memory_pressure(sk);
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100653 sk_stream_moderate_sndbuf(sk);
654 }
655 return NULL;
656}
657
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
659 size_t psize, int flags)
660{
661 struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700662 int mss_now, size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 int err;
664 ssize_t copied;
665 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
666
667 /* Wait for a connection to finish. */
668 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
669 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
670 goto out_err;
671
672 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
673
674 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700675 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 copied = 0;
677
678 err = -EPIPE;
679 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
680 goto do_error;
681
682 while (psize > 0) {
David S. Millerfe067e82007-03-07 12:12:44 -0800683 struct sk_buff *skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 struct page *page = pages[poffset / PAGE_SIZE];
685 int copy, i, can_coalesce;
686 int offset = poffset % PAGE_SIZE;
687 int size = min_t(size_t, psize, PAGE_SIZE - offset);
688
David S. Millerfe067e82007-03-07 12:12:44 -0800689 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690new_segment:
691 if (!sk_stream_memory_free(sk))
692 goto wait_for_sndbuf;
693
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100694 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 if (!skb)
696 goto wait_for_memory;
697
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700698 skb_entail(sk, skb);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700699 copy = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 }
701
702 if (copy > size)
703 copy = size;
704
705 i = skb_shinfo(skb)->nr_frags;
706 can_coalesce = skb_can_coalesce(skb, i, page, offset);
707 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
708 tcp_mark_push(tp, skb);
709 goto new_segment;
710 }
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800711 if (!sk_wmem_schedule(sk, copy))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 goto wait_for_memory;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900713
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 if (can_coalesce) {
715 skb_shinfo(skb)->frags[i - 1].size += copy;
716 } else {
717 get_page(page);
718 skb_fill_page_desc(skb, i, page, offset, copy);
719 }
720
721 skb->len += copy;
722 skb->data_len += copy;
723 skb->truesize += copy;
724 sk->sk_wmem_queued += copy;
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800725 sk_mem_charge(sk, copy);
Patrick McHardy84fa7932006-08-29 16:44:56 -0700726 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 tp->write_seq += copy;
728 TCP_SKB_CB(skb)->end_seq += copy;
Herbert Xu79671682006-06-22 02:40:14 -0700729 skb_shinfo(skb)->gso_segs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730
731 if (!copied)
732 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
733
734 copied += copy;
735 poffset += copy;
736 if (!(psize -= copy))
737 goto out;
738
Herbert Xu69d15062008-03-22 15:47:05 -0700739 if (skb->len < size_goal || (flags & MSG_OOB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 continue;
741
742 if (forced_push(tp)) {
743 tcp_mark_push(tp, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700744 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
David S. Millerfe067e82007-03-07 12:12:44 -0800745 } else if (skb == tcp_send_head(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 tcp_push_one(sk, mss_now);
747 continue;
748
749wait_for_sndbuf:
750 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
751wait_for_memory:
752 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700753 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754
755 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
756 goto do_error;
757
758 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700759 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 }
761
762out:
763 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700764 tcp_push(sk, flags, mss_now, tp->nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 return copied;
766
767do_error:
768 if (copied)
769 goto out;
770out_err:
771 return sk_stream_error(sk, flags, err);
772}
773
774ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
775 size_t size, int flags)
776{
777 ssize_t res;
778 struct sock *sk = sock->sk;
779
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 if (!(sk->sk_route_caps & NETIF_F_SG) ||
Herbert Xu8648b302006-06-17 22:06:05 -0700781 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 return sock_no_sendpage(sock, page, offset, size, flags);
783
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 lock_sock(sk);
785 TCP_CHECK_TIMER(sk);
786 res = do_tcp_sendpages(sk, &page, offset, size, flags);
787 TCP_CHECK_TIMER(sk);
788 release_sock(sk);
789 return res;
790}
791
792#define TCP_PAGE(sk) (sk->sk_sndmsg_page)
793#define TCP_OFF(sk) (sk->sk_sndmsg_off)
794
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700795static inline int select_size(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700797 struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700798 int tmp = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799
David S. Millerb4e26f52005-07-05 15:20:27 -0700800 if (sk->sk_route_caps & NETIF_F_SG) {
Herbert Xubcd76112006-06-30 13:36:35 -0700801 if (sk_can_gso(sk))
David S. Millerb4e26f52005-07-05 15:20:27 -0700802 tmp = 0;
803 else {
804 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
805
806 if (tmp >= pgbreak &&
807 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
808 tmp = pgbreak;
809 }
810 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 return tmp;
813}
814
David S. Miller3516ffb2007-08-02 19:23:56 -0700815int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 size_t size)
817{
David S. Miller3516ffb2007-08-02 19:23:56 -0700818 struct sock *sk = sock->sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 struct iovec *iov;
820 struct tcp_sock *tp = tcp_sk(sk);
821 struct sk_buff *skb;
822 int iovlen, flags;
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700823 int mss_now, size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824 int err, copied;
825 long timeo;
826
827 lock_sock(sk);
828 TCP_CHECK_TIMER(sk);
829
830 flags = msg->msg_flags;
831 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
832
833 /* Wait for a connection to finish. */
834 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
835 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
836 goto out_err;
837
838 /* This should be in poll */
839 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
840
841 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700842 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843
844 /* Ok commence sending. */
845 iovlen = msg->msg_iovlen;
846 iov = msg->msg_iov;
847 copied = 0;
848
849 err = -EPIPE;
850 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
851 goto do_error;
852
853 while (--iovlen >= 0) {
854 int seglen = iov->iov_len;
855 unsigned char __user *from = iov->iov_base;
856
857 iov++;
858
859 while (seglen > 0) {
860 int copy;
861
David S. Millerfe067e82007-03-07 12:12:44 -0800862 skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863
David S. Millerfe067e82007-03-07 12:12:44 -0800864 if (!tcp_send_head(sk) ||
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700865 (copy = size_goal - skb->len) <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866
867new_segment:
868 /* Allocate new segment. If the interface is SG,
869 * allocate skb fitting to single page.
870 */
871 if (!sk_stream_memory_free(sk))
872 goto wait_for_sndbuf;
873
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100874 skb = sk_stream_alloc_skb(sk, select_size(sk),
875 sk->sk_allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 if (!skb)
877 goto wait_for_memory;
878
879 /*
880 * Check whether we can use HW checksum.
881 */
Herbert Xu8648b302006-06-17 22:06:05 -0700882 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
Patrick McHardy84fa7932006-08-29 16:44:56 -0700883 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700885 skb_entail(sk, skb);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700886 copy = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 }
888
889 /* Try to append data to the end of skb. */
890 if (copy > seglen)
891 copy = seglen;
892
893 /* Where to copy to? */
894 if (skb_tailroom(skb) > 0) {
895 /* We have some space in skb head. Superb! */
896 if (copy > skb_tailroom(skb))
897 copy = skb_tailroom(skb);
898 if ((err = skb_add_data(skb, from, copy)) != 0)
899 goto do_fault;
900 } else {
901 int merge = 0;
902 int i = skb_shinfo(skb)->nr_frags;
903 struct page *page = TCP_PAGE(sk);
904 int off = TCP_OFF(sk);
905
906 if (skb_can_coalesce(skb, i, page, off) &&
907 off != PAGE_SIZE) {
908 /* We can extend the last page
909 * fragment. */
910 merge = 1;
911 } else if (i == MAX_SKB_FRAGS ||
912 (!i &&
913 !(sk->sk_route_caps & NETIF_F_SG))) {
914 /* Need to add new fragment and cannot
915 * do this because interface is non-SG,
916 * or because all the page slots are
917 * busy. */
918 tcp_mark_push(tp, skb);
919 goto new_segment;
920 } else if (page) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 if (off == PAGE_SIZE) {
922 put_page(page);
923 TCP_PAGE(sk) = page = NULL;
Herbert Xufb5f5e62005-09-05 18:55:48 -0700924 off = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 }
Herbert Xuef015782005-09-01 17:48:59 -0700926 } else
Herbert Xufb5f5e62005-09-05 18:55:48 -0700927 off = 0;
Herbert Xuef015782005-09-01 17:48:59 -0700928
929 if (copy > PAGE_SIZE - off)
930 copy = PAGE_SIZE - off;
931
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800932 if (!sk_wmem_schedule(sk, copy))
Herbert Xuef015782005-09-01 17:48:59 -0700933 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934
935 if (!page) {
936 /* Allocate new cache page. */
937 if (!(page = sk_stream_alloc_page(sk)))
938 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 }
940
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 /* Time to copy data. We are close to
942 * the end! */
943 err = skb_copy_to_page(sk, from, skb, page,
944 off, copy);
945 if (err) {
946 /* If this page was new, give it to the
947 * socket so it does not get leaked.
948 */
949 if (!TCP_PAGE(sk)) {
950 TCP_PAGE(sk) = page;
951 TCP_OFF(sk) = 0;
952 }
953 goto do_error;
954 }
955
956 /* Update the skb. */
957 if (merge) {
958 skb_shinfo(skb)->frags[i - 1].size +=
959 copy;
960 } else {
961 skb_fill_page_desc(skb, i, page, off, copy);
962 if (TCP_PAGE(sk)) {
963 get_page(page);
964 } else if (off + copy < PAGE_SIZE) {
965 get_page(page);
966 TCP_PAGE(sk) = page;
967 }
968 }
969
970 TCP_OFF(sk) = off + copy;
971 }
972
973 if (!copied)
974 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
975
976 tp->write_seq += copy;
977 TCP_SKB_CB(skb)->end_seq += copy;
Herbert Xu79671682006-06-22 02:40:14 -0700978 skb_shinfo(skb)->gso_segs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979
980 from += copy;
981 copied += copy;
982 if ((seglen -= copy) == 0 && iovlen == 0)
983 goto out;
984
Herbert Xu69d15062008-03-22 15:47:05 -0700985 if (skb->len < size_goal || (flags & MSG_OOB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 continue;
987
988 if (forced_push(tp)) {
989 tcp_mark_push(tp, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700990 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
David S. Millerfe067e82007-03-07 12:12:44 -0800991 } else if (skb == tcp_send_head(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 tcp_push_one(sk, mss_now);
993 continue;
994
995wait_for_sndbuf:
996 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
997wait_for_memory:
998 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700999 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000
1001 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1002 goto do_error;
1003
1004 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -07001005 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 }
1007 }
1008
1009out:
1010 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001011 tcp_push(sk, flags, mss_now, tp->nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 TCP_CHECK_TIMER(sk);
1013 release_sock(sk);
1014 return copied;
1015
1016do_fault:
1017 if (!skb->len) {
David S. Millerfe067e82007-03-07 12:12:44 -08001018 tcp_unlink_write_queue(skb, sk);
1019 /* It is the one place in all of TCP, except connection
1020 * reset, where we can be unlinking the send_head.
1021 */
1022 tcp_check_send_head(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001023 sk_wmem_free_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 }
1025
1026do_error:
1027 if (copied)
1028 goto out;
1029out_err:
1030 err = sk_stream_error(sk, flags, err);
1031 TCP_CHECK_TIMER(sk);
1032 release_sock(sk);
1033 return err;
1034}
1035
1036/*
1037 * Handle reading urgent data. BSD has very simple semantics for
1038 * this, no blocking and very strange errors 8)
1039 */
1040
1041static int tcp_recv_urg(struct sock *sk, long timeo,
1042 struct msghdr *msg, int len, int flags,
1043 int *addr_len)
1044{
1045 struct tcp_sock *tp = tcp_sk(sk);
1046
1047 /* No URG data to read. */
1048 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1049 tp->urg_data == TCP_URG_READ)
1050 return -EINVAL; /* Yes this is right ! */
1051
1052 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1053 return -ENOTCONN;
1054
1055 if (tp->urg_data & TCP_URG_VALID) {
1056 int err = 0;
1057 char c = tp->urg_data;
1058
1059 if (!(flags & MSG_PEEK))
1060 tp->urg_data = TCP_URG_READ;
1061
1062 /* Read urgent data. */
1063 msg->msg_flags |= MSG_OOB;
1064
1065 if (len > 0) {
1066 if (!(flags & MSG_TRUNC))
1067 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1068 len = 1;
1069 } else
1070 msg->msg_flags |= MSG_TRUNC;
1071
1072 return err ? -EFAULT : len;
1073 }
1074
1075 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1076 return 0;
1077
1078 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1079 * the available implementations agree in this case:
1080 * this call should never block, independent of the
1081 * blocking state of the socket.
1082 * Mike <pall@rz.uni-karlsruhe.de>
1083 */
1084 return -EAGAIN;
1085}
1086
1087/* Clean up the receive buffer for full frames taken by the user,
1088 * then send an ACK if necessary. COPIED is the number of bytes
1089 * tcp_recvmsg has given to the user so far, it speeds up the
1090 * calculation of whether or not we must ACK for the sake of
1091 * a window update.
1092 */
Chris Leech0e4b4992006-05-23 18:00:16 -07001093void tcp_cleanup_rbuf(struct sock *sk, int copied)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094{
1095 struct tcp_sock *tp = tcp_sk(sk);
1096 int time_to_ack = 0;
1097
1098#if TCP_DEBUG
1099 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1100
1101 BUG_TRAP(!skb || before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
1102#endif
1103
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001104 if (inet_csk_ack_scheduled(sk)) {
1105 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 /* Delayed ACKs frequently hit locked sockets during bulk
1107 * receive. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001108 if (icsk->icsk_ack.blocked ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109 /* Once-per-two-segments ACK was not sent by tcp_input.c */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001110 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 /*
1112 * If this read emptied read buffer, we send ACK, if
1113 * connection is not bidirectional, user drained
1114 * receive buffer and there was a small segment
1115 * in queue.
1116 */
Alexey Kuznetsov1ef96962006-09-19 12:52:50 -07001117 (copied > 0 &&
1118 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1119 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1120 !icsk->icsk_ack.pingpong)) &&
1121 !atomic_read(&sk->sk_rmem_alloc)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 time_to_ack = 1;
1123 }
1124
1125 /* We send an ACK if we can now advertise a non-zero window
1126 * which has been raised "significantly".
1127 *
1128 * Even if window raised up to infinity, do not send window open ACK
1129 * in states, where we will not receive more. It is useless.
1130 */
1131 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1132 __u32 rcv_window_now = tcp_receive_window(tp);
1133
1134 /* Optimize, __tcp_select_window() is not cheap. */
1135 if (2*rcv_window_now <= tp->window_clamp) {
1136 __u32 new_window = __tcp_select_window(sk);
1137
1138 /* Send ACK now, if this read freed lots of space
1139 * in our buffer. Certainly, new_window is new window.
1140 * We can advertise it now, if it is not less than current one.
1141 * "Lots" means "at least twice" here.
1142 */
1143 if (new_window && new_window >= 2 * rcv_window_now)
1144 time_to_ack = 1;
1145 }
1146 }
1147 if (time_to_ack)
1148 tcp_send_ack(sk);
1149}
1150
1151static void tcp_prequeue_process(struct sock *sk)
1152{
1153 struct sk_buff *skb;
1154 struct tcp_sock *tp = tcp_sk(sk);
1155
David S. Millerb03efcf2005-07-08 14:57:23 -07001156 NET_INC_STATS_USER(LINUX_MIB_TCPPREQUEUED);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157
1158 /* RX process wants to run with disabled BHs, though it is not
1159 * necessary */
1160 local_bh_disable();
1161 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1162 sk->sk_backlog_rcv(sk, skb);
1163 local_bh_enable();
1164
1165 /* Clear memory counter. */
1166 tp->ucopy.memory = 0;
1167}
1168
1169static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1170{
1171 struct sk_buff *skb;
1172 u32 offset;
1173
1174 skb_queue_walk(&sk->sk_receive_queue, skb) {
1175 offset = seq - TCP_SKB_CB(skb)->seq;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001176 if (tcp_hdr(skb)->syn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 offset--;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001178 if (offset < skb->len || tcp_hdr(skb)->fin) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 *off = offset;
1180 return skb;
1181 }
1182 }
1183 return NULL;
1184}
1185
1186/*
1187 * This routine provides an alternative to tcp_recvmsg() for routines
1188 * that would like to handle copying from skbuffs directly in 'sendfile'
1189 * fashion.
1190 * Note:
1191 * - It is assumed that the socket was locked by the caller.
1192 * - The routine does not block.
1193 * - At present, there is no support for reading OOB data
1194 * or for 'peeking' the socket using this routine
1195 * (although both would be easy to implement).
1196 */
1197int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1198 sk_read_actor_t recv_actor)
1199{
1200 struct sk_buff *skb;
1201 struct tcp_sock *tp = tcp_sk(sk);
1202 u32 seq = tp->copied_seq;
1203 u32 offset;
1204 int copied = 0;
1205
1206 if (sk->sk_state == TCP_LISTEN)
1207 return -ENOTCONN;
1208 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1209 if (offset < skb->len) {
Octavian Purdila374e7b52008-07-03 03:31:21 -07001210 int used;
1211 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212
1213 len = skb->len - offset;
1214 /* Stop reading if we hit a patch of urgent data */
1215 if (tp->urg_data) {
1216 u32 urg_offset = tp->urg_seq - seq;
1217 if (urg_offset < len)
1218 len = urg_offset;
1219 if (!len)
1220 break;
1221 }
1222 used = recv_actor(desc, skb, offset, len);
Jens Axboeddb61a52007-06-23 23:07:50 -07001223 if (used < 0) {
1224 if (!copied)
1225 copied = used;
1226 break;
1227 } else if (used <= len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 seq += used;
1229 copied += used;
1230 offset += used;
1231 }
Octavian Purdila293ad602008-06-04 15:45:58 -07001232 /*
1233 * If recv_actor drops the lock (e.g. TCP splice
1234 * receive) the skb pointer might be invalid when
1235 * getting here: tcp_collapse might have deleted it
1236 * while aggregating skbs from the socket queue.
1237 */
1238 skb = tcp_recv_skb(sk, seq-1, &offset);
1239 if (!skb || (offset+1 != skb->len))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 break;
1241 }
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001242 if (tcp_hdr(skb)->fin) {
Chris Leech624d1162006-05-23 18:01:28 -07001243 sk_eat_skb(sk, skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 ++seq;
1245 break;
1246 }
Chris Leech624d1162006-05-23 18:01:28 -07001247 sk_eat_skb(sk, skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248 if (!desc->count)
1249 break;
1250 }
1251 tp->copied_seq = seq;
1252
1253 tcp_rcv_space_adjust(sk);
1254
1255 /* Clean up data we have read: This will do ACK frames. */
Jens Axboeddb61a52007-06-23 23:07:50 -07001256 if (copied > 0)
Chris Leech0e4b4992006-05-23 18:00:16 -07001257 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 return copied;
1259}
1260
1261/*
1262 * This routine copies from a sock struct into the user buffer.
1263 *
1264 * Technical note: in 2.3 we work on _locked_ socket, so that
1265 * tricks with *seq access order and skb->users are not required.
1266 * Probably, code can be easily improved even more.
1267 */
1268
1269int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1270 size_t len, int nonblock, int flags, int *addr_len)
1271{
1272 struct tcp_sock *tp = tcp_sk(sk);
1273 int copied = 0;
1274 u32 peek_seq;
1275 u32 *seq;
1276 unsigned long used;
1277 int err;
1278 int target; /* Read at least this many bytes */
1279 long timeo;
1280 struct task_struct *user_recv = NULL;
Chris Leech1a2449a2006-05-23 18:05:53 -07001281 int copied_early = 0;
Chris Leech2b1244a2007-03-08 09:57:36 -08001282 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283
1284 lock_sock(sk);
1285
1286 TCP_CHECK_TIMER(sk);
1287
1288 err = -ENOTCONN;
1289 if (sk->sk_state == TCP_LISTEN)
1290 goto out;
1291
1292 timeo = sock_rcvtimeo(sk, nonblock);
1293
1294 /* Urgent data needs to be handled specially. */
1295 if (flags & MSG_OOB)
1296 goto recv_urg;
1297
1298 seq = &tp->copied_seq;
1299 if (flags & MSG_PEEK) {
1300 peek_seq = tp->copied_seq;
1301 seq = &peek_seq;
1302 }
1303
1304 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1305
Chris Leech1a2449a2006-05-23 18:05:53 -07001306#ifdef CONFIG_NET_DMA
1307 tp->ucopy.dma_chan = NULL;
1308 preempt_disable();
Chris Leech2b1244a2007-03-08 09:57:36 -08001309 skb = skb_peek_tail(&sk->sk_receive_queue);
Andrew Mortone00c5d82007-03-08 09:57:36 -08001310 {
1311 int available = 0;
1312
1313 if (skb)
1314 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1315 if ((available < target) &&
1316 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1317 !sysctl_tcp_low_latency &&
1318 __get_cpu_var(softnet_data).net_dma) {
1319 preempt_enable_no_resched();
1320 tp->ucopy.pinned_list =
1321 dma_pin_iovec_pages(msg->msg_iov, len);
1322 } else {
1323 preempt_enable_no_resched();
1324 }
1325 }
Chris Leech1a2449a2006-05-23 18:05:53 -07001326#endif
1327
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 u32 offset;
1330
1331 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1332 if (tp->urg_data && tp->urg_seq == *seq) {
1333 if (copied)
1334 break;
1335 if (signal_pending(current)) {
1336 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1337 break;
1338 }
1339 }
1340
1341 /* Next get a buffer. */
1342
1343 skb = skb_peek(&sk->sk_receive_queue);
1344 do {
1345 if (!skb)
1346 break;
1347
1348 /* Now that we have two receive queues this
1349 * shouldn't happen.
1350 */
1351 if (before(*seq, TCP_SKB_CB(skb)->seq)) {
1352 printk(KERN_INFO "recvmsg bug: copied %X "
1353 "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
1354 break;
1355 }
1356 offset = *seq - TCP_SKB_CB(skb)->seq;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001357 if (tcp_hdr(skb)->syn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001358 offset--;
1359 if (offset < skb->len)
1360 goto found_ok_skb;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001361 if (tcp_hdr(skb)->fin)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 goto found_fin_ok;
1363 BUG_TRAP(flags & MSG_PEEK);
1364 skb = skb->next;
1365 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
1366
1367 /* Well, if we have backlog, try to process it now yet. */
1368
1369 if (copied >= target && !sk->sk_backlog.tail)
1370 break;
1371
1372 if (copied) {
1373 if (sk->sk_err ||
1374 sk->sk_state == TCP_CLOSE ||
1375 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1376 !timeo ||
1377 signal_pending(current) ||
1378 (flags & MSG_PEEK))
1379 break;
1380 } else {
1381 if (sock_flag(sk, SOCK_DONE))
1382 break;
1383
1384 if (sk->sk_err) {
1385 copied = sock_error(sk);
1386 break;
1387 }
1388
1389 if (sk->sk_shutdown & RCV_SHUTDOWN)
1390 break;
1391
1392 if (sk->sk_state == TCP_CLOSE) {
1393 if (!sock_flag(sk, SOCK_DONE)) {
1394 /* This occurs when user tries to read
1395 * from never connected socket.
1396 */
1397 copied = -ENOTCONN;
1398 break;
1399 }
1400 break;
1401 }
1402
1403 if (!timeo) {
1404 copied = -EAGAIN;
1405 break;
1406 }
1407
1408 if (signal_pending(current)) {
1409 copied = sock_intr_errno(timeo);
1410 break;
1411 }
1412 }
1413
Chris Leech0e4b4992006-05-23 18:00:16 -07001414 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415
David S. Miller7df55122005-06-18 23:01:10 -07001416 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417 /* Install new reader */
1418 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1419 user_recv = current;
1420 tp->ucopy.task = user_recv;
1421 tp->ucopy.iov = msg->msg_iov;
1422 }
1423
1424 tp->ucopy.len = len;
1425
1426 BUG_TRAP(tp->copied_seq == tp->rcv_nxt ||
1427 (flags & (MSG_PEEK | MSG_TRUNC)));
1428
1429 /* Ugly... If prequeue is not empty, we have to
1430 * process it before releasing socket, otherwise
1431 * order will be broken at second iteration.
1432 * More elegant solution is required!!!
1433 *
1434 * Look: we have the following (pseudo)queues:
1435 *
1436 * 1. packets in flight
1437 * 2. backlog
1438 * 3. prequeue
1439 * 4. receive_queue
1440 *
1441 * Each queue can be processed only if the next ones
1442 * are empty. At this point we have empty receive_queue.
1443 * But prequeue _can_ be not empty after 2nd iteration,
1444 * when we jumped to start of loop because backlog
1445 * processing added something to receive_queue.
1446 * We cannot release_sock(), because backlog contains
1447 * packets arrived _after_ prequeued ones.
1448 *
1449 * Shortly, algorithm is clear --- to process all
1450 * the queues in order. We could make it more directly,
1451 * requeueing packets from backlog to prequeue, if
1452 * is not empty. It is more elegant, but eats cycles,
1453 * unfortunately.
1454 */
David S. Millerb03efcf2005-07-08 14:57:23 -07001455 if (!skb_queue_empty(&tp->ucopy.prequeue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456 goto do_prequeue;
1457
1458 /* __ Set realtime policy in scheduler __ */
1459 }
1460
1461 if (copied >= target) {
1462 /* Do not sleep, just process backlog. */
1463 release_sock(sk);
1464 lock_sock(sk);
1465 } else
1466 sk_wait_data(sk, &timeo);
1467
Chris Leech1a2449a2006-05-23 18:05:53 -07001468#ifdef CONFIG_NET_DMA
1469 tp->ucopy.wakeup = 0;
1470#endif
1471
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472 if (user_recv) {
1473 int chunk;
1474
1475 /* __ Restore normal policy in scheduler __ */
1476
1477 if ((chunk = len - tp->ucopy.len) != 0) {
1478 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1479 len -= chunk;
1480 copied += chunk;
1481 }
1482
1483 if (tp->rcv_nxt == tp->copied_seq &&
David S. Millerb03efcf2005-07-08 14:57:23 -07001484 !skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485do_prequeue:
1486 tcp_prequeue_process(sk);
1487
1488 if ((chunk = len - tp->ucopy.len) != 0) {
1489 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1490 len -= chunk;
1491 copied += chunk;
1492 }
1493 }
1494 }
1495 if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
1496 if (net_ratelimit())
1497 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -07001498 current->comm, task_pid_nr(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 peek_seq = tp->copied_seq;
1500 }
1501 continue;
1502
1503 found_ok_skb:
1504 /* Ok so how much can we use? */
1505 used = skb->len - offset;
1506 if (len < used)
1507 used = len;
1508
1509 /* Do we have urgent data here? */
1510 if (tp->urg_data) {
1511 u32 urg_offset = tp->urg_seq - *seq;
1512 if (urg_offset < used) {
1513 if (!urg_offset) {
1514 if (!sock_flag(sk, SOCK_URGINLINE)) {
1515 ++*seq;
1516 offset++;
1517 used--;
1518 if (!used)
1519 goto skip_copy;
1520 }
1521 } else
1522 used = urg_offset;
1523 }
1524 }
1525
1526 if (!(flags & MSG_TRUNC)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001527#ifdef CONFIG_NET_DMA
1528 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1529 tp->ucopy.dma_chan = get_softnet_dma();
1530
1531 if (tp->ucopy.dma_chan) {
1532 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1533 tp->ucopy.dma_chan, skb, offset,
1534 msg->msg_iov, used,
1535 tp->ucopy.pinned_list);
1536
1537 if (tp->ucopy.dma_cookie < 0) {
1538
1539 printk(KERN_ALERT "dma_cookie < 0\n");
1540
1541 /* Exception. Bailout! */
1542 if (!copied)
1543 copied = -EFAULT;
1544 break;
1545 }
1546 if ((offset + used) == skb->len)
1547 copied_early = 1;
1548
1549 } else
1550#endif
1551 {
1552 err = skb_copy_datagram_iovec(skb, offset,
1553 msg->msg_iov, used);
1554 if (err) {
1555 /* Exception. Bailout! */
1556 if (!copied)
1557 copied = -EFAULT;
1558 break;
1559 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560 }
1561 }
1562
1563 *seq += used;
1564 copied += used;
1565 len -= used;
1566
1567 tcp_rcv_space_adjust(sk);
1568
1569skip_copy:
1570 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1571 tp->urg_data = 0;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001572 tcp_fast_path_check(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573 }
1574 if (used + offset < skb->len)
1575 continue;
1576
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001577 if (tcp_hdr(skb)->fin)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 goto found_fin_ok;
Chris Leech1a2449a2006-05-23 18:05:53 -07001579 if (!(flags & MSG_PEEK)) {
1580 sk_eat_skb(sk, skb, copied_early);
1581 copied_early = 0;
1582 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 continue;
1584
1585 found_fin_ok:
1586 /* Process the FIN. */
1587 ++*seq;
Chris Leech1a2449a2006-05-23 18:05:53 -07001588 if (!(flags & MSG_PEEK)) {
1589 sk_eat_skb(sk, skb, copied_early);
1590 copied_early = 0;
1591 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001592 break;
1593 } while (len > 0);
1594
1595 if (user_recv) {
David S. Millerb03efcf2005-07-08 14:57:23 -07001596 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 int chunk;
1598
1599 tp->ucopy.len = copied > 0 ? len : 0;
1600
1601 tcp_prequeue_process(sk);
1602
1603 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1604 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1605 len -= chunk;
1606 copied += chunk;
1607 }
1608 }
1609
1610 tp->ucopy.task = NULL;
1611 tp->ucopy.len = 0;
1612 }
1613
Chris Leech1a2449a2006-05-23 18:05:53 -07001614#ifdef CONFIG_NET_DMA
1615 if (tp->ucopy.dma_chan) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001616 dma_cookie_t done, used;
1617
1618 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1619
1620 while (dma_async_memcpy_complete(tp->ucopy.dma_chan,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001621 tp->ucopy.dma_cookie, &done,
1622 &used) == DMA_IN_PROGRESS) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001623 /* do partial cleanup of sk_async_wait_queue */
1624 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1625 (dma_async_is_complete(skb->dma_cookie, done,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001626 used) == DMA_SUCCESS)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001627 __skb_dequeue(&sk->sk_async_wait_queue);
1628 kfree_skb(skb);
1629 }
1630 }
1631
1632 /* Safe to free early-copied skbs now */
1633 __skb_queue_purge(&sk->sk_async_wait_queue);
1634 dma_chan_put(tp->ucopy.dma_chan);
1635 tp->ucopy.dma_chan = NULL;
1636 }
1637 if (tp->ucopy.pinned_list) {
1638 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1639 tp->ucopy.pinned_list = NULL;
1640 }
1641#endif
1642
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 /* According to UNIX98, msg_name/msg_namelen are ignored
1644 * on connected socket. I was just happy when found this 8) --ANK
1645 */
1646
1647 /* Clean up data we have read: This will do ACK frames. */
Chris Leech0e4b4992006-05-23 18:00:16 -07001648 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649
1650 TCP_CHECK_TIMER(sk);
1651 release_sock(sk);
1652 return copied;
1653
1654out:
1655 TCP_CHECK_TIMER(sk);
1656 release_sock(sk);
1657 return err;
1658
1659recv_urg:
1660 err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len);
1661 goto out;
1662}
1663
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001664void tcp_set_state(struct sock *sk, int state)
1665{
1666 int oldstate = sk->sk_state;
1667
1668 switch (state) {
1669 case TCP_ESTABLISHED:
1670 if (oldstate != TCP_ESTABLISHED)
Pavel Emelyanov81cc8a72008-07-16 20:22:04 -07001671 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001672 break;
1673
1674 case TCP_CLOSE:
1675 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
Pavel Emelyanov81cc8a72008-07-16 20:22:04 -07001676 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001677
1678 sk->sk_prot->unhash(sk);
1679 if (inet_csk(sk)->icsk_bind_hash &&
1680 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001681 inet_put_port(sk);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001682 /* fall through */
1683 default:
1684 if (oldstate==TCP_ESTABLISHED)
Pavel Emelyanov74688e42008-07-16 20:22:46 -07001685 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001686 }
1687
1688 /* Change state AFTER socket is unhashed to avoid closed
1689 * socket sitting in hash tables.
1690 */
1691 sk->sk_state = state;
1692
1693#ifdef STATE_TRACE
1694 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
1695#endif
1696}
1697EXPORT_SYMBOL_GPL(tcp_set_state);
1698
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699/*
1700 * State processing on a close. This implements the state shift for
1701 * sending our FIN frame. Note that we only send a FIN for some
1702 * states. A shutdown() may have already sent the FIN, or we may be
1703 * closed.
1704 */
1705
Arjan van de Ven9b5b5cf2005-11-29 16:21:38 -08001706static const unsigned char new_state[16] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707 /* current state: new state: action: */
1708 /* (Invalid) */ TCP_CLOSE,
1709 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1710 /* TCP_SYN_SENT */ TCP_CLOSE,
1711 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1712 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1713 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1714 /* TCP_TIME_WAIT */ TCP_CLOSE,
1715 /* TCP_CLOSE */ TCP_CLOSE,
1716 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1717 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1718 /* TCP_LISTEN */ TCP_CLOSE,
1719 /* TCP_CLOSING */ TCP_CLOSING,
1720};
1721
1722static int tcp_close_state(struct sock *sk)
1723{
1724 int next = (int)new_state[sk->sk_state];
1725 int ns = next & TCP_STATE_MASK;
1726
1727 tcp_set_state(sk, ns);
1728
1729 return next & TCP_ACTION_FIN;
1730}
1731
1732/*
1733 * Shutdown the sending side of a connection. Much like close except
Satoru SATOH1f29b052008-04-21 02:27:58 -07001734 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 */
1736
1737void tcp_shutdown(struct sock *sk, int how)
1738{
1739 /* We need to grab some memory, and put together a FIN,
1740 * and then put it into the queue to be sent.
1741 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1742 */
1743 if (!(how & SEND_SHUTDOWN))
1744 return;
1745
1746 /* If we've already sent a FIN, or it's a closed state, skip this. */
1747 if ((1 << sk->sk_state) &
1748 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1749 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1750 /* Clear out any half completed packets. FIN if needed. */
1751 if (tcp_close_state(sk))
1752 tcp_send_fin(sk);
1753 }
1754}
1755
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756void tcp_close(struct sock *sk, long timeout)
1757{
1758 struct sk_buff *skb;
1759 int data_was_unread = 0;
Herbert Xu75c2d9072006-05-03 23:31:35 -07001760 int state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001761
1762 lock_sock(sk);
1763 sk->sk_shutdown = SHUTDOWN_MASK;
1764
1765 if (sk->sk_state == TCP_LISTEN) {
1766 tcp_set_state(sk, TCP_CLOSE);
1767
1768 /* Special case. */
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001769 inet_csk_listen_stop(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770
1771 goto adjudge_to_death;
1772 }
1773
1774 /* We need to flush the recv. buffs. We do this only on the
1775 * descriptor close, not protocol-sourced closes, because the
1776 * reader process may not have drained the data yet!
1777 */
1778 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1779 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001780 tcp_hdr(skb)->fin;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781 data_was_unread += len;
1782 __kfree_skb(skb);
1783 }
1784
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001785 sk_mem_reclaim(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786
Gerrit Renker65bb7232007-04-28 21:21:46 -07001787 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1788 * data was lost. To witness the awful effects of the old behavior of
1789 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1790 * GET in an FTP client, suspend the process, wait for the client to
1791 * advertise a zero window, then kill -9 the FTP client, wheee...
1792 * Note: timeout is always zero in such a case.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793 */
1794 if (data_was_unread) {
1795 /* Unread data was tossed, zap the connection. */
1796 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONCLOSE);
1797 tcp_set_state(sk, TCP_CLOSE);
1798 tcp_send_active_reset(sk, GFP_KERNEL);
1799 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1800 /* Check zero linger _after_ checking for unread data. */
1801 sk->sk_prot->disconnect(sk, 0);
1802 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONDATA);
1803 } else if (tcp_close_state(sk)) {
1804 /* We FIN if the application ate all the data before
1805 * zapping the connection.
1806 */
1807
1808 /* RED-PEN. Formally speaking, we have broken TCP state
1809 * machine. State transitions:
1810 *
1811 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1812 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1813 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1814 *
1815 * are legal only when FIN has been sent (i.e. in window),
1816 * rather than queued out of window. Purists blame.
1817 *
1818 * F.e. "RFC state" is ESTABLISHED,
1819 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1820 *
1821 * The visible declinations are that sometimes
1822 * we enter time-wait state, when it is not required really
1823 * (harmless), do not send active resets, when they are
1824 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1825 * they look as CLOSING or LAST_ACK for Linux)
1826 * Probably, I missed some more holelets.
1827 * --ANK
1828 */
1829 tcp_send_fin(sk);
1830 }
1831
1832 sk_stream_wait_close(sk, timeout);
1833
1834adjudge_to_death:
Herbert Xu75c2d9072006-05-03 23:31:35 -07001835 state = sk->sk_state;
1836 sock_hold(sk);
1837 sock_orphan(sk);
1838 atomic_inc(sk->sk_prot->orphan_count);
1839
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840 /* It is the last release_sock in its life. It will remove backlog. */
1841 release_sock(sk);
1842
1843
1844 /* Now socket is owned by kernel and we acquire BH lock
1845 to finish close. No need to check for user refs.
1846 */
1847 local_bh_disable();
1848 bh_lock_sock(sk);
1849 BUG_TRAP(!sock_owned_by_user(sk));
1850
Herbert Xu75c2d9072006-05-03 23:31:35 -07001851 /* Have we already been destroyed by a softirq or backlog? */
1852 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1853 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001854
1855 /* This is a (useful) BSD violating of the RFC. There is a
1856 * problem with TCP as specified in that the other end could
1857 * keep a socket open forever with no application left this end.
1858 * We use a 3 minute timeout (about the same as BSD) then kill
1859 * our end. If they send after that then tough - BUT: long enough
1860 * that we won't make the old 4*rto = almost no time - whoops
1861 * reset mistake.
1862 *
1863 * Nope, it was not mistake. It is really desired behaviour
1864 * f.e. on http servers, when such sockets are useless, but
1865 * consume significant resources. Let's do it with special
1866 * linger2 option. --ANK
1867 */
1868
1869 if (sk->sk_state == TCP_FIN_WAIT2) {
1870 struct tcp_sock *tp = tcp_sk(sk);
1871 if (tp->linger2 < 0) {
1872 tcp_set_state(sk, TCP_CLOSE);
1873 tcp_send_active_reset(sk, GFP_ATOMIC);
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001874 NET_INC_STATS_BH(sock_net(sk),
1875 LINUX_MIB_TCPABORTONLINGER);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001877 const int tmo = tcp_fin_time(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878
1879 if (tmo > TCP_TIMEWAIT_LEN) {
David S. Miller52499af2006-07-31 22:32:09 -07001880 inet_csk_reset_keepalive_timer(sk,
1881 tmo - TCP_TIMEWAIT_LEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001882 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
1884 goto out;
1885 }
1886 }
1887 }
1888 if (sk->sk_state != TCP_CLOSE) {
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001889 sk_mem_reclaim(sk);
Pavel Emelianove4fd5da2007-05-29 13:19:18 -07001890 if (tcp_too_many_orphans(sk,
1891 atomic_read(sk->sk_prot->orphan_count))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 if (net_ratelimit())
1893 printk(KERN_INFO "TCP: too many of orphaned "
1894 "sockets\n");
1895 tcp_set_state(sk, TCP_CLOSE);
1896 tcp_send_active_reset(sk, GFP_ATOMIC);
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001897 NET_INC_STATS_BH(sock_net(sk),
1898 LINUX_MIB_TCPABORTONMEMORY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899 }
1900 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001901
1902 if (sk->sk_state == TCP_CLOSE)
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001903 inet_csk_destroy_sock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001904 /* Otherwise, socket is reprieved until protocol close. */
1905
1906out:
1907 bh_unlock_sock(sk);
1908 local_bh_enable();
1909 sock_put(sk);
1910}
1911
1912/* These states need RST on ABORT according to RFC793 */
1913
1914static inline int tcp_need_reset(int state)
1915{
1916 return (1 << state) &
1917 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
1918 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
1919}
1920
1921int tcp_disconnect(struct sock *sk, int flags)
1922{
1923 struct inet_sock *inet = inet_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001924 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925 struct tcp_sock *tp = tcp_sk(sk);
1926 int err = 0;
1927 int old_state = sk->sk_state;
1928
1929 if (old_state != TCP_CLOSE)
1930 tcp_set_state(sk, TCP_CLOSE);
1931
1932 /* ABORT function of RFC793 */
1933 if (old_state == TCP_LISTEN) {
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001934 inet_csk_listen_stop(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001935 } else if (tcp_need_reset(old_state) ||
1936 (tp->snd_nxt != tp->write_seq &&
1937 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -08001938 /* The last check adjusts for discrepancy of Linux wrt. RFC
Linus Torvalds1da177e2005-04-16 15:20:36 -07001939 * states
1940 */
1941 tcp_send_active_reset(sk, gfp_any());
1942 sk->sk_err = ECONNRESET;
1943 } else if (old_state == TCP_SYN_SENT)
1944 sk->sk_err = ECONNRESET;
1945
1946 tcp_clear_xmit_timers(sk);
1947 __skb_queue_purge(&sk->sk_receive_queue);
David S. Millerfe067e82007-03-07 12:12:44 -08001948 tcp_write_queue_purge(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001949 __skb_queue_purge(&tp->out_of_order_queue);
Chris Leech1a2449a2006-05-23 18:05:53 -07001950#ifdef CONFIG_NET_DMA
1951 __skb_queue_purge(&sk->sk_async_wait_queue);
1952#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001953
1954 inet->dport = 0;
1955
1956 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1957 inet_reset_saddr(sk);
1958
1959 sk->sk_shutdown = 0;
1960 sock_reset_flag(sk, SOCK_DONE);
1961 tp->srtt = 0;
1962 if ((tp->write_seq += tp->max_window + 2) == 0)
1963 tp->write_seq = 1;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001964 icsk->icsk_backoff = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 tp->snd_cwnd = 2;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001966 icsk->icsk_probes_out = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001967 tp->packets_out = 0;
1968 tp->snd_ssthresh = 0x7fffffff;
1969 tp->snd_cwnd_cnt = 0;
Stephen Hemminger9772efb2005-11-10 17:09:53 -08001970 tp->bytes_acked = 0;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001971 tcp_set_ca_state(sk, TCP_CA_Open);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001972 tcp_clear_retrans(tp);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001973 inet_csk_delack_init(sk);
David S. Millerfe067e82007-03-07 12:12:44 -08001974 tcp_init_send_head(sk);
Srinivas Ajib40b4f72007-05-03 17:32:28 -07001975 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976 __sk_dst_reset(sk);
1977
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001978 BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979
1980 sk->sk_error_report(sk);
1981 return err;
1982}
1983
1984/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985 * Socket option code for TCP.
1986 */
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001987static int do_tcp_setsockopt(struct sock *sk, int level,
1988 int optname, char __user *optval, int optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989{
1990 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001991 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 int val;
1993 int err = 0;
1994
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07001995 /* This is a string value all the others are int's */
1996 if (optname == TCP_CONGESTION) {
1997 char name[TCP_CA_NAME_MAX];
1998
1999 if (optlen < 1)
2000 return -EINVAL;
2001
2002 val = strncpy_from_user(name, optval,
2003 min(TCP_CA_NAME_MAX-1, optlen));
2004 if (val < 0)
2005 return -EFAULT;
2006 name[val] = 0;
2007
2008 lock_sock(sk);
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002009 err = tcp_set_congestion_control(sk, name);
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002010 release_sock(sk);
2011 return err;
2012 }
2013
Linus Torvalds1da177e2005-04-16 15:20:36 -07002014 if (optlen < sizeof(int))
2015 return -EINVAL;
2016
2017 if (get_user(val, (int __user *)optval))
2018 return -EFAULT;
2019
2020 lock_sock(sk);
2021
2022 switch (optname) {
2023 case TCP_MAXSEG:
2024 /* Values greater than interface MTU won't take effect. However
2025 * at the point when this call is done we typically don't yet
2026 * know which interface is going to be used */
2027 if (val < 8 || val > MAX_TCP_WINDOW) {
2028 err = -EINVAL;
2029 break;
2030 }
2031 tp->rx_opt.user_mss = val;
2032 break;
2033
2034 case TCP_NODELAY:
2035 if (val) {
2036 /* TCP_NODELAY is weaker than TCP_CORK, so that
2037 * this option on corked socket is remembered, but
2038 * it is not activated until cork is cleared.
2039 *
2040 * However, when TCP_NODELAY is set we make
2041 * an explicit push, which overrides even TCP_CORK
2042 * for currently queued segments.
2043 */
2044 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002045 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046 } else {
2047 tp->nonagle &= ~TCP_NAGLE_OFF;
2048 }
2049 break;
2050
2051 case TCP_CORK:
2052 /* When set indicates to always queue non-full frames.
2053 * Later the user clears this option and we transmit
2054 * any pending partial frames in the queue. This is
2055 * meant to be used alongside sendfile() to get properly
2056 * filled frames when the user (for example) must write
2057 * out headers with a write() call first and then use
2058 * sendfile to send out the data parts.
2059 *
2060 * TCP_CORK can be set together with TCP_NODELAY and it is
2061 * stronger than TCP_NODELAY.
2062 */
2063 if (val) {
2064 tp->nonagle |= TCP_NAGLE_CORK;
2065 } else {
2066 tp->nonagle &= ~TCP_NAGLE_CORK;
2067 if (tp->nonagle&TCP_NAGLE_OFF)
2068 tp->nonagle |= TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002069 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002070 }
2071 break;
2072
2073 case TCP_KEEPIDLE:
2074 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2075 err = -EINVAL;
2076 else {
2077 tp->keepalive_time = val * HZ;
2078 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2079 !((1 << sk->sk_state) &
2080 (TCPF_CLOSE | TCPF_LISTEN))) {
2081 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
2082 if (tp->keepalive_time > elapsed)
2083 elapsed = tp->keepalive_time - elapsed;
2084 else
2085 elapsed = 0;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002086 inet_csk_reset_keepalive_timer(sk, elapsed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002087 }
2088 }
2089 break;
2090 case TCP_KEEPINTVL:
2091 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2092 err = -EINVAL;
2093 else
2094 tp->keepalive_intvl = val * HZ;
2095 break;
2096 case TCP_KEEPCNT:
2097 if (val < 1 || val > MAX_TCP_KEEPCNT)
2098 err = -EINVAL;
2099 else
2100 tp->keepalive_probes = val;
2101 break;
2102 case TCP_SYNCNT:
2103 if (val < 1 || val > MAX_TCP_SYNCNT)
2104 err = -EINVAL;
2105 else
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002106 icsk->icsk_syn_retries = val;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002107 break;
2108
2109 case TCP_LINGER2:
2110 if (val < 0)
2111 tp->linger2 = -1;
2112 else if (val > sysctl_tcp_fin_timeout / HZ)
2113 tp->linger2 = 0;
2114 else
2115 tp->linger2 = val * HZ;
2116 break;
2117
2118 case TCP_DEFER_ACCEPT:
David S. Millerec0a1962008-06-12 16:31:35 -07002119 icsk->icsk_accept_queue.rskq_defer_accept = 0;
2120 if (val > 0) {
2121 /* Translate value in seconds to number of
2122 * retransmits */
2123 while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
2124 val > ((TCP_TIMEOUT_INIT / HZ) <<
2125 icsk->icsk_accept_queue.rskq_defer_accept))
2126 icsk->icsk_accept_queue.rskq_defer_accept++;
2127 icsk->icsk_accept_queue.rskq_defer_accept++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002128 }
2129 break;
2130
2131 case TCP_WINDOW_CLAMP:
2132 if (!val) {
2133 if (sk->sk_state != TCP_CLOSE) {
2134 err = -EINVAL;
2135 break;
2136 }
2137 tp->window_clamp = 0;
2138 } else
2139 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2140 SOCK_MIN_RCVBUF / 2 : val;
2141 break;
2142
2143 case TCP_QUICKACK:
2144 if (!val) {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002145 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002146 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002147 icsk->icsk_ack.pingpong = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148 if ((1 << sk->sk_state) &
2149 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002150 inet_csk_ack_scheduled(sk)) {
2151 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
Chris Leech0e4b4992006-05-23 18:00:16 -07002152 tcp_cleanup_rbuf(sk, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002153 if (!(val & 1))
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002154 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155 }
2156 }
2157 break;
2158
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002159#ifdef CONFIG_TCP_MD5SIG
2160 case TCP_MD5SIG:
2161 /* Read the IP->Key mappings from userspace */
2162 err = tp->af_specific->md5_parse(sk, optval, optlen);
2163 break;
2164#endif
2165
Linus Torvalds1da177e2005-04-16 15:20:36 -07002166 default:
2167 err = -ENOPROTOOPT;
2168 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002169 }
2170
Linus Torvalds1da177e2005-04-16 15:20:36 -07002171 release_sock(sk);
2172 return err;
2173}
2174
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002175int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2176 int optlen)
2177{
2178 struct inet_connection_sock *icsk = inet_csk(sk);
2179
2180 if (level != SOL_TCP)
2181 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2182 optval, optlen);
2183 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2184}
2185
2186#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002187int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2188 char __user *optval, int optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002189{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002190 if (level != SOL_TCP)
2191 return inet_csk_compat_setsockopt(sk, level, optname,
2192 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002193 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2194}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002195
2196EXPORT_SYMBOL(compat_tcp_setsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002197#endif
2198
Linus Torvalds1da177e2005-04-16 15:20:36 -07002199/* Return information about state of tcp endpoint in API format. */
2200void tcp_get_info(struct sock *sk, struct tcp_info *info)
2201{
2202 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002203 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002204 u32 now = tcp_time_stamp;
2205
2206 memset(info, 0, sizeof(*info));
2207
2208 info->tcpi_state = sk->sk_state;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002209 info->tcpi_ca_state = icsk->icsk_ca_state;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002210 info->tcpi_retransmits = icsk->icsk_retransmits;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002211 info->tcpi_probes = icsk->icsk_probes_out;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002212 info->tcpi_backoff = icsk->icsk_backoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002213
2214 if (tp->rx_opt.tstamp_ok)
2215 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
Ilpo Järvinene60402d2007-08-09 15:14:46 +03002216 if (tcp_is_sack(tp))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002217 info->tcpi_options |= TCPI_OPT_SACK;
2218 if (tp->rx_opt.wscale_ok) {
2219 info->tcpi_options |= TCPI_OPT_WSCALE;
2220 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2221 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09002222 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002223
2224 if (tp->ecn_flags&TCP_ECN_OK)
2225 info->tcpi_options |= TCPI_OPT_ECN;
2226
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002227 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2228 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002229 info->tcpi_snd_mss = tp->mss_cache;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002230 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002231
Rick Jones5ee3afb2007-09-18 13:26:31 -07002232 if (sk->sk_state == TCP_LISTEN) {
2233 info->tcpi_unacked = sk->sk_ack_backlog;
2234 info->tcpi_sacked = sk->sk_max_ack_backlog;
2235 } else {
2236 info->tcpi_unacked = tp->packets_out;
2237 info->tcpi_sacked = tp->sacked_out;
2238 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002239 info->tcpi_lost = tp->lost_out;
2240 info->tcpi_retrans = tp->retrans_out;
2241 info->tcpi_fackets = tp->fackets_out;
2242
2243 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002244 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2246
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08002247 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002248 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2249 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2250 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2251 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2252 info->tcpi_snd_cwnd = tp->snd_cwnd;
2253 info->tcpi_advmss = tp->advmss;
2254 info->tcpi_reordering = tp->reordering;
2255
2256 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2257 info->tcpi_rcv_space = tp->rcvq_space.space;
2258
2259 info->tcpi_total_retrans = tp->total_retrans;
2260}
2261
2262EXPORT_SYMBOL_GPL(tcp_get_info);
2263
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002264static int do_tcp_getsockopt(struct sock *sk, int level,
2265 int optname, char __user *optval, int __user *optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002266{
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002267 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002268 struct tcp_sock *tp = tcp_sk(sk);
2269 int val, len;
2270
Linus Torvalds1da177e2005-04-16 15:20:36 -07002271 if (get_user(len, optlen))
2272 return -EFAULT;
2273
2274 len = min_t(unsigned int, len, sizeof(int));
2275
2276 if (len < 0)
2277 return -EINVAL;
2278
2279 switch (optname) {
2280 case TCP_MAXSEG:
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002281 val = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2283 val = tp->rx_opt.user_mss;
2284 break;
2285 case TCP_NODELAY:
2286 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2287 break;
2288 case TCP_CORK:
2289 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2290 break;
2291 case TCP_KEEPIDLE:
2292 val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
2293 break;
2294 case TCP_KEEPINTVL:
2295 val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
2296 break;
2297 case TCP_KEEPCNT:
2298 val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
2299 break;
2300 case TCP_SYNCNT:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002301 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002302 break;
2303 case TCP_LINGER2:
2304 val = tp->linger2;
2305 if (val >= 0)
2306 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2307 break;
2308 case TCP_DEFER_ACCEPT:
David S. Millerec0a1962008-06-12 16:31:35 -07002309 val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
2310 ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002311 break;
2312 case TCP_WINDOW_CLAMP:
2313 val = tp->window_clamp;
2314 break;
2315 case TCP_INFO: {
2316 struct tcp_info info;
2317
2318 if (get_user(len, optlen))
2319 return -EFAULT;
2320
2321 tcp_get_info(sk, &info);
2322
2323 len = min_t(unsigned int, len, sizeof(info));
2324 if (put_user(len, optlen))
2325 return -EFAULT;
2326 if (copy_to_user(optval, &info, len))
2327 return -EFAULT;
2328 return 0;
2329 }
2330 case TCP_QUICKACK:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002331 val = !icsk->icsk_ack.pingpong;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002332 break;
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002333
2334 case TCP_CONGESTION:
2335 if (get_user(len, optlen))
2336 return -EFAULT;
2337 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2338 if (put_user(len, optlen))
2339 return -EFAULT;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002340 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002341 return -EFAULT;
2342 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002343 default:
2344 return -ENOPROTOOPT;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002345 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002346
2347 if (put_user(len, optlen))
2348 return -EFAULT;
2349 if (copy_to_user(optval, &val, len))
2350 return -EFAULT;
2351 return 0;
2352}
2353
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002354int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2355 int __user *optlen)
2356{
2357 struct inet_connection_sock *icsk = inet_csk(sk);
2358
2359 if (level != SOL_TCP)
2360 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2361 optval, optlen);
2362 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2363}
2364
2365#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002366int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2367 char __user *optval, int __user *optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002368{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002369 if (level != SOL_TCP)
2370 return inet_csk_compat_getsockopt(sk, level, optname,
2371 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002372 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2373}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002374
2375EXPORT_SYMBOL(compat_tcp_getsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002376#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002377
Herbert Xu576a30e2006-06-27 13:22:38 -07002378struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
Herbert Xuf4c50d92006-06-22 03:02:40 -07002379{
2380 struct sk_buff *segs = ERR_PTR(-EINVAL);
2381 struct tcphdr *th;
2382 unsigned thlen;
2383 unsigned int seq;
Al Virod3bc23e2006-11-14 21:24:49 -08002384 __be32 delta;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002385 unsigned int oldlen;
2386 unsigned int len;
2387
2388 if (!pskb_may_pull(skb, sizeof(*th)))
2389 goto out;
2390
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002391 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002392 thlen = th->doff * 4;
2393 if (thlen < sizeof(*th))
2394 goto out;
2395
2396 if (!pskb_may_pull(skb, thlen))
2397 goto out;
2398
Herbert Xu0718bcc2006-06-25 23:55:46 -07002399 oldlen = (u16)~skb->len;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002400 __skb_pull(skb, thlen);
2401
Herbert Xu3820c3f2006-06-29 20:11:25 -07002402 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2403 /* Packet is from an untrusted source, reset gso_segs. */
Herbert Xubbcf4672006-07-03 19:38:35 -07002404 int type = skb_shinfo(skb)->gso_type;
2405 int mss;
Herbert Xu3820c3f2006-06-29 20:11:25 -07002406
Herbert Xubbcf4672006-07-03 19:38:35 -07002407 if (unlikely(type &
2408 ~(SKB_GSO_TCPV4 |
2409 SKB_GSO_DODGY |
2410 SKB_GSO_TCP_ECN |
2411 SKB_GSO_TCPV6 |
2412 0) ||
2413 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2414 goto out;
2415
2416 mss = skb_shinfo(skb)->gso_size;
Ilpo Järvinen172589c2007-08-28 15:50:33 -07002417 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
Herbert Xu3820c3f2006-06-29 20:11:25 -07002418
2419 segs = NULL;
2420 goto out;
2421 }
2422
Herbert Xu576a30e2006-06-27 13:22:38 -07002423 segs = skb_segment(skb, features);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002424 if (IS_ERR(segs))
2425 goto out;
2426
2427 len = skb_shinfo(skb)->gso_size;
Herbert Xu0718bcc2006-06-25 23:55:46 -07002428 delta = htonl(oldlen + (thlen + len));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002429
2430 skb = segs;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002431 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002432 seq = ntohl(th->seq);
2433
2434 do {
2435 th->fin = th->psh = 0;
2436
Al Virod3bc23e2006-11-14 21:24:49 -08002437 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2438 (__force u32)delta));
Patrick McHardy84fa7932006-08-29 16:44:56 -07002439 if (skb->ip_summed != CHECKSUM_PARTIAL)
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002440 th->check =
2441 csum_fold(csum_partial(skb_transport_header(skb),
2442 thlen, skb->csum));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002443
2444 seq += len;
2445 skb = skb->next;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002446 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002447
2448 th->seq = htonl(seq);
2449 th->cwr = 0;
2450 } while (skb->next);
2451
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07002452 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002453 skb->data_len);
Al Virod3bc23e2006-11-14 21:24:49 -08002454 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2455 (__force u32)delta));
Patrick McHardy84fa7932006-08-29 16:44:56 -07002456 if (skb->ip_summed != CHECKSUM_PARTIAL)
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002457 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2458 thlen, skb->csum));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002459
2460out:
2461 return segs;
2462}
Herbert Xuadcfc7d2006-06-30 13:36:15 -07002463EXPORT_SYMBOL(tcp_tso_segment);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002464
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002465#ifdef CONFIG_TCP_MD5SIG
2466static unsigned long tcp_md5sig_users;
2467static struct tcp_md5sig_pool **tcp_md5sig_pool;
2468static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2469
YOSHIFUJI Hideaki8d26d762008-04-17 13:19:16 +09002470int tcp_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
2471 int bplen,
2472 struct tcphdr *th, unsigned int tcplen,
2473 struct tcp_md5sig_pool *hp)
2474{
2475 struct scatterlist sg[4];
2476 __u16 data_len;
2477 int block = 0;
2478 __sum16 cksum;
2479 struct hash_desc *desc = &hp->md5_desc;
2480 int err;
2481 unsigned int nbytes = 0;
2482
2483 sg_init_table(sg, 4);
2484
2485 /* 1. The TCP pseudo-header */
2486 sg_set_buf(&sg[block++], &hp->md5_blk, bplen);
2487 nbytes += bplen;
2488
2489 /* 2. The TCP header, excluding options, and assuming a
2490 * checksum of zero
2491 */
2492 cksum = th->check;
2493 th->check = 0;
2494 sg_set_buf(&sg[block++], th, sizeof(*th));
2495 nbytes += sizeof(*th);
2496
2497 /* 3. The TCP segment data (if any) */
2498 data_len = tcplen - (th->doff << 2);
2499 if (data_len > 0) {
2500 u8 *data = (u8 *)th + (th->doff << 2);
2501 sg_set_buf(&sg[block++], data, data_len);
2502 nbytes += data_len;
2503 }
2504
2505 /* 4. an independently-specified key or password, known to both
2506 * TCPs and presumably connection-specific
2507 */
2508 sg_set_buf(&sg[block++], key->key, key->keylen);
2509 nbytes += key->keylen;
2510
2511 sg_mark_end(&sg[block - 1]);
2512
2513 /* Now store the hash into the packet */
2514 err = crypto_hash_init(desc);
2515 if (err) {
2516 if (net_ratelimit())
2517 printk(KERN_WARNING "%s(): hash_init failed\n", __func__);
2518 return -1;
2519 }
2520 err = crypto_hash_update(desc, sg, nbytes);
2521 if (err) {
2522 if (net_ratelimit())
2523 printk(KERN_WARNING "%s(): hash_update failed\n", __func__);
2524 return -1;
2525 }
2526 err = crypto_hash_final(desc, md5_hash);
2527 if (err) {
2528 if (net_ratelimit())
2529 printk(KERN_WARNING "%s(): hash_final failed\n", __func__);
2530 return -1;
2531 }
2532
2533 /* Reset header */
2534 th->check = cksum;
2535
2536 return 0;
2537}
2538EXPORT_SYMBOL(tcp_calc_md5_hash);
2539
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002540static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
2541{
2542 int cpu;
2543 for_each_possible_cpu(cpu) {
2544 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2545 if (p) {
2546 if (p->md5_desc.tfm)
2547 crypto_free_hash(p->md5_desc.tfm);
2548 kfree(p);
2549 p = NULL;
2550 }
2551 }
2552 free_percpu(pool);
2553}
2554
2555void tcp_free_md5sig_pool(void)
2556{
2557 struct tcp_md5sig_pool **pool = NULL;
2558
David S. Miller2c4f6212007-02-20 23:51:47 -08002559 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002560 if (--tcp_md5sig_users == 0) {
2561 pool = tcp_md5sig_pool;
2562 tcp_md5sig_pool = NULL;
2563 }
David S. Miller2c4f6212007-02-20 23:51:47 -08002564 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002565 if (pool)
2566 __tcp_free_md5sig_pool(pool);
2567}
2568
2569EXPORT_SYMBOL(tcp_free_md5sig_pool);
2570
Adrian Bunkf5b99bc2006-11-30 17:22:29 -08002571static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002572{
2573 int cpu;
2574 struct tcp_md5sig_pool **pool;
2575
2576 pool = alloc_percpu(struct tcp_md5sig_pool *);
2577 if (!pool)
2578 return NULL;
2579
2580 for_each_possible_cpu(cpu) {
2581 struct tcp_md5sig_pool *p;
2582 struct crypto_hash *hash;
2583
2584 p = kzalloc(sizeof(*p), GFP_KERNEL);
2585 if (!p)
2586 goto out_free;
2587 *per_cpu_ptr(pool, cpu) = p;
2588
2589 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2590 if (!hash || IS_ERR(hash))
2591 goto out_free;
2592
2593 p->md5_desc.tfm = hash;
2594 }
2595 return pool;
2596out_free:
2597 __tcp_free_md5sig_pool(pool);
2598 return NULL;
2599}
2600
2601struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
2602{
2603 struct tcp_md5sig_pool **pool;
2604 int alloc = 0;
2605
2606retry:
David S. Miller2c4f6212007-02-20 23:51:47 -08002607 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002608 pool = tcp_md5sig_pool;
2609 if (tcp_md5sig_users++ == 0) {
2610 alloc = 1;
David S. Miller2c4f6212007-02-20 23:51:47 -08002611 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002612 } else if (!pool) {
2613 tcp_md5sig_users--;
David S. Miller2c4f6212007-02-20 23:51:47 -08002614 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002615 cpu_relax();
2616 goto retry;
2617 } else
David S. Miller2c4f6212007-02-20 23:51:47 -08002618 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002619
2620 if (alloc) {
2621 /* we cannot hold spinlock here because this may sleep. */
2622 struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
David S. Miller2c4f6212007-02-20 23:51:47 -08002623 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002624 if (!p) {
2625 tcp_md5sig_users--;
David S. Miller2c4f6212007-02-20 23:51:47 -08002626 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002627 return NULL;
2628 }
2629 pool = tcp_md5sig_pool;
2630 if (pool) {
2631 /* oops, it has already been assigned. */
David S. Miller2c4f6212007-02-20 23:51:47 -08002632 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002633 __tcp_free_md5sig_pool(p);
2634 } else {
2635 tcp_md5sig_pool = pool = p;
David S. Miller2c4f6212007-02-20 23:51:47 -08002636 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002637 }
2638 }
2639 return pool;
2640}
2641
2642EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2643
2644struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
2645{
2646 struct tcp_md5sig_pool **p;
David S. Miller2c4f6212007-02-20 23:51:47 -08002647 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002648 p = tcp_md5sig_pool;
2649 if (p)
2650 tcp_md5sig_users++;
David S. Miller2c4f6212007-02-20 23:51:47 -08002651 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002652 return (p ? *per_cpu_ptr(p, cpu) : NULL);
2653}
2654
2655EXPORT_SYMBOL(__tcp_get_md5sig_pool);
2656
David S. Miller6931ba72006-12-13 16:25:44 -08002657void __tcp_put_md5sig_pool(void)
2658{
2659 tcp_free_md5sig_pool();
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002660}
2661
2662EXPORT_SYMBOL(__tcp_put_md5sig_pool);
2663#endif
2664
Andi Kleen4ac02ba2007-04-20 17:11:46 -07002665void tcp_done(struct sock *sk)
2666{
2667 if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07002668 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
Andi Kleen4ac02ba2007-04-20 17:11:46 -07002669
2670 tcp_set_state(sk, TCP_CLOSE);
2671 tcp_clear_xmit_timers(sk);
2672
2673 sk->sk_shutdown = SHUTDOWN_MASK;
2674
2675 if (!sock_flag(sk, SOCK_DEAD))
2676 sk->sk_state_change(sk);
2677 else
2678 inet_csk_destroy_sock(sk);
2679}
2680EXPORT_SYMBOL_GPL(tcp_done);
2681
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002682extern struct tcp_congestion_ops tcp_reno;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002683
2684static __initdata unsigned long thash_entries;
2685static int __init set_thash_entries(char *str)
2686{
2687 if (!str)
2688 return 0;
2689 thash_entries = simple_strtoul(str, &str, 0);
2690 return 1;
2691}
2692__setup("thash_entries=", set_thash_entries);
2693
2694void __init tcp_init(void)
2695{
2696 struct sk_buff *skb = NULL;
Miquel van Smoorenburg57413eb2008-06-27 17:23:57 -07002697 unsigned long nr_pages, limit;
John Heffner7b4f4b52006-03-25 01:34:07 -08002698 int order, i, max_share;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002699
Pavel Emelyanov1f9e6362007-12-11 02:12:04 -08002700 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002701
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002702 tcp_hashinfo.bind_bucket_cachep =
2703 kmem_cache_create("tcp_bind_bucket",
2704 sizeof(struct inet_bind_bucket), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09002705 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002706
Linus Torvalds1da177e2005-04-16 15:20:36 -07002707 /* Size and allocate the main established and bind bucket
2708 * hash tables.
2709 *
2710 * The methodology is similar to that of the buffer cache.
2711 */
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002712 tcp_hashinfo.ehash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002713 alloc_large_system_hash("TCP established",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002714 sizeof(struct inet_ehash_bucket),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002715 thash_entries,
2716 (num_physpages >= 128 * 1024) ?
Mike Stroyan18955cf2005-11-29 16:12:55 -08002717 13 : 15,
John Heffner9e950ef2006-11-06 23:10:51 -08002718 0,
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002719 &tcp_hashinfo.ehash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002720 NULL,
Jean Delvare0ccfe612007-10-30 00:59:25 -07002721 thash_entries ? 0 : 512 * 1024);
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002722 tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
2723 for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002724 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain);
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002725 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002726 }
Eric Dumazet230140c2007-11-07 02:40:20 -08002727 if (inet_ehash_locks_alloc(&tcp_hashinfo))
2728 panic("TCP: failed to alloc ehash_locks");
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002729 tcp_hashinfo.bhash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002730 alloc_large_system_hash("TCP bind",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002731 sizeof(struct inet_bind_hashbucket),
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002732 tcp_hashinfo.ehash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002733 (num_physpages >= 128 * 1024) ?
Mike Stroyan18955cf2005-11-29 16:12:55 -08002734 13 : 15,
John Heffner9e950ef2006-11-06 23:10:51 -08002735 0,
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002736 &tcp_hashinfo.bhash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002737 NULL,
2738 64 * 1024);
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002739 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
2740 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
2741 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
2742 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002743 }
2744
2745 /* Try to be a bit smarter and adjust defaults depending
2746 * on available memory.
2747 */
2748 for (order = 0; ((1 << order) << PAGE_SHIFT) <
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002749 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002750 order++)
2751 ;
Andi Kleene7626482005-06-13 14:24:52 -07002752 if (order >= 4) {
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07002753 tcp_death_row.sysctl_max_tw_buckets = 180000;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002754 sysctl_tcp_max_orphans = 4096 << (order - 4);
2755 sysctl_max_syn_backlog = 1024;
2756 } else if (order < 3) {
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07002757 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002758 sysctl_tcp_max_orphans >>= (3 - order);
2759 sysctl_max_syn_backlog = 128;
2760 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002761
John Heffner53cdcc02007-03-16 15:04:03 -07002762 /* Set the pressure threshold to be a fraction of global memory that
2763 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
2764 * memory, with a floor of 128 pages.
2765 */
Miquel van Smoorenburg57413eb2008-06-27 17:23:57 -07002766 nr_pages = totalram_pages - totalhigh_pages;
2767 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
2768 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
John Heffner53cdcc02007-03-16 15:04:03 -07002769 limit = max(limit, 128UL);
2770 sysctl_tcp_mem[0] = limit / 4 * 3;
2771 sysctl_tcp_mem[1] = limit;
John Heffner52bf3762006-11-14 20:25:17 -08002772 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002773
John Heffner53cdcc02007-03-16 15:04:03 -07002774 /* Set per-socket limits to no more than 1/128 the pressure threshold */
John Heffner7b4f4b52006-03-25 01:34:07 -08002775 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
2776 max_share = min(4UL*1024*1024, limit);
2777
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002778 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08002779 sysctl_tcp_wmem[1] = 16*1024;
2780 sysctl_tcp_wmem[2] = max(64*1024, max_share);
2781
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002782 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08002783 sysctl_tcp_rmem[1] = 87380;
2784 sysctl_tcp_rmem[2] = max(87380, max_share);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002785
2786 printk(KERN_INFO "TCP: Hash tables configured "
2787 "(established %d bind %d)\n",
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002788 tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
Stephen Hemminger317a76f2005-06-23 12:19:55 -07002789
2790 tcp_register_congestion_control(&tcp_reno);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002791}
2792
Linus Torvalds1da177e2005-04-16 15:20:36 -07002793EXPORT_SYMBOL(tcp_close);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002794EXPORT_SYMBOL(tcp_disconnect);
2795EXPORT_SYMBOL(tcp_getsockopt);
2796EXPORT_SYMBOL(tcp_ioctl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002797EXPORT_SYMBOL(tcp_poll);
2798EXPORT_SYMBOL(tcp_read_sock);
2799EXPORT_SYMBOL(tcp_recvmsg);
2800EXPORT_SYMBOL(tcp_sendmsg);
Jens Axboe9c55e012007-11-06 23:30:13 -08002801EXPORT_SYMBOL(tcp_splice_read);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002802EXPORT_SYMBOL(tcp_sendpage);
2803EXPORT_SYMBOL(tcp_setsockopt);
2804EXPORT_SYMBOL(tcp_shutdown);
2805EXPORT_SYMBOL(tcp_statistics);