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.
6 * Implementation of the Transmission Control Protocol(TCP).
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>
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
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
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
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
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
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
55 * Alan Cox : Tidied tcp_data to avoid a potential
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
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
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
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
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
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
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
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
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
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
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
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
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
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
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
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
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
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.
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.
213 * Description of States:
215 * TCP_SYN_SENT sent a connection request, waiting for ack
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
220 * TCP_ESTABLISHED connection established
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
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)
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)
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
245 * TCP_CLOSE socket is finished
248 #define pr_fmt(fmt) "TCP: " fmt
250 #include <linux/kernel.h>
251 #include <linux/module.h>
252 #include <linux/types.h>
253 #include <linux/fcntl.h>
254 #include <linux/poll.h>
255 #include <linux/init.h>
256 #include <linux/fs.h>
257 #include <linux/skbuff.h>
258 #include <linux/scatterlist.h>
259 #include <linux/splice.h>
260 #include <linux/net.h>
261 #include <linux/socket.h>
262 #include <linux/random.h>
263 #include <linux/bootmem.h>
264 #include <linux/highmem.h>
265 #include <linux/swap.h>
266 #include <linux/cache.h>
267 #include <linux/err.h>
268 #include <linux/crypto.h>
269 #include <linux/time.h>
270 #include <linux/slab.h>
272 #include <net/icmp.h>
273 #include <net/inet_common.h>
275 #include <net/xfrm.h>
277 #include <net/netdma.h>
278 #include <net/sock.h>
280 #include <asm/uaccess.h>
281 #include <asm/ioctls.h>
282 #include <net/busy_poll.h>
284 int sysctl_tcp_fin_timeout __read_mostly
= TCP_FIN_TIMEOUT
;
286 int sysctl_tcp_min_tso_segs __read_mostly
= 2;
288 struct percpu_counter tcp_orphan_count
;
289 EXPORT_SYMBOL_GPL(tcp_orphan_count
);
291 int sysctl_tcp_wmem
[3] __read_mostly
;
292 int sysctl_tcp_rmem
[3] __read_mostly
;
294 EXPORT_SYMBOL(sysctl_tcp_rmem
);
295 EXPORT_SYMBOL(sysctl_tcp_wmem
);
297 atomic_long_t tcp_memory_allocated
; /* Current allocated memory. */
298 EXPORT_SYMBOL(tcp_memory_allocated
);
301 * Current number of TCP sockets.
303 struct percpu_counter tcp_sockets_allocated
;
304 EXPORT_SYMBOL(tcp_sockets_allocated
);
309 struct tcp_splice_state
{
310 struct pipe_inode_info
*pipe
;
316 * Pressure flag: try to collapse.
317 * Technical note: it is used by multiple contexts non atomically.
318 * All the __sk_mem_schedule() is of this nature: accounting
319 * is strict, actions are advisory and have some latency.
321 int tcp_memory_pressure __read_mostly
;
322 EXPORT_SYMBOL(tcp_memory_pressure
);
324 void tcp_enter_memory_pressure(struct sock
*sk
)
326 if (!tcp_memory_pressure
) {
327 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMEMORYPRESSURES
);
328 tcp_memory_pressure
= 1;
331 EXPORT_SYMBOL(tcp_enter_memory_pressure
);
333 /* Convert seconds to retransmits based on initial and max timeout */
334 static u8
secs_to_retrans(int seconds
, int timeout
, int rto_max
)
339 int period
= timeout
;
342 while (seconds
> period
&& res
< 255) {
345 if (timeout
> rto_max
)
353 /* Convert retransmits to seconds based on initial and max timeout */
354 static int retrans_to_secs(u8 retrans
, int timeout
, int rto_max
)
362 if (timeout
> rto_max
)
370 /* Address-family independent initialization for a tcp_sock.
372 * NOTE: A lot of things set to zero explicitly by call to
373 * sk_alloc() so need not be done here.
375 void tcp_init_sock(struct sock
*sk
)
377 struct inet_connection_sock
*icsk
= inet_csk(sk
);
378 struct tcp_sock
*tp
= tcp_sk(sk
);
380 skb_queue_head_init(&tp
->out_of_order_queue
);
381 tcp_init_xmit_timers(sk
);
382 tcp_prequeue_init(tp
);
383 INIT_LIST_HEAD(&tp
->tsq_node
);
385 icsk
->icsk_rto
= TCP_TIMEOUT_INIT
;
386 tp
->mdev
= TCP_TIMEOUT_INIT
;
388 /* So many TCP implementations out there (incorrectly) count the
389 * initial SYN frame in their delayed-ACK and congestion control
390 * algorithms that we must have the following bandaid to talk
391 * efficiently to them. -DaveM
393 tp
->snd_cwnd
= TCP_INIT_CWND
;
395 /* See draft-stevens-tcpca-spec-01 for discussion of the
396 * initialization of these values.
398 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
399 tp
->snd_cwnd_clamp
= ~0;
400 tp
->mss_cache
= TCP_MSS_DEFAULT
;
402 tp
->reordering
= sysctl_tcp_reordering
;
403 tcp_enable_early_retrans(tp
);
404 icsk
->icsk_ca_ops
= &tcp_init_congestion_ops
;
408 sk
->sk_state
= TCP_CLOSE
;
410 sk
->sk_write_space
= sk_stream_write_space
;
411 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
413 icsk
->icsk_sync_mss
= tcp_sync_mss
;
415 sk
->sk_sndbuf
= sysctl_tcp_wmem
[1];
416 sk
->sk_rcvbuf
= sysctl_tcp_rmem
[1];
419 sock_update_memcg(sk
);
420 sk_sockets_allocated_inc(sk
);
423 EXPORT_SYMBOL(tcp_init_sock
);
426 * Wait for a TCP event.
428 * Note that we don't need to lock the socket, as the upper poll layers
429 * take care of normal races (between the test and the event) and we don't
430 * go look at any of the socket buffers directly.
432 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
435 struct sock
*sk
= sock
->sk
;
436 const struct tcp_sock
*tp
= tcp_sk(sk
);
438 sock_rps_record_flow(sk
);
440 sock_poll_wait(file
, sk_sleep(sk
), wait
);
441 if (sk
->sk_state
== TCP_LISTEN
)
442 return inet_csk_listen_poll(sk
);
444 /* Socket is not locked. We are protected from async events
445 * by poll logic and correct handling of state changes
446 * made by other threads is impossible in any case.
452 * POLLHUP is certainly not done right. But poll() doesn't
453 * have a notion of HUP in just one direction, and for a
454 * socket the read side is more interesting.
456 * Some poll() documentation says that POLLHUP is incompatible
457 * with the POLLOUT/POLLWR flags, so somebody should check this
458 * all. But careful, it tends to be safer to return too many
459 * bits than too few, and you can easily break real applications
460 * if you don't tell them that something has hung up!
464 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
465 * our fs/select.c). It means that after we received EOF,
466 * poll always returns immediately, making impossible poll() on write()
467 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
468 * if and only if shutdown has been made in both directions.
469 * Actually, it is interesting to look how Solaris and DUX
470 * solve this dilemma. I would prefer, if POLLHUP were maskable,
471 * then we could set it on SND_SHUTDOWN. BTW examples given
472 * in Stevens' books assume exactly this behaviour, it explains
473 * why POLLHUP is incompatible with POLLOUT. --ANK
475 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
476 * blocking on fresh not-connected or disconnected socket. --ANK
478 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== TCP_CLOSE
)
480 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
481 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
483 /* Connected or passive Fast Open socket? */
484 if (sk
->sk_state
!= TCP_SYN_SENT
&&
485 (sk
->sk_state
!= TCP_SYN_RECV
|| tp
->fastopen_rsk
!= NULL
)) {
486 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
488 if (tp
->urg_seq
== tp
->copied_seq
&&
489 !sock_flag(sk
, SOCK_URGINLINE
) &&
493 /* Potential race condition. If read of tp below will
494 * escape above sk->sk_state, we can be illegally awaken
495 * in SYN_* states. */
496 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
497 mask
|= POLLIN
| POLLRDNORM
;
499 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
500 if (sk_stream_is_writeable(sk
)) {
501 mask
|= POLLOUT
| POLLWRNORM
;
502 } else { /* send SIGIO later */
503 set_bit(SOCK_ASYNC_NOSPACE
,
504 &sk
->sk_socket
->flags
);
505 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
507 /* Race breaker. If space is freed after
508 * wspace test but before the flags are set,
509 * IO signal will be lost.
511 if (sk_stream_is_writeable(sk
))
512 mask
|= POLLOUT
| POLLWRNORM
;
515 mask
|= POLLOUT
| POLLWRNORM
;
517 if (tp
->urg_data
& TCP_URG_VALID
)
520 /* This barrier is coupled with smp_wmb() in tcp_reset() */
527 EXPORT_SYMBOL(tcp_poll
);
529 int tcp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
531 struct tcp_sock
*tp
= tcp_sk(sk
);
537 if (sk
->sk_state
== TCP_LISTEN
)
540 slow
= lock_sock_fast(sk
);
541 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
543 else if (sock_flag(sk
, SOCK_URGINLINE
) ||
545 before(tp
->urg_seq
, tp
->copied_seq
) ||
546 !before(tp
->urg_seq
, tp
->rcv_nxt
)) {
548 answ
= tp
->rcv_nxt
- tp
->copied_seq
;
550 /* Subtract 1, if FIN was received */
551 if (answ
&& sock_flag(sk
, SOCK_DONE
))
554 answ
= tp
->urg_seq
- tp
->copied_seq
;
555 unlock_sock_fast(sk
, slow
);
558 answ
= tp
->urg_data
&& tp
->urg_seq
== tp
->copied_seq
;
561 if (sk
->sk_state
== TCP_LISTEN
)
564 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
567 answ
= tp
->write_seq
- tp
->snd_una
;
570 if (sk
->sk_state
== TCP_LISTEN
)
573 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
576 answ
= tp
->write_seq
- tp
->snd_nxt
;
582 return put_user(answ
, (int __user
*)arg
);
584 EXPORT_SYMBOL(tcp_ioctl
);
586 static inline void tcp_mark_push(struct tcp_sock
*tp
, struct sk_buff
*skb
)
588 TCP_SKB_CB(skb
)->tcp_flags
|= TCPHDR_PSH
;
589 tp
->pushed_seq
= tp
->write_seq
;
592 static inline bool forced_push(const struct tcp_sock
*tp
)
594 return after(tp
->write_seq
, tp
->pushed_seq
+ (tp
->max_window
>> 1));
597 static inline void skb_entail(struct sock
*sk
, struct sk_buff
*skb
)
599 struct tcp_sock
*tp
= tcp_sk(sk
);
600 struct tcp_skb_cb
*tcb
= TCP_SKB_CB(skb
);
603 tcb
->seq
= tcb
->end_seq
= tp
->write_seq
;
604 tcb
->tcp_flags
= TCPHDR_ACK
;
606 skb_header_release(skb
);
607 tcp_add_write_queue_tail(sk
, skb
);
608 sk
->sk_wmem_queued
+= skb
->truesize
;
609 sk_mem_charge(sk
, skb
->truesize
);
610 if (tp
->nonagle
& TCP_NAGLE_PUSH
)
611 tp
->nonagle
&= ~TCP_NAGLE_PUSH
;
614 static inline void tcp_mark_urg(struct tcp_sock
*tp
, int flags
)
617 tp
->snd_up
= tp
->write_seq
;
620 static inline void tcp_push(struct sock
*sk
, int flags
, int mss_now
,
623 if (tcp_send_head(sk
)) {
624 struct tcp_sock
*tp
= tcp_sk(sk
);
626 if (!(flags
& MSG_MORE
) || forced_push(tp
))
627 tcp_mark_push(tp
, tcp_write_queue_tail(sk
));
629 tcp_mark_urg(tp
, flags
);
630 __tcp_push_pending_frames(sk
, mss_now
,
631 (flags
& MSG_MORE
) ? TCP_NAGLE_CORK
: nonagle
);
635 static int tcp_splice_data_recv(read_descriptor_t
*rd_desc
, struct sk_buff
*skb
,
636 unsigned int offset
, size_t len
)
638 struct tcp_splice_state
*tss
= rd_desc
->arg
.data
;
641 ret
= skb_splice_bits(skb
, offset
, tss
->pipe
, min(rd_desc
->count
, len
),
644 rd_desc
->count
-= ret
;
648 static int __tcp_splice_read(struct sock
*sk
, struct tcp_splice_state
*tss
)
650 /* Store TCP splice context information in read_descriptor_t. */
651 read_descriptor_t rd_desc
= {
656 return tcp_read_sock(sk
, &rd_desc
, tcp_splice_data_recv
);
660 * tcp_splice_read - splice data from TCP socket to a pipe
661 * @sock: socket to splice from
662 * @ppos: position (not valid)
663 * @pipe: pipe to splice to
664 * @len: number of bytes to splice
665 * @flags: splice modifier flags
668 * Will read pages from given socket and fill them into a pipe.
671 ssize_t
tcp_splice_read(struct socket
*sock
, loff_t
*ppos
,
672 struct pipe_inode_info
*pipe
, size_t len
,
675 struct sock
*sk
= sock
->sk
;
676 struct tcp_splice_state tss
= {
685 sock_rps_record_flow(sk
);
687 * We can't seek on a socket input
696 timeo
= sock_rcvtimeo(sk
, sock
->file
->f_flags
& O_NONBLOCK
);
698 ret
= __tcp_splice_read(sk
, &tss
);
704 if (sock_flag(sk
, SOCK_DONE
))
707 ret
= sock_error(sk
);
710 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
712 if (sk
->sk_state
== TCP_CLOSE
) {
714 * This occurs when user tries to read
715 * from never connected socket.
717 if (!sock_flag(sk
, SOCK_DONE
))
725 sk_wait_data(sk
, &timeo
);
726 if (signal_pending(current
)) {
727 ret
= sock_intr_errno(timeo
);
740 if (sk
->sk_err
|| sk
->sk_state
== TCP_CLOSE
||
741 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
742 signal_pending(current
))
753 EXPORT_SYMBOL(tcp_splice_read
);
755 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
)
759 /* The TCP header must be at least 32-bit aligned. */
760 size
= ALIGN(size
, 4);
762 skb
= alloc_skb_fclone(size
+ sk
->sk_prot
->max_header
, gfp
);
764 if (sk_wmem_schedule(sk
, skb
->truesize
)) {
765 skb_reserve(skb
, sk
->sk_prot
->max_header
);
767 * Make sure that we have exactly size bytes
768 * available to the caller, no more, no less.
770 skb
->reserved_tailroom
= skb
->end
- skb
->tail
- size
;
775 sk
->sk_prot
->enter_memory_pressure(sk
);
776 sk_stream_moderate_sndbuf(sk
);
781 static unsigned int tcp_xmit_size_goal(struct sock
*sk
, u32 mss_now
,
784 struct tcp_sock
*tp
= tcp_sk(sk
);
785 u32 xmit_size_goal
, old_size_goal
;
787 xmit_size_goal
= mss_now
;
789 if (large_allowed
&& sk_can_gso(sk
)) {
792 /* Maybe we should/could use sk->sk_prot->max_header here ? */
793 hlen
= inet_csk(sk
)->icsk_af_ops
->net_header_len
+
794 inet_csk(sk
)->icsk_ext_hdr_len
+
797 /* Goal is to send at least one packet per ms,
798 * not one big TSO packet every 100 ms.
799 * This preserves ACK clocking and is consistent
800 * with tcp_tso_should_defer() heuristic.
802 gso_size
= sk
->sk_pacing_rate
/ (2 * MSEC_PER_SEC
);
803 gso_size
= max_t(u32
, gso_size
,
804 sysctl_tcp_min_tso_segs
* mss_now
);
806 xmit_size_goal
= min_t(u32
, gso_size
,
807 sk
->sk_gso_max_size
- 1 - hlen
);
809 /* TSQ : try to have at least two segments in flight
810 * (one in NIC TX ring, another in Qdisc)
812 xmit_size_goal
= min_t(u32
, xmit_size_goal
,
813 sysctl_tcp_limit_output_bytes
>> 1);
815 xmit_size_goal
= tcp_bound_to_half_wnd(tp
, xmit_size_goal
);
817 /* We try hard to avoid divides here */
818 old_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
820 if (likely(old_size_goal
<= xmit_size_goal
&&
821 old_size_goal
+ mss_now
> xmit_size_goal
)) {
822 xmit_size_goal
= old_size_goal
;
824 tp
->xmit_size_goal_segs
=
825 min_t(u16
, xmit_size_goal
/ mss_now
,
826 sk
->sk_gso_max_segs
);
827 xmit_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
831 return max(xmit_size_goal
, mss_now
);
834 static int tcp_send_mss(struct sock
*sk
, int *size_goal
, int flags
)
838 mss_now
= tcp_current_mss(sk
);
839 *size_goal
= tcp_xmit_size_goal(sk
, mss_now
, !(flags
& MSG_OOB
));
844 static ssize_t
do_tcp_sendpages(struct sock
*sk
, struct page
*page
, int offset
,
845 size_t size
, int flags
)
847 struct tcp_sock
*tp
= tcp_sk(sk
);
848 int mss_now
, size_goal
;
851 long timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
853 /* Wait for a connection to finish. One exception is TCP Fast Open
854 * (passive side) where data is allowed to be sent before a connection
855 * is fully established.
857 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
858 !tcp_passive_fastopen(sk
)) {
859 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
863 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
865 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
869 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
873 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
877 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
879 if (!sk_stream_memory_free(sk
))
880 goto wait_for_sndbuf
;
882 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
);
884 goto wait_for_memory
;
893 i
= skb_shinfo(skb
)->nr_frags
;
894 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
895 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
896 tcp_mark_push(tp
, skb
);
899 if (!sk_wmem_schedule(sk
, copy
))
900 goto wait_for_memory
;
903 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
906 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
908 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
911 skb
->data_len
+= copy
;
912 skb
->truesize
+= copy
;
913 sk
->sk_wmem_queued
+= copy
;
914 sk_mem_charge(sk
, copy
);
915 skb
->ip_summed
= CHECKSUM_PARTIAL
;
916 tp
->write_seq
+= copy
;
917 TCP_SKB_CB(skb
)->end_seq
+= copy
;
918 skb_shinfo(skb
)->gso_segs
= 0;
921 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
928 if (skb
->len
< size_goal
|| (flags
& MSG_OOB
))
931 if (forced_push(tp
)) {
932 tcp_mark_push(tp
, skb
);
933 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
934 } else if (skb
== tcp_send_head(sk
))
935 tcp_push_one(sk
, mss_now
);
939 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
941 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
943 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
946 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
950 if (copied
&& !(flags
& MSG_SENDPAGE_NOTLAST
))
951 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
958 return sk_stream_error(sk
, flags
, err
);
961 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
962 size_t size
, int flags
)
966 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
967 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
968 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
972 res
= do_tcp_sendpages(sk
, page
, offset
, size
, flags
);
976 EXPORT_SYMBOL(tcp_sendpage
);
978 static inline int select_size(const struct sock
*sk
, bool sg
)
980 const struct tcp_sock
*tp
= tcp_sk(sk
);
981 int tmp
= tp
->mss_cache
;
984 if (sk_can_gso(sk
)) {
985 /* Small frames wont use a full page:
986 * Payload will immediately follow tcp header.
988 tmp
= SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER
);
990 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
992 if (tmp
>= pgbreak
&&
993 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
1001 void tcp_free_fastopen_req(struct tcp_sock
*tp
)
1003 if (tp
->fastopen_req
!= NULL
) {
1004 kfree(tp
->fastopen_req
);
1005 tp
->fastopen_req
= NULL
;
1009 static int tcp_sendmsg_fastopen(struct sock
*sk
, struct msghdr
*msg
, int *size
)
1011 struct tcp_sock
*tp
= tcp_sk(sk
);
1014 if (!(sysctl_tcp_fastopen
& TFO_CLIENT_ENABLE
))
1016 if (tp
->fastopen_req
!= NULL
)
1017 return -EALREADY
; /* Another Fast Open is in progress */
1019 tp
->fastopen_req
= kzalloc(sizeof(struct tcp_fastopen_request
),
1021 if (unlikely(tp
->fastopen_req
== NULL
))
1023 tp
->fastopen_req
->data
= msg
;
1025 flags
= (msg
->msg_flags
& MSG_DONTWAIT
) ? O_NONBLOCK
: 0;
1026 err
= __inet_stream_connect(sk
->sk_socket
, msg
->msg_name
,
1027 msg
->msg_namelen
, flags
);
1028 *size
= tp
->fastopen_req
->copied
;
1029 tcp_free_fastopen_req(tp
);
1033 int tcp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1037 struct tcp_sock
*tp
= tcp_sk(sk
);
1038 struct sk_buff
*skb
;
1039 int iovlen
, flags
, err
, copied
= 0;
1040 int mss_now
= 0, size_goal
, copied_syn
= 0, offset
= 0;
1046 flags
= msg
->msg_flags
;
1047 if (flags
& MSG_FASTOPEN
) {
1048 err
= tcp_sendmsg_fastopen(sk
, msg
, &copied_syn
);
1049 if (err
== -EINPROGRESS
&& copied_syn
> 0)
1053 offset
= copied_syn
;
1056 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
1058 /* Wait for a connection to finish. One exception is TCP Fast Open
1059 * (passive side) where data is allowed to be sent before a connection
1060 * is fully established.
1062 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
1063 !tcp_passive_fastopen(sk
)) {
1064 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
1068 if (unlikely(tp
->repair
)) {
1069 if (tp
->repair_queue
== TCP_RECV_QUEUE
) {
1070 copied
= tcp_send_rcvq(sk
, msg
, size
);
1075 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1078 /* 'common' sending to sendq */
1081 /* This should be in poll */
1082 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
1084 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1086 /* Ok commence sending. */
1087 iovlen
= msg
->msg_iovlen
;
1092 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
1095 sg
= !!(sk
->sk_route_caps
& NETIF_F_SG
);
1097 while (--iovlen
>= 0) {
1098 size_t seglen
= iov
->iov_len
;
1099 unsigned char __user
*from
= iov
->iov_base
;
1102 if (unlikely(offset
> 0)) { /* Skip bytes copied in SYN */
1103 if (offset
>= seglen
) {
1112 while (seglen
> 0) {
1114 int max
= size_goal
;
1116 skb
= tcp_write_queue_tail(sk
);
1117 if (tcp_send_head(sk
)) {
1118 if (skb
->ip_summed
== CHECKSUM_NONE
)
1120 copy
= max
- skb
->len
;
1125 /* Allocate new segment. If the interface is SG,
1126 * allocate skb fitting to single page.
1128 if (!sk_stream_memory_free(sk
))
1129 goto wait_for_sndbuf
;
1131 skb
= sk_stream_alloc_skb(sk
,
1132 select_size(sk
, sg
),
1135 goto wait_for_memory
;
1138 * All packets are restored as if they have
1139 * already been sent.
1142 TCP_SKB_CB(skb
)->when
= tcp_time_stamp
;
1145 * Check whether we can use HW checksum.
1147 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
1148 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1150 skb_entail(sk
, skb
);
1155 /* Try to append data to the end of skb. */
1159 /* Where to copy to? */
1160 if (skb_availroom(skb
) > 0) {
1161 /* We have some space in skb head. Superb! */
1162 copy
= min_t(int, copy
, skb_availroom(skb
));
1163 err
= skb_add_data_nocache(sk
, skb
, from
, copy
);
1168 int i
= skb_shinfo(skb
)->nr_frags
;
1169 struct page_frag
*pfrag
= sk_page_frag(sk
);
1171 if (!sk_page_frag_refill(sk
, pfrag
))
1172 goto wait_for_memory
;
1174 if (!skb_can_coalesce(skb
, i
, pfrag
->page
,
1176 if (i
== MAX_SKB_FRAGS
|| !sg
) {
1177 tcp_mark_push(tp
, skb
);
1183 copy
= min_t(int, copy
, pfrag
->size
- pfrag
->offset
);
1185 if (!sk_wmem_schedule(sk
, copy
))
1186 goto wait_for_memory
;
1188 err
= skb_copy_to_page_nocache(sk
, from
, skb
,
1195 /* Update the skb. */
1197 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
1199 skb_fill_page_desc(skb
, i
, pfrag
->page
,
1200 pfrag
->offset
, copy
);
1201 get_page(pfrag
->page
);
1203 pfrag
->offset
+= copy
;
1207 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
1209 tp
->write_seq
+= copy
;
1210 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1211 skb_shinfo(skb
)->gso_segs
= 0;
1215 if ((seglen
-= copy
) == 0 && iovlen
== 0)
1218 if (skb
->len
< max
|| (flags
& MSG_OOB
) || unlikely(tp
->repair
))
1221 if (forced_push(tp
)) {
1222 tcp_mark_push(tp
, skb
);
1223 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1224 } else if (skb
== tcp_send_head(sk
))
1225 tcp_push_one(sk
, mss_now
);
1229 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1232 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
1234 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1237 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1243 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
1245 return copied
+ copied_syn
;
1249 tcp_unlink_write_queue(skb
, sk
);
1250 /* It is the one place in all of TCP, except connection
1251 * reset, where we can be unlinking the send_head.
1253 tcp_check_send_head(sk
, skb
);
1254 sk_wmem_free_skb(sk
, skb
);
1258 if (copied
+ copied_syn
)
1261 err
= sk_stream_error(sk
, flags
, err
);
1265 EXPORT_SYMBOL(tcp_sendmsg
);
1268 * Handle reading urgent data. BSD has very simple semantics for
1269 * this, no blocking and very strange errors 8)
1272 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1274 struct tcp_sock
*tp
= tcp_sk(sk
);
1276 /* No URG data to read. */
1277 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1278 tp
->urg_data
== TCP_URG_READ
)
1279 return -EINVAL
; /* Yes this is right ! */
1281 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1284 if (tp
->urg_data
& TCP_URG_VALID
) {
1286 char c
= tp
->urg_data
;
1288 if (!(flags
& MSG_PEEK
))
1289 tp
->urg_data
= TCP_URG_READ
;
1291 /* Read urgent data. */
1292 msg
->msg_flags
|= MSG_OOB
;
1295 if (!(flags
& MSG_TRUNC
))
1296 err
= memcpy_toiovec(msg
->msg_iov
, &c
, 1);
1299 msg
->msg_flags
|= MSG_TRUNC
;
1301 return err
? -EFAULT
: len
;
1304 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1307 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1308 * the available implementations agree in this case:
1309 * this call should never block, independent of the
1310 * blocking state of the socket.
1311 * Mike <pall@rz.uni-karlsruhe.de>
1316 static int tcp_peek_sndq(struct sock
*sk
, struct msghdr
*msg
, int len
)
1318 struct sk_buff
*skb
;
1319 int copied
= 0, err
= 0;
1321 /* XXX -- need to support SO_PEEK_OFF */
1323 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
1324 err
= skb_copy_datagram_iovec(skb
, 0, msg
->msg_iov
, skb
->len
);
1331 return err
?: copied
;
1334 /* Clean up the receive buffer for full frames taken by the user,
1335 * then send an ACK if necessary. COPIED is the number of bytes
1336 * tcp_recvmsg has given to the user so far, it speeds up the
1337 * calculation of whether or not we must ACK for the sake of
1340 void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1342 struct tcp_sock
*tp
= tcp_sk(sk
);
1343 bool time_to_ack
= false;
1345 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1347 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1348 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1349 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1351 if (inet_csk_ack_scheduled(sk
)) {
1352 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1353 /* Delayed ACKs frequently hit locked sockets during bulk
1355 if (icsk
->icsk_ack
.blocked
||
1356 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1357 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1359 * If this read emptied read buffer, we send ACK, if
1360 * connection is not bidirectional, user drained
1361 * receive buffer and there was a small segment
1365 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1366 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1367 !icsk
->icsk_ack
.pingpong
)) &&
1368 !atomic_read(&sk
->sk_rmem_alloc
)))
1372 /* We send an ACK if we can now advertise a non-zero window
1373 * which has been raised "significantly".
1375 * Even if window raised up to infinity, do not send window open ACK
1376 * in states, where we will not receive more. It is useless.
1378 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1379 __u32 rcv_window_now
= tcp_receive_window(tp
);
1381 /* Optimize, __tcp_select_window() is not cheap. */
1382 if (2*rcv_window_now
<= tp
->window_clamp
) {
1383 __u32 new_window
= __tcp_select_window(sk
);
1385 /* Send ACK now, if this read freed lots of space
1386 * in our buffer. Certainly, new_window is new window.
1387 * We can advertise it now, if it is not less than current one.
1388 * "Lots" means "at least twice" here.
1390 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1398 static void tcp_prequeue_process(struct sock
*sk
)
1400 struct sk_buff
*skb
;
1401 struct tcp_sock
*tp
= tcp_sk(sk
);
1403 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1405 /* RX process wants to run with disabled BHs, though it is not
1408 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1409 sk_backlog_rcv(sk
, skb
);
1412 /* Clear memory counter. */
1413 tp
->ucopy
.memory
= 0;
1416 #ifdef CONFIG_NET_DMA
1417 static void tcp_service_net_dma(struct sock
*sk
, bool wait
)
1419 dma_cookie_t done
, used
;
1420 dma_cookie_t last_issued
;
1421 struct tcp_sock
*tp
= tcp_sk(sk
);
1423 if (!tp
->ucopy
.dma_chan
)
1426 last_issued
= tp
->ucopy
.dma_cookie
;
1427 dma_async_issue_pending(tp
->ucopy
.dma_chan
);
1430 if (dma_async_is_tx_complete(tp
->ucopy
.dma_chan
,
1432 &used
) == DMA_COMPLETE
) {
1433 /* Safe to free early-copied skbs now */
1434 __skb_queue_purge(&sk
->sk_async_wait_queue
);
1437 struct sk_buff
*skb
;
1438 while ((skb
= skb_peek(&sk
->sk_async_wait_queue
)) &&
1439 (dma_async_is_complete(skb
->dma_cookie
, done
,
1440 used
) == DMA_COMPLETE
)) {
1441 __skb_dequeue(&sk
->sk_async_wait_queue
);
1449 static struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1451 struct sk_buff
*skb
;
1454 while ((skb
= skb_peek(&sk
->sk_receive_queue
)) != NULL
) {
1455 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1456 if (tcp_hdr(skb
)->syn
)
1458 if (offset
< skb
->len
|| tcp_hdr(skb
)->fin
) {
1462 /* This looks weird, but this can happen if TCP collapsing
1463 * splitted a fat GRO packet, while we released socket lock
1464 * in skb_splice_bits()
1466 sk_eat_skb(sk
, skb
, false);
1472 * This routine provides an alternative to tcp_recvmsg() for routines
1473 * that would like to handle copying from skbuffs directly in 'sendfile'
1476 * - It is assumed that the socket was locked by the caller.
1477 * - The routine does not block.
1478 * - At present, there is no support for reading OOB data
1479 * or for 'peeking' the socket using this routine
1480 * (although both would be easy to implement).
1482 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1483 sk_read_actor_t recv_actor
)
1485 struct sk_buff
*skb
;
1486 struct tcp_sock
*tp
= tcp_sk(sk
);
1487 u32 seq
= tp
->copied_seq
;
1491 if (sk
->sk_state
== TCP_LISTEN
)
1493 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1494 if (offset
< skb
->len
) {
1498 len
= skb
->len
- offset
;
1499 /* Stop reading if we hit a patch of urgent data */
1501 u32 urg_offset
= tp
->urg_seq
- seq
;
1502 if (urg_offset
< len
)
1507 used
= recv_actor(desc
, skb
, offset
, len
);
1512 } else if (used
<= len
) {
1517 /* If recv_actor drops the lock (e.g. TCP splice
1518 * receive) the skb pointer might be invalid when
1519 * getting here: tcp_collapse might have deleted it
1520 * while aggregating skbs from the socket queue.
1522 skb
= tcp_recv_skb(sk
, seq
- 1, &offset
);
1525 /* TCP coalescing might have appended data to the skb.
1526 * Try to splice more frags
1528 if (offset
+ 1 != skb
->len
)
1531 if (tcp_hdr(skb
)->fin
) {
1532 sk_eat_skb(sk
, skb
, false);
1536 sk_eat_skb(sk
, skb
, false);
1539 tp
->copied_seq
= seq
;
1541 tp
->copied_seq
= seq
;
1543 tcp_rcv_space_adjust(sk
);
1545 /* Clean up data we have read: This will do ACK frames. */
1547 tcp_recv_skb(sk
, seq
, &offset
);
1548 tcp_cleanup_rbuf(sk
, copied
);
1552 EXPORT_SYMBOL(tcp_read_sock
);
1555 * This routine copies from a sock struct into the user buffer.
1557 * Technical note: in 2.3 we work on _locked_ socket, so that
1558 * tricks with *seq access order and skb->users are not required.
1559 * Probably, code can be easily improved even more.
1562 int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1563 size_t len
, int nonblock
, int flags
, int *addr_len
)
1565 struct tcp_sock
*tp
= tcp_sk(sk
);
1571 int target
; /* Read at least this many bytes */
1573 struct task_struct
*user_recv
= NULL
;
1574 bool copied_early
= false;
1575 struct sk_buff
*skb
;
1578 if (sk_can_busy_loop(sk
) && skb_queue_empty(&sk
->sk_receive_queue
) &&
1579 (sk
->sk_state
== TCP_ESTABLISHED
))
1580 sk_busy_loop(sk
, nonblock
);
1585 if (sk
->sk_state
== TCP_LISTEN
)
1588 timeo
= sock_rcvtimeo(sk
, nonblock
);
1590 /* Urgent data needs to be handled specially. */
1591 if (flags
& MSG_OOB
)
1594 if (unlikely(tp
->repair
)) {
1596 if (!(flags
& MSG_PEEK
))
1599 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
1603 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1606 /* 'common' recv queue MSG_PEEK-ing */
1609 seq
= &tp
->copied_seq
;
1610 if (flags
& MSG_PEEK
) {
1611 peek_seq
= tp
->copied_seq
;
1615 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1617 #ifdef CONFIG_NET_DMA
1618 tp
->ucopy
.dma_chan
= NULL
;
1620 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
1625 available
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- (*seq
);
1626 if ((available
< target
) &&
1627 (len
> sysctl_tcp_dma_copybreak
) && !(flags
& MSG_PEEK
) &&
1628 !sysctl_tcp_low_latency
&&
1629 net_dma_find_channel()) {
1630 preempt_enable_no_resched();
1631 tp
->ucopy
.pinned_list
=
1632 dma_pin_iovec_pages(msg
->msg_iov
, len
);
1634 preempt_enable_no_resched();
1642 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1643 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1646 if (signal_pending(current
)) {
1647 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1652 /* Next get a buffer. */
1654 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1655 /* Now that we have two receive queues this
1658 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1659 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1660 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1664 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1665 if (tcp_hdr(skb
)->syn
)
1667 if (offset
< skb
->len
)
1669 if (tcp_hdr(skb
)->fin
)
1671 WARN(!(flags
& MSG_PEEK
),
1672 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1673 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
, flags
);
1676 /* Well, if we have backlog, try to process it now yet. */
1678 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1683 sk
->sk_state
== TCP_CLOSE
||
1684 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1686 signal_pending(current
))
1689 if (sock_flag(sk
, SOCK_DONE
))
1693 copied
= sock_error(sk
);
1697 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1700 if (sk
->sk_state
== TCP_CLOSE
) {
1701 if (!sock_flag(sk
, SOCK_DONE
)) {
1702 /* This occurs when user tries to read
1703 * from never connected socket.
1716 if (signal_pending(current
)) {
1717 copied
= sock_intr_errno(timeo
);
1722 tcp_cleanup_rbuf(sk
, copied
);
1724 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1725 /* Install new reader */
1726 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1727 user_recv
= current
;
1728 tp
->ucopy
.task
= user_recv
;
1729 tp
->ucopy
.iov
= msg
->msg_iov
;
1732 tp
->ucopy
.len
= len
;
1734 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1735 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1737 /* Ugly... If prequeue is not empty, we have to
1738 * process it before releasing socket, otherwise
1739 * order will be broken at second iteration.
1740 * More elegant solution is required!!!
1742 * Look: we have the following (pseudo)queues:
1744 * 1. packets in flight
1749 * Each queue can be processed only if the next ones
1750 * are empty. At this point we have empty receive_queue.
1751 * But prequeue _can_ be not empty after 2nd iteration,
1752 * when we jumped to start of loop because backlog
1753 * processing added something to receive_queue.
1754 * We cannot release_sock(), because backlog contains
1755 * packets arrived _after_ prequeued ones.
1757 * Shortly, algorithm is clear --- to process all
1758 * the queues in order. We could make it more directly,
1759 * requeueing packets from backlog to prequeue, if
1760 * is not empty. It is more elegant, but eats cycles,
1763 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1766 /* __ Set realtime policy in scheduler __ */
1769 #ifdef CONFIG_NET_DMA
1770 if (tp
->ucopy
.dma_chan
) {
1771 if (tp
->rcv_wnd
== 0 &&
1772 !skb_queue_empty(&sk
->sk_async_wait_queue
)) {
1773 tcp_service_net_dma(sk
, true);
1774 tcp_cleanup_rbuf(sk
, copied
);
1776 dma_async_issue_pending(tp
->ucopy
.dma_chan
);
1779 if (copied
>= target
) {
1780 /* Do not sleep, just process backlog. */
1784 sk_wait_data(sk
, &timeo
);
1786 #ifdef CONFIG_NET_DMA
1787 tcp_service_net_dma(sk
, false); /* Don't block */
1788 tp
->ucopy
.wakeup
= 0;
1794 /* __ Restore normal policy in scheduler __ */
1796 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1797 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1802 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1803 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1805 tcp_prequeue_process(sk
);
1807 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1808 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1814 if ((flags
& MSG_PEEK
) &&
1815 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1816 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1818 task_pid_nr(current
));
1819 peek_seq
= tp
->copied_seq
;
1824 /* Ok so how much can we use? */
1825 used
= skb
->len
- offset
;
1829 /* Do we have urgent data here? */
1831 u32 urg_offset
= tp
->urg_seq
- *seq
;
1832 if (urg_offset
< used
) {
1834 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1847 if (!(flags
& MSG_TRUNC
)) {
1848 #ifdef CONFIG_NET_DMA
1849 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
1850 tp
->ucopy
.dma_chan
= net_dma_find_channel();
1852 if (tp
->ucopy
.dma_chan
) {
1853 tp
->ucopy
.dma_cookie
= dma_skb_copy_datagram_iovec(
1854 tp
->ucopy
.dma_chan
, skb
, offset
,
1856 tp
->ucopy
.pinned_list
);
1858 if (tp
->ucopy
.dma_cookie
< 0) {
1860 pr_alert("%s: dma_cookie < 0\n",
1863 /* Exception. Bailout! */
1869 dma_async_issue_pending(tp
->ucopy
.dma_chan
);
1871 if ((offset
+ used
) == skb
->len
)
1872 copied_early
= true;
1877 err
= skb_copy_datagram_iovec(skb
, offset
,
1878 msg
->msg_iov
, used
);
1880 /* Exception. Bailout! */
1892 tcp_rcv_space_adjust(sk
);
1895 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1897 tcp_fast_path_check(sk
);
1899 if (used
+ offset
< skb
->len
)
1902 if (tcp_hdr(skb
)->fin
)
1904 if (!(flags
& MSG_PEEK
)) {
1905 sk_eat_skb(sk
, skb
, copied_early
);
1906 copied_early
= false;
1911 /* Process the FIN. */
1913 if (!(flags
& MSG_PEEK
)) {
1914 sk_eat_skb(sk
, skb
, copied_early
);
1915 copied_early
= false;
1921 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1924 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1926 tcp_prequeue_process(sk
);
1928 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1929 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1935 tp
->ucopy
.task
= NULL
;
1939 #ifdef CONFIG_NET_DMA
1940 tcp_service_net_dma(sk
, true); /* Wait for queue to drain */
1941 tp
->ucopy
.dma_chan
= NULL
;
1943 if (tp
->ucopy
.pinned_list
) {
1944 dma_unpin_iovec_pages(tp
->ucopy
.pinned_list
);
1945 tp
->ucopy
.pinned_list
= NULL
;
1949 /* According to UNIX98, msg_name/msg_namelen are ignored
1950 * on connected socket. I was just happy when found this 8) --ANK
1953 /* Clean up data we have read: This will do ACK frames. */
1954 tcp_cleanup_rbuf(sk
, copied
);
1964 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1968 err
= tcp_peek_sndq(sk
, msg
, len
);
1971 EXPORT_SYMBOL(tcp_recvmsg
);
1973 void tcp_set_state(struct sock
*sk
, int state
)
1975 int oldstate
= sk
->sk_state
;
1978 case TCP_ESTABLISHED
:
1979 if (oldstate
!= TCP_ESTABLISHED
)
1980 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1984 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1985 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1987 sk
->sk_prot
->unhash(sk
);
1988 if (inet_csk(sk
)->icsk_bind_hash
&&
1989 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1993 if (oldstate
== TCP_ESTABLISHED
)
1994 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1997 /* Change state AFTER socket is unhashed to avoid closed
1998 * socket sitting in hash tables.
2000 sk
->sk_state
= state
;
2003 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
2006 EXPORT_SYMBOL_GPL(tcp_set_state
);
2009 * State processing on a close. This implements the state shift for
2010 * sending our FIN frame. Note that we only send a FIN for some
2011 * states. A shutdown() may have already sent the FIN, or we may be
2015 static const unsigned char new_state
[16] = {
2016 /* current state: new state: action: */
2017 /* (Invalid) */ TCP_CLOSE
,
2018 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
2019 /* TCP_SYN_SENT */ TCP_CLOSE
,
2020 /* TCP_SYN_RECV */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
2021 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1
,
2022 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2
,
2023 /* TCP_TIME_WAIT */ TCP_CLOSE
,
2024 /* TCP_CLOSE */ TCP_CLOSE
,
2025 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK
| TCP_ACTION_FIN
,
2026 /* TCP_LAST_ACK */ TCP_LAST_ACK
,
2027 /* TCP_LISTEN */ TCP_CLOSE
,
2028 /* TCP_CLOSING */ TCP_CLOSING
,
2031 static int tcp_close_state(struct sock
*sk
)
2033 int next
= (int)new_state
[sk
->sk_state
];
2034 int ns
= next
& TCP_STATE_MASK
;
2036 tcp_set_state(sk
, ns
);
2038 return next
& TCP_ACTION_FIN
;
2042 * Shutdown the sending side of a connection. Much like close except
2043 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
2046 void tcp_shutdown(struct sock
*sk
, int how
)
2048 /* We need to grab some memory, and put together a FIN,
2049 * and then put it into the queue to be sent.
2050 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
2052 if (!(how
& SEND_SHUTDOWN
))
2055 /* If we've already sent a FIN, or it's a closed state, skip this. */
2056 if ((1 << sk
->sk_state
) &
2057 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
2058 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
2059 /* Clear out any half completed packets. FIN if needed. */
2060 if (tcp_close_state(sk
))
2064 EXPORT_SYMBOL(tcp_shutdown
);
2066 bool tcp_check_oom(struct sock
*sk
, int shift
)
2068 bool too_many_orphans
, out_of_socket_memory
;
2070 too_many_orphans
= tcp_too_many_orphans(sk
, shift
);
2071 out_of_socket_memory
= tcp_out_of_memory(sk
);
2073 if (too_many_orphans
)
2074 net_info_ratelimited("too many orphaned sockets\n");
2075 if (out_of_socket_memory
)
2076 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2077 return too_many_orphans
|| out_of_socket_memory
;
2080 void tcp_close(struct sock
*sk
, long timeout
)
2082 struct sk_buff
*skb
;
2083 int data_was_unread
= 0;
2087 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2089 if (sk
->sk_state
== TCP_LISTEN
) {
2090 tcp_set_state(sk
, TCP_CLOSE
);
2093 inet_csk_listen_stop(sk
);
2095 goto adjudge_to_death
;
2098 /* We need to flush the recv. buffs. We do this only on the
2099 * descriptor close, not protocol-sourced closes, because the
2100 * reader process may not have drained the data yet!
2102 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
2103 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
-
2105 data_was_unread
+= len
;
2111 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2112 if (sk
->sk_state
== TCP_CLOSE
)
2113 goto adjudge_to_death
;
2115 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2116 * data was lost. To witness the awful effects of the old behavior of
2117 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2118 * GET in an FTP client, suspend the process, wait for the client to
2119 * advertise a zero window, then kill -9 the FTP client, wheee...
2120 * Note: timeout is always zero in such a case.
2122 if (unlikely(tcp_sk(sk
)->repair
)) {
2123 sk
->sk_prot
->disconnect(sk
, 0);
2124 } else if (data_was_unread
) {
2125 /* Unread data was tossed, zap the connection. */
2126 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
2127 tcp_set_state(sk
, TCP_CLOSE
);
2128 tcp_send_active_reset(sk
, sk
->sk_allocation
);
2129 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
2130 /* Check zero linger _after_ checking for unread data. */
2131 sk
->sk_prot
->disconnect(sk
, 0);
2132 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
2133 } else if (tcp_close_state(sk
)) {
2134 /* We FIN if the application ate all the data before
2135 * zapping the connection.
2138 /* RED-PEN. Formally speaking, we have broken TCP state
2139 * machine. State transitions:
2141 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2142 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2143 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2145 * are legal only when FIN has been sent (i.e. in window),
2146 * rather than queued out of window. Purists blame.
2148 * F.e. "RFC state" is ESTABLISHED,
2149 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2151 * The visible declinations are that sometimes
2152 * we enter time-wait state, when it is not required really
2153 * (harmless), do not send active resets, when they are
2154 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2155 * they look as CLOSING or LAST_ACK for Linux)
2156 * Probably, I missed some more holelets.
2158 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2159 * in a single packet! (May consider it later but will
2160 * probably need API support or TCP_CORK SYN-ACK until
2161 * data is written and socket is closed.)
2166 sk_stream_wait_close(sk
, timeout
);
2169 state
= sk
->sk_state
;
2173 /* It is the last release_sock in its life. It will remove backlog. */
2177 /* Now socket is owned by kernel and we acquire BH lock
2178 to finish close. No need to check for user refs.
2182 WARN_ON(sock_owned_by_user(sk
));
2184 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
2186 /* Have we already been destroyed by a softirq or backlog? */
2187 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
2190 /* This is a (useful) BSD violating of the RFC. There is a
2191 * problem with TCP as specified in that the other end could
2192 * keep a socket open forever with no application left this end.
2193 * We use a 3 minute timeout (about the same as BSD) then kill
2194 * our end. If they send after that then tough - BUT: long enough
2195 * that we won't make the old 4*rto = almost no time - whoops
2198 * Nope, it was not mistake. It is really desired behaviour
2199 * f.e. on http servers, when such sockets are useless, but
2200 * consume significant resources. Let's do it with special
2201 * linger2 option. --ANK
2204 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
2205 struct tcp_sock
*tp
= tcp_sk(sk
);
2206 if (tp
->linger2
< 0) {
2207 tcp_set_state(sk
, TCP_CLOSE
);
2208 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2209 NET_INC_STATS_BH(sock_net(sk
),
2210 LINUX_MIB_TCPABORTONLINGER
);
2212 const int tmo
= tcp_fin_time(sk
);
2214 if (tmo
> TCP_TIMEWAIT_LEN
) {
2215 inet_csk_reset_keepalive_timer(sk
,
2216 tmo
- TCP_TIMEWAIT_LEN
);
2218 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2223 if (sk
->sk_state
!= TCP_CLOSE
) {
2225 if (tcp_check_oom(sk
, 0)) {
2226 tcp_set_state(sk
, TCP_CLOSE
);
2227 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2228 NET_INC_STATS_BH(sock_net(sk
),
2229 LINUX_MIB_TCPABORTONMEMORY
);
2233 if (sk
->sk_state
== TCP_CLOSE
) {
2234 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
2235 /* We could get here with a non-NULL req if the socket is
2236 * aborted (e.g., closed with unread data) before 3WHS
2240 reqsk_fastopen_remove(sk
, req
, false);
2241 inet_csk_destroy_sock(sk
);
2243 /* Otherwise, socket is reprieved until protocol close. */
2250 EXPORT_SYMBOL(tcp_close
);
2252 /* These states need RST on ABORT according to RFC793 */
2254 static inline bool tcp_need_reset(int state
)
2256 return (1 << state
) &
2257 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2258 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2261 int tcp_disconnect(struct sock
*sk
, int flags
)
2263 struct inet_sock
*inet
= inet_sk(sk
);
2264 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2265 struct tcp_sock
*tp
= tcp_sk(sk
);
2267 int old_state
= sk
->sk_state
;
2269 if (old_state
!= TCP_CLOSE
)
2270 tcp_set_state(sk
, TCP_CLOSE
);
2272 /* ABORT function of RFC793 */
2273 if (old_state
== TCP_LISTEN
) {
2274 inet_csk_listen_stop(sk
);
2275 } else if (unlikely(tp
->repair
)) {
2276 sk
->sk_err
= ECONNABORTED
;
2277 } else if (tcp_need_reset(old_state
) ||
2278 (tp
->snd_nxt
!= tp
->write_seq
&&
2279 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2280 /* The last check adjusts for discrepancy of Linux wrt. RFC
2283 tcp_send_active_reset(sk
, gfp_any());
2284 sk
->sk_err
= ECONNRESET
;
2285 } else if (old_state
== TCP_SYN_SENT
)
2286 sk
->sk_err
= ECONNRESET
;
2288 tcp_clear_xmit_timers(sk
);
2289 __skb_queue_purge(&sk
->sk_receive_queue
);
2290 tcp_write_queue_purge(sk
);
2291 __skb_queue_purge(&tp
->out_of_order_queue
);
2292 #ifdef CONFIG_NET_DMA
2293 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2296 inet
->inet_dport
= 0;
2298 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2299 inet_reset_saddr(sk
);
2301 sk
->sk_shutdown
= 0;
2302 sock_reset_flag(sk
, SOCK_DONE
);
2304 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2306 icsk
->icsk_backoff
= 0;
2308 icsk
->icsk_probes_out
= 0;
2309 tp
->packets_out
= 0;
2310 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2311 tp
->snd_cwnd_cnt
= 0;
2312 tp
->window_clamp
= 0;
2313 tcp_set_ca_state(sk
, TCP_CA_Open
);
2314 tcp_clear_retrans(tp
);
2315 inet_csk_delack_init(sk
);
2316 tcp_init_send_head(sk
);
2317 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2320 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2322 sk
->sk_error_report(sk
);
2325 EXPORT_SYMBOL(tcp_disconnect
);
2327 void tcp_sock_destruct(struct sock
*sk
)
2329 inet_sock_destruct(sk
);
2331 kfree(inet_csk(sk
)->icsk_accept_queue
.fastopenq
);
2334 static inline bool tcp_can_repair_sock(const struct sock
*sk
)
2336 return ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
) &&
2337 ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_ESTABLISHED
));
2340 static int tcp_repair_options_est(struct tcp_sock
*tp
,
2341 struct tcp_repair_opt __user
*optbuf
, unsigned int len
)
2343 struct tcp_repair_opt opt
;
2345 while (len
>= sizeof(opt
)) {
2346 if (copy_from_user(&opt
, optbuf
, sizeof(opt
)))
2352 switch (opt
.opt_code
) {
2354 tp
->rx_opt
.mss_clamp
= opt
.opt_val
;
2358 u16 snd_wscale
= opt
.opt_val
& 0xFFFF;
2359 u16 rcv_wscale
= opt
.opt_val
>> 16;
2361 if (snd_wscale
> 14 || rcv_wscale
> 14)
2364 tp
->rx_opt
.snd_wscale
= snd_wscale
;
2365 tp
->rx_opt
.rcv_wscale
= rcv_wscale
;
2366 tp
->rx_opt
.wscale_ok
= 1;
2369 case TCPOPT_SACK_PERM
:
2370 if (opt
.opt_val
!= 0)
2373 tp
->rx_opt
.sack_ok
|= TCP_SACK_SEEN
;
2374 if (sysctl_tcp_fack
)
2375 tcp_enable_fack(tp
);
2377 case TCPOPT_TIMESTAMP
:
2378 if (opt
.opt_val
!= 0)
2381 tp
->rx_opt
.tstamp_ok
= 1;
2390 * Socket option code for TCP.
2392 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2393 int optname
, char __user
*optval
, unsigned int optlen
)
2395 struct tcp_sock
*tp
= tcp_sk(sk
);
2396 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2400 /* These are data/string values, all the others are ints */
2402 case TCP_CONGESTION
: {
2403 char name
[TCP_CA_NAME_MAX
];
2408 val
= strncpy_from_user(name
, optval
,
2409 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2415 err
= tcp_set_congestion_control(sk
, name
);
2424 if (optlen
< sizeof(int))
2427 if (get_user(val
, (int __user
*)optval
))
2434 /* Values greater than interface MTU won't take effect. However
2435 * at the point when this call is done we typically don't yet
2436 * know which interface is going to be used */
2437 if (val
< TCP_MIN_MSS
|| val
> MAX_TCP_WINDOW
) {
2441 tp
->rx_opt
.user_mss
= val
;
2446 /* TCP_NODELAY is weaker than TCP_CORK, so that
2447 * this option on corked socket is remembered, but
2448 * it is not activated until cork is cleared.
2450 * However, when TCP_NODELAY is set we make
2451 * an explicit push, which overrides even TCP_CORK
2452 * for currently queued segments.
2454 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2455 tcp_push_pending_frames(sk
);
2457 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2461 case TCP_THIN_LINEAR_TIMEOUTS
:
2462 if (val
< 0 || val
> 1)
2468 case TCP_THIN_DUPACK
:
2469 if (val
< 0 || val
> 1)
2472 tp
->thin_dupack
= val
;
2473 if (tp
->thin_dupack
)
2474 tcp_disable_early_retrans(tp
);
2479 if (!tcp_can_repair_sock(sk
))
2481 else if (val
== 1) {
2483 sk
->sk_reuse
= SK_FORCE_REUSE
;
2484 tp
->repair_queue
= TCP_NO_QUEUE
;
2485 } else if (val
== 0) {
2487 sk
->sk_reuse
= SK_NO_REUSE
;
2488 tcp_send_window_probe(sk
);
2494 case TCP_REPAIR_QUEUE
:
2497 else if (val
< TCP_QUEUES_NR
)
2498 tp
->repair_queue
= val
;
2504 if (sk
->sk_state
!= TCP_CLOSE
)
2506 else if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2507 tp
->write_seq
= val
;
2508 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2514 case TCP_REPAIR_OPTIONS
:
2517 else if (sk
->sk_state
== TCP_ESTABLISHED
)
2518 err
= tcp_repair_options_est(tp
,
2519 (struct tcp_repair_opt __user
*)optval
,
2526 /* When set indicates to always queue non-full frames.
2527 * Later the user clears this option and we transmit
2528 * any pending partial frames in the queue. This is
2529 * meant to be used alongside sendfile() to get properly
2530 * filled frames when the user (for example) must write
2531 * out headers with a write() call first and then use
2532 * sendfile to send out the data parts.
2534 * TCP_CORK can be set together with TCP_NODELAY and it is
2535 * stronger than TCP_NODELAY.
2538 tp
->nonagle
|= TCP_NAGLE_CORK
;
2540 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2541 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2542 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2543 tcp_push_pending_frames(sk
);
2548 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2551 tp
->keepalive_time
= val
* HZ
;
2552 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2553 !((1 << sk
->sk_state
) &
2554 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2555 u32 elapsed
= keepalive_time_elapsed(tp
);
2556 if (tp
->keepalive_time
> elapsed
)
2557 elapsed
= tp
->keepalive_time
- elapsed
;
2560 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2565 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2568 tp
->keepalive_intvl
= val
* HZ
;
2571 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2574 tp
->keepalive_probes
= val
;
2577 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2580 icsk
->icsk_syn_retries
= val
;
2586 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2589 tp
->linger2
= val
* HZ
;
2592 case TCP_DEFER_ACCEPT
:
2593 /* Translate value in seconds to number of retransmits */
2594 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2595 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2599 case TCP_WINDOW_CLAMP
:
2601 if (sk
->sk_state
!= TCP_CLOSE
) {
2605 tp
->window_clamp
= 0;
2607 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2608 SOCK_MIN_RCVBUF
/ 2 : val
;
2613 icsk
->icsk_ack
.pingpong
= 1;
2615 icsk
->icsk_ack
.pingpong
= 0;
2616 if ((1 << sk
->sk_state
) &
2617 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2618 inet_csk_ack_scheduled(sk
)) {
2619 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2620 tcp_cleanup_rbuf(sk
, 1);
2622 icsk
->icsk_ack
.pingpong
= 1;
2627 #ifdef CONFIG_TCP_MD5SIG
2629 /* Read the IP->Key mappings from userspace */
2630 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2633 case TCP_USER_TIMEOUT
:
2634 /* Cap the max timeout in ms TCP will retry/retrans
2635 * before giving up and aborting (ETIMEDOUT) a connection.
2640 icsk
->icsk_user_timeout
= msecs_to_jiffies(val
);
2644 if (val
>= 0 && ((1 << sk
->sk_state
) & (TCPF_CLOSE
|
2646 err
= fastopen_init_queue(sk
, val
);
2654 tp
->tsoffset
= val
- tcp_time_stamp
;
2656 case TCP_NOTSENT_LOWAT
:
2657 tp
->notsent_lowat
= val
;
2658 sk
->sk_write_space(sk
);
2669 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2670 unsigned int optlen
)
2672 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2674 if (level
!= SOL_TCP
)
2675 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2677 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2679 EXPORT_SYMBOL(tcp_setsockopt
);
2681 #ifdef CONFIG_COMPAT
2682 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2683 char __user
*optval
, unsigned int optlen
)
2685 if (level
!= SOL_TCP
)
2686 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2688 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2690 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2693 /* Return information about state of tcp endpoint in API format. */
2694 void tcp_get_info(const struct sock
*sk
, struct tcp_info
*info
)
2696 const struct tcp_sock
*tp
= tcp_sk(sk
);
2697 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2698 u32 now
= tcp_time_stamp
;
2700 memset(info
, 0, sizeof(*info
));
2702 info
->tcpi_state
= sk
->sk_state
;
2703 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2704 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2705 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2706 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2708 if (tp
->rx_opt
.tstamp_ok
)
2709 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2710 if (tcp_is_sack(tp
))
2711 info
->tcpi_options
|= TCPI_OPT_SACK
;
2712 if (tp
->rx_opt
.wscale_ok
) {
2713 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2714 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2715 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2718 if (tp
->ecn_flags
& TCP_ECN_OK
)
2719 info
->tcpi_options
|= TCPI_OPT_ECN
;
2720 if (tp
->ecn_flags
& TCP_ECN_SEEN
)
2721 info
->tcpi_options
|= TCPI_OPT_ECN_SEEN
;
2722 if (tp
->syn_data_acked
)
2723 info
->tcpi_options
|= TCPI_OPT_SYN_DATA
;
2725 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2726 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2727 info
->tcpi_snd_mss
= tp
->mss_cache
;
2728 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2730 if (sk
->sk_state
== TCP_LISTEN
) {
2731 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2732 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2734 info
->tcpi_unacked
= tp
->packets_out
;
2735 info
->tcpi_sacked
= tp
->sacked_out
;
2737 info
->tcpi_lost
= tp
->lost_out
;
2738 info
->tcpi_retrans
= tp
->retrans_out
;
2739 info
->tcpi_fackets
= tp
->fackets_out
;
2741 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2742 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2743 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2745 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2746 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2747 info
->tcpi_rtt
= jiffies_to_usecs(tp
->srtt
)>>3;
2748 info
->tcpi_rttvar
= jiffies_to_usecs(tp
->mdev
)>>2;
2749 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2750 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2751 info
->tcpi_advmss
= tp
->advmss
;
2752 info
->tcpi_reordering
= tp
->reordering
;
2754 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2755 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2757 info
->tcpi_total_retrans
= tp
->total_retrans
;
2759 EXPORT_SYMBOL_GPL(tcp_get_info
);
2761 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2762 int optname
, char __user
*optval
, int __user
*optlen
)
2764 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2765 struct tcp_sock
*tp
= tcp_sk(sk
);
2768 if (get_user(len
, optlen
))
2771 len
= min_t(unsigned int, len
, sizeof(int));
2778 val
= tp
->mss_cache
;
2779 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2780 val
= tp
->rx_opt
.user_mss
;
2782 val
= tp
->rx_opt
.mss_clamp
;
2785 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2788 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2791 val
= keepalive_time_when(tp
) / HZ
;
2794 val
= keepalive_intvl_when(tp
) / HZ
;
2797 val
= keepalive_probes(tp
);
2800 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2805 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2807 case TCP_DEFER_ACCEPT
:
2808 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2809 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2811 case TCP_WINDOW_CLAMP
:
2812 val
= tp
->window_clamp
;
2815 struct tcp_info info
;
2817 if (get_user(len
, optlen
))
2820 tcp_get_info(sk
, &info
);
2822 len
= min_t(unsigned int, len
, sizeof(info
));
2823 if (put_user(len
, optlen
))
2825 if (copy_to_user(optval
, &info
, len
))
2830 val
= !icsk
->icsk_ack
.pingpong
;
2833 case TCP_CONGESTION
:
2834 if (get_user(len
, optlen
))
2836 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2837 if (put_user(len
, optlen
))
2839 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2843 case TCP_THIN_LINEAR_TIMEOUTS
:
2846 case TCP_THIN_DUPACK
:
2847 val
= tp
->thin_dupack
;
2854 case TCP_REPAIR_QUEUE
:
2856 val
= tp
->repair_queue
;
2862 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2863 val
= tp
->write_seq
;
2864 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2870 case TCP_USER_TIMEOUT
:
2871 val
= jiffies_to_msecs(icsk
->icsk_user_timeout
);
2874 val
= tcp_time_stamp
+ tp
->tsoffset
;
2876 case TCP_NOTSENT_LOWAT
:
2877 val
= tp
->notsent_lowat
;
2880 return -ENOPROTOOPT
;
2883 if (put_user(len
, optlen
))
2885 if (copy_to_user(optval
, &val
, len
))
2890 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2893 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2895 if (level
!= SOL_TCP
)
2896 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2898 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2900 EXPORT_SYMBOL(tcp_getsockopt
);
2902 #ifdef CONFIG_COMPAT
2903 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2904 char __user
*optval
, int __user
*optlen
)
2906 if (level
!= SOL_TCP
)
2907 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2909 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2911 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2914 #ifdef CONFIG_TCP_MD5SIG
2915 static struct tcp_md5sig_pool __percpu
*tcp_md5sig_pool __read_mostly
;
2916 static DEFINE_MUTEX(tcp_md5sig_mutex
);
2918 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu
*pool
)
2922 for_each_possible_cpu(cpu
) {
2923 struct tcp_md5sig_pool
*p
= per_cpu_ptr(pool
, cpu
);
2925 if (p
->md5_desc
.tfm
)
2926 crypto_free_hash(p
->md5_desc
.tfm
);
2931 static void __tcp_alloc_md5sig_pool(void)
2934 struct tcp_md5sig_pool __percpu
*pool
;
2936 pool
= alloc_percpu(struct tcp_md5sig_pool
);
2940 for_each_possible_cpu(cpu
) {
2941 struct crypto_hash
*hash
;
2943 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
2944 if (IS_ERR_OR_NULL(hash
))
2947 per_cpu_ptr(pool
, cpu
)->md5_desc
.tfm
= hash
;
2949 /* before setting tcp_md5sig_pool, we must commit all writes
2950 * to memory. See ACCESS_ONCE() in tcp_get_md5sig_pool()
2953 tcp_md5sig_pool
= pool
;
2956 __tcp_free_md5sig_pool(pool
);
2959 bool tcp_alloc_md5sig_pool(void)
2961 if (unlikely(!tcp_md5sig_pool
)) {
2962 mutex_lock(&tcp_md5sig_mutex
);
2964 if (!tcp_md5sig_pool
)
2965 __tcp_alloc_md5sig_pool();
2967 mutex_unlock(&tcp_md5sig_mutex
);
2969 return tcp_md5sig_pool
!= NULL
;
2971 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
2975 * tcp_get_md5sig_pool - get md5sig_pool for this user
2977 * We use percpu structure, so if we succeed, we exit with preemption
2978 * and BH disabled, to make sure another thread or softirq handling
2979 * wont try to get same context.
2981 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
2983 struct tcp_md5sig_pool __percpu
*p
;
2986 p
= ACCESS_ONCE(tcp_md5sig_pool
);
2988 return __this_cpu_ptr(p
);
2993 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
2995 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
2996 const struct tcphdr
*th
)
2998 struct scatterlist sg
;
3002 /* We are not allowed to change tcphdr, make a local copy */
3003 memcpy(&hdr
, th
, sizeof(hdr
));
3006 /* options aren't included in the hash */
3007 sg_init_one(&sg
, &hdr
, sizeof(hdr
));
3008 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(hdr
));
3011 EXPORT_SYMBOL(tcp_md5_hash_header
);
3013 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
3014 const struct sk_buff
*skb
, unsigned int header_len
)
3016 struct scatterlist sg
;
3017 const struct tcphdr
*tp
= tcp_hdr(skb
);
3018 struct hash_desc
*desc
= &hp
->md5_desc
;
3020 const unsigned int head_data_len
= skb_headlen(skb
) > header_len
?
3021 skb_headlen(skb
) - header_len
: 0;
3022 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
3023 struct sk_buff
*frag_iter
;
3025 sg_init_table(&sg
, 1);
3027 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
3028 if (crypto_hash_update(desc
, &sg
, head_data_len
))
3031 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
3032 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
3033 unsigned int offset
= f
->page_offset
;
3034 struct page
*page
= skb_frag_page(f
) + (offset
>> PAGE_SHIFT
);
3036 sg_set_page(&sg
, page
, skb_frag_size(f
),
3037 offset_in_page(offset
));
3038 if (crypto_hash_update(desc
, &sg
, skb_frag_size(f
)))
3042 skb_walk_frags(skb
, frag_iter
)
3043 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3048 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3050 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, const struct tcp_md5sig_key
*key
)
3052 struct scatterlist sg
;
3054 sg_init_one(&sg
, key
->key
, key
->keylen
);
3055 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3057 EXPORT_SYMBOL(tcp_md5_hash_key
);
3061 void tcp_done(struct sock
*sk
)
3063 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
3065 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3066 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3068 tcp_set_state(sk
, TCP_CLOSE
);
3069 tcp_clear_xmit_timers(sk
);
3071 reqsk_fastopen_remove(sk
, req
, false);
3073 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3075 if (!sock_flag(sk
, SOCK_DEAD
))
3076 sk
->sk_state_change(sk
);
3078 inet_csk_destroy_sock(sk
);
3080 EXPORT_SYMBOL_GPL(tcp_done
);
3082 extern struct tcp_congestion_ops tcp_reno
;
3084 static __initdata
unsigned long thash_entries
;
3085 static int __init
set_thash_entries(char *str
)
3092 ret
= kstrtoul(str
, 0, &thash_entries
);
3098 __setup("thash_entries=", set_thash_entries
);
3100 void tcp_init_mem(struct net
*net
)
3102 unsigned long limit
= nr_free_buffer_pages() / 8;
3103 limit
= max(limit
, 128UL);
3104 net
->ipv4
.sysctl_tcp_mem
[0] = limit
/ 4 * 3;
3105 net
->ipv4
.sysctl_tcp_mem
[1] = limit
;
3106 net
->ipv4
.sysctl_tcp_mem
[2] = net
->ipv4
.sysctl_tcp_mem
[0] * 2;
3109 void __init
tcp_init(void)
3111 struct sk_buff
*skb
= NULL
;
3112 unsigned long limit
;
3113 int max_rshare
, max_wshare
, cnt
;
3116 BUILD_BUG_ON(sizeof(struct tcp_skb_cb
) > sizeof(skb
->cb
));
3118 percpu_counter_init(&tcp_sockets_allocated
, 0);
3119 percpu_counter_init(&tcp_orphan_count
, 0);
3120 tcp_hashinfo
.bind_bucket_cachep
=
3121 kmem_cache_create("tcp_bind_bucket",
3122 sizeof(struct inet_bind_bucket
), 0,
3123 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3125 /* Size and allocate the main established and bind bucket
3128 * The methodology is similar to that of the buffer cache.
3130 tcp_hashinfo
.ehash
=
3131 alloc_large_system_hash("TCP established",
3132 sizeof(struct inet_ehash_bucket
),
3134 17, /* one slot per 128 KB of memory */
3137 &tcp_hashinfo
.ehash_mask
,
3139 thash_entries
? 0 : 512 * 1024);
3140 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++) {
3141 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3142 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].twchain
, i
);
3144 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3145 panic("TCP: failed to alloc ehash_locks");
3146 tcp_hashinfo
.bhash
=
3147 alloc_large_system_hash("TCP bind",
3148 sizeof(struct inet_bind_hashbucket
),
3149 tcp_hashinfo
.ehash_mask
+ 1,
3150 17, /* one slot per 128 KB of memory */
3152 &tcp_hashinfo
.bhash_size
,
3156 tcp_hashinfo
.bhash_size
= 1U << tcp_hashinfo
.bhash_size
;
3157 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3158 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3159 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3163 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
3165 tcp_death_row
.sysctl_max_tw_buckets
= cnt
/ 2;
3166 sysctl_tcp_max_orphans
= cnt
/ 2;
3167 sysctl_max_syn_backlog
= max(128, cnt
/ 256);
3169 tcp_init_mem(&init_net
);
3170 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3171 limit
= nr_free_buffer_pages() << (PAGE_SHIFT
- 7);
3172 max_wshare
= min(4UL*1024*1024, limit
);
3173 max_rshare
= min(6UL*1024*1024, limit
);
3175 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3176 sysctl_tcp_wmem
[1] = 16*1024;
3177 sysctl_tcp_wmem
[2] = max(64*1024, max_wshare
);
3179 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3180 sysctl_tcp_rmem
[1] = 87380;
3181 sysctl_tcp_rmem
[2] = max(87380, max_rshare
);
3183 pr_info("Hash tables configured (established %u bind %u)\n",
3184 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3188 tcp_register_congestion_control(&tcp_reno
);