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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 *
8 * Version: $Id: tcp.c,v 1.216 2002/02/01 22:01:04 davem Exp $
9 *
Jesper Juhl02c30a82005-05-05 16:16:16 -070010 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Mark Evans, <evansmp@uhura.aston.ac.uk>
13 * Corey Minyard <wf-rch!minyard@relay.EU.net>
14 * Florian La Roche, <flla@stud.uni-sb.de>
15 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
16 * Linus Torvalds, <torvalds@cs.helsinki.fi>
17 * Alan Cox, <gw4pts@gw4pts.ampr.org>
18 * Matthew Dillon, <dillon@apollo.west.oic.com>
19 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
20 * Jorge Cwik, <jorge@laser.satlink.net>
21 *
22 * Fixes:
23 * Alan Cox : Numerous verify_area() calls
24 * Alan Cox : Set the ACK bit on a reset
25 * Alan Cox : Stopped it crashing if it closed while
26 * sk->inuse=1 and was trying to connect
27 * (tcp_err()).
28 * Alan Cox : All icmp error handling was broken
29 * pointers passed where wrong and the
30 * socket was looked up backwards. Nobody
31 * tested any icmp error code obviously.
32 * Alan Cox : tcp_err() now handled properly. It
33 * wakes people on errors. poll
34 * behaves and the icmp error race
35 * has gone by moving it into sock.c
36 * Alan Cox : tcp_send_reset() fixed to work for
37 * everything not just packets for
38 * unknown sockets.
39 * Alan Cox : tcp option processing.
40 * Alan Cox : Reset tweaked (still not 100%) [Had
41 * syn rule wrong]
42 * Herp Rosmanith : More reset fixes
43 * Alan Cox : No longer acks invalid rst frames.
44 * Acking any kind of RST is right out.
45 * Alan Cox : Sets an ignore me flag on an rst
46 * receive otherwise odd bits of prattle
47 * escape still
48 * Alan Cox : Fixed another acking RST frame bug.
49 * Should stop LAN workplace lockups.
50 * Alan Cox : Some tidyups using the new skb list
51 * facilities
52 * Alan Cox : sk->keepopen now seems to work
53 * Alan Cox : Pulls options out correctly on accepts
54 * Alan Cox : Fixed assorted sk->rqueue->next errors
55 * Alan Cox : PSH doesn't end a TCP read. Switched a
56 * bit to skb ops.
57 * Alan Cox : Tidied tcp_data to avoid a potential
58 * nasty.
59 * Alan Cox : Added some better commenting, as the
60 * tcp is hard to follow
61 * Alan Cox : Removed incorrect check for 20 * psh
62 * Michael O'Reilly : ack < copied bug fix.
63 * Johannes Stille : Misc tcp fixes (not all in yet).
64 * Alan Cox : FIN with no memory -> CRASH
65 * Alan Cox : Added socket option proto entries.
66 * Also added awareness of them to accept.
67 * Alan Cox : Added TCP options (SOL_TCP)
68 * Alan Cox : Switched wakeup calls to callbacks,
69 * so the kernel can layer network
70 * sockets.
71 * Alan Cox : Use ip_tos/ip_ttl settings.
72 * Alan Cox : Handle FIN (more) properly (we hope).
73 * Alan Cox : RST frames sent on unsynchronised
74 * state ack error.
75 * Alan Cox : Put in missing check for SYN bit.
76 * Alan Cox : Added tcp_select_window() aka NET2E
77 * window non shrink trick.
78 * Alan Cox : Added a couple of small NET2E timer
79 * fixes
80 * Charles Hedrick : TCP fixes
81 * Toomas Tamm : TCP window fixes
82 * Alan Cox : Small URG fix to rlogin ^C ack fight
83 * Charles Hedrick : Rewrote most of it to actually work
84 * Linus : Rewrote tcp_read() and URG handling
85 * completely
86 * Gerhard Koerting: Fixed some missing timer handling
87 * Matthew Dillon : Reworked TCP machine states as per RFC
88 * Gerhard Koerting: PC/TCP workarounds
89 * Adam Caldwell : Assorted timer/timing errors
90 * Matthew Dillon : Fixed another RST bug
91 * Alan Cox : Move to kernel side addressing changes.
92 * Alan Cox : Beginning work on TCP fastpathing
93 * (not yet usable)
94 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
95 * Alan Cox : TCP fast path debugging
96 * Alan Cox : Window clamping
97 * Michael Riepe : Bug in tcp_check()
98 * Matt Dillon : More TCP improvements and RST bug fixes
99 * Matt Dillon : Yet more small nasties remove from the
100 * TCP code (Be very nice to this man if
101 * tcp finally works 100%) 8)
102 * Alan Cox : BSD accept semantics.
103 * Alan Cox : Reset on closedown bug.
104 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
105 * Michael Pall : Handle poll() after URG properly in
106 * all cases.
107 * Michael Pall : Undo the last fix in tcp_read_urg()
108 * (multi URG PUSH broke rlogin).
109 * Michael Pall : Fix the multi URG PUSH problem in
110 * tcp_readable(), poll() after URG
111 * works now.
112 * Michael Pall : recv(...,MSG_OOB) never blocks in the
113 * BSD api.
114 * Alan Cox : Changed the semantics of sk->socket to
115 * fix a race and a signal problem with
116 * accept() and async I/O.
117 * Alan Cox : Relaxed the rules on tcp_sendto().
118 * Yury Shevchuk : Really fixed accept() blocking problem.
119 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
120 * clients/servers which listen in on
121 * fixed ports.
122 * Alan Cox : Cleaned the above up and shrank it to
123 * a sensible code size.
124 * Alan Cox : Self connect lockup fix.
125 * Alan Cox : No connect to multicast.
126 * Ross Biro : Close unaccepted children on master
127 * socket close.
128 * Alan Cox : Reset tracing code.
129 * Alan Cox : Spurious resets on shutdown.
130 * Alan Cox : Giant 15 minute/60 second timer error
131 * Alan Cox : Small whoops in polling before an
132 * accept.
133 * Alan Cox : Kept the state trace facility since
134 * it's handy for debugging.
135 * Alan Cox : More reset handler fixes.
136 * Alan Cox : Started rewriting the code based on
137 * the RFC's for other useful protocol
138 * references see: Comer, KA9Q NOS, and
139 * for a reference on the difference
140 * between specifications and how BSD
141 * works see the 4.4lite source.
142 * A.N.Kuznetsov : Don't time wait on completion of tidy
143 * close.
144 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
145 * Linus Torvalds : Fixed BSD port reuse to work first syn
146 * Alan Cox : Reimplemented timers as per the RFC
147 * and using multiple timers for sanity.
148 * Alan Cox : Small bug fixes, and a lot of new
149 * comments.
150 * Alan Cox : Fixed dual reader crash by locking
151 * the buffers (much like datagram.c)
152 * Alan Cox : Fixed stuck sockets in probe. A probe
153 * now gets fed up of retrying without
154 * (even a no space) answer.
155 * Alan Cox : Extracted closing code better
156 * Alan Cox : Fixed the closing state machine to
157 * resemble the RFC.
158 * Alan Cox : More 'per spec' fixes.
159 * Jorge Cwik : Even faster checksumming.
160 * Alan Cox : tcp_data() doesn't ack illegal PSH
161 * only frames. At least one pc tcp stack
162 * generates them.
163 * Alan Cox : Cache last socket.
164 * Alan Cox : Per route irtt.
165 * Matt Day : poll()->select() match BSD precisely on error
166 * Alan Cox : New buffers
167 * Marc Tamsky : Various sk->prot->retransmits and
168 * sk->retransmits misupdating fixed.
169 * Fixed tcp_write_timeout: stuck close,
170 * and TCP syn retries gets used now.
171 * Mark Yarvis : In tcp_read_wakeup(), don't send an
172 * ack if state is TCP_CLOSED.
173 * Alan Cox : Look up device on a retransmit - routes may
174 * change. Doesn't yet cope with MSS shrink right
175 * but it's a start!
176 * Marc Tamsky : Closing in closing fixes.
177 * Mike Shaver : RFC1122 verifications.
178 * Alan Cox : rcv_saddr errors.
179 * Alan Cox : Block double connect().
180 * Alan Cox : Small hooks for enSKIP.
181 * Alexey Kuznetsov: Path MTU discovery.
182 * Alan Cox : Support soft errors.
183 * Alan Cox : Fix MTU discovery pathological case
184 * when the remote claims no mtu!
185 * Marc Tamsky : TCP_CLOSE fix.
186 * Colin (G3TNE) : Send a reset on syn ack replies in
187 * window but wrong (fixes NT lpd problems)
188 * Pedro Roque : Better TCP window handling, delayed ack.
189 * Joerg Reuter : No modification of locked buffers in
190 * tcp_do_retransmit()
191 * Eric Schenk : Changed receiver side silly window
192 * avoidance algorithm to BSD style
193 * algorithm. This doubles throughput
194 * against machines running Solaris,
195 * and seems to result in general
196 * improvement.
197 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
198 * Willy Konynenberg : Transparent proxying support.
199 * Mike McLagan : Routing by source
200 * Keith Owens : Do proper merging with partial SKB's in
201 * tcp_do_sendmsg to avoid burstiness.
202 * Eric Schenk : Fix fast close down bug with
203 * shutdown() followed by close().
204 * Andi Kleen : Make poll agree with SIGIO
205 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
206 * lingertime == 0 (RFC 793 ABORT Call)
207 * Hirokazu Takahashi : Use copy_from_user() instead of
208 * csum_and_copy_from_user() if possible.
209 *
210 * This program is free software; you can redistribute it and/or
211 * modify it under the terms of the GNU General Public License
212 * as published by the Free Software Foundation; either version
213 * 2 of the License, or(at your option) any later version.
214 *
215 * Description of States:
216 *
217 * TCP_SYN_SENT sent a connection request, waiting for ack
218 *
219 * TCP_SYN_RECV received a connection request, sent ack,
220 * waiting for final ack in three-way handshake.
221 *
222 * TCP_ESTABLISHED connection established
223 *
224 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
225 * transmission of remaining buffered data
226 *
227 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
228 * to shutdown
229 *
230 * TCP_CLOSING both sides have shutdown but we still have
231 * data we have to finish sending
232 *
233 * TCP_TIME_WAIT timeout to catch resent junk before entering
234 * closed, can only be entered from FIN_WAIT2
235 * or CLOSING. Required because the other end
236 * may not have gotten our last ACK causing it
237 * to retransmit the data packet (which we ignore)
238 *
239 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
240 * us to finish writing our data and to shutdown
241 * (we have to close() to move on to LAST_ACK)
242 *
243 * TCP_LAST_ACK out side has shutdown after remote has
244 * shutdown. There may still be data in our
245 * buffer that we have to finish sending
246 *
247 * TCP_CLOSE socket is finished
248 */
249
Ilpo Järvinen172589c2007-08-28 15:50:33 -0700250#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251#include <linux/module.h>
252#include <linux/types.h>
253#include <linux/fcntl.h>
254#include <linux/poll.h>
255#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256#include <linux/fs.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800257#include <linux/skbuff.h>
258#include <linux/splice.h>
259#include <linux/net.h>
260#include <linux/socket.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261#include <linux/random.h>
262#include <linux/bootmem.h>
David S. Millerb8059ea2006-03-25 01:36:56 -0800263#include <linux/cache.h>
Herbert Xuf4c50d92006-06-22 03:02:40 -0700264#include <linux/err.h>
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800265#include <linux/crypto.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267#include <net/icmp.h>
268#include <net/tcp.h>
269#include <net/xfrm.h>
270#include <net/ip.h>
Chris Leech1a2449a2006-05-23 18:05:53 -0700271#include <net/netdma.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800272#include <net/sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274#include <asm/uaccess.h>
275#include <asm/ioctls.h>
276
Brian Haleyab32ea52006-09-22 14:15:41 -0700277int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
Eric Dumazetba899662005-08-26 12:05:31 -0700279DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics) __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281atomic_t tcp_orphan_count = ATOMIC_INIT(0);
282
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -0700283EXPORT_SYMBOL_GPL(tcp_orphan_count);
284
David S. Millerb8059ea2006-03-25 01:36:56 -0800285int sysctl_tcp_mem[3] __read_mostly;
286int sysctl_tcp_wmem[3] __read_mostly;
287int sysctl_tcp_rmem[3] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288
289EXPORT_SYMBOL(sysctl_tcp_mem);
290EXPORT_SYMBOL(sysctl_tcp_rmem);
291EXPORT_SYMBOL(sysctl_tcp_wmem);
292
293atomic_t tcp_memory_allocated; /* Current allocated memory. */
294atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */
295
296EXPORT_SYMBOL(tcp_memory_allocated);
297EXPORT_SYMBOL(tcp_sockets_allocated);
298
299/*
Jens Axboe9c55e012007-11-06 23:30:13 -0800300 * TCP splice context
301 */
302struct tcp_splice_state {
303 struct pipe_inode_info *pipe;
304 size_t len;
305 unsigned int flags;
306};
307
308/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 * Pressure flag: try to collapse.
310 * Technical note: it is used by multiple contexts non atomically.
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800311 * All the __sk_mem_schedule() is of this nature: accounting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 * is strict, actions are advisory and have some latency.
313 */
Eric Dumazet4103f8c2007-03-27 13:58:31 -0700314int tcp_memory_pressure __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315
316EXPORT_SYMBOL(tcp_memory_pressure);
317
318void tcp_enter_memory_pressure(void)
319{
320 if (!tcp_memory_pressure) {
321 NET_INC_STATS(LINUX_MIB_TCPMEMORYPRESSURES);
322 tcp_memory_pressure = 1;
323 }
324}
325
326EXPORT_SYMBOL(tcp_enter_memory_pressure);
327
328/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 * Wait for a TCP event.
330 *
331 * Note that we don't need to lock the socket, as the upper poll layers
332 * take care of normal races (between the test and the event) and we don't
333 * go look at any of the socket buffers directly.
334 */
335unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
336{
337 unsigned int mask;
338 struct sock *sk = sock->sk;
339 struct tcp_sock *tp = tcp_sk(sk);
340
341 poll_wait(file, sk->sk_sleep, wait);
342 if (sk->sk_state == TCP_LISTEN)
Arnaldo Carvalho de Melodc40c7b2005-08-23 21:52:58 -0700343 return inet_csk_listen_poll(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344
345 /* Socket is not locked. We are protected from async events
346 by poll logic and correct handling of state changes
347 made by another threads is impossible in any case.
348 */
349
350 mask = 0;
351 if (sk->sk_err)
352 mask = POLLERR;
353
354 /*
355 * POLLHUP is certainly not done right. But poll() doesn't
356 * have a notion of HUP in just one direction, and for a
357 * socket the read side is more interesting.
358 *
359 * Some poll() documentation says that POLLHUP is incompatible
360 * with the POLLOUT/POLLWR flags, so somebody should check this
361 * all. But careful, it tends to be safer to return too many
362 * bits than too few, and you can easily break real applications
363 * if you don't tell them that something has hung up!
364 *
365 * Check-me.
366 *
367 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
368 * our fs/select.c). It means that after we received EOF,
369 * poll always returns immediately, making impossible poll() on write()
370 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
371 * if and only if shutdown has been made in both directions.
372 * Actually, it is interesting to look how Solaris and DUX
373 * solve this dilemma. I would prefer, if PULLHUP were maskable,
374 * then we could set it on SND_SHUTDOWN. BTW examples given
375 * in Stevens' books assume exactly this behaviour, it explains
376 * why PULLHUP is incompatible with POLLOUT. --ANK
377 *
378 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
379 * blocking on fresh not-connected or disconnected socket. --ANK
380 */
381 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
382 mask |= POLLHUP;
383 if (sk->sk_shutdown & RCV_SHUTDOWN)
Davide Libenzif348d702006-03-25 03:07:39 -0800384 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
386 /* Connected? */
387 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
388 /* Potential race condition. If read of tp below will
389 * escape above sk->sk_state, we can be illegally awaken
390 * in SYN_* states. */
391 if ((tp->rcv_nxt != tp->copied_seq) &&
392 (tp->urg_seq != tp->copied_seq ||
393 tp->rcv_nxt != tp->copied_seq + 1 ||
394 sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data))
395 mask |= POLLIN | POLLRDNORM;
396
397 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
398 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
399 mask |= POLLOUT | POLLWRNORM;
400 } else { /* send SIGIO later */
401 set_bit(SOCK_ASYNC_NOSPACE,
402 &sk->sk_socket->flags);
403 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
404
405 /* Race breaker. If space is freed after
406 * wspace test but before the flags are set,
407 * IO signal will be lost.
408 */
409 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
410 mask |= POLLOUT | POLLWRNORM;
411 }
412 }
413
414 if (tp->urg_data & TCP_URG_VALID)
415 mask |= POLLPRI;
416 }
417 return mask;
418}
419
420int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
421{
422 struct tcp_sock *tp = tcp_sk(sk);
423 int answ;
424
425 switch (cmd) {
426 case SIOCINQ:
427 if (sk->sk_state == TCP_LISTEN)
428 return -EINVAL;
429
430 lock_sock(sk);
431 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
432 answ = 0;
433 else if (sock_flag(sk, SOCK_URGINLINE) ||
434 !tp->urg_data ||
435 before(tp->urg_seq, tp->copied_seq) ||
436 !before(tp->urg_seq, tp->rcv_nxt)) {
437 answ = tp->rcv_nxt - tp->copied_seq;
438
439 /* Subtract 1, if FIN is in queue. */
440 if (answ && !skb_queue_empty(&sk->sk_receive_queue))
441 answ -=
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700442 tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 } else
444 answ = tp->urg_seq - tp->copied_seq;
445 release_sock(sk);
446 break;
447 case SIOCATMARK:
448 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
449 break;
450 case SIOCOUTQ:
451 if (sk->sk_state == TCP_LISTEN)
452 return -EINVAL;
453
454 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
455 answ = 0;
456 else
457 answ = tp->write_seq - tp->snd_una;
458 break;
459 default:
460 return -ENOIOCTLCMD;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700461 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
463 return put_user(answ, (int __user *)arg);
464}
465
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
467{
468 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
469 tp->pushed_seq = tp->write_seq;
470}
471
472static inline int forced_push(struct tcp_sock *tp)
473{
474 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
475}
476
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700477static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700479 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo352d4802006-11-17 19:59:12 -0200480 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
481
482 skb->csum = 0;
483 tcb->seq = tcb->end_seq = tp->write_seq;
484 tcb->flags = TCPCB_FLAG_ACK;
485 tcb->sacked = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 skb_header_release(skb);
David S. Millerfe067e82007-03-07 12:12:44 -0800487 tcp_add_write_queue_tail(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800488 sk->sk_wmem_queued += skb->truesize;
489 sk_mem_charge(sk, skb->truesize);
David S. Miller89ebd192005-08-23 10:13:06 -0700490 if (tp->nonagle & TCP_NAGLE_PUSH)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900491 tp->nonagle &= ~TCP_NAGLE_PUSH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492}
493
494static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
495 struct sk_buff *skb)
496{
497 if (flags & MSG_OOB) {
498 tp->urg_mode = 1;
499 tp->snd_up = tp->write_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 }
501}
502
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700503static inline void tcp_push(struct sock *sk, int flags, int mss_now,
504 int nonagle)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700506 struct tcp_sock *tp = tcp_sk(sk);
507
David S. Millerfe067e82007-03-07 12:12:44 -0800508 if (tcp_send_head(sk)) {
509 struct sk_buff *skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 if (!(flags & MSG_MORE) || forced_push(tp))
511 tcp_mark_push(tp, skb);
512 tcp_mark_urg(tp, flags, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700513 __tcp_push_pending_frames(sk, mss_now,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
515 }
516}
517
Adrian Bunk6ff77512007-11-06 23:32:26 -0800518static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
519 unsigned int offset, size_t len)
Jens Axboe9c55e012007-11-06 23:30:13 -0800520{
521 struct tcp_splice_state *tss = rd_desc->arg.data;
522
523 return skb_splice_bits(skb, offset, tss->pipe, tss->len, tss->flags);
524}
525
526static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
527{
528 /* Store TCP splice context information in read_descriptor_t. */
529 read_descriptor_t rd_desc = {
530 .arg.data = tss,
531 };
532
533 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
534}
535
536/**
537 * tcp_splice_read - splice data from TCP socket to a pipe
538 * @sock: socket to splice from
539 * @ppos: position (not valid)
540 * @pipe: pipe to splice to
541 * @len: number of bytes to splice
542 * @flags: splice modifier flags
543 *
544 * Description:
545 * Will read pages from given socket and fill them into a pipe.
546 *
547 **/
548ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
549 struct pipe_inode_info *pipe, size_t len,
550 unsigned int flags)
551{
552 struct sock *sk = sock->sk;
553 struct tcp_splice_state tss = {
554 .pipe = pipe,
555 .len = len,
556 .flags = flags,
557 };
558 long timeo;
559 ssize_t spliced;
560 int ret;
561
562 /*
563 * We can't seek on a socket input
564 */
565 if (unlikely(*ppos))
566 return -ESPIPE;
567
568 ret = spliced = 0;
569
570 lock_sock(sk);
571
572 timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
573 while (tss.len) {
574 ret = __tcp_splice_read(sk, &tss);
575 if (ret < 0)
576 break;
577 else if (!ret) {
578 if (spliced)
579 break;
580 if (flags & SPLICE_F_NONBLOCK) {
581 ret = -EAGAIN;
582 break;
583 }
584 if (sock_flag(sk, SOCK_DONE))
585 break;
586 if (sk->sk_err) {
587 ret = sock_error(sk);
588 break;
589 }
590 if (sk->sk_shutdown & RCV_SHUTDOWN)
591 break;
592 if (sk->sk_state == TCP_CLOSE) {
593 /*
594 * This occurs when user tries to read
595 * from never connected socket.
596 */
597 if (!sock_flag(sk, SOCK_DONE))
598 ret = -ENOTCONN;
599 break;
600 }
601 if (!timeo) {
602 ret = -EAGAIN;
603 break;
604 }
605 sk_wait_data(sk, &timeo);
606 if (signal_pending(current)) {
607 ret = sock_intr_errno(timeo);
608 break;
609 }
610 continue;
611 }
612 tss.len -= ret;
613 spliced += ret;
614
615 release_sock(sk);
616 lock_sock(sk);
617
618 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
619 (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo ||
620 signal_pending(current))
621 break;
622 }
623
624 release_sock(sk);
625
626 if (spliced)
627 return spliced;
628
629 return ret;
630}
631
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100632struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100633{
634 struct sk_buff *skb;
635
636 /* The TCP header must be at least 32-bit aligned. */
637 size = ALIGN(size, 4);
638
639 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
640 if (skb) {
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800641 if (sk_wmem_schedule(sk, skb->truesize)) {
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100642 /*
643 * Make sure that we have exactly size bytes
644 * available to the caller, no more, no less.
645 */
646 skb_reserve(skb, skb_tailroom(skb) - size);
647 return skb;
648 }
649 __kfree_skb(skb);
650 } else {
651 sk->sk_prot->enter_memory_pressure();
652 sk_stream_moderate_sndbuf(sk);
653 }
654 return NULL;
655}
656
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
658 size_t psize, int flags)
659{
660 struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700661 int mss_now, size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 int err;
663 ssize_t copied;
664 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
665
666 /* Wait for a connection to finish. */
667 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
668 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
669 goto out_err;
670
671 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
672
673 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700674 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 copied = 0;
676
677 err = -EPIPE;
678 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
679 goto do_error;
680
681 while (psize > 0) {
David S. Millerfe067e82007-03-07 12:12:44 -0800682 struct sk_buff *skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 struct page *page = pages[poffset / PAGE_SIZE];
684 int copy, i, can_coalesce;
685 int offset = poffset % PAGE_SIZE;
686 int size = min_t(size_t, psize, PAGE_SIZE - offset);
687
David S. Millerfe067e82007-03-07 12:12:44 -0800688 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689new_segment:
690 if (!sk_stream_memory_free(sk))
691 goto wait_for_sndbuf;
692
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100693 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 if (!skb)
695 goto wait_for_memory;
696
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700697 skb_entail(sk, skb);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700698 copy = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 }
700
701 if (copy > size)
702 copy = size;
703
704 i = skb_shinfo(skb)->nr_frags;
705 can_coalesce = skb_can_coalesce(skb, i, page, offset);
706 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
707 tcp_mark_push(tp, skb);
708 goto new_segment;
709 }
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800710 if (!sk_wmem_schedule(sk, copy))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 goto wait_for_memory;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (can_coalesce) {
714 skb_shinfo(skb)->frags[i - 1].size += copy;
715 } else {
716 get_page(page);
717 skb_fill_page_desc(skb, i, page, offset, copy);
718 }
719
720 skb->len += copy;
721 skb->data_len += copy;
722 skb->truesize += copy;
723 sk->sk_wmem_queued += copy;
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800724 sk_mem_charge(sk, copy);
Patrick McHardy84fa7932006-08-29 16:44:56 -0700725 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 tp->write_seq += copy;
727 TCP_SKB_CB(skb)->end_seq += copy;
Herbert Xu79671682006-06-22 02:40:14 -0700728 skb_shinfo(skb)->gso_segs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
730 if (!copied)
731 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
732
733 copied += copy;
734 poffset += copy;
735 if (!(psize -= copy))
736 goto out;
737
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700738 if (skb->len < mss_now || (flags & MSG_OOB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 continue;
740
741 if (forced_push(tp)) {
742 tcp_mark_push(tp, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700743 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
David S. Millerfe067e82007-03-07 12:12:44 -0800744 } else if (skb == tcp_send_head(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 tcp_push_one(sk, mss_now);
746 continue;
747
748wait_for_sndbuf:
749 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
750wait_for_memory:
751 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700752 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753
754 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
755 goto do_error;
756
757 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700758 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 }
760
761out:
762 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700763 tcp_push(sk, flags, mss_now, tp->nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 return copied;
765
766do_error:
767 if (copied)
768 goto out;
769out_err:
770 return sk_stream_error(sk, flags, err);
771}
772
773ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
774 size_t size, int flags)
775{
776 ssize_t res;
777 struct sock *sk = sock->sk;
778
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 if (!(sk->sk_route_caps & NETIF_F_SG) ||
Herbert Xu8648b302006-06-17 22:06:05 -0700780 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 return sock_no_sendpage(sock, page, offset, size, flags);
782
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 lock_sock(sk);
784 TCP_CHECK_TIMER(sk);
785 res = do_tcp_sendpages(sk, &page, offset, size, flags);
786 TCP_CHECK_TIMER(sk);
787 release_sock(sk);
788 return res;
789}
790
791#define TCP_PAGE(sk) (sk->sk_sndmsg_page)
792#define TCP_OFF(sk) (sk->sk_sndmsg_off)
793
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700794static inline int select_size(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700796 struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700797 int tmp = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
David S. Millerb4e26f52005-07-05 15:20:27 -0700799 if (sk->sk_route_caps & NETIF_F_SG) {
Herbert Xubcd76112006-06-30 13:36:35 -0700800 if (sk_can_gso(sk))
David S. Millerb4e26f52005-07-05 15:20:27 -0700801 tmp = 0;
802 else {
803 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
804
805 if (tmp >= pgbreak &&
806 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
807 tmp = pgbreak;
808 }
809 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 return tmp;
812}
813
David S. Miller3516ffb2007-08-02 19:23:56 -0700814int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 size_t size)
816{
David S. Miller3516ffb2007-08-02 19:23:56 -0700817 struct sock *sk = sock->sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 struct iovec *iov;
819 struct tcp_sock *tp = tcp_sk(sk);
820 struct sk_buff *skb;
821 int iovlen, flags;
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700822 int mss_now, size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 int err, copied;
824 long timeo;
825
826 lock_sock(sk);
827 TCP_CHECK_TIMER(sk);
828
829 flags = msg->msg_flags;
830 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
831
832 /* Wait for a connection to finish. */
833 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
834 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
835 goto out_err;
836
837 /* This should be in poll */
838 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
839
840 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700841 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
843 /* Ok commence sending. */
844 iovlen = msg->msg_iovlen;
845 iov = msg->msg_iov;
846 copied = 0;
847
848 err = -EPIPE;
849 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
850 goto do_error;
851
852 while (--iovlen >= 0) {
853 int seglen = iov->iov_len;
854 unsigned char __user *from = iov->iov_base;
855
856 iov++;
857
858 while (seglen > 0) {
859 int copy;
860
David S. Millerfe067e82007-03-07 12:12:44 -0800861 skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862
David S. Millerfe067e82007-03-07 12:12:44 -0800863 if (!tcp_send_head(sk) ||
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700864 (copy = size_goal - skb->len) <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865
866new_segment:
867 /* Allocate new segment. If the interface is SG,
868 * allocate skb fitting to single page.
869 */
870 if (!sk_stream_memory_free(sk))
871 goto wait_for_sndbuf;
872
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100873 skb = sk_stream_alloc_skb(sk, select_size(sk),
874 sk->sk_allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 if (!skb)
876 goto wait_for_memory;
877
878 /*
879 * Check whether we can use HW checksum.
880 */
Herbert Xu8648b302006-06-17 22:06:05 -0700881 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
Patrick McHardy84fa7932006-08-29 16:44:56 -0700882 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700884 skb_entail(sk, skb);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700885 copy = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 }
887
888 /* Try to append data to the end of skb. */
889 if (copy > seglen)
890 copy = seglen;
891
892 /* Where to copy to? */
893 if (skb_tailroom(skb) > 0) {
894 /* We have some space in skb head. Superb! */
895 if (copy > skb_tailroom(skb))
896 copy = skb_tailroom(skb);
897 if ((err = skb_add_data(skb, from, copy)) != 0)
898 goto do_fault;
899 } else {
900 int merge = 0;
901 int i = skb_shinfo(skb)->nr_frags;
902 struct page *page = TCP_PAGE(sk);
903 int off = TCP_OFF(sk);
904
905 if (skb_can_coalesce(skb, i, page, off) &&
906 off != PAGE_SIZE) {
907 /* We can extend the last page
908 * fragment. */
909 merge = 1;
910 } else if (i == MAX_SKB_FRAGS ||
911 (!i &&
912 !(sk->sk_route_caps & NETIF_F_SG))) {
913 /* Need to add new fragment and cannot
914 * do this because interface is non-SG,
915 * or because all the page slots are
916 * busy. */
917 tcp_mark_push(tp, skb);
918 goto new_segment;
919 } else if (page) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 if (off == PAGE_SIZE) {
921 put_page(page);
922 TCP_PAGE(sk) = page = NULL;
Herbert Xufb5f5e62005-09-05 18:55:48 -0700923 off = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 }
Herbert Xuef015782005-09-01 17:48:59 -0700925 } else
Herbert Xufb5f5e62005-09-05 18:55:48 -0700926 off = 0;
Herbert Xuef015782005-09-01 17:48:59 -0700927
928 if (copy > PAGE_SIZE - off)
929 copy = PAGE_SIZE - off;
930
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800931 if (!sk_wmem_schedule(sk, copy))
Herbert Xuef015782005-09-01 17:48:59 -0700932 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933
934 if (!page) {
935 /* Allocate new cache page. */
936 if (!(page = sk_stream_alloc_page(sk)))
937 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 }
939
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940 /* Time to copy data. We are close to
941 * the end! */
942 err = skb_copy_to_page(sk, from, skb, page,
943 off, copy);
944 if (err) {
945 /* If this page was new, give it to the
946 * socket so it does not get leaked.
947 */
948 if (!TCP_PAGE(sk)) {
949 TCP_PAGE(sk) = page;
950 TCP_OFF(sk) = 0;
951 }
952 goto do_error;
953 }
954
955 /* Update the skb. */
956 if (merge) {
957 skb_shinfo(skb)->frags[i - 1].size +=
958 copy;
959 } else {
960 skb_fill_page_desc(skb, i, page, off, copy);
961 if (TCP_PAGE(sk)) {
962 get_page(page);
963 } else if (off + copy < PAGE_SIZE) {
964 get_page(page);
965 TCP_PAGE(sk) = page;
966 }
967 }
968
969 TCP_OFF(sk) = off + copy;
970 }
971
972 if (!copied)
973 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
974
975 tp->write_seq += copy;
976 TCP_SKB_CB(skb)->end_seq += copy;
Herbert Xu79671682006-06-22 02:40:14 -0700977 skb_shinfo(skb)->gso_segs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
979 from += copy;
980 copied += copy;
981 if ((seglen -= copy) == 0 && iovlen == 0)
982 goto out;
983
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700984 if (skb->len < mss_now || (flags & MSG_OOB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 continue;
986
987 if (forced_push(tp)) {
988 tcp_mark_push(tp, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700989 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
David S. Millerfe067e82007-03-07 12:12:44 -0800990 } else if (skb == tcp_send_head(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 tcp_push_one(sk, mss_now);
992 continue;
993
994wait_for_sndbuf:
995 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
996wait_for_memory:
997 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700998 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999
1000 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1001 goto do_error;
1002
1003 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -07001004 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 }
1006 }
1007
1008out:
1009 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001010 tcp_push(sk, flags, mss_now, tp->nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 TCP_CHECK_TIMER(sk);
1012 release_sock(sk);
1013 return copied;
1014
1015do_fault:
1016 if (!skb->len) {
David S. Millerfe067e82007-03-07 12:12:44 -08001017 tcp_unlink_write_queue(skb, sk);
1018 /* It is the one place in all of TCP, except connection
1019 * reset, where we can be unlinking the send_head.
1020 */
1021 tcp_check_send_head(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001022 sk_wmem_free_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 }
1024
1025do_error:
1026 if (copied)
1027 goto out;
1028out_err:
1029 err = sk_stream_error(sk, flags, err);
1030 TCP_CHECK_TIMER(sk);
1031 release_sock(sk);
1032 return err;
1033}
1034
1035/*
1036 * Handle reading urgent data. BSD has very simple semantics for
1037 * this, no blocking and very strange errors 8)
1038 */
1039
1040static int tcp_recv_urg(struct sock *sk, long timeo,
1041 struct msghdr *msg, int len, int flags,
1042 int *addr_len)
1043{
1044 struct tcp_sock *tp = tcp_sk(sk);
1045
1046 /* No URG data to read. */
1047 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1048 tp->urg_data == TCP_URG_READ)
1049 return -EINVAL; /* Yes this is right ! */
1050
1051 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1052 return -ENOTCONN;
1053
1054 if (tp->urg_data & TCP_URG_VALID) {
1055 int err = 0;
1056 char c = tp->urg_data;
1057
1058 if (!(flags & MSG_PEEK))
1059 tp->urg_data = TCP_URG_READ;
1060
1061 /* Read urgent data. */
1062 msg->msg_flags |= MSG_OOB;
1063
1064 if (len > 0) {
1065 if (!(flags & MSG_TRUNC))
1066 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1067 len = 1;
1068 } else
1069 msg->msg_flags |= MSG_TRUNC;
1070
1071 return err ? -EFAULT : len;
1072 }
1073
1074 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1075 return 0;
1076
1077 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1078 * the available implementations agree in this case:
1079 * this call should never block, independent of the
1080 * blocking state of the socket.
1081 * Mike <pall@rz.uni-karlsruhe.de>
1082 */
1083 return -EAGAIN;
1084}
1085
1086/* Clean up the receive buffer for full frames taken by the user,
1087 * then send an ACK if necessary. COPIED is the number of bytes
1088 * tcp_recvmsg has given to the user so far, it speeds up the
1089 * calculation of whether or not we must ACK for the sake of
1090 * a window update.
1091 */
Chris Leech0e4b4992006-05-23 18:00:16 -07001092void tcp_cleanup_rbuf(struct sock *sk, int copied)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093{
1094 struct tcp_sock *tp = tcp_sk(sk);
1095 int time_to_ack = 0;
1096
1097#if TCP_DEBUG
1098 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1099
1100 BUG_TRAP(!skb || before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
1101#endif
1102
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001103 if (inet_csk_ack_scheduled(sk)) {
1104 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 /* Delayed ACKs frequently hit locked sockets during bulk
1106 * receive. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001107 if (icsk->icsk_ack.blocked ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108 /* Once-per-two-segments ACK was not sent by tcp_input.c */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001109 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 /*
1111 * If this read emptied read buffer, we send ACK, if
1112 * connection is not bidirectional, user drained
1113 * receive buffer and there was a small segment
1114 * in queue.
1115 */
Alexey Kuznetsov1ef96962006-09-19 12:52:50 -07001116 (copied > 0 &&
1117 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1118 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1119 !icsk->icsk_ack.pingpong)) &&
1120 !atomic_read(&sk->sk_rmem_alloc)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121 time_to_ack = 1;
1122 }
1123
1124 /* We send an ACK if we can now advertise a non-zero window
1125 * which has been raised "significantly".
1126 *
1127 * Even if window raised up to infinity, do not send window open ACK
1128 * in states, where we will not receive more. It is useless.
1129 */
1130 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1131 __u32 rcv_window_now = tcp_receive_window(tp);
1132
1133 /* Optimize, __tcp_select_window() is not cheap. */
1134 if (2*rcv_window_now <= tp->window_clamp) {
1135 __u32 new_window = __tcp_select_window(sk);
1136
1137 /* Send ACK now, if this read freed lots of space
1138 * in our buffer. Certainly, new_window is new window.
1139 * We can advertise it now, if it is not less than current one.
1140 * "Lots" means "at least twice" here.
1141 */
1142 if (new_window && new_window >= 2 * rcv_window_now)
1143 time_to_ack = 1;
1144 }
1145 }
1146 if (time_to_ack)
1147 tcp_send_ack(sk);
1148}
1149
1150static void tcp_prequeue_process(struct sock *sk)
1151{
1152 struct sk_buff *skb;
1153 struct tcp_sock *tp = tcp_sk(sk);
1154
David S. Millerb03efcf2005-07-08 14:57:23 -07001155 NET_INC_STATS_USER(LINUX_MIB_TCPPREQUEUED);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156
1157 /* RX process wants to run with disabled BHs, though it is not
1158 * necessary */
1159 local_bh_disable();
1160 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1161 sk->sk_backlog_rcv(sk, skb);
1162 local_bh_enable();
1163
1164 /* Clear memory counter. */
1165 tp->ucopy.memory = 0;
1166}
1167
1168static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1169{
1170 struct sk_buff *skb;
1171 u32 offset;
1172
1173 skb_queue_walk(&sk->sk_receive_queue, skb) {
1174 offset = seq - TCP_SKB_CB(skb)->seq;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001175 if (tcp_hdr(skb)->syn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176 offset--;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001177 if (offset < skb->len || tcp_hdr(skb)->fin) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 *off = offset;
1179 return skb;
1180 }
1181 }
1182 return NULL;
1183}
1184
1185/*
1186 * This routine provides an alternative to tcp_recvmsg() for routines
1187 * that would like to handle copying from skbuffs directly in 'sendfile'
1188 * fashion.
1189 * Note:
1190 * - It is assumed that the socket was locked by the caller.
1191 * - The routine does not block.
1192 * - At present, there is no support for reading OOB data
1193 * or for 'peeking' the socket using this routine
1194 * (although both would be easy to implement).
1195 */
1196int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1197 sk_read_actor_t recv_actor)
1198{
1199 struct sk_buff *skb;
1200 struct tcp_sock *tp = tcp_sk(sk);
1201 u32 seq = tp->copied_seq;
1202 u32 offset;
1203 int copied = 0;
1204
1205 if (sk->sk_state == TCP_LISTEN)
1206 return -ENOTCONN;
1207 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1208 if (offset < skb->len) {
1209 size_t used, len;
1210
1211 len = skb->len - offset;
1212 /* Stop reading if we hit a patch of urgent data */
1213 if (tp->urg_data) {
1214 u32 urg_offset = tp->urg_seq - seq;
1215 if (urg_offset < len)
1216 len = urg_offset;
1217 if (!len)
1218 break;
1219 }
1220 used = recv_actor(desc, skb, offset, len);
Jens Axboeddb61a52007-06-23 23:07:50 -07001221 if (used < 0) {
1222 if (!copied)
1223 copied = used;
1224 break;
1225 } else if (used <= len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 seq += used;
1227 copied += used;
1228 offset += used;
1229 }
1230 if (offset != skb->len)
1231 break;
1232 }
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001233 if (tcp_hdr(skb)->fin) {
Chris Leech624d1162006-05-23 18:01:28 -07001234 sk_eat_skb(sk, skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 ++seq;
1236 break;
1237 }
Chris Leech624d1162006-05-23 18:01:28 -07001238 sk_eat_skb(sk, skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 if (!desc->count)
1240 break;
1241 }
1242 tp->copied_seq = seq;
1243
1244 tcp_rcv_space_adjust(sk);
1245
1246 /* Clean up data we have read: This will do ACK frames. */
Jens Axboeddb61a52007-06-23 23:07:50 -07001247 if (copied > 0)
Chris Leech0e4b4992006-05-23 18:00:16 -07001248 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 return copied;
1250}
1251
1252/*
1253 * This routine copies from a sock struct into the user buffer.
1254 *
1255 * Technical note: in 2.3 we work on _locked_ socket, so that
1256 * tricks with *seq access order and skb->users are not required.
1257 * Probably, code can be easily improved even more.
1258 */
1259
1260int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1261 size_t len, int nonblock, int flags, int *addr_len)
1262{
1263 struct tcp_sock *tp = tcp_sk(sk);
1264 int copied = 0;
1265 u32 peek_seq;
1266 u32 *seq;
1267 unsigned long used;
1268 int err;
1269 int target; /* Read at least this many bytes */
1270 long timeo;
1271 struct task_struct *user_recv = NULL;
Chris Leech1a2449a2006-05-23 18:05:53 -07001272 int copied_early = 0;
Chris Leech2b1244a2007-03-08 09:57:36 -08001273 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274
1275 lock_sock(sk);
1276
1277 TCP_CHECK_TIMER(sk);
1278
1279 err = -ENOTCONN;
1280 if (sk->sk_state == TCP_LISTEN)
1281 goto out;
1282
1283 timeo = sock_rcvtimeo(sk, nonblock);
1284
1285 /* Urgent data needs to be handled specially. */
1286 if (flags & MSG_OOB)
1287 goto recv_urg;
1288
1289 seq = &tp->copied_seq;
1290 if (flags & MSG_PEEK) {
1291 peek_seq = tp->copied_seq;
1292 seq = &peek_seq;
1293 }
1294
1295 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1296
Chris Leech1a2449a2006-05-23 18:05:53 -07001297#ifdef CONFIG_NET_DMA
1298 tp->ucopy.dma_chan = NULL;
1299 preempt_disable();
Chris Leech2b1244a2007-03-08 09:57:36 -08001300 skb = skb_peek_tail(&sk->sk_receive_queue);
Andrew Mortone00c5d82007-03-08 09:57:36 -08001301 {
1302 int available = 0;
1303
1304 if (skb)
1305 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1306 if ((available < target) &&
1307 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1308 !sysctl_tcp_low_latency &&
1309 __get_cpu_var(softnet_data).net_dma) {
1310 preempt_enable_no_resched();
1311 tp->ucopy.pinned_list =
1312 dma_pin_iovec_pages(msg->msg_iov, len);
1313 } else {
1314 preempt_enable_no_resched();
1315 }
1316 }
Chris Leech1a2449a2006-05-23 18:05:53 -07001317#endif
1318
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 u32 offset;
1321
1322 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1323 if (tp->urg_data && tp->urg_seq == *seq) {
1324 if (copied)
1325 break;
1326 if (signal_pending(current)) {
1327 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1328 break;
1329 }
1330 }
1331
1332 /* Next get a buffer. */
1333
1334 skb = skb_peek(&sk->sk_receive_queue);
1335 do {
1336 if (!skb)
1337 break;
1338
1339 /* Now that we have two receive queues this
1340 * shouldn't happen.
1341 */
1342 if (before(*seq, TCP_SKB_CB(skb)->seq)) {
1343 printk(KERN_INFO "recvmsg bug: copied %X "
1344 "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
1345 break;
1346 }
1347 offset = *seq - TCP_SKB_CB(skb)->seq;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001348 if (tcp_hdr(skb)->syn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 offset--;
1350 if (offset < skb->len)
1351 goto found_ok_skb;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001352 if (tcp_hdr(skb)->fin)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 goto found_fin_ok;
1354 BUG_TRAP(flags & MSG_PEEK);
1355 skb = skb->next;
1356 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
1357
1358 /* Well, if we have backlog, try to process it now yet. */
1359
1360 if (copied >= target && !sk->sk_backlog.tail)
1361 break;
1362
1363 if (copied) {
1364 if (sk->sk_err ||
1365 sk->sk_state == TCP_CLOSE ||
1366 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1367 !timeo ||
1368 signal_pending(current) ||
1369 (flags & MSG_PEEK))
1370 break;
1371 } else {
1372 if (sock_flag(sk, SOCK_DONE))
1373 break;
1374
1375 if (sk->sk_err) {
1376 copied = sock_error(sk);
1377 break;
1378 }
1379
1380 if (sk->sk_shutdown & RCV_SHUTDOWN)
1381 break;
1382
1383 if (sk->sk_state == TCP_CLOSE) {
1384 if (!sock_flag(sk, SOCK_DONE)) {
1385 /* This occurs when user tries to read
1386 * from never connected socket.
1387 */
1388 copied = -ENOTCONN;
1389 break;
1390 }
1391 break;
1392 }
1393
1394 if (!timeo) {
1395 copied = -EAGAIN;
1396 break;
1397 }
1398
1399 if (signal_pending(current)) {
1400 copied = sock_intr_errno(timeo);
1401 break;
1402 }
1403 }
1404
Chris Leech0e4b4992006-05-23 18:00:16 -07001405 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406
David S. Miller7df55122005-06-18 23:01:10 -07001407 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408 /* Install new reader */
1409 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1410 user_recv = current;
1411 tp->ucopy.task = user_recv;
1412 tp->ucopy.iov = msg->msg_iov;
1413 }
1414
1415 tp->ucopy.len = len;
1416
1417 BUG_TRAP(tp->copied_seq == tp->rcv_nxt ||
1418 (flags & (MSG_PEEK | MSG_TRUNC)));
1419
1420 /* Ugly... If prequeue is not empty, we have to
1421 * process it before releasing socket, otherwise
1422 * order will be broken at second iteration.
1423 * More elegant solution is required!!!
1424 *
1425 * Look: we have the following (pseudo)queues:
1426 *
1427 * 1. packets in flight
1428 * 2. backlog
1429 * 3. prequeue
1430 * 4. receive_queue
1431 *
1432 * Each queue can be processed only if the next ones
1433 * are empty. At this point we have empty receive_queue.
1434 * But prequeue _can_ be not empty after 2nd iteration,
1435 * when we jumped to start of loop because backlog
1436 * processing added something to receive_queue.
1437 * We cannot release_sock(), because backlog contains
1438 * packets arrived _after_ prequeued ones.
1439 *
1440 * Shortly, algorithm is clear --- to process all
1441 * the queues in order. We could make it more directly,
1442 * requeueing packets from backlog to prequeue, if
1443 * is not empty. It is more elegant, but eats cycles,
1444 * unfortunately.
1445 */
David S. Millerb03efcf2005-07-08 14:57:23 -07001446 if (!skb_queue_empty(&tp->ucopy.prequeue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447 goto do_prequeue;
1448
1449 /* __ Set realtime policy in scheduler __ */
1450 }
1451
1452 if (copied >= target) {
1453 /* Do not sleep, just process backlog. */
1454 release_sock(sk);
1455 lock_sock(sk);
1456 } else
1457 sk_wait_data(sk, &timeo);
1458
Chris Leech1a2449a2006-05-23 18:05:53 -07001459#ifdef CONFIG_NET_DMA
1460 tp->ucopy.wakeup = 0;
1461#endif
1462
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 if (user_recv) {
1464 int chunk;
1465
1466 /* __ Restore normal policy in scheduler __ */
1467
1468 if ((chunk = len - tp->ucopy.len) != 0) {
1469 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1470 len -= chunk;
1471 copied += chunk;
1472 }
1473
1474 if (tp->rcv_nxt == tp->copied_seq &&
David S. Millerb03efcf2005-07-08 14:57:23 -07001475 !skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476do_prequeue:
1477 tcp_prequeue_process(sk);
1478
1479 if ((chunk = len - tp->ucopy.len) != 0) {
1480 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1481 len -= chunk;
1482 copied += chunk;
1483 }
1484 }
1485 }
1486 if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
1487 if (net_ratelimit())
1488 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -07001489 current->comm, task_pid_nr(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 peek_seq = tp->copied_seq;
1491 }
1492 continue;
1493
1494 found_ok_skb:
1495 /* Ok so how much can we use? */
1496 used = skb->len - offset;
1497 if (len < used)
1498 used = len;
1499
1500 /* Do we have urgent data here? */
1501 if (tp->urg_data) {
1502 u32 urg_offset = tp->urg_seq - *seq;
1503 if (urg_offset < used) {
1504 if (!urg_offset) {
1505 if (!sock_flag(sk, SOCK_URGINLINE)) {
1506 ++*seq;
1507 offset++;
1508 used--;
1509 if (!used)
1510 goto skip_copy;
1511 }
1512 } else
1513 used = urg_offset;
1514 }
1515 }
1516
1517 if (!(flags & MSG_TRUNC)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001518#ifdef CONFIG_NET_DMA
1519 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1520 tp->ucopy.dma_chan = get_softnet_dma();
1521
1522 if (tp->ucopy.dma_chan) {
1523 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1524 tp->ucopy.dma_chan, skb, offset,
1525 msg->msg_iov, used,
1526 tp->ucopy.pinned_list);
1527
1528 if (tp->ucopy.dma_cookie < 0) {
1529
1530 printk(KERN_ALERT "dma_cookie < 0\n");
1531
1532 /* Exception. Bailout! */
1533 if (!copied)
1534 copied = -EFAULT;
1535 break;
1536 }
1537 if ((offset + used) == skb->len)
1538 copied_early = 1;
1539
1540 } else
1541#endif
1542 {
1543 err = skb_copy_datagram_iovec(skb, offset,
1544 msg->msg_iov, used);
1545 if (err) {
1546 /* Exception. Bailout! */
1547 if (!copied)
1548 copied = -EFAULT;
1549 break;
1550 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551 }
1552 }
1553
1554 *seq += used;
1555 copied += used;
1556 len -= used;
1557
1558 tcp_rcv_space_adjust(sk);
1559
1560skip_copy:
1561 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1562 tp->urg_data = 0;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001563 tcp_fast_path_check(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564 }
1565 if (used + offset < skb->len)
1566 continue;
1567
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001568 if (tcp_hdr(skb)->fin)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 goto found_fin_ok;
Chris Leech1a2449a2006-05-23 18:05:53 -07001570 if (!(flags & MSG_PEEK)) {
1571 sk_eat_skb(sk, skb, copied_early);
1572 copied_early = 0;
1573 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574 continue;
1575
1576 found_fin_ok:
1577 /* Process the FIN. */
1578 ++*seq;
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 break;
1584 } while (len > 0);
1585
1586 if (user_recv) {
David S. Millerb03efcf2005-07-08 14:57:23 -07001587 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588 int chunk;
1589
1590 tp->ucopy.len = copied > 0 ? len : 0;
1591
1592 tcp_prequeue_process(sk);
1593
1594 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1595 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1596 len -= chunk;
1597 copied += chunk;
1598 }
1599 }
1600
1601 tp->ucopy.task = NULL;
1602 tp->ucopy.len = 0;
1603 }
1604
Chris Leech1a2449a2006-05-23 18:05:53 -07001605#ifdef CONFIG_NET_DMA
1606 if (tp->ucopy.dma_chan) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001607 dma_cookie_t done, used;
1608
1609 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1610
1611 while (dma_async_memcpy_complete(tp->ucopy.dma_chan,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001612 tp->ucopy.dma_cookie, &done,
1613 &used) == DMA_IN_PROGRESS) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001614 /* do partial cleanup of sk_async_wait_queue */
1615 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1616 (dma_async_is_complete(skb->dma_cookie, done,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001617 used) == DMA_SUCCESS)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001618 __skb_dequeue(&sk->sk_async_wait_queue);
1619 kfree_skb(skb);
1620 }
1621 }
1622
1623 /* Safe to free early-copied skbs now */
1624 __skb_queue_purge(&sk->sk_async_wait_queue);
1625 dma_chan_put(tp->ucopy.dma_chan);
1626 tp->ucopy.dma_chan = NULL;
1627 }
1628 if (tp->ucopy.pinned_list) {
1629 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1630 tp->ucopy.pinned_list = NULL;
1631 }
1632#endif
1633
Linus Torvalds1da177e2005-04-16 15:20:36 -07001634 /* According to UNIX98, msg_name/msg_namelen are ignored
1635 * on connected socket. I was just happy when found this 8) --ANK
1636 */
1637
1638 /* Clean up data we have read: This will do ACK frames. */
Chris Leech0e4b4992006-05-23 18:00:16 -07001639 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640
1641 TCP_CHECK_TIMER(sk);
1642 release_sock(sk);
1643 return copied;
1644
1645out:
1646 TCP_CHECK_TIMER(sk);
1647 release_sock(sk);
1648 return err;
1649
1650recv_urg:
1651 err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len);
1652 goto out;
1653}
1654
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001655void tcp_set_state(struct sock *sk, int state)
1656{
1657 int oldstate = sk->sk_state;
1658
1659 switch (state) {
1660 case TCP_ESTABLISHED:
1661 if (oldstate != TCP_ESTABLISHED)
1662 TCP_INC_STATS(TCP_MIB_CURRESTAB);
1663 break;
1664
1665 case TCP_CLOSE:
1666 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1667 TCP_INC_STATS(TCP_MIB_ESTABRESETS);
1668
1669 sk->sk_prot->unhash(sk);
1670 if (inet_csk(sk)->icsk_bind_hash &&
1671 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1672 inet_put_port(&tcp_hashinfo, sk);
1673 /* fall through */
1674 default:
1675 if (oldstate==TCP_ESTABLISHED)
1676 TCP_DEC_STATS(TCP_MIB_CURRESTAB);
1677 }
1678
1679 /* Change state AFTER socket is unhashed to avoid closed
1680 * socket sitting in hash tables.
1681 */
1682 sk->sk_state = state;
1683
1684#ifdef STATE_TRACE
1685 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
1686#endif
1687}
1688EXPORT_SYMBOL_GPL(tcp_set_state);
1689
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690/*
1691 * State processing on a close. This implements the state shift for
1692 * sending our FIN frame. Note that we only send a FIN for some
1693 * states. A shutdown() may have already sent the FIN, or we may be
1694 * closed.
1695 */
1696
Arjan van de Ven9b5b5cf2005-11-29 16:21:38 -08001697static const unsigned char new_state[16] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698 /* current state: new state: action: */
1699 /* (Invalid) */ TCP_CLOSE,
1700 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1701 /* TCP_SYN_SENT */ TCP_CLOSE,
1702 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1703 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1704 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1705 /* TCP_TIME_WAIT */ TCP_CLOSE,
1706 /* TCP_CLOSE */ TCP_CLOSE,
1707 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1708 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1709 /* TCP_LISTEN */ TCP_CLOSE,
1710 /* TCP_CLOSING */ TCP_CLOSING,
1711};
1712
1713static int tcp_close_state(struct sock *sk)
1714{
1715 int next = (int)new_state[sk->sk_state];
1716 int ns = next & TCP_STATE_MASK;
1717
1718 tcp_set_state(sk, ns);
1719
1720 return next & TCP_ACTION_FIN;
1721}
1722
1723/*
1724 * Shutdown the sending side of a connection. Much like close except
1725 * that we don't receive shut down or set_sock_flag(sk, SOCK_DEAD).
1726 */
1727
1728void tcp_shutdown(struct sock *sk, int how)
1729{
1730 /* We need to grab some memory, and put together a FIN,
1731 * and then put it into the queue to be sent.
1732 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1733 */
1734 if (!(how & SEND_SHUTDOWN))
1735 return;
1736
1737 /* If we've already sent a FIN, or it's a closed state, skip this. */
1738 if ((1 << sk->sk_state) &
1739 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1740 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1741 /* Clear out any half completed packets. FIN if needed. */
1742 if (tcp_close_state(sk))
1743 tcp_send_fin(sk);
1744 }
1745}
1746
Linus Torvalds1da177e2005-04-16 15:20:36 -07001747void tcp_close(struct sock *sk, long timeout)
1748{
1749 struct sk_buff *skb;
1750 int data_was_unread = 0;
Herbert Xu75c2d9072006-05-03 23:31:35 -07001751 int state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752
1753 lock_sock(sk);
1754 sk->sk_shutdown = SHUTDOWN_MASK;
1755
1756 if (sk->sk_state == TCP_LISTEN) {
1757 tcp_set_state(sk, TCP_CLOSE);
1758
1759 /* Special case. */
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001760 inet_csk_listen_stop(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001761
1762 goto adjudge_to_death;
1763 }
1764
1765 /* We need to flush the recv. buffs. We do this only on the
1766 * descriptor close, not protocol-sourced closes, because the
1767 * reader process may not have drained the data yet!
1768 */
1769 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1770 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001771 tcp_hdr(skb)->fin;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772 data_was_unread += len;
1773 __kfree_skb(skb);
1774 }
1775
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001776 sk_mem_reclaim(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777
Gerrit Renker65bb7232007-04-28 21:21:46 -07001778 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1779 * data was lost. To witness the awful effects of the old behavior of
1780 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1781 * GET in an FTP client, suspend the process, wait for the client to
1782 * advertise a zero window, then kill -9 the FTP client, wheee...
1783 * Note: timeout is always zero in such a case.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784 */
1785 if (data_was_unread) {
1786 /* Unread data was tossed, zap the connection. */
1787 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONCLOSE);
1788 tcp_set_state(sk, TCP_CLOSE);
1789 tcp_send_active_reset(sk, GFP_KERNEL);
1790 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1791 /* Check zero linger _after_ checking for unread data. */
1792 sk->sk_prot->disconnect(sk, 0);
1793 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONDATA);
1794 } else if (tcp_close_state(sk)) {
1795 /* We FIN if the application ate all the data before
1796 * zapping the connection.
1797 */
1798
1799 /* RED-PEN. Formally speaking, we have broken TCP state
1800 * machine. State transitions:
1801 *
1802 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1803 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1804 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1805 *
1806 * are legal only when FIN has been sent (i.e. in window),
1807 * rather than queued out of window. Purists blame.
1808 *
1809 * F.e. "RFC state" is ESTABLISHED,
1810 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1811 *
1812 * The visible declinations are that sometimes
1813 * we enter time-wait state, when it is not required really
1814 * (harmless), do not send active resets, when they are
1815 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1816 * they look as CLOSING or LAST_ACK for Linux)
1817 * Probably, I missed some more holelets.
1818 * --ANK
1819 */
1820 tcp_send_fin(sk);
1821 }
1822
1823 sk_stream_wait_close(sk, timeout);
1824
1825adjudge_to_death:
Herbert Xu75c2d9072006-05-03 23:31:35 -07001826 state = sk->sk_state;
1827 sock_hold(sk);
1828 sock_orphan(sk);
1829 atomic_inc(sk->sk_prot->orphan_count);
1830
Linus Torvalds1da177e2005-04-16 15:20:36 -07001831 /* It is the last release_sock in its life. It will remove backlog. */
1832 release_sock(sk);
1833
1834
1835 /* Now socket is owned by kernel and we acquire BH lock
1836 to finish close. No need to check for user refs.
1837 */
1838 local_bh_disable();
1839 bh_lock_sock(sk);
1840 BUG_TRAP(!sock_owned_by_user(sk));
1841
Herbert Xu75c2d9072006-05-03 23:31:35 -07001842 /* Have we already been destroyed by a softirq or backlog? */
1843 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1844 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001845
1846 /* This is a (useful) BSD violating of the RFC. There is a
1847 * problem with TCP as specified in that the other end could
1848 * keep a socket open forever with no application left this end.
1849 * We use a 3 minute timeout (about the same as BSD) then kill
1850 * our end. If they send after that then tough - BUT: long enough
1851 * that we won't make the old 4*rto = almost no time - whoops
1852 * reset mistake.
1853 *
1854 * Nope, it was not mistake. It is really desired behaviour
1855 * f.e. on http servers, when such sockets are useless, but
1856 * consume significant resources. Let's do it with special
1857 * linger2 option. --ANK
1858 */
1859
1860 if (sk->sk_state == TCP_FIN_WAIT2) {
1861 struct tcp_sock *tp = tcp_sk(sk);
1862 if (tp->linger2 < 0) {
1863 tcp_set_state(sk, TCP_CLOSE);
1864 tcp_send_active_reset(sk, GFP_ATOMIC);
1865 NET_INC_STATS_BH(LINUX_MIB_TCPABORTONLINGER);
1866 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001867 const int tmo = tcp_fin_time(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868
1869 if (tmo > TCP_TIMEWAIT_LEN) {
David S. Miller52499af2006-07-31 22:32:09 -07001870 inet_csk_reset_keepalive_timer(sk,
1871 tmo - TCP_TIMEWAIT_LEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
1874 goto out;
1875 }
1876 }
1877 }
1878 if (sk->sk_state != TCP_CLOSE) {
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001879 sk_mem_reclaim(sk);
Pavel Emelianove4fd5da2007-05-29 13:19:18 -07001880 if (tcp_too_many_orphans(sk,
1881 atomic_read(sk->sk_prot->orphan_count))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001882 if (net_ratelimit())
1883 printk(KERN_INFO "TCP: too many of orphaned "
1884 "sockets\n");
1885 tcp_set_state(sk, TCP_CLOSE);
1886 tcp_send_active_reset(sk, GFP_ATOMIC);
1887 NET_INC_STATS_BH(LINUX_MIB_TCPABORTONMEMORY);
1888 }
1889 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001890
1891 if (sk->sk_state == TCP_CLOSE)
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001892 inet_csk_destroy_sock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893 /* Otherwise, socket is reprieved until protocol close. */
1894
1895out:
1896 bh_unlock_sock(sk);
1897 local_bh_enable();
1898 sock_put(sk);
1899}
1900
1901/* These states need RST on ABORT according to RFC793 */
1902
1903static inline int tcp_need_reset(int state)
1904{
1905 return (1 << state) &
1906 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
1907 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
1908}
1909
1910int tcp_disconnect(struct sock *sk, int flags)
1911{
1912 struct inet_sock *inet = inet_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001913 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914 struct tcp_sock *tp = tcp_sk(sk);
1915 int err = 0;
1916 int old_state = sk->sk_state;
1917
1918 if (old_state != TCP_CLOSE)
1919 tcp_set_state(sk, TCP_CLOSE);
1920
1921 /* ABORT function of RFC793 */
1922 if (old_state == TCP_LISTEN) {
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001923 inet_csk_listen_stop(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001924 } else if (tcp_need_reset(old_state) ||
1925 (tp->snd_nxt != tp->write_seq &&
1926 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -08001927 /* The last check adjusts for discrepancy of Linux wrt. RFC
Linus Torvalds1da177e2005-04-16 15:20:36 -07001928 * states
1929 */
1930 tcp_send_active_reset(sk, gfp_any());
1931 sk->sk_err = ECONNRESET;
1932 } else if (old_state == TCP_SYN_SENT)
1933 sk->sk_err = ECONNRESET;
1934
1935 tcp_clear_xmit_timers(sk);
1936 __skb_queue_purge(&sk->sk_receive_queue);
David S. Millerfe067e82007-03-07 12:12:44 -08001937 tcp_write_queue_purge(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001938 __skb_queue_purge(&tp->out_of_order_queue);
Chris Leech1a2449a2006-05-23 18:05:53 -07001939#ifdef CONFIG_NET_DMA
1940 __skb_queue_purge(&sk->sk_async_wait_queue);
1941#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942
1943 inet->dport = 0;
1944
1945 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1946 inet_reset_saddr(sk);
1947
1948 sk->sk_shutdown = 0;
1949 sock_reset_flag(sk, SOCK_DONE);
1950 tp->srtt = 0;
1951 if ((tp->write_seq += tp->max_window + 2) == 0)
1952 tp->write_seq = 1;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001953 icsk->icsk_backoff = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001954 tp->snd_cwnd = 2;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001955 icsk->icsk_probes_out = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001956 tp->packets_out = 0;
1957 tp->snd_ssthresh = 0x7fffffff;
1958 tp->snd_cwnd_cnt = 0;
Stephen Hemminger9772efb2005-11-10 17:09:53 -08001959 tp->bytes_acked = 0;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001960 tcp_set_ca_state(sk, TCP_CA_Open);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001961 tcp_clear_retrans(tp);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001962 inet_csk_delack_init(sk);
David S. Millerfe067e82007-03-07 12:12:44 -08001963 tcp_init_send_head(sk);
Srinivas Ajib40b4f72007-05-03 17:32:28 -07001964 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 __sk_dst_reset(sk);
1966
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001967 BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968
1969 sk->sk_error_report(sk);
1970 return err;
1971}
1972
1973/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001974 * Socket option code for TCP.
1975 */
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001976static int do_tcp_setsockopt(struct sock *sk, int level,
1977 int optname, char __user *optval, int optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001978{
1979 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001980 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001981 int val;
1982 int err = 0;
1983
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07001984 /* This is a string value all the others are int's */
1985 if (optname == TCP_CONGESTION) {
1986 char name[TCP_CA_NAME_MAX];
1987
1988 if (optlen < 1)
1989 return -EINVAL;
1990
1991 val = strncpy_from_user(name, optval,
1992 min(TCP_CA_NAME_MAX-1, optlen));
1993 if (val < 0)
1994 return -EFAULT;
1995 name[val] = 0;
1996
1997 lock_sock(sk);
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001998 err = tcp_set_congestion_control(sk, name);
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07001999 release_sock(sk);
2000 return err;
2001 }
2002
Linus Torvalds1da177e2005-04-16 15:20:36 -07002003 if (optlen < sizeof(int))
2004 return -EINVAL;
2005
2006 if (get_user(val, (int __user *)optval))
2007 return -EFAULT;
2008
2009 lock_sock(sk);
2010
2011 switch (optname) {
2012 case TCP_MAXSEG:
2013 /* Values greater than interface MTU won't take effect. However
2014 * at the point when this call is done we typically don't yet
2015 * know which interface is going to be used */
2016 if (val < 8 || val > MAX_TCP_WINDOW) {
2017 err = -EINVAL;
2018 break;
2019 }
2020 tp->rx_opt.user_mss = val;
2021 break;
2022
2023 case TCP_NODELAY:
2024 if (val) {
2025 /* TCP_NODELAY is weaker than TCP_CORK, so that
2026 * this option on corked socket is remembered, but
2027 * it is not activated until cork is cleared.
2028 *
2029 * However, when TCP_NODELAY is set we make
2030 * an explicit push, which overrides even TCP_CORK
2031 * for currently queued segments.
2032 */
2033 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002034 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002035 } else {
2036 tp->nonagle &= ~TCP_NAGLE_OFF;
2037 }
2038 break;
2039
2040 case TCP_CORK:
2041 /* When set indicates to always queue non-full frames.
2042 * Later the user clears this option and we transmit
2043 * any pending partial frames in the queue. This is
2044 * meant to be used alongside sendfile() to get properly
2045 * filled frames when the user (for example) must write
2046 * out headers with a write() call first and then use
2047 * sendfile to send out the data parts.
2048 *
2049 * TCP_CORK can be set together with TCP_NODELAY and it is
2050 * stronger than TCP_NODELAY.
2051 */
2052 if (val) {
2053 tp->nonagle |= TCP_NAGLE_CORK;
2054 } else {
2055 tp->nonagle &= ~TCP_NAGLE_CORK;
2056 if (tp->nonagle&TCP_NAGLE_OFF)
2057 tp->nonagle |= TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002058 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002059 }
2060 break;
2061
2062 case TCP_KEEPIDLE:
2063 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2064 err = -EINVAL;
2065 else {
2066 tp->keepalive_time = val * HZ;
2067 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2068 !((1 << sk->sk_state) &
2069 (TCPF_CLOSE | TCPF_LISTEN))) {
2070 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
2071 if (tp->keepalive_time > elapsed)
2072 elapsed = tp->keepalive_time - elapsed;
2073 else
2074 elapsed = 0;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002075 inet_csk_reset_keepalive_timer(sk, elapsed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002076 }
2077 }
2078 break;
2079 case TCP_KEEPINTVL:
2080 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2081 err = -EINVAL;
2082 else
2083 tp->keepalive_intvl = val * HZ;
2084 break;
2085 case TCP_KEEPCNT:
2086 if (val < 1 || val > MAX_TCP_KEEPCNT)
2087 err = -EINVAL;
2088 else
2089 tp->keepalive_probes = val;
2090 break;
2091 case TCP_SYNCNT:
2092 if (val < 1 || val > MAX_TCP_SYNCNT)
2093 err = -EINVAL;
2094 else
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002095 icsk->icsk_syn_retries = val;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002096 break;
2097
2098 case TCP_LINGER2:
2099 if (val < 0)
2100 tp->linger2 = -1;
2101 else if (val > sysctl_tcp_fin_timeout / HZ)
2102 tp->linger2 = 0;
2103 else
2104 tp->linger2 = val * HZ;
2105 break;
2106
2107 case TCP_DEFER_ACCEPT:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002108 icsk->icsk_accept_queue.rskq_defer_accept = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 if (val > 0) {
2110 /* Translate value in seconds to number of
2111 * retransmits */
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002112 while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07002113 val > ((TCP_TIMEOUT_INIT / HZ) <<
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002114 icsk->icsk_accept_queue.rskq_defer_accept))
2115 icsk->icsk_accept_queue.rskq_defer_accept++;
2116 icsk->icsk_accept_queue.rskq_defer_accept++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002117 }
2118 break;
2119
2120 case TCP_WINDOW_CLAMP:
2121 if (!val) {
2122 if (sk->sk_state != TCP_CLOSE) {
2123 err = -EINVAL;
2124 break;
2125 }
2126 tp->window_clamp = 0;
2127 } else
2128 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2129 SOCK_MIN_RCVBUF / 2 : val;
2130 break;
2131
2132 case TCP_QUICKACK:
2133 if (!val) {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002134 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002136 icsk->icsk_ack.pingpong = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002137 if ((1 << sk->sk_state) &
2138 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002139 inet_csk_ack_scheduled(sk)) {
2140 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
Chris Leech0e4b4992006-05-23 18:00:16 -07002141 tcp_cleanup_rbuf(sk, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002142 if (!(val & 1))
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002143 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002144 }
2145 }
2146 break;
2147
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002148#ifdef CONFIG_TCP_MD5SIG
2149 case TCP_MD5SIG:
2150 /* Read the IP->Key mappings from userspace */
2151 err = tp->af_specific->md5_parse(sk, optval, optlen);
2152 break;
2153#endif
2154
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155 default:
2156 err = -ENOPROTOOPT;
2157 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002158 }
2159
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160 release_sock(sk);
2161 return err;
2162}
2163
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002164int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2165 int optlen)
2166{
2167 struct inet_connection_sock *icsk = inet_csk(sk);
2168
2169 if (level != SOL_TCP)
2170 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2171 optval, optlen);
2172 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2173}
2174
2175#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002176int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2177 char __user *optval, int optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002178{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002179 if (level != SOL_TCP)
2180 return inet_csk_compat_setsockopt(sk, level, optname,
2181 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002182 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2183}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002184
2185EXPORT_SYMBOL(compat_tcp_setsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002186#endif
2187
Linus Torvalds1da177e2005-04-16 15:20:36 -07002188/* Return information about state of tcp endpoint in API format. */
2189void tcp_get_info(struct sock *sk, struct tcp_info *info)
2190{
2191 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002192 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002193 u32 now = tcp_time_stamp;
2194
2195 memset(info, 0, sizeof(*info));
2196
2197 info->tcpi_state = sk->sk_state;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002198 info->tcpi_ca_state = icsk->icsk_ca_state;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002199 info->tcpi_retransmits = icsk->icsk_retransmits;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002200 info->tcpi_probes = icsk->icsk_probes_out;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002201 info->tcpi_backoff = icsk->icsk_backoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002202
2203 if (tp->rx_opt.tstamp_ok)
2204 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
Ilpo Järvinene60402d2007-08-09 15:14:46 +03002205 if (tcp_is_sack(tp))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002206 info->tcpi_options |= TCPI_OPT_SACK;
2207 if (tp->rx_opt.wscale_ok) {
2208 info->tcpi_options |= TCPI_OPT_WSCALE;
2209 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2210 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09002211 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002212
2213 if (tp->ecn_flags&TCP_ECN_OK)
2214 info->tcpi_options |= TCPI_OPT_ECN;
2215
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002216 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2217 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002218 info->tcpi_snd_mss = tp->mss_cache;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002219 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002220
Rick Jones5ee3afb2007-09-18 13:26:31 -07002221 if (sk->sk_state == TCP_LISTEN) {
2222 info->tcpi_unacked = sk->sk_ack_backlog;
2223 info->tcpi_sacked = sk->sk_max_ack_backlog;
2224 } else {
2225 info->tcpi_unacked = tp->packets_out;
2226 info->tcpi_sacked = tp->sacked_out;
2227 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002228 info->tcpi_lost = tp->lost_out;
2229 info->tcpi_retrans = tp->retrans_out;
2230 info->tcpi_fackets = tp->fackets_out;
2231
2232 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002233 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002234 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2235
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08002236 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002237 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2238 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2239 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2240 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2241 info->tcpi_snd_cwnd = tp->snd_cwnd;
2242 info->tcpi_advmss = tp->advmss;
2243 info->tcpi_reordering = tp->reordering;
2244
2245 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2246 info->tcpi_rcv_space = tp->rcvq_space.space;
2247
2248 info->tcpi_total_retrans = tp->total_retrans;
2249}
2250
2251EXPORT_SYMBOL_GPL(tcp_get_info);
2252
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002253static int do_tcp_getsockopt(struct sock *sk, int level,
2254 int optname, char __user *optval, int __user *optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255{
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002256 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002257 struct tcp_sock *tp = tcp_sk(sk);
2258 int val, len;
2259
Linus Torvalds1da177e2005-04-16 15:20:36 -07002260 if (get_user(len, optlen))
2261 return -EFAULT;
2262
2263 len = min_t(unsigned int, len, sizeof(int));
2264
2265 if (len < 0)
2266 return -EINVAL;
2267
2268 switch (optname) {
2269 case TCP_MAXSEG:
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002270 val = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002271 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2272 val = tp->rx_opt.user_mss;
2273 break;
2274 case TCP_NODELAY:
2275 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2276 break;
2277 case TCP_CORK:
2278 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2279 break;
2280 case TCP_KEEPIDLE:
2281 val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
2282 break;
2283 case TCP_KEEPINTVL:
2284 val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
2285 break;
2286 case TCP_KEEPCNT:
2287 val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
2288 break;
2289 case TCP_SYNCNT:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002290 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002291 break;
2292 case TCP_LINGER2:
2293 val = tp->linger2;
2294 if (val >= 0)
2295 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2296 break;
2297 case TCP_DEFER_ACCEPT:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002298 val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
2299 ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002300 break;
2301 case TCP_WINDOW_CLAMP:
2302 val = tp->window_clamp;
2303 break;
2304 case TCP_INFO: {
2305 struct tcp_info info;
2306
2307 if (get_user(len, optlen))
2308 return -EFAULT;
2309
2310 tcp_get_info(sk, &info);
2311
2312 len = min_t(unsigned int, len, sizeof(info));
2313 if (put_user(len, optlen))
2314 return -EFAULT;
2315 if (copy_to_user(optval, &info, len))
2316 return -EFAULT;
2317 return 0;
2318 }
2319 case TCP_QUICKACK:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002320 val = !icsk->icsk_ack.pingpong;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002321 break;
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002322
2323 case TCP_CONGESTION:
2324 if (get_user(len, optlen))
2325 return -EFAULT;
2326 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2327 if (put_user(len, optlen))
2328 return -EFAULT;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002329 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002330 return -EFAULT;
2331 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002332 default:
2333 return -ENOPROTOOPT;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002334 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002335
2336 if (put_user(len, optlen))
2337 return -EFAULT;
2338 if (copy_to_user(optval, &val, len))
2339 return -EFAULT;
2340 return 0;
2341}
2342
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002343int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2344 int __user *optlen)
2345{
2346 struct inet_connection_sock *icsk = inet_csk(sk);
2347
2348 if (level != SOL_TCP)
2349 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2350 optval, optlen);
2351 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2352}
2353
2354#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002355int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2356 char __user *optval, int __user *optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002357{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002358 if (level != SOL_TCP)
2359 return inet_csk_compat_getsockopt(sk, level, optname,
2360 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002361 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2362}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002363
2364EXPORT_SYMBOL(compat_tcp_getsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002365#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002366
Herbert Xu576a30e2006-06-27 13:22:38 -07002367struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
Herbert Xuf4c50d92006-06-22 03:02:40 -07002368{
2369 struct sk_buff *segs = ERR_PTR(-EINVAL);
2370 struct tcphdr *th;
2371 unsigned thlen;
2372 unsigned int seq;
Al Virod3bc23e2006-11-14 21:24:49 -08002373 __be32 delta;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002374 unsigned int oldlen;
2375 unsigned int len;
2376
2377 if (!pskb_may_pull(skb, sizeof(*th)))
2378 goto out;
2379
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002380 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002381 thlen = th->doff * 4;
2382 if (thlen < sizeof(*th))
2383 goto out;
2384
2385 if (!pskb_may_pull(skb, thlen))
2386 goto out;
2387
Herbert Xu0718bcc2006-06-25 23:55:46 -07002388 oldlen = (u16)~skb->len;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002389 __skb_pull(skb, thlen);
2390
Herbert Xu3820c3f2006-06-29 20:11:25 -07002391 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2392 /* Packet is from an untrusted source, reset gso_segs. */
Herbert Xubbcf4672006-07-03 19:38:35 -07002393 int type = skb_shinfo(skb)->gso_type;
2394 int mss;
Herbert Xu3820c3f2006-06-29 20:11:25 -07002395
Herbert Xubbcf4672006-07-03 19:38:35 -07002396 if (unlikely(type &
2397 ~(SKB_GSO_TCPV4 |
2398 SKB_GSO_DODGY |
2399 SKB_GSO_TCP_ECN |
2400 SKB_GSO_TCPV6 |
2401 0) ||
2402 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2403 goto out;
2404
2405 mss = skb_shinfo(skb)->gso_size;
Ilpo Järvinen172589c2007-08-28 15:50:33 -07002406 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
Herbert Xu3820c3f2006-06-29 20:11:25 -07002407
2408 segs = NULL;
2409 goto out;
2410 }
2411
Herbert Xu576a30e2006-06-27 13:22:38 -07002412 segs = skb_segment(skb, features);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002413 if (IS_ERR(segs))
2414 goto out;
2415
2416 len = skb_shinfo(skb)->gso_size;
Herbert Xu0718bcc2006-06-25 23:55:46 -07002417 delta = htonl(oldlen + (thlen + len));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002418
2419 skb = segs;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002420 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002421 seq = ntohl(th->seq);
2422
2423 do {
2424 th->fin = th->psh = 0;
2425
Al Virod3bc23e2006-11-14 21:24:49 -08002426 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2427 (__force u32)delta));
Patrick McHardy84fa7932006-08-29 16:44:56 -07002428 if (skb->ip_summed != CHECKSUM_PARTIAL)
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002429 th->check =
2430 csum_fold(csum_partial(skb_transport_header(skb),
2431 thlen, skb->csum));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002432
2433 seq += len;
2434 skb = skb->next;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002435 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002436
2437 th->seq = htonl(seq);
2438 th->cwr = 0;
2439 } while (skb->next);
2440
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07002441 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002442 skb->data_len);
Al Virod3bc23e2006-11-14 21:24:49 -08002443 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2444 (__force u32)delta));
Patrick McHardy84fa7932006-08-29 16:44:56 -07002445 if (skb->ip_summed != CHECKSUM_PARTIAL)
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002446 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2447 thlen, skb->csum));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002448
2449out:
2450 return segs;
2451}
Herbert Xuadcfc7d2006-06-30 13:36:15 -07002452EXPORT_SYMBOL(tcp_tso_segment);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002453
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002454#ifdef CONFIG_TCP_MD5SIG
2455static unsigned long tcp_md5sig_users;
2456static struct tcp_md5sig_pool **tcp_md5sig_pool;
2457static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2458
2459static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
2460{
2461 int cpu;
2462 for_each_possible_cpu(cpu) {
2463 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2464 if (p) {
2465 if (p->md5_desc.tfm)
2466 crypto_free_hash(p->md5_desc.tfm);
2467 kfree(p);
2468 p = NULL;
2469 }
2470 }
2471 free_percpu(pool);
2472}
2473
2474void tcp_free_md5sig_pool(void)
2475{
2476 struct tcp_md5sig_pool **pool = NULL;
2477
David S. Miller2c4f6212007-02-20 23:51:47 -08002478 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002479 if (--tcp_md5sig_users == 0) {
2480 pool = tcp_md5sig_pool;
2481 tcp_md5sig_pool = NULL;
2482 }
David S. Miller2c4f6212007-02-20 23:51:47 -08002483 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002484 if (pool)
2485 __tcp_free_md5sig_pool(pool);
2486}
2487
2488EXPORT_SYMBOL(tcp_free_md5sig_pool);
2489
Adrian Bunkf5b99bc2006-11-30 17:22:29 -08002490static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002491{
2492 int cpu;
2493 struct tcp_md5sig_pool **pool;
2494
2495 pool = alloc_percpu(struct tcp_md5sig_pool *);
2496 if (!pool)
2497 return NULL;
2498
2499 for_each_possible_cpu(cpu) {
2500 struct tcp_md5sig_pool *p;
2501 struct crypto_hash *hash;
2502
2503 p = kzalloc(sizeof(*p), GFP_KERNEL);
2504 if (!p)
2505 goto out_free;
2506 *per_cpu_ptr(pool, cpu) = p;
2507
2508 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2509 if (!hash || IS_ERR(hash))
2510 goto out_free;
2511
2512 p->md5_desc.tfm = hash;
2513 }
2514 return pool;
2515out_free:
2516 __tcp_free_md5sig_pool(pool);
2517 return NULL;
2518}
2519
2520struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
2521{
2522 struct tcp_md5sig_pool **pool;
2523 int alloc = 0;
2524
2525retry:
David S. Miller2c4f6212007-02-20 23:51:47 -08002526 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002527 pool = tcp_md5sig_pool;
2528 if (tcp_md5sig_users++ == 0) {
2529 alloc = 1;
David S. Miller2c4f6212007-02-20 23:51:47 -08002530 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002531 } else if (!pool) {
2532 tcp_md5sig_users--;
David S. Miller2c4f6212007-02-20 23:51:47 -08002533 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002534 cpu_relax();
2535 goto retry;
2536 } else
David S. Miller2c4f6212007-02-20 23:51:47 -08002537 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002538
2539 if (alloc) {
2540 /* we cannot hold spinlock here because this may sleep. */
2541 struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
David S. Miller2c4f6212007-02-20 23:51:47 -08002542 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002543 if (!p) {
2544 tcp_md5sig_users--;
David S. Miller2c4f6212007-02-20 23:51:47 -08002545 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002546 return NULL;
2547 }
2548 pool = tcp_md5sig_pool;
2549 if (pool) {
2550 /* oops, it has already been assigned. */
David S. Miller2c4f6212007-02-20 23:51:47 -08002551 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002552 __tcp_free_md5sig_pool(p);
2553 } else {
2554 tcp_md5sig_pool = pool = p;
David S. Miller2c4f6212007-02-20 23:51:47 -08002555 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002556 }
2557 }
2558 return pool;
2559}
2560
2561EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2562
2563struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
2564{
2565 struct tcp_md5sig_pool **p;
David S. Miller2c4f6212007-02-20 23:51:47 -08002566 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002567 p = tcp_md5sig_pool;
2568 if (p)
2569 tcp_md5sig_users++;
David S. Miller2c4f6212007-02-20 23:51:47 -08002570 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002571 return (p ? *per_cpu_ptr(p, cpu) : NULL);
2572}
2573
2574EXPORT_SYMBOL(__tcp_get_md5sig_pool);
2575
David S. Miller6931ba72006-12-13 16:25:44 -08002576void __tcp_put_md5sig_pool(void)
2577{
2578 tcp_free_md5sig_pool();
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002579}
2580
2581EXPORT_SYMBOL(__tcp_put_md5sig_pool);
2582#endif
2583
Andi Kleen4ac02ba2007-04-20 17:11:46 -07002584void tcp_done(struct sock *sk)
2585{
2586 if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
2587 TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
2588
2589 tcp_set_state(sk, TCP_CLOSE);
2590 tcp_clear_xmit_timers(sk);
2591
2592 sk->sk_shutdown = SHUTDOWN_MASK;
2593
2594 if (!sock_flag(sk, SOCK_DEAD))
2595 sk->sk_state_change(sk);
2596 else
2597 inet_csk_destroy_sock(sk);
2598}
2599EXPORT_SYMBOL_GPL(tcp_done);
2600
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002601extern struct tcp_congestion_ops tcp_reno;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002602
2603static __initdata unsigned long thash_entries;
2604static int __init set_thash_entries(char *str)
2605{
2606 if (!str)
2607 return 0;
2608 thash_entries = simple_strtoul(str, &str, 0);
2609 return 1;
2610}
2611__setup("thash_entries=", set_thash_entries);
2612
2613void __init tcp_init(void)
2614{
2615 struct sk_buff *skb = NULL;
John Heffner7b4f4b52006-03-25 01:34:07 -08002616 unsigned long limit;
2617 int order, i, max_share;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002618
Pavel Emelyanov1f9e6362007-12-11 02:12:04 -08002619 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002620
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002621 tcp_hashinfo.bind_bucket_cachep =
2622 kmem_cache_create("tcp_bind_bucket",
2623 sizeof(struct inet_bind_bucket), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09002624 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002625
Linus Torvalds1da177e2005-04-16 15:20:36 -07002626 /* Size and allocate the main established and bind bucket
2627 * hash tables.
2628 *
2629 * The methodology is similar to that of the buffer cache.
2630 */
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002631 tcp_hashinfo.ehash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002632 alloc_large_system_hash("TCP established",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002633 sizeof(struct inet_ehash_bucket),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002634 thash_entries,
2635 (num_physpages >= 128 * 1024) ?
Mike Stroyan18955cf2005-11-29 16:12:55 -08002636 13 : 15,
John Heffner9e950ef2006-11-06 23:10:51 -08002637 0,
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002638 &tcp_hashinfo.ehash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002639 NULL,
Jean Delvare0ccfe612007-10-30 00:59:25 -07002640 thash_entries ? 0 : 512 * 1024);
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002641 tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
2642 for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002643 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain);
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002644 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002645 }
Eric Dumazet230140c2007-11-07 02:40:20 -08002646 if (inet_ehash_locks_alloc(&tcp_hashinfo))
2647 panic("TCP: failed to alloc ehash_locks");
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002648 tcp_hashinfo.bhash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002649 alloc_large_system_hash("TCP bind",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002650 sizeof(struct inet_bind_hashbucket),
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002651 tcp_hashinfo.ehash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002652 (num_physpages >= 128 * 1024) ?
Mike Stroyan18955cf2005-11-29 16:12:55 -08002653 13 : 15,
John Heffner9e950ef2006-11-06 23:10:51 -08002654 0,
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002655 &tcp_hashinfo.bhash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002656 NULL,
2657 64 * 1024);
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002658 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
2659 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
2660 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
2661 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002662 }
2663
2664 /* Try to be a bit smarter and adjust defaults depending
2665 * on available memory.
2666 */
2667 for (order = 0; ((1 << order) << PAGE_SHIFT) <
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002668 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002669 order++)
2670 ;
Andi Kleene7626482005-06-13 14:24:52 -07002671 if (order >= 4) {
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07002672 tcp_death_row.sysctl_max_tw_buckets = 180000;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002673 sysctl_tcp_max_orphans = 4096 << (order - 4);
2674 sysctl_max_syn_backlog = 1024;
2675 } else if (order < 3) {
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07002676 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002677 sysctl_tcp_max_orphans >>= (3 - order);
2678 sysctl_max_syn_backlog = 128;
2679 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002680
John Heffner53cdcc02007-03-16 15:04:03 -07002681 /* Set the pressure threshold to be a fraction of global memory that
2682 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
2683 * memory, with a floor of 128 pages.
2684 */
2685 limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
2686 limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
2687 limit = max(limit, 128UL);
2688 sysctl_tcp_mem[0] = limit / 4 * 3;
2689 sysctl_tcp_mem[1] = limit;
John Heffner52bf3762006-11-14 20:25:17 -08002690 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002691
John Heffner53cdcc02007-03-16 15:04:03 -07002692 /* Set per-socket limits to no more than 1/128 the pressure threshold */
John Heffner7b4f4b52006-03-25 01:34:07 -08002693 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
2694 max_share = min(4UL*1024*1024, limit);
2695
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002696 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08002697 sysctl_tcp_wmem[1] = 16*1024;
2698 sysctl_tcp_wmem[2] = max(64*1024, max_share);
2699
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002700 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08002701 sysctl_tcp_rmem[1] = 87380;
2702 sysctl_tcp_rmem[2] = max(87380, max_share);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002703
2704 printk(KERN_INFO "TCP: Hash tables configured "
2705 "(established %d bind %d)\n",
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002706 tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
Stephen Hemminger317a76f2005-06-23 12:19:55 -07002707
2708 tcp_register_congestion_control(&tcp_reno);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002709}
2710
Linus Torvalds1da177e2005-04-16 15:20:36 -07002711EXPORT_SYMBOL(tcp_close);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002712EXPORT_SYMBOL(tcp_disconnect);
2713EXPORT_SYMBOL(tcp_getsockopt);
2714EXPORT_SYMBOL(tcp_ioctl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002715EXPORT_SYMBOL(tcp_poll);
2716EXPORT_SYMBOL(tcp_read_sock);
2717EXPORT_SYMBOL(tcp_recvmsg);
2718EXPORT_SYMBOL(tcp_sendmsg);
Jens Axboe9c55e012007-11-06 23:30:13 -08002719EXPORT_SYMBOL(tcp_splice_read);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002720EXPORT_SYMBOL(tcp_sendpage);
2721EXPORT_SYMBOL(tcp_setsockopt);
2722EXPORT_SYMBOL(tcp_shutdown);
2723EXPORT_SYMBOL(tcp_statistics);