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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#include <linux/kernel.h>
249#include <linux/module.h>
250#include <linux/types.h>
251#include <linux/fcntl.h>
252#include <linux/poll.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/bootmem.h>
262#include <linux/highmem.h>
263#include <linux/swap.h>
264#include <linux/cache.h>
265#include <linux/err.h>
266#include <linux/crypto.h>
267#include <linux/time.h>
268#include <linux/slab.h>
269
270#include <net/icmp.h>
271#include <net/tcp.h>
272#include <net/xfrm.h>
273#include <net/ip.h>
274#include <net/netdma.h>
275#include <net/sock.h>
276
277#include <asm/uaccess.h>
278#include <asm/ioctls.h>
279
280int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
281
282struct percpu_counter tcp_orphan_count;
283EXPORT_SYMBOL_GPL(tcp_orphan_count);
284
285long sysctl_tcp_mem[3] __read_mostly;
286int sysctl_tcp_wmem[3] __read_mostly;
287int sysctl_tcp_rmem[3] __read_mostly;
288
289EXPORT_SYMBOL(sysctl_tcp_mem);
290EXPORT_SYMBOL(sysctl_tcp_rmem);
291EXPORT_SYMBOL(sysctl_tcp_wmem);
292
293atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
294EXPORT_SYMBOL(tcp_memory_allocated);
295
296/*
297 * Current number of TCP sockets.
298 */
299struct percpu_counter tcp_sockets_allocated;
300EXPORT_SYMBOL(tcp_sockets_allocated);
301
302/*
303 * TCP splice context
304 */
305struct tcp_splice_state {
306 struct pipe_inode_info *pipe;
307 size_t len;
308 unsigned int flags;
309};
310
311/*
312 * Pressure flag: try to collapse.
313 * Technical note: it is used by multiple contexts non atomically.
314 * All the __sk_mem_schedule() is of this nature: accounting
315 * is strict, actions are advisory and have some latency.
316 */
317int tcp_memory_pressure __read_mostly;
318EXPORT_SYMBOL(tcp_memory_pressure);
319
320void tcp_enter_memory_pressure(struct sock *sk)
321{
322 if (!tcp_memory_pressure) {
323 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
324 tcp_memory_pressure = 1;
325 }
326}
327EXPORT_SYMBOL(tcp_enter_memory_pressure);
328
329/* Convert seconds to retransmits based on initial and max timeout */
330static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
331{
332 u8 res = 0;
333
334 if (seconds > 0) {
335 int period = timeout;
336
337 res = 1;
338 while (seconds > period && res < 255) {
339 res++;
340 timeout <<= 1;
341 if (timeout > rto_max)
342 timeout = rto_max;
343 period += timeout;
344 }
345 }
346 return res;
347}
348
349/* Convert retransmits to seconds based on initial and max timeout */
350static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
351{
352 int period = 0;
353
354 if (retrans > 0) {
355 period = timeout;
356 while (--retrans) {
357 timeout <<= 1;
358 if (timeout > rto_max)
359 timeout = rto_max;
360 period += timeout;
361 }
362 }
363 return period;
364}
365
366/*
367 * Wait for a TCP event.
368 *
369 * Note that we don't need to lock the socket, as the upper poll layers
370 * take care of normal races (between the test and the event) and we don't
371 * go look at any of the socket buffers directly.
372 */
373unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
374{
375 unsigned int mask;
376 struct sock *sk = sock->sk;
377 struct tcp_sock *tp = tcp_sk(sk);
378
379 sock_poll_wait(file, sk_sleep(sk), wait);
380 if (sk->sk_state == TCP_LISTEN)
381 return inet_csk_listen_poll(sk);
382
383 /* Socket is not locked. We are protected from async events
384 * by poll logic and correct handling of state changes
385 * made by other threads is impossible in any case.
386 */
387
388 mask = 0;
389
390 /*
391 * POLLHUP is certainly not done right. But poll() doesn't
392 * have a notion of HUP in just one direction, and for a
393 * socket the read side is more interesting.
394 *
395 * Some poll() documentation says that POLLHUP is incompatible
396 * with the POLLOUT/POLLWR flags, so somebody should check this
397 * all. But careful, it tends to be safer to return too many
398 * bits than too few, and you can easily break real applications
399 * if you don't tell them that something has hung up!
400 *
401 * Check-me.
402 *
403 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
404 * our fs/select.c). It means that after we received EOF,
405 * poll always returns immediately, making impossible poll() on write()
406 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
407 * if and only if shutdown has been made in both directions.
408 * Actually, it is interesting to look how Solaris and DUX
409 * solve this dilemma. I would prefer, if POLLHUP were maskable,
410 * then we could set it on SND_SHUTDOWN. BTW examples given
411 * in Stevens' books assume exactly this behaviour, it explains
412 * why POLLHUP is incompatible with POLLOUT. --ANK
413 *
414 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
415 * blocking on fresh not-connected or disconnected socket. --ANK
416 */
417 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
418 mask |= POLLHUP;
419 if (sk->sk_shutdown & RCV_SHUTDOWN)
420 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
421
422 /* Connected? */
423 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
424 int target = sock_rcvlowat(sk, 0, INT_MAX);
425
426 if (tp->urg_seq == tp->copied_seq &&
427 !sock_flag(sk, SOCK_URGINLINE) &&
428 tp->urg_data)
429 target++;
430
431 /* Potential race condition. If read of tp below will
432 * escape above sk->sk_state, we can be illegally awaken
433 * in SYN_* states. */
434 if (tp->rcv_nxt - tp->copied_seq >= target)
435 mask |= POLLIN | POLLRDNORM;
436
437 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
438 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
439 mask |= POLLOUT | POLLWRNORM;
440 } else { /* send SIGIO later */
441 set_bit(SOCK_ASYNC_NOSPACE,
442 &sk->sk_socket->flags);
443 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
444
445 /* Race breaker. If space is freed after
446 * wspace test but before the flags are set,
447 * IO signal will be lost.
448 */
449 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
450 mask |= POLLOUT | POLLWRNORM;
451 }
452 } else
453 mask |= POLLOUT | POLLWRNORM;
454
455 if (tp->urg_data & TCP_URG_VALID)
456 mask |= POLLPRI;
457 }
458 /* This barrier is coupled with smp_wmb() in tcp_reset() */
459 smp_rmb();
460 if (sk->sk_err)
461 mask |= POLLERR;
462
463 return mask;
464}
465EXPORT_SYMBOL(tcp_poll);
466
467int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
468{
469 struct tcp_sock *tp = tcp_sk(sk);
470 int answ;
471
472 switch (cmd) {
473 case SIOCINQ:
474 if (sk->sk_state == TCP_LISTEN)
475 return -EINVAL;
476
477 lock_sock(sk);
478 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
479 answ = 0;
480 else if (sock_flag(sk, SOCK_URGINLINE) ||
481 !tp->urg_data ||
482 before(tp->urg_seq, tp->copied_seq) ||
483 !before(tp->urg_seq, tp->rcv_nxt)) {
484 struct sk_buff *skb;
485
486 answ = tp->rcv_nxt - tp->copied_seq;
487
488 /* Subtract 1, if FIN is in queue. */
489 skb = skb_peek_tail(&sk->sk_receive_queue);
490 if (answ && skb)
491 answ -= tcp_hdr(skb)->fin;
492 } else
493 answ = tp->urg_seq - tp->copied_seq;
494 release_sock(sk);
495 break;
496 case SIOCATMARK:
497 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
498 break;
499 case SIOCOUTQ:
500 if (sk->sk_state == TCP_LISTEN)
501 return -EINVAL;
502
503 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
504 answ = 0;
505 else
506 answ = tp->write_seq - tp->snd_una;
507 break;
508 case SIOCOUTQNSD:
509 if (sk->sk_state == TCP_LISTEN)
510 return -EINVAL;
511
512 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
513 answ = 0;
514 else
515 answ = tp->write_seq - tp->snd_nxt;
516 break;
517 default:
518 return -ENOIOCTLCMD;
519 }
520
521 return put_user(answ, (int __user *)arg);
522}
523EXPORT_SYMBOL(tcp_ioctl);
524
525static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
526{
527 TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
528 tp->pushed_seq = tp->write_seq;
529}
530
531static inline int forced_push(struct tcp_sock *tp)
532{
533 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
534}
535
536static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
537{
538 struct tcp_sock *tp = tcp_sk(sk);
539 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
540
541 skb->csum = 0;
542 tcb->seq = tcb->end_seq = tp->write_seq;
543 tcb->flags = TCPHDR_ACK;
544 tcb->sacked = 0;
545 skb_header_release(skb);
546 tcp_add_write_queue_tail(sk, skb);
547 sk->sk_wmem_queued += skb->truesize;
548 sk_mem_charge(sk, skb->truesize);
549 if (tp->nonagle & TCP_NAGLE_PUSH)
550 tp->nonagle &= ~TCP_NAGLE_PUSH;
551}
552
553static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
554{
555 if (flags & MSG_OOB)
556 tp->snd_up = tp->write_seq;
557}
558
559static inline void tcp_push(struct sock *sk, int flags, int mss_now,
560 int nonagle)
561{
562 if (tcp_send_head(sk)) {
563 struct tcp_sock *tp = tcp_sk(sk);
564
565 if (!(flags & MSG_MORE) || forced_push(tp))
566 tcp_mark_push(tp, tcp_write_queue_tail(sk));
567
568 tcp_mark_urg(tp, flags);
569 __tcp_push_pending_frames(sk, mss_now,
570 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
571 }
572}
573
574static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
575 unsigned int offset, size_t len)
576{
577 struct tcp_splice_state *tss = rd_desc->arg.data;
578 int ret;
579
580 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
581 tss->flags);
582 if (ret > 0)
583 rd_desc->count -= ret;
584 return ret;
585}
586
587static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
588{
589 /* Store TCP splice context information in read_descriptor_t. */
590 read_descriptor_t rd_desc = {
591 .arg.data = tss,
592 .count = tss->len,
593 };
594
595 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
596}
597
598/**
599 * tcp_splice_read - splice data from TCP socket to a pipe
600 * @sock: socket to splice from
601 * @ppos: position (not valid)
602 * @pipe: pipe to splice to
603 * @len: number of bytes to splice
604 * @flags: splice modifier flags
605 *
606 * Description:
607 * Will read pages from given socket and fill them into a pipe.
608 *
609 **/
610ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
611 struct pipe_inode_info *pipe, size_t len,
612 unsigned int flags)
613{
614 struct sock *sk = sock->sk;
615 struct tcp_splice_state tss = {
616 .pipe = pipe,
617 .len = len,
618 .flags = flags,
619 };
620 long timeo;
621 ssize_t spliced;
622 int ret;
623
624 sock_rps_record_flow(sk);
625 /*
626 * We can't seek on a socket input
627 */
628 if (unlikely(*ppos))
629 return -ESPIPE;
630
631 ret = spliced = 0;
632
633 lock_sock(sk);
634
635 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
636 while (tss.len) {
637 ret = __tcp_splice_read(sk, &tss);
638 if (ret < 0)
639 break;
640 else if (!ret) {
641 if (spliced)
642 break;
643 if (sock_flag(sk, SOCK_DONE))
644 break;
645 if (sk->sk_err) {
646 ret = sock_error(sk);
647 break;
648 }
649 if (sk->sk_shutdown & RCV_SHUTDOWN)
650 break;
651 if (sk->sk_state == TCP_CLOSE) {
652 /*
653 * This occurs when user tries to read
654 * from never connected socket.
655 */
656 if (!sock_flag(sk, SOCK_DONE))
657 ret = -ENOTCONN;
658 break;
659 }
660 if (!timeo) {
661 ret = -EAGAIN;
662 break;
663 }
664 sk_wait_data(sk, &timeo);
665 if (signal_pending(current)) {
666 ret = sock_intr_errno(timeo);
667 break;
668 }
669 continue;
670 }
671 tss.len -= ret;
672 spliced += ret;
673
674 if (!timeo)
675 break;
676 release_sock(sk);
677 lock_sock(sk);
678
679 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
680 (sk->sk_shutdown & RCV_SHUTDOWN) ||
681 signal_pending(current))
682 break;
683 }
684
685 release_sock(sk);
686
687 if (spliced)
688 return spliced;
689
690 return ret;
691}
692EXPORT_SYMBOL(tcp_splice_read);
693
694struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
695{
696 struct sk_buff *skb;
697
698 /* The TCP header must be at least 32-bit aligned. */
699 size = ALIGN(size, 4);
700
701 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
702 if (skb) {
703 if (sk_wmem_schedule(sk, skb->truesize)) {
704 /*
705 * Make sure that we have exactly size bytes
706 * available to the caller, no more, no less.
707 */
708 skb_reserve(skb, skb_tailroom(skb) - size);
709 return skb;
710 }
711 __kfree_skb(skb);
712 } else {
713 sk->sk_prot->enter_memory_pressure(sk);
714 sk_stream_moderate_sndbuf(sk);
715 }
716 return NULL;
717}
718
719static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
720 int large_allowed)
721{
722 struct tcp_sock *tp = tcp_sk(sk);
723 u32 xmit_size_goal, old_size_goal;
724
725 xmit_size_goal = mss_now;
726
727 if (large_allowed && sk_can_gso(sk)) {
728 xmit_size_goal = ((sk->sk_gso_max_size - 1) -
729 inet_csk(sk)->icsk_af_ops->net_header_len -
730 inet_csk(sk)->icsk_ext_hdr_len -
731 tp->tcp_header_len);
732
733 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
734
735 /* We try hard to avoid divides here */
736 old_size_goal = tp->xmit_size_goal_segs * mss_now;
737
738 if (likely(old_size_goal <= xmit_size_goal &&
739 old_size_goal + mss_now > xmit_size_goal)) {
740 xmit_size_goal = old_size_goal;
741 } else {
742 tp->xmit_size_goal_segs = xmit_size_goal / mss_now;
743 xmit_size_goal = tp->xmit_size_goal_segs * mss_now;
744 }
745 }
746
747 return max(xmit_size_goal, mss_now);
748}
749
750static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
751{
752 int mss_now;
753
754 mss_now = tcp_current_mss(sk);
755 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
756
757 return mss_now;
758}
759
760static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
761 size_t psize, int flags)
762{
763 struct tcp_sock *tp = tcp_sk(sk);
764 int mss_now, size_goal;
765 int err;
766 ssize_t copied;
767 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
768
769 /* Wait for a connection to finish. */
770 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
771 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
772 goto out_err;
773
774 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
775
776 mss_now = tcp_send_mss(sk, &size_goal, flags);
777 copied = 0;
778
779 err = -EPIPE;
780 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
781 goto out_err;
782
783 while (psize > 0) {
784 struct sk_buff *skb = tcp_write_queue_tail(sk);
785 struct page *page = pages[poffset / PAGE_SIZE];
786 int copy, i, can_coalesce;
787 int offset = poffset % PAGE_SIZE;
788 int size = min_t(size_t, psize, PAGE_SIZE - offset);
789
790 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
791new_segment:
792 if (!sk_stream_memory_free(sk))
793 goto wait_for_sndbuf;
794
795 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
796 if (!skb)
797 goto wait_for_memory;
798
799 skb_entail(sk, skb);
800 copy = size_goal;
801 }
802
803 if (copy > size)
804 copy = size;
805
806 i = skb_shinfo(skb)->nr_frags;
807 can_coalesce = skb_can_coalesce(skb, i, page, offset);
808 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
809 tcp_mark_push(tp, skb);
810 goto new_segment;
811 }
812 if (!sk_wmem_schedule(sk, copy))
813 goto wait_for_memory;
814
815 if (can_coalesce) {
816 skb_shinfo(skb)->frags[i - 1].size += copy;
817 } else {
818 get_page(page);
819 skb_fill_page_desc(skb, i, page, offset, copy);
820 }
821
822 skb->len += copy;
823 skb->data_len += copy;
824 skb->truesize += copy;
825 sk->sk_wmem_queued += copy;
826 sk_mem_charge(sk, copy);
827 skb->ip_summed = CHECKSUM_PARTIAL;
828 tp->write_seq += copy;
829 TCP_SKB_CB(skb)->end_seq += copy;
830 skb_shinfo(skb)->gso_segs = 0;
831
832 if (!copied)
833 TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
834
835 copied += copy;
836 poffset += copy;
837 if (!(psize -= copy))
838 goto out;
839
840 if (skb->len < size_goal || (flags & MSG_OOB))
841 continue;
842
843 if (forced_push(tp)) {
844 tcp_mark_push(tp, skb);
845 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
846 } else if (skb == tcp_send_head(sk))
847 tcp_push_one(sk, mss_now);
848 continue;
849
850wait_for_sndbuf:
851 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
852wait_for_memory:
853 if (copied)
854 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
855
856 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
857 goto do_error;
858
859 mss_now = tcp_send_mss(sk, &size_goal, flags);
860 }
861
862out:
863 if (copied)
864 tcp_push(sk, flags, mss_now, tp->nonagle);
865 return copied;
866
867do_error:
868 if (copied)
869 goto out;
870out_err:
871 return sk_stream_error(sk, flags, err);
872}
873
874int tcp_sendpage(struct sock *sk, struct page *page, int offset,
875 size_t size, int flags)
876{
877 ssize_t res;
878
879 if (!(sk->sk_route_caps & NETIF_F_SG) ||
880 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
881 return sock_no_sendpage(sk->sk_socket, page, offset, size,
882 flags);
883
884 lock_sock(sk);
885 res = do_tcp_sendpages(sk, &page, offset, size, flags);
886 release_sock(sk);
887 return res;
888}
889EXPORT_SYMBOL(tcp_sendpage);
890
891#define TCP_PAGE(sk) (sk->sk_sndmsg_page)
892#define TCP_OFF(sk) (sk->sk_sndmsg_off)
893
894static inline int select_size(struct sock *sk, int sg)
895{
896 struct tcp_sock *tp = tcp_sk(sk);
897 int tmp = tp->mss_cache;
898
899 if (sg) {
900 if (sk_can_gso(sk))
901 tmp = 0;
902 else {
903 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
904
905 if (tmp >= pgbreak &&
906 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
907 tmp = pgbreak;
908 }
909 }
910
911 return tmp;
912}
913
914int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
915 size_t size)
916{
917 struct iovec *iov;
918 struct tcp_sock *tp = tcp_sk(sk);
919 struct sk_buff *skb;
920 int iovlen, flags;
921 int mss_now, size_goal;
922 int sg, err, copied;
923 long timeo;
924
925 lock_sock(sk);
926
927 flags = msg->msg_flags;
928 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
929
930 /* Wait for a connection to finish. */
931 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
932 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
933 goto out_err;
934
935 /* This should be in poll */
936 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
937
938 mss_now = tcp_send_mss(sk, &size_goal, flags);
939
940 /* Ok commence sending. */
941 iovlen = msg->msg_iovlen;
942 iov = msg->msg_iov;
943 copied = 0;
944
945 err = -EPIPE;
946 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
947 goto out_err;
948
949 sg = sk->sk_route_caps & NETIF_F_SG;
950
951 while (--iovlen >= 0) {
952 size_t seglen = iov->iov_len;
953 unsigned char __user *from = iov->iov_base;
954
955 iov++;
956
957 while (seglen > 0) {
958 int copy = 0;
959 int max = size_goal;
960
961 skb = tcp_write_queue_tail(sk);
962 if (tcp_send_head(sk)) {
963 if (skb->ip_summed == CHECKSUM_NONE)
964 max = mss_now;
965 copy = max - skb->len;
966 }
967
968 if (copy <= 0) {
969new_segment:
970 /* Allocate new segment. If the interface is SG,
971 * allocate skb fitting to single page.
972 */
973 if (!sk_stream_memory_free(sk))
974 goto wait_for_sndbuf;
975
976 skb = sk_stream_alloc_skb(sk,
977 select_size(sk, sg),
978 sk->sk_allocation);
979 if (!skb)
980 goto wait_for_memory;
981
982 /*
983 * Check whether we can use HW checksum.
984 */
985 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
986 skb->ip_summed = CHECKSUM_PARTIAL;
987
988 skb_entail(sk, skb);
989 copy = size_goal;
990 max = size_goal;
991 }
992
993 /* Try to append data to the end of skb. */
994 if (copy > seglen)
995 copy = seglen;
996
997 /* Where to copy to? */
998 if (skb_tailroom(skb) > 0) {
999 /* We have some space in skb head. Superb! */
1000 if (copy > skb_tailroom(skb))
1001 copy = skb_tailroom(skb);
1002 err = skb_add_data_nocache(sk, skb, from, copy);
1003 if (err)
1004 goto do_fault;
1005 } else {
1006 int merge = 0;
1007 int i = skb_shinfo(skb)->nr_frags;
1008 struct page *page = TCP_PAGE(sk);
1009 int off = TCP_OFF(sk);
1010
1011 if (skb_can_coalesce(skb, i, page, off) &&
1012 off != PAGE_SIZE) {
1013 /* We can extend the last page
1014 * fragment. */
1015 merge = 1;
1016 } else if (i == MAX_SKB_FRAGS || !sg) {
1017 /* Need to add new fragment and cannot
1018 * do this because interface is non-SG,
1019 * or because all the page slots are
1020 * busy. */
1021 tcp_mark_push(tp, skb);
1022 goto new_segment;
1023 } else if (page) {
1024 if (off == PAGE_SIZE) {
1025 put_page(page);
1026 TCP_PAGE(sk) = page = NULL;
1027 off = 0;
1028 }
1029 } else
1030 off = 0;
1031
1032 if (copy > PAGE_SIZE - off)
1033 copy = PAGE_SIZE - off;
1034
1035 if (!sk_wmem_schedule(sk, copy))
1036 goto wait_for_memory;
1037
1038 if (!page) {
1039 /* Allocate new cache page. */
1040 if (!(page = sk_stream_alloc_page(sk)))
1041 goto wait_for_memory;
1042 }
1043
1044 /* Time to copy data. We are close to
1045 * the end! */
1046 err = skb_copy_to_page_nocache(sk, from, skb,
1047 page, off, copy);
1048 if (err) {
1049 /* If this page was new, give it to the
1050 * socket so it does not get leaked.
1051 */
1052 if (!TCP_PAGE(sk)) {
1053 TCP_PAGE(sk) = page;
1054 TCP_OFF(sk) = 0;
1055 }
1056 goto do_error;
1057 }
1058
1059 /* Update the skb. */
1060 if (merge) {
1061 skb_shinfo(skb)->frags[i - 1].size +=
1062 copy;
1063 } else {
1064 skb_fill_page_desc(skb, i, page, off, copy);
1065 if (TCP_PAGE(sk)) {
1066 get_page(page);
1067 } else if (off + copy < PAGE_SIZE) {
1068 get_page(page);
1069 TCP_PAGE(sk) = page;
1070 }
1071 }
1072
1073 TCP_OFF(sk) = off + copy;
1074 }
1075
1076 if (!copied)
1077 TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
1078
1079 tp->write_seq += copy;
1080 TCP_SKB_CB(skb)->end_seq += copy;
1081 skb_shinfo(skb)->gso_segs = 0;
1082
1083 from += copy;
1084 copied += copy;
1085 if ((seglen -= copy) == 0 && iovlen == 0)
1086 goto out;
1087
1088 if (skb->len < max || (flags & MSG_OOB))
1089 continue;
1090
1091 if (forced_push(tp)) {
1092 tcp_mark_push(tp, skb);
1093 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1094 } else if (skb == tcp_send_head(sk))
1095 tcp_push_one(sk, mss_now);
1096 continue;
1097
1098wait_for_sndbuf:
1099 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1100wait_for_memory:
1101 if (copied)
1102 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
1103
1104 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1105 goto do_error;
1106
1107 mss_now = tcp_send_mss(sk, &size_goal, flags);
1108 }
1109 }
1110
1111out:
1112 if (copied)
1113 tcp_push(sk, flags, mss_now, tp->nonagle);
1114 release_sock(sk);
1115 return copied;
1116
1117do_fault:
1118 if (!skb->len) {
1119 tcp_unlink_write_queue(skb, sk);
1120 /* It is the one place in all of TCP, except connection
1121 * reset, where we can be unlinking the send_head.
1122 */
1123 tcp_check_send_head(sk, skb);
1124 sk_wmem_free_skb(sk, skb);
1125 }
1126
1127do_error:
1128 if (copied)
1129 goto out;
1130out_err:
1131 err = sk_stream_error(sk, flags, err);
1132 release_sock(sk);
1133 return err;
1134}
1135EXPORT_SYMBOL(tcp_sendmsg);
1136
1137/*
1138 * Handle reading urgent data. BSD has very simple semantics for
1139 * this, no blocking and very strange errors 8)
1140 */
1141
1142static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1143{
1144 struct tcp_sock *tp = tcp_sk(sk);
1145
1146 /* No URG data to read. */
1147 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1148 tp->urg_data == TCP_URG_READ)
1149 return -EINVAL; /* Yes this is right ! */
1150
1151 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1152 return -ENOTCONN;
1153
1154 if (tp->urg_data & TCP_URG_VALID) {
1155 int err = 0;
1156 char c = tp->urg_data;
1157
1158 if (!(flags & MSG_PEEK))
1159 tp->urg_data = TCP_URG_READ;
1160
1161 /* Read urgent data. */
1162 msg->msg_flags |= MSG_OOB;
1163
1164 if (len > 0) {
1165 if (!(flags & MSG_TRUNC))
1166 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1167 len = 1;
1168 } else
1169 msg->msg_flags |= MSG_TRUNC;
1170
1171 return err ? -EFAULT : len;
1172 }
1173
1174 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1175 return 0;
1176
1177 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1178 * the available implementations agree in this case:
1179 * this call should never block, independent of the
1180 * blocking state of the socket.
1181 * Mike <pall@rz.uni-karlsruhe.de>
1182 */
1183 return -EAGAIN;
1184}
1185
1186/* Clean up the receive buffer for full frames taken by the user,
1187 * then send an ACK if necessary. COPIED is the number of bytes
1188 * tcp_recvmsg has given to the user so far, it speeds up the
1189 * calculation of whether or not we must ACK for the sake of
1190 * a window update.
1191 */
1192void tcp_cleanup_rbuf(struct sock *sk, int copied)
1193{
1194 struct tcp_sock *tp = tcp_sk(sk);
1195 int time_to_ack = 0;
1196
1197#if TCP_DEBUG
1198 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1199
1200 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1201 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1202 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1203#endif
1204
1205 if (inet_csk_ack_scheduled(sk)) {
1206 const struct inet_connection_sock *icsk = inet_csk(sk);
1207 /* Delayed ACKs frequently hit locked sockets during bulk
1208 * receive. */
1209 if (icsk->icsk_ack.blocked ||
1210 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1211 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1212 /*
1213 * If this read emptied read buffer, we send ACK, if
1214 * connection is not bidirectional, user drained
1215 * receive buffer and there was a small segment
1216 * in queue.
1217 */
1218 (copied > 0 &&
1219 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1220 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1221 !icsk->icsk_ack.pingpong)) &&
1222 !atomic_read(&sk->sk_rmem_alloc)))
1223 time_to_ack = 1;
1224 }
1225
1226 /* We send an ACK if we can now advertise a non-zero window
1227 * which has been raised "significantly".
1228 *
1229 * Even if window raised up to infinity, do not send window open ACK
1230 * in states, where we will not receive more. It is useless.
1231 */
1232 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1233 __u32 rcv_window_now = tcp_receive_window(tp);
1234
1235 /* Optimize, __tcp_select_window() is not cheap. */
1236 if (2*rcv_window_now <= tp->window_clamp) {
1237 __u32 new_window = __tcp_select_window(sk);
1238
1239 /* Send ACK now, if this read freed lots of space
1240 * in our buffer. Certainly, new_window is new window.
1241 * We can advertise it now, if it is not less than current one.
1242 * "Lots" means "at least twice" here.
1243 */
1244 if (new_window && new_window >= 2 * rcv_window_now)
1245 time_to_ack = 1;
1246 }
1247 }
1248 if (time_to_ack)
1249 tcp_send_ack(sk);
1250}
1251
1252static void tcp_prequeue_process(struct sock *sk)
1253{
1254 struct sk_buff *skb;
1255 struct tcp_sock *tp = tcp_sk(sk);
1256
1257 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
1258
1259 /* RX process wants to run with disabled BHs, though it is not
1260 * necessary */
1261 local_bh_disable();
1262 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1263 sk_backlog_rcv(sk, skb);
1264 local_bh_enable();
1265
1266 /* Clear memory counter. */
1267 tp->ucopy.memory = 0;
1268}
1269
1270#ifdef CONFIG_NET_DMA
1271static void tcp_service_net_dma(struct sock *sk, bool wait)
1272{
1273 dma_cookie_t done, used;
1274 dma_cookie_t last_issued;
1275 struct tcp_sock *tp = tcp_sk(sk);
1276
1277 if (!tp->ucopy.dma_chan)
1278 return;
1279
1280 last_issued = tp->ucopy.dma_cookie;
1281 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1282
1283 do {
1284 if (dma_async_memcpy_complete(tp->ucopy.dma_chan,
1285 last_issued, &done,
1286 &used) == DMA_SUCCESS) {
1287 /* Safe to free early-copied skbs now */
1288 __skb_queue_purge(&sk->sk_async_wait_queue);
1289 break;
1290 } else {
1291 struct sk_buff *skb;
1292 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1293 (dma_async_is_complete(skb->dma_cookie, done,
1294 used) == DMA_SUCCESS)) {
1295 __skb_dequeue(&sk->sk_async_wait_queue);
1296 kfree_skb(skb);
1297 }
1298 }
1299 } while (wait);
1300}
1301#endif
1302
1303static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1304{
1305 struct sk_buff *skb;
1306 u32 offset;
1307
1308 skb_queue_walk(&sk->sk_receive_queue, skb) {
1309 offset = seq - TCP_SKB_CB(skb)->seq;
1310 if (tcp_hdr(skb)->syn)
1311 offset--;
1312 if (offset < skb->len || tcp_hdr(skb)->fin) {
1313 *off = offset;
1314 return skb;
1315 }
1316 }
1317 return NULL;
1318}
1319
1320/*
1321 * This routine provides an alternative to tcp_recvmsg() for routines
1322 * that would like to handle copying from skbuffs directly in 'sendfile'
1323 * fashion.
1324 * Note:
1325 * - It is assumed that the socket was locked by the caller.
1326 * - The routine does not block.
1327 * - At present, there is no support for reading OOB data
1328 * or for 'peeking' the socket using this routine
1329 * (although both would be easy to implement).
1330 */
1331int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1332 sk_read_actor_t recv_actor)
1333{
1334 struct sk_buff *skb;
1335 struct tcp_sock *tp = tcp_sk(sk);
1336 u32 seq = tp->copied_seq;
1337 u32 offset;
1338 int copied = 0;
1339
1340 if (sk->sk_state == TCP_LISTEN)
1341 return -ENOTCONN;
1342 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1343 if (offset < skb->len) {
1344 int used;
1345 size_t len;
1346
1347 len = skb->len - offset;
1348 /* Stop reading if we hit a patch of urgent data */
1349 if (tp->urg_data) {
1350 u32 urg_offset = tp->urg_seq - seq;
1351 if (urg_offset < len)
1352 len = urg_offset;
1353 if (!len)
1354 break;
1355 }
1356 used = recv_actor(desc, skb, offset, len);
1357 if (used < 0) {
1358 if (!copied)
1359 copied = used;
1360 break;
1361 } else if (used <= len) {
1362 seq += used;
1363 copied += used;
1364 offset += used;
1365 }
1366 /*
1367 * If recv_actor drops the lock (e.g. TCP splice
1368 * receive) the skb pointer might be invalid when
1369 * getting here: tcp_collapse might have deleted it
1370 * while aggregating skbs from the socket queue.
1371 */
1372 skb = tcp_recv_skb(sk, seq-1, &offset);
1373 if (!skb || (offset+1 != skb->len))
1374 break;
1375 }
1376 if (tcp_hdr(skb)->fin) {
1377 sk_eat_skb(sk, skb, 0);
1378 ++seq;
1379 break;
1380 }
1381 sk_eat_skb(sk, skb, 0);
1382 if (!desc->count)
1383 break;
1384 tp->copied_seq = seq;
1385 }
1386 tp->copied_seq = seq;
1387
1388 tcp_rcv_space_adjust(sk);
1389
1390 /* Clean up data we have read: This will do ACK frames. */
1391 if (copied > 0)
1392 tcp_cleanup_rbuf(sk, copied);
1393 return copied;
1394}
1395EXPORT_SYMBOL(tcp_read_sock);
1396
1397/*
1398 * This routine copies from a sock struct into the user buffer.
1399 *
1400 * Technical note: in 2.3 we work on _locked_ socket, so that
1401 * tricks with *seq access order and skb->users are not required.
1402 * Probably, code can be easily improved even more.
1403 */
1404
1405int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1406 size_t len, int nonblock, int flags, int *addr_len)
1407{
1408 struct tcp_sock *tp = tcp_sk(sk);
1409 int copied = 0;
1410 u32 peek_seq;
1411 u32 *seq;
1412 unsigned long used;
1413 int err;
1414 int target; /* Read at least this many bytes */
1415 long timeo;
1416 struct task_struct *user_recv = NULL;
1417 int copied_early = 0;
1418 struct sk_buff *skb;
1419 u32 urg_hole = 0;
1420
1421 lock_sock(sk);
1422
1423 err = -ENOTCONN;
1424 if (sk->sk_state == TCP_LISTEN)
1425 goto out;
1426
1427 timeo = sock_rcvtimeo(sk, nonblock);
1428
1429 /* Urgent data needs to be handled specially. */
1430 if (flags & MSG_OOB)
1431 goto recv_urg;
1432
1433 seq = &tp->copied_seq;
1434 if (flags & MSG_PEEK) {
1435 peek_seq = tp->copied_seq;
1436 seq = &peek_seq;
1437 }
1438
1439 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1440
1441#ifdef CONFIG_NET_DMA
1442 tp->ucopy.dma_chan = NULL;
1443 preempt_disable();
1444 skb = skb_peek_tail(&sk->sk_receive_queue);
1445 {
1446 int available = 0;
1447
1448 if (skb)
1449 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1450 if ((available < target) &&
1451 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1452 !sysctl_tcp_low_latency &&
1453 dma_find_channel(DMA_MEMCPY)) {
1454 preempt_enable_no_resched();
1455 tp->ucopy.pinned_list =
1456 dma_pin_iovec_pages(msg->msg_iov, len);
1457 } else {
1458 preempt_enable_no_resched();
1459 }
1460 }
1461#endif
1462
1463 do {
1464 u32 offset;
1465
1466 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1467 if (tp->urg_data && tp->urg_seq == *seq) {
1468 if (copied)
1469 break;
1470 if (signal_pending(current)) {
1471 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1472 break;
1473 }
1474 }
1475
1476 /* Next get a buffer. */
1477
1478 skb_queue_walk(&sk->sk_receive_queue, skb) {
1479 /* Now that we have two receive queues this
1480 * shouldn't happen.
1481 */
1482 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1483 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1484 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1485 flags))
1486 break;
1487
1488 offset = *seq - TCP_SKB_CB(skb)->seq;
1489 if (tcp_hdr(skb)->syn)
1490 offset--;
1491 if (offset < skb->len)
1492 goto found_ok_skb;
1493 if (tcp_hdr(skb)->fin)
1494 goto found_fin_ok;
1495 WARN(!(flags & MSG_PEEK),
1496 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1497 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
1498 }
1499
1500 /* Well, if we have backlog, try to process it now yet. */
1501
1502 if (copied >= target && !sk->sk_backlog.tail)
1503 break;
1504
1505 if (copied) {
1506 if (sk->sk_err ||
1507 sk->sk_state == TCP_CLOSE ||
1508 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1509 !timeo ||
1510 signal_pending(current))
1511 break;
1512 } else {
1513 if (sock_flag(sk, SOCK_DONE))
1514 break;
1515
1516 if (sk->sk_err) {
1517 copied = sock_error(sk);
1518 break;
1519 }
1520
1521 if (sk->sk_shutdown & RCV_SHUTDOWN)
1522 break;
1523
1524 if (sk->sk_state == TCP_CLOSE) {
1525 if (!sock_flag(sk, SOCK_DONE)) {
1526 /* This occurs when user tries to read
1527 * from never connected socket.
1528 */
1529 copied = -ENOTCONN;
1530 break;
1531 }
1532 break;
1533 }
1534
1535 if (!timeo) {
1536 copied = -EAGAIN;
1537 break;
1538 }
1539
1540 if (signal_pending(current)) {
1541 copied = sock_intr_errno(timeo);
1542 break;
1543 }
1544 }
1545
1546 tcp_cleanup_rbuf(sk, copied);
1547
1548 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1549 /* Install new reader */
1550 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1551 user_recv = current;
1552 tp->ucopy.task = user_recv;
1553 tp->ucopy.iov = msg->msg_iov;
1554 }
1555
1556 tp->ucopy.len = len;
1557
1558 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1559 !(flags & (MSG_PEEK | MSG_TRUNC)));
1560
1561 /* Ugly... If prequeue is not empty, we have to
1562 * process it before releasing socket, otherwise
1563 * order will be broken at second iteration.
1564 * More elegant solution is required!!!
1565 *
1566 * Look: we have the following (pseudo)queues:
1567 *
1568 * 1. packets in flight
1569 * 2. backlog
1570 * 3. prequeue
1571 * 4. receive_queue
1572 *
1573 * Each queue can be processed only if the next ones
1574 * are empty. At this point we have empty receive_queue.
1575 * But prequeue _can_ be not empty after 2nd iteration,
1576 * when we jumped to start of loop because backlog
1577 * processing added something to receive_queue.
1578 * We cannot release_sock(), because backlog contains
1579 * packets arrived _after_ prequeued ones.
1580 *
1581 * Shortly, algorithm is clear --- to process all
1582 * the queues in order. We could make it more directly,
1583 * requeueing packets from backlog to prequeue, if
1584 * is not empty. It is more elegant, but eats cycles,
1585 * unfortunately.
1586 */
1587 if (!skb_queue_empty(&tp->ucopy.prequeue))
1588 goto do_prequeue;
1589
1590 /* __ Set realtime policy in scheduler __ */
1591 }
1592
1593#ifdef CONFIG_NET_DMA
1594 if (tp->ucopy.dma_chan)
1595 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1596#endif
1597 if (copied >= target) {
1598 /* Do not sleep, just process backlog. */
1599 release_sock(sk);
1600 lock_sock(sk);
1601 } else
1602 sk_wait_data(sk, &timeo);
1603
1604#ifdef CONFIG_NET_DMA
1605 tcp_service_net_dma(sk, false); /* Don't block */
1606 tp->ucopy.wakeup = 0;
1607#endif
1608
1609 if (user_recv) {
1610 int chunk;
1611
1612 /* __ Restore normal policy in scheduler __ */
1613
1614 if ((chunk = len - tp->ucopy.len) != 0) {
1615 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1616 len -= chunk;
1617 copied += chunk;
1618 }
1619
1620 if (tp->rcv_nxt == tp->copied_seq &&
1621 !skb_queue_empty(&tp->ucopy.prequeue)) {
1622do_prequeue:
1623 tcp_prequeue_process(sk);
1624
1625 if ((chunk = len - tp->ucopy.len) != 0) {
1626 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1627 len -= chunk;
1628 copied += chunk;
1629 }
1630 }
1631 }
1632 if ((flags & MSG_PEEK) &&
1633 (peek_seq - copied - urg_hole != tp->copied_seq)) {
1634 if (net_ratelimit())
1635 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1636 current->comm, task_pid_nr(current));
1637 peek_seq = tp->copied_seq;
1638 }
1639 continue;
1640
1641 found_ok_skb:
1642 /* Ok so how much can we use? */
1643 used = skb->len - offset;
1644 if (len < used)
1645 used = len;
1646
1647 /* Do we have urgent data here? */
1648 if (tp->urg_data) {
1649 u32 urg_offset = tp->urg_seq - *seq;
1650 if (urg_offset < used) {
1651 if (!urg_offset) {
1652 if (!sock_flag(sk, SOCK_URGINLINE)) {
1653 ++*seq;
1654 urg_hole++;
1655 offset++;
1656 used--;
1657 if (!used)
1658 goto skip_copy;
1659 }
1660 } else
1661 used = urg_offset;
1662 }
1663 }
1664
1665 if (!(flags & MSG_TRUNC)) {
1666#ifdef CONFIG_NET_DMA
1667 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1668 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1669
1670 if (tp->ucopy.dma_chan) {
1671 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1672 tp->ucopy.dma_chan, skb, offset,
1673 msg->msg_iov, used,
1674 tp->ucopy.pinned_list);
1675
1676 if (tp->ucopy.dma_cookie < 0) {
1677
1678 printk(KERN_ALERT "dma_cookie < 0\n");
1679
1680 /* Exception. Bailout! */
1681 if (!copied)
1682 copied = -EFAULT;
1683 break;
1684 }
1685
1686 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
1687
1688 if ((offset + used) == skb->len)
1689 copied_early = 1;
1690
1691 } else
1692#endif
1693 {
1694 err = skb_copy_datagram_iovec(skb, offset,
1695 msg->msg_iov, used);
1696 if (err) {
1697 /* Exception. Bailout! */
1698 if (!copied)
1699 copied = -EFAULT;
1700 break;
1701 }
1702 }
1703 }
1704
1705 *seq += used;
1706 copied += used;
1707 len -= used;
1708
1709 tcp_rcv_space_adjust(sk);
1710
1711skip_copy:
1712 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1713 tp->urg_data = 0;
1714 tcp_fast_path_check(sk);
1715 }
1716 if (used + offset < skb->len)
1717 continue;
1718
1719 if (tcp_hdr(skb)->fin)
1720 goto found_fin_ok;
1721 if (!(flags & MSG_PEEK)) {
1722 sk_eat_skb(sk, skb, copied_early);
1723 copied_early = 0;
1724 }
1725 continue;
1726
1727 found_fin_ok:
1728 /* Process the FIN. */
1729 ++*seq;
1730 if (!(flags & MSG_PEEK)) {
1731 sk_eat_skb(sk, skb, copied_early);
1732 copied_early = 0;
1733 }
1734 break;
1735 } while (len > 0);
1736
1737 if (user_recv) {
1738 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1739 int chunk;
1740
1741 tp->ucopy.len = copied > 0 ? len : 0;
1742
1743 tcp_prequeue_process(sk);
1744
1745 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1746 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1747 len -= chunk;
1748 copied += chunk;
1749 }
1750 }
1751
1752 tp->ucopy.task = NULL;
1753 tp->ucopy.len = 0;
1754 }
1755
1756#ifdef CONFIG_NET_DMA
1757 tcp_service_net_dma(sk, true); /* Wait for queue to drain */
1758 tp->ucopy.dma_chan = NULL;
1759
1760 if (tp->ucopy.pinned_list) {
1761 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1762 tp->ucopy.pinned_list = NULL;
1763 }
1764#endif
1765
1766 /* According to UNIX98, msg_name/msg_namelen are ignored
1767 * on connected socket. I was just happy when found this 8) --ANK
1768 */
1769
1770 /* Clean up data we have read: This will do ACK frames. */
1771 tcp_cleanup_rbuf(sk, copied);
1772
1773 release_sock(sk);
1774 return copied;
1775
1776out:
1777 release_sock(sk);
1778 return err;
1779
1780recv_urg:
1781 err = tcp_recv_urg(sk, msg, len, flags);
1782 goto out;
1783}
1784EXPORT_SYMBOL(tcp_recvmsg);
1785
1786void tcp_set_state(struct sock *sk, int state)
1787{
1788 int oldstate = sk->sk_state;
1789
1790 switch (state) {
1791 case TCP_ESTABLISHED:
1792 if (oldstate != TCP_ESTABLISHED)
1793 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1794 break;
1795
1796 case TCP_CLOSE:
1797 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1798 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
1799
1800 sk->sk_prot->unhash(sk);
1801 if (inet_csk(sk)->icsk_bind_hash &&
1802 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1803 inet_put_port(sk);
1804 /* fall through */
1805 default:
1806 if (oldstate == TCP_ESTABLISHED)
1807 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1808 }
1809
1810 /* Change state AFTER socket is unhashed to avoid closed
1811 * socket sitting in hash tables.
1812 */
1813 sk->sk_state = state;
1814
1815#ifdef STATE_TRACE
1816 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
1817#endif
1818}
1819EXPORT_SYMBOL_GPL(tcp_set_state);
1820
1821/*
1822 * State processing on a close. This implements the state shift for
1823 * sending our FIN frame. Note that we only send a FIN for some
1824 * states. A shutdown() may have already sent the FIN, or we may be
1825 * closed.
1826 */
1827
1828static const unsigned char new_state[16] = {
1829 /* current state: new state: action: */
1830 /* (Invalid) */ TCP_CLOSE,
1831 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1832 /* TCP_SYN_SENT */ TCP_CLOSE,
1833 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
1834 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
1835 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
1836 /* TCP_TIME_WAIT */ TCP_CLOSE,
1837 /* TCP_CLOSE */ TCP_CLOSE,
1838 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
1839 /* TCP_LAST_ACK */ TCP_LAST_ACK,
1840 /* TCP_LISTEN */ TCP_CLOSE,
1841 /* TCP_CLOSING */ TCP_CLOSING,
1842};
1843
1844static int tcp_close_state(struct sock *sk)
1845{
1846 int next = (int)new_state[sk->sk_state];
1847 int ns = next & TCP_STATE_MASK;
1848
1849 tcp_set_state(sk, ns);
1850
1851 return next & TCP_ACTION_FIN;
1852}
1853
1854/*
1855 * Shutdown the sending side of a connection. Much like close except
1856 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1857 */
1858
1859void tcp_shutdown(struct sock *sk, int how)
1860{
1861 /* We need to grab some memory, and put together a FIN,
1862 * and then put it into the queue to be sent.
1863 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1864 */
1865 if (!(how & SEND_SHUTDOWN))
1866 return;
1867
1868 /* If we've already sent a FIN, or it's a closed state, skip this. */
1869 if ((1 << sk->sk_state) &
1870 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1871 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
1872 /* Clear out any half completed packets. FIN if needed. */
1873 if (tcp_close_state(sk))
1874 tcp_send_fin(sk);
1875 }
1876}
1877EXPORT_SYMBOL(tcp_shutdown);
1878
1879void tcp_close(struct sock *sk, long timeout)
1880{
1881 struct sk_buff *skb;
1882 int data_was_unread = 0;
1883 int state;
1884
1885 lock_sock(sk);
1886 sk->sk_shutdown = SHUTDOWN_MASK;
1887
1888 if (sk->sk_state == TCP_LISTEN) {
1889 tcp_set_state(sk, TCP_CLOSE);
1890
1891 /* Special case. */
1892 inet_csk_listen_stop(sk);
1893
1894 goto adjudge_to_death;
1895 }
1896
1897 /* We need to flush the recv. buffs. We do this only on the
1898 * descriptor close, not protocol-sourced closes, because the
1899 * reader process may not have drained the data yet!
1900 */
1901 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1902 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
1903 tcp_hdr(skb)->fin;
1904 data_was_unread += len;
1905 __kfree_skb(skb);
1906 }
1907
1908 sk_mem_reclaim(sk);
1909
1910 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
1911 if (sk->sk_state == TCP_CLOSE)
1912 goto adjudge_to_death;
1913
1914 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1915 * data was lost. To witness the awful effects of the old behavior of
1916 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1917 * GET in an FTP client, suspend the process, wait for the client to
1918 * advertise a zero window, then kill -9 the FTP client, wheee...
1919 * Note: timeout is always zero in such a case.
1920 */
1921 if (data_was_unread) {
1922 /* Unread data was tossed, zap the connection. */
1923 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
1924 tcp_set_state(sk, TCP_CLOSE);
1925 tcp_send_active_reset(sk, sk->sk_allocation);
1926 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1927 /* Check zero linger _after_ checking for unread data. */
1928 sk->sk_prot->disconnect(sk, 0);
1929 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
1930 } else if (tcp_close_state(sk)) {
1931 /* We FIN if the application ate all the data before
1932 * zapping the connection.
1933 */
1934
1935 /* RED-PEN. Formally speaking, we have broken TCP state
1936 * machine. State transitions:
1937 *
1938 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1939 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1940 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1941 *
1942 * are legal only when FIN has been sent (i.e. in window),
1943 * rather than queued out of window. Purists blame.
1944 *
1945 * F.e. "RFC state" is ESTABLISHED,
1946 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1947 *
1948 * The visible declinations are that sometimes
1949 * we enter time-wait state, when it is not required really
1950 * (harmless), do not send active resets, when they are
1951 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1952 * they look as CLOSING or LAST_ACK for Linux)
1953 * Probably, I missed some more holelets.
1954 * --ANK
1955 */
1956 tcp_send_fin(sk);
1957 }
1958
1959 sk_stream_wait_close(sk, timeout);
1960
1961adjudge_to_death:
1962 state = sk->sk_state;
1963 sock_hold(sk);
1964 sock_orphan(sk);
1965
1966 /* It is the last release_sock in its life. It will remove backlog. */
1967 release_sock(sk);
1968
1969
1970 /* Now socket is owned by kernel and we acquire BH lock
1971 to finish close. No need to check for user refs.
1972 */
1973 local_bh_disable();
1974 bh_lock_sock(sk);
1975 WARN_ON(sock_owned_by_user(sk));
1976
1977 percpu_counter_inc(sk->sk_prot->orphan_count);
1978
1979 /* Have we already been destroyed by a softirq or backlog? */
1980 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
1981 goto out;
1982
1983 /* This is a (useful) BSD violating of the RFC. There is a
1984 * problem with TCP as specified in that the other end could
1985 * keep a socket open forever with no application left this end.
1986 * We use a 3 minute timeout (about the same as BSD) then kill
1987 * our end. If they send after that then tough - BUT: long enough
1988 * that we won't make the old 4*rto = almost no time - whoops
1989 * reset mistake.
1990 *
1991 * Nope, it was not mistake. It is really desired behaviour
1992 * f.e. on http servers, when such sockets are useless, but
1993 * consume significant resources. Let's do it with special
1994 * linger2 option. --ANK
1995 */
1996
1997 if (sk->sk_state == TCP_FIN_WAIT2) {
1998 struct tcp_sock *tp = tcp_sk(sk);
1999 if (tp->linger2 < 0) {
2000 tcp_set_state(sk, TCP_CLOSE);
2001 tcp_send_active_reset(sk, GFP_ATOMIC);
2002 NET_INC_STATS_BH(sock_net(sk),
2003 LINUX_MIB_TCPABORTONLINGER);
2004 } else {
2005 const int tmo = tcp_fin_time(sk);
2006
2007 if (tmo > TCP_TIMEWAIT_LEN) {
2008 inet_csk_reset_keepalive_timer(sk,
2009 tmo - TCP_TIMEWAIT_LEN);
2010 } else {
2011 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2012 goto out;
2013 }
2014 }
2015 }
2016 if (sk->sk_state != TCP_CLOSE) {
2017 sk_mem_reclaim(sk);
2018 if (tcp_too_many_orphans(sk, 0)) {
2019 if (net_ratelimit())
2020 printk(KERN_INFO "TCP: too many of orphaned "
2021 "sockets\n");
2022 tcp_set_state(sk, TCP_CLOSE);
2023 tcp_send_active_reset(sk, GFP_ATOMIC);
2024 NET_INC_STATS_BH(sock_net(sk),
2025 LINUX_MIB_TCPABORTONMEMORY);
2026 }
2027 }
2028
2029 if (sk->sk_state == TCP_CLOSE)
2030 inet_csk_destroy_sock(sk);
2031 /* Otherwise, socket is reprieved until protocol close. */
2032
2033out:
2034 bh_unlock_sock(sk);
2035 local_bh_enable();
2036 sock_put(sk);
2037}
2038EXPORT_SYMBOL(tcp_close);
2039
2040/* These states need RST on ABORT according to RFC793 */
2041
2042static inline int tcp_need_reset(int state)
2043{
2044 return (1 << state) &
2045 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2046 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2047}
2048
2049int tcp_disconnect(struct sock *sk, int flags)
2050{
2051 struct inet_sock *inet = inet_sk(sk);
2052 struct inet_connection_sock *icsk = inet_csk(sk);
2053 struct tcp_sock *tp = tcp_sk(sk);
2054 int err = 0;
2055 int old_state = sk->sk_state;
2056
2057 if (old_state != TCP_CLOSE)
2058 tcp_set_state(sk, TCP_CLOSE);
2059
2060 /* ABORT function of RFC793 */
2061 if (old_state == TCP_LISTEN) {
2062 inet_csk_listen_stop(sk);
2063 } else if (tcp_need_reset(old_state) ||
2064 (tp->snd_nxt != tp->write_seq &&
2065 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2066 /* The last check adjusts for discrepancy of Linux wrt. RFC
2067 * states
2068 */
2069 tcp_send_active_reset(sk, gfp_any());
2070 sk->sk_err = ECONNRESET;
2071 } else if (old_state == TCP_SYN_SENT)
2072 sk->sk_err = ECONNRESET;
2073
2074 tcp_clear_xmit_timers(sk);
2075 __skb_queue_purge(&sk->sk_receive_queue);
2076 tcp_write_queue_purge(sk);
2077 __skb_queue_purge(&tp->out_of_order_queue);
2078#ifdef CONFIG_NET_DMA
2079 __skb_queue_purge(&sk->sk_async_wait_queue);
2080#endif
2081
2082 inet->inet_dport = 0;
2083
2084 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2085 inet_reset_saddr(sk);
2086
2087 sk->sk_shutdown = 0;
2088 sock_reset_flag(sk, SOCK_DONE);
2089 tp->srtt = 0;
2090 if ((tp->write_seq += tp->max_window + 2) == 0)
2091 tp->write_seq = 1;
2092 icsk->icsk_backoff = 0;
2093 tp->snd_cwnd = 2;
2094 icsk->icsk_probes_out = 0;
2095 tp->packets_out = 0;
2096 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2097 tp->snd_cwnd_cnt = 0;
2098 tp->bytes_acked = 0;
2099 tp->window_clamp = 0;
2100 tcp_set_ca_state(sk, TCP_CA_Open);
2101 tcp_clear_retrans(tp);
2102 inet_csk_delack_init(sk);
2103 tcp_init_send_head(sk);
2104 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2105 __sk_dst_reset(sk);
2106
2107 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2108
2109 sk->sk_error_report(sk);
2110 return err;
2111}
2112EXPORT_SYMBOL(tcp_disconnect);
2113
2114/*
2115 * Socket option code for TCP.
2116 */
2117static int do_tcp_setsockopt(struct sock *sk, int level,
2118 int optname, char __user *optval, unsigned int optlen)
2119{
2120 struct tcp_sock *tp = tcp_sk(sk);
2121 struct inet_connection_sock *icsk = inet_csk(sk);
2122 int val;
2123 int err = 0;
2124
2125 /* These are data/string values, all the others are ints */
2126 switch (optname) {
2127 case TCP_CONGESTION: {
2128 char name[TCP_CA_NAME_MAX];
2129
2130 if (optlen < 1)
2131 return -EINVAL;
2132
2133 val = strncpy_from_user(name, optval,
2134 min_t(long, TCP_CA_NAME_MAX-1, optlen));
2135 if (val < 0)
2136 return -EFAULT;
2137 name[val] = 0;
2138
2139 lock_sock(sk);
2140 err = tcp_set_congestion_control(sk, name);
2141 release_sock(sk);
2142 return err;
2143 }
2144 case TCP_COOKIE_TRANSACTIONS: {
2145 struct tcp_cookie_transactions ctd;
2146 struct tcp_cookie_values *cvp = NULL;
2147
2148 if (sizeof(ctd) > optlen)
2149 return -EINVAL;
2150 if (copy_from_user(&ctd, optval, sizeof(ctd)))
2151 return -EFAULT;
2152
2153 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) ||
2154 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED)
2155 return -EINVAL;
2156
2157 if (ctd.tcpct_cookie_desired == 0) {
2158 /* default to global value */
2159 } else if ((0x1 & ctd.tcpct_cookie_desired) ||
2160 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX ||
2161 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) {
2162 return -EINVAL;
2163 }
2164
2165 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) {
2166 /* Supercedes all other values */
2167 lock_sock(sk);
2168 if (tp->cookie_values != NULL) {
2169 kref_put(&tp->cookie_values->kref,
2170 tcp_cookie_values_release);
2171 tp->cookie_values = NULL;
2172 }
2173 tp->rx_opt.cookie_in_always = 0; /* false */
2174 tp->rx_opt.cookie_out_never = 1; /* true */
2175 release_sock(sk);
2176 return err;
2177 }
2178
2179 /* Allocate ancillary memory before locking.
2180 */
2181 if (ctd.tcpct_used > 0 ||
2182 (tp->cookie_values == NULL &&
2183 (sysctl_tcp_cookie_size > 0 ||
2184 ctd.tcpct_cookie_desired > 0 ||
2185 ctd.tcpct_s_data_desired > 0))) {
2186 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used,
2187 GFP_KERNEL);
2188 if (cvp == NULL)
2189 return -ENOMEM;
2190
2191 kref_init(&cvp->kref);
2192 }
2193 lock_sock(sk);
2194 tp->rx_opt.cookie_in_always =
2195 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags);
2196 tp->rx_opt.cookie_out_never = 0; /* false */
2197
2198 if (tp->cookie_values != NULL) {
2199 if (cvp != NULL) {
2200 /* Changed values are recorded by a changed
2201 * pointer, ensuring the cookie will differ,
2202 * without separately hashing each value later.
2203 */
2204 kref_put(&tp->cookie_values->kref,
2205 tcp_cookie_values_release);
2206 } else {
2207 cvp = tp->cookie_values;
2208 }
2209 }
2210
2211 if (cvp != NULL) {
2212 cvp->cookie_desired = ctd.tcpct_cookie_desired;
2213
2214 if (ctd.tcpct_used > 0) {
2215 memcpy(cvp->s_data_payload, ctd.tcpct_value,
2216 ctd.tcpct_used);
2217 cvp->s_data_desired = ctd.tcpct_used;
2218 cvp->s_data_constant = 1; /* true */
2219 } else {
2220 /* No constant payload data. */
2221 cvp->s_data_desired = ctd.tcpct_s_data_desired;
2222 cvp->s_data_constant = 0; /* false */
2223 }
2224
2225 tp->cookie_values = cvp;
2226 }
2227 release_sock(sk);
2228 return err;
2229 }
2230 default:
2231 /* fallthru */
2232 break;
2233 }
2234
2235 if (optlen < sizeof(int))
2236 return -EINVAL;
2237
2238 if (get_user(val, (int __user *)optval))
2239 return -EFAULT;
2240
2241 lock_sock(sk);
2242
2243 switch (optname) {
2244 case TCP_MAXSEG:
2245 /* Values greater than interface MTU won't take effect. However
2246 * at the point when this call is done we typically don't yet
2247 * know which interface is going to be used */
2248 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
2249 err = -EINVAL;
2250 break;
2251 }
2252 tp->rx_opt.user_mss = val;
2253 break;
2254
2255 case TCP_NODELAY:
2256 if (val) {
2257 /* TCP_NODELAY is weaker than TCP_CORK, so that
2258 * this option on corked socket is remembered, but
2259 * it is not activated until cork is cleared.
2260 *
2261 * However, when TCP_NODELAY is set we make
2262 * an explicit push, which overrides even TCP_CORK
2263 * for currently queued segments.
2264 */
2265 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2266 tcp_push_pending_frames(sk);
2267 } else {
2268 tp->nonagle &= ~TCP_NAGLE_OFF;
2269 }
2270 break;
2271
2272 case TCP_THIN_LINEAR_TIMEOUTS:
2273 if (val < 0 || val > 1)
2274 err = -EINVAL;
2275 else
2276 tp->thin_lto = val;
2277 break;
2278
2279 case TCP_THIN_DUPACK:
2280 if (val < 0 || val > 1)
2281 err = -EINVAL;
2282 else
2283 tp->thin_dupack = val;
2284 break;
2285
2286 case TCP_CORK:
2287 /* When set indicates to always queue non-full frames.
2288 * Later the user clears this option and we transmit
2289 * any pending partial frames in the queue. This is
2290 * meant to be used alongside sendfile() to get properly
2291 * filled frames when the user (for example) must write
2292 * out headers with a write() call first and then use
2293 * sendfile to send out the data parts.
2294 *
2295 * TCP_CORK can be set together with TCP_NODELAY and it is
2296 * stronger than TCP_NODELAY.
2297 */
2298 if (val) {
2299 tp->nonagle |= TCP_NAGLE_CORK;
2300 } else {
2301 tp->nonagle &= ~TCP_NAGLE_CORK;
2302 if (tp->nonagle&TCP_NAGLE_OFF)
2303 tp->nonagle |= TCP_NAGLE_PUSH;
2304 tcp_push_pending_frames(sk);
2305 }
2306 break;
2307
2308 case TCP_KEEPIDLE:
2309 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2310 err = -EINVAL;
2311 else {
2312 tp->keepalive_time = val * HZ;
2313 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2314 !((1 << sk->sk_state) &
2315 (TCPF_CLOSE | TCPF_LISTEN))) {
2316 u32 elapsed = keepalive_time_elapsed(tp);
2317 if (tp->keepalive_time > elapsed)
2318 elapsed = tp->keepalive_time - elapsed;
2319 else
2320 elapsed = 0;
2321 inet_csk_reset_keepalive_timer(sk, elapsed);
2322 }
2323 }
2324 break;
2325 case TCP_KEEPINTVL:
2326 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2327 err = -EINVAL;
2328 else
2329 tp->keepalive_intvl = val * HZ;
2330 break;
2331 case TCP_KEEPCNT:
2332 if (val < 1 || val > MAX_TCP_KEEPCNT)
2333 err = -EINVAL;
2334 else
2335 tp->keepalive_probes = val;
2336 break;
2337 case TCP_SYNCNT:
2338 if (val < 1 || val > MAX_TCP_SYNCNT)
2339 err = -EINVAL;
2340 else
2341 icsk->icsk_syn_retries = val;
2342 break;
2343
2344 case TCP_LINGER2:
2345 if (val < 0)
2346 tp->linger2 = -1;
2347 else if (val > sysctl_tcp_fin_timeout / HZ)
2348 tp->linger2 = 0;
2349 else
2350 tp->linger2 = val * HZ;
2351 break;
2352
2353 case TCP_DEFER_ACCEPT:
2354 /* Translate value in seconds to number of retransmits */
2355 icsk->icsk_accept_queue.rskq_defer_accept =
2356 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2357 TCP_RTO_MAX / HZ);
2358 break;
2359
2360 case TCP_WINDOW_CLAMP:
2361 if (!val) {
2362 if (sk->sk_state != TCP_CLOSE) {
2363 err = -EINVAL;
2364 break;
2365 }
2366 tp->window_clamp = 0;
2367 } else
2368 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2369 SOCK_MIN_RCVBUF / 2 : val;
2370 break;
2371
2372 case TCP_QUICKACK:
2373 if (!val) {
2374 icsk->icsk_ack.pingpong = 1;
2375 } else {
2376 icsk->icsk_ack.pingpong = 0;
2377 if ((1 << sk->sk_state) &
2378 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2379 inet_csk_ack_scheduled(sk)) {
2380 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2381 tcp_cleanup_rbuf(sk, 1);
2382 if (!(val & 1))
2383 icsk->icsk_ack.pingpong = 1;
2384 }
2385 }
2386 break;
2387
2388#ifdef CONFIG_TCP_MD5SIG
2389 case TCP_MD5SIG:
2390 /* Read the IP->Key mappings from userspace */
2391 err = tp->af_specific->md5_parse(sk, optval, optlen);
2392 break;
2393#endif
2394 case TCP_USER_TIMEOUT:
2395 /* Cap the max timeout in ms TCP will retry/retrans
2396 * before giving up and aborting (ETIMEDOUT) a connection.
2397 */
2398 icsk->icsk_user_timeout = msecs_to_jiffies(val);
2399 break;
2400 default:
2401 err = -ENOPROTOOPT;
2402 break;
2403 }
2404
2405 release_sock(sk);
2406 return err;
2407}
2408
2409int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2410 unsigned int optlen)
2411{
2412 struct inet_connection_sock *icsk = inet_csk(sk);
2413
2414 if (level != SOL_TCP)
2415 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2416 optval, optlen);
2417 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2418}
2419EXPORT_SYMBOL(tcp_setsockopt);
2420
2421#ifdef CONFIG_COMPAT
2422int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2423 char __user *optval, unsigned int optlen)
2424{
2425 if (level != SOL_TCP)
2426 return inet_csk_compat_setsockopt(sk, level, optname,
2427 optval, optlen);
2428 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2429}
2430EXPORT_SYMBOL(compat_tcp_setsockopt);
2431#endif
2432
2433/* Return information about state of tcp endpoint in API format. */
2434void tcp_get_info(struct sock *sk, struct tcp_info *info)
2435{
2436 struct tcp_sock *tp = tcp_sk(sk);
2437 const struct inet_connection_sock *icsk = inet_csk(sk);
2438 u32 now = tcp_time_stamp;
2439
2440 memset(info, 0, sizeof(*info));
2441
2442 info->tcpi_state = sk->sk_state;
2443 info->tcpi_ca_state = icsk->icsk_ca_state;
2444 info->tcpi_retransmits = icsk->icsk_retransmits;
2445 info->tcpi_probes = icsk->icsk_probes_out;
2446 info->tcpi_backoff = icsk->icsk_backoff;
2447
2448 if (tp->rx_opt.tstamp_ok)
2449 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2450 if (tcp_is_sack(tp))
2451 info->tcpi_options |= TCPI_OPT_SACK;
2452 if (tp->rx_opt.wscale_ok) {
2453 info->tcpi_options |= TCPI_OPT_WSCALE;
2454 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2455 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2456 }
2457
2458 if (tp->ecn_flags&TCP_ECN_OK)
2459 info->tcpi_options |= TCPI_OPT_ECN;
2460
2461 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2462 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2463 info->tcpi_snd_mss = tp->mss_cache;
2464 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2465
2466 if (sk->sk_state == TCP_LISTEN) {
2467 info->tcpi_unacked = sk->sk_ack_backlog;
2468 info->tcpi_sacked = sk->sk_max_ack_backlog;
2469 } else {
2470 info->tcpi_unacked = tp->packets_out;
2471 info->tcpi_sacked = tp->sacked_out;
2472 }
2473 info->tcpi_lost = tp->lost_out;
2474 info->tcpi_retrans = tp->retrans_out;
2475 info->tcpi_fackets = tp->fackets_out;
2476
2477 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2478 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2479 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2480
2481 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2482 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2483 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2484 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2485 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2486 info->tcpi_snd_cwnd = tp->snd_cwnd;
2487 info->tcpi_advmss = tp->advmss;
2488 info->tcpi_reordering = tp->reordering;
2489
2490 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2491 info->tcpi_rcv_space = tp->rcvq_space.space;
2492
2493 info->tcpi_total_retrans = tp->total_retrans;
2494}
2495EXPORT_SYMBOL_GPL(tcp_get_info);
2496
2497static int do_tcp_getsockopt(struct sock *sk, int level,
2498 int optname, char __user *optval, int __user *optlen)
2499{
2500 struct inet_connection_sock *icsk = inet_csk(sk);
2501 struct tcp_sock *tp = tcp_sk(sk);
2502 int val, len;
2503
2504 if (get_user(len, optlen))
2505 return -EFAULT;
2506
2507 len = min_t(unsigned int, len, sizeof(int));
2508
2509 if (len < 0)
2510 return -EINVAL;
2511
2512 switch (optname) {
2513 case TCP_MAXSEG:
2514 val = tp->mss_cache;
2515 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2516 val = tp->rx_opt.user_mss;
2517 break;
2518 case TCP_NODELAY:
2519 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2520 break;
2521 case TCP_CORK:
2522 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2523 break;
2524 case TCP_KEEPIDLE:
2525 val = keepalive_time_when(tp) / HZ;
2526 break;
2527 case TCP_KEEPINTVL:
2528 val = keepalive_intvl_when(tp) / HZ;
2529 break;
2530 case TCP_KEEPCNT:
2531 val = keepalive_probes(tp);
2532 break;
2533 case TCP_SYNCNT:
2534 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2535 break;
2536 case TCP_LINGER2:
2537 val = tp->linger2;
2538 if (val >= 0)
2539 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2540 break;
2541 case TCP_DEFER_ACCEPT:
2542 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2543 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
2544 break;
2545 case TCP_WINDOW_CLAMP:
2546 val = tp->window_clamp;
2547 break;
2548 case TCP_INFO: {
2549 struct tcp_info info;
2550
2551 if (get_user(len, optlen))
2552 return -EFAULT;
2553
2554 tcp_get_info(sk, &info);
2555
2556 len = min_t(unsigned int, len, sizeof(info));
2557 if (put_user(len, optlen))
2558 return -EFAULT;
2559 if (copy_to_user(optval, &info, len))
2560 return -EFAULT;
2561 return 0;
2562 }
2563 case TCP_QUICKACK:
2564 val = !icsk->icsk_ack.pingpong;
2565 break;
2566
2567 case TCP_CONGESTION:
2568 if (get_user(len, optlen))
2569 return -EFAULT;
2570 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2571 if (put_user(len, optlen))
2572 return -EFAULT;
2573 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2574 return -EFAULT;
2575 return 0;
2576
2577 case TCP_COOKIE_TRANSACTIONS: {
2578 struct tcp_cookie_transactions ctd;
2579 struct tcp_cookie_values *cvp = tp->cookie_values;
2580
2581 if (get_user(len, optlen))
2582 return -EFAULT;
2583 if (len < sizeof(ctd))
2584 return -EINVAL;
2585
2586 memset(&ctd, 0, sizeof(ctd));
2587 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ?
2588 TCP_COOKIE_IN_ALWAYS : 0)
2589 | (tp->rx_opt.cookie_out_never ?
2590 TCP_COOKIE_OUT_NEVER : 0);
2591
2592 if (cvp != NULL) {
2593 ctd.tcpct_flags |= (cvp->s_data_in ?
2594 TCP_S_DATA_IN : 0)
2595 | (cvp->s_data_out ?
2596 TCP_S_DATA_OUT : 0);
2597
2598 ctd.tcpct_cookie_desired = cvp->cookie_desired;
2599 ctd.tcpct_s_data_desired = cvp->s_data_desired;
2600
2601 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0],
2602 cvp->cookie_pair_size);
2603 ctd.tcpct_used = cvp->cookie_pair_size;
2604 }
2605
2606 if (put_user(sizeof(ctd), optlen))
2607 return -EFAULT;
2608 if (copy_to_user(optval, &ctd, sizeof(ctd)))
2609 return -EFAULT;
2610 return 0;
2611 }
2612 case TCP_THIN_LINEAR_TIMEOUTS:
2613 val = tp->thin_lto;
2614 break;
2615 case TCP_THIN_DUPACK:
2616 val = tp->thin_dupack;
2617 break;
2618
2619 case TCP_USER_TIMEOUT:
2620 val = jiffies_to_msecs(icsk->icsk_user_timeout);
2621 break;
2622 default:
2623 return -ENOPROTOOPT;
2624 }
2625
2626 if (put_user(len, optlen))
2627 return -EFAULT;
2628 if (copy_to_user(optval, &val, len))
2629 return -EFAULT;
2630 return 0;
2631}
2632
2633int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2634 int __user *optlen)
2635{
2636 struct inet_connection_sock *icsk = inet_csk(sk);
2637
2638 if (level != SOL_TCP)
2639 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2640 optval, optlen);
2641 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2642}
2643EXPORT_SYMBOL(tcp_getsockopt);
2644
2645#ifdef CONFIG_COMPAT
2646int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2647 char __user *optval, int __user *optlen)
2648{
2649 if (level != SOL_TCP)
2650 return inet_csk_compat_getsockopt(sk, level, optname,
2651 optval, optlen);
2652 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2653}
2654EXPORT_SYMBOL(compat_tcp_getsockopt);
2655#endif
2656
2657struct sk_buff *tcp_tso_segment(struct sk_buff *skb, u32 features)
2658{
2659 struct sk_buff *segs = ERR_PTR(-EINVAL);
2660 struct tcphdr *th;
2661 unsigned thlen;
2662 unsigned int seq;
2663 __be32 delta;
2664 unsigned int oldlen;
2665 unsigned int mss;
2666
2667 if (!pskb_may_pull(skb, sizeof(*th)))
2668 goto out;
2669
2670 th = tcp_hdr(skb);
2671 thlen = th->doff * 4;
2672 if (thlen < sizeof(*th))
2673 goto out;
2674
2675 if (!pskb_may_pull(skb, thlen))
2676 goto out;
2677
2678 oldlen = (u16)~skb->len;
2679 __skb_pull(skb, thlen);
2680
2681 mss = skb_shinfo(skb)->gso_size;
2682 if (unlikely(skb->len <= mss))
2683 goto out;
2684
2685 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2686 /* Packet is from an untrusted source, reset gso_segs. */
2687 int type = skb_shinfo(skb)->gso_type;
2688
2689 if (unlikely(type &
2690 ~(SKB_GSO_TCPV4 |
2691 SKB_GSO_DODGY |
2692 SKB_GSO_TCP_ECN |
2693 SKB_GSO_TCPV6 |
2694 0) ||
2695 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2696 goto out;
2697
2698 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2699
2700 segs = NULL;
2701 goto out;
2702 }
2703
2704 segs = skb_segment(skb, features);
2705 if (IS_ERR(segs))
2706 goto out;
2707
2708 delta = htonl(oldlen + (thlen + mss));
2709
2710 skb = segs;
2711 th = tcp_hdr(skb);
2712 seq = ntohl(th->seq);
2713
2714 do {
2715 th->fin = th->psh = 0;
2716
2717 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2718 (__force u32)delta));
2719 if (skb->ip_summed != CHECKSUM_PARTIAL)
2720 th->check =
2721 csum_fold(csum_partial(skb_transport_header(skb),
2722 thlen, skb->csum));
2723
2724 seq += mss;
2725 skb = skb->next;
2726 th = tcp_hdr(skb);
2727
2728 th->seq = htonl(seq);
2729 th->cwr = 0;
2730 } while (skb->next);
2731
2732 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
2733 skb->data_len);
2734 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
2735 (__force u32)delta));
2736 if (skb->ip_summed != CHECKSUM_PARTIAL)
2737 th->check = csum_fold(csum_partial(skb_transport_header(skb),
2738 thlen, skb->csum));
2739
2740out:
2741 return segs;
2742}
2743EXPORT_SYMBOL(tcp_tso_segment);
2744
2745struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2746{
2747 struct sk_buff **pp = NULL;
2748 struct sk_buff *p;
2749 struct tcphdr *th;
2750 struct tcphdr *th2;
2751 unsigned int len;
2752 unsigned int thlen;
2753 __be32 flags;
2754 unsigned int mss = 1;
2755 unsigned int hlen;
2756 unsigned int off;
2757 int flush = 1;
2758 int i;
2759
2760 off = skb_gro_offset(skb);
2761 hlen = off + sizeof(*th);
2762 th = skb_gro_header_fast(skb, off);
2763 if (skb_gro_header_hard(skb, hlen)) {
2764 th = skb_gro_header_slow(skb, hlen, off);
2765 if (unlikely(!th))
2766 goto out;
2767 }
2768
2769 thlen = th->doff * 4;
2770 if (thlen < sizeof(*th))
2771 goto out;
2772
2773 hlen = off + thlen;
2774 if (skb_gro_header_hard(skb, hlen)) {
2775 th = skb_gro_header_slow(skb, hlen, off);
2776 if (unlikely(!th))
2777 goto out;
2778 }
2779
2780 skb_gro_pull(skb, thlen);
2781
2782 len = skb_gro_len(skb);
2783 flags = tcp_flag_word(th);
2784
2785 for (; (p = *head); head = &p->next) {
2786 if (!NAPI_GRO_CB(p)->same_flow)
2787 continue;
2788
2789 th2 = tcp_hdr(p);
2790
2791 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
2792 NAPI_GRO_CB(p)->same_flow = 0;
2793 continue;
2794 }
2795
2796 goto found;
2797 }
2798
2799 goto out_check_final;
2800
2801found:
2802 flush = NAPI_GRO_CB(p)->flush;
2803 flush |= (__force int)(flags & TCP_FLAG_CWR);
2804 flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
2805 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
2806 flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
2807 for (i = sizeof(*th); i < thlen; i += 4)
2808 flush |= *(u32 *)((u8 *)th + i) ^
2809 *(u32 *)((u8 *)th2 + i);
2810
2811 mss = skb_shinfo(p)->gso_size;
2812
2813 flush |= (len - 1) >= mss;
2814 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
2815
2816 if (flush || skb_gro_receive(head, skb)) {
2817 mss = 1;
2818 goto out_check_final;
2819 }
2820
2821 p = *head;
2822 th2 = tcp_hdr(p);
2823 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
2824
2825out_check_final:
2826 flush = len < mss;
2827 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH |
2828 TCP_FLAG_RST | TCP_FLAG_SYN |
2829 TCP_FLAG_FIN));
2830
2831 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
2832 pp = head;
2833
2834out:
2835 NAPI_GRO_CB(skb)->flush |= flush;
2836
2837 return pp;
2838}
2839EXPORT_SYMBOL(tcp_gro_receive);
2840
2841int tcp_gro_complete(struct sk_buff *skb)
2842{
2843 struct tcphdr *th = tcp_hdr(skb);
2844
2845 skb->csum_start = skb_transport_header(skb) - skb->head;
2846 skb->csum_offset = offsetof(struct tcphdr, check);
2847 skb->ip_summed = CHECKSUM_PARTIAL;
2848
2849 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
2850
2851 if (th->cwr)
2852 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
2853
2854 return 0;
2855}
2856EXPORT_SYMBOL(tcp_gro_complete);
2857
2858#ifdef CONFIG_TCP_MD5SIG
2859static unsigned long tcp_md5sig_users;
2860static struct tcp_md5sig_pool * __percpu *tcp_md5sig_pool;
2861static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
2862
2863static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool * __percpu *pool)
2864{
2865 int cpu;
2866 for_each_possible_cpu(cpu) {
2867 struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
2868 if (p) {
2869 if (p->md5_desc.tfm)
2870 crypto_free_hash(p->md5_desc.tfm);
2871 kfree(p);
2872 }
2873 }
2874 free_percpu(pool);
2875}
2876
2877void tcp_free_md5sig_pool(void)
2878{
2879 struct tcp_md5sig_pool * __percpu *pool = NULL;
2880
2881 spin_lock_bh(&tcp_md5sig_pool_lock);
2882 if (--tcp_md5sig_users == 0) {
2883 pool = tcp_md5sig_pool;
2884 tcp_md5sig_pool = NULL;
2885 }
2886 spin_unlock_bh(&tcp_md5sig_pool_lock);
2887 if (pool)
2888 __tcp_free_md5sig_pool(pool);
2889}
2890EXPORT_SYMBOL(tcp_free_md5sig_pool);
2891
2892static struct tcp_md5sig_pool * __percpu *
2893__tcp_alloc_md5sig_pool(struct sock *sk)
2894{
2895 int cpu;
2896 struct tcp_md5sig_pool * __percpu *pool;
2897
2898 pool = alloc_percpu(struct tcp_md5sig_pool *);
2899 if (!pool)
2900 return NULL;
2901
2902 for_each_possible_cpu(cpu) {
2903 struct tcp_md5sig_pool *p;
2904 struct crypto_hash *hash;
2905
2906 p = kzalloc(sizeof(*p), sk->sk_allocation);
2907 if (!p)
2908 goto out_free;
2909 *per_cpu_ptr(pool, cpu) = p;
2910
2911 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
2912 if (!hash || IS_ERR(hash))
2913 goto out_free;
2914
2915 p->md5_desc.tfm = hash;
2916 }
2917 return pool;
2918out_free:
2919 __tcp_free_md5sig_pool(pool);
2920 return NULL;
2921}
2922
2923struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *sk)
2924{
2925 struct tcp_md5sig_pool * __percpu *pool;
2926 int alloc = 0;
2927
2928retry:
2929 spin_lock_bh(&tcp_md5sig_pool_lock);
2930 pool = tcp_md5sig_pool;
2931 if (tcp_md5sig_users++ == 0) {
2932 alloc = 1;
2933 spin_unlock_bh(&tcp_md5sig_pool_lock);
2934 } else if (!pool) {
2935 tcp_md5sig_users--;
2936 spin_unlock_bh(&tcp_md5sig_pool_lock);
2937 cpu_relax();
2938 goto retry;
2939 } else
2940 spin_unlock_bh(&tcp_md5sig_pool_lock);
2941
2942 if (alloc) {
2943 /* we cannot hold spinlock here because this may sleep. */
2944 struct tcp_md5sig_pool * __percpu *p;
2945
2946 p = __tcp_alloc_md5sig_pool(sk);
2947 spin_lock_bh(&tcp_md5sig_pool_lock);
2948 if (!p) {
2949 tcp_md5sig_users--;
2950 spin_unlock_bh(&tcp_md5sig_pool_lock);
2951 return NULL;
2952 }
2953 pool = tcp_md5sig_pool;
2954 if (pool) {
2955 /* oops, it has already been assigned. */
2956 spin_unlock_bh(&tcp_md5sig_pool_lock);
2957 __tcp_free_md5sig_pool(p);
2958 } else {
2959 tcp_md5sig_pool = pool = p;
2960 spin_unlock_bh(&tcp_md5sig_pool_lock);
2961 }
2962 }
2963 return pool;
2964}
2965EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
2966
2967
2968/**
2969 * tcp_get_md5sig_pool - get md5sig_pool for this user
2970 *
2971 * We use percpu structure, so if we succeed, we exit with preemption
2972 * and BH disabled, to make sure another thread or softirq handling
2973 * wont try to get same context.
2974 */
2975struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
2976{
2977 struct tcp_md5sig_pool * __percpu *p;
2978
2979 local_bh_disable();
2980
2981 spin_lock(&tcp_md5sig_pool_lock);
2982 p = tcp_md5sig_pool;
2983 if (p)
2984 tcp_md5sig_users++;
2985 spin_unlock(&tcp_md5sig_pool_lock);
2986
2987 if (p)
2988 return *this_cpu_ptr(p);
2989
2990 local_bh_enable();
2991 return NULL;
2992}
2993EXPORT_SYMBOL(tcp_get_md5sig_pool);
2994
2995void tcp_put_md5sig_pool(void)
2996{
2997 local_bh_enable();
2998 tcp_free_md5sig_pool();
2999}
3000EXPORT_SYMBOL(tcp_put_md5sig_pool);
3001
3002int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
3003 struct tcphdr *th)
3004{
3005 struct scatterlist sg;
3006 int err;
3007
3008 __sum16 old_checksum = th->check;
3009 th->check = 0;
3010 /* options aren't included in the hash */
3011 sg_init_one(&sg, th, sizeof(struct tcphdr));
3012 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
3013 th->check = old_checksum;
3014 return err;
3015}
3016EXPORT_SYMBOL(tcp_md5_hash_header);
3017
3018int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3019 struct sk_buff *skb, unsigned header_len)
3020{
3021 struct scatterlist sg;
3022 const struct tcphdr *tp = tcp_hdr(skb);
3023 struct hash_desc *desc = &hp->md5_desc;
3024 unsigned i;
3025 const unsigned head_data_len = skb_headlen(skb) > header_len ?
3026 skb_headlen(skb) - header_len : 0;
3027 const struct skb_shared_info *shi = skb_shinfo(skb);
3028 struct sk_buff *frag_iter;
3029
3030 sg_init_table(&sg, 1);
3031
3032 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3033 if (crypto_hash_update(desc, &sg, head_data_len))
3034 return 1;
3035
3036 for (i = 0; i < shi->nr_frags; ++i) {
3037 const struct skb_frag_struct *f = &shi->frags[i];
3038 sg_set_page(&sg, f->page, f->size, f->page_offset);
3039 if (crypto_hash_update(desc, &sg, f->size))
3040 return 1;
3041 }
3042
3043 skb_walk_frags(skb, frag_iter)
3044 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3045 return 1;
3046
3047 return 0;
3048}
3049EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3050
3051int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
3052{
3053 struct scatterlist sg;
3054
3055 sg_init_one(&sg, key->key, key->keylen);
3056 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
3057}
3058EXPORT_SYMBOL(tcp_md5_hash_key);
3059
3060#endif
3061
3062/**
3063 * Each Responder maintains up to two secret values concurrently for
3064 * efficient secret rollover. Each secret value has 4 states:
3065 *
3066 * Generating. (tcp_secret_generating != tcp_secret_primary)
3067 * Generates new Responder-Cookies, but not yet used for primary
3068 * verification. This is a short-term state, typically lasting only
3069 * one round trip time (RTT).
3070 *
3071 * Primary. (tcp_secret_generating == tcp_secret_primary)
3072 * Used both for generation and primary verification.
3073 *
3074 * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
3075 * Used for verification, until the first failure that can be
3076 * verified by the newer Generating secret. At that time, this
3077 * cookie's state is changed to Secondary, and the Generating
3078 * cookie's state is changed to Primary. This is a short-term state,
3079 * typically lasting only one round trip time (RTT).
3080 *
3081 * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
3082 * Used for secondary verification, after primary verification
3083 * failures. This state lasts no more than twice the Maximum Segment
3084 * Lifetime (2MSL). Then, the secret is discarded.
3085 */
3086struct tcp_cookie_secret {
3087 /* The secret is divided into two parts. The digest part is the
3088 * equivalent of previously hashing a secret and saving the state,
3089 * and serves as an initialization vector (IV). The message part
3090 * serves as the trailing secret.
3091 */
3092 u32 secrets[COOKIE_WORKSPACE_WORDS];
3093 unsigned long expires;
3094};
3095
3096#define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
3097#define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
3098#define TCP_SECRET_LIFE (HZ * 600)
3099
3100static struct tcp_cookie_secret tcp_secret_one;
3101static struct tcp_cookie_secret tcp_secret_two;
3102
3103/* Essentially a circular list, without dynamic allocation. */
3104static struct tcp_cookie_secret *tcp_secret_generating;
3105static struct tcp_cookie_secret *tcp_secret_primary;
3106static struct tcp_cookie_secret *tcp_secret_retiring;
3107static struct tcp_cookie_secret *tcp_secret_secondary;
3108
3109static DEFINE_SPINLOCK(tcp_secret_locker);
3110
3111/* Select a pseudo-random word in the cookie workspace.
3112 */
3113static inline u32 tcp_cookie_work(const u32 *ws, const int n)
3114{
3115 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])];
3116}
3117
3118/* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
3119 * Called in softirq context.
3120 * Returns: 0 for success.
3121 */
3122int tcp_cookie_generator(u32 *bakery)
3123{
3124 unsigned long jiffy = jiffies;
3125
3126 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) {
3127 spin_lock_bh(&tcp_secret_locker);
3128 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) {
3129 /* refreshed by another */
3130 memcpy(bakery,
3131 &tcp_secret_generating->secrets[0],
3132 COOKIE_WORKSPACE_WORDS);
3133 } else {
3134 /* still needs refreshing */
3135 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS);
3136
3137 /* The first time, paranoia assumes that the
3138 * randomization function isn't as strong. But,
3139 * this secret initialization is delayed until
3140 * the last possible moment (packet arrival).
3141 * Although that time is observable, it is
3142 * unpredictably variable. Mash in the most
3143 * volatile clock bits available, and expire the
3144 * secret extra quickly.
3145 */
3146 if (unlikely(tcp_secret_primary->expires ==
3147 tcp_secret_secondary->expires)) {
3148 struct timespec tv;
3149
3150 getnstimeofday(&tv);
3151 bakery[COOKIE_DIGEST_WORDS+0] ^=
3152 (u32)tv.tv_nsec;
3153
3154 tcp_secret_secondary->expires = jiffy
3155 + TCP_SECRET_1MSL
3156 + (0x0f & tcp_cookie_work(bakery, 0));
3157 } else {
3158 tcp_secret_secondary->expires = jiffy
3159 + TCP_SECRET_LIFE
3160 + (0xff & tcp_cookie_work(bakery, 1));
3161 tcp_secret_primary->expires = jiffy
3162 + TCP_SECRET_2MSL
3163 + (0x1f & tcp_cookie_work(bakery, 2));
3164 }
3165 memcpy(&tcp_secret_secondary->secrets[0],
3166 bakery, COOKIE_WORKSPACE_WORDS);
3167
3168 rcu_assign_pointer(tcp_secret_generating,
3169 tcp_secret_secondary);
3170 rcu_assign_pointer(tcp_secret_retiring,
3171 tcp_secret_primary);
3172 /*
3173 * Neither call_rcu() nor synchronize_rcu() needed.
3174 * Retiring data is not freed. It is replaced after
3175 * further (locked) pointer updates, and a quiet time
3176 * (minimum 1MSL, maximum LIFE - 2MSL).
3177 */
3178 }
3179 spin_unlock_bh(&tcp_secret_locker);
3180 } else {
3181 rcu_read_lock_bh();
3182 memcpy(bakery,
3183 &rcu_dereference(tcp_secret_generating)->secrets[0],
3184 COOKIE_WORKSPACE_WORDS);
3185 rcu_read_unlock_bh();
3186 }
3187 return 0;
3188}
3189EXPORT_SYMBOL(tcp_cookie_generator);
3190
3191void tcp_done(struct sock *sk)
3192{
3193 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3194 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
3195
3196 tcp_set_state(sk, TCP_CLOSE);
3197 tcp_clear_xmit_timers(sk);
3198
3199 sk->sk_shutdown = SHUTDOWN_MASK;
3200
3201 if (!sock_flag(sk, SOCK_DEAD))
3202 sk->sk_state_change(sk);
3203 else
3204 inet_csk_destroy_sock(sk);
3205}
3206EXPORT_SYMBOL_GPL(tcp_done);
3207
3208extern struct tcp_congestion_ops tcp_reno;
3209
3210static __initdata unsigned long thash_entries;
3211static int __init set_thash_entries(char *str)
3212{
3213 if (!str)
3214 return 0;
3215 thash_entries = simple_strtoul(str, &str, 0);
3216 return 1;
3217}
3218__setup("thash_entries=", set_thash_entries);
3219
3220void __init tcp_init(void)
3221{
3222 struct sk_buff *skb = NULL;
3223 unsigned long limit;
3224 int i, max_share, cnt;
3225 unsigned long jiffy = jiffies;
3226
3227 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
3228
3229 percpu_counter_init(&tcp_sockets_allocated, 0);
3230 percpu_counter_init(&tcp_orphan_count, 0);
3231 tcp_hashinfo.bind_bucket_cachep =
3232 kmem_cache_create("tcp_bind_bucket",
3233 sizeof(struct inet_bind_bucket), 0,
3234 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3235
3236 /* Size and allocate the main established and bind bucket
3237 * hash tables.
3238 *
3239 * The methodology is similar to that of the buffer cache.
3240 */
3241 tcp_hashinfo.ehash =
3242 alloc_large_system_hash("TCP established",
3243 sizeof(struct inet_ehash_bucket),
3244 thash_entries,
3245 (totalram_pages >= 128 * 1024) ?
3246 13 : 15,
3247 0,
3248 NULL,
3249 &tcp_hashinfo.ehash_mask,
3250 thash_entries ? 0 : 512 * 1024);
3251 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
3252 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
3253 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
3254 }
3255 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3256 panic("TCP: failed to alloc ehash_locks");
3257 tcp_hashinfo.bhash =
3258 alloc_large_system_hash("TCP bind",
3259 sizeof(struct inet_bind_hashbucket),
3260 tcp_hashinfo.ehash_mask + 1,
3261 (totalram_pages >= 128 * 1024) ?
3262 13 : 15,
3263 0,
3264 &tcp_hashinfo.bhash_size,
3265 NULL,
3266 64 * 1024);
3267 tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
3268 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3269 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3270 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
3271 }
3272
3273
3274 cnt = tcp_hashinfo.ehash_mask + 1;
3275
3276 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3277 sysctl_tcp_max_orphans = cnt / 2;
3278 sysctl_max_syn_backlog = max(128, cnt / 256);
3279
3280 limit = nr_free_buffer_pages() / 8;
3281 limit = max(limit, 128UL);
3282 sysctl_tcp_mem[0] = limit / 4 * 3;
3283 sysctl_tcp_mem[1] = limit;
3284 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
3285
3286 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3287 limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
3288 max_share = min(4UL*1024*1024, limit);
3289
3290 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3291 sysctl_tcp_wmem[1] = 16*1024;
3292 sysctl_tcp_wmem[2] = max(64*1024, max_share);
3293
3294 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3295 sysctl_tcp_rmem[1] = 87380;
3296 sysctl_tcp_rmem[2] = max(87380, max_share);
3297
3298 printk(KERN_INFO "TCP: Hash tables configured "
3299 "(established %u bind %u)\n",
3300 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3301
3302 tcp_register_congestion_control(&tcp_reno);
3303
3304 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets));
3305 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets));
3306 tcp_secret_one.expires = jiffy; /* past due */
3307 tcp_secret_two.expires = jiffy; /* past due */
3308 tcp_secret_generating = &tcp_secret_one;
3309 tcp_secret_primary = &tcp_secret_one;
3310 tcp_secret_retiring = &tcp_secret_two;
3311 tcp_secret_secondary = &tcp_secret_two;
3312}
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}