?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
GUI: Fix Tomato RAF theme for all builds. Compilation typo.
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / net / ipv4 / tcp.c
blob93cdffcdeef4d9ffe23bb3626a43f86fade7c747
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 #include <linux/time.h>
268 #include <linux/slab.h>
269
270 #include <net/icmp.h>
271 #include <net/tcp.h>
272 #include <net/xfrm.h>
273 #include <net/ip.h>
274 #include <net/netdma.h>
275 #include <net/sock.h>
276
277 #include <asm/uaccess.h>
278 #include <asm/ioctls.h>
279
280 #include <typedefs.h>
281 #include <bcmdefs.h>
282
283 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
284
285 struct percpu_counter tcp_orphan_count;
286 EXPORT_SYMBOL_GPL(tcp_orphan_count);
287
288 int sysctl_tcp_mem[3] __read_mostly;
289 int sysctl_tcp_wmem[3] __read_mostly;
290 int sysctl_tcp_rmem[3] __read_mostly;
291
292 EXPORT_SYMBOL(sysctl_tcp_mem);
293 EXPORT_SYMBOL(sysctl_tcp_rmem);
294 EXPORT_SYMBOL(sysctl_tcp_wmem);
295
296 atomic_t tcp_memory_allocated; /* Current allocated memory. */
297 EXPORT_SYMBOL(tcp_memory_allocated);
298
299 /*
300 * Current number of TCP sockets.
301 */
302 struct percpu_counter tcp_sockets_allocated;
303 EXPORT_SYMBOL(tcp_sockets_allocated);
304
305 /*
306 * TCP splice context
307 */
308 struct tcp_splice_state {
309 struct pipe_inode_info *pipe;
310 size_t len;
311 unsigned int flags;
312 };
313
314 /*
315 * Pressure flag: try to collapse.
316 * Technical note: it is used by multiple contexts non atomically.
317 * All the __sk_mem_schedule() is of this nature: accounting
318 * is strict, actions are advisory and have some latency.
319 */
320 int tcp_memory_pressure __read_mostly;
321 EXPORT_SYMBOL(tcp_memory_pressure);
322
323 void tcp_enter_memory_pressure(struct sock *sk)
324 {
325 if (!tcp_memory_pressure) {
326 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
327 tcp_memory_pressure = 1;
328 }
329 }
330 EXPORT_SYMBOL(tcp_enter_memory_pressure);
331
332 /* Convert seconds to retransmits based on initial and max timeout */
333 static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
334 {
335 u8 res = 0;
336
337 if (seconds > 0) {
338 int period = timeout;
339
340 res = 1;
341 while (seconds > period && res < 255) {
342 res++;
343 timeout <<= 1;
344 if (timeout > rto_max)
345 timeout = rto_max;
346 period += timeout;
347 }
348 }
349 return res;
350 }
351
352 /* Convert retransmits to seconds based on initial and max timeout */
353 static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
354 {
355 int period = 0;
356
357 if (retrans > 0) {
358 period = timeout;
359 while (--retrans) {
360 timeout <<= 1;
361 if (timeout > rto_max)
362 timeout = rto_max;
363 period += timeout;
364 }
365 }
366 return period;
367 }
368
369 /*
370 * Wait for a TCP event.
371 *
372 * Note that we don't need to lock the socket, as the upper poll layers
373 * take care of normal races (between the test and the event) and we don't
374 * go look at any of the socket buffers directly.
375 */
376 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
377 {
378 unsigned int mask;
379 struct sock *sk = sock->sk;
380 struct tcp_sock *tp = tcp_sk(sk);
381
382 sock_poll_wait(file, sk_sleep(sk), wait);
383 if (sk->sk_state == TCP_LISTEN)
384 return inet_csk_listen_poll(sk);
385
386 /* Socket is not locked. We are protected from async events
387 * by poll logic and correct handling of state changes
388 * made by other threads is impossible in any case.
389 */
390
391 mask = 0;
392
393 /*
394 * POLLHUP is certainly not done right. But poll() doesn't
395 * have a notion of HUP in just one direction, and for a
396 * socket the read side is more interesting.
397 *
398 * Some poll() documentation says that POLLHUP is incompatible
399 * with the POLLOUT/POLLWR flags, so somebody should check this
400 * all. But careful, it tends to be safer to return too many
401 * bits than too few, and you can easily break real applications
402 * if you don't tell them that something has hung up!
403 *
404 * Check-me.
405 *
406 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
407 * our fs/select.c). It means that after we received EOF,
408 * poll always returns immediately, making impossible poll() on write()
409 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
410 * if and only if shutdown has been made in both directions.
411 * Actually, it is interesting to look how Solaris and DUX
412 * solve this dilemma. I would prefer, if POLLHUP were maskable,
413 * then we could set it on SND_SHUTDOWN. BTW examples given
414 * in Stevens' books assume exactly this behaviour, it explains
415 * why POLLHUP is incompatible with POLLOUT. --ANK
416 *
417 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
418 * blocking on fresh not-connected or disconnected socket. --ANK
419 */
420 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
421 mask |= POLLHUP;
422 if (sk->sk_shutdown & RCV_SHUTDOWN)
423 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
424
425 /* Connected? */
426 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
427 int target = sock_rcvlowat(sk, 0, INT_MAX);
428
429 if (tp->urg_seq == tp->copied_seq &&
430 !sock_flag(sk, SOCK_URGINLINE) &&
431 tp->urg_data)
432 target++;
433
434 /* Potential race condition. If read of tp below will
435 * escape above sk->sk_state, we can be illegally awaken
436 * in SYN_* states. */
437 if (tp->rcv_nxt - tp->copied_seq >= target)
438 mask |= POLLIN | POLLRDNORM;
439
440 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
441 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
442 mask |= POLLOUT | POLLWRNORM;
443 } else { /* send SIGIO later */
444 set_bit(SOCK_ASYNC_NOSPACE,
445 &sk->sk_socket->flags);
446 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
447
448 /* Race breaker. If space is freed after
449 * wspace test but before the flags are set,
450 * IO signal will be lost.
451 */
452 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
453 mask |= POLLOUT | POLLWRNORM;
454 }
455 } else
456 mask |= POLLOUT | POLLWRNORM;
457
458 if (tp->urg_data & TCP_URG_VALID)
459 mask |= POLLPRI;
460 }
461 /* This barrier is coupled with smp_wmb() in tcp_reset() */
462 smp_rmb();
463 if (sk->sk_err)
464 mask |= POLLERR;
465
466 return mask;
467 }
468 EXPORT_SYMBOL(tcp_poll);
469
470 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
471 {
472 struct tcp_sock *tp = tcp_sk(sk);
473 int answ;
474
475 switch (cmd) {
476 case SIOCINQ:
477 if (sk->sk_state == TCP_LISTEN)
478 return -EINVAL;
479
480 lock_sock(sk);
481 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
482 answ = 0;
483 else if (sock_flag(sk, SOCK_URGINLINE) ||
484 !tp->urg_data ||
485 before(tp->urg_seq, tp->copied_seq) ||
486 !before(tp->urg_seq, tp->rcv_nxt)) {
487 struct sk_buff *skb;
488
489 answ = tp->rcv_nxt - tp->copied_seq;
490
491 /* Subtract 1, if FIN is in queue. */
492 skb = skb_peek_tail(&sk->sk_receive_queue);
493 if (answ && skb)
494 answ -= tcp_hdr(skb)->fin;
495 } else
496 answ = tp->urg_seq - tp->copied_seq;
497 release_sock(sk);
498 break;
499 case SIOCATMARK:
500 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
501 break;
502 case SIOCOUTQ:
503 if (sk->sk_state == TCP_LISTEN)
504 return -EINVAL;
505
506 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
507 answ = 0;
508 else
509 answ = tp->write_seq - tp->snd_una;
510 break;
511 default:
512 return -ENOIOCTLCMD;
513 }
514
515 return put_user(answ, (int __user *)arg);
516 }
517 EXPORT_SYMBOL(tcp_ioctl);
518
519 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
520 {
521 TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
522 tp->pushed_seq = tp->write_seq;
523 }
524
525 static inline int forced_push(struct tcp_sock *tp)
526 {
527 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
528 }
529
530 static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
531 {
532 struct tcp_sock *tp = tcp_sk(sk);
533 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
534
535 skb->csum = 0;
536 tcb->seq = tcb->end_seq = tp->write_seq;
537 tcb->flags = TCPHDR_ACK;
538 tcb->sacked = 0;
539 skb_header_release(skb);
540 tcp_add_write_queue_tail(sk, skb);
541 sk->sk_wmem_queued += skb->truesize;
542 sk_mem_charge(sk, skb->truesize);
543 if (tp->nonagle & TCP_NAGLE_PUSH)
544 tp->nonagle &= ~TCP_NAGLE_PUSH;
545 }
546
547 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
548 {
549 if (flags & MSG_OOB)
550 tp->snd_up = tp->write_seq;
551 }
552
553 static inline void tcp_push(struct sock *sk, int flags, int mss_now,
554 int nonagle)
555 {
556 if (tcp_send_head(sk)) {
557 struct tcp_sock *tp = tcp_sk(sk);
558
559 if (!(flags & MSG_MORE) || forced_push(tp))
560 tcp_mark_push(tp, tcp_write_queue_tail(sk));
561
562 tcp_mark_urg(tp, flags);
563 __tcp_push_pending_frames(sk, mss_now,
564 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
565 }
566 }
567
568 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
569 unsigned int offset, size_t len)
570 {
571 struct tcp_splice_state *tss = rd_desc->arg.data;
572 int ret;
573
574 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
575 tss->flags);
576 if (ret > 0)
577 rd_desc->count -= ret;
578 return ret;
579 }
580
581 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
582 {
583 /* Store TCP splice context information in read_descriptor_t. */
584 read_descriptor_t rd_desc = {
585 .arg.data = tss,
586 .count = tss->len,
587 };
588
589 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
590 }
591
592 /**
593 * tcp_splice_read - splice data from TCP socket to a pipe
594 * @sock: socket to splice from
595 * @ppos: position (not valid)
596 * @pipe: pipe to splice to
597 * @len: number of bytes to splice
598 * @flags: splice modifier flags
599 *
600 * Description:
601 * Will read pages from given socket and fill them into a pipe.
602 *
603 **/
604 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
605 struct pipe_inode_info *pipe, size_t len,
606 unsigned int flags)
607 {
608 struct sock *sk = sock->sk;
609 struct tcp_splice_state tss = {
610 .pipe = pipe,
611 .len = len,
612 .flags = flags,
613 };
614 long timeo;
615 ssize_t spliced;
616 int ret;
617
618 sock_rps_record_flow(sk);
619 /*
620 * We can't seek on a socket input
621 */
622 if (unlikely(*ppos))
623 return -ESPIPE;
624
625 ret = spliced = 0;
626
627 lock_sock(sk);
628
629 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
630 while (tss.len) {
631 ret = __tcp_splice_read(sk, &tss);
632 if (ret < 0)
633 break;
634 else if (!ret) {
635 if (spliced)
636 break;
637 if (sock_flag(sk, SOCK_DONE))
638 break;
639 if (sk->sk_err) {
640 ret = sock_error(sk);
641 break;
642 }
643 if (sk->sk_shutdown & RCV_SHUTDOWN)
644 break;
645 if (sk->sk_state == TCP_CLOSE) {
646 /*
647 * This occurs when user tries to read
648 * from never connected socket.
649 */
650 if (!sock_flag(sk, SOCK_DONE))
651 ret = -ENOTCONN;
652 break;
653 }
654 if (!timeo) {
655 ret = -EAGAIN;
656 break;
657 }
658 sk_wait_data(sk, &timeo);
659 if (signal_pending(current)) {
660 ret = sock_intr_errno(timeo);
661 break;
662 }
663 continue;
664 }
665 tss.len -= ret;
666 spliced += ret;
667
668 if (!timeo)
669 break;
670 release_sock(sk);
671 lock_sock(sk);
672
673 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
674 (sk->sk_shutdown & RCV_SHUTDOWN) ||
675 signal_pending(current))
676 break;
677 }
678
679 release_sock(sk);
680
681 if (spliced)
682 return spliced;
683
684 return ret;
685 }
686 EXPORT_SYMBOL(tcp_splice_read);
687
688 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
689 {
690 struct sk_buff *skb;
691
692 /* The TCP header must be at least 32-bit aligned. */
693 size = ALIGN(size, 4);
694
695 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
696 if (skb) {
697 if (sk_wmem_schedule(sk, skb->truesize)) {
698 /*
699 * Make sure that we have exactly size bytes
700 * available to the caller, no more, no less.
701 */
702 skb_reserve(skb, skb_tailroom(skb) - size);
703 return skb;
704 }
705 __kfree_skb(skb);
706 } else {
707 sk->sk_prot->enter_memory_pressure(sk);
708 sk_stream_moderate_sndbuf(sk);
709 }
710 return NULL;
711 }
712
713 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
714 int large_allowed)
715 {
716 struct tcp_sock *tp = tcp_sk(sk);
717 u32 xmit_size_goal, old_size_goal;
718
719 xmit_size_goal = mss_now;
720
721 if (large_allowed && sk_can_gso(sk)) {
722 xmit_size_goal = ((sk->sk_gso_max_size - 1) -
723 inet_csk(sk)->icsk_af_ops->net_header_len -
724 inet_csk(sk)->icsk_ext_hdr_len -
725 tp->tcp_header_len);
726
727 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
728
729 /* We try hard to avoid divides here */
730 old_size_goal = tp->xmit_size_goal_segs * mss_now;
731
732 if (likely(old_size_goal <= xmit_size_goal &&
733 old_size_goal + mss_now > xmit_size_goal)) {
734 xmit_size_goal = old_size_goal;
735 } else {
736 tp->xmit_size_goal_segs = xmit_size_goal / mss_now;
737 xmit_size_goal = tp->xmit_size_goal_segs * mss_now;
738 }
739 }
740
741 return max(xmit_size_goal, mss_now);
742 }
743
744 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
745 {
746 int mss_now;
747
748 mss_now = tcp_current_mss(sk);
749 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
750
751 return mss_now;
752 }
753
754 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
755 size_t psize, int flags)
756 {
757 struct tcp_sock *tp = tcp_sk(sk);
758 int mss_now, size_goal;
759 int err;
760 ssize_t copied;
761 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
762
763 /* Wait for a connection to finish. */
764 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
765 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
766 goto out_err;
767
768 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
769
770 mss_now = tcp_send_mss(sk, &size_goal, flags);
771 copied = 0;
772
773 err = -EPIPE;
774 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
775 goto out_err;
776
777 while (psize > 0) {
778 struct sk_buff *skb = tcp_write_queue_tail(sk);
779 struct page *page = pages[poffset / PAGE_SIZE];
780 int copy, i, can_coalesce;
781 int offset = poffset % PAGE_SIZE;
782 int size = min_t(size_t, psize, PAGE_SIZE - offset);
783
784 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
785 new_segment:
786 if (!sk_stream_memory_free(sk))
787 goto wait_for_sndbuf;
788
789 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
790 if (!skb)
791 goto wait_for_memory;
792
793 skb_entail(sk, skb);
794 copy = size_goal;
795 }
796
797 if (copy > size)
798 copy = size;
799
800 i = skb_shinfo(skb)->nr_frags;
801 can_coalesce = skb_can_coalesce(skb, i, page, offset);
802 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
803 tcp_mark_push(tp, skb);
804 goto new_segment;
805 }
806 if (!sk_wmem_schedule(sk, copy))
807 goto wait_for_memory;
808
809 if (can_coalesce) {
810 skb_shinfo(skb)->frags[i - 1].size += copy;
811 } else {
812 get_page(page);
813 skb_fill_page_desc(skb, i, page, offset, copy);
814 }
815
816 skb->len += copy;
817 skb->data_len += copy;
818 skb->truesize += copy;
819 sk->sk_wmem_queued += copy;
820 sk_mem_charge(sk, copy);
821 skb->ip_summed = CHECKSUM_PARTIAL;
822 tp->write_seq += copy;
823 TCP_SKB_CB(skb)->end_seq += copy;
824 skb_shinfo(skb)->gso_segs = 0;
825
826 if (!copied)
827 TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
828
829 copied += copy;
830 poffset += copy;
831 if (!(psize -= copy))
832 goto out;
833
834 if (skb->len < size_goal || (flags & MSG_OOB))
835 continue;
836
837 if (forced_push(tp)) {
838 tcp_mark_push(tp, skb);
839 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
840 } else if (skb == tcp_send_head(sk))
841 tcp_push_one(sk, mss_now);
842 continue;
843
844 wait_for_sndbuf:
845 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
846 wait_for_memory:
847 if (copied)
848 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
849
850 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
851 goto do_error;
852
853 mss_now = tcp_send_mss(sk, &size_goal, flags);
854 }
855
856 out:
857 #ifdef CONFIG_BCM47XX
858 if (copied && !(flags & MSG_MORE))
859 #else
860 if (copied)
861 #endif
862 tcp_push(sk, flags, mss_now, tp->nonagle);
863 return copied;
864
865 do_error:
866 if (copied)
867 goto out;
868 out_err:
869 return sk_stream_error(sk, flags, err);
870 }
871
872 int BCMFASTPATH_HOST tcp_sendpage(struct sock *sk, struct page *page, int offset,
873 size_t size, int flags)
874 {
875 ssize_t res;
876
877 if (!(sk->sk_route_caps & NETIF_F_SG) ||
878 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
879 return sock_no_sendpage(sk->sk_socket, page, offset, size,
880 flags);
881
882 lock_sock(sk);
883 TCP_CHECK_TIMER(sk);
884 res = do_tcp_sendpages(sk, &page, offset, size, flags);
885 TCP_CHECK_TIMER(sk);
886 release_sock(sk);
887 return res;
888 }
889 EXPORT_SYMBOL(tcp_sendpage);
890
891 #define TCP_PAGE(sk) (sk->sk_sndmsg_page)
892 #define TCP_OFF(sk) (sk->sk_sndmsg_off)
893
894 static inline int select_size(struct sock *sk, int sg)
895 {
896 struct tcp_sock *tp = tcp_sk(sk);
897 int tmp = tp->mss_cache;
898
899 if (sg) {
900 if (sk_can_gso(sk))
901 tmp = 0;
902 else {
903 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
904
905 if (tmp >= pgbreak &&
906 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
907 tmp = pgbreak;
908 }
909 }
910
911 return tmp;
912 }
913
914 int BCMFASTPATH_HOST tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
915 size_t size)
916 {
917 struct iovec *iov;
918 struct tcp_sock *tp = tcp_sk(sk);
919 struct sk_buff *skb;
920 int iovlen, flags;
921 int mss_now, size_goal;
922 int sg, err, copied;
923 long timeo;
924
925 lock_sock(sk);
926 TCP_CHECK_TIMER(sk);
927
928 flags = msg->msg_flags;
929 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
930
931 /* Wait for a connection to finish. */
932 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
933 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
934 goto out_err;
935
936 /* This should be in poll */
937 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
938
939 mss_now = tcp_send_mss(sk, &size_goal, flags);
940
941 /* Ok commence sending. */
942 iovlen = msg->msg_iovlen;
943 iov = msg->msg_iov;
944 copied = 0;
945
946 err = -EPIPE;
947 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
948 goto out_err;
949
950 sg = sk->sk_route_caps & NETIF_F_SG;
951
952 while (--iovlen >= 0) {
953 size_t seglen = iov->iov_len;
954 unsigned char __user *from = iov->iov_base;
955
956 iov++;
957
958 while (seglen > 0) {
959 int copy = 0;
960 int max = size_goal;
961
962 skb = tcp_write_queue_tail(sk);
963 if (tcp_send_head(sk)) {
964 if (skb->ip_summed == CHECKSUM_NONE)
965 max = mss_now;
966 copy = max - skb->len;
967 }
968
969 if (copy <= 0) {
970 new_segment:
971 /* Allocate new segment. If the interface is SG,
972 * allocate skb fitting to single page.
973 */
974 if (!sk_stream_memory_free(sk))
975 goto wait_for_sndbuf;
976
977 skb = sk_stream_alloc_skb(sk,
978 select_size(sk, sg),
979 sk->sk_allocation);
980 if (!skb)
981 goto wait_for_memory;
982
983 /*
984 * Check whether we can use HW checksum.
985 */
986 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
987 skb->ip_summed = CHECKSUM_PARTIAL;
988
989 skb_entail(sk, skb);
990 copy = size_goal;
991 max = size_goal;
992 }
993
994 /* Try to append data to the end of skb. */
995 if (copy > seglen)
996 copy = seglen;
997
998 /* Where to copy to? */
999 if (skb_tailroom(skb) > 0) {
1000 /* We have some space in skb head. Superb! */
1001 if (copy > skb_tailroom(skb))
1002 copy = skb_tailroom(skb);
1003 if ((err = skb_add_data(skb, from, copy)) != 0)
1004 goto do_fault;
1005 } else {
1006 int merge = 0;
1007 int i = skb_shinfo(skb)->nr_frags;
1008 struct page *page = TCP_PAGE(sk);
1009 int off = TCP_OFF(sk);
1010
1011 if (skb_can_coalesce(skb, i, page, off) &&
1012 off != PAGE_SIZE) {
1013 /* We can extend the last page
1014 * fragment. */
1015 merge = 1;
1016 } else if (i == MAX_SKB_FRAGS || !sg) {
1017 /* Need to add new fragment and cannot
1018 * do this because interface is non-SG,
1019 * or because all the page slots are
1020 * busy. */
1021 tcp_mark_push(tp, skb);
1022 goto new_segment;
1023 } else if (page) {
1024 if (off == PAGE_SIZE) {
1025 put_page(page);
1026 TCP_PAGE(sk) = page = NULL;
1027 off = 0;
1028 }
1029 } else
1030 off = 0;
1031
1032 if (copy > PAGE_SIZE - off)
1033 copy = PAGE_SIZE - off;
1034
1035 if (!sk_wmem_schedule(sk, copy))
1036 goto wait_for_memory;
1037
1038 if (!page) {
1039 /* Allocate new cache page. */
1040 if (!(page = sk_stream_alloc_page(sk)))
1041 goto wait_for_memory;
1042 }
1043
1044 /* Time to copy data. We are close to
1045 * the end! */
1046 err = skb_copy_to_page(sk, from, skb, page,
1047 off, copy);
1048 if (err) {
1049 /* If this page was new, give it to the
1050 * socket so it does not get leaked.
1051 */
1052 if (!TCP_PAGE(sk)) {
1053 TCP_PAGE(sk) = page;
1054 TCP_OFF(sk) = 0;
1055 }
1056 goto do_error;
1057 }
1058
1059 /* Update the skb. */
1060 if (merge) {
1061 skb_shinfo(skb)->frags[i - 1].size +=
1062 copy;
1063 } else {
1064 skb_fill_page_desc(skb, i, page, off, copy);
1065 if (TCP_PAGE(sk)) {
1066 get_page(page);
1067 } else if (off + copy < PAGE_SIZE) {
1068 get_page(page);
1069 TCP_PAGE(sk) = page;
1070 }
1071 }
1072
1073 TCP_OFF(sk) = off + copy;
1074 }
1075
1076 if (!copied)
1077 TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
1078
1079 tp->write_seq += copy;
1080 TCP_SKB_CB(skb)->end_seq += copy;
1081 skb_shinfo(skb)->gso_segs = 0;
1082
1083 from += copy;
1084 copied += copy;
1085 if ((seglen -= copy) == 0 && iovlen == 0)
1086 goto out;
1087
1088 if (skb->len < max || (flags & MSG_OOB))
1089 continue;
1090
1091 if (forced_push(tp)) {
1092 tcp_mark_push(tp, skb);
1093 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1094 } else if (skb == tcp_send_head(sk))
1095 tcp_push_one(sk, mss_now);
1096 continue;
1097
1098 wait_for_sndbuf:
1099 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1100 wait_for_memory:
1101 if (copied)
1102 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
1103
1104 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1105 goto do_error;
1106
1107 mss_now = tcp_send_mss(sk, &size_goal, flags);
1108 }
1109 }
1110
1111 out:
1112 if (copied)
1113 tcp_push(sk, flags, mss_now, tp->nonagle);
1114 TCP_CHECK_TIMER(sk);
1115 release_sock(sk);
1116 return copied;
1117
1118 do_fault:
1119 if (!skb->len) {
1120 tcp_unlink_write_queue(skb, sk);
1121 /* It is the one place in all of TCP, except connection
1122 * reset, where we can be unlinking the send_head.
1123 */
1124 tcp_check_send_head(sk, skb);
1125 sk_wmem_free_skb(sk, skb);
1126 }
1127
1128 do_error:
1129 if (copied)
1130 goto out;
1131 out_err:
1132 err = sk_stream_error(sk, flags, err);
1133 TCP_CHECK_TIMER(sk);
1134 release_sock(sk);
1135 return err;
1136 }
1137 EXPORT_SYMBOL(tcp_sendmsg);
1138
1139 /*
1140 * Handle reading urgent data. BSD has very simple semantics for
1141 * this, no blocking and very strange errors 8)
1142 */
1143
1144 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1145 {
1146 struct tcp_sock *tp = tcp_sk(sk);
1147
1148 /* No URG data to read. */
1149 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1150 tp->urg_data == TCP_URG_READ)
1151 return -EINVAL; /* Yes this is right ! */
1152
1153 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1154 return -ENOTCONN;
1155
1156 if (tp->urg_data & TCP_URG_VALID) {
1157 int err = 0;
1158 char c = tp->urg_data;
1159
1160 if (!(flags & MSG_PEEK))
1161 tp->urg_data = TCP_URG_READ;
1162
1163 /* Read urgent data. */
1164 msg->msg_flags |= MSG_OOB;
1165
1166 if (len > 0) {
1167 if (!(flags & MSG_TRUNC))
1168 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1169 len = 1;
1170 } else
1171 msg->msg_flags |= MSG_TRUNC;
1172
1173 return err ? -EFAULT : len;
1174 }
1175
1176 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1177 return 0;
1178
1179 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1180 * the available implementations agree in this case:
1181 * this call should never block, independent of the
1182 * blocking state of the socket.
1183 * Mike <pall@rz.uni-karlsruhe.de>
1184 */
1185 return -EAGAIN;
1186 }
1187
1188 /* Clean up the receive buffer for full frames taken by the user,
1189 * then send an ACK if necessary. COPIED is the number of bytes
1190 * tcp_recvmsg has given to the user so far, it speeds up the
1191 * calculation of whether or not we must ACK for the sake of
1192 * a window update.
1193 */
1194 void tcp_cleanup_rbuf(struct sock *sk, int copied)
1195 {
1196 struct tcp_sock *tp = tcp_sk(sk);
1197 int time_to_ack = 0;
1198
1199 #if TCP_DEBUG
1200 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1201
1202 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1203 KERN_INFO "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1204 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1205 #endif
1206
1207 if (inet_csk_ack_scheduled(sk)) {
1208 const struct inet_connection_sock *icsk = inet_csk(sk);
1209 /* Delayed ACKs frequently hit locked sockets during bulk
1210 * receive. */
1211 if (icsk->icsk_ack.blocked ||
1212 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1213 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1214 /*
1215 * If this read emptied read buffer, we send ACK, if
1216 * connection is not bidirectional, user drained
1217 * receive buffer and there was a small segment
1218 * in queue.
1219 */
1220 (copied > 0 &&
1221 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1222 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1223 !icsk->icsk_ack.pingpong)) &&
1224 !atomic_read(&sk->sk_rmem_alloc)))
1225 time_to_ack = 1;
1226 }
1227
1228 /* We send an ACK if we can now advertise a non-zero window
1229 * which has been raised "significantly".
1230 *
1231 * Even if window raised up to infinity, do not send window open ACK
1232 * in states, where we will not receive more. It is useless.
1233 */
1234 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1235 __u32 rcv_window_now = tcp_receive_window(tp);
1236
1237 /* Optimize, __tcp_select_window() is not cheap. */
1238 if (2*rcv_window_now <= tp->window_clamp) {
1239 __u32 new_window = __tcp_select_window(sk);
1240
1241 /* Send ACK now, if this read freed lots of space
1242 * in our buffer. Certainly, new_window is new window.
1243 * We can advertise it now, if it is not less than current one.
1244 * "Lots" means "at least twice" here.
1245 */
1246 if (new_window && new_window >= 2 * rcv_window_now)
1247 time_to_ack = 1;
1248 }
1249 }
1250 if (time_to_ack)
1251 tcp_send_ack(sk);
1252 }
1253
1254 static void tcp_prequeue_process(struct sock *sk)
1255 {
1256 struct sk_buff *skb;
1257 struct tcp_sock *tp = tcp_sk(sk);
1258
1259 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
1260
1261 /* RX process wants to run with disabled BHs, though it is not
1262 * necessary */
1263 local_bh_disable();
1264 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1265 sk_backlog_rcv(sk, skb);
1266 local_bh_enable();
1267
1268 /* Clear memory counter. */
1269 tp->ucopy.memory = 0;
1270 }
1271
1272 #ifdef CONFIG_NET_DMA
1273 static void tcp_service_net_dma(struct sock *sk, bool wait)
1274 {
1275 dma_cookie_t done, used;
1276 dma_cookie_t last_issued;
1277 struct tcp_sock *tp = tcp_sk(sk);
1278
1279 if (!tp->ucopy.dma_chan)
1280 return;
1281
1282 last_issued = tp->ucopy.dma_cookie;
1283 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1284
1285 do {
1286 if (dma_async_memcpy_complete(tp->ucopy.dma_chan,
1287 last_issued, &done,
1288 &used) == DMA_SUCCESS) {
1289 /* Safe to free early-copied skbs now */
1290 __skb_queue_purge(&sk->sk_async_wait_queue);
1291 break;
1292 } else {
1293 struct sk_buff *skb;
1294 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1295 (dma_async_is_complete(skb->dma_cookie, done,
1296 used) == DMA_SUCCESS)) {
1297 __skb_dequeue(&sk->sk_async_wait_queue);
1298 kfree_skb(skb);
1299 }
1300 }
1301 } while (wait);
1302 }
1303 #endif
1304
1305 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1306 {
1307 struct sk_buff *skb;
1308 u32 offset;
1309
1310 skb_queue_walk(&sk->sk_receive_queue, skb) {
1311 offset = seq - TCP_SKB_CB(skb)->seq;
1312 if (tcp_hdr(skb)->syn)
1313 offset--;
1314 if (offset < skb->len || tcp_hdr(skb)->fin) {
1315 *off = offset;
1316 return skb;
1317 }
1318 }
1319 return NULL;
1320 }
1321
1322 /*
1323 * This routine provides an alternative to tcp_recvmsg() for routines
1324 * that would like to handle copying from skbuffs directly in 'sendfile'
1325 * fashion.
1326 * Note:
1327 * - It is assumed that the socket was locked by the caller.
1328 * - The routine does not block.
1329 * - At present, there is no support for reading OOB data
1330 * or for 'peeking' the socket using this routine
1331 * (although both would be easy to implement).
1332 */
1333 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1334 sk_read_actor_t recv_actor)
1335 {
1336 struct sk_buff *skb;
1337 struct tcp_sock *tp = tcp_sk(sk);
1338 u32 seq = tp->copied_seq;
1339 u32 offset;
1340 int copied = 0;
1341
1342 if (sk->sk_state == TCP_LISTEN)
1343 return -ENOTCONN;
1344 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1345 if (offset < skb->len) {
1346 int used;
1347 size_t len;
1348
1349 len = skb->len - offset;
1350 /* Stop reading if we hit a patch of urgent data */
1351 if (tp->urg_data) {
1352 u32 urg_offset = tp->urg_seq - seq;
1353 if (urg_offset < len)
1354 len = urg_offset;
1355 if (!len)
1356 break;
1357 }
1358 used = recv_actor(desc, skb, offset, len);
1359 if (used < 0) {
1360 if (!copied)
1361 copied = used;
1362 break;
1363 } else if (used <= len) {
1364 seq += used;
1365 copied += used;
1366 offset += used;
1367 }
1368 /*
1369 * If recv_actor drops the lock (e.g. TCP splice
1370 * receive) the skb pointer might be invalid when
1371 * getting here: tcp_collapse might have deleted it
1372 * while aggregating skbs from the socket queue.
1373 */
1374 skb = tcp_recv_skb(sk, seq-1, &offset);
1375 if (!skb || (offset+1 != skb->len))
1376 break;
1377 }
1378 if (tcp_hdr(skb)->fin) {
1379 sk_eat_skb(sk, skb, 0);
1380 ++seq;
1381 break;
1382 }
1383 sk_eat_skb(sk, skb, 0);
1384 if (!desc->count)
1385 break;
1386 tp->copied_seq = seq;
1387 }
1388 tp->copied_seq = seq;
1389
1390 tcp_rcv_space_adjust(sk);
1391
1392 /* Clean up data we have read: This will do ACK frames. */
1393 if (copied > 0)
1394 tcp_cleanup_rbuf(sk, copied);
1395 return copied;
1396 }
1397 EXPORT_SYMBOL(tcp_read_sock);
1398
1399 /*
1400 * This routine copies from a sock struct into the user buffer.
1401 *
1402 * Technical note: in 2.3 we work on _locked_ socket, so that
1403 * tricks with *seq access order and skb->users are not required.
1404 * Probably, code can be easily improved even more.
1405 */
1406
1407 int BCMFASTPATH_HOST tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1408 size_t len, int nonblock, int flags, int *addr_len)
1409 {
1410 struct tcp_sock *tp = tcp_sk(sk);
1411 int copied = 0;
1412 u32 peek_seq;
1413 u32 *seq;
1414 unsigned long used;
1415 int err;
1416 int target; /* Read at least this many bytes */
1417 long timeo;
1418 struct task_struct *user_recv = NULL;
1419 int copied_early = 0;
1420 struct sk_buff *skb;
1421 u32 urg_hole = 0;
1422
1423 lock_sock(sk);
1424
1425 TCP_CHECK_TIMER(sk);
1426
1427 err = -ENOTCONN;
1428 if (sk->sk_state == TCP_LISTEN)
1429 goto out;
1430
1431 timeo = sock_rcvtimeo(sk, nonblock);
1432
1433 /* Urgent data needs to be handled specially. */
1434 if (flags & MSG_OOB)
1435 goto recv_urg;
1436
1437 seq = &tp->copied_seq;
1438 if (flags & MSG_PEEK) {
1439 peek_seq = tp->copied_seq;
1440 seq = &peek_seq;
1441 }
1442
1443 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1444
1445 #ifdef CONFIG_NET_DMA
1446 tp->ucopy.dma_chan = NULL;
1447 preempt_disable();
1448 skb = skb_peek_tail(&sk->sk_receive_queue);
1449 {
1450 int available = 0;
1451
1452 if (skb)
1453 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1454 if ((available < target) &&
1455 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1456 !sysctl_tcp_low_latency &&
1457 dma_find_channel(DMA_MEMCPY)) {
1458 preempt_enable_no_resched();
1459 tp->ucopy.pinned_list =
1460 dma_pin_iovec_pages(msg->msg_iov, len);
1461 } else {
1462 preempt_enable_no_resched();
1463 }
1464 }
1465 #endif
1466
1467 do {
1468 u32 offset;
1469
1470 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1471 if (tp->urg_data && tp->urg_seq == *seq) {
1472 if (copied)
1473 break;
1474 if (signal_pending(current)) {
1475 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1476 break;
1477 }
1478 }
1479
1480 /* Next get a buffer. */
1481
1482 skb_queue_walk(&sk->sk_receive_queue, skb) {
1483 /* Now that we have two receive queues this
1484 * shouldn't happen.
1485 */
1486 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1487 KERN_INFO "recvmsg bug: copied %X "
1488 "seq %X rcvnxt %X fl %X\n", *seq,
1489 TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1490 flags))
1491 break;
1492
1493 offset = *seq - TCP_SKB_CB(skb)->seq;
1494 if (tcp_hdr(skb)->syn)
1495 offset--;
1496 if (offset < skb->len)
1497 goto found_ok_skb;
1498 if (tcp_hdr(skb)->fin)
1499 goto found_fin_ok;
1500 WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: "
1501 "copied %X seq %X rcvnxt %X fl %X\n",
1502 *seq, TCP_SKB_CB(skb)->seq,
1503 tp->rcv_nxt, flags);
1504 }
1505
1506 /* Well, if we have backlog, try to process it now yet. */
1507
1508 if (copied >= target && !sk->sk_backlog.tail)
1509 break;
1510
1511 if (copied) {
1512 if (sk->sk_err ||
1513 sk->sk_state == TCP_CLOSE ||
1514 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1515 !timeo ||
1516 signal_pending(current))
1517 break;
1518 } else {
1519 if (sock_flag(sk, SOCK_DONE))
1520 break;
1521
1522 if (sk->sk_err) {
1523 copied = sock_error(sk);
1524 break;
1525 }
1526
1527 if (sk->sk_shutdown & RCV_SHUTDOWN)
1528 break;
1529
1530 if (sk->sk_state == TCP_CLOSE) {
1531 if (!sock_flag(sk, SOCK_DONE)) {
1532 /* This occurs when user tries to read
1533 * from never connected socket.
1534 */
1535 copied = -ENOTCONN;
1536 break;
1537 }
1538 break;
1539 }
1540
1541 if (!timeo) {
1542 copied = -EAGAIN;
1543 break;
1544 }
1545
1546 if (signal_pending(current)) {
1547 copied = sock_intr_errno(timeo);
1548 break;
1549 }
1550 }
1551
1552 tcp_cleanup_rbuf(sk, copied);
1553
1554 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1555 /* Install new reader */
1556 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1557 user_recv = current;
1558 tp->ucopy.task = user_recv;
1559 tp->ucopy.iov = msg->msg_iov;
1560 }
1561
1562 tp->ucopy.len = len;
1563
1564 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1565 !(flags & (MSG_PEEK | MSG_TRUNC)));
1566
1567 /* Ugly... If prequeue is not empty, we have to
1568 * process it before releasing socket, otherwise
1569 * order will be broken at second iteration.
1570 * More elegant solution is required!!!
1571 *
1572 * Look: we have the following (pseudo)queues:
1573 *
1574 * 1. packets in flight
1575 * 2. backlog
1576 * 3. prequeue
1577 * 4. receive_queue
1578 *
1579 * Each queue can be processed only if the next ones
1580 * are empty. At this point we have empty receive_queue.
1581 * But prequeue _can_ be not empty after 2nd iteration,
1582 * when we jumped to start of loop because backlog
1583 * processing added something to receive_queue.
1584 * We cannot release_sock(), because backlog contains
1585 * packets arrived _after_ prequeued ones.
1586 *
1587 * Shortly, algorithm is clear --- to process all
1588 * the queues in order. We could make it more directly,
1589 * requeueing packets from backlog to prequeue, if
1590 * is not empty. It is more elegant, but eats cycles,
1591 * unfortunately.
1592 */
1593 if (!skb_queue_empty(&tp->ucopy.prequeue))
1594 goto do_prequeue;
1595
1596 /* __ Set realtime policy in scheduler __ */
1597 }
1598
1599 #ifdef CONFIG_NET_DMA
1600 if (tp->ucopy.dma_chan)
1601 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1602 #endif
1603 if (copied >= target) {
1604 /* Do not sleep, just process backlog. */
1605 release_sock(sk);
1606 lock_sock(sk);
1607 } else
1608 sk_wait_data(sk, &timeo);
1609
1610 #ifdef CONFIG_NET_DMA
1611 tcp_service_net_dma(sk, false); /* Don't block */
1612 tp->ucopy.wakeup = 0;
1613 #endif
1614
1615 if (user_recv) {
1616 int chunk;
1617
1618 /* __ Restore normal policy in scheduler __ */
1619
1620 if ((chunk = len - tp->ucopy.len) != 0) {
1621 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1622 len -= chunk;
1623 copied += chunk;
1624 }
1625
1626 if (tp->rcv_nxt == tp->copied_seq &&
1627 !skb_queue_empty(&tp->ucopy.prequeue)) {
1628 do_prequeue:
1629 tcp_prequeue_process(sk);
1630
1631 if ((chunk = len - tp->ucopy.len) != 0) {
1632 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1633 len -= chunk;
1634 copied += chunk;
1635 }
1636 }
1637 }
1638 if ((flags & MSG_PEEK) &&
1639 (peek_seq - copied - urg_hole != tp->copied_seq)) {
1640 if (net_ratelimit())
1641 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1642 current->comm, task_pid_nr(current));
1643 peek_seq = tp->copied_seq;
1644 }
1645 continue;
1646
1647 found_ok_skb:
1648 /* Ok so how much can we use? */
1649 used = skb->len - offset;
1650 if (len < used)
1651 used = len;
1652
1653 /* Do we have urgent data here? */
1654 if (tp->urg_data) {
1655 u32 urg_offset = tp->urg_seq - *seq;
1656 if (urg_offset < used) {
1657 if (!urg_offset) {
1658 if (!sock_flag(sk, SOCK_URGINLINE)) {
1659 ++*seq;
1660 urg_hole++;
1661 offset++;
1662 used--;
1663 if (!used)
1664 goto skip_copy;
1665 }
1666 } else
1667 used = urg_offset;
1668 }
1669 }
1670
1671 if (!(flags & MSG_TRUNC)) {
1672 #ifdef CONFIG_NET_DMA
1673 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1674 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1675
1676 if (tp->ucopy.dma_chan) {
1677 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1678 tp->ucopy.dma_chan, skb, offset,
1679 msg->msg_iov, used,
1680 tp->ucopy.pinned_list);
1681
1682 if (tp->ucopy.dma_cookie < 0) {
1683
1684 printk(KERN_ALERT "dma_cookie < 0\n");
1685
1686 /* Exception. Bailout! */
1687 if (!copied)
1688 copied = -EFAULT;
1689 break;
1690 }
1691
1692 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1693
1694 if ((offset + used) == skb->len)
1695 copied_early = 1;
1696
1697 } else
1698 #endif
1699 {
1700 err = skb_copy_datagram_iovec(skb, offset,
1701 msg->msg_iov, used);
1702 if (err) {
1703 /* Exception. Bailout! */
1704 if (!copied)
1705 copied = -EFAULT;
1706 break;
1707 }
1708 }
1709 }
1710
1711 *seq += used;
1712 copied += used;
1713 len -= used;
1714
1715 tcp_rcv_space_adjust(sk);
1716
1717 skip_copy:
1718 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1719 tp->urg_data = 0;
1720 tcp_fast_path_check(sk);
1721 }
1722 if (used + offset < skb->len)
1723 continue;
1724
1725 if (tcp_hdr(skb)->fin)
1726 goto found_fin_ok;
1727 if (!(flags & MSG_PEEK)) {
1728 sk_eat_skb(sk, skb, copied_early);
1729 copied_early = 0;
1730 }
1731 continue;
1732
1733 found_fin_ok:
1734 /* Process the FIN. */
1735 ++*seq;
1736 if (!(flags & MSG_PEEK)) {
1737 sk_eat_skb(sk, skb, copied_early);
1738 copied_early = 0;
1739 }
1740 break;
1741 } while (len > 0);
1742
1743 if (user_recv) {
1744 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1745 int chunk;
1746
1747 tp->ucopy.len = copied > 0 ? len : 0;
1748
1749 tcp_prequeue_process(sk);
1750
1751 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1752 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1753 len -= chunk;
1754 copied += chunk;
1755 }
1756 }
1757
1758 tp->ucopy.task = NULL;
1759 tp->ucopy.len = 0;
1760 }
1761
1762 #ifdef CONFIG_NET_DMA
1763 tcp_service_net_dma(sk, true); /* Wait for queue to drain */
1764 tp->ucopy.dma_chan = NULL;
1765
1766 if (tp->ucopy.pinned_list) {
1767 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1768 tp->ucopy.pinned_list = NULL;
1769 }
1770 #endif
1771
1772 /* According to UNIX98, msg_name/msg_namelen are ignored
1773 * on connected socket. I was just happy when found this 8) --ANK
1774 */
1775
1776 /* Clean up data we have read: This will do ACK frames. */
1777 tcp_cleanup_rbuf(sk, copied);
1778
1779 TCP_CHECK_TIMER(sk);
1780 release_sock(sk);
1781 return copied;
1782
1783 out:
1784 TCP_CHECK_TIMER(sk);
1785 release_sock(sk);
1786 return err;
1787
1788 recv_urg:
1789 err = tcp_recv_urg(sk, msg, len, flags);
1790 goto out;
1791 }
1792 EXPORT_SYMBOL(tcp_recvmsg);
1793
1794 void tcp_set_state(struct sock *sk, int state)
1795 {
1796 int oldstate = sk->sk_state;
1797
1798 switch (state) {
1799 case TCP_ESTABLISHED:
1800 if (oldstate != TCP_ESTABLISHED)
1801 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1802 break;
1803
1804 case TCP_CLOSE:
1805 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1806 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
1807
1808 sk->sk_prot->unhash(sk);
1809 if (inet_csk(sk)->icsk_bind_hash &&
1810 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1811 inet_put_port(sk);
1812 /* fall through */
1813 default:
1814 if (oldstate == TCP_ESTABLISHED)
1815 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1816 }
1817
1818 /* Change state AFTER socket is unhashed to avoid closed
1819 * socket sitting in hash tables.
1820 */
1821 sk->sk_state = state;
1822
1823 #ifdef STATE_TRACE
1824 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
1825 #endif
1826 }
1827 EXPORT_SYMBOL_GPL(tcp_set_state);
1828
1829 /*
1830 * State processing on a close. This implements the state shift for
1831 * sending our FIN frame. Note that we only send a FIN for some
1832 * states. A shutdown() may have already sent the FIN, or we may be
1833 * closed.
1834 */
1835
1836 static const unsigned char new_state[16] = {
1837 /* current state: new state: action: */
1838 /* (Invalid) */ TCP_CLOSE,
1839 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1840 /* TCP_SYN_SENT */ TCP_CLOSE,
1841 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1842 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1843 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1844 /* TCP_TIME_WAIT */ TCP_CLOSE,
1845 /* TCP_CLOSE */ TCP_CLOSE,
1846 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1847 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1848 /* TCP_LISTEN */ TCP_CLOSE,
1849 /* TCP_CLOSING */ TCP_CLOSING,
1850 };
1851
1852 static int tcp_close_state(struct sock *sk)
1853 {
1854 int next = (int)new_state[sk->sk_state];
1855 int ns = next & TCP_STATE_MASK;
1856
1857 tcp_set_state(sk, ns);
1858
1859 return next & TCP_ACTION_FIN;
1860 }
1861
1862 /*
1863 * Shutdown the sending side of a connection. Much like close except
1864 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1865 */
1866
1867 void tcp_shutdown(struct sock *sk, int how)
1868 {
1869 /* We need to grab some memory, and put together a FIN,
1870 * and then put it into the queue to be sent.
1871 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1872 */
1873 if (!(how & SEND_SHUTDOWN))
1874 return;
1875
1876 /* If we've already sent a FIN, or it's a closed state, skip this. */
1877 if ((1 << sk->sk_state) &
1878 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1879 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1880 /* Clear out any half completed packets. FIN if needed. */
1881 if (tcp_close_state(sk))
1882 tcp_send_fin(sk);
1883 }
1884 }
1885 EXPORT_SYMBOL(tcp_shutdown);
1886
1887 void tcp_close(struct sock *sk, long timeout)
1888 {
1889 struct sk_buff *skb;
1890 int data_was_unread = 0;
1891 int state;
1892
1893 lock_sock(sk);
1894 sk->sk_shutdown = SHUTDOWN_MASK;
1895
1896 if (sk->sk_state == TCP_LISTEN) {
1897 tcp_set_state(sk, TCP_CLOSE);
1898
1899 /* Special case. */
1900 inet_csk_listen_stop(sk);
1901
1902 goto adjudge_to_death;
1903 }
1904
1905 /* We need to flush the recv. buffs. We do this only on the
1906 * descriptor close, not protocol-sourced closes, because the
1907 * reader process may not have drained the data yet!
1908 */
1909 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1910 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
1911 tcp_hdr(skb)->fin;
1912 data_was_unread += len;
1913 __kfree_skb(skb);
1914 }
1915
1916 sk_mem_reclaim(sk);
1917
1918 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
1919 if (sk->sk_state == TCP_CLOSE)
1920 goto adjudge_to_death;
1921
1922 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1923 * data was lost. To witness the awful effects of the old behavior of
1924 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1925 * GET in an FTP client, suspend the process, wait for the client to
1926 * advertise a zero window, then kill -9 the FTP client, wheee...
1927 * Note: timeout is always zero in such a case.
1928 */
1929 if (data_was_unread) {
1930 /* Unread data was tossed, zap the connection. */
1931 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
1932 tcp_set_state(sk, TCP_CLOSE);
1933 tcp_send_active_reset(sk, sk->sk_allocation);
1934 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1935 /* Check zero linger _after_ checking for unread data. */
1936 sk->sk_prot->disconnect(sk, 0);
1937 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
1938 } else if (tcp_close_state(sk)) {
1939 /* We FIN if the application ate all the data before
1940 * zapping the connection.
1941 */
1942
1943 /* RED-PEN. Formally speaking, we have broken TCP state
1944 * machine. State transitions:
1945 *
1946 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1947 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1948 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1949 *
1950 * are legal only when FIN has been sent (i.e. in window),
1951 * rather than queued out of window. Purists blame.
1952 *
1953 * F.e. "RFC state" is ESTABLISHED,
1954 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1955 *
1956 * The visible declinations are that sometimes
1957 * we enter time-wait state, when it is not required really
1958 * (harmless), do not send active resets, when they are
1959 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1960 * they look as CLOSING or LAST_ACK for Linux)
1961 * Probably, I missed some more holelets.
1962 * --ANK
1963 */
1964 tcp_send_fin(sk);
1965 }
1966
1967 sk_stream_wait_close(sk, timeout);
1968
1969 adjudge_to_death:
1970 state = sk->sk_state;
1971 sock_hold(sk);
1972 sock_orphan(sk);
1973
1974 /* It is the last release_sock in its life. It will remove backlog. */
1975 release_sock(sk);
1976
1977
1978 /* Now socket is owned by kernel and we acquire BH lock
1979 to finish close. No need to check for user refs.
1980 */
1981 local_bh_disable();
1982 bh_lock_sock(sk);
1983 WARN_ON(sock_owned_by_user(sk));
1984
1985 percpu_counter_inc(sk->sk_prot->orphan_count);
1986
1987 /* Have we already been destroyed by a softirq or backlog? */
1988 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1989 goto out;
1990
1991 /* This is a (useful) BSD violating of the RFC. There is a
1992 * problem with TCP as specified in that the other end could
1993 * keep a socket open forever with no application left this end.
1994 * We use a 3 minute timeout (about the same as BSD) then kill
1995 * our end. If they send after that then tough - BUT: long enough
1996 * that we won't make the old 4*rto = almost no time - whoops
1997 * reset mistake.
1998 *
1999 * Nope, it was not mistake. It is really desired behaviour
2000 * f.e. on http servers, when such sockets are useless, but
2001 * consume significant resources. Let's do it with special
2002 * linger2 option. --ANK
2003 */
2004
2005 if (sk->sk_state == TCP_FIN_WAIT2) {
2006 struct tcp_sock *tp = tcp_sk(sk);
2007 if (tp->linger2 < 0) {
2008 tcp_set_state(sk, TCP_CLOSE);
2009 tcp_send_active_reset(sk, GFP_ATOMIC);
2010 NET_INC_STATS_BH(sock_net(sk),
2011 LINUX_MIB_TCPABORTONLINGER);
2012 } else {
2013 const int tmo = tcp_fin_time(sk);
2014
2015 if (tmo > TCP_TIMEWAIT_LEN) {
2016 inet_csk_reset_keepalive_timer(sk,
2017 tmo - TCP_TIMEWAIT_LEN);
2018 } else {
2019 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2020 goto out;
2021 }
2022 }
2023 }
2024 if (sk->sk_state != TCP_CLOSE) {
2025 sk_mem_reclaim(sk);
2026 if (tcp_too_many_orphans(sk, 0)) {
2027 if (net_ratelimit())
2028 printk(KERN_INFO "TCP: too many of orphaned "
2029 "sockets\n");
2030 tcp_set_state(sk, TCP_CLOSE);
2031 tcp_send_active_reset(sk, GFP_ATOMIC);
2032 NET_INC_STATS_BH(sock_net(sk),
2033 LINUX_MIB_TCPABORTONMEMORY);
2034 }
2035 }
2036
2037 if (sk->sk_state == TCP_CLOSE)
2038 inet_csk_destroy_sock(sk);
2039 /* Otherwise, socket is reprieved until protocol close. */
2040
2041 out:
2042 bh_unlock_sock(sk);
2043 local_bh_enable();
2044 sock_put(sk);
2045 }
2046 EXPORT_SYMBOL(tcp_close);
2047
2048 /* These states need RST on ABORT according to RFC793 */
2049
2050 static inline int tcp_need_reset(int state)
2051 {
2052 return (1 << state) &
2053 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2054 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2055 }
2056
2057 int tcp_disconnect(struct sock *sk, int flags)
2058 {
2059 struct inet_sock *inet = inet_sk(sk);
2060 struct inet_connection_sock *icsk = inet_csk(sk);
2061 struct tcp_sock *tp = tcp_sk(sk);
2062 int err = 0;
2063 int old_state = sk->sk_state;
2064
2065 if (old_state != TCP_CLOSE)
2066 tcp_set_state(sk, TCP_CLOSE);
2067
2068 /* ABORT function of RFC793 */
2069 if (old_state == TCP_LISTEN) {
2070 inet_csk_listen_stop(sk);
2071 } else if (tcp_need_reset(old_state) ||
2072 (tp->snd_nxt != tp->write_seq &&
2073 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2074 /* The last check adjusts for discrepancy of Linux wrt. RFC
2075 * states
2076 */
2077 tcp_send_active_reset(sk, gfp_any());
2078 sk->sk_err = ECONNRESET;
2079 } else if (old_state == TCP_SYN_SENT)
2080 sk->sk_err = ECONNRESET;
2081
2082 tcp_clear_xmit_timers(sk);
2083 __skb_queue_purge(&sk->sk_receive_queue);
2084 tcp_write_queue_purge(sk);
2085 __skb_queue_purge(&tp->out_of_order_queue);
2086 #ifdef CONFIG_NET_DMA
2087 __skb_queue_purge(&sk->sk_async_wait_queue);
2088 #endif
2089
2090 inet->inet_dport = 0;
2091
2092 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2093 inet_reset_saddr(sk);
2094
2095 sk->sk_shutdown = 0;
2096 sock_reset_flag(sk, SOCK_DONE);
2097 tp->srtt = 0;
2098 if ((tp->write_seq += tp->max_window + 2) == 0)
2099 tp->write_seq = 1;
2100 icsk->icsk_backoff = 0;
2101 tp->snd_cwnd = 2;
2102 icsk->icsk_probes_out = 0;
2103 tp->packets_out = 0;
2104 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2105 tp->snd_cwnd_cnt = 0;
2106 tp->bytes_acked = 0;
2107 tp->window_clamp = 0;
2108 tcp_set_ca_state(sk, TCP_CA_Open);
2109 tcp_clear_retrans(tp);
2110 inet_csk_delack_init(sk);
2111 tcp_init_send_head(sk);
2112 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2113 __sk_dst_reset(sk);
2114
2115 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2116
2117 sk->sk_error_report(sk);
2118 return err;
2119 }
2120 EXPORT_SYMBOL(tcp_disconnect);
2121
2122 /*
2123 * Socket option code for TCP.
2124 */
2125 static int do_tcp_setsockopt(struct sock *sk, int level,
2126 int optname, char __user *optval, unsigned int optlen)
2127 {
2128 struct tcp_sock *tp = tcp_sk(sk);
2129 struct inet_connection_sock *icsk = inet_csk(sk);
2130 int val;
2131 int err = 0;
2132
2133 /* These are data/string values, all the others are ints */
2134 switch (optname) {
2135 case TCP_CONGESTION: {
2136 char name[TCP_CA_NAME_MAX];
2137
2138 if (optlen < 1)
2139 return -EINVAL;
2140
2141 val = strncpy_from_user(name, optval,
2142 min_t(long, TCP_CA_NAME_MAX-1, optlen));
2143 if (val < 0)
2144 return -EFAULT;
2145 name[val] = 0;
2146
2147 lock_sock(sk);
2148 err = tcp_set_congestion_control(sk, name);
2149 release_sock(sk);
2150 return err;
2151 }
2152 case TCP_COOKIE_TRANSACTIONS: {
2153 struct tcp_cookie_transactions ctd;
2154 struct tcp_cookie_values *cvp = NULL;
2155
2156 if (sizeof(ctd) > optlen)
2157 return -EINVAL;
2158 if (copy_from_user(&ctd, optval, sizeof(ctd)))
2159 return -EFAULT;
2160
2161 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) ||
2162 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED)
2163 return -EINVAL;
2164
2165 if (ctd.tcpct_cookie_desired == 0) {
2166 /* default to global value */
2167 } else if ((0x1 & ctd.tcpct_cookie_desired) ||
2168 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX ||
2169 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) {
2170 return -EINVAL;
2171 }
2172
2173 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) {
2174 /* Supercedes all other values */
2175 lock_sock(sk);
2176 if (tp->cookie_values != NULL) {
2177 kref_put(&tp->cookie_values->kref,
2178 tcp_cookie_values_release);
2179 tp->cookie_values = NULL;
2180 }
2181 tp->rx_opt.cookie_in_always = 0; /* false */
2182 tp->rx_opt.cookie_out_never = 1; /* true */
2183 release_sock(sk);
2184 return err;
2185 }
2186
2187 /* Allocate ancillary memory before locking.
2188 */
2189 if (ctd.tcpct_used > 0 ||
2190 (tp->cookie_values == NULL &&
2191 (sysctl_tcp_cookie_size > 0 ||
2192 ctd.tcpct_cookie_desired > 0 ||
2193 ctd.tcpct_s_data_desired > 0))) {
2194 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used,
2195 GFP_KERNEL);
2196 if (cvp == NULL)
2197 return -ENOMEM;
2198
2199 kref_init(&cvp->kref);
2200 }
2201 lock_sock(sk);
2202 tp->rx_opt.cookie_in_always =
2203 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags);
2204 tp->rx_opt.cookie_out_never = 0; /* false */
2205
2206 if (tp->cookie_values != NULL) {
2207 if (cvp != NULL) {
2208 /* Changed values are recorded by a changed
2209 * pointer, ensuring the cookie will differ,
2210 * without separately hashing each value later.
2211 */
2212 kref_put(&tp->cookie_values->kref,
2213 tcp_cookie_values_release);
2214 } else {
2215 cvp = tp->cookie_values;
2216 }
2217 }
2218
2219 if (cvp != NULL) {
2220 cvp->cookie_desired = ctd.tcpct_cookie_desired;
2221
2222 if (ctd.tcpct_used > 0) {
2223 memcpy(cvp->s_data_payload, ctd.tcpct_value,
2224 ctd.tcpct_used);
2225 cvp->s_data_desired = ctd.tcpct_used;
2226 cvp->s_data_constant = 1; /* true */
2227 } else {
2228 /* No constant payload data. */
2229 cvp->s_data_desired = ctd.tcpct_s_data_desired;
2230 cvp->s_data_constant = 0; /* false */
2231 }
2232
2233 tp->cookie_values = cvp;
2234 }
2235 release_sock(sk);
2236 return err;
2237 }
2238 default:
2239 /* fallthru */
2240 break;
2241 }
2242
2243 if (optlen < sizeof(int))
2244 return -EINVAL;
2245
2246 if (get_user(val, (int __user *)optval))
2247 return -EFAULT;
2248
2249 lock_sock(sk);
2250
2251 switch (optname) {
2252 case TCP_MAXSEG:
2253 /* Values greater than interface MTU won't take effect. However
2254 * at the point when this call is done we typically don't yet
2255 * know which interface is going to be used */
2256 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
2257 err = -EINVAL;
2258 break;
2259 }
2260 tp->rx_opt.user_mss = val;
2261 break;
2262
2263 case TCP_NODELAY:
2264 if (val) {
2265 /* TCP_NODELAY is weaker than TCP_CORK, so that
2266 * this option on corked socket is remembered, but
2267 * it is not activated until cork is cleared.
2268 *
2269 * However, when TCP_NODELAY is set we make
2270 * an explicit push, which overrides even TCP_CORK
2271 * for currently queued segments.
2272 */
2273 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2274 tcp_push_pending_frames(sk);
2275 } else {
2276 tp->nonagle &= ~TCP_NAGLE_OFF;
2277 }
2278 break;
2279
2280 case TCP_THIN_LINEAR_TIMEOUTS:
2281 if (val < 0 || val > 1)
2282 err = -EINVAL;
2283 else
2284 tp->thin_lto = val;
2285 break;
2286
2287 case TCP_THIN_DUPACK:
2288 if (val < 0 || val > 1)
2289 err = -EINVAL;
2290 else
2291 tp->thin_dupack = val;
2292 break;
2293
2294 case TCP_CORK:
2295 /* When set indicates to always queue non-full frames.
2296 * Later the user clears this option and we transmit
2297 * any pending partial frames in the queue. This is
2298 * meant to be used alongside sendfile() to get properly
2299 * filled frames when the user (for example) must write
2300 * out headers with a write() call first and then use
2301 * sendfile to send out the data parts.
2302 *
2303 * TCP_CORK can be set together with TCP_NODELAY and it is
2304 * stronger than TCP_NODELAY.
2305 */
2306 if (val) {
2307 tp->nonagle |= TCP_NAGLE_CORK;
2308 } else {
2309 tp->nonagle &= ~TCP_NAGLE_CORK;
2310 if (tp->nonagle&TCP_NAGLE_OFF)
2311 tp->nonagle |= TCP_NAGLE_PUSH;
2312 tcp_push_pending_frames(sk);
2313 }
2314 break;
2315
2316 case TCP_KEEPIDLE:
2317 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2318 err = -EINVAL;
2319 else {
2320 tp->keepalive_time = val * HZ;
2321 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2322 !((1 << sk->sk_state) &
2323 (TCPF_CLOSE | TCPF_LISTEN))) {
2324 u32 elapsed = keepalive_time_elapsed(tp);
2325 if (tp->keepalive_time > elapsed)
2326 elapsed = tp->keepalive_time - elapsed;
2327 else
2328 elapsed = 0;
2329 inet_csk_reset_keepalive_timer(sk, elapsed);
2330 }
2331 }
2332 break;
2333 case TCP_KEEPINTVL:
2334 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2335 err = -EINVAL;
2336 else
2337 tp->keepalive_intvl = val * HZ;
2338 break;
2339 case TCP_KEEPCNT:
2340 if (val < 1 || val > MAX_TCP_KEEPCNT)
2341 err = -EINVAL;
2342 else
2343 tp->keepalive_probes = val;
2344 break;
2345 case TCP_SYNCNT:
2346 if (val < 1 || val > MAX_TCP_SYNCNT)
2347 err = -EINVAL;
2348 else
2349 icsk->icsk_syn_retries = val;
2350 break;
2351
2352 case TCP_LINGER2:
2353 if (val < 0)
2354 tp->linger2 = -1;
2355 else if (val > sysctl_tcp_fin_timeout / HZ)
2356 tp->linger2 = 0;
2357 else
2358 tp->linger2 = val * HZ;
2359 break;
2360
2361 case TCP_DEFER_ACCEPT:
2362 /* Translate value in seconds to number of retransmits */
2363 icsk->icsk_accept_queue.rskq_defer_accept =
2364 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2365 TCP_RTO_MAX / HZ);
2366 break;
2367
2368 case TCP_WINDOW_CLAMP:
2369 if (!val) {
2370 if (sk->sk_state != TCP_CLOSE) {
2371 err = -EINVAL;
2372 break;
2373 }
2374 tp->window_clamp = 0;
2375 } else
2376 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2377 SOCK_MIN_RCVBUF / 2 : val;
2378 break;
2379
2380 case TCP_QUICKACK:
2381 if (!val) {
2382 icsk->icsk_ack.pingpong = 1;
2383 } else {
2384 icsk->icsk_ack.pingpong = 0;
2385 if ((1 << sk->sk_state) &
2386 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2387 inet_csk_ack_scheduled(sk)) {
2388 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2389 tcp_cleanup_rbuf(sk, 1);
2390 if (!(val & 1))
2391 icsk->icsk_ack.pingpong = 1;
2392 }
2393 }
2394 break;
2395
2396 #ifdef CONFIG_TCP_MD5SIG
2397 case TCP_MD5SIG:
2398 /* Read the IP->Key mappings from userspace */
2399 err = tp->af_specific->md5_parse(sk, optval, optlen);
2400 break;
2401 #endif
2402
2403 default:
2404 err = -ENOPROTOOPT;
2405 break;
2406 }
2407
2408 release_sock(sk);
2409 return err;
2410 }
2411
2412 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2413 unsigned int optlen)
2414 {
2415 struct inet_connection_sock *icsk = inet_csk(sk);
2416
2417 if (level != SOL_TCP)
2418 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2419 optval, optlen);
2420 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2421 }
2422 EXPORT_SYMBOL(tcp_setsockopt);
2423
2424 #ifdef CONFIG_COMPAT
2425 int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2426 char __user *optval, unsigned int optlen)
2427 {
2428 if (level != SOL_TCP)
2429 return inet_csk_compat_setsockopt(sk, level, optname,
2430 optval, optlen);
2431 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2432 }
2433 EXPORT_SYMBOL(compat_tcp_setsockopt);
2434 #endif
2435
2436 /* Return information about state of tcp endpoint in API format. */
2437 void tcp_get_info(struct sock *sk, struct tcp_info *info)
2438 {
2439 struct tcp_sock *tp = tcp_sk(sk);
2440 const struct inet_connection_sock *icsk = inet_csk(sk);
2441 u32 now = tcp_time_stamp;
2442
2443 memset(info, 0, sizeof(*info));
2444
2445 info->tcpi_state = sk->sk_state;
2446 info->tcpi_ca_state = icsk->icsk_ca_state;
2447 info->tcpi_retransmits = icsk->icsk_retransmits;
2448 info->tcpi_probes = icsk->icsk_probes_out;
2449 info->tcpi_backoff = icsk->icsk_backoff;
2450
2451 if (tp->rx_opt.tstamp_ok)
2452 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2453 if (tcp_is_sack(tp))
2454 info->tcpi_options |= TCPI_OPT_SACK;
2455 if (tp->rx_opt.wscale_ok) {
2456 info->tcpi_options |= TCPI_OPT_WSCALE;
2457 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2458 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2459 }
2460
2461 if (tp->ecn_flags&TCP_ECN_OK)
2462 info->tcpi_options |= TCPI_OPT_ECN;
2463
2464 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2465 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2466 info->tcpi_snd_mss = tp->mss_cache;
2467 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2468
2469 if (sk->sk_state == TCP_LISTEN) {
2470 info->tcpi_unacked = sk->sk_ack_backlog;
2471 info->tcpi_sacked = sk->sk_max_ack_backlog;
2472 } else {
2473 info->tcpi_unacked = tp->packets_out;
2474 info->tcpi_sacked = tp->sacked_out;
2475 }
2476 info->tcpi_lost = tp->lost_out;
2477 info->tcpi_retrans = tp->retrans_out;
2478 info->tcpi_fackets = tp->fackets_out;
2479
2480 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2481 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2482 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2483
2484 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2485 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2486 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2487 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2488 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2489 info->tcpi_snd_cwnd = tp->snd_cwnd;
2490 info->tcpi_advmss = tp->advmss;
2491 info->tcpi_reordering = tp->reordering;
2492
2493 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2494 info->tcpi_rcv_space = tp->rcvq_space.space;
2495
2496 info->tcpi_total_retrans = tp->total_retrans;
2497 }
2498 EXPORT_SYMBOL_GPL(tcp_get_info);
2499
2500 static int do_tcp_getsockopt(struct sock *sk, int level,
2501 int optname, char __user *optval, int __user *optlen)
2502 {
2503 struct inet_connection_sock *icsk = inet_csk(sk);
2504 struct tcp_sock *tp = tcp_sk(sk);
2505 int val, len;
2506
2507 if (get_user(len, optlen))
2508 return -EFAULT;
2509
2510 len = min_t(unsigned int, len, sizeof(int));
2511
2512 if (len < 0)
2513 return -EINVAL;
2514
2515 switch (optname) {
2516 case TCP_MAXSEG:
2517 val = tp->mss_cache;
2518 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2519 val = tp->rx_opt.user_mss;
2520 break;
2521 case TCP_NODELAY:
2522 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2523 break;
2524 case TCP_CORK:
2525 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2526 break;
2527 case TCP_KEEPIDLE:
2528 val = keepalive_time_when(tp) / HZ;
2529 break;
2530 case TCP_KEEPINTVL:
2531 val = keepalive_intvl_when(tp) / HZ;
2532 break;
2533 case TCP_KEEPCNT:
2534 val = keepalive_probes(tp);
2535 break;
2536 case TCP_SYNCNT:
2537 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2538 break;
2539 case TCP_LINGER2:
2540 val = tp->linger2;
2541 if (val >= 0)
2542 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2543 break;
2544 case TCP_DEFER_ACCEPT:
2545 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2546 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
2547 break;
2548 case TCP_WINDOW_CLAMP:
2549 val = tp->window_clamp;
2550 break;
2551 case TCP_INFO: {
2552 struct tcp_info info;
2553
2554 if (get_user(len, optlen))
2555 return -EFAULT;
2556
2557 tcp_get_info(sk, &info);
2558
2559 len = min_t(unsigned int, len, sizeof(info));
2560 if (put_user(len, optlen))
2561 return -EFAULT;
2562 if (copy_to_user(optval, &info, len))
2563 return -EFAULT;
2564 return 0;
2565 }
2566 case TCP_QUICKACK:
2567 val = !icsk->icsk_ack.pingpong;
2568 break;
2569
2570 case TCP_CONGESTION:
2571 if (get_user(len, optlen))
2572 return -EFAULT;
2573 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2574 if (put_user(len, optlen))
2575 return -EFAULT;
2576 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2577 return -EFAULT;
2578 return 0;
2579
2580 case TCP_COOKIE_TRANSACTIONS: {
2581 struct tcp_cookie_transactions ctd;
2582 struct tcp_cookie_values *cvp = tp->cookie_values;
2583
2584 if (get_user(len, optlen))
2585 return -EFAULT;
2586 if (len < sizeof(ctd))
2587 return -EINVAL;
2588
2589 memset(&ctd, 0, sizeof(ctd));
2590 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ?
2591 TCP_COOKIE_IN_ALWAYS : 0)
2592 | (tp->rx_opt.cookie_out_never ?
2593 TCP_COOKIE_OUT_NEVER : 0);
2594
2595 if (cvp != NULL) {
2596 ctd.tcpct_flags |= (cvp->s_data_in ?
2597 TCP_S_DATA_IN : 0)
2598 | (cvp->s_data_out ?
2599 TCP_S_DATA_OUT : 0);
2600
2601 ctd.tcpct_cookie_desired = cvp->cookie_desired;
2602 ctd.tcpct_s_data_desired = cvp->s_data_desired;
2603
2604 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0],
2605 cvp->cookie_pair_size);
2606 ctd.tcpct_used = cvp->cookie_pair_size;
2607 }
2608
2609 if (put_user(sizeof(ctd), optlen))
2610 return -EFAULT;
2611 if (copy_to_user(optval, &ctd, sizeof(ctd)))
2612 return -EFAULT;
2613 return 0;
2614 }
2615 case TCP_THIN_LINEAR_TIMEOUTS:
2616 val = tp->thin_lto;
2617 break;
2618 case TCP_THIN_DUPACK:
2619 val = tp->thin_dupack;
2620 break;
2621 default:
2622 return -ENOPROTOOPT;
2623 }
2624
2625 if (put_user(len, optlen))
2626 return -EFAULT;
2627 if (copy_to_user(optval, &val, len))
2628 return -EFAULT;
2629 return 0;
2630 }
2631
2632 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2633 int __user *optlen)
2634 {
2635 struct inet_connection_sock *icsk = inet_csk(sk);
2636
2637 if (level != SOL_TCP)
2638 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2639 optval, optlen);
2640 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2641 }
2642 EXPORT_SYMBOL(tcp_getsockopt);
2643
2644 #ifdef CONFIG_COMPAT
2645 int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2646 char __user *optval, int __user *optlen)
2647 {
2648 if (level != SOL_TCP)
2649 return inet_csk_compat_getsockopt(sk, level, optname,
2650 optval, optlen);
2651 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2652 }
2653 EXPORT_SYMBOL(compat_tcp_getsockopt);
2654 #endif
2655
2656 struct sk_buff BCMFASTPATH_HOST *tcp_tso_segment(struct sk_buff *skb, int features)
2657 {
2658 struct sk_buff *segs = ERR_PTR(-EINVAL);
2659 struct tcphdr *th;
2660 unsigned thlen;
2661 unsigned int seq;
2662 __be32 delta;
2663 unsigned int oldlen;
2664 unsigned int mss;
2665
2666 if (!pskb_may_pull(skb, sizeof(*th)))
2667 goto out;
2668
2669 th = tcp_hdr(skb);
2670 thlen = th->doff * 4;
2671 if (thlen < sizeof(*th))
2672 goto out;
2673
2674 if (!pskb_may_pull(skb, thlen))
2675 goto out;
2676
2677 oldlen = (u16)~skb->len;
2678 __skb_pull(skb, thlen);
2679
2680 mss = skb_shinfo(skb)->gso_size;
2681 if (unlikely(skb->len <= mss))
2682 goto out;
2683
2684 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2685 /* Packet is from an untrusted source, reset gso_segs. */
2686 int type = skb_shinfo(skb)->gso_type;
2687
2688 if (unlikely(type &
2689 ~(SKB_GSO_TCPV4 |
2690 SKB_GSO_DODGY |
2691 SKB_GSO_TCP_ECN |
2692 SKB_GSO_TCPV6 |
2693 0) ||
2694 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2695 goto out;
2696
2697 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2698
2699 segs = NULL;
2700 goto out;
2701 }
2702
2703 /*
2704 * For normal optimized packet handling, it calls skb_tcp_segmented().
2705 * However, packets marked for Netfilter needs to be segmented using
2706 * the old method since the packets are passed up to the application
2707 * layer.
2708 */
2709 if (!skb->tcpf_nf && !(skb_shinfo(skb)->frag_list)) {
2710 return skb_tcp_segment(skb, features, oldlen, thlen);
2711 }
2712
2713 /* Old method */
2714 skb->tcpf_nf = 0;
2715 segs = skb_segment(skb, features);
2716 if (IS_ERR(segs))
2717 goto out;
2718
2719 delta = htonl(oldlen + (thlen + mss));
2720
2721 skb = segs;
2722 th = tcp_hdr(skb);
2723 seq = ntohl(th->seq);
2724
2725 do {
2726 th->fin = th->psh = 0;
2727
2728 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2729 (__force u32)delta));
2730 if (skb->ip_summed != CHECKSUM_PARTIAL)
2731 th->check =
2732 csum_fold(csum_partial(skb_transport_header(skb),
2733 thlen, skb->csum));
2734
2735 seq += mss;
2736 skb = skb->next;
2737 th = tcp_hdr(skb);
2738
2739 th->seq = htonl(seq);
2740 th->cwr = 0;
2741 } while (skb->next);
2742
2743 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
2744 skb->data_len);
2745 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2746 (__force u32)delta));
2747 if (skb->ip_summed != CHECKSUM_PARTIAL)
2748 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2749 thlen, skb->csum));
2750
2751 out:
2752 return segs;
2753 }
2754 EXPORT_SYMBOL(tcp_tso_segment);
2755
2756 struct sk_buff ** BCMFASTPATH_HOST tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2757 {
2758 struct sk_buff **pp = NULL;
2759 struct sk_buff *p;
2760 struct tcphdr *th;
2761 struct tcphdr *th2;
2762 unsigned int len;
2763 unsigned int thlen;
2764 __be32 flags;
2765 unsigned int mss = 1;
2766 unsigned int hlen;
2767 unsigned int off;
2768 int flush = 1;
2769 int i;
2770
2771 off = skb_gro_offset(skb);
2772 hlen = off + sizeof(*th);
2773 th = skb_gro_header_fast(skb, off);
2774 if (skb_gro_header_hard(skb, hlen)) {
2775 th = skb_gro_header_slow(skb, hlen, off);
2776 if (unlikely(!th))
2777 goto out;
2778 }
2779
2780 thlen = th->doff * 4;
2781 if (thlen < sizeof(*th))
2782 goto out;
2783
2784 hlen = off + thlen;
2785 if (skb_gro_header_hard(skb, hlen)) {
2786 th = skb_gro_header_slow(skb, hlen, off);
2787 if (unlikely(!th))
2788 goto out;
2789 }
2790
2791 skb_gro_pull(skb, thlen);
2792
2793 len = skb_gro_len(skb);
2794 flags = tcp_flag_word(th);
2795
2796 for (; (p = *head); head = &p->next) {
2797 if (!NAPI_GRO_CB(p)->same_flow)
2798 continue;
2799
2800 th2 = tcp_hdr(p);
2801
2802 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
2803 NAPI_GRO_CB(p)->same_flow = 0;
2804 continue;
2805 }
2806
2807 goto found;
2808 }
2809
2810 goto out_check_final;
2811
2812 found:
2813 flush = NAPI_GRO_CB(p)->flush;
2814 flush |= (__force int)(flags & TCP_FLAG_CWR);
2815 flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
2816 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
2817 flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
2818 for (i = sizeof(*th); i < thlen; i += 4)
2819 flush |= *(u32 *)((u8 *)th + i) ^
2820 *(u32 *)((u8 *)th2 + i);
2821
2822 mss = skb_shinfo(p)->gso_size;
2823
2824 flush |= (len - 1) >= mss;
2825 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
2826
2827 if (flush || skb_gro_receive(head, skb)) {
2828 mss = 1;
2829 goto out_check_final;
2830 }
2831
2832 p = *head;
2833 th2 = tcp_hdr(p);
2834 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
2835
2836 out_check_final:
2837 flush = len < mss;
2838 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH |
2839 TCP_FLAG_RST | TCP_FLAG_SYN |
2840 TCP_FLAG_FIN));
2841
2842 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
2843 pp = head;
2844
2845 out:
2846 NAPI_GRO_CB(skb)->flush |= flush;
2847
2848 return pp;
2849 }
2850 EXPORT_SYMBOL(tcp_gro_receive);
2851
2852 int BCMFASTPATH_HOST tcp_gro_complete(struct sk_buff *skb)
2853 {
2854 struct tcphdr *th = tcp_hdr(skb);
2855
2856 skb->csum_start = skb_transport_header(skb) - skb->head;
2857 skb->csum_offset = offsetof(struct tcphdr, check);
2858 skb->ip_summed = CHECKSUM_PARTIAL;
2859
2860 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
2861
2862 if (th->cwr)
2863 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
2864
2865 return 0;
2866 }
2867 EXPORT_SYMBOL(tcp_gro_complete);
2868
2869 #ifdef CONFIG_TCP_MD5SIG
2870 static unsigned long tcp_md5sig_users;
2871 static struct tcp_md5sig_pool * __percpu *tcp_md5sig_pool;
2872 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2873
2874 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool * __percpu *pool)
2875 {
2876 int cpu;
2877 for_each_possible_cpu(cpu) {
2878 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2879 if (p) {
2880 if (p->md5_desc.tfm)
2881 crypto_free_hash(p->md5_desc.tfm);
2882 kfree(p);
2883 }
2884 }
2885 free_percpu(pool);
2886 }
2887
2888 void tcp_free_md5sig_pool(void)
2889 {
2890 struct tcp_md5sig_pool * __percpu *pool = NULL;
2891
2892 spin_lock_bh(&tcp_md5sig_pool_lock);
2893 if (--tcp_md5sig_users == 0) {
2894 pool = tcp_md5sig_pool;
2895 tcp_md5sig_pool = NULL;
2896 }
2897 spin_unlock_bh(&tcp_md5sig_pool_lock);
2898 if (pool)
2899 __tcp_free_md5sig_pool(pool);
2900 }
2901 EXPORT_SYMBOL(tcp_free_md5sig_pool);
2902
2903 static struct tcp_md5sig_pool * __percpu *
2904 __tcp_alloc_md5sig_pool(struct sock *sk)
2905 {
2906 int cpu;
2907 struct tcp_md5sig_pool * __percpu *pool;
2908
2909 pool = alloc_percpu(struct tcp_md5sig_pool *);
2910 if (!pool)
2911 return NULL;
2912
2913 for_each_possible_cpu(cpu) {
2914 struct tcp_md5sig_pool *p;
2915 struct crypto_hash *hash;
2916
2917 p = kzalloc(sizeof(*p), sk->sk_allocation);
2918 if (!p)
2919 goto out_free;
2920 *per_cpu_ptr(pool, cpu) = p;
2921
2922 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2923 if (!hash || IS_ERR(hash))
2924 goto out_free;
2925
2926 p->md5_desc.tfm = hash;
2927 }
2928 return pool;
2929 out_free:
2930 __tcp_free_md5sig_pool(pool);
2931 return NULL;
2932 }
2933
2934 struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *sk)
2935 {
2936 struct tcp_md5sig_pool * __percpu *pool;
2937 int alloc = 0;
2938
2939 retry:
2940 spin_lock_bh(&tcp_md5sig_pool_lock);
2941 pool = tcp_md5sig_pool;
2942 if (tcp_md5sig_users++ == 0) {
2943 alloc = 1;
2944 spin_unlock_bh(&tcp_md5sig_pool_lock);
2945 } else if (!pool) {
2946 tcp_md5sig_users--;
2947 spin_unlock_bh(&tcp_md5sig_pool_lock);
2948 cpu_relax();
2949 goto retry;
2950 } else
2951 spin_unlock_bh(&tcp_md5sig_pool_lock);
2952
2953 if (alloc) {
2954 /* we cannot hold spinlock here because this may sleep. */
2955 struct tcp_md5sig_pool * __percpu *p;
2956
2957 p = __tcp_alloc_md5sig_pool(sk);
2958 spin_lock_bh(&tcp_md5sig_pool_lock);
2959 if (!p) {
2960 tcp_md5sig_users--;
2961 spin_unlock_bh(&tcp_md5sig_pool_lock);
2962 return NULL;
2963 }
2964 pool = tcp_md5sig_pool;
2965 if (pool) {
2966 /* oops, it has already been assigned. */
2967 spin_unlock_bh(&tcp_md5sig_pool_lock);
2968 __tcp_free_md5sig_pool(p);
2969 } else {
2970 tcp_md5sig_pool = pool = p;
2971 spin_unlock_bh(&tcp_md5sig_pool_lock);
2972 }
2973 }
2974 return pool;
2975 }
2976 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2977
2978
2979 /**
2980 * tcp_get_md5sig_pool - get md5sig_pool for this user
2981 *
2982 * We use percpu structure, so if we succeed, we exit with preemption
2983 * and BH disabled, to make sure another thread or softirq handling
2984 * wont try to get same context.
2985 */
2986 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
2987 {
2988 struct tcp_md5sig_pool * __percpu *p;
2989
2990 local_bh_disable();
2991
2992 spin_lock(&tcp_md5sig_pool_lock);
2993 p = tcp_md5sig_pool;
2994 if (p)
2995 tcp_md5sig_users++;
2996 spin_unlock(&tcp_md5sig_pool_lock);
2997
2998 if (p)
2999 return *this_cpu_ptr(p);
3000
3001 local_bh_enable();
3002 return NULL;
3003 }
3004 EXPORT_SYMBOL(tcp_get_md5sig_pool);
3005
3006 void tcp_put_md5sig_pool(void)
3007 {
3008 local_bh_enable();
3009 tcp_free_md5sig_pool();
3010 }
3011 EXPORT_SYMBOL(tcp_put_md5sig_pool);
3012
3013 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
3014 struct tcphdr *th)
3015 {
3016 struct scatterlist sg;
3017 int err;
3018
3019 __sum16 old_checksum = th->check;
3020 th->check = 0;
3021 /* options aren't included in the hash */
3022 sg_init_one(&sg, th, sizeof(struct tcphdr));
3023 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
3024 th->check = old_checksum;
3025 return err;
3026 }
3027 EXPORT_SYMBOL(tcp_md5_hash_header);
3028
3029 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3030 struct sk_buff *skb, unsigned header_len)
3031 {
3032 struct scatterlist sg;
3033 const struct tcphdr *tp = tcp_hdr(skb);
3034 struct hash_desc *desc = &hp->md5_desc;
3035 unsigned i;
3036 const unsigned head_data_len = skb_headlen(skb) > header_len ?
3037 skb_headlen(skb) - header_len : 0;
3038 const struct skb_shared_info *shi = skb_shinfo(skb);
3039 struct sk_buff *frag_iter;
3040
3041 sg_init_table(&sg, 1);
3042
3043 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3044 if (crypto_hash_update(desc, &sg, head_data_len))
3045 return 1;
3046
3047 for (i = 0; i < shi->nr_frags; ++i) {
3048 const struct skb_frag_struct *f = &shi->frags[i];
3049 sg_set_page(&sg, f->page, f->size, f->page_offset);
3050 if (crypto_hash_update(desc, &sg, f->size))
3051 return 1;
3052 }
3053
3054 skb_walk_frags(skb, frag_iter)
3055 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3056 return 1;
3057
3058 return 0;
3059 }
3060 EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3061
3062 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
3063 {
3064 struct scatterlist sg;
3065
3066 sg_init_one(&sg, key->key, key->keylen);
3067 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
3068 }
3069 EXPORT_SYMBOL(tcp_md5_hash_key);
3070
3071 #endif
3072
3073 /**
3074 * Each Responder maintains up to two secret values concurrently for
3075 * efficient secret rollover. Each secret value has 4 states:
3076 *
3077 * Generating. (tcp_secret_generating != tcp_secret_primary)
3078 * Generates new Responder-Cookies, but not yet used for primary
3079 * verification. This is a short-term state, typically lasting only
3080 * one round trip time (RTT).
3081 *
3082 * Primary. (tcp_secret_generating == tcp_secret_primary)
3083 * Used both for generation and primary verification.
3084 *
3085 * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
3086 * Used for verification, until the first failure that can be
3087 * verified by the newer Generating secret. At that time, this
3088 * cookie's state is changed to Secondary, and the Generating
3089 * cookie's state is changed to Primary. This is a short-term state,
3090 * typically lasting only one round trip time (RTT).
3091 *
3092 * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
3093 * Used for secondary verification, after primary verification
3094 * failures. This state lasts no more than twice the Maximum Segment
3095 * Lifetime (2MSL). Then, the secret is discarded.
3096 */
3097 struct tcp_cookie_secret {
3098 /* The secret is divided into two parts. The digest part is the
3099 * equivalent of previously hashing a secret and saving the state,
3100 * and serves as an initialization vector (IV). The message part
3101 * serves as the trailing secret.
3102 */
3103 u32 secrets[COOKIE_WORKSPACE_WORDS];
3104 unsigned long expires;
3105 };
3106
3107 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
3108 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
3109 #define TCP_SECRET_LIFE (HZ * 600)
3110
3111 static struct tcp_cookie_secret tcp_secret_one;
3112 static struct tcp_cookie_secret tcp_secret_two;
3113
3114 /* Essentially a circular list, without dynamic allocation. */
3115 static struct tcp_cookie_secret *tcp_secret_generating;
3116 static struct tcp_cookie_secret *tcp_secret_primary;
3117 static struct tcp_cookie_secret *tcp_secret_retiring;
3118 static struct tcp_cookie_secret *tcp_secret_secondary;
3119
3120 static DEFINE_SPINLOCK(tcp_secret_locker);
3121
3122 /* Select a pseudo-random word in the cookie workspace.
3123 */
3124 static inline u32 tcp_cookie_work(const u32 *ws, const int n)
3125 {
3126 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])];
3127 }
3128
3129 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
3130 * Called in softirq context.
3131 * Returns: 0 for success.
3132 */
3133 int tcp_cookie_generator(u32 *bakery)
3134 {
3135 unsigned long jiffy = jiffies;
3136
3137 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) {
3138 spin_lock_bh(&tcp_secret_locker);
3139 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) {
3140 /* refreshed by another */
3141 memcpy(bakery,
3142 &tcp_secret_generating->secrets[0],
3143 COOKIE_WORKSPACE_WORDS);
3144 } else {
3145 /* still needs refreshing */
3146 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS);
3147
3148 /* The first time, paranoia assumes that the
3149 * randomization function isn't as strong. But,
3150 * this secret initialization is delayed until
3151 * the last possible moment (packet arrival).
3152 * Although that time is observable, it is
3153 * unpredictably variable. Mash in the most
3154 * volatile clock bits available, and expire the
3155 * secret extra quickly.
3156 */
3157 if (unlikely(tcp_secret_primary->expires ==
3158 tcp_secret_secondary->expires)) {
3159 struct timespec tv;
3160
3161 getnstimeofday(&tv);
3162 bakery[COOKIE_DIGEST_WORDS+0] ^=
3163 (u32)tv.tv_nsec;
3164
3165 tcp_secret_secondary->expires = jiffy
3166 + TCP_SECRET_1MSL
3167 + (0x0f & tcp_cookie_work(bakery, 0));
3168 } else {
3169 tcp_secret_secondary->expires = jiffy
3170 + TCP_SECRET_LIFE
3171 + (0xff & tcp_cookie_work(bakery, 1));
3172 tcp_secret_primary->expires = jiffy
3173 + TCP_SECRET_2MSL
3174 + (0x1f & tcp_cookie_work(bakery, 2));
3175 }
3176 memcpy(&tcp_secret_secondary->secrets[0],
3177 bakery, COOKIE_WORKSPACE_WORDS);
3178
3179 rcu_assign_pointer(tcp_secret_generating,
3180 tcp_secret_secondary);
3181 rcu_assign_pointer(tcp_secret_retiring,
3182 tcp_secret_primary);
3183 /*
3184 * Neither call_rcu() nor synchronize_rcu() needed.
3185 * Retiring data is not freed. It is replaced after
3186 * further (locked) pointer updates, and a quiet time
3187 * (minimum 1MSL, maximum LIFE - 2MSL).
3188 */
3189 }
3190 spin_unlock_bh(&tcp_secret_locker);
3191 } else {
3192 rcu_read_lock_bh();
3193 memcpy(bakery,
3194 &rcu_dereference(tcp_secret_generating)->secrets[0],
3195 COOKIE_WORKSPACE_WORDS);
3196 rcu_read_unlock_bh();
3197 }
3198 return 0;
3199 }
3200 EXPORT_SYMBOL(tcp_cookie_generator);
3201
3202 void tcp_done(struct sock *sk)
3203 {
3204 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3205 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
3206
3207 tcp_set_state(sk, TCP_CLOSE);
3208 tcp_clear_xmit_timers(sk);
3209
3210 sk->sk_shutdown = SHUTDOWN_MASK;
3211
3212 if (!sock_flag(sk, SOCK_DEAD))
3213 sk->sk_state_change(sk);
3214 else
3215 inet_csk_destroy_sock(sk);
3216 }
3217 EXPORT_SYMBOL_GPL(tcp_done);
3218
3219 extern struct tcp_congestion_ops tcp_reno;
3220
3221 static __initdata unsigned long thash_entries;
3222 static int __init set_thash_entries(char *str)
3223 {
3224 if (!str)
3225 return 0;
3226 thash_entries = simple_strtoul(str, &str, 0);
3227 return 1;
3228 }
3229 __setup("thash_entries=", set_thash_entries);
3230
3231 void __init tcp_init(void)
3232 {
3233 struct sk_buff *skb = NULL;
3234 unsigned long nr_pages, limit;
3235 int i, max_share, cnt;
3236 unsigned long jiffy = jiffies;
3237
3238 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
3239
3240 percpu_counter_init(&tcp_sockets_allocated, 0);
3241 percpu_counter_init(&tcp_orphan_count, 0);
3242 tcp_hashinfo.bind_bucket_cachep =
3243 kmem_cache_create("tcp_bind_bucket",
3244 sizeof(struct inet_bind_bucket), 0,
3245 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3246
3247 /* Size and allocate the main established and bind bucket
3248 * hash tables.
3249 *
3250 * The methodology is similar to that of the buffer cache.
3251 */
3252 tcp_hashinfo.ehash =
3253 alloc_large_system_hash("TCP established",
3254 sizeof(struct inet_ehash_bucket),
3255 thash_entries,
3256 (totalram_pages >= 128 * 1024) ?
3257 13 : 15,
3258 0,
3259 NULL,
3260 &tcp_hashinfo.ehash_mask,
3261 thash_entries ? 0 : 512 * 1024);
3262 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
3263 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
3264 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
3265 }
3266 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3267 panic("TCP: failed to alloc ehash_locks");
3268 tcp_hashinfo.bhash =
3269 alloc_large_system_hash("TCP bind",
3270 sizeof(struct inet_bind_hashbucket),
3271 tcp_hashinfo.ehash_mask + 1,
3272 (totalram_pages >= 128 * 1024) ?
3273 13 : 15,
3274 0,
3275 &tcp_hashinfo.bhash_size,
3276 NULL,
3277 64 * 1024);
3278 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
3279 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3280 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3281 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
3282 }
3283
3284
3285 cnt = tcp_hashinfo.ehash_mask + 1;
3286
3287 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3288 sysctl_tcp_max_orphans = cnt / 2;
3289 sysctl_max_syn_backlog = max(128, cnt / 256);
3290
3291 /* Set the pressure threshold to be a fraction of global memory that
3292 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
3293 * memory, with a floor of 128 pages.
3294 */
3295 nr_pages = totalram_pages - totalhigh_pages;
3296 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
3297 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
3298 limit = max(limit, 128UL);
3299 sysctl_tcp_mem[0] = limit / 4 * 3;
3300 sysctl_tcp_mem[1] = limit;
3301 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
3302
3303 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3304 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
3305 max_share = min(4UL*1024*1024, limit);
3306
3307 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3308 sysctl_tcp_wmem[1] = 16*1024;
3309 sysctl_tcp_wmem[2] = max(64*1024, max_share);
3310
3311 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3312 sysctl_tcp_rmem[1] = 87380;
3313 sysctl_tcp_rmem[2] = max(87380, max_share);
3314
3315 printk(KERN_INFO "TCP: Hash tables configured "
3316 "(established %u bind %u)\n",
3317 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3318
3319 tcp_register_congestion_control(&tcp_reno);
3320
3321 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets));
3322 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets));
3323 tcp_secret_one.expires = jiffy; /* past due */
3324 tcp_secret_two.expires = jiffy; /* past due */
3325 tcp_secret_generating = &tcp_secret_one;
3326 tcp_secret_primary = &tcp_secret_one;
3327 tcp_secret_retiring = &tcp_secret_two;
3328 tcp_secret_secondary = &tcp_secret_two;
3329 }
Tomato firmware and modifications.