?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[ARM] S3C: Move regs-rtc.h to arch/arm/plat-s3c/include/plat
[linux-2.6/openmoko-kernel.git] / net / ipv4 / tcp.c
blobeccb7165a80c180f56c42a1261597b361966396d
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Implementation of the Transmission Control Protocol(TCP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Mark Evans, <evansmp@uhura.aston.ac.uk>
11 * Corey Minyard <wf-rch!minyard@relay.EU.net>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
14 * Linus Torvalds, <torvalds@cs.helsinki.fi>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Matthew Dillon, <dillon@apollo.west.oic.com>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Jorge Cwik, <jorge@laser.satlink.net>
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
248 #include <linux/kernel.h>
249 #include <linux/module.h>
250 #include <linux/types.h>
251 #include <linux/fcntl.h>
252 #include <linux/poll.h>
253 #include <linux/init.h>
254 #include <linux/fs.h>
255 #include <linux/skbuff.h>
256 #include <linux/scatterlist.h>
257 #include <linux/splice.h>
258 #include <linux/net.h>
259 #include <linux/socket.h>
260 #include <linux/random.h>
261 #include <linux/bootmem.h>
262 #include <linux/highmem.h>
263 #include <linux/swap.h>
264 #include <linux/cache.h>
265 #include <linux/err.h>
266 #include <linux/crypto.h>
267
268 #include <net/icmp.h>
269 #include <net/tcp.h>
270 #include <net/xfrm.h>
271 #include <net/ip.h>
272 #include <net/netdma.h>
273 #include <net/sock.h>
274
275 #include <asm/uaccess.h>
276 #include <asm/ioctls.h>
277
278 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
279
280 atomic_t tcp_orphan_count = ATOMIC_INIT(0);
281
282 EXPORT_SYMBOL_GPL(tcp_orphan_count);
283
284 int sysctl_tcp_mem[3] __read_mostly;
285 int sysctl_tcp_wmem[3] __read_mostly;
286 int sysctl_tcp_rmem[3] __read_mostly;
287
288 EXPORT_SYMBOL(sysctl_tcp_mem);
289 EXPORT_SYMBOL(sysctl_tcp_rmem);
290 EXPORT_SYMBOL(sysctl_tcp_wmem);
291
292 atomic_t tcp_memory_allocated; /* Current allocated memory. */
293 atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */
294
295 EXPORT_SYMBOL(tcp_memory_allocated);
296 EXPORT_SYMBOL(tcp_sockets_allocated);
297
298 /*
299 * TCP splice context
300 */
301 struct tcp_splice_state {
302 struct pipe_inode_info *pipe;
303 size_t len;
304 unsigned int flags;
305 };
306
307 /*
308 * Pressure flag: try to collapse.
309 * Technical note: it is used by multiple contexts non atomically.
310 * All the __sk_mem_schedule() is of this nature: accounting
311 * is strict, actions are advisory and have some latency.
312 */
313 int tcp_memory_pressure __read_mostly;
314
315 EXPORT_SYMBOL(tcp_memory_pressure);
316
317 void tcp_enter_memory_pressure(struct sock *sk)
318 {
319 if (!tcp_memory_pressure) {
320 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
321 tcp_memory_pressure = 1;
322 }
323 }
324
325 EXPORT_SYMBOL(tcp_enter_memory_pressure);
326
327 /*
328 * Wait for a TCP event.
329 *
330 * Note that we don't need to lock the socket, as the upper poll layers
331 * take care of normal races (between the test and the event) and we don't
332 * go look at any of the socket buffers directly.
333 */
334 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
335 {
336 unsigned int mask;
337 struct sock *sk = sock->sk;
338 struct tcp_sock *tp = tcp_sk(sk);
339
340 poll_wait(file, sk->sk_sleep, wait);
341 if (sk->sk_state == TCP_LISTEN)
342 return inet_csk_listen_poll(sk);
343
344 /* Socket is not locked. We are protected from async events
345 * by poll logic and correct handling of state changes
346 * made by other threads is impossible in any case.
347 */
348
349 mask = 0;
350 if (sk->sk_err)
351 mask = POLLERR;
352
353 /*
354 * POLLHUP is certainly not done right. But poll() doesn't
355 * have a notion of HUP in just one direction, and for a
356 * socket the read side is more interesting.
357 *
358 * Some poll() documentation says that POLLHUP is incompatible
359 * with the POLLOUT/POLLWR flags, so somebody should check this
360 * all. But careful, it tends to be safer to return too many
361 * bits than too few, and you can easily break real applications
362 * if you don't tell them that something has hung up!
363 *
364 * Check-me.
365 *
366 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
367 * our fs/select.c). It means that after we received EOF,
368 * poll always returns immediately, making impossible poll() on write()
369 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
370 * if and only if shutdown has been made in both directions.
371 * Actually, it is interesting to look how Solaris and DUX
372 * solve this dilemma. I would prefer, if POLLHUP were maskable,
373 * then we could set it on SND_SHUTDOWN. BTW examples given
374 * in Stevens' books assume exactly this behaviour, it explains
375 * why POLLHUP is incompatible with POLLOUT. --ANK
376 *
377 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
378 * blocking on fresh not-connected or disconnected socket. --ANK
379 */
380 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
381 mask |= POLLHUP;
382 if (sk->sk_shutdown & RCV_SHUTDOWN)
383 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
384
385 /* Connected? */
386 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
387 int target = sock_rcvlowat(sk, 0, INT_MAX);
388
389 if (tp->urg_seq == tp->copied_seq &&
390 !sock_flag(sk, SOCK_URGINLINE) &&
391 tp->urg_data)
392 target--;
393
394 /* Potential race condition. If read of tp below will
395 * escape above sk->sk_state, we can be illegally awaken
396 * in SYN_* states. */
397 if (tp->rcv_nxt - tp->copied_seq >= target)
398 mask |= POLLIN | POLLRDNORM;
399
400 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
401 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
402 mask |= POLLOUT | POLLWRNORM;
403 } else { /* send SIGIO later */
404 set_bit(SOCK_ASYNC_NOSPACE,
405 &sk->sk_socket->flags);
406 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
407
408 /* Race breaker. If space is freed after
409 * wspace test but before the flags are set,
410 * IO signal will be lost.
411 */
412 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
413 mask |= POLLOUT | POLLWRNORM;
414 }
415 }
416
417 if (tp->urg_data & TCP_URG_VALID)
418 mask |= POLLPRI;
419 }
420 return mask;
421 }
422
423 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
424 {
425 struct tcp_sock *tp = tcp_sk(sk);
426 int answ;
427
428 switch (cmd) {
429 case SIOCINQ:
430 if (sk->sk_state == TCP_LISTEN)
431 return -EINVAL;
432
433 lock_sock(sk);
434 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
435 answ = 0;
436 else if (sock_flag(sk, SOCK_URGINLINE) ||
437 !tp->urg_data ||
438 before(tp->urg_seq, tp->copied_seq) ||
439 !before(tp->urg_seq, tp->rcv_nxt)) {
440 answ = tp->rcv_nxt - tp->copied_seq;
441
442 /* Subtract 1, if FIN is in queue. */
443 if (answ && !skb_queue_empty(&sk->sk_receive_queue))
444 answ -=
445 tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin;
446 } else
447 answ = tp->urg_seq - tp->copied_seq;
448 release_sock(sk);
449 break;
450 case SIOCATMARK:
451 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
452 break;
453 case SIOCOUTQ:
454 if (sk->sk_state == TCP_LISTEN)
455 return -EINVAL;
456
457 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
458 answ = 0;
459 else
460 answ = tp->write_seq - tp->snd_una;
461 break;
462 default:
463 return -ENOIOCTLCMD;
464 }
465
466 return put_user(answ, (int __user *)arg);
467 }
468
469 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
470 {
471 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
472 tp->pushed_seq = tp->write_seq;
473 }
474
475 static inline int forced_push(struct tcp_sock *tp)
476 {
477 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
478 }
479
480 static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
481 {
482 struct tcp_sock *tp = tcp_sk(sk);
483 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
484
485 skb->csum = 0;
486 tcb->seq = tcb->end_seq = tp->write_seq;
487 tcb->flags = TCPCB_FLAG_ACK;
488 tcb->sacked = 0;
489 skb_header_release(skb);
490 tcp_add_write_queue_tail(sk, skb);
491 sk->sk_wmem_queued += skb->truesize;
492 sk_mem_charge(sk, skb->truesize);
493 if (tp->nonagle & TCP_NAGLE_PUSH)
494 tp->nonagle &= ~TCP_NAGLE_PUSH;
495 }
496
497 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
498 struct sk_buff *skb)
499 {
500 if (flags & MSG_OOB)
501 tp->snd_up = tp->write_seq;
502 }
503
504 static inline void tcp_push(struct sock *sk, int flags, int mss_now,
505 int nonagle)
506 {
507 struct tcp_sock *tp = tcp_sk(sk);
508
509 if (tcp_send_head(sk)) {
510 struct sk_buff *skb = tcp_write_queue_tail(sk);
511 if (!(flags & MSG_MORE) || forced_push(tp))
512 tcp_mark_push(tp, skb);
513 tcp_mark_urg(tp, flags, skb);
514 __tcp_push_pending_frames(sk, mss_now,
515 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
516 }
517 }
518
519 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
520 unsigned int offset, size_t len)
521 {
522 struct tcp_splice_state *tss = rd_desc->arg.data;
523
524 return skb_splice_bits(skb, offset, tss->pipe, tss->len, tss->flags);
525 }
526
527 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
528 {
529 /* Store TCP splice context information in read_descriptor_t. */
530 read_descriptor_t rd_desc = {
531 .arg.data = tss,
532 };
533
534 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
535 }
536
537 /**
538 * tcp_splice_read - splice data from TCP socket to a pipe
539 * @sock: socket to splice from
540 * @ppos: position (not valid)
541 * @pipe: pipe to splice to
542 * @len: number of bytes to splice
543 * @flags: splice modifier flags
544 *
545 * Description:
546 * Will read pages from given socket and fill them into a pipe.
547 *
548 **/
549 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
550 struct pipe_inode_info *pipe, size_t len,
551 unsigned int flags)
552 {
553 struct sock *sk = sock->sk;
554 struct tcp_splice_state tss = {
555 .pipe = pipe,
556 .len = len,
557 .flags = flags,
558 };
559 long timeo;
560 ssize_t spliced;
561 int ret;
562
563 /*
564 * We can't seek on a socket input
565 */
566 if (unlikely(*ppos))
567 return -ESPIPE;
568
569 ret = spliced = 0;
570
571 lock_sock(sk);
572
573 timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
574 while (tss.len) {
575 ret = __tcp_splice_read(sk, &tss);
576 if (ret < 0)
577 break;
578 else if (!ret) {
579 if (spliced)
580 break;
581 if (flags & SPLICE_F_NONBLOCK) {
582 ret = -EAGAIN;
583 break;
584 }
585 if (sock_flag(sk, SOCK_DONE))
586 break;
587 if (sk->sk_err) {
588 ret = sock_error(sk);
589 break;
590 }
591 if (sk->sk_shutdown & RCV_SHUTDOWN)
592 break;
593 if (sk->sk_state == TCP_CLOSE) {
594 /*
595 * This occurs when user tries to read
596 * from never connected socket.
597 */
598 if (!sock_flag(sk, SOCK_DONE))
599 ret = -ENOTCONN;
600 break;
601 }
602 if (!timeo) {
603 ret = -EAGAIN;
604 break;
605 }
606 sk_wait_data(sk, &timeo);
607 if (signal_pending(current)) {
608 ret = sock_intr_errno(timeo);
609 break;
610 }
611 continue;
612 }
613 tss.len -= ret;
614 spliced += ret;
615
616 release_sock(sk);
617 lock_sock(sk);
618
619 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
620 (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo ||
621 signal_pending(current))
622 break;
623 }
624
625 release_sock(sk);
626
627 if (spliced)
628 return spliced;
629
630 return ret;
631 }
632
633 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
634 {
635 struct sk_buff *skb;
636
637 /* The TCP header must be at least 32-bit aligned. */
638 size = ALIGN(size, 4);
639
640 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
641 if (skb) {
642 if (sk_wmem_schedule(sk, skb->truesize)) {
643 /*
644 * Make sure that we have exactly size bytes
645 * available to the caller, no more, no less.
646 */
647 skb_reserve(skb, skb_tailroom(skb) - size);
648 return skb;
649 }
650 __kfree_skb(skb);
651 } else {
652 sk->sk_prot->enter_memory_pressure(sk);
653 sk_stream_moderate_sndbuf(sk);
654 }
655 return NULL;
656 }
657
658 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
659 size_t psize, int flags)
660 {
661 struct tcp_sock *tp = tcp_sk(sk);
662 int mss_now, size_goal;
663 int err;
664 ssize_t copied;
665 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
666
667 /* Wait for a connection to finish. */
668 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
669 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
670 goto out_err;
671
672 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
673
674 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
675 size_goal = tp->xmit_size_goal;
676 copied = 0;
677
678 err = -EPIPE;
679 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
680 goto do_error;
681
682 while (psize > 0) {
683 struct sk_buff *skb = tcp_write_queue_tail(sk);
684 struct page *page = pages[poffset / PAGE_SIZE];
685 int copy, i, can_coalesce;
686 int offset = poffset % PAGE_SIZE;
687 int size = min_t(size_t, psize, PAGE_SIZE - offset);
688
689 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
690 new_segment:
691 if (!sk_stream_memory_free(sk))
692 goto wait_for_sndbuf;
693
694 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
695 if (!skb)
696 goto wait_for_memory;
697
698 skb_entail(sk, skb);
699 copy = size_goal;
700 }
701
702 if (copy > size)
703 copy = size;
704
705 i = skb_shinfo(skb)->nr_frags;
706 can_coalesce = skb_can_coalesce(skb, i, page, offset);
707 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
708 tcp_mark_push(tp, skb);
709 goto new_segment;
710 }
711 if (!sk_wmem_schedule(sk, copy))
712 goto wait_for_memory;
713
714 if (can_coalesce) {
715 skb_shinfo(skb)->frags[i - 1].size += copy;
716 } else {
717 get_page(page);
718 skb_fill_page_desc(skb, i, page, offset, copy);
719 }
720
721 skb->len += copy;
722 skb->data_len += copy;
723 skb->truesize += copy;
724 sk->sk_wmem_queued += copy;
725 sk_mem_charge(sk, copy);
726 skb->ip_summed = CHECKSUM_PARTIAL;
727 tp->write_seq += copy;
728 TCP_SKB_CB(skb)->end_seq += copy;
729 skb_shinfo(skb)->gso_segs = 0;
730
731 if (!copied)
732 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
733
734 copied += copy;
735 poffset += copy;
736 if (!(psize -= copy))
737 goto out;
738
739 if (skb->len < size_goal || (flags & MSG_OOB))
740 continue;
741
742 if (forced_push(tp)) {
743 tcp_mark_push(tp, skb);
744 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
745 } else if (skb == tcp_send_head(sk))
746 tcp_push_one(sk, mss_now);
747 continue;
748
749 wait_for_sndbuf:
750 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
751 wait_for_memory:
752 if (copied)
753 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
754
755 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
756 goto do_error;
757
758 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
759 size_goal = tp->xmit_size_goal;
760 }
761
762 out:
763 if (copied)
764 tcp_push(sk, flags, mss_now, tp->nonagle);
765 return copied;
766
767 do_error:
768 if (copied)
769 goto out;
770 out_err:
771 return sk_stream_error(sk, flags, err);
772 }
773
774 ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
775 size_t size, int flags)
776 {
777 ssize_t res;
778 struct sock *sk = sock->sk;
779
780 if (!(sk->sk_route_caps & NETIF_F_SG) ||
781 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
782 return sock_no_sendpage(sock, page, offset, size, flags);
783
784 lock_sock(sk);
785 TCP_CHECK_TIMER(sk);
786 res = do_tcp_sendpages(sk, &page, offset, size, flags);
787 TCP_CHECK_TIMER(sk);
788 release_sock(sk);
789 return res;
790 }
791
792 #define TCP_PAGE(sk) (sk->sk_sndmsg_page)
793 #define TCP_OFF(sk) (sk->sk_sndmsg_off)
794
795 static inline int select_size(struct sock *sk)
796 {
797 struct tcp_sock *tp = tcp_sk(sk);
798 int tmp = tp->mss_cache;
799
800 if (sk->sk_route_caps & NETIF_F_SG) {
801 if (sk_can_gso(sk))
802 tmp = 0;
803 else {
804 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
805
806 if (tmp >= pgbreak &&
807 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
808 tmp = pgbreak;
809 }
810 }
811
812 return tmp;
813 }
814
815 int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
816 size_t size)
817 {
818 struct sock *sk = sock->sk;
819 struct iovec *iov;
820 struct tcp_sock *tp = tcp_sk(sk);
821 struct sk_buff *skb;
822 int iovlen, flags;
823 int mss_now, size_goal;
824 int err, copied;
825 long timeo;
826
827 lock_sock(sk);
828 TCP_CHECK_TIMER(sk);
829
830 flags = msg->msg_flags;
831 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
832
833 /* Wait for a connection to finish. */
834 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
835 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
836 goto out_err;
837
838 /* This should be in poll */
839 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
840
841 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
842 size_goal = tp->xmit_size_goal;
843
844 /* Ok commence sending. */
845 iovlen = msg->msg_iovlen;
846 iov = msg->msg_iov;
847 copied = 0;
848
849 err = -EPIPE;
850 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
851 goto do_error;
852
853 while (--iovlen >= 0) {
854 int seglen = iov->iov_len;
855 unsigned char __user *from = iov->iov_base;
856
857 iov++;
858
859 while (seglen > 0) {
860 int copy;
861
862 skb = tcp_write_queue_tail(sk);
863
864 if (!tcp_send_head(sk) ||
865 (copy = size_goal - skb->len) <= 0) {
866
867 new_segment:
868 /* Allocate new segment. If the interface is SG,
869 * allocate skb fitting to single page.
870 */
871 if (!sk_stream_memory_free(sk))
872 goto wait_for_sndbuf;
873
874 skb = sk_stream_alloc_skb(sk, select_size(sk),
875 sk->sk_allocation);
876 if (!skb)
877 goto wait_for_memory;
878
879 /*
880 * Check whether we can use HW checksum.
881 */
882 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
883 skb->ip_summed = CHECKSUM_PARTIAL;
884
885 skb_entail(sk, skb);
886 copy = size_goal;
887 }
888
889 /* Try to append data to the end of skb. */
890 if (copy > seglen)
891 copy = seglen;
892
893 /* Where to copy to? */
894 if (skb_tailroom(skb) > 0) {
895 /* We have some space in skb head. Superb! */
896 if (copy > skb_tailroom(skb))
897 copy = skb_tailroom(skb);
898 if ((err = skb_add_data(skb, from, copy)) != 0)
899 goto do_fault;
900 } else {
901 int merge = 0;
902 int i = skb_shinfo(skb)->nr_frags;
903 struct page *page = TCP_PAGE(sk);
904 int off = TCP_OFF(sk);
905
906 if (skb_can_coalesce(skb, i, page, off) &&
907 off != PAGE_SIZE) {
908 /* We can extend the last page
909 * fragment. */
910 merge = 1;
911 } else if (i == MAX_SKB_FRAGS ||
912 (!i &&
913 !(sk->sk_route_caps & NETIF_F_SG))) {
914 /* Need to add new fragment and cannot
915 * do this because interface is non-SG,
916 * or because all the page slots are
917 * busy. */
918 tcp_mark_push(tp, skb);
919 goto new_segment;
920 } else if (page) {
921 if (off == PAGE_SIZE) {
922 put_page(page);
923 TCP_PAGE(sk) = page = NULL;
924 off = 0;
925 }
926 } else
927 off = 0;
928
929 if (copy > PAGE_SIZE - off)
930 copy = PAGE_SIZE - off;
931
932 if (!sk_wmem_schedule(sk, copy))
933 goto wait_for_memory;
934
935 if (!page) {
936 /* Allocate new cache page. */
937 if (!(page = sk_stream_alloc_page(sk)))
938 goto wait_for_memory;
939 }
940
941 /* Time to copy data. We are close to
942 * the end! */
943 err = skb_copy_to_page(sk, from, skb, page,
944 off, copy);
945 if (err) {
946 /* If this page was new, give it to the
947 * socket so it does not get leaked.
948 */
949 if (!TCP_PAGE(sk)) {
950 TCP_PAGE(sk) = page;
951 TCP_OFF(sk) = 0;
952 }
953 goto do_error;
954 }
955
956 /* Update the skb. */
957 if (merge) {
958 skb_shinfo(skb)->frags[i - 1].size +=
959 copy;
960 } else {
961 skb_fill_page_desc(skb, i, page, off, copy);
962 if (TCP_PAGE(sk)) {
963 get_page(page);
964 } else if (off + copy < PAGE_SIZE) {
965 get_page(page);
966 TCP_PAGE(sk) = page;
967 }
968 }
969
970 TCP_OFF(sk) = off + copy;
971 }
972
973 if (!copied)
974 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
975
976 tp->write_seq += copy;
977 TCP_SKB_CB(skb)->end_seq += copy;
978 skb_shinfo(skb)->gso_segs = 0;
979
980 from += copy;
981 copied += copy;
982 if ((seglen -= copy) == 0 && iovlen == 0)
983 goto out;
984
985 if (skb->len < size_goal || (flags & MSG_OOB))
986 continue;
987
988 if (forced_push(tp)) {
989 tcp_mark_push(tp, skb);
990 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
991 } else if (skb == tcp_send_head(sk))
992 tcp_push_one(sk, mss_now);
993 continue;
994
995 wait_for_sndbuf:
996 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
997 wait_for_memory:
998 if (copied)
999 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
1000
1001 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1002 goto do_error;
1003
1004 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
1005 size_goal = tp->xmit_size_goal;
1006 }
1007 }
1008
1009 out:
1010 if (copied)
1011 tcp_push(sk, flags, mss_now, tp->nonagle);
1012 TCP_CHECK_TIMER(sk);
1013 release_sock(sk);
1014 return copied;
1015
1016 do_fault:
1017 if (!skb->len) {
1018 tcp_unlink_write_queue(skb, sk);
1019 /* It is the one place in all of TCP, except connection
1020 * reset, where we can be unlinking the send_head.
1021 */
1022 tcp_check_send_head(sk, skb);
1023 sk_wmem_free_skb(sk, skb);
1024 }
1025
1026 do_error:
1027 if (copied)
1028 goto out;
1029 out_err:
1030 err = sk_stream_error(sk, flags, err);
1031 TCP_CHECK_TIMER(sk);
1032 release_sock(sk);
1033 return err;
1034 }
1035
1036 /*
1037 * Handle reading urgent data. BSD has very simple semantics for
1038 * this, no blocking and very strange errors 8)
1039 */
1040
1041 static int tcp_recv_urg(struct sock *sk, long timeo,
1042 struct msghdr *msg, int len, int flags,
1043 int *addr_len)
1044 {
1045 struct tcp_sock *tp = tcp_sk(sk);
1046
1047 /* No URG data to read. */
1048 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1049 tp->urg_data == TCP_URG_READ)
1050 return -EINVAL; /* Yes this is right ! */
1051
1052 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1053 return -ENOTCONN;
1054
1055 if (tp->urg_data & TCP_URG_VALID) {
1056 int err = 0;
1057 char c = tp->urg_data;
1058
1059 if (!(flags & MSG_PEEK))
1060 tp->urg_data = TCP_URG_READ;
1061
1062 /* Read urgent data. */
1063 msg->msg_flags |= MSG_OOB;
1064
1065 if (len > 0) {
1066 if (!(flags & MSG_TRUNC))
1067 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1068 len = 1;
1069 } else
1070 msg->msg_flags |= MSG_TRUNC;
1071
1072 return err ? -EFAULT : len;
1073 }
1074
1075 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1076 return 0;
1077
1078 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1079 * the available implementations agree in this case:
1080 * this call should never block, independent of the
1081 * blocking state of the socket.
1082 * Mike <pall@rz.uni-karlsruhe.de>
1083 */
1084 return -EAGAIN;
1085 }
1086
1087 /* Clean up the receive buffer for full frames taken by the user,
1088 * then send an ACK if necessary. COPIED is the number of bytes
1089 * tcp_recvmsg has given to the user so far, it speeds up the
1090 * calculation of whether or not we must ACK for the sake of
1091 * a window update.
1092 */
1093 void tcp_cleanup_rbuf(struct sock *sk, int copied)
1094 {
1095 struct tcp_sock *tp = tcp_sk(sk);
1096 int time_to_ack = 0;
1097
1098 #if TCP_DEBUG
1099 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1100
1101 WARN_ON(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
1102 #endif
1103
1104 if (inet_csk_ack_scheduled(sk)) {
1105 const struct inet_connection_sock *icsk = inet_csk(sk);
1106 /* Delayed ACKs frequently hit locked sockets during bulk
1107 * receive. */
1108 if (icsk->icsk_ack.blocked ||
1109 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1110 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1111 /*
1112 * If this read emptied read buffer, we send ACK, if
1113 * connection is not bidirectional, user drained
1114 * receive buffer and there was a small segment
1115 * in queue.
1116 */
1117 (copied > 0 &&
1118 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1119 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1120 !icsk->icsk_ack.pingpong)) &&
1121 !atomic_read(&sk->sk_rmem_alloc)))
1122 time_to_ack = 1;
1123 }
1124
1125 /* We send an ACK if we can now advertise a non-zero window
1126 * which has been raised "significantly".
1127 *
1128 * Even if window raised up to infinity, do not send window open ACK
1129 * in states, where we will not receive more. It is useless.
1130 */
1131 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1132 __u32 rcv_window_now = tcp_receive_window(tp);
1133
1134 /* Optimize, __tcp_select_window() is not cheap. */
1135 if (2*rcv_window_now <= tp->window_clamp) {
1136 __u32 new_window = __tcp_select_window(sk);
1137
1138 /* Send ACK now, if this read freed lots of space
1139 * in our buffer. Certainly, new_window is new window.
1140 * We can advertise it now, if it is not less than current one.
1141 * "Lots" means "at least twice" here.
1142 */
1143 if (new_window && new_window >= 2 * rcv_window_now)
1144 time_to_ack = 1;
1145 }
1146 }
1147 if (time_to_ack)
1148 tcp_send_ack(sk);
1149 }
1150
1151 static void tcp_prequeue_process(struct sock *sk)
1152 {
1153 struct sk_buff *skb;
1154 struct tcp_sock *tp = tcp_sk(sk);
1155
1156 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
1157
1158 /* RX process wants to run with disabled BHs, though it is not
1159 * necessary */
1160 local_bh_disable();
1161 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1162 sk_backlog_rcv(sk, skb);
1163 local_bh_enable();
1164
1165 /* Clear memory counter. */
1166 tp->ucopy.memory = 0;
1167 }
1168
1169 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1170 {
1171 struct sk_buff *skb;
1172 u32 offset;
1173
1174 skb_queue_walk(&sk->sk_receive_queue, skb) {
1175 offset = seq - TCP_SKB_CB(skb)->seq;
1176 if (tcp_hdr(skb)->syn)
1177 offset--;
1178 if (offset < skb->len || tcp_hdr(skb)->fin) {
1179 *off = offset;
1180 return skb;
1181 }
1182 }
1183 return NULL;
1184 }
1185
1186 /*
1187 * This routine provides an alternative to tcp_recvmsg() for routines
1188 * that would like to handle copying from skbuffs directly in 'sendfile'
1189 * fashion.
1190 * Note:
1191 * - It is assumed that the socket was locked by the caller.
1192 * - The routine does not block.
1193 * - At present, there is no support for reading OOB data
1194 * or for 'peeking' the socket using this routine
1195 * (although both would be easy to implement).
1196 */
1197 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1198 sk_read_actor_t recv_actor)
1199 {
1200 struct sk_buff *skb;
1201 struct tcp_sock *tp = tcp_sk(sk);
1202 u32 seq = tp->copied_seq;
1203 u32 offset;
1204 int copied = 0;
1205
1206 if (sk->sk_state == TCP_LISTEN)
1207 return -ENOTCONN;
1208 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1209 if (offset < skb->len) {
1210 int used;
1211 size_t len;
1212
1213 len = skb->len - offset;
1214 /* Stop reading if we hit a patch of urgent data */
1215 if (tp->urg_data) {
1216 u32 urg_offset = tp->urg_seq - seq;
1217 if (urg_offset < len)
1218 len = urg_offset;
1219 if (!len)
1220 break;
1221 }
1222 used = recv_actor(desc, skb, offset, len);
1223 if (used < 0) {
1224 if (!copied)
1225 copied = used;
1226 break;
1227 } else if (used <= len) {
1228 seq += used;
1229 copied += used;
1230 offset += used;
1231 }
1232 /*
1233 * If recv_actor drops the lock (e.g. TCP splice
1234 * receive) the skb pointer might be invalid when
1235 * getting here: tcp_collapse might have deleted it
1236 * while aggregating skbs from the socket queue.
1237 */
1238 skb = tcp_recv_skb(sk, seq-1, &offset);
1239 if (!skb || (offset+1 != skb->len))
1240 break;
1241 }
1242 if (tcp_hdr(skb)->fin) {
1243 sk_eat_skb(sk, skb, 0);
1244 ++seq;
1245 break;
1246 }
1247 sk_eat_skb(sk, skb, 0);
1248 if (!desc->count)
1249 break;
1250 }
1251 tp->copied_seq = seq;
1252
1253 tcp_rcv_space_adjust(sk);
1254
1255 /* Clean up data we have read: This will do ACK frames. */
1256 if (copied > 0)
1257 tcp_cleanup_rbuf(sk, copied);
1258 return copied;
1259 }
1260
1261 /*
1262 * This routine copies from a sock struct into the user buffer.
1263 *
1264 * Technical note: in 2.3 we work on _locked_ socket, so that
1265 * tricks with *seq access order and skb->users are not required.
1266 * Probably, code can be easily improved even more.
1267 */
1268
1269 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1270 size_t len, int nonblock, int flags, int *addr_len)
1271 {
1272 struct tcp_sock *tp = tcp_sk(sk);
1273 int copied = 0;
1274 u32 peek_seq;
1275 u32 *seq;
1276 unsigned long used;
1277 int err;
1278 int target; /* Read at least this many bytes */
1279 long timeo;
1280 struct task_struct *user_recv = NULL;
1281 int copied_early = 0;
1282 struct sk_buff *skb;
1283
1284 lock_sock(sk);
1285
1286 TCP_CHECK_TIMER(sk);
1287
1288 err = -ENOTCONN;
1289 if (sk->sk_state == TCP_LISTEN)
1290 goto out;
1291
1292 timeo = sock_rcvtimeo(sk, nonblock);
1293
1294 /* Urgent data needs to be handled specially. */
1295 if (flags & MSG_OOB)
1296 goto recv_urg;
1297
1298 seq = &tp->copied_seq;
1299 if (flags & MSG_PEEK) {
1300 peek_seq = tp->copied_seq;
1301 seq = &peek_seq;
1302 }
1303
1304 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1305
1306 #ifdef CONFIG_NET_DMA
1307 tp->ucopy.dma_chan = NULL;
1308 preempt_disable();
1309 skb = skb_peek_tail(&sk->sk_receive_queue);
1310 {
1311 int available = 0;
1312
1313 if (skb)
1314 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1315 if ((available < target) &&
1316 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1317 !sysctl_tcp_low_latency &&
1318 __get_cpu_var(softnet_data).net_dma) {
1319 preempt_enable_no_resched();
1320 tp->ucopy.pinned_list =
1321 dma_pin_iovec_pages(msg->msg_iov, len);
1322 } else {
1323 preempt_enable_no_resched();
1324 }
1325 }
1326 #endif
1327
1328 do {
1329 u32 offset;
1330
1331 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1332 if (tp->urg_data && tp->urg_seq == *seq) {
1333 if (copied)
1334 break;
1335 if (signal_pending(current)) {
1336 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1337 break;
1338 }
1339 }
1340
1341 /* Next get a buffer. */
1342
1343 skb = skb_peek(&sk->sk_receive_queue);
1344 do {
1345 if (!skb)
1346 break;
1347
1348 /* Now that we have two receive queues this
1349 * shouldn't happen.
1350 */
1351 if (before(*seq, TCP_SKB_CB(skb)->seq)) {
1352 printk(KERN_INFO "recvmsg bug: copied %X "
1353 "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
1354 break;
1355 }
1356 offset = *seq - TCP_SKB_CB(skb)->seq;
1357 if (tcp_hdr(skb)->syn)
1358 offset--;
1359 if (offset < skb->len)
1360 goto found_ok_skb;
1361 if (tcp_hdr(skb)->fin)
1362 goto found_fin_ok;
1363 WARN_ON(!(flags & MSG_PEEK));
1364 skb = skb->next;
1365 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
1366
1367 /* Well, if we have backlog, try to process it now yet. */
1368
1369 if (copied >= target && !sk->sk_backlog.tail)
1370 break;
1371
1372 if (copied) {
1373 if (sk->sk_err ||
1374 sk->sk_state == TCP_CLOSE ||
1375 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1376 !timeo ||
1377 signal_pending(current) ||
1378 (flags & MSG_PEEK))
1379 break;
1380 } else {
1381 if (sock_flag(sk, SOCK_DONE))
1382 break;
1383
1384 if (sk->sk_err) {
1385 copied = sock_error(sk);
1386 break;
1387 }
1388
1389 if (sk->sk_shutdown & RCV_SHUTDOWN)
1390 break;
1391
1392 if (sk->sk_state == TCP_CLOSE) {
1393 if (!sock_flag(sk, SOCK_DONE)) {
1394 /* This occurs when user tries to read
1395 * from never connected socket.
1396 */
1397 copied = -ENOTCONN;
1398 break;
1399 }
1400 break;
1401 }
1402
1403 if (!timeo) {
1404 copied = -EAGAIN;
1405 break;
1406 }
1407
1408 if (signal_pending(current)) {
1409 copied = sock_intr_errno(timeo);
1410 break;
1411 }
1412 }
1413
1414 tcp_cleanup_rbuf(sk, copied);
1415
1416 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1417 /* Install new reader */
1418 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1419 user_recv = current;
1420 tp->ucopy.task = user_recv;
1421 tp->ucopy.iov = msg->msg_iov;
1422 }
1423
1424 tp->ucopy.len = len;
1425
1426 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1427 !(flags & (MSG_PEEK | MSG_TRUNC)));
1428
1429 /* Ugly... If prequeue is not empty, we have to
1430 * process it before releasing socket, otherwise
1431 * order will be broken at second iteration.
1432 * More elegant solution is required!!!
1433 *
1434 * Look: we have the following (pseudo)queues:
1435 *
1436 * 1. packets in flight
1437 * 2. backlog
1438 * 3. prequeue
1439 * 4. receive_queue
1440 *
1441 * Each queue can be processed only if the next ones
1442 * are empty. At this point we have empty receive_queue.
1443 * But prequeue _can_ be not empty after 2nd iteration,
1444 * when we jumped to start of loop because backlog
1445 * processing added something to receive_queue.
1446 * We cannot release_sock(), because backlog contains
1447 * packets arrived _after_ prequeued ones.
1448 *
1449 * Shortly, algorithm is clear --- to process all
1450 * the queues in order. We could make it more directly,
1451 * requeueing packets from backlog to prequeue, if
1452 * is not empty. It is more elegant, but eats cycles,
1453 * unfortunately.
1454 */
1455 if (!skb_queue_empty(&tp->ucopy.prequeue))
1456 goto do_prequeue;
1457
1458 /* __ Set realtime policy in scheduler __ */
1459 }
1460
1461 if (copied >= target) {
1462 /* Do not sleep, just process backlog. */
1463 release_sock(sk);
1464 lock_sock(sk);
1465 } else
1466 sk_wait_data(sk, &timeo);
1467
1468 #ifdef CONFIG_NET_DMA
1469 tp->ucopy.wakeup = 0;
1470 #endif
1471
1472 if (user_recv) {
1473 int chunk;
1474
1475 /* __ Restore normal policy in scheduler __ */
1476
1477 if ((chunk = len - tp->ucopy.len) != 0) {
1478 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1479 len -= chunk;
1480 copied += chunk;
1481 }
1482
1483 if (tp->rcv_nxt == tp->copied_seq &&
1484 !skb_queue_empty(&tp->ucopy.prequeue)) {
1485 do_prequeue:
1486 tcp_prequeue_process(sk);
1487
1488 if ((chunk = len - tp->ucopy.len) != 0) {
1489 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1490 len -= chunk;
1491 copied += chunk;
1492 }
1493 }
1494 }
1495 if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
1496 if (net_ratelimit())
1497 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1498 current->comm, task_pid_nr(current));
1499 peek_seq = tp->copied_seq;
1500 }
1501 continue;
1502
1503 found_ok_skb:
1504 /* Ok so how much can we use? */
1505 used = skb->len - offset;
1506 if (len < used)
1507 used = len;
1508
1509 /* Do we have urgent data here? */
1510 if (tp->urg_data) {
1511 u32 urg_offset = tp->urg_seq - *seq;
1512 if (urg_offset < used) {
1513 if (!urg_offset) {
1514 if (!sock_flag(sk, SOCK_URGINLINE)) {
1515 ++*seq;
1516 offset++;
1517 used--;
1518 if (!used)
1519 goto skip_copy;
1520 }
1521 } else
1522 used = urg_offset;
1523 }
1524 }
1525
1526 if (!(flags & MSG_TRUNC)) {
1527 #ifdef CONFIG_NET_DMA
1528 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1529 tp->ucopy.dma_chan = get_softnet_dma();
1530
1531 if (tp->ucopy.dma_chan) {
1532 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1533 tp->ucopy.dma_chan, skb, offset,
1534 msg->msg_iov, used,
1535 tp->ucopy.pinned_list);
1536
1537 if (tp->ucopy.dma_cookie < 0) {
1538
1539 printk(KERN_ALERT "dma_cookie < 0\n");
1540
1541 /* Exception. Bailout! */
1542 if (!copied)
1543 copied = -EFAULT;
1544 break;
1545 }
1546 if ((offset + used) == skb->len)
1547 copied_early = 1;
1548
1549 } else
1550 #endif
1551 {
1552 err = skb_copy_datagram_iovec(skb, offset,
1553 msg->msg_iov, used);
1554 if (err) {
1555 /* Exception. Bailout! */
1556 if (!copied)
1557 copied = -EFAULT;
1558 break;
1559 }
1560 }
1561 }
1562
1563 *seq += used;
1564 copied += used;
1565 len -= used;
1566
1567 tcp_rcv_space_adjust(sk);
1568
1569 skip_copy:
1570 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1571 tp->urg_data = 0;
1572 tcp_fast_path_check(sk);
1573 }
1574 if (used + offset < skb->len)
1575 continue;
1576
1577 if (tcp_hdr(skb)->fin)
1578 goto found_fin_ok;
1579 if (!(flags & MSG_PEEK)) {
1580 sk_eat_skb(sk, skb, copied_early);
1581 copied_early = 0;
1582 }
1583 continue;
1584
1585 found_fin_ok:
1586 /* Process the FIN. */
1587 ++*seq;
1588 if (!(flags & MSG_PEEK)) {
1589 sk_eat_skb(sk, skb, copied_early);
1590 copied_early = 0;
1591 }
1592 break;
1593 } while (len > 0);
1594
1595 if (user_recv) {
1596 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1597 int chunk;
1598
1599 tp->ucopy.len = copied > 0 ? len : 0;
1600
1601 tcp_prequeue_process(sk);
1602
1603 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1604 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1605 len -= chunk;
1606 copied += chunk;
1607 }
1608 }
1609
1610 tp->ucopy.task = NULL;
1611 tp->ucopy.len = 0;
1612 }
1613
1614 #ifdef CONFIG_NET_DMA
1615 if (tp->ucopy.dma_chan) {
1616 dma_cookie_t done, used;
1617
1618 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1619
1620 while (dma_async_memcpy_complete(tp->ucopy.dma_chan,
1621 tp->ucopy.dma_cookie, &done,
1622 &used) == DMA_IN_PROGRESS) {
1623 /* do partial cleanup of sk_async_wait_queue */
1624 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1625 (dma_async_is_complete(skb->dma_cookie, done,
1626 used) == DMA_SUCCESS)) {
1627 __skb_dequeue(&sk->sk_async_wait_queue);
1628 kfree_skb(skb);
1629 }
1630 }
1631
1632 /* Safe to free early-copied skbs now */
1633 __skb_queue_purge(&sk->sk_async_wait_queue);
1634 dma_chan_put(tp->ucopy.dma_chan);
1635 tp->ucopy.dma_chan = NULL;
1636 }
1637 if (tp->ucopy.pinned_list) {
1638 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1639 tp->ucopy.pinned_list = NULL;
1640 }
1641 #endif
1642
1643 /* According to UNIX98, msg_name/msg_namelen are ignored
1644 * on connected socket. I was just happy when found this 8) --ANK
1645 */
1646
1647 /* Clean up data we have read: This will do ACK frames. */
1648 tcp_cleanup_rbuf(sk, copied);
1649
1650 TCP_CHECK_TIMER(sk);
1651 release_sock(sk);
1652 return copied;
1653
1654 out:
1655 TCP_CHECK_TIMER(sk);
1656 release_sock(sk);
1657 return err;
1658
1659 recv_urg:
1660 err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len);
1661 goto out;
1662 }
1663
1664 void tcp_set_state(struct sock *sk, int state)
1665 {
1666 int oldstate = sk->sk_state;
1667
1668 switch (state) {
1669 case TCP_ESTABLISHED:
1670 if (oldstate != TCP_ESTABLISHED)
1671 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1672 break;
1673
1674 case TCP_CLOSE:
1675 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1676 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
1677
1678 sk->sk_prot->unhash(sk);
1679 if (inet_csk(sk)->icsk_bind_hash &&
1680 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1681 inet_put_port(sk);
1682 /* fall through */
1683 default:
1684 if (oldstate==TCP_ESTABLISHED)
1685 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1686 }
1687
1688 /* Change state AFTER socket is unhashed to avoid closed
1689 * socket sitting in hash tables.
1690 */
1691 sk->sk_state = state;
1692
1693 #ifdef STATE_TRACE
1694 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
1695 #endif
1696 }
1697 EXPORT_SYMBOL_GPL(tcp_set_state);
1698
1699 /*
1700 * State processing on a close. This implements the state shift for
1701 * sending our FIN frame. Note that we only send a FIN for some
1702 * states. A shutdown() may have already sent the FIN, or we may be
1703 * closed.
1704 */
1705
1706 static const unsigned char new_state[16] = {
1707 /* current state: new state: action: */
1708 /* (Invalid) */ TCP_CLOSE,
1709 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1710 /* TCP_SYN_SENT */ TCP_CLOSE,
1711 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1712 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1713 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1714 /* TCP_TIME_WAIT */ TCP_CLOSE,
1715 /* TCP_CLOSE */ TCP_CLOSE,
1716 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1717 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1718 /* TCP_LISTEN */ TCP_CLOSE,
1719 /* TCP_CLOSING */ TCP_CLOSING,
1720 };
1721
1722 static int tcp_close_state(struct sock *sk)
1723 {
1724 int next = (int)new_state[sk->sk_state];
1725 int ns = next & TCP_STATE_MASK;
1726
1727 tcp_set_state(sk, ns);
1728
1729 return next & TCP_ACTION_FIN;
1730 }
1731
1732 /*
1733 * Shutdown the sending side of a connection. Much like close except
1734 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1735 */
1736
1737 void tcp_shutdown(struct sock *sk, int how)
1738 {
1739 /* We need to grab some memory, and put together a FIN,
1740 * and then put it into the queue to be sent.
1741 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1742 */
1743 if (!(how & SEND_SHUTDOWN))
1744 return;
1745
1746 /* If we've already sent a FIN, or it's a closed state, skip this. */
1747 if ((1 << sk->sk_state) &
1748 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1749 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1750 /* Clear out any half completed packets. FIN if needed. */
1751 if (tcp_close_state(sk))
1752 tcp_send_fin(sk);
1753 }
1754 }
1755
1756 void tcp_close(struct sock *sk, long timeout)
1757 {
1758 struct sk_buff *skb;
1759 int data_was_unread = 0;
1760 int state;
1761
1762 lock_sock(sk);
1763 sk->sk_shutdown = SHUTDOWN_MASK;
1764
1765 if (sk->sk_state == TCP_LISTEN) {
1766 tcp_set_state(sk, TCP_CLOSE);
1767
1768 /* Special case. */
1769 inet_csk_listen_stop(sk);
1770
1771 goto adjudge_to_death;
1772 }
1773
1774 /* We need to flush the recv. buffs. We do this only on the
1775 * descriptor close, not protocol-sourced closes, because the
1776 * reader process may not have drained the data yet!
1777 */
1778 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1779 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
1780 tcp_hdr(skb)->fin;
1781 data_was_unread += len;
1782 __kfree_skb(skb);
1783 }
1784
1785 sk_mem_reclaim(sk);
1786
1787 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1788 * data was lost. To witness the awful effects of the old behavior of
1789 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1790 * GET in an FTP client, suspend the process, wait for the client to
1791 * advertise a zero window, then kill -9 the FTP client, wheee...
1792 * Note: timeout is always zero in such a case.
1793 */
1794 if (data_was_unread) {
1795 /* Unread data was tossed, zap the connection. */
1796 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
1797 tcp_set_state(sk, TCP_CLOSE);
1798 tcp_send_active_reset(sk, GFP_KERNEL);
1799 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1800 /* Check zero linger _after_ checking for unread data. */
1801 sk->sk_prot->disconnect(sk, 0);
1802 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
1803 } else if (tcp_close_state(sk)) {
1804 /* We FIN if the application ate all the data before
1805 * zapping the connection.
1806 */
1807
1808 /* RED-PEN. Formally speaking, we have broken TCP state
1809 * machine. State transitions:
1810 *
1811 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1812 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1813 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1814 *
1815 * are legal only when FIN has been sent (i.e. in window),
1816 * rather than queued out of window. Purists blame.
1817 *
1818 * F.e. "RFC state" is ESTABLISHED,
1819 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1820 *
1821 * The visible declinations are that sometimes
1822 * we enter time-wait state, when it is not required really
1823 * (harmless), do not send active resets, when they are
1824 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1825 * they look as CLOSING or LAST_ACK for Linux)
1826 * Probably, I missed some more holelets.
1827 * --ANK
1828 */
1829 tcp_send_fin(sk);
1830 }
1831
1832 sk_stream_wait_close(sk, timeout);
1833
1834 adjudge_to_death:
1835 state = sk->sk_state;
1836 sock_hold(sk);
1837 sock_orphan(sk);
1838 atomic_inc(sk->sk_prot->orphan_count);
1839
1840 /* It is the last release_sock in its life. It will remove backlog. */
1841 release_sock(sk);
1842
1843
1844 /* Now socket is owned by kernel and we acquire BH lock
1845 to finish close. No need to check for user refs.
1846 */
1847 local_bh_disable();
1848 bh_lock_sock(sk);
1849 WARN_ON(sock_owned_by_user(sk));
1850
1851 /* Have we already been destroyed by a softirq or backlog? */
1852 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1853 goto out;
1854
1855 /* This is a (useful) BSD violating of the RFC. There is a
1856 * problem with TCP as specified in that the other end could
1857 * keep a socket open forever with no application left this end.
1858 * We use a 3 minute timeout (about the same as BSD) then kill
1859 * our end. If they send after that then tough - BUT: long enough
1860 * that we won't make the old 4*rto = almost no time - whoops
1861 * reset mistake.
1862 *
1863 * Nope, it was not mistake. It is really desired behaviour
1864 * f.e. on http servers, when such sockets are useless, but
1865 * consume significant resources. Let's do it with special
1866 * linger2 option. --ANK
1867 */
1868
1869 if (sk->sk_state == TCP_FIN_WAIT2) {
1870 struct tcp_sock *tp = tcp_sk(sk);
1871 if (tp->linger2 < 0) {
1872 tcp_set_state(sk, TCP_CLOSE);
1873 tcp_send_active_reset(sk, GFP_ATOMIC);
1874 NET_INC_STATS_BH(sock_net(sk),
1875 LINUX_MIB_TCPABORTONLINGER);
1876 } else {
1877 const int tmo = tcp_fin_time(sk);
1878
1879 if (tmo > TCP_TIMEWAIT_LEN) {
1880 inet_csk_reset_keepalive_timer(sk,
1881 tmo - TCP_TIMEWAIT_LEN);
1882 } else {
1883 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
1884 goto out;
1885 }
1886 }
1887 }
1888 if (sk->sk_state != TCP_CLOSE) {
1889 sk_mem_reclaim(sk);
1890 if (tcp_too_many_orphans(sk,
1891 atomic_read(sk->sk_prot->orphan_count))) {
1892 if (net_ratelimit())
1893 printk(KERN_INFO "TCP: too many of orphaned "
1894 "sockets\n");
1895 tcp_set_state(sk, TCP_CLOSE);
1896 tcp_send_active_reset(sk, GFP_ATOMIC);
1897 NET_INC_STATS_BH(sock_net(sk),
1898 LINUX_MIB_TCPABORTONMEMORY);
1899 }
1900 }
1901
1902 if (sk->sk_state == TCP_CLOSE)
1903 inet_csk_destroy_sock(sk);
1904 /* Otherwise, socket is reprieved until protocol close. */
1905
1906 out:
1907 bh_unlock_sock(sk);
1908 local_bh_enable();
1909 sock_put(sk);
1910 }
1911
1912 /* These states need RST on ABORT according to RFC793 */
1913
1914 static inline int tcp_need_reset(int state)
1915 {
1916 return (1 << state) &
1917 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
1918 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
1919 }
1920
1921 int tcp_disconnect(struct sock *sk, int flags)
1922 {
1923 struct inet_sock *inet = inet_sk(sk);
1924 struct inet_connection_sock *icsk = inet_csk(sk);
1925 struct tcp_sock *tp = tcp_sk(sk);
1926 int err = 0;
1927 int old_state = sk->sk_state;
1928
1929 if (old_state != TCP_CLOSE)
1930 tcp_set_state(sk, TCP_CLOSE);
1931
1932 /* ABORT function of RFC793 */
1933 if (old_state == TCP_LISTEN) {
1934 inet_csk_listen_stop(sk);
1935 } else if (tcp_need_reset(old_state) ||
1936 (tp->snd_nxt != tp->write_seq &&
1937 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
1938 /* The last check adjusts for discrepancy of Linux wrt. RFC
1939 * states
1940 */
1941 tcp_send_active_reset(sk, gfp_any());
1942 sk->sk_err = ECONNRESET;
1943 } else if (old_state == TCP_SYN_SENT)
1944 sk->sk_err = ECONNRESET;
1945
1946 tcp_clear_xmit_timers(sk);
1947 __skb_queue_purge(&sk->sk_receive_queue);
1948 tcp_write_queue_purge(sk);
1949 __skb_queue_purge(&tp->out_of_order_queue);
1950 #ifdef CONFIG_NET_DMA
1951 __skb_queue_purge(&sk->sk_async_wait_queue);
1952 #endif
1953
1954 inet->dport = 0;
1955
1956 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1957 inet_reset_saddr(sk);
1958
1959 sk->sk_shutdown = 0;
1960 sock_reset_flag(sk, SOCK_DONE);
1961 tp->srtt = 0;
1962 if ((tp->write_seq += tp->max_window + 2) == 0)
1963 tp->write_seq = 1;
1964 icsk->icsk_backoff = 0;
1965 tp->snd_cwnd = 2;
1966 icsk->icsk_probes_out = 0;
1967 tp->packets_out = 0;
1968 tp->snd_ssthresh = 0x7fffffff;
1969 tp->snd_cwnd_cnt = 0;
1970 tp->bytes_acked = 0;
1971 tcp_set_ca_state(sk, TCP_CA_Open);
1972 tcp_clear_retrans(tp);
1973 inet_csk_delack_init(sk);
1974 tcp_init_send_head(sk);
1975 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
1976 __sk_dst_reset(sk);
1977
1978 WARN_ON(inet->num && !icsk->icsk_bind_hash);
1979
1980 sk->sk_error_report(sk);
1981 return err;
1982 }
1983
1984 /*
1985 * Socket option code for TCP.
1986 */
1987 static int do_tcp_setsockopt(struct sock *sk, int level,
1988 int optname, char __user *optval, int optlen)
1989 {
1990 struct tcp_sock *tp = tcp_sk(sk);
1991 struct inet_connection_sock *icsk = inet_csk(sk);
1992 int val;
1993 int err = 0;
1994
1995 /* This is a string value all the others are int's */
1996 if (optname == TCP_CONGESTION) {
1997 char name[TCP_CA_NAME_MAX];
1998
1999 if (optlen < 1)
2000 return -EINVAL;
2001
2002 val = strncpy_from_user(name, optval,
2003 min(TCP_CA_NAME_MAX-1, optlen));
2004 if (val < 0)
2005 return -EFAULT;
2006 name[val] = 0;
2007
2008 lock_sock(sk);
2009 err = tcp_set_congestion_control(sk, name);
2010 release_sock(sk);
2011 return err;
2012 }
2013
2014 if (optlen < sizeof(int))
2015 return -EINVAL;
2016
2017 if (get_user(val, (int __user *)optval))
2018 return -EFAULT;
2019
2020 lock_sock(sk);
2021
2022 switch (optname) {
2023 case TCP_MAXSEG:
2024 /* Values greater than interface MTU won't take effect. However
2025 * at the point when this call is done we typically don't yet
2026 * know which interface is going to be used */
2027 if (val < 8 || val > MAX_TCP_WINDOW) {
2028 err = -EINVAL;
2029 break;
2030 }
2031 tp->rx_opt.user_mss = val;
2032 break;
2033
2034 case TCP_NODELAY:
2035 if (val) {
2036 /* TCP_NODELAY is weaker than TCP_CORK, so that
2037 * this option on corked socket is remembered, but
2038 * it is not activated until cork is cleared.
2039 *
2040 * However, when TCP_NODELAY is set we make
2041 * an explicit push, which overrides even TCP_CORK
2042 * for currently queued segments.
2043 */
2044 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2045 tcp_push_pending_frames(sk);
2046 } else {
2047 tp->nonagle &= ~TCP_NAGLE_OFF;
2048 }
2049 break;
2050
2051 case TCP_CORK:
2052 /* When set indicates to always queue non-full frames.
2053 * Later the user clears this option and we transmit
2054 * any pending partial frames in the queue. This is
2055 * meant to be used alongside sendfile() to get properly
2056 * filled frames when the user (for example) must write
2057 * out headers with a write() call first and then use
2058 * sendfile to send out the data parts.
2059 *
2060 * TCP_CORK can be set together with TCP_NODELAY and it is
2061 * stronger than TCP_NODELAY.
2062 */
2063 if (val) {
2064 tp->nonagle |= TCP_NAGLE_CORK;
2065 } else {
2066 tp->nonagle &= ~TCP_NAGLE_CORK;
2067 if (tp->nonagle&TCP_NAGLE_OFF)
2068 tp->nonagle |= TCP_NAGLE_PUSH;
2069 tcp_push_pending_frames(sk);
2070 }
2071 break;
2072
2073 case TCP_KEEPIDLE:
2074 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2075 err = -EINVAL;
2076 else {
2077 tp->keepalive_time = val * HZ;
2078 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2079 !((1 << sk->sk_state) &
2080 (TCPF_CLOSE | TCPF_LISTEN))) {
2081 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
2082 if (tp->keepalive_time > elapsed)
2083 elapsed = tp->keepalive_time - elapsed;
2084 else
2085 elapsed = 0;
2086 inet_csk_reset_keepalive_timer(sk, elapsed);
2087 }
2088 }
2089 break;
2090 case TCP_KEEPINTVL:
2091 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2092 err = -EINVAL;
2093 else
2094 tp->keepalive_intvl = val * HZ;
2095 break;
2096 case TCP_KEEPCNT:
2097 if (val < 1 || val > MAX_TCP_KEEPCNT)
2098 err = -EINVAL;
2099 else
2100 tp->keepalive_probes = val;
2101 break;
2102 case TCP_SYNCNT:
2103 if (val < 1 || val > MAX_TCP_SYNCNT)
2104 err = -EINVAL;
2105 else
2106 icsk->icsk_syn_retries = val;
2107 break;
2108
2109 case TCP_LINGER2:
2110 if (val < 0)
2111 tp->linger2 = -1;
2112 else if (val > sysctl_tcp_fin_timeout / HZ)
2113 tp->linger2 = 0;
2114 else
2115 tp->linger2 = val * HZ;
2116 break;
2117
2118 case TCP_DEFER_ACCEPT:
2119 icsk->icsk_accept_queue.rskq_defer_accept = 0;
2120 if (val > 0) {
2121 /* Translate value in seconds to number of
2122 * retransmits */
2123 while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
2124 val > ((TCP_TIMEOUT_INIT / HZ) <<
2125 icsk->icsk_accept_queue.rskq_defer_accept))
2126 icsk->icsk_accept_queue.rskq_defer_accept++;
2127 icsk->icsk_accept_queue.rskq_defer_accept++;
2128 }
2129 break;
2130
2131 case TCP_WINDOW_CLAMP:
2132 if (!val) {
2133 if (sk->sk_state != TCP_CLOSE) {
2134 err = -EINVAL;
2135 break;
2136 }
2137 tp->window_clamp = 0;
2138 } else
2139 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2140 SOCK_MIN_RCVBUF / 2 : val;
2141 break;
2142
2143 case TCP_QUICKACK:
2144 if (!val) {
2145 icsk->icsk_ack.pingpong = 1;
2146 } else {
2147 icsk->icsk_ack.pingpong = 0;
2148 if ((1 << sk->sk_state) &
2149 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2150 inet_csk_ack_scheduled(sk)) {
2151 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2152 tcp_cleanup_rbuf(sk, 1);
2153 if (!(val & 1))
2154 icsk->icsk_ack.pingpong = 1;
2155 }
2156 }
2157 break;
2158
2159 #ifdef CONFIG_TCP_MD5SIG
2160 case TCP_MD5SIG:
2161 /* Read the IP->Key mappings from userspace */
2162 err = tp->af_specific->md5_parse(sk, optval, optlen);
2163 break;
2164 #endif
2165
2166 default:
2167 err = -ENOPROTOOPT;
2168 break;
2169 }
2170
2171 release_sock(sk);
2172 return err;
2173 }
2174
2175 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2176 int optlen)
2177 {
2178 struct inet_connection_sock *icsk = inet_csk(sk);
2179
2180 if (level != SOL_TCP)
2181 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2182 optval, optlen);
2183 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2184 }
2185
2186 #ifdef CONFIG_COMPAT
2187 int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2188 char __user *optval, int optlen)
2189 {
2190 if (level != SOL_TCP)
2191 return inet_csk_compat_setsockopt(sk, level, optname,
2192 optval, optlen);
2193 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2194 }
2195
2196 EXPORT_SYMBOL(compat_tcp_setsockopt);
2197 #endif
2198
2199 /* Return information about state of tcp endpoint in API format. */
2200 void tcp_get_info(struct sock *sk, struct tcp_info *info)
2201 {
2202 struct tcp_sock *tp = tcp_sk(sk);
2203 const struct inet_connection_sock *icsk = inet_csk(sk);
2204 u32 now = tcp_time_stamp;
2205
2206 memset(info, 0, sizeof(*info));
2207
2208 info->tcpi_state = sk->sk_state;
2209 info->tcpi_ca_state = icsk->icsk_ca_state;
2210 info->tcpi_retransmits = icsk->icsk_retransmits;
2211 info->tcpi_probes = icsk->icsk_probes_out;
2212 info->tcpi_backoff = icsk->icsk_backoff;
2213
2214 if (tp->rx_opt.tstamp_ok)
2215 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2216 if (tcp_is_sack(tp))
2217 info->tcpi_options |= TCPI_OPT_SACK;
2218 if (tp->rx_opt.wscale_ok) {
2219 info->tcpi_options |= TCPI_OPT_WSCALE;
2220 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2221 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2222 }
2223
2224 if (tp->ecn_flags&TCP_ECN_OK)
2225 info->tcpi_options |= TCPI_OPT_ECN;
2226
2227 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2228 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2229 info->tcpi_snd_mss = tp->mss_cache;
2230 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2231
2232 if (sk->sk_state == TCP_LISTEN) {
2233 info->tcpi_unacked = sk->sk_ack_backlog;
2234 info->tcpi_sacked = sk->sk_max_ack_backlog;
2235 } else {
2236 info->tcpi_unacked = tp->packets_out;
2237 info->tcpi_sacked = tp->sacked_out;
2238 }
2239 info->tcpi_lost = tp->lost_out;
2240 info->tcpi_retrans = tp->retrans_out;
2241 info->tcpi_fackets = tp->fackets_out;
2242
2243 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2244 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2245 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2246
2247 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2248 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2249 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2250 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2251 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2252 info->tcpi_snd_cwnd = tp->snd_cwnd;
2253 info->tcpi_advmss = tp->advmss;
2254 info->tcpi_reordering = tp->reordering;
2255
2256 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2257 info->tcpi_rcv_space = tp->rcvq_space.space;
2258
2259 info->tcpi_total_retrans = tp->total_retrans;
2260 }
2261
2262 EXPORT_SYMBOL_GPL(tcp_get_info);
2263
2264 static int do_tcp_getsockopt(struct sock *sk, int level,
2265 int optname, char __user *optval, int __user *optlen)
2266 {
2267 struct inet_connection_sock *icsk = inet_csk(sk);
2268 struct tcp_sock *tp = tcp_sk(sk);
2269 int val, len;
2270
2271 if (get_user(len, optlen))
2272 return -EFAULT;
2273
2274 len = min_t(unsigned int, len, sizeof(int));
2275
2276 if (len < 0)
2277 return -EINVAL;
2278
2279 switch (optname) {
2280 case TCP_MAXSEG:
2281 val = tp->mss_cache;
2282 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2283 val = tp->rx_opt.user_mss;
2284 break;
2285 case TCP_NODELAY:
2286 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2287 break;
2288 case TCP_CORK:
2289 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2290 break;
2291 case TCP_KEEPIDLE:
2292 val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
2293 break;
2294 case TCP_KEEPINTVL:
2295 val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
2296 break;
2297 case TCP_KEEPCNT:
2298 val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
2299 break;
2300 case TCP_SYNCNT:
2301 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2302 break;
2303 case TCP_LINGER2:
2304 val = tp->linger2;
2305 if (val >= 0)
2306 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2307 break;
2308 case TCP_DEFER_ACCEPT:
2309 val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
2310 ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
2311 break;
2312 case TCP_WINDOW_CLAMP:
2313 val = tp->window_clamp;
2314 break;
2315 case TCP_INFO: {
2316 struct tcp_info info;
2317
2318 if (get_user(len, optlen))
2319 return -EFAULT;
2320
2321 tcp_get_info(sk, &info);
2322
2323 len = min_t(unsigned int, len, sizeof(info));
2324 if (put_user(len, optlen))
2325 return -EFAULT;
2326 if (copy_to_user(optval, &info, len))
2327 return -EFAULT;
2328 return 0;
2329 }
2330 case TCP_QUICKACK:
2331 val = !icsk->icsk_ack.pingpong;
2332 break;
2333
2334 case TCP_CONGESTION:
2335 if (get_user(len, optlen))
2336 return -EFAULT;
2337 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2338 if (put_user(len, optlen))
2339 return -EFAULT;
2340 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2341 return -EFAULT;
2342 return 0;
2343 default:
2344 return -ENOPROTOOPT;
2345 }
2346
2347 if (put_user(len, optlen))
2348 return -EFAULT;
2349 if (copy_to_user(optval, &val, len))
2350 return -EFAULT;
2351 return 0;
2352 }
2353
2354 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2355 int __user *optlen)
2356 {
2357 struct inet_connection_sock *icsk = inet_csk(sk);
2358
2359 if (level != SOL_TCP)
2360 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2361 optval, optlen);
2362 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2363 }
2364
2365 #ifdef CONFIG_COMPAT
2366 int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2367 char __user *optval, int __user *optlen)
2368 {
2369 if (level != SOL_TCP)
2370 return inet_csk_compat_getsockopt(sk, level, optname,
2371 optval, optlen);
2372 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2373 }
2374
2375 EXPORT_SYMBOL(compat_tcp_getsockopt);
2376 #endif
2377
2378 struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
2379 {
2380 struct sk_buff *segs = ERR_PTR(-EINVAL);
2381 struct tcphdr *th;
2382 unsigned thlen;
2383 unsigned int seq;
2384 __be32 delta;
2385 unsigned int oldlen;
2386 unsigned int len;
2387
2388 if (!pskb_may_pull(skb, sizeof(*th)))
2389 goto out;
2390
2391 th = tcp_hdr(skb);
2392 thlen = th->doff * 4;
2393 if (thlen < sizeof(*th))
2394 goto out;
2395
2396 if (!pskb_may_pull(skb, thlen))
2397 goto out;
2398
2399 oldlen = (u16)~skb->len;
2400 __skb_pull(skb, thlen);
2401
2402 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2403 /* Packet is from an untrusted source, reset gso_segs. */
2404 int type = skb_shinfo(skb)->gso_type;
2405 int mss;
2406
2407 if (unlikely(type &
2408 ~(SKB_GSO_TCPV4 |
2409 SKB_GSO_DODGY |
2410 SKB_GSO_TCP_ECN |
2411 SKB_GSO_TCPV6 |
2412 0) ||
2413 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2414 goto out;
2415
2416 mss = skb_shinfo(skb)->gso_size;
2417 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2418
2419 segs = NULL;
2420 goto out;
2421 }
2422
2423 segs = skb_segment(skb, features);
2424 if (IS_ERR(segs))
2425 goto out;
2426
2427 len = skb_shinfo(skb)->gso_size;
2428 delta = htonl(oldlen + (thlen + len));
2429
2430 skb = segs;
2431 th = tcp_hdr(skb);
2432 seq = ntohl(th->seq);
2433
2434 do {
2435 th->fin = th->psh = 0;
2436
2437 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2438 (__force u32)delta));
2439 if (skb->ip_summed != CHECKSUM_PARTIAL)
2440 th->check =
2441 csum_fold(csum_partial(skb_transport_header(skb),
2442 thlen, skb->csum));
2443
2444 seq += len;
2445 skb = skb->next;
2446 th = tcp_hdr(skb);
2447
2448 th->seq = htonl(seq);
2449 th->cwr = 0;
2450 } while (skb->next);
2451
2452 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
2453 skb->data_len);
2454 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2455 (__force u32)delta));
2456 if (skb->ip_summed != CHECKSUM_PARTIAL)
2457 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2458 thlen, skb->csum));
2459
2460 out:
2461 return segs;
2462 }
2463 EXPORT_SYMBOL(tcp_tso_segment);
2464
2465 #ifdef CONFIG_TCP_MD5SIG
2466 static unsigned long tcp_md5sig_users;
2467 static struct tcp_md5sig_pool **tcp_md5sig_pool;
2468 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2469
2470 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
2471 {
2472 int cpu;
2473 for_each_possible_cpu(cpu) {
2474 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2475 if (p) {
2476 if (p->md5_desc.tfm)
2477 crypto_free_hash(p->md5_desc.tfm);
2478 kfree(p);
2479 p = NULL;
2480 }
2481 }
2482 free_percpu(pool);
2483 }
2484
2485 void tcp_free_md5sig_pool(void)
2486 {
2487 struct tcp_md5sig_pool **pool = NULL;
2488
2489 spin_lock_bh(&tcp_md5sig_pool_lock);
2490 if (--tcp_md5sig_users == 0) {
2491 pool = tcp_md5sig_pool;
2492 tcp_md5sig_pool = NULL;
2493 }
2494 spin_unlock_bh(&tcp_md5sig_pool_lock);
2495 if (pool)
2496 __tcp_free_md5sig_pool(pool);
2497 }
2498
2499 EXPORT_SYMBOL(tcp_free_md5sig_pool);
2500
2501 static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
2502 {
2503 int cpu;
2504 struct tcp_md5sig_pool **pool;
2505
2506 pool = alloc_percpu(struct tcp_md5sig_pool *);
2507 if (!pool)
2508 return NULL;
2509
2510 for_each_possible_cpu(cpu) {
2511 struct tcp_md5sig_pool *p;
2512 struct crypto_hash *hash;
2513
2514 p = kzalloc(sizeof(*p), GFP_KERNEL);
2515 if (!p)
2516 goto out_free;
2517 *per_cpu_ptr(pool, cpu) = p;
2518
2519 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2520 if (!hash || IS_ERR(hash))
2521 goto out_free;
2522
2523 p->md5_desc.tfm = hash;
2524 }
2525 return pool;
2526 out_free:
2527 __tcp_free_md5sig_pool(pool);
2528 return NULL;
2529 }
2530
2531 struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
2532 {
2533 struct tcp_md5sig_pool **pool;
2534 int alloc = 0;
2535
2536 retry:
2537 spin_lock_bh(&tcp_md5sig_pool_lock);
2538 pool = tcp_md5sig_pool;
2539 if (tcp_md5sig_users++ == 0) {
2540 alloc = 1;
2541 spin_unlock_bh(&tcp_md5sig_pool_lock);
2542 } else if (!pool) {
2543 tcp_md5sig_users--;
2544 spin_unlock_bh(&tcp_md5sig_pool_lock);
2545 cpu_relax();
2546 goto retry;
2547 } else
2548 spin_unlock_bh(&tcp_md5sig_pool_lock);
2549
2550 if (alloc) {
2551 /* we cannot hold spinlock here because this may sleep. */
2552 struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
2553 spin_lock_bh(&tcp_md5sig_pool_lock);
2554 if (!p) {
2555 tcp_md5sig_users--;
2556 spin_unlock_bh(&tcp_md5sig_pool_lock);
2557 return NULL;
2558 }
2559 pool = tcp_md5sig_pool;
2560 if (pool) {
2561 /* oops, it has already been assigned. */
2562 spin_unlock_bh(&tcp_md5sig_pool_lock);
2563 __tcp_free_md5sig_pool(p);
2564 } else {
2565 tcp_md5sig_pool = pool = p;
2566 spin_unlock_bh(&tcp_md5sig_pool_lock);
2567 }
2568 }
2569 return pool;
2570 }
2571
2572 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2573
2574 struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
2575 {
2576 struct tcp_md5sig_pool **p;
2577 spin_lock_bh(&tcp_md5sig_pool_lock);
2578 p = tcp_md5sig_pool;
2579 if (p)
2580 tcp_md5sig_users++;
2581 spin_unlock_bh(&tcp_md5sig_pool_lock);
2582 return (p ? *per_cpu_ptr(p, cpu) : NULL);
2583 }
2584
2585 EXPORT_SYMBOL(__tcp_get_md5sig_pool);
2586
2587 void __tcp_put_md5sig_pool(void)
2588 {
2589 tcp_free_md5sig_pool();
2590 }
2591
2592 EXPORT_SYMBOL(__tcp_put_md5sig_pool);
2593
2594 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
2595 struct tcphdr *th)
2596 {
2597 struct scatterlist sg;
2598 int err;
2599
2600 __sum16 old_checksum = th->check;
2601 th->check = 0;
2602 /* options aren't included in the hash */
2603 sg_init_one(&sg, th, sizeof(struct tcphdr));
2604 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
2605 th->check = old_checksum;
2606 return err;
2607 }
2608
2609 EXPORT_SYMBOL(tcp_md5_hash_header);
2610
2611 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
2612 struct sk_buff *skb, unsigned header_len)
2613 {
2614 struct scatterlist sg;
2615 const struct tcphdr *tp = tcp_hdr(skb);
2616 struct hash_desc *desc = &hp->md5_desc;
2617 unsigned i;
2618 const unsigned head_data_len = skb_headlen(skb) > header_len ?
2619 skb_headlen(skb) - header_len : 0;
2620 const struct skb_shared_info *shi = skb_shinfo(skb);
2621
2622 sg_init_table(&sg, 1);
2623
2624 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
2625 if (crypto_hash_update(desc, &sg, head_data_len))
2626 return 1;
2627
2628 for (i = 0; i < shi->nr_frags; ++i) {
2629 const struct skb_frag_struct *f = &shi->frags[i];
2630 sg_set_page(&sg, f->page, f->size, f->page_offset);
2631 if (crypto_hash_update(desc, &sg, f->size))
2632 return 1;
2633 }
2634
2635 return 0;
2636 }
2637
2638 EXPORT_SYMBOL(tcp_md5_hash_skb_data);
2639
2640 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
2641 {
2642 struct scatterlist sg;
2643
2644 sg_init_one(&sg, key->key, key->keylen);
2645 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
2646 }
2647
2648 EXPORT_SYMBOL(tcp_md5_hash_key);
2649
2650 #endif
2651
2652 void tcp_done(struct sock *sk)
2653 {
2654 if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
2655 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
2656
2657 tcp_set_state(sk, TCP_CLOSE);
2658 tcp_clear_xmit_timers(sk);
2659
2660 sk->sk_shutdown = SHUTDOWN_MASK;
2661
2662 if (!sock_flag(sk, SOCK_DEAD))
2663 sk->sk_state_change(sk);
2664 else
2665 inet_csk_destroy_sock(sk);
2666 }
2667 EXPORT_SYMBOL_GPL(tcp_done);
2668
2669 extern struct tcp_congestion_ops tcp_reno;
2670
2671 static __initdata unsigned long thash_entries;
2672 static int __init set_thash_entries(char *str)
2673 {
2674 if (!str)
2675 return 0;
2676 thash_entries = simple_strtoul(str, &str, 0);
2677 return 1;
2678 }
2679 __setup("thash_entries=", set_thash_entries);
2680
2681 void __init tcp_init(void)
2682 {
2683 struct sk_buff *skb = NULL;
2684 unsigned long nr_pages, limit;
2685 int order, i, max_share;
2686
2687 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
2688
2689 tcp_hashinfo.bind_bucket_cachep =
2690 kmem_cache_create("tcp_bind_bucket",
2691 sizeof(struct inet_bind_bucket), 0,
2692 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2693
2694 /* Size and allocate the main established and bind bucket
2695 * hash tables.
2696 *
2697 * The methodology is similar to that of the buffer cache.
2698 */
2699 tcp_hashinfo.ehash =
2700 alloc_large_system_hash("TCP established",
2701 sizeof(struct inet_ehash_bucket),
2702 thash_entries,
2703 (num_physpages >= 128 * 1024) ?
2704 13 : 15,
2705 0,
2706 &tcp_hashinfo.ehash_size,
2707 NULL,
2708 thash_entries ? 0 : 512 * 1024);
2709 tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
2710 for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
2711 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain);
2712 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain);
2713 }
2714 if (inet_ehash_locks_alloc(&tcp_hashinfo))
2715 panic("TCP: failed to alloc ehash_locks");
2716 tcp_hashinfo.bhash =
2717 alloc_large_system_hash("TCP bind",
2718 sizeof(struct inet_bind_hashbucket),
2719 tcp_hashinfo.ehash_size,
2720 (num_physpages >= 128 * 1024) ?
2721 13 : 15,
2722 0,
2723 &tcp_hashinfo.bhash_size,
2724 NULL,
2725 64 * 1024);
2726 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
2727 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
2728 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
2729 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
2730 }
2731
2732 /* Try to be a bit smarter and adjust defaults depending
2733 * on available memory.
2734 */
2735 for (order = 0; ((1 << order) << PAGE_SHIFT) <
2736 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket));
2737 order++)
2738 ;
2739 if (order >= 4) {
2740 tcp_death_row.sysctl_max_tw_buckets = 180000;
2741 sysctl_tcp_max_orphans = 4096 << (order - 4);
2742 sysctl_max_syn_backlog = 1024;
2743 } else if (order < 3) {
2744 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order);
2745 sysctl_tcp_max_orphans >>= (3 - order);
2746 sysctl_max_syn_backlog = 128;
2747 }
2748
2749 /* Set the pressure threshold to be a fraction of global memory that
2750 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
2751 * memory, with a floor of 128 pages.
2752 */
2753 nr_pages = totalram_pages - totalhigh_pages;
2754 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
2755 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
2756 limit = max(limit, 128UL);
2757 sysctl_tcp_mem[0] = limit / 4 * 3;
2758 sysctl_tcp_mem[1] = limit;
2759 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
2760
2761 /* Set per-socket limits to no more than 1/128 the pressure threshold */
2762 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
2763 max_share = min(4UL*1024*1024, limit);
2764
2765 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
2766 sysctl_tcp_wmem[1] = 16*1024;
2767 sysctl_tcp_wmem[2] = max(64*1024, max_share);
2768
2769 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
2770 sysctl_tcp_rmem[1] = 87380;
2771 sysctl_tcp_rmem[2] = max(87380, max_share);
2772
2773 printk(KERN_INFO "TCP: Hash tables configured "
2774 "(established %d bind %d)\n",
2775 tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
2776
2777 tcp_register_congestion_control(&tcp_reno);
2778 }
2779
2780 EXPORT_SYMBOL(tcp_close);
2781 EXPORT_SYMBOL(tcp_disconnect);
2782 EXPORT_SYMBOL(tcp_getsockopt);
2783 EXPORT_SYMBOL(tcp_ioctl);
2784 EXPORT_SYMBOL(tcp_poll);
2785 EXPORT_SYMBOL(tcp_read_sock);
2786 EXPORT_SYMBOL(tcp_recvmsg);
2787 EXPORT_SYMBOL(tcp_sendmsg);
2788 EXPORT_SYMBOL(tcp_splice_read);
2789 EXPORT_SYMBOL(tcp_sendpage);
2790 EXPORT_SYMBOL(tcp_setsockopt);
2791 EXPORT_SYMBOL(tcp_shutdown);
Openmoko development kernel tree