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> | |
6e9250f5 | 255 | #include <linux/inet_diag.h> |
1da177e4 | 256 | #include <linux/init.h> |
1da177e4 | 257 | #include <linux/fs.h> |
9c55e01c | 258 | #include <linux/skbuff.h> |
81b23b4a | 259 | #include <linux/scatterlist.h> |
9c55e01c JA |
260 | #include <linux/splice.h> |
261 | #include <linux/net.h> | |
262 | #include <linux/socket.h> | |
1da177e4 LT |
263 | #include <linux/random.h> |
264 | #include <linux/bootmem.h> | |
57413ebc MS |
265 | #include <linux/highmem.h> |
266 | #include <linux/swap.h> | |
b8059ead | 267 | #include <linux/cache.h> |
f4c50d99 | 268 | #include <linux/err.h> |
cfb6eeb4 | 269 | #include <linux/crypto.h> |
da5c78c8 | 270 | #include <linux/time.h> |
5a0e3ad6 | 271 | #include <linux/slab.h> |
1da177e4 LT |
272 | |
273 | #include <net/icmp.h> | |
cf60af03 | 274 | #include <net/inet_common.h> |
1da177e4 LT |
275 | #include <net/tcp.h> |
276 | #include <net/xfrm.h> | |
277 | #include <net/ip.h> | |
9c55e01c | 278 | #include <net/sock.h> |
1da177e4 LT |
279 | |
280 | #include <asm/uaccess.h> | |
281 | #include <asm/ioctls.h> | |
076bb0c8 | 282 | #include <net/busy_poll.h> |
1da177e4 | 283 | |
ab32ea5d | 284 | int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; |
1da177e4 | 285 | |
95bd09eb ED |
286 | int sysctl_tcp_min_tso_segs __read_mostly = 2; |
287 | ||
f54b3111 ED |
288 | int sysctl_tcp_autocorking __read_mostly = 1; |
289 | ||
dd24c001 | 290 | struct percpu_counter tcp_orphan_count; |
0a5578cf ACM |
291 | EXPORT_SYMBOL_GPL(tcp_orphan_count); |
292 | ||
a4fe34bf | 293 | long sysctl_tcp_mem[3] __read_mostly; |
b8059ead DM |
294 | int sysctl_tcp_wmem[3] __read_mostly; |
295 | int sysctl_tcp_rmem[3] __read_mostly; | |
1da177e4 | 296 | |
a4fe34bf | 297 | EXPORT_SYMBOL(sysctl_tcp_mem); |
1da177e4 LT |
298 | EXPORT_SYMBOL(sysctl_tcp_rmem); |
299 | EXPORT_SYMBOL(sysctl_tcp_wmem); | |
300 | ||
8d987e5c | 301 | atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ |
1da177e4 | 302 | EXPORT_SYMBOL(tcp_memory_allocated); |
1748376b ED |
303 | |
304 | /* | |
305 | * Current number of TCP sockets. | |
306 | */ | |
307 | struct percpu_counter tcp_sockets_allocated; | |
1da177e4 LT |
308 | EXPORT_SYMBOL(tcp_sockets_allocated); |
309 | ||
9c55e01c JA |
310 | /* |
311 | * TCP splice context | |
312 | */ | |
313 | struct tcp_splice_state { | |
314 | struct pipe_inode_info *pipe; | |
315 | size_t len; | |
316 | unsigned int flags; | |
317 | }; | |
318 | ||
1da177e4 LT |
319 | /* |
320 | * Pressure flag: try to collapse. | |
321 | * Technical note: it is used by multiple contexts non atomically. | |
3ab224be | 322 | * All the __sk_mem_schedule() is of this nature: accounting |
1da177e4 LT |
323 | * is strict, actions are advisory and have some latency. |
324 | */ | |
4103f8cd | 325 | int tcp_memory_pressure __read_mostly; |
1da177e4 LT |
326 | EXPORT_SYMBOL(tcp_memory_pressure); |
327 | ||
5c52ba17 | 328 | void tcp_enter_memory_pressure(struct sock *sk) |
1da177e4 LT |
329 | { |
330 | if (!tcp_memory_pressure) { | |
4e673444 | 331 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); |
1da177e4 LT |
332 | tcp_memory_pressure = 1; |
333 | } | |
334 | } | |
1da177e4 LT |
335 | EXPORT_SYMBOL(tcp_enter_memory_pressure); |
336 | ||
b103cf34 JA |
337 | /* Convert seconds to retransmits based on initial and max timeout */ |
338 | static u8 secs_to_retrans(int seconds, int timeout, int rto_max) | |
339 | { | |
340 | u8 res = 0; | |
341 | ||
342 | if (seconds > 0) { | |
343 | int period = timeout; | |
344 | ||
345 | res = 1; | |
346 | while (seconds > period && res < 255) { | |
347 | res++; | |
348 | timeout <<= 1; | |
349 | if (timeout > rto_max) | |
350 | timeout = rto_max; | |
351 | period += timeout; | |
352 | } | |
353 | } | |
354 | return res; | |
355 | } | |
356 | ||
357 | /* Convert retransmits to seconds based on initial and max timeout */ | |
358 | static int retrans_to_secs(u8 retrans, int timeout, int rto_max) | |
359 | { | |
360 | int period = 0; | |
361 | ||
362 | if (retrans > 0) { | |
363 | period = timeout; | |
364 | while (--retrans) { | |
365 | timeout <<= 1; | |
366 | if (timeout > rto_max) | |
367 | timeout = rto_max; | |
368 | period += timeout; | |
369 | } | |
370 | } | |
371 | return period; | |
372 | } | |
373 | ||
900f65d3 NC |
374 | /* Address-family independent initialization for a tcp_sock. |
375 | * | |
376 | * NOTE: A lot of things set to zero explicitly by call to | |
377 | * sk_alloc() so need not be done here. | |
378 | */ | |
379 | void tcp_init_sock(struct sock *sk) | |
380 | { | |
381 | struct inet_connection_sock *icsk = inet_csk(sk); | |
382 | struct tcp_sock *tp = tcp_sk(sk); | |
383 | ||
996b175e | 384 | __skb_queue_head_init(&tp->out_of_order_queue); |
900f65d3 NC |
385 | tcp_init_xmit_timers(sk); |
386 | tcp_prequeue_init(tp); | |
46d3ceab | 387 | INIT_LIST_HEAD(&tp->tsq_node); |
900f65d3 NC |
388 | |
389 | icsk->icsk_rto = TCP_TIMEOUT_INIT; | |
740b0f18 | 390 | tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); |
900f65d3 NC |
391 | |
392 | /* So many TCP implementations out there (incorrectly) count the | |
393 | * initial SYN frame in their delayed-ACK and congestion control | |
394 | * algorithms that we must have the following bandaid to talk | |
395 | * efficiently to them. -DaveM | |
396 | */ | |
397 | tp->snd_cwnd = TCP_INIT_CWND; | |
398 | ||
399 | /* See draft-stevens-tcpca-spec-01 for discussion of the | |
400 | * initialization of these values. | |
401 | */ | |
402 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; | |
403 | tp->snd_cwnd_clamp = ~0; | |
404 | tp->mss_cache = TCP_MSS_DEFAULT; | |
d654976c | 405 | u64_stats_init(&tp->syncp); |
900f65d3 NC |
406 | |
407 | tp->reordering = sysctl_tcp_reordering; | |
eed530b6 | 408 | tcp_enable_early_retrans(tp); |
55d8694f | 409 | tcp_assign_congestion_control(sk); |
900f65d3 | 410 | |
ceaa1fef AV |
411 | tp->tsoffset = 0; |
412 | ||
900f65d3 NC |
413 | sk->sk_state = TCP_CLOSE; |
414 | ||
415 | sk->sk_write_space = sk_stream_write_space; | |
416 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
417 | ||
418 | icsk->icsk_sync_mss = tcp_sync_mss; | |
419 | ||
900f65d3 NC |
420 | sk->sk_sndbuf = sysctl_tcp_wmem[1]; |
421 | sk->sk_rcvbuf = sysctl_tcp_rmem[1]; | |
422 | ||
423 | local_bh_disable(); | |
424 | sock_update_memcg(sk); | |
425 | sk_sockets_allocated_inc(sk); | |
426 | local_bh_enable(); | |
427 | } | |
428 | EXPORT_SYMBOL(tcp_init_sock); | |
429 | ||
f066e2b0 | 430 | static void tcp_tx_timestamp(struct sock *sk, struct sk_buff *skb) |
4ed2d765 | 431 | { |
f066e2b0 WB |
432 | if (sk->sk_tsflags) { |
433 | struct skb_shared_info *shinfo = skb_shinfo(skb); | |
4ed2d765 | 434 | |
f066e2b0 WB |
435 | sock_tx_timestamp(sk, &shinfo->tx_flags); |
436 | if (shinfo->tx_flags & SKBTX_ANY_TSTAMP) | |
437 | shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; | |
438 | } | |
4ed2d765 WB |
439 | } |
440 | ||
1da177e4 LT |
441 | /* |
442 | * Wait for a TCP event. | |
443 | * | |
444 | * Note that we don't need to lock the socket, as the upper poll layers | |
445 | * take care of normal races (between the test and the event) and we don't | |
446 | * go look at any of the socket buffers directly. | |
447 | */ | |
448 | unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) | |
449 | { | |
450 | unsigned int mask; | |
451 | struct sock *sk = sock->sk; | |
cf533ea5 | 452 | const struct tcp_sock *tp = tcp_sk(sk); |
1da177e4 | 453 | |
c3f1dbaf DM |
454 | sock_rps_record_flow(sk); |
455 | ||
aa395145 | 456 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 | 457 | if (sk->sk_state == TCP_LISTEN) |
dc40c7bc | 458 | return inet_csk_listen_poll(sk); |
1da177e4 LT |
459 | |
460 | /* Socket is not locked. We are protected from async events | |
70efce27 WN |
461 | * by poll logic and correct handling of state changes |
462 | * made by other threads is impossible in any case. | |
1da177e4 LT |
463 | */ |
464 | ||
465 | mask = 0; | |
1da177e4 LT |
466 | |
467 | /* | |
468 | * POLLHUP is certainly not done right. But poll() doesn't | |
469 | * have a notion of HUP in just one direction, and for a | |
470 | * socket the read side is more interesting. | |
471 | * | |
472 | * Some poll() documentation says that POLLHUP is incompatible | |
473 | * with the POLLOUT/POLLWR flags, so somebody should check this | |
474 | * all. But careful, it tends to be safer to return too many | |
475 | * bits than too few, and you can easily break real applications | |
476 | * if you don't tell them that something has hung up! | |
477 | * | |
478 | * Check-me. | |
479 | * | |
480 | * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and | |
481 | * our fs/select.c). It means that after we received EOF, | |
482 | * poll always returns immediately, making impossible poll() on write() | |
483 | * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP | |
484 | * if and only if shutdown has been made in both directions. | |
485 | * Actually, it is interesting to look how Solaris and DUX | |
70efce27 | 486 | * solve this dilemma. I would prefer, if POLLHUP were maskable, |
1da177e4 LT |
487 | * then we could set it on SND_SHUTDOWN. BTW examples given |
488 | * in Stevens' books assume exactly this behaviour, it explains | |
70efce27 | 489 | * why POLLHUP is incompatible with POLLOUT. --ANK |
1da177e4 LT |
490 | * |
491 | * NOTE. Check for TCP_CLOSE is added. The goal is to prevent | |
492 | * blocking on fresh not-connected or disconnected socket. --ANK | |
493 | */ | |
494 | if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) | |
495 | mask |= POLLHUP; | |
496 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
f348d70a | 497 | mask |= POLLIN | POLLRDNORM | POLLRDHUP; |
1da177e4 | 498 | |
8336886f JC |
499 | /* Connected or passive Fast Open socket? */ |
500 | if (sk->sk_state != TCP_SYN_SENT && | |
00db4124 | 501 | (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk)) { |
c7004482 DM |
502 | int target = sock_rcvlowat(sk, 0, INT_MAX); |
503 | ||
504 | if (tp->urg_seq == tp->copied_seq && | |
505 | !sock_flag(sk, SOCK_URGINLINE) && | |
506 | tp->urg_data) | |
b634f875 | 507 | target++; |
c7004482 | 508 | |
1da177e4 LT |
509 | /* Potential race condition. If read of tp below will |
510 | * escape above sk->sk_state, we can be illegally awaken | |
511 | * in SYN_* states. */ | |
c7004482 | 512 | if (tp->rcv_nxt - tp->copied_seq >= target) |
1da177e4 LT |
513 | mask |= POLLIN | POLLRDNORM; |
514 | ||
515 | if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { | |
64dc6130 | 516 | if (sk_stream_is_writeable(sk)) { |
1da177e4 LT |
517 | mask |= POLLOUT | POLLWRNORM; |
518 | } else { /* send SIGIO later */ | |
519 | set_bit(SOCK_ASYNC_NOSPACE, | |
520 | &sk->sk_socket->flags); | |
521 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
522 | ||
523 | /* Race breaker. If space is freed after | |
524 | * wspace test but before the flags are set, | |
3c715127 | 525 | * IO signal will be lost. Memory barrier |
526 | * pairs with the input side. | |
1da177e4 | 527 | */ |
3c715127 | 528 | smp_mb__after_atomic(); |
64dc6130 | 529 | if (sk_stream_is_writeable(sk)) |
1da177e4 LT |
530 | mask |= POLLOUT | POLLWRNORM; |
531 | } | |
d84ba638 KM |
532 | } else |
533 | mask |= POLLOUT | POLLWRNORM; | |
1da177e4 LT |
534 | |
535 | if (tp->urg_data & TCP_URG_VALID) | |
536 | mask |= POLLPRI; | |
537 | } | |
a4d25803 TM |
538 | /* This barrier is coupled with smp_wmb() in tcp_reset() */ |
539 | smp_rmb(); | |
4ed2d765 | 540 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) |
a4d25803 TM |
541 | mask |= POLLERR; |
542 | ||
1da177e4 LT |
543 | return mask; |
544 | } | |
4bc2f18b | 545 | EXPORT_SYMBOL(tcp_poll); |
1da177e4 LT |
546 | |
547 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) | |
548 | { | |
549 | struct tcp_sock *tp = tcp_sk(sk); | |
550 | int answ; | |
0e71c55c | 551 | bool slow; |
1da177e4 LT |
552 | |
553 | switch (cmd) { | |
554 | case SIOCINQ: | |
555 | if (sk->sk_state == TCP_LISTEN) | |
556 | return -EINVAL; | |
557 | ||
0e71c55c | 558 | slow = lock_sock_fast(sk); |
1da177e4 LT |
559 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) |
560 | answ = 0; | |
561 | else if (sock_flag(sk, SOCK_URGINLINE) || | |
562 | !tp->urg_data || | |
563 | before(tp->urg_seq, tp->copied_seq) || | |
564 | !before(tp->urg_seq, tp->rcv_nxt)) { | |
91521944 | 565 | |
1da177e4 LT |
566 | answ = tp->rcv_nxt - tp->copied_seq; |
567 | ||
a3374c42 ED |
568 | /* Subtract 1, if FIN was received */ |
569 | if (answ && sock_flag(sk, SOCK_DONE)) | |
570 | answ--; | |
1da177e4 LT |
571 | } else |
572 | answ = tp->urg_seq - tp->copied_seq; | |
0e71c55c | 573 | unlock_sock_fast(sk, slow); |
1da177e4 LT |
574 | break; |
575 | case SIOCATMARK: | |
576 | answ = tp->urg_data && tp->urg_seq == tp->copied_seq; | |
577 | break; | |
578 | case SIOCOUTQ: | |
579 | if (sk->sk_state == TCP_LISTEN) | |
580 | return -EINVAL; | |
581 | ||
582 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
583 | answ = 0; | |
584 | else | |
585 | answ = tp->write_seq - tp->snd_una; | |
586 | break; | |
2f4e1b39 MS |
587 | case SIOCOUTQNSD: |
588 | if (sk->sk_state == TCP_LISTEN) | |
589 | return -EINVAL; | |
590 | ||
591 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
592 | answ = 0; | |
593 | else | |
594 | answ = tp->write_seq - tp->snd_nxt; | |
595 | break; | |
1da177e4 LT |
596 | default: |
597 | return -ENOIOCTLCMD; | |
3ff50b79 | 598 | } |
1da177e4 LT |
599 | |
600 | return put_user(answ, (int __user *)arg); | |
601 | } | |
4bc2f18b | 602 | EXPORT_SYMBOL(tcp_ioctl); |
1da177e4 | 603 | |
1da177e4 LT |
604 | static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) |
605 | { | |
4de075e0 | 606 | TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; |
1da177e4 LT |
607 | tp->pushed_seq = tp->write_seq; |
608 | } | |
609 | ||
a2a385d6 | 610 | static inline bool forced_push(const struct tcp_sock *tp) |
1da177e4 LT |
611 | { |
612 | return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); | |
613 | } | |
614 | ||
f4a775d1 | 615 | static void skb_entail(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 616 | { |
9e412ba7 | 617 | struct tcp_sock *tp = tcp_sk(sk); |
352d4800 ACM |
618 | struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); |
619 | ||
620 | skb->csum = 0; | |
621 | tcb->seq = tcb->end_seq = tp->write_seq; | |
4de075e0 | 622 | tcb->tcp_flags = TCPHDR_ACK; |
352d4800 | 623 | tcb->sacked = 0; |
f4a775d1 | 624 | __skb_header_release(skb); |
fe067e8a | 625 | tcp_add_write_queue_tail(sk, skb); |
3ab224be HA |
626 | sk->sk_wmem_queued += skb->truesize; |
627 | sk_mem_charge(sk, skb->truesize); | |
89ebd197 | 628 | if (tp->nonagle & TCP_NAGLE_PUSH) |
e905a9ed | 629 | tp->nonagle &= ~TCP_NAGLE_PUSH; |
6f021c62 ED |
630 | |
631 | tcp_slow_start_after_idle_check(sk); | |
1da177e4 LT |
632 | } |
633 | ||
afeca340 | 634 | static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) |
1da177e4 | 635 | { |
33f5f57e | 636 | if (flags & MSG_OOB) |
1da177e4 | 637 | tp->snd_up = tp->write_seq; |
1da177e4 LT |
638 | } |
639 | ||
f54b3111 | 640 | /* If a not yet filled skb is pushed, do not send it if |
a181ceb5 | 641 | * we have data packets in Qdisc or NIC queues : |
f54b3111 ED |
642 | * Because TX completion will happen shortly, it gives a chance |
643 | * to coalesce future sendmsg() payload into this skb, without | |
644 | * need for a timer, and with no latency trade off. | |
645 | * As packets containing data payload have a bigger truesize | |
a181ceb5 ED |
646 | * than pure acks (dataless) packets, the last checks prevent |
647 | * autocorking if we only have an ACK in Qdisc/NIC queues, | |
648 | * or if TX completion was delayed after we processed ACK packet. | |
f54b3111 ED |
649 | */ |
650 | static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, | |
651 | int size_goal) | |
1da177e4 | 652 | { |
f54b3111 ED |
653 | return skb->len < size_goal && |
654 | sysctl_tcp_autocorking && | |
a181ceb5 | 655 | skb != tcp_write_queue_head(sk) && |
f54b3111 ED |
656 | atomic_read(&sk->sk_wmem_alloc) > skb->truesize; |
657 | } | |
658 | ||
659 | static void tcp_push(struct sock *sk, int flags, int mss_now, | |
660 | int nonagle, int size_goal) | |
661 | { | |
662 | struct tcp_sock *tp = tcp_sk(sk); | |
663 | struct sk_buff *skb; | |
afeca340 | 664 | |
f54b3111 ED |
665 | if (!tcp_send_head(sk)) |
666 | return; | |
afeca340 | 667 | |
f54b3111 ED |
668 | skb = tcp_write_queue_tail(sk); |
669 | if (!(flags & MSG_MORE) || forced_push(tp)) | |
670 | tcp_mark_push(tp, skb); | |
671 | ||
672 | tcp_mark_urg(tp, flags); | |
673 | ||
674 | if (tcp_should_autocork(sk, skb, size_goal)) { | |
675 | ||
676 | /* avoid atomic op if TSQ_THROTTLED bit is already set */ | |
677 | if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) { | |
678 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); | |
679 | set_bit(TSQ_THROTTLED, &tp->tsq_flags); | |
680 | } | |
a181ceb5 ED |
681 | /* It is possible TX completion already happened |
682 | * before we set TSQ_THROTTLED. | |
683 | */ | |
684 | if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize) | |
685 | return; | |
1da177e4 | 686 | } |
f54b3111 ED |
687 | |
688 | if (flags & MSG_MORE) | |
689 | nonagle = TCP_NAGLE_CORK; | |
690 | ||
691 | __tcp_push_pending_frames(sk, mss_now, nonagle); | |
1da177e4 LT |
692 | } |
693 | ||
6ff7751d AB |
694 | static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, |
695 | unsigned int offset, size_t len) | |
9c55e01c JA |
696 | { |
697 | struct tcp_splice_state *tss = rd_desc->arg.data; | |
33966dd0 | 698 | int ret; |
9c55e01c | 699 | |
a60e3cc7 HFS |
700 | ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe, |
701 | min(rd_desc->count, len), tss->flags, | |
702 | skb_socket_splice); | |
33966dd0 WT |
703 | if (ret > 0) |
704 | rd_desc->count -= ret; | |
705 | return ret; | |
9c55e01c JA |
706 | } |
707 | ||
708 | static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) | |
709 | { | |
710 | /* Store TCP splice context information in read_descriptor_t. */ | |
711 | read_descriptor_t rd_desc = { | |
712 | .arg.data = tss, | |
33966dd0 | 713 | .count = tss->len, |
9c55e01c JA |
714 | }; |
715 | ||
716 | return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); | |
717 | } | |
718 | ||
719 | /** | |
720 | * tcp_splice_read - splice data from TCP socket to a pipe | |
721 | * @sock: socket to splice from | |
722 | * @ppos: position (not valid) | |
723 | * @pipe: pipe to splice to | |
724 | * @len: number of bytes to splice | |
725 | * @flags: splice modifier flags | |
726 | * | |
727 | * Description: | |
728 | * Will read pages from given socket and fill them into a pipe. | |
729 | * | |
730 | **/ | |
731 | ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, | |
732 | struct pipe_inode_info *pipe, size_t len, | |
733 | unsigned int flags) | |
734 | { | |
735 | struct sock *sk = sock->sk; | |
736 | struct tcp_splice_state tss = { | |
737 | .pipe = pipe, | |
738 | .len = len, | |
739 | .flags = flags, | |
740 | }; | |
741 | long timeo; | |
742 | ssize_t spliced; | |
743 | int ret; | |
744 | ||
3a047bf8 | 745 | sock_rps_record_flow(sk); |
9c55e01c JA |
746 | /* |
747 | * We can't seek on a socket input | |
748 | */ | |
749 | if (unlikely(*ppos)) | |
750 | return -ESPIPE; | |
751 | ||
752 | ret = spliced = 0; | |
753 | ||
754 | lock_sock(sk); | |
755 | ||
42324c62 | 756 | timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); |
9c55e01c JA |
757 | while (tss.len) { |
758 | ret = __tcp_splice_read(sk, &tss); | |
759 | if (ret < 0) | |
760 | break; | |
761 | else if (!ret) { | |
762 | if (spliced) | |
763 | break; | |
9c55e01c JA |
764 | if (sock_flag(sk, SOCK_DONE)) |
765 | break; | |
766 | if (sk->sk_err) { | |
767 | ret = sock_error(sk); | |
768 | break; | |
769 | } | |
770 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
771 | break; | |
772 | if (sk->sk_state == TCP_CLOSE) { | |
773 | /* | |
774 | * This occurs when user tries to read | |
775 | * from never connected socket. | |
776 | */ | |
777 | if (!sock_flag(sk, SOCK_DONE)) | |
778 | ret = -ENOTCONN; | |
779 | break; | |
780 | } | |
781 | if (!timeo) { | |
782 | ret = -EAGAIN; | |
783 | break; | |
784 | } | |
dfbafc99 | 785 | sk_wait_data(sk, &timeo, NULL); |
9c55e01c JA |
786 | if (signal_pending(current)) { |
787 | ret = sock_intr_errno(timeo); | |
788 | break; | |
789 | } | |
790 | continue; | |
791 | } | |
792 | tss.len -= ret; | |
793 | spliced += ret; | |
794 | ||
33966dd0 WT |
795 | if (!timeo) |
796 | break; | |
9c55e01c JA |
797 | release_sock(sk); |
798 | lock_sock(sk); | |
799 | ||
800 | if (sk->sk_err || sk->sk_state == TCP_CLOSE || | |
33966dd0 | 801 | (sk->sk_shutdown & RCV_SHUTDOWN) || |
9c55e01c JA |
802 | signal_pending(current)) |
803 | break; | |
804 | } | |
805 | ||
806 | release_sock(sk); | |
807 | ||
808 | if (spliced) | |
809 | return spliced; | |
810 | ||
811 | return ret; | |
812 | } | |
4bc2f18b | 813 | EXPORT_SYMBOL(tcp_splice_read); |
9c55e01c | 814 | |
eb934478 ED |
815 | struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, |
816 | bool force_schedule) | |
f561d0f2 PE |
817 | { |
818 | struct sk_buff *skb; | |
819 | ||
820 | /* The TCP header must be at least 32-bit aligned. */ | |
821 | size = ALIGN(size, 4); | |
822 | ||
8e4d980a ED |
823 | if (unlikely(tcp_under_memory_pressure(sk))) |
824 | sk_mem_reclaim_partial(sk); | |
825 | ||
f561d0f2 | 826 | skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); |
8e4d980a | 827 | if (likely(skb)) { |
eb934478 | 828 | bool mem_scheduled; |
8e4d980a | 829 | |
eb934478 ED |
830 | if (force_schedule) { |
831 | mem_scheduled = true; | |
8e4d980a ED |
832 | sk_forced_mem_schedule(sk, skb->truesize); |
833 | } else { | |
eb934478 | 834 | mem_scheduled = sk_wmem_schedule(sk, skb->truesize); |
8e4d980a | 835 | } |
eb934478 | 836 | if (likely(mem_scheduled)) { |
a21d4572 | 837 | skb_reserve(skb, sk->sk_prot->max_header); |
f561d0f2 PE |
838 | /* |
839 | * Make sure that we have exactly size bytes | |
840 | * available to the caller, no more, no less. | |
841 | */ | |
16fad69c | 842 | skb->reserved_tailroom = skb->end - skb->tail - size; |
f561d0f2 PE |
843 | return skb; |
844 | } | |
845 | __kfree_skb(skb); | |
846 | } else { | |
5c52ba17 | 847 | sk->sk_prot->enter_memory_pressure(sk); |
f561d0f2 PE |
848 | sk_stream_moderate_sndbuf(sk); |
849 | } | |
850 | return NULL; | |
851 | } | |
852 | ||
0c54b85f IJ |
853 | static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, |
854 | int large_allowed) | |
855 | { | |
856 | struct tcp_sock *tp = tcp_sk(sk); | |
6c09fa09 | 857 | u32 new_size_goal, size_goal; |
605ad7f1 ED |
858 | |
859 | if (!large_allowed || !sk_can_gso(sk)) | |
860 | return mss_now; | |
861 | ||
6c09fa09 ED |
862 | /* Note : tcp_tso_autosize() will eventually split this later */ |
863 | new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER; | |
605ad7f1 ED |
864 | new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal); |
865 | ||
866 | /* We try hard to avoid divides here */ | |
867 | size_goal = tp->gso_segs * mss_now; | |
868 | if (unlikely(new_size_goal < size_goal || | |
869 | new_size_goal >= size_goal + mss_now)) { | |
870 | tp->gso_segs = min_t(u16, new_size_goal / mss_now, | |
871 | sk->sk_gso_max_segs); | |
872 | size_goal = tp->gso_segs * mss_now; | |
0c54b85f IJ |
873 | } |
874 | ||
605ad7f1 | 875 | return max(size_goal, mss_now); |
0c54b85f IJ |
876 | } |
877 | ||
878 | static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) | |
879 | { | |
880 | int mss_now; | |
881 | ||
882 | mss_now = tcp_current_mss(sk); | |
883 | *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); | |
884 | ||
885 | return mss_now; | |
886 | } | |
887 | ||
64022d0b ED |
888 | static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, |
889 | size_t size, int flags) | |
1da177e4 LT |
890 | { |
891 | struct tcp_sock *tp = tcp_sk(sk); | |
c1b4a7e6 | 892 | int mss_now, size_goal; |
1da177e4 LT |
893 | int err; |
894 | ssize_t copied; | |
895 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
896 | ||
8336886f JC |
897 | /* Wait for a connection to finish. One exception is TCP Fast Open |
898 | * (passive side) where data is allowed to be sent before a connection | |
899 | * is fully established. | |
900 | */ | |
901 | if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && | |
902 | !tcp_passive_fastopen(sk)) { | |
1da177e4 LT |
903 | if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) |
904 | goto out_err; | |
8336886f | 905 | } |
1da177e4 LT |
906 | |
907 | clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
908 | ||
0c54b85f | 909 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
910 | copied = 0; |
911 | ||
912 | err = -EPIPE; | |
913 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
0d6a775e | 914 | goto out_err; |
1da177e4 | 915 | |
64022d0b | 916 | while (size > 0) { |
fe067e8a | 917 | struct sk_buff *skb = tcp_write_queue_tail(sk); |
38ba0a65 | 918 | int copy, i; |
38ba0a65 | 919 | bool can_coalesce; |
1da177e4 | 920 | |
fe067e8a | 921 | if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { |
1da177e4 LT |
922 | new_segment: |
923 | if (!sk_stream_memory_free(sk)) | |
924 | goto wait_for_sndbuf; | |
925 | ||
eb934478 ED |
926 | skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, |
927 | skb_queue_empty(&sk->sk_write_queue)); | |
1da177e4 LT |
928 | if (!skb) |
929 | goto wait_for_memory; | |
930 | ||
9e412ba7 | 931 | skb_entail(sk, skb); |
c1b4a7e6 | 932 | copy = size_goal; |
1da177e4 LT |
933 | } |
934 | ||
935 | if (copy > size) | |
936 | copy = size; | |
937 | ||
938 | i = skb_shinfo(skb)->nr_frags; | |
939 | can_coalesce = skb_can_coalesce(skb, i, page, offset); | |
940 | if (!can_coalesce && i >= MAX_SKB_FRAGS) { | |
941 | tcp_mark_push(tp, skb); | |
942 | goto new_segment; | |
943 | } | |
3ab224be | 944 | if (!sk_wmem_schedule(sk, copy)) |
1da177e4 | 945 | goto wait_for_memory; |
e905a9ed | 946 | |
1da177e4 | 947 | if (can_coalesce) { |
9e903e08 | 948 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
1da177e4 LT |
949 | } else { |
950 | get_page(page); | |
951 | skb_fill_page_desc(skb, i, page, offset, copy); | |
952 | } | |
c9af6db4 | 953 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
cef401de | 954 | |
1da177e4 LT |
955 | skb->len += copy; |
956 | skb->data_len += copy; | |
957 | skb->truesize += copy; | |
958 | sk->sk_wmem_queued += copy; | |
3ab224be | 959 | sk_mem_charge(sk, copy); |
84fa7933 | 960 | skb->ip_summed = CHECKSUM_PARTIAL; |
1da177e4 LT |
961 | tp->write_seq += copy; |
962 | TCP_SKB_CB(skb)->end_seq += copy; | |
cd7d8498 | 963 | tcp_skb_pcount_set(skb, 0); |
1da177e4 LT |
964 | |
965 | if (!copied) | |
4de075e0 | 966 | TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; |
1da177e4 LT |
967 | |
968 | copied += copy; | |
64022d0b | 969 | offset += copy; |
4ed2d765 WB |
970 | if (!(size -= copy)) { |
971 | tcp_tx_timestamp(sk, skb); | |
1da177e4 | 972 | goto out; |
4ed2d765 | 973 | } |
1da177e4 | 974 | |
69d15067 | 975 | if (skb->len < size_goal || (flags & MSG_OOB)) |
1da177e4 LT |
976 | continue; |
977 | ||
978 | if (forced_push(tp)) { | |
979 | tcp_mark_push(tp, skb); | |
9e412ba7 | 980 | __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); |
fe067e8a | 981 | } else if (skb == tcp_send_head(sk)) |
1da177e4 LT |
982 | tcp_push_one(sk, mss_now); |
983 | continue; | |
984 | ||
985 | wait_for_sndbuf: | |
986 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
987 | wait_for_memory: | |
f54b3111 ED |
988 | tcp_push(sk, flags & ~MSG_MORE, mss_now, |
989 | TCP_NAGLE_PUSH, size_goal); | |
1da177e4 LT |
990 | |
991 | if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) | |
992 | goto do_error; | |
993 | ||
0c54b85f | 994 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
995 | } |
996 | ||
997 | out: | |
35f9c09f | 998 | if (copied && !(flags & MSG_SENDPAGE_NOTLAST)) |
f54b3111 | 999 | tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); |
1da177e4 LT |
1000 | return copied; |
1001 | ||
1002 | do_error: | |
1003 | if (copied) | |
1004 | goto out; | |
1005 | out_err: | |
ce5ec440 JB |
1006 | /* make sure we wake any epoll edge trigger waiter */ |
1007 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
1008 | sk->sk_write_space(sk); | |
1da177e4 LT |
1009 | return sk_stream_error(sk, flags, err); |
1010 | } | |
1011 | ||
7ba42910 CG |
1012 | int tcp_sendpage(struct sock *sk, struct page *page, int offset, |
1013 | size_t size, int flags) | |
1da177e4 LT |
1014 | { |
1015 | ssize_t res; | |
1da177e4 | 1016 | |
1da177e4 | 1017 | if (!(sk->sk_route_caps & NETIF_F_SG) || |
8648b305 | 1018 | !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) |
7ba42910 CG |
1019 | return sock_no_sendpage(sk->sk_socket, page, offset, size, |
1020 | flags); | |
1da177e4 | 1021 | |
1da177e4 | 1022 | lock_sock(sk); |
64022d0b | 1023 | res = do_tcp_sendpages(sk, page, offset, size, flags); |
1da177e4 LT |
1024 | release_sock(sk); |
1025 | return res; | |
1026 | } | |
4bc2f18b | 1027 | EXPORT_SYMBOL(tcp_sendpage); |
1da177e4 | 1028 | |
690e99c4 | 1029 | static inline int select_size(const struct sock *sk, bool sg) |
1da177e4 | 1030 | { |
cf533ea5 | 1031 | const struct tcp_sock *tp = tcp_sk(sk); |
c1b4a7e6 | 1032 | int tmp = tp->mss_cache; |
1da177e4 | 1033 | |
def87cf4 | 1034 | if (sg) { |
f07d960d ED |
1035 | if (sk_can_gso(sk)) { |
1036 | /* Small frames wont use a full page: | |
1037 | * Payload will immediately follow tcp header. | |
1038 | */ | |
1039 | tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); | |
1040 | } else { | |
b4e26f5e DM |
1041 | int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); |
1042 | ||
1043 | if (tmp >= pgbreak && | |
1044 | tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) | |
1045 | tmp = pgbreak; | |
1046 | } | |
1047 | } | |
1da177e4 | 1048 | |
1da177e4 LT |
1049 | return tmp; |
1050 | } | |
1051 | ||
cf60af03 YC |
1052 | void tcp_free_fastopen_req(struct tcp_sock *tp) |
1053 | { | |
00db4124 | 1054 | if (tp->fastopen_req) { |
cf60af03 YC |
1055 | kfree(tp->fastopen_req); |
1056 | tp->fastopen_req = NULL; | |
1057 | } | |
1058 | } | |
1059 | ||
f5ddcbbb ED |
1060 | static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, |
1061 | int *copied, size_t size) | |
cf60af03 YC |
1062 | { |
1063 | struct tcp_sock *tp = tcp_sk(sk); | |
1064 | int err, flags; | |
1065 | ||
1066 | if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE)) | |
1067 | return -EOPNOTSUPP; | |
00db4124 | 1068 | if (tp->fastopen_req) |
cf60af03 YC |
1069 | return -EALREADY; /* Another Fast Open is in progress */ |
1070 | ||
1071 | tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), | |
1072 | sk->sk_allocation); | |
51456b29 | 1073 | if (unlikely(!tp->fastopen_req)) |
cf60af03 YC |
1074 | return -ENOBUFS; |
1075 | tp->fastopen_req->data = msg; | |
f5ddcbbb | 1076 | tp->fastopen_req->size = size; |
cf60af03 YC |
1077 | |
1078 | flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; | |
1079 | err = __inet_stream_connect(sk->sk_socket, msg->msg_name, | |
1080 | msg->msg_namelen, flags); | |
f5ddcbbb | 1081 | *copied = tp->fastopen_req->copied; |
cf60af03 YC |
1082 | tcp_free_fastopen_req(tp); |
1083 | return err; | |
1084 | } | |
1085 | ||
1b784140 | 1086 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) |
1da177e4 | 1087 | { |
1da177e4 LT |
1088 | struct tcp_sock *tp = tcp_sk(sk); |
1089 | struct sk_buff *skb; | |
57be5bda AV |
1090 | int flags, err, copied = 0; |
1091 | int mss_now = 0, size_goal, copied_syn = 0; | |
690e99c4 | 1092 | bool sg; |
1da177e4 LT |
1093 | long timeo; |
1094 | ||
1095 | lock_sock(sk); | |
1da177e4 LT |
1096 | |
1097 | flags = msg->msg_flags; | |
cf60af03 | 1098 | if (flags & MSG_FASTOPEN) { |
f5ddcbbb | 1099 | err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size); |
cf60af03 YC |
1100 | if (err == -EINPROGRESS && copied_syn > 0) |
1101 | goto out; | |
1102 | else if (err) | |
1103 | goto out_err; | |
cf60af03 YC |
1104 | } |
1105 | ||
1da177e4 LT |
1106 | timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); |
1107 | ||
8336886f JC |
1108 | /* Wait for a connection to finish. One exception is TCP Fast Open |
1109 | * (passive side) where data is allowed to be sent before a connection | |
1110 | * is fully established. | |
1111 | */ | |
1112 | if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && | |
1113 | !tcp_passive_fastopen(sk)) { | |
1da177e4 | 1114 | if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) |
cf60af03 | 1115 | goto do_error; |
8336886f | 1116 | } |
1da177e4 | 1117 | |
c0e88ff0 PE |
1118 | if (unlikely(tp->repair)) { |
1119 | if (tp->repair_queue == TCP_RECV_QUEUE) { | |
1120 | copied = tcp_send_rcvq(sk, msg, size); | |
5924f17a | 1121 | goto out_nopush; |
c0e88ff0 PE |
1122 | } |
1123 | ||
1124 | err = -EINVAL; | |
1125 | if (tp->repair_queue == TCP_NO_QUEUE) | |
1126 | goto out_err; | |
1127 | ||
1128 | /* 'common' sending to sendq */ | |
1129 | } | |
1130 | ||
1da177e4 LT |
1131 | /* This should be in poll */ |
1132 | clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
1133 | ||
0c54b85f | 1134 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
1135 | |
1136 | /* Ok commence sending. */ | |
1da177e4 LT |
1137 | copied = 0; |
1138 | ||
1139 | err = -EPIPE; | |
1140 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
0d6a775e | 1141 | goto out_err; |
1da177e4 | 1142 | |
690e99c4 | 1143 | sg = !!(sk->sk_route_caps & NETIF_F_SG); |
def87cf4 | 1144 | |
01e97e65 | 1145 | while (msg_data_left(msg)) { |
57be5bda AV |
1146 | int copy = 0; |
1147 | int max = size_goal; | |
1da177e4 | 1148 | |
57be5bda AV |
1149 | skb = tcp_write_queue_tail(sk); |
1150 | if (tcp_send_head(sk)) { | |
1151 | if (skb->ip_summed == CHECKSUM_NONE) | |
1152 | max = mss_now; | |
1153 | copy = max - skb->len; | |
cf60af03 | 1154 | } |
1da177e4 | 1155 | |
57be5bda | 1156 | if (copy <= 0) { |
1da177e4 | 1157 | new_segment: |
57be5bda AV |
1158 | /* Allocate new segment. If the interface is SG, |
1159 | * allocate skb fitting to single page. | |
1160 | */ | |
1161 | if (!sk_stream_memory_free(sk)) | |
1162 | goto wait_for_sndbuf; | |
1da177e4 | 1163 | |
57be5bda AV |
1164 | skb = sk_stream_alloc_skb(sk, |
1165 | select_size(sk, sg), | |
eb934478 ED |
1166 | sk->sk_allocation, |
1167 | skb_queue_empty(&sk->sk_write_queue)); | |
57be5bda AV |
1168 | if (!skb) |
1169 | goto wait_for_memory; | |
1da177e4 | 1170 | |
57be5bda AV |
1171 | /* |
1172 | * Check whether we can use HW checksum. | |
1173 | */ | |
1174 | if (sk->sk_route_caps & NETIF_F_ALL_CSUM) | |
1175 | skb->ip_summed = CHECKSUM_PARTIAL; | |
1da177e4 | 1176 | |
57be5bda AV |
1177 | skb_entail(sk, skb); |
1178 | copy = size_goal; | |
1179 | max = size_goal; | |
9d186cac | 1180 | |
57be5bda AV |
1181 | /* All packets are restored as if they have |
1182 | * already been sent. skb_mstamp isn't set to | |
1183 | * avoid wrong rtt estimation. | |
1184 | */ | |
1185 | if (tp->repair) | |
1186 | TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED; | |
1187 | } | |
1da177e4 | 1188 | |
57be5bda | 1189 | /* Try to append data to the end of skb. */ |
01e97e65 AV |
1190 | if (copy > msg_data_left(msg)) |
1191 | copy = msg_data_left(msg); | |
57be5bda AV |
1192 | |
1193 | /* Where to copy to? */ | |
1194 | if (skb_availroom(skb) > 0) { | |
1195 | /* We have some space in skb head. Superb! */ | |
1196 | copy = min_t(int, copy, skb_availroom(skb)); | |
1197 | err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy); | |
1198 | if (err) | |
1199 | goto do_fault; | |
1200 | } else { | |
1201 | bool merge = true; | |
1202 | int i = skb_shinfo(skb)->nr_frags; | |
1203 | struct page_frag *pfrag = sk_page_frag(sk); | |
1204 | ||
1205 | if (!sk_page_frag_refill(sk, pfrag)) | |
1206 | goto wait_for_memory; | |
ef015786 | 1207 | |
57be5bda AV |
1208 | if (!skb_can_coalesce(skb, i, pfrag->page, |
1209 | pfrag->offset)) { | |
1210 | if (i == MAX_SKB_FRAGS || !sg) { | |
1211 | tcp_mark_push(tp, skb); | |
1212 | goto new_segment; | |
1da177e4 | 1213 | } |
57be5bda | 1214 | merge = false; |
1da177e4 LT |
1215 | } |
1216 | ||
57be5bda AV |
1217 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
1218 | ||
1219 | if (!sk_wmem_schedule(sk, copy)) | |
1220 | goto wait_for_memory; | |
1da177e4 | 1221 | |
57be5bda AV |
1222 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, |
1223 | pfrag->page, | |
1224 | pfrag->offset, | |
1225 | copy); | |
1226 | if (err) | |
1227 | goto do_error; | |
1da177e4 | 1228 | |
57be5bda AV |
1229 | /* Update the skb. */ |
1230 | if (merge) { | |
1231 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1232 | } else { | |
1233 | skb_fill_page_desc(skb, i, pfrag->page, | |
1234 | pfrag->offset, copy); | |
1235 | get_page(pfrag->page); | |
4ed2d765 | 1236 | } |
57be5bda AV |
1237 | pfrag->offset += copy; |
1238 | } | |
1239 | ||
1240 | if (!copied) | |
1241 | TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; | |
1242 | ||
1243 | tp->write_seq += copy; | |
1244 | TCP_SKB_CB(skb)->end_seq += copy; | |
1245 | tcp_skb_pcount_set(skb, 0); | |
1da177e4 | 1246 | |
57be5bda | 1247 | copied += copy; |
01e97e65 | 1248 | if (!msg_data_left(msg)) { |
57be5bda AV |
1249 | tcp_tx_timestamp(sk, skb); |
1250 | goto out; | |
1251 | } | |
1da177e4 | 1252 | |
57be5bda | 1253 | if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair)) |
1da177e4 LT |
1254 | continue; |
1255 | ||
57be5bda AV |
1256 | if (forced_push(tp)) { |
1257 | tcp_mark_push(tp, skb); | |
1258 | __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); | |
1259 | } else if (skb == tcp_send_head(sk)) | |
1260 | tcp_push_one(sk, mss_now); | |
1261 | continue; | |
1262 | ||
1da177e4 | 1263 | wait_for_sndbuf: |
57be5bda | 1264 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
1da177e4 | 1265 | wait_for_memory: |
57be5bda AV |
1266 | if (copied) |
1267 | tcp_push(sk, flags & ~MSG_MORE, mss_now, | |
1268 | TCP_NAGLE_PUSH, size_goal); | |
1da177e4 | 1269 | |
57be5bda AV |
1270 | if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) |
1271 | goto do_error; | |
1da177e4 | 1272 | |
57be5bda | 1273 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
1274 | } |
1275 | ||
1276 | out: | |
ec342325 | 1277 | if (copied) |
f54b3111 | 1278 | tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); |
5924f17a | 1279 | out_nopush: |
1da177e4 | 1280 | release_sock(sk); |
cf60af03 | 1281 | return copied + copied_syn; |
1da177e4 LT |
1282 | |
1283 | do_fault: | |
1284 | if (!skb->len) { | |
fe067e8a DM |
1285 | tcp_unlink_write_queue(skb, sk); |
1286 | /* It is the one place in all of TCP, except connection | |
1287 | * reset, where we can be unlinking the send_head. | |
1288 | */ | |
1289 | tcp_check_send_head(sk, skb); | |
3ab224be | 1290 | sk_wmem_free_skb(sk, skb); |
1da177e4 LT |
1291 | } |
1292 | ||
1293 | do_error: | |
cf60af03 | 1294 | if (copied + copied_syn) |
1da177e4 LT |
1295 | goto out; |
1296 | out_err: | |
1297 | err = sk_stream_error(sk, flags, err); | |
ce5ec440 JB |
1298 | /* make sure we wake any epoll edge trigger waiter */ |
1299 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
1300 | sk->sk_write_space(sk); | |
1da177e4 LT |
1301 | release_sock(sk); |
1302 | return err; | |
1303 | } | |
4bc2f18b | 1304 | EXPORT_SYMBOL(tcp_sendmsg); |
1da177e4 LT |
1305 | |
1306 | /* | |
1307 | * Handle reading urgent data. BSD has very simple semantics for | |
1308 | * this, no blocking and very strange errors 8) | |
1309 | */ | |
1310 | ||
377f0a08 | 1311 | static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) |
1da177e4 LT |
1312 | { |
1313 | struct tcp_sock *tp = tcp_sk(sk); | |
1314 | ||
1315 | /* No URG data to read. */ | |
1316 | if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || | |
1317 | tp->urg_data == TCP_URG_READ) | |
1318 | return -EINVAL; /* Yes this is right ! */ | |
1319 | ||
1320 | if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) | |
1321 | return -ENOTCONN; | |
1322 | ||
1323 | if (tp->urg_data & TCP_URG_VALID) { | |
1324 | int err = 0; | |
1325 | char c = tp->urg_data; | |
1326 | ||
1327 | if (!(flags & MSG_PEEK)) | |
1328 | tp->urg_data = TCP_URG_READ; | |
1329 | ||
1330 | /* Read urgent data. */ | |
1331 | msg->msg_flags |= MSG_OOB; | |
1332 | ||
1333 | if (len > 0) { | |
1334 | if (!(flags & MSG_TRUNC)) | |
7eab8d9e | 1335 | err = memcpy_to_msg(msg, &c, 1); |
1da177e4 LT |
1336 | len = 1; |
1337 | } else | |
1338 | msg->msg_flags |= MSG_TRUNC; | |
1339 | ||
1340 | return err ? -EFAULT : len; | |
1341 | } | |
1342 | ||
1343 | if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1344 | return 0; | |
1345 | ||
1346 | /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and | |
1347 | * the available implementations agree in this case: | |
1348 | * this call should never block, independent of the | |
1349 | * blocking state of the socket. | |
1350 | * Mike <pall@rz.uni-karlsruhe.de> | |
1351 | */ | |
1352 | return -EAGAIN; | |
1353 | } | |
1354 | ||
c0e88ff0 PE |
1355 | static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len) |
1356 | { | |
1357 | struct sk_buff *skb; | |
1358 | int copied = 0, err = 0; | |
1359 | ||
1360 | /* XXX -- need to support SO_PEEK_OFF */ | |
1361 | ||
1362 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
51f3d02b | 1363 | err = skb_copy_datagram_msg(skb, 0, msg, skb->len); |
c0e88ff0 PE |
1364 | if (err) |
1365 | break; | |
1366 | ||
1367 | copied += skb->len; | |
1368 | } | |
1369 | ||
1370 | return err ?: copied; | |
1371 | } | |
1372 | ||
1da177e4 LT |
1373 | /* Clean up the receive buffer for full frames taken by the user, |
1374 | * then send an ACK if necessary. COPIED is the number of bytes | |
1375 | * tcp_recvmsg has given to the user so far, it speeds up the | |
1376 | * calculation of whether or not we must ACK for the sake of | |
1377 | * a window update. | |
1378 | */ | |
3f334078 | 1379 | static void tcp_cleanup_rbuf(struct sock *sk, int copied) |
1da177e4 LT |
1380 | { |
1381 | struct tcp_sock *tp = tcp_sk(sk); | |
a2a385d6 | 1382 | bool time_to_ack = false; |
1da177e4 | 1383 | |
1da177e4 LT |
1384 | struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); |
1385 | ||
d792c100 | 1386 | WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), |
2af6fd8b | 1387 | "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", |
d792c100 | 1388 | tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); |
1da177e4 | 1389 | |
463c84b9 ACM |
1390 | if (inet_csk_ack_scheduled(sk)) { |
1391 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
1da177e4 LT |
1392 | /* Delayed ACKs frequently hit locked sockets during bulk |
1393 | * receive. */ | |
463c84b9 | 1394 | if (icsk->icsk_ack.blocked || |
1da177e4 | 1395 | /* Once-per-two-segments ACK was not sent by tcp_input.c */ |
463c84b9 | 1396 | tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || |
1da177e4 LT |
1397 | /* |
1398 | * If this read emptied read buffer, we send ACK, if | |
1399 | * connection is not bidirectional, user drained | |
1400 | * receive buffer and there was a small segment | |
1401 | * in queue. | |
1402 | */ | |
1ef9696c AK |
1403 | (copied > 0 && |
1404 | ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || | |
1405 | ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && | |
1406 | !icsk->icsk_ack.pingpong)) && | |
1407 | !atomic_read(&sk->sk_rmem_alloc))) | |
a2a385d6 | 1408 | time_to_ack = true; |
1da177e4 LT |
1409 | } |
1410 | ||
1411 | /* We send an ACK if we can now advertise a non-zero window | |
1412 | * which has been raised "significantly". | |
1413 | * | |
1414 | * Even if window raised up to infinity, do not send window open ACK | |
1415 | * in states, where we will not receive more. It is useless. | |
1416 | */ | |
1417 | if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { | |
1418 | __u32 rcv_window_now = tcp_receive_window(tp); | |
1419 | ||
1420 | /* Optimize, __tcp_select_window() is not cheap. */ | |
1421 | if (2*rcv_window_now <= tp->window_clamp) { | |
1422 | __u32 new_window = __tcp_select_window(sk); | |
1423 | ||
1424 | /* Send ACK now, if this read freed lots of space | |
1425 | * in our buffer. Certainly, new_window is new window. | |
1426 | * We can advertise it now, if it is not less than current one. | |
1427 | * "Lots" means "at least twice" here. | |
1428 | */ | |
1429 | if (new_window && new_window >= 2 * rcv_window_now) | |
a2a385d6 | 1430 | time_to_ack = true; |
1da177e4 LT |
1431 | } |
1432 | } | |
1433 | if (time_to_ack) | |
1434 | tcp_send_ack(sk); | |
1435 | } | |
1436 | ||
1437 | static void tcp_prequeue_process(struct sock *sk) | |
1438 | { | |
1439 | struct sk_buff *skb; | |
1440 | struct tcp_sock *tp = tcp_sk(sk); | |
1441 | ||
6f67c817 | 1442 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); |
1da177e4 LT |
1443 | |
1444 | /* RX process wants to run with disabled BHs, though it is not | |
1445 | * necessary */ | |
1446 | local_bh_disable(); | |
1447 | while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) | |
c57943a1 | 1448 | sk_backlog_rcv(sk, skb); |
1da177e4 LT |
1449 | local_bh_enable(); |
1450 | ||
1451 | /* Clear memory counter. */ | |
1452 | tp->ucopy.memory = 0; | |
1453 | } | |
1454 | ||
f26845b4 | 1455 | static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) |
1da177e4 LT |
1456 | { |
1457 | struct sk_buff *skb; | |
1458 | u32 offset; | |
1459 | ||
f26845b4 | 1460 | while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { |
1da177e4 | 1461 | offset = seq - TCP_SKB_CB(skb)->seq; |
e11ecddf | 1462 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) |
1da177e4 | 1463 | offset--; |
e11ecddf | 1464 | if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) { |
1da177e4 LT |
1465 | *off = offset; |
1466 | return skb; | |
1467 | } | |
f26845b4 ED |
1468 | /* This looks weird, but this can happen if TCP collapsing |
1469 | * splitted a fat GRO packet, while we released socket lock | |
1470 | * in skb_splice_bits() | |
1471 | */ | |
7bced397 | 1472 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1473 | } |
1474 | return NULL; | |
1475 | } | |
1476 | ||
1477 | /* | |
1478 | * This routine provides an alternative to tcp_recvmsg() for routines | |
1479 | * that would like to handle copying from skbuffs directly in 'sendfile' | |
1480 | * fashion. | |
1481 | * Note: | |
1482 | * - It is assumed that the socket was locked by the caller. | |
1483 | * - The routine does not block. | |
1484 | * - At present, there is no support for reading OOB data | |
1485 | * or for 'peeking' the socket using this routine | |
1486 | * (although both would be easy to implement). | |
1487 | */ | |
1488 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, | |
1489 | sk_read_actor_t recv_actor) | |
1490 | { | |
1491 | struct sk_buff *skb; | |
1492 | struct tcp_sock *tp = tcp_sk(sk); | |
1493 | u32 seq = tp->copied_seq; | |
1494 | u32 offset; | |
1495 | int copied = 0; | |
1496 | ||
1497 | if (sk->sk_state == TCP_LISTEN) | |
1498 | return -ENOTCONN; | |
1499 | while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { | |
1500 | if (offset < skb->len) { | |
374e7b59 OP |
1501 | int used; |
1502 | size_t len; | |
1da177e4 LT |
1503 | |
1504 | len = skb->len - offset; | |
1505 | /* Stop reading if we hit a patch of urgent data */ | |
1506 | if (tp->urg_data) { | |
1507 | u32 urg_offset = tp->urg_seq - seq; | |
1508 | if (urg_offset < len) | |
1509 | len = urg_offset; | |
1510 | if (!len) | |
1511 | break; | |
1512 | } | |
1513 | used = recv_actor(desc, skb, offset, len); | |
ff905b1e | 1514 | if (used <= 0) { |
ddb61a57 JA |
1515 | if (!copied) |
1516 | copied = used; | |
1517 | break; | |
1518 | } else if (used <= len) { | |
1da177e4 LT |
1519 | seq += used; |
1520 | copied += used; | |
1521 | offset += used; | |
1522 | } | |
02275a2e | 1523 | /* If recv_actor drops the lock (e.g. TCP splice |
293ad604 OP |
1524 | * receive) the skb pointer might be invalid when |
1525 | * getting here: tcp_collapse might have deleted it | |
1526 | * while aggregating skbs from the socket queue. | |
1527 | */ | |
02275a2e WT |
1528 | skb = tcp_recv_skb(sk, seq - 1, &offset); |
1529 | if (!skb) | |
1da177e4 | 1530 | break; |
02275a2e WT |
1531 | /* TCP coalescing might have appended data to the skb. |
1532 | * Try to splice more frags | |
1533 | */ | |
1534 | if (offset + 1 != skb->len) | |
1535 | continue; | |
1da177e4 | 1536 | } |
e11ecddf | 1537 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) { |
7bced397 | 1538 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1539 | ++seq; |
1540 | break; | |
1541 | } | |
7bced397 | 1542 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1543 | if (!desc->count) |
1544 | break; | |
baff42ab | 1545 | tp->copied_seq = seq; |
1da177e4 LT |
1546 | } |
1547 | tp->copied_seq = seq; | |
1548 | ||
1549 | tcp_rcv_space_adjust(sk); | |
1550 | ||
1551 | /* Clean up data we have read: This will do ACK frames. */ | |
f26845b4 ED |
1552 | if (copied > 0) { |
1553 | tcp_recv_skb(sk, seq, &offset); | |
0e4b4992 | 1554 | tcp_cleanup_rbuf(sk, copied); |
f26845b4 | 1555 | } |
1da177e4 LT |
1556 | return copied; |
1557 | } | |
4bc2f18b | 1558 | EXPORT_SYMBOL(tcp_read_sock); |
1da177e4 LT |
1559 | |
1560 | /* | |
1561 | * This routine copies from a sock struct into the user buffer. | |
1562 | * | |
1563 | * Technical note: in 2.3 we work on _locked_ socket, so that | |
1564 | * tricks with *seq access order and skb->users are not required. | |
1565 | * Probably, code can be easily improved even more. | |
1566 | */ | |
1567 | ||
1b784140 YX |
1568 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, |
1569 | int flags, int *addr_len) | |
1da177e4 LT |
1570 | { |
1571 | struct tcp_sock *tp = tcp_sk(sk); | |
1572 | int copied = 0; | |
1573 | u32 peek_seq; | |
1574 | u32 *seq; | |
1575 | unsigned long used; | |
1576 | int err; | |
1577 | int target; /* Read at least this many bytes */ | |
1578 | long timeo; | |
1579 | struct task_struct *user_recv = NULL; | |
dfbafc99 | 1580 | struct sk_buff *skb, *last; |
77527313 | 1581 | u32 urg_hole = 0; |
1da177e4 | 1582 | |
4ed2d765 | 1583 | if (unlikely(flags & MSG_ERRQUEUE)) |
f4713a3d | 1584 | return inet_recv_error(sk, msg, len, addr_len); |
4ed2d765 | 1585 | |
cbf55001 ET |
1586 | if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) && |
1587 | (sk->sk_state == TCP_ESTABLISHED)) | |
1588 | sk_busy_loop(sk, nonblock); | |
d30e383b | 1589 | |
1da177e4 LT |
1590 | lock_sock(sk); |
1591 | ||
1da177e4 LT |
1592 | err = -ENOTCONN; |
1593 | if (sk->sk_state == TCP_LISTEN) | |
1594 | goto out; | |
1595 | ||
1596 | timeo = sock_rcvtimeo(sk, nonblock); | |
1597 | ||
1598 | /* Urgent data needs to be handled specially. */ | |
1599 | if (flags & MSG_OOB) | |
1600 | goto recv_urg; | |
1601 | ||
c0e88ff0 PE |
1602 | if (unlikely(tp->repair)) { |
1603 | err = -EPERM; | |
1604 | if (!(flags & MSG_PEEK)) | |
1605 | goto out; | |
1606 | ||
1607 | if (tp->repair_queue == TCP_SEND_QUEUE) | |
1608 | goto recv_sndq; | |
1609 | ||
1610 | err = -EINVAL; | |
1611 | if (tp->repair_queue == TCP_NO_QUEUE) | |
1612 | goto out; | |
1613 | ||
1614 | /* 'common' recv queue MSG_PEEK-ing */ | |
1615 | } | |
1616 | ||
1da177e4 LT |
1617 | seq = &tp->copied_seq; |
1618 | if (flags & MSG_PEEK) { | |
1619 | peek_seq = tp->copied_seq; | |
1620 | seq = &peek_seq; | |
1621 | } | |
1622 | ||
1623 | target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); | |
1624 | ||
1625 | do { | |
1da177e4 LT |
1626 | u32 offset; |
1627 | ||
1628 | /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ | |
1629 | if (tp->urg_data && tp->urg_seq == *seq) { | |
1630 | if (copied) | |
1631 | break; | |
1632 | if (signal_pending(current)) { | |
1633 | copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; | |
1634 | break; | |
1635 | } | |
1636 | } | |
1637 | ||
1638 | /* Next get a buffer. */ | |
1639 | ||
dfbafc99 | 1640 | last = skb_peek_tail(&sk->sk_receive_queue); |
91521944 | 1641 | skb_queue_walk(&sk->sk_receive_queue, skb) { |
dfbafc99 | 1642 | last = skb; |
1da177e4 LT |
1643 | /* Now that we have two receive queues this |
1644 | * shouldn't happen. | |
1645 | */ | |
d792c100 | 1646 | if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), |
2af6fd8b JP |
1647 | "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n", |
1648 | *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, | |
1649 | flags)) | |
1da177e4 | 1650 | break; |
d792c100 | 1651 | |
1da177e4 | 1652 | offset = *seq - TCP_SKB_CB(skb)->seq; |
e11ecddf | 1653 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) |
1da177e4 LT |
1654 | offset--; |
1655 | if (offset < skb->len) | |
1656 | goto found_ok_skb; | |
e11ecddf | 1657 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) |
1da177e4 | 1658 | goto found_fin_ok; |
2af6fd8b JP |
1659 | WARN(!(flags & MSG_PEEK), |
1660 | "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n", | |
1661 | *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); | |
91521944 | 1662 | } |
1da177e4 LT |
1663 | |
1664 | /* Well, if we have backlog, try to process it now yet. */ | |
1665 | ||
1666 | if (copied >= target && !sk->sk_backlog.tail) | |
1667 | break; | |
1668 | ||
1669 | if (copied) { | |
1670 | if (sk->sk_err || | |
1671 | sk->sk_state == TCP_CLOSE || | |
1672 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1673 | !timeo || | |
518a09ef | 1674 | signal_pending(current)) |
1da177e4 LT |
1675 | break; |
1676 | } else { | |
1677 | if (sock_flag(sk, SOCK_DONE)) | |
1678 | break; | |
1679 | ||
1680 | if (sk->sk_err) { | |
1681 | copied = sock_error(sk); | |
1682 | break; | |
1683 | } | |
1684 | ||
1685 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
1686 | break; | |
1687 | ||
1688 | if (sk->sk_state == TCP_CLOSE) { | |
1689 | if (!sock_flag(sk, SOCK_DONE)) { | |
1690 | /* This occurs when user tries to read | |
1691 | * from never connected socket. | |
1692 | */ | |
1693 | copied = -ENOTCONN; | |
1694 | break; | |
1695 | } | |
1696 | break; | |
1697 | } | |
1698 | ||
1699 | if (!timeo) { | |
1700 | copied = -EAGAIN; | |
1701 | break; | |
1702 | } | |
1703 | ||
1704 | if (signal_pending(current)) { | |
1705 | copied = sock_intr_errno(timeo); | |
1706 | break; | |
1707 | } | |
1708 | } | |
1709 | ||
0e4b4992 | 1710 | tcp_cleanup_rbuf(sk, copied); |
1da177e4 | 1711 | |
7df55125 | 1712 | if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { |
1da177e4 LT |
1713 | /* Install new reader */ |
1714 | if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { | |
1715 | user_recv = current; | |
1716 | tp->ucopy.task = user_recv; | |
f4362a2c | 1717 | tp->ucopy.msg = msg; |
1da177e4 LT |
1718 | } |
1719 | ||
1720 | tp->ucopy.len = len; | |
1721 | ||
547b792c IJ |
1722 | WARN_ON(tp->copied_seq != tp->rcv_nxt && |
1723 | !(flags & (MSG_PEEK | MSG_TRUNC))); | |
1da177e4 LT |
1724 | |
1725 | /* Ugly... If prequeue is not empty, we have to | |
1726 | * process it before releasing socket, otherwise | |
1727 | * order will be broken at second iteration. | |
1728 | * More elegant solution is required!!! | |
1729 | * | |
1730 | * Look: we have the following (pseudo)queues: | |
1731 | * | |
1732 | * 1. packets in flight | |
1733 | * 2. backlog | |
1734 | * 3. prequeue | |
1735 | * 4. receive_queue | |
1736 | * | |
1737 | * Each queue can be processed only if the next ones | |
1738 | * are empty. At this point we have empty receive_queue. | |
1739 | * But prequeue _can_ be not empty after 2nd iteration, | |
1740 | * when we jumped to start of loop because backlog | |
1741 | * processing added something to receive_queue. | |
1742 | * We cannot release_sock(), because backlog contains | |
1743 | * packets arrived _after_ prequeued ones. | |
1744 | * | |
1745 | * Shortly, algorithm is clear --- to process all | |
1746 | * the queues in order. We could make it more directly, | |
1747 | * requeueing packets from backlog to prequeue, if | |
1748 | * is not empty. It is more elegant, but eats cycles, | |
1749 | * unfortunately. | |
1750 | */ | |
b03efcfb | 1751 | if (!skb_queue_empty(&tp->ucopy.prequeue)) |
1da177e4 LT |
1752 | goto do_prequeue; |
1753 | ||
1754 | /* __ Set realtime policy in scheduler __ */ | |
1755 | } | |
1756 | ||
1757 | if (copied >= target) { | |
1758 | /* Do not sleep, just process backlog. */ | |
1759 | release_sock(sk); | |
1760 | lock_sock(sk); | |
dfbafc99 SD |
1761 | } else { |
1762 | sk_wait_data(sk, &timeo, last); | |
1763 | } | |
1da177e4 LT |
1764 | |
1765 | if (user_recv) { | |
1766 | int chunk; | |
1767 | ||
1768 | /* __ Restore normal policy in scheduler __ */ | |
1769 | ||
1770 | if ((chunk = len - tp->ucopy.len) != 0) { | |
ed88098e | 1771 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); |
1da177e4 LT |
1772 | len -= chunk; |
1773 | copied += chunk; | |
1774 | } | |
1775 | ||
1776 | if (tp->rcv_nxt == tp->copied_seq && | |
b03efcfb | 1777 | !skb_queue_empty(&tp->ucopy.prequeue)) { |
1da177e4 LT |
1778 | do_prequeue: |
1779 | tcp_prequeue_process(sk); | |
1780 | ||
1781 | if ((chunk = len - tp->ucopy.len) != 0) { | |
ed88098e | 1782 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); |
1da177e4 LT |
1783 | len -= chunk; |
1784 | copied += chunk; | |
1785 | } | |
1786 | } | |
1787 | } | |
77527313 IJ |
1788 | if ((flags & MSG_PEEK) && |
1789 | (peek_seq - copied - urg_hole != tp->copied_seq)) { | |
e87cc472 JP |
1790 | net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", |
1791 | current->comm, | |
1792 | task_pid_nr(current)); | |
1da177e4 LT |
1793 | peek_seq = tp->copied_seq; |
1794 | } | |
1795 | continue; | |
1796 | ||
1797 | found_ok_skb: | |
1798 | /* Ok so how much can we use? */ | |
1799 | used = skb->len - offset; | |
1800 | if (len < used) | |
1801 | used = len; | |
1802 | ||
1803 | /* Do we have urgent data here? */ | |
1804 | if (tp->urg_data) { | |
1805 | u32 urg_offset = tp->urg_seq - *seq; | |
1806 | if (urg_offset < used) { | |
1807 | if (!urg_offset) { | |
1808 | if (!sock_flag(sk, SOCK_URGINLINE)) { | |
1809 | ++*seq; | |
77527313 | 1810 | urg_hole++; |
1da177e4 LT |
1811 | offset++; |
1812 | used--; | |
1813 | if (!used) | |
1814 | goto skip_copy; | |
1815 | } | |
1816 | } else | |
1817 | used = urg_offset; | |
1818 | } | |
1819 | } | |
1820 | ||
1821 | if (!(flags & MSG_TRUNC)) { | |
51f3d02b | 1822 | err = skb_copy_datagram_msg(skb, offset, msg, used); |
7bced397 DW |
1823 | if (err) { |
1824 | /* Exception. Bailout! */ | |
1825 | if (!copied) | |
1826 | copied = -EFAULT; | |
1827 | break; | |
1da177e4 LT |
1828 | } |
1829 | } | |
1830 | ||
1831 | *seq += used; | |
1832 | copied += used; | |
1833 | len -= used; | |
1834 | ||
1835 | tcp_rcv_space_adjust(sk); | |
1836 | ||
1837 | skip_copy: | |
1838 | if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { | |
1839 | tp->urg_data = 0; | |
9e412ba7 | 1840 | tcp_fast_path_check(sk); |
1da177e4 LT |
1841 | } |
1842 | if (used + offset < skb->len) | |
1843 | continue; | |
1844 | ||
e11ecddf | 1845 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) |
1da177e4 | 1846 | goto found_fin_ok; |
7bced397 DW |
1847 | if (!(flags & MSG_PEEK)) |
1848 | sk_eat_skb(sk, skb); | |
1da177e4 LT |
1849 | continue; |
1850 | ||
1851 | found_fin_ok: | |
1852 | /* Process the FIN. */ | |
1853 | ++*seq; | |
7bced397 DW |
1854 | if (!(flags & MSG_PEEK)) |
1855 | sk_eat_skb(sk, skb); | |
1da177e4 LT |
1856 | break; |
1857 | } while (len > 0); | |
1858 | ||
1859 | if (user_recv) { | |
b03efcfb | 1860 | if (!skb_queue_empty(&tp->ucopy.prequeue)) { |
1da177e4 LT |
1861 | int chunk; |
1862 | ||
1863 | tp->ucopy.len = copied > 0 ? len : 0; | |
1864 | ||
1865 | tcp_prequeue_process(sk); | |
1866 | ||
1867 | if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { | |
ed88098e | 1868 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); |
1da177e4 LT |
1869 | len -= chunk; |
1870 | copied += chunk; | |
1871 | } | |
1872 | } | |
1873 | ||
1874 | tp->ucopy.task = NULL; | |
1875 | tp->ucopy.len = 0; | |
1876 | } | |
1877 | ||
1878 | /* According to UNIX98, msg_name/msg_namelen are ignored | |
1879 | * on connected socket. I was just happy when found this 8) --ANK | |
1880 | */ | |
1881 | ||
1882 | /* Clean up data we have read: This will do ACK frames. */ | |
0e4b4992 | 1883 | tcp_cleanup_rbuf(sk, copied); |
1da177e4 | 1884 | |
1da177e4 LT |
1885 | release_sock(sk); |
1886 | return copied; | |
1887 | ||
1888 | out: | |
1da177e4 LT |
1889 | release_sock(sk); |
1890 | return err; | |
1891 | ||
1892 | recv_urg: | |
377f0a08 | 1893 | err = tcp_recv_urg(sk, msg, len, flags); |
1da177e4 | 1894 | goto out; |
c0e88ff0 PE |
1895 | |
1896 | recv_sndq: | |
1897 | err = tcp_peek_sndq(sk, msg, len); | |
1898 | goto out; | |
1da177e4 | 1899 | } |
4bc2f18b | 1900 | EXPORT_SYMBOL(tcp_recvmsg); |
1da177e4 | 1901 | |
490d5046 IJ |
1902 | void tcp_set_state(struct sock *sk, int state) |
1903 | { | |
1904 | int oldstate = sk->sk_state; | |
1905 | ||
1906 | switch (state) { | |
1907 | case TCP_ESTABLISHED: | |
1908 | if (oldstate != TCP_ESTABLISHED) | |
81cc8a75 | 1909 | TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); |
490d5046 IJ |
1910 | break; |
1911 | ||
1912 | case TCP_CLOSE: | |
1913 | if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) | |
81cc8a75 | 1914 | TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); |
490d5046 IJ |
1915 | |
1916 | sk->sk_prot->unhash(sk); | |
1917 | if (inet_csk(sk)->icsk_bind_hash && | |
1918 | !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) | |
ab1e0a13 | 1919 | inet_put_port(sk); |
490d5046 IJ |
1920 | /* fall through */ |
1921 | default: | |
5a5f3a8d | 1922 | if (oldstate == TCP_ESTABLISHED) |
74688e48 | 1923 | TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); |
490d5046 IJ |
1924 | } |
1925 | ||
1926 | /* Change state AFTER socket is unhashed to avoid closed | |
1927 | * socket sitting in hash tables. | |
1928 | */ | |
1929 | sk->sk_state = state; | |
1930 | ||
1931 | #ifdef STATE_TRACE | |
5a5f3a8d | 1932 | SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); |
490d5046 IJ |
1933 | #endif |
1934 | } | |
1935 | EXPORT_SYMBOL_GPL(tcp_set_state); | |
1936 | ||
1da177e4 LT |
1937 | /* |
1938 | * State processing on a close. This implements the state shift for | |
1939 | * sending our FIN frame. Note that we only send a FIN for some | |
1940 | * states. A shutdown() may have already sent the FIN, or we may be | |
1941 | * closed. | |
1942 | */ | |
1943 | ||
9b5b5cff | 1944 | static const unsigned char new_state[16] = { |
1da177e4 | 1945 | /* current state: new state: action: */ |
0980c1e3 ED |
1946 | [0 /* (Invalid) */] = TCP_CLOSE, |
1947 | [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1948 | [TCP_SYN_SENT] = TCP_CLOSE, | |
1949 | [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1950 | [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, | |
1951 | [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, | |
1952 | [TCP_TIME_WAIT] = TCP_CLOSE, | |
1953 | [TCP_CLOSE] = TCP_CLOSE, | |
1954 | [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, | |
1955 | [TCP_LAST_ACK] = TCP_LAST_ACK, | |
1956 | [TCP_LISTEN] = TCP_CLOSE, | |
1957 | [TCP_CLOSING] = TCP_CLOSING, | |
1958 | [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ | |
1da177e4 LT |
1959 | }; |
1960 | ||
1961 | static int tcp_close_state(struct sock *sk) | |
1962 | { | |
1963 | int next = (int)new_state[sk->sk_state]; | |
1964 | int ns = next & TCP_STATE_MASK; | |
1965 | ||
1966 | tcp_set_state(sk, ns); | |
1967 | ||
1968 | return next & TCP_ACTION_FIN; | |
1969 | } | |
1970 | ||
1971 | /* | |
1972 | * Shutdown the sending side of a connection. Much like close except | |
1f29b058 | 1973 | * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). |
1da177e4 LT |
1974 | */ |
1975 | ||
1976 | void tcp_shutdown(struct sock *sk, int how) | |
1977 | { | |
1978 | /* We need to grab some memory, and put together a FIN, | |
1979 | * and then put it into the queue to be sent. | |
1980 | * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. | |
1981 | */ | |
1982 | if (!(how & SEND_SHUTDOWN)) | |
1983 | return; | |
1984 | ||
1985 | /* If we've already sent a FIN, or it's a closed state, skip this. */ | |
1986 | if ((1 << sk->sk_state) & | |
1987 | (TCPF_ESTABLISHED | TCPF_SYN_SENT | | |
1988 | TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { | |
1989 | /* Clear out any half completed packets. FIN if needed. */ | |
1990 | if (tcp_close_state(sk)) | |
1991 | tcp_send_fin(sk); | |
1992 | } | |
1993 | } | |
4bc2f18b | 1994 | EXPORT_SYMBOL(tcp_shutdown); |
1da177e4 | 1995 | |
efcdbf24 AS |
1996 | bool tcp_check_oom(struct sock *sk, int shift) |
1997 | { | |
1998 | bool too_many_orphans, out_of_socket_memory; | |
1999 | ||
2000 | too_many_orphans = tcp_too_many_orphans(sk, shift); | |
2001 | out_of_socket_memory = tcp_out_of_memory(sk); | |
2002 | ||
e87cc472 JP |
2003 | if (too_many_orphans) |
2004 | net_info_ratelimited("too many orphaned sockets\n"); | |
2005 | if (out_of_socket_memory) | |
2006 | net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); | |
efcdbf24 AS |
2007 | return too_many_orphans || out_of_socket_memory; |
2008 | } | |
2009 | ||
1da177e4 LT |
2010 | void tcp_close(struct sock *sk, long timeout) |
2011 | { | |
2012 | struct sk_buff *skb; | |
2013 | int data_was_unread = 0; | |
75c2d907 | 2014 | int state; |
1da177e4 LT |
2015 | |
2016 | lock_sock(sk); | |
2017 | sk->sk_shutdown = SHUTDOWN_MASK; | |
2018 | ||
2019 | if (sk->sk_state == TCP_LISTEN) { | |
2020 | tcp_set_state(sk, TCP_CLOSE); | |
2021 | ||
2022 | /* Special case. */ | |
0a5578cf | 2023 | inet_csk_listen_stop(sk); |
1da177e4 LT |
2024 | |
2025 | goto adjudge_to_death; | |
2026 | } | |
2027 | ||
2028 | /* We need to flush the recv. buffs. We do this only on the | |
2029 | * descriptor close, not protocol-sourced closes, because the | |
2030 | * reader process may not have drained the data yet! | |
2031 | */ | |
2032 | while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e11ecddf ED |
2033 | u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; |
2034 | ||
2035 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) | |
2036 | len--; | |
1da177e4 LT |
2037 | data_was_unread += len; |
2038 | __kfree_skb(skb); | |
2039 | } | |
2040 | ||
3ab224be | 2041 | sk_mem_reclaim(sk); |
1da177e4 | 2042 | |
565b7b2d KK |
2043 | /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ |
2044 | if (sk->sk_state == TCP_CLOSE) | |
2045 | goto adjudge_to_death; | |
2046 | ||
65bb723c GR |
2047 | /* As outlined in RFC 2525, section 2.17, we send a RST here because |
2048 | * data was lost. To witness the awful effects of the old behavior of | |
2049 | * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk | |
2050 | * GET in an FTP client, suspend the process, wait for the client to | |
2051 | * advertise a zero window, then kill -9 the FTP client, wheee... | |
2052 | * Note: timeout is always zero in such a case. | |
1da177e4 | 2053 | */ |
ee995283 PE |
2054 | if (unlikely(tcp_sk(sk)->repair)) { |
2055 | sk->sk_prot->disconnect(sk, 0); | |
2056 | } else if (data_was_unread) { | |
1da177e4 | 2057 | /* Unread data was tossed, zap the connection. */ |
6f67c817 | 2058 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); |
1da177e4 | 2059 | tcp_set_state(sk, TCP_CLOSE); |
aa133076 | 2060 | tcp_send_active_reset(sk, sk->sk_allocation); |
1da177e4 LT |
2061 | } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { |
2062 | /* Check zero linger _after_ checking for unread data. */ | |
2063 | sk->sk_prot->disconnect(sk, 0); | |
6f67c817 | 2064 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); |
1da177e4 LT |
2065 | } else if (tcp_close_state(sk)) { |
2066 | /* We FIN if the application ate all the data before | |
2067 | * zapping the connection. | |
2068 | */ | |
2069 | ||
2070 | /* RED-PEN. Formally speaking, we have broken TCP state | |
2071 | * machine. State transitions: | |
2072 | * | |
2073 | * TCP_ESTABLISHED -> TCP_FIN_WAIT1 | |
2074 | * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) | |
2075 | * TCP_CLOSE_WAIT -> TCP_LAST_ACK | |
2076 | * | |
2077 | * are legal only when FIN has been sent (i.e. in window), | |
2078 | * rather than queued out of window. Purists blame. | |
2079 | * | |
2080 | * F.e. "RFC state" is ESTABLISHED, | |
2081 | * if Linux state is FIN-WAIT-1, but FIN is still not sent. | |
2082 | * | |
2083 | * The visible declinations are that sometimes | |
2084 | * we enter time-wait state, when it is not required really | |
2085 | * (harmless), do not send active resets, when they are | |
2086 | * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when | |
2087 | * they look as CLOSING or LAST_ACK for Linux) | |
2088 | * Probably, I missed some more holelets. | |
2089 | * --ANK | |
8336886f JC |
2090 | * XXX (TFO) - To start off we don't support SYN+ACK+FIN |
2091 | * in a single packet! (May consider it later but will | |
2092 | * probably need API support or TCP_CORK SYN-ACK until | |
2093 | * data is written and socket is closed.) | |
1da177e4 LT |
2094 | */ |
2095 | tcp_send_fin(sk); | |
2096 | } | |
2097 | ||
2098 | sk_stream_wait_close(sk, timeout); | |
2099 | ||
2100 | adjudge_to_death: | |
75c2d907 HX |
2101 | state = sk->sk_state; |
2102 | sock_hold(sk); | |
2103 | sock_orphan(sk); | |
75c2d907 | 2104 | |
1da177e4 LT |
2105 | /* It is the last release_sock in its life. It will remove backlog. */ |
2106 | release_sock(sk); | |
2107 | ||
2108 | ||
2109 | /* Now socket is owned by kernel and we acquire BH lock | |
2110 | to finish close. No need to check for user refs. | |
2111 | */ | |
2112 | local_bh_disable(); | |
2113 | bh_lock_sock(sk); | |
547b792c | 2114 | WARN_ON(sock_owned_by_user(sk)); |
1da177e4 | 2115 | |
eb4dea58 HX |
2116 | percpu_counter_inc(sk->sk_prot->orphan_count); |
2117 | ||
75c2d907 HX |
2118 | /* Have we already been destroyed by a softirq or backlog? */ |
2119 | if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) | |
2120 | goto out; | |
1da177e4 LT |
2121 | |
2122 | /* This is a (useful) BSD violating of the RFC. There is a | |
2123 | * problem with TCP as specified in that the other end could | |
2124 | * keep a socket open forever with no application left this end. | |
b10bd54c | 2125 | * We use a 1 minute timeout (about the same as BSD) then kill |
1da177e4 LT |
2126 | * our end. If they send after that then tough - BUT: long enough |
2127 | * that we won't make the old 4*rto = almost no time - whoops | |
2128 | * reset mistake. | |
2129 | * | |
2130 | * Nope, it was not mistake. It is really desired behaviour | |
2131 | * f.e. on http servers, when such sockets are useless, but | |
2132 | * consume significant resources. Let's do it with special | |
2133 | * linger2 option. --ANK | |
2134 | */ | |
2135 | ||
2136 | if (sk->sk_state == TCP_FIN_WAIT2) { | |
2137 | struct tcp_sock *tp = tcp_sk(sk); | |
2138 | if (tp->linger2 < 0) { | |
2139 | tcp_set_state(sk, TCP_CLOSE); | |
2140 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
de0744af PE |
2141 | NET_INC_STATS_BH(sock_net(sk), |
2142 | LINUX_MIB_TCPABORTONLINGER); | |
1da177e4 | 2143 | } else { |
463c84b9 | 2144 | const int tmo = tcp_fin_time(sk); |
1da177e4 LT |
2145 | |
2146 | if (tmo > TCP_TIMEWAIT_LEN) { | |
52499afe DM |
2147 | inet_csk_reset_keepalive_timer(sk, |
2148 | tmo - TCP_TIMEWAIT_LEN); | |
1da177e4 | 2149 | } else { |
1da177e4 LT |
2150 | tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); |
2151 | goto out; | |
2152 | } | |
2153 | } | |
2154 | } | |
2155 | if (sk->sk_state != TCP_CLOSE) { | |
3ab224be | 2156 | sk_mem_reclaim(sk); |
efcdbf24 | 2157 | if (tcp_check_oom(sk, 0)) { |
1da177e4 LT |
2158 | tcp_set_state(sk, TCP_CLOSE); |
2159 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
de0744af PE |
2160 | NET_INC_STATS_BH(sock_net(sk), |
2161 | LINUX_MIB_TCPABORTONMEMORY); | |
1da177e4 LT |
2162 | } |
2163 | } | |
1da177e4 | 2164 | |
8336886f JC |
2165 | if (sk->sk_state == TCP_CLOSE) { |
2166 | struct request_sock *req = tcp_sk(sk)->fastopen_rsk; | |
2167 | /* We could get here with a non-NULL req if the socket is | |
2168 | * aborted (e.g., closed with unread data) before 3WHS | |
2169 | * finishes. | |
2170 | */ | |
00db4124 | 2171 | if (req) |
8336886f | 2172 | reqsk_fastopen_remove(sk, req, false); |
0a5578cf | 2173 | inet_csk_destroy_sock(sk); |
8336886f | 2174 | } |
1da177e4 LT |
2175 | /* Otherwise, socket is reprieved until protocol close. */ |
2176 | ||
2177 | out: | |
2178 | bh_unlock_sock(sk); | |
2179 | local_bh_enable(); | |
2180 | sock_put(sk); | |
2181 | } | |
4bc2f18b | 2182 | EXPORT_SYMBOL(tcp_close); |
1da177e4 LT |
2183 | |
2184 | /* These states need RST on ABORT according to RFC793 */ | |
2185 | ||
a2a385d6 | 2186 | static inline bool tcp_need_reset(int state) |
1da177e4 LT |
2187 | { |
2188 | return (1 << state) & | |
2189 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | | |
2190 | TCPF_FIN_WAIT2 | TCPF_SYN_RECV); | |
2191 | } | |
2192 | ||
2193 | int tcp_disconnect(struct sock *sk, int flags) | |
2194 | { | |
2195 | struct inet_sock *inet = inet_sk(sk); | |
463c84b9 | 2196 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2197 | struct tcp_sock *tp = tcp_sk(sk); |
2198 | int err = 0; | |
2199 | int old_state = sk->sk_state; | |
2200 | ||
2201 | if (old_state != TCP_CLOSE) | |
2202 | tcp_set_state(sk, TCP_CLOSE); | |
2203 | ||
2204 | /* ABORT function of RFC793 */ | |
2205 | if (old_state == TCP_LISTEN) { | |
0a5578cf | 2206 | inet_csk_listen_stop(sk); |
ee995283 PE |
2207 | } else if (unlikely(tp->repair)) { |
2208 | sk->sk_err = ECONNABORTED; | |
1da177e4 LT |
2209 | } else if (tcp_need_reset(old_state) || |
2210 | (tp->snd_nxt != tp->write_seq && | |
2211 | (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { | |
caa20d9a | 2212 | /* The last check adjusts for discrepancy of Linux wrt. RFC |
1da177e4 LT |
2213 | * states |
2214 | */ | |
2215 | tcp_send_active_reset(sk, gfp_any()); | |
2216 | sk->sk_err = ECONNRESET; | |
2217 | } else if (old_state == TCP_SYN_SENT) | |
2218 | sk->sk_err = ECONNRESET; | |
2219 | ||
2220 | tcp_clear_xmit_timers(sk); | |
2221 | __skb_queue_purge(&sk->sk_receive_queue); | |
fe067e8a | 2222 | tcp_write_queue_purge(sk); |
1da177e4 LT |
2223 | __skb_queue_purge(&tp->out_of_order_queue); |
2224 | ||
c720c7e8 | 2225 | inet->inet_dport = 0; |
1da177e4 LT |
2226 | |
2227 | if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) | |
2228 | inet_reset_saddr(sk); | |
2229 | ||
2230 | sk->sk_shutdown = 0; | |
2231 | sock_reset_flag(sk, SOCK_DONE); | |
740b0f18 | 2232 | tp->srtt_us = 0; |
1da177e4 LT |
2233 | if ((tp->write_seq += tp->max_window + 2) == 0) |
2234 | tp->write_seq = 1; | |
463c84b9 | 2235 | icsk->icsk_backoff = 0; |
1da177e4 | 2236 | tp->snd_cwnd = 2; |
6687e988 | 2237 | icsk->icsk_probes_out = 0; |
1da177e4 | 2238 | tp->packets_out = 0; |
0b6a05c1 | 2239 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
1da177e4 | 2240 | tp->snd_cwnd_cnt = 0; |
1fdf475a | 2241 | tp->window_clamp = 0; |
6687e988 | 2242 | tcp_set_ca_state(sk, TCP_CA_Open); |
1da177e4 | 2243 | tcp_clear_retrans(tp); |
463c84b9 | 2244 | inet_csk_delack_init(sk); |
fe067e8a | 2245 | tcp_init_send_head(sk); |
b40b4f79 | 2246 | memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); |
1da177e4 LT |
2247 | __sk_dst_reset(sk); |
2248 | ||
c720c7e8 | 2249 | WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); |
1da177e4 LT |
2250 | |
2251 | sk->sk_error_report(sk); | |
2252 | return err; | |
2253 | } | |
4bc2f18b | 2254 | EXPORT_SYMBOL(tcp_disconnect); |
1da177e4 | 2255 | |
bb68b647 CP |
2256 | void tcp_sock_destruct(struct sock *sk) |
2257 | { | |
2258 | inet_sock_destruct(sk); | |
2259 | ||
2260 | kfree(inet_csk(sk)->icsk_accept_queue.fastopenq); | |
2261 | } | |
2262 | ||
a2a385d6 | 2263 | static inline bool tcp_can_repair_sock(const struct sock *sk) |
ee995283 | 2264 | { |
52e804c6 | 2265 | return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && |
ee995283 PE |
2266 | ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED)); |
2267 | } | |
2268 | ||
de248a75 PE |
2269 | static int tcp_repair_options_est(struct tcp_sock *tp, |
2270 | struct tcp_repair_opt __user *optbuf, unsigned int len) | |
b139ba4e | 2271 | { |
de248a75 | 2272 | struct tcp_repair_opt opt; |
b139ba4e | 2273 | |
de248a75 PE |
2274 | while (len >= sizeof(opt)) { |
2275 | if (copy_from_user(&opt, optbuf, sizeof(opt))) | |
b139ba4e PE |
2276 | return -EFAULT; |
2277 | ||
2278 | optbuf++; | |
de248a75 | 2279 | len -= sizeof(opt); |
b139ba4e | 2280 | |
de248a75 PE |
2281 | switch (opt.opt_code) { |
2282 | case TCPOPT_MSS: | |
2283 | tp->rx_opt.mss_clamp = opt.opt_val; | |
b139ba4e | 2284 | break; |
de248a75 | 2285 | case TCPOPT_WINDOW: |
bc26ccd8 AV |
2286 | { |
2287 | u16 snd_wscale = opt.opt_val & 0xFFFF; | |
2288 | u16 rcv_wscale = opt.opt_val >> 16; | |
2289 | ||
2290 | if (snd_wscale > 14 || rcv_wscale > 14) | |
2291 | return -EFBIG; | |
b139ba4e | 2292 | |
bc26ccd8 AV |
2293 | tp->rx_opt.snd_wscale = snd_wscale; |
2294 | tp->rx_opt.rcv_wscale = rcv_wscale; | |
2295 | tp->rx_opt.wscale_ok = 1; | |
2296 | } | |
b139ba4e | 2297 | break; |
b139ba4e | 2298 | case TCPOPT_SACK_PERM: |
de248a75 PE |
2299 | if (opt.opt_val != 0) |
2300 | return -EINVAL; | |
2301 | ||
b139ba4e PE |
2302 | tp->rx_opt.sack_ok |= TCP_SACK_SEEN; |
2303 | if (sysctl_tcp_fack) | |
2304 | tcp_enable_fack(tp); | |
2305 | break; | |
2306 | case TCPOPT_TIMESTAMP: | |
de248a75 PE |
2307 | if (opt.opt_val != 0) |
2308 | return -EINVAL; | |
2309 | ||
b139ba4e PE |
2310 | tp->rx_opt.tstamp_ok = 1; |
2311 | break; | |
2312 | } | |
2313 | } | |
2314 | ||
2315 | return 0; | |
2316 | } | |
2317 | ||
1da177e4 LT |
2318 | /* |
2319 | * Socket option code for TCP. | |
2320 | */ | |
3fdadf7d | 2321 | static int do_tcp_setsockopt(struct sock *sk, int level, |
b7058842 | 2322 | int optname, char __user *optval, unsigned int optlen) |
1da177e4 LT |
2323 | { |
2324 | struct tcp_sock *tp = tcp_sk(sk); | |
463c84b9 | 2325 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2326 | int val; |
2327 | int err = 0; | |
2328 | ||
e56fb50f WAS |
2329 | /* These are data/string values, all the others are ints */ |
2330 | switch (optname) { | |
2331 | case TCP_CONGESTION: { | |
5f8ef48d SH |
2332 | char name[TCP_CA_NAME_MAX]; |
2333 | ||
2334 | if (optlen < 1) | |
2335 | return -EINVAL; | |
2336 | ||
2337 | val = strncpy_from_user(name, optval, | |
4fdb78d3 | 2338 | min_t(long, TCP_CA_NAME_MAX-1, optlen)); |
5f8ef48d SH |
2339 | if (val < 0) |
2340 | return -EFAULT; | |
2341 | name[val] = 0; | |
2342 | ||
2343 | lock_sock(sk); | |
6687e988 | 2344 | err = tcp_set_congestion_control(sk, name); |
5f8ef48d SH |
2345 | release_sock(sk); |
2346 | return err; | |
2347 | } | |
e56fb50f WAS |
2348 | default: |
2349 | /* fallthru */ | |
2350 | break; | |
ccbd6a5a | 2351 | } |
5f8ef48d | 2352 | |
1da177e4 LT |
2353 | if (optlen < sizeof(int)) |
2354 | return -EINVAL; | |
2355 | ||
2356 | if (get_user(val, (int __user *)optval)) | |
2357 | return -EFAULT; | |
2358 | ||
2359 | lock_sock(sk); | |
2360 | ||
2361 | switch (optname) { | |
2362 | case TCP_MAXSEG: | |
2363 | /* Values greater than interface MTU won't take effect. However | |
2364 | * at the point when this call is done we typically don't yet | |
2365 | * know which interface is going to be used */ | |
c39508d6 | 2366 | if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) { |
1da177e4 LT |
2367 | err = -EINVAL; |
2368 | break; | |
2369 | } | |
2370 | tp->rx_opt.user_mss = val; | |
2371 | break; | |
2372 | ||
2373 | case TCP_NODELAY: | |
2374 | if (val) { | |
2375 | /* TCP_NODELAY is weaker than TCP_CORK, so that | |
2376 | * this option on corked socket is remembered, but | |
2377 | * it is not activated until cork is cleared. | |
2378 | * | |
2379 | * However, when TCP_NODELAY is set we make | |
2380 | * an explicit push, which overrides even TCP_CORK | |
2381 | * for currently queued segments. | |
2382 | */ | |
2383 | tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; | |
9e412ba7 | 2384 | tcp_push_pending_frames(sk); |
1da177e4 LT |
2385 | } else { |
2386 | tp->nonagle &= ~TCP_NAGLE_OFF; | |
2387 | } | |
2388 | break; | |
2389 | ||
36e31b0a AP |
2390 | case TCP_THIN_LINEAR_TIMEOUTS: |
2391 | if (val < 0 || val > 1) | |
2392 | err = -EINVAL; | |
2393 | else | |
2394 | tp->thin_lto = val; | |
2395 | break; | |
2396 | ||
7e380175 AP |
2397 | case TCP_THIN_DUPACK: |
2398 | if (val < 0 || val > 1) | |
2399 | err = -EINVAL; | |
e2e5c4c0 | 2400 | else { |
7e380175 | 2401 | tp->thin_dupack = val; |
eed530b6 YC |
2402 | if (tp->thin_dupack) |
2403 | tcp_disable_early_retrans(tp); | |
e2e5c4c0 | 2404 | } |
7e380175 AP |
2405 | break; |
2406 | ||
ee995283 PE |
2407 | case TCP_REPAIR: |
2408 | if (!tcp_can_repair_sock(sk)) | |
2409 | err = -EPERM; | |
2410 | else if (val == 1) { | |
2411 | tp->repair = 1; | |
2412 | sk->sk_reuse = SK_FORCE_REUSE; | |
2413 | tp->repair_queue = TCP_NO_QUEUE; | |
2414 | } else if (val == 0) { | |
2415 | tp->repair = 0; | |
2416 | sk->sk_reuse = SK_NO_REUSE; | |
2417 | tcp_send_window_probe(sk); | |
2418 | } else | |
2419 | err = -EINVAL; | |
2420 | ||
2421 | break; | |
2422 | ||
2423 | case TCP_REPAIR_QUEUE: | |
2424 | if (!tp->repair) | |
2425 | err = -EPERM; | |
2426 | else if (val < TCP_QUEUES_NR) | |
2427 | tp->repair_queue = val; | |
2428 | else | |
2429 | err = -EINVAL; | |
2430 | break; | |
2431 | ||
2432 | case TCP_QUEUE_SEQ: | |
2433 | if (sk->sk_state != TCP_CLOSE) | |
2434 | err = -EPERM; | |
2435 | else if (tp->repair_queue == TCP_SEND_QUEUE) | |
2436 | tp->write_seq = val; | |
2437 | else if (tp->repair_queue == TCP_RECV_QUEUE) | |
2438 | tp->rcv_nxt = val; | |
2439 | else | |
2440 | err = -EINVAL; | |
2441 | break; | |
2442 | ||
b139ba4e PE |
2443 | case TCP_REPAIR_OPTIONS: |
2444 | if (!tp->repair) | |
2445 | err = -EINVAL; | |
2446 | else if (sk->sk_state == TCP_ESTABLISHED) | |
de248a75 PE |
2447 | err = tcp_repair_options_est(tp, |
2448 | (struct tcp_repair_opt __user *)optval, | |
2449 | optlen); | |
b139ba4e PE |
2450 | else |
2451 | err = -EPERM; | |
2452 | break; | |
2453 | ||
1da177e4 LT |
2454 | case TCP_CORK: |
2455 | /* When set indicates to always queue non-full frames. | |
2456 | * Later the user clears this option and we transmit | |
2457 | * any pending partial frames in the queue. This is | |
2458 | * meant to be used alongside sendfile() to get properly | |
2459 | * filled frames when the user (for example) must write | |
2460 | * out headers with a write() call first and then use | |
2461 | * sendfile to send out the data parts. | |
2462 | * | |
2463 | * TCP_CORK can be set together with TCP_NODELAY and it is | |
2464 | * stronger than TCP_NODELAY. | |
2465 | */ | |
2466 | if (val) { | |
2467 | tp->nonagle |= TCP_NAGLE_CORK; | |
2468 | } else { | |
2469 | tp->nonagle &= ~TCP_NAGLE_CORK; | |
2470 | if (tp->nonagle&TCP_NAGLE_OFF) | |
2471 | tp->nonagle |= TCP_NAGLE_PUSH; | |
9e412ba7 | 2472 | tcp_push_pending_frames(sk); |
1da177e4 LT |
2473 | } |
2474 | break; | |
2475 | ||
2476 | case TCP_KEEPIDLE: | |
2477 | if (val < 1 || val > MAX_TCP_KEEPIDLE) | |
2478 | err = -EINVAL; | |
2479 | else { | |
2480 | tp->keepalive_time = val * HZ; | |
2481 | if (sock_flag(sk, SOCK_KEEPOPEN) && | |
2482 | !((1 << sk->sk_state) & | |
2483 | (TCPF_CLOSE | TCPF_LISTEN))) { | |
6c37e5de | 2484 | u32 elapsed = keepalive_time_elapsed(tp); |
1da177e4 LT |
2485 | if (tp->keepalive_time > elapsed) |
2486 | elapsed = tp->keepalive_time - elapsed; | |
2487 | else | |
2488 | elapsed = 0; | |
463c84b9 | 2489 | inet_csk_reset_keepalive_timer(sk, elapsed); |
1da177e4 LT |
2490 | } |
2491 | } | |
2492 | break; | |
2493 | case TCP_KEEPINTVL: | |
2494 | if (val < 1 || val > MAX_TCP_KEEPINTVL) | |
2495 | err = -EINVAL; | |
2496 | else | |
2497 | tp->keepalive_intvl = val * HZ; | |
2498 | break; | |
2499 | case TCP_KEEPCNT: | |
2500 | if (val < 1 || val > MAX_TCP_KEEPCNT) | |
2501 | err = -EINVAL; | |
2502 | else | |
2503 | tp->keepalive_probes = val; | |
2504 | break; | |
2505 | case TCP_SYNCNT: | |
2506 | if (val < 1 || val > MAX_TCP_SYNCNT) | |
2507 | err = -EINVAL; | |
2508 | else | |
463c84b9 | 2509 | icsk->icsk_syn_retries = val; |
1da177e4 LT |
2510 | break; |
2511 | ||
cd8ae852 ED |
2512 | case TCP_SAVE_SYN: |
2513 | if (val < 0 || val > 1) | |
2514 | err = -EINVAL; | |
2515 | else | |
2516 | tp->save_syn = val; | |
2517 | break; | |
2518 | ||
1da177e4 LT |
2519 | case TCP_LINGER2: |
2520 | if (val < 0) | |
2521 | tp->linger2 = -1; | |
2522 | else if (val > sysctl_tcp_fin_timeout / HZ) | |
2523 | tp->linger2 = 0; | |
2524 | else | |
2525 | tp->linger2 = val * HZ; | |
2526 | break; | |
2527 | ||
2528 | case TCP_DEFER_ACCEPT: | |
b103cf34 JA |
2529 | /* Translate value in seconds to number of retransmits */ |
2530 | icsk->icsk_accept_queue.rskq_defer_accept = | |
2531 | secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, | |
2532 | TCP_RTO_MAX / HZ); | |
1da177e4 LT |
2533 | break; |
2534 | ||
2535 | case TCP_WINDOW_CLAMP: | |
2536 | if (!val) { | |
2537 | if (sk->sk_state != TCP_CLOSE) { | |
2538 | err = -EINVAL; | |
2539 | break; | |
2540 | } | |
2541 | tp->window_clamp = 0; | |
2542 | } else | |
2543 | tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? | |
2544 | SOCK_MIN_RCVBUF / 2 : val; | |
2545 | break; | |
2546 | ||
2547 | case TCP_QUICKACK: | |
2548 | if (!val) { | |
463c84b9 | 2549 | icsk->icsk_ack.pingpong = 1; |
1da177e4 | 2550 | } else { |
463c84b9 | 2551 | icsk->icsk_ack.pingpong = 0; |
1da177e4 LT |
2552 | if ((1 << sk->sk_state) & |
2553 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && | |
463c84b9 ACM |
2554 | inet_csk_ack_scheduled(sk)) { |
2555 | icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; | |
0e4b4992 | 2556 | tcp_cleanup_rbuf(sk, 1); |
1da177e4 | 2557 | if (!(val & 1)) |
463c84b9 | 2558 | icsk->icsk_ack.pingpong = 1; |
1da177e4 LT |
2559 | } |
2560 | } | |
2561 | break; | |
2562 | ||
cfb6eeb4 YH |
2563 | #ifdef CONFIG_TCP_MD5SIG |
2564 | case TCP_MD5SIG: | |
2565 | /* Read the IP->Key mappings from userspace */ | |
2566 | err = tp->af_specific->md5_parse(sk, optval, optlen); | |
2567 | break; | |
2568 | #endif | |
dca43c75 | 2569 | case TCP_USER_TIMEOUT: |
b248230c | 2570 | /* Cap the max time in ms TCP will retry or probe the window |
dca43c75 JC |
2571 | * before giving up and aborting (ETIMEDOUT) a connection. |
2572 | */ | |
42493570 HL |
2573 | if (val < 0) |
2574 | err = -EINVAL; | |
2575 | else | |
2576 | icsk->icsk_user_timeout = msecs_to_jiffies(val); | |
dca43c75 | 2577 | break; |
8336886f JC |
2578 | |
2579 | case TCP_FASTOPEN: | |
2580 | if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | | |
dfea2aa6 CP |
2581 | TCPF_LISTEN))) { |
2582 | tcp_fastopen_init_key_once(true); | |
2583 | ||
8336886f | 2584 | err = fastopen_init_queue(sk, val); |
dfea2aa6 | 2585 | } else { |
8336886f | 2586 | err = -EINVAL; |
dfea2aa6 | 2587 | } |
8336886f | 2588 | break; |
93be6ce0 AV |
2589 | case TCP_TIMESTAMP: |
2590 | if (!tp->repair) | |
2591 | err = -EPERM; | |
2592 | else | |
2593 | tp->tsoffset = val - tcp_time_stamp; | |
2594 | break; | |
c9bee3b7 ED |
2595 | case TCP_NOTSENT_LOWAT: |
2596 | tp->notsent_lowat = val; | |
2597 | sk->sk_write_space(sk); | |
2598 | break; | |
1da177e4 LT |
2599 | default: |
2600 | err = -ENOPROTOOPT; | |
2601 | break; | |
3ff50b79 SH |
2602 | } |
2603 | ||
1da177e4 LT |
2604 | release_sock(sk); |
2605 | return err; | |
2606 | } | |
2607 | ||
3fdadf7d | 2608 | int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, |
b7058842 | 2609 | unsigned int optlen) |
3fdadf7d | 2610 | { |
cf533ea5 | 2611 | const struct inet_connection_sock *icsk = inet_csk(sk); |
3fdadf7d DM |
2612 | |
2613 | if (level != SOL_TCP) | |
2614 | return icsk->icsk_af_ops->setsockopt(sk, level, optname, | |
2615 | optval, optlen); | |
2616 | return do_tcp_setsockopt(sk, level, optname, optval, optlen); | |
2617 | } | |
4bc2f18b | 2618 | EXPORT_SYMBOL(tcp_setsockopt); |
3fdadf7d DM |
2619 | |
2620 | #ifdef CONFIG_COMPAT | |
543d9cfe | 2621 | int compat_tcp_setsockopt(struct sock *sk, int level, int optname, |
b7058842 | 2622 | char __user *optval, unsigned int optlen) |
3fdadf7d | 2623 | { |
dec73ff0 ACM |
2624 | if (level != SOL_TCP) |
2625 | return inet_csk_compat_setsockopt(sk, level, optname, | |
2626 | optval, optlen); | |
3fdadf7d DM |
2627 | return do_tcp_setsockopt(sk, level, optname, optval, optlen); |
2628 | } | |
543d9cfe | 2629 | EXPORT_SYMBOL(compat_tcp_setsockopt); |
3fdadf7d DM |
2630 | #endif |
2631 | ||
1da177e4 | 2632 | /* Return information about state of tcp endpoint in API format. */ |
0df48c26 | 2633 | void tcp_get_info(struct sock *sk, struct tcp_info *info) |
1da177e4 | 2634 | { |
35ac838a | 2635 | const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ |
463c84b9 | 2636 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 | 2637 | u32 now = tcp_time_stamp; |
d654976c | 2638 | unsigned int start; |
fad9dfef | 2639 | u32 rate; |
1da177e4 LT |
2640 | |
2641 | memset(info, 0, sizeof(*info)); | |
35ac838a CG |
2642 | if (sk->sk_type != SOCK_STREAM) |
2643 | return; | |
1da177e4 LT |
2644 | |
2645 | info->tcpi_state = sk->sk_state; | |
6687e988 | 2646 | info->tcpi_ca_state = icsk->icsk_ca_state; |
463c84b9 | 2647 | info->tcpi_retransmits = icsk->icsk_retransmits; |
6687e988 | 2648 | info->tcpi_probes = icsk->icsk_probes_out; |
463c84b9 | 2649 | info->tcpi_backoff = icsk->icsk_backoff; |
1da177e4 LT |
2650 | |
2651 | if (tp->rx_opt.tstamp_ok) | |
2652 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; | |
e60402d0 | 2653 | if (tcp_is_sack(tp)) |
1da177e4 LT |
2654 | info->tcpi_options |= TCPI_OPT_SACK; |
2655 | if (tp->rx_opt.wscale_ok) { | |
2656 | info->tcpi_options |= TCPI_OPT_WSCALE; | |
2657 | info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; | |
2658 | info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; | |
e905a9ed | 2659 | } |
1da177e4 | 2660 | |
b5c5693b | 2661 | if (tp->ecn_flags & TCP_ECN_OK) |
1da177e4 | 2662 | info->tcpi_options |= TCPI_OPT_ECN; |
b5c5693b ED |
2663 | if (tp->ecn_flags & TCP_ECN_SEEN) |
2664 | info->tcpi_options |= TCPI_OPT_ECN_SEEN; | |
6f73601e YC |
2665 | if (tp->syn_data_acked) |
2666 | info->tcpi_options |= TCPI_OPT_SYN_DATA; | |
1da177e4 | 2667 | |
463c84b9 ACM |
2668 | info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); |
2669 | info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); | |
c1b4a7e6 | 2670 | info->tcpi_snd_mss = tp->mss_cache; |
463c84b9 | 2671 | info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; |
1da177e4 | 2672 | |
5ee3afba RJ |
2673 | if (sk->sk_state == TCP_LISTEN) { |
2674 | info->tcpi_unacked = sk->sk_ack_backlog; | |
2675 | info->tcpi_sacked = sk->sk_max_ack_backlog; | |
2676 | } else { | |
2677 | info->tcpi_unacked = tp->packets_out; | |
2678 | info->tcpi_sacked = tp->sacked_out; | |
2679 | } | |
1da177e4 LT |
2680 | info->tcpi_lost = tp->lost_out; |
2681 | info->tcpi_retrans = tp->retrans_out; | |
2682 | info->tcpi_fackets = tp->fackets_out; | |
2683 | ||
2684 | info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); | |
463c84b9 | 2685 | info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); |
1da177e4 LT |
2686 | info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); |
2687 | ||
d83d8461 | 2688 | info->tcpi_pmtu = icsk->icsk_pmtu_cookie; |
1da177e4 | 2689 | info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; |
740b0f18 ED |
2690 | info->tcpi_rtt = tp->srtt_us >> 3; |
2691 | info->tcpi_rttvar = tp->mdev_us >> 2; | |
1da177e4 LT |
2692 | info->tcpi_snd_ssthresh = tp->snd_ssthresh; |
2693 | info->tcpi_snd_cwnd = tp->snd_cwnd; | |
2694 | info->tcpi_advmss = tp->advmss; | |
2695 | info->tcpi_reordering = tp->reordering; | |
2696 | ||
2697 | info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; | |
2698 | info->tcpi_rcv_space = tp->rcvq_space.space; | |
2699 | ||
2700 | info->tcpi_total_retrans = tp->total_retrans; | |
977cb0ec | 2701 | |
fad9dfef ED |
2702 | rate = READ_ONCE(sk->sk_pacing_rate); |
2703 | info->tcpi_pacing_rate = rate != ~0U ? rate : ~0ULL; | |
2704 | ||
2705 | rate = READ_ONCE(sk->sk_max_pacing_rate); | |
2706 | info->tcpi_max_pacing_rate = rate != ~0U ? rate : ~0ULL; | |
0df48c26 | 2707 | |
d654976c ED |
2708 | do { |
2709 | start = u64_stats_fetch_begin_irq(&tp->syncp); | |
2710 | info->tcpi_bytes_acked = tp->bytes_acked; | |
2711 | info->tcpi_bytes_received = tp->bytes_received; | |
2712 | } while (u64_stats_fetch_retry_irq(&tp->syncp, start)); | |
2efd055c MRL |
2713 | info->tcpi_segs_out = tp->segs_out; |
2714 | info->tcpi_segs_in = tp->segs_in; | |
1da177e4 | 2715 | } |
1da177e4 LT |
2716 | EXPORT_SYMBOL_GPL(tcp_get_info); |
2717 | ||
3fdadf7d DM |
2718 | static int do_tcp_getsockopt(struct sock *sk, int level, |
2719 | int optname, char __user *optval, int __user *optlen) | |
1da177e4 | 2720 | { |
295f7324 | 2721 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2722 | struct tcp_sock *tp = tcp_sk(sk); |
2723 | int val, len; | |
2724 | ||
1da177e4 LT |
2725 | if (get_user(len, optlen)) |
2726 | return -EFAULT; | |
2727 | ||
2728 | len = min_t(unsigned int, len, sizeof(int)); | |
2729 | ||
2730 | if (len < 0) | |
2731 | return -EINVAL; | |
2732 | ||
2733 | switch (optname) { | |
2734 | case TCP_MAXSEG: | |
c1b4a7e6 | 2735 | val = tp->mss_cache; |
1da177e4 LT |
2736 | if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) |
2737 | val = tp->rx_opt.user_mss; | |
5e6a3ce6 PE |
2738 | if (tp->repair) |
2739 | val = tp->rx_opt.mss_clamp; | |
1da177e4 LT |
2740 | break; |
2741 | case TCP_NODELAY: | |
2742 | val = !!(tp->nonagle&TCP_NAGLE_OFF); | |
2743 | break; | |
2744 | case TCP_CORK: | |
2745 | val = !!(tp->nonagle&TCP_NAGLE_CORK); | |
2746 | break; | |
2747 | case TCP_KEEPIDLE: | |
df19a626 | 2748 | val = keepalive_time_when(tp) / HZ; |
1da177e4 LT |
2749 | break; |
2750 | case TCP_KEEPINTVL: | |
df19a626 | 2751 | val = keepalive_intvl_when(tp) / HZ; |
1da177e4 LT |
2752 | break; |
2753 | case TCP_KEEPCNT: | |
df19a626 | 2754 | val = keepalive_probes(tp); |
1da177e4 LT |
2755 | break; |
2756 | case TCP_SYNCNT: | |
295f7324 | 2757 | val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; |
1da177e4 LT |
2758 | break; |
2759 | case TCP_LINGER2: | |
2760 | val = tp->linger2; | |
2761 | if (val >= 0) | |
2762 | val = (val ? : sysctl_tcp_fin_timeout) / HZ; | |
2763 | break; | |
2764 | case TCP_DEFER_ACCEPT: | |
b103cf34 JA |
2765 | val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, |
2766 | TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); | |
1da177e4 LT |
2767 | break; |
2768 | case TCP_WINDOW_CLAMP: | |
2769 | val = tp->window_clamp; | |
2770 | break; | |
2771 | case TCP_INFO: { | |
2772 | struct tcp_info info; | |
2773 | ||
2774 | if (get_user(len, optlen)) | |
2775 | return -EFAULT; | |
2776 | ||
2777 | tcp_get_info(sk, &info); | |
2778 | ||
2779 | len = min_t(unsigned int, len, sizeof(info)); | |
2780 | if (put_user(len, optlen)) | |
2781 | return -EFAULT; | |
2782 | if (copy_to_user(optval, &info, len)) | |
2783 | return -EFAULT; | |
2784 | return 0; | |
2785 | } | |
6e9250f5 ED |
2786 | case TCP_CC_INFO: { |
2787 | const struct tcp_congestion_ops *ca_ops; | |
2788 | union tcp_cc_info info; | |
2789 | size_t sz = 0; | |
2790 | int attr; | |
2791 | ||
2792 | if (get_user(len, optlen)) | |
2793 | return -EFAULT; | |
2794 | ||
2795 | ca_ops = icsk->icsk_ca_ops; | |
2796 | if (ca_ops && ca_ops->get_info) | |
2797 | sz = ca_ops->get_info(sk, ~0U, &attr, &info); | |
2798 | ||
2799 | len = min_t(unsigned int, len, sz); | |
2800 | if (put_user(len, optlen)) | |
2801 | return -EFAULT; | |
2802 | if (copy_to_user(optval, &info, len)) | |
2803 | return -EFAULT; | |
2804 | return 0; | |
2805 | } | |
1da177e4 | 2806 | case TCP_QUICKACK: |
295f7324 | 2807 | val = !icsk->icsk_ack.pingpong; |
1da177e4 | 2808 | break; |
5f8ef48d SH |
2809 | |
2810 | case TCP_CONGESTION: | |
2811 | if (get_user(len, optlen)) | |
2812 | return -EFAULT; | |
2813 | len = min_t(unsigned int, len, TCP_CA_NAME_MAX); | |
2814 | if (put_user(len, optlen)) | |
2815 | return -EFAULT; | |
6687e988 | 2816 | if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) |
5f8ef48d SH |
2817 | return -EFAULT; |
2818 | return 0; | |
e56fb50f | 2819 | |
3c0fef0b JH |
2820 | case TCP_THIN_LINEAR_TIMEOUTS: |
2821 | val = tp->thin_lto; | |
2822 | break; | |
2823 | case TCP_THIN_DUPACK: | |
2824 | val = tp->thin_dupack; | |
2825 | break; | |
dca43c75 | 2826 | |
ee995283 PE |
2827 | case TCP_REPAIR: |
2828 | val = tp->repair; | |
2829 | break; | |
2830 | ||
2831 | case TCP_REPAIR_QUEUE: | |
2832 | if (tp->repair) | |
2833 | val = tp->repair_queue; | |
2834 | else | |
2835 | return -EINVAL; | |
2836 | break; | |
2837 | ||
2838 | case TCP_QUEUE_SEQ: | |
2839 | if (tp->repair_queue == TCP_SEND_QUEUE) | |
2840 | val = tp->write_seq; | |
2841 | else if (tp->repair_queue == TCP_RECV_QUEUE) | |
2842 | val = tp->rcv_nxt; | |
2843 | else | |
2844 | return -EINVAL; | |
2845 | break; | |
2846 | ||
dca43c75 JC |
2847 | case TCP_USER_TIMEOUT: |
2848 | val = jiffies_to_msecs(icsk->icsk_user_timeout); | |
2849 | break; | |
1536e285 KN |
2850 | |
2851 | case TCP_FASTOPEN: | |
00db4124 | 2852 | if (icsk->icsk_accept_queue.fastopenq) |
1536e285 KN |
2853 | val = icsk->icsk_accept_queue.fastopenq->max_qlen; |
2854 | else | |
2855 | val = 0; | |
2856 | break; | |
2857 | ||
93be6ce0 AV |
2858 | case TCP_TIMESTAMP: |
2859 | val = tcp_time_stamp + tp->tsoffset; | |
2860 | break; | |
c9bee3b7 ED |
2861 | case TCP_NOTSENT_LOWAT: |
2862 | val = tp->notsent_lowat; | |
2863 | break; | |
cd8ae852 ED |
2864 | case TCP_SAVE_SYN: |
2865 | val = tp->save_syn; | |
2866 | break; | |
2867 | case TCP_SAVED_SYN: { | |
2868 | if (get_user(len, optlen)) | |
2869 | return -EFAULT; | |
2870 | ||
2871 | lock_sock(sk); | |
2872 | if (tp->saved_syn) { | |
aea0929e EM |
2873 | if (len < tp->saved_syn[0]) { |
2874 | if (put_user(tp->saved_syn[0], optlen)) { | |
2875 | release_sock(sk); | |
2876 | return -EFAULT; | |
2877 | } | |
2878 | release_sock(sk); | |
2879 | return -EINVAL; | |
2880 | } | |
2881 | len = tp->saved_syn[0]; | |
cd8ae852 ED |
2882 | if (put_user(len, optlen)) { |
2883 | release_sock(sk); | |
2884 | return -EFAULT; | |
2885 | } | |
2886 | if (copy_to_user(optval, tp->saved_syn + 1, len)) { | |
2887 | release_sock(sk); | |
2888 | return -EFAULT; | |
2889 | } | |
2890 | tcp_saved_syn_free(tp); | |
2891 | release_sock(sk); | |
2892 | } else { | |
2893 | release_sock(sk); | |
2894 | len = 0; | |
2895 | if (put_user(len, optlen)) | |
2896 | return -EFAULT; | |
2897 | } | |
2898 | return 0; | |
2899 | } | |
1da177e4 LT |
2900 | default: |
2901 | return -ENOPROTOOPT; | |
3ff50b79 | 2902 | } |
1da177e4 LT |
2903 | |
2904 | if (put_user(len, optlen)) | |
2905 | return -EFAULT; | |
2906 | if (copy_to_user(optval, &val, len)) | |
2907 | return -EFAULT; | |
2908 | return 0; | |
2909 | } | |
2910 | ||
3fdadf7d DM |
2911 | int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, |
2912 | int __user *optlen) | |
2913 | { | |
2914 | struct inet_connection_sock *icsk = inet_csk(sk); | |
2915 | ||
2916 | if (level != SOL_TCP) | |
2917 | return icsk->icsk_af_ops->getsockopt(sk, level, optname, | |
2918 | optval, optlen); | |
2919 | return do_tcp_getsockopt(sk, level, optname, optval, optlen); | |
2920 | } | |
4bc2f18b | 2921 | EXPORT_SYMBOL(tcp_getsockopt); |
3fdadf7d DM |
2922 | |
2923 | #ifdef CONFIG_COMPAT | |
543d9cfe ACM |
2924 | int compat_tcp_getsockopt(struct sock *sk, int level, int optname, |
2925 | char __user *optval, int __user *optlen) | |
3fdadf7d | 2926 | { |
dec73ff0 ACM |
2927 | if (level != SOL_TCP) |
2928 | return inet_csk_compat_getsockopt(sk, level, optname, | |
2929 | optval, optlen); | |
3fdadf7d DM |
2930 | return do_tcp_getsockopt(sk, level, optname, optval, optlen); |
2931 | } | |
543d9cfe | 2932 | EXPORT_SYMBOL(compat_tcp_getsockopt); |
3fdadf7d | 2933 | #endif |
1da177e4 | 2934 | |
cfb6eeb4 | 2935 | #ifdef CONFIG_TCP_MD5SIG |
349ce993 | 2936 | static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool); |
71cea17e | 2937 | static DEFINE_MUTEX(tcp_md5sig_mutex); |
349ce993 | 2938 | static bool tcp_md5sig_pool_populated = false; |
cfb6eeb4 | 2939 | |
71cea17e | 2940 | static void __tcp_alloc_md5sig_pool(void) |
cfb6eeb4 YH |
2941 | { |
2942 | int cpu; | |
cfb6eeb4 YH |
2943 | |
2944 | for_each_possible_cpu(cpu) { | |
349ce993 ED |
2945 | if (!per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm) { |
2946 | struct crypto_hash *hash; | |
cfb6eeb4 | 2947 | |
349ce993 ED |
2948 | hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); |
2949 | if (IS_ERR_OR_NULL(hash)) | |
2950 | return; | |
2951 | per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm = hash; | |
2952 | } | |
cfb6eeb4 | 2953 | } |
349ce993 ED |
2954 | /* before setting tcp_md5sig_pool_populated, we must commit all writes |
2955 | * to memory. See smp_rmb() in tcp_get_md5sig_pool() | |
71cea17e ED |
2956 | */ |
2957 | smp_wmb(); | |
349ce993 | 2958 | tcp_md5sig_pool_populated = true; |
cfb6eeb4 YH |
2959 | } |
2960 | ||
71cea17e | 2961 | bool tcp_alloc_md5sig_pool(void) |
cfb6eeb4 | 2962 | { |
349ce993 | 2963 | if (unlikely(!tcp_md5sig_pool_populated)) { |
71cea17e ED |
2964 | mutex_lock(&tcp_md5sig_mutex); |
2965 | ||
349ce993 | 2966 | if (!tcp_md5sig_pool_populated) |
71cea17e ED |
2967 | __tcp_alloc_md5sig_pool(); |
2968 | ||
2969 | mutex_unlock(&tcp_md5sig_mutex); | |
cfb6eeb4 | 2970 | } |
349ce993 | 2971 | return tcp_md5sig_pool_populated; |
cfb6eeb4 | 2972 | } |
cfb6eeb4 YH |
2973 | EXPORT_SYMBOL(tcp_alloc_md5sig_pool); |
2974 | ||
35790c04 ED |
2975 | |
2976 | /** | |
2977 | * tcp_get_md5sig_pool - get md5sig_pool for this user | |
2978 | * | |
2979 | * We use percpu structure, so if we succeed, we exit with preemption | |
2980 | * and BH disabled, to make sure another thread or softirq handling | |
2981 | * wont try to get same context. | |
2982 | */ | |
2983 | struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) | |
cfb6eeb4 | 2984 | { |
35790c04 | 2985 | local_bh_disable(); |
cfb6eeb4 | 2986 | |
349ce993 ED |
2987 | if (tcp_md5sig_pool_populated) { |
2988 | /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */ | |
2989 | smp_rmb(); | |
2990 | return this_cpu_ptr(&tcp_md5sig_pool); | |
2991 | } | |
35790c04 ED |
2992 | local_bh_enable(); |
2993 | return NULL; | |
2994 | } | |
2995 | EXPORT_SYMBOL(tcp_get_md5sig_pool); | |
cfb6eeb4 | 2996 | |
49a72dfb | 2997 | int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, |
ca35a0ef | 2998 | const struct tcphdr *th) |
49a72dfb AL |
2999 | { |
3000 | struct scatterlist sg; | |
ca35a0ef | 3001 | struct tcphdr hdr; |
49a72dfb AL |
3002 | int err; |
3003 | ||
ca35a0ef ED |
3004 | /* We are not allowed to change tcphdr, make a local copy */ |
3005 | memcpy(&hdr, th, sizeof(hdr)); | |
3006 | hdr.check = 0; | |
3007 | ||
49a72dfb | 3008 | /* options aren't included in the hash */ |
ca35a0ef ED |
3009 | sg_init_one(&sg, &hdr, sizeof(hdr)); |
3010 | err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr)); | |
49a72dfb AL |
3011 | return err; |
3012 | } | |
49a72dfb AL |
3013 | EXPORT_SYMBOL(tcp_md5_hash_header); |
3014 | ||
3015 | int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, | |
cf533ea5 | 3016 | const struct sk_buff *skb, unsigned int header_len) |
49a72dfb AL |
3017 | { |
3018 | struct scatterlist sg; | |
3019 | const struct tcphdr *tp = tcp_hdr(skb); | |
3020 | struct hash_desc *desc = &hp->md5_desc; | |
95c96174 ED |
3021 | unsigned int i; |
3022 | const unsigned int head_data_len = skb_headlen(skb) > header_len ? | |
3023 | skb_headlen(skb) - header_len : 0; | |
49a72dfb | 3024 | const struct skb_shared_info *shi = skb_shinfo(skb); |
d7fd1b57 | 3025 | struct sk_buff *frag_iter; |
49a72dfb AL |
3026 | |
3027 | sg_init_table(&sg, 1); | |
3028 | ||
3029 | sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); | |
3030 | if (crypto_hash_update(desc, &sg, head_data_len)) | |
3031 | return 1; | |
3032 | ||
3033 | for (i = 0; i < shi->nr_frags; ++i) { | |
3034 | const struct skb_frag_struct *f = &shi->frags[i]; | |
54d27fcb ED |
3035 | unsigned int offset = f->page_offset; |
3036 | struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); | |
3037 | ||
3038 | sg_set_page(&sg, page, skb_frag_size(f), | |
3039 | offset_in_page(offset)); | |
9e903e08 | 3040 | if (crypto_hash_update(desc, &sg, skb_frag_size(f))) |
49a72dfb AL |
3041 | return 1; |
3042 | } | |
3043 | ||
d7fd1b57 ED |
3044 | skb_walk_frags(skb, frag_iter) |
3045 | if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) | |
3046 | return 1; | |
3047 | ||
49a72dfb AL |
3048 | return 0; |
3049 | } | |
49a72dfb AL |
3050 | EXPORT_SYMBOL(tcp_md5_hash_skb_data); |
3051 | ||
cf533ea5 | 3052 | int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) |
49a72dfb AL |
3053 | { |
3054 | struct scatterlist sg; | |
3055 | ||
3056 | sg_init_one(&sg, key->key, key->keylen); | |
3057 | return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); | |
3058 | } | |
49a72dfb AL |
3059 | EXPORT_SYMBOL(tcp_md5_hash_key); |
3060 | ||
cfb6eeb4 YH |
3061 | #endif |
3062 | ||
4ac02bab AK |
3063 | void tcp_done(struct sock *sk) |
3064 | { | |
8336886f JC |
3065 | struct request_sock *req = tcp_sk(sk)->fastopen_rsk; |
3066 | ||
5a5f3a8d | 3067 | if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) |
63231bdd | 3068 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); |
4ac02bab AK |
3069 | |
3070 | tcp_set_state(sk, TCP_CLOSE); | |
3071 | tcp_clear_xmit_timers(sk); | |
00db4124 | 3072 | if (req) |
8336886f | 3073 | reqsk_fastopen_remove(sk, req, false); |
4ac02bab AK |
3074 | |
3075 | sk->sk_shutdown = SHUTDOWN_MASK; | |
3076 | ||
3077 | if (!sock_flag(sk, SOCK_DEAD)) | |
3078 | sk->sk_state_change(sk); | |
3079 | else | |
3080 | inet_csk_destroy_sock(sk); | |
3081 | } | |
3082 | EXPORT_SYMBOL_GPL(tcp_done); | |
3083 | ||
5f8ef48d | 3084 | extern struct tcp_congestion_ops tcp_reno; |
1da177e4 LT |
3085 | |
3086 | static __initdata unsigned long thash_entries; | |
3087 | static int __init set_thash_entries(char *str) | |
3088 | { | |
413c27d8 EZ |
3089 | ssize_t ret; |
3090 | ||
1da177e4 LT |
3091 | if (!str) |
3092 | return 0; | |
413c27d8 EZ |
3093 | |
3094 | ret = kstrtoul(str, 0, &thash_entries); | |
3095 | if (ret) | |
3096 | return 0; | |
3097 | ||
1da177e4 LT |
3098 | return 1; |
3099 | } | |
3100 | __setup("thash_entries=", set_thash_entries); | |
3101 | ||
47d7a88c | 3102 | static void __init tcp_init_mem(void) |
4acb4190 | 3103 | { |
b66e91cc ED |
3104 | unsigned long limit = nr_free_buffer_pages() / 16; |
3105 | ||
4acb4190 | 3106 | limit = max(limit, 128UL); |
b66e91cc ED |
3107 | sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */ |
3108 | sysctl_tcp_mem[1] = limit; /* 6.25 % */ | |
3109 | sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */ | |
4acb4190 GC |
3110 | } |
3111 | ||
1da177e4 LT |
3112 | void __init tcp_init(void) |
3113 | { | |
f03d78db | 3114 | unsigned long limit; |
b49960a0 | 3115 | int max_rshare, max_wshare, cnt; |
074b8517 | 3116 | unsigned int i; |
1da177e4 | 3117 | |
b4772ef8 | 3118 | sock_skb_cb_check_size(sizeof(struct tcp_skb_cb)); |
1da177e4 | 3119 | |
908c7f19 TH |
3120 | percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); |
3121 | percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); | |
6e04e021 ACM |
3122 | tcp_hashinfo.bind_bucket_cachep = |
3123 | kmem_cache_create("tcp_bind_bucket", | |
3124 | sizeof(struct inet_bind_bucket), 0, | |
20c2df83 | 3125 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 | 3126 | |
1da177e4 LT |
3127 | /* Size and allocate the main established and bind bucket |
3128 | * hash tables. | |
3129 | * | |
3130 | * The methodology is similar to that of the buffer cache. | |
3131 | */ | |
6e04e021 | 3132 | tcp_hashinfo.ehash = |
1da177e4 | 3133 | alloc_large_system_hash("TCP established", |
0f7ff927 | 3134 | sizeof(struct inet_ehash_bucket), |
1da177e4 | 3135 | thash_entries, |
fd90b29d | 3136 | 17, /* one slot per 128 KB of memory */ |
9e950efa | 3137 | 0, |
1da177e4 | 3138 | NULL, |
f373b53b | 3139 | &tcp_hashinfo.ehash_mask, |
31fe62b9 | 3140 | 0, |
0ccfe618 | 3141 | thash_entries ? 0 : 512 * 1024); |
05dbc7b5 | 3142 | for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) |
3ab5aee7 | 3143 | INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); |
05dbc7b5 | 3144 | |
230140cf ED |
3145 | if (inet_ehash_locks_alloc(&tcp_hashinfo)) |
3146 | panic("TCP: failed to alloc ehash_locks"); | |
6e04e021 | 3147 | tcp_hashinfo.bhash = |
1da177e4 | 3148 | alloc_large_system_hash("TCP bind", |
0f7ff927 | 3149 | sizeof(struct inet_bind_hashbucket), |
f373b53b | 3150 | tcp_hashinfo.ehash_mask + 1, |
fd90b29d | 3151 | 17, /* one slot per 128 KB of memory */ |
9e950efa | 3152 | 0, |
6e04e021 | 3153 | &tcp_hashinfo.bhash_size, |
1da177e4 | 3154 | NULL, |
31fe62b9 | 3155 | 0, |
1da177e4 | 3156 | 64 * 1024); |
074b8517 | 3157 | tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; |
6e04e021 ACM |
3158 | for (i = 0; i < tcp_hashinfo.bhash_size; i++) { |
3159 | spin_lock_init(&tcp_hashinfo.bhash[i].lock); | |
3160 | INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); | |
1da177e4 LT |
3161 | } |
3162 | ||
c5ed63d6 ED |
3163 | |
3164 | cnt = tcp_hashinfo.ehash_mask + 1; | |
3165 | ||
3166 | tcp_death_row.sysctl_max_tw_buckets = cnt / 2; | |
3167 | sysctl_tcp_max_orphans = cnt / 2; | |
3168 | sysctl_max_syn_backlog = max(128, cnt / 256); | |
1da177e4 | 3169 | |
a4fe34bf | 3170 | tcp_init_mem(); |
c43b874d | 3171 | /* Set per-socket limits to no more than 1/128 the pressure threshold */ |
5fb84b14 | 3172 | limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); |
b49960a0 ED |
3173 | max_wshare = min(4UL*1024*1024, limit); |
3174 | max_rshare = min(6UL*1024*1024, limit); | |
7b4f4b5e | 3175 | |
3ab224be | 3176 | sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; |
7b4f4b5e | 3177 | sysctl_tcp_wmem[1] = 16*1024; |
b49960a0 | 3178 | sysctl_tcp_wmem[2] = max(64*1024, max_wshare); |
7b4f4b5e | 3179 | |
3ab224be | 3180 | sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; |
7b4f4b5e | 3181 | sysctl_tcp_rmem[1] = 87380; |
b49960a0 | 3182 | sysctl_tcp_rmem[2] = max(87380, max_rshare); |
1da177e4 | 3183 | |
afd46503 | 3184 | pr_info("Hash tables configured (established %u bind %u)\n", |
058bd4d2 | 3185 | tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); |
317a76f9 | 3186 | |
51c5d0c4 | 3187 | tcp_metrics_init(); |
55d8694f | 3188 | BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); |
46d3ceab | 3189 | tcp_tasklet_init(); |
1da177e4 | 3190 | } |