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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 *
Jesper Juhl02c30a82005-05-05 16:16:16 -07008 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Mark Evans, <evansmp@uhura.aston.ac.uk>
11 * Corey Minyard <wf-rch!minyard@relay.EU.net>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
14 * Linus Torvalds, <torvalds@cs.helsinki.fi>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Matthew Dillon, <dillon@apollo.west.oic.com>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Jorge Cwik, <jorge@laser.satlink.net>
19 *
20 * Fixes:
21 * Alan Cox : Numerous verify_area() calls
22 * Alan Cox : Set the ACK bit on a reset
23 * Alan Cox : Stopped it crashing if it closed while
24 * sk->inuse=1 and was trying to connect
25 * (tcp_err()).
26 * Alan Cox : All icmp error handling was broken
27 * pointers passed where wrong and the
28 * socket was looked up backwards. Nobody
29 * tested any icmp error code obviously.
30 * Alan Cox : tcp_err() now handled properly. It
31 * wakes people on errors. poll
32 * behaves and the icmp error race
33 * has gone by moving it into sock.c
34 * Alan Cox : tcp_send_reset() fixed to work for
35 * everything not just packets for
36 * unknown sockets.
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
39 * syn rule wrong]
40 * Herp Rosmanith : More reset fixes
41 * Alan Cox : No longer acks invalid rst frames.
42 * Acking any kind of RST is right out.
43 * Alan Cox : Sets an ignore me flag on an rst
44 * receive otherwise odd bits of prattle
45 * escape still
46 * Alan Cox : Fixed another acking RST frame bug.
47 * Should stop LAN workplace lockups.
48 * Alan Cox : Some tidyups using the new skb list
49 * facilities
50 * Alan Cox : sk->keepopen now seems to work
51 * Alan Cox : Pulls options out correctly on accepts
52 * Alan Cox : Fixed assorted sk->rqueue->next errors
53 * Alan Cox : PSH doesn't end a TCP read. Switched a
54 * bit to skb ops.
55 * Alan Cox : Tidied tcp_data to avoid a potential
56 * nasty.
57 * Alan Cox : Added some better commenting, as the
58 * tcp is hard to follow
59 * Alan Cox : Removed incorrect check for 20 * psh
60 * Michael O'Reilly : ack < copied bug fix.
61 * Johannes Stille : Misc tcp fixes (not all in yet).
62 * Alan Cox : FIN with no memory -> CRASH
63 * Alan Cox : Added socket option proto entries.
64 * Also added awareness of them to accept.
65 * Alan Cox : Added TCP options (SOL_TCP)
66 * Alan Cox : Switched wakeup calls to callbacks,
67 * so the kernel can layer network
68 * sockets.
69 * Alan Cox : Use ip_tos/ip_ttl settings.
70 * Alan Cox : Handle FIN (more) properly (we hope).
71 * Alan Cox : RST frames sent on unsynchronised
72 * state ack error.
73 * Alan Cox : Put in missing check for SYN bit.
74 * Alan Cox : Added tcp_select_window() aka NET2E
75 * window non shrink trick.
76 * Alan Cox : Added a couple of small NET2E timer
77 * fixes
78 * Charles Hedrick : TCP fixes
79 * Toomas Tamm : TCP window fixes
80 * Alan Cox : Small URG fix to rlogin ^C ack fight
81 * Charles Hedrick : Rewrote most of it to actually work
82 * Linus : Rewrote tcp_read() and URG handling
83 * completely
84 * Gerhard Koerting: Fixed some missing timer handling
85 * Matthew Dillon : Reworked TCP machine states as per RFC
86 * Gerhard Koerting: PC/TCP workarounds
87 * Adam Caldwell : Assorted timer/timing errors
88 * Matthew Dillon : Fixed another RST bug
89 * Alan Cox : Move to kernel side addressing changes.
90 * Alan Cox : Beginning work on TCP fastpathing
91 * (not yet usable)
92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
93 * Alan Cox : TCP fast path debugging
94 * Alan Cox : Window clamping
95 * Michael Riepe : Bug in tcp_check()
96 * Matt Dillon : More TCP improvements and RST bug fixes
97 * Matt Dillon : Yet more small nasties remove from the
98 * TCP code (Be very nice to this man if
99 * tcp finally works 100%) 8)
100 * Alan Cox : BSD accept semantics.
101 * Alan Cox : Reset on closedown bug.
102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
103 * Michael Pall : Handle poll() after URG properly in
104 * all cases.
105 * Michael Pall : Undo the last fix in tcp_read_urg()
106 * (multi URG PUSH broke rlogin).
107 * Michael Pall : Fix the multi URG PUSH problem in
108 * tcp_readable(), poll() after URG
109 * works now.
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
111 * BSD api.
112 * Alan Cox : Changed the semantics of sk->socket to
113 * fix a race and a signal problem with
114 * accept() and async I/O.
115 * Alan Cox : Relaxed the rules on tcp_sendto().
116 * Yury Shevchuk : Really fixed accept() blocking problem.
117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
118 * clients/servers which listen in on
119 * fixed ports.
120 * Alan Cox : Cleaned the above up and shrank it to
121 * a sensible code size.
122 * Alan Cox : Self connect lockup fix.
123 * Alan Cox : No connect to multicast.
124 * Ross Biro : Close unaccepted children on master
125 * socket close.
126 * Alan Cox : Reset tracing code.
127 * Alan Cox : Spurious resets on shutdown.
128 * Alan Cox : Giant 15 minute/60 second timer error
129 * Alan Cox : Small whoops in polling before an
130 * accept.
131 * Alan Cox : Kept the state trace facility since
132 * it's handy for debugging.
133 * Alan Cox : More reset handler fixes.
134 * Alan Cox : Started rewriting the code based on
135 * the RFC's for other useful protocol
136 * references see: Comer, KA9Q NOS, and
137 * for a reference on the difference
138 * between specifications and how BSD
139 * works see the 4.4lite source.
140 * A.N.Kuznetsov : Don't time wait on completion of tidy
141 * close.
142 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
143 * Linus Torvalds : Fixed BSD port reuse to work first syn
144 * Alan Cox : Reimplemented timers as per the RFC
145 * and using multiple timers for sanity.
146 * Alan Cox : Small bug fixes, and a lot of new
147 * comments.
148 * Alan Cox : Fixed dual reader crash by locking
149 * the buffers (much like datagram.c)
150 * Alan Cox : Fixed stuck sockets in probe. A probe
151 * now gets fed up of retrying without
152 * (even a no space) answer.
153 * Alan Cox : Extracted closing code better
154 * Alan Cox : Fixed the closing state machine to
155 * resemble the RFC.
156 * Alan Cox : More 'per spec' fixes.
157 * Jorge Cwik : Even faster checksumming.
158 * Alan Cox : tcp_data() doesn't ack illegal PSH
159 * only frames. At least one pc tcp stack
160 * generates them.
161 * Alan Cox : Cache last socket.
162 * Alan Cox : Per route irtt.
163 * Matt Day : poll()->select() match BSD precisely on error
164 * Alan Cox : New buffers
165 * Marc Tamsky : Various sk->prot->retransmits and
166 * sk->retransmits misupdating fixed.
167 * Fixed tcp_write_timeout: stuck close,
168 * and TCP syn retries gets used now.
169 * Mark Yarvis : In tcp_read_wakeup(), don't send an
170 * ack if state is TCP_CLOSED.
171 * Alan Cox : Look up device on a retransmit - routes may
172 * change. Doesn't yet cope with MSS shrink right
173 * but it's a start!
174 * Marc Tamsky : Closing in closing fixes.
175 * Mike Shaver : RFC1122 verifications.
176 * Alan Cox : rcv_saddr errors.
177 * Alan Cox : Block double connect().
178 * Alan Cox : Small hooks for enSKIP.
179 * Alexey Kuznetsov: Path MTU discovery.
180 * Alan Cox : Support soft errors.
181 * Alan Cox : Fix MTU discovery pathological case
182 * when the remote claims no mtu!
183 * Marc Tamsky : TCP_CLOSE fix.
184 * Colin (G3TNE) : Send a reset on syn ack replies in
185 * window but wrong (fixes NT lpd problems)
186 * Pedro Roque : Better TCP window handling, delayed ack.
187 * Joerg Reuter : No modification of locked buffers in
188 * tcp_do_retransmit()
189 * Eric Schenk : Changed receiver side silly window
190 * avoidance algorithm to BSD style
191 * algorithm. This doubles throughput
192 * against machines running Solaris,
193 * and seems to result in general
194 * improvement.
195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
196 * Willy Konynenberg : Transparent proxying support.
197 * Mike McLagan : Routing by source
198 * Keith Owens : Do proper merging with partial SKB's in
199 * tcp_do_sendmsg to avoid burstiness.
200 * Eric Schenk : Fix fast close down bug with
201 * shutdown() followed by close().
202 * Andi Kleen : Make poll agree with SIGIO
203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
204 * lingertime == 0 (RFC 793 ABORT Call)
205 * Hirokazu Takahashi : Use copy_from_user() instead of
206 * csum_and_copy_from_user() if possible.
207 *
208 * This program is free software; you can redistribute it and/or
209 * modify it under the terms of the GNU General Public License
210 * as published by the Free Software Foundation; either version
211 * 2 of the License, or(at your option) any later version.
212 *
213 * Description of States:
214 *
215 * TCP_SYN_SENT sent a connection request, waiting for ack
216 *
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
219 *
220 * TCP_ESTABLISHED connection established
221 *
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
224 *
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
226 * to shutdown
227 *
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
230 *
231 * TCP_TIME_WAIT timeout to catch resent junk before entering
232 * closed, can only be entered from FIN_WAIT2
233 * or CLOSING. Required because the other end
234 * may not have gotten our last ACK causing it
235 * to retransmit the data packet (which we ignore)
236 *
237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
238 * us to finish writing our data and to shutdown
239 * (we have to close() to move on to LAST_ACK)
240 *
241 * TCP_LAST_ACK out side has shutdown after remote has
242 * shutdown. There may still be data in our
243 * buffer that we have to finish sending
244 *
245 * TCP_CLOSE socket is finished
246 */
247
Ilpo Järvinen172589c2007-08-28 15:50:33 -0700248#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249#include <linux/module.h>
250#include <linux/types.h>
251#include <linux/fcntl.h>
252#include <linux/poll.h>
253#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254#include <linux/fs.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800255#include <linux/skbuff.h>
Andrew Morton81b23b42008-07-03 03:22:02 -0700256#include <linux/scatterlist.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800257#include <linux/splice.h>
258#include <linux/net.h>
259#include <linux/socket.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260#include <linux/random.h>
261#include <linux/bootmem.h>
Miquel van Smoorenburg57413eb2008-06-27 17:23:57 -0700262#include <linux/highmem.h>
263#include <linux/swap.h>
David S. Millerb8059ea2006-03-25 01:36:56 -0800264#include <linux/cache.h>
Herbert Xuf4c50d92006-06-22 03:02:40 -0700265#include <linux/err.h>
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800266#include <linux/crypto.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
268#include <net/icmp.h>
269#include <net/tcp.h>
270#include <net/xfrm.h>
271#include <net/ip.h>
Chris Leech1a2449a2006-05-23 18:05:53 -0700272#include <net/netdma.h>
Jens Axboe9c55e012007-11-06 23:30:13 -0800273#include <net/sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275#include <asm/uaccess.h>
276#include <asm/ioctls.h>
277
Brian Haleyab32ea52006-09-22 14:15:41 -0700278int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
Eric Dumazetdd24c002008-11-25 21:17:14 -0800280struct percpu_counter tcp_orphan_count;
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -0700281EXPORT_SYMBOL_GPL(tcp_orphan_count);
282
David S. Millerb8059ea2006-03-25 01:36:56 -0800283int sysctl_tcp_mem[3] __read_mostly;
284int sysctl_tcp_wmem[3] __read_mostly;
285int sysctl_tcp_rmem[3] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
287EXPORT_SYMBOL(sysctl_tcp_mem);
288EXPORT_SYMBOL(sysctl_tcp_rmem);
289EXPORT_SYMBOL(sysctl_tcp_wmem);
290
291atomic_t tcp_memory_allocated; /* Current allocated memory. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292EXPORT_SYMBOL(tcp_memory_allocated);
Eric Dumazet17483762008-11-25 21:16:35 -0800293
294/*
295 * Current number of TCP sockets.
296 */
297struct percpu_counter tcp_sockets_allocated;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298EXPORT_SYMBOL(tcp_sockets_allocated);
299
300/*
Jens Axboe9c55e012007-11-06 23:30:13 -0800301 * TCP splice context
302 */
303struct tcp_splice_state {
304 struct pipe_inode_info *pipe;
305 size_t len;
306 unsigned int flags;
307};
308
309/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 * Pressure flag: try to collapse.
311 * Technical note: it is used by multiple contexts non atomically.
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800312 * All the __sk_mem_schedule() is of this nature: accounting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 * is strict, actions are advisory and have some latency.
314 */
Eric Dumazet4103f8c2007-03-27 13:58:31 -0700315int tcp_memory_pressure __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
317EXPORT_SYMBOL(tcp_memory_pressure);
318
Pavel Emelyanov5c52ba12008-07-16 20:28:10 -0700319void tcp_enter_memory_pressure(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320{
321 if (!tcp_memory_pressure) {
Pavel Emelyanov4e673442008-07-16 20:30:14 -0700322 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 tcp_memory_pressure = 1;
324 }
325}
326
327EXPORT_SYMBOL(tcp_enter_memory_pressure);
328
329/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 * Wait for a TCP event.
331 *
332 * Note that we don't need to lock the socket, as the upper poll layers
333 * take care of normal races (between the test and the event) and we don't
334 * go look at any of the socket buffers directly.
335 */
336unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
337{
338 unsigned int mask;
339 struct sock *sk = sock->sk;
340 struct tcp_sock *tp = tcp_sk(sk);
341
342 poll_wait(file, sk->sk_sleep, wait);
343 if (sk->sk_state == TCP_LISTEN)
Arnaldo Carvalho de Melodc40c7b2005-08-23 21:52:58 -0700344 return inet_csk_listen_poll(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 /* Socket is not locked. We are protected from async events
Will Newton70efce22008-07-16 20:13:43 -0700347 * by poll logic and correct handling of state changes
348 * made by other threads is impossible in any case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 */
350
351 mask = 0;
352 if (sk->sk_err)
353 mask = POLLERR;
354
355 /*
356 * POLLHUP is certainly not done right. But poll() doesn't
357 * have a notion of HUP in just one direction, and for a
358 * socket the read side is more interesting.
359 *
360 * Some poll() documentation says that POLLHUP is incompatible
361 * with the POLLOUT/POLLWR flags, so somebody should check this
362 * all. But careful, it tends to be safer to return too many
363 * bits than too few, and you can easily break real applications
364 * if you don't tell them that something has hung up!
365 *
366 * Check-me.
367 *
368 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
369 * our fs/select.c). It means that after we received EOF,
370 * poll always returns immediately, making impossible poll() on write()
371 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
372 * if and only if shutdown has been made in both directions.
373 * Actually, it is interesting to look how Solaris and DUX
Will Newton70efce22008-07-16 20:13:43 -0700374 * solve this dilemma. I would prefer, if POLLHUP were maskable,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 * then we could set it on SND_SHUTDOWN. BTW examples given
376 * in Stevens' books assume exactly this behaviour, it explains
Will Newton70efce22008-07-16 20:13:43 -0700377 * why POLLHUP is incompatible with POLLOUT. --ANK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 *
379 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
380 * blocking on fresh not-connected or disconnected socket. --ANK
381 */
382 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
383 mask |= POLLHUP;
384 if (sk->sk_shutdown & RCV_SHUTDOWN)
Davide Libenzif348d702006-03-25 03:07:39 -0800385 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387 /* Connected? */
388 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
David S. Millerc7004482008-10-06 10:43:54 -0700389 int target = sock_rcvlowat(sk, 0, INT_MAX);
390
391 if (tp->urg_seq == tp->copied_seq &&
392 !sock_flag(sk, SOCK_URGINLINE) &&
393 tp->urg_data)
394 target--;
395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 /* Potential race condition. If read of tp below will
397 * escape above sk->sk_state, we can be illegally awaken
398 * in SYN_* states. */
David S. Millerc7004482008-10-06 10:43:54 -0700399 if (tp->rcv_nxt - tp->copied_seq >= target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 mask |= POLLIN | POLLRDNORM;
401
402 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
403 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
404 mask |= POLLOUT | POLLWRNORM;
405 } else { /* send SIGIO later */
406 set_bit(SOCK_ASYNC_NOSPACE,
407 &sk->sk_socket->flags);
408 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
409
410 /* Race breaker. If space is freed after
411 * wspace test but before the flags are set,
412 * IO signal will be lost.
413 */
414 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
415 mask |= POLLOUT | POLLWRNORM;
416 }
417 }
418
419 if (tp->urg_data & TCP_URG_VALID)
420 mask |= POLLPRI;
421 }
422 return mask;
423}
424
425int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
426{
427 struct tcp_sock *tp = tcp_sk(sk);
428 int answ;
429
430 switch (cmd) {
431 case SIOCINQ:
432 if (sk->sk_state == TCP_LISTEN)
433 return -EINVAL;
434
435 lock_sock(sk);
436 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
437 answ = 0;
438 else if (sock_flag(sk, SOCK_URGINLINE) ||
439 !tp->urg_data ||
440 before(tp->urg_seq, tp->copied_seq) ||
441 !before(tp->urg_seq, tp->rcv_nxt)) {
442 answ = tp->rcv_nxt - tp->copied_seq;
443
444 /* Subtract 1, if FIN is in queue. */
445 if (answ && !skb_queue_empty(&sk->sk_receive_queue))
446 answ -=
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700447 tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 } else
449 answ = tp->urg_seq - tp->copied_seq;
450 release_sock(sk);
451 break;
452 case SIOCATMARK:
453 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
454 break;
455 case SIOCOUTQ:
456 if (sk->sk_state == TCP_LISTEN)
457 return -EINVAL;
458
459 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
460 answ = 0;
461 else
462 answ = tp->write_seq - tp->snd_una;
463 break;
464 default:
465 return -ENOIOCTLCMD;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700466 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
468 return put_user(answ, (int __user *)arg);
469}
470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
472{
473 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
474 tp->pushed_seq = tp->write_seq;
475}
476
477static inline int forced_push(struct tcp_sock *tp)
478{
479 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
480}
481
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700482static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700484 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo352d4802006-11-17 19:59:12 -0200485 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
486
487 skb->csum = 0;
488 tcb->seq = tcb->end_seq = tp->write_seq;
489 tcb->flags = TCPCB_FLAG_ACK;
490 tcb->sacked = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 skb_header_release(skb);
David S. Millerfe067e82007-03-07 12:12:44 -0800492 tcp_add_write_queue_tail(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800493 sk->sk_wmem_queued += skb->truesize;
494 sk_mem_charge(sk, skb->truesize);
David S. Miller89ebd192005-08-23 10:13:06 -0700495 if (tp->nonagle & TCP_NAGLE_PUSH)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900496 tp->nonagle &= ~TCP_NAGLE_PUSH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497}
498
499static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
500 struct sk_buff *skb)
501{
Ilpo Järvinen33f5f572008-10-07 14:43:06 -0700502 if (flags & MSG_OOB)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 tp->snd_up = tp->write_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504}
505
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700506static inline void tcp_push(struct sock *sk, int flags, int mss_now,
507 int nonagle)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700509 struct tcp_sock *tp = tcp_sk(sk);
510
David S. Millerfe067e82007-03-07 12:12:44 -0800511 if (tcp_send_head(sk)) {
512 struct sk_buff *skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 if (!(flags & MSG_MORE) || forced_push(tp))
514 tcp_mark_push(tp, skb);
515 tcp_mark_urg(tp, flags, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700516 __tcp_push_pending_frames(sk, mss_now,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
518 }
519}
520
Adrian Bunk6ff77512007-11-06 23:32:26 -0800521static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
522 unsigned int offset, size_t len)
Jens Axboe9c55e012007-11-06 23:30:13 -0800523{
524 struct tcp_splice_state *tss = rd_desc->arg.data;
Willy Tarreau33966dd2009-01-13 16:04:36 -0800525 int ret;
Jens Axboe9c55e012007-11-06 23:30:13 -0800526
Dimitris Michailidis9fa5fdf2009-01-26 22:15:31 -0800527 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
528 tss->flags);
Willy Tarreau33966dd2009-01-13 16:04:36 -0800529 if (ret > 0)
530 rd_desc->count -= ret;
531 return ret;
Jens Axboe9c55e012007-11-06 23:30:13 -0800532}
533
534static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
535{
536 /* Store TCP splice context information in read_descriptor_t. */
537 read_descriptor_t rd_desc = {
538 .arg.data = tss,
Willy Tarreau33966dd2009-01-13 16:04:36 -0800539 .count = tss->len,
Jens Axboe9c55e012007-11-06 23:30:13 -0800540 };
541
542 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
543}
544
545/**
546 * tcp_splice_read - splice data from TCP socket to a pipe
547 * @sock: socket to splice from
548 * @ppos: position (not valid)
549 * @pipe: pipe to splice to
550 * @len: number of bytes to splice
551 * @flags: splice modifier flags
552 *
553 * Description:
554 * Will read pages from given socket and fill them into a pipe.
555 *
556 **/
557ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
558 struct pipe_inode_info *pipe, size_t len,
559 unsigned int flags)
560{
561 struct sock *sk = sock->sk;
562 struct tcp_splice_state tss = {
563 .pipe = pipe,
564 .len = len,
565 .flags = flags,
566 };
567 long timeo;
568 ssize_t spliced;
569 int ret;
570
571 /*
572 * We can't seek on a socket input
573 */
574 if (unlikely(*ppos))
575 return -ESPIPE;
576
577 ret = spliced = 0;
578
579 lock_sock(sk);
580
581 timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
582 while (tss.len) {
583 ret = __tcp_splice_read(sk, &tss);
584 if (ret < 0)
585 break;
586 else if (!ret) {
587 if (spliced)
588 break;
Jens Axboe9c55e012007-11-06 23:30:13 -0800589 if (sock_flag(sk, SOCK_DONE))
590 break;
591 if (sk->sk_err) {
592 ret = sock_error(sk);
593 break;
594 }
595 if (sk->sk_shutdown & RCV_SHUTDOWN)
596 break;
597 if (sk->sk_state == TCP_CLOSE) {
598 /*
599 * This occurs when user tries to read
600 * from never connected socket.
601 */
602 if (!sock_flag(sk, SOCK_DONE))
603 ret = -ENOTCONN;
604 break;
605 }
606 if (!timeo) {
607 ret = -EAGAIN;
608 break;
609 }
610 sk_wait_data(sk, &timeo);
611 if (signal_pending(current)) {
612 ret = sock_intr_errno(timeo);
613 break;
614 }
615 continue;
616 }
617 tss.len -= ret;
618 spliced += ret;
619
Willy Tarreau33966dd2009-01-13 16:04:36 -0800620 if (!timeo)
621 break;
Jens Axboe9c55e012007-11-06 23:30:13 -0800622 release_sock(sk);
623 lock_sock(sk);
624
625 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
Willy Tarreau33966dd2009-01-13 16:04:36 -0800626 (sk->sk_shutdown & RCV_SHUTDOWN) ||
Jens Axboe9c55e012007-11-06 23:30:13 -0800627 signal_pending(current))
628 break;
629 }
630
631 release_sock(sk);
632
633 if (spliced)
634 return spliced;
635
636 return ret;
637}
638
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100639struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100640{
641 struct sk_buff *skb;
642
643 /* The TCP header must be at least 32-bit aligned. */
644 size = ALIGN(size, 4);
645
646 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
647 if (skb) {
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800648 if (sk_wmem_schedule(sk, skb->truesize)) {
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100649 /*
650 * Make sure that we have exactly size bytes
651 * available to the caller, no more, no less.
652 */
653 skb_reserve(skb, skb_tailroom(skb) - size);
654 return skb;
655 }
656 __kfree_skb(skb);
657 } else {
Pavel Emelyanov5c52ba12008-07-16 20:28:10 -0700658 sk->sk_prot->enter_memory_pressure(sk);
Pavel Emelyanovf561d0f2007-11-29 20:28:50 +1100659 sk_stream_moderate_sndbuf(sk);
660 }
661 return NULL;
662}
663
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
665 size_t psize, int flags)
666{
667 struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700668 int mss_now, size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 int err;
670 ssize_t copied;
671 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
672
673 /* Wait for a connection to finish. */
674 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
675 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
676 goto out_err;
677
678 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
679
680 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700681 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 copied = 0;
683
684 err = -EPIPE;
685 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
686 goto do_error;
687
688 while (psize > 0) {
David S. Millerfe067e82007-03-07 12:12:44 -0800689 struct sk_buff *skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 struct page *page = pages[poffset / PAGE_SIZE];
691 int copy, i, can_coalesce;
692 int offset = poffset % PAGE_SIZE;
693 int size = min_t(size_t, psize, PAGE_SIZE - offset);
694
David S. Millerfe067e82007-03-07 12:12:44 -0800695 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696new_segment:
697 if (!sk_stream_memory_free(sk))
698 goto wait_for_sndbuf;
699
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100700 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 if (!skb)
702 goto wait_for_memory;
703
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700704 skb_entail(sk, skb);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700705 copy = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 }
707
708 if (copy > size)
709 copy = size;
710
711 i = skb_shinfo(skb)->nr_frags;
712 can_coalesce = skb_can_coalesce(skb, i, page, offset);
713 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
714 tcp_mark_push(tp, skb);
715 goto new_segment;
716 }
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800717 if (!sk_wmem_schedule(sk, copy))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 goto wait_for_memory;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900719
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 if (can_coalesce) {
721 skb_shinfo(skb)->frags[i - 1].size += copy;
722 } else {
723 get_page(page);
724 skb_fill_page_desc(skb, i, page, offset, copy);
725 }
726
727 skb->len += copy;
728 skb->data_len += copy;
729 skb->truesize += copy;
730 sk->sk_wmem_queued += copy;
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800731 sk_mem_charge(sk, copy);
Patrick McHardy84fa7932006-08-29 16:44:56 -0700732 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 tp->write_seq += copy;
734 TCP_SKB_CB(skb)->end_seq += copy;
Herbert Xu79671682006-06-22 02:40:14 -0700735 skb_shinfo(skb)->gso_segs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 if (!copied)
738 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
739
740 copied += copy;
741 poffset += copy;
742 if (!(psize -= copy))
743 goto out;
744
Herbert Xu69d15062008-03-22 15:47:05 -0700745 if (skb->len < size_goal || (flags & MSG_OOB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 continue;
747
748 if (forced_push(tp)) {
749 tcp_mark_push(tp, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700750 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
David S. Millerfe067e82007-03-07 12:12:44 -0800751 } else if (skb == tcp_send_head(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 tcp_push_one(sk, mss_now);
753 continue;
754
755wait_for_sndbuf:
756 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
757wait_for_memory:
758 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700759 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
761 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
762 goto do_error;
763
764 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700765 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 }
767
768out:
769 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700770 tcp_push(sk, flags, mss_now, tp->nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 return copied;
772
773do_error:
774 if (copied)
775 goto out;
776out_err:
777 return sk_stream_error(sk, flags, err);
778}
779
780ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
781 size_t size, int flags)
782{
783 ssize_t res;
784 struct sock *sk = sock->sk;
785
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 if (!(sk->sk_route_caps & NETIF_F_SG) ||
Herbert Xu8648b302006-06-17 22:06:05 -0700787 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 return sock_no_sendpage(sock, page, offset, size, flags);
789
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 lock_sock(sk);
791 TCP_CHECK_TIMER(sk);
792 res = do_tcp_sendpages(sk, &page, offset, size, flags);
793 TCP_CHECK_TIMER(sk);
794 release_sock(sk);
795 return res;
796}
797
798#define TCP_PAGE(sk) (sk->sk_sndmsg_page)
799#define TCP_OFF(sk) (sk->sk_sndmsg_off)
800
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700801static inline int select_size(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700803 struct tcp_sock *tp = tcp_sk(sk);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700804 int tmp = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805
David S. Millerb4e26f52005-07-05 15:20:27 -0700806 if (sk->sk_route_caps & NETIF_F_SG) {
Herbert Xubcd76112006-06-30 13:36:35 -0700807 if (sk_can_gso(sk))
David S. Millerb4e26f52005-07-05 15:20:27 -0700808 tmp = 0;
809 else {
810 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
811
812 if (tmp >= pgbreak &&
813 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
814 tmp = pgbreak;
815 }
816 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 return tmp;
819}
820
David S. Miller3516ffb2007-08-02 19:23:56 -0700821int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 size_t size)
823{
David S. Miller3516ffb2007-08-02 19:23:56 -0700824 struct sock *sk = sock->sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 struct iovec *iov;
826 struct tcp_sock *tp = tcp_sk(sk);
827 struct sk_buff *skb;
828 int iovlen, flags;
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700829 int mss_now, size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 int err, copied;
831 long timeo;
832
833 lock_sock(sk);
834 TCP_CHECK_TIMER(sk);
835
836 flags = msg->msg_flags;
837 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
838
839 /* Wait for a connection to finish. */
840 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
841 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
842 goto out_err;
843
844 /* This should be in poll */
845 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
846
847 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700848 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849
850 /* Ok commence sending. */
851 iovlen = msg->msg_iovlen;
852 iov = msg->msg_iov;
853 copied = 0;
854
855 err = -EPIPE;
856 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
857 goto do_error;
858
859 while (--iovlen >= 0) {
860 int seglen = iov->iov_len;
861 unsigned char __user *from = iov->iov_base;
862
863 iov++;
864
865 while (seglen > 0) {
866 int copy;
867
David S. Millerfe067e82007-03-07 12:12:44 -0800868 skb = tcp_write_queue_tail(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
David S. Millerfe067e82007-03-07 12:12:44 -0800870 if (!tcp_send_head(sk) ||
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700871 (copy = size_goal - skb->len) <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872
873new_segment:
874 /* Allocate new segment. If the interface is SG,
875 * allocate skb fitting to single page.
876 */
877 if (!sk_stream_memory_free(sk))
878 goto wait_for_sndbuf;
879
Pavel Emelyanovdf97c702007-11-29 21:22:33 +1100880 skb = sk_stream_alloc_skb(sk, select_size(sk),
881 sk->sk_allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 if (!skb)
883 goto wait_for_memory;
884
885 /*
886 * Check whether we can use HW checksum.
887 */
Herbert Xu8648b302006-06-17 22:06:05 -0700888 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
Patrick McHardy84fa7932006-08-29 16:44:56 -0700889 skb->ip_summed = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700891 skb_entail(sk, skb);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700892 copy = size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 }
894
895 /* Try to append data to the end of skb. */
896 if (copy > seglen)
897 copy = seglen;
898
899 /* Where to copy to? */
900 if (skb_tailroom(skb) > 0) {
901 /* We have some space in skb head. Superb! */
902 if (copy > skb_tailroom(skb))
903 copy = skb_tailroom(skb);
904 if ((err = skb_add_data(skb, from, copy)) != 0)
905 goto do_fault;
906 } else {
907 int merge = 0;
908 int i = skb_shinfo(skb)->nr_frags;
909 struct page *page = TCP_PAGE(sk);
910 int off = TCP_OFF(sk);
911
912 if (skb_can_coalesce(skb, i, page, off) &&
913 off != PAGE_SIZE) {
914 /* We can extend the last page
915 * fragment. */
916 merge = 1;
917 } else if (i == MAX_SKB_FRAGS ||
918 (!i &&
919 !(sk->sk_route_caps & NETIF_F_SG))) {
920 /* Need to add new fragment and cannot
921 * do this because interface is non-SG,
922 * or because all the page slots are
923 * busy. */
924 tcp_mark_push(tp, skb);
925 goto new_segment;
926 } else if (page) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 if (off == PAGE_SIZE) {
928 put_page(page);
929 TCP_PAGE(sk) = page = NULL;
Herbert Xufb5f5e62005-09-05 18:55:48 -0700930 off = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 }
Herbert Xuef015782005-09-01 17:48:59 -0700932 } else
Herbert Xufb5f5e62005-09-05 18:55:48 -0700933 off = 0;
Herbert Xuef015782005-09-01 17:48:59 -0700934
935 if (copy > PAGE_SIZE - off)
936 copy = PAGE_SIZE - off;
937
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800938 if (!sk_wmem_schedule(sk, copy))
Herbert Xuef015782005-09-01 17:48:59 -0700939 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940
941 if (!page) {
942 /* Allocate new cache page. */
943 if (!(page = sk_stream_alloc_page(sk)))
944 goto wait_for_memory;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 }
946
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 /* Time to copy data. We are close to
948 * the end! */
949 err = skb_copy_to_page(sk, from, skb, page,
950 off, copy);
951 if (err) {
952 /* If this page was new, give it to the
953 * socket so it does not get leaked.
954 */
955 if (!TCP_PAGE(sk)) {
956 TCP_PAGE(sk) = page;
957 TCP_OFF(sk) = 0;
958 }
959 goto do_error;
960 }
961
962 /* Update the skb. */
963 if (merge) {
964 skb_shinfo(skb)->frags[i - 1].size +=
965 copy;
966 } else {
967 skb_fill_page_desc(skb, i, page, off, copy);
968 if (TCP_PAGE(sk)) {
969 get_page(page);
970 } else if (off + copy < PAGE_SIZE) {
971 get_page(page);
972 TCP_PAGE(sk) = page;
973 }
974 }
975
976 TCP_OFF(sk) = off + copy;
977 }
978
979 if (!copied)
980 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
981
982 tp->write_seq += copy;
983 TCP_SKB_CB(skb)->end_seq += copy;
Herbert Xu79671682006-06-22 02:40:14 -0700984 skb_shinfo(skb)->gso_segs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
986 from += copy;
987 copied += copy;
988 if ((seglen -= copy) == 0 && iovlen == 0)
989 goto out;
990
Herbert Xu69d15062008-03-22 15:47:05 -0700991 if (skb->len < size_goal || (flags & MSG_OOB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 continue;
993
994 if (forced_push(tp)) {
995 tcp_mark_push(tp, skb);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700996 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
David S. Millerfe067e82007-03-07 12:12:44 -0800997 } else if (skb == tcp_send_head(sk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 tcp_push_one(sk, mss_now);
999 continue;
1000
1001wait_for_sndbuf:
1002 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1003wait_for_memory:
1004 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001005 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006
1007 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1008 goto do_error;
1009
1010 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
David S. Millerc1b4a7e2005-07-05 15:24:38 -07001011 size_goal = tp->xmit_size_goal;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 }
1013 }
1014
1015out:
1016 if (copied)
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001017 tcp_push(sk, flags, mss_now, tp->nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 TCP_CHECK_TIMER(sk);
1019 release_sock(sk);
1020 return copied;
1021
1022do_fault:
1023 if (!skb->len) {
David S. Millerfe067e82007-03-07 12:12:44 -08001024 tcp_unlink_write_queue(skb, sk);
1025 /* It is the one place in all of TCP, except connection
1026 * reset, where we can be unlinking the send_head.
1027 */
1028 tcp_check_send_head(sk, skb);
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001029 sk_wmem_free_skb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 }
1031
1032do_error:
1033 if (copied)
1034 goto out;
1035out_err:
1036 err = sk_stream_error(sk, flags, err);
1037 TCP_CHECK_TIMER(sk);
1038 release_sock(sk);
1039 return err;
1040}
1041
1042/*
1043 * Handle reading urgent data. BSD has very simple semantics for
1044 * this, no blocking and very strange errors 8)
1045 */
1046
1047static int tcp_recv_urg(struct sock *sk, long timeo,
1048 struct msghdr *msg, int len, int flags,
1049 int *addr_len)
1050{
1051 struct tcp_sock *tp = tcp_sk(sk);
1052
1053 /* No URG data to read. */
1054 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1055 tp->urg_data == TCP_URG_READ)
1056 return -EINVAL; /* Yes this is right ! */
1057
1058 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1059 return -ENOTCONN;
1060
1061 if (tp->urg_data & TCP_URG_VALID) {
1062 int err = 0;
1063 char c = tp->urg_data;
1064
1065 if (!(flags & MSG_PEEK))
1066 tp->urg_data = TCP_URG_READ;
1067
1068 /* Read urgent data. */
1069 msg->msg_flags |= MSG_OOB;
1070
1071 if (len > 0) {
1072 if (!(flags & MSG_TRUNC))
1073 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1074 len = 1;
1075 } else
1076 msg->msg_flags |= MSG_TRUNC;
1077
1078 return err ? -EFAULT : len;
1079 }
1080
1081 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1082 return 0;
1083
1084 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1085 * the available implementations agree in this case:
1086 * this call should never block, independent of the
1087 * blocking state of the socket.
1088 * Mike <pall@rz.uni-karlsruhe.de>
1089 */
1090 return -EAGAIN;
1091}
1092
1093/* Clean up the receive buffer for full frames taken by the user,
1094 * then send an ACK if necessary. COPIED is the number of bytes
1095 * tcp_recvmsg has given to the user so far, it speeds up the
1096 * calculation of whether or not we must ACK for the sake of
1097 * a window update.
1098 */
Chris Leech0e4b4992006-05-23 18:00:16 -07001099void tcp_cleanup_rbuf(struct sock *sk, int copied)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100{
1101 struct tcp_sock *tp = tcp_sk(sk);
1102 int time_to_ack = 0;
1103
1104#if TCP_DEBUG
1105 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1106
Ilpo Järvinen547b7922008-07-25 21:43:18 -07001107 WARN_ON(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108#endif
1109
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001110 if (inet_csk_ack_scheduled(sk)) {
1111 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112 /* Delayed ACKs frequently hit locked sockets during bulk
1113 * receive. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001114 if (icsk->icsk_ack.blocked ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 /* Once-per-two-segments ACK was not sent by tcp_input.c */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001116 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 /*
1118 * If this read emptied read buffer, we send ACK, if
1119 * connection is not bidirectional, user drained
1120 * receive buffer and there was a small segment
1121 * in queue.
1122 */
Alexey Kuznetsov1ef96962006-09-19 12:52:50 -07001123 (copied > 0 &&
1124 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1125 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1126 !icsk->icsk_ack.pingpong)) &&
1127 !atomic_read(&sk->sk_rmem_alloc)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 time_to_ack = 1;
1129 }
1130
1131 /* We send an ACK if we can now advertise a non-zero window
1132 * which has been raised "significantly".
1133 *
1134 * Even if window raised up to infinity, do not send window open ACK
1135 * in states, where we will not receive more. It is useless.
1136 */
1137 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1138 __u32 rcv_window_now = tcp_receive_window(tp);
1139
1140 /* Optimize, __tcp_select_window() is not cheap. */
1141 if (2*rcv_window_now <= tp->window_clamp) {
1142 __u32 new_window = __tcp_select_window(sk);
1143
1144 /* Send ACK now, if this read freed lots of space
1145 * in our buffer. Certainly, new_window is new window.
1146 * We can advertise it now, if it is not less than current one.
1147 * "Lots" means "at least twice" here.
1148 */
1149 if (new_window && new_window >= 2 * rcv_window_now)
1150 time_to_ack = 1;
1151 }
1152 }
1153 if (time_to_ack)
1154 tcp_send_ack(sk);
1155}
1156
1157static void tcp_prequeue_process(struct sock *sk)
1158{
1159 struct sk_buff *skb;
1160 struct tcp_sock *tp = tcp_sk(sk);
1161
Pavel Emelyanov6f67c812008-07-16 20:31:39 -07001162 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163
1164 /* RX process wants to run with disabled BHs, though it is not
1165 * necessary */
1166 local_bh_disable();
1167 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
Peter Zijlstrac57943a2008-10-07 14:18:42 -07001168 sk_backlog_rcv(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 local_bh_enable();
1170
1171 /* Clear memory counter. */
1172 tp->ucopy.memory = 0;
1173}
1174
1175static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1176{
1177 struct sk_buff *skb;
1178 u32 offset;
1179
1180 skb_queue_walk(&sk->sk_receive_queue, skb) {
1181 offset = seq - TCP_SKB_CB(skb)->seq;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001182 if (tcp_hdr(skb)->syn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 offset--;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001184 if (offset < skb->len || tcp_hdr(skb)->fin) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 *off = offset;
1186 return skb;
1187 }
1188 }
1189 return NULL;
1190}
1191
1192/*
1193 * This routine provides an alternative to tcp_recvmsg() for routines
1194 * that would like to handle copying from skbuffs directly in 'sendfile'
1195 * fashion.
1196 * Note:
1197 * - It is assumed that the socket was locked by the caller.
1198 * - The routine does not block.
1199 * - At present, there is no support for reading OOB data
1200 * or for 'peeking' the socket using this routine
1201 * (although both would be easy to implement).
1202 */
1203int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1204 sk_read_actor_t recv_actor)
1205{
1206 struct sk_buff *skb;
1207 struct tcp_sock *tp = tcp_sk(sk);
1208 u32 seq = tp->copied_seq;
1209 u32 offset;
1210 int copied = 0;
1211
1212 if (sk->sk_state == TCP_LISTEN)
1213 return -ENOTCONN;
1214 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1215 if (offset < skb->len) {
Octavian Purdila374e7b52008-07-03 03:31:21 -07001216 int used;
1217 size_t len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218
1219 len = skb->len - offset;
1220 /* Stop reading if we hit a patch of urgent data */
1221 if (tp->urg_data) {
1222 u32 urg_offset = tp->urg_seq - seq;
1223 if (urg_offset < len)
1224 len = urg_offset;
1225 if (!len)
1226 break;
1227 }
1228 used = recv_actor(desc, skb, offset, len);
Jens Axboeddb61a52007-06-23 23:07:50 -07001229 if (used < 0) {
1230 if (!copied)
1231 copied = used;
1232 break;
1233 } else if (used <= len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 seq += used;
1235 copied += used;
1236 offset += used;
1237 }
Octavian Purdila293ad602008-06-04 15:45:58 -07001238 /*
1239 * If recv_actor drops the lock (e.g. TCP splice
1240 * receive) the skb pointer might be invalid when
1241 * getting here: tcp_collapse might have deleted it
1242 * while aggregating skbs from the socket queue.
1243 */
1244 skb = tcp_recv_skb(sk, seq-1, &offset);
1245 if (!skb || (offset+1 != skb->len))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 break;
1247 }
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001248 if (tcp_hdr(skb)->fin) {
Chris Leech624d1162006-05-23 18:01:28 -07001249 sk_eat_skb(sk, skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 ++seq;
1251 break;
1252 }
Chris Leech624d1162006-05-23 18:01:28 -07001253 sk_eat_skb(sk, skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 if (!desc->count)
1255 break;
1256 }
1257 tp->copied_seq = seq;
1258
1259 tcp_rcv_space_adjust(sk);
1260
1261 /* Clean up data we have read: This will do ACK frames. */
Jens Axboeddb61a52007-06-23 23:07:50 -07001262 if (copied > 0)
Chris Leech0e4b4992006-05-23 18:00:16 -07001263 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264 return copied;
1265}
1266
1267/*
1268 * This routine copies from a sock struct into the user buffer.
1269 *
1270 * Technical note: in 2.3 we work on _locked_ socket, so that
1271 * tricks with *seq access order and skb->users are not required.
1272 * Probably, code can be easily improved even more.
1273 */
1274
1275int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1276 size_t len, int nonblock, int flags, int *addr_len)
1277{
1278 struct tcp_sock *tp = tcp_sk(sk);
1279 int copied = 0;
1280 u32 peek_seq;
1281 u32 *seq;
1282 unsigned long used;
1283 int err;
1284 int target; /* Read at least this many bytes */
1285 long timeo;
1286 struct task_struct *user_recv = NULL;
Chris Leech1a2449a2006-05-23 18:05:53 -07001287 int copied_early = 0;
Chris Leech2b1244a2007-03-08 09:57:36 -08001288 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289
1290 lock_sock(sk);
1291
1292 TCP_CHECK_TIMER(sk);
1293
1294 err = -ENOTCONN;
1295 if (sk->sk_state == TCP_LISTEN)
1296 goto out;
1297
1298 timeo = sock_rcvtimeo(sk, nonblock);
1299
1300 /* Urgent data needs to be handled specially. */
1301 if (flags & MSG_OOB)
1302 goto recv_urg;
1303
1304 seq = &tp->copied_seq;
1305 if (flags & MSG_PEEK) {
1306 peek_seq = tp->copied_seq;
1307 seq = &peek_seq;
1308 }
1309
1310 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1311
Chris Leech1a2449a2006-05-23 18:05:53 -07001312#ifdef CONFIG_NET_DMA
1313 tp->ucopy.dma_chan = NULL;
1314 preempt_disable();
Chris Leech2b1244a2007-03-08 09:57:36 -08001315 skb = skb_peek_tail(&sk->sk_receive_queue);
Andrew Mortone00c5d82007-03-08 09:57:36 -08001316 {
1317 int available = 0;
1318
1319 if (skb)
1320 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1321 if ((available < target) &&
1322 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1323 !sysctl_tcp_low_latency &&
Dan Williamsf67b4592009-01-06 11:38:15 -07001324 dma_find_channel(DMA_MEMCPY)) {
Andrew Mortone00c5d82007-03-08 09:57:36 -08001325 preempt_enable_no_resched();
1326 tp->ucopy.pinned_list =
1327 dma_pin_iovec_pages(msg->msg_iov, len);
1328 } else {
1329 preempt_enable_no_resched();
1330 }
1331 }
Chris Leech1a2449a2006-05-23 18:05:53 -07001332#endif
1333
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 do {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335 u32 offset;
1336
1337 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1338 if (tp->urg_data && tp->urg_seq == *seq) {
1339 if (copied)
1340 break;
1341 if (signal_pending(current)) {
1342 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1343 break;
1344 }
1345 }
1346
1347 /* Next get a buffer. */
1348
1349 skb = skb_peek(&sk->sk_receive_queue);
1350 do {
1351 if (!skb)
1352 break;
1353
1354 /* Now that we have two receive queues this
1355 * shouldn't happen.
1356 */
1357 if (before(*seq, TCP_SKB_CB(skb)->seq)) {
1358 printk(KERN_INFO "recvmsg bug: copied %X "
1359 "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
1360 break;
1361 }
1362 offset = *seq - TCP_SKB_CB(skb)->seq;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001363 if (tcp_hdr(skb)->syn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 offset--;
1365 if (offset < skb->len)
1366 goto found_ok_skb;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001367 if (tcp_hdr(skb)->fin)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368 goto found_fin_ok;
Ilpo Järvinen547b7922008-07-25 21:43:18 -07001369 WARN_ON(!(flags & MSG_PEEK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370 skb = skb->next;
1371 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
1372
1373 /* Well, if we have backlog, try to process it now yet. */
1374
1375 if (copied >= target && !sk->sk_backlog.tail)
1376 break;
1377
1378 if (copied) {
1379 if (sk->sk_err ||
1380 sk->sk_state == TCP_CLOSE ||
1381 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1382 !timeo ||
David S. Miller518a09e2008-11-05 03:36:01 -08001383 signal_pending(current))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 break;
1385 } else {
1386 if (sock_flag(sk, SOCK_DONE))
1387 break;
1388
1389 if (sk->sk_err) {
1390 copied = sock_error(sk);
1391 break;
1392 }
1393
1394 if (sk->sk_shutdown & RCV_SHUTDOWN)
1395 break;
1396
1397 if (sk->sk_state == TCP_CLOSE) {
1398 if (!sock_flag(sk, SOCK_DONE)) {
1399 /* This occurs when user tries to read
1400 * from never connected socket.
1401 */
1402 copied = -ENOTCONN;
1403 break;
1404 }
1405 break;
1406 }
1407
1408 if (!timeo) {
1409 copied = -EAGAIN;
1410 break;
1411 }
1412
1413 if (signal_pending(current)) {
1414 copied = sock_intr_errno(timeo);
1415 break;
1416 }
1417 }
1418
Chris Leech0e4b4992006-05-23 18:00:16 -07001419 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420
David S. Miller7df55122005-06-18 23:01:10 -07001421 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422 /* Install new reader */
1423 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1424 user_recv = current;
1425 tp->ucopy.task = user_recv;
1426 tp->ucopy.iov = msg->msg_iov;
1427 }
1428
1429 tp->ucopy.len = len;
1430
Ilpo Järvinen547b7922008-07-25 21:43:18 -07001431 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1432 !(flags & (MSG_PEEK | MSG_TRUNC)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433
1434 /* Ugly... If prequeue is not empty, we have to
1435 * process it before releasing socket, otherwise
1436 * order will be broken at second iteration.
1437 * More elegant solution is required!!!
1438 *
1439 * Look: we have the following (pseudo)queues:
1440 *
1441 * 1. packets in flight
1442 * 2. backlog
1443 * 3. prequeue
1444 * 4. receive_queue
1445 *
1446 * Each queue can be processed only if the next ones
1447 * are empty. At this point we have empty receive_queue.
1448 * But prequeue _can_ be not empty after 2nd iteration,
1449 * when we jumped to start of loop because backlog
1450 * processing added something to receive_queue.
1451 * We cannot release_sock(), because backlog contains
1452 * packets arrived _after_ prequeued ones.
1453 *
1454 * Shortly, algorithm is clear --- to process all
1455 * the queues in order. We could make it more directly,
1456 * requeueing packets from backlog to prequeue, if
1457 * is not empty. It is more elegant, but eats cycles,
1458 * unfortunately.
1459 */
David S. Millerb03efcf2005-07-08 14:57:23 -07001460 if (!skb_queue_empty(&tp->ucopy.prequeue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 goto do_prequeue;
1462
1463 /* __ Set realtime policy in scheduler __ */
1464 }
1465
1466 if (copied >= target) {
1467 /* Do not sleep, just process backlog. */
1468 release_sock(sk);
1469 lock_sock(sk);
1470 } else
1471 sk_wait_data(sk, &timeo);
1472
Chris Leech1a2449a2006-05-23 18:05:53 -07001473#ifdef CONFIG_NET_DMA
1474 tp->ucopy.wakeup = 0;
1475#endif
1476
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477 if (user_recv) {
1478 int chunk;
1479
1480 /* __ Restore normal policy in scheduler __ */
1481
1482 if ((chunk = len - tp->ucopy.len) != 0) {
Pavel Emelyanoved880982008-07-16 20:32:45 -07001483 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 len -= chunk;
1485 copied += chunk;
1486 }
1487
1488 if (tp->rcv_nxt == tp->copied_seq &&
David S. Millerb03efcf2005-07-08 14:57:23 -07001489 !skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490do_prequeue:
1491 tcp_prequeue_process(sk);
1492
1493 if ((chunk = len - tp->ucopy.len) != 0) {
Pavel Emelyanoved880982008-07-16 20:32:45 -07001494 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495 len -= chunk;
1496 copied += chunk;
1497 }
1498 }
1499 }
1500 if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
1501 if (net_ratelimit())
1502 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -07001503 current->comm, task_pid_nr(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504 peek_seq = tp->copied_seq;
1505 }
1506 continue;
1507
1508 found_ok_skb:
1509 /* Ok so how much can we use? */
1510 used = skb->len - offset;
1511 if (len < used)
1512 used = len;
1513
1514 /* Do we have urgent data here? */
1515 if (tp->urg_data) {
1516 u32 urg_offset = tp->urg_seq - *seq;
1517 if (urg_offset < used) {
1518 if (!urg_offset) {
1519 if (!sock_flag(sk, SOCK_URGINLINE)) {
1520 ++*seq;
1521 offset++;
1522 used--;
1523 if (!used)
1524 goto skip_copy;
1525 }
1526 } else
1527 used = urg_offset;
1528 }
1529 }
1530
1531 if (!(flags & MSG_TRUNC)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001532#ifdef CONFIG_NET_DMA
1533 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
Dan Williamsf67b4592009-01-06 11:38:15 -07001534 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
Chris Leech1a2449a2006-05-23 18:05:53 -07001535
1536 if (tp->ucopy.dma_chan) {
1537 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1538 tp->ucopy.dma_chan, skb, offset,
1539 msg->msg_iov, used,
1540 tp->ucopy.pinned_list);
1541
1542 if (tp->ucopy.dma_cookie < 0) {
1543
1544 printk(KERN_ALERT "dma_cookie < 0\n");
1545
1546 /* Exception. Bailout! */
1547 if (!copied)
1548 copied = -EFAULT;
1549 break;
1550 }
1551 if ((offset + used) == skb->len)
1552 copied_early = 1;
1553
1554 } else
1555#endif
1556 {
1557 err = skb_copy_datagram_iovec(skb, offset,
1558 msg->msg_iov, used);
1559 if (err) {
1560 /* Exception. Bailout! */
1561 if (!copied)
1562 copied = -EFAULT;
1563 break;
1564 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 }
1566 }
1567
1568 *seq += used;
1569 copied += used;
1570 len -= used;
1571
1572 tcp_rcv_space_adjust(sk);
1573
1574skip_copy:
1575 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1576 tp->urg_data = 0;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07001577 tcp_fast_path_check(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 }
1579 if (used + offset < skb->len)
1580 continue;
1581
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001582 if (tcp_hdr(skb)->fin)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 goto found_fin_ok;
Chris Leech1a2449a2006-05-23 18:05:53 -07001584 if (!(flags & MSG_PEEK)) {
1585 sk_eat_skb(sk, skb, copied_early);
1586 copied_early = 0;
1587 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588 continue;
1589
1590 found_fin_ok:
1591 /* Process the FIN. */
1592 ++*seq;
Chris Leech1a2449a2006-05-23 18:05:53 -07001593 if (!(flags & MSG_PEEK)) {
1594 sk_eat_skb(sk, skb, copied_early);
1595 copied_early = 0;
1596 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 break;
1598 } while (len > 0);
1599
1600 if (user_recv) {
David S. Millerb03efcf2005-07-08 14:57:23 -07001601 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602 int chunk;
1603
1604 tp->ucopy.len = copied > 0 ? len : 0;
1605
1606 tcp_prequeue_process(sk);
1607
1608 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
Pavel Emelyanoved880982008-07-16 20:32:45 -07001609 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 len -= chunk;
1611 copied += chunk;
1612 }
1613 }
1614
1615 tp->ucopy.task = NULL;
1616 tp->ucopy.len = 0;
1617 }
1618
Chris Leech1a2449a2006-05-23 18:05:53 -07001619#ifdef CONFIG_NET_DMA
1620 if (tp->ucopy.dma_chan) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001621 dma_cookie_t done, used;
1622
1623 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1624
1625 while (dma_async_memcpy_complete(tp->ucopy.dma_chan,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001626 tp->ucopy.dma_cookie, &done,
1627 &used) == DMA_IN_PROGRESS) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001628 /* do partial cleanup of sk_async_wait_queue */
1629 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1630 (dma_async_is_complete(skb->dma_cookie, done,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001631 used) == DMA_SUCCESS)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001632 __skb_dequeue(&sk->sk_async_wait_queue);
1633 kfree_skb(skb);
1634 }
1635 }
1636
1637 /* Safe to free early-copied skbs now */
1638 __skb_queue_purge(&sk->sk_async_wait_queue);
Chris Leech1a2449a2006-05-23 18:05:53 -07001639 tp->ucopy.dma_chan = NULL;
1640 }
1641 if (tp->ucopy.pinned_list) {
1642 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1643 tp->ucopy.pinned_list = NULL;
1644 }
1645#endif
1646
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647 /* According to UNIX98, msg_name/msg_namelen are ignored
1648 * on connected socket. I was just happy when found this 8) --ANK
1649 */
1650
1651 /* Clean up data we have read: This will do ACK frames. */
Chris Leech0e4b4992006-05-23 18:00:16 -07001652 tcp_cleanup_rbuf(sk, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001653
1654 TCP_CHECK_TIMER(sk);
1655 release_sock(sk);
1656 return copied;
1657
1658out:
1659 TCP_CHECK_TIMER(sk);
1660 release_sock(sk);
1661 return err;
1662
1663recv_urg:
1664 err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len);
1665 goto out;
1666}
1667
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001668void tcp_set_state(struct sock *sk, int state)
1669{
1670 int oldstate = sk->sk_state;
1671
1672 switch (state) {
1673 case TCP_ESTABLISHED:
1674 if (oldstate != TCP_ESTABLISHED)
Pavel Emelyanov81cc8a72008-07-16 20:22:04 -07001675 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001676 break;
1677
1678 case TCP_CLOSE:
1679 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
Pavel Emelyanov81cc8a72008-07-16 20:22:04 -07001680 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001681
1682 sk->sk_prot->unhash(sk);
1683 if (inet_csk(sk)->icsk_bind_hash &&
1684 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001685 inet_put_port(sk);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001686 /* fall through */
1687 default:
Jianjun Kong5a5f3a82008-11-03 00:24:34 -08001688 if (oldstate == TCP_ESTABLISHED)
Pavel Emelyanov74688e42008-07-16 20:22:46 -07001689 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001690 }
1691
1692 /* Change state AFTER socket is unhashed to avoid closed
1693 * socket sitting in hash tables.
1694 */
1695 sk->sk_state = state;
1696
1697#ifdef STATE_TRACE
Jianjun Kong5a5f3a82008-11-03 00:24:34 -08001698 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
Ilpo Järvinen490d5042008-01-12 03:17:20 -08001699#endif
1700}
1701EXPORT_SYMBOL_GPL(tcp_set_state);
1702
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703/*
1704 * State processing on a close. This implements the state shift for
1705 * sending our FIN frame. Note that we only send a FIN for some
1706 * states. A shutdown() may have already sent the FIN, or we may be
1707 * closed.
1708 */
1709
Arjan van de Ven9b5b5cf2005-11-29 16:21:38 -08001710static const unsigned char new_state[16] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 /* current state: new state: action: */
1712 /* (Invalid) */ TCP_CLOSE,
1713 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1714 /* TCP_SYN_SENT */ TCP_CLOSE,
1715 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1716 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1717 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1718 /* TCP_TIME_WAIT */ TCP_CLOSE,
1719 /* TCP_CLOSE */ TCP_CLOSE,
1720 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1721 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1722 /* TCP_LISTEN */ TCP_CLOSE,
1723 /* TCP_CLOSING */ TCP_CLOSING,
1724};
1725
1726static int tcp_close_state(struct sock *sk)
1727{
1728 int next = (int)new_state[sk->sk_state];
1729 int ns = next & TCP_STATE_MASK;
1730
1731 tcp_set_state(sk, ns);
1732
1733 return next & TCP_ACTION_FIN;
1734}
1735
1736/*
1737 * Shutdown the sending side of a connection. Much like close except
Satoru SATOH1f29b052008-04-21 02:27:58 -07001738 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001739 */
1740
1741void tcp_shutdown(struct sock *sk, int how)
1742{
1743 /* We need to grab some memory, and put together a FIN,
1744 * and then put it into the queue to be sent.
1745 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1746 */
1747 if (!(how & SEND_SHUTDOWN))
1748 return;
1749
1750 /* If we've already sent a FIN, or it's a closed state, skip this. */
1751 if ((1 << sk->sk_state) &
1752 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1753 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1754 /* Clear out any half completed packets. FIN if needed. */
1755 if (tcp_close_state(sk))
1756 tcp_send_fin(sk);
1757 }
1758}
1759
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760void tcp_close(struct sock *sk, long timeout)
1761{
1762 struct sk_buff *skb;
1763 int data_was_unread = 0;
Herbert Xu75c2d9072006-05-03 23:31:35 -07001764 int state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765
1766 lock_sock(sk);
1767 sk->sk_shutdown = SHUTDOWN_MASK;
1768
1769 if (sk->sk_state == TCP_LISTEN) {
1770 tcp_set_state(sk, TCP_CLOSE);
1771
1772 /* Special case. */
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001773 inet_csk_listen_stop(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001774
1775 goto adjudge_to_death;
1776 }
1777
1778 /* We need to flush the recv. buffs. We do this only on the
1779 * descriptor close, not protocol-sourced closes, because the
1780 * reader process may not have drained the data yet!
1781 */
1782 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1783 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001784 tcp_hdr(skb)->fin;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785 data_was_unread += len;
1786 __kfree_skb(skb);
1787 }
1788
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001789 sk_mem_reclaim(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790
Gerrit Renker65bb7232007-04-28 21:21:46 -07001791 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1792 * data was lost. To witness the awful effects of the old behavior of
1793 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1794 * GET in an FTP client, suspend the process, wait for the client to
1795 * advertise a zero window, then kill -9 the FTP client, wheee...
1796 * Note: timeout is always zero in such a case.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001797 */
1798 if (data_was_unread) {
1799 /* Unread data was tossed, zap the connection. */
Pavel Emelyanov6f67c812008-07-16 20:31:39 -07001800 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 tcp_set_state(sk, TCP_CLOSE);
1802 tcp_send_active_reset(sk, GFP_KERNEL);
1803 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1804 /* Check zero linger _after_ checking for unread data. */
1805 sk->sk_prot->disconnect(sk, 0);
Pavel Emelyanov6f67c812008-07-16 20:31:39 -07001806 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807 } else if (tcp_close_state(sk)) {
1808 /* We FIN if the application ate all the data before
1809 * zapping the connection.
1810 */
1811
1812 /* RED-PEN. Formally speaking, we have broken TCP state
1813 * machine. State transitions:
1814 *
1815 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1816 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1817 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1818 *
1819 * are legal only when FIN has been sent (i.e. in window),
1820 * rather than queued out of window. Purists blame.
1821 *
1822 * F.e. "RFC state" is ESTABLISHED,
1823 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1824 *
1825 * The visible declinations are that sometimes
1826 * we enter time-wait state, when it is not required really
1827 * (harmless), do not send active resets, when they are
1828 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1829 * they look as CLOSING or LAST_ACK for Linux)
1830 * Probably, I missed some more holelets.
1831 * --ANK
1832 */
1833 tcp_send_fin(sk);
1834 }
1835
1836 sk_stream_wait_close(sk, timeout);
1837
1838adjudge_to_death:
Herbert Xu75c2d9072006-05-03 23:31:35 -07001839 state = sk->sk_state;
1840 sock_hold(sk);
1841 sock_orphan(sk);
Herbert Xu75c2d9072006-05-03 23:31:35 -07001842
Linus Torvalds1da177e2005-04-16 15:20:36 -07001843 /* It is the last release_sock in its life. It will remove backlog. */
1844 release_sock(sk);
1845
1846
1847 /* Now socket is owned by kernel and we acquire BH lock
1848 to finish close. No need to check for user refs.
1849 */
1850 local_bh_disable();
1851 bh_lock_sock(sk);
Ilpo Järvinen547b7922008-07-25 21:43:18 -07001852 WARN_ON(sock_owned_by_user(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853
Herbert Xueb4dea52008-12-29 23:04:08 -08001854 percpu_counter_inc(sk->sk_prot->orphan_count);
1855
Herbert Xu75c2d9072006-05-03 23:31:35 -07001856 /* Have we already been destroyed by a softirq or backlog? */
1857 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1858 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001859
1860 /* This is a (useful) BSD violating of the RFC. There is a
1861 * problem with TCP as specified in that the other end could
1862 * keep a socket open forever with no application left this end.
1863 * We use a 3 minute timeout (about the same as BSD) then kill
1864 * our end. If they send after that then tough - BUT: long enough
1865 * that we won't make the old 4*rto = almost no time - whoops
1866 * reset mistake.
1867 *
1868 * Nope, it was not mistake. It is really desired behaviour
1869 * f.e. on http servers, when such sockets are useless, but
1870 * consume significant resources. Let's do it with special
1871 * linger2 option. --ANK
1872 */
1873
1874 if (sk->sk_state == TCP_FIN_WAIT2) {
1875 struct tcp_sock *tp = tcp_sk(sk);
1876 if (tp->linger2 < 0) {
1877 tcp_set_state(sk, TCP_CLOSE);
1878 tcp_send_active_reset(sk, GFP_ATOMIC);
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001879 NET_INC_STATS_BH(sock_net(sk),
1880 LINUX_MIB_TCPABORTONLINGER);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001881 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001882 const int tmo = tcp_fin_time(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883
1884 if (tmo > TCP_TIMEWAIT_LEN) {
David S. Miller52499af2006-07-31 22:32:09 -07001885 inet_csk_reset_keepalive_timer(sk,
1886 tmo - TCP_TIMEWAIT_LEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001887 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
1889 goto out;
1890 }
1891 }
1892 }
1893 if (sk->sk_state != TCP_CLOSE) {
Eric Dumazetdd24c002008-11-25 21:17:14 -08001894 int orphan_count = percpu_counter_read_positive(
1895 sk->sk_prot->orphan_count);
1896
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001897 sk_mem_reclaim(sk);
Eric Dumazetdd24c002008-11-25 21:17:14 -08001898 if (tcp_too_many_orphans(sk, orphan_count)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899 if (net_ratelimit())
1900 printk(KERN_INFO "TCP: too many of orphaned "
1901 "sockets\n");
1902 tcp_set_state(sk, TCP_CLOSE);
1903 tcp_send_active_reset(sk, GFP_ATOMIC);
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001904 NET_INC_STATS_BH(sock_net(sk),
1905 LINUX_MIB_TCPABORTONMEMORY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001906 }
1907 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001908
1909 if (sk->sk_state == TCP_CLOSE)
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001910 inet_csk_destroy_sock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911 /* Otherwise, socket is reprieved until protocol close. */
1912
1913out:
1914 bh_unlock_sock(sk);
1915 local_bh_enable();
1916 sock_put(sk);
1917}
1918
1919/* These states need RST on ABORT according to RFC793 */
1920
1921static inline int tcp_need_reset(int state)
1922{
1923 return (1 << state) &
1924 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
1925 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
1926}
1927
1928int tcp_disconnect(struct sock *sk, int flags)
1929{
1930 struct inet_sock *inet = inet_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001931 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001932 struct tcp_sock *tp = tcp_sk(sk);
1933 int err = 0;
1934 int old_state = sk->sk_state;
1935
1936 if (old_state != TCP_CLOSE)
1937 tcp_set_state(sk, TCP_CLOSE);
1938
1939 /* ABORT function of RFC793 */
1940 if (old_state == TCP_LISTEN) {
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07001941 inet_csk_listen_stop(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942 } else if (tcp_need_reset(old_state) ||
1943 (tp->snd_nxt != tp->write_seq &&
1944 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -08001945 /* The last check adjusts for discrepancy of Linux wrt. RFC
Linus Torvalds1da177e2005-04-16 15:20:36 -07001946 * states
1947 */
1948 tcp_send_active_reset(sk, gfp_any());
1949 sk->sk_err = ECONNRESET;
1950 } else if (old_state == TCP_SYN_SENT)
1951 sk->sk_err = ECONNRESET;
1952
1953 tcp_clear_xmit_timers(sk);
1954 __skb_queue_purge(&sk->sk_receive_queue);
David S. Millerfe067e82007-03-07 12:12:44 -08001955 tcp_write_queue_purge(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001956 __skb_queue_purge(&tp->out_of_order_queue);
Chris Leech1a2449a2006-05-23 18:05:53 -07001957#ifdef CONFIG_NET_DMA
1958 __skb_queue_purge(&sk->sk_async_wait_queue);
1959#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001960
1961 inet->dport = 0;
1962
1963 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1964 inet_reset_saddr(sk);
1965
1966 sk->sk_shutdown = 0;
1967 sock_reset_flag(sk, SOCK_DONE);
1968 tp->srtt = 0;
1969 if ((tp->write_seq += tp->max_window + 2) == 0)
1970 tp->write_seq = 1;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001971 icsk->icsk_backoff = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001972 tp->snd_cwnd = 2;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001973 icsk->icsk_probes_out = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001974 tp->packets_out = 0;
1975 tp->snd_ssthresh = 0x7fffffff;
1976 tp->snd_cwnd_cnt = 0;
Stephen Hemminger9772efb2005-11-10 17:09:53 -08001977 tp->bytes_acked = 0;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001978 tcp_set_ca_state(sk, TCP_CA_Open);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979 tcp_clear_retrans(tp);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001980 inet_csk_delack_init(sk);
David S. Millerfe067e82007-03-07 12:12:44 -08001981 tcp_init_send_head(sk);
Srinivas Ajib40b4f72007-05-03 17:32:28 -07001982 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001983 __sk_dst_reset(sk);
1984
Ilpo Järvinen547b7922008-07-25 21:43:18 -07001985 WARN_ON(inet->num && !icsk->icsk_bind_hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986
1987 sk->sk_error_report(sk);
1988 return err;
1989}
1990
1991/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 * Socket option code for TCP.
1993 */
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001994static int do_tcp_setsockopt(struct sock *sk, int level,
1995 int optname, char __user *optval, int optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001996{
1997 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001998 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999 int val;
2000 int err = 0;
2001
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002002 /* This is a string value all the others are int's */
2003 if (optname == TCP_CONGESTION) {
2004 char name[TCP_CA_NAME_MAX];
2005
2006 if (optlen < 1)
2007 return -EINVAL;
2008
2009 val = strncpy_from_user(name, optval,
2010 min(TCP_CA_NAME_MAX-1, optlen));
2011 if (val < 0)
2012 return -EFAULT;
2013 name[val] = 0;
2014
2015 lock_sock(sk);
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002016 err = tcp_set_congestion_control(sk, name);
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002017 release_sock(sk);
2018 return err;
2019 }
2020
Linus Torvalds1da177e2005-04-16 15:20:36 -07002021 if (optlen < sizeof(int))
2022 return -EINVAL;
2023
2024 if (get_user(val, (int __user *)optval))
2025 return -EFAULT;
2026
2027 lock_sock(sk);
2028
2029 switch (optname) {
2030 case TCP_MAXSEG:
2031 /* Values greater than interface MTU won't take effect. However
2032 * at the point when this call is done we typically don't yet
2033 * know which interface is going to be used */
2034 if (val < 8 || val > MAX_TCP_WINDOW) {
2035 err = -EINVAL;
2036 break;
2037 }
2038 tp->rx_opt.user_mss = val;
2039 break;
2040
2041 case TCP_NODELAY:
2042 if (val) {
2043 /* TCP_NODELAY is weaker than TCP_CORK, so that
2044 * this option on corked socket is remembered, but
2045 * it is not activated until cork is cleared.
2046 *
2047 * However, when TCP_NODELAY is set we make
2048 * an explicit push, which overrides even TCP_CORK
2049 * for currently queued segments.
2050 */
2051 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002052 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002053 } else {
2054 tp->nonagle &= ~TCP_NAGLE_OFF;
2055 }
2056 break;
2057
2058 case TCP_CORK:
2059 /* When set indicates to always queue non-full frames.
2060 * Later the user clears this option and we transmit
2061 * any pending partial frames in the queue. This is
2062 * meant to be used alongside sendfile() to get properly
2063 * filled frames when the user (for example) must write
2064 * out headers with a write() call first and then use
2065 * sendfile to send out the data parts.
2066 *
2067 * TCP_CORK can be set together with TCP_NODELAY and it is
2068 * stronger than TCP_NODELAY.
2069 */
2070 if (val) {
2071 tp->nonagle |= TCP_NAGLE_CORK;
2072 } else {
2073 tp->nonagle &= ~TCP_NAGLE_CORK;
2074 if (tp->nonagle&TCP_NAGLE_OFF)
2075 tp->nonagle |= TCP_NAGLE_PUSH;
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -07002076 tcp_push_pending_frames(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077 }
2078 break;
2079
2080 case TCP_KEEPIDLE:
2081 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2082 err = -EINVAL;
2083 else {
2084 tp->keepalive_time = val * HZ;
2085 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2086 !((1 << sk->sk_state) &
2087 (TCPF_CLOSE | TCPF_LISTEN))) {
2088 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
2089 if (tp->keepalive_time > elapsed)
2090 elapsed = tp->keepalive_time - elapsed;
2091 else
2092 elapsed = 0;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002093 inet_csk_reset_keepalive_timer(sk, elapsed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002094 }
2095 }
2096 break;
2097 case TCP_KEEPINTVL:
2098 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2099 err = -EINVAL;
2100 else
2101 tp->keepalive_intvl = val * HZ;
2102 break;
2103 case TCP_KEEPCNT:
2104 if (val < 1 || val > MAX_TCP_KEEPCNT)
2105 err = -EINVAL;
2106 else
2107 tp->keepalive_probes = val;
2108 break;
2109 case TCP_SYNCNT:
2110 if (val < 1 || val > MAX_TCP_SYNCNT)
2111 err = -EINVAL;
2112 else
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002113 icsk->icsk_syn_retries = val;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002114 break;
2115
2116 case TCP_LINGER2:
2117 if (val < 0)
2118 tp->linger2 = -1;
2119 else if (val > sysctl_tcp_fin_timeout / HZ)
2120 tp->linger2 = 0;
2121 else
2122 tp->linger2 = val * HZ;
2123 break;
2124
2125 case TCP_DEFER_ACCEPT:
David S. Millerec0a1962008-06-12 16:31:35 -07002126 icsk->icsk_accept_queue.rskq_defer_accept = 0;
2127 if (val > 0) {
2128 /* Translate value in seconds to number of
2129 * retransmits */
2130 while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
2131 val > ((TCP_TIMEOUT_INIT / HZ) <<
2132 icsk->icsk_accept_queue.rskq_defer_accept))
2133 icsk->icsk_accept_queue.rskq_defer_accept++;
2134 icsk->icsk_accept_queue.rskq_defer_accept++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 }
2136 break;
2137
2138 case TCP_WINDOW_CLAMP:
2139 if (!val) {
2140 if (sk->sk_state != TCP_CLOSE) {
2141 err = -EINVAL;
2142 break;
2143 }
2144 tp->window_clamp = 0;
2145 } else
2146 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2147 SOCK_MIN_RCVBUF / 2 : val;
2148 break;
2149
2150 case TCP_QUICKACK:
2151 if (!val) {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002152 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002153 } else {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002154 icsk->icsk_ack.pingpong = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155 if ((1 << sk->sk_state) &
2156 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002157 inet_csk_ack_scheduled(sk)) {
2158 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
Chris Leech0e4b4992006-05-23 18:00:16 -07002159 tcp_cleanup_rbuf(sk, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160 if (!(val & 1))
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002161 icsk->icsk_ack.pingpong = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162 }
2163 }
2164 break;
2165
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002166#ifdef CONFIG_TCP_MD5SIG
2167 case TCP_MD5SIG:
2168 /* Read the IP->Key mappings from userspace */
2169 err = tp->af_specific->md5_parse(sk, optval, optlen);
2170 break;
2171#endif
2172
Linus Torvalds1da177e2005-04-16 15:20:36 -07002173 default:
2174 err = -ENOPROTOOPT;
2175 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002176 }
2177
Linus Torvalds1da177e2005-04-16 15:20:36 -07002178 release_sock(sk);
2179 return err;
2180}
2181
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002182int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2183 int optlen)
2184{
2185 struct inet_connection_sock *icsk = inet_csk(sk);
2186
2187 if (level != SOL_TCP)
2188 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2189 optval, optlen);
2190 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2191}
2192
2193#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002194int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2195 char __user *optval, int optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002196{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002197 if (level != SOL_TCP)
2198 return inet_csk_compat_setsockopt(sk, level, optname,
2199 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002200 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2201}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002202
2203EXPORT_SYMBOL(compat_tcp_setsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002204#endif
2205
Linus Torvalds1da177e2005-04-16 15:20:36 -07002206/* Return information about state of tcp endpoint in API format. */
2207void tcp_get_info(struct sock *sk, struct tcp_info *info)
2208{
2209 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002210 const struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002211 u32 now = tcp_time_stamp;
2212
2213 memset(info, 0, sizeof(*info));
2214
2215 info->tcpi_state = sk->sk_state;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002216 info->tcpi_ca_state = icsk->icsk_ca_state;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002217 info->tcpi_retransmits = icsk->icsk_retransmits;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002218 info->tcpi_probes = icsk->icsk_probes_out;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002219 info->tcpi_backoff = icsk->icsk_backoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002220
2221 if (tp->rx_opt.tstamp_ok)
2222 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
Ilpo Järvinene60402d2007-08-09 15:14:46 +03002223 if (tcp_is_sack(tp))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002224 info->tcpi_options |= TCPI_OPT_SACK;
2225 if (tp->rx_opt.wscale_ok) {
2226 info->tcpi_options |= TCPI_OPT_WSCALE;
2227 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2228 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09002229 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002230
2231 if (tp->ecn_flags&TCP_ECN_OK)
2232 info->tcpi_options |= TCPI_OPT_ECN;
2233
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002234 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2235 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002236 info->tcpi_snd_mss = tp->mss_cache;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002237 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002238
Rick Jones5ee3afb2007-09-18 13:26:31 -07002239 if (sk->sk_state == TCP_LISTEN) {
2240 info->tcpi_unacked = sk->sk_ack_backlog;
2241 info->tcpi_sacked = sk->sk_max_ack_backlog;
2242 } else {
2243 info->tcpi_unacked = tp->packets_out;
2244 info->tcpi_sacked = tp->sacked_out;
2245 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002246 info->tcpi_lost = tp->lost_out;
2247 info->tcpi_retrans = tp->retrans_out;
2248 info->tcpi_fackets = tp->fackets_out;
2249
2250 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002251 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002252 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2253
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08002254 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2256 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2257 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2258 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2259 info->tcpi_snd_cwnd = tp->snd_cwnd;
2260 info->tcpi_advmss = tp->advmss;
2261 info->tcpi_reordering = tp->reordering;
2262
2263 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2264 info->tcpi_rcv_space = tp->rcvq_space.space;
2265
2266 info->tcpi_total_retrans = tp->total_retrans;
2267}
2268
2269EXPORT_SYMBOL_GPL(tcp_get_info);
2270
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002271static int do_tcp_getsockopt(struct sock *sk, int level,
2272 int optname, char __user *optval, int __user *optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273{
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002274 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002275 struct tcp_sock *tp = tcp_sk(sk);
2276 int val, len;
2277
Linus Torvalds1da177e2005-04-16 15:20:36 -07002278 if (get_user(len, optlen))
2279 return -EFAULT;
2280
2281 len = min_t(unsigned int, len, sizeof(int));
2282
2283 if (len < 0)
2284 return -EINVAL;
2285
2286 switch (optname) {
2287 case TCP_MAXSEG:
David S. Millerc1b4a7e2005-07-05 15:24:38 -07002288 val = tp->mss_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002289 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2290 val = tp->rx_opt.user_mss;
2291 break;
2292 case TCP_NODELAY:
2293 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2294 break;
2295 case TCP_CORK:
2296 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2297 break;
2298 case TCP_KEEPIDLE:
2299 val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
2300 break;
2301 case TCP_KEEPINTVL:
2302 val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
2303 break;
2304 case TCP_KEEPCNT:
2305 val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
2306 break;
2307 case TCP_SYNCNT:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002308 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002309 break;
2310 case TCP_LINGER2:
2311 val = tp->linger2;
2312 if (val >= 0)
2313 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2314 break;
2315 case TCP_DEFER_ACCEPT:
David S. Millerec0a1962008-06-12 16:31:35 -07002316 val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
2317 ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318 break;
2319 case TCP_WINDOW_CLAMP:
2320 val = tp->window_clamp;
2321 break;
2322 case TCP_INFO: {
2323 struct tcp_info info;
2324
2325 if (get_user(len, optlen))
2326 return -EFAULT;
2327
2328 tcp_get_info(sk, &info);
2329
2330 len = min_t(unsigned int, len, sizeof(info));
2331 if (put_user(len, optlen))
2332 return -EFAULT;
2333 if (copy_to_user(optval, &info, len))
2334 return -EFAULT;
2335 return 0;
2336 }
2337 case TCP_QUICKACK:
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -07002338 val = !icsk->icsk_ack.pingpong;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002339 break;
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002340
2341 case TCP_CONGESTION:
2342 if (get_user(len, optlen))
2343 return -EFAULT;
2344 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2345 if (put_user(len, optlen))
2346 return -EFAULT;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002347 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002348 return -EFAULT;
2349 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002350 default:
2351 return -ENOPROTOOPT;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002352 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002353
2354 if (put_user(len, optlen))
2355 return -EFAULT;
2356 if (copy_to_user(optval, &val, len))
2357 return -EFAULT;
2358 return 0;
2359}
2360
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002361int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2362 int __user *optlen)
2363{
2364 struct inet_connection_sock *icsk = inet_csk(sk);
2365
2366 if (level != SOL_TCP)
2367 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2368 optval, optlen);
2369 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2370}
2371
2372#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002373int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2374 char __user *optval, int __user *optlen)
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002375{
Arnaldo Carvalho de Melodec73ff2006-03-20 22:46:16 -08002376 if (level != SOL_TCP)
2377 return inet_csk_compat_getsockopt(sk, level, optname,
2378 optval, optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002379 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2380}
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002381
2382EXPORT_SYMBOL(compat_tcp_getsockopt);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08002383#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002384
Herbert Xu576a30e2006-06-27 13:22:38 -07002385struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
Herbert Xuf4c50d92006-06-22 03:02:40 -07002386{
2387 struct sk_buff *segs = ERR_PTR(-EINVAL);
2388 struct tcphdr *th;
2389 unsigned thlen;
2390 unsigned int seq;
Al Virod3bc23e2006-11-14 21:24:49 -08002391 __be32 delta;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002392 unsigned int oldlen;
Herbert Xu4e704ee2009-01-14 20:41:12 -08002393 unsigned int mss;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002394
2395 if (!pskb_may_pull(skb, sizeof(*th)))
2396 goto out;
2397
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002398 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002399 thlen = th->doff * 4;
2400 if (thlen < sizeof(*th))
2401 goto out;
2402
2403 if (!pskb_may_pull(skb, thlen))
2404 goto out;
2405
Herbert Xu0718bcc2006-06-25 23:55:46 -07002406 oldlen = (u16)~skb->len;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002407 __skb_pull(skb, thlen);
2408
Herbert Xu4e704ee2009-01-14 20:41:12 -08002409 mss = skb_shinfo(skb)->gso_size;
2410 if (unlikely(skb->len <= mss))
2411 goto out;
2412
Herbert Xu3820c3f2006-06-29 20:11:25 -07002413 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2414 /* Packet is from an untrusted source, reset gso_segs. */
Herbert Xubbcf4672006-07-03 19:38:35 -07002415 int type = skb_shinfo(skb)->gso_type;
Herbert Xu3820c3f2006-06-29 20:11:25 -07002416
Herbert Xubbcf4672006-07-03 19:38:35 -07002417 if (unlikely(type &
2418 ~(SKB_GSO_TCPV4 |
2419 SKB_GSO_DODGY |
2420 SKB_GSO_TCP_ECN |
2421 SKB_GSO_TCPV6 |
2422 0) ||
2423 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2424 goto out;
2425
Ilpo Järvinen172589c2007-08-28 15:50:33 -07002426 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
Herbert Xu3820c3f2006-06-29 20:11:25 -07002427
2428 segs = NULL;
2429 goto out;
2430 }
2431
Herbert Xu576a30e2006-06-27 13:22:38 -07002432 segs = skb_segment(skb, features);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002433 if (IS_ERR(segs))
2434 goto out;
2435
Herbert Xu4e704ee2009-01-14 20:41:12 -08002436 delta = htonl(oldlen + (thlen + mss));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002437
2438 skb = segs;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002439 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002440 seq = ntohl(th->seq);
2441
2442 do {
2443 th->fin = th->psh = 0;
2444
Al Virod3bc23e2006-11-14 21:24:49 -08002445 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2446 (__force u32)delta));
Patrick McHardy84fa7932006-08-29 16:44:56 -07002447 if (skb->ip_summed != CHECKSUM_PARTIAL)
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002448 th->check =
2449 csum_fold(csum_partial(skb_transport_header(skb),
2450 thlen, skb->csum));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002451
Herbert Xu4e704ee2009-01-14 20:41:12 -08002452 seq += mss;
Herbert Xuf4c50d92006-06-22 03:02:40 -07002453 skb = skb->next;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07002454 th = tcp_hdr(skb);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002455
2456 th->seq = htonl(seq);
2457 th->cwr = 0;
2458 } while (skb->next);
2459
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07002460 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002461 skb->data_len);
Al Virod3bc23e2006-11-14 21:24:49 -08002462 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2463 (__force u32)delta));
Patrick McHardy84fa7932006-08-29 16:44:56 -07002464 if (skb->ip_summed != CHECKSUM_PARTIAL)
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07002465 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2466 thlen, skb->csum));
Herbert Xuf4c50d92006-06-22 03:02:40 -07002467
2468out:
2469 return segs;
2470}
Herbert Xuadcfc7d2006-06-30 13:36:15 -07002471EXPORT_SYMBOL(tcp_tso_segment);
Herbert Xuf4c50d92006-06-22 03:02:40 -07002472
Herbert Xubf296b12008-12-15 23:43:36 -08002473struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2474{
2475 struct sk_buff **pp = NULL;
2476 struct sk_buff *p;
2477 struct tcphdr *th;
2478 struct tcphdr *th2;
2479 unsigned int thlen;
2480 unsigned int flags;
2481 unsigned int total;
2482 unsigned int mss = 1;
2483 int flush = 1;
2484
2485 if (!pskb_may_pull(skb, sizeof(*th)))
2486 goto out;
2487
2488 th = tcp_hdr(skb);
2489 thlen = th->doff * 4;
2490 if (thlen < sizeof(*th))
2491 goto out;
2492
2493 if (!pskb_may_pull(skb, thlen))
2494 goto out;
2495
2496 th = tcp_hdr(skb);
2497 __skb_pull(skb, thlen);
2498
2499 flags = tcp_flag_word(th);
2500
2501 for (; (p = *head); head = &p->next) {
2502 if (!NAPI_GRO_CB(p)->same_flow)
2503 continue;
2504
2505 th2 = tcp_hdr(p);
2506
2507 if (th->source != th2->source || th->dest != th2->dest) {
2508 NAPI_GRO_CB(p)->same_flow = 0;
2509 continue;
2510 }
2511
2512 goto found;
2513 }
2514
2515 goto out_check_final;
2516
2517found:
2518 flush = NAPI_GRO_CB(p)->flush;
2519 flush |= flags & TCP_FLAG_CWR;
2520 flush |= (flags ^ tcp_flag_word(th2)) &
2521 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH);
2522 flush |= th->ack_seq != th2->ack_seq || th->window != th2->window;
2523 flush |= memcmp(th + 1, th2 + 1, thlen - sizeof(*th));
2524
2525 total = p->len;
Herbert Xub5302562009-01-04 16:13:19 -08002526 mss = skb_shinfo(p)->gso_size;
Herbert Xubf296b12008-12-15 23:43:36 -08002527
2528 flush |= skb->len > mss || skb->len <= 0;
2529 flush |= ntohl(th2->seq) + total != ntohl(th->seq);
2530
2531 if (flush || skb_gro_receive(head, skb)) {
2532 mss = 1;
2533 goto out_check_final;
2534 }
2535
2536 p = *head;
2537 th2 = tcp_hdr(p);
2538 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
2539
2540out_check_final:
2541 flush = skb->len < mss;
2542 flush |= flags & (TCP_FLAG_URG | TCP_FLAG_PSH | TCP_FLAG_RST |
2543 TCP_FLAG_SYN | TCP_FLAG_FIN);
2544
2545 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
2546 pp = head;
2547
2548out:
2549 NAPI_GRO_CB(skb)->flush |= flush;
2550
2551 return pp;
2552}
Herbert Xu684f2172009-01-08 10:41:23 -08002553EXPORT_SYMBOL(tcp_gro_receive);
Herbert Xubf296b12008-12-15 23:43:36 -08002554
2555int tcp_gro_complete(struct sk_buff *skb)
2556{
2557 struct tcphdr *th = tcp_hdr(skb);
2558
2559 skb->csum_start = skb_transport_header(skb) - skb->head;
2560 skb->csum_offset = offsetof(struct tcphdr, check);
2561 skb->ip_summed = CHECKSUM_PARTIAL;
2562
Herbert Xubf296b12008-12-15 23:43:36 -08002563 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
2564
2565 if (th->cwr)
2566 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
2567
2568 return 0;
2569}
Herbert Xu684f2172009-01-08 10:41:23 -08002570EXPORT_SYMBOL(tcp_gro_complete);
Herbert Xubf296b12008-12-15 23:43:36 -08002571
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002572#ifdef CONFIG_TCP_MD5SIG
2573static unsigned long tcp_md5sig_users;
2574static struct tcp_md5sig_pool **tcp_md5sig_pool;
2575static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2576
2577static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
2578{
2579 int cpu;
2580 for_each_possible_cpu(cpu) {
2581 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2582 if (p) {
2583 if (p->md5_desc.tfm)
2584 crypto_free_hash(p->md5_desc.tfm);
2585 kfree(p);
2586 p = NULL;
2587 }
2588 }
2589 free_percpu(pool);
2590}
2591
2592void tcp_free_md5sig_pool(void)
2593{
2594 struct tcp_md5sig_pool **pool = NULL;
2595
David S. Miller2c4f6212007-02-20 23:51:47 -08002596 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002597 if (--tcp_md5sig_users == 0) {
2598 pool = tcp_md5sig_pool;
2599 tcp_md5sig_pool = NULL;
2600 }
David S. Miller2c4f6212007-02-20 23:51:47 -08002601 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002602 if (pool)
2603 __tcp_free_md5sig_pool(pool);
2604}
2605
2606EXPORT_SYMBOL(tcp_free_md5sig_pool);
2607
Adrian Bunkf5b99bc2006-11-30 17:22:29 -08002608static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002609{
2610 int cpu;
2611 struct tcp_md5sig_pool **pool;
2612
2613 pool = alloc_percpu(struct tcp_md5sig_pool *);
2614 if (!pool)
2615 return NULL;
2616
2617 for_each_possible_cpu(cpu) {
2618 struct tcp_md5sig_pool *p;
2619 struct crypto_hash *hash;
2620
2621 p = kzalloc(sizeof(*p), GFP_KERNEL);
2622 if (!p)
2623 goto out_free;
2624 *per_cpu_ptr(pool, cpu) = p;
2625
2626 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2627 if (!hash || IS_ERR(hash))
2628 goto out_free;
2629
2630 p->md5_desc.tfm = hash;
2631 }
2632 return pool;
2633out_free:
2634 __tcp_free_md5sig_pool(pool);
2635 return NULL;
2636}
2637
2638struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
2639{
2640 struct tcp_md5sig_pool **pool;
2641 int alloc = 0;
2642
2643retry:
David S. Miller2c4f6212007-02-20 23:51:47 -08002644 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002645 pool = tcp_md5sig_pool;
2646 if (tcp_md5sig_users++ == 0) {
2647 alloc = 1;
David S. Miller2c4f6212007-02-20 23:51:47 -08002648 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002649 } else if (!pool) {
2650 tcp_md5sig_users--;
David S. Miller2c4f6212007-02-20 23:51:47 -08002651 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002652 cpu_relax();
2653 goto retry;
2654 } else
David S. Miller2c4f6212007-02-20 23:51:47 -08002655 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002656
2657 if (alloc) {
2658 /* we cannot hold spinlock here because this may sleep. */
2659 struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
David S. Miller2c4f6212007-02-20 23:51:47 -08002660 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002661 if (!p) {
2662 tcp_md5sig_users--;
David S. Miller2c4f6212007-02-20 23:51:47 -08002663 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002664 return NULL;
2665 }
2666 pool = tcp_md5sig_pool;
2667 if (pool) {
2668 /* oops, it has already been assigned. */
David S. Miller2c4f6212007-02-20 23:51:47 -08002669 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002670 __tcp_free_md5sig_pool(p);
2671 } else {
2672 tcp_md5sig_pool = pool = p;
David S. Miller2c4f6212007-02-20 23:51:47 -08002673 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002674 }
2675 }
2676 return pool;
2677}
2678
2679EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2680
2681struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
2682{
2683 struct tcp_md5sig_pool **p;
David S. Miller2c4f6212007-02-20 23:51:47 -08002684 spin_lock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002685 p = tcp_md5sig_pool;
2686 if (p)
2687 tcp_md5sig_users++;
David S. Miller2c4f6212007-02-20 23:51:47 -08002688 spin_unlock_bh(&tcp_md5sig_pool_lock);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002689 return (p ? *per_cpu_ptr(p, cpu) : NULL);
2690}
2691
2692EXPORT_SYMBOL(__tcp_get_md5sig_pool);
2693
David S. Miller6931ba72006-12-13 16:25:44 -08002694void __tcp_put_md5sig_pool(void)
2695{
2696 tcp_free_md5sig_pool();
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002697}
2698
2699EXPORT_SYMBOL(__tcp_put_md5sig_pool);
Adam Langley49a72df2008-07-19 00:01:42 -07002700
2701int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
2702 struct tcphdr *th)
2703{
2704 struct scatterlist sg;
2705 int err;
2706
2707 __sum16 old_checksum = th->check;
2708 th->check = 0;
2709 /* options aren't included in the hash */
2710 sg_init_one(&sg, th, sizeof(struct tcphdr));
2711 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
2712 th->check = old_checksum;
2713 return err;
2714}
2715
2716EXPORT_SYMBOL(tcp_md5_hash_header);
2717
2718int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
2719 struct sk_buff *skb, unsigned header_len)
2720{
2721 struct scatterlist sg;
2722 const struct tcphdr *tp = tcp_hdr(skb);
2723 struct hash_desc *desc = &hp->md5_desc;
2724 unsigned i;
2725 const unsigned head_data_len = skb_headlen(skb) > header_len ?
2726 skb_headlen(skb) - header_len : 0;
2727 const struct skb_shared_info *shi = skb_shinfo(skb);
2728
2729 sg_init_table(&sg, 1);
2730
2731 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
2732 if (crypto_hash_update(desc, &sg, head_data_len))
2733 return 1;
2734
2735 for (i = 0; i < shi->nr_frags; ++i) {
2736 const struct skb_frag_struct *f = &shi->frags[i];
2737 sg_set_page(&sg, f->page, f->size, f->page_offset);
2738 if (crypto_hash_update(desc, &sg, f->size))
2739 return 1;
2740 }
2741
2742 return 0;
2743}
2744
2745EXPORT_SYMBOL(tcp_md5_hash_skb_data);
2746
2747int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
2748{
2749 struct scatterlist sg;
2750
2751 sg_init_one(&sg, key->key, key->keylen);
2752 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
2753}
2754
2755EXPORT_SYMBOL(tcp_md5_hash_key);
2756
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08002757#endif
2758
Andi Kleen4ac02ba2007-04-20 17:11:46 -07002759void tcp_done(struct sock *sk)
2760{
Jianjun Kong5a5f3a82008-11-03 00:24:34 -08002761 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07002762 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
Andi Kleen4ac02ba2007-04-20 17:11:46 -07002763
2764 tcp_set_state(sk, TCP_CLOSE);
2765 tcp_clear_xmit_timers(sk);
2766
2767 sk->sk_shutdown = SHUTDOWN_MASK;
2768
2769 if (!sock_flag(sk, SOCK_DEAD))
2770 sk->sk_state_change(sk);
2771 else
2772 inet_csk_destroy_sock(sk);
2773}
2774EXPORT_SYMBOL_GPL(tcp_done);
2775
Stephen Hemminger5f8ef482005-06-23 20:37:36 -07002776extern struct tcp_congestion_ops tcp_reno;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002777
2778static __initdata unsigned long thash_entries;
2779static int __init set_thash_entries(char *str)
2780{
2781 if (!str)
2782 return 0;
2783 thash_entries = simple_strtoul(str, &str, 0);
2784 return 1;
2785}
2786__setup("thash_entries=", set_thash_entries);
2787
2788void __init tcp_init(void)
2789{
2790 struct sk_buff *skb = NULL;
Miquel van Smoorenburg57413eb2008-06-27 17:23:57 -07002791 unsigned long nr_pages, limit;
John Heffner7b4f4b52006-03-25 01:34:07 -08002792 int order, i, max_share;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002793
Pavel Emelyanov1f9e6362007-12-11 02:12:04 -08002794 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002795
Eric Dumazet17483762008-11-25 21:16:35 -08002796 percpu_counter_init(&tcp_sockets_allocated, 0);
Eric Dumazetdd24c002008-11-25 21:17:14 -08002797 percpu_counter_init(&tcp_orphan_count, 0);
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002798 tcp_hashinfo.bind_bucket_cachep =
2799 kmem_cache_create("tcp_bind_bucket",
2800 sizeof(struct inet_bind_bucket), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09002801 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002802
Linus Torvalds1da177e2005-04-16 15:20:36 -07002803 /* Size and allocate the main established and bind bucket
2804 * hash tables.
2805 *
2806 * The methodology is similar to that of the buffer cache.
2807 */
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002808 tcp_hashinfo.ehash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002809 alloc_large_system_hash("TCP established",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002810 sizeof(struct inet_ehash_bucket),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002811 thash_entries,
2812 (num_physpages >= 128 * 1024) ?
Mike Stroyan18955cf2005-11-29 16:12:55 -08002813 13 : 15,
John Heffner9e950ef2006-11-06 23:10:51 -08002814 0,
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002815 &tcp_hashinfo.ehash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002816 NULL,
Jean Delvare0ccfe612007-10-30 00:59:25 -07002817 thash_entries ? 0 : 512 * 1024);
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002818 tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
2819 for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002820 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
2821 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002822 }
Eric Dumazet230140c2007-11-07 02:40:20 -08002823 if (inet_ehash_locks_alloc(&tcp_hashinfo))
2824 panic("TCP: failed to alloc ehash_locks");
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002825 tcp_hashinfo.bhash =
Linus Torvalds1da177e2005-04-16 15:20:36 -07002826 alloc_large_system_hash("TCP bind",
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002827 sizeof(struct inet_bind_hashbucket),
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002828 tcp_hashinfo.ehash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002829 (num_physpages >= 128 * 1024) ?
Mike Stroyan18955cf2005-11-29 16:12:55 -08002830 13 : 15,
John Heffner9e950ef2006-11-06 23:10:51 -08002831 0,
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002832 &tcp_hashinfo.bhash_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002833 NULL,
2834 64 * 1024);
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002835 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
2836 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
2837 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
2838 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002839 }
2840
2841 /* Try to be a bit smarter and adjust defaults depending
2842 * on available memory.
2843 */
2844 for (order = 0; ((1 << order) << PAGE_SHIFT) <
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002845 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002846 order++)
2847 ;
Andi Kleene7626482005-06-13 14:24:52 -07002848 if (order >= 4) {
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07002849 tcp_death_row.sysctl_max_tw_buckets = 180000;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002850 sysctl_tcp_max_orphans = 4096 << (order - 4);
2851 sysctl_max_syn_backlog = 1024;
2852 } else if (order < 3) {
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07002853 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002854 sysctl_tcp_max_orphans >>= (3 - order);
2855 sysctl_max_syn_backlog = 128;
2856 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002857
John Heffner53cdcc02007-03-16 15:04:03 -07002858 /* Set the pressure threshold to be a fraction of global memory that
2859 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
2860 * memory, with a floor of 128 pages.
2861 */
Miquel van Smoorenburg57413eb2008-06-27 17:23:57 -07002862 nr_pages = totalram_pages - totalhigh_pages;
2863 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
2864 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
John Heffner53cdcc02007-03-16 15:04:03 -07002865 limit = max(limit, 128UL);
2866 sysctl_tcp_mem[0] = limit / 4 * 3;
2867 sysctl_tcp_mem[1] = limit;
John Heffner52bf3762006-11-14 20:25:17 -08002868 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002869
John Heffner53cdcc02007-03-16 15:04:03 -07002870 /* Set per-socket limits to no more than 1/128 the pressure threshold */
John Heffner7b4f4b52006-03-25 01:34:07 -08002871 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
2872 max_share = min(4UL*1024*1024, limit);
2873
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002874 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08002875 sysctl_tcp_wmem[1] = 16*1024;
2876 sysctl_tcp_wmem[2] = max(64*1024, max_share);
2877
Hideo Aoki3ab224b2007-12-31 00:11:19 -08002878 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
John Heffner7b4f4b52006-03-25 01:34:07 -08002879 sysctl_tcp_rmem[1] = 87380;
2880 sysctl_tcp_rmem[2] = max(87380, max_share);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002881
2882 printk(KERN_INFO "TCP: Hash tables configured "
2883 "(established %d bind %d)\n",
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002884 tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
Stephen Hemminger317a76f2005-06-23 12:19:55 -07002885
2886 tcp_register_congestion_control(&tcp_reno);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002887}
2888
Linus Torvalds1da177e2005-04-16 15:20:36 -07002889EXPORT_SYMBOL(tcp_close);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002890EXPORT_SYMBOL(tcp_disconnect);
2891EXPORT_SYMBOL(tcp_getsockopt);
2892EXPORT_SYMBOL(tcp_ioctl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002893EXPORT_SYMBOL(tcp_poll);
2894EXPORT_SYMBOL(tcp_read_sock);
2895EXPORT_SYMBOL(tcp_recvmsg);
2896EXPORT_SYMBOL(tcp_sendmsg);
Jens Axboe9c55e012007-11-06 23:30:13 -08002897EXPORT_SYMBOL(tcp_splice_read);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002898EXPORT_SYMBOL(tcp_sendpage);
2899EXPORT_SYMBOL(tcp_setsockopt);
2900EXPORT_SYMBOL(tcp_shutdown);