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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> | |
ff5d7497 | 282 | #include <asm/unaligned.h> |
076bb0c8 | 283 | #include <net/busy_poll.h> |
1da177e4 | 284 | |
ab32ea5d | 285 | int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; |
1da177e4 | 286 | |
95bd09eb ED |
287 | int sysctl_tcp_min_tso_segs __read_mostly = 2; |
288 | ||
f54b3111 ED |
289 | int sysctl_tcp_autocorking __read_mostly = 1; |
290 | ||
dd24c001 | 291 | struct percpu_counter tcp_orphan_count; |
0a5578cf ACM |
292 | EXPORT_SYMBOL_GPL(tcp_orphan_count); |
293 | ||
a4fe34bf | 294 | long sysctl_tcp_mem[3] __read_mostly; |
b8059ead DM |
295 | int sysctl_tcp_wmem[3] __read_mostly; |
296 | int sysctl_tcp_rmem[3] __read_mostly; | |
1da177e4 | 297 | |
a4fe34bf | 298 | EXPORT_SYMBOL(sysctl_tcp_mem); |
1da177e4 LT |
299 | EXPORT_SYMBOL(sysctl_tcp_rmem); |
300 | EXPORT_SYMBOL(sysctl_tcp_wmem); | |
301 | ||
8d987e5c | 302 | atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ |
1da177e4 | 303 | EXPORT_SYMBOL(tcp_memory_allocated); |
1748376b ED |
304 | |
305 | /* | |
306 | * Current number of TCP sockets. | |
307 | */ | |
308 | struct percpu_counter tcp_sockets_allocated; | |
1da177e4 LT |
309 | EXPORT_SYMBOL(tcp_sockets_allocated); |
310 | ||
9c55e01c JA |
311 | /* |
312 | * TCP splice context | |
313 | */ | |
314 | struct tcp_splice_state { | |
315 | struct pipe_inode_info *pipe; | |
316 | size_t len; | |
317 | unsigned int flags; | |
318 | }; | |
319 | ||
1da177e4 LT |
320 | /* |
321 | * Pressure flag: try to collapse. | |
322 | * Technical note: it is used by multiple contexts non atomically. | |
3ab224be | 323 | * All the __sk_mem_schedule() is of this nature: accounting |
1da177e4 LT |
324 | * is strict, actions are advisory and have some latency. |
325 | */ | |
4103f8cd | 326 | int tcp_memory_pressure __read_mostly; |
1da177e4 LT |
327 | EXPORT_SYMBOL(tcp_memory_pressure); |
328 | ||
5c52ba17 | 329 | void tcp_enter_memory_pressure(struct sock *sk) |
1da177e4 LT |
330 | { |
331 | if (!tcp_memory_pressure) { | |
4e673444 | 332 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); |
1da177e4 LT |
333 | tcp_memory_pressure = 1; |
334 | } | |
335 | } | |
1da177e4 LT |
336 | EXPORT_SYMBOL(tcp_enter_memory_pressure); |
337 | ||
b103cf34 JA |
338 | /* Convert seconds to retransmits based on initial and max timeout */ |
339 | static u8 secs_to_retrans(int seconds, int timeout, int rto_max) | |
340 | { | |
341 | u8 res = 0; | |
342 | ||
343 | if (seconds > 0) { | |
344 | int period = timeout; | |
345 | ||
346 | res = 1; | |
347 | while (seconds > period && res < 255) { | |
348 | res++; | |
349 | timeout <<= 1; | |
350 | if (timeout > rto_max) | |
351 | timeout = rto_max; | |
352 | period += timeout; | |
353 | } | |
354 | } | |
355 | return res; | |
356 | } | |
357 | ||
358 | /* Convert retransmits to seconds based on initial and max timeout */ | |
359 | static int retrans_to_secs(u8 retrans, int timeout, int rto_max) | |
360 | { | |
361 | int period = 0; | |
362 | ||
363 | if (retrans > 0) { | |
364 | period = timeout; | |
365 | while (--retrans) { | |
366 | timeout <<= 1; | |
367 | if (timeout > rto_max) | |
368 | timeout = rto_max; | |
369 | period += timeout; | |
370 | } | |
371 | } | |
372 | return period; | |
373 | } | |
374 | ||
900f65d3 NC |
375 | /* Address-family independent initialization for a tcp_sock. |
376 | * | |
377 | * NOTE: A lot of things set to zero explicitly by call to | |
378 | * sk_alloc() so need not be done here. | |
379 | */ | |
380 | void tcp_init_sock(struct sock *sk) | |
381 | { | |
382 | struct inet_connection_sock *icsk = inet_csk(sk); | |
383 | struct tcp_sock *tp = tcp_sk(sk); | |
384 | ||
996b175e | 385 | __skb_queue_head_init(&tp->out_of_order_queue); |
900f65d3 NC |
386 | tcp_init_xmit_timers(sk); |
387 | tcp_prequeue_init(tp); | |
46d3ceab | 388 | INIT_LIST_HEAD(&tp->tsq_node); |
900f65d3 NC |
389 | |
390 | icsk->icsk_rto = TCP_TIMEOUT_INIT; | |
740b0f18 | 391 | tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); |
f6722583 | 392 | tp->rtt_min[0].rtt = ~0U; |
900f65d3 NC |
393 | |
394 | /* So many TCP implementations out there (incorrectly) count the | |
395 | * initial SYN frame in their delayed-ACK and congestion control | |
396 | * algorithms that we must have the following bandaid to talk | |
397 | * efficiently to them. -DaveM | |
398 | */ | |
399 | tp->snd_cwnd = TCP_INIT_CWND; | |
400 | ||
401 | /* See draft-stevens-tcpca-spec-01 for discussion of the | |
402 | * initialization of these values. | |
403 | */ | |
404 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; | |
405 | tp->snd_cwnd_clamp = ~0; | |
406 | tp->mss_cache = TCP_MSS_DEFAULT; | |
d654976c | 407 | u64_stats_init(&tp->syncp); |
900f65d3 NC |
408 | |
409 | tp->reordering = sysctl_tcp_reordering; | |
eed530b6 | 410 | tcp_enable_early_retrans(tp); |
55d8694f | 411 | tcp_assign_congestion_control(sk); |
900f65d3 | 412 | |
ceaa1fef AV |
413 | tp->tsoffset = 0; |
414 | ||
900f65d3 NC |
415 | sk->sk_state = TCP_CLOSE; |
416 | ||
417 | sk->sk_write_space = sk_stream_write_space; | |
418 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
419 | ||
420 | icsk->icsk_sync_mss = tcp_sync_mss; | |
421 | ||
900f65d3 NC |
422 | sk->sk_sndbuf = sysctl_tcp_wmem[1]; |
423 | sk->sk_rcvbuf = sysctl_tcp_rmem[1]; | |
424 | ||
425 | local_bh_disable(); | |
3d596f7b JW |
426 | if (mem_cgroup_sockets_enabled) |
427 | sock_update_memcg(sk); | |
900f65d3 NC |
428 | sk_sockets_allocated_inc(sk); |
429 | local_bh_enable(); | |
430 | } | |
431 | EXPORT_SYMBOL(tcp_init_sock); | |
432 | ||
f066e2b0 | 433 | static void tcp_tx_timestamp(struct sock *sk, struct sk_buff *skb) |
4ed2d765 | 434 | { |
f066e2b0 WB |
435 | if (sk->sk_tsflags) { |
436 | struct skb_shared_info *shinfo = skb_shinfo(skb); | |
4ed2d765 | 437 | |
f066e2b0 WB |
438 | sock_tx_timestamp(sk, &shinfo->tx_flags); |
439 | if (shinfo->tx_flags & SKBTX_ANY_TSTAMP) | |
440 | shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; | |
441 | } | |
4ed2d765 WB |
442 | } |
443 | ||
1da177e4 LT |
444 | /* |
445 | * Wait for a TCP event. | |
446 | * | |
447 | * Note that we don't need to lock the socket, as the upper poll layers | |
448 | * take care of normal races (between the test and the event) and we don't | |
449 | * go look at any of the socket buffers directly. | |
450 | */ | |
451 | unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) | |
452 | { | |
453 | unsigned int mask; | |
454 | struct sock *sk = sock->sk; | |
cf533ea5 | 455 | const struct tcp_sock *tp = tcp_sk(sk); |
00fd38d9 | 456 | int state; |
1da177e4 | 457 | |
c3f1dbaf DM |
458 | sock_rps_record_flow(sk); |
459 | ||
aa395145 | 460 | sock_poll_wait(file, sk_sleep(sk), wait); |
00fd38d9 ED |
461 | |
462 | state = sk_state_load(sk); | |
463 | if (state == TCP_LISTEN) | |
dc40c7bc | 464 | return inet_csk_listen_poll(sk); |
1da177e4 LT |
465 | |
466 | /* Socket is not locked. We are protected from async events | |
70efce27 WN |
467 | * by poll logic and correct handling of state changes |
468 | * made by other threads is impossible in any case. | |
1da177e4 LT |
469 | */ |
470 | ||
471 | mask = 0; | |
1da177e4 LT |
472 | |
473 | /* | |
474 | * POLLHUP is certainly not done right. But poll() doesn't | |
475 | * have a notion of HUP in just one direction, and for a | |
476 | * socket the read side is more interesting. | |
477 | * | |
478 | * Some poll() documentation says that POLLHUP is incompatible | |
479 | * with the POLLOUT/POLLWR flags, so somebody should check this | |
480 | * all. But careful, it tends to be safer to return too many | |
481 | * bits than too few, and you can easily break real applications | |
482 | * if you don't tell them that something has hung up! | |
483 | * | |
484 | * Check-me. | |
485 | * | |
486 | * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and | |
487 | * our fs/select.c). It means that after we received EOF, | |
488 | * poll always returns immediately, making impossible poll() on write() | |
489 | * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP | |
490 | * if and only if shutdown has been made in both directions. | |
491 | * Actually, it is interesting to look how Solaris and DUX | |
70efce27 | 492 | * solve this dilemma. I would prefer, if POLLHUP were maskable, |
1da177e4 LT |
493 | * then we could set it on SND_SHUTDOWN. BTW examples given |
494 | * in Stevens' books assume exactly this behaviour, it explains | |
70efce27 | 495 | * why POLLHUP is incompatible with POLLOUT. --ANK |
1da177e4 LT |
496 | * |
497 | * NOTE. Check for TCP_CLOSE is added. The goal is to prevent | |
498 | * blocking on fresh not-connected or disconnected socket. --ANK | |
499 | */ | |
00fd38d9 | 500 | if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE) |
1da177e4 LT |
501 | mask |= POLLHUP; |
502 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
f348d70a | 503 | mask |= POLLIN | POLLRDNORM | POLLRDHUP; |
1da177e4 | 504 | |
8336886f | 505 | /* Connected or passive Fast Open socket? */ |
00fd38d9 ED |
506 | if (state != TCP_SYN_SENT && |
507 | (state != TCP_SYN_RECV || tp->fastopen_rsk)) { | |
c7004482 DM |
508 | int target = sock_rcvlowat(sk, 0, INT_MAX); |
509 | ||
510 | if (tp->urg_seq == tp->copied_seq && | |
511 | !sock_flag(sk, SOCK_URGINLINE) && | |
512 | tp->urg_data) | |
b634f875 | 513 | target++; |
c7004482 | 514 | |
c7004482 | 515 | if (tp->rcv_nxt - tp->copied_seq >= target) |
1da177e4 LT |
516 | mask |= POLLIN | POLLRDNORM; |
517 | ||
518 | if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { | |
64dc6130 | 519 | if (sk_stream_is_writeable(sk)) { |
1da177e4 LT |
520 | mask |= POLLOUT | POLLWRNORM; |
521 | } else { /* send SIGIO later */ | |
9cd3e072 | 522 | sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
1da177e4 LT |
523 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
524 | ||
525 | /* Race breaker. If space is freed after | |
526 | * wspace test but before the flags are set, | |
3c715127 | 527 | * IO signal will be lost. Memory barrier |
528 | * pairs with the input side. | |
1da177e4 | 529 | */ |
3c715127 | 530 | smp_mb__after_atomic(); |
64dc6130 | 531 | if (sk_stream_is_writeable(sk)) |
1da177e4 LT |
532 | mask |= POLLOUT | POLLWRNORM; |
533 | } | |
d84ba638 KM |
534 | } else |
535 | mask |= POLLOUT | POLLWRNORM; | |
1da177e4 LT |
536 | |
537 | if (tp->urg_data & TCP_URG_VALID) | |
538 | mask |= POLLPRI; | |
539 | } | |
a4d25803 TM |
540 | /* This barrier is coupled with smp_wmb() in tcp_reset() */ |
541 | smp_rmb(); | |
4ed2d765 | 542 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) |
a4d25803 TM |
543 | mask |= POLLERR; |
544 | ||
1da177e4 LT |
545 | return mask; |
546 | } | |
4bc2f18b | 547 | EXPORT_SYMBOL(tcp_poll); |
1da177e4 LT |
548 | |
549 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) | |
550 | { | |
551 | struct tcp_sock *tp = tcp_sk(sk); | |
552 | int answ; | |
0e71c55c | 553 | bool slow; |
1da177e4 LT |
554 | |
555 | switch (cmd) { | |
556 | case SIOCINQ: | |
557 | if (sk->sk_state == TCP_LISTEN) | |
558 | return -EINVAL; | |
559 | ||
0e71c55c | 560 | slow = lock_sock_fast(sk); |
1da177e4 LT |
561 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) |
562 | answ = 0; | |
563 | else if (sock_flag(sk, SOCK_URGINLINE) || | |
564 | !tp->urg_data || | |
565 | before(tp->urg_seq, tp->copied_seq) || | |
566 | !before(tp->urg_seq, tp->rcv_nxt)) { | |
91521944 | 567 | |
1da177e4 LT |
568 | answ = tp->rcv_nxt - tp->copied_seq; |
569 | ||
a3374c42 ED |
570 | /* Subtract 1, if FIN was received */ |
571 | if (answ && sock_flag(sk, SOCK_DONE)) | |
572 | answ--; | |
1da177e4 LT |
573 | } else |
574 | answ = tp->urg_seq - tp->copied_seq; | |
0e71c55c | 575 | unlock_sock_fast(sk, slow); |
1da177e4 LT |
576 | break; |
577 | case SIOCATMARK: | |
578 | answ = tp->urg_data && tp->urg_seq == tp->copied_seq; | |
579 | break; | |
580 | case SIOCOUTQ: | |
581 | if (sk->sk_state == TCP_LISTEN) | |
582 | return -EINVAL; | |
583 | ||
584 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
585 | answ = 0; | |
586 | else | |
587 | answ = tp->write_seq - tp->snd_una; | |
588 | break; | |
2f4e1b39 MS |
589 | case SIOCOUTQNSD: |
590 | if (sk->sk_state == TCP_LISTEN) | |
591 | return -EINVAL; | |
592 | ||
593 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) | |
594 | answ = 0; | |
595 | else | |
596 | answ = tp->write_seq - tp->snd_nxt; | |
597 | break; | |
1da177e4 LT |
598 | default: |
599 | return -ENOIOCTLCMD; | |
3ff50b79 | 600 | } |
1da177e4 LT |
601 | |
602 | return put_user(answ, (int __user *)arg); | |
603 | } | |
4bc2f18b | 604 | EXPORT_SYMBOL(tcp_ioctl); |
1da177e4 | 605 | |
1da177e4 LT |
606 | static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) |
607 | { | |
4de075e0 | 608 | TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; |
1da177e4 LT |
609 | tp->pushed_seq = tp->write_seq; |
610 | } | |
611 | ||
a2a385d6 | 612 | static inline bool forced_push(const struct tcp_sock *tp) |
1da177e4 LT |
613 | { |
614 | return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); | |
615 | } | |
616 | ||
f4a775d1 | 617 | static void skb_entail(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 618 | { |
9e412ba7 | 619 | struct tcp_sock *tp = tcp_sk(sk); |
352d4800 ACM |
620 | struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); |
621 | ||
622 | skb->csum = 0; | |
623 | tcb->seq = tcb->end_seq = tp->write_seq; | |
4de075e0 | 624 | tcb->tcp_flags = TCPHDR_ACK; |
352d4800 | 625 | tcb->sacked = 0; |
f4a775d1 | 626 | __skb_header_release(skb); |
fe067e8a | 627 | tcp_add_write_queue_tail(sk, skb); |
3ab224be HA |
628 | sk->sk_wmem_queued += skb->truesize; |
629 | sk_mem_charge(sk, skb->truesize); | |
89ebd197 | 630 | if (tp->nonagle & TCP_NAGLE_PUSH) |
e905a9ed | 631 | tp->nonagle &= ~TCP_NAGLE_PUSH; |
6f021c62 ED |
632 | |
633 | tcp_slow_start_after_idle_check(sk); | |
1da177e4 LT |
634 | } |
635 | ||
afeca340 | 636 | static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) |
1da177e4 | 637 | { |
33f5f57e | 638 | if (flags & MSG_OOB) |
1da177e4 | 639 | tp->snd_up = tp->write_seq; |
1da177e4 LT |
640 | } |
641 | ||
f54b3111 | 642 | /* If a not yet filled skb is pushed, do not send it if |
a181ceb5 | 643 | * we have data packets in Qdisc or NIC queues : |
f54b3111 ED |
644 | * Because TX completion will happen shortly, it gives a chance |
645 | * to coalesce future sendmsg() payload into this skb, without | |
646 | * need for a timer, and with no latency trade off. | |
647 | * As packets containing data payload have a bigger truesize | |
a181ceb5 ED |
648 | * than pure acks (dataless) packets, the last checks prevent |
649 | * autocorking if we only have an ACK in Qdisc/NIC queues, | |
650 | * or if TX completion was delayed after we processed ACK packet. | |
f54b3111 ED |
651 | */ |
652 | static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, | |
653 | int size_goal) | |
1da177e4 | 654 | { |
f54b3111 ED |
655 | return skb->len < size_goal && |
656 | sysctl_tcp_autocorking && | |
a181ceb5 | 657 | skb != tcp_write_queue_head(sk) && |
f54b3111 ED |
658 | atomic_read(&sk->sk_wmem_alloc) > skb->truesize; |
659 | } | |
660 | ||
661 | static void tcp_push(struct sock *sk, int flags, int mss_now, | |
662 | int nonagle, int size_goal) | |
663 | { | |
664 | struct tcp_sock *tp = tcp_sk(sk); | |
665 | struct sk_buff *skb; | |
afeca340 | 666 | |
f54b3111 ED |
667 | if (!tcp_send_head(sk)) |
668 | return; | |
afeca340 | 669 | |
f54b3111 ED |
670 | skb = tcp_write_queue_tail(sk); |
671 | if (!(flags & MSG_MORE) || forced_push(tp)) | |
672 | tcp_mark_push(tp, skb); | |
673 | ||
674 | tcp_mark_urg(tp, flags); | |
675 | ||
676 | if (tcp_should_autocork(sk, skb, size_goal)) { | |
677 | ||
678 | /* avoid atomic op if TSQ_THROTTLED bit is already set */ | |
679 | if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) { | |
680 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); | |
681 | set_bit(TSQ_THROTTLED, &tp->tsq_flags); | |
682 | } | |
a181ceb5 ED |
683 | /* It is possible TX completion already happened |
684 | * before we set TSQ_THROTTLED. | |
685 | */ | |
686 | if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize) | |
687 | return; | |
1da177e4 | 688 | } |
f54b3111 ED |
689 | |
690 | if (flags & MSG_MORE) | |
691 | nonagle = TCP_NAGLE_CORK; | |
692 | ||
693 | __tcp_push_pending_frames(sk, mss_now, nonagle); | |
1da177e4 LT |
694 | } |
695 | ||
6ff7751d AB |
696 | static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, |
697 | unsigned int offset, size_t len) | |
9c55e01c JA |
698 | { |
699 | struct tcp_splice_state *tss = rd_desc->arg.data; | |
33966dd0 | 700 | int ret; |
9c55e01c | 701 | |
a60e3cc7 HFS |
702 | ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe, |
703 | min(rd_desc->count, len), tss->flags, | |
704 | skb_socket_splice); | |
33966dd0 WT |
705 | if (ret > 0) |
706 | rd_desc->count -= ret; | |
707 | return ret; | |
9c55e01c JA |
708 | } |
709 | ||
710 | static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) | |
711 | { | |
712 | /* Store TCP splice context information in read_descriptor_t. */ | |
713 | read_descriptor_t rd_desc = { | |
714 | .arg.data = tss, | |
33966dd0 | 715 | .count = tss->len, |
9c55e01c JA |
716 | }; |
717 | ||
718 | return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); | |
719 | } | |
720 | ||
721 | /** | |
722 | * tcp_splice_read - splice data from TCP socket to a pipe | |
723 | * @sock: socket to splice from | |
724 | * @ppos: position (not valid) | |
725 | * @pipe: pipe to splice to | |
726 | * @len: number of bytes to splice | |
727 | * @flags: splice modifier flags | |
728 | * | |
729 | * Description: | |
730 | * Will read pages from given socket and fill them into a pipe. | |
731 | * | |
732 | **/ | |
733 | ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, | |
734 | struct pipe_inode_info *pipe, size_t len, | |
735 | unsigned int flags) | |
736 | { | |
737 | struct sock *sk = sock->sk; | |
738 | struct tcp_splice_state tss = { | |
739 | .pipe = pipe, | |
740 | .len = len, | |
741 | .flags = flags, | |
742 | }; | |
743 | long timeo; | |
744 | ssize_t spliced; | |
745 | int ret; | |
746 | ||
3a047bf8 | 747 | sock_rps_record_flow(sk); |
9c55e01c JA |
748 | /* |
749 | * We can't seek on a socket input | |
750 | */ | |
751 | if (unlikely(*ppos)) | |
752 | return -ESPIPE; | |
753 | ||
754 | ret = spliced = 0; | |
755 | ||
756 | lock_sock(sk); | |
757 | ||
42324c62 | 758 | timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); |
9c55e01c JA |
759 | while (tss.len) { |
760 | ret = __tcp_splice_read(sk, &tss); | |
761 | if (ret < 0) | |
762 | break; | |
763 | else if (!ret) { | |
764 | if (spliced) | |
765 | break; | |
9c55e01c JA |
766 | if (sock_flag(sk, SOCK_DONE)) |
767 | break; | |
768 | if (sk->sk_err) { | |
769 | ret = sock_error(sk); | |
770 | break; | |
771 | } | |
772 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
773 | break; | |
774 | if (sk->sk_state == TCP_CLOSE) { | |
775 | /* | |
776 | * This occurs when user tries to read | |
777 | * from never connected socket. | |
778 | */ | |
779 | if (!sock_flag(sk, SOCK_DONE)) | |
780 | ret = -ENOTCONN; | |
781 | break; | |
782 | } | |
783 | if (!timeo) { | |
784 | ret = -EAGAIN; | |
785 | break; | |
786 | } | |
dfbafc99 | 787 | sk_wait_data(sk, &timeo, NULL); |
9c55e01c JA |
788 | if (signal_pending(current)) { |
789 | ret = sock_intr_errno(timeo); | |
790 | break; | |
791 | } | |
792 | continue; | |
793 | } | |
794 | tss.len -= ret; | |
795 | spliced += ret; | |
796 | ||
33966dd0 WT |
797 | if (!timeo) |
798 | break; | |
9c55e01c JA |
799 | release_sock(sk); |
800 | lock_sock(sk); | |
801 | ||
802 | if (sk->sk_err || sk->sk_state == TCP_CLOSE || | |
33966dd0 | 803 | (sk->sk_shutdown & RCV_SHUTDOWN) || |
9c55e01c JA |
804 | signal_pending(current)) |
805 | break; | |
806 | } | |
807 | ||
808 | release_sock(sk); | |
809 | ||
810 | if (spliced) | |
811 | return spliced; | |
812 | ||
813 | return ret; | |
814 | } | |
4bc2f18b | 815 | EXPORT_SYMBOL(tcp_splice_read); |
9c55e01c | 816 | |
eb934478 ED |
817 | struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, |
818 | bool force_schedule) | |
f561d0f2 PE |
819 | { |
820 | struct sk_buff *skb; | |
821 | ||
822 | /* The TCP header must be at least 32-bit aligned. */ | |
823 | size = ALIGN(size, 4); | |
824 | ||
8e4d980a ED |
825 | if (unlikely(tcp_under_memory_pressure(sk))) |
826 | sk_mem_reclaim_partial(sk); | |
827 | ||
f561d0f2 | 828 | skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); |
8e4d980a | 829 | if (likely(skb)) { |
eb934478 | 830 | bool mem_scheduled; |
8e4d980a | 831 | |
eb934478 ED |
832 | if (force_schedule) { |
833 | mem_scheduled = true; | |
8e4d980a ED |
834 | sk_forced_mem_schedule(sk, skb->truesize); |
835 | } else { | |
eb934478 | 836 | mem_scheduled = sk_wmem_schedule(sk, skb->truesize); |
8e4d980a | 837 | } |
eb934478 | 838 | if (likely(mem_scheduled)) { |
a21d4572 | 839 | skb_reserve(skb, sk->sk_prot->max_header); |
f561d0f2 PE |
840 | /* |
841 | * Make sure that we have exactly size bytes | |
842 | * available to the caller, no more, no less. | |
843 | */ | |
16fad69c | 844 | skb->reserved_tailroom = skb->end - skb->tail - size; |
f561d0f2 PE |
845 | return skb; |
846 | } | |
847 | __kfree_skb(skb); | |
848 | } else { | |
5c52ba17 | 849 | sk->sk_prot->enter_memory_pressure(sk); |
f561d0f2 PE |
850 | sk_stream_moderate_sndbuf(sk); |
851 | } | |
852 | return NULL; | |
853 | } | |
854 | ||
0c54b85f IJ |
855 | static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, |
856 | int large_allowed) | |
857 | { | |
858 | struct tcp_sock *tp = tcp_sk(sk); | |
6c09fa09 | 859 | u32 new_size_goal, size_goal; |
605ad7f1 ED |
860 | |
861 | if (!large_allowed || !sk_can_gso(sk)) | |
862 | return mss_now; | |
863 | ||
6c09fa09 ED |
864 | /* Note : tcp_tso_autosize() will eventually split this later */ |
865 | new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER; | |
605ad7f1 ED |
866 | new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal); |
867 | ||
868 | /* We try hard to avoid divides here */ | |
869 | size_goal = tp->gso_segs * mss_now; | |
870 | if (unlikely(new_size_goal < size_goal || | |
871 | new_size_goal >= size_goal + mss_now)) { | |
872 | tp->gso_segs = min_t(u16, new_size_goal / mss_now, | |
873 | sk->sk_gso_max_segs); | |
874 | size_goal = tp->gso_segs * mss_now; | |
0c54b85f IJ |
875 | } |
876 | ||
605ad7f1 | 877 | return max(size_goal, mss_now); |
0c54b85f IJ |
878 | } |
879 | ||
880 | static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) | |
881 | { | |
882 | int mss_now; | |
883 | ||
884 | mss_now = tcp_current_mss(sk); | |
885 | *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); | |
886 | ||
887 | return mss_now; | |
888 | } | |
889 | ||
64022d0b ED |
890 | static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, |
891 | size_t size, int flags) | |
1da177e4 LT |
892 | { |
893 | struct tcp_sock *tp = tcp_sk(sk); | |
c1b4a7e6 | 894 | int mss_now, size_goal; |
1da177e4 LT |
895 | int err; |
896 | ssize_t copied; | |
897 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
898 | ||
8336886f JC |
899 | /* Wait for a connection to finish. One exception is TCP Fast Open |
900 | * (passive side) where data is allowed to be sent before a connection | |
901 | * is fully established. | |
902 | */ | |
903 | if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && | |
904 | !tcp_passive_fastopen(sk)) { | |
686a5624 YM |
905 | err = sk_stream_wait_connect(sk, &timeo); |
906 | if (err != 0) | |
1da177e4 | 907 | goto out_err; |
8336886f | 908 | } |
1da177e4 | 909 | |
9cd3e072 | 910 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
1da177e4 | 911 | |
0c54b85f | 912 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
913 | copied = 0; |
914 | ||
915 | err = -EPIPE; | |
916 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
0d6a775e | 917 | goto out_err; |
1da177e4 | 918 | |
64022d0b | 919 | while (size > 0) { |
fe067e8a | 920 | struct sk_buff *skb = tcp_write_queue_tail(sk); |
38ba0a65 | 921 | int copy, i; |
38ba0a65 | 922 | bool can_coalesce; |
1da177e4 | 923 | |
fe067e8a | 924 | if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { |
1da177e4 LT |
925 | new_segment: |
926 | if (!sk_stream_memory_free(sk)) | |
927 | goto wait_for_sndbuf; | |
928 | ||
eb934478 ED |
929 | skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, |
930 | skb_queue_empty(&sk->sk_write_queue)); | |
1da177e4 LT |
931 | if (!skb) |
932 | goto wait_for_memory; | |
933 | ||
9e412ba7 | 934 | skb_entail(sk, skb); |
c1b4a7e6 | 935 | copy = size_goal; |
1da177e4 LT |
936 | } |
937 | ||
938 | if (copy > size) | |
939 | copy = size; | |
940 | ||
941 | i = skb_shinfo(skb)->nr_frags; | |
942 | can_coalesce = skb_can_coalesce(skb, i, page, offset); | |
5f74f82e | 943 | if (!can_coalesce && i >= sysctl_max_skb_frags) { |
1da177e4 LT |
944 | tcp_mark_push(tp, skb); |
945 | goto new_segment; | |
946 | } | |
3ab224be | 947 | if (!sk_wmem_schedule(sk, copy)) |
1da177e4 | 948 | goto wait_for_memory; |
e905a9ed | 949 | |
1da177e4 | 950 | if (can_coalesce) { |
9e903e08 | 951 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
1da177e4 LT |
952 | } else { |
953 | get_page(page); | |
954 | skb_fill_page_desc(skb, i, page, offset, copy); | |
955 | } | |
c9af6db4 | 956 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
cef401de | 957 | |
1da177e4 LT |
958 | skb->len += copy; |
959 | skb->data_len += copy; | |
960 | skb->truesize += copy; | |
961 | sk->sk_wmem_queued += copy; | |
3ab224be | 962 | sk_mem_charge(sk, copy); |
84fa7933 | 963 | skb->ip_summed = CHECKSUM_PARTIAL; |
1da177e4 LT |
964 | tp->write_seq += copy; |
965 | TCP_SKB_CB(skb)->end_seq += copy; | |
cd7d8498 | 966 | tcp_skb_pcount_set(skb, 0); |
1da177e4 LT |
967 | |
968 | if (!copied) | |
4de075e0 | 969 | TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; |
1da177e4 LT |
970 | |
971 | copied += copy; | |
64022d0b | 972 | offset += copy; |
686a5624 YM |
973 | size -= copy; |
974 | if (!size) { | |
4ed2d765 | 975 | tcp_tx_timestamp(sk, skb); |
1da177e4 | 976 | goto out; |
4ed2d765 | 977 | } |
1da177e4 | 978 | |
69d15067 | 979 | if (skb->len < size_goal || (flags & MSG_OOB)) |
1da177e4 LT |
980 | continue; |
981 | ||
982 | if (forced_push(tp)) { | |
983 | tcp_mark_push(tp, skb); | |
9e412ba7 | 984 | __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); |
fe067e8a | 985 | } else if (skb == tcp_send_head(sk)) |
1da177e4 LT |
986 | tcp_push_one(sk, mss_now); |
987 | continue; | |
988 | ||
989 | wait_for_sndbuf: | |
990 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
991 | wait_for_memory: | |
f54b3111 ED |
992 | tcp_push(sk, flags & ~MSG_MORE, mss_now, |
993 | TCP_NAGLE_PUSH, size_goal); | |
1da177e4 | 994 | |
686a5624 YM |
995 | err = sk_stream_wait_memory(sk, &timeo); |
996 | if (err != 0) | |
1da177e4 LT |
997 | goto do_error; |
998 | ||
0c54b85f | 999 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
1000 | } |
1001 | ||
1002 | out: | |
35f9c09f | 1003 | if (copied && !(flags & MSG_SENDPAGE_NOTLAST)) |
f54b3111 | 1004 | tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); |
1da177e4 LT |
1005 | return copied; |
1006 | ||
1007 | do_error: | |
1008 | if (copied) | |
1009 | goto out; | |
1010 | out_err: | |
ce5ec440 JB |
1011 | /* make sure we wake any epoll edge trigger waiter */ |
1012 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
1013 | sk->sk_write_space(sk); | |
1da177e4 LT |
1014 | return sk_stream_error(sk, flags, err); |
1015 | } | |
1016 | ||
7ba42910 CG |
1017 | int tcp_sendpage(struct sock *sk, struct page *page, int offset, |
1018 | size_t size, int flags) | |
1da177e4 LT |
1019 | { |
1020 | ssize_t res; | |
1da177e4 | 1021 | |
1da177e4 | 1022 | if (!(sk->sk_route_caps & NETIF_F_SG) || |
9a49850d | 1023 | !sk_check_csum_caps(sk)) |
7ba42910 CG |
1024 | return sock_no_sendpage(sk->sk_socket, page, offset, size, |
1025 | flags); | |
1da177e4 | 1026 | |
1da177e4 | 1027 | lock_sock(sk); |
64022d0b | 1028 | res = do_tcp_sendpages(sk, page, offset, size, flags); |
1da177e4 LT |
1029 | release_sock(sk); |
1030 | return res; | |
1031 | } | |
4bc2f18b | 1032 | EXPORT_SYMBOL(tcp_sendpage); |
1da177e4 | 1033 | |
690e99c4 | 1034 | static inline int select_size(const struct sock *sk, bool sg) |
1da177e4 | 1035 | { |
cf533ea5 | 1036 | const struct tcp_sock *tp = tcp_sk(sk); |
c1b4a7e6 | 1037 | int tmp = tp->mss_cache; |
1da177e4 | 1038 | |
def87cf4 | 1039 | if (sg) { |
f07d960d ED |
1040 | if (sk_can_gso(sk)) { |
1041 | /* Small frames wont use a full page: | |
1042 | * Payload will immediately follow tcp header. | |
1043 | */ | |
1044 | tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); | |
1045 | } else { | |
b4e26f5e DM |
1046 | int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); |
1047 | ||
1048 | if (tmp >= pgbreak && | |
1049 | tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) | |
1050 | tmp = pgbreak; | |
1051 | } | |
1052 | } | |
1da177e4 | 1053 | |
1da177e4 LT |
1054 | return tmp; |
1055 | } | |
1056 | ||
cf60af03 YC |
1057 | void tcp_free_fastopen_req(struct tcp_sock *tp) |
1058 | { | |
00db4124 | 1059 | if (tp->fastopen_req) { |
cf60af03 YC |
1060 | kfree(tp->fastopen_req); |
1061 | tp->fastopen_req = NULL; | |
1062 | } | |
1063 | } | |
1064 | ||
f5ddcbbb ED |
1065 | static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, |
1066 | int *copied, size_t size) | |
cf60af03 YC |
1067 | { |
1068 | struct tcp_sock *tp = tcp_sk(sk); | |
1069 | int err, flags; | |
1070 | ||
1071 | if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE)) | |
1072 | return -EOPNOTSUPP; | |
00db4124 | 1073 | if (tp->fastopen_req) |
cf60af03 YC |
1074 | return -EALREADY; /* Another Fast Open is in progress */ |
1075 | ||
1076 | tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), | |
1077 | sk->sk_allocation); | |
51456b29 | 1078 | if (unlikely(!tp->fastopen_req)) |
cf60af03 YC |
1079 | return -ENOBUFS; |
1080 | tp->fastopen_req->data = msg; | |
f5ddcbbb | 1081 | tp->fastopen_req->size = size; |
cf60af03 YC |
1082 | |
1083 | flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; | |
1084 | err = __inet_stream_connect(sk->sk_socket, msg->msg_name, | |
1085 | msg->msg_namelen, flags); | |
f5ddcbbb | 1086 | *copied = tp->fastopen_req->copied; |
cf60af03 YC |
1087 | tcp_free_fastopen_req(tp); |
1088 | return err; | |
1089 | } | |
1090 | ||
1b784140 | 1091 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) |
1da177e4 | 1092 | { |
1da177e4 LT |
1093 | struct tcp_sock *tp = tcp_sk(sk); |
1094 | struct sk_buff *skb; | |
57be5bda AV |
1095 | int flags, err, copied = 0; |
1096 | int mss_now = 0, size_goal, copied_syn = 0; | |
690e99c4 | 1097 | bool sg; |
1da177e4 LT |
1098 | long timeo; |
1099 | ||
1100 | lock_sock(sk); | |
1da177e4 LT |
1101 | |
1102 | flags = msg->msg_flags; | |
cf60af03 | 1103 | if (flags & MSG_FASTOPEN) { |
f5ddcbbb | 1104 | err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size); |
cf60af03 YC |
1105 | if (err == -EINPROGRESS && copied_syn > 0) |
1106 | goto out; | |
1107 | else if (err) | |
1108 | goto out_err; | |
cf60af03 YC |
1109 | } |
1110 | ||
1da177e4 LT |
1111 | timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); |
1112 | ||
8336886f JC |
1113 | /* Wait for a connection to finish. One exception is TCP Fast Open |
1114 | * (passive side) where data is allowed to be sent before a connection | |
1115 | * is fully established. | |
1116 | */ | |
1117 | if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && | |
1118 | !tcp_passive_fastopen(sk)) { | |
686a5624 YM |
1119 | err = sk_stream_wait_connect(sk, &timeo); |
1120 | if (err != 0) | |
cf60af03 | 1121 | goto do_error; |
8336886f | 1122 | } |
1da177e4 | 1123 | |
c0e88ff0 PE |
1124 | if (unlikely(tp->repair)) { |
1125 | if (tp->repair_queue == TCP_RECV_QUEUE) { | |
1126 | copied = tcp_send_rcvq(sk, msg, size); | |
5924f17a | 1127 | goto out_nopush; |
c0e88ff0 PE |
1128 | } |
1129 | ||
1130 | err = -EINVAL; | |
1131 | if (tp->repair_queue == TCP_NO_QUEUE) | |
1132 | goto out_err; | |
1133 | ||
1134 | /* 'common' sending to sendq */ | |
1135 | } | |
1136 | ||
1da177e4 | 1137 | /* This should be in poll */ |
9cd3e072 | 1138 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
1da177e4 | 1139 | |
0c54b85f | 1140 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
1141 | |
1142 | /* Ok commence sending. */ | |
1da177e4 LT |
1143 | copied = 0; |
1144 | ||
1145 | err = -EPIPE; | |
1146 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
0d6a775e | 1147 | goto out_err; |
1da177e4 | 1148 | |
690e99c4 | 1149 | sg = !!(sk->sk_route_caps & NETIF_F_SG); |
def87cf4 | 1150 | |
01e97e65 | 1151 | while (msg_data_left(msg)) { |
57be5bda AV |
1152 | int copy = 0; |
1153 | int max = size_goal; | |
1da177e4 | 1154 | |
57be5bda AV |
1155 | skb = tcp_write_queue_tail(sk); |
1156 | if (tcp_send_head(sk)) { | |
1157 | if (skb->ip_summed == CHECKSUM_NONE) | |
1158 | max = mss_now; | |
1159 | copy = max - skb->len; | |
cf60af03 | 1160 | } |
1da177e4 | 1161 | |
57be5bda | 1162 | if (copy <= 0) { |
1da177e4 | 1163 | new_segment: |
57be5bda AV |
1164 | /* Allocate new segment. If the interface is SG, |
1165 | * allocate skb fitting to single page. | |
1166 | */ | |
1167 | if (!sk_stream_memory_free(sk)) | |
1168 | goto wait_for_sndbuf; | |
1da177e4 | 1169 | |
57be5bda AV |
1170 | skb = sk_stream_alloc_skb(sk, |
1171 | select_size(sk, sg), | |
eb934478 ED |
1172 | sk->sk_allocation, |
1173 | skb_queue_empty(&sk->sk_write_queue)); | |
57be5bda AV |
1174 | if (!skb) |
1175 | goto wait_for_memory; | |
1da177e4 | 1176 | |
57be5bda AV |
1177 | /* |
1178 | * Check whether we can use HW checksum. | |
1179 | */ | |
9a49850d | 1180 | if (sk_check_csum_caps(sk)) |
57be5bda | 1181 | skb->ip_summed = CHECKSUM_PARTIAL; |
1da177e4 | 1182 | |
57be5bda AV |
1183 | skb_entail(sk, skb); |
1184 | copy = size_goal; | |
1185 | max = size_goal; | |
9d186cac | 1186 | |
57be5bda AV |
1187 | /* All packets are restored as if they have |
1188 | * already been sent. skb_mstamp isn't set to | |
1189 | * avoid wrong rtt estimation. | |
1190 | */ | |
1191 | if (tp->repair) | |
1192 | TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED; | |
1193 | } | |
1da177e4 | 1194 | |
57be5bda | 1195 | /* Try to append data to the end of skb. */ |
01e97e65 AV |
1196 | if (copy > msg_data_left(msg)) |
1197 | copy = msg_data_left(msg); | |
57be5bda AV |
1198 | |
1199 | /* Where to copy to? */ | |
1200 | if (skb_availroom(skb) > 0) { | |
1201 | /* We have some space in skb head. Superb! */ | |
1202 | copy = min_t(int, copy, skb_availroom(skb)); | |
1203 | err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy); | |
1204 | if (err) | |
1205 | goto do_fault; | |
1206 | } else { | |
1207 | bool merge = true; | |
1208 | int i = skb_shinfo(skb)->nr_frags; | |
1209 | struct page_frag *pfrag = sk_page_frag(sk); | |
1210 | ||
1211 | if (!sk_page_frag_refill(sk, pfrag)) | |
1212 | goto wait_for_memory; | |
ef015786 | 1213 | |
57be5bda AV |
1214 | if (!skb_can_coalesce(skb, i, pfrag->page, |
1215 | pfrag->offset)) { | |
5f74f82e | 1216 | if (i == sysctl_max_skb_frags || !sg) { |
57be5bda AV |
1217 | tcp_mark_push(tp, skb); |
1218 | goto new_segment; | |
1da177e4 | 1219 | } |
57be5bda | 1220 | merge = false; |
1da177e4 LT |
1221 | } |
1222 | ||
57be5bda AV |
1223 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
1224 | ||
1225 | if (!sk_wmem_schedule(sk, copy)) | |
1226 | goto wait_for_memory; | |
1da177e4 | 1227 | |
57be5bda AV |
1228 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, |
1229 | pfrag->page, | |
1230 | pfrag->offset, | |
1231 | copy); | |
1232 | if (err) | |
1233 | goto do_error; | |
1da177e4 | 1234 | |
57be5bda AV |
1235 | /* Update the skb. */ |
1236 | if (merge) { | |
1237 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1238 | } else { | |
1239 | skb_fill_page_desc(skb, i, pfrag->page, | |
1240 | pfrag->offset, copy); | |
1241 | get_page(pfrag->page); | |
4ed2d765 | 1242 | } |
57be5bda AV |
1243 | pfrag->offset += copy; |
1244 | } | |
1245 | ||
1246 | if (!copied) | |
1247 | TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; | |
1248 | ||
1249 | tp->write_seq += copy; | |
1250 | TCP_SKB_CB(skb)->end_seq += copy; | |
1251 | tcp_skb_pcount_set(skb, 0); | |
1da177e4 | 1252 | |
57be5bda | 1253 | copied += copy; |
01e97e65 | 1254 | if (!msg_data_left(msg)) { |
57be5bda AV |
1255 | tcp_tx_timestamp(sk, skb); |
1256 | goto out; | |
1257 | } | |
1da177e4 | 1258 | |
57be5bda | 1259 | if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair)) |
1da177e4 LT |
1260 | continue; |
1261 | ||
57be5bda AV |
1262 | if (forced_push(tp)) { |
1263 | tcp_mark_push(tp, skb); | |
1264 | __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); | |
1265 | } else if (skb == tcp_send_head(sk)) | |
1266 | tcp_push_one(sk, mss_now); | |
1267 | continue; | |
1268 | ||
1da177e4 | 1269 | wait_for_sndbuf: |
57be5bda | 1270 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
1da177e4 | 1271 | wait_for_memory: |
57be5bda AV |
1272 | if (copied) |
1273 | tcp_push(sk, flags & ~MSG_MORE, mss_now, | |
1274 | TCP_NAGLE_PUSH, size_goal); | |
1da177e4 | 1275 | |
686a5624 YM |
1276 | err = sk_stream_wait_memory(sk, &timeo); |
1277 | if (err != 0) | |
57be5bda | 1278 | goto do_error; |
1da177e4 | 1279 | |
57be5bda | 1280 | mss_now = tcp_send_mss(sk, &size_goal, flags); |
1da177e4 LT |
1281 | } |
1282 | ||
1283 | out: | |
ec342325 | 1284 | if (copied) |
f54b3111 | 1285 | tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); |
5924f17a | 1286 | out_nopush: |
1da177e4 | 1287 | release_sock(sk); |
cf60af03 | 1288 | return copied + copied_syn; |
1da177e4 LT |
1289 | |
1290 | do_fault: | |
1291 | if (!skb->len) { | |
fe067e8a DM |
1292 | tcp_unlink_write_queue(skb, sk); |
1293 | /* It is the one place in all of TCP, except connection | |
1294 | * reset, where we can be unlinking the send_head. | |
1295 | */ | |
1296 | tcp_check_send_head(sk, skb); | |
3ab224be | 1297 | sk_wmem_free_skb(sk, skb); |
1da177e4 LT |
1298 | } |
1299 | ||
1300 | do_error: | |
cf60af03 | 1301 | if (copied + copied_syn) |
1da177e4 LT |
1302 | goto out; |
1303 | out_err: | |
1304 | err = sk_stream_error(sk, flags, err); | |
ce5ec440 JB |
1305 | /* make sure we wake any epoll edge trigger waiter */ |
1306 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
1307 | sk->sk_write_space(sk); | |
1da177e4 LT |
1308 | release_sock(sk); |
1309 | return err; | |
1310 | } | |
4bc2f18b | 1311 | EXPORT_SYMBOL(tcp_sendmsg); |
1da177e4 LT |
1312 | |
1313 | /* | |
1314 | * Handle reading urgent data. BSD has very simple semantics for | |
1315 | * this, no blocking and very strange errors 8) | |
1316 | */ | |
1317 | ||
377f0a08 | 1318 | static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) |
1da177e4 LT |
1319 | { |
1320 | struct tcp_sock *tp = tcp_sk(sk); | |
1321 | ||
1322 | /* No URG data to read. */ | |
1323 | if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || | |
1324 | tp->urg_data == TCP_URG_READ) | |
1325 | return -EINVAL; /* Yes this is right ! */ | |
1326 | ||
1327 | if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) | |
1328 | return -ENOTCONN; | |
1329 | ||
1330 | if (tp->urg_data & TCP_URG_VALID) { | |
1331 | int err = 0; | |
1332 | char c = tp->urg_data; | |
1333 | ||
1334 | if (!(flags & MSG_PEEK)) | |
1335 | tp->urg_data = TCP_URG_READ; | |
1336 | ||
1337 | /* Read urgent data. */ | |
1338 | msg->msg_flags |= MSG_OOB; | |
1339 | ||
1340 | if (len > 0) { | |
1341 | if (!(flags & MSG_TRUNC)) | |
7eab8d9e | 1342 | err = memcpy_to_msg(msg, &c, 1); |
1da177e4 LT |
1343 | len = 1; |
1344 | } else | |
1345 | msg->msg_flags |= MSG_TRUNC; | |
1346 | ||
1347 | return err ? -EFAULT : len; | |
1348 | } | |
1349 | ||
1350 | if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
1351 | return 0; | |
1352 | ||
1353 | /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and | |
1354 | * the available implementations agree in this case: | |
1355 | * this call should never block, independent of the | |
1356 | * blocking state of the socket. | |
1357 | * Mike <pall@rz.uni-karlsruhe.de> | |
1358 | */ | |
1359 | return -EAGAIN; | |
1360 | } | |
1361 | ||
c0e88ff0 PE |
1362 | static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len) |
1363 | { | |
1364 | struct sk_buff *skb; | |
1365 | int copied = 0, err = 0; | |
1366 | ||
1367 | /* XXX -- need to support SO_PEEK_OFF */ | |
1368 | ||
1369 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
51f3d02b | 1370 | err = skb_copy_datagram_msg(skb, 0, msg, skb->len); |
c0e88ff0 PE |
1371 | if (err) |
1372 | break; | |
1373 | ||
1374 | copied += skb->len; | |
1375 | } | |
1376 | ||
1377 | return err ?: copied; | |
1378 | } | |
1379 | ||
1da177e4 LT |
1380 | /* Clean up the receive buffer for full frames taken by the user, |
1381 | * then send an ACK if necessary. COPIED is the number of bytes | |
1382 | * tcp_recvmsg has given to the user so far, it speeds up the | |
1383 | * calculation of whether or not we must ACK for the sake of | |
1384 | * a window update. | |
1385 | */ | |
3f334078 | 1386 | static void tcp_cleanup_rbuf(struct sock *sk, int copied) |
1da177e4 LT |
1387 | { |
1388 | struct tcp_sock *tp = tcp_sk(sk); | |
a2a385d6 | 1389 | bool time_to_ack = false; |
1da177e4 | 1390 | |
1da177e4 LT |
1391 | struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); |
1392 | ||
d792c100 | 1393 | WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), |
2af6fd8b | 1394 | "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", |
d792c100 | 1395 | tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); |
1da177e4 | 1396 | |
463c84b9 ACM |
1397 | if (inet_csk_ack_scheduled(sk)) { |
1398 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
1da177e4 LT |
1399 | /* Delayed ACKs frequently hit locked sockets during bulk |
1400 | * receive. */ | |
463c84b9 | 1401 | if (icsk->icsk_ack.blocked || |
1da177e4 | 1402 | /* Once-per-two-segments ACK was not sent by tcp_input.c */ |
463c84b9 | 1403 | tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || |
1da177e4 LT |
1404 | /* |
1405 | * If this read emptied read buffer, we send ACK, if | |
1406 | * connection is not bidirectional, user drained | |
1407 | * receive buffer and there was a small segment | |
1408 | * in queue. | |
1409 | */ | |
1ef9696c AK |
1410 | (copied > 0 && |
1411 | ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || | |
1412 | ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && | |
1413 | !icsk->icsk_ack.pingpong)) && | |
1414 | !atomic_read(&sk->sk_rmem_alloc))) | |
a2a385d6 | 1415 | time_to_ack = true; |
1da177e4 LT |
1416 | } |
1417 | ||
1418 | /* We send an ACK if we can now advertise a non-zero window | |
1419 | * which has been raised "significantly". | |
1420 | * | |
1421 | * Even if window raised up to infinity, do not send window open ACK | |
1422 | * in states, where we will not receive more. It is useless. | |
1423 | */ | |
1424 | if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { | |
1425 | __u32 rcv_window_now = tcp_receive_window(tp); | |
1426 | ||
1427 | /* Optimize, __tcp_select_window() is not cheap. */ | |
1428 | if (2*rcv_window_now <= tp->window_clamp) { | |
1429 | __u32 new_window = __tcp_select_window(sk); | |
1430 | ||
1431 | /* Send ACK now, if this read freed lots of space | |
1432 | * in our buffer. Certainly, new_window is new window. | |
1433 | * We can advertise it now, if it is not less than current one. | |
1434 | * "Lots" means "at least twice" here. | |
1435 | */ | |
1436 | if (new_window && new_window >= 2 * rcv_window_now) | |
a2a385d6 | 1437 | time_to_ack = true; |
1da177e4 LT |
1438 | } |
1439 | } | |
1440 | if (time_to_ack) | |
1441 | tcp_send_ack(sk); | |
1442 | } | |
1443 | ||
1444 | static void tcp_prequeue_process(struct sock *sk) | |
1445 | { | |
1446 | struct sk_buff *skb; | |
1447 | struct tcp_sock *tp = tcp_sk(sk); | |
1448 | ||
6f67c817 | 1449 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); |
1da177e4 LT |
1450 | |
1451 | /* RX process wants to run with disabled BHs, though it is not | |
1452 | * necessary */ | |
1453 | local_bh_disable(); | |
1454 | while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) | |
c57943a1 | 1455 | sk_backlog_rcv(sk, skb); |
1da177e4 LT |
1456 | local_bh_enable(); |
1457 | ||
1458 | /* Clear memory counter. */ | |
1459 | tp->ucopy.memory = 0; | |
1460 | } | |
1461 | ||
f26845b4 | 1462 | static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) |
1da177e4 LT |
1463 | { |
1464 | struct sk_buff *skb; | |
1465 | u32 offset; | |
1466 | ||
f26845b4 | 1467 | while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { |
1da177e4 | 1468 | offset = seq - TCP_SKB_CB(skb)->seq; |
e11ecddf | 1469 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) |
1da177e4 | 1470 | offset--; |
e11ecddf | 1471 | if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) { |
1da177e4 LT |
1472 | *off = offset; |
1473 | return skb; | |
1474 | } | |
f26845b4 ED |
1475 | /* This looks weird, but this can happen if TCP collapsing |
1476 | * splitted a fat GRO packet, while we released socket lock | |
1477 | * in skb_splice_bits() | |
1478 | */ | |
7bced397 | 1479 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1480 | } |
1481 | return NULL; | |
1482 | } | |
1483 | ||
1484 | /* | |
1485 | * This routine provides an alternative to tcp_recvmsg() for routines | |
1486 | * that would like to handle copying from skbuffs directly in 'sendfile' | |
1487 | * fashion. | |
1488 | * Note: | |
1489 | * - It is assumed that the socket was locked by the caller. | |
1490 | * - The routine does not block. | |
1491 | * - At present, there is no support for reading OOB data | |
1492 | * or for 'peeking' the socket using this routine | |
1493 | * (although both would be easy to implement). | |
1494 | */ | |
1495 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, | |
1496 | sk_read_actor_t recv_actor) | |
1497 | { | |
1498 | struct sk_buff *skb; | |
1499 | struct tcp_sock *tp = tcp_sk(sk); | |
1500 | u32 seq = tp->copied_seq; | |
1501 | u32 offset; | |
1502 | int copied = 0; | |
1503 | ||
1504 | if (sk->sk_state == TCP_LISTEN) | |
1505 | return -ENOTCONN; | |
1506 | while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { | |
1507 | if (offset < skb->len) { | |
374e7b59 OP |
1508 | int used; |
1509 | size_t len; | |
1da177e4 LT |
1510 | |
1511 | len = skb->len - offset; | |
1512 | /* Stop reading if we hit a patch of urgent data */ | |
1513 | if (tp->urg_data) { | |
1514 | u32 urg_offset = tp->urg_seq - seq; | |
1515 | if (urg_offset < len) | |
1516 | len = urg_offset; | |
1517 | if (!len) | |
1518 | break; | |
1519 | } | |
1520 | used = recv_actor(desc, skb, offset, len); | |
ff905b1e | 1521 | if (used <= 0) { |
ddb61a57 JA |
1522 | if (!copied) |
1523 | copied = used; | |
1524 | break; | |
1525 | } else if (used <= len) { | |
1da177e4 LT |
1526 | seq += used; |
1527 | copied += used; | |
1528 | offset += used; | |
1529 | } | |
02275a2e | 1530 | /* If recv_actor drops the lock (e.g. TCP splice |
293ad604 OP |
1531 | * receive) the skb pointer might be invalid when |
1532 | * getting here: tcp_collapse might have deleted it | |
1533 | * while aggregating skbs from the socket queue. | |
1534 | */ | |
02275a2e WT |
1535 | skb = tcp_recv_skb(sk, seq - 1, &offset); |
1536 | if (!skb) | |
1da177e4 | 1537 | break; |
02275a2e WT |
1538 | /* TCP coalescing might have appended data to the skb. |
1539 | * Try to splice more frags | |
1540 | */ | |
1541 | if (offset + 1 != skb->len) | |
1542 | continue; | |
1da177e4 | 1543 | } |
e11ecddf | 1544 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) { |
7bced397 | 1545 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1546 | ++seq; |
1547 | break; | |
1548 | } | |
7bced397 | 1549 | sk_eat_skb(sk, skb); |
1da177e4 LT |
1550 | if (!desc->count) |
1551 | break; | |
baff42ab | 1552 | tp->copied_seq = seq; |
1da177e4 LT |
1553 | } |
1554 | tp->copied_seq = seq; | |
1555 | ||
1556 | tcp_rcv_space_adjust(sk); | |
1557 | ||
1558 | /* Clean up data we have read: This will do ACK frames. */ | |
f26845b4 ED |
1559 | if (copied > 0) { |
1560 | tcp_recv_skb(sk, seq, &offset); | |
0e4b4992 | 1561 | tcp_cleanup_rbuf(sk, copied); |
f26845b4 | 1562 | } |
1da177e4 LT |
1563 | return copied; |
1564 | } | |
4bc2f18b | 1565 | EXPORT_SYMBOL(tcp_read_sock); |
1da177e4 LT |
1566 | |
1567 | /* | |
1568 | * This routine copies from a sock struct into the user buffer. | |
1569 | * | |
1570 | * Technical note: in 2.3 we work on _locked_ socket, so that | |
1571 | * tricks with *seq access order and skb->users are not required. | |
1572 | * Probably, code can be easily improved even more. | |
1573 | */ | |
1574 | ||
1b784140 YX |
1575 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, |
1576 | int flags, int *addr_len) | |
1da177e4 LT |
1577 | { |
1578 | struct tcp_sock *tp = tcp_sk(sk); | |
1579 | int copied = 0; | |
1580 | u32 peek_seq; | |
1581 | u32 *seq; | |
1582 | unsigned long used; | |
1583 | int err; | |
1584 | int target; /* Read at least this many bytes */ | |
1585 | long timeo; | |
1586 | struct task_struct *user_recv = NULL; | |
dfbafc99 | 1587 | struct sk_buff *skb, *last; |
77527313 | 1588 | u32 urg_hole = 0; |
1da177e4 | 1589 | |
4ed2d765 | 1590 | if (unlikely(flags & MSG_ERRQUEUE)) |
f4713a3d | 1591 | return inet_recv_error(sk, msg, len, addr_len); |
4ed2d765 | 1592 | |
cbf55001 ET |
1593 | if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) && |
1594 | (sk->sk_state == TCP_ESTABLISHED)) | |
1595 | sk_busy_loop(sk, nonblock); | |
d30e383b | 1596 | |
1da177e4 LT |
1597 | lock_sock(sk); |
1598 | ||
1da177e4 LT |
1599 | err = -ENOTCONN; |
1600 | if (sk->sk_state == TCP_LISTEN) | |
1601 | goto out; | |
1602 | ||
1603 | timeo = sock_rcvtimeo(sk, nonblock); | |
1604 | ||
1605 | /* Urgent data needs to be handled specially. */ | |
1606 | if (flags & MSG_OOB) | |
1607 | goto recv_urg; | |
1608 | ||
c0e88ff0 PE |
1609 | if (unlikely(tp->repair)) { |
1610 | err = -EPERM; | |
1611 | if (!(flags & MSG_PEEK)) | |
1612 | goto out; | |
1613 | ||
1614 | if (tp->repair_queue == TCP_SEND_QUEUE) | |
1615 | goto recv_sndq; | |
1616 | ||
1617 | err = -EINVAL; | |
1618 | if (tp->repair_queue == TCP_NO_QUEUE) | |
1619 | goto out; | |
1620 | ||
1621 | /* 'common' recv queue MSG_PEEK-ing */ | |
1622 | } | |
1623 | ||
1da177e4 LT |
1624 | seq = &tp->copied_seq; |
1625 | if (flags & MSG_PEEK) { | |
1626 | peek_seq = tp->copied_seq; | |
1627 | seq = &peek_seq; | |
1628 | } | |
1629 | ||
1630 | target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); | |
1631 | ||
1632 | do { | |
1da177e4 LT |
1633 | u32 offset; |
1634 | ||
1635 | /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ | |
1636 | if (tp->urg_data && tp->urg_seq == *seq) { | |
1637 | if (copied) | |
1638 | break; | |
1639 | if (signal_pending(current)) { | |
1640 | copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; | |
1641 | break; | |
1642 | } | |
1643 | } | |
1644 | ||
1645 | /* Next get a buffer. */ | |
1646 | ||
dfbafc99 | 1647 | last = skb_peek_tail(&sk->sk_receive_queue); |
91521944 | 1648 | skb_queue_walk(&sk->sk_receive_queue, skb) { |
dfbafc99 | 1649 | last = skb; |
1da177e4 LT |
1650 | /* Now that we have two receive queues this |
1651 | * shouldn't happen. | |
1652 | */ | |
d792c100 | 1653 | if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), |
2af6fd8b JP |
1654 | "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n", |
1655 | *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, | |
1656 | flags)) | |
1da177e4 | 1657 | break; |
d792c100 | 1658 | |
1da177e4 | 1659 | offset = *seq - TCP_SKB_CB(skb)->seq; |
e11ecddf | 1660 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) |
1da177e4 LT |
1661 | offset--; |
1662 | if (offset < skb->len) | |
1663 | goto found_ok_skb; | |
e11ecddf | 1664 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) |
1da177e4 | 1665 | goto found_fin_ok; |
2af6fd8b JP |
1666 | WARN(!(flags & MSG_PEEK), |
1667 | "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n", | |
1668 | *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); | |
91521944 | 1669 | } |
1da177e4 LT |
1670 | |
1671 | /* Well, if we have backlog, try to process it now yet. */ | |
1672 | ||
1673 | if (copied >= target && !sk->sk_backlog.tail) | |
1674 | break; | |
1675 | ||
1676 | if (copied) { | |
1677 | if (sk->sk_err || | |
1678 | sk->sk_state == TCP_CLOSE || | |
1679 | (sk->sk_shutdown & RCV_SHUTDOWN) || | |
1680 | !timeo || | |
518a09ef | 1681 | signal_pending(current)) |
1da177e4 LT |
1682 | break; |
1683 | } else { | |
1684 | if (sock_flag(sk, SOCK_DONE)) | |
1685 | break; | |
1686 | ||
1687 | if (sk->sk_err) { | |
1688 | copied = sock_error(sk); | |
1689 | break; | |
1690 | } | |
1691 | ||
1692 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
1693 | break; | |
1694 | ||
1695 | if (sk->sk_state == TCP_CLOSE) { | |
1696 | if (!sock_flag(sk, SOCK_DONE)) { | |
1697 | /* This occurs when user tries to read | |
1698 | * from never connected socket. | |
1699 | */ | |
1700 | copied = -ENOTCONN; | |
1701 | break; | |
1702 | } | |
1703 | break; | |
1704 | } | |
1705 | ||
1706 | if (!timeo) { | |
1707 | copied = -EAGAIN; | |
1708 | break; | |
1709 | } | |
1710 | ||
1711 | if (signal_pending(current)) { | |
1712 | copied = sock_intr_errno(timeo); | |
1713 | break; | |
1714 | } | |
1715 | } | |
1716 | ||
0e4b4992 | 1717 | tcp_cleanup_rbuf(sk, copied); |
1da177e4 | 1718 | |
7df55125 | 1719 | if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { |
1da177e4 LT |
1720 | /* Install new reader */ |
1721 | if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { | |
1722 | user_recv = current; | |
1723 | tp->ucopy.task = user_recv; | |
f4362a2c | 1724 | tp->ucopy.msg = msg; |
1da177e4 LT |
1725 | } |
1726 | ||
1727 | tp->ucopy.len = len; | |
1728 | ||
547b792c IJ |
1729 | WARN_ON(tp->copied_seq != tp->rcv_nxt && |
1730 | !(flags & (MSG_PEEK | MSG_TRUNC))); | |
1da177e4 LT |
1731 | |
1732 | /* Ugly... If prequeue is not empty, we have to | |
1733 | * process it before releasing socket, otherwise | |
1734 | * order will be broken at second iteration. | |
1735 | * More elegant solution is required!!! | |
1736 | * | |
1737 | * Look: we have the following (pseudo)queues: | |
1738 | * | |
1739 | * 1. packets in flight | |
1740 | * 2. backlog | |
1741 | * 3. prequeue | |
1742 | * 4. receive_queue | |
1743 | * | |
1744 | * Each queue can be processed only if the next ones | |
1745 | * are empty. At this point we have empty receive_queue. | |
1746 | * But prequeue _can_ be not empty after 2nd iteration, | |
1747 | * when we jumped to start of loop because backlog | |
1748 | * processing added something to receive_queue. | |
1749 | * We cannot release_sock(), because backlog contains | |
1750 | * packets arrived _after_ prequeued ones. | |
1751 | * | |
1752 | * Shortly, algorithm is clear --- to process all | |
1753 | * the queues in order. We could make it more directly, | |
1754 | * requeueing packets from backlog to prequeue, if | |
1755 | * is not empty. It is more elegant, but eats cycles, | |
1756 | * unfortunately. | |
1757 | */ | |
b03efcfb | 1758 | if (!skb_queue_empty(&tp->ucopy.prequeue)) |
1da177e4 LT |
1759 | goto do_prequeue; |
1760 | ||
1761 | /* __ Set realtime policy in scheduler __ */ | |
1762 | } | |
1763 | ||
1764 | if (copied >= target) { | |
1765 | /* Do not sleep, just process backlog. */ | |
1766 | release_sock(sk); | |
1767 | lock_sock(sk); | |
dfbafc99 SD |
1768 | } else { |
1769 | sk_wait_data(sk, &timeo, last); | |
1770 | } | |
1da177e4 LT |
1771 | |
1772 | if (user_recv) { | |
1773 | int chunk; | |
1774 | ||
1775 | /* __ Restore normal policy in scheduler __ */ | |
1776 | ||
686a5624 YM |
1777 | chunk = len - tp->ucopy.len; |
1778 | if (chunk != 0) { | |
ed88098e | 1779 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); |
1da177e4 LT |
1780 | len -= chunk; |
1781 | copied += chunk; | |
1782 | } | |
1783 | ||
1784 | if (tp->rcv_nxt == tp->copied_seq && | |
b03efcfb | 1785 | !skb_queue_empty(&tp->ucopy.prequeue)) { |
1da177e4 LT |
1786 | do_prequeue: |
1787 | tcp_prequeue_process(sk); | |
1788 | ||
686a5624 YM |
1789 | chunk = len - tp->ucopy.len; |
1790 | if (chunk != 0) { | |
ed88098e | 1791 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); |
1da177e4 LT |
1792 | len -= chunk; |
1793 | copied += chunk; | |
1794 | } | |
1795 | } | |
1796 | } | |
77527313 IJ |
1797 | if ((flags & MSG_PEEK) && |
1798 | (peek_seq - copied - urg_hole != tp->copied_seq)) { | |
e87cc472 JP |
1799 | net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", |
1800 | current->comm, | |
1801 | task_pid_nr(current)); | |
1da177e4 LT |
1802 | peek_seq = tp->copied_seq; |
1803 | } | |
1804 | continue; | |
1805 | ||
1806 | found_ok_skb: | |
1807 | /* Ok so how much can we use? */ | |
1808 | used = skb->len - offset; | |
1809 | if (len < used) | |
1810 | used = len; | |
1811 | ||
1812 | /* Do we have urgent data here? */ | |
1813 | if (tp->urg_data) { | |
1814 | u32 urg_offset = tp->urg_seq - *seq; | |
1815 | if (urg_offset < used) { | |
1816 | if (!urg_offset) { | |
1817 | if (!sock_flag(sk, SOCK_URGINLINE)) { | |
1818 | ++*seq; | |
77527313 | 1819 | urg_hole++; |
1da177e4 LT |
1820 | offset++; |
1821 | used--; | |
1822 | if (!used) | |
1823 | goto skip_copy; | |
1824 | } | |
1825 | } else | |
1826 | used = urg_offset; | |
1827 | } | |
1828 | } | |
1829 | ||
1830 | if (!(flags & MSG_TRUNC)) { | |
51f3d02b | 1831 | err = skb_copy_datagram_msg(skb, offset, msg, used); |
7bced397 DW |
1832 | if (err) { |
1833 | /* Exception. Bailout! */ | |
1834 | if (!copied) | |
1835 | copied = -EFAULT; | |
1836 | break; | |
1da177e4 LT |
1837 | } |
1838 | } | |
1839 | ||
1840 | *seq += used; | |
1841 | copied += used; | |
1842 | len -= used; | |
1843 | ||
1844 | tcp_rcv_space_adjust(sk); | |
1845 | ||
1846 | skip_copy: | |
1847 | if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { | |
1848 | tp->urg_data = 0; | |
9e412ba7 | 1849 | tcp_fast_path_check(sk); |
1da177e4 LT |
1850 | } |
1851 | if (used + offset < skb->len) | |
1852 | continue; | |
1853 | ||
e11ecddf | 1854 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) |
1da177e4 | 1855 | goto found_fin_ok; |
7bced397 DW |
1856 | if (!(flags & MSG_PEEK)) |
1857 | sk_eat_skb(sk, skb); | |
1da177e4 LT |
1858 | continue; |
1859 | ||
1860 | found_fin_ok: | |
1861 | /* Process the FIN. */ | |
1862 | ++*seq; | |
7bced397 DW |
1863 | if (!(flags & MSG_PEEK)) |
1864 | sk_eat_skb(sk, skb); | |
1da177e4 LT |
1865 | break; |
1866 | } while (len > 0); | |
1867 | ||
1868 | if (user_recv) { | |
b03efcfb | 1869 | if (!skb_queue_empty(&tp->ucopy.prequeue)) { |
1da177e4 LT |
1870 | int chunk; |
1871 | ||
1872 | tp->ucopy.len = copied > 0 ? len : 0; | |
1873 | ||
1874 | tcp_prequeue_process(sk); | |
1875 | ||
1876 | if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { | |
ed88098e | 1877 | NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); |
1da177e4 LT |
1878 | len -= chunk; |
1879 | copied += chunk; | |
1880 | } | |
1881 | } | |
1882 | ||
1883 | tp->ucopy.task = NULL; | |
1884 | tp->ucopy.len = 0; | |
1885 | } | |
1886 | ||
1887 | /* According to UNIX98, msg_name/msg_namelen are ignored | |
1888 | * on connected socket. I was just happy when found this 8) --ANK | |
1889 | */ | |
1890 | ||
1891 | /* Clean up data we have read: This will do ACK frames. */ | |
0e4b4992 | 1892 | tcp_cleanup_rbuf(sk, copied); |
1da177e4 | 1893 | |
1da177e4 LT |
1894 | release_sock(sk); |
1895 | return copied; | |
1896 | ||
1897 | out: | |
1da177e4 LT |
1898 | release_sock(sk); |
1899 | return err; | |
1900 | ||
1901 | recv_urg: | |
377f0a08 | 1902 | err = tcp_recv_urg(sk, msg, len, flags); |
1da177e4 | 1903 | goto out; |
c0e88ff0 PE |
1904 | |
1905 | recv_sndq: | |
1906 | err = tcp_peek_sndq(sk, msg, len); | |
1907 | goto out; | |
1da177e4 | 1908 | } |
4bc2f18b | 1909 | EXPORT_SYMBOL(tcp_recvmsg); |
1da177e4 | 1910 | |
490d5046 IJ |
1911 | void tcp_set_state(struct sock *sk, int state) |
1912 | { | |
1913 | int oldstate = sk->sk_state; | |
1914 | ||
1915 | switch (state) { | |
1916 | case TCP_ESTABLISHED: | |
1917 | if (oldstate != TCP_ESTABLISHED) | |
81cc8a75 | 1918 | TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); |
490d5046 IJ |
1919 | break; |
1920 | ||
1921 | case TCP_CLOSE: | |
1922 | if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) | |
81cc8a75 | 1923 | TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); |
490d5046 IJ |
1924 | |
1925 | sk->sk_prot->unhash(sk); | |
1926 | if (inet_csk(sk)->icsk_bind_hash && | |
1927 | !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) | |
ab1e0a13 | 1928 | inet_put_port(sk); |
490d5046 IJ |
1929 | /* fall through */ |
1930 | default: | |
5a5f3a8d | 1931 | if (oldstate == TCP_ESTABLISHED) |
74688e48 | 1932 | TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); |
490d5046 IJ |
1933 | } |
1934 | ||
1935 | /* Change state AFTER socket is unhashed to avoid closed | |
1936 | * socket sitting in hash tables. | |
1937 | */ | |
00fd38d9 | 1938 | sk_state_store(sk, state); |
490d5046 IJ |
1939 | |
1940 | #ifdef STATE_TRACE | |
5a5f3a8d | 1941 | SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); |
490d5046 IJ |
1942 | #endif |
1943 | } | |
1944 | EXPORT_SYMBOL_GPL(tcp_set_state); | |
1945 | ||
1da177e4 LT |
1946 | /* |
1947 | * State processing on a close. This implements the state shift for | |
1948 | * sending our FIN frame. Note that we only send a FIN for some | |
1949 | * states. A shutdown() may have already sent the FIN, or we may be | |
1950 | * closed. | |
1951 | */ | |
1952 | ||
9b5b5cff | 1953 | static const unsigned char new_state[16] = { |
1da177e4 | 1954 | /* current state: new state: action: */ |
0980c1e3 ED |
1955 | [0 /* (Invalid) */] = TCP_CLOSE, |
1956 | [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1957 | [TCP_SYN_SENT] = TCP_CLOSE, | |
1958 | [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, | |
1959 | [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, | |
1960 | [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, | |
1961 | [TCP_TIME_WAIT] = TCP_CLOSE, | |
1962 | [TCP_CLOSE] = TCP_CLOSE, | |
1963 | [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, | |
1964 | [TCP_LAST_ACK] = TCP_LAST_ACK, | |
1965 | [TCP_LISTEN] = TCP_CLOSE, | |
1966 | [TCP_CLOSING] = TCP_CLOSING, | |
1967 | [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ | |
1da177e4 LT |
1968 | }; |
1969 | ||
1970 | static int tcp_close_state(struct sock *sk) | |
1971 | { | |
1972 | int next = (int)new_state[sk->sk_state]; | |
1973 | int ns = next & TCP_STATE_MASK; | |
1974 | ||
1975 | tcp_set_state(sk, ns); | |
1976 | ||
1977 | return next & TCP_ACTION_FIN; | |
1978 | } | |
1979 | ||
1980 | /* | |
1981 | * Shutdown the sending side of a connection. Much like close except | |
1f29b058 | 1982 | * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). |
1da177e4 LT |
1983 | */ |
1984 | ||
1985 | void tcp_shutdown(struct sock *sk, int how) | |
1986 | { | |
1987 | /* We need to grab some memory, and put together a FIN, | |
1988 | * and then put it into the queue to be sent. | |
1989 | * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. | |
1990 | */ | |
1991 | if (!(how & SEND_SHUTDOWN)) | |
1992 | return; | |
1993 | ||
1994 | /* If we've already sent a FIN, or it's a closed state, skip this. */ | |
1995 | if ((1 << sk->sk_state) & | |
1996 | (TCPF_ESTABLISHED | TCPF_SYN_SENT | | |
1997 | TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { | |
1998 | /* Clear out any half completed packets. FIN if needed. */ | |
1999 | if (tcp_close_state(sk)) | |
2000 | tcp_send_fin(sk); | |
2001 | } | |
2002 | } | |
4bc2f18b | 2003 | EXPORT_SYMBOL(tcp_shutdown); |
1da177e4 | 2004 | |
efcdbf24 AS |
2005 | bool tcp_check_oom(struct sock *sk, int shift) |
2006 | { | |
2007 | bool too_many_orphans, out_of_socket_memory; | |
2008 | ||
2009 | too_many_orphans = tcp_too_many_orphans(sk, shift); | |
2010 | out_of_socket_memory = tcp_out_of_memory(sk); | |
2011 | ||
e87cc472 JP |
2012 | if (too_many_orphans) |
2013 | net_info_ratelimited("too many orphaned sockets\n"); | |
2014 | if (out_of_socket_memory) | |
2015 | net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); | |
efcdbf24 AS |
2016 | return too_many_orphans || out_of_socket_memory; |
2017 | } | |
2018 | ||
1da177e4 LT |
2019 | void tcp_close(struct sock *sk, long timeout) |
2020 | { | |
2021 | struct sk_buff *skb; | |
2022 | int data_was_unread = 0; | |
75c2d907 | 2023 | int state; |
1da177e4 LT |
2024 | |
2025 | lock_sock(sk); | |
2026 | sk->sk_shutdown = SHUTDOWN_MASK; | |
2027 | ||
2028 | if (sk->sk_state == TCP_LISTEN) { | |
2029 | tcp_set_state(sk, TCP_CLOSE); | |
2030 | ||
2031 | /* Special case. */ | |
0a5578cf | 2032 | inet_csk_listen_stop(sk); |
1da177e4 LT |
2033 | |
2034 | goto adjudge_to_death; | |
2035 | } | |
2036 | ||
2037 | /* We need to flush the recv. buffs. We do this only on the | |
2038 | * descriptor close, not protocol-sourced closes, because the | |
2039 | * reader process may not have drained the data yet! | |
2040 | */ | |
2041 | while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { | |
e11ecddf ED |
2042 | u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; |
2043 | ||
2044 | if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) | |
2045 | len--; | |
1da177e4 LT |
2046 | data_was_unread += len; |
2047 | __kfree_skb(skb); | |
2048 | } | |
2049 | ||
3ab224be | 2050 | sk_mem_reclaim(sk); |
1da177e4 | 2051 | |
565b7b2d KK |
2052 | /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ |
2053 | if (sk->sk_state == TCP_CLOSE) | |
2054 | goto adjudge_to_death; | |
2055 | ||
65bb723c GR |
2056 | /* As outlined in RFC 2525, section 2.17, we send a RST here because |
2057 | * data was lost. To witness the awful effects of the old behavior of | |
2058 | * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk | |
2059 | * GET in an FTP client, suspend the process, wait for the client to | |
2060 | * advertise a zero window, then kill -9 the FTP client, wheee... | |
2061 | * Note: timeout is always zero in such a case. | |
1da177e4 | 2062 | */ |
ee995283 PE |
2063 | if (unlikely(tcp_sk(sk)->repair)) { |
2064 | sk->sk_prot->disconnect(sk, 0); | |
2065 | } else if (data_was_unread) { | |
1da177e4 | 2066 | /* Unread data was tossed, zap the connection. */ |
6f67c817 | 2067 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); |
1da177e4 | 2068 | tcp_set_state(sk, TCP_CLOSE); |
aa133076 | 2069 | tcp_send_active_reset(sk, sk->sk_allocation); |
1da177e4 LT |
2070 | } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { |
2071 | /* Check zero linger _after_ checking for unread data. */ | |
2072 | sk->sk_prot->disconnect(sk, 0); | |
6f67c817 | 2073 | NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); |
1da177e4 LT |
2074 | } else if (tcp_close_state(sk)) { |
2075 | /* We FIN if the application ate all the data before | |
2076 | * zapping the connection. | |
2077 | */ | |
2078 | ||
2079 | /* RED-PEN. Formally speaking, we have broken TCP state | |
2080 | * machine. State transitions: | |
2081 | * | |
2082 | * TCP_ESTABLISHED -> TCP_FIN_WAIT1 | |
2083 | * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) | |
2084 | * TCP_CLOSE_WAIT -> TCP_LAST_ACK | |
2085 | * | |
2086 | * are legal only when FIN has been sent (i.e. in window), | |
2087 | * rather than queued out of window. Purists blame. | |
2088 | * | |
2089 | * F.e. "RFC state" is ESTABLISHED, | |
2090 | * if Linux state is FIN-WAIT-1, but FIN is still not sent. | |
2091 | * | |
2092 | * The visible declinations are that sometimes | |
2093 | * we enter time-wait state, when it is not required really | |
2094 | * (harmless), do not send active resets, when they are | |
2095 | * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when | |
2096 | * they look as CLOSING or LAST_ACK for Linux) | |
2097 | * Probably, I missed some more holelets. | |
2098 | * --ANK | |
8336886f JC |
2099 | * XXX (TFO) - To start off we don't support SYN+ACK+FIN |
2100 | * in a single packet! (May consider it later but will | |
2101 | * probably need API support or TCP_CORK SYN-ACK until | |
2102 | * data is written and socket is closed.) | |
1da177e4 LT |
2103 | */ |
2104 | tcp_send_fin(sk); | |
2105 | } | |
2106 | ||
2107 | sk_stream_wait_close(sk, timeout); | |
2108 | ||
2109 | adjudge_to_death: | |
75c2d907 HX |
2110 | state = sk->sk_state; |
2111 | sock_hold(sk); | |
2112 | sock_orphan(sk); | |
75c2d907 | 2113 | |
1da177e4 LT |
2114 | /* It is the last release_sock in its life. It will remove backlog. */ |
2115 | release_sock(sk); | |
2116 | ||
2117 | ||
2118 | /* Now socket is owned by kernel and we acquire BH lock | |
2119 | to finish close. No need to check for user refs. | |
2120 | */ | |
2121 | local_bh_disable(); | |
2122 | bh_lock_sock(sk); | |
547b792c | 2123 | WARN_ON(sock_owned_by_user(sk)); |
1da177e4 | 2124 | |
eb4dea58 HX |
2125 | percpu_counter_inc(sk->sk_prot->orphan_count); |
2126 | ||
75c2d907 HX |
2127 | /* Have we already been destroyed by a softirq or backlog? */ |
2128 | if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) | |
2129 | goto out; | |
1da177e4 LT |
2130 | |
2131 | /* This is a (useful) BSD violating of the RFC. There is a | |
2132 | * problem with TCP as specified in that the other end could | |
2133 | * keep a socket open forever with no application left this end. | |
b10bd54c | 2134 | * We use a 1 minute timeout (about the same as BSD) then kill |
1da177e4 LT |
2135 | * our end. If they send after that then tough - BUT: long enough |
2136 | * that we won't make the old 4*rto = almost no time - whoops | |
2137 | * reset mistake. | |
2138 | * | |
2139 | * Nope, it was not mistake. It is really desired behaviour | |
2140 | * f.e. on http servers, when such sockets are useless, but | |
2141 | * consume significant resources. Let's do it with special | |
2142 | * linger2 option. --ANK | |
2143 | */ | |
2144 | ||
2145 | if (sk->sk_state == TCP_FIN_WAIT2) { | |
2146 | struct tcp_sock *tp = tcp_sk(sk); | |
2147 | if (tp->linger2 < 0) { | |
2148 | tcp_set_state(sk, TCP_CLOSE); | |
2149 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
de0744af PE |
2150 | NET_INC_STATS_BH(sock_net(sk), |
2151 | LINUX_MIB_TCPABORTONLINGER); | |
1da177e4 | 2152 | } else { |
463c84b9 | 2153 | const int tmo = tcp_fin_time(sk); |
1da177e4 LT |
2154 | |
2155 | if (tmo > TCP_TIMEWAIT_LEN) { | |
52499afe DM |
2156 | inet_csk_reset_keepalive_timer(sk, |
2157 | tmo - TCP_TIMEWAIT_LEN); | |
1da177e4 | 2158 | } else { |
1da177e4 LT |
2159 | tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); |
2160 | goto out; | |
2161 | } | |
2162 | } | |
2163 | } | |
2164 | if (sk->sk_state != TCP_CLOSE) { | |
3ab224be | 2165 | sk_mem_reclaim(sk); |
efcdbf24 | 2166 | if (tcp_check_oom(sk, 0)) { |
1da177e4 LT |
2167 | tcp_set_state(sk, TCP_CLOSE); |
2168 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
de0744af PE |
2169 | NET_INC_STATS_BH(sock_net(sk), |
2170 | LINUX_MIB_TCPABORTONMEMORY); | |
1da177e4 LT |
2171 | } |
2172 | } | |
1da177e4 | 2173 | |
8336886f JC |
2174 | if (sk->sk_state == TCP_CLOSE) { |
2175 | struct request_sock *req = tcp_sk(sk)->fastopen_rsk; | |
2176 | /* We could get here with a non-NULL req if the socket is | |
2177 | * aborted (e.g., closed with unread data) before 3WHS | |
2178 | * finishes. | |
2179 | */ | |
00db4124 | 2180 | if (req) |
8336886f | 2181 | reqsk_fastopen_remove(sk, req, false); |
0a5578cf | 2182 | inet_csk_destroy_sock(sk); |
8336886f | 2183 | } |
1da177e4 LT |
2184 | /* Otherwise, socket is reprieved until protocol close. */ |
2185 | ||
2186 | out: | |
2187 | bh_unlock_sock(sk); | |
2188 | local_bh_enable(); | |
2189 | sock_put(sk); | |
2190 | } | |
4bc2f18b | 2191 | EXPORT_SYMBOL(tcp_close); |
1da177e4 LT |
2192 | |
2193 | /* These states need RST on ABORT according to RFC793 */ | |
2194 | ||
a2a385d6 | 2195 | static inline bool tcp_need_reset(int state) |
1da177e4 LT |
2196 | { |
2197 | return (1 << state) & | |
2198 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | | |
2199 | TCPF_FIN_WAIT2 | TCPF_SYN_RECV); | |
2200 | } | |
2201 | ||
2202 | int tcp_disconnect(struct sock *sk, int flags) | |
2203 | { | |
2204 | struct inet_sock *inet = inet_sk(sk); | |
463c84b9 | 2205 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2206 | struct tcp_sock *tp = tcp_sk(sk); |
2207 | int err = 0; | |
2208 | int old_state = sk->sk_state; | |
2209 | ||
2210 | if (old_state != TCP_CLOSE) | |
2211 | tcp_set_state(sk, TCP_CLOSE); | |
2212 | ||
2213 | /* ABORT function of RFC793 */ | |
2214 | if (old_state == TCP_LISTEN) { | |
0a5578cf | 2215 | inet_csk_listen_stop(sk); |
ee995283 PE |
2216 | } else if (unlikely(tp->repair)) { |
2217 | sk->sk_err = ECONNABORTED; | |
1da177e4 LT |
2218 | } else if (tcp_need_reset(old_state) || |
2219 | (tp->snd_nxt != tp->write_seq && | |
2220 | (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { | |
caa20d9a | 2221 | /* The last check adjusts for discrepancy of Linux wrt. RFC |
1da177e4 LT |
2222 | * states |
2223 | */ | |
2224 | tcp_send_active_reset(sk, gfp_any()); | |
2225 | sk->sk_err = ECONNRESET; | |
2226 | } else if (old_state == TCP_SYN_SENT) | |
2227 | sk->sk_err = ECONNRESET; | |
2228 | ||
2229 | tcp_clear_xmit_timers(sk); | |
2230 | __skb_queue_purge(&sk->sk_receive_queue); | |
fe067e8a | 2231 | tcp_write_queue_purge(sk); |
1da177e4 LT |
2232 | __skb_queue_purge(&tp->out_of_order_queue); |
2233 | ||
c720c7e8 | 2234 | inet->inet_dport = 0; |
1da177e4 LT |
2235 | |
2236 | if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) | |
2237 | inet_reset_saddr(sk); | |
2238 | ||
2239 | sk->sk_shutdown = 0; | |
2240 | sock_reset_flag(sk, SOCK_DONE); | |
740b0f18 | 2241 | tp->srtt_us = 0; |
686a5624 YM |
2242 | tp->write_seq += tp->max_window + 2; |
2243 | if (tp->write_seq == 0) | |
1da177e4 | 2244 | tp->write_seq = 1; |
463c84b9 | 2245 | icsk->icsk_backoff = 0; |
1da177e4 | 2246 | tp->snd_cwnd = 2; |
6687e988 | 2247 | icsk->icsk_probes_out = 0; |
1da177e4 | 2248 | tp->packets_out = 0; |
0b6a05c1 | 2249 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
1da177e4 | 2250 | tp->snd_cwnd_cnt = 0; |
1fdf475a | 2251 | tp->window_clamp = 0; |
6687e988 | 2252 | tcp_set_ca_state(sk, TCP_CA_Open); |
1da177e4 | 2253 | tcp_clear_retrans(tp); |
463c84b9 | 2254 | inet_csk_delack_init(sk); |
fe067e8a | 2255 | tcp_init_send_head(sk); |
b40b4f79 | 2256 | memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); |
1da177e4 LT |
2257 | __sk_dst_reset(sk); |
2258 | ||
c720c7e8 | 2259 | WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); |
1da177e4 LT |
2260 | |
2261 | sk->sk_error_report(sk); | |
2262 | return err; | |
2263 | } | |
4bc2f18b | 2264 | EXPORT_SYMBOL(tcp_disconnect); |
1da177e4 | 2265 | |
a2a385d6 | 2266 | static inline bool tcp_can_repair_sock(const struct sock *sk) |
ee995283 | 2267 | { |
52e804c6 | 2268 | return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && |
ee995283 PE |
2269 | ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED)); |
2270 | } | |
2271 | ||
de248a75 PE |
2272 | static int tcp_repair_options_est(struct tcp_sock *tp, |
2273 | struct tcp_repair_opt __user *optbuf, unsigned int len) | |
b139ba4e | 2274 | { |
de248a75 | 2275 | struct tcp_repair_opt opt; |
b139ba4e | 2276 | |
de248a75 PE |
2277 | while (len >= sizeof(opt)) { |
2278 | if (copy_from_user(&opt, optbuf, sizeof(opt))) | |
b139ba4e PE |
2279 | return -EFAULT; |
2280 | ||
2281 | optbuf++; | |
de248a75 | 2282 | len -= sizeof(opt); |
b139ba4e | 2283 | |
de248a75 PE |
2284 | switch (opt.opt_code) { |
2285 | case TCPOPT_MSS: | |
2286 | tp->rx_opt.mss_clamp = opt.opt_val; | |
b139ba4e | 2287 | break; |
de248a75 | 2288 | case TCPOPT_WINDOW: |
bc26ccd8 AV |
2289 | { |
2290 | u16 snd_wscale = opt.opt_val & 0xFFFF; | |
2291 | u16 rcv_wscale = opt.opt_val >> 16; | |
2292 | ||
2293 | if (snd_wscale > 14 || rcv_wscale > 14) | |
2294 | return -EFBIG; | |
b139ba4e | 2295 | |
bc26ccd8 AV |
2296 | tp->rx_opt.snd_wscale = snd_wscale; |
2297 | tp->rx_opt.rcv_wscale = rcv_wscale; | |
2298 | tp->rx_opt.wscale_ok = 1; | |
2299 | } | |
b139ba4e | 2300 | break; |
b139ba4e | 2301 | case TCPOPT_SACK_PERM: |
de248a75 PE |
2302 | if (opt.opt_val != 0) |
2303 | return -EINVAL; | |
2304 | ||
b139ba4e PE |
2305 | tp->rx_opt.sack_ok |= TCP_SACK_SEEN; |
2306 | if (sysctl_tcp_fack) | |
2307 | tcp_enable_fack(tp); | |
2308 | break; | |
2309 | case TCPOPT_TIMESTAMP: | |
de248a75 PE |
2310 | if (opt.opt_val != 0) |
2311 | return -EINVAL; | |
2312 | ||
b139ba4e PE |
2313 | tp->rx_opt.tstamp_ok = 1; |
2314 | break; | |
2315 | } | |
2316 | } | |
2317 | ||
2318 | return 0; | |
2319 | } | |
2320 | ||
1da177e4 LT |
2321 | /* |
2322 | * Socket option code for TCP. | |
2323 | */ | |
3fdadf7d | 2324 | static int do_tcp_setsockopt(struct sock *sk, int level, |
b7058842 | 2325 | int optname, char __user *optval, unsigned int optlen) |
1da177e4 LT |
2326 | { |
2327 | struct tcp_sock *tp = tcp_sk(sk); | |
463c84b9 | 2328 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2329 | int val; |
2330 | int err = 0; | |
2331 | ||
e56fb50f WAS |
2332 | /* These are data/string values, all the others are ints */ |
2333 | switch (optname) { | |
2334 | case TCP_CONGESTION: { | |
5f8ef48d SH |
2335 | char name[TCP_CA_NAME_MAX]; |
2336 | ||
2337 | if (optlen < 1) | |
2338 | return -EINVAL; | |
2339 | ||
2340 | val = strncpy_from_user(name, optval, | |
4fdb78d3 | 2341 | min_t(long, TCP_CA_NAME_MAX-1, optlen)); |
5f8ef48d SH |
2342 | if (val < 0) |
2343 | return -EFAULT; | |
2344 | name[val] = 0; | |
2345 | ||
2346 | lock_sock(sk); | |
6687e988 | 2347 | err = tcp_set_congestion_control(sk, name); |
5f8ef48d SH |
2348 | release_sock(sk); |
2349 | return err; | |
2350 | } | |
e56fb50f WAS |
2351 | default: |
2352 | /* fallthru */ | |
2353 | break; | |
ccbd6a5a | 2354 | } |
5f8ef48d | 2355 | |
1da177e4 LT |
2356 | if (optlen < sizeof(int)) |
2357 | return -EINVAL; | |
2358 | ||
2359 | if (get_user(val, (int __user *)optval)) | |
2360 | return -EFAULT; | |
2361 | ||
2362 | lock_sock(sk); | |
2363 | ||
2364 | switch (optname) { | |
2365 | case TCP_MAXSEG: | |
2366 | /* Values greater than interface MTU won't take effect. However | |
2367 | * at the point when this call is done we typically don't yet | |
2368 | * know which interface is going to be used */ | |
c39508d6 | 2369 | if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) { |
1da177e4 LT |
2370 | err = -EINVAL; |
2371 | break; | |
2372 | } | |
2373 | tp->rx_opt.user_mss = val; | |
2374 | break; | |
2375 | ||
2376 | case TCP_NODELAY: | |
2377 | if (val) { | |
2378 | /* TCP_NODELAY is weaker than TCP_CORK, so that | |
2379 | * this option on corked socket is remembered, but | |
2380 | * it is not activated until cork is cleared. | |
2381 | * | |
2382 | * However, when TCP_NODELAY is set we make | |
2383 | * an explicit push, which overrides even TCP_CORK | |
2384 | * for currently queued segments. | |
2385 | */ | |
2386 | tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; | |
9e412ba7 | 2387 | tcp_push_pending_frames(sk); |
1da177e4 LT |
2388 | } else { |
2389 | tp->nonagle &= ~TCP_NAGLE_OFF; | |
2390 | } | |
2391 | break; | |
2392 | ||
36e31b0a AP |
2393 | case TCP_THIN_LINEAR_TIMEOUTS: |
2394 | if (val < 0 || val > 1) | |
2395 | err = -EINVAL; | |
2396 | else | |
2397 | tp->thin_lto = val; | |
2398 | break; | |
2399 | ||
7e380175 AP |
2400 | case TCP_THIN_DUPACK: |
2401 | if (val < 0 || val > 1) | |
2402 | err = -EINVAL; | |
e2e5c4c0 | 2403 | else { |
7e380175 | 2404 | tp->thin_dupack = val; |
eed530b6 YC |
2405 | if (tp->thin_dupack) |
2406 | tcp_disable_early_retrans(tp); | |
e2e5c4c0 | 2407 | } |
7e380175 AP |
2408 | break; |
2409 | ||
ee995283 PE |
2410 | case TCP_REPAIR: |
2411 | if (!tcp_can_repair_sock(sk)) | |
2412 | err = -EPERM; | |
2413 | else if (val == 1) { | |
2414 | tp->repair = 1; | |
2415 | sk->sk_reuse = SK_FORCE_REUSE; | |
2416 | tp->repair_queue = TCP_NO_QUEUE; | |
2417 | } else if (val == 0) { | |
2418 | tp->repair = 0; | |
2419 | sk->sk_reuse = SK_NO_REUSE; | |
2420 | tcp_send_window_probe(sk); | |
2421 | } else | |
2422 | err = -EINVAL; | |
2423 | ||
2424 | break; | |
2425 | ||
2426 | case TCP_REPAIR_QUEUE: | |
2427 | if (!tp->repair) | |
2428 | err = -EPERM; | |
2429 | else if (val < TCP_QUEUES_NR) | |
2430 | tp->repair_queue = val; | |
2431 | else | |
2432 | err = -EINVAL; | |
2433 | break; | |
2434 | ||
2435 | case TCP_QUEUE_SEQ: | |
2436 | if (sk->sk_state != TCP_CLOSE) | |
2437 | err = -EPERM; | |
2438 | else if (tp->repair_queue == TCP_SEND_QUEUE) | |
2439 | tp->write_seq = val; | |
2440 | else if (tp->repair_queue == TCP_RECV_QUEUE) | |
2441 | tp->rcv_nxt = val; | |
2442 | else | |
2443 | err = -EINVAL; | |
2444 | break; | |
2445 | ||
b139ba4e PE |
2446 | case TCP_REPAIR_OPTIONS: |
2447 | if (!tp->repair) | |
2448 | err = -EINVAL; | |
2449 | else if (sk->sk_state == TCP_ESTABLISHED) | |
de248a75 PE |
2450 | err = tcp_repair_options_est(tp, |
2451 | (struct tcp_repair_opt __user *)optval, | |
2452 | optlen); | |
b139ba4e PE |
2453 | else |
2454 | err = -EPERM; | |
2455 | break; | |
2456 | ||
1da177e4 LT |
2457 | case TCP_CORK: |
2458 | /* When set indicates to always queue non-full frames. | |
2459 | * Later the user clears this option and we transmit | |
2460 | * any pending partial frames in the queue. This is | |
2461 | * meant to be used alongside sendfile() to get properly | |
2462 | * filled frames when the user (for example) must write | |
2463 | * out headers with a write() call first and then use | |
2464 | * sendfile to send out the data parts. | |
2465 | * | |
2466 | * TCP_CORK can be set together with TCP_NODELAY and it is | |
2467 | * stronger than TCP_NODELAY. | |
2468 | */ | |
2469 | if (val) { | |
2470 | tp->nonagle |= TCP_NAGLE_CORK; | |
2471 | } else { | |
2472 | tp->nonagle &= ~TCP_NAGLE_CORK; | |
2473 | if (tp->nonagle&TCP_NAGLE_OFF) | |
2474 | tp->nonagle |= TCP_NAGLE_PUSH; | |
9e412ba7 | 2475 | tcp_push_pending_frames(sk); |
1da177e4 LT |
2476 | } |
2477 | break; | |
2478 | ||
2479 | case TCP_KEEPIDLE: | |
2480 | if (val < 1 || val > MAX_TCP_KEEPIDLE) | |
2481 | err = -EINVAL; | |
2482 | else { | |
2483 | tp->keepalive_time = val * HZ; | |
2484 | if (sock_flag(sk, SOCK_KEEPOPEN) && | |
2485 | !((1 << sk->sk_state) & | |
2486 | (TCPF_CLOSE | TCPF_LISTEN))) { | |
6c37e5de | 2487 | u32 elapsed = keepalive_time_elapsed(tp); |
1da177e4 LT |
2488 | if (tp->keepalive_time > elapsed) |
2489 | elapsed = tp->keepalive_time - elapsed; | |
2490 | else | |
2491 | elapsed = 0; | |
463c84b9 | 2492 | inet_csk_reset_keepalive_timer(sk, elapsed); |
1da177e4 LT |
2493 | } |
2494 | } | |
2495 | break; | |
2496 | case TCP_KEEPINTVL: | |
2497 | if (val < 1 || val > MAX_TCP_KEEPINTVL) | |
2498 | err = -EINVAL; | |
2499 | else | |
2500 | tp->keepalive_intvl = val * HZ; | |
2501 | break; | |
2502 | case TCP_KEEPCNT: | |
2503 | if (val < 1 || val > MAX_TCP_KEEPCNT) | |
2504 | err = -EINVAL; | |
2505 | else | |
2506 | tp->keepalive_probes = val; | |
2507 | break; | |
2508 | case TCP_SYNCNT: | |
2509 | if (val < 1 || val > MAX_TCP_SYNCNT) | |
2510 | err = -EINVAL; | |
2511 | else | |
463c84b9 | 2512 | icsk->icsk_syn_retries = val; |
1da177e4 LT |
2513 | break; |
2514 | ||
cd8ae852 ED |
2515 | case TCP_SAVE_SYN: |
2516 | if (val < 0 || val > 1) | |
2517 | err = -EINVAL; | |
2518 | else | |
2519 | tp->save_syn = val; | |
2520 | break; | |
2521 | ||
1da177e4 LT |
2522 | case TCP_LINGER2: |
2523 | if (val < 0) | |
2524 | tp->linger2 = -1; | |
2525 | else if (val > sysctl_tcp_fin_timeout / HZ) | |
2526 | tp->linger2 = 0; | |
2527 | else | |
2528 | tp->linger2 = val * HZ; | |
2529 | break; | |
2530 | ||
2531 | case TCP_DEFER_ACCEPT: | |
b103cf34 JA |
2532 | /* Translate value in seconds to number of retransmits */ |
2533 | icsk->icsk_accept_queue.rskq_defer_accept = | |
2534 | secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, | |
2535 | TCP_RTO_MAX / HZ); | |
1da177e4 LT |
2536 | break; |
2537 | ||
2538 | case TCP_WINDOW_CLAMP: | |
2539 | if (!val) { | |
2540 | if (sk->sk_state != TCP_CLOSE) { | |
2541 | err = -EINVAL; | |
2542 | break; | |
2543 | } | |
2544 | tp->window_clamp = 0; | |
2545 | } else | |
2546 | tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? | |
2547 | SOCK_MIN_RCVBUF / 2 : val; | |
2548 | break; | |
2549 | ||
2550 | case TCP_QUICKACK: | |
2551 | if (!val) { | |
463c84b9 | 2552 | icsk->icsk_ack.pingpong = 1; |
1da177e4 | 2553 | } else { |
463c84b9 | 2554 | icsk->icsk_ack.pingpong = 0; |
1da177e4 LT |
2555 | if ((1 << sk->sk_state) & |
2556 | (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && | |
463c84b9 ACM |
2557 | inet_csk_ack_scheduled(sk)) { |
2558 | icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; | |
0e4b4992 | 2559 | tcp_cleanup_rbuf(sk, 1); |
1da177e4 | 2560 | if (!(val & 1)) |
463c84b9 | 2561 | icsk->icsk_ack.pingpong = 1; |
1da177e4 LT |
2562 | } |
2563 | } | |
2564 | break; | |
2565 | ||
cfb6eeb4 YH |
2566 | #ifdef CONFIG_TCP_MD5SIG |
2567 | case TCP_MD5SIG: | |
2568 | /* Read the IP->Key mappings from userspace */ | |
2569 | err = tp->af_specific->md5_parse(sk, optval, optlen); | |
2570 | break; | |
2571 | #endif | |
dca43c75 | 2572 | case TCP_USER_TIMEOUT: |
b248230c | 2573 | /* Cap the max time in ms TCP will retry or probe the window |
dca43c75 JC |
2574 | * before giving up and aborting (ETIMEDOUT) a connection. |
2575 | */ | |
42493570 HL |
2576 | if (val < 0) |
2577 | err = -EINVAL; | |
2578 | else | |
2579 | icsk->icsk_user_timeout = msecs_to_jiffies(val); | |
dca43c75 | 2580 | break; |
8336886f JC |
2581 | |
2582 | case TCP_FASTOPEN: | |
2583 | if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | | |
dfea2aa6 CP |
2584 | TCPF_LISTEN))) { |
2585 | tcp_fastopen_init_key_once(true); | |
2586 | ||
0536fcc0 | 2587 | fastopen_queue_tune(sk, val); |
dfea2aa6 | 2588 | } else { |
8336886f | 2589 | err = -EINVAL; |
dfea2aa6 | 2590 | } |
8336886f | 2591 | break; |
93be6ce0 AV |
2592 | case TCP_TIMESTAMP: |
2593 | if (!tp->repair) | |
2594 | err = -EPERM; | |
2595 | else | |
2596 | tp->tsoffset = val - tcp_time_stamp; | |
2597 | break; | |
c9bee3b7 ED |
2598 | case TCP_NOTSENT_LOWAT: |
2599 | tp->notsent_lowat = val; | |
2600 | sk->sk_write_space(sk); | |
2601 | break; | |
1da177e4 LT |
2602 | default: |
2603 | err = -ENOPROTOOPT; | |
2604 | break; | |
3ff50b79 SH |
2605 | } |
2606 | ||
1da177e4 LT |
2607 | release_sock(sk); |
2608 | return err; | |
2609 | } | |
2610 | ||
3fdadf7d | 2611 | int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, |
b7058842 | 2612 | unsigned int optlen) |
3fdadf7d | 2613 | { |
cf533ea5 | 2614 | const struct inet_connection_sock *icsk = inet_csk(sk); |
3fdadf7d DM |
2615 | |
2616 | if (level != SOL_TCP) | |
2617 | return icsk->icsk_af_ops->setsockopt(sk, level, optname, | |
2618 | optval, optlen); | |
2619 | return do_tcp_setsockopt(sk, level, optname, optval, optlen); | |
2620 | } | |
4bc2f18b | 2621 | EXPORT_SYMBOL(tcp_setsockopt); |
3fdadf7d DM |
2622 | |
2623 | #ifdef CONFIG_COMPAT | |
543d9cfe | 2624 | int compat_tcp_setsockopt(struct sock *sk, int level, int optname, |
b7058842 | 2625 | char __user *optval, unsigned int optlen) |
3fdadf7d | 2626 | { |
dec73ff0 ACM |
2627 | if (level != SOL_TCP) |
2628 | return inet_csk_compat_setsockopt(sk, level, optname, | |
2629 | optval, optlen); | |
3fdadf7d DM |
2630 | return do_tcp_setsockopt(sk, level, optname, optval, optlen); |
2631 | } | |
543d9cfe | 2632 | EXPORT_SYMBOL(compat_tcp_setsockopt); |
3fdadf7d DM |
2633 | #endif |
2634 | ||
1da177e4 | 2635 | /* Return information about state of tcp endpoint in API format. */ |
0df48c26 | 2636 | void tcp_get_info(struct sock *sk, struct tcp_info *info) |
1da177e4 | 2637 | { |
35ac838a | 2638 | const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ |
463c84b9 | 2639 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 | 2640 | u32 now = tcp_time_stamp; |
d654976c | 2641 | unsigned int start; |
ff5d7497 | 2642 | u64 rate64; |
fad9dfef | 2643 | u32 rate; |
1da177e4 LT |
2644 | |
2645 | memset(info, 0, sizeof(*info)); | |
35ac838a CG |
2646 | if (sk->sk_type != SOCK_STREAM) |
2647 | return; | |
1da177e4 | 2648 | |
00fd38d9 ED |
2649 | info->tcpi_state = sk_state_load(sk); |
2650 | ||
6687e988 | 2651 | info->tcpi_ca_state = icsk->icsk_ca_state; |
463c84b9 | 2652 | info->tcpi_retransmits = icsk->icsk_retransmits; |
6687e988 | 2653 | info->tcpi_probes = icsk->icsk_probes_out; |
463c84b9 | 2654 | info->tcpi_backoff = icsk->icsk_backoff; |
1da177e4 LT |
2655 | |
2656 | if (tp->rx_opt.tstamp_ok) | |
2657 | info->tcpi_options |= TCPI_OPT_TIMESTAMPS; | |
e60402d0 | 2658 | if (tcp_is_sack(tp)) |
1da177e4 LT |
2659 | info->tcpi_options |= TCPI_OPT_SACK; |
2660 | if (tp->rx_opt.wscale_ok) { | |
2661 | info->tcpi_options |= TCPI_OPT_WSCALE; | |
2662 | info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; | |
2663 | info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; | |
e905a9ed | 2664 | } |
1da177e4 | 2665 | |
b5c5693b | 2666 | if (tp->ecn_flags & TCP_ECN_OK) |
1da177e4 | 2667 | info->tcpi_options |= TCPI_OPT_ECN; |
b5c5693b ED |
2668 | if (tp->ecn_flags & TCP_ECN_SEEN) |
2669 | info->tcpi_options |= TCPI_OPT_ECN_SEEN; | |
6f73601e YC |
2670 | if (tp->syn_data_acked) |
2671 | info->tcpi_options |= TCPI_OPT_SYN_DATA; | |
1da177e4 | 2672 | |
463c84b9 ACM |
2673 | info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); |
2674 | info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); | |
c1b4a7e6 | 2675 | info->tcpi_snd_mss = tp->mss_cache; |
463c84b9 | 2676 | info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; |
1da177e4 | 2677 | |
00fd38d9 | 2678 | if (info->tcpi_state == TCP_LISTEN) { |
5ee3afba RJ |
2679 | info->tcpi_unacked = sk->sk_ack_backlog; |
2680 | info->tcpi_sacked = sk->sk_max_ack_backlog; | |
2681 | } else { | |
2682 | info->tcpi_unacked = tp->packets_out; | |
2683 | info->tcpi_sacked = tp->sacked_out; | |
2684 | } | |
1da177e4 LT |
2685 | info->tcpi_lost = tp->lost_out; |
2686 | info->tcpi_retrans = tp->retrans_out; | |
2687 | info->tcpi_fackets = tp->fackets_out; | |
2688 | ||
2689 | info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); | |
463c84b9 | 2690 | info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); |
1da177e4 LT |
2691 | info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); |
2692 | ||
d83d8461 | 2693 | info->tcpi_pmtu = icsk->icsk_pmtu_cookie; |
1da177e4 | 2694 | info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; |
740b0f18 ED |
2695 | info->tcpi_rtt = tp->srtt_us >> 3; |
2696 | info->tcpi_rttvar = tp->mdev_us >> 2; | |
1da177e4 LT |
2697 | info->tcpi_snd_ssthresh = tp->snd_ssthresh; |
2698 | info->tcpi_snd_cwnd = tp->snd_cwnd; | |
2699 | info->tcpi_advmss = tp->advmss; | |
2700 | info->tcpi_reordering = tp->reordering; | |
2701 | ||
2702 | info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; | |
2703 | info->tcpi_rcv_space = tp->rcvq_space.space; | |
2704 | ||
2705 | info->tcpi_total_retrans = tp->total_retrans; | |
977cb0ec | 2706 | |
fad9dfef | 2707 | rate = READ_ONCE(sk->sk_pacing_rate); |
ff5d7497 ED |
2708 | rate64 = rate != ~0U ? rate : ~0ULL; |
2709 | put_unaligned(rate64, &info->tcpi_pacing_rate); | |
fad9dfef ED |
2710 | |
2711 | rate = READ_ONCE(sk->sk_max_pacing_rate); | |
ff5d7497 ED |
2712 | rate64 = rate != ~0U ? rate : ~0ULL; |
2713 | put_unaligned(rate64, &info->tcpi_max_pacing_rate); | |
0df48c26 | 2714 | |
d654976c ED |
2715 | do { |
2716 | start = u64_stats_fetch_begin_irq(&tp->syncp); | |
ff5d7497 ED |
2717 | put_unaligned(tp->bytes_acked, &info->tcpi_bytes_acked); |
2718 | put_unaligned(tp->bytes_received, &info->tcpi_bytes_received); | |
d654976c | 2719 | } while (u64_stats_fetch_retry_irq(&tp->syncp, start)); |
2efd055c MRL |
2720 | info->tcpi_segs_out = tp->segs_out; |
2721 | info->tcpi_segs_in = tp->segs_in; | |
1da177e4 | 2722 | } |
1da177e4 LT |
2723 | EXPORT_SYMBOL_GPL(tcp_get_info); |
2724 | ||
3fdadf7d DM |
2725 | static int do_tcp_getsockopt(struct sock *sk, int level, |
2726 | int optname, char __user *optval, int __user *optlen) | |
1da177e4 | 2727 | { |
295f7324 | 2728 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
2729 | struct tcp_sock *tp = tcp_sk(sk); |
2730 | int val, len; | |
2731 | ||
1da177e4 LT |
2732 | if (get_user(len, optlen)) |
2733 | return -EFAULT; | |
2734 | ||
2735 | len = min_t(unsigned int, len, sizeof(int)); | |
2736 | ||
2737 | if (len < 0) | |
2738 | return -EINVAL; | |
2739 | ||
2740 | switch (optname) { | |
2741 | case TCP_MAXSEG: | |
c1b4a7e6 | 2742 | val = tp->mss_cache; |
1da177e4 LT |
2743 | if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) |
2744 | val = tp->rx_opt.user_mss; | |
5e6a3ce6 PE |
2745 | if (tp->repair) |
2746 | val = tp->rx_opt.mss_clamp; | |
1da177e4 LT |
2747 | break; |
2748 | case TCP_NODELAY: | |
2749 | val = !!(tp->nonagle&TCP_NAGLE_OFF); | |
2750 | break; | |
2751 | case TCP_CORK: | |
2752 | val = !!(tp->nonagle&TCP_NAGLE_CORK); | |
2753 | break; | |
2754 | case TCP_KEEPIDLE: | |
df19a626 | 2755 | val = keepalive_time_when(tp) / HZ; |
1da177e4 LT |
2756 | break; |
2757 | case TCP_KEEPINTVL: | |
df19a626 | 2758 | val = keepalive_intvl_when(tp) / HZ; |
1da177e4 LT |
2759 | break; |
2760 | case TCP_KEEPCNT: | |
df19a626 | 2761 | val = keepalive_probes(tp); |
1da177e4 LT |
2762 | break; |
2763 | case TCP_SYNCNT: | |
295f7324 | 2764 | val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; |
1da177e4 LT |
2765 | break; |
2766 | case TCP_LINGER2: | |
2767 | val = tp->linger2; | |
2768 | if (val >= 0) | |
2769 | val = (val ? : sysctl_tcp_fin_timeout) / HZ; | |
2770 | break; | |
2771 | case TCP_DEFER_ACCEPT: | |
b103cf34 JA |
2772 | val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, |
2773 | TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); | |
1da177e4 LT |
2774 | break; |
2775 | case TCP_WINDOW_CLAMP: | |
2776 | val = tp->window_clamp; | |
2777 | break; | |
2778 | case TCP_INFO: { | |
2779 | struct tcp_info info; | |
2780 | ||
2781 | if (get_user(len, optlen)) | |
2782 | return -EFAULT; | |
2783 | ||
2784 | tcp_get_info(sk, &info); | |
2785 | ||
2786 | len = min_t(unsigned int, len, sizeof(info)); | |
2787 | if (put_user(len, optlen)) | |
2788 | return -EFAULT; | |
2789 | if (copy_to_user(optval, &info, len)) | |
2790 | return -EFAULT; | |
2791 | return 0; | |
2792 | } | |
6e9250f5 ED |
2793 | case TCP_CC_INFO: { |
2794 | const struct tcp_congestion_ops *ca_ops; | |
2795 | union tcp_cc_info info; | |
2796 | size_t sz = 0; | |
2797 | int attr; | |
2798 | ||
2799 | if (get_user(len, optlen)) | |
2800 | return -EFAULT; | |
2801 | ||
2802 | ca_ops = icsk->icsk_ca_ops; | |
2803 | if (ca_ops && ca_ops->get_info) | |
2804 | sz = ca_ops->get_info(sk, ~0U, &attr, &info); | |
2805 | ||
2806 | len = min_t(unsigned int, len, sz); | |
2807 | if (put_user(len, optlen)) | |
2808 | return -EFAULT; | |
2809 | if (copy_to_user(optval, &info, len)) | |
2810 | return -EFAULT; | |
2811 | return 0; | |
2812 | } | |
1da177e4 | 2813 | case TCP_QUICKACK: |
295f7324 | 2814 | val = !icsk->icsk_ack.pingpong; |
1da177e4 | 2815 | break; |
5f8ef48d SH |
2816 | |
2817 | case TCP_CONGESTION: | |
2818 | if (get_user(len, optlen)) | |
2819 | return -EFAULT; | |
2820 | len = min_t(unsigned int, len, TCP_CA_NAME_MAX); | |
2821 | if (put_user(len, optlen)) | |
2822 | return -EFAULT; | |
6687e988 | 2823 | if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) |
5f8ef48d SH |
2824 | return -EFAULT; |
2825 | return 0; | |
e56fb50f | 2826 | |
3c0fef0b JH |
2827 | case TCP_THIN_LINEAR_TIMEOUTS: |
2828 | val = tp->thin_lto; | |
2829 | break; | |
2830 | case TCP_THIN_DUPACK: | |
2831 | val = tp->thin_dupack; | |
2832 | break; | |
dca43c75 | 2833 | |
ee995283 PE |
2834 | case TCP_REPAIR: |
2835 | val = tp->repair; | |
2836 | break; | |
2837 | ||
2838 | case TCP_REPAIR_QUEUE: | |
2839 | if (tp->repair) | |
2840 | val = tp->repair_queue; | |
2841 | else | |
2842 | return -EINVAL; | |
2843 | break; | |
2844 | ||
2845 | case TCP_QUEUE_SEQ: | |
2846 | if (tp->repair_queue == TCP_SEND_QUEUE) | |
2847 | val = tp->write_seq; | |
2848 | else if (tp->repair_queue == TCP_RECV_QUEUE) | |
2849 | val = tp->rcv_nxt; | |
2850 | else | |
2851 | return -EINVAL; | |
2852 | break; | |
2853 | ||
dca43c75 JC |
2854 | case TCP_USER_TIMEOUT: |
2855 | val = jiffies_to_msecs(icsk->icsk_user_timeout); | |
2856 | break; | |
1536e285 KN |
2857 | |
2858 | case TCP_FASTOPEN: | |
0536fcc0 | 2859 | val = icsk->icsk_accept_queue.fastopenq.max_qlen; |
1536e285 KN |
2860 | break; |
2861 | ||
93be6ce0 AV |
2862 | case TCP_TIMESTAMP: |
2863 | val = tcp_time_stamp + tp->tsoffset; | |
2864 | break; | |
c9bee3b7 ED |
2865 | case TCP_NOTSENT_LOWAT: |
2866 | val = tp->notsent_lowat; | |
2867 | break; | |
cd8ae852 ED |
2868 | case TCP_SAVE_SYN: |
2869 | val = tp->save_syn; | |
2870 | break; | |
2871 | case TCP_SAVED_SYN: { | |
2872 | if (get_user(len, optlen)) | |
2873 | return -EFAULT; | |
2874 | ||
2875 | lock_sock(sk); | |
2876 | if (tp->saved_syn) { | |
aea0929e EM |
2877 | if (len < tp->saved_syn[0]) { |
2878 | if (put_user(tp->saved_syn[0], optlen)) { | |
2879 | release_sock(sk); | |
2880 | return -EFAULT; | |
2881 | } | |
2882 | release_sock(sk); | |
2883 | return -EINVAL; | |
2884 | } | |
2885 | len = tp->saved_syn[0]; | |
cd8ae852 ED |
2886 | if (put_user(len, optlen)) { |
2887 | release_sock(sk); | |
2888 | return -EFAULT; | |
2889 | } | |
2890 | if (copy_to_user(optval, tp->saved_syn + 1, len)) { | |
2891 | release_sock(sk); | |
2892 | return -EFAULT; | |
2893 | } | |
2894 | tcp_saved_syn_free(tp); | |
2895 | release_sock(sk); | |
2896 | } else { | |
2897 | release_sock(sk); | |
2898 | len = 0; | |
2899 | if (put_user(len, optlen)) | |
2900 | return -EFAULT; | |
2901 | } | |
2902 | return 0; | |
2903 | } | |
1da177e4 LT |
2904 | default: |
2905 | return -ENOPROTOOPT; | |
3ff50b79 | 2906 | } |
1da177e4 LT |
2907 | |
2908 | if (put_user(len, optlen)) | |
2909 | return -EFAULT; | |
2910 | if (copy_to_user(optval, &val, len)) | |
2911 | return -EFAULT; | |
2912 | return 0; | |
2913 | } | |
2914 | ||
3fdadf7d DM |
2915 | int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, |
2916 | int __user *optlen) | |
2917 | { | |
2918 | struct inet_connection_sock *icsk = inet_csk(sk); | |
2919 | ||
2920 | if (level != SOL_TCP) | |
2921 | return icsk->icsk_af_ops->getsockopt(sk, level, optname, | |
2922 | optval, optlen); | |
2923 | return do_tcp_getsockopt(sk, level, optname, optval, optlen); | |
2924 | } | |
4bc2f18b | 2925 | EXPORT_SYMBOL(tcp_getsockopt); |
3fdadf7d DM |
2926 | |
2927 | #ifdef CONFIG_COMPAT | |
543d9cfe ACM |
2928 | int compat_tcp_getsockopt(struct sock *sk, int level, int optname, |
2929 | char __user *optval, int __user *optlen) | |
3fdadf7d | 2930 | { |
dec73ff0 ACM |
2931 | if (level != SOL_TCP) |
2932 | return inet_csk_compat_getsockopt(sk, level, optname, | |
2933 | optval, optlen); | |
3fdadf7d DM |
2934 | return do_tcp_getsockopt(sk, level, optname, optval, optlen); |
2935 | } | |
543d9cfe | 2936 | EXPORT_SYMBOL(compat_tcp_getsockopt); |
3fdadf7d | 2937 | #endif |
1da177e4 | 2938 | |
cfb6eeb4 | 2939 | #ifdef CONFIG_TCP_MD5SIG |
349ce993 | 2940 | static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool); |
71cea17e | 2941 | static DEFINE_MUTEX(tcp_md5sig_mutex); |
349ce993 | 2942 | static bool tcp_md5sig_pool_populated = false; |
cfb6eeb4 | 2943 | |
71cea17e | 2944 | static void __tcp_alloc_md5sig_pool(void) |
cfb6eeb4 YH |
2945 | { |
2946 | int cpu; | |
cfb6eeb4 YH |
2947 | |
2948 | for_each_possible_cpu(cpu) { | |
349ce993 ED |
2949 | if (!per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm) { |
2950 | struct crypto_hash *hash; | |
cfb6eeb4 | 2951 | |
349ce993 | 2952 | hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); |
1eea84b7 | 2953 | if (IS_ERR(hash)) |
349ce993 ED |
2954 | return; |
2955 | per_cpu(tcp_md5sig_pool, cpu).md5_desc.tfm = hash; | |
2956 | } | |
cfb6eeb4 | 2957 | } |
349ce993 ED |
2958 | /* before setting tcp_md5sig_pool_populated, we must commit all writes |
2959 | * to memory. See smp_rmb() in tcp_get_md5sig_pool() | |
71cea17e ED |
2960 | */ |
2961 | smp_wmb(); | |
349ce993 | 2962 | tcp_md5sig_pool_populated = true; |
cfb6eeb4 YH |
2963 | } |
2964 | ||
71cea17e | 2965 | bool tcp_alloc_md5sig_pool(void) |
cfb6eeb4 | 2966 | { |
349ce993 | 2967 | if (unlikely(!tcp_md5sig_pool_populated)) { |
71cea17e ED |
2968 | mutex_lock(&tcp_md5sig_mutex); |
2969 | ||
349ce993 | 2970 | if (!tcp_md5sig_pool_populated) |
71cea17e ED |
2971 | __tcp_alloc_md5sig_pool(); |
2972 | ||
2973 | mutex_unlock(&tcp_md5sig_mutex); | |
cfb6eeb4 | 2974 | } |
349ce993 | 2975 | return tcp_md5sig_pool_populated; |
cfb6eeb4 | 2976 | } |
cfb6eeb4 YH |
2977 | EXPORT_SYMBOL(tcp_alloc_md5sig_pool); |
2978 | ||
35790c04 ED |
2979 | |
2980 | /** | |
2981 | * tcp_get_md5sig_pool - get md5sig_pool for this user | |
2982 | * | |
2983 | * We use percpu structure, so if we succeed, we exit with preemption | |
2984 | * and BH disabled, to make sure another thread or softirq handling | |
2985 | * wont try to get same context. | |
2986 | */ | |
2987 | struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) | |
cfb6eeb4 | 2988 | { |
35790c04 | 2989 | local_bh_disable(); |
cfb6eeb4 | 2990 | |
349ce993 ED |
2991 | if (tcp_md5sig_pool_populated) { |
2992 | /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */ | |
2993 | smp_rmb(); | |
2994 | return this_cpu_ptr(&tcp_md5sig_pool); | |
2995 | } | |
35790c04 ED |
2996 | local_bh_enable(); |
2997 | return NULL; | |
2998 | } | |
2999 | EXPORT_SYMBOL(tcp_get_md5sig_pool); | |
cfb6eeb4 | 3000 | |
49a72dfb | 3001 | int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, |
ca35a0ef | 3002 | const struct tcphdr *th) |
49a72dfb AL |
3003 | { |
3004 | struct scatterlist sg; | |
ca35a0ef | 3005 | struct tcphdr hdr; |
49a72dfb AL |
3006 | int err; |
3007 | ||
ca35a0ef ED |
3008 | /* We are not allowed to change tcphdr, make a local copy */ |
3009 | memcpy(&hdr, th, sizeof(hdr)); | |
3010 | hdr.check = 0; | |
3011 | ||
49a72dfb | 3012 | /* options aren't included in the hash */ |
ca35a0ef ED |
3013 | sg_init_one(&sg, &hdr, sizeof(hdr)); |
3014 | err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr)); | |
49a72dfb AL |
3015 | return err; |
3016 | } | |
49a72dfb AL |
3017 | EXPORT_SYMBOL(tcp_md5_hash_header); |
3018 | ||
3019 | int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, | |
cf533ea5 | 3020 | const struct sk_buff *skb, unsigned int header_len) |
49a72dfb AL |
3021 | { |
3022 | struct scatterlist sg; | |
3023 | const struct tcphdr *tp = tcp_hdr(skb); | |
3024 | struct hash_desc *desc = &hp->md5_desc; | |
95c96174 ED |
3025 | unsigned int i; |
3026 | const unsigned int head_data_len = skb_headlen(skb) > header_len ? | |
3027 | skb_headlen(skb) - header_len : 0; | |
49a72dfb | 3028 | const struct skb_shared_info *shi = skb_shinfo(skb); |
d7fd1b57 | 3029 | struct sk_buff *frag_iter; |
49a72dfb AL |
3030 | |
3031 | sg_init_table(&sg, 1); | |
3032 | ||
3033 | sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); | |
3034 | if (crypto_hash_update(desc, &sg, head_data_len)) | |
3035 | return 1; | |
3036 | ||
3037 | for (i = 0; i < shi->nr_frags; ++i) { | |
3038 | const struct skb_frag_struct *f = &shi->frags[i]; | |
54d27fcb ED |
3039 | unsigned int offset = f->page_offset; |
3040 | struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); | |
3041 | ||
3042 | sg_set_page(&sg, page, skb_frag_size(f), | |
3043 | offset_in_page(offset)); | |
9e903e08 | 3044 | if (crypto_hash_update(desc, &sg, skb_frag_size(f))) |
49a72dfb AL |
3045 | return 1; |
3046 | } | |
3047 | ||
d7fd1b57 ED |
3048 | skb_walk_frags(skb, frag_iter) |
3049 | if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) | |
3050 | return 1; | |
3051 | ||
49a72dfb AL |
3052 | return 0; |
3053 | } | |
49a72dfb AL |
3054 | EXPORT_SYMBOL(tcp_md5_hash_skb_data); |
3055 | ||
cf533ea5 | 3056 | int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) |
49a72dfb AL |
3057 | { |
3058 | struct scatterlist sg; | |
3059 | ||
3060 | sg_init_one(&sg, key->key, key->keylen); | |
3061 | return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); | |
3062 | } | |
49a72dfb AL |
3063 | EXPORT_SYMBOL(tcp_md5_hash_key); |
3064 | ||
cfb6eeb4 YH |
3065 | #endif |
3066 | ||
4ac02bab AK |
3067 | void tcp_done(struct sock *sk) |
3068 | { | |
8336886f JC |
3069 | struct request_sock *req = tcp_sk(sk)->fastopen_rsk; |
3070 | ||
5a5f3a8d | 3071 | if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) |
63231bdd | 3072 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); |
4ac02bab AK |
3073 | |
3074 | tcp_set_state(sk, TCP_CLOSE); | |
3075 | tcp_clear_xmit_timers(sk); | |
00db4124 | 3076 | if (req) |
8336886f | 3077 | reqsk_fastopen_remove(sk, req, false); |
4ac02bab AK |
3078 | |
3079 | sk->sk_shutdown = SHUTDOWN_MASK; | |
3080 | ||
3081 | if (!sock_flag(sk, SOCK_DEAD)) | |
3082 | sk->sk_state_change(sk); | |
3083 | else | |
3084 | inet_csk_destroy_sock(sk); | |
3085 | } | |
3086 | EXPORT_SYMBOL_GPL(tcp_done); | |
3087 | ||
c1e64e29 LC |
3088 | int tcp_abort(struct sock *sk, int err) |
3089 | { | |
3090 | if (!sk_fullsock(sk)) { | |
07f6f4a3 ED |
3091 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
3092 | struct request_sock *req = inet_reqsk(sk); | |
3093 | ||
3094 | local_bh_disable(); | |
3095 | inet_csk_reqsk_queue_drop_and_put(req->rsk_listener, | |
3096 | req); | |
3097 | local_bh_enable(); | |
3098 | return 0; | |
3099 | } | |
c1e64e29 LC |
3100 | sock_gen_put(sk); |
3101 | return -EOPNOTSUPP; | |
3102 | } | |
3103 | ||
3104 | /* Don't race with userspace socket closes such as tcp_close. */ | |
3105 | lock_sock(sk); | |
3106 | ||
2010b93e LC |
3107 | if (sk->sk_state == TCP_LISTEN) { |
3108 | tcp_set_state(sk, TCP_CLOSE); | |
3109 | inet_csk_listen_stop(sk); | |
3110 | } | |
3111 | ||
c1e64e29 LC |
3112 | /* Don't race with BH socket closes such as inet_csk_listen_stop. */ |
3113 | local_bh_disable(); | |
3114 | bh_lock_sock(sk); | |
3115 | ||
3116 | if (!sock_flag(sk, SOCK_DEAD)) { | |
3117 | sk->sk_err = err; | |
3118 | /* This barrier is coupled with smp_rmb() in tcp_poll() */ | |
3119 | smp_wmb(); | |
3120 | sk->sk_error_report(sk); | |
3121 | if (tcp_need_reset(sk->sk_state)) | |
3122 | tcp_send_active_reset(sk, GFP_ATOMIC); | |
3123 | tcp_done(sk); | |
3124 | } | |
3125 | ||
3126 | bh_unlock_sock(sk); | |
3127 | local_bh_enable(); | |
3128 | release_sock(sk); | |
3129 | sock_put(sk); | |
3130 | return 0; | |
3131 | } | |
3132 | EXPORT_SYMBOL_GPL(tcp_abort); | |
3133 | ||
5f8ef48d | 3134 | extern struct tcp_congestion_ops tcp_reno; |
1da177e4 LT |
3135 | |
3136 | static __initdata unsigned long thash_entries; | |
3137 | static int __init set_thash_entries(char *str) | |
3138 | { | |
413c27d8 EZ |
3139 | ssize_t ret; |
3140 | ||
1da177e4 LT |
3141 | if (!str) |
3142 | return 0; | |
413c27d8 EZ |
3143 | |
3144 | ret = kstrtoul(str, 0, &thash_entries); | |
3145 | if (ret) | |
3146 | return 0; | |
3147 | ||
1da177e4 LT |
3148 | return 1; |
3149 | } | |
3150 | __setup("thash_entries=", set_thash_entries); | |
3151 | ||
47d7a88c | 3152 | static void __init tcp_init_mem(void) |
4acb4190 | 3153 | { |
b66e91cc ED |
3154 | unsigned long limit = nr_free_buffer_pages() / 16; |
3155 | ||
4acb4190 | 3156 | limit = max(limit, 128UL); |
b66e91cc ED |
3157 | sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */ |
3158 | sysctl_tcp_mem[1] = limit; /* 6.25 % */ | |
3159 | sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */ | |
4acb4190 GC |
3160 | } |
3161 | ||
1da177e4 LT |
3162 | void __init tcp_init(void) |
3163 | { | |
f03d78db | 3164 | unsigned long limit; |
b49960a0 | 3165 | int max_rshare, max_wshare, cnt; |
074b8517 | 3166 | unsigned int i; |
1da177e4 | 3167 | |
b4772ef8 | 3168 | sock_skb_cb_check_size(sizeof(struct tcp_skb_cb)); |
1da177e4 | 3169 | |
908c7f19 TH |
3170 | percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); |
3171 | percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); | |
6e04e021 ACM |
3172 | tcp_hashinfo.bind_bucket_cachep = |
3173 | kmem_cache_create("tcp_bind_bucket", | |
3174 | sizeof(struct inet_bind_bucket), 0, | |
20c2df83 | 3175 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 | 3176 | |
1da177e4 LT |
3177 | /* Size and allocate the main established and bind bucket |
3178 | * hash tables. | |
3179 | * | |
3180 | * The methodology is similar to that of the buffer cache. | |
3181 | */ | |
6e04e021 | 3182 | tcp_hashinfo.ehash = |
1da177e4 | 3183 | alloc_large_system_hash("TCP established", |
0f7ff927 | 3184 | sizeof(struct inet_ehash_bucket), |
1da177e4 | 3185 | thash_entries, |
fd90b29d | 3186 | 17, /* one slot per 128 KB of memory */ |
9e950efa | 3187 | 0, |
1da177e4 | 3188 | NULL, |
f373b53b | 3189 | &tcp_hashinfo.ehash_mask, |
31fe62b9 | 3190 | 0, |
0ccfe618 | 3191 | thash_entries ? 0 : 512 * 1024); |
05dbc7b5 | 3192 | for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) |
3ab5aee7 | 3193 | INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); |
05dbc7b5 | 3194 | |
230140cf ED |
3195 | if (inet_ehash_locks_alloc(&tcp_hashinfo)) |
3196 | panic("TCP: failed to alloc ehash_locks"); | |
6e04e021 | 3197 | tcp_hashinfo.bhash = |
1da177e4 | 3198 | alloc_large_system_hash("TCP bind", |
0f7ff927 | 3199 | sizeof(struct inet_bind_hashbucket), |
f373b53b | 3200 | tcp_hashinfo.ehash_mask + 1, |
fd90b29d | 3201 | 17, /* one slot per 128 KB of memory */ |
9e950efa | 3202 | 0, |
6e04e021 | 3203 | &tcp_hashinfo.bhash_size, |
1da177e4 | 3204 | NULL, |
31fe62b9 | 3205 | 0, |
1da177e4 | 3206 | 64 * 1024); |
074b8517 | 3207 | tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; |
6e04e021 ACM |
3208 | for (i = 0; i < tcp_hashinfo.bhash_size; i++) { |
3209 | spin_lock_init(&tcp_hashinfo.bhash[i].lock); | |
3210 | INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); | |
1da177e4 LT |
3211 | } |
3212 | ||
c5ed63d6 ED |
3213 | |
3214 | cnt = tcp_hashinfo.ehash_mask + 1; | |
3215 | ||
3216 | tcp_death_row.sysctl_max_tw_buckets = cnt / 2; | |
3217 | sysctl_tcp_max_orphans = cnt / 2; | |
3218 | sysctl_max_syn_backlog = max(128, cnt / 256); | |
1da177e4 | 3219 | |
a4fe34bf | 3220 | tcp_init_mem(); |
c43b874d | 3221 | /* Set per-socket limits to no more than 1/128 the pressure threshold */ |
5fb84b14 | 3222 | limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); |
b49960a0 ED |
3223 | max_wshare = min(4UL*1024*1024, limit); |
3224 | max_rshare = min(6UL*1024*1024, limit); | |
7b4f4b5e | 3225 | |
3ab224be | 3226 | sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; |
7b4f4b5e | 3227 | sysctl_tcp_wmem[1] = 16*1024; |
b49960a0 | 3228 | sysctl_tcp_wmem[2] = max(64*1024, max_wshare); |
7b4f4b5e | 3229 | |
3ab224be | 3230 | sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; |
7b4f4b5e | 3231 | sysctl_tcp_rmem[1] = 87380; |
b49960a0 | 3232 | sysctl_tcp_rmem[2] = max(87380, max_rshare); |
1da177e4 | 3233 | |
afd46503 | 3234 | pr_info("Hash tables configured (established %u bind %u)\n", |
058bd4d2 | 3235 | tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); |
317a76f9 | 3236 | |
51c5d0c4 | 3237 | tcp_metrics_init(); |
55d8694f | 3238 | BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); |
46d3ceab | 3239 | tcp_tasklet_init(); |
1da177e4 | 3240 | } |