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Merge branch 'msm-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/davidb/linux...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / tcp.c
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 #define pr_fmt(fmt) "TCP: " fmt
249
250 #include <linux/kernel.h>
251 #include <linux/module.h>
252 #include <linux/types.h>
253 #include <linux/fcntl.h>
254 #include <linux/poll.h>
255 #include <linux/init.h>
256 #include <linux/fs.h>
257 #include <linux/skbuff.h>
258 #include <linux/scatterlist.h>
259 #include <linux/splice.h>
260 #include <linux/net.h>
261 #include <linux/socket.h>
262 #include <linux/random.h>
263 #include <linux/bootmem.h>
264 #include <linux/highmem.h>
265 #include <linux/swap.h>
266 #include <linux/cache.h>
267 #include <linux/err.h>
268 #include <linux/crypto.h>
269 #include <linux/time.h>
270 #include <linux/slab.h>
271
272 #include <net/icmp.h>
273 #include <net/tcp.h>
274 #include <net/xfrm.h>
275 #include <net/ip.h>
276 #include <net/netdma.h>
277 #include <net/sock.h>
278
279 #include <asm/uaccess.h>
280 #include <asm/ioctls.h>
281
282 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
283
284 struct percpu_counter tcp_orphan_count;
285 EXPORT_SYMBOL_GPL(tcp_orphan_count);
286
287 int sysctl_tcp_wmem[3] __read_mostly;
288 int sysctl_tcp_rmem[3] __read_mostly;
289
290 EXPORT_SYMBOL(sysctl_tcp_rmem);
291 EXPORT_SYMBOL(sysctl_tcp_wmem);
292
293 atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
294 EXPORT_SYMBOL(tcp_memory_allocated);
295
296 /*
297 * Current number of TCP sockets.
298 */
299 struct percpu_counter tcp_sockets_allocated;
300 EXPORT_SYMBOL(tcp_sockets_allocated);
301
302 /*
303 * TCP splice context
304 */
305 struct tcp_splice_state {
306 struct pipe_inode_info *pipe;
307 size_t len;
308 unsigned int flags;
309 };
310
311 /*
312 * Pressure flag: try to collapse.
313 * Technical note: it is used by multiple contexts non atomically.
314 * All the __sk_mem_schedule() is of this nature: accounting
315 * is strict, actions are advisory and have some latency.
316 */
317 int tcp_memory_pressure __read_mostly;
318 EXPORT_SYMBOL(tcp_memory_pressure);
319
320 void tcp_enter_memory_pressure(struct sock *sk)
321 {
322 if (!tcp_memory_pressure) {
323 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
324 tcp_memory_pressure = 1;
325 }
326 }
327 EXPORT_SYMBOL(tcp_enter_memory_pressure);
328
329 /* Convert seconds to retransmits based on initial and max timeout */
330 static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
331 {
332 u8 res = 0;
333
334 if (seconds > 0) {
335 int period = timeout;
336
337 res = 1;
338 while (seconds > period && res < 255) {
339 res++;
340 timeout <<= 1;
341 if (timeout > rto_max)
342 timeout = rto_max;
343 period += timeout;
344 }
345 }
346 return res;
347 }
348
349 /* Convert retransmits to seconds based on initial and max timeout */
350 static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
351 {
352 int period = 0;
353
354 if (retrans > 0) {
355 period = timeout;
356 while (--retrans) {
357 timeout <<= 1;
358 if (timeout > rto_max)
359 timeout = rto_max;
360 period += timeout;
361 }
362 }
363 return period;
364 }
365
366 /*
367 * Wait for a TCP event.
368 *
369 * Note that we don't need to lock the socket, as the upper poll layers
370 * take care of normal races (between the test and the event) and we don't
371 * go look at any of the socket buffers directly.
372 */
373 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
374 {
375 unsigned int mask;
376 struct sock *sk = sock->sk;
377 const struct tcp_sock *tp = tcp_sk(sk);
378
379 sock_poll_wait(file, sk_sleep(sk), wait);
380 if (sk->sk_state == TCP_LISTEN)
381 return inet_csk_listen_poll(sk);
382
383 /* Socket is not locked. We are protected from async events
384 * by poll logic and correct handling of state changes
385 * made by other threads is impossible in any case.
386 */
387
388 mask = 0;
389
390 /*
391 * POLLHUP is certainly not done right. But poll() doesn't
392 * have a notion of HUP in just one direction, and for a
393 * socket the read side is more interesting.
394 *
395 * Some poll() documentation says that POLLHUP is incompatible
396 * with the POLLOUT/POLLWR flags, so somebody should check this
397 * all. But careful, it tends to be safer to return too many
398 * bits than too few, and you can easily break real applications
399 * if you don't tell them that something has hung up!
400 *
401 * Check-me.
402 *
403 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
404 * our fs/select.c). It means that after we received EOF,
405 * poll always returns immediately, making impossible poll() on write()
406 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
407 * if and only if shutdown has been made in both directions.
408 * Actually, it is interesting to look how Solaris and DUX
409 * solve this dilemma. I would prefer, if POLLHUP were maskable,
410 * then we could set it on SND_SHUTDOWN. BTW examples given
411 * in Stevens' books assume exactly this behaviour, it explains
412 * why POLLHUP is incompatible with POLLOUT. --ANK
413 *
414 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
415 * blocking on fresh not-connected or disconnected socket. --ANK
416 */
417 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
418 mask |= POLLHUP;
419 if (sk->sk_shutdown & RCV_SHUTDOWN)
420 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
421
422 /* Connected? */
423 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
424 int target = sock_rcvlowat(sk, 0, INT_MAX);
425
426 if (tp->urg_seq == tp->copied_seq &&
427 !sock_flag(sk, SOCK_URGINLINE) &&
428 tp->urg_data)
429 target++;
430
431 /* Potential race condition. If read of tp below will
432 * escape above sk->sk_state, we can be illegally awaken
433 * in SYN_* states. */
434 if (tp->rcv_nxt - tp->copied_seq >= target)
435 mask |= POLLIN | POLLRDNORM;
436
437 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
438 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
439 mask |= POLLOUT | POLLWRNORM;
440 } else { /* send SIGIO later */
441 set_bit(SOCK_ASYNC_NOSPACE,
442 &sk->sk_socket->flags);
443 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
444
445 /* Race breaker. If space is freed after
446 * wspace test but before the flags are set,
447 * IO signal will be lost.
448 */
449 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
450 mask |= POLLOUT | POLLWRNORM;
451 }
452 } else
453 mask |= POLLOUT | POLLWRNORM;
454
455 if (tp->urg_data & TCP_URG_VALID)
456 mask |= POLLPRI;
457 }
458 /* This barrier is coupled with smp_wmb() in tcp_reset() */
459 smp_rmb();
460 if (sk->sk_err)
461 mask |= POLLERR;
462
463 return mask;
464 }
465 EXPORT_SYMBOL(tcp_poll);
466
467 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
468 {
469 struct tcp_sock *tp = tcp_sk(sk);
470 int answ;
471
472 switch (cmd) {
473 case SIOCINQ:
474 if (sk->sk_state == TCP_LISTEN)
475 return -EINVAL;
476
477 lock_sock(sk);
478 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
479 answ = 0;
480 else if (sock_flag(sk, SOCK_URGINLINE) ||
481 !tp->urg_data ||
482 before(tp->urg_seq, tp->copied_seq) ||
483 !before(tp->urg_seq, tp->rcv_nxt)) {
484 struct sk_buff *skb;
485
486 answ = tp->rcv_nxt - tp->copied_seq;
487
488 /* Subtract 1, if FIN is in queue. */
489 skb = skb_peek_tail(&sk->sk_receive_queue);
490 if (answ && skb)
491 answ -= tcp_hdr(skb)->fin;
492 } else
493 answ = tp->urg_seq - tp->copied_seq;
494 release_sock(sk);
495 break;
496 case SIOCATMARK:
497 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
498 break;
499 case SIOCOUTQ:
500 if (sk->sk_state == TCP_LISTEN)
501 return -EINVAL;
502
503 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
504 answ = 0;
505 else
506 answ = tp->write_seq - tp->snd_una;
507 break;
508 case SIOCOUTQNSD:
509 if (sk->sk_state == TCP_LISTEN)
510 return -EINVAL;
511
512 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
513 answ = 0;
514 else
515 answ = tp->write_seq - tp->snd_nxt;
516 break;
517 default:
518 return -ENOIOCTLCMD;
519 }
520
521 return put_user(answ, (int __user *)arg);
522 }
523 EXPORT_SYMBOL(tcp_ioctl);
524
525 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
526 {
527 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
528 tp->pushed_seq = tp->write_seq;
529 }
530
531 static inline int forced_push(const struct tcp_sock *tp)
532 {
533 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
534 }
535
536 static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
537 {
538 struct tcp_sock *tp = tcp_sk(sk);
539 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
540
541 skb->csum = 0;
542 tcb->seq = tcb->end_seq = tp->write_seq;
543 tcb->tcp_flags = TCPHDR_ACK;
544 tcb->sacked = 0;
545 skb_header_release(skb);
546 tcp_add_write_queue_tail(sk, skb);
547 sk->sk_wmem_queued += skb->truesize;
548 sk_mem_charge(sk, skb->truesize);
549 if (tp->nonagle & TCP_NAGLE_PUSH)
550 tp->nonagle &= ~TCP_NAGLE_PUSH;
551 }
552
553 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
554 {
555 if (flags & MSG_OOB)
556 tp->snd_up = tp->write_seq;
557 }
558
559 static inline void tcp_push(struct sock *sk, int flags, int mss_now,
560 int nonagle)
561 {
562 if (tcp_send_head(sk)) {
563 struct tcp_sock *tp = tcp_sk(sk);
564
565 if (!(flags & MSG_MORE) || forced_push(tp))
566 tcp_mark_push(tp, tcp_write_queue_tail(sk));
567
568 tcp_mark_urg(tp, flags);
569 __tcp_push_pending_frames(sk, mss_now,
570 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
571 }
572 }
573
574 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
575 unsigned int offset, size_t len)
576 {
577 struct tcp_splice_state *tss = rd_desc->arg.data;
578 int ret;
579
580 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
581 tss->flags);
582 if (ret > 0)
583 rd_desc->count -= ret;
584 return ret;
585 }
586
587 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
588 {
589 /* Store TCP splice context information in read_descriptor_t. */
590 read_descriptor_t rd_desc = {
591 .arg.data = tss,
592 .count = tss->len,
593 };
594
595 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
596 }
597
598 /**
599 * tcp_splice_read - splice data from TCP socket to a pipe
600 * @sock: socket to splice from
601 * @ppos: position (not valid)
602 * @pipe: pipe to splice to
603 * @len: number of bytes to splice
604 * @flags: splice modifier flags
605 *
606 * Description:
607 * Will read pages from given socket and fill them into a pipe.
608 *
609 **/
610 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
611 struct pipe_inode_info *pipe, size_t len,
612 unsigned int flags)
613 {
614 struct sock *sk = sock->sk;
615 struct tcp_splice_state tss = {
616 .pipe = pipe,
617 .len = len,
618 .flags = flags,
619 };
620 long timeo;
621 ssize_t spliced;
622 int ret;
623
624 sock_rps_record_flow(sk);
625 /*
626 * We can't seek on a socket input
627 */
628 if (unlikely(*ppos))
629 return -ESPIPE;
630
631 ret = spliced = 0;
632
633 lock_sock(sk);
634
635 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
636 while (tss.len) {
637 ret = __tcp_splice_read(sk, &tss);
638 if (ret < 0)
639 break;
640 else if (!ret) {
641 if (spliced)
642 break;
643 if (sock_flag(sk, SOCK_DONE))
644 break;
645 if (sk->sk_err) {
646 ret = sock_error(sk);
647 break;
648 }
649 if (sk->sk_shutdown & RCV_SHUTDOWN)
650 break;
651 if (sk->sk_state == TCP_CLOSE) {
652 /*
653 * This occurs when user tries to read
654 * from never connected socket.
655 */
656 if (!sock_flag(sk, SOCK_DONE))
657 ret = -ENOTCONN;
658 break;
659 }
660 if (!timeo) {
661 ret = -EAGAIN;
662 break;
663 }
664 sk_wait_data(sk, &timeo);
665 if (signal_pending(current)) {
666 ret = sock_intr_errno(timeo);
667 break;
668 }
669 continue;
670 }
671 tss.len -= ret;
672 spliced += ret;
673
674 if (!timeo)
675 break;
676 release_sock(sk);
677 lock_sock(sk);
678
679 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
680 (sk->sk_shutdown & RCV_SHUTDOWN) ||
681 signal_pending(current))
682 break;
683 }
684
685 release_sock(sk);
686
687 if (spliced)
688 return spliced;
689
690 return ret;
691 }
692 EXPORT_SYMBOL(tcp_splice_read);
693
694 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
695 {
696 struct sk_buff *skb;
697
698 /* The TCP header must be at least 32-bit aligned. */
699 size = ALIGN(size, 4);
700
701 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
702 if (skb) {
703 if (sk_wmem_schedule(sk, skb->truesize)) {
704 skb_reserve(skb, sk->sk_prot->max_header);
705 /*
706 * Make sure that we have exactly size bytes
707 * available to the caller, no more, no less.
708 */
709 skb->avail_size = size;
710 return skb;
711 }
712 __kfree_skb(skb);
713 } else {
714 sk->sk_prot->enter_memory_pressure(sk);
715 sk_stream_moderate_sndbuf(sk);
716 }
717 return NULL;
718 }
719
720 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
721 int large_allowed)
722 {
723 struct tcp_sock *tp = tcp_sk(sk);
724 u32 xmit_size_goal, old_size_goal;
725
726 xmit_size_goal = mss_now;
727
728 if (large_allowed && sk_can_gso(sk)) {
729 xmit_size_goal = ((sk->sk_gso_max_size - 1) -
730 inet_csk(sk)->icsk_af_ops->net_header_len -
731 inet_csk(sk)->icsk_ext_hdr_len -
732 tp->tcp_header_len);
733
734 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
735
736 /* We try hard to avoid divides here */
737 old_size_goal = tp->xmit_size_goal_segs * mss_now;
738
739 if (likely(old_size_goal <= xmit_size_goal &&
740 old_size_goal + mss_now > xmit_size_goal)) {
741 xmit_size_goal = old_size_goal;
742 } else {
743 tp->xmit_size_goal_segs = xmit_size_goal / mss_now;
744 xmit_size_goal = tp->xmit_size_goal_segs * mss_now;
745 }
746 }
747
748 return max(xmit_size_goal, mss_now);
749 }
750
751 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
752 {
753 int mss_now;
754
755 mss_now = tcp_current_mss(sk);
756 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
757
758 return mss_now;
759 }
760
761 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
762 size_t psize, int flags)
763 {
764 struct tcp_sock *tp = tcp_sk(sk);
765 int mss_now, size_goal;
766 int err;
767 ssize_t copied;
768 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
769
770 /* Wait for a connection to finish. */
771 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
772 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
773 goto out_err;
774
775 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
776
777 mss_now = tcp_send_mss(sk, &size_goal, flags);
778 copied = 0;
779
780 err = -EPIPE;
781 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
782 goto out_err;
783
784 while (psize > 0) {
785 struct sk_buff *skb = tcp_write_queue_tail(sk);
786 struct page *page = pages[poffset / PAGE_SIZE];
787 int copy, i, can_coalesce;
788 int offset = poffset % PAGE_SIZE;
789 int size = min_t(size_t, psize, PAGE_SIZE - offset);
790
791 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
792 new_segment:
793 if (!sk_stream_memory_free(sk))
794 goto wait_for_sndbuf;
795
796 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
797 if (!skb)
798 goto wait_for_memory;
799
800 skb_entail(sk, skb);
801 copy = size_goal;
802 }
803
804 if (copy > size)
805 copy = size;
806
807 i = skb_shinfo(skb)->nr_frags;
808 can_coalesce = skb_can_coalesce(skb, i, page, offset);
809 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
810 tcp_mark_push(tp, skb);
811 goto new_segment;
812 }
813 if (!sk_wmem_schedule(sk, copy))
814 goto wait_for_memory;
815
816 if (can_coalesce) {
817 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
818 } else {
819 get_page(page);
820 skb_fill_page_desc(skb, i, page, offset, copy);
821 }
822
823 skb->len += copy;
824 skb->data_len += copy;
825 skb->truesize += copy;
826 sk->sk_wmem_queued += copy;
827 sk_mem_charge(sk, copy);
828 skb->ip_summed = CHECKSUM_PARTIAL;
829 tp->write_seq += copy;
830 TCP_SKB_CB(skb)->end_seq += copy;
831 skb_shinfo(skb)->gso_segs = 0;
832
833 if (!copied)
834 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
835
836 copied += copy;
837 poffset += copy;
838 if (!(psize -= copy))
839 goto out;
840
841 if (skb->len < size_goal || (flags & MSG_OOB))
842 continue;
843
844 if (forced_push(tp)) {
845 tcp_mark_push(tp, skb);
846 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
847 } else if (skb == tcp_send_head(sk))
848 tcp_push_one(sk, mss_now);
849 continue;
850
851 wait_for_sndbuf:
852 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
853 wait_for_memory:
854 if (copied)
855 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
856
857 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
858 goto do_error;
859
860 mss_now = tcp_send_mss(sk, &size_goal, flags);
861 }
862
863 out:
864 if (copied && !(flags & MSG_SENDPAGE_NOTLAST))
865 tcp_push(sk, flags, mss_now, tp->nonagle);
866 return copied;
867
868 do_error:
869 if (copied)
870 goto out;
871 out_err:
872 return sk_stream_error(sk, flags, err);
873 }
874
875 int tcp_sendpage(struct sock *sk, struct page *page, int offset,
876 size_t size, int flags)
877 {
878 ssize_t res;
879
880 if (!(sk->sk_route_caps & NETIF_F_SG) ||
881 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
882 return sock_no_sendpage(sk->sk_socket, page, offset, size,
883 flags);
884
885 lock_sock(sk);
886 res = do_tcp_sendpages(sk, &page, offset, size, flags);
887 release_sock(sk);
888 return res;
889 }
890 EXPORT_SYMBOL(tcp_sendpage);
891
892 static inline int select_size(const struct sock *sk, bool sg)
893 {
894 const struct tcp_sock *tp = tcp_sk(sk);
895 int tmp = tp->mss_cache;
896
897 if (sg) {
898 if (sk_can_gso(sk)) {
899 /* Small frames wont use a full page:
900 * Payload will immediately follow tcp header.
901 */
902 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
903 } else {
904 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
905
906 if (tmp >= pgbreak &&
907 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
908 tmp = pgbreak;
909 }
910 }
911
912 return tmp;
913 }
914
915 int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
916 size_t size)
917 {
918 struct iovec *iov;
919 struct tcp_sock *tp = tcp_sk(sk);
920 struct sk_buff *skb;
921 int iovlen, flags, err, copied;
922 int mss_now, size_goal;
923 bool sg;
924 long timeo;
925
926 lock_sock(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_availroom(skb) > 0) {
1000 /* We have some space in skb head. Superb! */
1001 copy = min_t(int, copy, skb_availroom(skb));
1002 err = skb_add_data_nocache(sk, skb, from, copy);
1003 if (err)
1004 goto do_fault;
1005 } else {
1006 int merge = 0;
1007 int i = skb_shinfo(skb)->nr_frags;
1008 struct page *page = sk->sk_sndmsg_page;
1009 int off;
1010
1011 if (page && page_count(page) == 1)
1012 sk->sk_sndmsg_off = 0;
1013
1014 off = sk->sk_sndmsg_off;
1015
1016 if (skb_can_coalesce(skb, i, page, off) &&
1017 off != PAGE_SIZE) {
1018 /* We can extend the last page
1019 * fragment. */
1020 merge = 1;
1021 } else if (i == MAX_SKB_FRAGS || !sg) {
1022 /* Need to add new fragment and cannot
1023 * do this because interface is non-SG,
1024 * or because all the page slots are
1025 * busy. */
1026 tcp_mark_push(tp, skb);
1027 goto new_segment;
1028 } else if (page) {
1029 if (off == PAGE_SIZE) {
1030 put_page(page);
1031 sk->sk_sndmsg_page = page = NULL;
1032 off = 0;
1033 }
1034 } else
1035 off = 0;
1036
1037 if (copy > PAGE_SIZE - off)
1038 copy = PAGE_SIZE - off;
1039
1040 if (!sk_wmem_schedule(sk, copy))
1041 goto wait_for_memory;
1042
1043 if (!page) {
1044 /* Allocate new cache page. */
1045 if (!(page = sk_stream_alloc_page(sk)))
1046 goto wait_for_memory;
1047 }
1048
1049 /* Time to copy data. We are close to
1050 * the end! */
1051 err = skb_copy_to_page_nocache(sk, from, skb,
1052 page, off, copy);
1053 if (err) {
1054 /* If this page was new, give it to the
1055 * socket so it does not get leaked.
1056 */
1057 if (!sk->sk_sndmsg_page) {
1058 sk->sk_sndmsg_page = page;
1059 sk->sk_sndmsg_off = 0;
1060 }
1061 goto do_error;
1062 }
1063
1064 /* Update the skb. */
1065 if (merge) {
1066 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1067 } else {
1068 skb_fill_page_desc(skb, i, page, off, copy);
1069 if (sk->sk_sndmsg_page) {
1070 get_page(page);
1071 } else if (off + copy < PAGE_SIZE) {
1072 get_page(page);
1073 sk->sk_sndmsg_page = page;
1074 }
1075 }
1076
1077 sk->sk_sndmsg_off = off + copy;
1078 }
1079
1080 if (!copied)
1081 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1082
1083 tp->write_seq += copy;
1084 TCP_SKB_CB(skb)->end_seq += copy;
1085 skb_shinfo(skb)->gso_segs = 0;
1086
1087 from += copy;
1088 copied += copy;
1089 if ((seglen -= copy) == 0 && iovlen == 0)
1090 goto out;
1091
1092 if (skb->len < max || (flags & MSG_OOB))
1093 continue;
1094
1095 if (forced_push(tp)) {
1096 tcp_mark_push(tp, skb);
1097 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1098 } else if (skb == tcp_send_head(sk))
1099 tcp_push_one(sk, mss_now);
1100 continue;
1101
1102 wait_for_sndbuf:
1103 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1104 wait_for_memory:
1105 if (copied)
1106 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
1107
1108 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1109 goto do_error;
1110
1111 mss_now = tcp_send_mss(sk, &size_goal, flags);
1112 }
1113 }
1114
1115 out:
1116 if (copied)
1117 tcp_push(sk, flags, mss_now, tp->nonagle);
1118 release_sock(sk);
1119 return copied;
1120
1121 do_fault:
1122 if (!skb->len) {
1123 tcp_unlink_write_queue(skb, sk);
1124 /* It is the one place in all of TCP, except connection
1125 * reset, where we can be unlinking the send_head.
1126 */
1127 tcp_check_send_head(sk, skb);
1128 sk_wmem_free_skb(sk, skb);
1129 }
1130
1131 do_error:
1132 if (copied)
1133 goto out;
1134 out_err:
1135 err = sk_stream_error(sk, flags, err);
1136 release_sock(sk);
1137 return err;
1138 }
1139 EXPORT_SYMBOL(tcp_sendmsg);
1140
1141 /*
1142 * Handle reading urgent data. BSD has very simple semantics for
1143 * this, no blocking and very strange errors 8)
1144 */
1145
1146 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1147 {
1148 struct tcp_sock *tp = tcp_sk(sk);
1149
1150 /* No URG data to read. */
1151 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1152 tp->urg_data == TCP_URG_READ)
1153 return -EINVAL; /* Yes this is right ! */
1154
1155 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1156 return -ENOTCONN;
1157
1158 if (tp->urg_data & TCP_URG_VALID) {
1159 int err = 0;
1160 char c = tp->urg_data;
1161
1162 if (!(flags & MSG_PEEK))
1163 tp->urg_data = TCP_URG_READ;
1164
1165 /* Read urgent data. */
1166 msg->msg_flags |= MSG_OOB;
1167
1168 if (len > 0) {
1169 if (!(flags & MSG_TRUNC))
1170 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1171 len = 1;
1172 } else
1173 msg->msg_flags |= MSG_TRUNC;
1174
1175 return err ? -EFAULT : len;
1176 }
1177
1178 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1179 return 0;
1180
1181 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1182 * the available implementations agree in this case:
1183 * this call should never block, independent of the
1184 * blocking state of the socket.
1185 * Mike <pall@rz.uni-karlsruhe.de>
1186 */
1187 return -EAGAIN;
1188 }
1189
1190 /* Clean up the receive buffer for full frames taken by the user,
1191 * then send an ACK if necessary. COPIED is the number of bytes
1192 * tcp_recvmsg has given to the user so far, it speeds up the
1193 * calculation of whether or not we must ACK for the sake of
1194 * a window update.
1195 */
1196 void tcp_cleanup_rbuf(struct sock *sk, int copied)
1197 {
1198 struct tcp_sock *tp = tcp_sk(sk);
1199 int time_to_ack = 0;
1200
1201 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1202
1203 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1204 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1205 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
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 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 err = -ENOTCONN;
1426 if (sk->sk_state == TCP_LISTEN)
1427 goto out;
1428
1429 timeo = sock_rcvtimeo(sk, nonblock);
1430
1431 /* Urgent data needs to be handled specially. */
1432 if (flags & MSG_OOB)
1433 goto recv_urg;
1434
1435 seq = &tp->copied_seq;
1436 if (flags & MSG_PEEK) {
1437 peek_seq = tp->copied_seq;
1438 seq = &peek_seq;
1439 }
1440
1441 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1442
1443 #ifdef CONFIG_NET_DMA
1444 tp->ucopy.dma_chan = NULL;
1445 preempt_disable();
1446 skb = skb_peek_tail(&sk->sk_receive_queue);
1447 {
1448 int available = 0;
1449
1450 if (skb)
1451 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1452 if ((available < target) &&
1453 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1454 !sysctl_tcp_low_latency &&
1455 net_dma_find_channel()) {
1456 preempt_enable_no_resched();
1457 tp->ucopy.pinned_list =
1458 dma_pin_iovec_pages(msg->msg_iov, len);
1459 } else {
1460 preempt_enable_no_resched();
1461 }
1462 }
1463 #endif
1464
1465 do {
1466 u32 offset;
1467
1468 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1469 if (tp->urg_data && tp->urg_seq == *seq) {
1470 if (copied)
1471 break;
1472 if (signal_pending(current)) {
1473 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1474 break;
1475 }
1476 }
1477
1478 /* Next get a buffer. */
1479
1480 skb_queue_walk(&sk->sk_receive_queue, skb) {
1481 /* Now that we have two receive queues this
1482 * shouldn't happen.
1483 */
1484 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1485 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1486 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1487 flags))
1488 break;
1489
1490 offset = *seq - TCP_SKB_CB(skb)->seq;
1491 if (tcp_hdr(skb)->syn)
1492 offset--;
1493 if (offset < skb->len)
1494 goto found_ok_skb;
1495 if (tcp_hdr(skb)->fin)
1496 goto found_fin_ok;
1497 WARN(!(flags & MSG_PEEK),
1498 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1499 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
1500 }
1501
1502 /* Well, if we have backlog, try to process it now yet. */
1503
1504 if (copied >= target && !sk->sk_backlog.tail)
1505 break;
1506
1507 if (copied) {
1508 if (sk->sk_err ||
1509 sk->sk_state == TCP_CLOSE ||
1510 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1511 !timeo ||
1512 signal_pending(current))
1513 break;
1514 } else {
1515 if (sock_flag(sk, SOCK_DONE))
1516 break;
1517
1518 if (sk->sk_err) {
1519 copied = sock_error(sk);
1520 break;
1521 }
1522
1523 if (sk->sk_shutdown & RCV_SHUTDOWN)
1524 break;
1525
1526 if (sk->sk_state == TCP_CLOSE) {
1527 if (!sock_flag(sk, SOCK_DONE)) {
1528 /* This occurs when user tries to read
1529 * from never connected socket.
1530 */
1531 copied = -ENOTCONN;
1532 break;
1533 }
1534 break;
1535 }
1536
1537 if (!timeo) {
1538 copied = -EAGAIN;
1539 break;
1540 }
1541
1542 if (signal_pending(current)) {
1543 copied = sock_intr_errno(timeo);
1544 break;
1545 }
1546 }
1547
1548 tcp_cleanup_rbuf(sk, copied);
1549
1550 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1551 /* Install new reader */
1552 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1553 user_recv = current;
1554 tp->ucopy.task = user_recv;
1555 tp->ucopy.iov = msg->msg_iov;
1556 }
1557
1558 tp->ucopy.len = len;
1559
1560 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1561 !(flags & (MSG_PEEK | MSG_TRUNC)));
1562
1563 /* Ugly... If prequeue is not empty, we have to
1564 * process it before releasing socket, otherwise
1565 * order will be broken at second iteration.
1566 * More elegant solution is required!!!
1567 *
1568 * Look: we have the following (pseudo)queues:
1569 *
1570 * 1. packets in flight
1571 * 2. backlog
1572 * 3. prequeue
1573 * 4. receive_queue
1574 *
1575 * Each queue can be processed only if the next ones
1576 * are empty. At this point we have empty receive_queue.
1577 * But prequeue _can_ be not empty after 2nd iteration,
1578 * when we jumped to start of loop because backlog
1579 * processing added something to receive_queue.
1580 * We cannot release_sock(), because backlog contains
1581 * packets arrived _after_ prequeued ones.
1582 *
1583 * Shortly, algorithm is clear --- to process all
1584 * the queues in order. We could make it more directly,
1585 * requeueing packets from backlog to prequeue, if
1586 * is not empty. It is more elegant, but eats cycles,
1587 * unfortunately.
1588 */
1589 if (!skb_queue_empty(&tp->ucopy.prequeue))
1590 goto do_prequeue;
1591
1592 /* __ Set realtime policy in scheduler __ */
1593 }
1594
1595 #ifdef CONFIG_NET_DMA
1596 if (tp->ucopy.dma_chan)
1597 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1598 #endif
1599 if (copied >= target) {
1600 /* Do not sleep, just process backlog. */
1601 release_sock(sk);
1602 lock_sock(sk);
1603 } else
1604 sk_wait_data(sk, &timeo);
1605
1606 #ifdef CONFIG_NET_DMA
1607 tcp_service_net_dma(sk, false); /* Don't block */
1608 tp->ucopy.wakeup = 0;
1609 #endif
1610
1611 if (user_recv) {
1612 int chunk;
1613
1614 /* __ Restore normal policy in scheduler __ */
1615
1616 if ((chunk = len - tp->ucopy.len) != 0) {
1617 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1618 len -= chunk;
1619 copied += chunk;
1620 }
1621
1622 if (tp->rcv_nxt == tp->copied_seq &&
1623 !skb_queue_empty(&tp->ucopy.prequeue)) {
1624 do_prequeue:
1625 tcp_prequeue_process(sk);
1626
1627 if ((chunk = len - tp->ucopy.len) != 0) {
1628 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1629 len -= chunk;
1630 copied += chunk;
1631 }
1632 }
1633 }
1634 if ((flags & MSG_PEEK) &&
1635 (peek_seq - copied - urg_hole != tp->copied_seq)) {
1636 if (net_ratelimit())
1637 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1638 current->comm, task_pid_nr(current));
1639 peek_seq = tp->copied_seq;
1640 }
1641 continue;
1642
1643 found_ok_skb:
1644 /* Ok so how much can we use? */
1645 used = skb->len - offset;
1646 if (len < used)
1647 used = len;
1648
1649 /* Do we have urgent data here? */
1650 if (tp->urg_data) {
1651 u32 urg_offset = tp->urg_seq - *seq;
1652 if (urg_offset < used) {
1653 if (!urg_offset) {
1654 if (!sock_flag(sk, SOCK_URGINLINE)) {
1655 ++*seq;
1656 urg_hole++;
1657 offset++;
1658 used--;
1659 if (!used)
1660 goto skip_copy;
1661 }
1662 } else
1663 used = urg_offset;
1664 }
1665 }
1666
1667 if (!(flags & MSG_TRUNC)) {
1668 #ifdef CONFIG_NET_DMA
1669 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1670 tp->ucopy.dma_chan = net_dma_find_channel();
1671
1672 if (tp->ucopy.dma_chan) {
1673 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1674 tp->ucopy.dma_chan, skb, offset,
1675 msg->msg_iov, used,
1676 tp->ucopy.pinned_list);
1677
1678 if (tp->ucopy.dma_cookie < 0) {
1679
1680 pr_alert("%s: dma_cookie < 0\n",
1681 __func__);
1682
1683 /* Exception. Bailout! */
1684 if (!copied)
1685 copied = -EFAULT;
1686 break;
1687 }
1688
1689 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1690
1691 if ((offset + used) == skb->len)
1692 copied_early = 1;
1693
1694 } else
1695 #endif
1696 {
1697 err = skb_copy_datagram_iovec(skb, offset,
1698 msg->msg_iov, used);
1699 if (err) {
1700 /* Exception. Bailout! */
1701 if (!copied)
1702 copied = -EFAULT;
1703 break;
1704 }
1705 }
1706 }
1707
1708 *seq += used;
1709 copied += used;
1710 len -= used;
1711
1712 tcp_rcv_space_adjust(sk);
1713
1714 skip_copy:
1715 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1716 tp->urg_data = 0;
1717 tcp_fast_path_check(sk);
1718 }
1719 if (used + offset < skb->len)
1720 continue;
1721
1722 if (tcp_hdr(skb)->fin)
1723 goto found_fin_ok;
1724 if (!(flags & MSG_PEEK)) {
1725 sk_eat_skb(sk, skb, copied_early);
1726 copied_early = 0;
1727 }
1728 continue;
1729
1730 found_fin_ok:
1731 /* Process the FIN. */
1732 ++*seq;
1733 if (!(flags & MSG_PEEK)) {
1734 sk_eat_skb(sk, skb, copied_early);
1735 copied_early = 0;
1736 }
1737 break;
1738 } while (len > 0);
1739
1740 if (user_recv) {
1741 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1742 int chunk;
1743
1744 tp->ucopy.len = copied > 0 ? len : 0;
1745
1746 tcp_prequeue_process(sk);
1747
1748 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1749 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1750 len -= chunk;
1751 copied += chunk;
1752 }
1753 }
1754
1755 tp->ucopy.task = NULL;
1756 tp->ucopy.len = 0;
1757 }
1758
1759 #ifdef CONFIG_NET_DMA
1760 tcp_service_net_dma(sk, true); /* Wait for queue to drain */
1761 tp->ucopy.dma_chan = NULL;
1762
1763 if (tp->ucopy.pinned_list) {
1764 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1765 tp->ucopy.pinned_list = NULL;
1766 }
1767 #endif
1768
1769 /* According to UNIX98, msg_name/msg_namelen are ignored
1770 * on connected socket. I was just happy when found this 8) --ANK
1771 */
1772
1773 /* Clean up data we have read: This will do ACK frames. */
1774 tcp_cleanup_rbuf(sk, copied);
1775
1776 release_sock(sk);
1777 return copied;
1778
1779 out:
1780 release_sock(sk);
1781 return err;
1782
1783 recv_urg:
1784 err = tcp_recv_urg(sk, msg, len, flags);
1785 goto out;
1786 }
1787 EXPORT_SYMBOL(tcp_recvmsg);
1788
1789 void tcp_set_state(struct sock *sk, int state)
1790 {
1791 int oldstate = sk->sk_state;
1792
1793 switch (state) {
1794 case TCP_ESTABLISHED:
1795 if (oldstate != TCP_ESTABLISHED)
1796 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1797 break;
1798
1799 case TCP_CLOSE:
1800 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1801 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
1802
1803 sk->sk_prot->unhash(sk);
1804 if (inet_csk(sk)->icsk_bind_hash &&
1805 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1806 inet_put_port(sk);
1807 /* fall through */
1808 default:
1809 if (oldstate == TCP_ESTABLISHED)
1810 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1811 }
1812
1813 /* Change state AFTER socket is unhashed to avoid closed
1814 * socket sitting in hash tables.
1815 */
1816 sk->sk_state = state;
1817
1818 #ifdef STATE_TRACE
1819 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
1820 #endif
1821 }
1822 EXPORT_SYMBOL_GPL(tcp_set_state);
1823
1824 /*
1825 * State processing on a close. This implements the state shift for
1826 * sending our FIN frame. Note that we only send a FIN for some
1827 * states. A shutdown() may have already sent the FIN, or we may be
1828 * closed.
1829 */
1830
1831 static const unsigned char new_state[16] = {
1832 /* current state: new state: action: */
1833 /* (Invalid) */ TCP_CLOSE,
1834 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1835 /* TCP_SYN_SENT */ TCP_CLOSE,
1836 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1837 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1838 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1839 /* TCP_TIME_WAIT */ TCP_CLOSE,
1840 /* TCP_CLOSE */ TCP_CLOSE,
1841 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1842 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1843 /* TCP_LISTEN */ TCP_CLOSE,
1844 /* TCP_CLOSING */ TCP_CLOSING,
1845 };
1846
1847 static int tcp_close_state(struct sock *sk)
1848 {
1849 int next = (int)new_state[sk->sk_state];
1850 int ns = next & TCP_STATE_MASK;
1851
1852 tcp_set_state(sk, ns);
1853
1854 return next & TCP_ACTION_FIN;
1855 }
1856
1857 /*
1858 * Shutdown the sending side of a connection. Much like close except
1859 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1860 */
1861
1862 void tcp_shutdown(struct sock *sk, int how)
1863 {
1864 /* We need to grab some memory, and put together a FIN,
1865 * and then put it into the queue to be sent.
1866 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1867 */
1868 if (!(how & SEND_SHUTDOWN))
1869 return;
1870
1871 /* If we've already sent a FIN, or it's a closed state, skip this. */
1872 if ((1 << sk->sk_state) &
1873 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1874 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1875 /* Clear out any half completed packets. FIN if needed. */
1876 if (tcp_close_state(sk))
1877 tcp_send_fin(sk);
1878 }
1879 }
1880 EXPORT_SYMBOL(tcp_shutdown);
1881
1882 bool tcp_check_oom(struct sock *sk, int shift)
1883 {
1884 bool too_many_orphans, out_of_socket_memory;
1885
1886 too_many_orphans = tcp_too_many_orphans(sk, shift);
1887 out_of_socket_memory = tcp_out_of_memory(sk);
1888
1889 if (too_many_orphans && net_ratelimit())
1890 pr_info("too many orphaned sockets\n");
1891 if (out_of_socket_memory && net_ratelimit())
1892 pr_info("out of memory -- consider tuning tcp_mem\n");
1893 return too_many_orphans || out_of_socket_memory;
1894 }
1895
1896 void tcp_close(struct sock *sk, long timeout)
1897 {
1898 struct sk_buff *skb;
1899 int data_was_unread = 0;
1900 int state;
1901
1902 lock_sock(sk);
1903 sk->sk_shutdown = SHUTDOWN_MASK;
1904
1905 if (sk->sk_state == TCP_LISTEN) {
1906 tcp_set_state(sk, TCP_CLOSE);
1907
1908 /* Special case. */
1909 inet_csk_listen_stop(sk);
1910
1911 goto adjudge_to_death;
1912 }
1913
1914 /* We need to flush the recv. buffs. We do this only on the
1915 * descriptor close, not protocol-sourced closes, because the
1916 * reader process may not have drained the data yet!
1917 */
1918 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1919 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
1920 tcp_hdr(skb)->fin;
1921 data_was_unread += len;
1922 __kfree_skb(skb);
1923 }
1924
1925 sk_mem_reclaim(sk);
1926
1927 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
1928 if (sk->sk_state == TCP_CLOSE)
1929 goto adjudge_to_death;
1930
1931 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1932 * data was lost. To witness the awful effects of the old behavior of
1933 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1934 * GET in an FTP client, suspend the process, wait for the client to
1935 * advertise a zero window, then kill -9 the FTP client, wheee...
1936 * Note: timeout is always zero in such a case.
1937 */
1938 if (data_was_unread) {
1939 /* Unread data was tossed, zap the connection. */
1940 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
1941 tcp_set_state(sk, TCP_CLOSE);
1942 tcp_send_active_reset(sk, sk->sk_allocation);
1943 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1944 /* Check zero linger _after_ checking for unread data. */
1945 sk->sk_prot->disconnect(sk, 0);
1946 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
1947 } else if (tcp_close_state(sk)) {
1948 /* We FIN if the application ate all the data before
1949 * zapping the connection.
1950 */
1951
1952 /* RED-PEN. Formally speaking, we have broken TCP state
1953 * machine. State transitions:
1954 *
1955 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1956 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1957 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1958 *
1959 * are legal only when FIN has been sent (i.e. in window),
1960 * rather than queued out of window. Purists blame.
1961 *
1962 * F.e. "RFC state" is ESTABLISHED,
1963 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1964 *
1965 * The visible declinations are that sometimes
1966 * we enter time-wait state, when it is not required really
1967 * (harmless), do not send active resets, when they are
1968 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1969 * they look as CLOSING or LAST_ACK for Linux)
1970 * Probably, I missed some more holelets.
1971 * --ANK
1972 */
1973 tcp_send_fin(sk);
1974 }
1975
1976 sk_stream_wait_close(sk, timeout);
1977
1978 adjudge_to_death:
1979 state = sk->sk_state;
1980 sock_hold(sk);
1981 sock_orphan(sk);
1982
1983 /* It is the last release_sock in its life. It will remove backlog. */
1984 release_sock(sk);
1985
1986
1987 /* Now socket is owned by kernel and we acquire BH lock
1988 to finish close. No need to check for user refs.
1989 */
1990 local_bh_disable();
1991 bh_lock_sock(sk);
1992 WARN_ON(sock_owned_by_user(sk));
1993
1994 percpu_counter_inc(sk->sk_prot->orphan_count);
1995
1996 /* Have we already been destroyed by a softirq or backlog? */
1997 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1998 goto out;
1999
2000 /* This is a (useful) BSD violating of the RFC. There is a
2001 * problem with TCP as specified in that the other end could
2002 * keep a socket open forever with no application left this end.
2003 * We use a 3 minute timeout (about the same as BSD) then kill
2004 * our end. If they send after that then tough - BUT: long enough
2005 * that we won't make the old 4*rto = almost no time - whoops
2006 * reset mistake.
2007 *
2008 * Nope, it was not mistake. It is really desired behaviour
2009 * f.e. on http servers, when such sockets are useless, but
2010 * consume significant resources. Let's do it with special
2011 * linger2 option. --ANK
2012 */
2013
2014 if (sk->sk_state == TCP_FIN_WAIT2) {
2015 struct tcp_sock *tp = tcp_sk(sk);
2016 if (tp->linger2 < 0) {
2017 tcp_set_state(sk, TCP_CLOSE);
2018 tcp_send_active_reset(sk, GFP_ATOMIC);
2019 NET_INC_STATS_BH(sock_net(sk),
2020 LINUX_MIB_TCPABORTONLINGER);
2021 } else {
2022 const int tmo = tcp_fin_time(sk);
2023
2024 if (tmo > TCP_TIMEWAIT_LEN) {
2025 inet_csk_reset_keepalive_timer(sk,
2026 tmo - TCP_TIMEWAIT_LEN);
2027 } else {
2028 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2029 goto out;
2030 }
2031 }
2032 }
2033 if (sk->sk_state != TCP_CLOSE) {
2034 sk_mem_reclaim(sk);
2035 if (tcp_check_oom(sk, 0)) {
2036 tcp_set_state(sk, TCP_CLOSE);
2037 tcp_send_active_reset(sk, GFP_ATOMIC);
2038 NET_INC_STATS_BH(sock_net(sk),
2039 LINUX_MIB_TCPABORTONMEMORY);
2040 }
2041 }
2042
2043 if (sk->sk_state == TCP_CLOSE)
2044 inet_csk_destroy_sock(sk);
2045 /* Otherwise, socket is reprieved until protocol close. */
2046
2047 out:
2048 bh_unlock_sock(sk);
2049 local_bh_enable();
2050 sock_put(sk);
2051 }
2052 EXPORT_SYMBOL(tcp_close);
2053
2054 /* These states need RST on ABORT according to RFC793 */
2055
2056 static inline int tcp_need_reset(int state)
2057 {
2058 return (1 << state) &
2059 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2060 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2061 }
2062
2063 int tcp_disconnect(struct sock *sk, int flags)
2064 {
2065 struct inet_sock *inet = inet_sk(sk);
2066 struct inet_connection_sock *icsk = inet_csk(sk);
2067 struct tcp_sock *tp = tcp_sk(sk);
2068 int err = 0;
2069 int old_state = sk->sk_state;
2070
2071 if (old_state != TCP_CLOSE)
2072 tcp_set_state(sk, TCP_CLOSE);
2073
2074 /* ABORT function of RFC793 */
2075 if (old_state == TCP_LISTEN) {
2076 inet_csk_listen_stop(sk);
2077 } else if (tcp_need_reset(old_state) ||
2078 (tp->snd_nxt != tp->write_seq &&
2079 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2080 /* The last check adjusts for discrepancy of Linux wrt. RFC
2081 * states
2082 */
2083 tcp_send_active_reset(sk, gfp_any());
2084 sk->sk_err = ECONNRESET;
2085 } else if (old_state == TCP_SYN_SENT)
2086 sk->sk_err = ECONNRESET;
2087
2088 tcp_clear_xmit_timers(sk);
2089 __skb_queue_purge(&sk->sk_receive_queue);
2090 tcp_write_queue_purge(sk);
2091 __skb_queue_purge(&tp->out_of_order_queue);
2092 #ifdef CONFIG_NET_DMA
2093 __skb_queue_purge(&sk->sk_async_wait_queue);
2094 #endif
2095
2096 inet->inet_dport = 0;
2097
2098 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2099 inet_reset_saddr(sk);
2100
2101 sk->sk_shutdown = 0;
2102 sock_reset_flag(sk, SOCK_DONE);
2103 tp->srtt = 0;
2104 if ((tp->write_seq += tp->max_window + 2) == 0)
2105 tp->write_seq = 1;
2106 icsk->icsk_backoff = 0;
2107 tp->snd_cwnd = 2;
2108 icsk->icsk_probes_out = 0;
2109 tp->packets_out = 0;
2110 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2111 tp->snd_cwnd_cnt = 0;
2112 tp->bytes_acked = 0;
2113 tp->window_clamp = 0;
2114 tcp_set_ca_state(sk, TCP_CA_Open);
2115 tcp_clear_retrans(tp);
2116 inet_csk_delack_init(sk);
2117 tcp_init_send_head(sk);
2118 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2119 __sk_dst_reset(sk);
2120
2121 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2122
2123 sk->sk_error_report(sk);
2124 return err;
2125 }
2126 EXPORT_SYMBOL(tcp_disconnect);
2127
2128 /*
2129 * Socket option code for TCP.
2130 */
2131 static int do_tcp_setsockopt(struct sock *sk, int level,
2132 int optname, char __user *optval, unsigned int optlen)
2133 {
2134 struct tcp_sock *tp = tcp_sk(sk);
2135 struct inet_connection_sock *icsk = inet_csk(sk);
2136 int val;
2137 int err = 0;
2138
2139 /* These are data/string values, all the others are ints */
2140 switch (optname) {
2141 case TCP_CONGESTION: {
2142 char name[TCP_CA_NAME_MAX];
2143
2144 if (optlen < 1)
2145 return -EINVAL;
2146
2147 val = strncpy_from_user(name, optval,
2148 min_t(long, TCP_CA_NAME_MAX-1, optlen));
2149 if (val < 0)
2150 return -EFAULT;
2151 name[val] = 0;
2152
2153 lock_sock(sk);
2154 err = tcp_set_congestion_control(sk, name);
2155 release_sock(sk);
2156 return err;
2157 }
2158 case TCP_COOKIE_TRANSACTIONS: {
2159 struct tcp_cookie_transactions ctd;
2160 struct tcp_cookie_values *cvp = NULL;
2161
2162 if (sizeof(ctd) > optlen)
2163 return -EINVAL;
2164 if (copy_from_user(&ctd, optval, sizeof(ctd)))
2165 return -EFAULT;
2166
2167 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) ||
2168 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED)
2169 return -EINVAL;
2170
2171 if (ctd.tcpct_cookie_desired == 0) {
2172 /* default to global value */
2173 } else if ((0x1 & ctd.tcpct_cookie_desired) ||
2174 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX ||
2175 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) {
2176 return -EINVAL;
2177 }
2178
2179 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) {
2180 /* Supercedes all other values */
2181 lock_sock(sk);
2182 if (tp->cookie_values != NULL) {
2183 kref_put(&tp->cookie_values->kref,
2184 tcp_cookie_values_release);
2185 tp->cookie_values = NULL;
2186 }
2187 tp->rx_opt.cookie_in_always = 0; /* false */
2188 tp->rx_opt.cookie_out_never = 1; /* true */
2189 release_sock(sk);
2190 return err;
2191 }
2192
2193 /* Allocate ancillary memory before locking.
2194 */
2195 if (ctd.tcpct_used > 0 ||
2196 (tp->cookie_values == NULL &&
2197 (sysctl_tcp_cookie_size > 0 ||
2198 ctd.tcpct_cookie_desired > 0 ||
2199 ctd.tcpct_s_data_desired > 0))) {
2200 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used,
2201 GFP_KERNEL);
2202 if (cvp == NULL)
2203 return -ENOMEM;
2204
2205 kref_init(&cvp->kref);
2206 }
2207 lock_sock(sk);
2208 tp->rx_opt.cookie_in_always =
2209 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags);
2210 tp->rx_opt.cookie_out_never = 0; /* false */
2211
2212 if (tp->cookie_values != NULL) {
2213 if (cvp != NULL) {
2214 /* Changed values are recorded by a changed
2215 * pointer, ensuring the cookie will differ,
2216 * without separately hashing each value later.
2217 */
2218 kref_put(&tp->cookie_values->kref,
2219 tcp_cookie_values_release);
2220 } else {
2221 cvp = tp->cookie_values;
2222 }
2223 }
2224
2225 if (cvp != NULL) {
2226 cvp->cookie_desired = ctd.tcpct_cookie_desired;
2227
2228 if (ctd.tcpct_used > 0) {
2229 memcpy(cvp->s_data_payload, ctd.tcpct_value,
2230 ctd.tcpct_used);
2231 cvp->s_data_desired = ctd.tcpct_used;
2232 cvp->s_data_constant = 1; /* true */
2233 } else {
2234 /* No constant payload data. */
2235 cvp->s_data_desired = ctd.tcpct_s_data_desired;
2236 cvp->s_data_constant = 0; /* false */
2237 }
2238
2239 tp->cookie_values = cvp;
2240 }
2241 release_sock(sk);
2242 return err;
2243 }
2244 default:
2245 /* fallthru */
2246 break;
2247 }
2248
2249 if (optlen < sizeof(int))
2250 return -EINVAL;
2251
2252 if (get_user(val, (int __user *)optval))
2253 return -EFAULT;
2254
2255 lock_sock(sk);
2256
2257 switch (optname) {
2258 case TCP_MAXSEG:
2259 /* Values greater than interface MTU won't take effect. However
2260 * at the point when this call is done we typically don't yet
2261 * know which interface is going to be used */
2262 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
2263 err = -EINVAL;
2264 break;
2265 }
2266 tp->rx_opt.user_mss = val;
2267 break;
2268
2269 case TCP_NODELAY:
2270 if (val) {
2271 /* TCP_NODELAY is weaker than TCP_CORK, so that
2272 * this option on corked socket is remembered, but
2273 * it is not activated until cork is cleared.
2274 *
2275 * However, when TCP_NODELAY is set we make
2276 * an explicit push, which overrides even TCP_CORK
2277 * for currently queued segments.
2278 */
2279 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2280 tcp_push_pending_frames(sk);
2281 } else {
2282 tp->nonagle &= ~TCP_NAGLE_OFF;
2283 }
2284 break;
2285
2286 case TCP_THIN_LINEAR_TIMEOUTS:
2287 if (val < 0 || val > 1)
2288 err = -EINVAL;
2289 else
2290 tp->thin_lto = val;
2291 break;
2292
2293 case TCP_THIN_DUPACK:
2294 if (val < 0 || val > 1)
2295 err = -EINVAL;
2296 else
2297 tp->thin_dupack = val;
2298 break;
2299
2300 case TCP_CORK:
2301 /* When set indicates to always queue non-full frames.
2302 * Later the user clears this option and we transmit
2303 * any pending partial frames in the queue. This is
2304 * meant to be used alongside sendfile() to get properly
2305 * filled frames when the user (for example) must write
2306 * out headers with a write() call first and then use
2307 * sendfile to send out the data parts.
2308 *
2309 * TCP_CORK can be set together with TCP_NODELAY and it is
2310 * stronger than TCP_NODELAY.
2311 */
2312 if (val) {
2313 tp->nonagle |= TCP_NAGLE_CORK;
2314 } else {
2315 tp->nonagle &= ~TCP_NAGLE_CORK;
2316 if (tp->nonagle&TCP_NAGLE_OFF)
2317 tp->nonagle |= TCP_NAGLE_PUSH;
2318 tcp_push_pending_frames(sk);
2319 }
2320 break;
2321
2322 case TCP_KEEPIDLE:
2323 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2324 err = -EINVAL;
2325 else {
2326 tp->keepalive_time = val * HZ;
2327 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2328 !((1 << sk->sk_state) &
2329 (TCPF_CLOSE | TCPF_LISTEN))) {
2330 u32 elapsed = keepalive_time_elapsed(tp);
2331 if (tp->keepalive_time > elapsed)
2332 elapsed = tp->keepalive_time - elapsed;
2333 else
2334 elapsed = 0;
2335 inet_csk_reset_keepalive_timer(sk, elapsed);
2336 }
2337 }
2338 break;
2339 case TCP_KEEPINTVL:
2340 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2341 err = -EINVAL;
2342 else
2343 tp->keepalive_intvl = val * HZ;
2344 break;
2345 case TCP_KEEPCNT:
2346 if (val < 1 || val > MAX_TCP_KEEPCNT)
2347 err = -EINVAL;
2348 else
2349 tp->keepalive_probes = val;
2350 break;
2351 case TCP_SYNCNT:
2352 if (val < 1 || val > MAX_TCP_SYNCNT)
2353 err = -EINVAL;
2354 else
2355 icsk->icsk_syn_retries = val;
2356 break;
2357
2358 case TCP_LINGER2:
2359 if (val < 0)
2360 tp->linger2 = -1;
2361 else if (val > sysctl_tcp_fin_timeout / HZ)
2362 tp->linger2 = 0;
2363 else
2364 tp->linger2 = val * HZ;
2365 break;
2366
2367 case TCP_DEFER_ACCEPT:
2368 /* Translate value in seconds to number of retransmits */
2369 icsk->icsk_accept_queue.rskq_defer_accept =
2370 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2371 TCP_RTO_MAX / HZ);
2372 break;
2373
2374 case TCP_WINDOW_CLAMP:
2375 if (!val) {
2376 if (sk->sk_state != TCP_CLOSE) {
2377 err = -EINVAL;
2378 break;
2379 }
2380 tp->window_clamp = 0;
2381 } else
2382 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2383 SOCK_MIN_RCVBUF / 2 : val;
2384 break;
2385
2386 case TCP_QUICKACK:
2387 if (!val) {
2388 icsk->icsk_ack.pingpong = 1;
2389 } else {
2390 icsk->icsk_ack.pingpong = 0;
2391 if ((1 << sk->sk_state) &
2392 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2393 inet_csk_ack_scheduled(sk)) {
2394 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2395 tcp_cleanup_rbuf(sk, 1);
2396 if (!(val & 1))
2397 icsk->icsk_ack.pingpong = 1;
2398 }
2399 }
2400 break;
2401
2402 #ifdef CONFIG_TCP_MD5SIG
2403 case TCP_MD5SIG:
2404 /* Read the IP->Key mappings from userspace */
2405 err = tp->af_specific->md5_parse(sk, optval, optlen);
2406 break;
2407 #endif
2408 case TCP_USER_TIMEOUT:
2409 /* Cap the max timeout in ms TCP will retry/retrans
2410 * before giving up and aborting (ETIMEDOUT) a connection.
2411 */
2412 icsk->icsk_user_timeout = msecs_to_jiffies(val);
2413 break;
2414 default:
2415 err = -ENOPROTOOPT;
2416 break;
2417 }
2418
2419 release_sock(sk);
2420 return err;
2421 }
2422
2423 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2424 unsigned int optlen)
2425 {
2426 const struct inet_connection_sock *icsk = inet_csk(sk);
2427
2428 if (level != SOL_TCP)
2429 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2430 optval, optlen);
2431 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2432 }
2433 EXPORT_SYMBOL(tcp_setsockopt);
2434
2435 #ifdef CONFIG_COMPAT
2436 int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2437 char __user *optval, unsigned int optlen)
2438 {
2439 if (level != SOL_TCP)
2440 return inet_csk_compat_setsockopt(sk, level, optname,
2441 optval, optlen);
2442 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2443 }
2444 EXPORT_SYMBOL(compat_tcp_setsockopt);
2445 #endif
2446
2447 /* Return information about state of tcp endpoint in API format. */
2448 void tcp_get_info(const struct sock *sk, struct tcp_info *info)
2449 {
2450 const struct tcp_sock *tp = tcp_sk(sk);
2451 const struct inet_connection_sock *icsk = inet_csk(sk);
2452 u32 now = tcp_time_stamp;
2453
2454 memset(info, 0, sizeof(*info));
2455
2456 info->tcpi_state = sk->sk_state;
2457 info->tcpi_ca_state = icsk->icsk_ca_state;
2458 info->tcpi_retransmits = icsk->icsk_retransmits;
2459 info->tcpi_probes = icsk->icsk_probes_out;
2460 info->tcpi_backoff = icsk->icsk_backoff;
2461
2462 if (tp->rx_opt.tstamp_ok)
2463 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2464 if (tcp_is_sack(tp))
2465 info->tcpi_options |= TCPI_OPT_SACK;
2466 if (tp->rx_opt.wscale_ok) {
2467 info->tcpi_options |= TCPI_OPT_WSCALE;
2468 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2469 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2470 }
2471
2472 if (tp->ecn_flags & TCP_ECN_OK)
2473 info->tcpi_options |= TCPI_OPT_ECN;
2474 if (tp->ecn_flags & TCP_ECN_SEEN)
2475 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
2476
2477 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2478 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2479 info->tcpi_snd_mss = tp->mss_cache;
2480 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2481
2482 if (sk->sk_state == TCP_LISTEN) {
2483 info->tcpi_unacked = sk->sk_ack_backlog;
2484 info->tcpi_sacked = sk->sk_max_ack_backlog;
2485 } else {
2486 info->tcpi_unacked = tp->packets_out;
2487 info->tcpi_sacked = tp->sacked_out;
2488 }
2489 info->tcpi_lost = tp->lost_out;
2490 info->tcpi_retrans = tp->retrans_out;
2491 info->tcpi_fackets = tp->fackets_out;
2492
2493 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2494 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2495 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2496
2497 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2498 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2499 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2500 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2501 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2502 info->tcpi_snd_cwnd = tp->snd_cwnd;
2503 info->tcpi_advmss = tp->advmss;
2504 info->tcpi_reordering = tp->reordering;
2505
2506 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2507 info->tcpi_rcv_space = tp->rcvq_space.space;
2508
2509 info->tcpi_total_retrans = tp->total_retrans;
2510 }
2511 EXPORT_SYMBOL_GPL(tcp_get_info);
2512
2513 static int do_tcp_getsockopt(struct sock *sk, int level,
2514 int optname, char __user *optval, int __user *optlen)
2515 {
2516 struct inet_connection_sock *icsk = inet_csk(sk);
2517 struct tcp_sock *tp = tcp_sk(sk);
2518 int val, len;
2519
2520 if (get_user(len, optlen))
2521 return -EFAULT;
2522
2523 len = min_t(unsigned int, len, sizeof(int));
2524
2525 if (len < 0)
2526 return -EINVAL;
2527
2528 switch (optname) {
2529 case TCP_MAXSEG:
2530 val = tp->mss_cache;
2531 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2532 val = tp->rx_opt.user_mss;
2533 break;
2534 case TCP_NODELAY:
2535 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2536 break;
2537 case TCP_CORK:
2538 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2539 break;
2540 case TCP_KEEPIDLE:
2541 val = keepalive_time_when(tp) / HZ;
2542 break;
2543 case TCP_KEEPINTVL:
2544 val = keepalive_intvl_when(tp) / HZ;
2545 break;
2546 case TCP_KEEPCNT:
2547 val = keepalive_probes(tp);
2548 break;
2549 case TCP_SYNCNT:
2550 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2551 break;
2552 case TCP_LINGER2:
2553 val = tp->linger2;
2554 if (val >= 0)
2555 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2556 break;
2557 case TCP_DEFER_ACCEPT:
2558 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2559 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
2560 break;
2561 case TCP_WINDOW_CLAMP:
2562 val = tp->window_clamp;
2563 break;
2564 case TCP_INFO: {
2565 struct tcp_info info;
2566
2567 if (get_user(len, optlen))
2568 return -EFAULT;
2569
2570 tcp_get_info(sk, &info);
2571
2572 len = min_t(unsigned int, len, sizeof(info));
2573 if (put_user(len, optlen))
2574 return -EFAULT;
2575 if (copy_to_user(optval, &info, len))
2576 return -EFAULT;
2577 return 0;
2578 }
2579 case TCP_QUICKACK:
2580 val = !icsk->icsk_ack.pingpong;
2581 break;
2582
2583 case TCP_CONGESTION:
2584 if (get_user(len, optlen))
2585 return -EFAULT;
2586 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2587 if (put_user(len, optlen))
2588 return -EFAULT;
2589 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2590 return -EFAULT;
2591 return 0;
2592
2593 case TCP_COOKIE_TRANSACTIONS: {
2594 struct tcp_cookie_transactions ctd;
2595 struct tcp_cookie_values *cvp = tp->cookie_values;
2596
2597 if (get_user(len, optlen))
2598 return -EFAULT;
2599 if (len < sizeof(ctd))
2600 return -EINVAL;
2601
2602 memset(&ctd, 0, sizeof(ctd));
2603 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ?
2604 TCP_COOKIE_IN_ALWAYS : 0)
2605 | (tp->rx_opt.cookie_out_never ?
2606 TCP_COOKIE_OUT_NEVER : 0);
2607
2608 if (cvp != NULL) {
2609 ctd.tcpct_flags |= (cvp->s_data_in ?
2610 TCP_S_DATA_IN : 0)
2611 | (cvp->s_data_out ?
2612 TCP_S_DATA_OUT : 0);
2613
2614 ctd.tcpct_cookie_desired = cvp->cookie_desired;
2615 ctd.tcpct_s_data_desired = cvp->s_data_desired;
2616
2617 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0],
2618 cvp->cookie_pair_size);
2619 ctd.tcpct_used = cvp->cookie_pair_size;
2620 }
2621
2622 if (put_user(sizeof(ctd), optlen))
2623 return -EFAULT;
2624 if (copy_to_user(optval, &ctd, sizeof(ctd)))
2625 return -EFAULT;
2626 return 0;
2627 }
2628 case TCP_THIN_LINEAR_TIMEOUTS:
2629 val = tp->thin_lto;
2630 break;
2631 case TCP_THIN_DUPACK:
2632 val = tp->thin_dupack;
2633 break;
2634
2635 case TCP_USER_TIMEOUT:
2636 val = jiffies_to_msecs(icsk->icsk_user_timeout);
2637 break;
2638 default:
2639 return -ENOPROTOOPT;
2640 }
2641
2642 if (put_user(len, optlen))
2643 return -EFAULT;
2644 if (copy_to_user(optval, &val, len))
2645 return -EFAULT;
2646 return 0;
2647 }
2648
2649 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2650 int __user *optlen)
2651 {
2652 struct inet_connection_sock *icsk = inet_csk(sk);
2653
2654 if (level != SOL_TCP)
2655 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2656 optval, optlen);
2657 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2658 }
2659 EXPORT_SYMBOL(tcp_getsockopt);
2660
2661 #ifdef CONFIG_COMPAT
2662 int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2663 char __user *optval, int __user *optlen)
2664 {
2665 if (level != SOL_TCP)
2666 return inet_csk_compat_getsockopt(sk, level, optname,
2667 optval, optlen);
2668 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2669 }
2670 EXPORT_SYMBOL(compat_tcp_getsockopt);
2671 #endif
2672
2673 struct sk_buff *tcp_tso_segment(struct sk_buff *skb,
2674 netdev_features_t features)
2675 {
2676 struct sk_buff *segs = ERR_PTR(-EINVAL);
2677 struct tcphdr *th;
2678 unsigned thlen;
2679 unsigned int seq;
2680 __be32 delta;
2681 unsigned int oldlen;
2682 unsigned int mss;
2683
2684 if (!pskb_may_pull(skb, sizeof(*th)))
2685 goto out;
2686
2687 th = tcp_hdr(skb);
2688 thlen = th->doff * 4;
2689 if (thlen < sizeof(*th))
2690 goto out;
2691
2692 if (!pskb_may_pull(skb, thlen))
2693 goto out;
2694
2695 oldlen = (u16)~skb->len;
2696 __skb_pull(skb, thlen);
2697
2698 mss = skb_shinfo(skb)->gso_size;
2699 if (unlikely(skb->len <= mss))
2700 goto out;
2701
2702 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2703 /* Packet is from an untrusted source, reset gso_segs. */
2704 int type = skb_shinfo(skb)->gso_type;
2705
2706 if (unlikely(type &
2707 ~(SKB_GSO_TCPV4 |
2708 SKB_GSO_DODGY |
2709 SKB_GSO_TCP_ECN |
2710 SKB_GSO_TCPV6 |
2711 0) ||
2712 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2713 goto out;
2714
2715 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2716
2717 segs = NULL;
2718 goto out;
2719 }
2720
2721 segs = skb_segment(skb, features);
2722 if (IS_ERR(segs))
2723 goto out;
2724
2725 delta = htonl(oldlen + (thlen + mss));
2726
2727 skb = segs;
2728 th = tcp_hdr(skb);
2729 seq = ntohl(th->seq);
2730
2731 do {
2732 th->fin = th->psh = 0;
2733
2734 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2735 (__force u32)delta));
2736 if (skb->ip_summed != CHECKSUM_PARTIAL)
2737 th->check =
2738 csum_fold(csum_partial(skb_transport_header(skb),
2739 thlen, skb->csum));
2740
2741 seq += mss;
2742 skb = skb->next;
2743 th = tcp_hdr(skb);
2744
2745 th->seq = htonl(seq);
2746 th->cwr = 0;
2747 } while (skb->next);
2748
2749 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
2750 skb->data_len);
2751 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2752 (__force u32)delta));
2753 if (skb->ip_summed != CHECKSUM_PARTIAL)
2754 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2755 thlen, skb->csum));
2756
2757 out:
2758 return segs;
2759 }
2760 EXPORT_SYMBOL(tcp_tso_segment);
2761
2762 struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2763 {
2764 struct sk_buff **pp = NULL;
2765 struct sk_buff *p;
2766 struct tcphdr *th;
2767 struct tcphdr *th2;
2768 unsigned int len;
2769 unsigned int thlen;
2770 __be32 flags;
2771 unsigned int mss = 1;
2772 unsigned int hlen;
2773 unsigned int off;
2774 int flush = 1;
2775 int i;
2776
2777 off = skb_gro_offset(skb);
2778 hlen = off + sizeof(*th);
2779 th = skb_gro_header_fast(skb, off);
2780 if (skb_gro_header_hard(skb, hlen)) {
2781 th = skb_gro_header_slow(skb, hlen, off);
2782 if (unlikely(!th))
2783 goto out;
2784 }
2785
2786 thlen = th->doff * 4;
2787 if (thlen < sizeof(*th))
2788 goto out;
2789
2790 hlen = off + thlen;
2791 if (skb_gro_header_hard(skb, hlen)) {
2792 th = skb_gro_header_slow(skb, hlen, off);
2793 if (unlikely(!th))
2794 goto out;
2795 }
2796
2797 skb_gro_pull(skb, thlen);
2798
2799 len = skb_gro_len(skb);
2800 flags = tcp_flag_word(th);
2801
2802 for (; (p = *head); head = &p->next) {
2803 if (!NAPI_GRO_CB(p)->same_flow)
2804 continue;
2805
2806 th2 = tcp_hdr(p);
2807
2808 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
2809 NAPI_GRO_CB(p)->same_flow = 0;
2810 continue;
2811 }
2812
2813 goto found;
2814 }
2815
2816 goto out_check_final;
2817
2818 found:
2819 flush = NAPI_GRO_CB(p)->flush;
2820 flush |= (__force int)(flags & TCP_FLAG_CWR);
2821 flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
2822 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
2823 flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
2824 for (i = sizeof(*th); i < thlen; i += 4)
2825 flush |= *(u32 *)((u8 *)th + i) ^
2826 *(u32 *)((u8 *)th2 + i);
2827
2828 mss = skb_shinfo(p)->gso_size;
2829
2830 flush |= (len - 1) >= mss;
2831 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
2832
2833 if (flush || skb_gro_receive(head, skb)) {
2834 mss = 1;
2835 goto out_check_final;
2836 }
2837
2838 p = *head;
2839 th2 = tcp_hdr(p);
2840 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
2841
2842 out_check_final:
2843 flush = len < mss;
2844 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH |
2845 TCP_FLAG_RST | TCP_FLAG_SYN |
2846 TCP_FLAG_FIN));
2847
2848 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
2849 pp = head;
2850
2851 out:
2852 NAPI_GRO_CB(skb)->flush |= flush;
2853
2854 return pp;
2855 }
2856 EXPORT_SYMBOL(tcp_gro_receive);
2857
2858 int tcp_gro_complete(struct sk_buff *skb)
2859 {
2860 struct tcphdr *th = tcp_hdr(skb);
2861
2862 skb->csum_start = skb_transport_header(skb) - skb->head;
2863 skb->csum_offset = offsetof(struct tcphdr, check);
2864 skb->ip_summed = CHECKSUM_PARTIAL;
2865
2866 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
2867
2868 if (th->cwr)
2869 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
2870
2871 return 0;
2872 }
2873 EXPORT_SYMBOL(tcp_gro_complete);
2874
2875 #ifdef CONFIG_TCP_MD5SIG
2876 static unsigned long tcp_md5sig_users;
2877 static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool;
2878 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2879
2880 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool)
2881 {
2882 int cpu;
2883
2884 for_each_possible_cpu(cpu) {
2885 struct tcp_md5sig_pool *p = per_cpu_ptr(pool, cpu);
2886
2887 if (p->md5_desc.tfm)
2888 crypto_free_hash(p->md5_desc.tfm);
2889 }
2890 free_percpu(pool);
2891 }
2892
2893 void tcp_free_md5sig_pool(void)
2894 {
2895 struct tcp_md5sig_pool __percpu *pool = NULL;
2896
2897 spin_lock_bh(&tcp_md5sig_pool_lock);
2898 if (--tcp_md5sig_users == 0) {
2899 pool = tcp_md5sig_pool;
2900 tcp_md5sig_pool = NULL;
2901 }
2902 spin_unlock_bh(&tcp_md5sig_pool_lock);
2903 if (pool)
2904 __tcp_free_md5sig_pool(pool);
2905 }
2906 EXPORT_SYMBOL(tcp_free_md5sig_pool);
2907
2908 static struct tcp_md5sig_pool __percpu *
2909 __tcp_alloc_md5sig_pool(struct sock *sk)
2910 {
2911 int cpu;
2912 struct tcp_md5sig_pool __percpu *pool;
2913
2914 pool = alloc_percpu(struct tcp_md5sig_pool);
2915 if (!pool)
2916 return NULL;
2917
2918 for_each_possible_cpu(cpu) {
2919 struct crypto_hash *hash;
2920
2921 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2922 if (!hash || IS_ERR(hash))
2923 goto out_free;
2924
2925 per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash;
2926 }
2927 return pool;
2928 out_free:
2929 __tcp_free_md5sig_pool(pool);
2930 return NULL;
2931 }
2932
2933 struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *sk)
2934 {
2935 struct tcp_md5sig_pool __percpu *pool;
2936 int alloc = 0;
2937
2938 retry:
2939 spin_lock_bh(&tcp_md5sig_pool_lock);
2940 pool = tcp_md5sig_pool;
2941 if (tcp_md5sig_users++ == 0) {
2942 alloc = 1;
2943 spin_unlock_bh(&tcp_md5sig_pool_lock);
2944 } else if (!pool) {
2945 tcp_md5sig_users--;
2946 spin_unlock_bh(&tcp_md5sig_pool_lock);
2947 cpu_relax();
2948 goto retry;
2949 } else
2950 spin_unlock_bh(&tcp_md5sig_pool_lock);
2951
2952 if (alloc) {
2953 /* we cannot hold spinlock here because this may sleep. */
2954 struct tcp_md5sig_pool __percpu *p;
2955
2956 p = __tcp_alloc_md5sig_pool(sk);
2957 spin_lock_bh(&tcp_md5sig_pool_lock);
2958 if (!p) {
2959 tcp_md5sig_users--;
2960 spin_unlock_bh(&tcp_md5sig_pool_lock);
2961 return NULL;
2962 }
2963 pool = tcp_md5sig_pool;
2964 if (pool) {
2965 /* oops, it has already been assigned. */
2966 spin_unlock_bh(&tcp_md5sig_pool_lock);
2967 __tcp_free_md5sig_pool(p);
2968 } else {
2969 tcp_md5sig_pool = pool = p;
2970 spin_unlock_bh(&tcp_md5sig_pool_lock);
2971 }
2972 }
2973 return pool;
2974 }
2975 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2976
2977
2978 /**
2979 * tcp_get_md5sig_pool - get md5sig_pool for this user
2980 *
2981 * We use percpu structure, so if we succeed, we exit with preemption
2982 * and BH disabled, to make sure another thread or softirq handling
2983 * wont try to get same context.
2984 */
2985 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
2986 {
2987 struct tcp_md5sig_pool __percpu *p;
2988
2989 local_bh_disable();
2990
2991 spin_lock(&tcp_md5sig_pool_lock);
2992 p = tcp_md5sig_pool;
2993 if (p)
2994 tcp_md5sig_users++;
2995 spin_unlock(&tcp_md5sig_pool_lock);
2996
2997 if (p)
2998 return this_cpu_ptr(p);
2999
3000 local_bh_enable();
3001 return NULL;
3002 }
3003 EXPORT_SYMBOL(tcp_get_md5sig_pool);
3004
3005 void tcp_put_md5sig_pool(void)
3006 {
3007 local_bh_enable();
3008 tcp_free_md5sig_pool();
3009 }
3010 EXPORT_SYMBOL(tcp_put_md5sig_pool);
3011
3012 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
3013 const struct tcphdr *th)
3014 {
3015 struct scatterlist sg;
3016 struct tcphdr hdr;
3017 int err;
3018
3019 /* We are not allowed to change tcphdr, make a local copy */
3020 memcpy(&hdr, th, sizeof(hdr));
3021 hdr.check = 0;
3022
3023 /* options aren't included in the hash */
3024 sg_init_one(&sg, &hdr, sizeof(hdr));
3025 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr));
3026 return err;
3027 }
3028 EXPORT_SYMBOL(tcp_md5_hash_header);
3029
3030 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3031 const struct sk_buff *skb, unsigned int header_len)
3032 {
3033 struct scatterlist sg;
3034 const struct tcphdr *tp = tcp_hdr(skb);
3035 struct hash_desc *desc = &hp->md5_desc;
3036 unsigned i;
3037 const unsigned head_data_len = skb_headlen(skb) > header_len ?
3038 skb_headlen(skb) - header_len : 0;
3039 const struct skb_shared_info *shi = skb_shinfo(skb);
3040 struct sk_buff *frag_iter;
3041
3042 sg_init_table(&sg, 1);
3043
3044 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3045 if (crypto_hash_update(desc, &sg, head_data_len))
3046 return 1;
3047
3048 for (i = 0; i < shi->nr_frags; ++i) {
3049 const struct skb_frag_struct *f = &shi->frags[i];
3050 struct page *page = skb_frag_page(f);
3051 sg_set_page(&sg, page, skb_frag_size(f), f->page_offset);
3052 if (crypto_hash_update(desc, &sg, skb_frag_size(f)))
3053 return 1;
3054 }
3055
3056 skb_walk_frags(skb, frag_iter)
3057 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3058 return 1;
3059
3060 return 0;
3061 }
3062 EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3063
3064 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3065 {
3066 struct scatterlist sg;
3067
3068 sg_init_one(&sg, key->key, key->keylen);
3069 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
3070 }
3071 EXPORT_SYMBOL(tcp_md5_hash_key);
3072
3073 #endif
3074
3075 /**
3076 * Each Responder maintains up to two secret values concurrently for
3077 * efficient secret rollover. Each secret value has 4 states:
3078 *
3079 * Generating. (tcp_secret_generating != tcp_secret_primary)
3080 * Generates new Responder-Cookies, but not yet used for primary
3081 * verification. This is a short-term state, typically lasting only
3082 * one round trip time (RTT).
3083 *
3084 * Primary. (tcp_secret_generating == tcp_secret_primary)
3085 * Used both for generation and primary verification.
3086 *
3087 * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
3088 * Used for verification, until the first failure that can be
3089 * verified by the newer Generating secret. At that time, this
3090 * cookie's state is changed to Secondary, and the Generating
3091 * cookie's state is changed to Primary. This is a short-term state,
3092 * typically lasting only one round trip time (RTT).
3093 *
3094 * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
3095 * Used for secondary verification, after primary verification
3096 * failures. This state lasts no more than twice the Maximum Segment
3097 * Lifetime (2MSL). Then, the secret is discarded.
3098 */
3099 struct tcp_cookie_secret {
3100 /* The secret is divided into two parts. The digest part is the
3101 * equivalent of previously hashing a secret and saving the state,
3102 * and serves as an initialization vector (IV). The message part
3103 * serves as the trailing secret.
3104 */
3105 u32 secrets[COOKIE_WORKSPACE_WORDS];
3106 unsigned long expires;
3107 };
3108
3109 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
3110 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
3111 #define TCP_SECRET_LIFE (HZ * 600)
3112
3113 static struct tcp_cookie_secret tcp_secret_one;
3114 static struct tcp_cookie_secret tcp_secret_two;
3115
3116 /* Essentially a circular list, without dynamic allocation. */
3117 static struct tcp_cookie_secret *tcp_secret_generating;
3118 static struct tcp_cookie_secret *tcp_secret_primary;
3119 static struct tcp_cookie_secret *tcp_secret_retiring;
3120 static struct tcp_cookie_secret *tcp_secret_secondary;
3121
3122 static DEFINE_SPINLOCK(tcp_secret_locker);
3123
3124 /* Select a pseudo-random word in the cookie workspace.
3125 */
3126 static inline u32 tcp_cookie_work(const u32 *ws, const int n)
3127 {
3128 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])];
3129 }
3130
3131 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
3132 * Called in softirq context.
3133 * Returns: 0 for success.
3134 */
3135 int tcp_cookie_generator(u32 *bakery)
3136 {
3137 unsigned long jiffy = jiffies;
3138
3139 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) {
3140 spin_lock_bh(&tcp_secret_locker);
3141 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) {
3142 /* refreshed by another */
3143 memcpy(bakery,
3144 &tcp_secret_generating->secrets[0],
3145 COOKIE_WORKSPACE_WORDS);
3146 } else {
3147 /* still needs refreshing */
3148 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS);
3149
3150 /* The first time, paranoia assumes that the
3151 * randomization function isn't as strong. But,
3152 * this secret initialization is delayed until
3153 * the last possible moment (packet arrival).
3154 * Although that time is observable, it is
3155 * unpredictably variable. Mash in the most
3156 * volatile clock bits available, and expire the
3157 * secret extra quickly.
3158 */
3159 if (unlikely(tcp_secret_primary->expires ==
3160 tcp_secret_secondary->expires)) {
3161 struct timespec tv;
3162
3163 getnstimeofday(&tv);
3164 bakery[COOKIE_DIGEST_WORDS+0] ^=
3165 (u32)tv.tv_nsec;
3166
3167 tcp_secret_secondary->expires = jiffy
3168 + TCP_SECRET_1MSL
3169 + (0x0f & tcp_cookie_work(bakery, 0));
3170 } else {
3171 tcp_secret_secondary->expires = jiffy
3172 + TCP_SECRET_LIFE
3173 + (0xff & tcp_cookie_work(bakery, 1));
3174 tcp_secret_primary->expires = jiffy
3175 + TCP_SECRET_2MSL
3176 + (0x1f & tcp_cookie_work(bakery, 2));
3177 }
3178 memcpy(&tcp_secret_secondary->secrets[0],
3179 bakery, COOKIE_WORKSPACE_WORDS);
3180
3181 rcu_assign_pointer(tcp_secret_generating,
3182 tcp_secret_secondary);
3183 rcu_assign_pointer(tcp_secret_retiring,
3184 tcp_secret_primary);
3185 /*
3186 * Neither call_rcu() nor synchronize_rcu() needed.
3187 * Retiring data is not freed. It is replaced after
3188 * further (locked) pointer updates, and a quiet time
3189 * (minimum 1MSL, maximum LIFE - 2MSL).
3190 */
3191 }
3192 spin_unlock_bh(&tcp_secret_locker);
3193 } else {
3194 rcu_read_lock_bh();
3195 memcpy(bakery,
3196 &rcu_dereference(tcp_secret_generating)->secrets[0],
3197 COOKIE_WORKSPACE_WORDS);
3198 rcu_read_unlock_bh();
3199 }
3200 return 0;
3201 }
3202 EXPORT_SYMBOL(tcp_cookie_generator);
3203
3204 void tcp_done(struct sock *sk)
3205 {
3206 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3207 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
3208
3209 tcp_set_state(sk, TCP_CLOSE);
3210 tcp_clear_xmit_timers(sk);
3211
3212 sk->sk_shutdown = SHUTDOWN_MASK;
3213
3214 if (!sock_flag(sk, SOCK_DEAD))
3215 sk->sk_state_change(sk);
3216 else
3217 inet_csk_destroy_sock(sk);
3218 }
3219 EXPORT_SYMBOL_GPL(tcp_done);
3220
3221 extern struct tcp_congestion_ops tcp_reno;
3222
3223 static __initdata unsigned long thash_entries;
3224 static int __init set_thash_entries(char *str)
3225 {
3226 if (!str)
3227 return 0;
3228 thash_entries = simple_strtoul(str, &str, 0);
3229 return 1;
3230 }
3231 __setup("thash_entries=", set_thash_entries);
3232
3233 void tcp_init_mem(struct net *net)
3234 {
3235 unsigned long limit = nr_free_buffer_pages() / 8;
3236 limit = max(limit, 128UL);
3237 net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3;
3238 net->ipv4.sysctl_tcp_mem[1] = limit;
3239 net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2;
3240 }
3241
3242 void __init tcp_init(void)
3243 {
3244 struct sk_buff *skb = NULL;
3245 unsigned long limit;
3246 int max_share, cnt;
3247 unsigned int i;
3248 unsigned long jiffy = jiffies;
3249
3250 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
3251
3252 percpu_counter_init(&tcp_sockets_allocated, 0);
3253 percpu_counter_init(&tcp_orphan_count, 0);
3254 tcp_hashinfo.bind_bucket_cachep =
3255 kmem_cache_create("tcp_bind_bucket",
3256 sizeof(struct inet_bind_bucket), 0,
3257 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3258
3259 /* Size and allocate the main established and bind bucket
3260 * hash tables.
3261 *
3262 * The methodology is similar to that of the buffer cache.
3263 */
3264 tcp_hashinfo.ehash =
3265 alloc_large_system_hash("TCP established",
3266 sizeof(struct inet_ehash_bucket),
3267 thash_entries,
3268 (totalram_pages >= 128 * 1024) ?
3269 13 : 15,
3270 0,
3271 NULL,
3272 &tcp_hashinfo.ehash_mask,
3273 thash_entries ? 0 : 512 * 1024);
3274 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
3275 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
3276 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
3277 }
3278 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3279 panic("TCP: failed to alloc ehash_locks");
3280 tcp_hashinfo.bhash =
3281 alloc_large_system_hash("TCP bind",
3282 sizeof(struct inet_bind_hashbucket),
3283 tcp_hashinfo.ehash_mask + 1,
3284 (totalram_pages >= 128 * 1024) ?
3285 13 : 15,
3286 0,
3287 &tcp_hashinfo.bhash_size,
3288 NULL,
3289 64 * 1024);
3290 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3291 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3292 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3293 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
3294 }
3295
3296
3297 cnt = tcp_hashinfo.ehash_mask + 1;
3298
3299 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3300 sysctl_tcp_max_orphans = cnt / 2;
3301 sysctl_max_syn_backlog = max(128, cnt / 256);
3302
3303 tcp_init_mem(&init_net);
3304 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3305 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3306 max_share = min(4UL*1024*1024, limit);
3307
3308 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3309 sysctl_tcp_wmem[1] = 16*1024;
3310 sysctl_tcp_wmem[2] = max(64*1024, max_share);
3311
3312 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3313 sysctl_tcp_rmem[1] = 87380;
3314 sysctl_tcp_rmem[2] = max(87380, max_share);
3315
3316 pr_info("Hash tables configured (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 }
kernel source for telekom puls (alcatel/mediatek)