Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Implementation of the Transmission Control Protocol(TCP). | |
7 | * | |
8 | * Version: $Id: tcp.c,v 1.216 2002/02/01 22:01:04 davem Exp $ | |
9 | * | |
02c30a84 | 10 | * Authors: Ross Biro |
1da177e4 LT |
11 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
12 | * Mark Evans, <evansmp@uhura.aston.ac.uk> | |
13 | * Corey Minyard <wf-rch!minyard@relay.EU.net> | |
14 | * Florian La Roche, <flla@stud.uni-sb.de> | |
15 | * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> | |
16 | * Linus Torvalds, <torvalds@cs.helsinki.fi> | |
17 | * Alan Cox, <gw4pts@gw4pts.ampr.org> | |
18 | * Matthew Dillon, <dillon@apollo.west.oic.com> | |
19 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | |
20 | * Jorge Cwik, <jorge@laser.satlink.net> | |
21 | * | |
22 | * Fixes: | |
23 | * Alan Cox : Numerous verify_area() calls | |
24 | * Alan Cox : Set the ACK bit on a reset | |
25 | * Alan Cox : Stopped it crashing if it closed while | |
26 | * sk->inuse=1 and was trying to connect | |
27 | * (tcp_err()). | |
28 | * Alan Cox : All icmp error handling was broken | |
29 | * pointers passed where wrong and the | |
30 | * socket was looked up backwards. Nobody | |
31 | * tested any icmp error code obviously. | |
32 | * Alan Cox : tcp_err() now handled properly. It | |
33 | * wakes people on errors. poll | |
34 | * behaves and the icmp error race | |
35 | * has gone by moving it into sock.c | |
36 | * Alan Cox : tcp_send_reset() fixed to work for | |
37 | * everything not just packets for | |
38 | * unknown sockets. | |
39 | * Alan Cox : tcp option processing. | |
40 | * Alan Cox : Reset tweaked (still not 100%) [Had | |
41 | * syn rule wrong] | |
42 | * Herp Rosmanith : More reset fixes | |
43 | * Alan Cox : No longer acks invalid rst frames. | |
44 | * Acking any kind of RST is right out. | |
45 | * Alan Cox : Sets an ignore me flag on an rst | |
46 | * receive otherwise odd bits of prattle | |
47 | * escape still | |
48 | * Alan Cox : Fixed another acking RST frame bug. | |
49 | * Should stop LAN workplace lockups. | |
50 | * Alan Cox : Some tidyups using the new skb list | |
51 | * facilities | |
52 | * Alan Cox : sk->keepopen now seems to work | |
53 | * Alan Cox : Pulls options out correctly on accepts | |
54 | * Alan Cox : Fixed assorted sk->rqueue->next errors | |
55 | * Alan Cox : PSH doesn't end a TCP read. Switched a | |
56 | * bit to skb ops. | |
57 | * Alan Cox : Tidied tcp_data to avoid a potential | |
58 | * nasty. | |
59 | * Alan Cox : Added some better commenting, as the | |
60 | * tcp is hard to follow | |
61 | * Alan Cox : Removed incorrect check for 20 * psh | |
62 | * Michael O'Reilly : ack < copied bug fix. | |
63 | * Johannes Stille : Misc tcp fixes (not all in yet). | |
64 | * Alan Cox : FIN with no memory -> CRASH | |
65 | * Alan Cox : Added socket option proto entries. | |
66 | * Also added awareness of them to accept. | |
67 | * Alan Cox : Added TCP options (SOL_TCP) | |
68 | * Alan Cox : Switched wakeup calls to callbacks, | |
69 | * so the kernel can layer network | |
70 | * sockets. | |
71 | * Alan Cox : Use ip_tos/ip_ttl settings. | |
72 | * Alan Cox : Handle FIN (more) properly (we hope). | |
73 | * Alan Cox : RST frames sent on unsynchronised | |
74 | * state ack error. | |
75 | * Alan Cox : Put in missing check for SYN bit. | |
76 | * Alan Cox : Added tcp_select_window() aka NET2E | |
77 | * window non shrink trick. | |
78 | * Alan Cox : Added a couple of small NET2E timer | |
79 | * fixes | |
80 | * Charles Hedrick : TCP fixes | |
81 | * Toomas Tamm : TCP window fixes | |
82 | * Alan Cox : Small URG fix to rlogin ^C ack fight | |
83 | * Charles Hedrick : Rewrote most of it to actually work | |
84 | * Linus : Rewrote tcp_read() and URG handling | |
85 | * completely | |
86 | * Gerhard Koerting: Fixed some missing timer handling | |
87 | * Matthew Dillon : Reworked TCP machine states as per RFC | |
88 | * Gerhard Koerting: PC/TCP workarounds | |
89 | * Adam Caldwell : Assorted timer/timing errors | |
90 | * Matthew Dillon : Fixed another RST bug | |
91 | * Alan Cox : Move to kernel side addressing changes. | |
92 | * Alan Cox : Beginning work on TCP fastpathing | |
93 | * (not yet usable) | |
94 | * Arnt Gulbrandsen: Turbocharged tcp_check() routine. | |
95 | * Alan Cox : TCP fast path debugging | |
96 | * Alan Cox : Window clamping | |
97 | * Michael Riepe : Bug in tcp_check() | |
98 | * Matt Dillon : More TCP improvements and RST bug fixes | |
99 | * Matt Dillon : Yet more small nasties remove from the | |
100 | * TCP code (Be very nice to this man if | |
101 | * tcp finally works 100%) 8) | |
102 | * Alan Cox : BSD accept semantics. | |
103 | * Alan Cox : Reset on closedown bug. | |
104 | * Peter De Schrijver : ENOTCONN check missing in tcp_sendto(). | |
105 | * Michael Pall : Handle poll() after URG properly in | |
106 | * all cases. | |
107 | * Michael Pall : Undo the last fix in tcp_read_urg() | |
108 | * (multi URG PUSH broke rlogin). | |
109 | * Michael Pall : Fix the multi URG PUSH problem in | |
110 | * tcp_readable(), poll() after URG | |
111 | * works now. | |
112 | * Michael Pall : recv(...,MSG_OOB) never blocks in the | |
113 | * BSD api. | |
114 | * Alan Cox : Changed the semantics of sk->socket to | |
115 | * fix a race and a signal problem with | |
116 | * accept() and async I/O. | |
117 | * Alan Cox : Relaxed the rules on tcp_sendto(). | |
118 | * Yury Shevchuk : Really fixed accept() blocking problem. | |
119 | * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for | |
120 | * clients/servers which listen in on | |
121 | * fixed ports. | |
122 | * Alan Cox : Cleaned the above up and shrank it to | |
123 | * a sensible code size. | |
124 | * Alan Cox : Self connect lockup fix. | |
125 | * Alan Cox : No connect to multicast. | |
126 | * Ross Biro : Close unaccepted children on master | |
127 | * socket close. | |
128 | * Alan Cox : Reset tracing code. | |
129 | * Alan Cox : Spurious resets on shutdown. | |
130 | * Alan Cox : Giant 15 minute/60 second timer error | |
131 | * Alan Cox : Small whoops in polling before an | |
132 | * accept. | |
133 | * Alan Cox : Kept the state trace facility since | |
134 | * it's handy for debugging. | |
135 | * Alan Cox : More reset handler fixes. | |
136 | * Alan Cox : Started rewriting the code based on | |
137 | * the RFC's for other useful protocol | |
138 | * references see: Comer, KA9Q NOS, and | |
139 | * for a reference on the difference | |
140 | * between specifications and how BSD | |
141 | * works see the 4.4lite source. | |
142 | * A.N.Kuznetsov : Don't time wait on completion of tidy | |
143 | * close. | |
144 | * Linus Torvalds : Fin/Shutdown & copied_seq changes. | |
145 | * Linus Torvalds : Fixed BSD port reuse to work first syn | |
146 | * Alan Cox : Reimplemented timers as per the RFC | |
147 | * and using multiple timers for sanity. | |
148 | * Alan Cox : Small bug fixes, and a lot of new | |
149 | * comments. | |
150 | * Alan Cox : Fixed dual reader crash by locking | |
151 | * the buffers (much like datagram.c) | |
152 | * Alan Cox : Fixed stuck sockets in probe. A probe | |
153 | * now gets fed up of retrying without | |
154 | * (even a no space) answer. | |
155 | * Alan Cox : Extracted closing code better | |
156 | * Alan Cox : Fixed the closing state machine to | |
157 | * resemble the RFC. | |
158 | * Alan Cox : More 'per spec' fixes. | |
159 | * Jorge Cwik : Even faster checksumming. | |
160 | * Alan Cox : tcp_data() doesn't ack illegal PSH | |
161 | * only frames. At least one pc tcp stack | |
162 | * generates them. | |
163 | * Alan Cox : Cache last socket. | |
164 | * Alan Cox : Per route irtt. | |
165 | * Matt Day : poll()->select() match BSD precisely on error | |
166 | * Alan Cox : New buffers | |
167 | * Marc Tamsky : Various sk->prot->retransmits and | |
168 | * sk->retransmits misupdating fixed. | |
169 | * Fixed tcp_write_timeout: stuck close, | |
170 | * and TCP syn retries gets used now. | |
171 | * Mark Yarvis : In tcp_read_wakeup(), don't send an | |
172 | * ack if state is TCP_CLOSED. | |
173 | * Alan Cox : Look up device on a retransmit - routes may | |
174 | * change. Doesn't yet cope with MSS shrink right | |
175 | * but it's a start! | |
176 | * Marc Tamsky : Closing in closing fixes. | |
177 | * Mike Shaver : RFC1122 verifications. | |
178 | * Alan Cox : rcv_saddr errors. | |
179 | * Alan Cox : Block double connect(). | |
180 | * Alan Cox : Small hooks for enSKIP. | |
181 | * Alexey Kuznetsov: Path MTU discovery. | |
182 | * Alan Cox : Support soft errors. | |
183 | * Alan Cox : Fix MTU discovery pathological case | |
184 | * when the remote claims no mtu! | |
185 | * Marc Tamsky : TCP_CLOSE fix. | |
186 | * Colin (G3TNE) : Send a reset on syn ack replies in | |
187 | * window but wrong (fixes NT lpd problems) | |
188 | * Pedro Roque : Better TCP window handling, delayed ack. | |
189 | * Joerg Reuter : No modification of locked buffers in | |
190 | * tcp_do_retransmit() | |
191 | * Eric Schenk : Changed receiver side silly window | |
192 | * avoidance algorithm to BSD style | |
193 | * algorithm. This doubles throughput | |
194 | * against machines running Solaris, | |
195 | * and seems to result in general | |
196 | * improvement. | |
197 | * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD | |
198 | * Willy Konynenberg : Transparent proxying support. | |
199 | * Mike McLagan : Routing by source | |
200 | * Keith Owens : Do proper merging with partial SKB's in | |
201 | * tcp_do_sendmsg to avoid burstiness. | |
202 | * Eric Schenk : Fix fast close down bug with | |
203 | * shutdown() followed by close(). | |
204 | * Andi Kleen : Make poll agree with SIGIO | |
205 | * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and | |
206 | * lingertime == 0 (RFC 793 ABORT Call) | |
207 | * Hirokazu Takahashi : Use copy_from_user() instead of | |
208 | * csum_and_copy_from_user() if possible. | |
209 | * | |
210 | * This program is free software; you can redistribute it and/or | |
211 | * modify it under the terms of the GNU General Public License | |
212 | * as published by the Free Software Foundation; either version | |
213 | * 2 of the License, or(at your option) any later version. | |
214 | * | |
215 | * Description of States: | |
216 | * | |
217 | * TCP_SYN_SENT sent a connection request, waiting for ack | |
218 | * | |
219 | * TCP_SYN_RECV received a connection request, sent ack, | |
220 | * waiting for final ack in three-way handshake. | |
221 | * | |
222 | * TCP_ESTABLISHED connection established | |
223 | * | |
224 | * TCP_FIN_WAIT1 our side has shutdown, waiting to complete | |
225 | * transmission of remaining buffered data | |
226 | * | |
227 | * TCP_FIN_WAIT2 all buffered data sent, waiting for remote | |
228 | * to shutdown | |
229 | * | |
230 | * TCP_CLOSING both sides have shutdown but we still have | |
231 | * data we have to finish sending | |
232 | * | |
233 | * TCP_TIME_WAIT timeout to catch resent junk before entering | |
234 | * closed, can only be entered from FIN_WAIT2 | |
235 | * or CLOSING. Required because the other end | |
236 | * may not have gotten our last ACK causing it | |
237 | * to retransmit the data packet (which we ignore) | |
238 | * | |
239 | * TCP_CLOSE_WAIT remote side has shutdown and is waiting for | |
240 | * us to finish writing our data and to shutdown | |
241 | * (we have to close() to move on to LAST_ACK) | |
242 | * | |
243 | * TCP_LAST_ACK out side has shutdown after remote has | |
244 | * shutdown. There may still be data in our | |
245 | * buffer that we have to finish sending | |
246 | * | |
247 | * TCP_CLOSE socket is finished | |
248 | */ | |
249 | ||
250 | #include <linux/config.h> | |
251 | #include <linux/module.h> | |
252 | #include <linux/types.h> | |
253 | #include <linux/fcntl.h> | |
254 | #include <linux/poll.h> | |
255 | #include <linux/init.h> | |
256 | #include <linux/smp_lock.h> | |
257 | #include <linux/fs.h> | |
258 | #include <linux/random.h> | |
259 | #include <linux/bootmem.h> | |
260 | ||
261 | #include <net/icmp.h> | |
262 | #include <net/tcp.h> | |
263 | #include <net/xfrm.h> | |
264 | #include <net/ip.h> | |
265 | ||
266 | ||
267 | #include <asm/uaccess.h> | |
268 | #include <asm/ioctls.h> | |
269 | ||
270 | int sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT; | |
271 | ||
272 | DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics); | |
273 | ||
274 | kmem_cache_t *tcp_openreq_cachep; | |
275 | kmem_cache_t *tcp_bucket_cachep; | |
276 | kmem_cache_t *tcp_timewait_cachep; | |
277 | ||
278 | atomic_t tcp_orphan_count = ATOMIC_INIT(0); | |
279 | ||
280 | int sysctl_tcp_mem[3]; | |
281 | int sysctl_tcp_wmem[3] = { 4 * 1024, 16 * 1024, 128 * 1024 }; | |
282 | int sysctl_tcp_rmem[3] = { 4 * 1024, 87380, 87380 * 2 }; | |
283 | ||
284 | EXPORT_SYMBOL(sysctl_tcp_mem); | |
285 | EXPORT_SYMBOL(sysctl_tcp_rmem); | |
286 | EXPORT_SYMBOL(sysctl_tcp_wmem); | |
287 | ||
288 | atomic_t tcp_memory_allocated; /* Current allocated memory. */ | |
289 | atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */ | |
290 | ||
291 | EXPORT_SYMBOL(tcp_memory_allocated); | |
292 | EXPORT_SYMBOL(tcp_sockets_allocated); | |
293 | ||
294 | /* | |
295 | * Pressure flag: try to collapse. | |
296 | * Technical note: it is used by multiple contexts non atomically. | |
297 | * All the sk_stream_mem_schedule() is of this nature: accounting | |
298 | * is strict, actions are advisory and have some latency. | |
299 | */ | |
300 | int tcp_memory_pressure; | |
301 | ||
302 | EXPORT_SYMBOL(tcp_memory_pressure); | |
303 | ||
304 | void tcp_enter_memory_pressure(void) | |
305 | { | |
306 | if (!tcp_memory_pressure) { | |
307 | NET_INC_STATS(LINUX_MIB_TCPMEMORYPRESSURES); | |
308 | tcp_memory_pressure = 1; | |
309 | } | |
310 | } | |
311 | ||
312 | EXPORT_SYMBOL(tcp_enter_memory_pressure); | |
313 | ||
314 | /* | |
315 | * LISTEN is a special case for poll.. | |
316 | */ | |
317 | static __inline__ unsigned int tcp_listen_poll(struct sock *sk, | |
318 | poll_table *wait) | |
319 | { | |
320 | return tcp_sk(sk)->accept_queue ? (POLLIN | POLLRDNORM) : 0; | |
321 | } | |
322 | ||
323 | /* | |
324 | * Wait for a TCP event. | |
325 | * | |
326 | * Note that we don't need to lock the socket, as the upper poll layers | |
327 | * take care of normal races (between the test and the event) and we don't | |
328 | * go look at any of the socket buffers directly. | |
329 | */ | |
330 | unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) | |
331 | { | |
332 | unsigned int mask; | |
333 | struct sock *sk = sock->sk; | |
334 | struct tcp_sock *tp = tcp_sk(sk); | |
335 | ||
336 | poll_wait(file, sk->sk_sleep, wait); | |
337 | if (sk->sk_state == TCP_LISTEN) | |
338 | return tcp_listen_poll(sk, wait); | |
339 | ||
340 | /* Socket is not locked. We are protected from async events | |
341 | by poll logic and correct handling of state changes | |
342 | made by another threads is impossible in any case. | |
343 | */ | |
344 | ||
345 | mask = 0; | |
346 | if (sk->sk_err) | |
347 | mask = POLLERR; | |
348 | ||
349 | /* | |
350 | * POLLHUP is certainly not done right. But poll() doesn't | |
351 | * have a notion of HUP in just one direction, and for a | |
352 | * socket the read side is more interesting. | |
353 | * | |
354 | * Some poll() documentation says that POLLHUP is incompatible | |
355 | * with the POLLOUT/POLLWR flags, so somebody should check this | |
356 | * all. But careful, it tends to be safer to return too many | |
357 | * bits than too few, and you can easily break real applications | |
358 | * if you don't tell them that something has hung up! | |
359 | * | |
360 | * Check-me. | |
361 | * | |
362 | * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and | |
363 | * our fs/select.c). It means that after we received EOF, | |
364 | * poll always returns immediately, making impossible poll() on write() | |
365 | * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP | |
366 | * if and only if shutdown has been made in both directions. | |
367 | * Actually, it is interesting to look how Solaris and DUX | |
368 | * solve this dilemma. I would prefer, if PULLHUP were maskable, | |
369 | * then we could set it on SND_SHUTDOWN. BTW examples given | |
370 | * in Stevens' books assume exactly this behaviour, it explains | |
371 | * why PULLHUP is incompatible with POLLOUT. --ANK | |
372 | * | |
373 | * NOTE. Check for TCP_CLOSE is added. The goal is to prevent | |
374 | * blocking on fresh not-connected or disconnected socket. --ANK | |
375 | */ | |
376 | if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) | |
377 | mask |= POLLHUP; | |
378 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
379 | mask |= POLLIN | POLLRDNORM; | |
380 | ||
381 | /* Connected? */ | |
382 | if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { | |
383 | /* Potential race condition. If read of tp below will | |
384 | * escape above sk->sk_state, we can be illegally awaken | |
385 | * in SYN_* states. */ | |
386 | if ((tp->rcv_nxt != tp->copied_seq) && | |
387 | (tp->urg_seq != tp->copied_seq || | |
388 | tp->rcv_nxt != tp->copied_seq + 1 || | |
389 | sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data)) | |
390 | mask |= POLLIN | POLLRDNORM; | |
391 | ||
392 | if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { | |
393 | if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { | |
394 | mask |= POLLOUT | POLLWRNORM; | |
395 | } else { /* send SIGIO later */ | |
396 | set_bit(SOCK_ASYNC_NOSPACE, | |
397 | &sk->sk_socket->flags); | |
398 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
399 | ||
400 | /* Race breaker. If space is freed after | |
401 | * wspace test but before the flags are set, | |
402 | * IO signal will be lost. | |
403 | */ | |
404 | if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) | |
405 | mask |= POLLOUT | POLLWRNORM; | |
406 | } | |
407 | } | |
408 | ||
409 | if (tp->urg_data & TCP_URG_VALID) | |
410 | mask |= POLLPRI; | |
411 | } | |
412 | return mask; | |
413 | } | |
414 | ||
415 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) | |
416 | { | |
417 | struct tcp_sock *tp = tcp_sk(sk); | |
418 | int answ; | |
419 | ||
420 | switch (cmd) { | |
421 | case SIOCINQ: | |
422 | if (sk->sk_state == TCP_LISTEN) | |
423 | return -EINVAL; | |
424 | ||
425 | lock_sock(sk); | |
426 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
427 | answ = 0; | |
428 | else if (sock_flag(sk, SOCK_URGINLINE) || | |
429 | !tp->urg_data || | |
430 | before(tp->urg_seq, tp->copied_seq) || | |
431 | !before(tp->urg_seq, tp->rcv_nxt)) { | |
432 | answ = tp->rcv_nxt - tp->copied_seq; | |
433 | ||
434 | /* Subtract 1, if FIN is in queue. */ | |
435 | if (answ && !skb_queue_empty(&sk->sk_receive_queue)) | |
436 | answ -= | |
437 | ((struct sk_buff *)sk->sk_receive_queue.prev)->h.th->fin; | |
438 | } else | |
439 | answ = tp->urg_seq - tp->copied_seq; | |
440 | release_sock(sk); | |
441 | break; | |
442 | case SIOCATMARK: | |
443 | answ = tp->urg_data && tp->urg_seq == tp->copied_seq; | |
444 | break; | |
445 | case SIOCOUTQ: | |
446 | if (sk->sk_state == TCP_LISTEN) | |
447 | return -EINVAL; | |
448 | ||
449 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
450 | answ = 0; | |
451 | else | |
452 | answ = tp->write_seq - tp->snd_una; | |
453 | break; | |
454 | default: | |
455 | return -ENOIOCTLCMD; | |
456 | }; | |
457 | ||
458 | return put_user(answ, (int __user *)arg); | |
459 | } | |
460 | ||
461 | ||
462 | int tcp_listen_start(struct sock *sk) | |
463 | { | |
464 | struct inet_sock *inet = inet_sk(sk); | |
465 | struct tcp_sock *tp = tcp_sk(sk); | |
466 | struct tcp_listen_opt *lopt; | |
467 | ||
468 | sk->sk_max_ack_backlog = 0; | |
469 | sk->sk_ack_backlog = 0; | |
470 | tp->accept_queue = tp->accept_queue_tail = NULL; | |
471 | rwlock_init(&tp->syn_wait_lock); | |
472 | tcp_delack_init(tp); | |
473 | ||
474 | lopt = kmalloc(sizeof(struct tcp_listen_opt), GFP_KERNEL); | |
475 | if (!lopt) | |
476 | return -ENOMEM; | |
477 | ||
478 | memset(lopt, 0, sizeof(struct tcp_listen_opt)); | |
479 | for (lopt->max_qlen_log = 6; ; lopt->max_qlen_log++) | |
480 | if ((1 << lopt->max_qlen_log) >= sysctl_max_syn_backlog) | |
481 | break; | |
482 | get_random_bytes(&lopt->hash_rnd, 4); | |
483 | ||
484 | write_lock_bh(&tp->syn_wait_lock); | |
485 | tp->listen_opt = lopt; | |
486 | write_unlock_bh(&tp->syn_wait_lock); | |
487 | ||
488 | /* There is race window here: we announce ourselves listening, | |
489 | * but this transition is still not validated by get_port(). | |
490 | * It is OK, because this socket enters to hash table only | |
491 | * after validation is complete. | |
492 | */ | |
493 | sk->sk_state = TCP_LISTEN; | |
494 | if (!sk->sk_prot->get_port(sk, inet->num)) { | |
495 | inet->sport = htons(inet->num); | |
496 | ||
497 | sk_dst_reset(sk); | |
498 | sk->sk_prot->hash(sk); | |
499 | ||
500 | return 0; | |
501 | } | |
502 | ||
503 | sk->sk_state = TCP_CLOSE; | |
504 | write_lock_bh(&tp->syn_wait_lock); | |
505 | tp->listen_opt = NULL; | |
506 | write_unlock_bh(&tp->syn_wait_lock); | |
507 | kfree(lopt); | |
508 | return -EADDRINUSE; | |
509 | } | |
510 | ||
511 | /* | |
512 | * This routine closes sockets which have been at least partially | |
513 | * opened, but not yet accepted. | |
514 | */ | |
515 | ||
516 | static void tcp_listen_stop (struct sock *sk) | |
517 | { | |
518 | struct tcp_sock *tp = tcp_sk(sk); | |
519 | struct tcp_listen_opt *lopt = tp->listen_opt; | |
520 | struct open_request *acc_req = tp->accept_queue; | |
521 | struct open_request *req; | |
522 | int i; | |
523 | ||
524 | tcp_delete_keepalive_timer(sk); | |
525 | ||
526 | /* make all the listen_opt local to us */ | |
527 | write_lock_bh(&tp->syn_wait_lock); | |
528 | tp->listen_opt = NULL; | |
529 | write_unlock_bh(&tp->syn_wait_lock); | |
530 | tp->accept_queue = tp->accept_queue_tail = NULL; | |
531 | ||
532 | if (lopt->qlen) { | |
533 | for (i = 0; i < TCP_SYNQ_HSIZE; i++) { | |
534 | while ((req = lopt->syn_table[i]) != NULL) { | |
535 | lopt->syn_table[i] = req->dl_next; | |
536 | lopt->qlen--; | |
537 | tcp_openreq_free(req); | |
538 | ||
539 | /* Following specs, it would be better either to send FIN | |
540 | * (and enter FIN-WAIT-1, it is normal close) | |
541 | * or to send active reset (abort). | |
542 | * Certainly, it is pretty dangerous while synflood, but it is | |
543 | * bad justification for our negligence 8) | |
544 | * To be honest, we are not able to make either | |
545 | * of the variants now. --ANK | |
546 | */ | |
547 | } | |
548 | } | |
549 | } | |
550 | BUG_TRAP(!lopt->qlen); | |
551 | ||
552 | kfree(lopt); | |
553 | ||
554 | while ((req = acc_req) != NULL) { | |
555 | struct sock *child = req->sk; | |
556 | ||
557 | acc_req = req->dl_next; | |
558 | ||
559 | local_bh_disable(); | |
560 | bh_lock_sock(child); | |
561 | BUG_TRAP(!sock_owned_by_user(child)); | |
562 | sock_hold(child); | |
563 | ||
564 | tcp_disconnect(child, O_NONBLOCK); | |
565 | ||
566 | sock_orphan(child); | |
567 | ||
568 | atomic_inc(&tcp_orphan_count); | |
569 | ||
570 | tcp_destroy_sock(child); | |
571 | ||
572 | bh_unlock_sock(child); | |
573 | local_bh_enable(); | |
574 | sock_put(child); | |
575 | ||
576 | sk_acceptq_removed(sk); | |
577 | tcp_openreq_fastfree(req); | |
578 | } | |
579 | BUG_TRAP(!sk->sk_ack_backlog); | |
580 | } | |
581 | ||
582 | static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) | |
583 | { | |
584 | TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH; | |
585 | tp->pushed_seq = tp->write_seq; | |
586 | } | |
587 | ||
588 | static inline int forced_push(struct tcp_sock *tp) | |
589 | { | |
590 | return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); | |
591 | } | |
592 | ||
593 | static inline void skb_entail(struct sock *sk, struct tcp_sock *tp, | |
594 | struct sk_buff *skb) | |
595 | { | |
596 | skb->csum = 0; | |
597 | TCP_SKB_CB(skb)->seq = tp->write_seq; | |
598 | TCP_SKB_CB(skb)->end_seq = tp->write_seq; | |
599 | TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK; | |
600 | TCP_SKB_CB(skb)->sacked = 0; | |
601 | skb_header_release(skb); | |
602 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
603 | sk_charge_skb(sk, skb); | |
604 | if (!sk->sk_send_head) | |
605 | sk->sk_send_head = skb; | |
606 | else if (tp->nonagle&TCP_NAGLE_PUSH) | |
607 | tp->nonagle &= ~TCP_NAGLE_PUSH; | |
608 | } | |
609 | ||
610 | static inline void tcp_mark_urg(struct tcp_sock *tp, int flags, | |
611 | struct sk_buff *skb) | |
612 | { | |
613 | if (flags & MSG_OOB) { | |
614 | tp->urg_mode = 1; | |
615 | tp->snd_up = tp->write_seq; | |
616 | TCP_SKB_CB(skb)->sacked |= TCPCB_URG; | |
617 | } | |
618 | } | |
619 | ||
620 | static inline void tcp_push(struct sock *sk, struct tcp_sock *tp, int flags, | |
621 | int mss_now, int nonagle) | |
622 | { | |
623 | if (sk->sk_send_head) { | |
624 | struct sk_buff *skb = sk->sk_write_queue.prev; | |
625 | if (!(flags & MSG_MORE) || forced_push(tp)) | |
626 | tcp_mark_push(tp, skb); | |
627 | tcp_mark_urg(tp, flags, skb); | |
628 | __tcp_push_pending_frames(sk, tp, mss_now, | |
629 | (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); | |
630 | } | |
631 | } | |
632 | ||
633 | static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, | |
634 | size_t psize, int flags) | |
635 | { | |
636 | struct tcp_sock *tp = tcp_sk(sk); | |
637 | int mss_now; | |
638 | int err; | |
639 | ssize_t copied; | |
640 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
641 | ||
642 | /* Wait for a connection to finish. */ | |
643 | if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) | |
644 | if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) | |
645 | goto out_err; | |
646 | ||
647 | clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
648 | ||
649 | mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); | |
650 | copied = 0; | |
651 | ||
652 | err = -EPIPE; | |
653 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
654 | goto do_error; | |
655 | ||
656 | while (psize > 0) { | |
657 | struct sk_buff *skb = sk->sk_write_queue.prev; | |
658 | struct page *page = pages[poffset / PAGE_SIZE]; | |
659 | int copy, i, can_coalesce; | |
660 | int offset = poffset % PAGE_SIZE; | |
661 | int size = min_t(size_t, psize, PAGE_SIZE - offset); | |
662 | ||
663 | if (!sk->sk_send_head || (copy = mss_now - skb->len) <= 0) { | |
664 | new_segment: | |
665 | if (!sk_stream_memory_free(sk)) | |
666 | goto wait_for_sndbuf; | |
667 | ||
668 | skb = sk_stream_alloc_pskb(sk, 0, 0, | |
669 | sk->sk_allocation); | |
670 | if (!skb) | |
671 | goto wait_for_memory; | |
672 | ||
673 | skb_entail(sk, tp, skb); | |
674 | copy = mss_now; | |
675 | } | |
676 | ||
677 | if (copy > size) | |
678 | copy = size; | |
679 | ||
680 | i = skb_shinfo(skb)->nr_frags; | |
681 | can_coalesce = skb_can_coalesce(skb, i, page, offset); | |
682 | if (!can_coalesce && i >= MAX_SKB_FRAGS) { | |
683 | tcp_mark_push(tp, skb); | |
684 | goto new_segment; | |
685 | } | |
686 | if (sk->sk_forward_alloc < copy && | |
687 | !sk_stream_mem_schedule(sk, copy, 0)) | |
688 | goto wait_for_memory; | |
689 | ||
690 | if (can_coalesce) { | |
691 | skb_shinfo(skb)->frags[i - 1].size += copy; | |
692 | } else { | |
693 | get_page(page); | |
694 | skb_fill_page_desc(skb, i, page, offset, copy); | |
695 | } | |
696 | ||
697 | skb->len += copy; | |
698 | skb->data_len += copy; | |
699 | skb->truesize += copy; | |
700 | sk->sk_wmem_queued += copy; | |
701 | sk->sk_forward_alloc -= copy; | |
702 | skb->ip_summed = CHECKSUM_HW; | |
703 | tp->write_seq += copy; | |
704 | TCP_SKB_CB(skb)->end_seq += copy; | |
705 | skb_shinfo(skb)->tso_segs = 0; | |
706 | ||
707 | if (!copied) | |
708 | TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; | |
709 | ||
710 | copied += copy; | |
711 | poffset += copy; | |
712 | if (!(psize -= copy)) | |
713 | goto out; | |
714 | ||
715 | if (skb->len != mss_now || (flags & MSG_OOB)) | |
716 | continue; | |
717 | ||
718 | if (forced_push(tp)) { | |
719 | tcp_mark_push(tp, skb); | |
720 | __tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH); | |
721 | } else if (skb == sk->sk_send_head) | |
722 | tcp_push_one(sk, mss_now); | |
723 | continue; | |
724 | ||
725 | wait_for_sndbuf: | |
726 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
727 | wait_for_memory: | |
728 | if (copied) | |
729 | tcp_push(sk, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); | |
730 | ||
731 | if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) | |
732 | goto do_error; | |
733 | ||
734 | mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); | |
735 | } | |
736 | ||
737 | out: | |
738 | if (copied) | |
739 | tcp_push(sk, tp, flags, mss_now, tp->nonagle); | |
740 | return copied; | |
741 | ||
742 | do_error: | |
743 | if (copied) | |
744 | goto out; | |
745 | out_err: | |
746 | return sk_stream_error(sk, flags, err); | |
747 | } | |
748 | ||
749 | ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, | |
750 | size_t size, int flags) | |
751 | { | |
752 | ssize_t res; | |
753 | struct sock *sk = sock->sk; | |
754 | ||
755 | #define TCP_ZC_CSUM_FLAGS (NETIF_F_IP_CSUM | NETIF_F_NO_CSUM | NETIF_F_HW_CSUM) | |
756 | ||
757 | if (!(sk->sk_route_caps & NETIF_F_SG) || | |
758 | !(sk->sk_route_caps & TCP_ZC_CSUM_FLAGS)) | |
759 | return sock_no_sendpage(sock, page, offset, size, flags); | |
760 | ||
761 | #undef TCP_ZC_CSUM_FLAGS | |
762 | ||
763 | lock_sock(sk); | |
764 | TCP_CHECK_TIMER(sk); | |
765 | res = do_tcp_sendpages(sk, &page, offset, size, flags); | |
766 | TCP_CHECK_TIMER(sk); | |
767 | release_sock(sk); | |
768 | return res; | |
769 | } | |
770 | ||
771 | #define TCP_PAGE(sk) (sk->sk_sndmsg_page) | |
772 | #define TCP_OFF(sk) (sk->sk_sndmsg_off) | |
773 | ||
774 | static inline int select_size(struct sock *sk, struct tcp_sock *tp) | |
775 | { | |
776 | int tmp = tp->mss_cache_std; | |
777 | ||
778 | if (sk->sk_route_caps & NETIF_F_SG) { | |
779 | int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); | |
780 | ||
781 | if (tmp >= pgbreak && | |
782 | tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) | |
783 | tmp = pgbreak; | |
784 | } | |
785 | return tmp; | |
786 | } | |
787 | ||
788 | int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, | |
789 | size_t size) | |
790 | { | |
791 | struct iovec *iov; | |
792 | struct tcp_sock *tp = tcp_sk(sk); | |
793 | struct sk_buff *skb; | |
794 | int iovlen, flags; | |
795 | int mss_now; | |
796 | int err, copied; | |
797 | long timeo; | |
798 | ||
799 | lock_sock(sk); | |
800 | TCP_CHECK_TIMER(sk); | |
801 | ||
802 | flags = msg->msg_flags; | |
803 | timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
804 | ||
805 | /* Wait for a connection to finish. */ | |
806 | if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) | |
807 | if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) | |
808 | goto out_err; | |
809 | ||
810 | /* This should be in poll */ | |
811 | clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
812 | ||
813 | mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); | |
814 | ||
815 | /* Ok commence sending. */ | |
816 | iovlen = msg->msg_iovlen; | |
817 | iov = msg->msg_iov; | |
818 | copied = 0; | |
819 | ||
820 | err = -EPIPE; | |
821 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
822 | goto do_error; | |
823 | ||
824 | while (--iovlen >= 0) { | |
825 | int seglen = iov->iov_len; | |
826 | unsigned char __user *from = iov->iov_base; | |
827 | ||
828 | iov++; | |
829 | ||
830 | while (seglen > 0) { | |
831 | int copy; | |
832 | ||
833 | skb = sk->sk_write_queue.prev; | |
834 | ||
835 | if (!sk->sk_send_head || | |
836 | (copy = mss_now - skb->len) <= 0) { | |
837 | ||
838 | new_segment: | |
839 | /* Allocate new segment. If the interface is SG, | |
840 | * allocate skb fitting to single page. | |
841 | */ | |
842 | if (!sk_stream_memory_free(sk)) | |
843 | goto wait_for_sndbuf; | |
844 | ||
845 | skb = sk_stream_alloc_pskb(sk, select_size(sk, tp), | |
846 | 0, sk->sk_allocation); | |
847 | if (!skb) | |
848 | goto wait_for_memory; | |
849 | ||
850 | /* | |
851 | * Check whether we can use HW checksum. | |
852 | */ | |
853 | if (sk->sk_route_caps & | |
854 | (NETIF_F_IP_CSUM | NETIF_F_NO_CSUM | | |
855 | NETIF_F_HW_CSUM)) | |
856 | skb->ip_summed = CHECKSUM_HW; | |
857 | ||
858 | skb_entail(sk, tp, skb); | |
859 | copy = mss_now; | |
860 | } | |
861 | ||
862 | /* Try to append data to the end of skb. */ | |
863 | if (copy > seglen) | |
864 | copy = seglen; | |
865 | ||
866 | /* Where to copy to? */ | |
867 | if (skb_tailroom(skb) > 0) { | |
868 | /* We have some space in skb head. Superb! */ | |
869 | if (copy > skb_tailroom(skb)) | |
870 | copy = skb_tailroom(skb); | |
871 | if ((err = skb_add_data(skb, from, copy)) != 0) | |
872 | goto do_fault; | |
873 | } else { | |
874 | int merge = 0; | |
875 | int i = skb_shinfo(skb)->nr_frags; | |
876 | struct page *page = TCP_PAGE(sk); | |
877 | int off = TCP_OFF(sk); | |
878 | ||
879 | if (skb_can_coalesce(skb, i, page, off) && | |
880 | off != PAGE_SIZE) { | |
881 | /* We can extend the last page | |
882 | * fragment. */ | |
883 | merge = 1; | |
884 | } else if (i == MAX_SKB_FRAGS || | |
885 | (!i && | |
886 | !(sk->sk_route_caps & NETIF_F_SG))) { | |
887 | /* Need to add new fragment and cannot | |
888 | * do this because interface is non-SG, | |
889 | * or because all the page slots are | |
890 | * busy. */ | |
891 | tcp_mark_push(tp, skb); | |
892 | goto new_segment; | |
893 | } else if (page) { | |
894 | /* If page is cached, align | |
895 | * offset to L1 cache boundary | |
896 | */ | |
897 | off = (off + L1_CACHE_BYTES - 1) & | |
898 | ~(L1_CACHE_BYTES - 1); | |
899 | if (off == PAGE_SIZE) { | |
900 | put_page(page); | |
901 | TCP_PAGE(sk) = page = NULL; | |
902 | } | |
903 | } | |
904 | ||
905 | if (!page) { | |
906 | /* Allocate new cache page. */ | |
907 | if (!(page = sk_stream_alloc_page(sk))) | |
908 | goto wait_for_memory; | |
909 | off = 0; | |
910 | } | |
911 | ||
912 | if (copy > PAGE_SIZE - off) | |
913 | copy = PAGE_SIZE - off; | |
914 | ||
915 | /* Time to copy data. We are close to | |
916 | * the end! */ | |
917 | err = skb_copy_to_page(sk, from, skb, page, | |
918 | off, copy); | |
919 | if (err) { | |
920 | /* If this page was new, give it to the | |
921 | * socket so it does not get leaked. | |
922 | */ | |
923 | if (!TCP_PAGE(sk)) { | |
924 | TCP_PAGE(sk) = page; | |
925 | TCP_OFF(sk) = 0; | |
926 | } | |
927 | goto do_error; | |
928 | } | |
929 | ||
930 | /* Update the skb. */ | |
931 | if (merge) { | |
932 | skb_shinfo(skb)->frags[i - 1].size += | |
933 | copy; | |
934 | } else { | |
935 | skb_fill_page_desc(skb, i, page, off, copy); | |
936 | if (TCP_PAGE(sk)) { | |
937 | get_page(page); | |
938 | } else if (off + copy < PAGE_SIZE) { | |
939 | get_page(page); | |
940 | TCP_PAGE(sk) = page; | |
941 | } | |
942 | } | |
943 | ||
944 | TCP_OFF(sk) = off + copy; | |
945 | } | |
946 | ||
947 | if (!copied) | |
948 | TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH; | |
949 | ||
950 | tp->write_seq += copy; | |
951 | TCP_SKB_CB(skb)->end_seq += copy; | |
952 | skb_shinfo(skb)->tso_segs = 0; | |
953 | ||
954 | from += copy; | |
955 | copied += copy; | |
956 | if ((seglen -= copy) == 0 && iovlen == 0) | |
957 | goto out; | |
958 | ||
959 | if (skb->len != mss_now || (flags & MSG_OOB)) | |
960 | continue; | |
961 | ||
962 | if (forced_push(tp)) { | |
963 | tcp_mark_push(tp, skb); | |
964 | __tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH); | |
965 | } else if (skb == sk->sk_send_head) | |
966 | tcp_push_one(sk, mss_now); | |
967 | continue; | |
968 | ||
969 | wait_for_sndbuf: | |
970 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
971 | wait_for_memory: | |
972 | if (copied) | |
973 | tcp_push(sk, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); | |
974 | ||
975 | if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) | |
976 | goto do_error; | |
977 | ||
978 | mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); | |
979 | } | |
980 | } | |
981 | ||
982 | out: | |
983 | if (copied) | |
984 | tcp_push(sk, tp, flags, mss_now, tp->nonagle); | |
985 | TCP_CHECK_TIMER(sk); | |
986 | release_sock(sk); | |
987 | return copied; | |
988 | ||
989 | do_fault: | |
990 | if (!skb->len) { | |
991 | if (sk->sk_send_head == skb) | |
992 | sk->sk_send_head = NULL; | |
993 | __skb_unlink(skb, skb->list); | |
994 | sk_stream_free_skb(sk, skb); | |
995 | } | |
996 | ||
997 | do_error: | |
998 | if (copied) | |
999 | goto out; | |
1000 | out_err: | |
1001 | err = sk_stream_error(sk, flags, err); | |
1002 | TCP_CHECK_TIMER(sk); | |
1003 | release_sock(sk); | |
1004 | return err; | |
1005 | } | |
1006 | ||
1007 | /* | |
1008 | * Handle reading urgent data. BSD has very simple semantics for | |
1009 | * this, no blocking and very strange errors 8) | |
1010 | */ | |
1011 | ||
1012 | static int tcp_recv_urg(struct sock *sk, long timeo, | |
1013 | struct msghdr *msg, int len, int flags, | |
1014 | int *addr_len) | |
1015 | { | |
1016 | struct tcp_sock *tp = tcp_sk(sk); | |
1017 | ||
1018 | /* No URG data to read. */ | |
1019 | if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || | |
1020 | tp->urg_data == TCP_URG_READ) | |
1021 | return -EINVAL; /* Yes this is right ! */ | |
1022 | ||
1023 | if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) | |
1024 | return -ENOTCONN; | |
1025 | ||
1026 | if (tp->urg_data & TCP_URG_VALID) { | |
1027 | int err = 0; | |
1028 | char c = tp->urg_data; | |
1029 | ||
1030 | if (!(flags & MSG_PEEK)) | |
1031 | tp->urg_data = TCP_URG_READ; | |
1032 | ||
1033 | /* Read urgent data. */ | |
1034 | msg->msg_flags |= MSG_OOB; | |
1035 | ||
1036 | if (len > 0) { | |
1037 | if (!(flags & MSG_TRUNC)) | |
1038 | err = memcpy_toiovec(msg->msg_iov, &c, 1); | |
1039 | len = 1; | |
1040 | } else | |
1041 | msg->msg_flags |= MSG_TRUNC; | |
1042 | ||
1043 | return err ? -EFAULT : len; | |
1044 | } | |
1045 | ||
1046 | if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1047 | return 0; | |
1048 | ||
1049 | /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and | |
1050 | * the available implementations agree in this case: | |
1051 | * this call should never block, independent of the | |
1052 | * blocking state of the socket. | |
1053 | * Mike <pall@rz.uni-karlsruhe.de> | |
1054 | */ | |
1055 | return -EAGAIN; | |
1056 | } | |
1057 | ||
1058 | /* Clean up the receive buffer for full frames taken by the user, | |
1059 | * then send an ACK if necessary. COPIED is the number of bytes | |
1060 | * tcp_recvmsg has given to the user so far, it speeds up the | |
1061 | * calculation of whether or not we must ACK for the sake of | |
1062 | * a window update. | |
1063 | */ | |
1064 | static void cleanup_rbuf(struct sock *sk, int copied) | |
1065 | { | |
1066 | struct tcp_sock *tp = tcp_sk(sk); | |
1067 | int time_to_ack = 0; | |
1068 | ||
1069 | #if TCP_DEBUG | |
1070 | struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); | |
1071 | ||
1072 | BUG_TRAP(!skb || before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)); | |
1073 | #endif | |
1074 | ||
1075 | if (tcp_ack_scheduled(tp)) { | |
1076 | /* Delayed ACKs frequently hit locked sockets during bulk | |
1077 | * receive. */ | |
1078 | if (tp->ack.blocked || | |
1079 | /* Once-per-two-segments ACK was not sent by tcp_input.c */ | |
1080 | tp->rcv_nxt - tp->rcv_wup > tp->ack.rcv_mss || | |
1081 | /* | |
1082 | * If this read emptied read buffer, we send ACK, if | |
1083 | * connection is not bidirectional, user drained | |
1084 | * receive buffer and there was a small segment | |
1085 | * in queue. | |
1086 | */ | |
1087 | (copied > 0 && (tp->ack.pending & TCP_ACK_PUSHED) && | |
1088 | !tp->ack.pingpong && !atomic_read(&sk->sk_rmem_alloc))) | |
1089 | time_to_ack = 1; | |
1090 | } | |
1091 | ||
1092 | /* We send an ACK if we can now advertise a non-zero window | |
1093 | * which has been raised "significantly". | |
1094 | * | |
1095 | * Even if window raised up to infinity, do not send window open ACK | |
1096 | * in states, where we will not receive more. It is useless. | |
1097 | */ | |
1098 | if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { | |
1099 | __u32 rcv_window_now = tcp_receive_window(tp); | |
1100 | ||
1101 | /* Optimize, __tcp_select_window() is not cheap. */ | |
1102 | if (2*rcv_window_now <= tp->window_clamp) { | |
1103 | __u32 new_window = __tcp_select_window(sk); | |
1104 | ||
1105 | /* Send ACK now, if this read freed lots of space | |
1106 | * in our buffer. Certainly, new_window is new window. | |
1107 | * We can advertise it now, if it is not less than current one. | |
1108 | * "Lots" means "at least twice" here. | |
1109 | */ | |
1110 | if (new_window && new_window >= 2 * rcv_window_now) | |
1111 | time_to_ack = 1; | |
1112 | } | |
1113 | } | |
1114 | if (time_to_ack) | |
1115 | tcp_send_ack(sk); | |
1116 | } | |
1117 | ||
1118 | static void tcp_prequeue_process(struct sock *sk) | |
1119 | { | |
1120 | struct sk_buff *skb; | |
1121 | struct tcp_sock *tp = tcp_sk(sk); | |
1122 | ||
1123 | NET_ADD_STATS_USER(LINUX_MIB_TCPPREQUEUED, skb_queue_len(&tp->ucopy.prequeue)); | |
1124 | ||
1125 | /* RX process wants to run with disabled BHs, though it is not | |
1126 | * necessary */ | |
1127 | local_bh_disable(); | |
1128 | while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) | |
1129 | sk->sk_backlog_rcv(sk, skb); | |
1130 | local_bh_enable(); | |
1131 | ||
1132 | /* Clear memory counter. */ | |
1133 | tp->ucopy.memory = 0; | |
1134 | } | |
1135 | ||
1136 | static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) | |
1137 | { | |
1138 | struct sk_buff *skb; | |
1139 | u32 offset; | |
1140 | ||
1141 | skb_queue_walk(&sk->sk_receive_queue, skb) { | |
1142 | offset = seq - TCP_SKB_CB(skb)->seq; | |
1143 | if (skb->h.th->syn) | |
1144 | offset--; | |
1145 | if (offset < skb->len || skb->h.th->fin) { | |
1146 | *off = offset; | |
1147 | return skb; | |
1148 | } | |
1149 | } | |
1150 | return NULL; | |
1151 | } | |
1152 | ||
1153 | /* | |
1154 | * This routine provides an alternative to tcp_recvmsg() for routines | |
1155 | * that would like to handle copying from skbuffs directly in 'sendfile' | |
1156 | * fashion. | |
1157 | * Note: | |
1158 | * - It is assumed that the socket was locked by the caller. | |
1159 | * - The routine does not block. | |
1160 | * - At present, there is no support for reading OOB data | |
1161 | * or for 'peeking' the socket using this routine | |
1162 | * (although both would be easy to implement). | |
1163 | */ | |
1164 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, | |
1165 | sk_read_actor_t recv_actor) | |
1166 | { | |
1167 | struct sk_buff *skb; | |
1168 | struct tcp_sock *tp = tcp_sk(sk); | |
1169 | u32 seq = tp->copied_seq; | |
1170 | u32 offset; | |
1171 | int copied = 0; | |
1172 | ||
1173 | if (sk->sk_state == TCP_LISTEN) | |
1174 | return -ENOTCONN; | |
1175 | while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { | |
1176 | if (offset < skb->len) { | |
1177 | size_t used, len; | |
1178 | ||
1179 | len = skb->len - offset; | |
1180 | /* Stop reading if we hit a patch of urgent data */ | |
1181 | if (tp->urg_data) { | |
1182 | u32 urg_offset = tp->urg_seq - seq; | |
1183 | if (urg_offset < len) | |
1184 | len = urg_offset; | |
1185 | if (!len) | |
1186 | break; | |
1187 | } | |
1188 | used = recv_actor(desc, skb, offset, len); | |
1189 | if (used <= len) { | |
1190 | seq += used; | |
1191 | copied += used; | |
1192 | offset += used; | |
1193 | } | |
1194 | if (offset != skb->len) | |
1195 | break; | |
1196 | } | |
1197 | if (skb->h.th->fin) { | |
1198 | sk_eat_skb(sk, skb); | |
1199 | ++seq; | |
1200 | break; | |
1201 | } | |
1202 | sk_eat_skb(sk, skb); | |
1203 | if (!desc->count) | |
1204 | break; | |
1205 | } | |
1206 | tp->copied_seq = seq; | |
1207 | ||
1208 | tcp_rcv_space_adjust(sk); | |
1209 | ||
1210 | /* Clean up data we have read: This will do ACK frames. */ | |
1211 | if (copied) | |
1212 | cleanup_rbuf(sk, copied); | |
1213 | return copied; | |
1214 | } | |
1215 | ||
1216 | /* | |
1217 | * This routine copies from a sock struct into the user buffer. | |
1218 | * | |
1219 | * Technical note: in 2.3 we work on _locked_ socket, so that | |
1220 | * tricks with *seq access order and skb->users are not required. | |
1221 | * Probably, code can be easily improved even more. | |
1222 | */ | |
1223 | ||
1224 | int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, | |
1225 | size_t len, int nonblock, int flags, int *addr_len) | |
1226 | { | |
1227 | struct tcp_sock *tp = tcp_sk(sk); | |
1228 | int copied = 0; | |
1229 | u32 peek_seq; | |
1230 | u32 *seq; | |
1231 | unsigned long used; | |
1232 | int err; | |
1233 | int target; /* Read at least this many bytes */ | |
1234 | long timeo; | |
1235 | struct task_struct *user_recv = NULL; | |
1236 | ||
1237 | lock_sock(sk); | |
1238 | ||
1239 | TCP_CHECK_TIMER(sk); | |
1240 | ||
1241 | err = -ENOTCONN; | |
1242 | if (sk->sk_state == TCP_LISTEN) | |
1243 | goto out; | |
1244 | ||
1245 | timeo = sock_rcvtimeo(sk, nonblock); | |
1246 | ||
1247 | /* Urgent data needs to be handled specially. */ | |
1248 | if (flags & MSG_OOB) | |
1249 | goto recv_urg; | |
1250 | ||
1251 | seq = &tp->copied_seq; | |
1252 | if (flags & MSG_PEEK) { | |
1253 | peek_seq = tp->copied_seq; | |
1254 | seq = &peek_seq; | |
1255 | } | |
1256 | ||
1257 | target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); | |
1258 | ||
1259 | do { | |
1260 | struct sk_buff *skb; | |
1261 | u32 offset; | |
1262 | ||
1263 | /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ | |
1264 | if (tp->urg_data && tp->urg_seq == *seq) { | |
1265 | if (copied) | |
1266 | break; | |
1267 | if (signal_pending(current)) { | |
1268 | copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; | |
1269 | break; | |
1270 | } | |
1271 | } | |
1272 | ||
1273 | /* Next get a buffer. */ | |
1274 | ||
1275 | skb = skb_peek(&sk->sk_receive_queue); | |
1276 | do { | |
1277 | if (!skb) | |
1278 | break; | |
1279 | ||
1280 | /* Now that we have two receive queues this | |
1281 | * shouldn't happen. | |
1282 | */ | |
1283 | if (before(*seq, TCP_SKB_CB(skb)->seq)) { | |
1284 | printk(KERN_INFO "recvmsg bug: copied %X " | |
1285 | "seq %X\n", *seq, TCP_SKB_CB(skb)->seq); | |
1286 | break; | |
1287 | } | |
1288 | offset = *seq - TCP_SKB_CB(skb)->seq; | |
1289 | if (skb->h.th->syn) | |
1290 | offset--; | |
1291 | if (offset < skb->len) | |
1292 | goto found_ok_skb; | |
1293 | if (skb->h.th->fin) | |
1294 | goto found_fin_ok; | |
1295 | BUG_TRAP(flags & MSG_PEEK); | |
1296 | skb = skb->next; | |
1297 | } while (skb != (struct sk_buff *)&sk->sk_receive_queue); | |
1298 | ||
1299 | /* Well, if we have backlog, try to process it now yet. */ | |
1300 | ||
1301 | if (copied >= target && !sk->sk_backlog.tail) | |
1302 | break; | |
1303 | ||
1304 | if (copied) { | |
1305 | if (sk->sk_err || | |
1306 | sk->sk_state == TCP_CLOSE || | |
1307 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1308 | !timeo || | |
1309 | signal_pending(current) || | |
1310 | (flags & MSG_PEEK)) | |
1311 | break; | |
1312 | } else { | |
1313 | if (sock_flag(sk, SOCK_DONE)) | |
1314 | break; | |
1315 | ||
1316 | if (sk->sk_err) { | |
1317 | copied = sock_error(sk); | |
1318 | break; | |
1319 | } | |
1320 | ||
1321 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
1322 | break; | |
1323 | ||
1324 | if (sk->sk_state == TCP_CLOSE) { | |
1325 | if (!sock_flag(sk, SOCK_DONE)) { | |
1326 | /* This occurs when user tries to read | |
1327 | * from never connected socket. | |
1328 | */ | |
1329 | copied = -ENOTCONN; | |
1330 | break; | |
1331 | } | |
1332 | break; | |
1333 | } | |
1334 | ||
1335 | if (!timeo) { | |
1336 | copied = -EAGAIN; | |
1337 | break; | |
1338 | } | |
1339 | ||
1340 | if (signal_pending(current)) { | |
1341 | copied = sock_intr_errno(timeo); | |
1342 | break; | |
1343 | } | |
1344 | } | |
1345 | ||
1346 | cleanup_rbuf(sk, copied); | |
1347 | ||
1348 | if (tp->ucopy.task == user_recv) { | |
1349 | /* Install new reader */ | |
1350 | if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { | |
1351 | user_recv = current; | |
1352 | tp->ucopy.task = user_recv; | |
1353 | tp->ucopy.iov = msg->msg_iov; | |
1354 | } | |
1355 | ||
1356 | tp->ucopy.len = len; | |
1357 | ||
1358 | BUG_TRAP(tp->copied_seq == tp->rcv_nxt || | |
1359 | (flags & (MSG_PEEK | MSG_TRUNC))); | |
1360 | ||
1361 | /* Ugly... If prequeue is not empty, we have to | |
1362 | * process it before releasing socket, otherwise | |
1363 | * order will be broken at second iteration. | |
1364 | * More elegant solution is required!!! | |
1365 | * | |
1366 | * Look: we have the following (pseudo)queues: | |
1367 | * | |
1368 | * 1. packets in flight | |
1369 | * 2. backlog | |
1370 | * 3. prequeue | |
1371 | * 4. receive_queue | |
1372 | * | |
1373 | * Each queue can be processed only if the next ones | |
1374 | * are empty. At this point we have empty receive_queue. | |
1375 | * But prequeue _can_ be not empty after 2nd iteration, | |
1376 | * when we jumped to start of loop because backlog | |
1377 | * processing added something to receive_queue. | |
1378 | * We cannot release_sock(), because backlog contains | |
1379 | * packets arrived _after_ prequeued ones. | |
1380 | * | |
1381 | * Shortly, algorithm is clear --- to process all | |
1382 | * the queues in order. We could make it more directly, | |
1383 | * requeueing packets from backlog to prequeue, if | |
1384 | * is not empty. It is more elegant, but eats cycles, | |
1385 | * unfortunately. | |
1386 | */ | |
1387 | if (skb_queue_len(&tp->ucopy.prequeue)) | |
1388 | goto do_prequeue; | |
1389 | ||
1390 | /* __ Set realtime policy in scheduler __ */ | |
1391 | } | |
1392 | ||
1393 | if (copied >= target) { | |
1394 | /* Do not sleep, just process backlog. */ | |
1395 | release_sock(sk); | |
1396 | lock_sock(sk); | |
1397 | } else | |
1398 | sk_wait_data(sk, &timeo); | |
1399 | ||
1400 | if (user_recv) { | |
1401 | int chunk; | |
1402 | ||
1403 | /* __ Restore normal policy in scheduler __ */ | |
1404 | ||
1405 | if ((chunk = len - tp->ucopy.len) != 0) { | |
1406 | NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); | |
1407 | len -= chunk; | |
1408 | copied += chunk; | |
1409 | } | |
1410 | ||
1411 | if (tp->rcv_nxt == tp->copied_seq && | |
1412 | skb_queue_len(&tp->ucopy.prequeue)) { | |
1413 | do_prequeue: | |
1414 | tcp_prequeue_process(sk); | |
1415 | ||
1416 | if ((chunk = len - tp->ucopy.len) != 0) { | |
1417 | NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); | |
1418 | len -= chunk; | |
1419 | copied += chunk; | |
1420 | } | |
1421 | } | |
1422 | } | |
1423 | if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) { | |
1424 | if (net_ratelimit()) | |
1425 | printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", | |
1426 | current->comm, current->pid); | |
1427 | peek_seq = tp->copied_seq; | |
1428 | } | |
1429 | continue; | |
1430 | ||
1431 | found_ok_skb: | |
1432 | /* Ok so how much can we use? */ | |
1433 | used = skb->len - offset; | |
1434 | if (len < used) | |
1435 | used = len; | |
1436 | ||
1437 | /* Do we have urgent data here? */ | |
1438 | if (tp->urg_data) { | |
1439 | u32 urg_offset = tp->urg_seq - *seq; | |
1440 | if (urg_offset < used) { | |
1441 | if (!urg_offset) { | |
1442 | if (!sock_flag(sk, SOCK_URGINLINE)) { | |
1443 | ++*seq; | |
1444 | offset++; | |
1445 | used--; | |
1446 | if (!used) | |
1447 | goto skip_copy; | |
1448 | } | |
1449 | } else | |
1450 | used = urg_offset; | |
1451 | } | |
1452 | } | |
1453 | ||
1454 | if (!(flags & MSG_TRUNC)) { | |
1455 | err = skb_copy_datagram_iovec(skb, offset, | |
1456 | msg->msg_iov, used); | |
1457 | if (err) { | |
1458 | /* Exception. Bailout! */ | |
1459 | if (!copied) | |
1460 | copied = -EFAULT; | |
1461 | break; | |
1462 | } | |
1463 | } | |
1464 | ||
1465 | *seq += used; | |
1466 | copied += used; | |
1467 | len -= used; | |
1468 | ||
1469 | tcp_rcv_space_adjust(sk); | |
1470 | ||
1471 | skip_copy: | |
1472 | if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { | |
1473 | tp->urg_data = 0; | |
1474 | tcp_fast_path_check(sk, tp); | |
1475 | } | |
1476 | if (used + offset < skb->len) | |
1477 | continue; | |
1478 | ||
1479 | if (skb->h.th->fin) | |
1480 | goto found_fin_ok; | |
1481 | if (!(flags & MSG_PEEK)) | |
1482 | sk_eat_skb(sk, skb); | |
1483 | continue; | |
1484 | ||
1485 | found_fin_ok: | |
1486 | /* Process the FIN. */ | |
1487 | ++*seq; | |
1488 | if (!(flags & MSG_PEEK)) | |
1489 | sk_eat_skb(sk, skb); | |
1490 | break; | |
1491 | } while (len > 0); | |
1492 | ||
1493 | if (user_recv) { | |
1494 | if (skb_queue_len(&tp->ucopy.prequeue)) { | |
1495 | int chunk; | |
1496 | ||
1497 | tp->ucopy.len = copied > 0 ? len : 0; | |
1498 | ||
1499 | tcp_prequeue_process(sk); | |
1500 | ||
1501 | if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { | |
1502 | NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); | |
1503 | len -= chunk; | |
1504 | copied += chunk; | |
1505 | } | |
1506 | } | |
1507 | ||
1508 | tp->ucopy.task = NULL; | |
1509 | tp->ucopy.len = 0; | |
1510 | } | |
1511 | ||
1512 | /* According to UNIX98, msg_name/msg_namelen are ignored | |
1513 | * on connected socket. I was just happy when found this 8) --ANK | |
1514 | */ | |
1515 | ||
1516 | /* Clean up data we have read: This will do ACK frames. */ | |
1517 | cleanup_rbuf(sk, copied); | |
1518 | ||
1519 | TCP_CHECK_TIMER(sk); | |
1520 | release_sock(sk); | |
1521 | return copied; | |
1522 | ||
1523 | out: | |
1524 | TCP_CHECK_TIMER(sk); | |
1525 | release_sock(sk); | |
1526 | return err; | |
1527 | ||
1528 | recv_urg: | |
1529 | err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len); | |
1530 | goto out; | |
1531 | } | |
1532 | ||
1533 | /* | |
1534 | * State processing on a close. This implements the state shift for | |
1535 | * sending our FIN frame. Note that we only send a FIN for some | |
1536 | * states. A shutdown() may have already sent the FIN, or we may be | |
1537 | * closed. | |
1538 | */ | |
1539 | ||
1540 | static unsigned char new_state[16] = { | |
1541 | /* current state: new state: action: */ | |
1542 | /* (Invalid) */ TCP_CLOSE, | |
1543 | /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1544 | /* TCP_SYN_SENT */ TCP_CLOSE, | |
1545 | /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1546 | /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, | |
1547 | /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, | |
1548 | /* TCP_TIME_WAIT */ TCP_CLOSE, | |
1549 | /* TCP_CLOSE */ TCP_CLOSE, | |
1550 | /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, | |
1551 | /* TCP_LAST_ACK */ TCP_LAST_ACK, | |
1552 | /* TCP_LISTEN */ TCP_CLOSE, | |
1553 | /* TCP_CLOSING */ TCP_CLOSING, | |
1554 | }; | |
1555 | ||
1556 | static int tcp_close_state(struct sock *sk) | |
1557 | { | |
1558 | int next = (int)new_state[sk->sk_state]; | |
1559 | int ns = next & TCP_STATE_MASK; | |
1560 | ||
1561 | tcp_set_state(sk, ns); | |
1562 | ||
1563 | return next & TCP_ACTION_FIN; | |
1564 | } | |
1565 | ||
1566 | /* | |
1567 | * Shutdown the sending side of a connection. Much like close except | |
1568 | * that we don't receive shut down or set_sock_flag(sk, SOCK_DEAD). | |
1569 | */ | |
1570 | ||
1571 | void tcp_shutdown(struct sock *sk, int how) | |
1572 | { | |
1573 | /* We need to grab some memory, and put together a FIN, | |
1574 | * and then put it into the queue to be sent. | |
1575 | * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. | |
1576 | */ | |
1577 | if (!(how & SEND_SHUTDOWN)) | |
1578 | return; | |
1579 | ||
1580 | /* If we've already sent a FIN, or it's a closed state, skip this. */ | |
1581 | if ((1 << sk->sk_state) & | |
1582 | (TCPF_ESTABLISHED | TCPF_SYN_SENT | | |
1583 | TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { | |
1584 | /* Clear out any half completed packets. FIN if needed. */ | |
1585 | if (tcp_close_state(sk)) | |
1586 | tcp_send_fin(sk); | |
1587 | } | |
1588 | } | |
1589 | ||
1590 | /* | |
1591 | * At this point, there should be no process reference to this | |
1592 | * socket, and thus no user references at all. Therefore we | |
1593 | * can assume the socket waitqueue is inactive and nobody will | |
1594 | * try to jump onto it. | |
1595 | */ | |
1596 | void tcp_destroy_sock(struct sock *sk) | |
1597 | { | |
1598 | BUG_TRAP(sk->sk_state == TCP_CLOSE); | |
1599 | BUG_TRAP(sock_flag(sk, SOCK_DEAD)); | |
1600 | ||
1601 | /* It cannot be in hash table! */ | |
1602 | BUG_TRAP(sk_unhashed(sk)); | |
1603 | ||
1604 | /* If it has not 0 inet_sk(sk)->num, it must be bound */ | |
1605 | BUG_TRAP(!inet_sk(sk)->num || tcp_sk(sk)->bind_hash); | |
1606 | ||
1607 | sk->sk_prot->destroy(sk); | |
1608 | ||
1609 | sk_stream_kill_queues(sk); | |
1610 | ||
1611 | xfrm_sk_free_policy(sk); | |
1612 | ||
1613 | #ifdef INET_REFCNT_DEBUG | |
1614 | if (atomic_read(&sk->sk_refcnt) != 1) { | |
1615 | printk(KERN_DEBUG "Destruction TCP %p delayed, c=%d\n", | |
1616 | sk, atomic_read(&sk->sk_refcnt)); | |
1617 | } | |
1618 | #endif | |
1619 | ||
1620 | atomic_dec(&tcp_orphan_count); | |
1621 | sock_put(sk); | |
1622 | } | |
1623 | ||
1624 | void tcp_close(struct sock *sk, long timeout) | |
1625 | { | |
1626 | struct sk_buff *skb; | |
1627 | int data_was_unread = 0; | |
1628 | ||
1629 | lock_sock(sk); | |
1630 | sk->sk_shutdown = SHUTDOWN_MASK; | |
1631 | ||
1632 | if (sk->sk_state == TCP_LISTEN) { | |
1633 | tcp_set_state(sk, TCP_CLOSE); | |
1634 | ||
1635 | /* Special case. */ | |
1636 | tcp_listen_stop(sk); | |
1637 | ||
1638 | goto adjudge_to_death; | |
1639 | } | |
1640 | ||
1641 | /* We need to flush the recv. buffs. We do this only on the | |
1642 | * descriptor close, not protocol-sourced closes, because the | |
1643 | * reader process may not have drained the data yet! | |
1644 | */ | |
1645 | while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
1646 | u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - | |
1647 | skb->h.th->fin; | |
1648 | data_was_unread += len; | |
1649 | __kfree_skb(skb); | |
1650 | } | |
1651 | ||
1652 | sk_stream_mem_reclaim(sk); | |
1653 | ||
1654 | /* As outlined in draft-ietf-tcpimpl-prob-03.txt, section | |
1655 | * 3.10, we send a RST here because data was lost. To | |
1656 | * witness the awful effects of the old behavior of always | |
1657 | * doing a FIN, run an older 2.1.x kernel or 2.0.x, start | |
1658 | * a bulk GET in an FTP client, suspend the process, wait | |
1659 | * for the client to advertise a zero window, then kill -9 | |
1660 | * the FTP client, wheee... Note: timeout is always zero | |
1661 | * in such a case. | |
1662 | */ | |
1663 | if (data_was_unread) { | |
1664 | /* Unread data was tossed, zap the connection. */ | |
1665 | NET_INC_STATS_USER(LINUX_MIB_TCPABORTONCLOSE); | |
1666 | tcp_set_state(sk, TCP_CLOSE); | |
1667 | tcp_send_active_reset(sk, GFP_KERNEL); | |
1668 | } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { | |
1669 | /* Check zero linger _after_ checking for unread data. */ | |
1670 | sk->sk_prot->disconnect(sk, 0); | |
1671 | NET_INC_STATS_USER(LINUX_MIB_TCPABORTONDATA); | |
1672 | } else if (tcp_close_state(sk)) { | |
1673 | /* We FIN if the application ate all the data before | |
1674 | * zapping the connection. | |
1675 | */ | |
1676 | ||
1677 | /* RED-PEN. Formally speaking, we have broken TCP state | |
1678 | * machine. State transitions: | |
1679 | * | |
1680 | * TCP_ESTABLISHED -> TCP_FIN_WAIT1 | |
1681 | * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) | |
1682 | * TCP_CLOSE_WAIT -> TCP_LAST_ACK | |
1683 | * | |
1684 | * are legal only when FIN has been sent (i.e. in window), | |
1685 | * rather than queued out of window. Purists blame. | |
1686 | * | |
1687 | * F.e. "RFC state" is ESTABLISHED, | |
1688 | * if Linux state is FIN-WAIT-1, but FIN is still not sent. | |
1689 | * | |
1690 | * The visible declinations are that sometimes | |
1691 | * we enter time-wait state, when it is not required really | |
1692 | * (harmless), do not send active resets, when they are | |
1693 | * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when | |
1694 | * they look as CLOSING or LAST_ACK for Linux) | |
1695 | * Probably, I missed some more holelets. | |
1696 | * --ANK | |
1697 | */ | |
1698 | tcp_send_fin(sk); | |
1699 | } | |
1700 | ||
1701 | sk_stream_wait_close(sk, timeout); | |
1702 | ||
1703 | adjudge_to_death: | |
1704 | /* It is the last release_sock in its life. It will remove backlog. */ | |
1705 | release_sock(sk); | |
1706 | ||
1707 | ||
1708 | /* Now socket is owned by kernel and we acquire BH lock | |
1709 | to finish close. No need to check for user refs. | |
1710 | */ | |
1711 | local_bh_disable(); | |
1712 | bh_lock_sock(sk); | |
1713 | BUG_TRAP(!sock_owned_by_user(sk)); | |
1714 | ||
1715 | sock_hold(sk); | |
1716 | sock_orphan(sk); | |
1717 | ||
1718 | /* This is a (useful) BSD violating of the RFC. There is a | |
1719 | * problem with TCP as specified in that the other end could | |
1720 | * keep a socket open forever with no application left this end. | |
1721 | * We use a 3 minute timeout (about the same as BSD) then kill | |
1722 | * our end. If they send after that then tough - BUT: long enough | |
1723 | * that we won't make the old 4*rto = almost no time - whoops | |
1724 | * reset mistake. | |
1725 | * | |
1726 | * Nope, it was not mistake. It is really desired behaviour | |
1727 | * f.e. on http servers, when such sockets are useless, but | |
1728 | * consume significant resources. Let's do it with special | |
1729 | * linger2 option. --ANK | |
1730 | */ | |
1731 | ||
1732 | if (sk->sk_state == TCP_FIN_WAIT2) { | |
1733 | struct tcp_sock *tp = tcp_sk(sk); | |
1734 | if (tp->linger2 < 0) { | |
1735 | tcp_set_state(sk, TCP_CLOSE); | |
1736 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
1737 | NET_INC_STATS_BH(LINUX_MIB_TCPABORTONLINGER); | |
1738 | } else { | |
1739 | int tmo = tcp_fin_time(tp); | |
1740 | ||
1741 | if (tmo > TCP_TIMEWAIT_LEN) { | |
1742 | tcp_reset_keepalive_timer(sk, tcp_fin_time(tp)); | |
1743 | } else { | |
1744 | atomic_inc(&tcp_orphan_count); | |
1745 | tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); | |
1746 | goto out; | |
1747 | } | |
1748 | } | |
1749 | } | |
1750 | if (sk->sk_state != TCP_CLOSE) { | |
1751 | sk_stream_mem_reclaim(sk); | |
1752 | if (atomic_read(&tcp_orphan_count) > sysctl_tcp_max_orphans || | |
1753 | (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && | |
1754 | atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2])) { | |
1755 | if (net_ratelimit()) | |
1756 | printk(KERN_INFO "TCP: too many of orphaned " | |
1757 | "sockets\n"); | |
1758 | tcp_set_state(sk, TCP_CLOSE); | |
1759 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
1760 | NET_INC_STATS_BH(LINUX_MIB_TCPABORTONMEMORY); | |
1761 | } | |
1762 | } | |
1763 | atomic_inc(&tcp_orphan_count); | |
1764 | ||
1765 | if (sk->sk_state == TCP_CLOSE) | |
1766 | tcp_destroy_sock(sk); | |
1767 | /* Otherwise, socket is reprieved until protocol close. */ | |
1768 | ||
1769 | out: | |
1770 | bh_unlock_sock(sk); | |
1771 | local_bh_enable(); | |
1772 | sock_put(sk); | |
1773 | } | |
1774 | ||
1775 | /* These states need RST on ABORT according to RFC793 */ | |
1776 | ||
1777 | static inline int tcp_need_reset(int state) | |
1778 | { | |
1779 | return (1 << state) & | |
1780 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | | |
1781 | TCPF_FIN_WAIT2 | TCPF_SYN_RECV); | |
1782 | } | |
1783 | ||
1784 | int tcp_disconnect(struct sock *sk, int flags) | |
1785 | { | |
1786 | struct inet_sock *inet = inet_sk(sk); | |
1787 | struct tcp_sock *tp = tcp_sk(sk); | |
1788 | int err = 0; | |
1789 | int old_state = sk->sk_state; | |
1790 | ||
1791 | if (old_state != TCP_CLOSE) | |
1792 | tcp_set_state(sk, TCP_CLOSE); | |
1793 | ||
1794 | /* ABORT function of RFC793 */ | |
1795 | if (old_state == TCP_LISTEN) { | |
1796 | tcp_listen_stop(sk); | |
1797 | } else if (tcp_need_reset(old_state) || | |
1798 | (tp->snd_nxt != tp->write_seq && | |
1799 | (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { | |
1800 | /* The last check adjusts for discrepance of Linux wrt. RFC | |
1801 | * states | |
1802 | */ | |
1803 | tcp_send_active_reset(sk, gfp_any()); | |
1804 | sk->sk_err = ECONNRESET; | |
1805 | } else if (old_state == TCP_SYN_SENT) | |
1806 | sk->sk_err = ECONNRESET; | |
1807 | ||
1808 | tcp_clear_xmit_timers(sk); | |
1809 | __skb_queue_purge(&sk->sk_receive_queue); | |
1810 | sk_stream_writequeue_purge(sk); | |
1811 | __skb_queue_purge(&tp->out_of_order_queue); | |
1812 | ||
1813 | inet->dport = 0; | |
1814 | ||
1815 | if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) | |
1816 | inet_reset_saddr(sk); | |
1817 | ||
1818 | sk->sk_shutdown = 0; | |
1819 | sock_reset_flag(sk, SOCK_DONE); | |
1820 | tp->srtt = 0; | |
1821 | if ((tp->write_seq += tp->max_window + 2) == 0) | |
1822 | tp->write_seq = 1; | |
1823 | tp->backoff = 0; | |
1824 | tp->snd_cwnd = 2; | |
1825 | tp->probes_out = 0; | |
1826 | tp->packets_out = 0; | |
1827 | tp->snd_ssthresh = 0x7fffffff; | |
1828 | tp->snd_cwnd_cnt = 0; | |
1829 | tcp_set_ca_state(tp, TCP_CA_Open); | |
1830 | tcp_clear_retrans(tp); | |
1831 | tcp_delack_init(tp); | |
1832 | sk->sk_send_head = NULL; | |
1833 | tp->rx_opt.saw_tstamp = 0; | |
1834 | tcp_sack_reset(&tp->rx_opt); | |
1835 | __sk_dst_reset(sk); | |
1836 | ||
1837 | BUG_TRAP(!inet->num || tp->bind_hash); | |
1838 | ||
1839 | sk->sk_error_report(sk); | |
1840 | return err; | |
1841 | } | |
1842 | ||
1843 | /* | |
1844 | * Wait for an incoming connection, avoid race | |
1845 | * conditions. This must be called with the socket locked. | |
1846 | */ | |
1847 | static int wait_for_connect(struct sock *sk, long timeo) | |
1848 | { | |
1849 | struct tcp_sock *tp = tcp_sk(sk); | |
1850 | DEFINE_WAIT(wait); | |
1851 | int err; | |
1852 | ||
1853 | /* | |
1854 | * True wake-one mechanism for incoming connections: only | |
1855 | * one process gets woken up, not the 'whole herd'. | |
1856 | * Since we do not 'race & poll' for established sockets | |
1857 | * anymore, the common case will execute the loop only once. | |
1858 | * | |
1859 | * Subtle issue: "add_wait_queue_exclusive()" will be added | |
1860 | * after any current non-exclusive waiters, and we know that | |
1861 | * it will always _stay_ after any new non-exclusive waiters | |
1862 | * because all non-exclusive waiters are added at the | |
1863 | * beginning of the wait-queue. As such, it's ok to "drop" | |
1864 | * our exclusiveness temporarily when we get woken up without | |
1865 | * having to remove and re-insert us on the wait queue. | |
1866 | */ | |
1867 | for (;;) { | |
1868 | prepare_to_wait_exclusive(sk->sk_sleep, &wait, | |
1869 | TASK_INTERRUPTIBLE); | |
1870 | release_sock(sk); | |
1871 | if (!tp->accept_queue) | |
1872 | timeo = schedule_timeout(timeo); | |
1873 | lock_sock(sk); | |
1874 | err = 0; | |
1875 | if (tp->accept_queue) | |
1876 | break; | |
1877 | err = -EINVAL; | |
1878 | if (sk->sk_state != TCP_LISTEN) | |
1879 | break; | |
1880 | err = sock_intr_errno(timeo); | |
1881 | if (signal_pending(current)) | |
1882 | break; | |
1883 | err = -EAGAIN; | |
1884 | if (!timeo) | |
1885 | break; | |
1886 | } | |
1887 | finish_wait(sk->sk_sleep, &wait); | |
1888 | return err; | |
1889 | } | |
1890 | ||
1891 | /* | |
1892 | * This will accept the next outstanding connection. | |
1893 | */ | |
1894 | ||
1895 | struct sock *tcp_accept(struct sock *sk, int flags, int *err) | |
1896 | { | |
1897 | struct tcp_sock *tp = tcp_sk(sk); | |
1898 | struct open_request *req; | |
1899 | struct sock *newsk; | |
1900 | int error; | |
1901 | ||
1902 | lock_sock(sk); | |
1903 | ||
1904 | /* We need to make sure that this socket is listening, | |
1905 | * and that it has something pending. | |
1906 | */ | |
1907 | error = -EINVAL; | |
1908 | if (sk->sk_state != TCP_LISTEN) | |
1909 | goto out; | |
1910 | ||
1911 | /* Find already established connection */ | |
1912 | if (!tp->accept_queue) { | |
1913 | long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); | |
1914 | ||
1915 | /* If this is a non blocking socket don't sleep */ | |
1916 | error = -EAGAIN; | |
1917 | if (!timeo) | |
1918 | goto out; | |
1919 | ||
1920 | error = wait_for_connect(sk, timeo); | |
1921 | if (error) | |
1922 | goto out; | |
1923 | } | |
1924 | ||
1925 | req = tp->accept_queue; | |
1926 | if ((tp->accept_queue = req->dl_next) == NULL) | |
1927 | tp->accept_queue_tail = NULL; | |
1928 | ||
1929 | newsk = req->sk; | |
1930 | sk_acceptq_removed(sk); | |
1931 | tcp_openreq_fastfree(req); | |
1932 | BUG_TRAP(newsk->sk_state != TCP_SYN_RECV); | |
1933 | release_sock(sk); | |
1934 | return newsk; | |
1935 | ||
1936 | out: | |
1937 | release_sock(sk); | |
1938 | *err = error; | |
1939 | return NULL; | |
1940 | } | |
1941 | ||
1942 | /* | |
1943 | * Socket option code for TCP. | |
1944 | */ | |
1945 | int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, | |
1946 | int optlen) | |
1947 | { | |
1948 | struct tcp_sock *tp = tcp_sk(sk); | |
1949 | int val; | |
1950 | int err = 0; | |
1951 | ||
1952 | if (level != SOL_TCP) | |
1953 | return tp->af_specific->setsockopt(sk, level, optname, | |
1954 | optval, optlen); | |
1955 | ||
1956 | if (optlen < sizeof(int)) | |
1957 | return -EINVAL; | |
1958 | ||
1959 | if (get_user(val, (int __user *)optval)) | |
1960 | return -EFAULT; | |
1961 | ||
1962 | lock_sock(sk); | |
1963 | ||
1964 | switch (optname) { | |
1965 | case TCP_MAXSEG: | |
1966 | /* Values greater than interface MTU won't take effect. However | |
1967 | * at the point when this call is done we typically don't yet | |
1968 | * know which interface is going to be used */ | |
1969 | if (val < 8 || val > MAX_TCP_WINDOW) { | |
1970 | err = -EINVAL; | |
1971 | break; | |
1972 | } | |
1973 | tp->rx_opt.user_mss = val; | |
1974 | break; | |
1975 | ||
1976 | case TCP_NODELAY: | |
1977 | if (val) { | |
1978 | /* TCP_NODELAY is weaker than TCP_CORK, so that | |
1979 | * this option on corked socket is remembered, but | |
1980 | * it is not activated until cork is cleared. | |
1981 | * | |
1982 | * However, when TCP_NODELAY is set we make | |
1983 | * an explicit push, which overrides even TCP_CORK | |
1984 | * for currently queued segments. | |
1985 | */ | |
1986 | tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; | |
1987 | tcp_push_pending_frames(sk, tp); | |
1988 | } else { | |
1989 | tp->nonagle &= ~TCP_NAGLE_OFF; | |
1990 | } | |
1991 | break; | |
1992 | ||
1993 | case TCP_CORK: | |
1994 | /* When set indicates to always queue non-full frames. | |
1995 | * Later the user clears this option and we transmit | |
1996 | * any pending partial frames in the queue. This is | |
1997 | * meant to be used alongside sendfile() to get properly | |
1998 | * filled frames when the user (for example) must write | |
1999 | * out headers with a write() call first and then use | |
2000 | * sendfile to send out the data parts. | |
2001 | * | |
2002 | * TCP_CORK can be set together with TCP_NODELAY and it is | |
2003 | * stronger than TCP_NODELAY. | |
2004 | */ | |
2005 | if (val) { | |
2006 | tp->nonagle |= TCP_NAGLE_CORK; | |
2007 | } else { | |
2008 | tp->nonagle &= ~TCP_NAGLE_CORK; | |
2009 | if (tp->nonagle&TCP_NAGLE_OFF) | |
2010 | tp->nonagle |= TCP_NAGLE_PUSH; | |
2011 | tcp_push_pending_frames(sk, tp); | |
2012 | } | |
2013 | break; | |
2014 | ||
2015 | case TCP_KEEPIDLE: | |
2016 | if (val < 1 || val > MAX_TCP_KEEPIDLE) | |
2017 | err = -EINVAL; | |
2018 | else { | |
2019 | tp->keepalive_time = val * HZ; | |
2020 | if (sock_flag(sk, SOCK_KEEPOPEN) && | |
2021 | !((1 << sk->sk_state) & | |
2022 | (TCPF_CLOSE | TCPF_LISTEN))) { | |
2023 | __u32 elapsed = tcp_time_stamp - tp->rcv_tstamp; | |
2024 | if (tp->keepalive_time > elapsed) | |
2025 | elapsed = tp->keepalive_time - elapsed; | |
2026 | else | |
2027 | elapsed = 0; | |
2028 | tcp_reset_keepalive_timer(sk, elapsed); | |
2029 | } | |
2030 | } | |
2031 | break; | |
2032 | case TCP_KEEPINTVL: | |
2033 | if (val < 1 || val > MAX_TCP_KEEPINTVL) | |
2034 | err = -EINVAL; | |
2035 | else | |
2036 | tp->keepalive_intvl = val * HZ; | |
2037 | break; | |
2038 | case TCP_KEEPCNT: | |
2039 | if (val < 1 || val > MAX_TCP_KEEPCNT) | |
2040 | err = -EINVAL; | |
2041 | else | |
2042 | tp->keepalive_probes = val; | |
2043 | break; | |
2044 | case TCP_SYNCNT: | |
2045 | if (val < 1 || val > MAX_TCP_SYNCNT) | |
2046 | err = -EINVAL; | |
2047 | else | |
2048 | tp->syn_retries = val; | |
2049 | break; | |
2050 | ||
2051 | case TCP_LINGER2: | |
2052 | if (val < 0) | |
2053 | tp->linger2 = -1; | |
2054 | else if (val > sysctl_tcp_fin_timeout / HZ) | |
2055 | tp->linger2 = 0; | |
2056 | else | |
2057 | tp->linger2 = val * HZ; | |
2058 | break; | |
2059 | ||
2060 | case TCP_DEFER_ACCEPT: | |
2061 | tp->defer_accept = 0; | |
2062 | if (val > 0) { | |
2063 | /* Translate value in seconds to number of | |
2064 | * retransmits */ | |
2065 | while (tp->defer_accept < 32 && | |
2066 | val > ((TCP_TIMEOUT_INIT / HZ) << | |
2067 | tp->defer_accept)) | |
2068 | tp->defer_accept++; | |
2069 | tp->defer_accept++; | |
2070 | } | |
2071 | break; | |
2072 | ||
2073 | case TCP_WINDOW_CLAMP: | |
2074 | if (!val) { | |
2075 | if (sk->sk_state != TCP_CLOSE) { | |
2076 | err = -EINVAL; | |
2077 | break; | |
2078 | } | |
2079 | tp->window_clamp = 0; | |
2080 | } else | |
2081 | tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? | |
2082 | SOCK_MIN_RCVBUF / 2 : val; | |
2083 | break; | |
2084 | ||
2085 | case TCP_QUICKACK: | |
2086 | if (!val) { | |
2087 | tp->ack.pingpong = 1; | |
2088 | } else { | |
2089 | tp->ack.pingpong = 0; | |
2090 | if ((1 << sk->sk_state) & | |
2091 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && | |
2092 | tcp_ack_scheduled(tp)) { | |
2093 | tp->ack.pending |= TCP_ACK_PUSHED; | |
2094 | cleanup_rbuf(sk, 1); | |
2095 | if (!(val & 1)) | |
2096 | tp->ack.pingpong = 1; | |
2097 | } | |
2098 | } | |
2099 | break; | |
2100 | ||
2101 | default: | |
2102 | err = -ENOPROTOOPT; | |
2103 | break; | |
2104 | }; | |
2105 | release_sock(sk); | |
2106 | return err; | |
2107 | } | |
2108 | ||
2109 | /* Return information about state of tcp endpoint in API format. */ | |
2110 | void tcp_get_info(struct sock *sk, struct tcp_info *info) | |
2111 | { | |
2112 | struct tcp_sock *tp = tcp_sk(sk); | |
2113 | u32 now = tcp_time_stamp; | |
2114 | ||
2115 | memset(info, 0, sizeof(*info)); | |
2116 | ||
2117 | info->tcpi_state = sk->sk_state; | |
2118 | info->tcpi_ca_state = tp->ca_state; | |
2119 | info->tcpi_retransmits = tp->retransmits; | |
2120 | info->tcpi_probes = tp->probes_out; | |
2121 | info->tcpi_backoff = tp->backoff; | |
2122 | ||
2123 | if (tp->rx_opt.tstamp_ok) | |
2124 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; | |
2125 | if (tp->rx_opt.sack_ok) | |
2126 | info->tcpi_options |= TCPI_OPT_SACK; | |
2127 | if (tp->rx_opt.wscale_ok) { | |
2128 | info->tcpi_options |= TCPI_OPT_WSCALE; | |
2129 | info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; | |
2130 | info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; | |
2131 | } | |
2132 | ||
2133 | if (tp->ecn_flags&TCP_ECN_OK) | |
2134 | info->tcpi_options |= TCPI_OPT_ECN; | |
2135 | ||
2136 | info->tcpi_rto = jiffies_to_usecs(tp->rto); | |
2137 | info->tcpi_ato = jiffies_to_usecs(tp->ack.ato); | |
2138 | info->tcpi_snd_mss = tp->mss_cache_std; | |
2139 | info->tcpi_rcv_mss = tp->ack.rcv_mss; | |
2140 | ||
2141 | info->tcpi_unacked = tp->packets_out; | |
2142 | info->tcpi_sacked = tp->sacked_out; | |
2143 | info->tcpi_lost = tp->lost_out; | |
2144 | info->tcpi_retrans = tp->retrans_out; | |
2145 | info->tcpi_fackets = tp->fackets_out; | |
2146 | ||
2147 | info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); | |
2148 | info->tcpi_last_data_recv = jiffies_to_msecs(now - tp->ack.lrcvtime); | |
2149 | info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); | |
2150 | ||
2151 | info->tcpi_pmtu = tp->pmtu_cookie; | |
2152 | info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; | |
2153 | info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; | |
2154 | info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; | |
2155 | info->tcpi_snd_ssthresh = tp->snd_ssthresh; | |
2156 | info->tcpi_snd_cwnd = tp->snd_cwnd; | |
2157 | info->tcpi_advmss = tp->advmss; | |
2158 | info->tcpi_reordering = tp->reordering; | |
2159 | ||
2160 | info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; | |
2161 | info->tcpi_rcv_space = tp->rcvq_space.space; | |
2162 | ||
2163 | info->tcpi_total_retrans = tp->total_retrans; | |
2164 | } | |
2165 | ||
2166 | EXPORT_SYMBOL_GPL(tcp_get_info); | |
2167 | ||
2168 | int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, | |
2169 | int __user *optlen) | |
2170 | { | |
2171 | struct tcp_sock *tp = tcp_sk(sk); | |
2172 | int val, len; | |
2173 | ||
2174 | if (level != SOL_TCP) | |
2175 | return tp->af_specific->getsockopt(sk, level, optname, | |
2176 | optval, optlen); | |
2177 | ||
2178 | if (get_user(len, optlen)) | |
2179 | return -EFAULT; | |
2180 | ||
2181 | len = min_t(unsigned int, len, sizeof(int)); | |
2182 | ||
2183 | if (len < 0) | |
2184 | return -EINVAL; | |
2185 | ||
2186 | switch (optname) { | |
2187 | case TCP_MAXSEG: | |
2188 | val = tp->mss_cache_std; | |
2189 | if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) | |
2190 | val = tp->rx_opt.user_mss; | |
2191 | break; | |
2192 | case TCP_NODELAY: | |
2193 | val = !!(tp->nonagle&TCP_NAGLE_OFF); | |
2194 | break; | |
2195 | case TCP_CORK: | |
2196 | val = !!(tp->nonagle&TCP_NAGLE_CORK); | |
2197 | break; | |
2198 | case TCP_KEEPIDLE: | |
2199 | val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ; | |
2200 | break; | |
2201 | case TCP_KEEPINTVL: | |
2202 | val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ; | |
2203 | break; | |
2204 | case TCP_KEEPCNT: | |
2205 | val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; | |
2206 | break; | |
2207 | case TCP_SYNCNT: | |
2208 | val = tp->syn_retries ? : sysctl_tcp_syn_retries; | |
2209 | break; | |
2210 | case TCP_LINGER2: | |
2211 | val = tp->linger2; | |
2212 | if (val >= 0) | |
2213 | val = (val ? : sysctl_tcp_fin_timeout) / HZ; | |
2214 | break; | |
2215 | case TCP_DEFER_ACCEPT: | |
2216 | val = !tp->defer_accept ? 0 : ((TCP_TIMEOUT_INIT / HZ) << | |
2217 | (tp->defer_accept - 1)); | |
2218 | break; | |
2219 | case TCP_WINDOW_CLAMP: | |
2220 | val = tp->window_clamp; | |
2221 | break; | |
2222 | case TCP_INFO: { | |
2223 | struct tcp_info info; | |
2224 | ||
2225 | if (get_user(len, optlen)) | |
2226 | return -EFAULT; | |
2227 | ||
2228 | tcp_get_info(sk, &info); | |
2229 | ||
2230 | len = min_t(unsigned int, len, sizeof(info)); | |
2231 | if (put_user(len, optlen)) | |
2232 | return -EFAULT; | |
2233 | if (copy_to_user(optval, &info, len)) | |
2234 | return -EFAULT; | |
2235 | return 0; | |
2236 | } | |
2237 | case TCP_QUICKACK: | |
2238 | val = !tp->ack.pingpong; | |
2239 | break; | |
2240 | default: | |
2241 | return -ENOPROTOOPT; | |
2242 | }; | |
2243 | ||
2244 | if (put_user(len, optlen)) | |
2245 | return -EFAULT; | |
2246 | if (copy_to_user(optval, &val, len)) | |
2247 | return -EFAULT; | |
2248 | return 0; | |
2249 | } | |
2250 | ||
2251 | ||
2252 | extern void __skb_cb_too_small_for_tcp(int, int); | |
2253 | extern void tcpdiag_init(void); | |
2254 | ||
2255 | static __initdata unsigned long thash_entries; | |
2256 | static int __init set_thash_entries(char *str) | |
2257 | { | |
2258 | if (!str) | |
2259 | return 0; | |
2260 | thash_entries = simple_strtoul(str, &str, 0); | |
2261 | return 1; | |
2262 | } | |
2263 | __setup("thash_entries=", set_thash_entries); | |
2264 | ||
2265 | void __init tcp_init(void) | |
2266 | { | |
2267 | struct sk_buff *skb = NULL; | |
2268 | int order, i; | |
2269 | ||
2270 | if (sizeof(struct tcp_skb_cb) > sizeof(skb->cb)) | |
2271 | __skb_cb_too_small_for_tcp(sizeof(struct tcp_skb_cb), | |
2272 | sizeof(skb->cb)); | |
2273 | ||
2274 | tcp_openreq_cachep = kmem_cache_create("tcp_open_request", | |
2275 | sizeof(struct open_request), | |
2276 | 0, SLAB_HWCACHE_ALIGN, | |
2277 | NULL, NULL); | |
2278 | if (!tcp_openreq_cachep) | |
2279 | panic("tcp_init: Cannot alloc open_request cache."); | |
2280 | ||
2281 | tcp_bucket_cachep = kmem_cache_create("tcp_bind_bucket", | |
2282 | sizeof(struct tcp_bind_bucket), | |
2283 | 0, SLAB_HWCACHE_ALIGN, | |
2284 | NULL, NULL); | |
2285 | if (!tcp_bucket_cachep) | |
2286 | panic("tcp_init: Cannot alloc tcp_bind_bucket cache."); | |
2287 | ||
2288 | tcp_timewait_cachep = kmem_cache_create("tcp_tw_bucket", | |
2289 | sizeof(struct tcp_tw_bucket), | |
2290 | 0, SLAB_HWCACHE_ALIGN, | |
2291 | NULL, NULL); | |
2292 | if (!tcp_timewait_cachep) | |
2293 | panic("tcp_init: Cannot alloc tcp_tw_bucket cache."); | |
2294 | ||
2295 | /* Size and allocate the main established and bind bucket | |
2296 | * hash tables. | |
2297 | * | |
2298 | * The methodology is similar to that of the buffer cache. | |
2299 | */ | |
2300 | tcp_ehash = (struct tcp_ehash_bucket *) | |
2301 | alloc_large_system_hash("TCP established", | |
2302 | sizeof(struct tcp_ehash_bucket), | |
2303 | thash_entries, | |
2304 | (num_physpages >= 128 * 1024) ? | |
2305 | (25 - PAGE_SHIFT) : | |
2306 | (27 - PAGE_SHIFT), | |
2307 | HASH_HIGHMEM, | |
2308 | &tcp_ehash_size, | |
2309 | NULL, | |
2310 | 0); | |
2311 | tcp_ehash_size = (1 << tcp_ehash_size) >> 1; | |
2312 | for (i = 0; i < (tcp_ehash_size << 1); i++) { | |
2313 | rwlock_init(&tcp_ehash[i].lock); | |
2314 | INIT_HLIST_HEAD(&tcp_ehash[i].chain); | |
2315 | } | |
2316 | ||
2317 | tcp_bhash = (struct tcp_bind_hashbucket *) | |
2318 | alloc_large_system_hash("TCP bind", | |
2319 | sizeof(struct tcp_bind_hashbucket), | |
2320 | tcp_ehash_size, | |
2321 | (num_physpages >= 128 * 1024) ? | |
2322 | (25 - PAGE_SHIFT) : | |
2323 | (27 - PAGE_SHIFT), | |
2324 | HASH_HIGHMEM, | |
2325 | &tcp_bhash_size, | |
2326 | NULL, | |
2327 | 64 * 1024); | |
2328 | tcp_bhash_size = 1 << tcp_bhash_size; | |
2329 | for (i = 0; i < tcp_bhash_size; i++) { | |
2330 | spin_lock_init(&tcp_bhash[i].lock); | |
2331 | INIT_HLIST_HEAD(&tcp_bhash[i].chain); | |
2332 | } | |
2333 | ||
2334 | /* Try to be a bit smarter and adjust defaults depending | |
2335 | * on available memory. | |
2336 | */ | |
2337 | for (order = 0; ((1 << order) << PAGE_SHIFT) < | |
2338 | (tcp_bhash_size * sizeof(struct tcp_bind_hashbucket)); | |
2339 | order++) | |
2340 | ; | |
2341 | if (order > 4) { | |
2342 | sysctl_local_port_range[0] = 32768; | |
2343 | sysctl_local_port_range[1] = 61000; | |
2344 | sysctl_tcp_max_tw_buckets = 180000; | |
2345 | sysctl_tcp_max_orphans = 4096 << (order - 4); | |
2346 | sysctl_max_syn_backlog = 1024; | |
2347 | } else if (order < 3) { | |
2348 | sysctl_local_port_range[0] = 1024 * (3 - order); | |
2349 | sysctl_tcp_max_tw_buckets >>= (3 - order); | |
2350 | sysctl_tcp_max_orphans >>= (3 - order); | |
2351 | sysctl_max_syn_backlog = 128; | |
2352 | } | |
2353 | tcp_port_rover = sysctl_local_port_range[0] - 1; | |
2354 | ||
2355 | sysctl_tcp_mem[0] = 768 << order; | |
2356 | sysctl_tcp_mem[1] = 1024 << order; | |
2357 | sysctl_tcp_mem[2] = 1536 << order; | |
2358 | ||
2359 | if (order < 3) { | |
2360 | sysctl_tcp_wmem[2] = 64 * 1024; | |
2361 | sysctl_tcp_rmem[0] = PAGE_SIZE; | |
2362 | sysctl_tcp_rmem[1] = 43689; | |
2363 | sysctl_tcp_rmem[2] = 2 * 43689; | |
2364 | } | |
2365 | ||
2366 | printk(KERN_INFO "TCP: Hash tables configured " | |
2367 | "(established %d bind %d)\n", | |
2368 | tcp_ehash_size << 1, tcp_bhash_size); | |
2369 | } | |
2370 | ||
2371 | EXPORT_SYMBOL(tcp_accept); | |
2372 | EXPORT_SYMBOL(tcp_close); | |
2373 | EXPORT_SYMBOL(tcp_destroy_sock); | |
2374 | EXPORT_SYMBOL(tcp_disconnect); | |
2375 | EXPORT_SYMBOL(tcp_getsockopt); | |
2376 | EXPORT_SYMBOL(tcp_ioctl); | |
2377 | EXPORT_SYMBOL(tcp_openreq_cachep); | |
2378 | EXPORT_SYMBOL(tcp_poll); | |
2379 | EXPORT_SYMBOL(tcp_read_sock); | |
2380 | EXPORT_SYMBOL(tcp_recvmsg); | |
2381 | EXPORT_SYMBOL(tcp_sendmsg); | |
2382 | EXPORT_SYMBOL(tcp_sendpage); | |
2383 | EXPORT_SYMBOL(tcp_setsockopt); | |
2384 | EXPORT_SYMBOL(tcp_shutdown); | |
2385 | EXPORT_SYMBOL(tcp_statistics); | |
2386 | EXPORT_SYMBOL(tcp_timewait_cachep); |