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1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Implementation of the Transmission Control Protocol(TCP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Mark Evans, <evansmp@uhura.aston.ac.uk>
11 * Corey Minyard <wf-rch!minyard@relay.EU.net>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
14 * Linus Torvalds, <torvalds@cs.helsinki.fi>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Matthew Dillon, <dillon@apollo.west.oic.com>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Jorge Cwik, <jorge@laser.satlink.net>
19 *
20 * Fixes:
21 * Alan Cox : Numerous verify_area() calls
22 * Alan Cox : Set the ACK bit on a reset
23 * Alan Cox : Stopped it crashing if it closed while
24 * sk->inuse=1 and was trying to connect
25 * (tcp_err()).
26 * Alan Cox : All icmp error handling was broken
27 * pointers passed where wrong and the
28 * socket was looked up backwards. Nobody
29 * tested any icmp error code obviously.
30 * Alan Cox : tcp_err() now handled properly. It
31 * wakes people on errors. poll
32 * behaves and the icmp error race
33 * has gone by moving it into sock.c
34 * Alan Cox : tcp_send_reset() fixed to work for
35 * everything not just packets for
36 * unknown sockets.
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
39 * syn rule wrong]
40 * Herp Rosmanith : More reset fixes
41 * Alan Cox : No longer acks invalid rst frames.
42 * Acking any kind of RST is right out.
43 * Alan Cox : Sets an ignore me flag on an rst
44 * receive otherwise odd bits of prattle
45 * escape still
46 * Alan Cox : Fixed another acking RST frame bug.
47 * Should stop LAN workplace lockups.
48 * Alan Cox : Some tidyups using the new skb list
49 * facilities
50 * Alan Cox : sk->keepopen now seems to work
51 * Alan Cox : Pulls options out correctly on accepts
52 * Alan Cox : Fixed assorted sk->rqueue->next errors
53 * Alan Cox : PSH doesn't end a TCP read. Switched a
54 * bit to skb ops.
55 * Alan Cox : Tidied tcp_data to avoid a potential
56 * nasty.
57 * Alan Cox : Added some better commenting, as the
58 * tcp is hard to follow
59 * Alan Cox : Removed incorrect check for 20 * psh
60 * Michael O'Reilly : ack < copied bug fix.
61 * Johannes Stille : Misc tcp fixes (not all in yet).
62 * Alan Cox : FIN with no memory -> CRASH
63 * Alan Cox : Added socket option proto entries.
64 * Also added awareness of them to accept.
65 * Alan Cox : Added TCP options (SOL_TCP)
66 * Alan Cox : Switched wakeup calls to callbacks,
67 * so the kernel can layer network
68 * sockets.
69 * Alan Cox : Use ip_tos/ip_ttl settings.
70 * Alan Cox : Handle FIN (more) properly (we hope).
71 * Alan Cox : RST frames sent on unsynchronised
72 * state ack error.
73 * Alan Cox : Put in missing check for SYN bit.
74 * Alan Cox : Added tcp_select_window() aka NET2E
75 * window non shrink trick.
76 * Alan Cox : Added a couple of small NET2E timer
77 * fixes
78 * Charles Hedrick : TCP fixes
79 * Toomas Tamm : TCP window fixes
80 * Alan Cox : Small URG fix to rlogin ^C ack fight
81 * Charles Hedrick : Rewrote most of it to actually work
82 * Linus : Rewrote tcp_read() and URG handling
83 * completely
84 * Gerhard Koerting: Fixed some missing timer handling
85 * Matthew Dillon : Reworked TCP machine states as per RFC
86 * Gerhard Koerting: PC/TCP workarounds
87 * Adam Caldwell : Assorted timer/timing errors
88 * Matthew Dillon : Fixed another RST bug
89 * Alan Cox : Move to kernel side addressing changes.
90 * Alan Cox : Beginning work on TCP fastpathing
91 * (not yet usable)
92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
93 * Alan Cox : TCP fast path debugging
94 * Alan Cox : Window clamping
95 * Michael Riepe : Bug in tcp_check()
96 * Matt Dillon : More TCP improvements and RST bug fixes
97 * Matt Dillon : Yet more small nasties remove from the
98 * TCP code (Be very nice to this man if
99 * tcp finally works 100%) 8)
100 * Alan Cox : BSD accept semantics.
101 * Alan Cox : Reset on closedown bug.
102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
103 * Michael Pall : Handle poll() after URG properly in
104 * all cases.
105 * Michael Pall : Undo the last fix in tcp_read_urg()
106 * (multi URG PUSH broke rlogin).
107 * Michael Pall : Fix the multi URG PUSH problem in
108 * tcp_readable(), poll() after URG
109 * works now.
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
111 * BSD api.
112 * Alan Cox : Changed the semantics of sk->socket to
113 * fix a race and a signal problem with
114 * accept() and async I/O.
115 * Alan Cox : Relaxed the rules on tcp_sendto().
116 * Yury Shevchuk : Really fixed accept() blocking problem.
117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
118 * clients/servers which listen in on
119 * fixed ports.
120 * Alan Cox : Cleaned the above up and shrank it to
121 * a sensible code size.
122 * Alan Cox : Self connect lockup fix.
123 * Alan Cox : No connect to multicast.
124 * Ross Biro : Close unaccepted children on master
125 * socket close.
126 * Alan Cox : Reset tracing code.
127 * Alan Cox : Spurious resets on shutdown.
128 * Alan Cox : Giant 15 minute/60 second timer error
129 * Alan Cox : Small whoops in polling before an
130 * accept.
131 * Alan Cox : Kept the state trace facility since
132 * it's handy for debugging.
133 * Alan Cox : More reset handler fixes.
134 * Alan Cox : Started rewriting the code based on
135 * the RFC's for other useful protocol
136 * references see: Comer, KA9Q NOS, and
137 * for a reference on the difference
138 * between specifications and how BSD
139 * works see the 4.4lite source.
140 * A.N.Kuznetsov : Don't time wait on completion of tidy
141 * close.
142 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
143 * Linus Torvalds : Fixed BSD port reuse to work first syn
144 * Alan Cox : Reimplemented timers as per the RFC
145 * and using multiple timers for sanity.
146 * Alan Cox : Small bug fixes, and a lot of new
147 * comments.
148 * Alan Cox : Fixed dual reader crash by locking
149 * the buffers (much like datagram.c)
150 * Alan Cox : Fixed stuck sockets in probe. A probe
151 * now gets fed up of retrying without
152 * (even a no space) answer.
153 * Alan Cox : Extracted closing code better
154 * Alan Cox : Fixed the closing state machine to
155 * resemble the RFC.
156 * Alan Cox : More 'per spec' fixes.
157 * Jorge Cwik : Even faster checksumming.
158 * Alan Cox : tcp_data() doesn't ack illegal PSH
159 * only frames. At least one pc tcp stack
160 * generates them.
161 * Alan Cox : Cache last socket.
162 * Alan Cox : Per route irtt.
163 * Matt Day : poll()->select() match BSD precisely on error
164 * Alan Cox : New buffers
165 * Marc Tamsky : Various sk->prot->retransmits and
166 * sk->retransmits misupdating fixed.
167 * Fixed tcp_write_timeout: stuck close,
168 * and TCP syn retries gets used now.
169 * Mark Yarvis : In tcp_read_wakeup(), don't send an
170 * ack if state is TCP_CLOSED.
171 * Alan Cox : Look up device on a retransmit - routes may
172 * change. Doesn't yet cope with MSS shrink right
173 * but it's a start!
174 * Marc Tamsky : Closing in closing fixes.
175 * Mike Shaver : RFC1122 verifications.
176 * Alan Cox : rcv_saddr errors.
177 * Alan Cox : Block double connect().
178 * Alan Cox : Small hooks for enSKIP.
179 * Alexey Kuznetsov: Path MTU discovery.
180 * Alan Cox : Support soft errors.
181 * Alan Cox : Fix MTU discovery pathological case
182 * when the remote claims no mtu!
183 * Marc Tamsky : TCP_CLOSE fix.
184 * Colin (G3TNE) : Send a reset on syn ack replies in
185 * window but wrong (fixes NT lpd problems)
186 * Pedro Roque : Better TCP window handling, delayed ack.
187 * Joerg Reuter : No modification of locked buffers in
188 * tcp_do_retransmit()
189 * Eric Schenk : Changed receiver side silly window
190 * avoidance algorithm to BSD style
191 * algorithm. This doubles throughput
192 * against machines running Solaris,
193 * and seems to result in general
194 * improvement.
195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
196 * Willy Konynenberg : Transparent proxying support.
197 * Mike McLagan : Routing by source
198 * Keith Owens : Do proper merging with partial SKB's in
199 * tcp_do_sendmsg to avoid burstiness.
200 * Eric Schenk : Fix fast close down bug with
201 * shutdown() followed by close().
202 * Andi Kleen : Make poll agree with SIGIO
203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
204 * lingertime == 0 (RFC 793 ABORT Call)
205 * Hirokazu Takahashi : Use copy_from_user() instead of
206 * csum_and_copy_from_user() if possible.
207 *
208 * This program is free software; you can redistribute it and/or
209 * modify it under the terms of the GNU General Public License
210 * as published by the Free Software Foundation; either version
211 * 2 of the License, or(at your option) any later version.
212 *
213 * Description of States:
214 *
215 * TCP_SYN_SENT sent a connection request, waiting for ack
216 *
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
219 *
220 * TCP_ESTABLISHED connection established
221 *
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
224 *
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
226 * to shutdown
227 *
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
230 *
231 * TCP_TIME_WAIT timeout to catch resent junk before entering
232 * closed, can only be entered from FIN_WAIT2
233 * or CLOSING. Required because the other end
234 * may not have gotten our last ACK causing it
235 * to retransmit the data packet (which we ignore)
236 *
237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
238 * us to finish writing our data and to shutdown
239 * (we have to close() to move on to LAST_ACK)
240 *
241 * TCP_LAST_ACK out side has shutdown after remote has
242 * shutdown. There may still be data in our
243 * buffer that we have to finish sending
244 *
245 * TCP_CLOSE socket is finished
246 */
247
248#define pr_fmt(fmt) "TCP: " fmt
249
250#include <crypto/hash.h>
251#include <linux/kernel.h>
252#include <linux/module.h>
253#include <linux/types.h>
254#include <linux/fcntl.h>
255#include <linux/poll.h>
256#include <linux/inet_diag.h>
257#include <linux/init.h>
258#include <linux/fs.h>
259#include <linux/skbuff.h>
260#include <linux/scatterlist.h>
261#include <linux/splice.h>
262#include <linux/net.h>
263#include <linux/socket.h>
264#include <linux/random.h>
265#include <linux/bootmem.h>
266#include <linux/highmem.h>
267#include <linux/swap.h>
268#include <linux/cache.h>
269#include <linux/err.h>
270#include <linux/time.h>
271#include <linux/slab.h>
272
273#include <net/icmp.h>
274#include <net/inet_common.h>
275#include <net/tcp.h>
276#include <net/xfrm.h>
277#include <net/ip.h>
278#include <net/sock.h>
279
280#include <asm/uaccess.h>
281#include <asm/ioctls.h>
282#include <asm/unaligned.h>
283#include <net/busy_poll.h>
284
285int sysctl_tcp_min_tso_segs __read_mostly = 2;
286
287int sysctl_tcp_autocorking __read_mostly = 1;
288
289struct percpu_counter tcp_orphan_count;
290EXPORT_SYMBOL_GPL(tcp_orphan_count);
291
292long sysctl_tcp_mem[3] __read_mostly;
293int sysctl_tcp_wmem[3] __read_mostly;
294int sysctl_tcp_rmem[3] __read_mostly;
295
296EXPORT_SYMBOL(sysctl_tcp_mem);
297EXPORT_SYMBOL(sysctl_tcp_rmem);
298EXPORT_SYMBOL(sysctl_tcp_wmem);
299
300atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
301EXPORT_SYMBOL(tcp_memory_allocated);
302
303/*
304 * Current number of TCP sockets.
305 */
306struct percpu_counter tcp_sockets_allocated;
307EXPORT_SYMBOL(tcp_sockets_allocated);
308
309/*
310 * TCP splice context
311 */
312struct tcp_splice_state {
313 struct pipe_inode_info *pipe;
314 size_t len;
315 unsigned int flags;
316};
317
318/*
319 * Pressure flag: try to collapse.
320 * Technical note: it is used by multiple contexts non atomically.
321 * All the __sk_mem_schedule() is of this nature: accounting
322 * is strict, actions are advisory and have some latency.
323 */
324int tcp_memory_pressure __read_mostly;
325EXPORT_SYMBOL(tcp_memory_pressure);
326
327void tcp_enter_memory_pressure(struct sock *sk)
328{
329 if (!tcp_memory_pressure) {
330 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
331 tcp_memory_pressure = 1;
332 }
333}
334EXPORT_SYMBOL(tcp_enter_memory_pressure);
335
336/* Convert seconds to retransmits based on initial and max timeout */
337static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
338{
339 u8 res = 0;
340
341 if (seconds > 0) {
342 int period = timeout;
343
344 res = 1;
345 while (seconds > period && res < 255) {
346 res++;
347 timeout <<= 1;
348 if (timeout > rto_max)
349 timeout = rto_max;
350 period += timeout;
351 }
352 }
353 return res;
354}
355
356/* Convert retransmits to seconds based on initial and max timeout */
357static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
358{
359 int period = 0;
360
361 if (retrans > 0) {
362 period = timeout;
363 while (--retrans) {
364 timeout <<= 1;
365 if (timeout > rto_max)
366 timeout = rto_max;
367 period += timeout;
368 }
369 }
370 return period;
371}
372
373/* Address-family independent initialization for a tcp_sock.
374 *
375 * NOTE: A lot of things set to zero explicitly by call to
376 * sk_alloc() so need not be done here.
377 */
378void tcp_init_sock(struct sock *sk)
379{
380 struct inet_connection_sock *icsk = inet_csk(sk);
381 struct tcp_sock *tp = tcp_sk(sk);
382
383 __skb_queue_head_init(&tp->out_of_order_queue);
384 tcp_init_xmit_timers(sk);
385 tcp_prequeue_init(tp);
386 INIT_LIST_HEAD(&tp->tsq_node);
387
388 icsk->icsk_rto = TCP_TIMEOUT_INIT;
389 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
390 tp->rtt_min[0].rtt = ~0U;
391
392 /* So many TCP implementations out there (incorrectly) count the
393 * initial SYN frame in their delayed-ACK and congestion control
394 * algorithms that we must have the following bandaid to talk
395 * efficiently to them. -DaveM
396 */
397 tp->snd_cwnd = TCP_INIT_CWND;
398
399 /* See draft-stevens-tcpca-spec-01 for discussion of the
400 * initialization of these values.
401 */
402 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
403 tp->snd_cwnd_clamp = ~0;
404 tp->mss_cache = TCP_MSS_DEFAULT;
405 u64_stats_init(&tp->syncp);
406
407 tp->reordering = sock_net(sk)->ipv4.sysctl_tcp_reordering;
408 tcp_enable_early_retrans(tp);
409 tcp_assign_congestion_control(sk);
410
411 tp->tsoffset = 0;
412
413 sk->sk_state = TCP_CLOSE;
414
415 sk->sk_write_space = sk_stream_write_space;
416 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
417
418 icsk->icsk_sync_mss = tcp_sync_mss;
419
420 sk->sk_sndbuf = sysctl_tcp_wmem[1];
421 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
422
423 local_bh_disable();
424 if (mem_cgroup_sockets_enabled)
425 sock_update_memcg(sk);
426 sk_sockets_allocated_inc(sk);
427 local_bh_enable();
428}
429EXPORT_SYMBOL(tcp_init_sock);
430
431static void tcp_tx_timestamp(struct sock *sk, struct sk_buff *skb)
432{
433 if (sk->sk_tsflags) {
434 struct skb_shared_info *shinfo = skb_shinfo(skb);
435
436 sock_tx_timestamp(sk, &shinfo->tx_flags);
437 if (shinfo->tx_flags & SKBTX_ANY_TSTAMP)
438 shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
439 }
440}
441
442/*
443 * Wait for a TCP event.
444 *
445 * Note that we don't need to lock the socket, as the upper poll layers
446 * take care of normal races (between the test and the event) and we don't
447 * go look at any of the socket buffers directly.
448 */
449unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
450{
451 unsigned int mask;
452 struct sock *sk = sock->sk;
453 const struct tcp_sock *tp = tcp_sk(sk);
454 int state;
455
456 sock_rps_record_flow(sk);
457
458 sock_poll_wait(file, sk_sleep(sk), wait);
459
460 state = sk_state_load(sk);
461 if (state == TCP_LISTEN)
462 return inet_csk_listen_poll(sk);
463
464 /* Socket is not locked. We are protected from async events
465 * by poll logic and correct handling of state changes
466 * made by other threads is impossible in any case.
467 */
468
469 mask = 0;
470
471 /*
472 * POLLHUP is certainly not done right. But poll() doesn't
473 * have a notion of HUP in just one direction, and for a
474 * socket the read side is more interesting.
475 *
476 * Some poll() documentation says that POLLHUP is incompatible
477 * with the POLLOUT/POLLWR flags, so somebody should check this
478 * all. But careful, it tends to be safer to return too many
479 * bits than too few, and you can easily break real applications
480 * if you don't tell them that something has hung up!
481 *
482 * Check-me.
483 *
484 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
485 * our fs/select.c). It means that after we received EOF,
486 * poll always returns immediately, making impossible poll() on write()
487 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
488 * if and only if shutdown has been made in both directions.
489 * Actually, it is interesting to look how Solaris and DUX
490 * solve this dilemma. I would prefer, if POLLHUP were maskable,
491 * then we could set it on SND_SHUTDOWN. BTW examples given
492 * in Stevens' books assume exactly this behaviour, it explains
493 * why POLLHUP is incompatible with POLLOUT. --ANK
494 *
495 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
496 * blocking on fresh not-connected or disconnected socket. --ANK
497 */
498 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
499 mask |= POLLHUP;
500 if (sk->sk_shutdown & RCV_SHUTDOWN)
501 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
502
503 /* Connected or passive Fast Open socket? */
504 if (state != TCP_SYN_SENT &&
505 (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
506 int target = sock_rcvlowat(sk, 0, INT_MAX);
507
508 if (tp->urg_seq == tp->copied_seq &&
509 !sock_flag(sk, SOCK_URGINLINE) &&
510 tp->urg_data)
511 target++;
512
513 if (tp->rcv_nxt - tp->copied_seq >= target)
514 mask |= POLLIN | POLLRDNORM;
515
516 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
517 if (sk_stream_is_writeable(sk)) {
518 mask |= POLLOUT | POLLWRNORM;
519 } else { /* send SIGIO later */
520 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
521 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
522
523 /* Race breaker. If space is freed after
524 * wspace test but before the flags are set,
525 * IO signal will be lost. Memory barrier
526 * pairs with the input side.
527 */
528 smp_mb__after_atomic();
529 if (sk_stream_is_writeable(sk))
530 mask |= POLLOUT | POLLWRNORM;
531 }
532 } else
533 mask |= POLLOUT | POLLWRNORM;
534
535 if (tp->urg_data & TCP_URG_VALID)
536 mask |= POLLPRI;
537 }
538 /* This barrier is coupled with smp_wmb() in tcp_reset() */
539 smp_rmb();
540 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
541 mask |= POLLERR;
542
543 return mask;
544}
545EXPORT_SYMBOL(tcp_poll);
546
547int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
548{
549 struct tcp_sock *tp = tcp_sk(sk);
550 int answ;
551 bool slow;
552
553 switch (cmd) {
554 case SIOCINQ:
555 if (sk->sk_state == TCP_LISTEN)
556 return -EINVAL;
557
558 slow = lock_sock_fast(sk);
559 answ = tcp_inq(sk);
560 unlock_sock_fast(sk, slow);
561 break;
562 case SIOCATMARK:
563 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
564 break;
565 case SIOCOUTQ:
566 if (sk->sk_state == TCP_LISTEN)
567 return -EINVAL;
568
569 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
570 answ = 0;
571 else
572 answ = tp->write_seq - tp->snd_una;
573 break;
574 case SIOCOUTQNSD:
575 if (sk->sk_state == TCP_LISTEN)
576 return -EINVAL;
577
578 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
579 answ = 0;
580 else
581 answ = tp->write_seq - tp->snd_nxt;
582 break;
583 default:
584 return -ENOIOCTLCMD;
585 }
586
587 return put_user(answ, (int __user *)arg);
588}
589EXPORT_SYMBOL(tcp_ioctl);
590
591static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
592{
593 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
594 tp->pushed_seq = tp->write_seq;
595}
596
597static inline bool forced_push(const struct tcp_sock *tp)
598{
599 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
600}
601
602static void skb_entail(struct sock *sk, struct sk_buff *skb)
603{
604 struct tcp_sock *tp = tcp_sk(sk);
605 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
606
607 skb->csum = 0;
608 tcb->seq = tcb->end_seq = tp->write_seq;
609 tcb->tcp_flags = TCPHDR_ACK;
610 tcb->sacked = 0;
611 __skb_header_release(skb);
612 tcp_add_write_queue_tail(sk, skb);
613 sk->sk_wmem_queued += skb->truesize;
614 sk_mem_charge(sk, skb->truesize);
615 if (tp->nonagle & TCP_NAGLE_PUSH)
616 tp->nonagle &= ~TCP_NAGLE_PUSH;
617
618 tcp_slow_start_after_idle_check(sk);
619}
620
621static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
622{
623 if (flags & MSG_OOB)
624 tp->snd_up = tp->write_seq;
625}
626
627/* If a not yet filled skb is pushed, do not send it if
628 * we have data packets in Qdisc or NIC queues :
629 * Because TX completion will happen shortly, it gives a chance
630 * to coalesce future sendmsg() payload into this skb, without
631 * need for a timer, and with no latency trade off.
632 * As packets containing data payload have a bigger truesize
633 * than pure acks (dataless) packets, the last checks prevent
634 * autocorking if we only have an ACK in Qdisc/NIC queues,
635 * or if TX completion was delayed after we processed ACK packet.
636 */
637static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
638 int size_goal)
639{
640 return skb->len < size_goal &&
641 sysctl_tcp_autocorking &&
642 skb != tcp_write_queue_head(sk) &&
643 atomic_read(&sk->sk_wmem_alloc) > skb->truesize;
644}
645
646static void tcp_push(struct sock *sk, int flags, int mss_now,
647 int nonagle, int size_goal)
648{
649 struct tcp_sock *tp = tcp_sk(sk);
650 struct sk_buff *skb;
651
652 if (!tcp_send_head(sk))
653 return;
654
655 skb = tcp_write_queue_tail(sk);
656 if (!(flags & MSG_MORE) || forced_push(tp))
657 tcp_mark_push(tp, skb);
658
659 tcp_mark_urg(tp, flags);
660
661 if (tcp_should_autocork(sk, skb, size_goal)) {
662
663 /* avoid atomic op if TSQ_THROTTLED bit is already set */
664 if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) {
665 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
666 set_bit(TSQ_THROTTLED, &tp->tsq_flags);
667 }
668 /* It is possible TX completion already happened
669 * before we set TSQ_THROTTLED.
670 */
671 if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize)
672 return;
673 }
674
675 if (flags & MSG_MORE)
676 nonagle = TCP_NAGLE_CORK;
677
678 __tcp_push_pending_frames(sk, mss_now, nonagle);
679}
680
681static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
682 unsigned int offset, size_t len)
683{
684 struct tcp_splice_state *tss = rd_desc->arg.data;
685 int ret;
686
687 ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
688 min(rd_desc->count, len), tss->flags,
689 skb_socket_splice);
690 if (ret > 0)
691 rd_desc->count -= ret;
692 return ret;
693}
694
695static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
696{
697 /* Store TCP splice context information in read_descriptor_t. */
698 read_descriptor_t rd_desc = {
699 .arg.data = tss,
700 .count = tss->len,
701 };
702
703 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
704}
705
706/**
707 * tcp_splice_read - splice data from TCP socket to a pipe
708 * @sock: socket to splice from
709 * @ppos: position (not valid)
710 * @pipe: pipe to splice to
711 * @len: number of bytes to splice
712 * @flags: splice modifier flags
713 *
714 * Description:
715 * Will read pages from given socket and fill them into a pipe.
716 *
717 **/
718ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
719 struct pipe_inode_info *pipe, size_t len,
720 unsigned int flags)
721{
722 struct sock *sk = sock->sk;
723 struct tcp_splice_state tss = {
724 .pipe = pipe,
725 .len = len,
726 .flags = flags,
727 };
728 long timeo;
729 ssize_t spliced;
730 int ret;
731
732 sock_rps_record_flow(sk);
733 /*
734 * We can't seek on a socket input
735 */
736 if (unlikely(*ppos))
737 return -ESPIPE;
738
739 ret = spliced = 0;
740
741 lock_sock(sk);
742
743 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
744 while (tss.len) {
745 ret = __tcp_splice_read(sk, &tss);
746 if (ret < 0)
747 break;
748 else if (!ret) {
749 if (spliced)
750 break;
751 if (sock_flag(sk, SOCK_DONE))
752 break;
753 if (sk->sk_err) {
754 ret = sock_error(sk);
755 break;
756 }
757 if (sk->sk_shutdown & RCV_SHUTDOWN)
758 break;
759 if (sk->sk_state == TCP_CLOSE) {
760 /*
761 * This occurs when user tries to read
762 * from never connected socket.
763 */
764 if (!sock_flag(sk, SOCK_DONE))
765 ret = -ENOTCONN;
766 break;
767 }
768 if (!timeo) {
769 ret = -EAGAIN;
770 break;
771 }
772 sk_wait_data(sk, &timeo, NULL);
773 if (signal_pending(current)) {
774 ret = sock_intr_errno(timeo);
775 break;
776 }
777 continue;
778 }
779 tss.len -= ret;
780 spliced += ret;
781
782 if (!timeo)
783 break;
784 release_sock(sk);
785 lock_sock(sk);
786
787 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
788 (sk->sk_shutdown & RCV_SHUTDOWN) ||
789 signal_pending(current))
790 break;
791 }
792
793 release_sock(sk);
794
795 if (spliced)
796 return spliced;
797
798 return ret;
799}
800EXPORT_SYMBOL(tcp_splice_read);
801
802struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
803 bool force_schedule)
804{
805 struct sk_buff *skb;
806
807 /* The TCP header must be at least 32-bit aligned. */
808 size = ALIGN(size, 4);
809
810 if (unlikely(tcp_under_memory_pressure(sk)))
811 sk_mem_reclaim_partial(sk);
812
813 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
814 if (likely(skb)) {
815 bool mem_scheduled;
816
817 if (force_schedule) {
818 mem_scheduled = true;
819 sk_forced_mem_schedule(sk, skb->truesize);
820 } else {
821 mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
822 }
823 if (likely(mem_scheduled)) {
824 skb_reserve(skb, sk->sk_prot->max_header);
825 /*
826 * Make sure that we have exactly size bytes
827 * available to the caller, no more, no less.
828 */
829 skb->reserved_tailroom = skb->end - skb->tail - size;
830 return skb;
831 }
832 __kfree_skb(skb);
833 } else {
834 sk->sk_prot->enter_memory_pressure(sk);
835 sk_stream_moderate_sndbuf(sk);
836 }
837 return NULL;
838}
839
840static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
841 int large_allowed)
842{
843 struct tcp_sock *tp = tcp_sk(sk);
844 u32 new_size_goal, size_goal;
845
846 if (!large_allowed || !sk_can_gso(sk))
847 return mss_now;
848
849 /* Note : tcp_tso_autosize() will eventually split this later */
850 new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER;
851 new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal);
852
853 /* We try hard to avoid divides here */
854 size_goal = tp->gso_segs * mss_now;
855 if (unlikely(new_size_goal < size_goal ||
856 new_size_goal >= size_goal + mss_now)) {
857 tp->gso_segs = min_t(u16, new_size_goal / mss_now,
858 sk->sk_gso_max_segs);
859 size_goal = tp->gso_segs * mss_now;
860 }
861
862 return max(size_goal, mss_now);
863}
864
865static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
866{
867 int mss_now;
868
869 mss_now = tcp_current_mss(sk);
870 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
871
872 return mss_now;
873}
874
875static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
876 size_t size, int flags)
877{
878 struct tcp_sock *tp = tcp_sk(sk);
879 int mss_now, size_goal;
880 int err;
881 ssize_t copied;
882 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
883
884 /* Wait for a connection to finish. One exception is TCP Fast Open
885 * (passive side) where data is allowed to be sent before a connection
886 * is fully established.
887 */
888 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
889 !tcp_passive_fastopen(sk)) {
890 err = sk_stream_wait_connect(sk, &timeo);
891 if (err != 0)
892 goto out_err;
893 }
894
895 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
896
897 mss_now = tcp_send_mss(sk, &size_goal, flags);
898 copied = 0;
899
900 err = -EPIPE;
901 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
902 goto out_err;
903
904 while (size > 0) {
905 struct sk_buff *skb = tcp_write_queue_tail(sk);
906 int copy, i;
907 bool can_coalesce;
908
909 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
910new_segment:
911 if (!sk_stream_memory_free(sk))
912 goto wait_for_sndbuf;
913
914 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
915 skb_queue_empty(&sk->sk_write_queue));
916 if (!skb)
917 goto wait_for_memory;
918
919 skb_entail(sk, skb);
920 copy = size_goal;
921 }
922
923 if (copy > size)
924 copy = size;
925
926 i = skb_shinfo(skb)->nr_frags;
927 can_coalesce = skb_can_coalesce(skb, i, page, offset);
928 if (!can_coalesce && i >= sysctl_max_skb_frags) {
929 tcp_mark_push(tp, skb);
930 goto new_segment;
931 }
932 if (!sk_wmem_schedule(sk, copy))
933 goto wait_for_memory;
934
935 if (can_coalesce) {
936 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
937 } else {
938 get_page(page);
939 skb_fill_page_desc(skb, i, page, offset, copy);
940 }
941 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
942
943 skb->len += copy;
944 skb->data_len += copy;
945 skb->truesize += copy;
946 sk->sk_wmem_queued += copy;
947 sk_mem_charge(sk, copy);
948 skb->ip_summed = CHECKSUM_PARTIAL;
949 tp->write_seq += copy;
950 TCP_SKB_CB(skb)->end_seq += copy;
951 tcp_skb_pcount_set(skb, 0);
952
953 if (!copied)
954 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
955
956 copied += copy;
957 offset += copy;
958 size -= copy;
959 if (!size) {
960 tcp_tx_timestamp(sk, skb);
961 goto out;
962 }
963
964 if (skb->len < size_goal || (flags & MSG_OOB))
965 continue;
966
967 if (forced_push(tp)) {
968 tcp_mark_push(tp, skb);
969 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
970 } else if (skb == tcp_send_head(sk))
971 tcp_push_one(sk, mss_now);
972 continue;
973
974wait_for_sndbuf:
975 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
976wait_for_memory:
977 tcp_push(sk, flags & ~MSG_MORE, mss_now,
978 TCP_NAGLE_PUSH, size_goal);
979
980 err = sk_stream_wait_memory(sk, &timeo);
981 if (err != 0)
982 goto do_error;
983
984 mss_now = tcp_send_mss(sk, &size_goal, flags);
985 }
986
987out:
988 if (copied && !(flags & MSG_SENDPAGE_NOTLAST))
989 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
990 return copied;
991
992do_error:
993 if (copied)
994 goto out;
995out_err:
996 /* make sure we wake any epoll edge trigger waiter */
997 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
998 sk->sk_write_space(sk);
999 return sk_stream_error(sk, flags, err);
1000}
1001
1002int tcp_sendpage(struct sock *sk, struct page *page, int offset,
1003 size_t size, int flags)
1004{
1005 ssize_t res;
1006
1007 if (!(sk->sk_route_caps & NETIF_F_SG) ||
1008 !sk_check_csum_caps(sk))
1009 return sock_no_sendpage(sk->sk_socket, page, offset, size,
1010 flags);
1011
1012 lock_sock(sk);
1013 res = do_tcp_sendpages(sk, page, offset, size, flags);
1014 release_sock(sk);
1015 return res;
1016}
1017EXPORT_SYMBOL(tcp_sendpage);
1018
1019static inline int select_size(const struct sock *sk, bool sg)
1020{
1021 const struct tcp_sock *tp = tcp_sk(sk);
1022 int tmp = tp->mss_cache;
1023
1024 if (sg) {
1025 if (sk_can_gso(sk)) {
1026 /* Small frames wont use a full page:
1027 * Payload will immediately follow tcp header.
1028 */
1029 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
1030 } else {
1031 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
1032
1033 if (tmp >= pgbreak &&
1034 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
1035 tmp = pgbreak;
1036 }
1037 }
1038
1039 return tmp;
1040}
1041
1042void tcp_free_fastopen_req(struct tcp_sock *tp)
1043{
1044 if (tp->fastopen_req) {
1045 kfree(tp->fastopen_req);
1046 tp->fastopen_req = NULL;
1047 }
1048}
1049
1050static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
1051 int *copied, size_t size)
1052{
1053 struct tcp_sock *tp = tcp_sk(sk);
1054 int err, flags;
1055
1056 if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE))
1057 return -EOPNOTSUPP;
1058 if (tp->fastopen_req)
1059 return -EALREADY; /* Another Fast Open is in progress */
1060
1061 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
1062 sk->sk_allocation);
1063 if (unlikely(!tp->fastopen_req))
1064 return -ENOBUFS;
1065 tp->fastopen_req->data = msg;
1066 tp->fastopen_req->size = size;
1067
1068 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1069 err = __inet_stream_connect(sk->sk_socket, msg->msg_name,
1070 msg->msg_namelen, flags);
1071 *copied = tp->fastopen_req->copied;
1072 tcp_free_fastopen_req(tp);
1073 return err;
1074}
1075
1076int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
1077{
1078 struct tcp_sock *tp = tcp_sk(sk);
1079 struct sk_buff *skb;
1080 int flags, err, copied = 0;
1081 int mss_now = 0, size_goal, copied_syn = 0;
1082 bool sg;
1083 long timeo;
1084
1085 lock_sock(sk);
1086
1087 flags = msg->msg_flags;
1088 if (flags & MSG_FASTOPEN) {
1089 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1090 if (err == -EINPROGRESS && copied_syn > 0)
1091 goto out;
1092 else if (err)
1093 goto out_err;
1094 }
1095
1096 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1097
1098 /* Wait for a connection to finish. One exception is TCP Fast Open
1099 * (passive side) where data is allowed to be sent before a connection
1100 * is fully established.
1101 */
1102 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
1103 !tcp_passive_fastopen(sk)) {
1104 err = sk_stream_wait_connect(sk, &timeo);
1105 if (err != 0)
1106 goto do_error;
1107 }
1108
1109 if (unlikely(tp->repair)) {
1110 if (tp->repair_queue == TCP_RECV_QUEUE) {
1111 copied = tcp_send_rcvq(sk, msg, size);
1112 goto out_nopush;
1113 }
1114
1115 err = -EINVAL;
1116 if (tp->repair_queue == TCP_NO_QUEUE)
1117 goto out_err;
1118
1119 /* 'common' sending to sendq */
1120 }
1121
1122 /* This should be in poll */
1123 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1124
1125 mss_now = tcp_send_mss(sk, &size_goal, flags);
1126
1127 /* Ok commence sending. */
1128 copied = 0;
1129
1130 err = -EPIPE;
1131 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1132 goto out_err;
1133
1134 sg = !!(sk->sk_route_caps & NETIF_F_SG);
1135
1136 while (msg_data_left(msg)) {
1137 int copy = 0;
1138 int max = size_goal;
1139
1140 skb = tcp_write_queue_tail(sk);
1141 if (tcp_send_head(sk)) {
1142 if (skb->ip_summed == CHECKSUM_NONE)
1143 max = mss_now;
1144 copy = max - skb->len;
1145 }
1146
1147 if (copy <= 0) {
1148new_segment:
1149 /* Allocate new segment. If the interface is SG,
1150 * allocate skb fitting to single page.
1151 */
1152 if (!sk_stream_memory_free(sk))
1153 goto wait_for_sndbuf;
1154
1155 skb = sk_stream_alloc_skb(sk,
1156 select_size(sk, sg),
1157 sk->sk_allocation,
1158 skb_queue_empty(&sk->sk_write_queue));
1159 if (!skb)
1160 goto wait_for_memory;
1161
1162 /*
1163 * Check whether we can use HW checksum.
1164 */
1165 if (sk_check_csum_caps(sk))
1166 skb->ip_summed = CHECKSUM_PARTIAL;
1167
1168 skb_entail(sk, skb);
1169 copy = size_goal;
1170 max = size_goal;
1171
1172 /* All packets are restored as if they have
1173 * already been sent. skb_mstamp isn't set to
1174 * avoid wrong rtt estimation.
1175 */
1176 if (tp->repair)
1177 TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
1178 }
1179
1180 /* Try to append data to the end of skb. */
1181 if (copy > msg_data_left(msg))
1182 copy = msg_data_left(msg);
1183
1184 /* Where to copy to? */
1185 if (skb_availroom(skb) > 0) {
1186 /* We have some space in skb head. Superb! */
1187 copy = min_t(int, copy, skb_availroom(skb));
1188 err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy);
1189 if (err)
1190 goto do_fault;
1191 } else {
1192 bool merge = true;
1193 int i = skb_shinfo(skb)->nr_frags;
1194 struct page_frag *pfrag = sk_page_frag(sk);
1195
1196 if (!sk_page_frag_refill(sk, pfrag))
1197 goto wait_for_memory;
1198
1199 if (!skb_can_coalesce(skb, i, pfrag->page,
1200 pfrag->offset)) {
1201 if (i == sysctl_max_skb_frags || !sg) {
1202 tcp_mark_push(tp, skb);
1203 goto new_segment;
1204 }
1205 merge = false;
1206 }
1207
1208 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1209
1210 if (!sk_wmem_schedule(sk, copy))
1211 goto wait_for_memory;
1212
1213 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
1214 pfrag->page,
1215 pfrag->offset,
1216 copy);
1217 if (err)
1218 goto do_error;
1219
1220 /* Update the skb. */
1221 if (merge) {
1222 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1223 } else {
1224 skb_fill_page_desc(skb, i, pfrag->page,
1225 pfrag->offset, copy);
1226 get_page(pfrag->page);
1227 }
1228 pfrag->offset += copy;
1229 }
1230
1231 if (!copied)
1232 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1233
1234 tp->write_seq += copy;
1235 TCP_SKB_CB(skb)->end_seq += copy;
1236 tcp_skb_pcount_set(skb, 0);
1237
1238 copied += copy;
1239 if (!msg_data_left(msg)) {
1240 tcp_tx_timestamp(sk, skb);
1241 goto out;
1242 }
1243
1244 if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
1245 continue;
1246
1247 if (forced_push(tp)) {
1248 tcp_mark_push(tp, skb);
1249 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1250 } else if (skb == tcp_send_head(sk))
1251 tcp_push_one(sk, mss_now);
1252 continue;
1253
1254wait_for_sndbuf:
1255 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1256wait_for_memory:
1257 if (copied)
1258 tcp_push(sk, flags & ~MSG_MORE, mss_now,
1259 TCP_NAGLE_PUSH, size_goal);
1260
1261 err = sk_stream_wait_memory(sk, &timeo);
1262 if (err != 0)
1263 goto do_error;
1264
1265 mss_now = tcp_send_mss(sk, &size_goal, flags);
1266 }
1267
1268out:
1269 if (copied)
1270 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1271out_nopush:
1272 release_sock(sk);
1273 return copied + copied_syn;
1274
1275do_fault:
1276 if (!skb->len) {
1277 tcp_unlink_write_queue(skb, sk);
1278 /* It is the one place in all of TCP, except connection
1279 * reset, where we can be unlinking the send_head.
1280 */
1281 tcp_check_send_head(sk, skb);
1282 sk_wmem_free_skb(sk, skb);
1283 }
1284
1285do_error:
1286 if (copied + copied_syn)
1287 goto out;
1288out_err:
1289 err = sk_stream_error(sk, flags, err);
1290 /* make sure we wake any epoll edge trigger waiter */
1291 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
1292 sk->sk_write_space(sk);
1293 release_sock(sk);
1294 return err;
1295}
1296EXPORT_SYMBOL(tcp_sendmsg);
1297
1298/*
1299 * Handle reading urgent data. BSD has very simple semantics for
1300 * this, no blocking and very strange errors 8)
1301 */
1302
1303static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1304{
1305 struct tcp_sock *tp = tcp_sk(sk);
1306
1307 /* No URG data to read. */
1308 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1309 tp->urg_data == TCP_URG_READ)
1310 return -EINVAL; /* Yes this is right ! */
1311
1312 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1313 return -ENOTCONN;
1314
1315 if (tp->urg_data & TCP_URG_VALID) {
1316 int err = 0;
1317 char c = tp->urg_data;
1318
1319 if (!(flags & MSG_PEEK))
1320 tp->urg_data = TCP_URG_READ;
1321
1322 /* Read urgent data. */
1323 msg->msg_flags |= MSG_OOB;
1324
1325 if (len > 0) {
1326 if (!(flags & MSG_TRUNC))
1327 err = memcpy_to_msg(msg, &c, 1);
1328 len = 1;
1329 } else
1330 msg->msg_flags |= MSG_TRUNC;
1331
1332 return err ? -EFAULT : len;
1333 }
1334
1335 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1336 return 0;
1337
1338 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1339 * the available implementations agree in this case:
1340 * this call should never block, independent of the
1341 * blocking state of the socket.
1342 * Mike <pall@rz.uni-karlsruhe.de>
1343 */
1344 return -EAGAIN;
1345}
1346
1347static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
1348{
1349 struct sk_buff *skb;
1350 int copied = 0, err = 0;
1351
1352 /* XXX -- need to support SO_PEEK_OFF */
1353
1354 skb_queue_walk(&sk->sk_write_queue, skb) {
1355 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
1356 if (err)
1357 break;
1358
1359 copied += skb->len;
1360 }
1361
1362 return err ?: copied;
1363}
1364
1365/* Clean up the receive buffer for full frames taken by the user,
1366 * then send an ACK if necessary. COPIED is the number of bytes
1367 * tcp_recvmsg has given to the user so far, it speeds up the
1368 * calculation of whether or not we must ACK for the sake of
1369 * a window update.
1370 */
1371static void tcp_cleanup_rbuf(struct sock *sk, int copied)
1372{
1373 struct tcp_sock *tp = tcp_sk(sk);
1374 bool time_to_ack = false;
1375
1376 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1377
1378 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1379 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1380 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1381
1382 if (inet_csk_ack_scheduled(sk)) {
1383 const struct inet_connection_sock *icsk = inet_csk(sk);
1384 /* Delayed ACKs frequently hit locked sockets during bulk
1385 * receive. */
1386 if (icsk->icsk_ack.blocked ||
1387 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1388 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1389 /*
1390 * If this read emptied read buffer, we send ACK, if
1391 * connection is not bidirectional, user drained
1392 * receive buffer and there was a small segment
1393 * in queue.
1394 */
1395 (copied > 0 &&
1396 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1397 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1398 !icsk->icsk_ack.pingpong)) &&
1399 !atomic_read(&sk->sk_rmem_alloc)))
1400 time_to_ack = true;
1401 }
1402
1403 /* We send an ACK if we can now advertise a non-zero window
1404 * which has been raised "significantly".
1405 *
1406 * Even if window raised up to infinity, do not send window open ACK
1407 * in states, where we will not receive more. It is useless.
1408 */
1409 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1410 __u32 rcv_window_now = tcp_receive_window(tp);
1411
1412 /* Optimize, __tcp_select_window() is not cheap. */
1413 if (2*rcv_window_now <= tp->window_clamp) {
1414 __u32 new_window = __tcp_select_window(sk);
1415
1416 /* Send ACK now, if this read freed lots of space
1417 * in our buffer. Certainly, new_window is new window.
1418 * We can advertise it now, if it is not less than current one.
1419 * "Lots" means "at least twice" here.
1420 */
1421 if (new_window && new_window >= 2 * rcv_window_now)
1422 time_to_ack = true;
1423 }
1424 }
1425 if (time_to_ack)
1426 tcp_send_ack(sk);
1427}
1428
1429static void tcp_prequeue_process(struct sock *sk)
1430{
1431 struct sk_buff *skb;
1432 struct tcp_sock *tp = tcp_sk(sk);
1433
1434 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
1435
1436 /* RX process wants to run with disabled BHs, though it is not
1437 * necessary */
1438 local_bh_disable();
1439 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1440 sk_backlog_rcv(sk, skb);
1441 local_bh_enable();
1442
1443 /* Clear memory counter. */
1444 tp->ucopy.memory = 0;
1445}
1446
1447static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1448{
1449 struct sk_buff *skb;
1450 u32 offset;
1451
1452 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1453 offset = seq - TCP_SKB_CB(skb)->seq;
1454 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
1455 pr_err_once("%s: found a SYN, please report !\n", __func__);
1456 offset--;
1457 }
1458 if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
1459 *off = offset;
1460 return skb;
1461 }
1462 /* This looks weird, but this can happen if TCP collapsing
1463 * splitted a fat GRO packet, while we released socket lock
1464 * in skb_splice_bits()
1465 */
1466 sk_eat_skb(sk, skb);
1467 }
1468 return NULL;
1469}
1470
1471/*
1472 * This routine provides an alternative to tcp_recvmsg() for routines
1473 * that would like to handle copying from skbuffs directly in 'sendfile'
1474 * fashion.
1475 * Note:
1476 * - It is assumed that the socket was locked by the caller.
1477 * - The routine does not block.
1478 * - At present, there is no support for reading OOB data
1479 * or for 'peeking' the socket using this routine
1480 * (although both would be easy to implement).
1481 */
1482int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1483 sk_read_actor_t recv_actor)
1484{
1485 struct sk_buff *skb;
1486 struct tcp_sock *tp = tcp_sk(sk);
1487 u32 seq = tp->copied_seq;
1488 u32 offset;
1489 int copied = 0;
1490
1491 if (sk->sk_state == TCP_LISTEN)
1492 return -ENOTCONN;
1493 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1494 if (offset < skb->len) {
1495 int used;
1496 size_t len;
1497
1498 len = skb->len - offset;
1499 /* Stop reading if we hit a patch of urgent data */
1500 if (tp->urg_data) {
1501 u32 urg_offset = tp->urg_seq - seq;
1502 if (urg_offset < len)
1503 len = urg_offset;
1504 if (!len)
1505 break;
1506 }
1507 used = recv_actor(desc, skb, offset, len);
1508 if (used <= 0) {
1509 if (!copied)
1510 copied = used;
1511 break;
1512 } else if (used <= len) {
1513 seq += used;
1514 copied += used;
1515 offset += used;
1516 }
1517 /* If recv_actor drops the lock (e.g. TCP splice
1518 * receive) the skb pointer might be invalid when
1519 * getting here: tcp_collapse might have deleted it
1520 * while aggregating skbs from the socket queue.
1521 */
1522 skb = tcp_recv_skb(sk, seq - 1, &offset);
1523 if (!skb)
1524 break;
1525 /* TCP coalescing might have appended data to the skb.
1526 * Try to splice more frags
1527 */
1528 if (offset + 1 != skb->len)
1529 continue;
1530 }
1531 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
1532 sk_eat_skb(sk, skb);
1533 ++seq;
1534 break;
1535 }
1536 sk_eat_skb(sk, skb);
1537 if (!desc->count)
1538 break;
1539 tp->copied_seq = seq;
1540 }
1541 tp->copied_seq = seq;
1542
1543 tcp_rcv_space_adjust(sk);
1544
1545 /* Clean up data we have read: This will do ACK frames. */
1546 if (copied > 0) {
1547 tcp_recv_skb(sk, seq, &offset);
1548 tcp_cleanup_rbuf(sk, copied);
1549 }
1550 return copied;
1551}
1552EXPORT_SYMBOL(tcp_read_sock);
1553
1554/*
1555 * This routine copies from a sock struct into the user buffer.
1556 *
1557 * Technical note: in 2.3 we work on _locked_ socket, so that
1558 * tricks with *seq access order and skb->users are not required.
1559 * Probably, code can be easily improved even more.
1560 */
1561
1562int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
1563 int flags, int *addr_len)
1564{
1565 struct tcp_sock *tp = tcp_sk(sk);
1566 int copied = 0;
1567 u32 peek_seq;
1568 u32 *seq;
1569 unsigned long used;
1570 int err;
1571 int target; /* Read at least this many bytes */
1572 long timeo;
1573 struct task_struct *user_recv = NULL;
1574 struct sk_buff *skb, *last;
1575 u32 urg_hole = 0;
1576
1577 if (unlikely(flags & MSG_ERRQUEUE))
1578 return inet_recv_error(sk, msg, len, addr_len);
1579
1580 if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
1581 (sk->sk_state == TCP_ESTABLISHED))
1582 sk_busy_loop(sk, nonblock);
1583
1584 lock_sock(sk);
1585
1586 err = -ENOTCONN;
1587 if (sk->sk_state == TCP_LISTEN)
1588 goto out;
1589
1590 timeo = sock_rcvtimeo(sk, nonblock);
1591
1592 /* Urgent data needs to be handled specially. */
1593 if (flags & MSG_OOB)
1594 goto recv_urg;
1595
1596 if (unlikely(tp->repair)) {
1597 err = -EPERM;
1598 if (!(flags & MSG_PEEK))
1599 goto out;
1600
1601 if (tp->repair_queue == TCP_SEND_QUEUE)
1602 goto recv_sndq;
1603
1604 err = -EINVAL;
1605 if (tp->repair_queue == TCP_NO_QUEUE)
1606 goto out;
1607
1608 /* 'common' recv queue MSG_PEEK-ing */
1609 }
1610
1611 seq = &tp->copied_seq;
1612 if (flags & MSG_PEEK) {
1613 peek_seq = tp->copied_seq;
1614 seq = &peek_seq;
1615 }
1616
1617 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1618
1619 do {
1620 u32 offset;
1621
1622 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1623 if (tp->urg_data && tp->urg_seq == *seq) {
1624 if (copied)
1625 break;
1626 if (signal_pending(current)) {
1627 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1628 break;
1629 }
1630 }
1631
1632 /* Next get a buffer. */
1633
1634 last = skb_peek_tail(&sk->sk_receive_queue);
1635 skb_queue_walk(&sk->sk_receive_queue, skb) {
1636 last = skb;
1637 /* Now that we have two receive queues this
1638 * shouldn't happen.
1639 */
1640 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1641 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1642 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1643 flags))
1644 break;
1645
1646 offset = *seq - TCP_SKB_CB(skb)->seq;
1647 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
1648 pr_err_once("%s: found a SYN, please report !\n", __func__);
1649 offset--;
1650 }
1651 if (offset < skb->len)
1652 goto found_ok_skb;
1653 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
1654 goto found_fin_ok;
1655 WARN(!(flags & MSG_PEEK),
1656 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1657 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
1658 }
1659
1660 /* Well, if we have backlog, try to process it now yet. */
1661
1662 if (copied >= target && !sk->sk_backlog.tail)
1663 break;
1664
1665 if (copied) {
1666 if (sk->sk_err ||
1667 sk->sk_state == TCP_CLOSE ||
1668 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1669 !timeo ||
1670 signal_pending(current))
1671 break;
1672 } else {
1673 if (sock_flag(sk, SOCK_DONE))
1674 break;
1675
1676 if (sk->sk_err) {
1677 copied = sock_error(sk);
1678 break;
1679 }
1680
1681 if (sk->sk_shutdown & RCV_SHUTDOWN)
1682 break;
1683
1684 if (sk->sk_state == TCP_CLOSE) {
1685 if (!sock_flag(sk, SOCK_DONE)) {
1686 /* This occurs when user tries to read
1687 * from never connected socket.
1688 */
1689 copied = -ENOTCONN;
1690 break;
1691 }
1692 break;
1693 }
1694
1695 if (!timeo) {
1696 copied = -EAGAIN;
1697 break;
1698 }
1699
1700 if (signal_pending(current)) {
1701 copied = sock_intr_errno(timeo);
1702 break;
1703 }
1704 }
1705
1706 tcp_cleanup_rbuf(sk, copied);
1707
1708 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1709 /* Install new reader */
1710 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1711 user_recv = current;
1712 tp->ucopy.task = user_recv;
1713 tp->ucopy.msg = msg;
1714 }
1715
1716 tp->ucopy.len = len;
1717
1718 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1719 !(flags & (MSG_PEEK | MSG_TRUNC)));
1720
1721 /* Ugly... If prequeue is not empty, we have to
1722 * process it before releasing socket, otherwise
1723 * order will be broken at second iteration.
1724 * More elegant solution is required!!!
1725 *
1726 * Look: we have the following (pseudo)queues:
1727 *
1728 * 1. packets in flight
1729 * 2. backlog
1730 * 3. prequeue
1731 * 4. receive_queue
1732 *
1733 * Each queue can be processed only if the next ones
1734 * are empty. At this point we have empty receive_queue.
1735 * But prequeue _can_ be not empty after 2nd iteration,
1736 * when we jumped to start of loop because backlog
1737 * processing added something to receive_queue.
1738 * We cannot release_sock(), because backlog contains
1739 * packets arrived _after_ prequeued ones.
1740 *
1741 * Shortly, algorithm is clear --- to process all
1742 * the queues in order. We could make it more directly,
1743 * requeueing packets from backlog to prequeue, if
1744 * is not empty. It is more elegant, but eats cycles,
1745 * unfortunately.
1746 */
1747 if (!skb_queue_empty(&tp->ucopy.prequeue))
1748 goto do_prequeue;
1749
1750 /* __ Set realtime policy in scheduler __ */
1751 }
1752
1753 if (copied >= target) {
1754 /* Do not sleep, just process backlog. */
1755 release_sock(sk);
1756 lock_sock(sk);
1757 } else {
1758 sk_wait_data(sk, &timeo, last);
1759 }
1760
1761 if (user_recv) {
1762 int chunk;
1763
1764 /* __ Restore normal policy in scheduler __ */
1765
1766 chunk = len - tp->ucopy.len;
1767 if (chunk != 0) {
1768 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1769 len -= chunk;
1770 copied += chunk;
1771 }
1772
1773 if (tp->rcv_nxt == tp->copied_seq &&
1774 !skb_queue_empty(&tp->ucopy.prequeue)) {
1775do_prequeue:
1776 tcp_prequeue_process(sk);
1777
1778 chunk = len - tp->ucopy.len;
1779 if (chunk != 0) {
1780 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1781 len -= chunk;
1782 copied += chunk;
1783 }
1784 }
1785 }
1786 if ((flags & MSG_PEEK) &&
1787 (peek_seq - copied - urg_hole != tp->copied_seq)) {
1788 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1789 current->comm,
1790 task_pid_nr(current));
1791 peek_seq = tp->copied_seq;
1792 }
1793 continue;
1794
1795 found_ok_skb:
1796 /* Ok so how much can we use? */
1797 used = skb->len - offset;
1798 if (len < used)
1799 used = len;
1800
1801 /* Do we have urgent data here? */
1802 if (tp->urg_data) {
1803 u32 urg_offset = tp->urg_seq - *seq;
1804 if (urg_offset < used) {
1805 if (!urg_offset) {
1806 if (!sock_flag(sk, SOCK_URGINLINE)) {
1807 ++*seq;
1808 urg_hole++;
1809 offset++;
1810 used--;
1811 if (!used)
1812 goto skip_copy;
1813 }
1814 } else
1815 used = urg_offset;
1816 }
1817 }
1818
1819 if (!(flags & MSG_TRUNC)) {
1820 err = skb_copy_datagram_msg(skb, offset, msg, used);
1821 if (err) {
1822 /* Exception. Bailout! */
1823 if (!copied)
1824 copied = -EFAULT;
1825 break;
1826 }
1827 }
1828
1829 *seq += used;
1830 copied += used;
1831 len -= used;
1832
1833 tcp_rcv_space_adjust(sk);
1834
1835skip_copy:
1836 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1837 tp->urg_data = 0;
1838 tcp_fast_path_check(sk);
1839 }
1840 if (used + offset < skb->len)
1841 continue;
1842
1843 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
1844 goto found_fin_ok;
1845 if (!(flags & MSG_PEEK))
1846 sk_eat_skb(sk, skb);
1847 continue;
1848
1849 found_fin_ok:
1850 /* Process the FIN. */
1851 ++*seq;
1852 if (!(flags & MSG_PEEK))
1853 sk_eat_skb(sk, skb);
1854 break;
1855 } while (len > 0);
1856
1857 if (user_recv) {
1858 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1859 int chunk;
1860
1861 tp->ucopy.len = copied > 0 ? len : 0;
1862
1863 tcp_prequeue_process(sk);
1864
1865 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1866 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1867 len -= chunk;
1868 copied += chunk;
1869 }
1870 }
1871
1872 tp->ucopy.task = NULL;
1873 tp->ucopy.len = 0;
1874 }
1875
1876 /* According to UNIX98, msg_name/msg_namelen are ignored
1877 * on connected socket. I was just happy when found this 8) --ANK
1878 */
1879
1880 /* Clean up data we have read: This will do ACK frames. */
1881 tcp_cleanup_rbuf(sk, copied);
1882
1883 release_sock(sk);
1884 return copied;
1885
1886out:
1887 release_sock(sk);
1888 return err;
1889
1890recv_urg:
1891 err = tcp_recv_urg(sk, msg, len, flags);
1892 goto out;
1893
1894recv_sndq:
1895 err = tcp_peek_sndq(sk, msg, len);
1896 goto out;
1897}
1898EXPORT_SYMBOL(tcp_recvmsg);
1899
1900void tcp_set_state(struct sock *sk, int state)
1901{
1902 int oldstate = sk->sk_state;
1903
1904 switch (state) {
1905 case TCP_ESTABLISHED:
1906 if (oldstate != TCP_ESTABLISHED)
1907 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1908 break;
1909
1910 case TCP_CLOSE:
1911 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1912 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
1913
1914 sk->sk_prot->unhash(sk);
1915 if (inet_csk(sk)->icsk_bind_hash &&
1916 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1917 inet_put_port(sk);
1918 /* fall through */
1919 default:
1920 if (oldstate == TCP_ESTABLISHED)
1921 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1922 }
1923
1924 /* Change state AFTER socket is unhashed to avoid closed
1925 * socket sitting in hash tables.
1926 */
1927 sk_state_store(sk, state);
1928
1929#ifdef STATE_TRACE
1930 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
1931#endif
1932}
1933EXPORT_SYMBOL_GPL(tcp_set_state);
1934
1935/*
1936 * State processing on a close. This implements the state shift for
1937 * sending our FIN frame. Note that we only send a FIN for some
1938 * states. A shutdown() may have already sent the FIN, or we may be
1939 * closed.
1940 */
1941
1942static const unsigned char new_state[16] = {
1943 /* current state: new state: action: */
1944 [0 /* (Invalid) */] = TCP_CLOSE,
1945 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1946 [TCP_SYN_SENT] = TCP_CLOSE,
1947 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1948 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
1949 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
1950 [TCP_TIME_WAIT] = TCP_CLOSE,
1951 [TCP_CLOSE] = TCP_CLOSE,
1952 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
1953 [TCP_LAST_ACK] = TCP_LAST_ACK,
1954 [TCP_LISTEN] = TCP_CLOSE,
1955 [TCP_CLOSING] = TCP_CLOSING,
1956 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
1957};
1958
1959static int tcp_close_state(struct sock *sk)
1960{
1961 int next = (int)new_state[sk->sk_state];
1962 int ns = next & TCP_STATE_MASK;
1963
1964 tcp_set_state(sk, ns);
1965
1966 return next & TCP_ACTION_FIN;
1967}
1968
1969/*
1970 * Shutdown the sending side of a connection. Much like close except
1971 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1972 */
1973
1974void tcp_shutdown(struct sock *sk, int how)
1975{
1976 /* We need to grab some memory, and put together a FIN,
1977 * and then put it into the queue to be sent.
1978 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1979 */
1980 if (!(how & SEND_SHUTDOWN))
1981 return;
1982
1983 /* If we've already sent a FIN, or it's a closed state, skip this. */
1984 if ((1 << sk->sk_state) &
1985 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1986 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1987 /* Clear out any half completed packets. FIN if needed. */
1988 if (tcp_close_state(sk))
1989 tcp_send_fin(sk);
1990 }
1991}
1992EXPORT_SYMBOL(tcp_shutdown);
1993
1994bool tcp_check_oom(struct sock *sk, int shift)
1995{
1996 bool too_many_orphans, out_of_socket_memory;
1997
1998 too_many_orphans = tcp_too_many_orphans(sk, shift);
1999 out_of_socket_memory = tcp_out_of_memory(sk);
2000
2001 if (too_many_orphans)
2002 net_info_ratelimited("too many orphaned sockets\n");
2003 if (out_of_socket_memory)
2004 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2005 return too_many_orphans || out_of_socket_memory;
2006}
2007
2008void tcp_close(struct sock *sk, long timeout)
2009{
2010 struct sk_buff *skb;
2011 int data_was_unread = 0;
2012 int state;
2013
2014 lock_sock(sk);
2015 sk->sk_shutdown = SHUTDOWN_MASK;
2016
2017 if (sk->sk_state == TCP_LISTEN) {
2018 tcp_set_state(sk, TCP_CLOSE);
2019
2020 /* Special case. */
2021 inet_csk_listen_stop(sk);
2022
2023 goto adjudge_to_death;
2024 }
2025
2026 /* We need to flush the recv. buffs. We do this only on the
2027 * descriptor close, not protocol-sourced closes, because the
2028 * reader process may not have drained the data yet!
2029 */
2030 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
2031 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq;
2032
2033 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2034 len--;
2035 data_was_unread += len;
2036 __kfree_skb(skb);
2037 }
2038
2039 sk_mem_reclaim(sk);
2040
2041 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2042 if (sk->sk_state == TCP_CLOSE)
2043 goto adjudge_to_death;
2044
2045 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2046 * data was lost. To witness the awful effects of the old behavior of
2047 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2048 * GET in an FTP client, suspend the process, wait for the client to
2049 * advertise a zero window, then kill -9 the FTP client, wheee...
2050 * Note: timeout is always zero in such a case.
2051 */
2052 if (unlikely(tcp_sk(sk)->repair)) {
2053 sk->sk_prot->disconnect(sk, 0);
2054 } else if (data_was_unread) {
2055 /* Unread data was tossed, zap the connection. */
2056 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
2057 tcp_set_state(sk, TCP_CLOSE);
2058 tcp_send_active_reset(sk, sk->sk_allocation);
2059 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
2060 /* Check zero linger _after_ checking for unread data. */
2061 sk->sk_prot->disconnect(sk, 0);
2062 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
2063 } else if (tcp_close_state(sk)) {
2064 /* We FIN if the application ate all the data before
2065 * zapping the connection.
2066 */
2067
2068 /* RED-PEN. Formally speaking, we have broken TCP state
2069 * machine. State transitions:
2070 *
2071 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2072 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2073 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2074 *
2075 * are legal only when FIN has been sent (i.e. in window),
2076 * rather than queued out of window. Purists blame.
2077 *
2078 * F.e. "RFC state" is ESTABLISHED,
2079 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2080 *
2081 * The visible declinations are that sometimes
2082 * we enter time-wait state, when it is not required really
2083 * (harmless), do not send active resets, when they are
2084 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2085 * they look as CLOSING or LAST_ACK for Linux)
2086 * Probably, I missed some more holelets.
2087 * --ANK
2088 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2089 * in a single packet! (May consider it later but will
2090 * probably need API support or TCP_CORK SYN-ACK until
2091 * data is written and socket is closed.)
2092 */
2093 tcp_send_fin(sk);
2094 }
2095
2096 sk_stream_wait_close(sk, timeout);
2097
2098adjudge_to_death:
2099 state = sk->sk_state;
2100 sock_hold(sk);
2101 sock_orphan(sk);
2102
2103 /* It is the last release_sock in its life. It will remove backlog. */
2104 release_sock(sk);
2105
2106
2107 /* Now socket is owned by kernel and we acquire BH lock
2108 to finish close. No need to check for user refs.
2109 */
2110 local_bh_disable();
2111 bh_lock_sock(sk);
2112 WARN_ON(sock_owned_by_user(sk));
2113
2114 percpu_counter_inc(sk->sk_prot->orphan_count);
2115
2116 /* Have we already been destroyed by a softirq or backlog? */
2117 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
2118 goto out;
2119
2120 /* This is a (useful) BSD violating of the RFC. There is a
2121 * problem with TCP as specified in that the other end could
2122 * keep a socket open forever with no application left this end.
2123 * We use a 1 minute timeout (about the same as BSD) then kill
2124 * our end. If they send after that then tough - BUT: long enough
2125 * that we won't make the old 4*rto = almost no time - whoops
2126 * reset mistake.
2127 *
2128 * Nope, it was not mistake. It is really desired behaviour
2129 * f.e. on http servers, when such sockets are useless, but
2130 * consume significant resources. Let's do it with special
2131 * linger2 option. --ANK
2132 */
2133
2134 if (sk->sk_state == TCP_FIN_WAIT2) {
2135 struct tcp_sock *tp = tcp_sk(sk);
2136 if (tp->linger2 < 0) {
2137 tcp_set_state(sk, TCP_CLOSE);
2138 tcp_send_active_reset(sk, GFP_ATOMIC);
2139 NET_INC_STATS_BH(sock_net(sk),
2140 LINUX_MIB_TCPABORTONLINGER);
2141 } else {
2142 const int tmo = tcp_fin_time(sk);
2143
2144 if (tmo > TCP_TIMEWAIT_LEN) {
2145 inet_csk_reset_keepalive_timer(sk,
2146 tmo - TCP_TIMEWAIT_LEN);
2147 } else {
2148 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2149 goto out;
2150 }
2151 }
2152 }
2153 if (sk->sk_state != TCP_CLOSE) {
2154 sk_mem_reclaim(sk);
2155 if (tcp_check_oom(sk, 0)) {
2156 tcp_set_state(sk, TCP_CLOSE);
2157 tcp_send_active_reset(sk, GFP_ATOMIC);
2158 NET_INC_STATS_BH(sock_net(sk),
2159 LINUX_MIB_TCPABORTONMEMORY);
2160 }
2161 }
2162
2163 if (sk->sk_state == TCP_CLOSE) {
2164 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
2165 /* We could get here with a non-NULL req if the socket is
2166 * aborted (e.g., closed with unread data) before 3WHS
2167 * finishes.
2168 */
2169 if (req)
2170 reqsk_fastopen_remove(sk, req, false);
2171 inet_csk_destroy_sock(sk);
2172 }
2173 /* Otherwise, socket is reprieved until protocol close. */
2174
2175out:
2176 bh_unlock_sock(sk);
2177 local_bh_enable();
2178 sock_put(sk);
2179}
2180EXPORT_SYMBOL(tcp_close);
2181
2182/* These states need RST on ABORT according to RFC793 */
2183
2184static inline bool tcp_need_reset(int state)
2185{
2186 return (1 << state) &
2187 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2188 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2189}
2190
2191int tcp_disconnect(struct sock *sk, int flags)
2192{
2193 struct inet_sock *inet = inet_sk(sk);
2194 struct inet_connection_sock *icsk = inet_csk(sk);
2195 struct tcp_sock *tp = tcp_sk(sk);
2196 int err = 0;
2197 int old_state = sk->sk_state;
2198
2199 if (old_state != TCP_CLOSE)
2200 tcp_set_state(sk, TCP_CLOSE);
2201
2202 /* ABORT function of RFC793 */
2203 if (old_state == TCP_LISTEN) {
2204 inet_csk_listen_stop(sk);
2205 } else if (unlikely(tp->repair)) {
2206 sk->sk_err = ECONNABORTED;
2207 } else if (tcp_need_reset(old_state) ||
2208 (tp->snd_nxt != tp->write_seq &&
2209 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2210 /* The last check adjusts for discrepancy of Linux wrt. RFC
2211 * states
2212 */
2213 tcp_send_active_reset(sk, gfp_any());
2214 sk->sk_err = ECONNRESET;
2215 } else if (old_state == TCP_SYN_SENT)
2216 sk->sk_err = ECONNRESET;
2217
2218 tcp_clear_xmit_timers(sk);
2219 __skb_queue_purge(&sk->sk_receive_queue);
2220 tcp_write_queue_purge(sk);
2221 __skb_queue_purge(&tp->out_of_order_queue);
2222
2223 inet->inet_dport = 0;
2224
2225 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2226 inet_reset_saddr(sk);
2227
2228 sk->sk_shutdown = 0;
2229 sock_reset_flag(sk, SOCK_DONE);
2230 tp->srtt_us = 0;
2231 tp->write_seq += tp->max_window + 2;
2232 if (tp->write_seq == 0)
2233 tp->write_seq = 1;
2234 icsk->icsk_backoff = 0;
2235 tp->snd_cwnd = 2;
2236 icsk->icsk_probes_out = 0;
2237 tp->packets_out = 0;
2238 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2239 tp->snd_cwnd_cnt = 0;
2240 tp->window_clamp = 0;
2241 tcp_set_ca_state(sk, TCP_CA_Open);
2242 tcp_clear_retrans(tp);
2243 inet_csk_delack_init(sk);
2244 tcp_init_send_head(sk);
2245 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2246 __sk_dst_reset(sk);
2247
2248 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2249
2250 sk->sk_error_report(sk);
2251 return err;
2252}
2253EXPORT_SYMBOL(tcp_disconnect);
2254
2255static inline bool tcp_can_repair_sock(const struct sock *sk)
2256{
2257 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2258 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED));
2259}
2260
2261static int tcp_repair_options_est(struct tcp_sock *tp,
2262 struct tcp_repair_opt __user *optbuf, unsigned int len)
2263{
2264 struct tcp_repair_opt opt;
2265
2266 while (len >= sizeof(opt)) {
2267 if (copy_from_user(&opt, optbuf, sizeof(opt)))
2268 return -EFAULT;
2269
2270 optbuf++;
2271 len -= sizeof(opt);
2272
2273 switch (opt.opt_code) {
2274 case TCPOPT_MSS:
2275 tp->rx_opt.mss_clamp = opt.opt_val;
2276 break;
2277 case TCPOPT_WINDOW:
2278 {
2279 u16 snd_wscale = opt.opt_val & 0xFFFF;
2280 u16 rcv_wscale = opt.opt_val >> 16;
2281
2282 if (snd_wscale > 14 || rcv_wscale > 14)
2283 return -EFBIG;
2284
2285 tp->rx_opt.snd_wscale = snd_wscale;
2286 tp->rx_opt.rcv_wscale = rcv_wscale;
2287 tp->rx_opt.wscale_ok = 1;
2288 }
2289 break;
2290 case TCPOPT_SACK_PERM:
2291 if (opt.opt_val != 0)
2292 return -EINVAL;
2293
2294 tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
2295 if (sysctl_tcp_fack)
2296 tcp_enable_fack(tp);
2297 break;
2298 case TCPOPT_TIMESTAMP:
2299 if (opt.opt_val != 0)
2300 return -EINVAL;
2301
2302 tp->rx_opt.tstamp_ok = 1;
2303 break;
2304 }
2305 }
2306
2307 return 0;
2308}
2309
2310/*
2311 * Socket option code for TCP.
2312 */
2313static int do_tcp_setsockopt(struct sock *sk, int level,
2314 int optname, char __user *optval, unsigned int optlen)
2315{
2316 struct tcp_sock *tp = tcp_sk(sk);
2317 struct inet_connection_sock *icsk = inet_csk(sk);
2318 struct net *net = sock_net(sk);
2319 int val;
2320 int err = 0;
2321
2322 /* These are data/string values, all the others are ints */
2323 switch (optname) {
2324 case TCP_CONGESTION: {
2325 char name[TCP_CA_NAME_MAX];
2326
2327 if (optlen < 1)
2328 return -EINVAL;
2329
2330 val = strncpy_from_user(name, optval,
2331 min_t(long, TCP_CA_NAME_MAX-1, optlen));
2332 if (val < 0)
2333 return -EFAULT;
2334 name[val] = 0;
2335
2336 lock_sock(sk);
2337 err = tcp_set_congestion_control(sk, name);
2338 release_sock(sk);
2339 return err;
2340 }
2341 default:
2342 /* fallthru */
2343 break;
2344 }
2345
2346 if (optlen < sizeof(int))
2347 return -EINVAL;
2348
2349 if (get_user(val, (int __user *)optval))
2350 return -EFAULT;
2351
2352 lock_sock(sk);
2353
2354 switch (optname) {
2355 case TCP_MAXSEG:
2356 /* Values greater than interface MTU won't take effect. However
2357 * at the point when this call is done we typically don't yet
2358 * know which interface is going to be used */
2359 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
2360 err = -EINVAL;
2361 break;
2362 }
2363 tp->rx_opt.user_mss = val;
2364 break;
2365
2366 case TCP_NODELAY:
2367 if (val) {
2368 /* TCP_NODELAY is weaker than TCP_CORK, so that
2369 * this option on corked socket is remembered, but
2370 * it is not activated until cork is cleared.
2371 *
2372 * However, when TCP_NODELAY is set we make
2373 * an explicit push, which overrides even TCP_CORK
2374 * for currently queued segments.
2375 */
2376 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2377 tcp_push_pending_frames(sk);
2378 } else {
2379 tp->nonagle &= ~TCP_NAGLE_OFF;
2380 }
2381 break;
2382
2383 case TCP_THIN_LINEAR_TIMEOUTS:
2384 if (val < 0 || val > 1)
2385 err = -EINVAL;
2386 else
2387 tp->thin_lto = val;
2388 break;
2389
2390 case TCP_THIN_DUPACK:
2391 if (val < 0 || val > 1)
2392 err = -EINVAL;
2393 else {
2394 tp->thin_dupack = val;
2395 if (tp->thin_dupack)
2396 tcp_disable_early_retrans(tp);
2397 }
2398 break;
2399
2400 case TCP_REPAIR:
2401 if (!tcp_can_repair_sock(sk))
2402 err = -EPERM;
2403 else if (val == 1) {
2404 tp->repair = 1;
2405 sk->sk_reuse = SK_FORCE_REUSE;
2406 tp->repair_queue = TCP_NO_QUEUE;
2407 } else if (val == 0) {
2408 tp->repair = 0;
2409 sk->sk_reuse = SK_NO_REUSE;
2410 tcp_send_window_probe(sk);
2411 } else
2412 err = -EINVAL;
2413
2414 break;
2415
2416 case TCP_REPAIR_QUEUE:
2417 if (!tp->repair)
2418 err = -EPERM;
2419 else if (val < TCP_QUEUES_NR)
2420 tp->repair_queue = val;
2421 else
2422 err = -EINVAL;
2423 break;
2424
2425 case TCP_QUEUE_SEQ:
2426 if (sk->sk_state != TCP_CLOSE)
2427 err = -EPERM;
2428 else if (tp->repair_queue == TCP_SEND_QUEUE)
2429 tp->write_seq = val;
2430 else if (tp->repair_queue == TCP_RECV_QUEUE)
2431 tp->rcv_nxt = val;
2432 else
2433 err = -EINVAL;
2434 break;
2435
2436 case TCP_REPAIR_OPTIONS:
2437 if (!tp->repair)
2438 err = -EINVAL;
2439 else if (sk->sk_state == TCP_ESTABLISHED)
2440 err = tcp_repair_options_est(tp,
2441 (struct tcp_repair_opt __user *)optval,
2442 optlen);
2443 else
2444 err = -EPERM;
2445 break;
2446
2447 case TCP_CORK:
2448 /* When set indicates to always queue non-full frames.
2449 * Later the user clears this option and we transmit
2450 * any pending partial frames in the queue. This is
2451 * meant to be used alongside sendfile() to get properly
2452 * filled frames when the user (for example) must write
2453 * out headers with a write() call first and then use
2454 * sendfile to send out the data parts.
2455 *
2456 * TCP_CORK can be set together with TCP_NODELAY and it is
2457 * stronger than TCP_NODELAY.
2458 */
2459 if (val) {
2460 tp->nonagle |= TCP_NAGLE_CORK;
2461 } else {
2462 tp->nonagle &= ~TCP_NAGLE_CORK;
2463 if (tp->nonagle&TCP_NAGLE_OFF)
2464 tp->nonagle |= TCP_NAGLE_PUSH;
2465 tcp_push_pending_frames(sk);
2466 }
2467 break;
2468
2469 case TCP_KEEPIDLE:
2470 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2471 err = -EINVAL;
2472 else {
2473 tp->keepalive_time = val * HZ;
2474 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2475 !((1 << sk->sk_state) &
2476 (TCPF_CLOSE | TCPF_LISTEN))) {
2477 u32 elapsed = keepalive_time_elapsed(tp);
2478 if (tp->keepalive_time > elapsed)
2479 elapsed = tp->keepalive_time - elapsed;
2480 else
2481 elapsed = 0;
2482 inet_csk_reset_keepalive_timer(sk, elapsed);
2483 }
2484 }
2485 break;
2486 case TCP_KEEPINTVL:
2487 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2488 err = -EINVAL;
2489 else
2490 tp->keepalive_intvl = val * HZ;
2491 break;
2492 case TCP_KEEPCNT:
2493 if (val < 1 || val > MAX_TCP_KEEPCNT)
2494 err = -EINVAL;
2495 else
2496 tp->keepalive_probes = val;
2497 break;
2498 case TCP_SYNCNT:
2499 if (val < 1 || val > MAX_TCP_SYNCNT)
2500 err = -EINVAL;
2501 else
2502 icsk->icsk_syn_retries = val;
2503 break;
2504
2505 case TCP_SAVE_SYN:
2506 if (val < 0 || val > 1)
2507 err = -EINVAL;
2508 else
2509 tp->save_syn = val;
2510 break;
2511
2512 case TCP_LINGER2:
2513 if (val < 0)
2514 tp->linger2 = -1;
2515 else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
2516 tp->linger2 = 0;
2517 else
2518 tp->linger2 = val * HZ;
2519 break;
2520
2521 case TCP_DEFER_ACCEPT:
2522 /* Translate value in seconds to number of retransmits */
2523 icsk->icsk_accept_queue.rskq_defer_accept =
2524 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2525 TCP_RTO_MAX / HZ);
2526 break;
2527
2528 case TCP_WINDOW_CLAMP:
2529 if (!val) {
2530 if (sk->sk_state != TCP_CLOSE) {
2531 err = -EINVAL;
2532 break;
2533 }
2534 tp->window_clamp = 0;
2535 } else
2536 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2537 SOCK_MIN_RCVBUF / 2 : val;
2538 break;
2539
2540 case TCP_QUICKACK:
2541 if (!val) {
2542 icsk->icsk_ack.pingpong = 1;
2543 } else {
2544 icsk->icsk_ack.pingpong = 0;
2545 if ((1 << sk->sk_state) &
2546 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2547 inet_csk_ack_scheduled(sk)) {
2548 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2549 tcp_cleanup_rbuf(sk, 1);
2550 if (!(val & 1))
2551 icsk->icsk_ack.pingpong = 1;
2552 }
2553 }
2554 break;
2555
2556#ifdef CONFIG_TCP_MD5SIG
2557 case TCP_MD5SIG:
2558 /* Read the IP->Key mappings from userspace */
2559 err = tp->af_specific->md5_parse(sk, optval, optlen);
2560 break;
2561#endif
2562 case TCP_USER_TIMEOUT:
2563 /* Cap the max time in ms TCP will retry or probe the window
2564 * before giving up and aborting (ETIMEDOUT) a connection.
2565 */
2566 if (val < 0)
2567 err = -EINVAL;
2568 else
2569 icsk->icsk_user_timeout = msecs_to_jiffies(val);
2570 break;
2571
2572 case TCP_FASTOPEN:
2573 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2574 TCPF_LISTEN))) {
2575 tcp_fastopen_init_key_once(true);
2576
2577 fastopen_queue_tune(sk, val);
2578 } else {
2579 err = -EINVAL;
2580 }
2581 break;
2582 case TCP_TIMESTAMP:
2583 if (!tp->repair)
2584 err = -EPERM;
2585 else
2586 tp->tsoffset = val - tcp_time_stamp;
2587 break;
2588 case TCP_NOTSENT_LOWAT:
2589 tp->notsent_lowat = val;
2590 sk->sk_write_space(sk);
2591 break;
2592 default:
2593 err = -ENOPROTOOPT;
2594 break;
2595 }
2596
2597 release_sock(sk);
2598 return err;
2599}
2600
2601int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2602 unsigned int optlen)
2603{
2604 const struct inet_connection_sock *icsk = inet_csk(sk);
2605
2606 if (level != SOL_TCP)
2607 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2608 optval, optlen);
2609 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2610}
2611EXPORT_SYMBOL(tcp_setsockopt);
2612
2613#ifdef CONFIG_COMPAT
2614int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2615 char __user *optval, unsigned int optlen)
2616{
2617 if (level != SOL_TCP)
2618 return inet_csk_compat_setsockopt(sk, level, optname,
2619 optval, optlen);
2620 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2621}
2622EXPORT_SYMBOL(compat_tcp_setsockopt);
2623#endif
2624
2625/* Return information about state of tcp endpoint in API format. */
2626void tcp_get_info(struct sock *sk, struct tcp_info *info)
2627{
2628 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2629 const struct inet_connection_sock *icsk = inet_csk(sk);
2630 u32 now = tcp_time_stamp;
2631 unsigned int start;
2632 int notsent_bytes;
2633 u64 rate64;
2634 u32 rate;
2635
2636 memset(info, 0, sizeof(*info));
2637 if (sk->sk_type != SOCK_STREAM)
2638 return;
2639
2640 info->tcpi_state = sk_state_load(sk);
2641
2642 info->tcpi_ca_state = icsk->icsk_ca_state;
2643 info->tcpi_retransmits = icsk->icsk_retransmits;
2644 info->tcpi_probes = icsk->icsk_probes_out;
2645 info->tcpi_backoff = icsk->icsk_backoff;
2646
2647 if (tp->rx_opt.tstamp_ok)
2648 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2649 if (tcp_is_sack(tp))
2650 info->tcpi_options |= TCPI_OPT_SACK;
2651 if (tp->rx_opt.wscale_ok) {
2652 info->tcpi_options |= TCPI_OPT_WSCALE;
2653 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2654 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2655 }
2656
2657 if (tp->ecn_flags & TCP_ECN_OK)
2658 info->tcpi_options |= TCPI_OPT_ECN;
2659 if (tp->ecn_flags & TCP_ECN_SEEN)
2660 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
2661 if (tp->syn_data_acked)
2662 info->tcpi_options |= TCPI_OPT_SYN_DATA;
2663
2664 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2665 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2666 info->tcpi_snd_mss = tp->mss_cache;
2667 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2668
2669 if (info->tcpi_state == TCP_LISTEN) {
2670 info->tcpi_unacked = sk->sk_ack_backlog;
2671 info->tcpi_sacked = sk->sk_max_ack_backlog;
2672 } else {
2673 info->tcpi_unacked = tp->packets_out;
2674 info->tcpi_sacked = tp->sacked_out;
2675 }
2676 info->tcpi_lost = tp->lost_out;
2677 info->tcpi_retrans = tp->retrans_out;
2678 info->tcpi_fackets = tp->fackets_out;
2679
2680 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2681 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2682 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2683
2684 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2685 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2686 info->tcpi_rtt = tp->srtt_us >> 3;
2687 info->tcpi_rttvar = tp->mdev_us >> 2;
2688 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2689 info->tcpi_snd_cwnd = tp->snd_cwnd;
2690 info->tcpi_advmss = tp->advmss;
2691 info->tcpi_reordering = tp->reordering;
2692
2693 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2694 info->tcpi_rcv_space = tp->rcvq_space.space;
2695
2696 info->tcpi_total_retrans = tp->total_retrans;
2697
2698 rate = READ_ONCE(sk->sk_pacing_rate);
2699 rate64 = rate != ~0U ? rate : ~0ULL;
2700 put_unaligned(rate64, &info->tcpi_pacing_rate);
2701
2702 rate = READ_ONCE(sk->sk_max_pacing_rate);
2703 rate64 = rate != ~0U ? rate : ~0ULL;
2704 put_unaligned(rate64, &info->tcpi_max_pacing_rate);
2705
2706 do {
2707 start = u64_stats_fetch_begin_irq(&tp->syncp);
2708 put_unaligned(tp->bytes_acked, &info->tcpi_bytes_acked);
2709 put_unaligned(tp->bytes_received, &info->tcpi_bytes_received);
2710 } while (u64_stats_fetch_retry_irq(&tp->syncp, start));
2711 info->tcpi_segs_out = tp->segs_out;
2712 info->tcpi_segs_in = tp->segs_in;
2713
2714 notsent_bytes = READ_ONCE(tp->write_seq) - READ_ONCE(tp->snd_nxt);
2715 info->tcpi_notsent_bytes = max(0, notsent_bytes);
2716
2717 info->tcpi_min_rtt = tcp_min_rtt(tp);
2718 info->tcpi_data_segs_in = tp->data_segs_in;
2719 info->tcpi_data_segs_out = tp->data_segs_out;
2720}
2721EXPORT_SYMBOL_GPL(tcp_get_info);
2722
2723static int do_tcp_getsockopt(struct sock *sk, int level,
2724 int optname, char __user *optval, int __user *optlen)
2725{
2726 struct inet_connection_sock *icsk = inet_csk(sk);
2727 struct tcp_sock *tp = tcp_sk(sk);
2728 struct net *net = sock_net(sk);
2729 int val, len;
2730
2731 if (get_user(len, optlen))
2732 return -EFAULT;
2733
2734 len = min_t(unsigned int, len, sizeof(int));
2735
2736 if (len < 0)
2737 return -EINVAL;
2738
2739 switch (optname) {
2740 case TCP_MAXSEG:
2741 val = tp->mss_cache;
2742 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2743 val = tp->rx_opt.user_mss;
2744 if (tp->repair)
2745 val = tp->rx_opt.mss_clamp;
2746 break;
2747 case TCP_NODELAY:
2748 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2749 break;
2750 case TCP_CORK:
2751 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2752 break;
2753 case TCP_KEEPIDLE:
2754 val = keepalive_time_when(tp) / HZ;
2755 break;
2756 case TCP_KEEPINTVL:
2757 val = keepalive_intvl_when(tp) / HZ;
2758 break;
2759 case TCP_KEEPCNT:
2760 val = keepalive_probes(tp);
2761 break;
2762 case TCP_SYNCNT:
2763 val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
2764 break;
2765 case TCP_LINGER2:
2766 val = tp->linger2;
2767 if (val >= 0)
2768 val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
2769 break;
2770 case TCP_DEFER_ACCEPT:
2771 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2772 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
2773 break;
2774 case TCP_WINDOW_CLAMP:
2775 val = tp->window_clamp;
2776 break;
2777 case TCP_INFO: {
2778 struct tcp_info info;
2779
2780 if (get_user(len, optlen))
2781 return -EFAULT;
2782
2783 tcp_get_info(sk, &info);
2784
2785 len = min_t(unsigned int, len, sizeof(info));
2786 if (put_user(len, optlen))
2787 return -EFAULT;
2788 if (copy_to_user(optval, &info, len))
2789 return -EFAULT;
2790 return 0;
2791 }
2792 case TCP_CC_INFO: {
2793 const struct tcp_congestion_ops *ca_ops;
2794 union tcp_cc_info info;
2795 size_t sz = 0;
2796 int attr;
2797
2798 if (get_user(len, optlen))
2799 return -EFAULT;
2800
2801 ca_ops = icsk->icsk_ca_ops;
2802 if (ca_ops && ca_ops->get_info)
2803 sz = ca_ops->get_info(sk, ~0U, &attr, &info);
2804
2805 len = min_t(unsigned int, len, sz);
2806 if (put_user(len, optlen))
2807 return -EFAULT;
2808 if (copy_to_user(optval, &info, len))
2809 return -EFAULT;
2810 return 0;
2811 }
2812 case TCP_QUICKACK:
2813 val = !icsk->icsk_ack.pingpong;
2814 break;
2815
2816 case TCP_CONGESTION:
2817 if (get_user(len, optlen))
2818 return -EFAULT;
2819 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2820 if (put_user(len, optlen))
2821 return -EFAULT;
2822 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2823 return -EFAULT;
2824 return 0;
2825
2826 case TCP_THIN_LINEAR_TIMEOUTS:
2827 val = tp->thin_lto;
2828 break;
2829 case TCP_THIN_DUPACK:
2830 val = tp->thin_dupack;
2831 break;
2832
2833 case TCP_REPAIR:
2834 val = tp->repair;
2835 break;
2836
2837 case TCP_REPAIR_QUEUE:
2838 if (tp->repair)
2839 val = tp->repair_queue;
2840 else
2841 return -EINVAL;
2842 break;
2843
2844 case TCP_QUEUE_SEQ:
2845 if (tp->repair_queue == TCP_SEND_QUEUE)
2846 val = tp->write_seq;
2847 else if (tp->repair_queue == TCP_RECV_QUEUE)
2848 val = tp->rcv_nxt;
2849 else
2850 return -EINVAL;
2851 break;
2852
2853 case TCP_USER_TIMEOUT:
2854 val = jiffies_to_msecs(icsk->icsk_user_timeout);
2855 break;
2856
2857 case TCP_FASTOPEN:
2858 val = icsk->icsk_accept_queue.fastopenq.max_qlen;
2859 break;
2860
2861 case TCP_TIMESTAMP:
2862 val = tcp_time_stamp + tp->tsoffset;
2863 break;
2864 case TCP_NOTSENT_LOWAT:
2865 val = tp->notsent_lowat;
2866 break;
2867 case TCP_SAVE_SYN:
2868 val = tp->save_syn;
2869 break;
2870 case TCP_SAVED_SYN: {
2871 if (get_user(len, optlen))
2872 return -EFAULT;
2873
2874 lock_sock(sk);
2875 if (tp->saved_syn) {
2876 if (len < tp->saved_syn[0]) {
2877 if (put_user(tp->saved_syn[0], optlen)) {
2878 release_sock(sk);
2879 return -EFAULT;
2880 }
2881 release_sock(sk);
2882 return -EINVAL;
2883 }
2884 len = tp->saved_syn[0];
2885 if (put_user(len, optlen)) {
2886 release_sock(sk);
2887 return -EFAULT;
2888 }
2889 if (copy_to_user(optval, tp->saved_syn + 1, len)) {
2890 release_sock(sk);
2891 return -EFAULT;
2892 }
2893 tcp_saved_syn_free(tp);
2894 release_sock(sk);
2895 } else {
2896 release_sock(sk);
2897 len = 0;
2898 if (put_user(len, optlen))
2899 return -EFAULT;
2900 }
2901 return 0;
2902 }
2903 default:
2904 return -ENOPROTOOPT;
2905 }
2906
2907 if (put_user(len, optlen))
2908 return -EFAULT;
2909 if (copy_to_user(optval, &val, len))
2910 return -EFAULT;
2911 return 0;
2912}
2913
2914int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2915 int __user *optlen)
2916{
2917 struct inet_connection_sock *icsk = inet_csk(sk);
2918
2919 if (level != SOL_TCP)
2920 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2921 optval, optlen);
2922 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2923}
2924EXPORT_SYMBOL(tcp_getsockopt);
2925
2926#ifdef CONFIG_COMPAT
2927int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2928 char __user *optval, int __user *optlen)
2929{
2930 if (level != SOL_TCP)
2931 return inet_csk_compat_getsockopt(sk, level, optname,
2932 optval, optlen);
2933 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2934}
2935EXPORT_SYMBOL(compat_tcp_getsockopt);
2936#endif
2937
2938#ifdef CONFIG_TCP_MD5SIG
2939static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
2940static DEFINE_MUTEX(tcp_md5sig_mutex);
2941static bool tcp_md5sig_pool_populated = false;
2942
2943static void __tcp_alloc_md5sig_pool(void)
2944{
2945 struct crypto_ahash *hash;
2946 int cpu;
2947
2948 hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
2949 if (IS_ERR(hash))
2950 return;
2951
2952 for_each_possible_cpu(cpu) {
2953 struct ahash_request *req;
2954
2955 if (per_cpu(tcp_md5sig_pool, cpu).md5_req)
2956 continue;
2957
2958 req = ahash_request_alloc(hash, GFP_KERNEL);
2959 if (!req)
2960 return;
2961
2962 ahash_request_set_callback(req, 0, NULL, NULL);
2963
2964 per_cpu(tcp_md5sig_pool, cpu).md5_req = req;
2965 }
2966 /* before setting tcp_md5sig_pool_populated, we must commit all writes
2967 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
2968 */
2969 smp_wmb();
2970 tcp_md5sig_pool_populated = true;
2971}
2972
2973bool tcp_alloc_md5sig_pool(void)
2974{
2975 if (unlikely(!tcp_md5sig_pool_populated)) {
2976 mutex_lock(&tcp_md5sig_mutex);
2977
2978 if (!tcp_md5sig_pool_populated)
2979 __tcp_alloc_md5sig_pool();
2980
2981 mutex_unlock(&tcp_md5sig_mutex);
2982 }
2983 return tcp_md5sig_pool_populated;
2984}
2985EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2986
2987
2988/**
2989 * tcp_get_md5sig_pool - get md5sig_pool for this user
2990 *
2991 * We use percpu structure, so if we succeed, we exit with preemption
2992 * and BH disabled, to make sure another thread or softirq handling
2993 * wont try to get same context.
2994 */
2995struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
2996{
2997 local_bh_disable();
2998
2999 if (tcp_md5sig_pool_populated) {
3000 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
3001 smp_rmb();
3002 return this_cpu_ptr(&tcp_md5sig_pool);
3003 }
3004 local_bh_enable();
3005 return NULL;
3006}
3007EXPORT_SYMBOL(tcp_get_md5sig_pool);
3008
3009int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
3010 const struct tcphdr *th)
3011{
3012 struct scatterlist sg;
3013 struct tcphdr hdr;
3014
3015 /* We are not allowed to change tcphdr, make a local copy */
3016 memcpy(&hdr, th, sizeof(hdr));
3017 hdr.check = 0;
3018
3019 /* options aren't included in the hash */
3020 sg_init_one(&sg, &hdr, sizeof(hdr));
3021 ahash_request_set_crypt(hp->md5_req, &sg, NULL, sizeof(hdr));
3022 return crypto_ahash_update(hp->md5_req);
3023}
3024EXPORT_SYMBOL(tcp_md5_hash_header);
3025
3026int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3027 const struct sk_buff *skb, unsigned int header_len)
3028{
3029 struct scatterlist sg;
3030 const struct tcphdr *tp = tcp_hdr(skb);
3031 struct ahash_request *req = hp->md5_req;
3032 unsigned int i;
3033 const unsigned int head_data_len = skb_headlen(skb) > header_len ?
3034 skb_headlen(skb) - header_len : 0;
3035 const struct skb_shared_info *shi = skb_shinfo(skb);
3036 struct sk_buff *frag_iter;
3037
3038 sg_init_table(&sg, 1);
3039
3040 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3041 ahash_request_set_crypt(req, &sg, NULL, head_data_len);
3042 if (crypto_ahash_update(req))
3043 return 1;
3044
3045 for (i = 0; i < shi->nr_frags; ++i) {
3046 const struct skb_frag_struct *f = &shi->frags[i];
3047 unsigned int offset = f->page_offset;
3048 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
3049
3050 sg_set_page(&sg, page, skb_frag_size(f),
3051 offset_in_page(offset));
3052 ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
3053 if (crypto_ahash_update(req))
3054 return 1;
3055 }
3056
3057 skb_walk_frags(skb, frag_iter)
3058 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3059 return 1;
3060
3061 return 0;
3062}
3063EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3064
3065int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3066{
3067 struct scatterlist sg;
3068
3069 sg_init_one(&sg, key->key, key->keylen);
3070 ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
3071 return crypto_ahash_update(hp->md5_req);
3072}
3073EXPORT_SYMBOL(tcp_md5_hash_key);
3074
3075#endif
3076
3077void tcp_done(struct sock *sk)
3078{
3079 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
3080
3081 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3082 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
3083
3084 tcp_set_state(sk, TCP_CLOSE);
3085 tcp_clear_xmit_timers(sk);
3086 if (req)
3087 reqsk_fastopen_remove(sk, req, false);
3088
3089 sk->sk_shutdown = SHUTDOWN_MASK;
3090
3091 if (!sock_flag(sk, SOCK_DEAD))
3092 sk->sk_state_change(sk);
3093 else
3094 inet_csk_destroy_sock(sk);
3095}
3096EXPORT_SYMBOL_GPL(tcp_done);
3097
3098int tcp_abort(struct sock *sk, int err)
3099{
3100 if (!sk_fullsock(sk)) {
3101 if (sk->sk_state == TCP_NEW_SYN_RECV) {
3102 struct request_sock *req = inet_reqsk(sk);
3103
3104 local_bh_disable();
3105 inet_csk_reqsk_queue_drop_and_put(req->rsk_listener,
3106 req);
3107 local_bh_enable();
3108 return 0;
3109 }
3110 sock_gen_put(sk);
3111 return -EOPNOTSUPP;
3112 }
3113
3114 /* Don't race with userspace socket closes such as tcp_close. */
3115 lock_sock(sk);
3116
3117 if (sk->sk_state == TCP_LISTEN) {
3118 tcp_set_state(sk, TCP_CLOSE);
3119 inet_csk_listen_stop(sk);
3120 }
3121
3122 /* Don't race with BH socket closes such as inet_csk_listen_stop. */
3123 local_bh_disable();
3124 bh_lock_sock(sk);
3125
3126 if (!sock_flag(sk, SOCK_DEAD)) {
3127 sk->sk_err = err;
3128 /* This barrier is coupled with smp_rmb() in tcp_poll() */
3129 smp_wmb();
3130 sk->sk_error_report(sk);
3131 if (tcp_need_reset(sk->sk_state))
3132 tcp_send_active_reset(sk, GFP_ATOMIC);
3133 tcp_done(sk);
3134 }
3135
3136 bh_unlock_sock(sk);
3137 local_bh_enable();
3138 release_sock(sk);
3139 sock_put(sk);
3140 return 0;
3141}
3142EXPORT_SYMBOL_GPL(tcp_abort);
3143
3144extern struct tcp_congestion_ops tcp_reno;
3145
3146static __initdata unsigned long thash_entries;
3147static int __init set_thash_entries(char *str)
3148{
3149 ssize_t ret;
3150
3151 if (!str)
3152 return 0;
3153
3154 ret = kstrtoul(str, 0, &thash_entries);
3155 if (ret)
3156 return 0;
3157
3158 return 1;
3159}
3160__setup("thash_entries=", set_thash_entries);
3161
3162static void __init tcp_init_mem(void)
3163{
3164 unsigned long limit = nr_free_buffer_pages() / 16;
3165
3166 limit = max(limit, 128UL);
3167 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */
3168 sysctl_tcp_mem[1] = limit; /* 6.25 % */
3169 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */
3170}
3171
3172void __init tcp_init(void)
3173{
3174 unsigned long limit;
3175 int max_rshare, max_wshare, cnt;
3176 unsigned int i;
3177
3178 sock_skb_cb_check_size(sizeof(struct tcp_skb_cb));
3179
3180 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
3181 percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3182 tcp_hashinfo.bind_bucket_cachep =
3183 kmem_cache_create("tcp_bind_bucket",
3184 sizeof(struct inet_bind_bucket), 0,
3185 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3186
3187 /* Size and allocate the main established and bind bucket
3188 * hash tables.
3189 *
3190 * The methodology is similar to that of the buffer cache.
3191 */
3192 tcp_hashinfo.ehash =
3193 alloc_large_system_hash("TCP established",
3194 sizeof(struct inet_ehash_bucket),
3195 thash_entries,
3196 17, /* one slot per 128 KB of memory */
3197 0,
3198 NULL,
3199 &tcp_hashinfo.ehash_mask,
3200 0,
3201 thash_entries ? 0 : 512 * 1024);
3202 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3203 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
3204
3205 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3206 panic("TCP: failed to alloc ehash_locks");
3207 tcp_hashinfo.bhash =
3208 alloc_large_system_hash("TCP bind",
3209 sizeof(struct inet_bind_hashbucket),
3210 tcp_hashinfo.ehash_mask + 1,
3211 17, /* one slot per 128 KB of memory */
3212 0,
3213 &tcp_hashinfo.bhash_size,
3214 NULL,
3215 0,
3216 64 * 1024);
3217 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3218 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3219 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3220 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
3221 }
3222
3223
3224 cnt = tcp_hashinfo.ehash_mask + 1;
3225
3226 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3227 sysctl_tcp_max_orphans = cnt / 2;
3228 sysctl_max_syn_backlog = max(128, cnt / 256);
3229
3230 tcp_init_mem();
3231 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3232 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3233 max_wshare = min(4UL*1024*1024, limit);
3234 max_rshare = min(6UL*1024*1024, limit);
3235
3236 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3237 sysctl_tcp_wmem[1] = 16*1024;
3238 sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3239
3240 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3241 sysctl_tcp_rmem[1] = 87380;
3242 sysctl_tcp_rmem[2] = max(87380, max_rshare);
3243
3244 pr_info("Hash tables configured (established %u bind %u)\n",
3245 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3246
3247 tcp_metrics_init();
3248 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
3249 tcp_tasklet_init();
3250}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Implementation of the Transmission Control Protocol(TCP).
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Mark Evans, <evansmp@uhura.aston.ac.uk>
12 * Corey Minyard <wf-rch!minyard@relay.EU.net>
13 * Florian La Roche, <flla@stud.uni-sb.de>
14 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
15 * Linus Torvalds, <torvalds@cs.helsinki.fi>
16 * Alan Cox, <gw4pts@gw4pts.ampr.org>
17 * Matthew Dillon, <dillon@apollo.west.oic.com>
18 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
19 * Jorge Cwik, <jorge@laser.satlink.net>
20 *
21 * Fixes:
22 * Alan Cox : Numerous verify_area() calls
23 * Alan Cox : Set the ACK bit on a reset
24 * Alan Cox : Stopped it crashing if it closed while
25 * sk->inuse=1 and was trying to connect
26 * (tcp_err()).
27 * Alan Cox : All icmp error handling was broken
28 * pointers passed where wrong and the
29 * socket was looked up backwards. Nobody
30 * tested any icmp error code obviously.
31 * Alan Cox : tcp_err() now handled properly. It
32 * wakes people on errors. poll
33 * behaves and the icmp error race
34 * has gone by moving it into sock.c
35 * Alan Cox : tcp_send_reset() fixed to work for
36 * everything not just packets for
37 * unknown sockets.
38 * Alan Cox : tcp option processing.
39 * Alan Cox : Reset tweaked (still not 100%) [Had
40 * syn rule wrong]
41 * Herp Rosmanith : More reset fixes
42 * Alan Cox : No longer acks invalid rst frames.
43 * Acking any kind of RST is right out.
44 * Alan Cox : Sets an ignore me flag on an rst
45 * receive otherwise odd bits of prattle
46 * escape still
47 * Alan Cox : Fixed another acking RST frame bug.
48 * Should stop LAN workplace lockups.
49 * Alan Cox : Some tidyups using the new skb list
50 * facilities
51 * Alan Cox : sk->keepopen now seems to work
52 * Alan Cox : Pulls options out correctly on accepts
53 * Alan Cox : Fixed assorted sk->rqueue->next errors
54 * Alan Cox : PSH doesn't end a TCP read. Switched a
55 * bit to skb ops.
56 * Alan Cox : Tidied tcp_data to avoid a potential
57 * nasty.
58 * Alan Cox : Added some better commenting, as the
59 * tcp is hard to follow
60 * Alan Cox : Removed incorrect check for 20 * psh
61 * Michael O'Reilly : ack < copied bug fix.
62 * Johannes Stille : Misc tcp fixes (not all in yet).
63 * Alan Cox : FIN with no memory -> CRASH
64 * Alan Cox : Added socket option proto entries.
65 * Also added awareness of them to accept.
66 * Alan Cox : Added TCP options (SOL_TCP)
67 * Alan Cox : Switched wakeup calls to callbacks,
68 * so the kernel can layer network
69 * sockets.
70 * Alan Cox : Use ip_tos/ip_ttl settings.
71 * Alan Cox : Handle FIN (more) properly (we hope).
72 * Alan Cox : RST frames sent on unsynchronised
73 * state ack error.
74 * Alan Cox : Put in missing check for SYN bit.
75 * Alan Cox : Added tcp_select_window() aka NET2E
76 * window non shrink trick.
77 * Alan Cox : Added a couple of small NET2E timer
78 * fixes
79 * Charles Hedrick : TCP fixes
80 * Toomas Tamm : TCP window fixes
81 * Alan Cox : Small URG fix to rlogin ^C ack fight
82 * Charles Hedrick : Rewrote most of it to actually work
83 * Linus : Rewrote tcp_read() and URG handling
84 * completely
85 * Gerhard Koerting: Fixed some missing timer handling
86 * Matthew Dillon : Reworked TCP machine states as per RFC
87 * Gerhard Koerting: PC/TCP workarounds
88 * Adam Caldwell : Assorted timer/timing errors
89 * Matthew Dillon : Fixed another RST bug
90 * Alan Cox : Move to kernel side addressing changes.
91 * Alan Cox : Beginning work on TCP fastpathing
92 * (not yet usable)
93 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
94 * Alan Cox : TCP fast path debugging
95 * Alan Cox : Window clamping
96 * Michael Riepe : Bug in tcp_check()
97 * Matt Dillon : More TCP improvements and RST bug fixes
98 * Matt Dillon : Yet more small nasties remove from the
99 * TCP code (Be very nice to this man if
100 * tcp finally works 100%) 8)
101 * Alan Cox : BSD accept semantics.
102 * Alan Cox : Reset on closedown bug.
103 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
104 * Michael Pall : Handle poll() after URG properly in
105 * all cases.
106 * Michael Pall : Undo the last fix in tcp_read_urg()
107 * (multi URG PUSH broke rlogin).
108 * Michael Pall : Fix the multi URG PUSH problem in
109 * tcp_readable(), poll() after URG
110 * works now.
111 * Michael Pall : recv(...,MSG_OOB) never blocks in the
112 * BSD api.
113 * Alan Cox : Changed the semantics of sk->socket to
114 * fix a race and a signal problem with
115 * accept() and async I/O.
116 * Alan Cox : Relaxed the rules on tcp_sendto().
117 * Yury Shevchuk : Really fixed accept() blocking problem.
118 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
119 * clients/servers which listen in on
120 * fixed ports.
121 * Alan Cox : Cleaned the above up and shrank it to
122 * a sensible code size.
123 * Alan Cox : Self connect lockup fix.
124 * Alan Cox : No connect to multicast.
125 * Ross Biro : Close unaccepted children on master
126 * socket close.
127 * Alan Cox : Reset tracing code.
128 * Alan Cox : Spurious resets on shutdown.
129 * Alan Cox : Giant 15 minute/60 second timer error
130 * Alan Cox : Small whoops in polling before an
131 * accept.
132 * Alan Cox : Kept the state trace facility since
133 * it's handy for debugging.
134 * Alan Cox : More reset handler fixes.
135 * Alan Cox : Started rewriting the code based on
136 * the RFC's for other useful protocol
137 * references see: Comer, KA9Q NOS, and
138 * for a reference on the difference
139 * between specifications and how BSD
140 * works see the 4.4lite source.
141 * A.N.Kuznetsov : Don't time wait on completion of tidy
142 * close.
143 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
144 * Linus Torvalds : Fixed BSD port reuse to work first syn
145 * Alan Cox : Reimplemented timers as per the RFC
146 * and using multiple timers for sanity.
147 * Alan Cox : Small bug fixes, and a lot of new
148 * comments.
149 * Alan Cox : Fixed dual reader crash by locking
150 * the buffers (much like datagram.c)
151 * Alan Cox : Fixed stuck sockets in probe. A probe
152 * now gets fed up of retrying without
153 * (even a no space) answer.
154 * Alan Cox : Extracted closing code better
155 * Alan Cox : Fixed the closing state machine to
156 * resemble the RFC.
157 * Alan Cox : More 'per spec' fixes.
158 * Jorge Cwik : Even faster checksumming.
159 * Alan Cox : tcp_data() doesn't ack illegal PSH
160 * only frames. At least one pc tcp stack
161 * generates them.
162 * Alan Cox : Cache last socket.
163 * Alan Cox : Per route irtt.
164 * Matt Day : poll()->select() match BSD precisely on error
165 * Alan Cox : New buffers
166 * Marc Tamsky : Various sk->prot->retransmits and
167 * sk->retransmits misupdating fixed.
168 * Fixed tcp_write_timeout: stuck close,
169 * and TCP syn retries gets used now.
170 * Mark Yarvis : In tcp_read_wakeup(), don't send an
171 * ack if state is TCP_CLOSED.
172 * Alan Cox : Look up device on a retransmit - routes may
173 * change. Doesn't yet cope with MSS shrink right
174 * but it's a start!
175 * Marc Tamsky : Closing in closing fixes.
176 * Mike Shaver : RFC1122 verifications.
177 * Alan Cox : rcv_saddr errors.
178 * Alan Cox : Block double connect().
179 * Alan Cox : Small hooks for enSKIP.
180 * Alexey Kuznetsov: Path MTU discovery.
181 * Alan Cox : Support soft errors.
182 * Alan Cox : Fix MTU discovery pathological case
183 * when the remote claims no mtu!
184 * Marc Tamsky : TCP_CLOSE fix.
185 * Colin (G3TNE) : Send a reset on syn ack replies in
186 * window but wrong (fixes NT lpd problems)
187 * Pedro Roque : Better TCP window handling, delayed ack.
188 * Joerg Reuter : No modification of locked buffers in
189 * tcp_do_retransmit()
190 * Eric Schenk : Changed receiver side silly window
191 * avoidance algorithm to BSD style
192 * algorithm. This doubles throughput
193 * against machines running Solaris,
194 * and seems to result in general
195 * improvement.
196 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
197 * Willy Konynenberg : Transparent proxying support.
198 * Mike McLagan : Routing by source
199 * Keith Owens : Do proper merging with partial SKB's in
200 * tcp_do_sendmsg to avoid burstiness.
201 * Eric Schenk : Fix fast close down bug with
202 * shutdown() followed by close().
203 * Andi Kleen : Make poll agree with SIGIO
204 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
205 * lingertime == 0 (RFC 793 ABORT Call)
206 * Hirokazu Takahashi : Use copy_from_user() instead of
207 * csum_and_copy_from_user() if possible.
208 *
209 * Description of States:
210 *
211 * TCP_SYN_SENT sent a connection request, waiting for ack
212 *
213 * TCP_SYN_RECV received a connection request, sent ack,
214 * waiting for final ack in three-way handshake.
215 *
216 * TCP_ESTABLISHED connection established
217 *
218 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
219 * transmission of remaining buffered data
220 *
221 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
222 * to shutdown
223 *
224 * TCP_CLOSING both sides have shutdown but we still have
225 * data we have to finish sending
226 *
227 * TCP_TIME_WAIT timeout to catch resent junk before entering
228 * closed, can only be entered from FIN_WAIT2
229 * or CLOSING. Required because the other end
230 * may not have gotten our last ACK causing it
231 * to retransmit the data packet (which we ignore)
232 *
233 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
234 * us to finish writing our data and to shutdown
235 * (we have to close() to move on to LAST_ACK)
236 *
237 * TCP_LAST_ACK out side has shutdown after remote has
238 * shutdown. There may still be data in our
239 * buffer that we have to finish sending
240 *
241 * TCP_CLOSE socket is finished
242 */
243
244#define pr_fmt(fmt) "TCP: " fmt
245
246#include <crypto/hash.h>
247#include <linux/kernel.h>
248#include <linux/module.h>
249#include <linux/types.h>
250#include <linux/fcntl.h>
251#include <linux/poll.h>
252#include <linux/inet_diag.h>
253#include <linux/init.h>
254#include <linux/fs.h>
255#include <linux/skbuff.h>
256#include <linux/scatterlist.h>
257#include <linux/splice.h>
258#include <linux/net.h>
259#include <linux/socket.h>
260#include <linux/random.h>
261#include <linux/memblock.h>
262#include <linux/highmem.h>
263#include <linux/cache.h>
264#include <linux/err.h>
265#include <linux/time.h>
266#include <linux/slab.h>
267#include <linux/errqueue.h>
268#include <linux/static_key.h>
269#include <linux/btf.h>
270
271#include <net/icmp.h>
272#include <net/inet_common.h>
273#include <net/tcp.h>
274#include <net/mptcp.h>
275#include <net/xfrm.h>
276#include <net/ip.h>
277#include <net/sock.h>
278
279#include <linux/uaccess.h>
280#include <asm/ioctls.h>
281#include <net/busy_poll.h>
282#include <net/rps.h>
283
284/* Track pending CMSGs. */
285enum {
286 TCP_CMSG_INQ = 1,
287 TCP_CMSG_TS = 2
288};
289
290DEFINE_PER_CPU(unsigned int, tcp_orphan_count);
291EXPORT_PER_CPU_SYMBOL_GPL(tcp_orphan_count);
292
293long sysctl_tcp_mem[3] __read_mostly;
294EXPORT_SYMBOL(sysctl_tcp_mem);
295
296atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp; /* Current allocated memory. */
297EXPORT_SYMBOL(tcp_memory_allocated);
298DEFINE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc);
299EXPORT_PER_CPU_SYMBOL_GPL(tcp_memory_per_cpu_fw_alloc);
300
301#if IS_ENABLED(CONFIG_SMC)
302DEFINE_STATIC_KEY_FALSE(tcp_have_smc);
303EXPORT_SYMBOL(tcp_have_smc);
304#endif
305
306/*
307 * Current number of TCP sockets.
308 */
309struct percpu_counter tcp_sockets_allocated ____cacheline_aligned_in_smp;
310EXPORT_SYMBOL(tcp_sockets_allocated);
311
312/*
313 * TCP splice context
314 */
315struct tcp_splice_state {
316 struct pipe_inode_info *pipe;
317 size_t len;
318 unsigned int flags;
319};
320
321/*
322 * Pressure flag: try to collapse.
323 * Technical note: it is used by multiple contexts non atomically.
324 * All the __sk_mem_schedule() is of this nature: accounting
325 * is strict, actions are advisory and have some latency.
326 */
327unsigned long tcp_memory_pressure __read_mostly;
328EXPORT_SYMBOL_GPL(tcp_memory_pressure);
329
330void tcp_enter_memory_pressure(struct sock *sk)
331{
332 unsigned long val;
333
334 if (READ_ONCE(tcp_memory_pressure))
335 return;
336 val = jiffies;
337
338 if (!val)
339 val--;
340 if (!cmpxchg(&tcp_memory_pressure, 0, val))
341 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
342}
343EXPORT_SYMBOL_GPL(tcp_enter_memory_pressure);
344
345void tcp_leave_memory_pressure(struct sock *sk)
346{
347 unsigned long val;
348
349 if (!READ_ONCE(tcp_memory_pressure))
350 return;
351 val = xchg(&tcp_memory_pressure, 0);
352 if (val)
353 NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURESCHRONO,
354 jiffies_to_msecs(jiffies - val));
355}
356EXPORT_SYMBOL_GPL(tcp_leave_memory_pressure);
357
358/* Convert seconds to retransmits based on initial and max timeout */
359static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
360{
361 u8 res = 0;
362
363 if (seconds > 0) {
364 int period = timeout;
365
366 res = 1;
367 while (seconds > period && res < 255) {
368 res++;
369 timeout <<= 1;
370 if (timeout > rto_max)
371 timeout = rto_max;
372 period += timeout;
373 }
374 }
375 return res;
376}
377
378/* Convert retransmits to seconds based on initial and max timeout */
379static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
380{
381 int period = 0;
382
383 if (retrans > 0) {
384 period = timeout;
385 while (--retrans) {
386 timeout <<= 1;
387 if (timeout > rto_max)
388 timeout = rto_max;
389 period += timeout;
390 }
391 }
392 return period;
393}
394
395static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp)
396{
397 u32 rate = READ_ONCE(tp->rate_delivered);
398 u32 intv = READ_ONCE(tp->rate_interval_us);
399 u64 rate64 = 0;
400
401 if (rate && intv) {
402 rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC;
403 do_div(rate64, intv);
404 }
405 return rate64;
406}
407
408/* Address-family independent initialization for a tcp_sock.
409 *
410 * NOTE: A lot of things set to zero explicitly by call to
411 * sk_alloc() so need not be done here.
412 */
413void tcp_init_sock(struct sock *sk)
414{
415 struct inet_connection_sock *icsk = inet_csk(sk);
416 struct tcp_sock *tp = tcp_sk(sk);
417
418 tp->out_of_order_queue = RB_ROOT;
419 sk->tcp_rtx_queue = RB_ROOT;
420 tcp_init_xmit_timers(sk);
421 INIT_LIST_HEAD(&tp->tsq_node);
422 INIT_LIST_HEAD(&tp->tsorted_sent_queue);
423
424 icsk->icsk_rto = TCP_TIMEOUT_INIT;
425 icsk->icsk_rto_min = TCP_RTO_MIN;
426 icsk->icsk_delack_max = TCP_DELACK_MAX;
427 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
428 minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U);
429
430 /* So many TCP implementations out there (incorrectly) count the
431 * initial SYN frame in their delayed-ACK and congestion control
432 * algorithms that we must have the following bandaid to talk
433 * efficiently to them. -DaveM
434 */
435 tcp_snd_cwnd_set(tp, TCP_INIT_CWND);
436
437 /* There's a bubble in the pipe until at least the first ACK. */
438 tp->app_limited = ~0U;
439 tp->rate_app_limited = 1;
440
441 /* See draft-stevens-tcpca-spec-01 for discussion of the
442 * initialization of these values.
443 */
444 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
445 tp->snd_cwnd_clamp = ~0;
446 tp->mss_cache = TCP_MSS_DEFAULT;
447
448 tp->reordering = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reordering);
449 tcp_assign_congestion_control(sk);
450
451 tp->tsoffset = 0;
452 tp->rack.reo_wnd_steps = 1;
453
454 sk->sk_write_space = sk_stream_write_space;
455 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
456
457 icsk->icsk_sync_mss = tcp_sync_mss;
458
459 WRITE_ONCE(sk->sk_sndbuf, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[1]));
460 WRITE_ONCE(sk->sk_rcvbuf, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[1]));
461 tcp_scaling_ratio_init(sk);
462
463 set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
464 sk_sockets_allocated_inc(sk);
465}
466EXPORT_SYMBOL(tcp_init_sock);
467
468static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
469{
470 struct sk_buff *skb = tcp_write_queue_tail(sk);
471
472 if (tsflags && skb) {
473 struct skb_shared_info *shinfo = skb_shinfo(skb);
474 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
475
476 sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags);
477 if (tsflags & SOF_TIMESTAMPING_TX_ACK)
478 tcb->txstamp_ack = 1;
479 if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
480 shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
481 }
482}
483
484static bool tcp_stream_is_readable(struct sock *sk, int target)
485{
486 if (tcp_epollin_ready(sk, target))
487 return true;
488 return sk_is_readable(sk);
489}
490
491/*
492 * Wait for a TCP event.
493 *
494 * Note that we don't need to lock the socket, as the upper poll layers
495 * take care of normal races (between the test and the event) and we don't
496 * go look at any of the socket buffers directly.
497 */
498__poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
499{
500 __poll_t mask;
501 struct sock *sk = sock->sk;
502 const struct tcp_sock *tp = tcp_sk(sk);
503 u8 shutdown;
504 int state;
505
506 sock_poll_wait(file, sock, wait);
507
508 state = inet_sk_state_load(sk);
509 if (state == TCP_LISTEN)
510 return inet_csk_listen_poll(sk);
511
512 /* Socket is not locked. We are protected from async events
513 * by poll logic and correct handling of state changes
514 * made by other threads is impossible in any case.
515 */
516
517 mask = 0;
518
519 /*
520 * EPOLLHUP is certainly not done right. But poll() doesn't
521 * have a notion of HUP in just one direction, and for a
522 * socket the read side is more interesting.
523 *
524 * Some poll() documentation says that EPOLLHUP is incompatible
525 * with the EPOLLOUT/POLLWR flags, so somebody should check this
526 * all. But careful, it tends to be safer to return too many
527 * bits than too few, and you can easily break real applications
528 * if you don't tell them that something has hung up!
529 *
530 * Check-me.
531 *
532 * Check number 1. EPOLLHUP is _UNMASKABLE_ event (see UNIX98 and
533 * our fs/select.c). It means that after we received EOF,
534 * poll always returns immediately, making impossible poll() on write()
535 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP
536 * if and only if shutdown has been made in both directions.
537 * Actually, it is interesting to look how Solaris and DUX
538 * solve this dilemma. I would prefer, if EPOLLHUP were maskable,
539 * then we could set it on SND_SHUTDOWN. BTW examples given
540 * in Stevens' books assume exactly this behaviour, it explains
541 * why EPOLLHUP is incompatible with EPOLLOUT. --ANK
542 *
543 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
544 * blocking on fresh not-connected or disconnected socket. --ANK
545 */
546 shutdown = READ_ONCE(sk->sk_shutdown);
547 if (shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
548 mask |= EPOLLHUP;
549 if (shutdown & RCV_SHUTDOWN)
550 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
551
552 /* Connected or passive Fast Open socket? */
553 if (state != TCP_SYN_SENT &&
554 (state != TCP_SYN_RECV || rcu_access_pointer(tp->fastopen_rsk))) {
555 int target = sock_rcvlowat(sk, 0, INT_MAX);
556 u16 urg_data = READ_ONCE(tp->urg_data);
557
558 if (unlikely(urg_data) &&
559 READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq) &&
560 !sock_flag(sk, SOCK_URGINLINE))
561 target++;
562
563 if (tcp_stream_is_readable(sk, target))
564 mask |= EPOLLIN | EPOLLRDNORM;
565
566 if (!(shutdown & SEND_SHUTDOWN)) {
567 if (__sk_stream_is_writeable(sk, 1)) {
568 mask |= EPOLLOUT | EPOLLWRNORM;
569 } else { /* send SIGIO later */
570 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
571 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
572
573 /* Race breaker. If space is freed after
574 * wspace test but before the flags are set,
575 * IO signal will be lost. Memory barrier
576 * pairs with the input side.
577 */
578 smp_mb__after_atomic();
579 if (__sk_stream_is_writeable(sk, 1))
580 mask |= EPOLLOUT | EPOLLWRNORM;
581 }
582 } else
583 mask |= EPOLLOUT | EPOLLWRNORM;
584
585 if (urg_data & TCP_URG_VALID)
586 mask |= EPOLLPRI;
587 } else if (state == TCP_SYN_SENT &&
588 inet_test_bit(DEFER_CONNECT, sk)) {
589 /* Active TCP fastopen socket with defer_connect
590 * Return EPOLLOUT so application can call write()
591 * in order for kernel to generate SYN+data
592 */
593 mask |= EPOLLOUT | EPOLLWRNORM;
594 }
595 /* This barrier is coupled with smp_wmb() in tcp_reset() */
596 smp_rmb();
597 if (READ_ONCE(sk->sk_err) ||
598 !skb_queue_empty_lockless(&sk->sk_error_queue))
599 mask |= EPOLLERR;
600
601 return mask;
602}
603EXPORT_SYMBOL(tcp_poll);
604
605int tcp_ioctl(struct sock *sk, int cmd, int *karg)
606{
607 struct tcp_sock *tp = tcp_sk(sk);
608 int answ;
609 bool slow;
610
611 switch (cmd) {
612 case SIOCINQ:
613 if (sk->sk_state == TCP_LISTEN)
614 return -EINVAL;
615
616 slow = lock_sock_fast(sk);
617 answ = tcp_inq(sk);
618 unlock_sock_fast(sk, slow);
619 break;
620 case SIOCATMARK:
621 answ = READ_ONCE(tp->urg_data) &&
622 READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq);
623 break;
624 case SIOCOUTQ:
625 if (sk->sk_state == TCP_LISTEN)
626 return -EINVAL;
627
628 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
629 answ = 0;
630 else
631 answ = READ_ONCE(tp->write_seq) - tp->snd_una;
632 break;
633 case SIOCOUTQNSD:
634 if (sk->sk_state == TCP_LISTEN)
635 return -EINVAL;
636
637 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
638 answ = 0;
639 else
640 answ = READ_ONCE(tp->write_seq) -
641 READ_ONCE(tp->snd_nxt);
642 break;
643 default:
644 return -ENOIOCTLCMD;
645 }
646
647 *karg = answ;
648 return 0;
649}
650EXPORT_SYMBOL(tcp_ioctl);
651
652void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
653{
654 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
655 tp->pushed_seq = tp->write_seq;
656}
657
658static inline bool forced_push(const struct tcp_sock *tp)
659{
660 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
661}
662
663void tcp_skb_entail(struct sock *sk, struct sk_buff *skb)
664{
665 struct tcp_sock *tp = tcp_sk(sk);
666 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
667
668 tcb->seq = tcb->end_seq = tp->write_seq;
669 tcb->tcp_flags = TCPHDR_ACK;
670 __skb_header_release(skb);
671 tcp_add_write_queue_tail(sk, skb);
672 sk_wmem_queued_add(sk, skb->truesize);
673 sk_mem_charge(sk, skb->truesize);
674 if (tp->nonagle & TCP_NAGLE_PUSH)
675 tp->nonagle &= ~TCP_NAGLE_PUSH;
676
677 tcp_slow_start_after_idle_check(sk);
678}
679
680static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
681{
682 if (flags & MSG_OOB)
683 tp->snd_up = tp->write_seq;
684}
685
686/* If a not yet filled skb is pushed, do not send it if
687 * we have data packets in Qdisc or NIC queues :
688 * Because TX completion will happen shortly, it gives a chance
689 * to coalesce future sendmsg() payload into this skb, without
690 * need for a timer, and with no latency trade off.
691 * As packets containing data payload have a bigger truesize
692 * than pure acks (dataless) packets, the last checks prevent
693 * autocorking if we only have an ACK in Qdisc/NIC queues,
694 * or if TX completion was delayed after we processed ACK packet.
695 */
696static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
697 int size_goal)
698{
699 return skb->len < size_goal &&
700 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_autocorking) &&
701 !tcp_rtx_queue_empty(sk) &&
702 refcount_read(&sk->sk_wmem_alloc) > skb->truesize &&
703 tcp_skb_can_collapse_to(skb);
704}
705
706void tcp_push(struct sock *sk, int flags, int mss_now,
707 int nonagle, int size_goal)
708{
709 struct tcp_sock *tp = tcp_sk(sk);
710 struct sk_buff *skb;
711
712 skb = tcp_write_queue_tail(sk);
713 if (!skb)
714 return;
715 if (!(flags & MSG_MORE) || forced_push(tp))
716 tcp_mark_push(tp, skb);
717
718 tcp_mark_urg(tp, flags);
719
720 if (tcp_should_autocork(sk, skb, size_goal)) {
721
722 /* avoid atomic op if TSQ_THROTTLED bit is already set */
723 if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
724 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
725 set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
726 smp_mb__after_atomic();
727 }
728 /* It is possible TX completion already happened
729 * before we set TSQ_THROTTLED.
730 */
731 if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
732 return;
733 }
734
735 if (flags & MSG_MORE)
736 nonagle = TCP_NAGLE_CORK;
737
738 __tcp_push_pending_frames(sk, mss_now, nonagle);
739}
740
741static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
742 unsigned int offset, size_t len)
743{
744 struct tcp_splice_state *tss = rd_desc->arg.data;
745 int ret;
746
747 ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
748 min(rd_desc->count, len), tss->flags);
749 if (ret > 0)
750 rd_desc->count -= ret;
751 return ret;
752}
753
754static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
755{
756 /* Store TCP splice context information in read_descriptor_t. */
757 read_descriptor_t rd_desc = {
758 .arg.data = tss,
759 .count = tss->len,
760 };
761
762 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
763}
764
765/**
766 * tcp_splice_read - splice data from TCP socket to a pipe
767 * @sock: socket to splice from
768 * @ppos: position (not valid)
769 * @pipe: pipe to splice to
770 * @len: number of bytes to splice
771 * @flags: splice modifier flags
772 *
773 * Description:
774 * Will read pages from given socket and fill them into a pipe.
775 *
776 **/
777ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
778 struct pipe_inode_info *pipe, size_t len,
779 unsigned int flags)
780{
781 struct sock *sk = sock->sk;
782 struct tcp_splice_state tss = {
783 .pipe = pipe,
784 .len = len,
785 .flags = flags,
786 };
787 long timeo;
788 ssize_t spliced;
789 int ret;
790
791 sock_rps_record_flow(sk);
792 /*
793 * We can't seek on a socket input
794 */
795 if (unlikely(*ppos))
796 return -ESPIPE;
797
798 ret = spliced = 0;
799
800 lock_sock(sk);
801
802 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
803 while (tss.len) {
804 ret = __tcp_splice_read(sk, &tss);
805 if (ret < 0)
806 break;
807 else if (!ret) {
808 if (spliced)
809 break;
810 if (sock_flag(sk, SOCK_DONE))
811 break;
812 if (sk->sk_err) {
813 ret = sock_error(sk);
814 break;
815 }
816 if (sk->sk_shutdown & RCV_SHUTDOWN)
817 break;
818 if (sk->sk_state == TCP_CLOSE) {
819 /*
820 * This occurs when user tries to read
821 * from never connected socket.
822 */
823 ret = -ENOTCONN;
824 break;
825 }
826 if (!timeo) {
827 ret = -EAGAIN;
828 break;
829 }
830 /* if __tcp_splice_read() got nothing while we have
831 * an skb in receive queue, we do not want to loop.
832 * This might happen with URG data.
833 */
834 if (!skb_queue_empty(&sk->sk_receive_queue))
835 break;
836 ret = sk_wait_data(sk, &timeo, NULL);
837 if (ret < 0)
838 break;
839 if (signal_pending(current)) {
840 ret = sock_intr_errno(timeo);
841 break;
842 }
843 continue;
844 }
845 tss.len -= ret;
846 spliced += ret;
847
848 if (!tss.len || !timeo)
849 break;
850 release_sock(sk);
851 lock_sock(sk);
852
853 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
854 (sk->sk_shutdown & RCV_SHUTDOWN) ||
855 signal_pending(current))
856 break;
857 }
858
859 release_sock(sk);
860
861 if (spliced)
862 return spliced;
863
864 return ret;
865}
866EXPORT_SYMBOL(tcp_splice_read);
867
868struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp,
869 bool force_schedule)
870{
871 struct sk_buff *skb;
872
873 skb = alloc_skb_fclone(MAX_TCP_HEADER, gfp);
874 if (likely(skb)) {
875 bool mem_scheduled;
876
877 skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
878 if (force_schedule) {
879 mem_scheduled = true;
880 sk_forced_mem_schedule(sk, skb->truesize);
881 } else {
882 mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
883 }
884 if (likely(mem_scheduled)) {
885 skb_reserve(skb, MAX_TCP_HEADER);
886 skb->ip_summed = CHECKSUM_PARTIAL;
887 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
888 return skb;
889 }
890 __kfree_skb(skb);
891 } else {
892 sk->sk_prot->enter_memory_pressure(sk);
893 sk_stream_moderate_sndbuf(sk);
894 }
895 return NULL;
896}
897
898static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
899 int large_allowed)
900{
901 struct tcp_sock *tp = tcp_sk(sk);
902 u32 new_size_goal, size_goal;
903
904 if (!large_allowed)
905 return mss_now;
906
907 /* Note : tcp_tso_autosize() will eventually split this later */
908 new_size_goal = tcp_bound_to_half_wnd(tp, sk->sk_gso_max_size);
909
910 /* We try hard to avoid divides here */
911 size_goal = tp->gso_segs * mss_now;
912 if (unlikely(new_size_goal < size_goal ||
913 new_size_goal >= size_goal + mss_now)) {
914 tp->gso_segs = min_t(u16, new_size_goal / mss_now,
915 sk->sk_gso_max_segs);
916 size_goal = tp->gso_segs * mss_now;
917 }
918
919 return max(size_goal, mss_now);
920}
921
922int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
923{
924 int mss_now;
925
926 mss_now = tcp_current_mss(sk);
927 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
928
929 return mss_now;
930}
931
932/* In some cases, sendmsg() could have added an skb to the write queue,
933 * but failed adding payload on it. We need to remove it to consume less
934 * memory, but more importantly be able to generate EPOLLOUT for Edge Trigger
935 * epoll() users. Another reason is that tcp_write_xmit() does not like
936 * finding an empty skb in the write queue.
937 */
938void tcp_remove_empty_skb(struct sock *sk)
939{
940 struct sk_buff *skb = tcp_write_queue_tail(sk);
941
942 if (skb && TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) {
943 tcp_unlink_write_queue(skb, sk);
944 if (tcp_write_queue_empty(sk))
945 tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
946 tcp_wmem_free_skb(sk, skb);
947 }
948}
949
950/* skb changing from pure zc to mixed, must charge zc */
951static int tcp_downgrade_zcopy_pure(struct sock *sk, struct sk_buff *skb)
952{
953 if (unlikely(skb_zcopy_pure(skb))) {
954 u32 extra = skb->truesize -
955 SKB_TRUESIZE(skb_end_offset(skb));
956
957 if (!sk_wmem_schedule(sk, extra))
958 return -ENOMEM;
959
960 sk_mem_charge(sk, extra);
961 skb_shinfo(skb)->flags &= ~SKBFL_PURE_ZEROCOPY;
962 }
963 return 0;
964}
965
966
967int tcp_wmem_schedule(struct sock *sk, int copy)
968{
969 int left;
970
971 if (likely(sk_wmem_schedule(sk, copy)))
972 return copy;
973
974 /* We could be in trouble if we have nothing queued.
975 * Use whatever is left in sk->sk_forward_alloc and tcp_wmem[0]
976 * to guarantee some progress.
977 */
978 left = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[0]) - sk->sk_wmem_queued;
979 if (left > 0)
980 sk_forced_mem_schedule(sk, min(left, copy));
981 return min(copy, sk->sk_forward_alloc);
982}
983
984void tcp_free_fastopen_req(struct tcp_sock *tp)
985{
986 if (tp->fastopen_req) {
987 kfree(tp->fastopen_req);
988 tp->fastopen_req = NULL;
989 }
990}
991
992int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied,
993 size_t size, struct ubuf_info *uarg)
994{
995 struct tcp_sock *tp = tcp_sk(sk);
996 struct inet_sock *inet = inet_sk(sk);
997 struct sockaddr *uaddr = msg->msg_name;
998 int err, flags;
999
1000 if (!(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen) &
1001 TFO_CLIENT_ENABLE) ||
1002 (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
1003 uaddr->sa_family == AF_UNSPEC))
1004 return -EOPNOTSUPP;
1005 if (tp->fastopen_req)
1006 return -EALREADY; /* Another Fast Open is in progress */
1007
1008 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
1009 sk->sk_allocation);
1010 if (unlikely(!tp->fastopen_req))
1011 return -ENOBUFS;
1012 tp->fastopen_req->data = msg;
1013 tp->fastopen_req->size = size;
1014 tp->fastopen_req->uarg = uarg;
1015
1016 if (inet_test_bit(DEFER_CONNECT, sk)) {
1017 err = tcp_connect(sk);
1018 /* Same failure procedure as in tcp_v4/6_connect */
1019 if (err) {
1020 tcp_set_state(sk, TCP_CLOSE);
1021 inet->inet_dport = 0;
1022 sk->sk_route_caps = 0;
1023 }
1024 }
1025 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1026 err = __inet_stream_connect(sk->sk_socket, uaddr,
1027 msg->msg_namelen, flags, 1);
1028 /* fastopen_req could already be freed in __inet_stream_connect
1029 * if the connection times out or gets rst
1030 */
1031 if (tp->fastopen_req) {
1032 *copied = tp->fastopen_req->copied;
1033 tcp_free_fastopen_req(tp);
1034 inet_clear_bit(DEFER_CONNECT, sk);
1035 }
1036 return err;
1037}
1038
1039int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
1040{
1041 struct tcp_sock *tp = tcp_sk(sk);
1042 struct ubuf_info *uarg = NULL;
1043 struct sk_buff *skb;
1044 struct sockcm_cookie sockc;
1045 int flags, err, copied = 0;
1046 int mss_now = 0, size_goal, copied_syn = 0;
1047 int process_backlog = 0;
1048 int zc = 0;
1049 long timeo;
1050
1051 flags = msg->msg_flags;
1052
1053 if ((flags & MSG_ZEROCOPY) && size) {
1054 if (msg->msg_ubuf) {
1055 uarg = msg->msg_ubuf;
1056 if (sk->sk_route_caps & NETIF_F_SG)
1057 zc = MSG_ZEROCOPY;
1058 } else if (sock_flag(sk, SOCK_ZEROCOPY)) {
1059 skb = tcp_write_queue_tail(sk);
1060 uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb));
1061 if (!uarg) {
1062 err = -ENOBUFS;
1063 goto out_err;
1064 }
1065 if (sk->sk_route_caps & NETIF_F_SG)
1066 zc = MSG_ZEROCOPY;
1067 else
1068 uarg_to_msgzc(uarg)->zerocopy = 0;
1069 }
1070 } else if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES) && size) {
1071 if (sk->sk_route_caps & NETIF_F_SG)
1072 zc = MSG_SPLICE_PAGES;
1073 }
1074
1075 if (unlikely(flags & MSG_FASTOPEN ||
1076 inet_test_bit(DEFER_CONNECT, sk)) &&
1077 !tp->repair) {
1078 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size, uarg);
1079 if (err == -EINPROGRESS && copied_syn > 0)
1080 goto out;
1081 else if (err)
1082 goto out_err;
1083 }
1084
1085 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1086
1087 tcp_rate_check_app_limited(sk); /* is sending application-limited? */
1088
1089 /* Wait for a connection to finish. One exception is TCP Fast Open
1090 * (passive side) where data is allowed to be sent before a connection
1091 * is fully established.
1092 */
1093 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
1094 !tcp_passive_fastopen(sk)) {
1095 err = sk_stream_wait_connect(sk, &timeo);
1096 if (err != 0)
1097 goto do_error;
1098 }
1099
1100 if (unlikely(tp->repair)) {
1101 if (tp->repair_queue == TCP_RECV_QUEUE) {
1102 copied = tcp_send_rcvq(sk, msg, size);
1103 goto out_nopush;
1104 }
1105
1106 err = -EINVAL;
1107 if (tp->repair_queue == TCP_NO_QUEUE)
1108 goto out_err;
1109
1110 /* 'common' sending to sendq */
1111 }
1112
1113 sockcm_init(&sockc, sk);
1114 if (msg->msg_controllen) {
1115 err = sock_cmsg_send(sk, msg, &sockc);
1116 if (unlikely(err)) {
1117 err = -EINVAL;
1118 goto out_err;
1119 }
1120 }
1121
1122 /* This should be in poll */
1123 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1124
1125 /* Ok commence sending. */
1126 copied = 0;
1127
1128restart:
1129 mss_now = tcp_send_mss(sk, &size_goal, flags);
1130
1131 err = -EPIPE;
1132 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1133 goto do_error;
1134
1135 while (msg_data_left(msg)) {
1136 ssize_t copy = 0;
1137
1138 skb = tcp_write_queue_tail(sk);
1139 if (skb)
1140 copy = size_goal - skb->len;
1141
1142 if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1143 bool first_skb;
1144
1145new_segment:
1146 if (!sk_stream_memory_free(sk))
1147 goto wait_for_space;
1148
1149 if (unlikely(process_backlog >= 16)) {
1150 process_backlog = 0;
1151 if (sk_flush_backlog(sk))
1152 goto restart;
1153 }
1154 first_skb = tcp_rtx_and_write_queues_empty(sk);
1155 skb = tcp_stream_alloc_skb(sk, sk->sk_allocation,
1156 first_skb);
1157 if (!skb)
1158 goto wait_for_space;
1159
1160 process_backlog++;
1161
1162 tcp_skb_entail(sk, skb);
1163 copy = size_goal;
1164
1165 /* All packets are restored as if they have
1166 * already been sent. skb_mstamp_ns isn't set to
1167 * avoid wrong rtt estimation.
1168 */
1169 if (tp->repair)
1170 TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
1171 }
1172
1173 /* Try to append data to the end of skb. */
1174 if (copy > msg_data_left(msg))
1175 copy = msg_data_left(msg);
1176
1177 if (zc == 0) {
1178 bool merge = true;
1179 int i = skb_shinfo(skb)->nr_frags;
1180 struct page_frag *pfrag = sk_page_frag(sk);
1181
1182 if (!sk_page_frag_refill(sk, pfrag))
1183 goto wait_for_space;
1184
1185 if (!skb_can_coalesce(skb, i, pfrag->page,
1186 pfrag->offset)) {
1187 if (i >= READ_ONCE(sysctl_max_skb_frags)) {
1188 tcp_mark_push(tp, skb);
1189 goto new_segment;
1190 }
1191 merge = false;
1192 }
1193
1194 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1195
1196 if (unlikely(skb_zcopy_pure(skb) || skb_zcopy_managed(skb))) {
1197 if (tcp_downgrade_zcopy_pure(sk, skb))
1198 goto wait_for_space;
1199 skb_zcopy_downgrade_managed(skb);
1200 }
1201
1202 copy = tcp_wmem_schedule(sk, copy);
1203 if (!copy)
1204 goto wait_for_space;
1205
1206 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
1207 pfrag->page,
1208 pfrag->offset,
1209 copy);
1210 if (err)
1211 goto do_error;
1212
1213 /* Update the skb. */
1214 if (merge) {
1215 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1216 } else {
1217 skb_fill_page_desc(skb, i, pfrag->page,
1218 pfrag->offset, copy);
1219 page_ref_inc(pfrag->page);
1220 }
1221 pfrag->offset += copy;
1222 } else if (zc == MSG_ZEROCOPY) {
1223 /* First append to a fragless skb builds initial
1224 * pure zerocopy skb
1225 */
1226 if (!skb->len)
1227 skb_shinfo(skb)->flags |= SKBFL_PURE_ZEROCOPY;
1228
1229 if (!skb_zcopy_pure(skb)) {
1230 copy = tcp_wmem_schedule(sk, copy);
1231 if (!copy)
1232 goto wait_for_space;
1233 }
1234
1235 err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
1236 if (err == -EMSGSIZE || err == -EEXIST) {
1237 tcp_mark_push(tp, skb);
1238 goto new_segment;
1239 }
1240 if (err < 0)
1241 goto do_error;
1242 copy = err;
1243 } else if (zc == MSG_SPLICE_PAGES) {
1244 /* Splice in data if we can; copy if we can't. */
1245 if (tcp_downgrade_zcopy_pure(sk, skb))
1246 goto wait_for_space;
1247 copy = tcp_wmem_schedule(sk, copy);
1248 if (!copy)
1249 goto wait_for_space;
1250
1251 err = skb_splice_from_iter(skb, &msg->msg_iter, copy,
1252 sk->sk_allocation);
1253 if (err < 0) {
1254 if (err == -EMSGSIZE) {
1255 tcp_mark_push(tp, skb);
1256 goto new_segment;
1257 }
1258 goto do_error;
1259 }
1260 copy = err;
1261
1262 if (!(flags & MSG_NO_SHARED_FRAGS))
1263 skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG;
1264
1265 sk_wmem_queued_add(sk, copy);
1266 sk_mem_charge(sk, copy);
1267 }
1268
1269 if (!copied)
1270 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1271
1272 WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
1273 TCP_SKB_CB(skb)->end_seq += copy;
1274 tcp_skb_pcount_set(skb, 0);
1275
1276 copied += copy;
1277 if (!msg_data_left(msg)) {
1278 if (unlikely(flags & MSG_EOR))
1279 TCP_SKB_CB(skb)->eor = 1;
1280 goto out;
1281 }
1282
1283 if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
1284 continue;
1285
1286 if (forced_push(tp)) {
1287 tcp_mark_push(tp, skb);
1288 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1289 } else if (skb == tcp_send_head(sk))
1290 tcp_push_one(sk, mss_now);
1291 continue;
1292
1293wait_for_space:
1294 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1295 tcp_remove_empty_skb(sk);
1296 if (copied)
1297 tcp_push(sk, flags & ~MSG_MORE, mss_now,
1298 TCP_NAGLE_PUSH, size_goal);
1299
1300 err = sk_stream_wait_memory(sk, &timeo);
1301 if (err != 0)
1302 goto do_error;
1303
1304 mss_now = tcp_send_mss(sk, &size_goal, flags);
1305 }
1306
1307out:
1308 if (copied) {
1309 tcp_tx_timestamp(sk, sockc.tsflags);
1310 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1311 }
1312out_nopush:
1313 /* msg->msg_ubuf is pinned by the caller so we don't take extra refs */
1314 if (uarg && !msg->msg_ubuf)
1315 net_zcopy_put(uarg);
1316 return copied + copied_syn;
1317
1318do_error:
1319 tcp_remove_empty_skb(sk);
1320
1321 if (copied + copied_syn)
1322 goto out;
1323out_err:
1324 /* msg->msg_ubuf is pinned by the caller so we don't take extra refs */
1325 if (uarg && !msg->msg_ubuf)
1326 net_zcopy_put_abort(uarg, true);
1327 err = sk_stream_error(sk, flags, err);
1328 /* make sure we wake any epoll edge trigger waiter */
1329 if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) {
1330 sk->sk_write_space(sk);
1331 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
1332 }
1333 return err;
1334}
1335EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1336
1337int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
1338{
1339 int ret;
1340
1341 lock_sock(sk);
1342 ret = tcp_sendmsg_locked(sk, msg, size);
1343 release_sock(sk);
1344
1345 return ret;
1346}
1347EXPORT_SYMBOL(tcp_sendmsg);
1348
1349void tcp_splice_eof(struct socket *sock)
1350{
1351 struct sock *sk = sock->sk;
1352 struct tcp_sock *tp = tcp_sk(sk);
1353 int mss_now, size_goal;
1354
1355 if (!tcp_write_queue_tail(sk))
1356 return;
1357
1358 lock_sock(sk);
1359 mss_now = tcp_send_mss(sk, &size_goal, 0);
1360 tcp_push(sk, 0, mss_now, tp->nonagle, size_goal);
1361 release_sock(sk);
1362}
1363EXPORT_SYMBOL_GPL(tcp_splice_eof);
1364
1365/*
1366 * Handle reading urgent data. BSD has very simple semantics for
1367 * this, no blocking and very strange errors 8)
1368 */
1369
1370static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1371{
1372 struct tcp_sock *tp = tcp_sk(sk);
1373
1374 /* No URG data to read. */
1375 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1376 tp->urg_data == TCP_URG_READ)
1377 return -EINVAL; /* Yes this is right ! */
1378
1379 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1380 return -ENOTCONN;
1381
1382 if (tp->urg_data & TCP_URG_VALID) {
1383 int err = 0;
1384 char c = tp->urg_data;
1385
1386 if (!(flags & MSG_PEEK))
1387 WRITE_ONCE(tp->urg_data, TCP_URG_READ);
1388
1389 /* Read urgent data. */
1390 msg->msg_flags |= MSG_OOB;
1391
1392 if (len > 0) {
1393 if (!(flags & MSG_TRUNC))
1394 err = memcpy_to_msg(msg, &c, 1);
1395 len = 1;
1396 } else
1397 msg->msg_flags |= MSG_TRUNC;
1398
1399 return err ? -EFAULT : len;
1400 }
1401
1402 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1403 return 0;
1404
1405 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1406 * the available implementations agree in this case:
1407 * this call should never block, independent of the
1408 * blocking state of the socket.
1409 * Mike <pall@rz.uni-karlsruhe.de>
1410 */
1411 return -EAGAIN;
1412}
1413
1414static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
1415{
1416 struct sk_buff *skb;
1417 int copied = 0, err = 0;
1418
1419 /* XXX -- need to support SO_PEEK_OFF */
1420
1421 skb_rbtree_walk(skb, &sk->tcp_rtx_queue) {
1422 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
1423 if (err)
1424 return err;
1425 copied += skb->len;
1426 }
1427
1428 skb_queue_walk(&sk->sk_write_queue, skb) {
1429 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
1430 if (err)
1431 break;
1432
1433 copied += skb->len;
1434 }
1435
1436 return err ?: copied;
1437}
1438
1439/* Clean up the receive buffer for full frames taken by the user,
1440 * then send an ACK if necessary. COPIED is the number of bytes
1441 * tcp_recvmsg has given to the user so far, it speeds up the
1442 * calculation of whether or not we must ACK for the sake of
1443 * a window update.
1444 */
1445void __tcp_cleanup_rbuf(struct sock *sk, int copied)
1446{
1447 struct tcp_sock *tp = tcp_sk(sk);
1448 bool time_to_ack = false;
1449
1450 if (inet_csk_ack_scheduled(sk)) {
1451 const struct inet_connection_sock *icsk = inet_csk(sk);
1452
1453 if (/* Once-per-two-segments ACK was not sent by tcp_input.c */
1454 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1455 /*
1456 * If this read emptied read buffer, we send ACK, if
1457 * connection is not bidirectional, user drained
1458 * receive buffer and there was a small segment
1459 * in queue.
1460 */
1461 (copied > 0 &&
1462 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1463 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1464 !inet_csk_in_pingpong_mode(sk))) &&
1465 !atomic_read(&sk->sk_rmem_alloc)))
1466 time_to_ack = true;
1467 }
1468
1469 /* We send an ACK if we can now advertise a non-zero window
1470 * which has been raised "significantly".
1471 *
1472 * Even if window raised up to infinity, do not send window open ACK
1473 * in states, where we will not receive more. It is useless.
1474 */
1475 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1476 __u32 rcv_window_now = tcp_receive_window(tp);
1477
1478 /* Optimize, __tcp_select_window() is not cheap. */
1479 if (2*rcv_window_now <= tp->window_clamp) {
1480 __u32 new_window = __tcp_select_window(sk);
1481
1482 /* Send ACK now, if this read freed lots of space
1483 * in our buffer. Certainly, new_window is new window.
1484 * We can advertise it now, if it is not less than current one.
1485 * "Lots" means "at least twice" here.
1486 */
1487 if (new_window && new_window >= 2 * rcv_window_now)
1488 time_to_ack = true;
1489 }
1490 }
1491 if (time_to_ack)
1492 tcp_send_ack(sk);
1493}
1494
1495void tcp_cleanup_rbuf(struct sock *sk, int copied)
1496{
1497 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1498 struct tcp_sock *tp = tcp_sk(sk);
1499
1500 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1501 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1502 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1503 __tcp_cleanup_rbuf(sk, copied);
1504}
1505
1506static void tcp_eat_recv_skb(struct sock *sk, struct sk_buff *skb)
1507{
1508 __skb_unlink(skb, &sk->sk_receive_queue);
1509 if (likely(skb->destructor == sock_rfree)) {
1510 sock_rfree(skb);
1511 skb->destructor = NULL;
1512 skb->sk = NULL;
1513 return skb_attempt_defer_free(skb);
1514 }
1515 __kfree_skb(skb);
1516}
1517
1518struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1519{
1520 struct sk_buff *skb;
1521 u32 offset;
1522
1523 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1524 offset = seq - TCP_SKB_CB(skb)->seq;
1525 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
1526 pr_err_once("%s: found a SYN, please report !\n", __func__);
1527 offset--;
1528 }
1529 if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
1530 *off = offset;
1531 return skb;
1532 }
1533 /* This looks weird, but this can happen if TCP collapsing
1534 * splitted a fat GRO packet, while we released socket lock
1535 * in skb_splice_bits()
1536 */
1537 tcp_eat_recv_skb(sk, skb);
1538 }
1539 return NULL;
1540}
1541EXPORT_SYMBOL(tcp_recv_skb);
1542
1543/*
1544 * This routine provides an alternative to tcp_recvmsg() for routines
1545 * that would like to handle copying from skbuffs directly in 'sendfile'
1546 * fashion.
1547 * Note:
1548 * - It is assumed that the socket was locked by the caller.
1549 * - The routine does not block.
1550 * - At present, there is no support for reading OOB data
1551 * or for 'peeking' the socket using this routine
1552 * (although both would be easy to implement).
1553 */
1554int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1555 sk_read_actor_t recv_actor)
1556{
1557 struct sk_buff *skb;
1558 struct tcp_sock *tp = tcp_sk(sk);
1559 u32 seq = tp->copied_seq;
1560 u32 offset;
1561 int copied = 0;
1562
1563 if (sk->sk_state == TCP_LISTEN)
1564 return -ENOTCONN;
1565 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1566 if (offset < skb->len) {
1567 int used;
1568 size_t len;
1569
1570 len = skb->len - offset;
1571 /* Stop reading if we hit a patch of urgent data */
1572 if (unlikely(tp->urg_data)) {
1573 u32 urg_offset = tp->urg_seq - seq;
1574 if (urg_offset < len)
1575 len = urg_offset;
1576 if (!len)
1577 break;
1578 }
1579 used = recv_actor(desc, skb, offset, len);
1580 if (used <= 0) {
1581 if (!copied)
1582 copied = used;
1583 break;
1584 }
1585 if (WARN_ON_ONCE(used > len))
1586 used = len;
1587 seq += used;
1588 copied += used;
1589 offset += used;
1590
1591 /* If recv_actor drops the lock (e.g. TCP splice
1592 * receive) the skb pointer might be invalid when
1593 * getting here: tcp_collapse might have deleted it
1594 * while aggregating skbs from the socket queue.
1595 */
1596 skb = tcp_recv_skb(sk, seq - 1, &offset);
1597 if (!skb)
1598 break;
1599 /* TCP coalescing might have appended data to the skb.
1600 * Try to splice more frags
1601 */
1602 if (offset + 1 != skb->len)
1603 continue;
1604 }
1605 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
1606 tcp_eat_recv_skb(sk, skb);
1607 ++seq;
1608 break;
1609 }
1610 tcp_eat_recv_skb(sk, skb);
1611 if (!desc->count)
1612 break;
1613 WRITE_ONCE(tp->copied_seq, seq);
1614 }
1615 WRITE_ONCE(tp->copied_seq, seq);
1616
1617 tcp_rcv_space_adjust(sk);
1618
1619 /* Clean up data we have read: This will do ACK frames. */
1620 if (copied > 0) {
1621 tcp_recv_skb(sk, seq, &offset);
1622 tcp_cleanup_rbuf(sk, copied);
1623 }
1624 return copied;
1625}
1626EXPORT_SYMBOL(tcp_read_sock);
1627
1628int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
1629{
1630 struct sk_buff *skb;
1631 int copied = 0;
1632
1633 if (sk->sk_state == TCP_LISTEN)
1634 return -ENOTCONN;
1635
1636 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1637 u8 tcp_flags;
1638 int used;
1639
1640 __skb_unlink(skb, &sk->sk_receive_queue);
1641 WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
1642 tcp_flags = TCP_SKB_CB(skb)->tcp_flags;
1643 used = recv_actor(sk, skb);
1644 if (used < 0) {
1645 if (!copied)
1646 copied = used;
1647 break;
1648 }
1649 copied += used;
1650
1651 if (tcp_flags & TCPHDR_FIN)
1652 break;
1653 }
1654 return copied;
1655}
1656EXPORT_SYMBOL(tcp_read_skb);
1657
1658void tcp_read_done(struct sock *sk, size_t len)
1659{
1660 struct tcp_sock *tp = tcp_sk(sk);
1661 u32 seq = tp->copied_seq;
1662 struct sk_buff *skb;
1663 size_t left;
1664 u32 offset;
1665
1666 if (sk->sk_state == TCP_LISTEN)
1667 return;
1668
1669 left = len;
1670 while (left && (skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1671 int used;
1672
1673 used = min_t(size_t, skb->len - offset, left);
1674 seq += used;
1675 left -= used;
1676
1677 if (skb->len > offset + used)
1678 break;
1679
1680 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
1681 tcp_eat_recv_skb(sk, skb);
1682 ++seq;
1683 break;
1684 }
1685 tcp_eat_recv_skb(sk, skb);
1686 }
1687 WRITE_ONCE(tp->copied_seq, seq);
1688
1689 tcp_rcv_space_adjust(sk);
1690
1691 /* Clean up data we have read: This will do ACK frames. */
1692 if (left != len)
1693 tcp_cleanup_rbuf(sk, len - left);
1694}
1695EXPORT_SYMBOL(tcp_read_done);
1696
1697int tcp_peek_len(struct socket *sock)
1698{
1699 return tcp_inq(sock->sk);
1700}
1701EXPORT_SYMBOL(tcp_peek_len);
1702
1703/* Make sure sk_rcvbuf is big enough to satisfy SO_RCVLOWAT hint */
1704int tcp_set_rcvlowat(struct sock *sk, int val)
1705{
1706 int space, cap;
1707
1708 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
1709 cap = sk->sk_rcvbuf >> 1;
1710 else
1711 cap = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2]) >> 1;
1712 val = min(val, cap);
1713 WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1714
1715 /* Check if we need to signal EPOLLIN right now */
1716 tcp_data_ready(sk);
1717
1718 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
1719 return 0;
1720
1721 space = tcp_space_from_win(sk, val);
1722 if (space > sk->sk_rcvbuf) {
1723 WRITE_ONCE(sk->sk_rcvbuf, space);
1724 tcp_sk(sk)->window_clamp = val;
1725 }
1726 return 0;
1727}
1728EXPORT_SYMBOL(tcp_set_rcvlowat);
1729
1730void tcp_update_recv_tstamps(struct sk_buff *skb,
1731 struct scm_timestamping_internal *tss)
1732{
1733 if (skb->tstamp)
1734 tss->ts[0] = ktime_to_timespec64(skb->tstamp);
1735 else
1736 tss->ts[0] = (struct timespec64) {0};
1737
1738 if (skb_hwtstamps(skb)->hwtstamp)
1739 tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp);
1740 else
1741 tss->ts[2] = (struct timespec64) {0};
1742}
1743
1744#ifdef CONFIG_MMU
1745static const struct vm_operations_struct tcp_vm_ops = {
1746};
1747
1748int tcp_mmap(struct file *file, struct socket *sock,
1749 struct vm_area_struct *vma)
1750{
1751 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
1752 return -EPERM;
1753 vm_flags_clear(vma, VM_MAYWRITE | VM_MAYEXEC);
1754
1755 /* Instruct vm_insert_page() to not mmap_read_lock(mm) */
1756 vm_flags_set(vma, VM_MIXEDMAP);
1757
1758 vma->vm_ops = &tcp_vm_ops;
1759 return 0;
1760}
1761EXPORT_SYMBOL(tcp_mmap);
1762
1763static skb_frag_t *skb_advance_to_frag(struct sk_buff *skb, u32 offset_skb,
1764 u32 *offset_frag)
1765{
1766 skb_frag_t *frag;
1767
1768 if (unlikely(offset_skb >= skb->len))
1769 return NULL;
1770
1771 offset_skb -= skb_headlen(skb);
1772 if ((int)offset_skb < 0 || skb_has_frag_list(skb))
1773 return NULL;
1774
1775 frag = skb_shinfo(skb)->frags;
1776 while (offset_skb) {
1777 if (skb_frag_size(frag) > offset_skb) {
1778 *offset_frag = offset_skb;
1779 return frag;
1780 }
1781 offset_skb -= skb_frag_size(frag);
1782 ++frag;
1783 }
1784 *offset_frag = 0;
1785 return frag;
1786}
1787
1788static bool can_map_frag(const skb_frag_t *frag)
1789{
1790 struct page *page;
1791
1792 if (skb_frag_size(frag) != PAGE_SIZE || skb_frag_off(frag))
1793 return false;
1794
1795 page = skb_frag_page(frag);
1796
1797 if (PageCompound(page) || page->mapping)
1798 return false;
1799
1800 return true;
1801}
1802
1803static int find_next_mappable_frag(const skb_frag_t *frag,
1804 int remaining_in_skb)
1805{
1806 int offset = 0;
1807
1808 if (likely(can_map_frag(frag)))
1809 return 0;
1810
1811 while (offset < remaining_in_skb && !can_map_frag(frag)) {
1812 offset += skb_frag_size(frag);
1813 ++frag;
1814 }
1815 return offset;
1816}
1817
1818static void tcp_zerocopy_set_hint_for_skb(struct sock *sk,
1819 struct tcp_zerocopy_receive *zc,
1820 struct sk_buff *skb, u32 offset)
1821{
1822 u32 frag_offset, partial_frag_remainder = 0;
1823 int mappable_offset;
1824 skb_frag_t *frag;
1825
1826 /* worst case: skip to next skb. try to improve on this case below */
1827 zc->recv_skip_hint = skb->len - offset;
1828
1829 /* Find the frag containing this offset (and how far into that frag) */
1830 frag = skb_advance_to_frag(skb, offset, &frag_offset);
1831 if (!frag)
1832 return;
1833
1834 if (frag_offset) {
1835 struct skb_shared_info *info = skb_shinfo(skb);
1836
1837 /* We read part of the last frag, must recvmsg() rest of skb. */
1838 if (frag == &info->frags[info->nr_frags - 1])
1839 return;
1840
1841 /* Else, we must at least read the remainder in this frag. */
1842 partial_frag_remainder = skb_frag_size(frag) - frag_offset;
1843 zc->recv_skip_hint -= partial_frag_remainder;
1844 ++frag;
1845 }
1846
1847 /* partial_frag_remainder: If part way through a frag, must read rest.
1848 * mappable_offset: Bytes till next mappable frag, *not* counting bytes
1849 * in partial_frag_remainder.
1850 */
1851 mappable_offset = find_next_mappable_frag(frag, zc->recv_skip_hint);
1852 zc->recv_skip_hint = mappable_offset + partial_frag_remainder;
1853}
1854
1855static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
1856 int flags, struct scm_timestamping_internal *tss,
1857 int *cmsg_flags);
1858static int receive_fallback_to_copy(struct sock *sk,
1859 struct tcp_zerocopy_receive *zc, int inq,
1860 struct scm_timestamping_internal *tss)
1861{
1862 unsigned long copy_address = (unsigned long)zc->copybuf_address;
1863 struct msghdr msg = {};
1864 int err;
1865
1866 zc->length = 0;
1867 zc->recv_skip_hint = 0;
1868
1869 if (copy_address != zc->copybuf_address)
1870 return -EINVAL;
1871
1872 err = import_ubuf(ITER_DEST, (void __user *)copy_address, inq,
1873 &msg.msg_iter);
1874 if (err)
1875 return err;
1876
1877 err = tcp_recvmsg_locked(sk, &msg, inq, MSG_DONTWAIT,
1878 tss, &zc->msg_flags);
1879 if (err < 0)
1880 return err;
1881
1882 zc->copybuf_len = err;
1883 if (likely(zc->copybuf_len)) {
1884 struct sk_buff *skb;
1885 u32 offset;
1886
1887 skb = tcp_recv_skb(sk, tcp_sk(sk)->copied_seq, &offset);
1888 if (skb)
1889 tcp_zerocopy_set_hint_for_skb(sk, zc, skb, offset);
1890 }
1891 return 0;
1892}
1893
1894static int tcp_copy_straggler_data(struct tcp_zerocopy_receive *zc,
1895 struct sk_buff *skb, u32 copylen,
1896 u32 *offset, u32 *seq)
1897{
1898 unsigned long copy_address = (unsigned long)zc->copybuf_address;
1899 struct msghdr msg = {};
1900 int err;
1901
1902 if (copy_address != zc->copybuf_address)
1903 return -EINVAL;
1904
1905 err = import_ubuf(ITER_DEST, (void __user *)copy_address, copylen,
1906 &msg.msg_iter);
1907 if (err)
1908 return err;
1909 err = skb_copy_datagram_msg(skb, *offset, &msg, copylen);
1910 if (err)
1911 return err;
1912 zc->recv_skip_hint -= copylen;
1913 *offset += copylen;
1914 *seq += copylen;
1915 return (__s32)copylen;
1916}
1917
1918static int tcp_zc_handle_leftover(struct tcp_zerocopy_receive *zc,
1919 struct sock *sk,
1920 struct sk_buff *skb,
1921 u32 *seq,
1922 s32 copybuf_len,
1923 struct scm_timestamping_internal *tss)
1924{
1925 u32 offset, copylen = min_t(u32, copybuf_len, zc->recv_skip_hint);
1926
1927 if (!copylen)
1928 return 0;
1929 /* skb is null if inq < PAGE_SIZE. */
1930 if (skb) {
1931 offset = *seq - TCP_SKB_CB(skb)->seq;
1932 } else {
1933 skb = tcp_recv_skb(sk, *seq, &offset);
1934 if (TCP_SKB_CB(skb)->has_rxtstamp) {
1935 tcp_update_recv_tstamps(skb, tss);
1936 zc->msg_flags |= TCP_CMSG_TS;
1937 }
1938 }
1939
1940 zc->copybuf_len = tcp_copy_straggler_data(zc, skb, copylen, &offset,
1941 seq);
1942 return zc->copybuf_len < 0 ? 0 : copylen;
1943}
1944
1945static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma,
1946 struct page **pending_pages,
1947 unsigned long pages_remaining,
1948 unsigned long *address,
1949 u32 *length,
1950 u32 *seq,
1951 struct tcp_zerocopy_receive *zc,
1952 u32 total_bytes_to_map,
1953 int err)
1954{
1955 /* At least one page did not map. Try zapping if we skipped earlier. */
1956 if (err == -EBUSY &&
1957 zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT) {
1958 u32 maybe_zap_len;
1959
1960 maybe_zap_len = total_bytes_to_map - /* All bytes to map */
1961 *length + /* Mapped or pending */
1962 (pages_remaining * PAGE_SIZE); /* Failed map. */
1963 zap_page_range_single(vma, *address, maybe_zap_len, NULL);
1964 err = 0;
1965 }
1966
1967 if (!err) {
1968 unsigned long leftover_pages = pages_remaining;
1969 int bytes_mapped;
1970
1971 /* We called zap_page_range_single, try to reinsert. */
1972 err = vm_insert_pages(vma, *address,
1973 pending_pages,
1974 &pages_remaining);
1975 bytes_mapped = PAGE_SIZE * (leftover_pages - pages_remaining);
1976 *seq += bytes_mapped;
1977 *address += bytes_mapped;
1978 }
1979 if (err) {
1980 /* Either we were unable to zap, OR we zapped, retried an
1981 * insert, and still had an issue. Either ways, pages_remaining
1982 * is the number of pages we were unable to map, and we unroll
1983 * some state we speculatively touched before.
1984 */
1985 const int bytes_not_mapped = PAGE_SIZE * pages_remaining;
1986
1987 *length -= bytes_not_mapped;
1988 zc->recv_skip_hint += bytes_not_mapped;
1989 }
1990 return err;
1991}
1992
1993static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma,
1994 struct page **pages,
1995 unsigned int pages_to_map,
1996 unsigned long *address,
1997 u32 *length,
1998 u32 *seq,
1999 struct tcp_zerocopy_receive *zc,
2000 u32 total_bytes_to_map)
2001{
2002 unsigned long pages_remaining = pages_to_map;
2003 unsigned int pages_mapped;
2004 unsigned int bytes_mapped;
2005 int err;
2006
2007 err = vm_insert_pages(vma, *address, pages, &pages_remaining);
2008 pages_mapped = pages_to_map - (unsigned int)pages_remaining;
2009 bytes_mapped = PAGE_SIZE * pages_mapped;
2010 /* Even if vm_insert_pages fails, it may have partially succeeded in
2011 * mapping (some but not all of the pages).
2012 */
2013 *seq += bytes_mapped;
2014 *address += bytes_mapped;
2015
2016 if (likely(!err))
2017 return 0;
2018
2019 /* Error: maybe zap and retry + rollback state for failed inserts. */
2020 return tcp_zerocopy_vm_insert_batch_error(vma, pages + pages_mapped,
2021 pages_remaining, address, length, seq, zc, total_bytes_to_map,
2022 err);
2023}
2024
2025#define TCP_VALID_ZC_MSG_FLAGS (TCP_CMSG_TS)
2026static void tcp_zc_finalize_rx_tstamp(struct sock *sk,
2027 struct tcp_zerocopy_receive *zc,
2028 struct scm_timestamping_internal *tss)
2029{
2030 unsigned long msg_control_addr;
2031 struct msghdr cmsg_dummy;
2032
2033 msg_control_addr = (unsigned long)zc->msg_control;
2034 cmsg_dummy.msg_control_user = (void __user *)msg_control_addr;
2035 cmsg_dummy.msg_controllen =
2036 (__kernel_size_t)zc->msg_controllen;
2037 cmsg_dummy.msg_flags = in_compat_syscall()
2038 ? MSG_CMSG_COMPAT : 0;
2039 cmsg_dummy.msg_control_is_user = true;
2040 zc->msg_flags = 0;
2041 if (zc->msg_control == msg_control_addr &&
2042 zc->msg_controllen == cmsg_dummy.msg_controllen) {
2043 tcp_recv_timestamp(&cmsg_dummy, sk, tss);
2044 zc->msg_control = (__u64)
2045 ((uintptr_t)cmsg_dummy.msg_control_user);
2046 zc->msg_controllen =
2047 (__u64)cmsg_dummy.msg_controllen;
2048 zc->msg_flags = (__u32)cmsg_dummy.msg_flags;
2049 }
2050}
2051
2052static struct vm_area_struct *find_tcp_vma(struct mm_struct *mm,
2053 unsigned long address,
2054 bool *mmap_locked)
2055{
2056 struct vm_area_struct *vma = lock_vma_under_rcu(mm, address);
2057
2058 if (vma) {
2059 if (vma->vm_ops != &tcp_vm_ops) {
2060 vma_end_read(vma);
2061 return NULL;
2062 }
2063 *mmap_locked = false;
2064 return vma;
2065 }
2066
2067 mmap_read_lock(mm);
2068 vma = vma_lookup(mm, address);
2069 if (!vma || vma->vm_ops != &tcp_vm_ops) {
2070 mmap_read_unlock(mm);
2071 return NULL;
2072 }
2073 *mmap_locked = true;
2074 return vma;
2075}
2076
2077#define TCP_ZEROCOPY_PAGE_BATCH_SIZE 32
2078static int tcp_zerocopy_receive(struct sock *sk,
2079 struct tcp_zerocopy_receive *zc,
2080 struct scm_timestamping_internal *tss)
2081{
2082 u32 length = 0, offset, vma_len, avail_len, copylen = 0;
2083 unsigned long address = (unsigned long)zc->address;
2084 struct page *pages[TCP_ZEROCOPY_PAGE_BATCH_SIZE];
2085 s32 copybuf_len = zc->copybuf_len;
2086 struct tcp_sock *tp = tcp_sk(sk);
2087 const skb_frag_t *frags = NULL;
2088 unsigned int pages_to_map = 0;
2089 struct vm_area_struct *vma;
2090 struct sk_buff *skb = NULL;
2091 u32 seq = tp->copied_seq;
2092 u32 total_bytes_to_map;
2093 int inq = tcp_inq(sk);
2094 bool mmap_locked;
2095 int ret;
2096
2097 zc->copybuf_len = 0;
2098 zc->msg_flags = 0;
2099
2100 if (address & (PAGE_SIZE - 1) || address != zc->address)
2101 return -EINVAL;
2102
2103 if (sk->sk_state == TCP_LISTEN)
2104 return -ENOTCONN;
2105
2106 sock_rps_record_flow(sk);
2107
2108 if (inq && inq <= copybuf_len)
2109 return receive_fallback_to_copy(sk, zc, inq, tss);
2110
2111 if (inq < PAGE_SIZE) {
2112 zc->length = 0;
2113 zc->recv_skip_hint = inq;
2114 if (!inq && sock_flag(sk, SOCK_DONE))
2115 return -EIO;
2116 return 0;
2117 }
2118
2119 vma = find_tcp_vma(current->mm, address, &mmap_locked);
2120 if (!vma)
2121 return -EINVAL;
2122
2123 vma_len = min_t(unsigned long, zc->length, vma->vm_end - address);
2124 avail_len = min_t(u32, vma_len, inq);
2125 total_bytes_to_map = avail_len & ~(PAGE_SIZE - 1);
2126 if (total_bytes_to_map) {
2127 if (!(zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT))
2128 zap_page_range_single(vma, address, total_bytes_to_map,
2129 NULL);
2130 zc->length = total_bytes_to_map;
2131 zc->recv_skip_hint = 0;
2132 } else {
2133 zc->length = avail_len;
2134 zc->recv_skip_hint = avail_len;
2135 }
2136 ret = 0;
2137 while (length + PAGE_SIZE <= zc->length) {
2138 int mappable_offset;
2139 struct page *page;
2140
2141 if (zc->recv_skip_hint < PAGE_SIZE) {
2142 u32 offset_frag;
2143
2144 if (skb) {
2145 if (zc->recv_skip_hint > 0)
2146 break;
2147 skb = skb->next;
2148 offset = seq - TCP_SKB_CB(skb)->seq;
2149 } else {
2150 skb = tcp_recv_skb(sk, seq, &offset);
2151 }
2152
2153 if (TCP_SKB_CB(skb)->has_rxtstamp) {
2154 tcp_update_recv_tstamps(skb, tss);
2155 zc->msg_flags |= TCP_CMSG_TS;
2156 }
2157 zc->recv_skip_hint = skb->len - offset;
2158 frags = skb_advance_to_frag(skb, offset, &offset_frag);
2159 if (!frags || offset_frag)
2160 break;
2161 }
2162
2163 mappable_offset = find_next_mappable_frag(frags,
2164 zc->recv_skip_hint);
2165 if (mappable_offset) {
2166 zc->recv_skip_hint = mappable_offset;
2167 break;
2168 }
2169 page = skb_frag_page(frags);
2170 prefetchw(page);
2171 pages[pages_to_map++] = page;
2172 length += PAGE_SIZE;
2173 zc->recv_skip_hint -= PAGE_SIZE;
2174 frags++;
2175 if (pages_to_map == TCP_ZEROCOPY_PAGE_BATCH_SIZE ||
2176 zc->recv_skip_hint < PAGE_SIZE) {
2177 /* Either full batch, or we're about to go to next skb
2178 * (and we cannot unroll failed ops across skbs).
2179 */
2180 ret = tcp_zerocopy_vm_insert_batch(vma, pages,
2181 pages_to_map,
2182 &address, &length,
2183 &seq, zc,
2184 total_bytes_to_map);
2185 if (ret)
2186 goto out;
2187 pages_to_map = 0;
2188 }
2189 }
2190 if (pages_to_map) {
2191 ret = tcp_zerocopy_vm_insert_batch(vma, pages, pages_to_map,
2192 &address, &length, &seq,
2193 zc, total_bytes_to_map);
2194 }
2195out:
2196 if (mmap_locked)
2197 mmap_read_unlock(current->mm);
2198 else
2199 vma_end_read(vma);
2200 /* Try to copy straggler data. */
2201 if (!ret)
2202 copylen = tcp_zc_handle_leftover(zc, sk, skb, &seq, copybuf_len, tss);
2203
2204 if (length + copylen) {
2205 WRITE_ONCE(tp->copied_seq, seq);
2206 tcp_rcv_space_adjust(sk);
2207
2208 /* Clean up data we have read: This will do ACK frames. */
2209 tcp_recv_skb(sk, seq, &offset);
2210 tcp_cleanup_rbuf(sk, length + copylen);
2211 ret = 0;
2212 if (length == zc->length)
2213 zc->recv_skip_hint = 0;
2214 } else {
2215 if (!zc->recv_skip_hint && sock_flag(sk, SOCK_DONE))
2216 ret = -EIO;
2217 }
2218 zc->length = length;
2219 return ret;
2220}
2221#endif
2222
2223/* Similar to __sock_recv_timestamp, but does not require an skb */
2224void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
2225 struct scm_timestamping_internal *tss)
2226{
2227 int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
2228 bool has_timestamping = false;
2229
2230 if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) {
2231 if (sock_flag(sk, SOCK_RCVTSTAMP)) {
2232 if (sock_flag(sk, SOCK_RCVTSTAMPNS)) {
2233 if (new_tstamp) {
2234 struct __kernel_timespec kts = {
2235 .tv_sec = tss->ts[0].tv_sec,
2236 .tv_nsec = tss->ts[0].tv_nsec,
2237 };
2238 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
2239 sizeof(kts), &kts);
2240 } else {
2241 struct __kernel_old_timespec ts_old = {
2242 .tv_sec = tss->ts[0].tv_sec,
2243 .tv_nsec = tss->ts[0].tv_nsec,
2244 };
2245 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
2246 sizeof(ts_old), &ts_old);
2247 }
2248 } else {
2249 if (new_tstamp) {
2250 struct __kernel_sock_timeval stv = {
2251 .tv_sec = tss->ts[0].tv_sec,
2252 .tv_usec = tss->ts[0].tv_nsec / 1000,
2253 };
2254 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
2255 sizeof(stv), &stv);
2256 } else {
2257 struct __kernel_old_timeval tv = {
2258 .tv_sec = tss->ts[0].tv_sec,
2259 .tv_usec = tss->ts[0].tv_nsec / 1000,
2260 };
2261 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
2262 sizeof(tv), &tv);
2263 }
2264 }
2265 }
2266
2267 if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_SOFTWARE)
2268 has_timestamping = true;
2269 else
2270 tss->ts[0] = (struct timespec64) {0};
2271 }
2272
2273 if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
2274 if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_RAW_HARDWARE)
2275 has_timestamping = true;
2276 else
2277 tss->ts[2] = (struct timespec64) {0};
2278 }
2279
2280 if (has_timestamping) {
2281 tss->ts[1] = (struct timespec64) {0};
2282 if (sock_flag(sk, SOCK_TSTAMP_NEW))
2283 put_cmsg_scm_timestamping64(msg, tss);
2284 else
2285 put_cmsg_scm_timestamping(msg, tss);
2286 }
2287}
2288
2289static int tcp_inq_hint(struct sock *sk)
2290{
2291 const struct tcp_sock *tp = tcp_sk(sk);
2292 u32 copied_seq = READ_ONCE(tp->copied_seq);
2293 u32 rcv_nxt = READ_ONCE(tp->rcv_nxt);
2294 int inq;
2295
2296 inq = rcv_nxt - copied_seq;
2297 if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) {
2298 lock_sock(sk);
2299 inq = tp->rcv_nxt - tp->copied_seq;
2300 release_sock(sk);
2301 }
2302 /* After receiving a FIN, tell the user-space to continue reading
2303 * by returning a non-zero inq.
2304 */
2305 if (inq == 0 && sock_flag(sk, SOCK_DONE))
2306 inq = 1;
2307 return inq;
2308}
2309
2310/*
2311 * This routine copies from a sock struct into the user buffer.
2312 *
2313 * Technical note: in 2.3 we work on _locked_ socket, so that
2314 * tricks with *seq access order and skb->users are not required.
2315 * Probably, code can be easily improved even more.
2316 */
2317
2318static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
2319 int flags, struct scm_timestamping_internal *tss,
2320 int *cmsg_flags)
2321{
2322 struct tcp_sock *tp = tcp_sk(sk);
2323 int copied = 0;
2324 u32 peek_seq;
2325 u32 *seq;
2326 unsigned long used;
2327 int err;
2328 int target; /* Read at least this many bytes */
2329 long timeo;
2330 struct sk_buff *skb, *last;
2331 u32 urg_hole = 0;
2332
2333 err = -ENOTCONN;
2334 if (sk->sk_state == TCP_LISTEN)
2335 goto out;
2336
2337 if (tp->recvmsg_inq) {
2338 *cmsg_flags = TCP_CMSG_INQ;
2339 msg->msg_get_inq = 1;
2340 }
2341 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2342
2343 /* Urgent data needs to be handled specially. */
2344 if (flags & MSG_OOB)
2345 goto recv_urg;
2346
2347 if (unlikely(tp->repair)) {
2348 err = -EPERM;
2349 if (!(flags & MSG_PEEK))
2350 goto out;
2351
2352 if (tp->repair_queue == TCP_SEND_QUEUE)
2353 goto recv_sndq;
2354
2355 err = -EINVAL;
2356 if (tp->repair_queue == TCP_NO_QUEUE)
2357 goto out;
2358
2359 /* 'common' recv queue MSG_PEEK-ing */
2360 }
2361
2362 seq = &tp->copied_seq;
2363 if (flags & MSG_PEEK) {
2364 peek_seq = tp->copied_seq;
2365 seq = &peek_seq;
2366 }
2367
2368 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2369
2370 do {
2371 u32 offset;
2372
2373 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
2374 if (unlikely(tp->urg_data) && tp->urg_seq == *seq) {
2375 if (copied)
2376 break;
2377 if (signal_pending(current)) {
2378 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
2379 break;
2380 }
2381 }
2382
2383 /* Next get a buffer. */
2384
2385 last = skb_peek_tail(&sk->sk_receive_queue);
2386 skb_queue_walk(&sk->sk_receive_queue, skb) {
2387 last = skb;
2388 /* Now that we have two receive queues this
2389 * shouldn't happen.
2390 */
2391 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
2392 "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n",
2393 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
2394 flags))
2395 break;
2396
2397 offset = *seq - TCP_SKB_CB(skb)->seq;
2398 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
2399 pr_err_once("%s: found a SYN, please report !\n", __func__);
2400 offset--;
2401 }
2402 if (offset < skb->len)
2403 goto found_ok_skb;
2404 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2405 goto found_fin_ok;
2406 WARN(!(flags & MSG_PEEK),
2407 "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n",
2408 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
2409 }
2410
2411 /* Well, if we have backlog, try to process it now yet. */
2412
2413 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
2414 break;
2415
2416 if (copied) {
2417 if (!timeo ||
2418 sk->sk_err ||
2419 sk->sk_state == TCP_CLOSE ||
2420 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2421 signal_pending(current))
2422 break;
2423 } else {
2424 if (sock_flag(sk, SOCK_DONE))
2425 break;
2426
2427 if (sk->sk_err) {
2428 copied = sock_error(sk);
2429 break;
2430 }
2431
2432 if (sk->sk_shutdown & RCV_SHUTDOWN)
2433 break;
2434
2435 if (sk->sk_state == TCP_CLOSE) {
2436 /* This occurs when user tries to read
2437 * from never connected socket.
2438 */
2439 copied = -ENOTCONN;
2440 break;
2441 }
2442
2443 if (!timeo) {
2444 copied = -EAGAIN;
2445 break;
2446 }
2447
2448 if (signal_pending(current)) {
2449 copied = sock_intr_errno(timeo);
2450 break;
2451 }
2452 }
2453
2454 if (copied >= target) {
2455 /* Do not sleep, just process backlog. */
2456 __sk_flush_backlog(sk);
2457 } else {
2458 tcp_cleanup_rbuf(sk, copied);
2459 err = sk_wait_data(sk, &timeo, last);
2460 if (err < 0) {
2461 err = copied ? : err;
2462 goto out;
2463 }
2464 }
2465
2466 if ((flags & MSG_PEEK) &&
2467 (peek_seq - copied - urg_hole != tp->copied_seq)) {
2468 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
2469 current->comm,
2470 task_pid_nr(current));
2471 peek_seq = tp->copied_seq;
2472 }
2473 continue;
2474
2475found_ok_skb:
2476 /* Ok so how much can we use? */
2477 used = skb->len - offset;
2478 if (len < used)
2479 used = len;
2480
2481 /* Do we have urgent data here? */
2482 if (unlikely(tp->urg_data)) {
2483 u32 urg_offset = tp->urg_seq - *seq;
2484 if (urg_offset < used) {
2485 if (!urg_offset) {
2486 if (!sock_flag(sk, SOCK_URGINLINE)) {
2487 WRITE_ONCE(*seq, *seq + 1);
2488 urg_hole++;
2489 offset++;
2490 used--;
2491 if (!used)
2492 goto skip_copy;
2493 }
2494 } else
2495 used = urg_offset;
2496 }
2497 }
2498
2499 if (!(flags & MSG_TRUNC)) {
2500 err = skb_copy_datagram_msg(skb, offset, msg, used);
2501 if (err) {
2502 /* Exception. Bailout! */
2503 if (!copied)
2504 copied = -EFAULT;
2505 break;
2506 }
2507 }
2508
2509 WRITE_ONCE(*seq, *seq + used);
2510 copied += used;
2511 len -= used;
2512
2513 tcp_rcv_space_adjust(sk);
2514
2515skip_copy:
2516 if (unlikely(tp->urg_data) && after(tp->copied_seq, tp->urg_seq)) {
2517 WRITE_ONCE(tp->urg_data, 0);
2518 tcp_fast_path_check(sk);
2519 }
2520
2521 if (TCP_SKB_CB(skb)->has_rxtstamp) {
2522 tcp_update_recv_tstamps(skb, tss);
2523 *cmsg_flags |= TCP_CMSG_TS;
2524 }
2525
2526 if (used + offset < skb->len)
2527 continue;
2528
2529 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2530 goto found_fin_ok;
2531 if (!(flags & MSG_PEEK))
2532 tcp_eat_recv_skb(sk, skb);
2533 continue;
2534
2535found_fin_ok:
2536 /* Process the FIN. */
2537 WRITE_ONCE(*seq, *seq + 1);
2538 if (!(flags & MSG_PEEK))
2539 tcp_eat_recv_skb(sk, skb);
2540 break;
2541 } while (len > 0);
2542
2543 /* According to UNIX98, msg_name/msg_namelen are ignored
2544 * on connected socket. I was just happy when found this 8) --ANK
2545 */
2546
2547 /* Clean up data we have read: This will do ACK frames. */
2548 tcp_cleanup_rbuf(sk, copied);
2549 return copied;
2550
2551out:
2552 return err;
2553
2554recv_urg:
2555 err = tcp_recv_urg(sk, msg, len, flags);
2556 goto out;
2557
2558recv_sndq:
2559 err = tcp_peek_sndq(sk, msg, len);
2560 goto out;
2561}
2562
2563int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
2564 int *addr_len)
2565{
2566 int cmsg_flags = 0, ret;
2567 struct scm_timestamping_internal tss;
2568
2569 if (unlikely(flags & MSG_ERRQUEUE))
2570 return inet_recv_error(sk, msg, len, addr_len);
2571
2572 if (sk_can_busy_loop(sk) &&
2573 skb_queue_empty_lockless(&sk->sk_receive_queue) &&
2574 sk->sk_state == TCP_ESTABLISHED)
2575 sk_busy_loop(sk, flags & MSG_DONTWAIT);
2576
2577 lock_sock(sk);
2578 ret = tcp_recvmsg_locked(sk, msg, len, flags, &tss, &cmsg_flags);
2579 release_sock(sk);
2580
2581 if ((cmsg_flags || msg->msg_get_inq) && ret >= 0) {
2582 if (cmsg_flags & TCP_CMSG_TS)
2583 tcp_recv_timestamp(msg, sk, &tss);
2584 if (msg->msg_get_inq) {
2585 msg->msg_inq = tcp_inq_hint(sk);
2586 if (cmsg_flags & TCP_CMSG_INQ)
2587 put_cmsg(msg, SOL_TCP, TCP_CM_INQ,
2588 sizeof(msg->msg_inq), &msg->msg_inq);
2589 }
2590 }
2591 return ret;
2592}
2593EXPORT_SYMBOL(tcp_recvmsg);
2594
2595void tcp_set_state(struct sock *sk, int state)
2596{
2597 int oldstate = sk->sk_state;
2598
2599 /* We defined a new enum for TCP states that are exported in BPF
2600 * so as not force the internal TCP states to be frozen. The
2601 * following checks will detect if an internal state value ever
2602 * differs from the BPF value. If this ever happens, then we will
2603 * need to remap the internal value to the BPF value before calling
2604 * tcp_call_bpf_2arg.
2605 */
2606 BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED);
2607 BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT);
2608 BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV);
2609 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1);
2610 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2);
2611 BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT);
2612 BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE);
2613 BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT);
2614 BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK);
2615 BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN);
2616 BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING);
2617 BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV);
2618 BUILD_BUG_ON((int)BPF_TCP_BOUND_INACTIVE != (int)TCP_BOUND_INACTIVE);
2619 BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES);
2620
2621 /* bpf uapi header bpf.h defines an anonymous enum with values
2622 * BPF_TCP_* used by bpf programs. Currently gcc built vmlinux
2623 * is able to emit this enum in DWARF due to the above BUILD_BUG_ON.
2624 * But clang built vmlinux does not have this enum in DWARF
2625 * since clang removes the above code before generating IR/debuginfo.
2626 * Let us explicitly emit the type debuginfo to ensure the
2627 * above-mentioned anonymous enum in the vmlinux DWARF and hence BTF
2628 * regardless of which compiler is used.
2629 */
2630 BTF_TYPE_EMIT_ENUM(BPF_TCP_ESTABLISHED);
2631
2632 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG))
2633 tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state);
2634
2635 switch (state) {
2636 case TCP_ESTABLISHED:
2637 if (oldstate != TCP_ESTABLISHED)
2638 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2639 break;
2640
2641 case TCP_CLOSE:
2642 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
2643 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
2644
2645 sk->sk_prot->unhash(sk);
2646 if (inet_csk(sk)->icsk_bind_hash &&
2647 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2648 inet_put_port(sk);
2649 fallthrough;
2650 default:
2651 if (oldstate == TCP_ESTABLISHED)
2652 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2653 }
2654
2655 /* Change state AFTER socket is unhashed to avoid closed
2656 * socket sitting in hash tables.
2657 */
2658 inet_sk_state_store(sk, state);
2659}
2660EXPORT_SYMBOL_GPL(tcp_set_state);
2661
2662/*
2663 * State processing on a close. This implements the state shift for
2664 * sending our FIN frame. Note that we only send a FIN for some
2665 * states. A shutdown() may have already sent the FIN, or we may be
2666 * closed.
2667 */
2668
2669static const unsigned char new_state[16] = {
2670 /* current state: new state: action: */
2671 [0 /* (Invalid) */] = TCP_CLOSE,
2672 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2673 [TCP_SYN_SENT] = TCP_CLOSE,
2674 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2675 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
2676 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
2677 [TCP_TIME_WAIT] = TCP_CLOSE,
2678 [TCP_CLOSE] = TCP_CLOSE,
2679 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
2680 [TCP_LAST_ACK] = TCP_LAST_ACK,
2681 [TCP_LISTEN] = TCP_CLOSE,
2682 [TCP_CLOSING] = TCP_CLOSING,
2683 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
2684};
2685
2686static int tcp_close_state(struct sock *sk)
2687{
2688 int next = (int)new_state[sk->sk_state];
2689 int ns = next & TCP_STATE_MASK;
2690
2691 tcp_set_state(sk, ns);
2692
2693 return next & TCP_ACTION_FIN;
2694}
2695
2696/*
2697 * Shutdown the sending side of a connection. Much like close except
2698 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
2699 */
2700
2701void tcp_shutdown(struct sock *sk, int how)
2702{
2703 /* We need to grab some memory, and put together a FIN,
2704 * and then put it into the queue to be sent.
2705 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
2706 */
2707 if (!(how & SEND_SHUTDOWN))
2708 return;
2709
2710 /* If we've already sent a FIN, or it's a closed state, skip this. */
2711 if ((1 << sk->sk_state) &
2712 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
2713 TCPF_CLOSE_WAIT)) {
2714 /* Clear out any half completed packets. FIN if needed. */
2715 if (tcp_close_state(sk))
2716 tcp_send_fin(sk);
2717 }
2718}
2719EXPORT_SYMBOL(tcp_shutdown);
2720
2721int tcp_orphan_count_sum(void)
2722{
2723 int i, total = 0;
2724
2725 for_each_possible_cpu(i)
2726 total += per_cpu(tcp_orphan_count, i);
2727
2728 return max(total, 0);
2729}
2730
2731static int tcp_orphan_cache;
2732static struct timer_list tcp_orphan_timer;
2733#define TCP_ORPHAN_TIMER_PERIOD msecs_to_jiffies(100)
2734
2735static void tcp_orphan_update(struct timer_list *unused)
2736{
2737 WRITE_ONCE(tcp_orphan_cache, tcp_orphan_count_sum());
2738 mod_timer(&tcp_orphan_timer, jiffies + TCP_ORPHAN_TIMER_PERIOD);
2739}
2740
2741static bool tcp_too_many_orphans(int shift)
2742{
2743 return READ_ONCE(tcp_orphan_cache) << shift >
2744 READ_ONCE(sysctl_tcp_max_orphans);
2745}
2746
2747bool tcp_check_oom(struct sock *sk, int shift)
2748{
2749 bool too_many_orphans, out_of_socket_memory;
2750
2751 too_many_orphans = tcp_too_many_orphans(shift);
2752 out_of_socket_memory = tcp_out_of_memory(sk);
2753
2754 if (too_many_orphans)
2755 net_info_ratelimited("too many orphaned sockets\n");
2756 if (out_of_socket_memory)
2757 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2758 return too_many_orphans || out_of_socket_memory;
2759}
2760
2761void __tcp_close(struct sock *sk, long timeout)
2762{
2763 struct sk_buff *skb;
2764 int data_was_unread = 0;
2765 int state;
2766
2767 WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);
2768
2769 if (sk->sk_state == TCP_LISTEN) {
2770 tcp_set_state(sk, TCP_CLOSE);
2771
2772 /* Special case. */
2773 inet_csk_listen_stop(sk);
2774
2775 goto adjudge_to_death;
2776 }
2777
2778 /* We need to flush the recv. buffs. We do this only on the
2779 * descriptor close, not protocol-sourced closes, because the
2780 * reader process may not have drained the data yet!
2781 */
2782 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
2783 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq;
2784
2785 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2786 len--;
2787 data_was_unread += len;
2788 __kfree_skb(skb);
2789 }
2790
2791 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2792 if (sk->sk_state == TCP_CLOSE)
2793 goto adjudge_to_death;
2794
2795 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2796 * data was lost. To witness the awful effects of the old behavior of
2797 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2798 * GET in an FTP client, suspend the process, wait for the client to
2799 * advertise a zero window, then kill -9 the FTP client, wheee...
2800 * Note: timeout is always zero in such a case.
2801 */
2802 if (unlikely(tcp_sk(sk)->repair)) {
2803 sk->sk_prot->disconnect(sk, 0);
2804 } else if (data_was_unread) {
2805 /* Unread data was tossed, zap the connection. */
2806 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
2807 tcp_set_state(sk, TCP_CLOSE);
2808 tcp_send_active_reset(sk, sk->sk_allocation);
2809 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
2810 /* Check zero linger _after_ checking for unread data. */
2811 sk->sk_prot->disconnect(sk, 0);
2812 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
2813 } else if (tcp_close_state(sk)) {
2814 /* We FIN if the application ate all the data before
2815 * zapping the connection.
2816 */
2817
2818 /* RED-PEN. Formally speaking, we have broken TCP state
2819 * machine. State transitions:
2820 *
2821 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2822 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (it is difficult)
2823 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2824 *
2825 * are legal only when FIN has been sent (i.e. in window),
2826 * rather than queued out of window. Purists blame.
2827 *
2828 * F.e. "RFC state" is ESTABLISHED,
2829 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2830 *
2831 * The visible declinations are that sometimes
2832 * we enter time-wait state, when it is not required really
2833 * (harmless), do not send active resets, when they are
2834 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2835 * they look as CLOSING or LAST_ACK for Linux)
2836 * Probably, I missed some more holelets.
2837 * --ANK
2838 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2839 * in a single packet! (May consider it later but will
2840 * probably need API support or TCP_CORK SYN-ACK until
2841 * data is written and socket is closed.)
2842 */
2843 tcp_send_fin(sk);
2844 }
2845
2846 sk_stream_wait_close(sk, timeout);
2847
2848adjudge_to_death:
2849 state = sk->sk_state;
2850 sock_hold(sk);
2851 sock_orphan(sk);
2852
2853 local_bh_disable();
2854 bh_lock_sock(sk);
2855 /* remove backlog if any, without releasing ownership. */
2856 __release_sock(sk);
2857
2858 this_cpu_inc(tcp_orphan_count);
2859
2860 /* Have we already been destroyed by a softirq or backlog? */
2861 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
2862 goto out;
2863
2864 /* This is a (useful) BSD violating of the RFC. There is a
2865 * problem with TCP as specified in that the other end could
2866 * keep a socket open forever with no application left this end.
2867 * We use a 1 minute timeout (about the same as BSD) then kill
2868 * our end. If they send after that then tough - BUT: long enough
2869 * that we won't make the old 4*rto = almost no time - whoops
2870 * reset mistake.
2871 *
2872 * Nope, it was not mistake. It is really desired behaviour
2873 * f.e. on http servers, when such sockets are useless, but
2874 * consume significant resources. Let's do it with special
2875 * linger2 option. --ANK
2876 */
2877
2878 if (sk->sk_state == TCP_FIN_WAIT2) {
2879 struct tcp_sock *tp = tcp_sk(sk);
2880 if (READ_ONCE(tp->linger2) < 0) {
2881 tcp_set_state(sk, TCP_CLOSE);
2882 tcp_send_active_reset(sk, GFP_ATOMIC);
2883 __NET_INC_STATS(sock_net(sk),
2884 LINUX_MIB_TCPABORTONLINGER);
2885 } else {
2886 const int tmo = tcp_fin_time(sk);
2887
2888 if (tmo > TCP_TIMEWAIT_LEN) {
2889 inet_csk_reset_keepalive_timer(sk,
2890 tmo - TCP_TIMEWAIT_LEN);
2891 } else {
2892 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2893 goto out;
2894 }
2895 }
2896 }
2897 if (sk->sk_state != TCP_CLOSE) {
2898 if (tcp_check_oom(sk, 0)) {
2899 tcp_set_state(sk, TCP_CLOSE);
2900 tcp_send_active_reset(sk, GFP_ATOMIC);
2901 __NET_INC_STATS(sock_net(sk),
2902 LINUX_MIB_TCPABORTONMEMORY);
2903 } else if (!check_net(sock_net(sk))) {
2904 /* Not possible to send reset; just close */
2905 tcp_set_state(sk, TCP_CLOSE);
2906 }
2907 }
2908
2909 if (sk->sk_state == TCP_CLOSE) {
2910 struct request_sock *req;
2911
2912 req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk,
2913 lockdep_sock_is_held(sk));
2914 /* We could get here with a non-NULL req if the socket is
2915 * aborted (e.g., closed with unread data) before 3WHS
2916 * finishes.
2917 */
2918 if (req)
2919 reqsk_fastopen_remove(sk, req, false);
2920 inet_csk_destroy_sock(sk);
2921 }
2922 /* Otherwise, socket is reprieved until protocol close. */
2923
2924out:
2925 bh_unlock_sock(sk);
2926 local_bh_enable();
2927}
2928
2929void tcp_close(struct sock *sk, long timeout)
2930{
2931 lock_sock(sk);
2932 __tcp_close(sk, timeout);
2933 release_sock(sk);
2934 if (!sk->sk_net_refcnt)
2935 inet_csk_clear_xmit_timers_sync(sk);
2936 sock_put(sk);
2937}
2938EXPORT_SYMBOL(tcp_close);
2939
2940/* These states need RST on ABORT according to RFC793 */
2941
2942static inline bool tcp_need_reset(int state)
2943{
2944 return (1 << state) &
2945 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2946 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2947}
2948
2949static void tcp_rtx_queue_purge(struct sock *sk)
2950{
2951 struct rb_node *p = rb_first(&sk->tcp_rtx_queue);
2952
2953 tcp_sk(sk)->highest_sack = NULL;
2954 while (p) {
2955 struct sk_buff *skb = rb_to_skb(p);
2956
2957 p = rb_next(p);
2958 /* Since we are deleting whole queue, no need to
2959 * list_del(&skb->tcp_tsorted_anchor)
2960 */
2961 tcp_rtx_queue_unlink(skb, sk);
2962 tcp_wmem_free_skb(sk, skb);
2963 }
2964}
2965
2966void tcp_write_queue_purge(struct sock *sk)
2967{
2968 struct sk_buff *skb;
2969
2970 tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
2971 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
2972 tcp_skb_tsorted_anchor_cleanup(skb);
2973 tcp_wmem_free_skb(sk, skb);
2974 }
2975 tcp_rtx_queue_purge(sk);
2976 INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
2977 tcp_clear_all_retrans_hints(tcp_sk(sk));
2978 tcp_sk(sk)->packets_out = 0;
2979 inet_csk(sk)->icsk_backoff = 0;
2980}
2981
2982int tcp_disconnect(struct sock *sk, int flags)
2983{
2984 struct inet_sock *inet = inet_sk(sk);
2985 struct inet_connection_sock *icsk = inet_csk(sk);
2986 struct tcp_sock *tp = tcp_sk(sk);
2987 int old_state = sk->sk_state;
2988 u32 seq;
2989
2990 if (old_state != TCP_CLOSE)
2991 tcp_set_state(sk, TCP_CLOSE);
2992
2993 /* ABORT function of RFC793 */
2994 if (old_state == TCP_LISTEN) {
2995 inet_csk_listen_stop(sk);
2996 } else if (unlikely(tp->repair)) {
2997 WRITE_ONCE(sk->sk_err, ECONNABORTED);
2998 } else if (tcp_need_reset(old_state) ||
2999 (tp->snd_nxt != tp->write_seq &&
3000 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
3001 /* The last check adjusts for discrepancy of Linux wrt. RFC
3002 * states
3003 */
3004 tcp_send_active_reset(sk, gfp_any());
3005 WRITE_ONCE(sk->sk_err, ECONNRESET);
3006 } else if (old_state == TCP_SYN_SENT)
3007 WRITE_ONCE(sk->sk_err, ECONNRESET);
3008
3009 tcp_clear_xmit_timers(sk);
3010 __skb_queue_purge(&sk->sk_receive_queue);
3011 WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
3012 WRITE_ONCE(tp->urg_data, 0);
3013 tcp_write_queue_purge(sk);
3014 tcp_fastopen_active_disable_ofo_check(sk);
3015 skb_rbtree_purge(&tp->out_of_order_queue);
3016
3017 inet->inet_dport = 0;
3018
3019 inet_bhash2_reset_saddr(sk);
3020
3021 WRITE_ONCE(sk->sk_shutdown, 0);
3022 sock_reset_flag(sk, SOCK_DONE);
3023 tp->srtt_us = 0;
3024 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
3025 tp->rcv_rtt_last_tsecr = 0;
3026
3027 seq = tp->write_seq + tp->max_window + 2;
3028 if (!seq)
3029 seq = 1;
3030 WRITE_ONCE(tp->write_seq, seq);
3031
3032 icsk->icsk_backoff = 0;
3033 icsk->icsk_probes_out = 0;
3034 icsk->icsk_probes_tstamp = 0;
3035 icsk->icsk_rto = TCP_TIMEOUT_INIT;
3036 icsk->icsk_rto_min = TCP_RTO_MIN;
3037 icsk->icsk_delack_max = TCP_DELACK_MAX;
3038 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
3039 tcp_snd_cwnd_set(tp, TCP_INIT_CWND);
3040 tp->snd_cwnd_cnt = 0;
3041 tp->is_cwnd_limited = 0;
3042 tp->max_packets_out = 0;
3043 tp->window_clamp = 0;
3044 tp->delivered = 0;
3045 tp->delivered_ce = 0;
3046 if (icsk->icsk_ca_ops->release)
3047 icsk->icsk_ca_ops->release(sk);
3048 memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
3049 icsk->icsk_ca_initialized = 0;
3050 tcp_set_ca_state(sk, TCP_CA_Open);
3051 tp->is_sack_reneg = 0;
3052 tcp_clear_retrans(tp);
3053 tp->total_retrans = 0;
3054 inet_csk_delack_init(sk);
3055 /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0
3056 * issue in __tcp_select_window()
3057 */
3058 icsk->icsk_ack.rcv_mss = TCP_MIN_MSS;
3059 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
3060 __sk_dst_reset(sk);
3061 dst_release(xchg((__force struct dst_entry **)&sk->sk_rx_dst, NULL));
3062 tcp_saved_syn_free(tp);
3063 tp->compressed_ack = 0;
3064 tp->segs_in = 0;
3065 tp->segs_out = 0;
3066 tp->bytes_sent = 0;
3067 tp->bytes_acked = 0;
3068 tp->bytes_received = 0;
3069 tp->bytes_retrans = 0;
3070 tp->data_segs_in = 0;
3071 tp->data_segs_out = 0;
3072 tp->duplicate_sack[0].start_seq = 0;
3073 tp->duplicate_sack[0].end_seq = 0;
3074 tp->dsack_dups = 0;
3075 tp->reord_seen = 0;
3076 tp->retrans_out = 0;
3077 tp->sacked_out = 0;
3078 tp->tlp_high_seq = 0;
3079 tp->last_oow_ack_time = 0;
3080 tp->plb_rehash = 0;
3081 /* There's a bubble in the pipe until at least the first ACK. */
3082 tp->app_limited = ~0U;
3083 tp->rate_app_limited = 1;
3084 tp->rack.mstamp = 0;
3085 tp->rack.advanced = 0;
3086 tp->rack.reo_wnd_steps = 1;
3087 tp->rack.last_delivered = 0;
3088 tp->rack.reo_wnd_persist = 0;
3089 tp->rack.dsack_seen = 0;
3090 tp->syn_data_acked = 0;
3091 tp->rx_opt.saw_tstamp = 0;
3092 tp->rx_opt.dsack = 0;
3093 tp->rx_opt.num_sacks = 0;
3094 tp->rcv_ooopack = 0;
3095
3096
3097 /* Clean up fastopen related fields */
3098 tcp_free_fastopen_req(tp);
3099 inet_clear_bit(DEFER_CONNECT, sk);
3100 tp->fastopen_client_fail = 0;
3101
3102 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
3103
3104 if (sk->sk_frag.page) {
3105 put_page(sk->sk_frag.page);
3106 sk->sk_frag.page = NULL;
3107 sk->sk_frag.offset = 0;
3108 }
3109 sk_error_report(sk);
3110 return 0;
3111}
3112EXPORT_SYMBOL(tcp_disconnect);
3113
3114static inline bool tcp_can_repair_sock(const struct sock *sk)
3115{
3116 return sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
3117 (sk->sk_state != TCP_LISTEN);
3118}
3119
3120static int tcp_repair_set_window(struct tcp_sock *tp, sockptr_t optbuf, int len)
3121{
3122 struct tcp_repair_window opt;
3123
3124 if (!tp->repair)
3125 return -EPERM;
3126
3127 if (len != sizeof(opt))
3128 return -EINVAL;
3129
3130 if (copy_from_sockptr(&opt, optbuf, sizeof(opt)))
3131 return -EFAULT;
3132
3133 if (opt.max_window < opt.snd_wnd)
3134 return -EINVAL;
3135
3136 if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd))
3137 return -EINVAL;
3138
3139 if (after(opt.rcv_wup, tp->rcv_nxt))
3140 return -EINVAL;
3141
3142 tp->snd_wl1 = opt.snd_wl1;
3143 tp->snd_wnd = opt.snd_wnd;
3144 tp->max_window = opt.max_window;
3145
3146 tp->rcv_wnd = opt.rcv_wnd;
3147 tp->rcv_wup = opt.rcv_wup;
3148
3149 return 0;
3150}
3151
3152static int tcp_repair_options_est(struct sock *sk, sockptr_t optbuf,
3153 unsigned int len)
3154{
3155 struct tcp_sock *tp = tcp_sk(sk);
3156 struct tcp_repair_opt opt;
3157 size_t offset = 0;
3158
3159 while (len >= sizeof(opt)) {
3160 if (copy_from_sockptr_offset(&opt, optbuf, offset, sizeof(opt)))
3161 return -EFAULT;
3162
3163 offset += sizeof(opt);
3164 len -= sizeof(opt);
3165
3166 switch (opt.opt_code) {
3167 case TCPOPT_MSS:
3168 tp->rx_opt.mss_clamp = opt.opt_val;
3169 tcp_mtup_init(sk);
3170 break;
3171 case TCPOPT_WINDOW:
3172 {
3173 u16 snd_wscale = opt.opt_val & 0xFFFF;
3174 u16 rcv_wscale = opt.opt_val >> 16;
3175
3176 if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
3177 return -EFBIG;
3178
3179 tp->rx_opt.snd_wscale = snd_wscale;
3180 tp->rx_opt.rcv_wscale = rcv_wscale;
3181 tp->rx_opt.wscale_ok = 1;
3182 }
3183 break;
3184 case TCPOPT_SACK_PERM:
3185 if (opt.opt_val != 0)
3186 return -EINVAL;
3187
3188 tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
3189 break;
3190 case TCPOPT_TIMESTAMP:
3191 if (opt.opt_val != 0)
3192 return -EINVAL;
3193
3194 tp->rx_opt.tstamp_ok = 1;
3195 break;
3196 }
3197 }
3198
3199 return 0;
3200}
3201
3202DEFINE_STATIC_KEY_FALSE(tcp_tx_delay_enabled);
3203EXPORT_SYMBOL(tcp_tx_delay_enabled);
3204
3205static void tcp_enable_tx_delay(void)
3206{
3207 if (!static_branch_unlikely(&tcp_tx_delay_enabled)) {
3208 static int __tcp_tx_delay_enabled = 0;
3209
3210 if (cmpxchg(&__tcp_tx_delay_enabled, 0, 1) == 0) {
3211 static_branch_enable(&tcp_tx_delay_enabled);
3212 pr_info("TCP_TX_DELAY enabled\n");
3213 }
3214 }
3215}
3216
3217/* When set indicates to always queue non-full frames. Later the user clears
3218 * this option and we transmit any pending partial frames in the queue. This is
3219 * meant to be used alongside sendfile() to get properly filled frames when the
3220 * user (for example) must write out headers with a write() call first and then
3221 * use sendfile to send out the data parts.
3222 *
3223 * TCP_CORK can be set together with TCP_NODELAY and it is stronger than
3224 * TCP_NODELAY.
3225 */
3226void __tcp_sock_set_cork(struct sock *sk, bool on)
3227{
3228 struct tcp_sock *tp = tcp_sk(sk);
3229
3230 if (on) {
3231 tp->nonagle |= TCP_NAGLE_CORK;
3232 } else {
3233 tp->nonagle &= ~TCP_NAGLE_CORK;
3234 if (tp->nonagle & TCP_NAGLE_OFF)
3235 tp->nonagle |= TCP_NAGLE_PUSH;
3236 tcp_push_pending_frames(sk);
3237 }
3238}
3239
3240void tcp_sock_set_cork(struct sock *sk, bool on)
3241{
3242 lock_sock(sk);
3243 __tcp_sock_set_cork(sk, on);
3244 release_sock(sk);
3245}
3246EXPORT_SYMBOL(tcp_sock_set_cork);
3247
3248/* TCP_NODELAY is weaker than TCP_CORK, so that this option on corked socket is
3249 * remembered, but it is not activated until cork is cleared.
3250 *
3251 * However, when TCP_NODELAY is set we make an explicit push, which overrides
3252 * even TCP_CORK for currently queued segments.
3253 */
3254void __tcp_sock_set_nodelay(struct sock *sk, bool on)
3255{
3256 if (on) {
3257 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
3258 tcp_push_pending_frames(sk);
3259 } else {
3260 tcp_sk(sk)->nonagle &= ~TCP_NAGLE_OFF;
3261 }
3262}
3263
3264void tcp_sock_set_nodelay(struct sock *sk)
3265{
3266 lock_sock(sk);
3267 __tcp_sock_set_nodelay(sk, true);
3268 release_sock(sk);
3269}
3270EXPORT_SYMBOL(tcp_sock_set_nodelay);
3271
3272static void __tcp_sock_set_quickack(struct sock *sk, int val)
3273{
3274 if (!val) {
3275 inet_csk_enter_pingpong_mode(sk);
3276 return;
3277 }
3278
3279 inet_csk_exit_pingpong_mode(sk);
3280 if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
3281 inet_csk_ack_scheduled(sk)) {
3282 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_PUSHED;
3283 tcp_cleanup_rbuf(sk, 1);
3284 if (!(val & 1))
3285 inet_csk_enter_pingpong_mode(sk);
3286 }
3287}
3288
3289void tcp_sock_set_quickack(struct sock *sk, int val)
3290{
3291 lock_sock(sk);
3292 __tcp_sock_set_quickack(sk, val);
3293 release_sock(sk);
3294}
3295EXPORT_SYMBOL(tcp_sock_set_quickack);
3296
3297int tcp_sock_set_syncnt(struct sock *sk, int val)
3298{
3299 if (val < 1 || val > MAX_TCP_SYNCNT)
3300 return -EINVAL;
3301
3302 WRITE_ONCE(inet_csk(sk)->icsk_syn_retries, val);
3303 return 0;
3304}
3305EXPORT_SYMBOL(tcp_sock_set_syncnt);
3306
3307int tcp_sock_set_user_timeout(struct sock *sk, int val)
3308{
3309 /* Cap the max time in ms TCP will retry or probe the window
3310 * before giving up and aborting (ETIMEDOUT) a connection.
3311 */
3312 if (val < 0)
3313 return -EINVAL;
3314
3315 WRITE_ONCE(inet_csk(sk)->icsk_user_timeout, val);
3316 return 0;
3317}
3318EXPORT_SYMBOL(tcp_sock_set_user_timeout);
3319
3320int tcp_sock_set_keepidle_locked(struct sock *sk, int val)
3321{
3322 struct tcp_sock *tp = tcp_sk(sk);
3323
3324 if (val < 1 || val > MAX_TCP_KEEPIDLE)
3325 return -EINVAL;
3326
3327 /* Paired with WRITE_ONCE() in keepalive_time_when() */
3328 WRITE_ONCE(tp->keepalive_time, val * HZ);
3329 if (sock_flag(sk, SOCK_KEEPOPEN) &&
3330 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
3331 u32 elapsed = keepalive_time_elapsed(tp);
3332
3333 if (tp->keepalive_time > elapsed)
3334 elapsed = tp->keepalive_time - elapsed;
3335 else
3336 elapsed = 0;
3337 inet_csk_reset_keepalive_timer(sk, elapsed);
3338 }
3339
3340 return 0;
3341}
3342
3343int tcp_sock_set_keepidle(struct sock *sk, int val)
3344{
3345 int err;
3346
3347 lock_sock(sk);
3348 err = tcp_sock_set_keepidle_locked(sk, val);
3349 release_sock(sk);
3350 return err;
3351}
3352EXPORT_SYMBOL(tcp_sock_set_keepidle);
3353
3354int tcp_sock_set_keepintvl(struct sock *sk, int val)
3355{
3356 if (val < 1 || val > MAX_TCP_KEEPINTVL)
3357 return -EINVAL;
3358
3359 WRITE_ONCE(tcp_sk(sk)->keepalive_intvl, val * HZ);
3360 return 0;
3361}
3362EXPORT_SYMBOL(tcp_sock_set_keepintvl);
3363
3364int tcp_sock_set_keepcnt(struct sock *sk, int val)
3365{
3366 if (val < 1 || val > MAX_TCP_KEEPCNT)
3367 return -EINVAL;
3368
3369 /* Paired with READ_ONCE() in keepalive_probes() */
3370 WRITE_ONCE(tcp_sk(sk)->keepalive_probes, val);
3371 return 0;
3372}
3373EXPORT_SYMBOL(tcp_sock_set_keepcnt);
3374
3375int tcp_set_window_clamp(struct sock *sk, int val)
3376{
3377 struct tcp_sock *tp = tcp_sk(sk);
3378
3379 if (!val) {
3380 if (sk->sk_state != TCP_CLOSE)
3381 return -EINVAL;
3382 tp->window_clamp = 0;
3383 } else {
3384 u32 new_rcv_ssthresh, old_window_clamp = tp->window_clamp;
3385 u32 new_window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
3386 SOCK_MIN_RCVBUF / 2 : val;
3387
3388 if (new_window_clamp == old_window_clamp)
3389 return 0;
3390
3391 tp->window_clamp = new_window_clamp;
3392 if (new_window_clamp < old_window_clamp) {
3393 /* need to apply the reserved mem provisioning only
3394 * when shrinking the window clamp
3395 */
3396 __tcp_adjust_rcv_ssthresh(sk, tp->window_clamp);
3397
3398 } else {
3399 new_rcv_ssthresh = min(tp->rcv_wnd, tp->window_clamp);
3400 tp->rcv_ssthresh = max(new_rcv_ssthresh,
3401 tp->rcv_ssthresh);
3402 }
3403 }
3404 return 0;
3405}
3406
3407/*
3408 * Socket option code for TCP.
3409 */
3410int do_tcp_setsockopt(struct sock *sk, int level, int optname,
3411 sockptr_t optval, unsigned int optlen)
3412{
3413 struct tcp_sock *tp = tcp_sk(sk);
3414 struct inet_connection_sock *icsk = inet_csk(sk);
3415 struct net *net = sock_net(sk);
3416 int val;
3417 int err = 0;
3418
3419 /* These are data/string values, all the others are ints */
3420 switch (optname) {
3421 case TCP_CONGESTION: {
3422 char name[TCP_CA_NAME_MAX];
3423
3424 if (optlen < 1)
3425 return -EINVAL;
3426
3427 val = strncpy_from_sockptr(name, optval,
3428 min_t(long, TCP_CA_NAME_MAX-1, optlen));
3429 if (val < 0)
3430 return -EFAULT;
3431 name[val] = 0;
3432
3433 sockopt_lock_sock(sk);
3434 err = tcp_set_congestion_control(sk, name, !has_current_bpf_ctx(),
3435 sockopt_ns_capable(sock_net(sk)->user_ns,
3436 CAP_NET_ADMIN));
3437 sockopt_release_sock(sk);
3438 return err;
3439 }
3440 case TCP_ULP: {
3441 char name[TCP_ULP_NAME_MAX];
3442
3443 if (optlen < 1)
3444 return -EINVAL;
3445
3446 val = strncpy_from_sockptr(name, optval,
3447 min_t(long, TCP_ULP_NAME_MAX - 1,
3448 optlen));
3449 if (val < 0)
3450 return -EFAULT;
3451 name[val] = 0;
3452
3453 sockopt_lock_sock(sk);
3454 err = tcp_set_ulp(sk, name);
3455 sockopt_release_sock(sk);
3456 return err;
3457 }
3458 case TCP_FASTOPEN_KEY: {
3459 __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH];
3460 __u8 *backup_key = NULL;
3461
3462 /* Allow a backup key as well to facilitate key rotation
3463 * First key is the active one.
3464 */
3465 if (optlen != TCP_FASTOPEN_KEY_LENGTH &&
3466 optlen != TCP_FASTOPEN_KEY_BUF_LENGTH)
3467 return -EINVAL;
3468
3469 if (copy_from_sockptr(key, optval, optlen))
3470 return -EFAULT;
3471
3472 if (optlen == TCP_FASTOPEN_KEY_BUF_LENGTH)
3473 backup_key = key + TCP_FASTOPEN_KEY_LENGTH;
3474
3475 return tcp_fastopen_reset_cipher(net, sk, key, backup_key);
3476 }
3477 default:
3478 /* fallthru */
3479 break;
3480 }
3481
3482 if (optlen < sizeof(int))
3483 return -EINVAL;
3484
3485 if (copy_from_sockptr(&val, optval, sizeof(val)))
3486 return -EFAULT;
3487
3488 /* Handle options that can be set without locking the socket. */
3489 switch (optname) {
3490 case TCP_SYNCNT:
3491 return tcp_sock_set_syncnt(sk, val);
3492 case TCP_USER_TIMEOUT:
3493 return tcp_sock_set_user_timeout(sk, val);
3494 case TCP_KEEPINTVL:
3495 return tcp_sock_set_keepintvl(sk, val);
3496 case TCP_KEEPCNT:
3497 return tcp_sock_set_keepcnt(sk, val);
3498 case TCP_LINGER2:
3499 if (val < 0)
3500 WRITE_ONCE(tp->linger2, -1);
3501 else if (val > TCP_FIN_TIMEOUT_MAX / HZ)
3502 WRITE_ONCE(tp->linger2, TCP_FIN_TIMEOUT_MAX);
3503 else
3504 WRITE_ONCE(tp->linger2, val * HZ);
3505 return 0;
3506 case TCP_DEFER_ACCEPT:
3507 /* Translate value in seconds to number of retransmits */
3508 WRITE_ONCE(icsk->icsk_accept_queue.rskq_defer_accept,
3509 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
3510 TCP_RTO_MAX / HZ));
3511 return 0;
3512 }
3513
3514 sockopt_lock_sock(sk);
3515
3516 switch (optname) {
3517 case TCP_MAXSEG:
3518 /* Values greater than interface MTU won't take effect. However
3519 * at the point when this call is done we typically don't yet
3520 * know which interface is going to be used
3521 */
3522 if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
3523 err = -EINVAL;
3524 break;
3525 }
3526 tp->rx_opt.user_mss = val;
3527 break;
3528
3529 case TCP_NODELAY:
3530 __tcp_sock_set_nodelay(sk, val);
3531 break;
3532
3533 case TCP_THIN_LINEAR_TIMEOUTS:
3534 if (val < 0 || val > 1)
3535 err = -EINVAL;
3536 else
3537 tp->thin_lto = val;
3538 break;
3539
3540 case TCP_THIN_DUPACK:
3541 if (val < 0 || val > 1)
3542 err = -EINVAL;
3543 break;
3544
3545 case TCP_REPAIR:
3546 if (!tcp_can_repair_sock(sk))
3547 err = -EPERM;
3548 else if (val == TCP_REPAIR_ON) {
3549 tp->repair = 1;
3550 sk->sk_reuse = SK_FORCE_REUSE;
3551 tp->repair_queue = TCP_NO_QUEUE;
3552 } else if (val == TCP_REPAIR_OFF) {
3553 tp->repair = 0;
3554 sk->sk_reuse = SK_NO_REUSE;
3555 tcp_send_window_probe(sk);
3556 } else if (val == TCP_REPAIR_OFF_NO_WP) {
3557 tp->repair = 0;
3558 sk->sk_reuse = SK_NO_REUSE;
3559 } else
3560 err = -EINVAL;
3561
3562 break;
3563
3564 case TCP_REPAIR_QUEUE:
3565 if (!tp->repair)
3566 err = -EPERM;
3567 else if ((unsigned int)val < TCP_QUEUES_NR)
3568 tp->repair_queue = val;
3569 else
3570 err = -EINVAL;
3571 break;
3572
3573 case TCP_QUEUE_SEQ:
3574 if (sk->sk_state != TCP_CLOSE) {
3575 err = -EPERM;
3576 } else if (tp->repair_queue == TCP_SEND_QUEUE) {
3577 if (!tcp_rtx_queue_empty(sk))
3578 err = -EPERM;
3579 else
3580 WRITE_ONCE(tp->write_seq, val);
3581 } else if (tp->repair_queue == TCP_RECV_QUEUE) {
3582 if (tp->rcv_nxt != tp->copied_seq) {
3583 err = -EPERM;
3584 } else {
3585 WRITE_ONCE(tp->rcv_nxt, val);
3586 WRITE_ONCE(tp->copied_seq, val);
3587 }
3588 } else {
3589 err = -EINVAL;
3590 }
3591 break;
3592
3593 case TCP_REPAIR_OPTIONS:
3594 if (!tp->repair)
3595 err = -EINVAL;
3596 else if (sk->sk_state == TCP_ESTABLISHED && !tp->bytes_sent)
3597 err = tcp_repair_options_est(sk, optval, optlen);
3598 else
3599 err = -EPERM;
3600 break;
3601
3602 case TCP_CORK:
3603 __tcp_sock_set_cork(sk, val);
3604 break;
3605
3606 case TCP_KEEPIDLE:
3607 err = tcp_sock_set_keepidle_locked(sk, val);
3608 break;
3609 case TCP_SAVE_SYN:
3610 /* 0: disable, 1: enable, 2: start from ether_header */
3611 if (val < 0 || val > 2)
3612 err = -EINVAL;
3613 else
3614 tp->save_syn = val;
3615 break;
3616
3617 case TCP_WINDOW_CLAMP:
3618 err = tcp_set_window_clamp(sk, val);
3619 break;
3620
3621 case TCP_QUICKACK:
3622 __tcp_sock_set_quickack(sk, val);
3623 break;
3624
3625 case TCP_AO_REPAIR:
3626 if (!tcp_can_repair_sock(sk)) {
3627 err = -EPERM;
3628 break;
3629 }
3630 err = tcp_ao_set_repair(sk, optval, optlen);
3631 break;
3632#ifdef CONFIG_TCP_AO
3633 case TCP_AO_ADD_KEY:
3634 case TCP_AO_DEL_KEY:
3635 case TCP_AO_INFO: {
3636 /* If this is the first TCP-AO setsockopt() on the socket,
3637 * sk_state has to be LISTEN or CLOSE. Allow TCP_REPAIR
3638 * in any state.
3639 */
3640 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
3641 goto ao_parse;
3642 if (rcu_dereference_protected(tcp_sk(sk)->ao_info,
3643 lockdep_sock_is_held(sk)))
3644 goto ao_parse;
3645 if (tp->repair)
3646 goto ao_parse;
3647 err = -EISCONN;
3648 break;
3649ao_parse:
3650 err = tp->af_specific->ao_parse(sk, optname, optval, optlen);
3651 break;
3652 }
3653#endif
3654#ifdef CONFIG_TCP_MD5SIG
3655 case TCP_MD5SIG:
3656 case TCP_MD5SIG_EXT:
3657 err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
3658 break;
3659#endif
3660 case TCP_FASTOPEN:
3661 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
3662 TCPF_LISTEN))) {
3663 tcp_fastopen_init_key_once(net);
3664
3665 fastopen_queue_tune(sk, val);
3666 } else {
3667 err = -EINVAL;
3668 }
3669 break;
3670 case TCP_FASTOPEN_CONNECT:
3671 if (val > 1 || val < 0) {
3672 err = -EINVAL;
3673 } else if (READ_ONCE(net->ipv4.sysctl_tcp_fastopen) &
3674 TFO_CLIENT_ENABLE) {
3675 if (sk->sk_state == TCP_CLOSE)
3676 tp->fastopen_connect = val;
3677 else
3678 err = -EINVAL;
3679 } else {
3680 err = -EOPNOTSUPP;
3681 }
3682 break;
3683 case TCP_FASTOPEN_NO_COOKIE:
3684 if (val > 1 || val < 0)
3685 err = -EINVAL;
3686 else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
3687 err = -EINVAL;
3688 else
3689 tp->fastopen_no_cookie = val;
3690 break;
3691 case TCP_TIMESTAMP:
3692 if (!tp->repair) {
3693 err = -EPERM;
3694 break;
3695 }
3696 /* val is an opaque field,
3697 * and low order bit contains usec_ts enable bit.
3698 * Its a best effort, and we do not care if user makes an error.
3699 */
3700 tp->tcp_usec_ts = val & 1;
3701 WRITE_ONCE(tp->tsoffset, val - tcp_clock_ts(tp->tcp_usec_ts));
3702 break;
3703 case TCP_REPAIR_WINDOW:
3704 err = tcp_repair_set_window(tp, optval, optlen);
3705 break;
3706 case TCP_NOTSENT_LOWAT:
3707 WRITE_ONCE(tp->notsent_lowat, val);
3708 sk->sk_write_space(sk);
3709 break;
3710 case TCP_INQ:
3711 if (val > 1 || val < 0)
3712 err = -EINVAL;
3713 else
3714 tp->recvmsg_inq = val;
3715 break;
3716 case TCP_TX_DELAY:
3717 if (val)
3718 tcp_enable_tx_delay();
3719 WRITE_ONCE(tp->tcp_tx_delay, val);
3720 break;
3721 default:
3722 err = -ENOPROTOOPT;
3723 break;
3724 }
3725
3726 sockopt_release_sock(sk);
3727 return err;
3728}
3729
3730int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
3731 unsigned int optlen)
3732{
3733 const struct inet_connection_sock *icsk = inet_csk(sk);
3734
3735 if (level != SOL_TCP)
3736 /* Paired with WRITE_ONCE() in do_ipv6_setsockopt() and tcp_v6_connect() */
3737 return READ_ONCE(icsk->icsk_af_ops)->setsockopt(sk, level, optname,
3738 optval, optlen);
3739 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
3740}
3741EXPORT_SYMBOL(tcp_setsockopt);
3742
3743static void tcp_get_info_chrono_stats(const struct tcp_sock *tp,
3744 struct tcp_info *info)
3745{
3746 u64 stats[__TCP_CHRONO_MAX], total = 0;
3747 enum tcp_chrono i;
3748
3749 for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) {
3750 stats[i] = tp->chrono_stat[i - 1];
3751 if (i == tp->chrono_type)
3752 stats[i] += tcp_jiffies32 - tp->chrono_start;
3753 stats[i] *= USEC_PER_SEC / HZ;
3754 total += stats[i];
3755 }
3756
3757 info->tcpi_busy_time = total;
3758 info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED];
3759 info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED];
3760}
3761
3762/* Return information about state of tcp endpoint in API format. */
3763void tcp_get_info(struct sock *sk, struct tcp_info *info)
3764{
3765 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
3766 const struct inet_connection_sock *icsk = inet_csk(sk);
3767 unsigned long rate;
3768 u32 now;
3769 u64 rate64;
3770 bool slow;
3771
3772 memset(info, 0, sizeof(*info));
3773 if (sk->sk_type != SOCK_STREAM)
3774 return;
3775
3776 info->tcpi_state = inet_sk_state_load(sk);
3777
3778 /* Report meaningful fields for all TCP states, including listeners */
3779 rate = READ_ONCE(sk->sk_pacing_rate);
3780 rate64 = (rate != ~0UL) ? rate : ~0ULL;
3781 info->tcpi_pacing_rate = rate64;
3782
3783 rate = READ_ONCE(sk->sk_max_pacing_rate);
3784 rate64 = (rate != ~0UL) ? rate : ~0ULL;
3785 info->tcpi_max_pacing_rate = rate64;
3786
3787 info->tcpi_reordering = tp->reordering;
3788 info->tcpi_snd_cwnd = tcp_snd_cwnd(tp);
3789
3790 if (info->tcpi_state == TCP_LISTEN) {
3791 /* listeners aliased fields :
3792 * tcpi_unacked -> Number of children ready for accept()
3793 * tcpi_sacked -> max backlog
3794 */
3795 info->tcpi_unacked = READ_ONCE(sk->sk_ack_backlog);
3796 info->tcpi_sacked = READ_ONCE(sk->sk_max_ack_backlog);
3797 return;
3798 }
3799
3800 slow = lock_sock_fast(sk);
3801
3802 info->tcpi_ca_state = icsk->icsk_ca_state;
3803 info->tcpi_retransmits = icsk->icsk_retransmits;
3804 info->tcpi_probes = icsk->icsk_probes_out;
3805 info->tcpi_backoff = icsk->icsk_backoff;
3806
3807 if (tp->rx_opt.tstamp_ok)
3808 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
3809 if (tcp_is_sack(tp))
3810 info->tcpi_options |= TCPI_OPT_SACK;
3811 if (tp->rx_opt.wscale_ok) {
3812 info->tcpi_options |= TCPI_OPT_WSCALE;
3813 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
3814 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
3815 }
3816
3817 if (tp->ecn_flags & TCP_ECN_OK)
3818 info->tcpi_options |= TCPI_OPT_ECN;
3819 if (tp->ecn_flags & TCP_ECN_SEEN)
3820 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
3821 if (tp->syn_data_acked)
3822 info->tcpi_options |= TCPI_OPT_SYN_DATA;
3823 if (tp->tcp_usec_ts)
3824 info->tcpi_options |= TCPI_OPT_USEC_TS;
3825
3826 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
3827 info->tcpi_ato = jiffies_to_usecs(min_t(u32, icsk->icsk_ack.ato,
3828 tcp_delack_max(sk)));
3829 info->tcpi_snd_mss = tp->mss_cache;
3830 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
3831
3832 info->tcpi_unacked = tp->packets_out;
3833 info->tcpi_sacked = tp->sacked_out;
3834
3835 info->tcpi_lost = tp->lost_out;
3836 info->tcpi_retrans = tp->retrans_out;
3837
3838 now = tcp_jiffies32;
3839 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
3840 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
3841 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
3842
3843 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
3844 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
3845 info->tcpi_rtt = tp->srtt_us >> 3;
3846 info->tcpi_rttvar = tp->mdev_us >> 2;
3847 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
3848 info->tcpi_advmss = tp->advmss;
3849
3850 info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
3851 info->tcpi_rcv_space = tp->rcvq_space.space;
3852
3853 info->tcpi_total_retrans = tp->total_retrans;
3854
3855 info->tcpi_bytes_acked = tp->bytes_acked;
3856 info->tcpi_bytes_received = tp->bytes_received;
3857 info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
3858 tcp_get_info_chrono_stats(tp, info);
3859
3860 info->tcpi_segs_out = tp->segs_out;
3861
3862 /* segs_in and data_segs_in can be updated from tcp_segs_in() from BH */
3863 info->tcpi_segs_in = READ_ONCE(tp->segs_in);
3864 info->tcpi_data_segs_in = READ_ONCE(tp->data_segs_in);
3865
3866 info->tcpi_min_rtt = tcp_min_rtt(tp);
3867 info->tcpi_data_segs_out = tp->data_segs_out;
3868
3869 info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
3870 rate64 = tcp_compute_delivery_rate(tp);
3871 if (rate64)
3872 info->tcpi_delivery_rate = rate64;
3873 info->tcpi_delivered = tp->delivered;
3874 info->tcpi_delivered_ce = tp->delivered_ce;
3875 info->tcpi_bytes_sent = tp->bytes_sent;
3876 info->tcpi_bytes_retrans = tp->bytes_retrans;
3877 info->tcpi_dsack_dups = tp->dsack_dups;
3878 info->tcpi_reord_seen = tp->reord_seen;
3879 info->tcpi_rcv_ooopack = tp->rcv_ooopack;
3880 info->tcpi_snd_wnd = tp->snd_wnd;
3881 info->tcpi_rcv_wnd = tp->rcv_wnd;
3882 info->tcpi_rehash = tp->plb_rehash + tp->timeout_rehash;
3883 info->tcpi_fastopen_client_fail = tp->fastopen_client_fail;
3884
3885 info->tcpi_total_rto = tp->total_rto;
3886 info->tcpi_total_rto_recoveries = tp->total_rto_recoveries;
3887 info->tcpi_total_rto_time = tp->total_rto_time;
3888 if (tp->rto_stamp)
3889 info->tcpi_total_rto_time += tcp_clock_ms() - tp->rto_stamp;
3890
3891 unlock_sock_fast(sk, slow);
3892}
3893EXPORT_SYMBOL_GPL(tcp_get_info);
3894
3895static size_t tcp_opt_stats_get_size(void)
3896{
3897 return
3898 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BUSY */
3899 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_RWND_LIMITED */
3900 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_SNDBUF_LIMITED */
3901 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DATA_SEGS_OUT */
3902 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_TOTAL_RETRANS */
3903 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_PACING_RATE */
3904 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DELIVERY_RATE */
3905 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_CWND */
3906 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORDERING */
3907 nla_total_size(sizeof(u32)) + /* TCP_NLA_MIN_RTT */
3908 nla_total_size(sizeof(u8)) + /* TCP_NLA_RECUR_RETRANS */
3909 nla_total_size(sizeof(u8)) + /* TCP_NLA_DELIVERY_RATE_APP_LMT */
3910 nla_total_size(sizeof(u32)) + /* TCP_NLA_SNDQ_SIZE */
3911 nla_total_size(sizeof(u8)) + /* TCP_NLA_CA_STATE */
3912 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_SSTHRESH */
3913 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED */
3914 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */
3915 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */
3916 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */
3917 nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */
3918 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */
3919 nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */
3920 nla_total_size(sizeof(u16)) + /* TCP_NLA_TIMEOUT_REHASH */
3921 nla_total_size(sizeof(u32)) + /* TCP_NLA_BYTES_NOTSENT */
3922 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_EDT */
3923 nla_total_size(sizeof(u8)) + /* TCP_NLA_TTL */
3924 nla_total_size(sizeof(u32)) + /* TCP_NLA_REHASH */
3925 0;
3926}
3927
3928/* Returns TTL or hop limit of an incoming packet from skb. */
3929static u8 tcp_skb_ttl_or_hop_limit(const struct sk_buff *skb)
3930{
3931 if (skb->protocol == htons(ETH_P_IP))
3932 return ip_hdr(skb)->ttl;
3933 else if (skb->protocol == htons(ETH_P_IPV6))
3934 return ipv6_hdr(skb)->hop_limit;
3935 else
3936 return 0;
3937}
3938
3939struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
3940 const struct sk_buff *orig_skb,
3941 const struct sk_buff *ack_skb)
3942{
3943 const struct tcp_sock *tp = tcp_sk(sk);
3944 struct sk_buff *stats;
3945 struct tcp_info info;
3946 unsigned long rate;
3947 u64 rate64;
3948
3949 stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC);
3950 if (!stats)
3951 return NULL;
3952
3953 tcp_get_info_chrono_stats(tp, &info);
3954 nla_put_u64_64bit(stats, TCP_NLA_BUSY,
3955 info.tcpi_busy_time, TCP_NLA_PAD);
3956 nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED,
3957 info.tcpi_rwnd_limited, TCP_NLA_PAD);
3958 nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED,
3959 info.tcpi_sndbuf_limited, TCP_NLA_PAD);
3960 nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT,
3961 tp->data_segs_out, TCP_NLA_PAD);
3962 nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS,
3963 tp->total_retrans, TCP_NLA_PAD);
3964
3965 rate = READ_ONCE(sk->sk_pacing_rate);
3966 rate64 = (rate != ~0UL) ? rate : ~0ULL;
3967 nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD);
3968
3969 rate64 = tcp_compute_delivery_rate(tp);
3970 nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD);
3971
3972 nla_put_u32(stats, TCP_NLA_SND_CWND, tcp_snd_cwnd(tp));
3973 nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering);
3974 nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp));
3975
3976 nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits);
3977 nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited);
3978 nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh);
3979 nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered);
3980 nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce);
3981
3982 nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
3983 nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state);
3984
3985 nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent,
3986 TCP_NLA_PAD);
3987 nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans,
3988 TCP_NLA_PAD);
3989 nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups);
3990 nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen);
3991 nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3);
3992 nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash);
3993 nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT,
3994 max_t(int, 0, tp->write_seq - tp->snd_nxt));
3995 nla_put_u64_64bit(stats, TCP_NLA_EDT, orig_skb->skb_mstamp_ns,
3996 TCP_NLA_PAD);
3997 if (ack_skb)
3998 nla_put_u8(stats, TCP_NLA_TTL,
3999 tcp_skb_ttl_or_hop_limit(ack_skb));
4000
4001 nla_put_u32(stats, TCP_NLA_REHASH, tp->plb_rehash + tp->timeout_rehash);
4002 return stats;
4003}
4004
4005int do_tcp_getsockopt(struct sock *sk, int level,
4006 int optname, sockptr_t optval, sockptr_t optlen)
4007{
4008 struct inet_connection_sock *icsk = inet_csk(sk);
4009 struct tcp_sock *tp = tcp_sk(sk);
4010 struct net *net = sock_net(sk);
4011 int val, len;
4012
4013 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4014 return -EFAULT;
4015
4016 if (len < 0)
4017 return -EINVAL;
4018
4019 len = min_t(unsigned int, len, sizeof(int));
4020
4021 switch (optname) {
4022 case TCP_MAXSEG:
4023 val = tp->mss_cache;
4024 if (tp->rx_opt.user_mss &&
4025 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
4026 val = tp->rx_opt.user_mss;
4027 if (tp->repair)
4028 val = tp->rx_opt.mss_clamp;
4029 break;
4030 case TCP_NODELAY:
4031 val = !!(tp->nonagle&TCP_NAGLE_OFF);
4032 break;
4033 case TCP_CORK:
4034 val = !!(tp->nonagle&TCP_NAGLE_CORK);
4035 break;
4036 case TCP_KEEPIDLE:
4037 val = keepalive_time_when(tp) / HZ;
4038 break;
4039 case TCP_KEEPINTVL:
4040 val = keepalive_intvl_when(tp) / HZ;
4041 break;
4042 case TCP_KEEPCNT:
4043 val = keepalive_probes(tp);
4044 break;
4045 case TCP_SYNCNT:
4046 val = READ_ONCE(icsk->icsk_syn_retries) ? :
4047 READ_ONCE(net->ipv4.sysctl_tcp_syn_retries);
4048 break;
4049 case TCP_LINGER2:
4050 val = READ_ONCE(tp->linger2);
4051 if (val >= 0)
4052 val = (val ? : READ_ONCE(net->ipv4.sysctl_tcp_fin_timeout)) / HZ;
4053 break;
4054 case TCP_DEFER_ACCEPT:
4055 val = READ_ONCE(icsk->icsk_accept_queue.rskq_defer_accept);
4056 val = retrans_to_secs(val, TCP_TIMEOUT_INIT / HZ,
4057 TCP_RTO_MAX / HZ);
4058 break;
4059 case TCP_WINDOW_CLAMP:
4060 val = tp->window_clamp;
4061 break;
4062 case TCP_INFO: {
4063 struct tcp_info info;
4064
4065 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4066 return -EFAULT;
4067
4068 tcp_get_info(sk, &info);
4069
4070 len = min_t(unsigned int, len, sizeof(info));
4071 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4072 return -EFAULT;
4073 if (copy_to_sockptr(optval, &info, len))
4074 return -EFAULT;
4075 return 0;
4076 }
4077 case TCP_CC_INFO: {
4078 const struct tcp_congestion_ops *ca_ops;
4079 union tcp_cc_info info;
4080 size_t sz = 0;
4081 int attr;
4082
4083 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4084 return -EFAULT;
4085
4086 ca_ops = icsk->icsk_ca_ops;
4087 if (ca_ops && ca_ops->get_info)
4088 sz = ca_ops->get_info(sk, ~0U, &attr, &info);
4089
4090 len = min_t(unsigned int, len, sz);
4091 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4092 return -EFAULT;
4093 if (copy_to_sockptr(optval, &info, len))
4094 return -EFAULT;
4095 return 0;
4096 }
4097 case TCP_QUICKACK:
4098 val = !inet_csk_in_pingpong_mode(sk);
4099 break;
4100
4101 case TCP_CONGESTION:
4102 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4103 return -EFAULT;
4104 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
4105 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4106 return -EFAULT;
4107 if (copy_to_sockptr(optval, icsk->icsk_ca_ops->name, len))
4108 return -EFAULT;
4109 return 0;
4110
4111 case TCP_ULP:
4112 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4113 return -EFAULT;
4114 len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
4115 if (!icsk->icsk_ulp_ops) {
4116 len = 0;
4117 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4118 return -EFAULT;
4119 return 0;
4120 }
4121 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4122 return -EFAULT;
4123 if (copy_to_sockptr(optval, icsk->icsk_ulp_ops->name, len))
4124 return -EFAULT;
4125 return 0;
4126
4127 case TCP_FASTOPEN_KEY: {
4128 u64 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u64)];
4129 unsigned int key_len;
4130
4131 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4132 return -EFAULT;
4133
4134 key_len = tcp_fastopen_get_cipher(net, icsk, key) *
4135 TCP_FASTOPEN_KEY_LENGTH;
4136 len = min_t(unsigned int, len, key_len);
4137 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4138 return -EFAULT;
4139 if (copy_to_sockptr(optval, key, len))
4140 return -EFAULT;
4141 return 0;
4142 }
4143 case TCP_THIN_LINEAR_TIMEOUTS:
4144 val = tp->thin_lto;
4145 break;
4146
4147 case TCP_THIN_DUPACK:
4148 val = 0;
4149 break;
4150
4151 case TCP_REPAIR:
4152 val = tp->repair;
4153 break;
4154
4155 case TCP_REPAIR_QUEUE:
4156 if (tp->repair)
4157 val = tp->repair_queue;
4158 else
4159 return -EINVAL;
4160 break;
4161
4162 case TCP_REPAIR_WINDOW: {
4163 struct tcp_repair_window opt;
4164
4165 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4166 return -EFAULT;
4167
4168 if (len != sizeof(opt))
4169 return -EINVAL;
4170
4171 if (!tp->repair)
4172 return -EPERM;
4173
4174 opt.snd_wl1 = tp->snd_wl1;
4175 opt.snd_wnd = tp->snd_wnd;
4176 opt.max_window = tp->max_window;
4177 opt.rcv_wnd = tp->rcv_wnd;
4178 opt.rcv_wup = tp->rcv_wup;
4179
4180 if (copy_to_sockptr(optval, &opt, len))
4181 return -EFAULT;
4182 return 0;
4183 }
4184 case TCP_QUEUE_SEQ:
4185 if (tp->repair_queue == TCP_SEND_QUEUE)
4186 val = tp->write_seq;
4187 else if (tp->repair_queue == TCP_RECV_QUEUE)
4188 val = tp->rcv_nxt;
4189 else
4190 return -EINVAL;
4191 break;
4192
4193 case TCP_USER_TIMEOUT:
4194 val = READ_ONCE(icsk->icsk_user_timeout);
4195 break;
4196
4197 case TCP_FASTOPEN:
4198 val = READ_ONCE(icsk->icsk_accept_queue.fastopenq.max_qlen);
4199 break;
4200
4201 case TCP_FASTOPEN_CONNECT:
4202 val = tp->fastopen_connect;
4203 break;
4204
4205 case TCP_FASTOPEN_NO_COOKIE:
4206 val = tp->fastopen_no_cookie;
4207 break;
4208
4209 case TCP_TX_DELAY:
4210 val = READ_ONCE(tp->tcp_tx_delay);
4211 break;
4212
4213 case TCP_TIMESTAMP:
4214 val = tcp_clock_ts(tp->tcp_usec_ts) + READ_ONCE(tp->tsoffset);
4215 if (tp->tcp_usec_ts)
4216 val |= 1;
4217 else
4218 val &= ~1;
4219 break;
4220 case TCP_NOTSENT_LOWAT:
4221 val = READ_ONCE(tp->notsent_lowat);
4222 break;
4223 case TCP_INQ:
4224 val = tp->recvmsg_inq;
4225 break;
4226 case TCP_SAVE_SYN:
4227 val = tp->save_syn;
4228 break;
4229 case TCP_SAVED_SYN: {
4230 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4231 return -EFAULT;
4232
4233 sockopt_lock_sock(sk);
4234 if (tp->saved_syn) {
4235 if (len < tcp_saved_syn_len(tp->saved_syn)) {
4236 len = tcp_saved_syn_len(tp->saved_syn);
4237 if (copy_to_sockptr(optlen, &len, sizeof(int))) {
4238 sockopt_release_sock(sk);
4239 return -EFAULT;
4240 }
4241 sockopt_release_sock(sk);
4242 return -EINVAL;
4243 }
4244 len = tcp_saved_syn_len(tp->saved_syn);
4245 if (copy_to_sockptr(optlen, &len, sizeof(int))) {
4246 sockopt_release_sock(sk);
4247 return -EFAULT;
4248 }
4249 if (copy_to_sockptr(optval, tp->saved_syn->data, len)) {
4250 sockopt_release_sock(sk);
4251 return -EFAULT;
4252 }
4253 tcp_saved_syn_free(tp);
4254 sockopt_release_sock(sk);
4255 } else {
4256 sockopt_release_sock(sk);
4257 len = 0;
4258 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4259 return -EFAULT;
4260 }
4261 return 0;
4262 }
4263#ifdef CONFIG_MMU
4264 case TCP_ZEROCOPY_RECEIVE: {
4265 struct scm_timestamping_internal tss;
4266 struct tcp_zerocopy_receive zc = {};
4267 int err;
4268
4269 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4270 return -EFAULT;
4271 if (len < 0 ||
4272 len < offsetofend(struct tcp_zerocopy_receive, length))
4273 return -EINVAL;
4274 if (unlikely(len > sizeof(zc))) {
4275 err = check_zeroed_sockptr(optval, sizeof(zc),
4276 len - sizeof(zc));
4277 if (err < 1)
4278 return err == 0 ? -EINVAL : err;
4279 len = sizeof(zc);
4280 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4281 return -EFAULT;
4282 }
4283 if (copy_from_sockptr(&zc, optval, len))
4284 return -EFAULT;
4285 if (zc.reserved)
4286 return -EINVAL;
4287 if (zc.msg_flags & ~(TCP_VALID_ZC_MSG_FLAGS))
4288 return -EINVAL;
4289 sockopt_lock_sock(sk);
4290 err = tcp_zerocopy_receive(sk, &zc, &tss);
4291 err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname,
4292 &zc, &len, err);
4293 sockopt_release_sock(sk);
4294 if (len >= offsetofend(struct tcp_zerocopy_receive, msg_flags))
4295 goto zerocopy_rcv_cmsg;
4296 switch (len) {
4297 case offsetofend(struct tcp_zerocopy_receive, msg_flags):
4298 goto zerocopy_rcv_cmsg;
4299 case offsetofend(struct tcp_zerocopy_receive, msg_controllen):
4300 case offsetofend(struct tcp_zerocopy_receive, msg_control):
4301 case offsetofend(struct tcp_zerocopy_receive, flags):
4302 case offsetofend(struct tcp_zerocopy_receive, copybuf_len):
4303 case offsetofend(struct tcp_zerocopy_receive, copybuf_address):
4304 case offsetofend(struct tcp_zerocopy_receive, err):
4305 goto zerocopy_rcv_sk_err;
4306 case offsetofend(struct tcp_zerocopy_receive, inq):
4307 goto zerocopy_rcv_inq;
4308 case offsetofend(struct tcp_zerocopy_receive, length):
4309 default:
4310 goto zerocopy_rcv_out;
4311 }
4312zerocopy_rcv_cmsg:
4313 if (zc.msg_flags & TCP_CMSG_TS)
4314 tcp_zc_finalize_rx_tstamp(sk, &zc, &tss);
4315 else
4316 zc.msg_flags = 0;
4317zerocopy_rcv_sk_err:
4318 if (!err)
4319 zc.err = sock_error(sk);
4320zerocopy_rcv_inq:
4321 zc.inq = tcp_inq_hint(sk);
4322zerocopy_rcv_out:
4323 if (!err && copy_to_sockptr(optval, &zc, len))
4324 err = -EFAULT;
4325 return err;
4326 }
4327#endif
4328 case TCP_AO_REPAIR:
4329 if (!tcp_can_repair_sock(sk))
4330 return -EPERM;
4331 return tcp_ao_get_repair(sk, optval, optlen);
4332 case TCP_AO_GET_KEYS:
4333 case TCP_AO_INFO: {
4334 int err;
4335
4336 sockopt_lock_sock(sk);
4337 if (optname == TCP_AO_GET_KEYS)
4338 err = tcp_ao_get_mkts(sk, optval, optlen);
4339 else
4340 err = tcp_ao_get_sock_info(sk, optval, optlen);
4341 sockopt_release_sock(sk);
4342
4343 return err;
4344 }
4345 default:
4346 return -ENOPROTOOPT;
4347 }
4348
4349 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4350 return -EFAULT;
4351 if (copy_to_sockptr(optval, &val, len))
4352 return -EFAULT;
4353 return 0;
4354}
4355
4356bool tcp_bpf_bypass_getsockopt(int level, int optname)
4357{
4358 /* TCP do_tcp_getsockopt has optimized getsockopt implementation
4359 * to avoid extra socket lock for TCP_ZEROCOPY_RECEIVE.
4360 */
4361 if (level == SOL_TCP && optname == TCP_ZEROCOPY_RECEIVE)
4362 return true;
4363
4364 return false;
4365}
4366EXPORT_SYMBOL(tcp_bpf_bypass_getsockopt);
4367
4368int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
4369 int __user *optlen)
4370{
4371 struct inet_connection_sock *icsk = inet_csk(sk);
4372
4373 if (level != SOL_TCP)
4374 /* Paired with WRITE_ONCE() in do_ipv6_setsockopt() and tcp_v6_connect() */
4375 return READ_ONCE(icsk->icsk_af_ops)->getsockopt(sk, level, optname,
4376 optval, optlen);
4377 return do_tcp_getsockopt(sk, level, optname, USER_SOCKPTR(optval),
4378 USER_SOCKPTR(optlen));
4379}
4380EXPORT_SYMBOL(tcp_getsockopt);
4381
4382#ifdef CONFIG_TCP_MD5SIG
4383int tcp_md5_sigpool_id = -1;
4384EXPORT_SYMBOL_GPL(tcp_md5_sigpool_id);
4385
4386int tcp_md5_alloc_sigpool(void)
4387{
4388 size_t scratch_size;
4389 int ret;
4390
4391 scratch_size = sizeof(union tcp_md5sum_block) + sizeof(struct tcphdr);
4392 ret = tcp_sigpool_alloc_ahash("md5", scratch_size);
4393 if (ret >= 0) {
4394 /* As long as any md5 sigpool was allocated, the return
4395 * id would stay the same. Re-write the id only for the case
4396 * when previously all MD5 keys were deleted and this call
4397 * allocates the first MD5 key, which may return a different
4398 * sigpool id than was used previously.
4399 */
4400 WRITE_ONCE(tcp_md5_sigpool_id, ret); /* Avoids the compiler potentially being smart here */
4401 return 0;
4402 }
4403 return ret;
4404}
4405
4406void tcp_md5_release_sigpool(void)
4407{
4408 tcp_sigpool_release(READ_ONCE(tcp_md5_sigpool_id));
4409}
4410
4411void tcp_md5_add_sigpool(void)
4412{
4413 tcp_sigpool_get(READ_ONCE(tcp_md5_sigpool_id));
4414}
4415
4416int tcp_md5_hash_key(struct tcp_sigpool *hp,
4417 const struct tcp_md5sig_key *key)
4418{
4419 u8 keylen = READ_ONCE(key->keylen); /* paired with WRITE_ONCE() in tcp_md5_do_add */
4420 struct scatterlist sg;
4421
4422 sg_init_one(&sg, key->key, keylen);
4423 ahash_request_set_crypt(hp->req, &sg, NULL, keylen);
4424
4425 /* We use data_race() because tcp_md5_do_add() might change
4426 * key->key under us
4427 */
4428 return data_race(crypto_ahash_update(hp->req));
4429}
4430EXPORT_SYMBOL(tcp_md5_hash_key);
4431
4432/* Called with rcu_read_lock() */
4433enum skb_drop_reason
4434tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
4435 const void *saddr, const void *daddr,
4436 int family, int l3index, const __u8 *hash_location)
4437{
4438 /* This gets called for each TCP segment that has TCP-MD5 option.
4439 * We have 3 drop cases:
4440 * o No MD5 hash and one expected.
4441 * o MD5 hash and we're not expecting one.
4442 * o MD5 hash and its wrong.
4443 */
4444 const struct tcp_sock *tp = tcp_sk(sk);
4445 struct tcp_md5sig_key *key;
4446 u8 newhash[16];
4447 int genhash;
4448
4449 key = tcp_md5_do_lookup(sk, l3index, saddr, family);
4450
4451 if (!key && hash_location) {
4452 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
4453 tcp_hash_fail("Unexpected MD5 Hash found", family, skb, "");
4454 return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
4455 }
4456
4457 /* Check the signature.
4458 * To support dual stack listeners, we need to handle
4459 * IPv4-mapped case.
4460 */
4461 if (family == AF_INET)
4462 genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
4463 else
4464 genhash = tp->af_specific->calc_md5_hash(newhash, key,
4465 NULL, skb);
4466 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
4467 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
4468 if (family == AF_INET) {
4469 tcp_hash_fail("MD5 Hash failed", AF_INET, skb, "%s L3 index %d",
4470 genhash ? "tcp_v4_calc_md5_hash failed"
4471 : "", l3index);
4472 } else {
4473 if (genhash) {
4474 tcp_hash_fail("MD5 Hash failed",
4475 AF_INET6, skb, "L3 index %d",
4476 l3index);
4477 } else {
4478 tcp_hash_fail("MD5 Hash mismatch",
4479 AF_INET6, skb, "L3 index %d",
4480 l3index);
4481 }
4482 }
4483 return SKB_DROP_REASON_TCP_MD5FAILURE;
4484 }
4485 return SKB_NOT_DROPPED_YET;
4486}
4487EXPORT_SYMBOL(tcp_inbound_md5_hash);
4488
4489#endif
4490
4491void tcp_done(struct sock *sk)
4492{
4493 struct request_sock *req;
4494
4495 /* We might be called with a new socket, after
4496 * inet_csk_prepare_forced_close() has been called
4497 * so we can not use lockdep_sock_is_held(sk)
4498 */
4499 req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, 1);
4500
4501 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
4502 TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
4503
4504 tcp_set_state(sk, TCP_CLOSE);
4505 tcp_clear_xmit_timers(sk);
4506 if (req)
4507 reqsk_fastopen_remove(sk, req, false);
4508
4509 WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);
4510
4511 if (!sock_flag(sk, SOCK_DEAD))
4512 sk->sk_state_change(sk);
4513 else
4514 inet_csk_destroy_sock(sk);
4515}
4516EXPORT_SYMBOL_GPL(tcp_done);
4517
4518int tcp_abort(struct sock *sk, int err)
4519{
4520 int state = inet_sk_state_load(sk);
4521
4522 if (state == TCP_NEW_SYN_RECV) {
4523 struct request_sock *req = inet_reqsk(sk);
4524
4525 local_bh_disable();
4526 inet_csk_reqsk_queue_drop(req->rsk_listener, req);
4527 local_bh_enable();
4528 return 0;
4529 }
4530 if (state == TCP_TIME_WAIT) {
4531 struct inet_timewait_sock *tw = inet_twsk(sk);
4532
4533 refcount_inc(&tw->tw_refcnt);
4534 local_bh_disable();
4535 inet_twsk_deschedule_put(tw);
4536 local_bh_enable();
4537 return 0;
4538 }
4539
4540 /* BPF context ensures sock locking. */
4541 if (!has_current_bpf_ctx())
4542 /* Don't race with userspace socket closes such as tcp_close. */
4543 lock_sock(sk);
4544
4545 if (sk->sk_state == TCP_LISTEN) {
4546 tcp_set_state(sk, TCP_CLOSE);
4547 inet_csk_listen_stop(sk);
4548 }
4549
4550 /* Don't race with BH socket closes such as inet_csk_listen_stop. */
4551 local_bh_disable();
4552 bh_lock_sock(sk);
4553
4554 if (!sock_flag(sk, SOCK_DEAD)) {
4555 WRITE_ONCE(sk->sk_err, err);
4556 /* This barrier is coupled with smp_rmb() in tcp_poll() */
4557 smp_wmb();
4558 sk_error_report(sk);
4559 if (tcp_need_reset(sk->sk_state))
4560 tcp_send_active_reset(sk, GFP_ATOMIC);
4561 tcp_done(sk);
4562 }
4563
4564 bh_unlock_sock(sk);
4565 local_bh_enable();
4566 tcp_write_queue_purge(sk);
4567 if (!has_current_bpf_ctx())
4568 release_sock(sk);
4569 return 0;
4570}
4571EXPORT_SYMBOL_GPL(tcp_abort);
4572
4573extern struct tcp_congestion_ops tcp_reno;
4574
4575static __initdata unsigned long thash_entries;
4576static int __init set_thash_entries(char *str)
4577{
4578 ssize_t ret;
4579
4580 if (!str)
4581 return 0;
4582
4583 ret = kstrtoul(str, 0, &thash_entries);
4584 if (ret)
4585 return 0;
4586
4587 return 1;
4588}
4589__setup("thash_entries=", set_thash_entries);
4590
4591static void __init tcp_init_mem(void)
4592{
4593 unsigned long limit = nr_free_buffer_pages() / 16;
4594
4595 limit = max(limit, 128UL);
4596 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */
4597 sysctl_tcp_mem[1] = limit; /* 6.25 % */
4598 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */
4599}
4600
4601static void __init tcp_struct_check(void)
4602{
4603 /* TX read-mostly hotpath cache lines */
4604 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, max_window);
4605 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, rcv_ssthresh);
4606 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, reordering);
4607 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, notsent_lowat);
4608 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, gso_segs);
4609 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, lost_skb_hint);
4610 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, retransmit_skb_hint);
4611 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_read_tx, 40);
4612
4613 /* TXRX read-mostly hotpath cache lines */
4614 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, tsoffset);
4615 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, snd_wnd);
4616 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, mss_cache);
4617 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, snd_cwnd);
4618 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, prr_out);
4619 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, lost_out);
4620 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, sacked_out);
4621 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, scaling_ratio);
4622 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_read_txrx, 32);
4623
4624 /* RX read-mostly hotpath cache lines */
4625 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, copied_seq);
4626 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, rcv_tstamp);
4627 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, snd_wl1);
4628 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, tlp_high_seq);
4629 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, rttvar_us);
4630 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, retrans_out);
4631 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, advmss);
4632 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, urg_data);
4633 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, lost);
4634 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, rtt_min);
4635 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, out_of_order_queue);
4636 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, snd_ssthresh);
4637 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_read_rx, 69);
4638
4639 /* TX read-write hotpath cache lines */
4640 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, segs_out);
4641 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, data_segs_out);
4642 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, bytes_sent);
4643 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, snd_sml);
4644 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, chrono_start);
4645 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, chrono_stat);
4646 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, write_seq);
4647 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, pushed_seq);
4648 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, lsndtime);
4649 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, mdev_us);
4650 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, tcp_wstamp_ns);
4651 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, tcp_clock_cache);
4652 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, tcp_mstamp);
4653 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, rtt_seq);
4654 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, tsorted_sent_queue);
4655 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, highest_sack);
4656 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, ecn_flags);
4657 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_tx, 105);
4658
4659 /* TXRX read-write hotpath cache lines */
4660 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, pred_flags);
4661 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_nxt);
4662 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, snd_nxt);
4663 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, snd_una);
4664 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, window_clamp);
4665 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, srtt_us);
4666 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, packets_out);
4667 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, snd_up);
4668 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, delivered);
4669 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, delivered_ce);
4670 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, app_limited);
4671 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_wnd);
4672 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rx_opt);
4673 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_txrx, 76);
4674
4675 /* RX read-write hotpath cache lines */
4676 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, bytes_received);
4677 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, segs_in);
4678 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, data_segs_in);
4679 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcv_wup);
4680 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, max_packets_out);
4681 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, cwnd_usage_seq);
4682 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rate_delivered);
4683 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rate_interval_us);
4684 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcv_rtt_last_tsecr);
4685 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, first_tx_mstamp);
4686 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, delivered_mstamp);
4687 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, bytes_acked);
4688 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcv_rtt_est);
4689 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcvq_space);
4690 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_rx, 99);
4691}
4692
4693void __init tcp_init(void)
4694{
4695 int max_rshare, max_wshare, cnt;
4696 unsigned long limit;
4697 unsigned int i;
4698
4699 BUILD_BUG_ON(TCP_MIN_SND_MSS <= MAX_TCP_OPTION_SPACE);
4700 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
4701 sizeof_field(struct sk_buff, cb));
4702
4703 tcp_struct_check();
4704
4705 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
4706
4707 timer_setup(&tcp_orphan_timer, tcp_orphan_update, TIMER_DEFERRABLE);
4708 mod_timer(&tcp_orphan_timer, jiffies + TCP_ORPHAN_TIMER_PERIOD);
4709
4710 inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash",
4711 thash_entries, 21, /* one slot per 2 MB*/
4712 0, 64 * 1024);
4713 tcp_hashinfo.bind_bucket_cachep =
4714 kmem_cache_create("tcp_bind_bucket",
4715 sizeof(struct inet_bind_bucket), 0,
4716 SLAB_HWCACHE_ALIGN | SLAB_PANIC |
4717 SLAB_ACCOUNT,
4718 NULL);
4719 tcp_hashinfo.bind2_bucket_cachep =
4720 kmem_cache_create("tcp_bind2_bucket",
4721 sizeof(struct inet_bind2_bucket), 0,
4722 SLAB_HWCACHE_ALIGN | SLAB_PANIC |
4723 SLAB_ACCOUNT,
4724 NULL);
4725
4726 /* Size and allocate the main established and bind bucket
4727 * hash tables.
4728 *
4729 * The methodology is similar to that of the buffer cache.
4730 */
4731 tcp_hashinfo.ehash =
4732 alloc_large_system_hash("TCP established",
4733 sizeof(struct inet_ehash_bucket),
4734 thash_entries,
4735 17, /* one slot per 128 KB of memory */
4736 0,
4737 NULL,
4738 &tcp_hashinfo.ehash_mask,
4739 0,
4740 thash_entries ? 0 : 512 * 1024);
4741 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
4742 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
4743
4744 if (inet_ehash_locks_alloc(&tcp_hashinfo))
4745 panic("TCP: failed to alloc ehash_locks");
4746 tcp_hashinfo.bhash =
4747 alloc_large_system_hash("TCP bind",
4748 2 * sizeof(struct inet_bind_hashbucket),
4749 tcp_hashinfo.ehash_mask + 1,
4750 17, /* one slot per 128 KB of memory */
4751 0,
4752 &tcp_hashinfo.bhash_size,
4753 NULL,
4754 0,
4755 64 * 1024);
4756 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
4757 tcp_hashinfo.bhash2 = tcp_hashinfo.bhash + tcp_hashinfo.bhash_size;
4758 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
4759 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
4760 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
4761 spin_lock_init(&tcp_hashinfo.bhash2[i].lock);
4762 INIT_HLIST_HEAD(&tcp_hashinfo.bhash2[i].chain);
4763 }
4764
4765 tcp_hashinfo.pernet = false;
4766
4767 cnt = tcp_hashinfo.ehash_mask + 1;
4768 sysctl_tcp_max_orphans = cnt / 2;
4769
4770 tcp_init_mem();
4771 /* Set per-socket limits to no more than 1/128 the pressure threshold */
4772 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
4773 max_wshare = min(4UL*1024*1024, limit);
4774 max_rshare = min(6UL*1024*1024, limit);
4775
4776 init_net.ipv4.sysctl_tcp_wmem[0] = PAGE_SIZE;
4777 init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024;
4778 init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
4779
4780 init_net.ipv4.sysctl_tcp_rmem[0] = PAGE_SIZE;
4781 init_net.ipv4.sysctl_tcp_rmem[1] = 131072;
4782 init_net.ipv4.sysctl_tcp_rmem[2] = max(131072, max_rshare);
4783
4784 pr_info("Hash tables configured (established %u bind %u)\n",
4785 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
4786
4787 tcp_v4_init();
4788 tcp_metrics_init();
4789 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
4790 tcp_tasklet_init();
4791 mptcp_init();
4792}