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parisc: cleanup console handling
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / tcp.c
blob1664a0590bb8f28fe5662e2cfdbc3a6d660d4549
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Implementation of the Transmission Control Protocol(TCP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Mark Evans, <evansmp@uhura.aston.ac.uk>
11 * Corey Minyard <wf-rch!minyard@relay.EU.net>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
14 * Linus Torvalds, <torvalds@cs.helsinki.fi>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Matthew Dillon, <dillon@apollo.west.oic.com>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Jorge Cwik, <jorge@laser.satlink.net>
19 *
20 * Fixes:
21 * Alan Cox : Numerous verify_area() calls
22 * Alan Cox : Set the ACK bit on a reset
23 * Alan Cox : Stopped it crashing if it closed while
24 * sk->inuse=1 and was trying to connect
25 * (tcp_err()).
26 * Alan Cox : All icmp error handling was broken
27 * pointers passed where wrong and the
28 * socket was looked up backwards. Nobody
29 * tested any icmp error code obviously.
30 * Alan Cox : tcp_err() now handled properly. It
31 * wakes people on errors. poll
32 * behaves and the icmp error race
33 * has gone by moving it into sock.c
34 * Alan Cox : tcp_send_reset() fixed to work for
35 * everything not just packets for
36 * unknown sockets.
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
39 * syn rule wrong]
40 * Herp Rosmanith : More reset fixes
41 * Alan Cox : No longer acks invalid rst frames.
42 * Acking any kind of RST is right out.
43 * Alan Cox : Sets an ignore me flag on an rst
44 * receive otherwise odd bits of prattle
45 * escape still
46 * Alan Cox : Fixed another acking RST frame bug.
47 * Should stop LAN workplace lockups.
48 * Alan Cox : Some tidyups using the new skb list
49 * facilities
50 * Alan Cox : sk->keepopen now seems to work
51 * Alan Cox : Pulls options out correctly on accepts
52 * Alan Cox : Fixed assorted sk->rqueue->next errors
53 * Alan Cox : PSH doesn't end a TCP read. Switched a
54 * bit to skb ops.
55 * Alan Cox : Tidied tcp_data to avoid a potential
56 * nasty.
57 * Alan Cox : Added some better commenting, as the
58 * tcp is hard to follow
59 * Alan Cox : Removed incorrect check for 20 * psh
60 * Michael O'Reilly : ack < copied bug fix.
61 * Johannes Stille : Misc tcp fixes (not all in yet).
62 * Alan Cox : FIN with no memory -> CRASH
63 * Alan Cox : Added socket option proto entries.
64 * Also added awareness of them to accept.
65 * Alan Cox : Added TCP options (SOL_TCP)
66 * Alan Cox : Switched wakeup calls to callbacks,
67 * so the kernel can layer network
68 * sockets.
69 * Alan Cox : Use ip_tos/ip_ttl settings.
70 * Alan Cox : Handle FIN (more) properly (we hope).
71 * Alan Cox : RST frames sent on unsynchronised
72 * state ack error.
73 * Alan Cox : Put in missing check for SYN bit.
74 * Alan Cox : Added tcp_select_window() aka NET2E
75 * window non shrink trick.
76 * Alan Cox : Added a couple of small NET2E timer
77 * fixes
78 * Charles Hedrick : TCP fixes
79 * Toomas Tamm : TCP window fixes
80 * Alan Cox : Small URG fix to rlogin ^C ack fight
81 * Charles Hedrick : Rewrote most of it to actually work
82 * Linus : Rewrote tcp_read() and URG handling
83 * completely
84 * Gerhard Koerting: Fixed some missing timer handling
85 * Matthew Dillon : Reworked TCP machine states as per RFC
86 * Gerhard Koerting: PC/TCP workarounds
87 * Adam Caldwell : Assorted timer/timing errors
88 * Matthew Dillon : Fixed another RST bug
89 * Alan Cox : Move to kernel side addressing changes.
90 * Alan Cox : Beginning work on TCP fastpathing
91 * (not yet usable)
92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
93 * Alan Cox : TCP fast path debugging
94 * Alan Cox : Window clamping
95 * Michael Riepe : Bug in tcp_check()
96 * Matt Dillon : More TCP improvements and RST bug fixes
97 * Matt Dillon : Yet more small nasties remove from the
98 * TCP code (Be very nice to this man if
99 * tcp finally works 100%) 8)
100 * Alan Cox : BSD accept semantics.
101 * Alan Cox : Reset on closedown bug.
102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
103 * Michael Pall : Handle poll() after URG properly in
104 * all cases.
105 * Michael Pall : Undo the last fix in tcp_read_urg()
106 * (multi URG PUSH broke rlogin).
107 * Michael Pall : Fix the multi URG PUSH problem in
108 * tcp_readable(), poll() after URG
109 * works now.
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
111 * BSD api.
112 * Alan Cox : Changed the semantics of sk->socket to
113 * fix a race and a signal problem with
114 * accept() and async I/O.
115 * Alan Cox : Relaxed the rules on tcp_sendto().
116 * Yury Shevchuk : Really fixed accept() blocking problem.
117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
118 * clients/servers which listen in on
119 * fixed ports.
120 * Alan Cox : Cleaned the above up and shrank it to
121 * a sensible code size.
122 * Alan Cox : Self connect lockup fix.
123 * Alan Cox : No connect to multicast.
124 * Ross Biro : Close unaccepted children on master
125 * socket close.
126 * Alan Cox : Reset tracing code.
127 * Alan Cox : Spurious resets on shutdown.
128 * Alan Cox : Giant 15 minute/60 second timer error
129 * Alan Cox : Small whoops in polling before an
130 * accept.
131 * Alan Cox : Kept the state trace facility since
132 * it's handy for debugging.
133 * Alan Cox : More reset handler fixes.
134 * Alan Cox : Started rewriting the code based on
135 * the RFC's for other useful protocol
136 * references see: Comer, KA9Q NOS, and
137 * for a reference on the difference
138 * between specifications and how BSD
139 * works see the 4.4lite source.
140 * A.N.Kuznetsov : Don't time wait on completion of tidy
141 * close.
142 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
143 * Linus Torvalds : Fixed BSD port reuse to work first syn
144 * Alan Cox : Reimplemented timers as per the RFC
145 * and using multiple timers for sanity.
146 * Alan Cox : Small bug fixes, and a lot of new
147 * comments.
148 * Alan Cox : Fixed dual reader crash by locking
149 * the buffers (much like datagram.c)
150 * Alan Cox : Fixed stuck sockets in probe. A probe
151 * now gets fed up of retrying without
152 * (even a no space) answer.
153 * Alan Cox : Extracted closing code better
154 * Alan Cox : Fixed the closing state machine to
155 * resemble the RFC.
156 * Alan Cox : More 'per spec' fixes.
157 * Jorge Cwik : Even faster checksumming.
158 * Alan Cox : tcp_data() doesn't ack illegal PSH
159 * only frames. At least one pc tcp stack
160 * generates them.
161 * Alan Cox : Cache last socket.
162 * Alan Cox : Per route irtt.
163 * Matt Day : poll()->select() match BSD precisely on error
164 * Alan Cox : New buffers
165 * Marc Tamsky : Various sk->prot->retransmits and
166 * sk->retransmits misupdating fixed.
167 * Fixed tcp_write_timeout: stuck close,
168 * and TCP syn retries gets used now.
169 * Mark Yarvis : In tcp_read_wakeup(), don't send an
170 * ack if state is TCP_CLOSED.
171 * Alan Cox : Look up device on a retransmit - routes may
172 * change. Doesn't yet cope with MSS shrink right
173 * but it's a start!
174 * Marc Tamsky : Closing in closing fixes.
175 * Mike Shaver : RFC1122 verifications.
176 * Alan Cox : rcv_saddr errors.
177 * Alan Cox : Block double connect().
178 * Alan Cox : Small hooks for enSKIP.
179 * Alexey Kuznetsov: Path MTU discovery.
180 * Alan Cox : Support soft errors.
181 * Alan Cox : Fix MTU discovery pathological case
182 * when the remote claims no mtu!
183 * Marc Tamsky : TCP_CLOSE fix.
184 * Colin (G3TNE) : Send a reset on syn ack replies in
185 * window but wrong (fixes NT lpd problems)
186 * Pedro Roque : Better TCP window handling, delayed ack.
187 * Joerg Reuter : No modification of locked buffers in
188 * tcp_do_retransmit()
189 * Eric Schenk : Changed receiver side silly window
190 * avoidance algorithm to BSD style
191 * algorithm. This doubles throughput
192 * against machines running Solaris,
193 * and seems to result in general
194 * improvement.
195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
196 * Willy Konynenberg : Transparent proxying support.
197 * Mike McLagan : Routing by source
198 * Keith Owens : Do proper merging with partial SKB's in
199 * tcp_do_sendmsg to avoid burstiness.
200 * Eric Schenk : Fix fast close down bug with
201 * shutdown() followed by close().
202 * Andi Kleen : Make poll agree with SIGIO
203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
204 * lingertime == 0 (RFC 793 ABORT Call)
205 * Hirokazu Takahashi : Use copy_from_user() instead of
206 * csum_and_copy_from_user() if possible.
207 *
208 * This program is free software; you can redistribute it and/or
209 * modify it under the terms of the GNU General Public License
210 * as published by the Free Software Foundation; either version
211 * 2 of the License, or(at your option) any later version.
212 *
213 * Description of States:
214 *
215 * TCP_SYN_SENT sent a connection request, waiting for ack
216 *
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
219 *
220 * TCP_ESTABLISHED connection established
221 *
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
224 *
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
226 * to shutdown
227 *
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
230 *
231 * TCP_TIME_WAIT timeout to catch resent junk before entering
232 * closed, can only be entered from FIN_WAIT2
233 * or CLOSING. Required because the other end
234 * may not have gotten our last ACK causing it
235 * to retransmit the data packet (which we ignore)
236 *
237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
238 * us to finish writing our data and to shutdown
239 * (we have to close() to move on to LAST_ACK)
240 *
241 * TCP_LAST_ACK out side has shutdown after remote has
242 * shutdown. There may still be data in our
243 * buffer that we have to finish sending
244 *
245 * TCP_CLOSE socket is finished
246 */
247
248 #include <linux/kernel.h>
249 #include <linux/module.h>
250 #include <linux/types.h>
251 #include <linux/fcntl.h>
252 #include <linux/poll.h>
253 #include <linux/init.h>
254 #include <linux/fs.h>
255 #include <linux/skbuff.h>
256 #include <linux/scatterlist.h>
257 #include <linux/splice.h>
258 #include <linux/net.h>
259 #include <linux/socket.h>
260 #include <linux/random.h>
261 #include <linux/bootmem.h>
262 #include <linux/highmem.h>
263 #include <linux/swap.h>
264 #include <linux/cache.h>
265 #include <linux/err.h>
266 #include <linux/crypto.h>
267 #include <linux/time.h>
268 #include <linux/slab.h>
269
270 #include <net/icmp.h>
271 #include <net/tcp.h>
272 #include <net/xfrm.h>
273 #include <net/ip.h>
274 #include <net/netdma.h>
275 #include <net/sock.h>
276
277 #include <asm/uaccess.h>
278 #include <asm/ioctls.h>
279
280 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
281
282 struct percpu_counter tcp_orphan_count;
283 EXPORT_SYMBOL_GPL(tcp_orphan_count);
284
285 int sysctl_tcp_mem[3] __read_mostly;
286 int sysctl_tcp_wmem[3] __read_mostly;
287 int sysctl_tcp_rmem[3] __read_mostly;
288
289 EXPORT_SYMBOL(sysctl_tcp_mem);
290 EXPORT_SYMBOL(sysctl_tcp_rmem);
291 EXPORT_SYMBOL(sysctl_tcp_wmem);
292
293 atomic_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 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 default:
509 return -ENOIOCTLCMD;
510 }
511
512 return put_user(answ, (int __user *)arg);
513 }
514 EXPORT_SYMBOL(tcp_ioctl);
515
516 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
517 {
518 TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
519 tp->pushed_seq = tp->write_seq;
520 }
521
522 static inline int forced_push(struct tcp_sock *tp)
523 {
524 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
525 }
526
527 static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
528 {
529 struct tcp_sock *tp = tcp_sk(sk);
530 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
531
532 skb->csum = 0;
533 tcb->seq = tcb->end_seq = tp->write_seq;
534 tcb->flags = TCPHDR_ACK;
535 tcb->sacked = 0;
536 skb_header_release(skb);
537 tcp_add_write_queue_tail(sk, skb);
538 sk->sk_wmem_queued += skb->truesize;
539 sk_mem_charge(sk, skb->truesize);
540 if (tp->nonagle & TCP_NAGLE_PUSH)
541 tp->nonagle &= ~TCP_NAGLE_PUSH;
542 }
543
544 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
545 {
546 if (flags & MSG_OOB)
547 tp->snd_up = tp->write_seq;
548 }
549
550 static inline void tcp_push(struct sock *sk, int flags, int mss_now,
551 int nonagle)
552 {
553 if (tcp_send_head(sk)) {
554 struct tcp_sock *tp = tcp_sk(sk);
555
556 if (!(flags & MSG_MORE) || forced_push(tp))
557 tcp_mark_push(tp, tcp_write_queue_tail(sk));
558
559 tcp_mark_urg(tp, flags);
560 __tcp_push_pending_frames(sk, mss_now,
561 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
562 }
563 }
564
565 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
566 unsigned int offset, size_t len)
567 {
568 struct tcp_splice_state *tss = rd_desc->arg.data;
569 int ret;
570
571 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
572 tss->flags);
573 if (ret > 0)
574 rd_desc->count -= ret;
575 return ret;
576 }
577
578 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
579 {
580 /* Store TCP splice context information in read_descriptor_t. */
581 read_descriptor_t rd_desc = {
582 .arg.data = tss,
583 .count = tss->len,
584 };
585
586 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
587 }
588
589 /**
590 * tcp_splice_read - splice data from TCP socket to a pipe
591 * @sock: socket to splice from
592 * @ppos: position (not valid)
593 * @pipe: pipe to splice to
594 * @len: number of bytes to splice
595 * @flags: splice modifier flags
596 *
597 * Description:
598 * Will read pages from given socket and fill them into a pipe.
599 *
600 **/
601 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
602 struct pipe_inode_info *pipe, size_t len,
603 unsigned int flags)
604 {
605 struct sock *sk = sock->sk;
606 struct tcp_splice_state tss = {
607 .pipe = pipe,
608 .len = len,
609 .flags = flags,
610 };
611 long timeo;
612 ssize_t spliced;
613 int ret;
614
615 sock_rps_record_flow(sk);
616 /*
617 * We can't seek on a socket input
618 */
619 if (unlikely(*ppos))
620 return -ESPIPE;
621
622 ret = spliced = 0;
623
624 lock_sock(sk);
625
626 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
627 while (tss.len) {
628 ret = __tcp_splice_read(sk, &tss);
629 if (ret < 0)
630 break;
631 else if (!ret) {
632 if (spliced)
633 break;
634 if (sock_flag(sk, SOCK_DONE))
635 break;
636 if (sk->sk_err) {
637 ret = sock_error(sk);
638 break;
639 }
640 if (sk->sk_shutdown & RCV_SHUTDOWN)
641 break;
642 if (sk->sk_state == TCP_CLOSE) {
643 /*
644 * This occurs when user tries to read
645 * from never connected socket.
646 */
647 if (!sock_flag(sk, SOCK_DONE))
648 ret = -ENOTCONN;
649 break;
650 }
651 if (!timeo) {
652 ret = -EAGAIN;
653 break;
654 }
655 sk_wait_data(sk, &timeo);
656 if (signal_pending(current)) {
657 ret = sock_intr_errno(timeo);
658 break;
659 }
660 continue;
661 }
662 tss.len -= ret;
663 spliced += ret;
664
665 if (!timeo)
666 break;
667 release_sock(sk);
668 lock_sock(sk);
669
670 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
671 (sk->sk_shutdown & RCV_SHUTDOWN) ||
672 signal_pending(current))
673 break;
674 }
675
676 release_sock(sk);
677
678 if (spliced)
679 return spliced;
680
681 return ret;
682 }
683 EXPORT_SYMBOL(tcp_splice_read);
684
685 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
686 {
687 struct sk_buff *skb;
688
689 /* The TCP header must be at least 32-bit aligned. */
690 size = ALIGN(size, 4);
691
692 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
693 if (skb) {
694 if (sk_wmem_schedule(sk, skb->truesize)) {
695 /*
696 * Make sure that we have exactly size bytes
697 * available to the caller, no more, no less.
698 */
699 skb_reserve(skb, skb_tailroom(skb) - size);
700 return skb;
701 }
702 __kfree_skb(skb);
703 } else {
704 sk->sk_prot->enter_memory_pressure(sk);
705 sk_stream_moderate_sndbuf(sk);
706 }
707 return NULL;
708 }
709
710 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
711 int large_allowed)
712 {
713 struct tcp_sock *tp = tcp_sk(sk);
714 u32 xmit_size_goal, old_size_goal;
715
716 xmit_size_goal = mss_now;
717
718 if (large_allowed && sk_can_gso(sk)) {
719 xmit_size_goal = ((sk->sk_gso_max_size - 1) -
720 inet_csk(sk)->icsk_af_ops->net_header_len -
721 inet_csk(sk)->icsk_ext_hdr_len -
722 tp->tcp_header_len);
723
724 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
725
726 /* We try hard to avoid divides here */
727 old_size_goal = tp->xmit_size_goal_segs * mss_now;
728
729 if (likely(old_size_goal <= xmit_size_goal &&
730 old_size_goal + mss_now > xmit_size_goal)) {
731 xmit_size_goal = old_size_goal;
732 } else {
733 tp->xmit_size_goal_segs = xmit_size_goal / mss_now;
734 xmit_size_goal = tp->xmit_size_goal_segs * mss_now;
735 }
736 }
737
738 return max(xmit_size_goal, mss_now);
739 }
740
741 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
742 {
743 int mss_now;
744
745 mss_now = tcp_current_mss(sk);
746 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
747
748 return mss_now;
749 }
750
751 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
752 size_t psize, int flags)
753 {
754 struct tcp_sock *tp = tcp_sk(sk);
755 int mss_now, size_goal;
756 int err;
757 ssize_t copied;
758 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
759
760 /* Wait for a connection to finish. */
761 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
762 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
763 goto out_err;
764
765 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
766
767 mss_now = tcp_send_mss(sk, &size_goal, flags);
768 copied = 0;
769
770 err = -EPIPE;
771 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
772 goto out_err;
773
774 while (psize > 0) {
775 struct sk_buff *skb = tcp_write_queue_tail(sk);
776 struct page *page = pages[poffset / PAGE_SIZE];
777 int copy, i, can_coalesce;
778 int offset = poffset % PAGE_SIZE;
779 int size = min_t(size_t, psize, PAGE_SIZE - offset);
780
781 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
782 new_segment:
783 if (!sk_stream_memory_free(sk))
784 goto wait_for_sndbuf;
785
786 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
787 if (!skb)
788 goto wait_for_memory;
789
790 skb_entail(sk, skb);
791 copy = size_goal;
792 }
793
794 if (copy > size)
795 copy = size;
796
797 i = skb_shinfo(skb)->nr_frags;
798 can_coalesce = skb_can_coalesce(skb, i, page, offset);
799 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
800 tcp_mark_push(tp, skb);
801 goto new_segment;
802 }
803 if (!sk_wmem_schedule(sk, copy))
804 goto wait_for_memory;
805
806 if (can_coalesce) {
807 skb_shinfo(skb)->frags[i - 1].size += copy;
808 } else {
809 get_page(page);
810 skb_fill_page_desc(skb, i, page, offset, copy);
811 }
812
813 skb->len += copy;
814 skb->data_len += copy;
815 skb->truesize += copy;
816 sk->sk_wmem_queued += copy;
817 sk_mem_charge(sk, copy);
818 skb->ip_summed = CHECKSUM_PARTIAL;
819 tp->write_seq += copy;
820 TCP_SKB_CB(skb)->end_seq += copy;
821 skb_shinfo(skb)->gso_segs = 0;
822
823 if (!copied)
824 TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
825
826 copied += copy;
827 poffset += copy;
828 if (!(psize -= copy))
829 goto out;
830
831 if (skb->len < size_goal || (flags & MSG_OOB))
832 continue;
833
834 if (forced_push(tp)) {
835 tcp_mark_push(tp, skb);
836 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
837 } else if (skb == tcp_send_head(sk))
838 tcp_push_one(sk, mss_now);
839 continue;
840
841 wait_for_sndbuf:
842 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
843 wait_for_memory:
844 if (copied)
845 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
846
847 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
848 goto do_error;
849
850 mss_now = tcp_send_mss(sk, &size_goal, flags);
851 }
852
853 out:
854 if (copied)
855 tcp_push(sk, flags, mss_now, tp->nonagle);
856 return copied;
857
858 do_error:
859 if (copied)
860 goto out;
861 out_err:
862 return sk_stream_error(sk, flags, err);
863 }
864
865 int tcp_sendpage(struct sock *sk, struct page *page, int offset,
866 size_t size, int flags)
867 {
868 ssize_t res;
869
870 if (!(sk->sk_route_caps & NETIF_F_SG) ||
871 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
872 return sock_no_sendpage(sk->sk_socket, page, offset, size,
873 flags);
874
875 lock_sock(sk);
876 TCP_CHECK_TIMER(sk);
877 res = do_tcp_sendpages(sk, &page, offset, size, flags);
878 TCP_CHECK_TIMER(sk);
879 release_sock(sk);
880 return res;
881 }
882 EXPORT_SYMBOL(tcp_sendpage);
883
884 #define TCP_PAGE(sk) (sk->sk_sndmsg_page)
885 #define TCP_OFF(sk) (sk->sk_sndmsg_off)
886
887 static inline int select_size(struct sock *sk, int sg)
888 {
889 struct tcp_sock *tp = tcp_sk(sk);
890 int tmp = tp->mss_cache;
891
892 if (sg) {
893 if (sk_can_gso(sk))
894 tmp = 0;
895 else {
896 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
897
898 if (tmp >= pgbreak &&
899 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
900 tmp = pgbreak;
901 }
902 }
903
904 return tmp;
905 }
906
907 int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
908 size_t size)
909 {
910 struct iovec *iov;
911 struct tcp_sock *tp = tcp_sk(sk);
912 struct sk_buff *skb;
913 int iovlen, flags;
914 int mss_now, size_goal;
915 int sg, err, copied;
916 long timeo;
917
918 lock_sock(sk);
919 TCP_CHECK_TIMER(sk);
920
921 flags = msg->msg_flags;
922 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
923
924 /* Wait for a connection to finish. */
925 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
926 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
927 goto out_err;
928
929 /* This should be in poll */
930 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
931
932 mss_now = tcp_send_mss(sk, &size_goal, flags);
933
934 /* Ok commence sending. */
935 iovlen = msg->msg_iovlen;
936 iov = msg->msg_iov;
937 copied = 0;
938
939 err = -EPIPE;
940 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
941 goto out_err;
942
943 sg = sk->sk_route_caps & NETIF_F_SG;
944
945 while (--iovlen >= 0) {
946 size_t seglen = iov->iov_len;
947 unsigned char __user *from = iov->iov_base;
948
949 iov++;
950
951 while (seglen > 0) {
952 int copy = 0;
953 int max = size_goal;
954
955 skb = tcp_write_queue_tail(sk);
956 if (tcp_send_head(sk)) {
957 if (skb->ip_summed == CHECKSUM_NONE)
958 max = mss_now;
959 copy = max - skb->len;
960 }
961
962 if (copy <= 0) {
963 new_segment:
964 /* Allocate new segment. If the interface is SG,
965 * allocate skb fitting to single page.
966 */
967 if (!sk_stream_memory_free(sk))
968 goto wait_for_sndbuf;
969
970 skb = sk_stream_alloc_skb(sk,
971 select_size(sk, sg),
972 sk->sk_allocation);
973 if (!skb)
974 goto wait_for_memory;
975
976 /*
977 * Check whether we can use HW checksum.
978 */
979 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
980 skb->ip_summed = CHECKSUM_PARTIAL;
981
982 skb_entail(sk, skb);
983 copy = size_goal;
984 max = size_goal;
985 }
986
987 /* Try to append data to the end of skb. */
988 if (copy > seglen)
989 copy = seglen;
990
991 /* Where to copy to? */
992 if (skb_tailroom(skb) > 0) {
993 /* We have some space in skb head. Superb! */
994 if (copy > skb_tailroom(skb))
995 copy = skb_tailroom(skb);
996 if ((err = skb_add_data(skb, from, copy)) != 0)
997 goto do_fault;
998 } else {
999 int merge = 0;
1000 int i = skb_shinfo(skb)->nr_frags;
1001 struct page *page = TCP_PAGE(sk);
1002 int off = TCP_OFF(sk);
1003
1004 if (skb_can_coalesce(skb, i, page, off) &&
1005 off != PAGE_SIZE) {
1006 /* We can extend the last page
1007 * fragment. */
1008 merge = 1;
1009 } else if (i == MAX_SKB_FRAGS || !sg) {
1010 /* Need to add new fragment and cannot
1011 * do this because interface is non-SG,
1012 * or because all the page slots are
1013 * busy. */
1014 tcp_mark_push(tp, skb);
1015 goto new_segment;
1016 } else if (page) {
1017 if (off == PAGE_SIZE) {
1018 put_page(page);
1019 TCP_PAGE(sk) = page = NULL;
1020 off = 0;
1021 }
1022 } else
1023 off = 0;
1024
1025 if (copy > PAGE_SIZE - off)
1026 copy = PAGE_SIZE - off;
1027
1028 if (!sk_wmem_schedule(sk, copy))
1029 goto wait_for_memory;
1030
1031 if (!page) {
1032 /* Allocate new cache page. */
1033 if (!(page = sk_stream_alloc_page(sk)))
1034 goto wait_for_memory;
1035 }
1036
1037 /* Time to copy data. We are close to
1038 * the end! */
1039 err = skb_copy_to_page(sk, from, skb, page,
1040 off, copy);
1041 if (err) {
1042 /* If this page was new, give it to the
1043 * socket so it does not get leaked.
1044 */
1045 if (!TCP_PAGE(sk)) {
1046 TCP_PAGE(sk) = page;
1047 TCP_OFF(sk) = 0;
1048 }
1049 goto do_error;
1050 }
1051
1052 /* Update the skb. */
1053 if (merge) {
1054 skb_shinfo(skb)->frags[i - 1].size +=
1055 copy;
1056 } else {
1057 skb_fill_page_desc(skb, i, page, off, copy);
1058 if (TCP_PAGE(sk)) {
1059 get_page(page);
1060 } else if (off + copy < PAGE_SIZE) {
1061 get_page(page);
1062 TCP_PAGE(sk) = page;
1063 }
1064 }
1065
1066 TCP_OFF(sk) = off + copy;
1067 }
1068
1069 if (!copied)
1070 TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
1071
1072 tp->write_seq += copy;
1073 TCP_SKB_CB(skb)->end_seq += copy;
1074 skb_shinfo(skb)->gso_segs = 0;
1075
1076 from += copy;
1077 copied += copy;
1078 if ((seglen -= copy) == 0 && iovlen == 0)
1079 goto out;
1080
1081 if (skb->len < max || (flags & MSG_OOB))
1082 continue;
1083
1084 if (forced_push(tp)) {
1085 tcp_mark_push(tp, skb);
1086 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1087 } else if (skb == tcp_send_head(sk))
1088 tcp_push_one(sk, mss_now);
1089 continue;
1090
1091 wait_for_sndbuf:
1092 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1093 wait_for_memory:
1094 if (copied)
1095 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
1096
1097 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1098 goto do_error;
1099
1100 mss_now = tcp_send_mss(sk, &size_goal, flags);
1101 }
1102 }
1103
1104 out:
1105 if (copied)
1106 tcp_push(sk, flags, mss_now, tp->nonagle);
1107 TCP_CHECK_TIMER(sk);
1108 release_sock(sk);
1109 return copied;
1110
1111 do_fault:
1112 if (!skb->len) {
1113 tcp_unlink_write_queue(skb, sk);
1114 /* It is the one place in all of TCP, except connection
1115 * reset, where we can be unlinking the send_head.
1116 */
1117 tcp_check_send_head(sk, skb);
1118 sk_wmem_free_skb(sk, skb);
1119 }
1120
1121 do_error:
1122 if (copied)
1123 goto out;
1124 out_err:
1125 err = sk_stream_error(sk, flags, err);
1126 TCP_CHECK_TIMER(sk);
1127 release_sock(sk);
1128 return err;
1129 }
1130 EXPORT_SYMBOL(tcp_sendmsg);
1131
1132 /*
1133 * Handle reading urgent data. BSD has very simple semantics for
1134 * this, no blocking and very strange errors 8)
1135 */
1136
1137 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1138 {
1139 struct tcp_sock *tp = tcp_sk(sk);
1140
1141 /* No URG data to read. */
1142 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1143 tp->urg_data == TCP_URG_READ)
1144 return -EINVAL; /* Yes this is right ! */
1145
1146 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1147 return -ENOTCONN;
1148
1149 if (tp->urg_data & TCP_URG_VALID) {
1150 int err = 0;
1151 char c = tp->urg_data;
1152
1153 if (!(flags & MSG_PEEK))
1154 tp->urg_data = TCP_URG_READ;
1155
1156 /* Read urgent data. */
1157 msg->msg_flags |= MSG_OOB;
1158
1159 if (len > 0) {
1160 if (!(flags & MSG_TRUNC))
1161 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1162 len = 1;
1163 } else
1164 msg->msg_flags |= MSG_TRUNC;
1165
1166 return err ? -EFAULT : len;
1167 }
1168
1169 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1170 return 0;
1171
1172 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1173 * the available implementations agree in this case:
1174 * this call should never block, independent of the
1175 * blocking state of the socket.
1176 * Mike <pall@rz.uni-karlsruhe.de>
1177 */
1178 return -EAGAIN;
1179 }
1180
1181 /* Clean up the receive buffer for full frames taken by the user,
1182 * then send an ACK if necessary. COPIED is the number of bytes
1183 * tcp_recvmsg has given to the user so far, it speeds up the
1184 * calculation of whether or not we must ACK for the sake of
1185 * a window update.
1186 */
1187 void tcp_cleanup_rbuf(struct sock *sk, int copied)
1188 {
1189 struct tcp_sock *tp = tcp_sk(sk);
1190 int time_to_ack = 0;
1191
1192 #if TCP_DEBUG
1193 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1194
1195 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1196 KERN_INFO "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1197 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1198 #endif
1199
1200 if (inet_csk_ack_scheduled(sk)) {
1201 const struct inet_connection_sock *icsk = inet_csk(sk);
1202 /* Delayed ACKs frequently hit locked sockets during bulk
1203 * receive. */
1204 if (icsk->icsk_ack.blocked ||
1205 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1206 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1207 /*
1208 * If this read emptied read buffer, we send ACK, if
1209 * connection is not bidirectional, user drained
1210 * receive buffer and there was a small segment
1211 * in queue.
1212 */
1213 (copied > 0 &&
1214 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1215 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1216 !icsk->icsk_ack.pingpong)) &&
1217 !atomic_read(&sk->sk_rmem_alloc)))
1218 time_to_ack = 1;
1219 }
1220
1221 /* We send an ACK if we can now advertise a non-zero window
1222 * which has been raised "significantly".
1223 *
1224 * Even if window raised up to infinity, do not send window open ACK
1225 * in states, where we will not receive more. It is useless.
1226 */
1227 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1228 __u32 rcv_window_now = tcp_receive_window(tp);
1229
1230 /* Optimize, __tcp_select_window() is not cheap. */
1231 if (2*rcv_window_now <= tp->window_clamp) {
1232 __u32 new_window = __tcp_select_window(sk);
1233
1234 /* Send ACK now, if this read freed lots of space
1235 * in our buffer. Certainly, new_window is new window.
1236 * We can advertise it now, if it is not less than current one.
1237 * "Lots" means "at least twice" here.
1238 */
1239 if (new_window && new_window >= 2 * rcv_window_now)
1240 time_to_ack = 1;
1241 }
1242 }
1243 if (time_to_ack)
1244 tcp_send_ack(sk);
1245 }
1246
1247 static void tcp_prequeue_process(struct sock *sk)
1248 {
1249 struct sk_buff *skb;
1250 struct tcp_sock *tp = tcp_sk(sk);
1251
1252 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
1253
1254 /* RX process wants to run with disabled BHs, though it is not
1255 * necessary */
1256 local_bh_disable();
1257 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1258 sk_backlog_rcv(sk, skb);
1259 local_bh_enable();
1260
1261 /* Clear memory counter. */
1262 tp->ucopy.memory = 0;
1263 }
1264
1265 #ifdef CONFIG_NET_DMA
1266 static void tcp_service_net_dma(struct sock *sk, bool wait)
1267 {
1268 dma_cookie_t done, used;
1269 dma_cookie_t last_issued;
1270 struct tcp_sock *tp = tcp_sk(sk);
1271
1272 if (!tp->ucopy.dma_chan)
1273 return;
1274
1275 last_issued = tp->ucopy.dma_cookie;
1276 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1277
1278 do {
1279 if (dma_async_memcpy_complete(tp->ucopy.dma_chan,
1280 last_issued, &done,
1281 &used) == DMA_SUCCESS) {
1282 /* Safe to free early-copied skbs now */
1283 __skb_queue_purge(&sk->sk_async_wait_queue);
1284 break;
1285 } else {
1286 struct sk_buff *skb;
1287 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1288 (dma_async_is_complete(skb->dma_cookie, done,
1289 used) == DMA_SUCCESS)) {
1290 __skb_dequeue(&sk->sk_async_wait_queue);
1291 kfree_skb(skb);
1292 }
1293 }
1294 } while (wait);
1295 }
1296 #endif
1297
1298 static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1299 {
1300 struct sk_buff *skb;
1301 u32 offset;
1302
1303 skb_queue_walk(&sk->sk_receive_queue, skb) {
1304 offset = seq - TCP_SKB_CB(skb)->seq;
1305 if (tcp_hdr(skb)->syn)
1306 offset--;
1307 if (offset < skb->len || tcp_hdr(skb)->fin) {
1308 *off = offset;
1309 return skb;
1310 }
1311 }
1312 return NULL;
1313 }
1314
1315 /*
1316 * This routine provides an alternative to tcp_recvmsg() for routines
1317 * that would like to handle copying from skbuffs directly in 'sendfile'
1318 * fashion.
1319 * Note:
1320 * - It is assumed that the socket was locked by the caller.
1321 * - The routine does not block.
1322 * - At present, there is no support for reading OOB data
1323 * or for 'peeking' the socket using this routine
1324 * (although both would be easy to implement).
1325 */
1326 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1327 sk_read_actor_t recv_actor)
1328 {
1329 struct sk_buff *skb;
1330 struct tcp_sock *tp = tcp_sk(sk);
1331 u32 seq = tp->copied_seq;
1332 u32 offset;
1333 int copied = 0;
1334
1335 if (sk->sk_state == TCP_LISTEN)
1336 return -ENOTCONN;
1337 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1338 if (offset < skb->len) {
1339 int used;
1340 size_t len;
1341
1342 len = skb->len - offset;
1343 /* Stop reading if we hit a patch of urgent data */
1344 if (tp->urg_data) {
1345 u32 urg_offset = tp->urg_seq - seq;
1346 if (urg_offset < len)
1347 len = urg_offset;
1348 if (!len)
1349 break;
1350 }
1351 used = recv_actor(desc, skb, offset, len);
1352 if (used < 0) {
1353 if (!copied)
1354 copied = used;
1355 break;
1356 } else if (used <= len) {
1357 seq += used;
1358 copied += used;
1359 offset += used;
1360 }
1361 /*
1362 * If recv_actor drops the lock (e.g. TCP splice
1363 * receive) the skb pointer might be invalid when
1364 * getting here: tcp_collapse might have deleted it
1365 * while aggregating skbs from the socket queue.
1366 */
1367 skb = tcp_recv_skb(sk, seq-1, &offset);
1368 if (!skb || (offset+1 != skb->len))
1369 break;
1370 }
1371 if (tcp_hdr(skb)->fin) {
1372 sk_eat_skb(sk, skb, 0);
1373 ++seq;
1374 break;
1375 }
1376 sk_eat_skb(sk, skb, 0);
1377 if (!desc->count)
1378 break;
1379 tp->copied_seq = seq;
1380 }
1381 tp->copied_seq = seq;
1382
1383 tcp_rcv_space_adjust(sk);
1384
1385 /* Clean up data we have read: This will do ACK frames. */
1386 if (copied > 0)
1387 tcp_cleanup_rbuf(sk, copied);
1388 return copied;
1389 }
1390 EXPORT_SYMBOL(tcp_read_sock);
1391
1392 /*
1393 * This routine copies from a sock struct into the user buffer.
1394 *
1395 * Technical note: in 2.3 we work on _locked_ socket, so that
1396 * tricks with *seq access order and skb->users are not required.
1397 * Probably, code can be easily improved even more.
1398 */
1399
1400 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1401 size_t len, int nonblock, int flags, int *addr_len)
1402 {
1403 struct tcp_sock *tp = tcp_sk(sk);
1404 int copied = 0;
1405 u32 peek_seq;
1406 u32 *seq;
1407 unsigned long used;
1408 int err;
1409 int target; /* Read at least this many bytes */
1410 long timeo;
1411 struct task_struct *user_recv = NULL;
1412 int copied_early = 0;
1413 struct sk_buff *skb;
1414 u32 urg_hole = 0;
1415
1416 lock_sock(sk);
1417
1418 TCP_CHECK_TIMER(sk);
1419
1420 err = -ENOTCONN;
1421 if (sk->sk_state == TCP_LISTEN)
1422 goto out;
1423
1424 timeo = sock_rcvtimeo(sk, nonblock);
1425
1426 /* Urgent data needs to be handled specially. */
1427 if (flags & MSG_OOB)
1428 goto recv_urg;
1429
1430 seq = &tp->copied_seq;
1431 if (flags & MSG_PEEK) {
1432 peek_seq = tp->copied_seq;
1433 seq = &peek_seq;
1434 }
1435
1436 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1437
1438 #ifdef CONFIG_NET_DMA
1439 tp->ucopy.dma_chan = NULL;
1440 preempt_disable();
1441 skb = skb_peek_tail(&sk->sk_receive_queue);
1442 {
1443 int available = 0;
1444
1445 if (skb)
1446 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1447 if ((available < target) &&
1448 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1449 !sysctl_tcp_low_latency &&
1450 dma_find_channel(DMA_MEMCPY)) {
1451 preempt_enable_no_resched();
1452 tp->ucopy.pinned_list =
1453 dma_pin_iovec_pages(msg->msg_iov, len);
1454 } else {
1455 preempt_enable_no_resched();
1456 }
1457 }
1458 #endif
1459
1460 do {
1461 u32 offset;
1462
1463 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1464 if (tp->urg_data && tp->urg_seq == *seq) {
1465 if (copied)
1466 break;
1467 if (signal_pending(current)) {
1468 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1469 break;
1470 }
1471 }
1472
1473 /* Next get a buffer. */
1474
1475 skb_queue_walk(&sk->sk_receive_queue, skb) {
1476 /* Now that we have two receive queues this
1477 * shouldn't happen.
1478 */
1479 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1480 KERN_INFO "recvmsg bug: copied %X "
1481 "seq %X rcvnxt %X fl %X\n", *seq,
1482 TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1483 flags))
1484 break;
1485
1486 offset = *seq - TCP_SKB_CB(skb)->seq;
1487 if (tcp_hdr(skb)->syn)
1488 offset--;
1489 if (offset < skb->len)
1490 goto found_ok_skb;
1491 if (tcp_hdr(skb)->fin)
1492 goto found_fin_ok;
1493 WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: "
1494 "copied %X seq %X rcvnxt %X fl %X\n",
1495 *seq, TCP_SKB_CB(skb)->seq,
1496 tp->rcv_nxt, flags);
1497 }
1498
1499 /* Well, if we have backlog, try to process it now yet. */
1500
1501 if (copied >= target && !sk->sk_backlog.tail)
1502 break;
1503
1504 if (copied) {
1505 if (sk->sk_err ||
1506 sk->sk_state == TCP_CLOSE ||
1507 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1508 !timeo ||
1509 signal_pending(current))
1510 break;
1511 } else {
1512 if (sock_flag(sk, SOCK_DONE))
1513 break;
1514
1515 if (sk->sk_err) {
1516 copied = sock_error(sk);
1517 break;
1518 }
1519
1520 if (sk->sk_shutdown & RCV_SHUTDOWN)
1521 break;
1522
1523 if (sk->sk_state == TCP_CLOSE) {
1524 if (!sock_flag(sk, SOCK_DONE)) {
1525 /* This occurs when user tries to read
1526 * from never connected socket.
1527 */
1528 copied = -ENOTCONN;
1529 break;
1530 }
1531 break;
1532 }
1533
1534 if (!timeo) {
1535 copied = -EAGAIN;
1536 break;
1537 }
1538
1539 if (signal_pending(current)) {
1540 copied = sock_intr_errno(timeo);
1541 break;
1542 }
1543 }
1544
1545 tcp_cleanup_rbuf(sk, copied);
1546
1547 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1548 /* Install new reader */
1549 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1550 user_recv = current;
1551 tp->ucopy.task = user_recv;
1552 tp->ucopy.iov = msg->msg_iov;
1553 }
1554
1555 tp->ucopy.len = len;
1556
1557 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1558 !(flags & (MSG_PEEK | MSG_TRUNC)));
1559
1560 /* Ugly... If prequeue is not empty, we have to
1561 * process it before releasing socket, otherwise
1562 * order will be broken at second iteration.
1563 * More elegant solution is required!!!
1564 *
1565 * Look: we have the following (pseudo)queues:
1566 *
1567 * 1. packets in flight
1568 * 2. backlog
1569 * 3. prequeue
1570 * 4. receive_queue
1571 *
1572 * Each queue can be processed only if the next ones
1573 * are empty. At this point we have empty receive_queue.
1574 * But prequeue _can_ be not empty after 2nd iteration,
1575 * when we jumped to start of loop because backlog
1576 * processing added something to receive_queue.
1577 * We cannot release_sock(), because backlog contains
1578 * packets arrived _after_ prequeued ones.
1579 *
1580 * Shortly, algorithm is clear --- to process all
1581 * the queues in order. We could make it more directly,
1582 * requeueing packets from backlog to prequeue, if
1583 * is not empty. It is more elegant, but eats cycles,
1584 * unfortunately.
1585 */
1586 if (!skb_queue_empty(&tp->ucopy.prequeue))
1587 goto do_prequeue;
1588
1589 /* __ Set realtime policy in scheduler __ */
1590 }
1591
1592 #ifdef CONFIG_NET_DMA
1593 if (tp->ucopy.dma_chan)
1594 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1595 #endif
1596 if (copied >= target) {
1597 /* Do not sleep, just process backlog. */
1598 release_sock(sk);
1599 lock_sock(sk);
1600 } else
1601 sk_wait_data(sk, &timeo);
1602
1603 #ifdef CONFIG_NET_DMA
1604 tcp_service_net_dma(sk, false); /* Don't block */
1605 tp->ucopy.wakeup = 0;
1606 #endif
1607
1608 if (user_recv) {
1609 int chunk;
1610
1611 /* __ Restore normal policy in scheduler __ */
1612
1613 if ((chunk = len - tp->ucopy.len) != 0) {
1614 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1615 len -= chunk;
1616 copied += chunk;
1617 }
1618
1619 if (tp->rcv_nxt == tp->copied_seq &&
1620 !skb_queue_empty(&tp->ucopy.prequeue)) {
1621 do_prequeue:
1622 tcp_prequeue_process(sk);
1623
1624 if ((chunk = len - tp->ucopy.len) != 0) {
1625 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1626 len -= chunk;
1627 copied += chunk;
1628 }
1629 }
1630 }
1631 if ((flags & MSG_PEEK) &&
1632 (peek_seq - copied - urg_hole != tp->copied_seq)) {
1633 if (net_ratelimit())
1634 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1635 current->comm, task_pid_nr(current));
1636 peek_seq = tp->copied_seq;
1637 }
1638 continue;
1639
1640 found_ok_skb:
1641 /* Ok so how much can we use? */
1642 used = skb->len - offset;
1643 if (len < used)
1644 used = len;
1645
1646 /* Do we have urgent data here? */
1647 if (tp->urg_data) {
1648 u32 urg_offset = tp->urg_seq - *seq;
1649 if (urg_offset < used) {
1650 if (!urg_offset) {
1651 if (!sock_flag(sk, SOCK_URGINLINE)) {
1652 ++*seq;
1653 urg_hole++;
1654 offset++;
1655 used--;
1656 if (!used)
1657 goto skip_copy;
1658 }
1659 } else
1660 used = urg_offset;
1661 }
1662 }
1663
1664 if (!(flags & MSG_TRUNC)) {
1665 #ifdef CONFIG_NET_DMA
1666 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1667 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1668
1669 if (tp->ucopy.dma_chan) {
1670 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1671 tp->ucopy.dma_chan, skb, offset,
1672 msg->msg_iov, used,
1673 tp->ucopy.pinned_list);
1674
1675 if (tp->ucopy.dma_cookie < 0) {
1676
1677 printk(KERN_ALERT "dma_cookie < 0\n");
1678
1679 /* Exception. Bailout! */
1680 if (!copied)
1681 copied = -EFAULT;
1682 break;
1683 }
1684
1685 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1686
1687 if ((offset + used) == skb->len)
1688 copied_early = 1;
1689
1690 } else
1691 #endif
1692 {
1693 err = skb_copy_datagram_iovec(skb, offset,
1694 msg->msg_iov, used);
1695 if (err) {
1696 /* Exception. Bailout! */
1697 if (!copied)
1698 copied = -EFAULT;
1699 break;
1700 }
1701 }
1702 }
1703
1704 *seq += used;
1705 copied += used;
1706 len -= used;
1707
1708 tcp_rcv_space_adjust(sk);
1709
1710 skip_copy:
1711 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1712 tp->urg_data = 0;
1713 tcp_fast_path_check(sk);
1714 }
1715 if (used + offset < skb->len)
1716 continue;
1717
1718 if (tcp_hdr(skb)->fin)
1719 goto found_fin_ok;
1720 if (!(flags & MSG_PEEK)) {
1721 sk_eat_skb(sk, skb, copied_early);
1722 copied_early = 0;
1723 }
1724 continue;
1725
1726 found_fin_ok:
1727 /* Process the FIN. */
1728 ++*seq;
1729 if (!(flags & MSG_PEEK)) {
1730 sk_eat_skb(sk, skb, copied_early);
1731 copied_early = 0;
1732 }
1733 break;
1734 } while (len > 0);
1735
1736 if (user_recv) {
1737 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1738 int chunk;
1739
1740 tp->ucopy.len = copied > 0 ? len : 0;
1741
1742 tcp_prequeue_process(sk);
1743
1744 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1745 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1746 len -= chunk;
1747 copied += chunk;
1748 }
1749 }
1750
1751 tp->ucopy.task = NULL;
1752 tp->ucopy.len = 0;
1753 }
1754
1755 #ifdef CONFIG_NET_DMA
1756 tcp_service_net_dma(sk, true); /* Wait for queue to drain */
1757 tp->ucopy.dma_chan = NULL;
1758
1759 if (tp->ucopy.pinned_list) {
1760 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1761 tp->ucopy.pinned_list = NULL;
1762 }
1763 #endif
1764
1765 /* According to UNIX98, msg_name/msg_namelen are ignored
1766 * on connected socket. I was just happy when found this 8) --ANK
1767 */
1768
1769 /* Clean up data we have read: This will do ACK frames. */
1770 tcp_cleanup_rbuf(sk, copied);
1771
1772 TCP_CHECK_TIMER(sk);
1773 release_sock(sk);
1774 return copied;
1775
1776 out:
1777 TCP_CHECK_TIMER(sk);
1778 release_sock(sk);
1779 return err;
1780
1781 recv_urg:
1782 err = tcp_recv_urg(sk, msg, len, flags);
1783 goto out;
1784 }
1785 EXPORT_SYMBOL(tcp_recvmsg);
1786
1787 void tcp_set_state(struct sock *sk, int state)
1788 {
1789 int oldstate = sk->sk_state;
1790
1791 switch (state) {
1792 case TCP_ESTABLISHED:
1793 if (oldstate != TCP_ESTABLISHED)
1794 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1795 break;
1796
1797 case TCP_CLOSE:
1798 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1799 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
1800
1801 sk->sk_prot->unhash(sk);
1802 if (inet_csk(sk)->icsk_bind_hash &&
1803 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1804 inet_put_port(sk);
1805 /* fall through */
1806 default:
1807 if (oldstate == TCP_ESTABLISHED)
1808 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1809 }
1810
1811 /* Change state AFTER socket is unhashed to avoid closed
1812 * socket sitting in hash tables.
1813 */
1814 sk->sk_state = state;
1815
1816 #ifdef STATE_TRACE
1817 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
1818 #endif
1819 }
1820 EXPORT_SYMBOL_GPL(tcp_set_state);
1821
1822 /*
1823 * State processing on a close. This implements the state shift for
1824 * sending our FIN frame. Note that we only send a FIN for some
1825 * states. A shutdown() may have already sent the FIN, or we may be
1826 * closed.
1827 */
1828
1829 static const unsigned char new_state[16] = {
1830 /* current state: new state: action: */
1831 /* (Invalid) */ TCP_CLOSE,
1832 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1833 /* TCP_SYN_SENT */ TCP_CLOSE,
1834 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1835 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1836 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1837 /* TCP_TIME_WAIT */ TCP_CLOSE,
1838 /* TCP_CLOSE */ TCP_CLOSE,
1839 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1840 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1841 /* TCP_LISTEN */ TCP_CLOSE,
1842 /* TCP_CLOSING */ TCP_CLOSING,
1843 };
1844
1845 static int tcp_close_state(struct sock *sk)
1846 {
1847 int next = (int)new_state[sk->sk_state];
1848 int ns = next & TCP_STATE_MASK;
1849
1850 tcp_set_state(sk, ns);
1851
1852 return next & TCP_ACTION_FIN;
1853 }
1854
1855 /*
1856 * Shutdown the sending side of a connection. Much like close except
1857 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1858 */
1859
1860 void tcp_shutdown(struct sock *sk, int how)
1861 {
1862 /* We need to grab some memory, and put together a FIN,
1863 * and then put it into the queue to be sent.
1864 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1865 */
1866 if (!(how & SEND_SHUTDOWN))
1867 return;
1868
1869 /* If we've already sent a FIN, or it's a closed state, skip this. */
1870 if ((1 << sk->sk_state) &
1871 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1872 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1873 /* Clear out any half completed packets. FIN if needed. */
1874 if (tcp_close_state(sk))
1875 tcp_send_fin(sk);
1876 }
1877 }
1878 EXPORT_SYMBOL(tcp_shutdown);
1879
1880 void tcp_close(struct sock *sk, long timeout)
1881 {
1882 struct sk_buff *skb;
1883 int data_was_unread = 0;
1884 int state;
1885
1886 lock_sock(sk);
1887 sk->sk_shutdown = SHUTDOWN_MASK;
1888
1889 if (sk->sk_state == TCP_LISTEN) {
1890 tcp_set_state(sk, TCP_CLOSE);
1891
1892 /* Special case. */
1893 inet_csk_listen_stop(sk);
1894
1895 goto adjudge_to_death;
1896 }
1897
1898 /* We need to flush the recv. buffs. We do this only on the
1899 * descriptor close, not protocol-sourced closes, because the
1900 * reader process may not have drained the data yet!
1901 */
1902 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1903 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
1904 tcp_hdr(skb)->fin;
1905 data_was_unread += len;
1906 __kfree_skb(skb);
1907 }
1908
1909 sk_mem_reclaim(sk);
1910
1911 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
1912 if (sk->sk_state == TCP_CLOSE)
1913 goto adjudge_to_death;
1914
1915 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1916 * data was lost. To witness the awful effects of the old behavior of
1917 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1918 * GET in an FTP client, suspend the process, wait for the client to
1919 * advertise a zero window, then kill -9 the FTP client, wheee...
1920 * Note: timeout is always zero in such a case.
1921 */
1922 if (data_was_unread) {
1923 /* Unread data was tossed, zap the connection. */
1924 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
1925 tcp_set_state(sk, TCP_CLOSE);
1926 tcp_send_active_reset(sk, sk->sk_allocation);
1927 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1928 /* Check zero linger _after_ checking for unread data. */
1929 sk->sk_prot->disconnect(sk, 0);
1930 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
1931 } else if (tcp_close_state(sk)) {
1932 /* We FIN if the application ate all the data before
1933 * zapping the connection.
1934 */
1935
1936 /* RED-PEN. Formally speaking, we have broken TCP state
1937 * machine. State transitions:
1938 *
1939 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1940 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1941 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1942 *
1943 * are legal only when FIN has been sent (i.e. in window),
1944 * rather than queued out of window. Purists blame.
1945 *
1946 * F.e. "RFC state" is ESTABLISHED,
1947 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1948 *
1949 * The visible declinations are that sometimes
1950 * we enter time-wait state, when it is not required really
1951 * (harmless), do not send active resets, when they are
1952 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1953 * they look as CLOSING or LAST_ACK for Linux)
1954 * Probably, I missed some more holelets.
1955 * --ANK
1956 */
1957 tcp_send_fin(sk);
1958 }
1959
1960 sk_stream_wait_close(sk, timeout);
1961
1962 adjudge_to_death:
1963 state = sk->sk_state;
1964 sock_hold(sk);
1965 sock_orphan(sk);
1966
1967 /* It is the last release_sock in its life. It will remove backlog. */
1968 release_sock(sk);
1969
1970
1971 /* Now socket is owned by kernel and we acquire BH lock
1972 to finish close. No need to check for user refs.
1973 */
1974 local_bh_disable();
1975 bh_lock_sock(sk);
1976 WARN_ON(sock_owned_by_user(sk));
1977
1978 percpu_counter_inc(sk->sk_prot->orphan_count);
1979
1980 /* Have we already been destroyed by a softirq or backlog? */
1981 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1982 goto out;
1983
1984 /* This is a (useful) BSD violating of the RFC. There is a
1985 * problem with TCP as specified in that the other end could
1986 * keep a socket open forever with no application left this end.
1987 * We use a 3 minute timeout (about the same as BSD) then kill
1988 * our end. If they send after that then tough - BUT: long enough
1989 * that we won't make the old 4*rto = almost no time - whoops
1990 * reset mistake.
1991 *
1992 * Nope, it was not mistake. It is really desired behaviour
1993 * f.e. on http servers, when such sockets are useless, but
1994 * consume significant resources. Let's do it with special
1995 * linger2 option. --ANK
1996 */
1997
1998 if (sk->sk_state == TCP_FIN_WAIT2) {
1999 struct tcp_sock *tp = tcp_sk(sk);
2000 if (tp->linger2 < 0) {
2001 tcp_set_state(sk, TCP_CLOSE);
2002 tcp_send_active_reset(sk, GFP_ATOMIC);
2003 NET_INC_STATS_BH(sock_net(sk),
2004 LINUX_MIB_TCPABORTONLINGER);
2005 } else {
2006 const int tmo = tcp_fin_time(sk);
2007
2008 if (tmo > TCP_TIMEWAIT_LEN) {
2009 inet_csk_reset_keepalive_timer(sk,
2010 tmo - TCP_TIMEWAIT_LEN);
2011 } else {
2012 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2013 goto out;
2014 }
2015 }
2016 }
2017 if (sk->sk_state != TCP_CLOSE) {
2018 sk_mem_reclaim(sk);
2019 if (tcp_too_many_orphans(sk, 0)) {
2020 if (net_ratelimit())
2021 printk(KERN_INFO "TCP: too many of orphaned "
2022 "sockets\n");
2023 tcp_set_state(sk, TCP_CLOSE);
2024 tcp_send_active_reset(sk, GFP_ATOMIC);
2025 NET_INC_STATS_BH(sock_net(sk),
2026 LINUX_MIB_TCPABORTONMEMORY);
2027 }
2028 }
2029
2030 if (sk->sk_state == TCP_CLOSE)
2031 inet_csk_destroy_sock(sk);
2032 /* Otherwise, socket is reprieved until protocol close. */
2033
2034 out:
2035 bh_unlock_sock(sk);
2036 local_bh_enable();
2037 sock_put(sk);
2038 }
2039 EXPORT_SYMBOL(tcp_close);
2040
2041 /* These states need RST on ABORT according to RFC793 */
2042
2043 static inline int tcp_need_reset(int state)
2044 {
2045 return (1 << state) &
2046 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2047 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2048 }
2049
2050 int tcp_disconnect(struct sock *sk, int flags)
2051 {
2052 struct inet_sock *inet = inet_sk(sk);
2053 struct inet_connection_sock *icsk = inet_csk(sk);
2054 struct tcp_sock *tp = tcp_sk(sk);
2055 int err = 0;
2056 int old_state = sk->sk_state;
2057
2058 if (old_state != TCP_CLOSE)
2059 tcp_set_state(sk, TCP_CLOSE);
2060
2061 /* ABORT function of RFC793 */
2062 if (old_state == TCP_LISTEN) {
2063 inet_csk_listen_stop(sk);
2064 } else if (tcp_need_reset(old_state) ||
2065 (tp->snd_nxt != tp->write_seq &&
2066 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2067 /* The last check adjusts for discrepancy of Linux wrt. RFC
2068 * states
2069 */
2070 tcp_send_active_reset(sk, gfp_any());
2071 sk->sk_err = ECONNRESET;
2072 } else if (old_state == TCP_SYN_SENT)
2073 sk->sk_err = ECONNRESET;
2074
2075 tcp_clear_xmit_timers(sk);
2076 __skb_queue_purge(&sk->sk_receive_queue);
2077 tcp_write_queue_purge(sk);
2078 __skb_queue_purge(&tp->out_of_order_queue);
2079 #ifdef CONFIG_NET_DMA
2080 __skb_queue_purge(&sk->sk_async_wait_queue);
2081 #endif
2082
2083 inet->inet_dport = 0;
2084
2085 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2086 inet_reset_saddr(sk);
2087
2088 sk->sk_shutdown = 0;
2089 sock_reset_flag(sk, SOCK_DONE);
2090 tp->srtt = 0;
2091 if ((tp->write_seq += tp->max_window + 2) == 0)
2092 tp->write_seq = 1;
2093 icsk->icsk_backoff = 0;
2094 tp->snd_cwnd = 2;
2095 icsk->icsk_probes_out = 0;
2096 tp->packets_out = 0;
2097 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2098 tp->snd_cwnd_cnt = 0;
2099 tp->bytes_acked = 0;
2100 tp->window_clamp = 0;
2101 tcp_set_ca_state(sk, TCP_CA_Open);
2102 tcp_clear_retrans(tp);
2103 inet_csk_delack_init(sk);
2104 tcp_init_send_head(sk);
2105 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2106 __sk_dst_reset(sk);
2107
2108 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2109
2110 sk->sk_error_report(sk);
2111 return err;
2112 }
2113 EXPORT_SYMBOL(tcp_disconnect);
2114
2115 /*
2116 * Socket option code for TCP.
2117 */
2118 static int do_tcp_setsockopt(struct sock *sk, int level,
2119 int optname, char __user *optval, unsigned int optlen)
2120 {
2121 struct tcp_sock *tp = tcp_sk(sk);
2122 struct inet_connection_sock *icsk = inet_csk(sk);
2123 int val;
2124 int err = 0;
2125
2126 /* These are data/string values, all the others are ints */
2127 switch (optname) {
2128 case TCP_CONGESTION: {
2129 char name[TCP_CA_NAME_MAX];
2130
2131 if (optlen < 1)
2132 return -EINVAL;
2133
2134 val = strncpy_from_user(name, optval,
2135 min_t(long, TCP_CA_NAME_MAX-1, optlen));
2136 if (val < 0)
2137 return -EFAULT;
2138 name[val] = 0;
2139
2140 lock_sock(sk);
2141 err = tcp_set_congestion_control(sk, name);
2142 release_sock(sk);
2143 return err;
2144 }
2145 case TCP_COOKIE_TRANSACTIONS: {
2146 struct tcp_cookie_transactions ctd;
2147 struct tcp_cookie_values *cvp = NULL;
2148
2149 if (sizeof(ctd) > optlen)
2150 return -EINVAL;
2151 if (copy_from_user(&ctd, optval, sizeof(ctd)))
2152 return -EFAULT;
2153
2154 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) ||
2155 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED)
2156 return -EINVAL;
2157
2158 if (ctd.tcpct_cookie_desired == 0) {
2159 /* default to global value */
2160 } else if ((0x1 & ctd.tcpct_cookie_desired) ||
2161 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX ||
2162 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) {
2163 return -EINVAL;
2164 }
2165
2166 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) {
2167 /* Supercedes all other values */
2168 lock_sock(sk);
2169 if (tp->cookie_values != NULL) {
2170 kref_put(&tp->cookie_values->kref,
2171 tcp_cookie_values_release);
2172 tp->cookie_values = NULL;
2173 }
2174 tp->rx_opt.cookie_in_always = 0; /* false */
2175 tp->rx_opt.cookie_out_never = 1; /* true */
2176 release_sock(sk);
2177 return err;
2178 }
2179
2180 /* Allocate ancillary memory before locking.
2181 */
2182 if (ctd.tcpct_used > 0 ||
2183 (tp->cookie_values == NULL &&
2184 (sysctl_tcp_cookie_size > 0 ||
2185 ctd.tcpct_cookie_desired > 0 ||
2186 ctd.tcpct_s_data_desired > 0))) {
2187 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used,
2188 GFP_KERNEL);
2189 if (cvp == NULL)
2190 return -ENOMEM;
2191
2192 kref_init(&cvp->kref);
2193 }
2194 lock_sock(sk);
2195 tp->rx_opt.cookie_in_always =
2196 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags);
2197 tp->rx_opt.cookie_out_never = 0; /* false */
2198
2199 if (tp->cookie_values != NULL) {
2200 if (cvp != NULL) {
2201 /* Changed values are recorded by a changed
2202 * pointer, ensuring the cookie will differ,
2203 * without separately hashing each value later.
2204 */
2205 kref_put(&tp->cookie_values->kref,
2206 tcp_cookie_values_release);
2207 } else {
2208 cvp = tp->cookie_values;
2209 }
2210 }
2211
2212 if (cvp != NULL) {
2213 cvp->cookie_desired = ctd.tcpct_cookie_desired;
2214
2215 if (ctd.tcpct_used > 0) {
2216 memcpy(cvp->s_data_payload, ctd.tcpct_value,
2217 ctd.tcpct_used);
2218 cvp->s_data_desired = ctd.tcpct_used;
2219 cvp->s_data_constant = 1; /* true */
2220 } else {
2221 /* No constant payload data. */
2222 cvp->s_data_desired = ctd.tcpct_s_data_desired;
2223 cvp->s_data_constant = 0; /* false */
2224 }
2225
2226 tp->cookie_values = cvp;
2227 }
2228 release_sock(sk);
2229 return err;
2230 }
2231 default:
2232 /* fallthru */
2233 break;
2234 }
2235
2236 if (optlen < sizeof(int))
2237 return -EINVAL;
2238
2239 if (get_user(val, (int __user *)optval))
2240 return -EFAULT;
2241
2242 lock_sock(sk);
2243
2244 switch (optname) {
2245 case TCP_MAXSEG:
2246 /* Values greater than interface MTU won't take effect. However
2247 * at the point when this call is done we typically don't yet
2248 * know which interface is going to be used */
2249 if (val < 8 || val > MAX_TCP_WINDOW) {
2250 err = -EINVAL;
2251 break;
2252 }
2253 tp->rx_opt.user_mss = val;
2254 break;
2255
2256 case TCP_NODELAY:
2257 if (val) {
2258 /* TCP_NODELAY is weaker than TCP_CORK, so that
2259 * this option on corked socket is remembered, but
2260 * it is not activated until cork is cleared.
2261 *
2262 * However, when TCP_NODELAY is set we make
2263 * an explicit push, which overrides even TCP_CORK
2264 * for currently queued segments.
2265 */
2266 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2267 tcp_push_pending_frames(sk);
2268 } else {
2269 tp->nonagle &= ~TCP_NAGLE_OFF;
2270 }
2271 break;
2272
2273 case TCP_THIN_LINEAR_TIMEOUTS:
2274 if (val < 0 || val > 1)
2275 err = -EINVAL;
2276 else
2277 tp->thin_lto = val;
2278 break;
2279
2280 case TCP_THIN_DUPACK:
2281 if (val < 0 || val > 1)
2282 err = -EINVAL;
2283 else
2284 tp->thin_dupack = val;
2285 break;
2286
2287 case TCP_CORK:
2288 /* When set indicates to always queue non-full frames.
2289 * Later the user clears this option and we transmit
2290 * any pending partial frames in the queue. This is
2291 * meant to be used alongside sendfile() to get properly
2292 * filled frames when the user (for example) must write
2293 * out headers with a write() call first and then use
2294 * sendfile to send out the data parts.
2295 *
2296 * TCP_CORK can be set together with TCP_NODELAY and it is
2297 * stronger than TCP_NODELAY.
2298 */
2299 if (val) {
2300 tp->nonagle |= TCP_NAGLE_CORK;
2301 } else {
2302 tp->nonagle &= ~TCP_NAGLE_CORK;
2303 if (tp->nonagle&TCP_NAGLE_OFF)
2304 tp->nonagle |= TCP_NAGLE_PUSH;
2305 tcp_push_pending_frames(sk);
2306 }
2307 break;
2308
2309 case TCP_KEEPIDLE:
2310 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2311 err = -EINVAL;
2312 else {
2313 tp->keepalive_time = val * HZ;
2314 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2315 !((1 << sk->sk_state) &
2316 (TCPF_CLOSE | TCPF_LISTEN))) {
2317 u32 elapsed = keepalive_time_elapsed(tp);
2318 if (tp->keepalive_time > elapsed)
2319 elapsed = tp->keepalive_time - elapsed;
2320 else
2321 elapsed = 0;
2322 inet_csk_reset_keepalive_timer(sk, elapsed);
2323 }
2324 }
2325 break;
2326 case TCP_KEEPINTVL:
2327 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2328 err = -EINVAL;
2329 else
2330 tp->keepalive_intvl = val * HZ;
2331 break;
2332 case TCP_KEEPCNT:
2333 if (val < 1 || val > MAX_TCP_KEEPCNT)
2334 err = -EINVAL;
2335 else
2336 tp->keepalive_probes = val;
2337 break;
2338 case TCP_SYNCNT:
2339 if (val < 1 || val > MAX_TCP_SYNCNT)
2340 err = -EINVAL;
2341 else
2342 icsk->icsk_syn_retries = val;
2343 break;
2344
2345 case TCP_LINGER2:
2346 if (val < 0)
2347 tp->linger2 = -1;
2348 else if (val > sysctl_tcp_fin_timeout / HZ)
2349 tp->linger2 = 0;
2350 else
2351 tp->linger2 = val * HZ;
2352 break;
2353
2354 case TCP_DEFER_ACCEPT:
2355 /* Translate value in seconds to number of retransmits */
2356 icsk->icsk_accept_queue.rskq_defer_accept =
2357 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2358 TCP_RTO_MAX / HZ);
2359 break;
2360
2361 case TCP_WINDOW_CLAMP:
2362 if (!val) {
2363 if (sk->sk_state != TCP_CLOSE) {
2364 err = -EINVAL;
2365 break;
2366 }
2367 tp->window_clamp = 0;
2368 } else
2369 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2370 SOCK_MIN_RCVBUF / 2 : val;
2371 break;
2372
2373 case TCP_QUICKACK:
2374 if (!val) {
2375 icsk->icsk_ack.pingpong = 1;
2376 } else {
2377 icsk->icsk_ack.pingpong = 0;
2378 if ((1 << sk->sk_state) &
2379 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2380 inet_csk_ack_scheduled(sk)) {
2381 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2382 tcp_cleanup_rbuf(sk, 1);
2383 if (!(val & 1))
2384 icsk->icsk_ack.pingpong = 1;
2385 }
2386 }
2387 break;
2388
2389 #ifdef CONFIG_TCP_MD5SIG
2390 case TCP_MD5SIG:
2391 /* Read the IP->Key mappings from userspace */
2392 err = tp->af_specific->md5_parse(sk, optval, optlen);
2393 break;
2394 #endif
2395 case TCP_USER_TIMEOUT:
2396 /* Cap the max timeout in ms TCP will retry/retrans
2397 * before giving up and aborting (ETIMEDOUT) a connection.
2398 */
2399 icsk->icsk_user_timeout = msecs_to_jiffies(val);
2400 break;
2401 default:
2402 err = -ENOPROTOOPT;
2403 break;
2404 }
2405
2406 release_sock(sk);
2407 return err;
2408 }
2409
2410 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2411 unsigned int optlen)
2412 {
2413 struct inet_connection_sock *icsk = inet_csk(sk);
2414
2415 if (level != SOL_TCP)
2416 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2417 optval, optlen);
2418 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2419 }
2420 EXPORT_SYMBOL(tcp_setsockopt);
2421
2422 #ifdef CONFIG_COMPAT
2423 int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2424 char __user *optval, unsigned int optlen)
2425 {
2426 if (level != SOL_TCP)
2427 return inet_csk_compat_setsockopt(sk, level, optname,
2428 optval, optlen);
2429 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2430 }
2431 EXPORT_SYMBOL(compat_tcp_setsockopt);
2432 #endif
2433
2434 /* Return information about state of tcp endpoint in API format. */
2435 void tcp_get_info(struct sock *sk, struct tcp_info *info)
2436 {
2437 struct tcp_sock *tp = tcp_sk(sk);
2438 const struct inet_connection_sock *icsk = inet_csk(sk);
2439 u32 now = tcp_time_stamp;
2440
2441 memset(info, 0, sizeof(*info));
2442
2443 info->tcpi_state = sk->sk_state;
2444 info->tcpi_ca_state = icsk->icsk_ca_state;
2445 info->tcpi_retransmits = icsk->icsk_retransmits;
2446 info->tcpi_probes = icsk->icsk_probes_out;
2447 info->tcpi_backoff = icsk->icsk_backoff;
2448
2449 if (tp->rx_opt.tstamp_ok)
2450 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2451 if (tcp_is_sack(tp))
2452 info->tcpi_options |= TCPI_OPT_SACK;
2453 if (tp->rx_opt.wscale_ok) {
2454 info->tcpi_options |= TCPI_OPT_WSCALE;
2455 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2456 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2457 }
2458
2459 if (tp->ecn_flags&TCP_ECN_OK)
2460 info->tcpi_options |= TCPI_OPT_ECN;
2461
2462 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2463 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2464 info->tcpi_snd_mss = tp->mss_cache;
2465 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2466
2467 if (sk->sk_state == TCP_LISTEN) {
2468 info->tcpi_unacked = sk->sk_ack_backlog;
2469 info->tcpi_sacked = sk->sk_max_ack_backlog;
2470 } else {
2471 info->tcpi_unacked = tp->packets_out;
2472 info->tcpi_sacked = tp->sacked_out;
2473 }
2474 info->tcpi_lost = tp->lost_out;
2475 info->tcpi_retrans = tp->retrans_out;
2476 info->tcpi_fackets = tp->fackets_out;
2477
2478 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2479 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2480 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2481
2482 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2483 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2484 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2485 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2486 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2487 info->tcpi_snd_cwnd = tp->snd_cwnd;
2488 info->tcpi_advmss = tp->advmss;
2489 info->tcpi_reordering = tp->reordering;
2490
2491 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2492 info->tcpi_rcv_space = tp->rcvq_space.space;
2493
2494 info->tcpi_total_retrans = tp->total_retrans;
2495 }
2496 EXPORT_SYMBOL_GPL(tcp_get_info);
2497
2498 static int do_tcp_getsockopt(struct sock *sk, int level,
2499 int optname, char __user *optval, int __user *optlen)
2500 {
2501 struct inet_connection_sock *icsk = inet_csk(sk);
2502 struct tcp_sock *tp = tcp_sk(sk);
2503 int val, len;
2504
2505 if (get_user(len, optlen))
2506 return -EFAULT;
2507
2508 len = min_t(unsigned int, len, sizeof(int));
2509
2510 if (len < 0)
2511 return -EINVAL;
2512
2513 switch (optname) {
2514 case TCP_MAXSEG:
2515 val = tp->mss_cache;
2516 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2517 val = tp->rx_opt.user_mss;
2518 break;
2519 case TCP_NODELAY:
2520 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2521 break;
2522 case TCP_CORK:
2523 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2524 break;
2525 case TCP_KEEPIDLE:
2526 val = keepalive_time_when(tp) / HZ;
2527 break;
2528 case TCP_KEEPINTVL:
2529 val = keepalive_intvl_when(tp) / HZ;
2530 break;
2531 case TCP_KEEPCNT:
2532 val = keepalive_probes(tp);
2533 break;
2534 case TCP_SYNCNT:
2535 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2536 break;
2537 case TCP_LINGER2:
2538 val = tp->linger2;
2539 if (val >= 0)
2540 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2541 break;
2542 case TCP_DEFER_ACCEPT:
2543 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2544 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
2545 break;
2546 case TCP_WINDOW_CLAMP:
2547 val = tp->window_clamp;
2548 break;
2549 case TCP_INFO: {
2550 struct tcp_info info;
2551
2552 if (get_user(len, optlen))
2553 return -EFAULT;
2554
2555 tcp_get_info(sk, &info);
2556
2557 len = min_t(unsigned int, len, sizeof(info));
2558 if (put_user(len, optlen))
2559 return -EFAULT;
2560 if (copy_to_user(optval, &info, len))
2561 return -EFAULT;
2562 return 0;
2563 }
2564 case TCP_QUICKACK:
2565 val = !icsk->icsk_ack.pingpong;
2566 break;
2567
2568 case TCP_CONGESTION:
2569 if (get_user(len, optlen))
2570 return -EFAULT;
2571 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2572 if (put_user(len, optlen))
2573 return -EFAULT;
2574 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2575 return -EFAULT;
2576 return 0;
2577
2578 case TCP_COOKIE_TRANSACTIONS: {
2579 struct tcp_cookie_transactions ctd;
2580 struct tcp_cookie_values *cvp = tp->cookie_values;
2581
2582 if (get_user(len, optlen))
2583 return -EFAULT;
2584 if (len < sizeof(ctd))
2585 return -EINVAL;
2586
2587 memset(&ctd, 0, sizeof(ctd));
2588 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ?
2589 TCP_COOKIE_IN_ALWAYS : 0)
2590 | (tp->rx_opt.cookie_out_never ?
2591 TCP_COOKIE_OUT_NEVER : 0);
2592
2593 if (cvp != NULL) {
2594 ctd.tcpct_flags |= (cvp->s_data_in ?
2595 TCP_S_DATA_IN : 0)
2596 | (cvp->s_data_out ?
2597 TCP_S_DATA_OUT : 0);
2598
2599 ctd.tcpct_cookie_desired = cvp->cookie_desired;
2600 ctd.tcpct_s_data_desired = cvp->s_data_desired;
2601
2602 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0],
2603 cvp->cookie_pair_size);
2604 ctd.tcpct_used = cvp->cookie_pair_size;
2605 }
2606
2607 if (put_user(sizeof(ctd), optlen))
2608 return -EFAULT;
2609 if (copy_to_user(optval, &ctd, sizeof(ctd)))
2610 return -EFAULT;
2611 return 0;
2612 }
2613 case TCP_THIN_LINEAR_TIMEOUTS:
2614 val = tp->thin_lto;
2615 break;
2616 case TCP_THIN_DUPACK:
2617 val = tp->thin_dupack;
2618 break;
2619
2620 case TCP_USER_TIMEOUT:
2621 val = jiffies_to_msecs(icsk->icsk_user_timeout);
2622 break;
2623 default:
2624 return -ENOPROTOOPT;
2625 }
2626
2627 if (put_user(len, optlen))
2628 return -EFAULT;
2629 if (copy_to_user(optval, &val, len))
2630 return -EFAULT;
2631 return 0;
2632 }
2633
2634 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2635 int __user *optlen)
2636 {
2637 struct inet_connection_sock *icsk = inet_csk(sk);
2638
2639 if (level != SOL_TCP)
2640 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2641 optval, optlen);
2642 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2643 }
2644 EXPORT_SYMBOL(tcp_getsockopt);
2645
2646 #ifdef CONFIG_COMPAT
2647 int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2648 char __user *optval, int __user *optlen)
2649 {
2650 if (level != SOL_TCP)
2651 return inet_csk_compat_getsockopt(sk, level, optname,
2652 optval, optlen);
2653 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2654 }
2655 EXPORT_SYMBOL(compat_tcp_getsockopt);
2656 #endif
2657
2658 struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
2659 {
2660 struct sk_buff *segs = ERR_PTR(-EINVAL);
2661 struct tcphdr *th;
2662 unsigned thlen;
2663 unsigned int seq;
2664 __be32 delta;
2665 unsigned int oldlen;
2666 unsigned int mss;
2667
2668 if (!pskb_may_pull(skb, sizeof(*th)))
2669 goto out;
2670
2671 th = tcp_hdr(skb);
2672 thlen = th->doff * 4;
2673 if (thlen < sizeof(*th))
2674 goto out;
2675
2676 if (!pskb_may_pull(skb, thlen))
2677 goto out;
2678
2679 oldlen = (u16)~skb->len;
2680 __skb_pull(skb, thlen);
2681
2682 mss = skb_shinfo(skb)->gso_size;
2683 if (unlikely(skb->len <= mss))
2684 goto out;
2685
2686 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2687 /* Packet is from an untrusted source, reset gso_segs. */
2688 int type = skb_shinfo(skb)->gso_type;
2689
2690 if (unlikely(type &
2691 ~(SKB_GSO_TCPV4 |
2692 SKB_GSO_DODGY |
2693 SKB_GSO_TCP_ECN |
2694 SKB_GSO_TCPV6 |
2695 0) ||
2696 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2697 goto out;
2698
2699 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2700
2701 segs = NULL;
2702 goto out;
2703 }
2704
2705 segs = skb_segment(skb, features);
2706 if (IS_ERR(segs))
2707 goto out;
2708
2709 delta = htonl(oldlen + (thlen + mss));
2710
2711 skb = segs;
2712 th = tcp_hdr(skb);
2713 seq = ntohl(th->seq);
2714
2715 do {
2716 th->fin = th->psh = 0;
2717
2718 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2719 (__force u32)delta));
2720 if (skb->ip_summed != CHECKSUM_PARTIAL)
2721 th->check =
2722 csum_fold(csum_partial(skb_transport_header(skb),
2723 thlen, skb->csum));
2724
2725 seq += mss;
2726 skb = skb->next;
2727 th = tcp_hdr(skb);
2728
2729 th->seq = htonl(seq);
2730 th->cwr = 0;
2731 } while (skb->next);
2732
2733 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
2734 skb->data_len);
2735 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2736 (__force u32)delta));
2737 if (skb->ip_summed != CHECKSUM_PARTIAL)
2738 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2739 thlen, skb->csum));
2740
2741 out:
2742 return segs;
2743 }
2744 EXPORT_SYMBOL(tcp_tso_segment);
2745
2746 struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2747 {
2748 struct sk_buff **pp = NULL;
2749 struct sk_buff *p;
2750 struct tcphdr *th;
2751 struct tcphdr *th2;
2752 unsigned int len;
2753 unsigned int thlen;
2754 __be32 flags;
2755 unsigned int mss = 1;
2756 unsigned int hlen;
2757 unsigned int off;
2758 int flush = 1;
2759 int i;
2760
2761 off = skb_gro_offset(skb);
2762 hlen = off + sizeof(*th);
2763 th = skb_gro_header_fast(skb, off);
2764 if (skb_gro_header_hard(skb, hlen)) {
2765 th = skb_gro_header_slow(skb, hlen, off);
2766 if (unlikely(!th))
2767 goto out;
2768 }
2769
2770 thlen = th->doff * 4;
2771 if (thlen < sizeof(*th))
2772 goto out;
2773
2774 hlen = off + thlen;
2775 if (skb_gro_header_hard(skb, hlen)) {
2776 th = skb_gro_header_slow(skb, hlen, off);
2777 if (unlikely(!th))
2778 goto out;
2779 }
2780
2781 skb_gro_pull(skb, thlen);
2782
2783 len = skb_gro_len(skb);
2784 flags = tcp_flag_word(th);
2785
2786 for (; (p = *head); head = &p->next) {
2787 if (!NAPI_GRO_CB(p)->same_flow)
2788 continue;
2789
2790 th2 = tcp_hdr(p);
2791
2792 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
2793 NAPI_GRO_CB(p)->same_flow = 0;
2794 continue;
2795 }
2796
2797 goto found;
2798 }
2799
2800 goto out_check_final;
2801
2802 found:
2803 flush = NAPI_GRO_CB(p)->flush;
2804 flush |= (__force int)(flags & TCP_FLAG_CWR);
2805 flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
2806 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
2807 flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
2808 for (i = sizeof(*th); i < thlen; i += 4)
2809 flush |= *(u32 *)((u8 *)th + i) ^
2810 *(u32 *)((u8 *)th2 + i);
2811
2812 mss = skb_shinfo(p)->gso_size;
2813
2814 flush |= (len - 1) >= mss;
2815 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
2816
2817 if (flush || skb_gro_receive(head, skb)) {
2818 mss = 1;
2819 goto out_check_final;
2820 }
2821
2822 p = *head;
2823 th2 = tcp_hdr(p);
2824 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
2825
2826 out_check_final:
2827 flush = len < mss;
2828 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH |
2829 TCP_FLAG_RST | TCP_FLAG_SYN |
2830 TCP_FLAG_FIN));
2831
2832 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
2833 pp = head;
2834
2835 out:
2836 NAPI_GRO_CB(skb)->flush |= flush;
2837
2838 return pp;
2839 }
2840 EXPORT_SYMBOL(tcp_gro_receive);
2841
2842 int tcp_gro_complete(struct sk_buff *skb)
2843 {
2844 struct tcphdr *th = tcp_hdr(skb);
2845
2846 skb->csum_start = skb_transport_header(skb) - skb->head;
2847 skb->csum_offset = offsetof(struct tcphdr, check);
2848 skb->ip_summed = CHECKSUM_PARTIAL;
2849
2850 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
2851
2852 if (th->cwr)
2853 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
2854
2855 return 0;
2856 }
2857 EXPORT_SYMBOL(tcp_gro_complete);
2858
2859 #ifdef CONFIG_TCP_MD5SIG
2860 static unsigned long tcp_md5sig_users;
2861 static struct tcp_md5sig_pool * __percpu *tcp_md5sig_pool;
2862 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2863
2864 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool * __percpu *pool)
2865 {
2866 int cpu;
2867 for_each_possible_cpu(cpu) {
2868 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2869 if (p) {
2870 if (p->md5_desc.tfm)
2871 crypto_free_hash(p->md5_desc.tfm);
2872 kfree(p);
2873 }
2874 }
2875 free_percpu(pool);
2876 }
2877
2878 void tcp_free_md5sig_pool(void)
2879 {
2880 struct tcp_md5sig_pool * __percpu *pool = NULL;
2881
2882 spin_lock_bh(&tcp_md5sig_pool_lock);
2883 if (--tcp_md5sig_users == 0) {
2884 pool = tcp_md5sig_pool;
2885 tcp_md5sig_pool = NULL;
2886 }
2887 spin_unlock_bh(&tcp_md5sig_pool_lock);
2888 if (pool)
2889 __tcp_free_md5sig_pool(pool);
2890 }
2891 EXPORT_SYMBOL(tcp_free_md5sig_pool);
2892
2893 static struct tcp_md5sig_pool * __percpu *
2894 __tcp_alloc_md5sig_pool(struct sock *sk)
2895 {
2896 int cpu;
2897 struct tcp_md5sig_pool * __percpu *pool;
2898
2899 pool = alloc_percpu(struct tcp_md5sig_pool *);
2900 if (!pool)
2901 return NULL;
2902
2903 for_each_possible_cpu(cpu) {
2904 struct tcp_md5sig_pool *p;
2905 struct crypto_hash *hash;
2906
2907 p = kzalloc(sizeof(*p), sk->sk_allocation);
2908 if (!p)
2909 goto out_free;
2910 *per_cpu_ptr(pool, cpu) = p;
2911
2912 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2913 if (!hash || IS_ERR(hash))
2914 goto out_free;
2915
2916 p->md5_desc.tfm = hash;
2917 }
2918 return pool;
2919 out_free:
2920 __tcp_free_md5sig_pool(pool);
2921 return NULL;
2922 }
2923
2924 struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *sk)
2925 {
2926 struct tcp_md5sig_pool * __percpu *pool;
2927 int alloc = 0;
2928
2929 retry:
2930 spin_lock_bh(&tcp_md5sig_pool_lock);
2931 pool = tcp_md5sig_pool;
2932 if (tcp_md5sig_users++ == 0) {
2933 alloc = 1;
2934 spin_unlock_bh(&tcp_md5sig_pool_lock);
2935 } else if (!pool) {
2936 tcp_md5sig_users--;
2937 spin_unlock_bh(&tcp_md5sig_pool_lock);
2938 cpu_relax();
2939 goto retry;
2940 } else
2941 spin_unlock_bh(&tcp_md5sig_pool_lock);
2942
2943 if (alloc) {
2944 /* we cannot hold spinlock here because this may sleep. */
2945 struct tcp_md5sig_pool * __percpu *p;
2946
2947 p = __tcp_alloc_md5sig_pool(sk);
2948 spin_lock_bh(&tcp_md5sig_pool_lock);
2949 if (!p) {
2950 tcp_md5sig_users--;
2951 spin_unlock_bh(&tcp_md5sig_pool_lock);
2952 return NULL;
2953 }
2954 pool = tcp_md5sig_pool;
2955 if (pool) {
2956 /* oops, it has already been assigned. */
2957 spin_unlock_bh(&tcp_md5sig_pool_lock);
2958 __tcp_free_md5sig_pool(p);
2959 } else {
2960 tcp_md5sig_pool = pool = p;
2961 spin_unlock_bh(&tcp_md5sig_pool_lock);
2962 }
2963 }
2964 return pool;
2965 }
2966 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2967
2968
2969 /**
2970 * tcp_get_md5sig_pool - get md5sig_pool for this user
2971 *
2972 * We use percpu structure, so if we succeed, we exit with preemption
2973 * and BH disabled, to make sure another thread or softirq handling
2974 * wont try to get same context.
2975 */
2976 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
2977 {
2978 struct tcp_md5sig_pool * __percpu *p;
2979
2980 local_bh_disable();
2981
2982 spin_lock(&tcp_md5sig_pool_lock);
2983 p = tcp_md5sig_pool;
2984 if (p)
2985 tcp_md5sig_users++;
2986 spin_unlock(&tcp_md5sig_pool_lock);
2987
2988 if (p)
2989 return *this_cpu_ptr(p);
2990
2991 local_bh_enable();
2992 return NULL;
2993 }
2994 EXPORT_SYMBOL(tcp_get_md5sig_pool);
2995
2996 void tcp_put_md5sig_pool(void)
2997 {
2998 local_bh_enable();
2999 tcp_free_md5sig_pool();
3000 }
3001 EXPORT_SYMBOL(tcp_put_md5sig_pool);
3002
3003 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
3004 struct tcphdr *th)
3005 {
3006 struct scatterlist sg;
3007 int err;
3008
3009 __sum16 old_checksum = th->check;
3010 th->check = 0;
3011 /* options aren't included in the hash */
3012 sg_init_one(&sg, th, sizeof(struct tcphdr));
3013 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
3014 th->check = old_checksum;
3015 return err;
3016 }
3017 EXPORT_SYMBOL(tcp_md5_hash_header);
3018
3019 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3020 struct sk_buff *skb, unsigned header_len)
3021 {
3022 struct scatterlist sg;
3023 const struct tcphdr *tp = tcp_hdr(skb);
3024 struct hash_desc *desc = &hp->md5_desc;
3025 unsigned i;
3026 const unsigned head_data_len = skb_headlen(skb) > header_len ?
3027 skb_headlen(skb) - header_len : 0;
3028 const struct skb_shared_info *shi = skb_shinfo(skb);
3029 struct sk_buff *frag_iter;
3030
3031 sg_init_table(&sg, 1);
3032
3033 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3034 if (crypto_hash_update(desc, &sg, head_data_len))
3035 return 1;
3036
3037 for (i = 0; i < shi->nr_frags; ++i) {
3038 const struct skb_frag_struct *f = &shi->frags[i];
3039 sg_set_page(&sg, f->page, f->size, f->page_offset);
3040 if (crypto_hash_update(desc, &sg, f->size))
3041 return 1;
3042 }
3043
3044 skb_walk_frags(skb, frag_iter)
3045 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3046 return 1;
3047
3048 return 0;
3049 }
3050 EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3051
3052 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
3053 {
3054 struct scatterlist sg;
3055
3056 sg_init_one(&sg, key->key, key->keylen);
3057 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
3058 }
3059 EXPORT_SYMBOL(tcp_md5_hash_key);
3060
3061 #endif
3062
3063 /**
3064 * Each Responder maintains up to two secret values concurrently for
3065 * efficient secret rollover. Each secret value has 4 states:
3066 *
3067 * Generating. (tcp_secret_generating != tcp_secret_primary)
3068 * Generates new Responder-Cookies, but not yet used for primary
3069 * verification. This is a short-term state, typically lasting only
3070 * one round trip time (RTT).
3071 *
3072 * Primary. (tcp_secret_generating == tcp_secret_primary)
3073 * Used both for generation and primary verification.
3074 *
3075 * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
3076 * Used for verification, until the first failure that can be
3077 * verified by the newer Generating secret. At that time, this
3078 * cookie's state is changed to Secondary, and the Generating
3079 * cookie's state is changed to Primary. This is a short-term state,
3080 * typically lasting only one round trip time (RTT).
3081 *
3082 * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
3083 * Used for secondary verification, after primary verification
3084 * failures. This state lasts no more than twice the Maximum Segment
3085 * Lifetime (2MSL). Then, the secret is discarded.
3086 */
3087 struct tcp_cookie_secret {
3088 /* The secret is divided into two parts. The digest part is the
3089 * equivalent of previously hashing a secret and saving the state,
3090 * and serves as an initialization vector (IV). The message part
3091 * serves as the trailing secret.
3092 */
3093 u32 secrets[COOKIE_WORKSPACE_WORDS];
3094 unsigned long expires;
3095 };
3096
3097 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
3098 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
3099 #define TCP_SECRET_LIFE (HZ * 600)
3100
3101 static struct tcp_cookie_secret tcp_secret_one;
3102 static struct tcp_cookie_secret tcp_secret_two;
3103
3104 /* Essentially a circular list, without dynamic allocation. */
3105 static struct tcp_cookie_secret *tcp_secret_generating;
3106 static struct tcp_cookie_secret *tcp_secret_primary;
3107 static struct tcp_cookie_secret *tcp_secret_retiring;
3108 static struct tcp_cookie_secret *tcp_secret_secondary;
3109
3110 static DEFINE_SPINLOCK(tcp_secret_locker);
3111
3112 /* Select a pseudo-random word in the cookie workspace.
3113 */
3114 static inline u32 tcp_cookie_work(const u32 *ws, const int n)
3115 {
3116 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])];
3117 }
3118
3119 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
3120 * Called in softirq context.
3121 * Returns: 0 for success.
3122 */
3123 int tcp_cookie_generator(u32 *bakery)
3124 {
3125 unsigned long jiffy = jiffies;
3126
3127 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) {
3128 spin_lock_bh(&tcp_secret_locker);
3129 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) {
3130 /* refreshed by another */
3131 memcpy(bakery,
3132 &tcp_secret_generating->secrets[0],
3133 COOKIE_WORKSPACE_WORDS);
3134 } else {
3135 /* still needs refreshing */
3136 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS);
3137
3138 /* The first time, paranoia assumes that the
3139 * randomization function isn't as strong. But,
3140 * this secret initialization is delayed until
3141 * the last possible moment (packet arrival).
3142 * Although that time is observable, it is
3143 * unpredictably variable. Mash in the most
3144 * volatile clock bits available, and expire the
3145 * secret extra quickly.
3146 */
3147 if (unlikely(tcp_secret_primary->expires ==
3148 tcp_secret_secondary->expires)) {
3149 struct timespec tv;
3150
3151 getnstimeofday(&tv);
3152 bakery[COOKIE_DIGEST_WORDS+0] ^=
3153 (u32)tv.tv_nsec;
3154
3155 tcp_secret_secondary->expires = jiffy
3156 + TCP_SECRET_1MSL
3157 + (0x0f & tcp_cookie_work(bakery, 0));
3158 } else {
3159 tcp_secret_secondary->expires = jiffy
3160 + TCP_SECRET_LIFE
3161 + (0xff & tcp_cookie_work(bakery, 1));
3162 tcp_secret_primary->expires = jiffy
3163 + TCP_SECRET_2MSL
3164 + (0x1f & tcp_cookie_work(bakery, 2));
3165 }
3166 memcpy(&tcp_secret_secondary->secrets[0],
3167 bakery, COOKIE_WORKSPACE_WORDS);
3168
3169 rcu_assign_pointer(tcp_secret_generating,
3170 tcp_secret_secondary);
3171 rcu_assign_pointer(tcp_secret_retiring,
3172 tcp_secret_primary);
3173 /*
3174 * Neither call_rcu() nor synchronize_rcu() needed.
3175 * Retiring data is not freed. It is replaced after
3176 * further (locked) pointer updates, and a quiet time
3177 * (minimum 1MSL, maximum LIFE - 2MSL).
3178 */
3179 }
3180 spin_unlock_bh(&tcp_secret_locker);
3181 } else {
3182 rcu_read_lock_bh();
3183 memcpy(bakery,
3184 &rcu_dereference(tcp_secret_generating)->secrets[0],
3185 COOKIE_WORKSPACE_WORDS);
3186 rcu_read_unlock_bh();
3187 }
3188 return 0;
3189 }
3190 EXPORT_SYMBOL(tcp_cookie_generator);
3191
3192 void tcp_done(struct sock *sk)
3193 {
3194 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3195 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
3196
3197 tcp_set_state(sk, TCP_CLOSE);
3198 tcp_clear_xmit_timers(sk);
3199
3200 sk->sk_shutdown = SHUTDOWN_MASK;
3201
3202 if (!sock_flag(sk, SOCK_DEAD))
3203 sk->sk_state_change(sk);
3204 else
3205 inet_csk_destroy_sock(sk);
3206 }
3207 EXPORT_SYMBOL_GPL(tcp_done);
3208
3209 extern struct tcp_congestion_ops tcp_reno;
3210
3211 static __initdata unsigned long thash_entries;
3212 static int __init set_thash_entries(char *str)
3213 {
3214 if (!str)
3215 return 0;
3216 thash_entries = simple_strtoul(str, &str, 0);
3217 return 1;
3218 }
3219 __setup("thash_entries=", set_thash_entries);
3220
3221 void __init tcp_init(void)
3222 {
3223 struct sk_buff *skb = NULL;
3224 unsigned long nr_pages, limit;
3225 int i, max_share, cnt;
3226 unsigned long jiffy = jiffies;
3227
3228 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
3229
3230 percpu_counter_init(&tcp_sockets_allocated, 0);
3231 percpu_counter_init(&tcp_orphan_count, 0);
3232 tcp_hashinfo.bind_bucket_cachep =
3233 kmem_cache_create("tcp_bind_bucket",
3234 sizeof(struct inet_bind_bucket), 0,
3235 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3236
3237 /* Size and allocate the main established and bind bucket
3238 * hash tables.
3239 *
3240 * The methodology is similar to that of the buffer cache.
3241 */
3242 tcp_hashinfo.ehash =
3243 alloc_large_system_hash("TCP established",
3244 sizeof(struct inet_ehash_bucket),
3245 thash_entries,
3246 (totalram_pages >= 128 * 1024) ?
3247 13 : 15,
3248 0,
3249 NULL,
3250 &tcp_hashinfo.ehash_mask,
3251 thash_entries ? 0 : 512 * 1024);
3252 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
3253 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
3254 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
3255 }
3256 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3257 panic("TCP: failed to alloc ehash_locks");
3258 tcp_hashinfo.bhash =
3259 alloc_large_system_hash("TCP bind",
3260 sizeof(struct inet_bind_hashbucket),
3261 tcp_hashinfo.ehash_mask + 1,
3262 (totalram_pages >= 128 * 1024) ?
3263 13 : 15,
3264 0,
3265 &tcp_hashinfo.bhash_size,
3266 NULL,
3267 64 * 1024);
3268 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
3269 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3270 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3271 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
3272 }
3273
3274
3275 cnt = tcp_hashinfo.ehash_mask + 1;
3276
3277 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3278 sysctl_tcp_max_orphans = cnt / 2;
3279 sysctl_max_syn_backlog = max(128, cnt / 256);
3280
3281 /* Set the pressure threshold to be a fraction of global memory that
3282 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
3283 * memory, with a floor of 128 pages.
3284 */
3285 nr_pages = totalram_pages - totalhigh_pages;
3286 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
3287 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
3288 limit = max(limit, 128UL);
3289 sysctl_tcp_mem[0] = limit / 4 * 3;
3290 sysctl_tcp_mem[1] = limit;
3291 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
3292
3293 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3294 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
3295 max_share = min(4UL*1024*1024, limit);
3296
3297 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3298 sysctl_tcp_wmem[1] = 16*1024;
3299 sysctl_tcp_wmem[2] = max(64*1024, max_share);
3300
3301 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3302 sysctl_tcp_rmem[1] = 87380;
3303 sysctl_tcp_rmem[2] = max(87380, max_share);
3304
3305 printk(KERN_INFO "TCP: Hash tables configured "
3306 "(established %u bind %u)\n",
3307 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3308
3309 tcp_register_congestion_control(&tcp_reno);
3310
3311 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets));
3312 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets));
3313 tcp_secret_one.expires = jiffy; /* past due */
3314 tcp_secret_two.expires = jiffy; /* past due */
3315 tcp_secret_generating = &tcp_secret_one;
3316 tcp_secret_primary = &tcp_secret_one;
3317 tcp_secret_retiring = &tcp_secret_two;
3318 tcp_secret_secondary = &tcp_secret_two;
3319 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree