Commit | Line | Data |
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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 | * | |
02c30a84 | 8 | * Authors: Ross Biro |
1da177e4 LT |
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 | ||
afd46503 JP |
248 | #define pr_fmt(fmt) "TCP: " fmt |
249 | ||
172589cc | 250 | #include <linux/kernel.h> |
1da177e4 LT |
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> | |
1da177e4 | 256 | #include <linux/fs.h> |
9c55e01c | 257 | #include <linux/skbuff.h> |
81b23b4a | 258 | #include <linux/scatterlist.h> |
9c55e01c JA |
259 | #include <linux/splice.h> |
260 | #include <linux/net.h> | |
261 | #include <linux/socket.h> | |
1da177e4 LT |
262 | #include <linux/random.h> |
263 | #include <linux/bootmem.h> | |
57413ebc MS |
264 | #include <linux/highmem.h> |
265 | #include <linux/swap.h> | |
b8059ead | 266 | #include <linux/cache.h> |
f4c50d99 | 267 | #include <linux/err.h> |
cfb6eeb4 | 268 | #include <linux/crypto.h> |
da5c78c8 | 269 | #include <linux/time.h> |
5a0e3ad6 | 270 | #include <linux/slab.h> |
1da177e4 LT |
271 | |
272 | #include <net/icmp.h> | |
cf60af03 | 273 | #include <net/inet_common.h> |
1da177e4 LT |
274 | #include <net/tcp.h> |
275 | #include <net/xfrm.h> | |
276 | #include <net/ip.h> | |
9c55e01c | 277 | #include <net/sock.h> |
1da177e4 LT |
278 | |
279 | #include <asm/uaccess.h> | |
280 | #include <asm/ioctls.h> | |
076bb0c8 | 281 | #include <net/busy_poll.h> |
1da177e4 | 282 | |
ab32ea5d | 283 | int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; |
1da177e4 | 284 | |
95bd09eb ED |
285 | int sysctl_tcp_min_tso_segs __read_mostly = 2; |
286 | ||
f54b3111 ED |
287 | int sysctl_tcp_autocorking __read_mostly = 1; |
288 | ||
dd24c001 | 289 | struct percpu_counter tcp_orphan_count; |
0a5578cf ACM |
290 | EXPORT_SYMBOL_GPL(tcp_orphan_count); |
291 | ||
a4fe34bf | 292 | long sysctl_tcp_mem[3] __read_mostly; |
b8059ead DM |
293 | int sysctl_tcp_wmem[3] __read_mostly; |
294 | int sysctl_tcp_rmem[3] __read_mostly; | |
1da177e4 | 295 | |
a4fe34bf | 296 | EXPORT_SYMBOL(sysctl_tcp_mem); |
1da177e4 LT |
297 | EXPORT_SYMBOL(sysctl_tcp_rmem); |
298 | EXPORT_SYMBOL(sysctl_tcp_wmem); | |
299 | ||
8d987e5c | 300 | atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ |
1da177e4 | 301 | EXPORT_SYMBOL(tcp_memory_allocated); |
1748376b ED |
302 | |
303 | /* | |
304 | * Current number of TCP sockets. | |
305 | */ | |
306 | struct percpu_counter tcp_sockets_allocated; | |
1da177e4 LT |
307 | EXPORT_SYMBOL(tcp_sockets_allocated); |
308 | ||
9c55e01c JA |
309 | /* |
310 | * TCP splice context | |
311 | */ | |
312 | struct tcp_splice_state { | |
313 | struct pipe_inode_info *pipe; | |
314 | size_t len; | |
315 | unsigned int flags; | |
316 | }; | |
317 | ||
1da177e4 LT |
318 | /* |
319 | * Pressure flag: try to collapse. | |
320 | * Technical note: it is used by multiple contexts non atomically. | |
3ab224be | 321 | * All the __sk_mem_schedule() is of this nature: accounting |
1da177e4 LT |
322 | * is strict, actions are advisory and have some latency. |
323 | */ | |
4103f8cd | 324 | int tcp_memory_pressure __read_mostly; |
1da177e4 LT |
325 | EXPORT_SYMBOL(tcp_memory_pressure); |
326 | ||
5c52ba17 | 327 | void tcp_enter_memory_pressure(struct sock *sk) |
1da177e4 LT |
328 | { |
329 | if (!tcp_memory_pressure) { | |
4e673444 | 330 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); |
1da177e4 LT |
331 | tcp_memory_pressure = 1; |
332 | } | |
333 | } | |
1da177e4 LT |
334 | EXPORT_SYMBOL(tcp_enter_memory_pressure); |
335 | ||
b103cf34 JA |
336 | /* Convert seconds to retransmits based on initial and max timeout */ |
337 | static u8 secs_to_retrans(int seconds, int timeout, int rto_max) | |
338 | { | |
339 | u8 res = 0; | |
340 | ||
341 | if (seconds > 0) { | |
342 | int period = timeout; | |
343 | ||
344 | res = 1; | |
345 | while (seconds > period && res < 255) { | |
346 | res++; | |
347 | timeout <<= 1; | |
348 | if (timeout > rto_max) | |
349 | timeout = rto_max; | |
350 | period += timeout; | |
351 | } | |
352 | } | |
353 | return res; | |
354 | } | |
355 | ||
356 | /* Convert retransmits to seconds based on initial and max timeout */ | |
357 | static int retrans_to_secs(u8 retrans, int timeout, int rto_max) | |
358 | { | |
359 | int period = 0; | |
360 | ||
361 | if (retrans > 0) { | |
362 | period = timeout; | |
363 | while (--retrans) { | |
364 | timeout <<= 1; | |
365 | if (timeout > rto_max) | |
366 | timeout = rto_max; | |
367 | period += timeout; | |
368 | } | |
369 | } | |
370 | return period; | |
371 | } | |
372 | ||
900f65d3 NC |
373 | /* Address-family independent initialization for a tcp_sock. |
374 | * | |
375 | * NOTE: A lot of things set to zero explicitly by call to | |
376 | * sk_alloc() so need not be done here. | |
377 | */ | |
378 | void tcp_init_sock(struct sock *sk) | |
379 | { | |
380 | struct inet_connection_sock *icsk = inet_csk(sk); | |
381 | struct tcp_sock *tp = tcp_sk(sk); | |
382 | ||
996b175e | 383 | __skb_queue_head_init(&tp->out_of_order_queue); |
900f65d3 NC |
384 | tcp_init_xmit_timers(sk); |
385 | tcp_prequeue_init(tp); | |
46d3ceab | 386 | INIT_LIST_HEAD(&tp->tsq_node); |
900f65d3 NC |
387 | |
388 | icsk->icsk_rto = TCP_TIMEOUT_INIT; | |
740b0f18 | 389 | tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); |
900f65d3 NC |
390 | |
391 | /* So many TCP implementations out there (incorrectly) count the | |
392 | * initial SYN frame in their delayed-ACK and congestion control | |
393 | * algorithms that we must have the following bandaid to talk | |
394 | * efficiently to them. -DaveM | |
395 | */ | |
396 | tp->snd_cwnd = TCP_INIT_CWND; | |
397 | ||
398 | /* See draft-stevens-tcpca-spec-01 for discussion of the | |
399 | * initialization of these values. | |
400 | */ | |
401 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; | |
402 | tp->snd_cwnd_clamp = ~0; | |
403 | tp->mss_cache = TCP_MSS_DEFAULT; | |
404 | ||
405 | tp->reordering = sysctl_tcp_reordering; | |
eed530b6 | 406 | tcp_enable_early_retrans(tp); |
55d8694f | 407 | tcp_assign_congestion_control(sk); |
900f65d3 | 408 | |
ceaa1fef AV |
409 | tp->tsoffset = 0; |
410 | ||
900f65d3 NC |
411 | sk->sk_state = TCP_CLOSE; |
412 | ||
413 | sk->sk_write_space = sk_stream_write_space; | |
414 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
415 | ||
416 | icsk->icsk_sync_mss = tcp_sync_mss; | |
417 | ||
900f65d3 NC |
418 | sk->sk_sndbuf = sysctl_tcp_wmem[1]; |
419 | sk->sk_rcvbuf = sysctl_tcp_rmem[1]; | |
420 | ||
421 | local_bh_disable(); | |
422 | sock_update_memcg(sk); | |
423 | sk_sockets_allocated_inc(sk); | |
424 | local_bh_enable(); | |
425 | } | |
426 | EXPORT_SYMBOL(tcp_init_sock); | |
427 | ||
f066e2b0 | 428 | static void tcp_tx_timestamp(struct sock *sk, struct sk_buff *skb) |
4ed2d765 | 429 | { |
f066e2b0 WB |
430 | if (sk->sk_tsflags) { |
431 | struct skb_shared_info *shinfo = skb_shinfo(skb); | |
4ed2d765 | 432 | |
f066e2b0 WB |
433 | sock_tx_timestamp(sk, &shinfo->tx_flags); |
434 | if (shinfo->tx_flags & SKBTX_ANY_TSTAMP) | |
435 | shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; | |
436 | } | |
4ed2d765 WB |
437 | } |
438 | ||
1da177e4 LT |
439 | /* |
440 | * Wait for a TCP event. | |
441 | * | |
442 | * Note that we don't need to lock the socket, as the upper poll layers | |
443 | * take care of normal races (between the test and the event) and we don't | |
444 | * go look at any of the socket buffers directly. | |
445 | */ | |
446 | unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) | |
447 | { | |
448 | unsigned int mask; | |
449 | struct sock *sk = sock->sk; | |
cf533ea5 | 450 | const struct tcp_sock *tp = tcp_sk(sk); |
1da177e4 | 451 | |
c3f1dbaf DM |
452 | sock_rps_record_flow(sk); |
453 | ||
aa395145 | 454 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 | 455 | if (sk->sk_state == TCP_LISTEN) |
dc40c7bc | 456 | return inet_csk_listen_poll(sk); |
1da177e4 LT |
457 | |
458 | /* Socket is not locked. We are protected from async events | |
70efce27 WN |
459 | * by poll logic and correct handling of state changes |
460 | * made by other threads is impossible in any case. | |
1da177e4 LT |
461 | */ |
462 | ||
463 | mask = 0; | |
1da177e4 LT |
464 | |
465 | /* | |
466 | * POLLHUP is certainly not done right. But poll() doesn't | |
467 | * have a notion of HUP in just one direction, and for a | |
468 | * socket the read side is more interesting. | |
469 | * | |
470 | * Some poll() documentation says that POLLHUP is incompatible | |
471 | * with the POLLOUT/POLLWR flags, so somebody should check this | |
472 | * all. But careful, it tends to be safer to return too many | |
473 | * bits than too few, and you can easily break real applications | |
474 | * if you don't tell them that something has hung up! | |
475 | * | |
476 | * Check-me. | |
477 | * | |
478 | * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and | |
479 | * our fs/select.c). It means that after we received EOF, | |
480 | * poll always returns immediately, making impossible poll() on write() | |
481 | * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP | |
482 | * if and only if shutdown has been made in both directions. | |
483 | * Actually, it is interesting to look how Solaris and DUX | |
70efce27 | 484 | * solve this dilemma. I would prefer, if POLLHUP were maskable, |
1da177e4 LT |
485 | * then we could set it on SND_SHUTDOWN. BTW examples given |
486 | * in Stevens' books assume exactly this behaviour, it explains | |
70efce27 | 487 | * why POLLHUP is incompatible with POLLOUT. --ANK |
1da177e4 LT |
488 | * |
489 | * NOTE. Check for TCP_CLOSE is added. The goal is to prevent | |
490 | * blocking on fresh not-connected or disconnected socket. --ANK | |
491 | */ | |
492 | if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) | |
493 | mask |= POLLHUP; | |
494 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
f348d70a | 495 | mask |= POLLIN | POLLRDNORM | POLLRDHUP; |
1da177e4 | 496 | |
8336886f JC |
497 | /* Connected or passive Fast Open socket? */ |
498 | if (sk->sk_state != TCP_SYN_SENT && | |
499 | (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk != NULL)) { | |
c7004482 DM |
500 | int target = sock_rcvlowat(sk, 0, INT_MAX); |
501 | ||
502 | if (tp->urg_seq == tp->copied_seq && | |
503 | !sock_flag(sk, SOCK_URGINLINE) && | |
504 | tp->urg_data) | |
b634f875 | 505 | target++; |
c7004482 | 506 | |
1da177e4 LT |
507 | /* Potential race condition. If read of tp below will |
508 | * escape above sk->sk_state, we can be illegally awaken | |
509 | * in SYN_* states. */ | |
c7004482 | 510 | if (tp->rcv_nxt - tp->copied_seq >= target) |
1da177e4 LT |
511 | mask |= POLLIN | POLLRDNORM; |
512 | ||
513 | if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { | |
64dc6130 | 514 | if (sk_stream_is_writeable(sk)) { |
1da177e4 LT |
515 | mask |= POLLOUT | POLLWRNORM; |
516 | } else { /* send SIGIO later */ | |
517 | set_bit(SOCK_ASYNC_NOSPACE, | |
518 | &sk->sk_socket->flags); | |
519 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
520 | ||
521 | /* Race breaker. If space is freed after | |
522 | * wspace test but before the flags are set, | |
523 | * IO signal will be lost. | |
524 | */ | |
64dc6130 | 525 | if (sk_stream_is_writeable(sk)) |
1da177e4 LT |
526 | mask |= POLLOUT | POLLWRNORM; |
527 | } | |
d84ba638 KM |
528 | } else |
529 | mask |= POLLOUT | POLLWRNORM; | |
1da177e4 LT |
530 | |
531 | if (tp->urg_data & TCP_URG_VALID) | |
532 | mask |= POLLPRI; | |
533 | } | |
a4d25803 TM |
534 | /* This barrier is coupled with smp_wmb() in tcp_reset() */ |
535 | smp_rmb(); | |
4ed2d765 | 536 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) |
a4d25803 TM |
537 | mask |= POLLERR; |
538 | ||
1da177e4 LT |
539 | return mask; |
540 | } | |
4bc2f18b | 541 | EXPORT_SYMBOL(tcp_poll); |
1da177e4 LT |
542 | |
543 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) | |
544 | { | |
545 | struct tcp_sock *tp = tcp_sk(sk); | |
546 | int answ; | |
0e71c55c | 547 | bool slow; |
1da177e4 LT |
548 | |
549 | switch (cmd) { | |
550 | case SIOCINQ: | |
551 | if (sk->sk_state == TCP_LISTEN) | |
552 | return -EINVAL; | |
553 | ||
0e71c55c | 554 | slow = lock_sock_fast(sk); |
1da177e4 LT |
555 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) |
556 | answ = 0; | |
557 | else if (sock_flag(sk, SOCK_URGINLINE) || | |
558 | !tp->urg_data || | |
559 | before(tp->urg_seq, tp->copied_seq) || | |
560 | !before(tp->urg_seq, tp->rcv_nxt)) { | |
91521944 | 561 | |
1da177e4 LT |
562 | answ = tp->rcv_nxt - tp->copied_seq; |
563 | ||
a3374c42 ED |
564 | /* Subtract 1, if FIN was received */ |
565 | if (answ && sock_flag(sk, SOCK_DONE)) | |
566 | answ--; | |
1da177e4 LT |
567 | } else |
568 | answ = tp->urg_seq - tp->copied_seq; | |
0e71c55c | 569 | unlock_sock_fast(sk, slow); |
1da177e4 LT |
570 | break; |
571 | case SIOCATMARK: | |
572 | answ = tp->urg_data && tp->urg_seq == tp->copied_seq; | |
573 | break; | |
574 | case SIOCOUTQ: | |
575 | if (sk->sk_state == TCP_LISTEN) | |
576 | return -EINVAL; | |
577 | ||
578 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
579 | answ = 0; | |
580 | else | |
581 | answ = tp->write_seq - tp->snd_una; | |
582 | break; | |
2f4e1b39 MS |
583 | case SIOCOUTQNSD: |
584 | if (sk->sk_state == TCP_LISTEN) | |
585 | return -EINVAL; | |
586 | ||
587 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
588 | answ = 0; | |
589 | else | |
590 | answ = tp->write_seq - tp->snd_nxt; | |
591 | break; | |
1da177e4 LT |
592 | default: |
593 | return -ENOIOCTLCMD; | |
3ff50b79 | 594 | } |
1da177e4 LT |
595 | |
596 | return put_user(answ, (int __user *)arg); | |
597 | } | |
4bc2f18b | 598 | EXPORT_SYMBOL(tcp_ioctl); |
1da177e4 | 599 | |
1da177e4 LT |
600 | static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) |
601 | { | |
4de075e0 | 602 | TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; |
1da177e4 LT |
603 | tp->pushed_seq = tp->write_seq; |
604 | } | |
605 | ||
a2a385d6 | 606 | static inline bool forced_push(const struct tcp_sock *tp) |
1da177e4 LT |
607 | { |
608 | return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); | |
609 | } | |
610 | ||
f4a775d1 | 611 | static void skb_entail(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 612 | { |
9e412ba7 | 613 | struct tcp_sock *tp = tcp_sk(sk); |
352d4800 ACM |
614 | struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); |
615 | ||
616 | skb->csum = 0; | |
617 | tcb->seq = tcb->end_seq = tp->write_seq; | |
4de075e0 | 618 | tcb->tcp_flags = TCPHDR_ACK; |
352d4800 | 619 | tcb->sacked = 0; |
f4a775d1 | 620 | __skb_header_release(skb); |
fe067e8a | 621 | tcp_add_write_queue_tail(sk, skb); |
3ab224be HA |
622 | sk->sk_wmem_queued += skb->truesize; |
623 | sk_mem_charge(sk, skb->truesize); | |
89ebd197 | 624 | if (tp->nonagle & TCP_NAGLE_PUSH) |
e905a9ed | 625 | tp->nonagle &= ~TCP_NAGLE_PUSH; |
1da177e4 LT |
626 | } |
627 | ||
afeca340 | 628 | static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) |
1da177e4 | 629 | { |
33f5f57e | 630 | if (flags & MSG_OOB) |
1da177e4 | 631 | tp->snd_up = tp->write_seq; |
1da177e4 LT |
632 | } |
633 | ||
f54b3111 | 634 | /* If a not yet filled skb is pushed, do not send it if |
a181ceb5 | 635 | * we have data packets in Qdisc or NIC queues : |
f54b3111 ED |
636 | * Because TX completion will happen shortly, it gives a chance |
637 | * to coalesce future sendmsg() payload into this skb, without | |
638 | * need for a timer, and with no latency trade off. | |
639 | * As packets containing data payload have a bigger truesize | |
a181ceb5 ED |
640 | * than pure acks (dataless) packets, the last checks prevent |
641 | * autocorking if we only have an ACK in Qdisc/NIC queues, | |
642 | * or if TX completion was delayed after we processed ACK packet. | |
f54b3111 ED |
643 | */ |
644 | static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, | |
645 | int size_goal) | |
1da177e4 | 646 | { |
f54b3111 ED |
647 | return skb->len < size_goal && |
648 | sysctl_tcp_autocorking && | |
a181ceb5 | 649 | skb != tcp_write_queue_head(sk) && |
f54b3111 ED |
650 | atomic_read(&sk->sk_wmem_alloc) > skb->truesize; |
651 | } | |
652 | ||
653 | static void tcp_push(struct sock *sk, int flags, int mss_now, | |
654 | int nonagle, int size_goal) | |
655 | { | |
656 | struct tcp_sock *tp = tcp_sk(sk); | |
657 | struct sk_buff *skb; | |
afeca340 | 658 | |
f54b3111 ED |
659 | if (!tcp_send_head(sk)) |
660 | return; | |
afeca340 | 661 | |
f54b3111 ED |
662 | skb = tcp_write_queue_tail(sk); |
663 | if (!(flags & MSG_MORE) || forced_push(tp)) | |
664 | tcp_mark_push(tp, skb); | |
665 | ||
666 | tcp_mark_urg(tp, flags); | |
667 | ||
668 | if (tcp_should_autocork(sk, skb, size_goal)) { | |
669 | ||
670 | /* avoid atomic op if TSQ_THROTTLED bit is already set */ | |
671 | if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) { | |
672 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); | |
673 | set_bit(TSQ_THROTTLED, &tp->tsq_flags); | |
674 | } | |
a181ceb5 ED |
675 | /* It is possible TX completion already happened |
676 | * before we set TSQ_THROTTLED. | |
677 | */ | |
678 | if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize) | |
679 | return; | |
1da177e4 | 680 | } |
f54b3111 ED |
681 | |
682 | if (flags & MSG_MORE) | |
683 | nonagle = TCP_NAGLE_CORK; | |
684 | ||
685 | __tcp_push_pending_frames(sk, mss_now, nonagle); | |
1da177e4 LT |
686 | } |
687 | ||
6ff7751d AB |
688 | static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, |
689 | unsigned int offset, size_t len) | |
9c55e01c JA |
690 | { |
691 | struct tcp_splice_state *tss = rd_desc->arg.data; | |
33966dd0 | 692 | int ret; |
9c55e01c | 693 | |
9fa5fdf2 DM |
694 | ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len), |
695 | tss->flags); | |
33966dd0 WT |
696 | if (ret > 0) |
697 | rd_desc->count -= ret; | |
698 | return ret; | |
9c55e01c JA |
699 | } |
700 | ||
701 | static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) | |
702 | { | |
703 | /* Store TCP splice context information in read_descriptor_t. */ | |
704 | read_descriptor_t rd_desc = { | |
705 | .arg.data = tss, | |
33966dd0 | 706 | .count = tss->len, |
9c55e01c JA |
707 | }; |
708 | ||
709 | return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); | |
710 | } | |
711 | ||
712 | /** | |
713 | * tcp_splice_read - splice data from TCP socket to a pipe | |
714 | * @sock: socket to splice from | |
715 | * @ppos: position (not valid) | |
716 | * @pipe: pipe to splice to | |
717 | * @len: number of bytes to splice | |
718 | * @flags: splice modifier flags | |
719 | * | |
720 | * Description: | |
721 | * Will read pages from given socket and fill them into a pipe. | |
722 | * | |
723 | **/ | |
724 | ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, | |
725 | struct pipe_inode_info *pipe, size_t len, | |
726 | unsigned int flags) | |
727 | { | |
728 | struct sock *sk = sock->sk; | |
729 | struct tcp_splice_state tss = { | |
730 | .pipe = pipe, | |
731 | .len = len, | |
732 | .flags = flags, | |
733 | }; | |
734 | long timeo; | |
735 | ssize_t spliced; | |
736 | int ret; | |
737 | ||
3a047bf8 | 738 | sock_rps_record_flow(sk); |
9c55e01c JA |
739 | /* |
740 | * We can't seek on a socket input | |
741 | */ | |
742 | if (unlikely(*ppos)) | |
743 | return -ESPIPE; | |
744 | ||
745 | ret = spliced = 0; | |
746 | ||
747 | lock_sock(sk); | |
748 | ||
42324c62 | 749 | timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); |
9c55e01c JA |
750 | while (tss.len) { |
751 | ret = __tcp_splice_read(sk, &tss); | |
752 | if (ret < 0) | |
753 | break; | |
754 | else if (!ret) { | |
755 | if (spliced) | |
756 | break; | |
9c55e01c JA |
757 | if (sock_flag(sk, SOCK_DONE)) |
758 | break; | |
759 | if (sk->sk_err) { | |
760 | ret = sock_error(sk); | |
761 | break; | |
762 | } | |
763 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
764 | break; | |
765 | if (sk->sk_state == TCP_CLOSE) { | |
766 | /* | |
767 | * This occurs when user tries to read | |
768 | * from never connected socket. | |
769 | */ | |
770 | if (!sock_flag(sk, SOCK_DONE)) | |
771 | ret = -ENOTCONN; | |
772 | break; | |
773 | } | |
774 | if (!timeo) { | |
775 | ret = -EAGAIN; | |
776 | break; | |
777 | } | |
778 | sk_wait_data(sk, &timeo); | |
779 | if (signal_pending(current)) { | |
780 | ret = sock_intr_errno(timeo); | |
781 | break; | |
782 | } | |
783 | continue; | |
784 | } | |
785 | tss.len -= ret; | |
786 | spliced += ret; | |
787 | ||
33966dd0 WT |
788 | if (!timeo) |
789 | break; | |
9c55e01c JA |
790 | release_sock(sk); |
791 | lock_sock(sk); | |
792 | ||
793 | if (sk->sk_err || sk->sk_state == TCP_CLOSE || | |
33966dd0 | 794 | (sk->sk_shutdown & RCV_SHUTDOWN) || |
9c55e01c JA |
795 | signal_pending(current)) |
796 | break; | |
797 | } | |
798 | ||
799 | release_sock(sk); | |
800 | ||
801 | if (spliced) | |
802 | return spliced; | |
803 | ||
804 | return ret; | |
805 | } | |
4bc2f18b | 806 | EXPORT_SYMBOL(tcp_splice_read); |
9c55e01c | 807 | |
df97c708 | 808 | struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) |
f561d0f2 PE |
809 | { |
810 | struct sk_buff *skb; | |
811 | ||
812 | /* The TCP header must be at least 32-bit aligned. */ | |
813 | size = ALIGN(size, 4); | |
814 | ||
815 | skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); | |
816 | if (skb) { | |
3ab224be | 817 | if (sk_wmem_schedule(sk, skb->truesize)) { |
a21d4572 | 818 | skb_reserve(skb, sk->sk_prot->max_header); |
f561d0f2 PE |
819 | /* |
820 | * Make sure that we have exactly size bytes | |
821 | * available to the caller, no more, no less. | |
822 | */ | |
16fad69c | 823 | skb->reserved_tailroom = skb->end - skb->tail - size; |
f561d0f2 PE |
824 | return skb; |
825 | } | |
826 | __kfree_skb(skb); | |
827 | } else { | |
5c52ba17 | 828 | sk->sk_prot->enter_memory_pressure(sk); |
f561d0f2 PE |
829 | sk_stream_moderate_sndbuf(sk); |
830 | } | |
831 | return NULL; | |
832 | } | |
833 | ||
0c54b85f IJ |
834 | static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, |
835 | int large_allowed) | |
836 | { | |
837 | struct tcp_sock *tp = tcp_sk(sk); | |
6c09fa09 | 838 | u32 new_size_goal, size_goal; |
605ad7f1 ED |
839 | |
840 | if (!large_allowed || !sk_can_gso(sk)) | |
841 | return mss_now; | |
842 | ||
6c09fa09 ED |
843 | /* Note : tcp_tso_autosize() will eventually split this later */ |
844 | new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER; | |
605ad7f1 ED |
845 | new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal); |
846 | ||
847 | /* We try hard to avoid divides here */ | |
848 | size_goal = tp->gso_segs * mss_now; | |
849 | if (unlikely(new_size_goal < size_goal || | |
850 | new_size_goal >= size_goal + mss_now)) { | |
851 | tp->gso_segs = min_t(u16, new_size_goal / mss_now, | |
852 | sk->sk_gso_max_segs); | |
853 | size_goal = tp->gso_segs * mss_now; | |
0c54b85f IJ |
854 | } |
855 | ||
605ad7f1 | 856 | return max(size_goal, mss_now); |
0c54b85f IJ |
857 | } |
858 | ||
859 | static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) | |
860 | { | |
861 | int mss_now; | |
862 | ||
863 | mss_now = tcp_current_mss(sk); | |
864 | *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); | |
865 | ||
866 | return mss_now; | |
867 | } | |
868 | ||
64022d0b ED |
869 | static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, |
870 | size_t size, int flags) | |
1da177e4 LT |
871 | { |
872 | struct tcp_sock *tp = tcp_sk(sk); | |
c1b4a7e6 | 873 | int mss_now, size_goal; |
1da177e4 LT |
874 | int err; |
875 | ssize_t copied; | |
876 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
877 | ||
8336886f JC |
878 | /* Wait for a connection to finish. One exception is TCP Fast Open |
879 | * (passive side) where data is allowed to be sent before a connection | |
880 | * is fully established. | |
881 | */ | |
882 | if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && | |
883 | !tcp_passive_fastopen(sk)) { | |
1da177e4 LT |
884 | if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) |
885 | goto out_err; | |
8336886f | 886 | } |
1da177e4 LT |
887 | |
888 | clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
889 | ||
0c54b85f | 890 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
891 | copied = 0; |
892 | ||
893 | err = -EPIPE; | |
894 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
0d6a775e | 895 | goto out_err; |
1da177e4 | 896 | |
64022d0b | 897 | while (size > 0) { |
fe067e8a | 898 | struct sk_buff *skb = tcp_write_queue_tail(sk); |
38ba0a65 | 899 | int copy, i; |
38ba0a65 | 900 | bool can_coalesce; |
1da177e4 | 901 | |
fe067e8a | 902 | if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { |
1da177e4 LT |
903 | new_segment: |
904 | if (!sk_stream_memory_free(sk)) | |
905 | goto wait_for_sndbuf; | |
906 | ||
df97c708 | 907 | skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); |
1da177e4 LT |
908 | if (!skb) |
909 | goto wait_for_memory; | |
910 | ||
9e412ba7 | 911 | skb_entail(sk, skb); |
c1b4a7e6 | 912 | copy = size_goal; |
1da177e4 LT |
913 | } |
914 | ||
915 | if (copy > size) | |
916 | copy = size; | |
917 | ||
918 | i = skb_shinfo(skb)->nr_frags; | |
919 | can_coalesce = skb_can_coalesce(skb, i, page, offset); | |
920 | if (!can_coalesce && i >= MAX_SKB_FRAGS) { | |
921 | tcp_mark_push(tp, skb); | |
922 | goto new_segment; | |
923 | } | |
3ab224be | 924 | if (!sk_wmem_schedule(sk, copy)) |
1da177e4 | 925 | goto wait_for_memory; |
e905a9ed | 926 | |
1da177e4 | 927 | if (can_coalesce) { |
9e903e08 | 928 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
1da177e4 LT |
929 | } else { |
930 | get_page(page); | |
931 | skb_fill_page_desc(skb, i, page, offset, copy); | |
932 | } | |
c9af6db4 | 933 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
cef401de | 934 | |
1da177e4 LT |
935 | skb->len += copy; |
936 | skb->data_len += copy; | |
937 | skb->truesize += copy; | |
938 | sk->sk_wmem_queued += copy; | |
3ab224be | 939 | sk_mem_charge(sk, copy); |
84fa7933 | 940 | skb->ip_summed = CHECKSUM_PARTIAL; |
1da177e4 LT |
941 | tp->write_seq += copy; |
942 | TCP_SKB_CB(skb)->end_seq += copy; | |
cd7d8498 | 943 | tcp_skb_pcount_set(skb, 0); |
1da177e4 LT |
944 | |
945 | if (!copied) | |
4de075e0 | 946 | TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; |
1da177e4 LT |
947 | |
948 | copied += copy; | |
64022d0b | 949 | offset += copy; |
4ed2d765 WB |
950 | if (!(size -= copy)) { |
951 | tcp_tx_timestamp(sk, skb); | |
1da177e4 | 952 | goto out; |
4ed2d765 | 953 | } |
1da177e4 | 954 | |
69d15067 | 955 | if (skb->len < size_goal || (flags & MSG_OOB)) |
1da177e4 LT |
956 | continue; |
957 | ||
958 | if (forced_push(tp)) { | |
959 | tcp_mark_push(tp, skb); | |
9e412ba7 | 960 | __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); |
fe067e8a | 961 | } else if (skb == tcp_send_head(sk)) |
1da177e4 LT |
962 | tcp_push_one(sk, mss_now); |
963 | continue; | |
964 | ||
965 | wait_for_sndbuf: | |
966 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
967 | wait_for_memory: | |
f54b3111 ED |
968 | tcp_push(sk, flags & ~MSG_MORE, mss_now, |
969 | TCP_NAGLE_PUSH, size_goal); | |
1da177e4 LT |
970 | |
971 | if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) | |
972 | goto do_error; | |
973 | ||
0c54b85f | 974 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
975 | } |
976 | ||
977 | out: | |
35f9c09f | 978 | if (copied && !(flags & MSG_SENDPAGE_NOTLAST)) |
f54b3111 | 979 | tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); |
1da177e4 LT |
980 | return copied; |
981 | ||
982 | do_error: | |
983 | if (copied) | |
984 | goto out; | |
985 | out_err: | |
986 | return sk_stream_error(sk, flags, err); | |
987 | } | |
988 | ||
7ba42910 CG |
989 | int tcp_sendpage(struct sock *sk, struct page *page, int offset, |
990 | size_t size, int flags) | |
1da177e4 LT |
991 | { |
992 | ssize_t res; | |
1da177e4 | 993 | |
1da177e4 | 994 | if (!(sk->sk_route_caps & NETIF_F_SG) || |
8648b305 | 995 | !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) |
7ba42910 CG |
996 | return sock_no_sendpage(sk->sk_socket, page, offset, size, |
997 | flags); | |
1da177e4 | 998 | |
1da177e4 | 999 | lock_sock(sk); |
64022d0b | 1000 | res = do_tcp_sendpages(sk, page, offset, size, flags); |
1da177e4 LT |
1001 | release_sock(sk); |
1002 | return res; | |
1003 | } | |
4bc2f18b | 1004 | EXPORT_SYMBOL(tcp_sendpage); |
1da177e4 | 1005 | |
690e99c4 | 1006 | static inline int select_size(const struct sock *sk, bool sg) |
1da177e4 | 1007 | { |
cf533ea5 | 1008 | const struct tcp_sock *tp = tcp_sk(sk); |
c1b4a7e6 | 1009 | int tmp = tp->mss_cache; |
1da177e4 | 1010 | |
def87cf4 | 1011 | if (sg) { |
f07d960d ED |
1012 | if (sk_can_gso(sk)) { |
1013 | /* Small frames wont use a full page: | |
1014 | * Payload will immediately follow tcp header. | |
1015 | */ | |
1016 | tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); | |
1017 | } else { | |
b4e26f5e DM |
1018 | int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); |
1019 | ||
1020 | if (tmp >= pgbreak && | |
1021 | tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) | |
1022 | tmp = pgbreak; | |
1023 | } | |
1024 | } | |
1da177e4 | 1025 | |
1da177e4 LT |
1026 | return tmp; |
1027 | } | |
1028 | ||
cf60af03 YC |
1029 | void tcp_free_fastopen_req(struct tcp_sock *tp) |
1030 | { | |
1031 | if (tp->fastopen_req != NULL) { | |
1032 | kfree(tp->fastopen_req); | |
1033 | tp->fastopen_req = NULL; | |
1034 | } | |
1035 | } | |
1036 | ||
f5ddcbbb ED |
1037 | static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, |
1038 | int *copied, size_t size) | |
cf60af03 YC |
1039 | { |
1040 | struct tcp_sock *tp = tcp_sk(sk); | |
1041 | int err, flags; | |
1042 | ||
1043 | if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE)) | |
1044 | return -EOPNOTSUPP; | |
1045 | if (tp->fastopen_req != NULL) | |
1046 | return -EALREADY; /* Another Fast Open is in progress */ | |
1047 | ||
1048 | tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), | |
1049 | sk->sk_allocation); | |
1050 | if (unlikely(tp->fastopen_req == NULL)) | |
1051 | return -ENOBUFS; | |
1052 | tp->fastopen_req->data = msg; | |
f5ddcbbb | 1053 | tp->fastopen_req->size = size; |
cf60af03 YC |
1054 | |
1055 | flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; | |
1056 | err = __inet_stream_connect(sk->sk_socket, msg->msg_name, | |
1057 | msg->msg_namelen, flags); | |
f5ddcbbb | 1058 | *copied = tp->fastopen_req->copied; |
cf60af03 YC |
1059 | tcp_free_fastopen_req(tp); |
1060 | return err; | |
1061 | } | |
1062 | ||
7ba42910 | 1063 | int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |
1da177e4 LT |
1064 | size_t size) |
1065 | { | |
1da177e4 LT |
1066 | struct tcp_sock *tp = tcp_sk(sk); |
1067 | struct sk_buff *skb; | |
57be5bda AV |
1068 | int flags, err, copied = 0; |
1069 | int mss_now = 0, size_goal, copied_syn = 0; | |
690e99c4 | 1070 | bool sg; |
1da177e4 LT |
1071 | long timeo; |
1072 | ||
1073 | lock_sock(sk); | |
1da177e4 LT |
1074 | |
1075 | flags = msg->msg_flags; | |
cf60af03 | 1076 | if (flags & MSG_FASTOPEN) { |
f5ddcbbb | 1077 | err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size); |
cf60af03 YC |
1078 | if (err == -EINPROGRESS && copied_syn > 0) |
1079 | goto out; | |
1080 | else if (err) | |
1081 | goto out_err; | |
cf60af03 YC |
1082 | } |
1083 | ||
1da177e4 LT |
1084 | timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); |
1085 | ||
8336886f JC |
1086 | /* Wait for a connection to finish. One exception is TCP Fast Open |
1087 | * (passive side) where data is allowed to be sent before a connection | |
1088 | * is fully established. | |
1089 | */ | |
1090 | if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && | |
1091 | !tcp_passive_fastopen(sk)) { | |
1da177e4 | 1092 | if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) |
cf60af03 | 1093 | goto do_error; |
8336886f | 1094 | } |
1da177e4 | 1095 | |
c0e88ff0 PE |
1096 | if (unlikely(tp->repair)) { |
1097 | if (tp->repair_queue == TCP_RECV_QUEUE) { | |
1098 | copied = tcp_send_rcvq(sk, msg, size); | |
5924f17a | 1099 | goto out_nopush; |
c0e88ff0 PE |
1100 | } |
1101 | ||
1102 | err = -EINVAL; | |
1103 | if (tp->repair_queue == TCP_NO_QUEUE) | |
1104 | goto out_err; | |
1105 | ||
1106 | /* 'common' sending to sendq */ | |
1107 | } | |
1108 | ||
1da177e4 LT |
1109 | /* This should be in poll */ |
1110 | clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
1111 | ||
0c54b85f | 1112 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
1113 | |
1114 | /* Ok commence sending. */ | |
1da177e4 LT |
1115 | copied = 0; |
1116 | ||
1117 | err = -EPIPE; | |
1118 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
0d6a775e | 1119 | goto out_err; |
1da177e4 | 1120 | |
690e99c4 | 1121 | sg = !!(sk->sk_route_caps & NETIF_F_SG); |
def87cf4 | 1122 | |
57be5bda AV |
1123 | while (iov_iter_count(&msg->msg_iter)) { |
1124 | int copy = 0; | |
1125 | int max = size_goal; | |
1da177e4 | 1126 | |
57be5bda AV |
1127 | skb = tcp_write_queue_tail(sk); |
1128 | if (tcp_send_head(sk)) { | |
1129 | if (skb->ip_summed == CHECKSUM_NONE) | |
1130 | max = mss_now; | |
1131 | copy = max - skb->len; | |
cf60af03 | 1132 | } |
1da177e4 | 1133 | |
57be5bda | 1134 | if (copy <= 0) { |
1da177e4 | 1135 | new_segment: |
57be5bda AV |
1136 | /* Allocate new segment. If the interface is SG, |
1137 | * allocate skb fitting to single page. | |
1138 | */ | |
1139 | if (!sk_stream_memory_free(sk)) | |
1140 | goto wait_for_sndbuf; | |
1da177e4 | 1141 | |
57be5bda AV |
1142 | skb = sk_stream_alloc_skb(sk, |
1143 | select_size(sk, sg), | |
1144 | sk->sk_allocation); | |
1145 | if (!skb) | |
1146 | goto wait_for_memory; | |
1da177e4 | 1147 | |
57be5bda AV |
1148 | /* |
1149 | * Check whether we can use HW checksum. | |
1150 | */ | |
1151 | if (sk->sk_route_caps & NETIF_F_ALL_CSUM) | |
1152 | skb->ip_summed = CHECKSUM_PARTIAL; | |
1da177e4 | 1153 | |
57be5bda AV |
1154 | skb_entail(sk, skb); |
1155 | copy = size_goal; | |
1156 | max = size_goal; | |
9d186cac | 1157 | |
57be5bda AV |
1158 | /* All packets are restored as if they have |
1159 | * already been sent. skb_mstamp isn't set to | |
1160 | * avoid wrong rtt estimation. | |
1161 | */ | |
1162 | if (tp->repair) | |
1163 | TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED; | |
1164 | } | |
1da177e4 | 1165 | |
57be5bda AV |
1166 | /* Try to append data to the end of skb. */ |
1167 | if (copy > iov_iter_count(&msg->msg_iter)) | |
1168 | copy = iov_iter_count(&msg->msg_iter); | |
1169 | ||
1170 | /* Where to copy to? */ | |
1171 | if (skb_availroom(skb) > 0) { | |
1172 | /* We have some space in skb head. Superb! */ | |
1173 | copy = min_t(int, copy, skb_availroom(skb)); | |
1174 | err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy); | |
1175 | if (err) | |
1176 | goto do_fault; | |
1177 | } else { | |
1178 | bool merge = true; | |
1179 | int i = skb_shinfo(skb)->nr_frags; | |
1180 | struct page_frag *pfrag = sk_page_frag(sk); | |
1181 | ||
1182 | if (!sk_page_frag_refill(sk, pfrag)) | |
1183 | goto wait_for_memory; | |
ef015786 | 1184 | |
57be5bda AV |
1185 | if (!skb_can_coalesce(skb, i, pfrag->page, |
1186 | pfrag->offset)) { | |
1187 | if (i == MAX_SKB_FRAGS || !sg) { | |
1188 | tcp_mark_push(tp, skb); | |
1189 | goto new_segment; | |
1da177e4 | 1190 | } |
57be5bda | 1191 | merge = false; |
1da177e4 LT |
1192 | } |
1193 | ||
57be5bda AV |
1194 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
1195 | ||
1196 | if (!sk_wmem_schedule(sk, copy)) | |
1197 | goto wait_for_memory; | |
1da177e4 | 1198 | |
57be5bda AV |
1199 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, |
1200 | pfrag->page, | |
1201 | pfrag->offset, | |
1202 | copy); | |
1203 | if (err) | |
1204 | goto do_error; | |
1da177e4 | 1205 | |
57be5bda AV |
1206 | /* Update the skb. */ |
1207 | if (merge) { | |
1208 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1209 | } else { | |
1210 | skb_fill_page_desc(skb, i, pfrag->page, | |
1211 | pfrag->offset, copy); | |
1212 | get_page(pfrag->page); | |
4ed2d765 | 1213 | } |
57be5bda AV |
1214 | pfrag->offset += copy; |
1215 | } | |
1216 | ||
1217 | if (!copied) | |
1218 | TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; | |
1219 | ||
1220 | tp->write_seq += copy; | |
1221 | TCP_SKB_CB(skb)->end_seq += copy; | |
1222 | tcp_skb_pcount_set(skb, 0); | |
1da177e4 | 1223 | |
57be5bda AV |
1224 | copied += copy; |
1225 | if (!iov_iter_count(&msg->msg_iter)) { | |
1226 | tcp_tx_timestamp(sk, skb); | |
1227 | goto out; | |
1228 | } | |
1da177e4 | 1229 | |
57be5bda | 1230 | if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair)) |
1da177e4 LT |
1231 | continue; |
1232 | ||
57be5bda AV |
1233 | if (forced_push(tp)) { |
1234 | tcp_mark_push(tp, skb); | |
1235 | __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); | |
1236 | } else if (skb == tcp_send_head(sk)) | |
1237 | tcp_push_one(sk, mss_now); | |
1238 | continue; | |
1239 | ||
1da177e4 | 1240 | wait_for_sndbuf: |
57be5bda | 1241 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
1da177e4 | 1242 | wait_for_memory: |
57be5bda AV |
1243 | if (copied) |
1244 | tcp_push(sk, flags & ~MSG_MORE, mss_now, | |
1245 | TCP_NAGLE_PUSH, size_goal); | |
1da177e4 | 1246 | |
57be5bda AV |
1247 | if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) |
1248 | goto do_error; | |
1da177e4 | 1249 | |
57be5bda | 1250 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
1251 | } |
1252 | ||
1253 | out: | |
ec342325 | 1254 | if (copied) |
f54b3111 | 1255 | tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); |
5924f17a | 1256 | out_nopush: |
1da177e4 | 1257 | release_sock(sk); |
cf60af03 | 1258 | return copied + copied_syn; |
1da177e4 LT |
1259 | |
1260 | do_fault: | |
1261 | if (!skb->len) { | |
fe067e8a DM |
1262 | tcp_unlink_write_queue(skb, sk); |
1263 | /* It is the one place in all of TCP, except connection | |
1264 | * reset, where we can be unlinking the send_head. | |
1265 | */ | |
1266 | tcp_check_send_head(sk, skb); | |
3ab224be | 1267 | sk_wmem_free_skb(sk, skb); |
1da177e4 LT |
1268 | } |
1269 | ||
1270 | do_error: | |
cf60af03 | 1271 | if (copied + copied_syn) |
1da177e4 LT |
1272 | goto out; |
1273 | out_err: | |
1274 | err = sk_stream_error(sk, flags, err); | |
1da177e4 LT |
1275 | release_sock(sk); |
1276 | return err; | |
1277 | } | |
4bc2f18b | 1278 | EXPORT_SYMBOL(tcp_sendmsg); |
1da177e4 LT |
1279 | |
1280 | /* | |
1281 | * Handle reading urgent data. BSD has very simple semantics for | |
1282 | * this, no blocking and very strange errors 8) | |
1283 | */ | |
1284 | ||
377f0a08 | 1285 | static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) |
1da177e4 LT |
1286 | { |
1287 | struct tcp_sock *tp = tcp_sk(sk); | |
1288 | ||
1289 | /* No URG data to read. */ | |
1290 | if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || | |
1291 | tp->urg_data == TCP_URG_READ) | |
1292 | return -EINVAL; /* Yes this is right ! */ | |
1293 | ||
1294 | if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) | |
1295 | return -ENOTCONN; | |
1296 | ||
1297 | if (tp->urg_data & TCP_URG_VALID) { | |
1298 | int err = 0; | |
1299 | char c = tp->urg_data; | |
1300 | ||
1301 | if (!(flags & MSG_PEEK)) | |
1302 | tp->urg_data = TCP_URG_READ; | |
1303 | ||
1304 | /* Read urgent data. */ | |
1305 | msg->msg_flags |= MSG_OOB; | |
1306 | ||
1307 | if (len > 0) { | |
1308 | if (!(flags & MSG_TRUNC)) | |
7eab8d9e | 1309 | err = memcpy_to_msg(msg, &c, 1); |
1da177e4 LT |
1310 | len = 1; |
1311 | } else | |
1312 | msg->msg_flags |= MSG_TRUNC; | |
1313 | ||
1314 | return err ? -EFAULT : len; | |
1315 | } | |
1316 | ||
1317 | if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1318 | return 0; | |
1319 | ||
1320 | /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and | |
1321 | * the available implementations agree in this case: | |
1322 | * this call should never block, independent of the | |
1323 | * blocking state of the socket. | |
1324 | * Mike <pall@rz.uni-karlsruhe.de> | |
1325 | */ | |
1326 | return -EAGAIN; | |
1327 | } | |
1328 | ||
c0e88ff0 PE |
1329 | static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len) |
1330 | { | |
1331 | struct sk_buff *skb; | |
1332 | int copied = 0, err = 0; | |
1333 | ||
1334 | /* XXX -- need to support SO_PEEK_OFF */ | |
1335 | ||
1336 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
51f3d02b | 1337 | err = skb_copy_datagram_msg(skb, 0, msg, skb->len); |
c0e88ff0 PE |
1338 | if (err) |
1339 | break; | |
1340 | ||
1341 | copied += skb->len; | |
1342 | } | |
1343 | ||
1344 | return err ?: copied; | |
1345 | } | |
1346 | ||
1da177e4 LT |
1347 | /* Clean up the receive buffer for full frames taken by the user, |
1348 | * then send an ACK if necessary. COPIED is the number of bytes | |
1349 | * tcp_recvmsg has given to the user so far, it speeds up the | |
1350 | * calculation of whether or not we must ACK for the sake of | |
1351 | * a window update. | |
1352 | */ | |
3f334078 | 1353 | static void tcp_cleanup_rbuf(struct sock *sk, int copied) |
1da177e4 LT |
1354 | { |
1355 | struct tcp_sock *tp = tcp_sk(sk); | |
a2a385d6 | 1356 | bool time_to_ack = false; |
1da177e4 | 1357 | |
1da177e4 LT |
1358 | struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); |
1359 | ||
d792c100 | 1360 | WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), |
2af6fd8b | 1361 | "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", |
d792c100 | 1362 | tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); |
1da177e4 | 1363 | |
463c84b9 ACM |
1364 | if (inet_csk_ack_scheduled(sk)) { |
1365 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
1da177e4 LT |
1366 | /* Delayed ACKs frequently hit locked sockets during bulk |
1367 | * receive. */ | |
463c84b9 | 1368 | if (icsk->icsk_ack.blocked || |
1da177e4 | 1369 | /* Once-per-two-segments ACK was not sent by tcp_input.c */ |
463c84b9 | 1370 | tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || |
1da177e4 LT |
1371 | /* |
1372 | * If this read emptied read buffer, we send ACK, if | |
1373 | * connection is not bidirectional, user drained | |
1374 | * receive buffer and there was a small segment | |
1375 | * in queue. | |
1376 | */ | |
1ef9696c AK |
1377 | (copied > 0 && |
1378 | ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || | |
1379 | ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && | |
1380 | !icsk->icsk_ack.pingpong)) && | |
1381 | !atomic_read(&sk->sk_rmem_alloc))) | |
a2a385d6 | 1382 | time_to_ack = true; |
1da177e4 LT |
1383 | } |
1384 | ||
1385 | /* We send an ACK if we can now advertise a non-zero window | |
1386 | * which has been raised "significantly". | |
1387 | * | |
1388 | * Even if window raised up to infinity, do not send window open ACK | |
1389 | * in states, where we will not receive more. It is useless. | |
1390 | */ | |
1391 | if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { | |
1392 | __u32 rcv_window_now = tcp_receive_window(tp); | |
1393 | ||
1394 | /* Optimize, __tcp_select_window() is not cheap. */ | |
1395 | if (2*rcv_window_now <= tp->window_clamp) { | |
1396 | __u32 new_window = __tcp_select_window(sk); | |
1397 | ||
1398 | /* Send ACK now, if this read freed lots of space | |
1399 | * in our buffer. Certainly, new_window is new window. | |
1400 | * We can advertise it now, if it is not less than current one. | |
1401 | * "Lots" means "at least twice" here. | |
1402 | */ | |
1403 | if (new_window && new_window >= 2 * rcv_window_now) | |
a2a385d6 | 1404 | time_to_ack = true; |
1da177e4 LT |
1405 | } |
1406 | } | |
1407 | if (time_to_ack) | |
1408 | tcp_send_ack(sk); | |
1409 | } | |
1410 | ||
1411 | static void tcp_prequeue_process(struct sock *sk) | |
1412 | { | |
1413 | struct sk_buff *skb; | |
1414 | struct tcp_sock *tp = tcp_sk(sk); | |
1415 | ||
6f67c817 | 1416 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); |
1da177e4 LT |
1417 | |
1418 | /* RX process wants to run with disabled BHs, though it is not | |
1419 | * necessary */ | |
1420 | local_bh_disable(); | |
1421 | while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) | |
c57943a1 | 1422 | sk_backlog_rcv(sk, skb); |
1da177e4 LT |
1423 | local_bh_enable(); |
1424 | ||
1425 | /* Clear memory counter. */ | |
1426 | tp->ucopy.memory = 0; | |
1427 | } | |
1428 | ||
f26845b4 | 1429 | static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) |
1da177e4 LT |
1430 | { |
1431 | struct sk_buff *skb; | |
1432 | u32 offset; | |
1433 | ||
f26845b4 | 1434 | while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { |
1da177e4 | 1435 | offset = seq - TCP_SKB_CB(skb)->seq; |
e11ecddf | 1436 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) |
1da177e4 | 1437 | offset--; |
e11ecddf | 1438 | if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) { |
1da177e4 LT |
1439 | *off = offset; |
1440 | return skb; | |
1441 | } | |
f26845b4 ED |
1442 | /* This looks weird, but this can happen if TCP collapsing |
1443 | * splitted a fat GRO packet, while we released socket lock | |
1444 | * in skb_splice_bits() | |
1445 | */ | |
7bced397 | 1446 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1447 | } |
1448 | return NULL; | |
1449 | } | |
1450 | ||
1451 | /* | |
1452 | * This routine provides an alternative to tcp_recvmsg() for routines | |
1453 | * that would like to handle copying from skbuffs directly in 'sendfile' | |
1454 | * fashion. | |
1455 | * Note: | |
1456 | * - It is assumed that the socket was locked by the caller. | |
1457 | * - The routine does not block. | |
1458 | * - At present, there is no support for reading OOB data | |
1459 | * or for 'peeking' the socket using this routine | |
1460 | * (although both would be easy to implement). | |
1461 | */ | |
1462 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, | |
1463 | sk_read_actor_t recv_actor) | |
1464 | { | |
1465 | struct sk_buff *skb; | |
1466 | struct tcp_sock *tp = tcp_sk(sk); | |
1467 | u32 seq = tp->copied_seq; | |
1468 | u32 offset; | |
1469 | int copied = 0; | |
1470 | ||
1471 | if (sk->sk_state == TCP_LISTEN) | |
1472 | return -ENOTCONN; | |
1473 | while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { | |
1474 | if (offset < skb->len) { | |
374e7b59 OP |
1475 | int used; |
1476 | size_t len; | |
1da177e4 LT |
1477 | |
1478 | len = skb->len - offset; | |
1479 | /* Stop reading if we hit a patch of urgent data */ | |
1480 | if (tp->urg_data) { | |
1481 | u32 urg_offset = tp->urg_seq - seq; | |
1482 | if (urg_offset < len) | |
1483 | len = urg_offset; | |
1484 | if (!len) | |
1485 | break; | |
1486 | } | |
1487 | used = recv_actor(desc, skb, offset, len); | |
ff905b1e | 1488 | if (used <= 0) { |
ddb61a57 JA |
1489 | if (!copied) |
1490 | copied = used; | |
1491 | break; | |
1492 | } else if (used <= len) { | |
1da177e4 LT |
1493 | seq += used; |
1494 | copied += used; | |
1495 | offset += used; | |
1496 | } | |
02275a2e | 1497 | /* If recv_actor drops the lock (e.g. TCP splice |
293ad604 OP |
1498 | * receive) the skb pointer might be invalid when |
1499 | * getting here: tcp_collapse might have deleted it | |
1500 | * while aggregating skbs from the socket queue. | |
1501 | */ | |
02275a2e WT |
1502 | skb = tcp_recv_skb(sk, seq - 1, &offset); |
1503 | if (!skb) | |
1da177e4 | 1504 | break; |
02275a2e WT |
1505 | /* TCP coalescing might have appended data to the skb. |
1506 | * Try to splice more frags | |
1507 | */ | |
1508 | if (offset + 1 != skb->len) | |
1509 | continue; | |
1da177e4 | 1510 | } |
e11ecddf | 1511 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) { |
7bced397 | 1512 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1513 | ++seq; |
1514 | break; | |
1515 | } | |
7bced397 | 1516 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1517 | if (!desc->count) |
1518 | break; | |
baff42ab | 1519 | tp->copied_seq = seq; |
1da177e4 LT |
1520 | } |
1521 | tp->copied_seq = seq; | |
1522 | ||
1523 | tcp_rcv_space_adjust(sk); | |
1524 | ||
1525 | /* Clean up data we have read: This will do ACK frames. */ | |
f26845b4 ED |
1526 | if (copied > 0) { |
1527 | tcp_recv_skb(sk, seq, &offset); | |
0e4b4992 | 1528 | tcp_cleanup_rbuf(sk, copied); |
f26845b4 | 1529 | } |
1da177e4 LT |
1530 | return copied; |
1531 | } | |
4bc2f18b | 1532 | EXPORT_SYMBOL(tcp_read_sock); |
1da177e4 LT |
1533 | |
1534 | /* | |
1535 | * This routine copies from a sock struct into the user buffer. | |
1536 | * | |
1537 | * Technical note: in 2.3 we work on _locked_ socket, so that | |
1538 | * tricks with *seq access order and skb->users are not required. | |
1539 | * Probably, code can be easily improved even more. | |
1540 | */ | |
1541 | ||
1542 | int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, | |
1543 | size_t len, int nonblock, int flags, int *addr_len) | |
1544 | { | |
1545 | struct tcp_sock *tp = tcp_sk(sk); | |
1546 | int copied = 0; | |
1547 | u32 peek_seq; | |
1548 | u32 *seq; | |
1549 | unsigned long used; | |
1550 | int err; | |
1551 | int target; /* Read at least this many bytes */ | |
1552 | long timeo; | |
1553 | struct task_struct *user_recv = NULL; | |
2b1244a4 | 1554 | struct sk_buff *skb; |
77527313 | 1555 | u32 urg_hole = 0; |
1da177e4 | 1556 | |
4ed2d765 | 1557 | if (unlikely(flags & MSG_ERRQUEUE)) |
f4713a3d | 1558 | return inet_recv_error(sk, msg, len, addr_len); |
4ed2d765 | 1559 | |
cbf55001 ET |
1560 | if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) && |
1561 | (sk->sk_state == TCP_ESTABLISHED)) | |
1562 | sk_busy_loop(sk, nonblock); | |
d30e383b | 1563 | |
1da177e4 LT |
1564 | lock_sock(sk); |
1565 | ||
1da177e4 LT |
1566 | err = -ENOTCONN; |
1567 | if (sk->sk_state == TCP_LISTEN) | |
1568 | goto out; | |
1569 | ||
1570 | timeo = sock_rcvtimeo(sk, nonblock); | |
1571 | ||
1572 | /* Urgent data needs to be handled specially. */ | |
1573 | if (flags & MSG_OOB) | |
1574 | goto recv_urg; | |
1575 | ||
c0e88ff0 PE |
1576 | if (unlikely(tp->repair)) { |
1577 | err = -EPERM; | |
1578 | if (!(flags & MSG_PEEK)) | |
1579 | goto out; | |
1580 | ||
1581 | if (tp->repair_queue == TCP_SEND_QUEUE) | |
1582 | goto recv_sndq; | |
1583 | ||
1584 | err = -EINVAL; | |
1585 | if (tp->repair_queue == TCP_NO_QUEUE) | |
1586 | goto out; | |
1587 | ||
1588 | /* 'common' recv queue MSG_PEEK-ing */ | |
1589 | } | |
1590 | ||
1da177e4 LT |
1591 | seq = &tp->copied_seq; |
1592 | if (flags & MSG_PEEK) { | |
1593 | peek_seq = tp->copied_seq; | |
1594 | seq = &peek_seq; | |
1595 | } | |
1596 | ||
1597 | target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); | |
1598 | ||
1599 | do { | |
1da177e4 LT |
1600 | u32 offset; |
1601 | ||
1602 | /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ | |
1603 | if (tp->urg_data && tp->urg_seq == *seq) { | |
1604 | if (copied) | |
1605 | break; | |
1606 | if (signal_pending(current)) { | |
1607 | copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; | |
1608 | break; | |
1609 | } | |
1610 | } | |
1611 | ||
1612 | /* Next get a buffer. */ | |
1613 | ||
91521944 | 1614 | skb_queue_walk(&sk->sk_receive_queue, skb) { |
1da177e4 LT |
1615 | /* Now that we have two receive queues this |
1616 | * shouldn't happen. | |
1617 | */ | |
d792c100 | 1618 | if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), |
2af6fd8b JP |
1619 | "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n", |
1620 | *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, | |
1621 | flags)) | |
1da177e4 | 1622 | break; |
d792c100 | 1623 | |
1da177e4 | 1624 | offset = *seq - TCP_SKB_CB(skb)->seq; |
e11ecddf | 1625 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) |
1da177e4 LT |
1626 | offset--; |
1627 | if (offset < skb->len) | |
1628 | goto found_ok_skb; | |
e11ecddf | 1629 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) |
1da177e4 | 1630 | goto found_fin_ok; |
2af6fd8b JP |
1631 | WARN(!(flags & MSG_PEEK), |
1632 | "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n", | |
1633 | *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); | |
91521944 | 1634 | } |
1da177e4 LT |
1635 | |
1636 | /* Well, if we have backlog, try to process it now yet. */ | |
1637 | ||
1638 | if (copied >= target && !sk->sk_backlog.tail) | |
1639 | break; | |
1640 | ||
1641 | if (copied) { | |
1642 | if (sk->sk_err || | |
1643 | sk->sk_state == TCP_CLOSE || | |
1644 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1645 | !timeo || | |
518a09ef | 1646 | signal_pending(current)) |
1da177e4 LT |
1647 | break; |
1648 | } else { | |
1649 | if (sock_flag(sk, SOCK_DONE)) | |
1650 | break; | |
1651 | ||
1652 | if (sk->sk_err) { | |
1653 | copied = sock_error(sk); | |
1654 | break; | |
1655 | } | |
1656 | ||
1657 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
1658 | break; | |
1659 | ||
1660 | if (sk->sk_state == TCP_CLOSE) { | |
1661 | if (!sock_flag(sk, SOCK_DONE)) { | |
1662 | /* This occurs when user tries to read | |
1663 | * from never connected socket. | |
1664 | */ | |
1665 | copied = -ENOTCONN; | |
1666 | break; | |
1667 | } | |
1668 | break; | |
1669 | } | |
1670 | ||
1671 | if (!timeo) { | |
1672 | copied = -EAGAIN; | |
1673 | break; | |
1674 | } | |
1675 | ||
1676 | if (signal_pending(current)) { | |
1677 | copied = sock_intr_errno(timeo); | |
1678 | break; | |
1679 | } | |
1680 | } | |
1681 | ||
0e4b4992 | 1682 | tcp_cleanup_rbuf(sk, copied); |
1da177e4 | 1683 | |
7df55125 | 1684 | if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { |
1da177e4 LT |
1685 | /* Install new reader */ |
1686 | if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { | |
1687 | user_recv = current; | |
1688 | tp->ucopy.task = user_recv; | |
f4362a2c | 1689 | tp->ucopy.msg = msg; |
1da177e4 LT |
1690 | } |
1691 | ||
1692 | tp->ucopy.len = len; | |
1693 | ||
547b792c IJ |
1694 | WARN_ON(tp->copied_seq != tp->rcv_nxt && |
1695 | !(flags & (MSG_PEEK | MSG_TRUNC))); | |
1da177e4 LT |
1696 | |
1697 | /* Ugly... If prequeue is not empty, we have to | |
1698 | * process it before releasing socket, otherwise | |
1699 | * order will be broken at second iteration. | |
1700 | * More elegant solution is required!!! | |
1701 | * | |
1702 | * Look: we have the following (pseudo)queues: | |
1703 | * | |
1704 | * 1. packets in flight | |
1705 | * 2. backlog | |
1706 | * 3. prequeue | |
1707 | * 4. receive_queue | |
1708 | * | |
1709 | * Each queue can be processed only if the next ones | |
1710 | * are empty. At this point we have empty receive_queue. | |
1711 | * But prequeue _can_ be not empty after 2nd iteration, | |
1712 | * when we jumped to start of loop because backlog | |
1713 | * processing added something to receive_queue. | |
1714 | * We cannot release_sock(), because backlog contains | |
1715 | * packets arrived _after_ prequeued ones. | |
1716 | * | |
1717 | * Shortly, algorithm is clear --- to process all | |
1718 | * the queues in order. We could make it more directly, | |
1719 | * requeueing packets from backlog to prequeue, if | |
1720 | * is not empty. It is more elegant, but eats cycles, | |
1721 | * unfortunately. | |
1722 | */ | |
b03efcfb | 1723 | if (!skb_queue_empty(&tp->ucopy.prequeue)) |
1da177e4 LT |
1724 | goto do_prequeue; |
1725 | ||
1726 | /* __ Set realtime policy in scheduler __ */ | |
1727 | } | |
1728 | ||
1729 | if (copied >= target) { | |
1730 | /* Do not sleep, just process backlog. */ | |
1731 | release_sock(sk); | |
1732 | lock_sock(sk); | |
1733 | } else | |
1734 | sk_wait_data(sk, &timeo); | |
1735 | ||
1736 | if (user_recv) { | |
1737 | int chunk; | |
1738 | ||
1739 | /* __ Restore normal policy in scheduler __ */ | |
1740 | ||
1741 | if ((chunk = len - tp->ucopy.len) != 0) { | |
ed88098e | 1742 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); |
1da177e4 LT |
1743 | len -= chunk; |
1744 | copied += chunk; | |
1745 | } | |
1746 | ||
1747 | if (tp->rcv_nxt == tp->copied_seq && | |
b03efcfb | 1748 | !skb_queue_empty(&tp->ucopy.prequeue)) { |
1da177e4 LT |
1749 | do_prequeue: |
1750 | tcp_prequeue_process(sk); | |
1751 | ||
1752 | if ((chunk = len - tp->ucopy.len) != 0) { | |
ed88098e | 1753 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); |
1da177e4 LT |
1754 | len -= chunk; |
1755 | copied += chunk; | |
1756 | } | |
1757 | } | |
1758 | } | |
77527313 IJ |
1759 | if ((flags & MSG_PEEK) && |
1760 | (peek_seq - copied - urg_hole != tp->copied_seq)) { | |
e87cc472 JP |
1761 | net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", |
1762 | current->comm, | |
1763 | task_pid_nr(current)); | |
1da177e4 LT |
1764 | peek_seq = tp->copied_seq; |
1765 | } | |
1766 | continue; | |
1767 | ||
1768 | found_ok_skb: | |
1769 | /* Ok so how much can we use? */ | |
1770 | used = skb->len - offset; | |
1771 | if (len < used) | |
1772 | used = len; | |
1773 | ||
1774 | /* Do we have urgent data here? */ | |
1775 | if (tp->urg_data) { | |
1776 | u32 urg_offset = tp->urg_seq - *seq; | |
1777 | if (urg_offset < used) { | |
1778 | if (!urg_offset) { | |
1779 | if (!sock_flag(sk, SOCK_URGINLINE)) { | |
1780 | ++*seq; | |
77527313 | 1781 | urg_hole++; |
1da177e4 LT |
1782 | offset++; |
1783 | used--; | |
1784 | if (!used) | |
1785 | goto skip_copy; | |
1786 | } | |
1787 | } else | |
1788 | used = urg_offset; | |
1789 | } | |
1790 | } | |
1791 | ||
1792 | if (!(flags & MSG_TRUNC)) { | |
51f3d02b | 1793 | err = skb_copy_datagram_msg(skb, offset, msg, used); |
7bced397 DW |
1794 | if (err) { |
1795 | /* Exception. Bailout! */ | |
1796 | if (!copied) | |
1797 | copied = -EFAULT; | |
1798 | break; | |
1da177e4 LT |
1799 | } |
1800 | } | |
1801 | ||
1802 | *seq += used; | |
1803 | copied += used; | |
1804 | len -= used; | |
1805 | ||
1806 | tcp_rcv_space_adjust(sk); | |
1807 | ||
1808 | skip_copy: | |
1809 | if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { | |
1810 | tp->urg_data = 0; | |
9e412ba7 | 1811 | tcp_fast_path_check(sk); |
1da177e4 LT |
1812 | } |
1813 | if (used + offset < skb->len) | |
1814 | continue; | |
1815 | ||
e11ecddf | 1816 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) |
1da177e4 | 1817 | goto found_fin_ok; |
7bced397 DW |
1818 | if (!(flags & MSG_PEEK)) |
1819 | sk_eat_skb(sk, skb); | |
1da177e4 LT |
1820 | continue; |
1821 | ||
1822 | found_fin_ok: | |
1823 | /* Process the FIN. */ | |
1824 | ++*seq; | |
7bced397 DW |
1825 | if (!(flags & MSG_PEEK)) |
1826 | sk_eat_skb(sk, skb); | |
1da177e4 LT |
1827 | break; |
1828 | } while (len > 0); | |
1829 | ||
1830 | if (user_recv) { | |
b03efcfb | 1831 | if (!skb_queue_empty(&tp->ucopy.prequeue)) { |
1da177e4 LT |
1832 | int chunk; |
1833 | ||
1834 | tp->ucopy.len = copied > 0 ? len : 0; | |
1835 | ||
1836 | tcp_prequeue_process(sk); | |
1837 | ||
1838 | if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { | |
ed88098e | 1839 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); |
1da177e4 LT |
1840 | len -= chunk; |
1841 | copied += chunk; | |
1842 | } | |
1843 | } | |
1844 | ||
1845 | tp->ucopy.task = NULL; | |
1846 | tp->ucopy.len = 0; | |
1847 | } | |
1848 | ||
1849 | /* According to UNIX98, msg_name/msg_namelen are ignored | |
1850 | * on connected socket. I was just happy when found this 8) --ANK | |
1851 | */ | |
1852 | ||
1853 | /* Clean up data we have read: This will do ACK frames. */ | |
0e4b4992 | 1854 | tcp_cleanup_rbuf(sk, copied); |
1da177e4 | 1855 | |
1da177e4 LT |
1856 | release_sock(sk); |
1857 | return copied; | |
1858 | ||
1859 | out: | |
1da177e4 LT |
1860 | release_sock(sk); |
1861 | return err; | |
1862 | ||
1863 | recv_urg: | |
377f0a08 | 1864 | err = tcp_recv_urg(sk, msg, len, flags); |
1da177e4 | 1865 | goto out; |
c0e88ff0 PE |
1866 | |
1867 | recv_sndq: | |
1868 | err = tcp_peek_sndq(sk, msg, len); | |
1869 | goto out; | |
1da177e4 | 1870 | } |
4bc2f18b | 1871 | EXPORT_SYMBOL(tcp_recvmsg); |
1da177e4 | 1872 | |
490d5046 IJ |
1873 | void tcp_set_state(struct sock *sk, int state) |
1874 | { | |
1875 | int oldstate = sk->sk_state; | |
1876 | ||
1877 | switch (state) { | |
1878 | case TCP_ESTABLISHED: | |
1879 | if (oldstate != TCP_ESTABLISHED) | |
81cc8a75 | 1880 | TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); |
490d5046 IJ |
1881 | break; |
1882 | ||
1883 | case TCP_CLOSE: | |
1884 | if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) | |
81cc8a75 | 1885 | TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); |
490d5046 IJ |
1886 | |
1887 | sk->sk_prot->unhash(sk); | |
1888 | if (inet_csk(sk)->icsk_bind_hash && | |
1889 | !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) | |
ab1e0a13 | 1890 | inet_put_port(sk); |
490d5046 IJ |
1891 | /* fall through */ |
1892 | default: | |
5a5f3a8d | 1893 | if (oldstate == TCP_ESTABLISHED) |
74688e48 | 1894 | TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); |
490d5046 IJ |
1895 | } |
1896 | ||
1897 | /* Change state AFTER socket is unhashed to avoid closed | |
1898 | * socket sitting in hash tables. | |
1899 | */ | |
1900 | sk->sk_state = state; | |
1901 | ||
1902 | #ifdef STATE_TRACE | |
5a5f3a8d | 1903 | SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); |
490d5046 IJ |
1904 | #endif |
1905 | } | |
1906 | EXPORT_SYMBOL_GPL(tcp_set_state); | |
1907 | ||
1da177e4 LT |
1908 | /* |
1909 | * State processing on a close. This implements the state shift for | |
1910 | * sending our FIN frame. Note that we only send a FIN for some | |
1911 | * states. A shutdown() may have already sent the FIN, or we may be | |
1912 | * closed. | |
1913 | */ | |
1914 | ||
9b5b5cff | 1915 | static const unsigned char new_state[16] = { |
1da177e4 LT |
1916 | /* current state: new state: action: */ |
1917 | /* (Invalid) */ TCP_CLOSE, | |
1918 | /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1919 | /* TCP_SYN_SENT */ TCP_CLOSE, | |
1920 | /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1921 | /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, | |
1922 | /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, | |
1923 | /* TCP_TIME_WAIT */ TCP_CLOSE, | |
1924 | /* TCP_CLOSE */ TCP_CLOSE, | |
1925 | /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, | |
1926 | /* TCP_LAST_ACK */ TCP_LAST_ACK, | |
1927 | /* TCP_LISTEN */ TCP_CLOSE, | |
1928 | /* TCP_CLOSING */ TCP_CLOSING, | |
1929 | }; | |
1930 | ||
1931 | static int tcp_close_state(struct sock *sk) | |
1932 | { | |
1933 | int next = (int)new_state[sk->sk_state]; | |
1934 | int ns = next & TCP_STATE_MASK; | |
1935 | ||
1936 | tcp_set_state(sk, ns); | |
1937 | ||
1938 | return next & TCP_ACTION_FIN; | |
1939 | } | |
1940 | ||
1941 | /* | |
1942 | * Shutdown the sending side of a connection. Much like close except | |
1f29b058 | 1943 | * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). |
1da177e4 LT |
1944 | */ |
1945 | ||
1946 | void tcp_shutdown(struct sock *sk, int how) | |
1947 | { | |
1948 | /* We need to grab some memory, and put together a FIN, | |
1949 | * and then put it into the queue to be sent. | |
1950 | * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. | |
1951 | */ | |
1952 | if (!(how & SEND_SHUTDOWN)) | |
1953 | return; | |
1954 | ||
1955 | /* If we've already sent a FIN, or it's a closed state, skip this. */ | |
1956 | if ((1 << sk->sk_state) & | |
1957 | (TCPF_ESTABLISHED | TCPF_SYN_SENT | | |
1958 | TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { | |
1959 | /* Clear out any half completed packets. FIN if needed. */ | |
1960 | if (tcp_close_state(sk)) | |
1961 | tcp_send_fin(sk); | |
1962 | } | |
1963 | } | |
4bc2f18b | 1964 | EXPORT_SYMBOL(tcp_shutdown); |
1da177e4 | 1965 | |
efcdbf24 AS |
1966 | bool tcp_check_oom(struct sock *sk, int shift) |
1967 | { | |
1968 | bool too_many_orphans, out_of_socket_memory; | |
1969 | ||
1970 | too_many_orphans = tcp_too_many_orphans(sk, shift); | |
1971 | out_of_socket_memory = tcp_out_of_memory(sk); | |
1972 | ||
e87cc472 JP |
1973 | if (too_many_orphans) |
1974 | net_info_ratelimited("too many orphaned sockets\n"); | |
1975 | if (out_of_socket_memory) | |
1976 | net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); | |
efcdbf24 AS |
1977 | return too_many_orphans || out_of_socket_memory; |
1978 | } | |
1979 | ||
1da177e4 LT |
1980 | void tcp_close(struct sock *sk, long timeout) |
1981 | { | |
1982 | struct sk_buff *skb; | |
1983 | int data_was_unread = 0; | |
75c2d907 | 1984 | int state; |
1da177e4 LT |
1985 | |
1986 | lock_sock(sk); | |
1987 | sk->sk_shutdown = SHUTDOWN_MASK; | |
1988 | ||
1989 | if (sk->sk_state == TCP_LISTEN) { | |
1990 | tcp_set_state(sk, TCP_CLOSE); | |
1991 | ||
1992 | /* Special case. */ | |
0a5578cf | 1993 | inet_csk_listen_stop(sk); |
1da177e4 LT |
1994 | |
1995 | goto adjudge_to_death; | |
1996 | } | |
1997 | ||
1998 | /* We need to flush the recv. buffs. We do this only on the | |
1999 | * descriptor close, not protocol-sourced closes, because the | |
2000 | * reader process may not have drained the data yet! | |
2001 | */ | |
2002 | while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e11ecddf ED |
2003 | u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; |
2004 | ||
2005 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) | |
2006 | len--; | |
1da177e4 LT |
2007 | data_was_unread += len; |
2008 | __kfree_skb(skb); | |
2009 | } | |
2010 | ||
3ab224be | 2011 | sk_mem_reclaim(sk); |
1da177e4 | 2012 | |
565b7b2d KK |
2013 | /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ |
2014 | if (sk->sk_state == TCP_CLOSE) | |
2015 | goto adjudge_to_death; | |
2016 | ||
65bb723c GR |
2017 | /* As outlined in RFC 2525, section 2.17, we send a RST here because |
2018 | * data was lost. To witness the awful effects of the old behavior of | |
2019 | * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk | |
2020 | * GET in an FTP client, suspend the process, wait for the client to | |
2021 | * advertise a zero window, then kill -9 the FTP client, wheee... | |
2022 | * Note: timeout is always zero in such a case. | |
1da177e4 | 2023 | */ |
ee995283 PE |
2024 | if (unlikely(tcp_sk(sk)->repair)) { |
2025 | sk->sk_prot->disconnect(sk, 0); | |
2026 | } else if (data_was_unread) { | |
1da177e4 | 2027 | /* Unread data was tossed, zap the connection. */ |
6f67c817 | 2028 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); |
1da177e4 | 2029 | tcp_set_state(sk, TCP_CLOSE); |
aa133076 | 2030 | tcp_send_active_reset(sk, sk->sk_allocation); |
1da177e4 LT |
2031 | } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { |
2032 | /* Check zero linger _after_ checking for unread data. */ | |
2033 | sk->sk_prot->disconnect(sk, 0); | |
6f67c817 | 2034 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); |
1da177e4 LT |
2035 | } else if (tcp_close_state(sk)) { |
2036 | /* We FIN if the application ate all the data before | |
2037 | * zapping the connection. | |
2038 | */ | |
2039 | ||
2040 | /* RED-PEN. Formally speaking, we have broken TCP state | |
2041 | * machine. State transitions: | |
2042 | * | |
2043 | * TCP_ESTABLISHED -> TCP_FIN_WAIT1 | |
2044 | * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) | |
2045 | * TCP_CLOSE_WAIT -> TCP_LAST_ACK | |
2046 | * | |
2047 | * are legal only when FIN has been sent (i.e. in window), | |
2048 | * rather than queued out of window. Purists blame. | |
2049 | * | |
2050 | * F.e. "RFC state" is ESTABLISHED, | |
2051 | * if Linux state is FIN-WAIT-1, but FIN is still not sent. | |
2052 | * | |
2053 | * The visible declinations are that sometimes | |
2054 | * we enter time-wait state, when it is not required really | |
2055 | * (harmless), do not send active resets, when they are | |
2056 | * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when | |
2057 | * they look as CLOSING or LAST_ACK for Linux) | |
2058 | * Probably, I missed some more holelets. | |
2059 | * --ANK | |
8336886f JC |
2060 | * XXX (TFO) - To start off we don't support SYN+ACK+FIN |
2061 | * in a single packet! (May consider it later but will | |
2062 | * probably need API support or TCP_CORK SYN-ACK until | |
2063 | * data is written and socket is closed.) | |
1da177e4 LT |
2064 | */ |
2065 | tcp_send_fin(sk); | |
2066 | } | |
2067 | ||
2068 | sk_stream_wait_close(sk, timeout); | |
2069 | ||
2070 | adjudge_to_death: | |
75c2d907 HX |
2071 | state = sk->sk_state; |
2072 | sock_hold(sk); | |
2073 | sock_orphan(sk); | |
75c2d907 | 2074 | |
1da177e4 LT |
2075 | /* It is the last release_sock in its life. It will remove backlog. */ |
2076 | release_sock(sk); | |
2077 | ||
2078 | ||
2079 | /* Now socket is owned by kernel and we acquire BH lock | |
2080 | to finish close. No need to check for user refs. | |
2081 | */ | |
2082 | local_bh_disable(); | |
2083 | bh_lock_sock(sk); | |
547b792c | 2084 | WARN_ON(sock_owned_by_user(sk)); |
1da177e4 | 2085 | |
eb4dea58 HX |
2086 | percpu_counter_inc(sk->sk_prot->orphan_count); |
2087 | ||
75c2d907 HX |
2088 | /* Have we already been destroyed by a softirq or backlog? */ |
2089 | if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) | |
2090 | goto out; | |
1da177e4 LT |
2091 | |
2092 | /* This is a (useful) BSD violating of the RFC. There is a | |
2093 | * problem with TCP as specified in that the other end could | |
2094 | * keep a socket open forever with no application left this end. | |
b10bd54c | 2095 | * We use a 1 minute timeout (about the same as BSD) then kill |
1da177e4 LT |
2096 | * our end. If they send after that then tough - BUT: long enough |
2097 | * that we won't make the old 4*rto = almost no time - whoops | |
2098 | * reset mistake. | |
2099 | * | |
2100 | * Nope, it was not mistake. It is really desired behaviour | |
2101 | * f.e. on http servers, when such sockets are useless, but | |
2102 | * consume significant resources. Let's do it with special | |
2103 | * linger2 option. --ANK | |
2104 | */ | |
2105 | ||
2106 | if (sk->sk_state == TCP_FIN_WAIT2) { | |
2107 | struct tcp_sock *tp = tcp_sk(sk); | |
2108 | if (tp->linger2 < 0) { | |
2109 | tcp_set_state(sk, TCP_CLOSE); | |
2110 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
de0744af PE |
2111 | NET_INC_STATS_BH(sock_net(sk), |
2112 | LINUX_MIB_TCPABORTONLINGER); | |
1da177e4 | 2113 | } else { |
463c84b9 | 2114 | const int tmo = tcp_fin_time(sk); |
1da177e4 LT |
2115 | |
2116 | if (tmo > TCP_TIMEWAIT_LEN) { | |
52499afe DM |
2117 | inet_csk_reset_keepalive_timer(sk, |
2118 | tmo - TCP_TIMEWAIT_LEN); | |
1da177e4 | 2119 | } else { |
1da177e4 LT |
2120 | tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); |
2121 | goto out; | |
2122 | } | |
2123 | } | |
2124 | } | |
2125 | if (sk->sk_state != TCP_CLOSE) { | |
3ab224be | 2126 | sk_mem_reclaim(sk); |
efcdbf24 | 2127 | if (tcp_check_oom(sk, 0)) { |
1da177e4 LT |
2128 | tcp_set_state(sk, TCP_CLOSE); |
2129 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
de0744af PE |
2130 | NET_INC_STATS_BH(sock_net(sk), |
2131 | LINUX_MIB_TCPABORTONMEMORY); | |
1da177e4 LT |
2132 | } |
2133 | } | |
1da177e4 | 2134 | |
8336886f JC |
2135 | if (sk->sk_state == TCP_CLOSE) { |
2136 | struct request_sock *req = tcp_sk(sk)->fastopen_rsk; | |
2137 | /* We could get here with a non-NULL req if the socket is | |
2138 | * aborted (e.g., closed with unread data) before 3WHS | |
2139 | * finishes. | |
2140 | */ | |
2141 | if (req != NULL) | |
2142 | reqsk_fastopen_remove(sk, req, false); | |
0a5578cf | 2143 | inet_csk_destroy_sock(sk); |
8336886f | 2144 | } |
1da177e4 LT |
2145 | /* Otherwise, socket is reprieved until protocol close. */ |
2146 | ||
2147 | out: | |
2148 | bh_unlock_sock(sk); | |
2149 | local_bh_enable(); | |
2150 | sock_put(sk); | |
2151 | } | |
4bc2f18b | 2152 | EXPORT_SYMBOL(tcp_close); |
1da177e4 LT |
2153 | |
2154 | /* These states need RST on ABORT according to RFC793 */ | |
2155 | ||
a2a385d6 | 2156 | static inline bool tcp_need_reset(int state) |
1da177e4 LT |
2157 | { |
2158 | return (1 << state) & | |
2159 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | | |
2160 | TCPF_FIN_WAIT2 | TCPF_SYN_RECV); | |
2161 | } | |
2162 | ||
2163 | int tcp_disconnect(struct sock *sk, int flags) | |
2164 | { | |
2165 | struct inet_sock *inet = inet_sk(sk); | |
463c84b9 | 2166 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2167 | struct tcp_sock *tp = tcp_sk(sk); |
2168 | int err = 0; | |
2169 | int old_state = sk->sk_state; | |
2170 | ||
2171 | if (old_state != TCP_CLOSE) | |
2172 | tcp_set_state(sk, TCP_CLOSE); | |
2173 | ||
2174 | /* ABORT function of RFC793 */ | |
2175 | if (old_state == TCP_LISTEN) { | |
0a5578cf | 2176 | inet_csk_listen_stop(sk); |
ee995283 PE |
2177 | } else if (unlikely(tp->repair)) { |
2178 | sk->sk_err = ECONNABORTED; | |
1da177e4 LT |
2179 | } else if (tcp_need_reset(old_state) || |
2180 | (tp->snd_nxt != tp->write_seq && | |
2181 | (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { | |
caa20d9a | 2182 | /* The last check adjusts for discrepancy of Linux wrt. RFC |
1da177e4 LT |
2183 | * states |
2184 | */ | |
2185 | tcp_send_active_reset(sk, gfp_any()); | |
2186 | sk->sk_err = ECONNRESET; | |
2187 | } else if (old_state == TCP_SYN_SENT) | |
2188 | sk->sk_err = ECONNRESET; | |
2189 | ||
2190 | tcp_clear_xmit_timers(sk); | |
2191 | __skb_queue_purge(&sk->sk_receive_queue); | |
fe067e8a | 2192 | tcp_write_queue_purge(sk); |
1da177e4 LT |
2193 | __skb_queue_purge(&tp->out_of_order_queue); |
2194 | ||
c720c7e8 | 2195 | inet->inet_dport = 0; |
1da177e4 LT |
2196 | |
2197 | if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) | |
2198 | inet_reset_saddr(sk); | |
2199 | ||
2200 | sk->sk_shutdown = 0; | |
2201 | sock_reset_flag(sk, SOCK_DONE); | |
740b0f18 | 2202 | tp->srtt_us = 0; |
1da177e4 LT |
2203 | if ((tp->write_seq += tp->max_window + 2) == 0) |
2204 | tp->write_seq = 1; | |
463c84b9 | 2205 | icsk->icsk_backoff = 0; |
1da177e4 | 2206 | tp->snd_cwnd = 2; |
6687e988 | 2207 | icsk->icsk_probes_out = 0; |
1da177e4 | 2208 | tp->packets_out = 0; |
0b6a05c1 | 2209 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
1da177e4 | 2210 | tp->snd_cwnd_cnt = 0; |
1fdf475a | 2211 | tp->window_clamp = 0; |
6687e988 | 2212 | tcp_set_ca_state(sk, TCP_CA_Open); |
1da177e4 | 2213 | tcp_clear_retrans(tp); |
463c84b9 | 2214 | inet_csk_delack_init(sk); |
fe067e8a | 2215 | tcp_init_send_head(sk); |
b40b4f79 | 2216 | memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); |
1da177e4 LT |
2217 | __sk_dst_reset(sk); |
2218 | ||
c720c7e8 | 2219 | WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); |
1da177e4 LT |
2220 | |
2221 | sk->sk_error_report(sk); | |
2222 | return err; | |
2223 | } | |
4bc2f18b | 2224 | EXPORT_SYMBOL(tcp_disconnect); |
1da177e4 | 2225 | |
bb68b647 CP |
2226 | void tcp_sock_destruct(struct sock *sk) |
2227 | { | |
2228 | inet_sock_destruct(sk); | |
2229 | ||
2230 | kfree(inet_csk(sk)->icsk_accept_queue.fastopenq); | |
2231 | } | |
2232 | ||
a2a385d6 | 2233 | static inline bool tcp_can_repair_sock(const struct sock *sk) |
ee995283 | 2234 | { |
52e804c6 | 2235 | return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && |
ee995283 PE |
2236 | ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED)); |
2237 | } | |
2238 | ||
de248a75 PE |
2239 | static int tcp_repair_options_est(struct tcp_sock *tp, |
2240 | struct tcp_repair_opt __user *optbuf, unsigned int len) | |
b139ba4e | 2241 | { |
de248a75 | 2242 | struct tcp_repair_opt opt; |
b139ba4e | 2243 | |
de248a75 PE |
2244 | while (len >= sizeof(opt)) { |
2245 | if (copy_from_user(&opt, optbuf, sizeof(opt))) | |
b139ba4e PE |
2246 | return -EFAULT; |
2247 | ||
2248 | optbuf++; | |
de248a75 | 2249 | len -= sizeof(opt); |
b139ba4e | 2250 | |
de248a75 PE |
2251 | switch (opt.opt_code) { |
2252 | case TCPOPT_MSS: | |
2253 | tp->rx_opt.mss_clamp = opt.opt_val; | |
b139ba4e | 2254 | break; |
de248a75 | 2255 | case TCPOPT_WINDOW: |
bc26ccd8 AV |
2256 | { |
2257 | u16 snd_wscale = opt.opt_val & 0xFFFF; | |
2258 | u16 rcv_wscale = opt.opt_val >> 16; | |
2259 | ||
2260 | if (snd_wscale > 14 || rcv_wscale > 14) | |
2261 | return -EFBIG; | |
b139ba4e | 2262 | |
bc26ccd8 AV |
2263 | tp->rx_opt.snd_wscale = snd_wscale; |
2264 | tp->rx_opt.rcv_wscale = rcv_wscale; | |
2265 | tp->rx_opt.wscale_ok = 1; | |
2266 | } | |
b139ba4e | 2267 | break; |
b139ba4e | 2268 | case TCPOPT_SACK_PERM: |
de248a75 PE |
2269 | if (opt.opt_val != 0) |
2270 | return -EINVAL; | |
2271 | ||
b139ba4e PE |
2272 | tp->rx_opt.sack_ok |= TCP_SACK_SEEN; |
2273 | if (sysctl_tcp_fack) | |
2274 | tcp_enable_fack(tp); | |
2275 | break; | |
2276 | case TCPOPT_TIMESTAMP: | |
de248a75 PE |
2277 | if (opt.opt_val != 0) |
2278 | return -EINVAL; | |
2279 | ||
b139ba4e PE |
2280 | tp->rx_opt.tstamp_ok = 1; |
2281 | break; | |
2282 | } | |
2283 | } | |
2284 | ||
2285 | return 0; | |
2286 | } | |
2287 | ||
1da177e4 LT |
2288 | /* |
2289 | * Socket option code for TCP. | |
2290 | */ | |
3fdadf7d | 2291 | static int do_tcp_setsockopt(struct sock *sk, int level, |
b7058842 | 2292 | int optname, char __user *optval, unsigned int optlen) |
1da177e4 LT |
2293 | { |
2294 | struct tcp_sock *tp = tcp_sk(sk); | |
463c84b9 | 2295 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2296 | int val; |
2297 | int err = 0; | |
2298 | ||
e56fb50f WAS |
2299 | /* These are data/string values, all the others are ints */ |
2300 | switch (optname) { | |
2301 | case TCP_CONGESTION: { | |
5f8ef48d SH |
2302 | char name[TCP_CA_NAME_MAX]; |
2303 | ||
2304 | if (optlen < 1) | |
2305 | return -EINVAL; | |
2306 | ||
2307 | val = strncpy_from_user(name, optval, | |
4fdb78d3 | 2308 | min_t(long, TCP_CA_NAME_MAX-1, optlen)); |
5f8ef48d SH |
2309 | if (val < 0) |
2310 | return -EFAULT; | |
2311 | name[val] = 0; | |
2312 | ||
2313 | lock_sock(sk); | |
6687e988 | 2314 | err = tcp_set_congestion_control(sk, name); |
5f8ef48d SH |
2315 | release_sock(sk); |
2316 | return err; | |
2317 | } | |
e56fb50f WAS |
2318 | default: |
2319 | /* fallthru */ | |
2320 | break; | |
ccbd6a5a | 2321 | } |
5f8ef48d | 2322 | |
1da177e4 LT |
2323 | if (optlen < sizeof(int)) |
2324 | return -EINVAL; | |
2325 | ||
2326 | if (get_user(val, (int __user *)optval)) | |
2327 | return -EFAULT; | |
2328 | ||
2329 | lock_sock(sk); | |
2330 | ||
2331 | switch (optname) { | |
2332 | case TCP_MAXSEG: | |
2333 | /* Values greater than interface MTU won't take effect. However | |
2334 | * at the point when this call is done we typically don't yet | |
2335 | * know which interface is going to be used */ | |
c39508d6 | 2336 | if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) { |
1da177e4 LT |
2337 | err = -EINVAL; |
2338 | break; | |
2339 | } | |
2340 | tp->rx_opt.user_mss = val; | |
2341 | break; | |
2342 | ||
2343 | case TCP_NODELAY: | |
2344 | if (val) { | |
2345 | /* TCP_NODELAY is weaker than TCP_CORK, so that | |
2346 | * this option on corked socket is remembered, but | |
2347 | * it is not activated until cork is cleared. | |
2348 | * | |
2349 | * However, when TCP_NODELAY is set we make | |
2350 | * an explicit push, which overrides even TCP_CORK | |
2351 | * for currently queued segments. | |
2352 | */ | |
2353 | tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; | |
9e412ba7 | 2354 | tcp_push_pending_frames(sk); |
1da177e4 LT |
2355 | } else { |
2356 | tp->nonagle &= ~TCP_NAGLE_OFF; | |
2357 | } | |
2358 | break; | |
2359 | ||
36e31b0a AP |
2360 | case TCP_THIN_LINEAR_TIMEOUTS: |
2361 | if (val < 0 || val > 1) | |
2362 | err = -EINVAL; | |
2363 | else | |
2364 | tp->thin_lto = val; | |
2365 | break; | |
2366 | ||
7e380175 AP |
2367 | case TCP_THIN_DUPACK: |
2368 | if (val < 0 || val > 1) | |
2369 | err = -EINVAL; | |
e2e5c4c0 | 2370 | else { |
7e380175 | 2371 | tp->thin_dupack = val; |
eed530b6 YC |
2372 | if (tp->thin_dupack) |
2373 | tcp_disable_early_retrans(tp); | |
e2e5c4c0 | 2374 | } |
7e380175 AP |
2375 | break; |
2376 | ||
ee995283 PE |
2377 | case TCP_REPAIR: |
2378 | if (!tcp_can_repair_sock(sk)) | |
2379 | err = -EPERM; | |
2380 | else if (val == 1) { | |
2381 | tp->repair = 1; | |
2382 | sk->sk_reuse = SK_FORCE_REUSE; | |
2383 | tp->repair_queue = TCP_NO_QUEUE; | |
2384 | } else if (val == 0) { | |
2385 | tp->repair = 0; | |
2386 | sk->sk_reuse = SK_NO_REUSE; | |
2387 | tcp_send_window_probe(sk); | |
2388 | } else | |
2389 | err = -EINVAL; | |
2390 | ||
2391 | break; | |
2392 | ||
2393 | case TCP_REPAIR_QUEUE: | |
2394 | if (!tp->repair) | |
2395 | err = -EPERM; | |
2396 | else if (val < TCP_QUEUES_NR) | |
2397 | tp->repair_queue = val; | |
2398 | else | |
2399 | err = -EINVAL; | |
2400 | break; | |
2401 | ||
2402 | case TCP_QUEUE_SEQ: | |
2403 | if (sk->sk_state != TCP_CLOSE) | |
2404 | err = -EPERM; | |
2405 | else if (tp->repair_queue == TCP_SEND_QUEUE) | |
2406 | tp->write_seq = val; | |
2407 | else if (tp->repair_queue == TCP_RECV_QUEUE) | |
2408 | tp->rcv_nxt = val; | |
2409 | else | |
2410 | err = -EINVAL; | |
2411 | break; | |
2412 | ||
b139ba4e PE |
2413 | case TCP_REPAIR_OPTIONS: |
2414 | if (!tp->repair) | |
2415 | err = -EINVAL; | |
2416 | else if (sk->sk_state == TCP_ESTABLISHED) | |
de248a75 PE |
2417 | err = tcp_repair_options_est(tp, |
2418 | (struct tcp_repair_opt __user *)optval, | |
2419 | optlen); | |
b139ba4e PE |
2420 | else |
2421 | err = -EPERM; | |
2422 | break; | |
2423 | ||
1da177e4 LT |
2424 | case TCP_CORK: |
2425 | /* When set indicates to always queue non-full frames. | |
2426 | * Later the user clears this option and we transmit | |
2427 | * any pending partial frames in the queue. This is | |
2428 | * meant to be used alongside sendfile() to get properly | |
2429 | * filled frames when the user (for example) must write | |
2430 | * out headers with a write() call first and then use | |
2431 | * sendfile to send out the data parts. | |
2432 | * | |
2433 | * TCP_CORK can be set together with TCP_NODELAY and it is | |
2434 | * stronger than TCP_NODELAY. | |
2435 | */ | |
2436 | if (val) { | |
2437 | tp->nonagle |= TCP_NAGLE_CORK; | |
2438 | } else { | |
2439 | tp->nonagle &= ~TCP_NAGLE_CORK; | |
2440 | if (tp->nonagle&TCP_NAGLE_OFF) | |
2441 | tp->nonagle |= TCP_NAGLE_PUSH; | |
9e412ba7 | 2442 | tcp_push_pending_frames(sk); |
1da177e4 LT |
2443 | } |
2444 | break; | |
2445 | ||
2446 | case TCP_KEEPIDLE: | |
2447 | if (val < 1 || val > MAX_TCP_KEEPIDLE) | |
2448 | err = -EINVAL; | |
2449 | else { | |
2450 | tp->keepalive_time = val * HZ; | |
2451 | if (sock_flag(sk, SOCK_KEEPOPEN) && | |
2452 | !((1 << sk->sk_state) & | |
2453 | (TCPF_CLOSE | TCPF_LISTEN))) { | |
6c37e5de | 2454 | u32 elapsed = keepalive_time_elapsed(tp); |
1da177e4 LT |
2455 | if (tp->keepalive_time > elapsed) |
2456 | elapsed = tp->keepalive_time - elapsed; | |
2457 | else | |
2458 | elapsed = 0; | |
463c84b9 | 2459 | inet_csk_reset_keepalive_timer(sk, elapsed); |
1da177e4 LT |
2460 | } |
2461 | } | |
2462 | break; | |
2463 | case TCP_KEEPINTVL: | |
2464 | if (val < 1 || val > MAX_TCP_KEEPINTVL) | |
2465 | err = -EINVAL; | |
2466 | else | |
2467 | tp->keepalive_intvl = val * HZ; | |
2468 | break; | |
2469 | case TCP_KEEPCNT: | |
2470 | if (val < 1 || val > MAX_TCP_KEEPCNT) | |
2471 | err = -EINVAL; | |
2472 | else | |
2473 | tp->keepalive_probes = val; | |
2474 | break; | |
2475 | case TCP_SYNCNT: | |
2476 | if (val < 1 || val > MAX_TCP_SYNCNT) | |
2477 | err = -EINVAL; | |
2478 | else | |
463c84b9 | 2479 | icsk->icsk_syn_retries = val; |
1da177e4 LT |
2480 | break; |
2481 | ||
2482 | case TCP_LINGER2: | |
2483 | if (val < 0) | |
2484 | tp->linger2 = -1; | |
2485 | else if (val > sysctl_tcp_fin_timeout / HZ) | |
2486 | tp->linger2 = 0; | |
2487 | else | |
2488 | tp->linger2 = val * HZ; | |
2489 | break; | |
2490 | ||
2491 | case TCP_DEFER_ACCEPT: | |
b103cf34 JA |
2492 | /* Translate value in seconds to number of retransmits */ |
2493 | icsk->icsk_accept_queue.rskq_defer_accept = | |
2494 | secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, | |
2495 | TCP_RTO_MAX / HZ); | |
1da177e4 LT |
2496 | break; |
2497 | ||
2498 | case TCP_WINDOW_CLAMP: | |
2499 | if (!val) { | |
2500 | if (sk->sk_state != TCP_CLOSE) { | |
2501 | err = -EINVAL; | |
2502 | break; | |
2503 | } | |
2504 | tp->window_clamp = 0; | |
2505 | } else | |
2506 | tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? | |
2507 | SOCK_MIN_RCVBUF / 2 : val; | |
2508 | break; | |
2509 | ||
2510 | case TCP_QUICKACK: | |
2511 | if (!val) { | |
463c84b9 | 2512 | icsk->icsk_ack.pingpong = 1; |
1da177e4 | 2513 | } else { |
463c84b9 | 2514 | icsk->icsk_ack.pingpong = 0; |
1da177e4 LT |
2515 | if ((1 << sk->sk_state) & |
2516 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && | |
463c84b9 ACM |
2517 | inet_csk_ack_scheduled(sk)) { |
2518 | icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; | |
0e4b4992 | 2519 | tcp_cleanup_rbuf(sk, 1); |
1da177e4 | 2520 | if (!(val & 1)) |
463c84b9 | 2521 | icsk->icsk_ack.pingpong = 1; |
1da177e4 LT |
2522 | } |
2523 | } | |
2524 | break; | |
2525 | ||
cfb6eeb4 YH |
2526 | #ifdef CONFIG_TCP_MD5SIG |
2527 | case TCP_MD5SIG: | |
2528 | /* Read the IP->Key mappings from userspace */ | |
2529 | err = tp->af_specific->md5_parse(sk, optval, optlen); | |
2530 | break; | |
2531 | #endif | |
dca43c75 | 2532 | case TCP_USER_TIMEOUT: |
b248230c | 2533 | /* Cap the max time in ms TCP will retry or probe the window |
dca43c75 JC |
2534 | * before giving up and aborting (ETIMEDOUT) a connection. |
2535 | */ | |
42493570 HL |
2536 | if (val < 0) |
2537 | err = -EINVAL; | |
2538 | else | |
2539 | icsk->icsk_user_timeout = msecs_to_jiffies(val); | |
dca43c75 | 2540 | break; |
8336886f JC |
2541 | |
2542 | case TCP_FASTOPEN: | |
2543 | if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | | |
2544 | TCPF_LISTEN))) | |
2545 | err = fastopen_init_queue(sk, val); | |
2546 | else | |
2547 | err = -EINVAL; | |
2548 | break; | |
93be6ce0 AV |
2549 | case TCP_TIMESTAMP: |
2550 | if (!tp->repair) | |
2551 | err = -EPERM; | |
2552 | else | |
2553 | tp->tsoffset = val - tcp_time_stamp; | |
2554 | break; | |
c9bee3b7 ED |
2555 | case TCP_NOTSENT_LOWAT: |
2556 | tp->notsent_lowat = val; | |
2557 | sk->sk_write_space(sk); | |
2558 | break; | |
1da177e4 LT |
2559 | default: |
2560 | err = -ENOPROTOOPT; | |
2561 | break; | |
3ff50b79 SH |
2562 | } |
2563 | ||
1da177e4 LT |
2564 | release_sock(sk); |
2565 | return err; | |
2566 | } | |
2567 | ||
3fdadf7d | 2568 | int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, |
b7058842 | 2569 | unsigned int optlen) |
3fdadf7d | 2570 | { |
cf533ea5 | 2571 | const struct inet_connection_sock *icsk = inet_csk(sk); |
3fdadf7d DM |
2572 | |
2573 | if (level != SOL_TCP) | |
2574 | return icsk->icsk_af_ops->setsockopt(sk, level, optname, | |
2575 | optval, optlen); | |
2576 | return do_tcp_setsockopt(sk, level, optname, optval, optlen); | |
2577 | } | |
4bc2f18b | 2578 | EXPORT_SYMBOL(tcp_setsockopt); |
3fdadf7d DM |
2579 | |
2580 | #ifdef CONFIG_COMPAT | |
543d9cfe | 2581 | int compat_tcp_setsockopt(struct sock *sk, int level, int optname, |
b7058842 | 2582 | char __user *optval, unsigned int optlen) |
3fdadf7d | 2583 | { |
dec73ff0 ACM |
2584 | if (level != SOL_TCP) |
2585 | return inet_csk_compat_setsockopt(sk, level, optname, | |
2586 | optval, optlen); | |
3fdadf7d DM |
2587 | return do_tcp_setsockopt(sk, level, optname, optval, optlen); |
2588 | } | |
543d9cfe | 2589 | EXPORT_SYMBOL(compat_tcp_setsockopt); |
3fdadf7d DM |
2590 | #endif |
2591 | ||
1da177e4 | 2592 | /* Return information about state of tcp endpoint in API format. */ |
cf533ea5 | 2593 | void tcp_get_info(const struct sock *sk, struct tcp_info *info) |
1da177e4 | 2594 | { |
cf533ea5 | 2595 | const struct tcp_sock *tp = tcp_sk(sk); |
463c84b9 | 2596 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2597 | u32 now = tcp_time_stamp; |
2598 | ||
2599 | memset(info, 0, sizeof(*info)); | |
2600 | ||
2601 | info->tcpi_state = sk->sk_state; | |
6687e988 | 2602 | info->tcpi_ca_state = icsk->icsk_ca_state; |
463c84b9 | 2603 | info->tcpi_retransmits = icsk->icsk_retransmits; |
6687e988 | 2604 | info->tcpi_probes = icsk->icsk_probes_out; |
463c84b9 | 2605 | info->tcpi_backoff = icsk->icsk_backoff; |
1da177e4 LT |
2606 | |
2607 | if (tp->rx_opt.tstamp_ok) | |
2608 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; | |
e60402d0 | 2609 | if (tcp_is_sack(tp)) |
1da177e4 LT |
2610 | info->tcpi_options |= TCPI_OPT_SACK; |
2611 | if (tp->rx_opt.wscale_ok) { | |
2612 | info->tcpi_options |= TCPI_OPT_WSCALE; | |
2613 | info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; | |
2614 | info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; | |
e905a9ed | 2615 | } |
1da177e4 | 2616 | |
b5c5693b | 2617 | if (tp->ecn_flags & TCP_ECN_OK) |
1da177e4 | 2618 | info->tcpi_options |= TCPI_OPT_ECN; |
b5c5693b ED |
2619 | if (tp->ecn_flags & TCP_ECN_SEEN) |
2620 | info->tcpi_options |= TCPI_OPT_ECN_SEEN; | |
6f73601e YC |
2621 | if (tp->syn_data_acked) |
2622 | info->tcpi_options |= TCPI_OPT_SYN_DATA; | |
1da177e4 | 2623 | |
463c84b9 ACM |
2624 | info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); |
2625 | info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); | |
c1b4a7e6 | 2626 | info->tcpi_snd_mss = tp->mss_cache; |
463c84b9 | 2627 | info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; |
1da177e4 | 2628 | |
5ee3afba RJ |
2629 | if (sk->sk_state == TCP_LISTEN) { |
2630 | info->tcpi_unacked = sk->sk_ack_backlog; | |
2631 | info->tcpi_sacked = sk->sk_max_ack_backlog; | |
2632 | } else { | |
2633 | info->tcpi_unacked = tp->packets_out; | |
2634 | info->tcpi_sacked = tp->sacked_out; | |
2635 | } | |
1da177e4 LT |
2636 | info->tcpi_lost = tp->lost_out; |
2637 | info->tcpi_retrans = tp->retrans_out; | |
2638 | info->tcpi_fackets = tp->fackets_out; | |
2639 | ||
2640 | info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); | |
463c84b9 | 2641 | info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); |
1da177e4 LT |
2642 | info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); |
2643 | ||
d83d8461 | 2644 | info->tcpi_pmtu = icsk->icsk_pmtu_cookie; |
1da177e4 | 2645 | info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; |
740b0f18 ED |
2646 | info->tcpi_rtt = tp->srtt_us >> 3; |
2647 | info->tcpi_rttvar = tp->mdev_us >> 2; | |
1da177e4 LT |
2648 | info->tcpi_snd_ssthresh = tp->snd_ssthresh; |
2649 | info->tcpi_snd_cwnd = tp->snd_cwnd; | |
2650 | info->tcpi_advmss = tp->advmss; | |
2651 | info->tcpi_reordering = tp->reordering; | |
2652 | ||
2653 | info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; | |
2654 | info->tcpi_rcv_space = tp->rcvq_space.space; | |
2655 | ||
2656 | info->tcpi_total_retrans = tp->total_retrans; | |
977cb0ec ED |
2657 | |
2658 | info->tcpi_pacing_rate = sk->sk_pacing_rate != ~0U ? | |
2659 | sk->sk_pacing_rate : ~0ULL; | |
2660 | info->tcpi_max_pacing_rate = sk->sk_max_pacing_rate != ~0U ? | |
2661 | sk->sk_max_pacing_rate : ~0ULL; | |
1da177e4 | 2662 | } |
1da177e4 LT |
2663 | EXPORT_SYMBOL_GPL(tcp_get_info); |
2664 | ||
3fdadf7d DM |
2665 | static int do_tcp_getsockopt(struct sock *sk, int level, |
2666 | int optname, char __user *optval, int __user *optlen) | |
1da177e4 | 2667 | { |
295f7324 | 2668 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2669 | struct tcp_sock *tp = tcp_sk(sk); |
2670 | int val, len; | |
2671 | ||
1da177e4 LT |
2672 | if (get_user(len, optlen)) |
2673 | return -EFAULT; | |
2674 | ||
2675 | len = min_t(unsigned int, len, sizeof(int)); | |
2676 | ||
2677 | if (len < 0) | |
2678 | return -EINVAL; | |
2679 | ||
2680 | switch (optname) { | |
2681 | case TCP_MAXSEG: | |
c1b4a7e6 | 2682 | val = tp->mss_cache; |
1da177e4 LT |
2683 | if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) |
2684 | val = tp->rx_opt.user_mss; | |
5e6a3ce6 PE |
2685 | if (tp->repair) |
2686 | val = tp->rx_opt.mss_clamp; | |
1da177e4 LT |
2687 | break; |
2688 | case TCP_NODELAY: | |
2689 | val = !!(tp->nonagle&TCP_NAGLE_OFF); | |
2690 | break; | |
2691 | case TCP_CORK: | |
2692 | val = !!(tp->nonagle&TCP_NAGLE_CORK); | |
2693 | break; | |
2694 | case TCP_KEEPIDLE: | |
df19a626 | 2695 | val = keepalive_time_when(tp) / HZ; |
1da177e4 LT |
2696 | break; |
2697 | case TCP_KEEPINTVL: | |
df19a626 | 2698 | val = keepalive_intvl_when(tp) / HZ; |
1da177e4 LT |
2699 | break; |
2700 | case TCP_KEEPCNT: | |
df19a626 | 2701 | val = keepalive_probes(tp); |
1da177e4 LT |
2702 | break; |
2703 | case TCP_SYNCNT: | |
295f7324 | 2704 | val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; |
1da177e4 LT |
2705 | break; |
2706 | case TCP_LINGER2: | |
2707 | val = tp->linger2; | |
2708 | if (val >= 0) | |
2709 | val = (val ? : sysctl_tcp_fin_timeout) / HZ; | |
2710 | break; | |
2711 | case TCP_DEFER_ACCEPT: | |
b103cf34 JA |
2712 | val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, |
2713 | TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); | |
1da177e4 LT |
2714 | break; |
2715 | case TCP_WINDOW_CLAMP: | |
2716 | val = tp->window_clamp; | |
2717 | break; | |
2718 | case TCP_INFO: { | |
2719 | struct tcp_info info; | |
2720 | ||
2721 | if (get_user(len, optlen)) | |
2722 | return -EFAULT; | |
2723 | ||
2724 | tcp_get_info(sk, &info); | |
2725 | ||
2726 | len = min_t(unsigned int, len, sizeof(info)); | |
2727 | if (put_user(len, optlen)) | |
2728 | return -EFAULT; | |
2729 | if (copy_to_user(optval, &info, len)) | |
2730 | return -EFAULT; | |
2731 | return 0; | |
2732 | } | |
2733 | case TCP_QUICKACK: | |
295f7324 | 2734 | val = !icsk->icsk_ack.pingpong; |
1da177e4 | 2735 | break; |
5f8ef48d SH |
2736 | |
2737 | case TCP_CONGESTION: | |
2738 | if (get_user(len, optlen)) | |
2739 | return -EFAULT; | |
2740 | len = min_t(unsigned int, len, TCP_CA_NAME_MAX); | |
2741 | if (put_user(len, optlen)) | |
2742 | return -EFAULT; | |
6687e988 | 2743 | if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) |
5f8ef48d SH |
2744 | return -EFAULT; |
2745 | return 0; | |
e56fb50f | 2746 | |
3c0fef0b JH |
2747 | case TCP_THIN_LINEAR_TIMEOUTS: |
2748 | val = tp->thin_lto; | |
2749 | break; | |
2750 | case TCP_THIN_DUPACK: | |
2751 | val = tp->thin_dupack; | |
2752 | break; | |
dca43c75 | 2753 | |
ee995283 PE |
2754 | case TCP_REPAIR: |
2755 | val = tp->repair; | |
2756 | break; | |
2757 | ||
2758 | case TCP_REPAIR_QUEUE: | |
2759 | if (tp->repair) | |
2760 | val = tp->repair_queue; | |
2761 | else | |
2762 | return -EINVAL; | |
2763 | break; | |
2764 | ||
2765 | case TCP_QUEUE_SEQ: | |
2766 | if (tp->repair_queue == TCP_SEND_QUEUE) | |
2767 | val = tp->write_seq; | |
2768 | else if (tp->repair_queue == TCP_RECV_QUEUE) | |
2769 | val = tp->rcv_nxt; | |
2770 | else | |
2771 | return -EINVAL; | |
2772 | break; | |
2773 | ||
dca43c75 JC |
2774 | case TCP_USER_TIMEOUT: |
2775 | val = jiffies_to_msecs(icsk->icsk_user_timeout); | |
2776 | break; | |
1536e285 KN |
2777 | |
2778 | case TCP_FASTOPEN: | |
2779 | if (icsk->icsk_accept_queue.fastopenq != NULL) | |
2780 | val = icsk->icsk_accept_queue.fastopenq->max_qlen; | |
2781 | else | |
2782 | val = 0; | |
2783 | break; | |
2784 | ||
93be6ce0 AV |
2785 | case TCP_TIMESTAMP: |
2786 | val = tcp_time_stamp + tp->tsoffset; | |
2787 | break; | |
c9bee3b7 ED |
2788 | case TCP_NOTSENT_LOWAT: |
2789 | val = tp->notsent_lowat; | |
2790 | break; | |
1da177e4 LT |
2791 | default: |
2792 | return -ENOPROTOOPT; | |
3ff50b79 | 2793 | } |
1da177e4 LT |
2794 | |
2795 | if (put_user(len, optlen)) | |
2796 | return -EFAULT; | |
2797 | if (copy_to_user(optval, &val, len)) | |
2798 | return -EFAULT; | |
2799 | return 0; | |
2800 | } | |
2801 | ||
3fdadf7d DM |
2802 | int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, |
2803 | int __user *optlen) | |
2804 | { | |
2805 | struct inet_connection_sock *icsk = inet_csk(sk); | |
2806 | ||
2807 | if (level != SOL_TCP) | |
2808 | return icsk->icsk_af_ops->getsockopt(sk, level, optname, | |
2809 | optval, optlen); | |
2810 | return do_tcp_getsockopt(sk, level, optname, optval, optlen); | |
2811 | } | |
4bc2f18b | 2812 | EXPORT_SYMBOL(tcp_getsockopt); |
3fdadf7d DM |
2813 | |
2814 | #ifdef CONFIG_COMPAT | |
543d9cfe ACM |
2815 | int compat_tcp_getsockopt(struct sock *sk, int level, int optname, |
2816 | char __user *optval, int __user *optlen) | |
3fdadf7d | 2817 | { |
dec73ff0 ACM |
2818 | if (level != SOL_TCP) |
2819 | return inet_csk_compat_getsockopt(sk, level, optname, | |
2820 | optval, optlen); | |
3fdadf7d DM |
2821 | return do_tcp_getsockopt(sk, level, optname, optval, optlen); |
2822 | } | |
543d9cfe | 2823 | EXPORT_SYMBOL(compat_tcp_getsockopt); |
3fdadf7d | 2824 | #endif |
1da177e4 | 2825 | |
cfb6eeb4 | 2826 | #ifdef CONFIG_TCP_MD5SIG |
349ce993 | 2827 | static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool); |
71cea17e | 2828 | static DEFINE_MUTEX(tcp_md5sig_mutex); |
349ce993 | 2829 | static bool tcp_md5sig_pool_populated = false; |
cfb6eeb4 | 2830 | |
71cea17e | 2831 | static void __tcp_alloc_md5sig_pool(void) |
cfb6eeb4 YH |
2832 | { |
2833 | int cpu; | |
cfb6eeb4 YH |
2834 | |
2835 | for_each_possible_cpu(cpu) { | |
349ce993 ED |
2836 | if (!per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm) { |
2837 | struct crypto_hash *hash; | |
cfb6eeb4 | 2838 | |
349ce993 ED |
2839 | hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); |
2840 | if (IS_ERR_OR_NULL(hash)) | |
2841 | return; | |
2842 | per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm = hash; | |
2843 | } | |
cfb6eeb4 | 2844 | } |
349ce993 ED |
2845 | /* before setting tcp_md5sig_pool_populated, we must commit all writes |
2846 | * to memory. See smp_rmb() in tcp_get_md5sig_pool() | |
71cea17e ED |
2847 | */ |
2848 | smp_wmb(); | |
349ce993 | 2849 | tcp_md5sig_pool_populated = true; |
cfb6eeb4 YH |
2850 | } |
2851 | ||
71cea17e | 2852 | bool tcp_alloc_md5sig_pool(void) |
cfb6eeb4 | 2853 | { |
349ce993 | 2854 | if (unlikely(!tcp_md5sig_pool_populated)) { |
71cea17e ED |
2855 | mutex_lock(&tcp_md5sig_mutex); |
2856 | ||
349ce993 | 2857 | if (!tcp_md5sig_pool_populated) |
71cea17e ED |
2858 | __tcp_alloc_md5sig_pool(); |
2859 | ||
2860 | mutex_unlock(&tcp_md5sig_mutex); | |
cfb6eeb4 | 2861 | } |
349ce993 | 2862 | return tcp_md5sig_pool_populated; |
cfb6eeb4 | 2863 | } |
cfb6eeb4 YH |
2864 | EXPORT_SYMBOL(tcp_alloc_md5sig_pool); |
2865 | ||
35790c04 ED |
2866 | |
2867 | /** | |
2868 | * tcp_get_md5sig_pool - get md5sig_pool for this user | |
2869 | * | |
2870 | * We use percpu structure, so if we succeed, we exit with preemption | |
2871 | * and BH disabled, to make sure another thread or softirq handling | |
2872 | * wont try to get same context. | |
2873 | */ | |
2874 | struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) | |
cfb6eeb4 | 2875 | { |
35790c04 | 2876 | local_bh_disable(); |
cfb6eeb4 | 2877 | |
349ce993 ED |
2878 | if (tcp_md5sig_pool_populated) { |
2879 | /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */ | |
2880 | smp_rmb(); | |
2881 | return this_cpu_ptr(&tcp_md5sig_pool); | |
2882 | } | |
35790c04 ED |
2883 | local_bh_enable(); |
2884 | return NULL; | |
2885 | } | |
2886 | EXPORT_SYMBOL(tcp_get_md5sig_pool); | |
cfb6eeb4 | 2887 | |
49a72dfb | 2888 | int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, |
ca35a0ef | 2889 | const struct tcphdr *th) |
49a72dfb AL |
2890 | { |
2891 | struct scatterlist sg; | |
ca35a0ef | 2892 | struct tcphdr hdr; |
49a72dfb AL |
2893 | int err; |
2894 | ||
ca35a0ef ED |
2895 | /* We are not allowed to change tcphdr, make a local copy */ |
2896 | memcpy(&hdr, th, sizeof(hdr)); | |
2897 | hdr.check = 0; | |
2898 | ||
49a72dfb | 2899 | /* options aren't included in the hash */ |
ca35a0ef ED |
2900 | sg_init_one(&sg, &hdr, sizeof(hdr)); |
2901 | err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr)); | |
49a72dfb AL |
2902 | return err; |
2903 | } | |
49a72dfb AL |
2904 | EXPORT_SYMBOL(tcp_md5_hash_header); |
2905 | ||
2906 | int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, | |
cf533ea5 | 2907 | const struct sk_buff *skb, unsigned int header_len) |
49a72dfb AL |
2908 | { |
2909 | struct scatterlist sg; | |
2910 | const struct tcphdr *tp = tcp_hdr(skb); | |
2911 | struct hash_desc *desc = &hp->md5_desc; | |
95c96174 ED |
2912 | unsigned int i; |
2913 | const unsigned int head_data_len = skb_headlen(skb) > header_len ? | |
2914 | skb_headlen(skb) - header_len : 0; | |
49a72dfb | 2915 | const struct skb_shared_info *shi = skb_shinfo(skb); |
d7fd1b57 | 2916 | struct sk_buff *frag_iter; |
49a72dfb AL |
2917 | |
2918 | sg_init_table(&sg, 1); | |
2919 | ||
2920 | sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); | |
2921 | if (crypto_hash_update(desc, &sg, head_data_len)) | |
2922 | return 1; | |
2923 | ||
2924 | for (i = 0; i < shi->nr_frags; ++i) { | |
2925 | const struct skb_frag_struct *f = &shi->frags[i]; | |
54d27fcb ED |
2926 | unsigned int offset = f->page_offset; |
2927 | struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); | |
2928 | ||
2929 | sg_set_page(&sg, page, skb_frag_size(f), | |
2930 | offset_in_page(offset)); | |
9e903e08 | 2931 | if (crypto_hash_update(desc, &sg, skb_frag_size(f))) |
49a72dfb AL |
2932 | return 1; |
2933 | } | |
2934 | ||
d7fd1b57 ED |
2935 | skb_walk_frags(skb, frag_iter) |
2936 | if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) | |
2937 | return 1; | |
2938 | ||
49a72dfb AL |
2939 | return 0; |
2940 | } | |
49a72dfb AL |
2941 | EXPORT_SYMBOL(tcp_md5_hash_skb_data); |
2942 | ||
cf533ea5 | 2943 | int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) |
49a72dfb AL |
2944 | { |
2945 | struct scatterlist sg; | |
2946 | ||
2947 | sg_init_one(&sg, key->key, key->keylen); | |
2948 | return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); | |
2949 | } | |
49a72dfb AL |
2950 | EXPORT_SYMBOL(tcp_md5_hash_key); |
2951 | ||
cfb6eeb4 YH |
2952 | #endif |
2953 | ||
4ac02bab AK |
2954 | void tcp_done(struct sock *sk) |
2955 | { | |
8336886f JC |
2956 | struct request_sock *req = tcp_sk(sk)->fastopen_rsk; |
2957 | ||
5a5f3a8d | 2958 | if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) |
63231bdd | 2959 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); |
4ac02bab AK |
2960 | |
2961 | tcp_set_state(sk, TCP_CLOSE); | |
2962 | tcp_clear_xmit_timers(sk); | |
8336886f JC |
2963 | if (req != NULL) |
2964 | reqsk_fastopen_remove(sk, req, false); | |
4ac02bab AK |
2965 | |
2966 | sk->sk_shutdown = SHUTDOWN_MASK; | |
2967 | ||
2968 | if (!sock_flag(sk, SOCK_DEAD)) | |
2969 | sk->sk_state_change(sk); | |
2970 | else | |
2971 | inet_csk_destroy_sock(sk); | |
2972 | } | |
2973 | EXPORT_SYMBOL_GPL(tcp_done); | |
2974 | ||
5f8ef48d | 2975 | extern struct tcp_congestion_ops tcp_reno; |
1da177e4 LT |
2976 | |
2977 | static __initdata unsigned long thash_entries; | |
2978 | static int __init set_thash_entries(char *str) | |
2979 | { | |
413c27d8 EZ |
2980 | ssize_t ret; |
2981 | ||
1da177e4 LT |
2982 | if (!str) |
2983 | return 0; | |
413c27d8 EZ |
2984 | |
2985 | ret = kstrtoul(str, 0, &thash_entries); | |
2986 | if (ret) | |
2987 | return 0; | |
2988 | ||
1da177e4 LT |
2989 | return 1; |
2990 | } | |
2991 | __setup("thash_entries=", set_thash_entries); | |
2992 | ||
47d7a88c | 2993 | static void __init tcp_init_mem(void) |
4acb4190 | 2994 | { |
4acb4190 GC |
2995 | unsigned long limit = nr_free_buffer_pages() / 8; |
2996 | limit = max(limit, 128UL); | |
a4fe34bf EB |
2997 | sysctl_tcp_mem[0] = limit / 4 * 3; |
2998 | sysctl_tcp_mem[1] = limit; | |
2999 | sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; | |
4acb4190 GC |
3000 | } |
3001 | ||
1da177e4 LT |
3002 | void __init tcp_init(void) |
3003 | { | |
3004 | struct sk_buff *skb = NULL; | |
f03d78db | 3005 | unsigned long limit; |
b49960a0 | 3006 | int max_rshare, max_wshare, cnt; |
074b8517 | 3007 | unsigned int i; |
1da177e4 | 3008 | |
1f9e636e | 3009 | BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); |
1da177e4 | 3010 | |
908c7f19 TH |
3011 | percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); |
3012 | percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); | |
6e04e021 ACM |
3013 | tcp_hashinfo.bind_bucket_cachep = |
3014 | kmem_cache_create("tcp_bind_bucket", | |
3015 | sizeof(struct inet_bind_bucket), 0, | |
20c2df83 | 3016 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 | 3017 | |
1da177e4 LT |
3018 | /* Size and allocate the main established and bind bucket |
3019 | * hash tables. | |
3020 | * | |
3021 | * The methodology is similar to that of the buffer cache. | |
3022 | */ | |
6e04e021 | 3023 | tcp_hashinfo.ehash = |
1da177e4 | 3024 | alloc_large_system_hash("TCP established", |
0f7ff927 | 3025 | sizeof(struct inet_ehash_bucket), |
1da177e4 | 3026 | thash_entries, |
fd90b29d | 3027 | 17, /* one slot per 128 KB of memory */ |
9e950efa | 3028 | 0, |
1da177e4 | 3029 | NULL, |
f373b53b | 3030 | &tcp_hashinfo.ehash_mask, |
31fe62b9 | 3031 | 0, |
0ccfe618 | 3032 | thash_entries ? 0 : 512 * 1024); |
05dbc7b5 | 3033 | for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) |
3ab5aee7 | 3034 | INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); |
05dbc7b5 | 3035 | |
230140cf ED |
3036 | if (inet_ehash_locks_alloc(&tcp_hashinfo)) |
3037 | panic("TCP: failed to alloc ehash_locks"); | |
6e04e021 | 3038 | tcp_hashinfo.bhash = |
1da177e4 | 3039 | alloc_large_system_hash("TCP bind", |
0f7ff927 | 3040 | sizeof(struct inet_bind_hashbucket), |
f373b53b | 3041 | tcp_hashinfo.ehash_mask + 1, |
fd90b29d | 3042 | 17, /* one slot per 128 KB of memory */ |
9e950efa | 3043 | 0, |
6e04e021 | 3044 | &tcp_hashinfo.bhash_size, |
1da177e4 | 3045 | NULL, |
31fe62b9 | 3046 | 0, |
1da177e4 | 3047 | 64 * 1024); |
074b8517 | 3048 | tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; |
6e04e021 ACM |
3049 | for (i = 0; i < tcp_hashinfo.bhash_size; i++) { |
3050 | spin_lock_init(&tcp_hashinfo.bhash[i].lock); | |
3051 | INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); | |
1da177e4 LT |
3052 | } |
3053 | ||
c5ed63d6 ED |
3054 | |
3055 | cnt = tcp_hashinfo.ehash_mask + 1; | |
3056 | ||
3057 | tcp_death_row.sysctl_max_tw_buckets = cnt / 2; | |
3058 | sysctl_tcp_max_orphans = cnt / 2; | |
3059 | sysctl_max_syn_backlog = max(128, cnt / 256); | |
1da177e4 | 3060 | |
a4fe34bf | 3061 | tcp_init_mem(); |
c43b874d | 3062 | /* Set per-socket limits to no more than 1/128 the pressure threshold */ |
5fb84b14 | 3063 | limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); |
b49960a0 ED |
3064 | max_wshare = min(4UL*1024*1024, limit); |
3065 | max_rshare = min(6UL*1024*1024, limit); | |
7b4f4b5e | 3066 | |
3ab224be | 3067 | sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; |
7b4f4b5e | 3068 | sysctl_tcp_wmem[1] = 16*1024; |
b49960a0 | 3069 | sysctl_tcp_wmem[2] = max(64*1024, max_wshare); |
7b4f4b5e | 3070 | |
3ab224be | 3071 | sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; |
7b4f4b5e | 3072 | sysctl_tcp_rmem[1] = 87380; |
b49960a0 | 3073 | sysctl_tcp_rmem[2] = max(87380, max_rshare); |
1da177e4 | 3074 | |
afd46503 | 3075 | pr_info("Hash tables configured (established %u bind %u)\n", |
058bd4d2 | 3076 | tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); |
317a76f9 | 3077 | |
51c5d0c4 | 3078 | tcp_metrics_init(); |
55d8694f | 3079 | BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); |
46d3ceab | 3080 | tcp_tasklet_init(); |
1da177e4 | 3081 | } |