?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[PATCH] TCP: zero out rx_opt in tcp_disconnect()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / tcp.c
blob824c6b9c6af9d49854e1edcc0b7e44fc9be88f22
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 * Version: $Id: tcp.c,v 1.216 2002/02/01 22:01:04 davem Exp $
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Mark Evans, <evansmp@uhura.aston.ac.uk>
13 * Corey Minyard <wf-rch!minyard@relay.EU.net>
14 * Florian La Roche, <flla@stud.uni-sb.de>
15 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
16 * Linus Torvalds, <torvalds@cs.helsinki.fi>
17 * Alan Cox, <gw4pts@gw4pts.ampr.org>
18 * Matthew Dillon, <dillon@apollo.west.oic.com>
19 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
20 * Jorge Cwik, <jorge@laser.satlink.net>
21 *
22 * Fixes:
23 * Alan Cox : Numerous verify_area() calls
24 * Alan Cox : Set the ACK bit on a reset
25 * Alan Cox : Stopped it crashing if it closed while
26 * sk->inuse=1 and was trying to connect
27 * (tcp_err()).
28 * Alan Cox : All icmp error handling was broken
29 * pointers passed where wrong and the
30 * socket was looked up backwards. Nobody
31 * tested any icmp error code obviously.
32 * Alan Cox : tcp_err() now handled properly. It
33 * wakes people on errors. poll
34 * behaves and the icmp error race
35 * has gone by moving it into sock.c
36 * Alan Cox : tcp_send_reset() fixed to work for
37 * everything not just packets for
38 * unknown sockets.
39 * Alan Cox : tcp option processing.
40 * Alan Cox : Reset tweaked (still not 100%) [Had
41 * syn rule wrong]
42 * Herp Rosmanith : More reset fixes
43 * Alan Cox : No longer acks invalid rst frames.
44 * Acking any kind of RST is right out.
45 * Alan Cox : Sets an ignore me flag on an rst
46 * receive otherwise odd bits of prattle
47 * escape still
48 * Alan Cox : Fixed another acking RST frame bug.
49 * Should stop LAN workplace lockups.
50 * Alan Cox : Some tidyups using the new skb list
51 * facilities
52 * Alan Cox : sk->keepopen now seems to work
53 * Alan Cox : Pulls options out correctly on accepts
54 * Alan Cox : Fixed assorted sk->rqueue->next errors
55 * Alan Cox : PSH doesn't end a TCP read. Switched a
56 * bit to skb ops.
57 * Alan Cox : Tidied tcp_data to avoid a potential
58 * nasty.
59 * Alan Cox : Added some better commenting, as the
60 * tcp is hard to follow
61 * Alan Cox : Removed incorrect check for 20 * psh
62 * Michael O'Reilly : ack < copied bug fix.
63 * Johannes Stille : Misc tcp fixes (not all in yet).
64 * Alan Cox : FIN with no memory -> CRASH
65 * Alan Cox : Added socket option proto entries.
66 * Also added awareness of them to accept.
67 * Alan Cox : Added TCP options (SOL_TCP)
68 * Alan Cox : Switched wakeup calls to callbacks,
69 * so the kernel can layer network
70 * sockets.
71 * Alan Cox : Use ip_tos/ip_ttl settings.
72 * Alan Cox : Handle FIN (more) properly (we hope).
73 * Alan Cox : RST frames sent on unsynchronised
74 * state ack error.
75 * Alan Cox : Put in missing check for SYN bit.
76 * Alan Cox : Added tcp_select_window() aka NET2E
77 * window non shrink trick.
78 * Alan Cox : Added a couple of small NET2E timer
79 * fixes
80 * Charles Hedrick : TCP fixes
81 * Toomas Tamm : TCP window fixes
82 * Alan Cox : Small URG fix to rlogin ^C ack fight
83 * Charles Hedrick : Rewrote most of it to actually work
84 * Linus : Rewrote tcp_read() and URG handling
85 * completely
86 * Gerhard Koerting: Fixed some missing timer handling
87 * Matthew Dillon : Reworked TCP machine states as per RFC
88 * Gerhard Koerting: PC/TCP workarounds
89 * Adam Caldwell : Assorted timer/timing errors
90 * Matthew Dillon : Fixed another RST bug
91 * Alan Cox : Move to kernel side addressing changes.
92 * Alan Cox : Beginning work on TCP fastpathing
93 * (not yet usable)
94 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
95 * Alan Cox : TCP fast path debugging
96 * Alan Cox : Window clamping
97 * Michael Riepe : Bug in tcp_check()
98 * Matt Dillon : More TCP improvements and RST bug fixes
99 * Matt Dillon : Yet more small nasties remove from the
100 * TCP code (Be very nice to this man if
101 * tcp finally works 100%) 8)
102 * Alan Cox : BSD accept semantics.
103 * Alan Cox : Reset on closedown bug.
104 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
105 * Michael Pall : Handle poll() after URG properly in
106 * all cases.
107 * Michael Pall : Undo the last fix in tcp_read_urg()
108 * (multi URG PUSH broke rlogin).
109 * Michael Pall : Fix the multi URG PUSH problem in
110 * tcp_readable(), poll() after URG
111 * works now.
112 * Michael Pall : recv(...,MSG_OOB) never blocks in the
113 * BSD api.
114 * Alan Cox : Changed the semantics of sk->socket to
115 * fix a race and a signal problem with
116 * accept() and async I/O.
117 * Alan Cox : Relaxed the rules on tcp_sendto().
118 * Yury Shevchuk : Really fixed accept() blocking problem.
119 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
120 * clients/servers which listen in on
121 * fixed ports.
122 * Alan Cox : Cleaned the above up and shrank it to
123 * a sensible code size.
124 * Alan Cox : Self connect lockup fix.
125 * Alan Cox : No connect to multicast.
126 * Ross Biro : Close unaccepted children on master
127 * socket close.
128 * Alan Cox : Reset tracing code.
129 * Alan Cox : Spurious resets on shutdown.
130 * Alan Cox : Giant 15 minute/60 second timer error
131 * Alan Cox : Small whoops in polling before an
132 * accept.
133 * Alan Cox : Kept the state trace facility since
134 * it's handy for debugging.
135 * Alan Cox : More reset handler fixes.
136 * Alan Cox : Started rewriting the code based on
137 * the RFC's for other useful protocol
138 * references see: Comer, KA9Q NOS, and
139 * for a reference on the difference
140 * between specifications and how BSD
141 * works see the 4.4lite source.
142 * A.N.Kuznetsov : Don't time wait on completion of tidy
143 * close.
144 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
145 * Linus Torvalds : Fixed BSD port reuse to work first syn
146 * Alan Cox : Reimplemented timers as per the RFC
147 * and using multiple timers for sanity.
148 * Alan Cox : Small bug fixes, and a lot of new
149 * comments.
150 * Alan Cox : Fixed dual reader crash by locking
151 * the buffers (much like datagram.c)
152 * Alan Cox : Fixed stuck sockets in probe. A probe
153 * now gets fed up of retrying without
154 * (even a no space) answer.
155 * Alan Cox : Extracted closing code better
156 * Alan Cox : Fixed the closing state machine to
157 * resemble the RFC.
158 * Alan Cox : More 'per spec' fixes.
159 * Jorge Cwik : Even faster checksumming.
160 * Alan Cox : tcp_data() doesn't ack illegal PSH
161 * only frames. At least one pc tcp stack
162 * generates them.
163 * Alan Cox : Cache last socket.
164 * Alan Cox : Per route irtt.
165 * Matt Day : poll()->select() match BSD precisely on error
166 * Alan Cox : New buffers
167 * Marc Tamsky : Various sk->prot->retransmits and
168 * sk->retransmits misupdating fixed.
169 * Fixed tcp_write_timeout: stuck close,
170 * and TCP syn retries gets used now.
171 * Mark Yarvis : In tcp_read_wakeup(), don't send an
172 * ack if state is TCP_CLOSED.
173 * Alan Cox : Look up device on a retransmit - routes may
174 * change. Doesn't yet cope with MSS shrink right
175 * but it's a start!
176 * Marc Tamsky : Closing in closing fixes.
177 * Mike Shaver : RFC1122 verifications.
178 * Alan Cox : rcv_saddr errors.
179 * Alan Cox : Block double connect().
180 * Alan Cox : Small hooks for enSKIP.
181 * Alexey Kuznetsov: Path MTU discovery.
182 * Alan Cox : Support soft errors.
183 * Alan Cox : Fix MTU discovery pathological case
184 * when the remote claims no mtu!
185 * Marc Tamsky : TCP_CLOSE fix.
186 * Colin (G3TNE) : Send a reset on syn ack replies in
187 * window but wrong (fixes NT lpd problems)
188 * Pedro Roque : Better TCP window handling, delayed ack.
189 * Joerg Reuter : No modification of locked buffers in
190 * tcp_do_retransmit()
191 * Eric Schenk : Changed receiver side silly window
192 * avoidance algorithm to BSD style
193 * algorithm. This doubles throughput
194 * against machines running Solaris,
195 * and seems to result in general
196 * improvement.
197 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
198 * Willy Konynenberg : Transparent proxying support.
199 * Mike McLagan : Routing by source
200 * Keith Owens : Do proper merging with partial SKB's in
201 * tcp_do_sendmsg to avoid burstiness.
202 * Eric Schenk : Fix fast close down bug with
203 * shutdown() followed by close().
204 * Andi Kleen : Make poll agree with SIGIO
205 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
206 * lingertime == 0 (RFC 793 ABORT Call)
207 * Hirokazu Takahashi : Use copy_from_user() instead of
208 * csum_and_copy_from_user() if possible.
209 *
210 * This program is free software; you can redistribute it and/or
211 * modify it under the terms of the GNU General Public License
212 * as published by the Free Software Foundation; either version
213 * 2 of the License, or(at your option) any later version.
214 *
215 * Description of States:
216 *
217 * TCP_SYN_SENT sent a connection request, waiting for ack
218 *
219 * TCP_SYN_RECV received a connection request, sent ack,
220 * waiting for final ack in three-way handshake.
221 *
222 * TCP_ESTABLISHED connection established
223 *
224 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
225 * transmission of remaining buffered data
226 *
227 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
228 * to shutdown
229 *
230 * TCP_CLOSING both sides have shutdown but we still have
231 * data we have to finish sending
232 *
233 * TCP_TIME_WAIT timeout to catch resent junk before entering
234 * closed, can only be entered from FIN_WAIT2
235 * or CLOSING. Required because the other end
236 * may not have gotten our last ACK causing it
237 * to retransmit the data packet (which we ignore)
238 *
239 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
240 * us to finish writing our data and to shutdown
241 * (we have to close() to move on to LAST_ACK)
242 *
243 * TCP_LAST_ACK out side has shutdown after remote has
244 * shutdown. There may still be data in our
245 * buffer that we have to finish sending
246 *
247 * TCP_CLOSE socket is finished
248 */
249
250 #include <linux/module.h>
251 #include <linux/types.h>
252 #include <linux/fcntl.h>
253 #include <linux/poll.h>
254 #include <linux/init.h>
255 #include <linux/smp_lock.h>
256 #include <linux/fs.h>
257 #include <linux/random.h>
258 #include <linux/bootmem.h>
259 #include <linux/cache.h>
260 #include <linux/err.h>
261 #include <linux/crypto.h>
262
263 #include <net/icmp.h>
264 #include <net/tcp.h>
265 #include <net/xfrm.h>
266 #include <net/ip.h>
267 #include <net/netdma.h>
268
269 #include <asm/uaccess.h>
270 #include <asm/ioctls.h>
271
272 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
273
274 DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics) __read_mostly;
275
276 atomic_t tcp_orphan_count = ATOMIC_INIT(0);
277
278 EXPORT_SYMBOL_GPL(tcp_orphan_count);
279
280 int sysctl_tcp_mem[3] __read_mostly;
281 int sysctl_tcp_wmem[3] __read_mostly;
282 int sysctl_tcp_rmem[3] __read_mostly;
283
284 EXPORT_SYMBOL(sysctl_tcp_mem);
285 EXPORT_SYMBOL(sysctl_tcp_rmem);
286 EXPORT_SYMBOL(sysctl_tcp_wmem);
287
288 atomic_t tcp_memory_allocated; /* Current allocated memory. */
289 atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */
290
291 EXPORT_SYMBOL(tcp_memory_allocated);
292 EXPORT_SYMBOL(tcp_sockets_allocated);
293
294 /*
295 * Pressure flag: try to collapse.
296 * Technical note: it is used by multiple contexts non atomically.
297 * All the sk_stream_mem_schedule() is of this nature: accounting
298 * is strict, actions are advisory and have some latency.
299 */
300 int tcp_memory_pressure;
301
302 EXPORT_SYMBOL(tcp_memory_pressure);
303
304 void tcp_enter_memory_pressure(void)
305 {
306 if (!tcp_memory_pressure) {
307 NET_INC_STATS(LINUX_MIB_TCPMEMORYPRESSURES);
308 tcp_memory_pressure = 1;
309 }
310 }
311
312 EXPORT_SYMBOL(tcp_enter_memory_pressure);
313
314 /*
315 * Wait for a TCP event.
316 *
317 * Note that we don't need to lock the socket, as the upper poll layers
318 * take care of normal races (between the test and the event) and we don't
319 * go look at any of the socket buffers directly.
320 */
321 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
322 {
323 unsigned int mask;
324 struct sock *sk = sock->sk;
325 struct tcp_sock *tp = tcp_sk(sk);
326
327 poll_wait(file, sk->sk_sleep, wait);
328 if (sk->sk_state == TCP_LISTEN)
329 return inet_csk_listen_poll(sk);
330
331 /* Socket is not locked. We are protected from async events
332 by poll logic and correct handling of state changes
333 made by another threads is impossible in any case.
334 */
335
336 mask = 0;
337 if (sk->sk_err)
338 mask = POLLERR;
339
340 /*
341 * POLLHUP is certainly not done right. But poll() doesn't
342 * have a notion of HUP in just one direction, and for a
343 * socket the read side is more interesting.
344 *
345 * Some poll() documentation says that POLLHUP is incompatible
346 * with the POLLOUT/POLLWR flags, so somebody should check this
347 * all. But careful, it tends to be safer to return too many
348 * bits than too few, and you can easily break real applications
349 * if you don't tell them that something has hung up!
350 *
351 * Check-me.
352 *
353 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
354 * our fs/select.c). It means that after we received EOF,
355 * poll always returns immediately, making impossible poll() on write()
356 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
357 * if and only if shutdown has been made in both directions.
358 * Actually, it is interesting to look how Solaris and DUX
359 * solve this dilemma. I would prefer, if PULLHUP were maskable,
360 * then we could set it on SND_SHUTDOWN. BTW examples given
361 * in Stevens' books assume exactly this behaviour, it explains
362 * why PULLHUP is incompatible with POLLOUT. --ANK
363 *
364 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
365 * blocking on fresh not-connected or disconnected socket. --ANK
366 */
367 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
368 mask |= POLLHUP;
369 if (sk->sk_shutdown & RCV_SHUTDOWN)
370 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
371
372 /* Connected? */
373 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
374 /* Potential race condition. If read of tp below will
375 * escape above sk->sk_state, we can be illegally awaken
376 * in SYN_* states. */
377 if ((tp->rcv_nxt != tp->copied_seq) &&
378 (tp->urg_seq != tp->copied_seq ||
379 tp->rcv_nxt != tp->copied_seq + 1 ||
380 sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data))
381 mask |= POLLIN | POLLRDNORM;
382
383 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
384 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
385 mask |= POLLOUT | POLLWRNORM;
386 } else { /* send SIGIO later */
387 set_bit(SOCK_ASYNC_NOSPACE,
388 &sk->sk_socket->flags);
389 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
390
391 /* Race breaker. If space is freed after
392 * wspace test but before the flags are set,
393 * IO signal will be lost.
394 */
395 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
396 mask |= POLLOUT | POLLWRNORM;
397 }
398 }
399
400 if (tp->urg_data & TCP_URG_VALID)
401 mask |= POLLPRI;
402 }
403 return mask;
404 }
405
406 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
407 {
408 struct tcp_sock *tp = tcp_sk(sk);
409 int answ;
410
411 switch (cmd) {
412 case SIOCINQ:
413 if (sk->sk_state == TCP_LISTEN)
414 return -EINVAL;
415
416 lock_sock(sk);
417 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
418 answ = 0;
419 else if (sock_flag(sk, SOCK_URGINLINE) ||
420 !tp->urg_data ||
421 before(tp->urg_seq, tp->copied_seq) ||
422 !before(tp->urg_seq, tp->rcv_nxt)) {
423 answ = tp->rcv_nxt - tp->copied_seq;
424
425 /* Subtract 1, if FIN is in queue. */
426 if (answ && !skb_queue_empty(&sk->sk_receive_queue))
427 answ -=
428 ((struct sk_buff *)sk->sk_receive_queue.prev)->h.th->fin;
429 } else
430 answ = tp->urg_seq - tp->copied_seq;
431 release_sock(sk);
432 break;
433 case SIOCATMARK:
434 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
435 break;
436 case SIOCOUTQ:
437 if (sk->sk_state == TCP_LISTEN)
438 return -EINVAL;
439
440 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
441 answ = 0;
442 else
443 answ = tp->write_seq - tp->snd_una;
444 break;
445 default:
446 return -ENOIOCTLCMD;
447 };
448
449 return put_user(answ, (int __user *)arg);
450 }
451
452 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
453 {
454 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
455 tp->pushed_seq = tp->write_seq;
456 }
457
458 static inline int forced_push(struct tcp_sock *tp)
459 {
460 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
461 }
462
463 static inline void skb_entail(struct sock *sk, struct tcp_sock *tp,
464 struct sk_buff *skb)
465 {
466 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
467
468 skb->csum = 0;
469 tcb->seq = tcb->end_seq = tp->write_seq;
470 tcb->flags = TCPCB_FLAG_ACK;
471 tcb->sacked = 0;
472 skb_header_release(skb);
473 __skb_queue_tail(&sk->sk_write_queue, skb);
474 sk_charge_skb(sk, skb);
475 if (!sk->sk_send_head)
476 sk->sk_send_head = skb;
477 if (tp->nonagle & TCP_NAGLE_PUSH)
478 tp->nonagle &= ~TCP_NAGLE_PUSH;
479 }
480
481 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
482 struct sk_buff *skb)
483 {
484 if (flags & MSG_OOB) {
485 tp->urg_mode = 1;
486 tp->snd_up = tp->write_seq;
487 TCP_SKB_CB(skb)->sacked |= TCPCB_URG;
488 }
489 }
490
491 static inline void tcp_push(struct sock *sk, struct tcp_sock *tp, int flags,
492 int mss_now, int nonagle)
493 {
494 if (sk->sk_send_head) {
495 struct sk_buff *skb = sk->sk_write_queue.prev;
496 if (!(flags & MSG_MORE) || forced_push(tp))
497 tcp_mark_push(tp, skb);
498 tcp_mark_urg(tp, flags, skb);
499 __tcp_push_pending_frames(sk, tp, mss_now,
500 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
501 }
502 }
503
504 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
505 size_t psize, int flags)
506 {
507 struct tcp_sock *tp = tcp_sk(sk);
508 int mss_now, size_goal;
509 int err;
510 ssize_t copied;
511 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
512
513 /* Wait for a connection to finish. */
514 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
515 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
516 goto out_err;
517
518 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
519
520 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
521 size_goal = tp->xmit_size_goal;
522 copied = 0;
523
524 err = -EPIPE;
525 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
526 goto do_error;
527
528 while (psize > 0) {
529 struct sk_buff *skb = sk->sk_write_queue.prev;
530 struct page *page = pages[poffset / PAGE_SIZE];
531 int copy, i, can_coalesce;
532 int offset = poffset % PAGE_SIZE;
533 int size = min_t(size_t, psize, PAGE_SIZE - offset);
534
535 if (!sk->sk_send_head || (copy = size_goal - skb->len) <= 0) {
536 new_segment:
537 if (!sk_stream_memory_free(sk))
538 goto wait_for_sndbuf;
539
540 skb = sk_stream_alloc_pskb(sk, 0, 0,
541 sk->sk_allocation);
542 if (!skb)
543 goto wait_for_memory;
544
545 skb_entail(sk, tp, skb);
546 copy = size_goal;
547 }
548
549 if (copy > size)
550 copy = size;
551
552 i = skb_shinfo(skb)->nr_frags;
553 can_coalesce = skb_can_coalesce(skb, i, page, offset);
554 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
555 tcp_mark_push(tp, skb);
556 goto new_segment;
557 }
558 if (!sk_stream_wmem_schedule(sk, copy))
559 goto wait_for_memory;
560
561 if (can_coalesce) {
562 skb_shinfo(skb)->frags[i - 1].size += copy;
563 } else {
564 get_page(page);
565 skb_fill_page_desc(skb, i, page, offset, copy);
566 }
567
568 skb->len += copy;
569 skb->data_len += copy;
570 skb->truesize += copy;
571 sk->sk_wmem_queued += copy;
572 sk->sk_forward_alloc -= copy;
573 skb->ip_summed = CHECKSUM_PARTIAL;
574 tp->write_seq += copy;
575 TCP_SKB_CB(skb)->end_seq += copy;
576 skb_shinfo(skb)->gso_segs = 0;
577
578 if (!copied)
579 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
580
581 copied += copy;
582 poffset += copy;
583 if (!(psize -= copy))
584 goto out;
585
586 if (skb->len < mss_now || (flags & MSG_OOB))
587 continue;
588
589 if (forced_push(tp)) {
590 tcp_mark_push(tp, skb);
591 __tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH);
592 } else if (skb == sk->sk_send_head)
593 tcp_push_one(sk, mss_now);
594 continue;
595
596 wait_for_sndbuf:
597 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
598 wait_for_memory:
599 if (copied)
600 tcp_push(sk, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
601
602 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
603 goto do_error;
604
605 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
606 size_goal = tp->xmit_size_goal;
607 }
608
609 out:
610 if (copied)
611 tcp_push(sk, tp, flags, mss_now, tp->nonagle);
612 return copied;
613
614 do_error:
615 if (copied)
616 goto out;
617 out_err:
618 return sk_stream_error(sk, flags, err);
619 }
620
621 ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
622 size_t size, int flags)
623 {
624 ssize_t res;
625 struct sock *sk = sock->sk;
626
627 if (!(sk->sk_route_caps & NETIF_F_SG) ||
628 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
629 return sock_no_sendpage(sock, page, offset, size, flags);
630
631 lock_sock(sk);
632 TCP_CHECK_TIMER(sk);
633 res = do_tcp_sendpages(sk, &page, offset, size, flags);
634 TCP_CHECK_TIMER(sk);
635 release_sock(sk);
636 return res;
637 }
638
639 #define TCP_PAGE(sk) (sk->sk_sndmsg_page)
640 #define TCP_OFF(sk) (sk->sk_sndmsg_off)
641
642 static inline int select_size(struct sock *sk, struct tcp_sock *tp)
643 {
644 int tmp = tp->mss_cache;
645
646 if (sk->sk_route_caps & NETIF_F_SG) {
647 if (sk_can_gso(sk))
648 tmp = 0;
649 else {
650 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
651
652 if (tmp >= pgbreak &&
653 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
654 tmp = pgbreak;
655 }
656 }
657
658 return tmp;
659 }
660
661 int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
662 size_t size)
663 {
664 struct iovec *iov;
665 struct tcp_sock *tp = tcp_sk(sk);
666 struct sk_buff *skb;
667 int iovlen, flags;
668 int mss_now, size_goal;
669 int err, copied;
670 long timeo;
671
672 lock_sock(sk);
673 TCP_CHECK_TIMER(sk);
674
675 flags = msg->msg_flags;
676 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
677
678 /* Wait for a connection to finish. */
679 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
680 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
681 goto out_err;
682
683 /* This should be in poll */
684 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
685
686 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
687 size_goal = tp->xmit_size_goal;
688
689 /* Ok commence sending. */
690 iovlen = msg->msg_iovlen;
691 iov = msg->msg_iov;
692 copied = 0;
693
694 err = -EPIPE;
695 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
696 goto do_error;
697
698 while (--iovlen >= 0) {
699 int seglen = iov->iov_len;
700 unsigned char __user *from = iov->iov_base;
701
702 iov++;
703
704 while (seglen > 0) {
705 int copy;
706
707 skb = sk->sk_write_queue.prev;
708
709 if (!sk->sk_send_head ||
710 (copy = size_goal - skb->len) <= 0) {
711
712 new_segment:
713 /* Allocate new segment. If the interface is SG,
714 * allocate skb fitting to single page.
715 */
716 if (!sk_stream_memory_free(sk))
717 goto wait_for_sndbuf;
718
719 skb = sk_stream_alloc_pskb(sk, select_size(sk, tp),
720 0, sk->sk_allocation);
721 if (!skb)
722 goto wait_for_memory;
723
724 /*
725 * Check whether we can use HW checksum.
726 */
727 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
728 skb->ip_summed = CHECKSUM_PARTIAL;
729
730 skb_entail(sk, tp, skb);
731 copy = size_goal;
732 }
733
734 /* Try to append data to the end of skb. */
735 if (copy > seglen)
736 copy = seglen;
737
738 /* Where to copy to? */
739 if (skb_tailroom(skb) > 0) {
740 /* We have some space in skb head. Superb! */
741 if (copy > skb_tailroom(skb))
742 copy = skb_tailroom(skb);
743 if ((err = skb_add_data(skb, from, copy)) != 0)
744 goto do_fault;
745 } else {
746 int merge = 0;
747 int i = skb_shinfo(skb)->nr_frags;
748 struct page *page = TCP_PAGE(sk);
749 int off = TCP_OFF(sk);
750
751 if (skb_can_coalesce(skb, i, page, off) &&
752 off != PAGE_SIZE) {
753 /* We can extend the last page
754 * fragment. */
755 merge = 1;
756 } else if (i == MAX_SKB_FRAGS ||
757 (!i &&
758 !(sk->sk_route_caps & NETIF_F_SG))) {
759 /* Need to add new fragment and cannot
760 * do this because interface is non-SG,
761 * or because all the page slots are
762 * busy. */
763 tcp_mark_push(tp, skb);
764 goto new_segment;
765 } else if (page) {
766 if (off == PAGE_SIZE) {
767 put_page(page);
768 TCP_PAGE(sk) = page = NULL;
769 off = 0;
770 }
771 } else
772 off = 0;
773
774 if (copy > PAGE_SIZE - off)
775 copy = PAGE_SIZE - off;
776
777 if (!sk_stream_wmem_schedule(sk, copy))
778 goto wait_for_memory;
779
780 if (!page) {
781 /* Allocate new cache page. */
782 if (!(page = sk_stream_alloc_page(sk)))
783 goto wait_for_memory;
784 }
785
786 /* Time to copy data. We are close to
787 * the end! */
788 err = skb_copy_to_page(sk, from, skb, page,
789 off, copy);
790 if (err) {
791 /* If this page was new, give it to the
792 * socket so it does not get leaked.
793 */
794 if (!TCP_PAGE(sk)) {
795 TCP_PAGE(sk) = page;
796 TCP_OFF(sk) = 0;
797 }
798 goto do_error;
799 }
800
801 /* Update the skb. */
802 if (merge) {
803 skb_shinfo(skb)->frags[i - 1].size +=
804 copy;
805 } else {
806 skb_fill_page_desc(skb, i, page, off, copy);
807 if (TCP_PAGE(sk)) {
808 get_page(page);
809 } else if (off + copy < PAGE_SIZE) {
810 get_page(page);
811 TCP_PAGE(sk) = page;
812 }
813 }
814
815 TCP_OFF(sk) = off + copy;
816 }
817
818 if (!copied)
819 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
820
821 tp->write_seq += copy;
822 TCP_SKB_CB(skb)->end_seq += copy;
823 skb_shinfo(skb)->gso_segs = 0;
824
825 from += copy;
826 copied += copy;
827 if ((seglen -= copy) == 0 && iovlen == 0)
828 goto out;
829
830 if (skb->len < mss_now || (flags & MSG_OOB))
831 continue;
832
833 if (forced_push(tp)) {
834 tcp_mark_push(tp, skb);
835 __tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH);
836 } else if (skb == sk->sk_send_head)
837 tcp_push_one(sk, mss_now);
838 continue;
839
840 wait_for_sndbuf:
841 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
842 wait_for_memory:
843 if (copied)
844 tcp_push(sk, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
845
846 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
847 goto do_error;
848
849 mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
850 size_goal = tp->xmit_size_goal;
851 }
852 }
853
854 out:
855 if (copied)
856 tcp_push(sk, tp, flags, mss_now, tp->nonagle);
857 TCP_CHECK_TIMER(sk);
858 release_sock(sk);
859 return copied;
860
861 do_fault:
862 if (!skb->len) {
863 if (sk->sk_send_head == skb)
864 sk->sk_send_head = NULL;
865 __skb_unlink(skb, &sk->sk_write_queue);
866 sk_stream_free_skb(sk, skb);
867 }
868
869 do_error:
870 if (copied)
871 goto out;
872 out_err:
873 err = sk_stream_error(sk, flags, err);
874 TCP_CHECK_TIMER(sk);
875 release_sock(sk);
876 return err;
877 }
878
879 /*
880 * Handle reading urgent data. BSD has very simple semantics for
881 * this, no blocking and very strange errors 8)
882 */
883
884 static int tcp_recv_urg(struct sock *sk, long timeo,
885 struct msghdr *msg, int len, int flags,
886 int *addr_len)
887 {
888 struct tcp_sock *tp = tcp_sk(sk);
889
890 /* No URG data to read. */
891 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
892 tp->urg_data == TCP_URG_READ)
893 return -EINVAL; /* Yes this is right ! */
894
895 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
896 return -ENOTCONN;
897
898 if (tp->urg_data & TCP_URG_VALID) {
899 int err = 0;
900 char c = tp->urg_data;
901
902 if (!(flags & MSG_PEEK))
903 tp->urg_data = TCP_URG_READ;
904
905 /* Read urgent data. */
906 msg->msg_flags |= MSG_OOB;
907
908 if (len > 0) {
909 if (!(flags & MSG_TRUNC))
910 err = memcpy_toiovec(msg->msg_iov, &c, 1);
911 len = 1;
912 } else
913 msg->msg_flags |= MSG_TRUNC;
914
915 return err ? -EFAULT : len;
916 }
917
918 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
919 return 0;
920
921 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
922 * the available implementations agree in this case:
923 * this call should never block, independent of the
924 * blocking state of the socket.
925 * Mike <pall@rz.uni-karlsruhe.de>
926 */
927 return -EAGAIN;
928 }
929
930 /* Clean up the receive buffer for full frames taken by the user,
931 * then send an ACK if necessary. COPIED is the number of bytes
932 * tcp_recvmsg has given to the user so far, it speeds up the
933 * calculation of whether or not we must ACK for the sake of
934 * a window update.
935 */
936 void tcp_cleanup_rbuf(struct sock *sk, int copied)
937 {
938 struct tcp_sock *tp = tcp_sk(sk);
939 int time_to_ack = 0;
940
941 #if TCP_DEBUG
942 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
943
944 BUG_TRAP(!skb || before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
945 #endif
946
947 if (inet_csk_ack_scheduled(sk)) {
948 const struct inet_connection_sock *icsk = inet_csk(sk);
949 /* Delayed ACKs frequently hit locked sockets during bulk
950 * receive. */
951 if (icsk->icsk_ack.blocked ||
952 /* Once-per-two-segments ACK was not sent by tcp_input.c */
953 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
954 /*
955 * If this read emptied read buffer, we send ACK, if
956 * connection is not bidirectional, user drained
957 * receive buffer and there was a small segment
958 * in queue.
959 */
960 (copied > 0 &&
961 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
962 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
963 !icsk->icsk_ack.pingpong)) &&
964 !atomic_read(&sk->sk_rmem_alloc)))
965 time_to_ack = 1;
966 }
967
968 /* We send an ACK if we can now advertise a non-zero window
969 * which has been raised "significantly".
970 *
971 * Even if window raised up to infinity, do not send window open ACK
972 * in states, where we will not receive more. It is useless.
973 */
974 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
975 __u32 rcv_window_now = tcp_receive_window(tp);
976
977 /* Optimize, __tcp_select_window() is not cheap. */
978 if (2*rcv_window_now <= tp->window_clamp) {
979 __u32 new_window = __tcp_select_window(sk);
980
981 /* Send ACK now, if this read freed lots of space
982 * in our buffer. Certainly, new_window is new window.
983 * We can advertise it now, if it is not less than current one.
984 * "Lots" means "at least twice" here.
985 */
986 if (new_window && new_window >= 2 * rcv_window_now)
987 time_to_ack = 1;
988 }
989 }
990 if (time_to_ack)
991 tcp_send_ack(sk);
992 }
993
994 static void tcp_prequeue_process(struct sock *sk)
995 {
996 struct sk_buff *skb;
997 struct tcp_sock *tp = tcp_sk(sk);
998
999 NET_INC_STATS_USER(LINUX_MIB_TCPPREQUEUED);
1000
1001 /* RX process wants to run with disabled BHs, though it is not
1002 * necessary */
1003 local_bh_disable();
1004 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1005 sk->sk_backlog_rcv(sk, skb);
1006 local_bh_enable();
1007
1008 /* Clear memory counter. */
1009 tp->ucopy.memory = 0;
1010 }
1011
1012 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1013 {
1014 struct sk_buff *skb;
1015 u32 offset;
1016
1017 skb_queue_walk(&sk->sk_receive_queue, skb) {
1018 offset = seq - TCP_SKB_CB(skb)->seq;
1019 if (skb->h.th->syn)
1020 offset--;
1021 if (offset < skb->len || skb->h.th->fin) {
1022 *off = offset;
1023 return skb;
1024 }
1025 }
1026 return NULL;
1027 }
1028
1029 /*
1030 * This routine provides an alternative to tcp_recvmsg() for routines
1031 * that would like to handle copying from skbuffs directly in 'sendfile'
1032 * fashion.
1033 * Note:
1034 * - It is assumed that the socket was locked by the caller.
1035 * - The routine does not block.
1036 * - At present, there is no support for reading OOB data
1037 * or for 'peeking' the socket using this routine
1038 * (although both would be easy to implement).
1039 */
1040 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1041 sk_read_actor_t recv_actor)
1042 {
1043 struct sk_buff *skb;
1044 struct tcp_sock *tp = tcp_sk(sk);
1045 u32 seq = tp->copied_seq;
1046 u32 offset;
1047 int copied = 0;
1048
1049 if (sk->sk_state == TCP_LISTEN)
1050 return -ENOTCONN;
1051 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1052 if (offset < skb->len) {
1053 size_t used, len;
1054
1055 len = skb->len - offset;
1056 /* Stop reading if we hit a patch of urgent data */
1057 if (tp->urg_data) {
1058 u32 urg_offset = tp->urg_seq - seq;
1059 if (urg_offset < len)
1060 len = urg_offset;
1061 if (!len)
1062 break;
1063 }
1064 used = recv_actor(desc, skb, offset, len);
1065 if (used <= len) {
1066 seq += used;
1067 copied += used;
1068 offset += used;
1069 }
1070 if (offset != skb->len)
1071 break;
1072 }
1073 if (skb->h.th->fin) {
1074 sk_eat_skb(sk, skb, 0);
1075 ++seq;
1076 break;
1077 }
1078 sk_eat_skb(sk, skb, 0);
1079 if (!desc->count)
1080 break;
1081 }
1082 tp->copied_seq = seq;
1083
1084 tcp_rcv_space_adjust(sk);
1085
1086 /* Clean up data we have read: This will do ACK frames. */
1087 if (copied)
1088 tcp_cleanup_rbuf(sk, copied);
1089 return copied;
1090 }
1091
1092 /*
1093 * This routine copies from a sock struct into the user buffer.
1094 *
1095 * Technical note: in 2.3 we work on _locked_ socket, so that
1096 * tricks with *seq access order and skb->users are not required.
1097 * Probably, code can be easily improved even more.
1098 */
1099
1100 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1101 size_t len, int nonblock, int flags, int *addr_len)
1102 {
1103 struct tcp_sock *tp = tcp_sk(sk);
1104 int copied = 0;
1105 u32 peek_seq;
1106 u32 *seq;
1107 unsigned long used;
1108 int err;
1109 int target; /* Read at least this many bytes */
1110 long timeo;
1111 struct task_struct *user_recv = NULL;
1112 int copied_early = 0;
1113
1114 lock_sock(sk);
1115
1116 TCP_CHECK_TIMER(sk);
1117
1118 err = -ENOTCONN;
1119 if (sk->sk_state == TCP_LISTEN)
1120 goto out;
1121
1122 timeo = sock_rcvtimeo(sk, nonblock);
1123
1124 /* Urgent data needs to be handled specially. */
1125 if (flags & MSG_OOB)
1126 goto recv_urg;
1127
1128 seq = &tp->copied_seq;
1129 if (flags & MSG_PEEK) {
1130 peek_seq = tp->copied_seq;
1131 seq = &peek_seq;
1132 }
1133
1134 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1135
1136 #ifdef CONFIG_NET_DMA
1137 tp->ucopy.dma_chan = NULL;
1138 preempt_disable();
1139 if ((len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1140 !sysctl_tcp_low_latency && __get_cpu_var(softnet_data).net_dma) {
1141 preempt_enable_no_resched();
1142 tp->ucopy.pinned_list = dma_pin_iovec_pages(msg->msg_iov, len);
1143 } else
1144 preempt_enable_no_resched();
1145 #endif
1146
1147 do {
1148 struct sk_buff *skb;
1149 u32 offset;
1150
1151 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1152 if (tp->urg_data && tp->urg_seq == *seq) {
1153 if (copied)
1154 break;
1155 if (signal_pending(current)) {
1156 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1157 break;
1158 }
1159 }
1160
1161 /* Next get a buffer. */
1162
1163 skb = skb_peek(&sk->sk_receive_queue);
1164 do {
1165 if (!skb)
1166 break;
1167
1168 /* Now that we have two receive queues this
1169 * shouldn't happen.
1170 */
1171 if (before(*seq, TCP_SKB_CB(skb)->seq)) {
1172 printk(KERN_INFO "recvmsg bug: copied %X "
1173 "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
1174 break;
1175 }
1176 offset = *seq - TCP_SKB_CB(skb)->seq;
1177 if (skb->h.th->syn)
1178 offset--;
1179 if (offset < skb->len)
1180 goto found_ok_skb;
1181 if (skb->h.th->fin)
1182 goto found_fin_ok;
1183 BUG_TRAP(flags & MSG_PEEK);
1184 skb = skb->next;
1185 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
1186
1187 /* Well, if we have backlog, try to process it now yet. */
1188
1189 if (copied >= target && !sk->sk_backlog.tail)
1190 break;
1191
1192 if (copied) {
1193 if (sk->sk_err ||
1194 sk->sk_state == TCP_CLOSE ||
1195 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1196 !timeo ||
1197 signal_pending(current) ||
1198 (flags & MSG_PEEK))
1199 break;
1200 } else {
1201 if (sock_flag(sk, SOCK_DONE))
1202 break;
1203
1204 if (sk->sk_err) {
1205 copied = sock_error(sk);
1206 break;
1207 }
1208
1209 if (sk->sk_shutdown & RCV_SHUTDOWN)
1210 break;
1211
1212 if (sk->sk_state == TCP_CLOSE) {
1213 if (!sock_flag(sk, SOCK_DONE)) {
1214 /* This occurs when user tries to read
1215 * from never connected socket.
1216 */
1217 copied = -ENOTCONN;
1218 break;
1219 }
1220 break;
1221 }
1222
1223 if (!timeo) {
1224 copied = -EAGAIN;
1225 break;
1226 }
1227
1228 if (signal_pending(current)) {
1229 copied = sock_intr_errno(timeo);
1230 break;
1231 }
1232 }
1233
1234 tcp_cleanup_rbuf(sk, copied);
1235
1236 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1237 /* Install new reader */
1238 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1239 user_recv = current;
1240 tp->ucopy.task = user_recv;
1241 tp->ucopy.iov = msg->msg_iov;
1242 }
1243
1244 tp->ucopy.len = len;
1245
1246 BUG_TRAP(tp->copied_seq == tp->rcv_nxt ||
1247 (flags & (MSG_PEEK | MSG_TRUNC)));
1248
1249 /* Ugly... If prequeue is not empty, we have to
1250 * process it before releasing socket, otherwise
1251 * order will be broken at second iteration.
1252 * More elegant solution is required!!!
1253 *
1254 * Look: we have the following (pseudo)queues:
1255 *
1256 * 1. packets in flight
1257 * 2. backlog
1258 * 3. prequeue
1259 * 4. receive_queue
1260 *
1261 * Each queue can be processed only if the next ones
1262 * are empty. At this point we have empty receive_queue.
1263 * But prequeue _can_ be not empty after 2nd iteration,
1264 * when we jumped to start of loop because backlog
1265 * processing added something to receive_queue.
1266 * We cannot release_sock(), because backlog contains
1267 * packets arrived _after_ prequeued ones.
1268 *
1269 * Shortly, algorithm is clear --- to process all
1270 * the queues in order. We could make it more directly,
1271 * requeueing packets from backlog to prequeue, if
1272 * is not empty. It is more elegant, but eats cycles,
1273 * unfortunately.
1274 */
1275 if (!skb_queue_empty(&tp->ucopy.prequeue))
1276 goto do_prequeue;
1277
1278 /* __ Set realtime policy in scheduler __ */
1279 }
1280
1281 if (copied >= target) {
1282 /* Do not sleep, just process backlog. */
1283 release_sock(sk);
1284 lock_sock(sk);
1285 } else
1286 sk_wait_data(sk, &timeo);
1287
1288 #ifdef CONFIG_NET_DMA
1289 tp->ucopy.wakeup = 0;
1290 #endif
1291
1292 if (user_recv) {
1293 int chunk;
1294
1295 /* __ Restore normal policy in scheduler __ */
1296
1297 if ((chunk = len - tp->ucopy.len) != 0) {
1298 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1299 len -= chunk;
1300 copied += chunk;
1301 }
1302
1303 if (tp->rcv_nxt == tp->copied_seq &&
1304 !skb_queue_empty(&tp->ucopy.prequeue)) {
1305 do_prequeue:
1306 tcp_prequeue_process(sk);
1307
1308 if ((chunk = len - tp->ucopy.len) != 0) {
1309 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1310 len -= chunk;
1311 copied += chunk;
1312 }
1313 }
1314 }
1315 if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
1316 if (net_ratelimit())
1317 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1318 current->comm, current->pid);
1319 peek_seq = tp->copied_seq;
1320 }
1321 continue;
1322
1323 found_ok_skb:
1324 /* Ok so how much can we use? */
1325 used = skb->len - offset;
1326 if (len < used)
1327 used = len;
1328
1329 /* Do we have urgent data here? */
1330 if (tp->urg_data) {
1331 u32 urg_offset = tp->urg_seq - *seq;
1332 if (urg_offset < used) {
1333 if (!urg_offset) {
1334 if (!sock_flag(sk, SOCK_URGINLINE)) {
1335 ++*seq;
1336 offset++;
1337 used--;
1338 if (!used)
1339 goto skip_copy;
1340 }
1341 } else
1342 used = urg_offset;
1343 }
1344 }
1345
1346 if (!(flags & MSG_TRUNC)) {
1347 #ifdef CONFIG_NET_DMA
1348 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1349 tp->ucopy.dma_chan = get_softnet_dma();
1350
1351 if (tp->ucopy.dma_chan) {
1352 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1353 tp->ucopy.dma_chan, skb, offset,
1354 msg->msg_iov, used,
1355 tp->ucopy.pinned_list);
1356
1357 if (tp->ucopy.dma_cookie < 0) {
1358
1359 printk(KERN_ALERT "dma_cookie < 0\n");
1360
1361 /* Exception. Bailout! */
1362 if (!copied)
1363 copied = -EFAULT;
1364 break;
1365 }
1366 if ((offset + used) == skb->len)
1367 copied_early = 1;
1368
1369 } else
1370 #endif
1371 {
1372 err = skb_copy_datagram_iovec(skb, offset,
1373 msg->msg_iov, used);
1374 if (err) {
1375 /* Exception. Bailout! */
1376 if (!copied)
1377 copied = -EFAULT;
1378 break;
1379 }
1380 }
1381 }
1382
1383 *seq += used;
1384 copied += used;
1385 len -= used;
1386
1387 tcp_rcv_space_adjust(sk);
1388
1389 skip_copy:
1390 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1391 tp->urg_data = 0;
1392 tcp_fast_path_check(sk, tp);
1393 }
1394 if (used + offset < skb->len)
1395 continue;
1396
1397 if (skb->h.th->fin)
1398 goto found_fin_ok;
1399 if (!(flags & MSG_PEEK)) {
1400 sk_eat_skb(sk, skb, copied_early);
1401 copied_early = 0;
1402 }
1403 continue;
1404
1405 found_fin_ok:
1406 /* Process the FIN. */
1407 ++*seq;
1408 if (!(flags & MSG_PEEK)) {
1409 sk_eat_skb(sk, skb, copied_early);
1410 copied_early = 0;
1411 }
1412 break;
1413 } while (len > 0);
1414
1415 if (user_recv) {
1416 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1417 int chunk;
1418
1419 tp->ucopy.len = copied > 0 ? len : 0;
1420
1421 tcp_prequeue_process(sk);
1422
1423 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1424 NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1425 len -= chunk;
1426 copied += chunk;
1427 }
1428 }
1429
1430 tp->ucopy.task = NULL;
1431 tp->ucopy.len = 0;
1432 }
1433
1434 #ifdef CONFIG_NET_DMA
1435 if (tp->ucopy.dma_chan) {
1436 struct sk_buff *skb;
1437 dma_cookie_t done, used;
1438
1439 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1440
1441 while (dma_async_memcpy_complete(tp->ucopy.dma_chan,
1442 tp->ucopy.dma_cookie, &done,
1443 &used) == DMA_IN_PROGRESS) {
1444 /* do partial cleanup of sk_async_wait_queue */
1445 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1446 (dma_async_is_complete(skb->dma_cookie, done,
1447 used) == DMA_SUCCESS)) {
1448 __skb_dequeue(&sk->sk_async_wait_queue);
1449 kfree_skb(skb);
1450 }
1451 }
1452
1453 /* Safe to free early-copied skbs now */
1454 __skb_queue_purge(&sk->sk_async_wait_queue);
1455 dma_chan_put(tp->ucopy.dma_chan);
1456 tp->ucopy.dma_chan = NULL;
1457 }
1458 if (tp->ucopy.pinned_list) {
1459 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1460 tp->ucopy.pinned_list = NULL;
1461 }
1462 #endif
1463
1464 /* According to UNIX98, msg_name/msg_namelen are ignored
1465 * on connected socket. I was just happy when found this 8) --ANK
1466 */
1467
1468 /* Clean up data we have read: This will do ACK frames. */
1469 tcp_cleanup_rbuf(sk, copied);
1470
1471 TCP_CHECK_TIMER(sk);
1472 release_sock(sk);
1473 return copied;
1474
1475 out:
1476 TCP_CHECK_TIMER(sk);
1477 release_sock(sk);
1478 return err;
1479
1480 recv_urg:
1481 err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len);
1482 goto out;
1483 }
1484
1485 /*
1486 * State processing on a close. This implements the state shift for
1487 * sending our FIN frame. Note that we only send a FIN for some
1488 * states. A shutdown() may have already sent the FIN, or we may be
1489 * closed.
1490 */
1491
1492 static const unsigned char new_state[16] = {
1493 /* current state: new state: action: */
1494 /* (Invalid) */ TCP_CLOSE,
1495 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1496 /* TCP_SYN_SENT */ TCP_CLOSE,
1497 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1498 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1499 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1500 /* TCP_TIME_WAIT */ TCP_CLOSE,
1501 /* TCP_CLOSE */ TCP_CLOSE,
1502 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1503 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1504 /* TCP_LISTEN */ TCP_CLOSE,
1505 /* TCP_CLOSING */ TCP_CLOSING,
1506 };
1507
1508 static int tcp_close_state(struct sock *sk)
1509 {
1510 int next = (int)new_state[sk->sk_state];
1511 int ns = next & TCP_STATE_MASK;
1512
1513 tcp_set_state(sk, ns);
1514
1515 return next & TCP_ACTION_FIN;
1516 }
1517
1518 /*
1519 * Shutdown the sending side of a connection. Much like close except
1520 * that we don't receive shut down or set_sock_flag(sk, SOCK_DEAD).
1521 */
1522
1523 void tcp_shutdown(struct sock *sk, int how)
1524 {
1525 /* We need to grab some memory, and put together a FIN,
1526 * and then put it into the queue to be sent.
1527 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1528 */
1529 if (!(how & SEND_SHUTDOWN))
1530 return;
1531
1532 /* If we've already sent a FIN, or it's a closed state, skip this. */
1533 if ((1 << sk->sk_state) &
1534 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1535 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1536 /* Clear out any half completed packets. FIN if needed. */
1537 if (tcp_close_state(sk))
1538 tcp_send_fin(sk);
1539 }
1540 }
1541
1542 void tcp_close(struct sock *sk, long timeout)
1543 {
1544 struct sk_buff *skb;
1545 int data_was_unread = 0;
1546 int state;
1547
1548 lock_sock(sk);
1549 sk->sk_shutdown = SHUTDOWN_MASK;
1550
1551 if (sk->sk_state == TCP_LISTEN) {
1552 tcp_set_state(sk, TCP_CLOSE);
1553
1554 /* Special case. */
1555 inet_csk_listen_stop(sk);
1556
1557 goto adjudge_to_death;
1558 }
1559
1560 /* We need to flush the recv. buffs. We do this only on the
1561 * descriptor close, not protocol-sourced closes, because the
1562 * reader process may not have drained the data yet!
1563 */
1564 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1565 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
1566 skb->h.th->fin;
1567 data_was_unread += len;
1568 __kfree_skb(skb);
1569 }
1570
1571 sk_stream_mem_reclaim(sk);
1572
1573 /* As outlined in draft-ietf-tcpimpl-prob-03.txt, section
1574 * 3.10, we send a RST here because data was lost. To
1575 * witness the awful effects of the old behavior of always
1576 * doing a FIN, run an older 2.1.x kernel or 2.0.x, start
1577 * a bulk GET in an FTP client, suspend the process, wait
1578 * for the client to advertise a zero window, then kill -9
1579 * the FTP client, wheee... Note: timeout is always zero
1580 * in such a case.
1581 */
1582 if (data_was_unread) {
1583 /* Unread data was tossed, zap the connection. */
1584 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONCLOSE);
1585 tcp_set_state(sk, TCP_CLOSE);
1586 tcp_send_active_reset(sk, GFP_KERNEL);
1587 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1588 /* Check zero linger _after_ checking for unread data. */
1589 sk->sk_prot->disconnect(sk, 0);
1590 NET_INC_STATS_USER(LINUX_MIB_TCPABORTONDATA);
1591 } else if (tcp_close_state(sk)) {
1592 /* We FIN if the application ate all the data before
1593 * zapping the connection.
1594 */
1595
1596 /* RED-PEN. Formally speaking, we have broken TCP state
1597 * machine. State transitions:
1598 *
1599 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1600 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1601 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1602 *
1603 * are legal only when FIN has been sent (i.e. in window),
1604 * rather than queued out of window. Purists blame.
1605 *
1606 * F.e. "RFC state" is ESTABLISHED,
1607 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1608 *
1609 * The visible declinations are that sometimes
1610 * we enter time-wait state, when it is not required really
1611 * (harmless), do not send active resets, when they are
1612 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1613 * they look as CLOSING or LAST_ACK for Linux)
1614 * Probably, I missed some more holelets.
1615 * --ANK
1616 */
1617 tcp_send_fin(sk);
1618 }
1619
1620 sk_stream_wait_close(sk, timeout);
1621
1622 adjudge_to_death:
1623 state = sk->sk_state;
1624 sock_hold(sk);
1625 sock_orphan(sk);
1626 atomic_inc(sk->sk_prot->orphan_count);
1627
1628 /* It is the last release_sock in its life. It will remove backlog. */
1629 release_sock(sk);
1630
1631
1632 /* Now socket is owned by kernel and we acquire BH lock
1633 to finish close. No need to check for user refs.
1634 */
1635 local_bh_disable();
1636 bh_lock_sock(sk);
1637 BUG_TRAP(!sock_owned_by_user(sk));
1638
1639 /* Have we already been destroyed by a softirq or backlog? */
1640 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1641 goto out;
1642
1643 /* This is a (useful) BSD violating of the RFC. There is a
1644 * problem with TCP as specified in that the other end could
1645 * keep a socket open forever with no application left this end.
1646 * We use a 3 minute timeout (about the same as BSD) then kill
1647 * our end. If they send after that then tough - BUT: long enough
1648 * that we won't make the old 4*rto = almost no time - whoops
1649 * reset mistake.
1650 *
1651 * Nope, it was not mistake. It is really desired behaviour
1652 * f.e. on http servers, when such sockets are useless, but
1653 * consume significant resources. Let's do it with special
1654 * linger2 option. --ANK
1655 */
1656
1657 if (sk->sk_state == TCP_FIN_WAIT2) {
1658 struct tcp_sock *tp = tcp_sk(sk);
1659 if (tp->linger2 < 0) {
1660 tcp_set_state(sk, TCP_CLOSE);
1661 tcp_send_active_reset(sk, GFP_ATOMIC);
1662 NET_INC_STATS_BH(LINUX_MIB_TCPABORTONLINGER);
1663 } else {
1664 const int tmo = tcp_fin_time(sk);
1665
1666 if (tmo > TCP_TIMEWAIT_LEN) {
1667 inet_csk_reset_keepalive_timer(sk,
1668 tmo - TCP_TIMEWAIT_LEN);
1669 } else {
1670 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
1671 goto out;
1672 }
1673 }
1674 }
1675 if (sk->sk_state != TCP_CLOSE) {
1676 sk_stream_mem_reclaim(sk);
1677 if (atomic_read(sk->sk_prot->orphan_count) > sysctl_tcp_max_orphans ||
1678 (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
1679 atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2])) {
1680 if (net_ratelimit())
1681 printk(KERN_INFO "TCP: too many of orphaned "
1682 "sockets\n");
1683 tcp_set_state(sk, TCP_CLOSE);
1684 tcp_send_active_reset(sk, GFP_ATOMIC);
1685 NET_INC_STATS_BH(LINUX_MIB_TCPABORTONMEMORY);
1686 }
1687 }
1688
1689 if (sk->sk_state == TCP_CLOSE)
1690 inet_csk_destroy_sock(sk);
1691 /* Otherwise, socket is reprieved until protocol close. */
1692
1693 out:
1694 bh_unlock_sock(sk);
1695 local_bh_enable();
1696 sock_put(sk);
1697 }
1698
1699 /* These states need RST on ABORT according to RFC793 */
1700
1701 static inline int tcp_need_reset(int state)
1702 {
1703 return (1 << state) &
1704 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
1705 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
1706 }
1707
1708 int tcp_disconnect(struct sock *sk, int flags)
1709 {
1710 struct inet_sock *inet = inet_sk(sk);
1711 struct inet_connection_sock *icsk = inet_csk(sk);
1712 struct tcp_sock *tp = tcp_sk(sk);
1713 int err = 0;
1714 int old_state = sk->sk_state;
1715
1716 if (old_state != TCP_CLOSE)
1717 tcp_set_state(sk, TCP_CLOSE);
1718
1719 /* ABORT function of RFC793 */
1720 if (old_state == TCP_LISTEN) {
1721 inet_csk_listen_stop(sk);
1722 } else if (tcp_need_reset(old_state) ||
1723 (tp->snd_nxt != tp->write_seq &&
1724 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
1725 /* The last check adjusts for discrepancy of Linux wrt. RFC
1726 * states
1727 */
1728 tcp_send_active_reset(sk, gfp_any());
1729 sk->sk_err = ECONNRESET;
1730 } else if (old_state == TCP_SYN_SENT)
1731 sk->sk_err = ECONNRESET;
1732
1733 tcp_clear_xmit_timers(sk);
1734 __skb_queue_purge(&sk->sk_receive_queue);
1735 sk_stream_writequeue_purge(sk);
1736 __skb_queue_purge(&tp->out_of_order_queue);
1737 #ifdef CONFIG_NET_DMA
1738 __skb_queue_purge(&sk->sk_async_wait_queue);
1739 #endif
1740
1741 inet->dport = 0;
1742
1743 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1744 inet_reset_saddr(sk);
1745
1746 sk->sk_shutdown = 0;
1747 sock_reset_flag(sk, SOCK_DONE);
1748 tp->srtt = 0;
1749 if ((tp->write_seq += tp->max_window + 2) == 0)
1750 tp->write_seq = 1;
1751 icsk->icsk_backoff = 0;
1752 tp->snd_cwnd = 2;
1753 icsk->icsk_probes_out = 0;
1754 tp->packets_out = 0;
1755 tp->snd_ssthresh = 0x7fffffff;
1756 tp->snd_cwnd_cnt = 0;
1757 tp->bytes_acked = 0;
1758 tcp_set_ca_state(sk, TCP_CA_Open);
1759 tcp_clear_retrans(tp);
1760 inet_csk_delack_init(sk);
1761 sk->sk_send_head = NULL;
1762 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
1763 __sk_dst_reset(sk);
1764
1765 BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
1766
1767 sk->sk_error_report(sk);
1768 return err;
1769 }
1770
1771 /*
1772 * Socket option code for TCP.
1773 */
1774 static int do_tcp_setsockopt(struct sock *sk, int level,
1775 int optname, char __user *optval, int optlen)
1776 {
1777 struct tcp_sock *tp = tcp_sk(sk);
1778 struct inet_connection_sock *icsk = inet_csk(sk);
1779 int val;
1780 int err = 0;
1781
1782 /* This is a string value all the others are int's */
1783 if (optname == TCP_CONGESTION) {
1784 char name[TCP_CA_NAME_MAX];
1785
1786 if (optlen < 1)
1787 return -EINVAL;
1788
1789 val = strncpy_from_user(name, optval,
1790 min(TCP_CA_NAME_MAX-1, optlen));
1791 if (val < 0)
1792 return -EFAULT;
1793 name[val] = 0;
1794
1795 lock_sock(sk);
1796 err = tcp_set_congestion_control(sk, name);
1797 release_sock(sk);
1798 return err;
1799 }
1800
1801 if (optlen < sizeof(int))
1802 return -EINVAL;
1803
1804 if (get_user(val, (int __user *)optval))
1805 return -EFAULT;
1806
1807 lock_sock(sk);
1808
1809 switch (optname) {
1810 case TCP_MAXSEG:
1811 /* Values greater than interface MTU won't take effect. However
1812 * at the point when this call is done we typically don't yet
1813 * know which interface is going to be used */
1814 if (val < 8 || val > MAX_TCP_WINDOW) {
1815 err = -EINVAL;
1816 break;
1817 }
1818 tp->rx_opt.user_mss = val;
1819 break;
1820
1821 case TCP_NODELAY:
1822 if (val) {
1823 /* TCP_NODELAY is weaker than TCP_CORK, so that
1824 * this option on corked socket is remembered, but
1825 * it is not activated until cork is cleared.
1826 *
1827 * However, when TCP_NODELAY is set we make
1828 * an explicit push, which overrides even TCP_CORK
1829 * for currently queued segments.
1830 */
1831 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
1832 tcp_push_pending_frames(sk, tp);
1833 } else {
1834 tp->nonagle &= ~TCP_NAGLE_OFF;
1835 }
1836 break;
1837
1838 case TCP_CORK:
1839 /* When set indicates to always queue non-full frames.
1840 * Later the user clears this option and we transmit
1841 * any pending partial frames in the queue. This is
1842 * meant to be used alongside sendfile() to get properly
1843 * filled frames when the user (for example) must write
1844 * out headers with a write() call first and then use
1845 * sendfile to send out the data parts.
1846 *
1847 * TCP_CORK can be set together with TCP_NODELAY and it is
1848 * stronger than TCP_NODELAY.
1849 */
1850 if (val) {
1851 tp->nonagle |= TCP_NAGLE_CORK;
1852 } else {
1853 tp->nonagle &= ~TCP_NAGLE_CORK;
1854 if (tp->nonagle&TCP_NAGLE_OFF)
1855 tp->nonagle |= TCP_NAGLE_PUSH;
1856 tcp_push_pending_frames(sk, tp);
1857 }
1858 break;
1859
1860 case TCP_KEEPIDLE:
1861 if (val < 1 || val > MAX_TCP_KEEPIDLE)
1862 err = -EINVAL;
1863 else {
1864 tp->keepalive_time = val * HZ;
1865 if (sock_flag(sk, SOCK_KEEPOPEN) &&
1866 !((1 << sk->sk_state) &
1867 (TCPF_CLOSE | TCPF_LISTEN))) {
1868 __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
1869 if (tp->keepalive_time > elapsed)
1870 elapsed = tp->keepalive_time - elapsed;
1871 else
1872 elapsed = 0;
1873 inet_csk_reset_keepalive_timer(sk, elapsed);
1874 }
1875 }
1876 break;
1877 case TCP_KEEPINTVL:
1878 if (val < 1 || val > MAX_TCP_KEEPINTVL)
1879 err = -EINVAL;
1880 else
1881 tp->keepalive_intvl = val * HZ;
1882 break;
1883 case TCP_KEEPCNT:
1884 if (val < 1 || val > MAX_TCP_KEEPCNT)
1885 err = -EINVAL;
1886 else
1887 tp->keepalive_probes = val;
1888 break;
1889 case TCP_SYNCNT:
1890 if (val < 1 || val > MAX_TCP_SYNCNT)
1891 err = -EINVAL;
1892 else
1893 icsk->icsk_syn_retries = val;
1894 break;
1895
1896 case TCP_LINGER2:
1897 if (val < 0)
1898 tp->linger2 = -1;
1899 else if (val > sysctl_tcp_fin_timeout / HZ)
1900 tp->linger2 = 0;
1901 else
1902 tp->linger2 = val * HZ;
1903 break;
1904
1905 case TCP_DEFER_ACCEPT:
1906 icsk->icsk_accept_queue.rskq_defer_accept = 0;
1907 if (val > 0) {
1908 /* Translate value in seconds to number of
1909 * retransmits */
1910 while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
1911 val > ((TCP_TIMEOUT_INIT / HZ) <<
1912 icsk->icsk_accept_queue.rskq_defer_accept))
1913 icsk->icsk_accept_queue.rskq_defer_accept++;
1914 icsk->icsk_accept_queue.rskq_defer_accept++;
1915 }
1916 break;
1917
1918 case TCP_WINDOW_CLAMP:
1919 if (!val) {
1920 if (sk->sk_state != TCP_CLOSE) {
1921 err = -EINVAL;
1922 break;
1923 }
1924 tp->window_clamp = 0;
1925 } else
1926 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
1927 SOCK_MIN_RCVBUF / 2 : val;
1928 break;
1929
1930 case TCP_QUICKACK:
1931 if (!val) {
1932 icsk->icsk_ack.pingpong = 1;
1933 } else {
1934 icsk->icsk_ack.pingpong = 0;
1935 if ((1 << sk->sk_state) &
1936 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
1937 inet_csk_ack_scheduled(sk)) {
1938 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
1939 tcp_cleanup_rbuf(sk, 1);
1940 if (!(val & 1))
1941 icsk->icsk_ack.pingpong = 1;
1942 }
1943 }
1944 break;
1945
1946 #ifdef CONFIG_TCP_MD5SIG
1947 case TCP_MD5SIG:
1948 /* Read the IP->Key mappings from userspace */
1949 err = tp->af_specific->md5_parse(sk, optval, optlen);
1950 break;
1951 #endif
1952
1953 default:
1954 err = -ENOPROTOOPT;
1955 break;
1956 };
1957 release_sock(sk);
1958 return err;
1959 }
1960
1961 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
1962 int optlen)
1963 {
1964 struct inet_connection_sock *icsk = inet_csk(sk);
1965
1966 if (level != SOL_TCP)
1967 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
1968 optval, optlen);
1969 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
1970 }
1971
1972 #ifdef CONFIG_COMPAT
1973 int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
1974 char __user *optval, int optlen)
1975 {
1976 if (level != SOL_TCP)
1977 return inet_csk_compat_setsockopt(sk, level, optname,
1978 optval, optlen);
1979 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
1980 }
1981
1982 EXPORT_SYMBOL(compat_tcp_setsockopt);
1983 #endif
1984
1985 /* Return information about state of tcp endpoint in API format. */
1986 void tcp_get_info(struct sock *sk, struct tcp_info *info)
1987 {
1988 struct tcp_sock *tp = tcp_sk(sk);
1989 const struct inet_connection_sock *icsk = inet_csk(sk);
1990 u32 now = tcp_time_stamp;
1991
1992 memset(info, 0, sizeof(*info));
1993
1994 info->tcpi_state = sk->sk_state;
1995 info->tcpi_ca_state = icsk->icsk_ca_state;
1996 info->tcpi_retransmits = icsk->icsk_retransmits;
1997 info->tcpi_probes = icsk->icsk_probes_out;
1998 info->tcpi_backoff = icsk->icsk_backoff;
1999
2000 if (tp->rx_opt.tstamp_ok)
2001 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2002 if (tp->rx_opt.sack_ok)
2003 info->tcpi_options |= TCPI_OPT_SACK;
2004 if (tp->rx_opt.wscale_ok) {
2005 info->tcpi_options |= TCPI_OPT_WSCALE;
2006 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2007 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2008 }
2009
2010 if (tp->ecn_flags&TCP_ECN_OK)
2011 info->tcpi_options |= TCPI_OPT_ECN;
2012
2013 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2014 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2015 info->tcpi_snd_mss = tp->mss_cache;
2016 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2017
2018 info->tcpi_unacked = tp->packets_out;
2019 info->tcpi_sacked = tp->sacked_out;
2020 info->tcpi_lost = tp->lost_out;
2021 info->tcpi_retrans = tp->retrans_out;
2022 info->tcpi_fackets = tp->fackets_out;
2023
2024 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2025 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2026 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2027
2028 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2029 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2030 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2031 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2032 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2033 info->tcpi_snd_cwnd = tp->snd_cwnd;
2034 info->tcpi_advmss = tp->advmss;
2035 info->tcpi_reordering = tp->reordering;
2036
2037 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2038 info->tcpi_rcv_space = tp->rcvq_space.space;
2039
2040 info->tcpi_total_retrans = tp->total_retrans;
2041 }
2042
2043 EXPORT_SYMBOL_GPL(tcp_get_info);
2044
2045 static int do_tcp_getsockopt(struct sock *sk, int level,
2046 int optname, char __user *optval, int __user *optlen)
2047 {
2048 struct inet_connection_sock *icsk = inet_csk(sk);
2049 struct tcp_sock *tp = tcp_sk(sk);
2050 int val, len;
2051
2052 if (get_user(len, optlen))
2053 return -EFAULT;
2054
2055 len = min_t(unsigned int, len, sizeof(int));
2056
2057 if (len < 0)
2058 return -EINVAL;
2059
2060 switch (optname) {
2061 case TCP_MAXSEG:
2062 val = tp->mss_cache;
2063 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2064 val = tp->rx_opt.user_mss;
2065 break;
2066 case TCP_NODELAY:
2067 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2068 break;
2069 case TCP_CORK:
2070 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2071 break;
2072 case TCP_KEEPIDLE:
2073 val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
2074 break;
2075 case TCP_KEEPINTVL:
2076 val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
2077 break;
2078 case TCP_KEEPCNT:
2079 val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
2080 break;
2081 case TCP_SYNCNT:
2082 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2083 break;
2084 case TCP_LINGER2:
2085 val = tp->linger2;
2086 if (val >= 0)
2087 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2088 break;
2089 case TCP_DEFER_ACCEPT:
2090 val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
2091 ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
2092 break;
2093 case TCP_WINDOW_CLAMP:
2094 val = tp->window_clamp;
2095 break;
2096 case TCP_INFO: {
2097 struct tcp_info info;
2098
2099 if (get_user(len, optlen))
2100 return -EFAULT;
2101
2102 tcp_get_info(sk, &info);
2103
2104 len = min_t(unsigned int, len, sizeof(info));
2105 if (put_user(len, optlen))
2106 return -EFAULT;
2107 if (copy_to_user(optval, &info, len))
2108 return -EFAULT;
2109 return 0;
2110 }
2111 case TCP_QUICKACK:
2112 val = !icsk->icsk_ack.pingpong;
2113 break;
2114
2115 case TCP_CONGESTION:
2116 if (get_user(len, optlen))
2117 return -EFAULT;
2118 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2119 if (put_user(len, optlen))
2120 return -EFAULT;
2121 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2122 return -EFAULT;
2123 return 0;
2124 default:
2125 return -ENOPROTOOPT;
2126 };
2127
2128 if (put_user(len, optlen))
2129 return -EFAULT;
2130 if (copy_to_user(optval, &val, len))
2131 return -EFAULT;
2132 return 0;
2133 }
2134
2135 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2136 int __user *optlen)
2137 {
2138 struct inet_connection_sock *icsk = inet_csk(sk);
2139
2140 if (level != SOL_TCP)
2141 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2142 optval, optlen);
2143 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2144 }
2145
2146 #ifdef CONFIG_COMPAT
2147 int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2148 char __user *optval, int __user *optlen)
2149 {
2150 if (level != SOL_TCP)
2151 return inet_csk_compat_getsockopt(sk, level, optname,
2152 optval, optlen);
2153 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2154 }
2155
2156 EXPORT_SYMBOL(compat_tcp_getsockopt);
2157 #endif
2158
2159 struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
2160 {
2161 struct sk_buff *segs = ERR_PTR(-EINVAL);
2162 struct tcphdr *th;
2163 unsigned thlen;
2164 unsigned int seq;
2165 __be32 delta;
2166 unsigned int oldlen;
2167 unsigned int len;
2168
2169 if (!pskb_may_pull(skb, sizeof(*th)))
2170 goto out;
2171
2172 th = skb->h.th;
2173 thlen = th->doff * 4;
2174 if (thlen < sizeof(*th))
2175 goto out;
2176
2177 if (!pskb_may_pull(skb, thlen))
2178 goto out;
2179
2180 oldlen = (u16)~skb->len;
2181 __skb_pull(skb, thlen);
2182
2183 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2184 /* Packet is from an untrusted source, reset gso_segs. */
2185 int type = skb_shinfo(skb)->gso_type;
2186 int mss;
2187
2188 if (unlikely(type &
2189 ~(SKB_GSO_TCPV4 |
2190 SKB_GSO_DODGY |
2191 SKB_GSO_TCP_ECN |
2192 SKB_GSO_TCPV6 |
2193 0) ||
2194 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2195 goto out;
2196
2197 mss = skb_shinfo(skb)->gso_size;
2198 skb_shinfo(skb)->gso_segs = (skb->len + mss - 1) / mss;
2199
2200 segs = NULL;
2201 goto out;
2202 }
2203
2204 segs = skb_segment(skb, features);
2205 if (IS_ERR(segs))
2206 goto out;
2207
2208 len = skb_shinfo(skb)->gso_size;
2209 delta = htonl(oldlen + (thlen + len));
2210
2211 skb = segs;
2212 th = skb->h.th;
2213 seq = ntohl(th->seq);
2214
2215 do {
2216 th->fin = th->psh = 0;
2217
2218 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2219 (__force u32)delta));
2220 if (skb->ip_summed != CHECKSUM_PARTIAL)
2221 th->check = csum_fold(csum_partial(skb->h.raw, thlen,
2222 skb->csum));
2223
2224 seq += len;
2225 skb = skb->next;
2226 th = skb->h.th;
2227
2228 th->seq = htonl(seq);
2229 th->cwr = 0;
2230 } while (skb->next);
2231
2232 delta = htonl(oldlen + (skb->tail - skb->h.raw) + skb->data_len);
2233 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2234 (__force u32)delta));
2235 if (skb->ip_summed != CHECKSUM_PARTIAL)
2236 th->check = csum_fold(csum_partial(skb->h.raw, thlen,
2237 skb->csum));
2238
2239 out:
2240 return segs;
2241 }
2242 EXPORT_SYMBOL(tcp_tso_segment);
2243
2244 #ifdef CONFIG_TCP_MD5SIG
2245 static unsigned long tcp_md5sig_users;
2246 static struct tcp_md5sig_pool **tcp_md5sig_pool;
2247 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2248
2249 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
2250 {
2251 int cpu;
2252 for_each_possible_cpu(cpu) {
2253 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2254 if (p) {
2255 if (p->md5_desc.tfm)
2256 crypto_free_hash(p->md5_desc.tfm);
2257 kfree(p);
2258 p = NULL;
2259 }
2260 }
2261 free_percpu(pool);
2262 }
2263
2264 void tcp_free_md5sig_pool(void)
2265 {
2266 struct tcp_md5sig_pool **pool = NULL;
2267
2268 spin_lock_bh(&tcp_md5sig_pool_lock);
2269 if (--tcp_md5sig_users == 0) {
2270 pool = tcp_md5sig_pool;
2271 tcp_md5sig_pool = NULL;
2272 }
2273 spin_unlock_bh(&tcp_md5sig_pool_lock);
2274 if (pool)
2275 __tcp_free_md5sig_pool(pool);
2276 }
2277
2278 EXPORT_SYMBOL(tcp_free_md5sig_pool);
2279
2280 static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
2281 {
2282 int cpu;
2283 struct tcp_md5sig_pool **pool;
2284
2285 pool = alloc_percpu(struct tcp_md5sig_pool *);
2286 if (!pool)
2287 return NULL;
2288
2289 for_each_possible_cpu(cpu) {
2290 struct tcp_md5sig_pool *p;
2291 struct crypto_hash *hash;
2292
2293 p = kzalloc(sizeof(*p), GFP_KERNEL);
2294 if (!p)
2295 goto out_free;
2296 *per_cpu_ptr(pool, cpu) = p;
2297
2298 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2299 if (!hash || IS_ERR(hash))
2300 goto out_free;
2301
2302 p->md5_desc.tfm = hash;
2303 }
2304 return pool;
2305 out_free:
2306 __tcp_free_md5sig_pool(pool);
2307 return NULL;
2308 }
2309
2310 struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
2311 {
2312 struct tcp_md5sig_pool **pool;
2313 int alloc = 0;
2314
2315 retry:
2316 spin_lock_bh(&tcp_md5sig_pool_lock);
2317 pool = tcp_md5sig_pool;
2318 if (tcp_md5sig_users++ == 0) {
2319 alloc = 1;
2320 spin_unlock_bh(&tcp_md5sig_pool_lock);
2321 } else if (!pool) {
2322 tcp_md5sig_users--;
2323 spin_unlock_bh(&tcp_md5sig_pool_lock);
2324 cpu_relax();
2325 goto retry;
2326 } else
2327 spin_unlock_bh(&tcp_md5sig_pool_lock);
2328
2329 if (alloc) {
2330 /* we cannot hold spinlock here because this may sleep. */
2331 struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
2332 spin_lock_bh(&tcp_md5sig_pool_lock);
2333 if (!p) {
2334 tcp_md5sig_users--;
2335 spin_unlock_bh(&tcp_md5sig_pool_lock);
2336 return NULL;
2337 }
2338 pool = tcp_md5sig_pool;
2339 if (pool) {
2340 /* oops, it has already been assigned. */
2341 spin_unlock_bh(&tcp_md5sig_pool_lock);
2342 __tcp_free_md5sig_pool(p);
2343 } else {
2344 tcp_md5sig_pool = pool = p;
2345 spin_unlock_bh(&tcp_md5sig_pool_lock);
2346 }
2347 }
2348 return pool;
2349 }
2350
2351 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2352
2353 struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
2354 {
2355 struct tcp_md5sig_pool **p;
2356 spin_lock_bh(&tcp_md5sig_pool_lock);
2357 p = tcp_md5sig_pool;
2358 if (p)
2359 tcp_md5sig_users++;
2360 spin_unlock_bh(&tcp_md5sig_pool_lock);
2361 return (p ? *per_cpu_ptr(p, cpu) : NULL);
2362 }
2363
2364 EXPORT_SYMBOL(__tcp_get_md5sig_pool);
2365
2366 void __tcp_put_md5sig_pool(void)
2367 {
2368 tcp_free_md5sig_pool();
2369 }
2370
2371 EXPORT_SYMBOL(__tcp_put_md5sig_pool);
2372 #endif
2373
2374 extern void __skb_cb_too_small_for_tcp(int, int);
2375 extern struct tcp_congestion_ops tcp_reno;
2376
2377 static __initdata unsigned long thash_entries;
2378 static int __init set_thash_entries(char *str)
2379 {
2380 if (!str)
2381 return 0;
2382 thash_entries = simple_strtoul(str, &str, 0);
2383 return 1;
2384 }
2385 __setup("thash_entries=", set_thash_entries);
2386
2387 void __init tcp_init(void)
2388 {
2389 struct sk_buff *skb = NULL;
2390 unsigned long limit;
2391 int order, i, max_share;
2392
2393 if (sizeof(struct tcp_skb_cb) > sizeof(skb->cb))
2394 __skb_cb_too_small_for_tcp(sizeof(struct tcp_skb_cb),
2395 sizeof(skb->cb));
2396
2397 tcp_hashinfo.bind_bucket_cachep =
2398 kmem_cache_create("tcp_bind_bucket",
2399 sizeof(struct inet_bind_bucket), 0,
2400 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
2401
2402 /* Size and allocate the main established and bind bucket
2403 * hash tables.
2404 *
2405 * The methodology is similar to that of the buffer cache.
2406 */
2407 tcp_hashinfo.ehash =
2408 alloc_large_system_hash("TCP established",
2409 sizeof(struct inet_ehash_bucket),
2410 thash_entries,
2411 (num_physpages >= 128 * 1024) ?
2412 13 : 15,
2413 0,
2414 &tcp_hashinfo.ehash_size,
2415 NULL,
2416 0);
2417 tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
2418 for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
2419 rwlock_init(&tcp_hashinfo.ehash[i].lock);
2420 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain);
2421 INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain);
2422 }
2423
2424 tcp_hashinfo.bhash =
2425 alloc_large_system_hash("TCP bind",
2426 sizeof(struct inet_bind_hashbucket),
2427 tcp_hashinfo.ehash_size,
2428 (num_physpages >= 128 * 1024) ?
2429 13 : 15,
2430 0,
2431 &tcp_hashinfo.bhash_size,
2432 NULL,
2433 64 * 1024);
2434 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
2435 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
2436 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
2437 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
2438 }
2439
2440 /* Try to be a bit smarter and adjust defaults depending
2441 * on available memory.
2442 */
2443 for (order = 0; ((1 << order) << PAGE_SHIFT) <
2444 (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket));
2445 order++)
2446 ;
2447 if (order >= 4) {
2448 sysctl_local_port_range[0] = 32768;
2449 sysctl_local_port_range[1] = 61000;
2450 tcp_death_row.sysctl_max_tw_buckets = 180000;
2451 sysctl_tcp_max_orphans = 4096 << (order - 4);
2452 sysctl_max_syn_backlog = 1024;
2453 } else if (order < 3) {
2454 sysctl_local_port_range[0] = 1024 * (3 - order);
2455 tcp_death_row.sysctl_max_tw_buckets >>= (3 - order);
2456 sysctl_tcp_max_orphans >>= (3 - order);
2457 sysctl_max_syn_backlog = 128;
2458 }
2459
2460 /* Set the pressure threshold to be a fraction of global memory that
2461 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
2462 * memory, with a floor of 128 pages.
2463 */
2464 limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
2465 limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
2466 limit = max(limit, 128UL);
2467 sysctl_tcp_mem[0] = limit / 4 * 3;
2468 sysctl_tcp_mem[1] = limit;
2469 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
2470
2471 /* Set per-socket limits to no more than 1/128 the pressure threshold */
2472 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
2473 max_share = min(4UL*1024*1024, limit);
2474
2475 sysctl_tcp_wmem[0] = SK_STREAM_MEM_QUANTUM;
2476 sysctl_tcp_wmem[1] = 16*1024;
2477 sysctl_tcp_wmem[2] = max(64*1024, max_share);
2478
2479 sysctl_tcp_rmem[0] = SK_STREAM_MEM_QUANTUM;
2480 sysctl_tcp_rmem[1] = 87380;
2481 sysctl_tcp_rmem[2] = max(87380, max_share);
2482
2483 printk(KERN_INFO "TCP: Hash tables configured "
2484 "(established %d bind %d)\n",
2485 tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
2486
2487 tcp_register_congestion_control(&tcp_reno);
2488 }
2489
2490 EXPORT_SYMBOL(tcp_close);
2491 EXPORT_SYMBOL(tcp_disconnect);
2492 EXPORT_SYMBOL(tcp_getsockopt);
2493 EXPORT_SYMBOL(tcp_ioctl);
2494 EXPORT_SYMBOL(tcp_poll);
2495 EXPORT_SYMBOL(tcp_read_sock);
2496 EXPORT_SYMBOL(tcp_recvmsg);
2497 EXPORT_SYMBOL(tcp_sendmsg);
2498 EXPORT_SYMBOL(tcp_sendpage);
2499 EXPORT_SYMBOL(tcp_setsockopt);
2500 EXPORT_SYMBOL(tcp_shutdown);
2501 EXPORT_SYMBOL(tcp_statistics);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree