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 long sysctl_tcp_mem
[3] __read_mostly
;
292 int sysctl_tcp_wmem
[3] __read_mostly
;
293 int sysctl_tcp_rmem
[3] __read_mostly
;
295 EXPORT_SYMBOL(sysctl_tcp_mem
);
296 EXPORT_SYMBOL(sysctl_tcp_rmem
);
297 EXPORT_SYMBOL(sysctl_tcp_wmem
);
299 atomic_long_t tcp_memory_allocated
; /* Current allocated memory. */
300 EXPORT_SYMBOL(tcp_memory_allocated
);
303 * Current number of TCP sockets.
305 struct percpu_counter tcp_sockets_allocated
;
306 EXPORT_SYMBOL(tcp_sockets_allocated
);
311 struct tcp_splice_state
{
312 struct pipe_inode_info
*pipe
;
318 * Pressure flag: try to collapse.
319 * Technical note: it is used by multiple contexts non atomically.
320 * All the __sk_mem_schedule() is of this nature: accounting
321 * is strict, actions are advisory and have some latency.
323 int tcp_memory_pressure __read_mostly
;
324 EXPORT_SYMBOL(tcp_memory_pressure
);
326 void tcp_enter_memory_pressure(struct sock
*sk
)
328 if (!tcp_memory_pressure
) {
329 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMEMORYPRESSURES
);
330 tcp_memory_pressure
= 1;
333 EXPORT_SYMBOL(tcp_enter_memory_pressure
);
335 /* Convert seconds to retransmits based on initial and max timeout */
336 static u8
secs_to_retrans(int seconds
, int timeout
, int rto_max
)
341 int period
= timeout
;
344 while (seconds
> period
&& res
< 255) {
347 if (timeout
> rto_max
)
355 /* Convert retransmits to seconds based on initial and max timeout */
356 static int retrans_to_secs(u8 retrans
, int timeout
, int rto_max
)
364 if (timeout
> rto_max
)
372 /* Address-family independent initialization for a tcp_sock.
374 * NOTE: A lot of things set to zero explicitly by call to
375 * sk_alloc() so need not be done here.
377 void tcp_init_sock(struct sock
*sk
)
379 struct inet_connection_sock
*icsk
= inet_csk(sk
);
380 struct tcp_sock
*tp
= tcp_sk(sk
);
382 skb_queue_head_init(&tp
->out_of_order_queue
);
383 tcp_init_xmit_timers(sk
);
384 tcp_prequeue_init(tp
);
385 INIT_LIST_HEAD(&tp
->tsq_node
);
387 icsk
->icsk_rto
= TCP_TIMEOUT_INIT
;
388 tp
->mdev
= TCP_TIMEOUT_INIT
;
390 /* So many TCP implementations out there (incorrectly) count the
391 * initial SYN frame in their delayed-ACK and congestion control
392 * algorithms that we must have the following bandaid to talk
393 * efficiently to them. -DaveM
395 tp
->snd_cwnd
= TCP_INIT_CWND
;
397 /* See draft-stevens-tcpca-spec-01 for discussion of the
398 * initialization of these values.
400 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
401 tp
->snd_cwnd_clamp
= ~0;
402 tp
->mss_cache
= TCP_MSS_DEFAULT
;
404 tp
->reordering
= sysctl_tcp_reordering
;
405 tcp_enable_early_retrans(tp
);
406 icsk
->icsk_ca_ops
= &tcp_init_congestion_ops
;
410 sk
->sk_state
= TCP_CLOSE
;
412 sk
->sk_write_space
= sk_stream_write_space
;
413 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
415 icsk
->icsk_sync_mss
= tcp_sync_mss
;
417 sk
->sk_sndbuf
= sysctl_tcp_wmem
[1];
418 sk
->sk_rcvbuf
= sysctl_tcp_rmem
[1];
421 sock_update_memcg(sk
);
422 sk_sockets_allocated_inc(sk
);
425 EXPORT_SYMBOL(tcp_init_sock
);
428 * Wait for a TCP event.
430 * Note that we don't need to lock the socket, as the upper poll layers
431 * take care of normal races (between the test and the event) and we don't
432 * go look at any of the socket buffers directly.
434 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
437 struct sock
*sk
= sock
->sk
;
438 const struct tcp_sock
*tp
= tcp_sk(sk
);
440 sock_rps_record_flow(sk
);
442 sock_poll_wait(file
, sk_sleep(sk
), wait
);
443 if (sk
->sk_state
== TCP_LISTEN
)
444 return inet_csk_listen_poll(sk
);
446 /* Socket is not locked. We are protected from async events
447 * by poll logic and correct handling of state changes
448 * made by other threads is impossible in any case.
454 * POLLHUP is certainly not done right. But poll() doesn't
455 * have a notion of HUP in just one direction, and for a
456 * socket the read side is more interesting.
458 * Some poll() documentation says that POLLHUP is incompatible
459 * with the POLLOUT/POLLWR flags, so somebody should check this
460 * all. But careful, it tends to be safer to return too many
461 * bits than too few, and you can easily break real applications
462 * if you don't tell them that something has hung up!
466 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
467 * our fs/select.c). It means that after we received EOF,
468 * poll always returns immediately, making impossible poll() on write()
469 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
470 * if and only if shutdown has been made in both directions.
471 * Actually, it is interesting to look how Solaris and DUX
472 * solve this dilemma. I would prefer, if POLLHUP were maskable,
473 * then we could set it on SND_SHUTDOWN. BTW examples given
474 * in Stevens' books assume exactly this behaviour, it explains
475 * why POLLHUP is incompatible with POLLOUT. --ANK
477 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
478 * blocking on fresh not-connected or disconnected socket. --ANK
480 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== TCP_CLOSE
)
482 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
483 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
485 /* Connected or passive Fast Open socket? */
486 if (sk
->sk_state
!= TCP_SYN_SENT
&&
487 (sk
->sk_state
!= TCP_SYN_RECV
|| tp
->fastopen_rsk
!= NULL
)) {
488 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
490 if (tp
->urg_seq
== tp
->copied_seq
&&
491 !sock_flag(sk
, SOCK_URGINLINE
) &&
495 /* Potential race condition. If read of tp below will
496 * escape above sk->sk_state, we can be illegally awaken
497 * in SYN_* states. */
498 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
499 mask
|= POLLIN
| POLLRDNORM
;
501 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
502 if (sk_stream_is_writeable(sk
)) {
503 mask
|= POLLOUT
| POLLWRNORM
;
504 } else { /* send SIGIO later */
505 set_bit(SOCK_ASYNC_NOSPACE
,
506 &sk
->sk_socket
->flags
);
507 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
509 /* Race breaker. If space is freed after
510 * wspace test but before the flags are set,
511 * IO signal will be lost.
513 if (sk_stream_is_writeable(sk
))
514 mask
|= POLLOUT
| POLLWRNORM
;
517 mask
|= POLLOUT
| POLLWRNORM
;
519 if (tp
->urg_data
& TCP_URG_VALID
)
522 /* This barrier is coupled with smp_wmb() in tcp_reset() */
529 EXPORT_SYMBOL(tcp_poll
);
531 int tcp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
533 struct tcp_sock
*tp
= tcp_sk(sk
);
539 if (sk
->sk_state
== TCP_LISTEN
)
542 slow
= lock_sock_fast(sk
);
543 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
545 else if (sock_flag(sk
, SOCK_URGINLINE
) ||
547 before(tp
->urg_seq
, tp
->copied_seq
) ||
548 !before(tp
->urg_seq
, tp
->rcv_nxt
)) {
550 answ
= tp
->rcv_nxt
- tp
->copied_seq
;
552 /* Subtract 1, if FIN was received */
553 if (answ
&& sock_flag(sk
, SOCK_DONE
))
556 answ
= tp
->urg_seq
- tp
->copied_seq
;
557 unlock_sock_fast(sk
, slow
);
560 answ
= tp
->urg_data
&& tp
->urg_seq
== tp
->copied_seq
;
563 if (sk
->sk_state
== TCP_LISTEN
)
566 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
569 answ
= tp
->write_seq
- tp
->snd_una
;
572 if (sk
->sk_state
== TCP_LISTEN
)
575 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
578 answ
= tp
->write_seq
- tp
->snd_nxt
;
584 return put_user(answ
, (int __user
*)arg
);
586 EXPORT_SYMBOL(tcp_ioctl
);
588 static inline void tcp_mark_push(struct tcp_sock
*tp
, struct sk_buff
*skb
)
590 TCP_SKB_CB(skb
)->tcp_flags
|= TCPHDR_PSH
;
591 tp
->pushed_seq
= tp
->write_seq
;
594 static inline bool forced_push(const struct tcp_sock
*tp
)
596 return after(tp
->write_seq
, tp
->pushed_seq
+ (tp
->max_window
>> 1));
599 static inline void skb_entail(struct sock
*sk
, struct sk_buff
*skb
)
601 struct tcp_sock
*tp
= tcp_sk(sk
);
602 struct tcp_skb_cb
*tcb
= TCP_SKB_CB(skb
);
605 tcb
->seq
= tcb
->end_seq
= tp
->write_seq
;
606 tcb
->tcp_flags
= TCPHDR_ACK
;
608 skb_header_release(skb
);
609 tcp_add_write_queue_tail(sk
, skb
);
610 sk
->sk_wmem_queued
+= skb
->truesize
;
611 sk_mem_charge(sk
, skb
->truesize
);
612 if (tp
->nonagle
& TCP_NAGLE_PUSH
)
613 tp
->nonagle
&= ~TCP_NAGLE_PUSH
;
616 static inline void tcp_mark_urg(struct tcp_sock
*tp
, int flags
)
619 tp
->snd_up
= tp
->write_seq
;
622 static inline void tcp_push(struct sock
*sk
, int flags
, int mss_now
,
625 if (tcp_send_head(sk
)) {
626 struct tcp_sock
*tp
= tcp_sk(sk
);
628 if (!(flags
& MSG_MORE
) || forced_push(tp
))
629 tcp_mark_push(tp
, tcp_write_queue_tail(sk
));
631 tcp_mark_urg(tp
, flags
);
632 __tcp_push_pending_frames(sk
, mss_now
,
633 (flags
& MSG_MORE
) ? TCP_NAGLE_CORK
: nonagle
);
637 static int tcp_splice_data_recv(read_descriptor_t
*rd_desc
, struct sk_buff
*skb
,
638 unsigned int offset
, size_t len
)
640 struct tcp_splice_state
*tss
= rd_desc
->arg
.data
;
643 ret
= skb_splice_bits(skb
, offset
, tss
->pipe
, min(rd_desc
->count
, len
),
646 rd_desc
->count
-= ret
;
650 static int __tcp_splice_read(struct sock
*sk
, struct tcp_splice_state
*tss
)
652 /* Store TCP splice context information in read_descriptor_t. */
653 read_descriptor_t rd_desc
= {
658 return tcp_read_sock(sk
, &rd_desc
, tcp_splice_data_recv
);
662 * tcp_splice_read - splice data from TCP socket to a pipe
663 * @sock: socket to splice from
664 * @ppos: position (not valid)
665 * @pipe: pipe to splice to
666 * @len: number of bytes to splice
667 * @flags: splice modifier flags
670 * Will read pages from given socket and fill them into a pipe.
673 ssize_t
tcp_splice_read(struct socket
*sock
, loff_t
*ppos
,
674 struct pipe_inode_info
*pipe
, size_t len
,
677 struct sock
*sk
= sock
->sk
;
678 struct tcp_splice_state tss
= {
687 sock_rps_record_flow(sk
);
689 * We can't seek on a socket input
698 timeo
= sock_rcvtimeo(sk
, sock
->file
->f_flags
& O_NONBLOCK
);
700 ret
= __tcp_splice_read(sk
, &tss
);
706 if (sock_flag(sk
, SOCK_DONE
))
709 ret
= sock_error(sk
);
712 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
714 if (sk
->sk_state
== TCP_CLOSE
) {
716 * This occurs when user tries to read
717 * from never connected socket.
719 if (!sock_flag(sk
, SOCK_DONE
))
727 sk_wait_data(sk
, &timeo
);
728 if (signal_pending(current
)) {
729 ret
= sock_intr_errno(timeo
);
742 if (sk
->sk_err
|| sk
->sk_state
== TCP_CLOSE
||
743 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
744 signal_pending(current
))
755 EXPORT_SYMBOL(tcp_splice_read
);
757 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
)
761 /* The TCP header must be at least 32-bit aligned. */
762 size
= ALIGN(size
, 4);
764 skb
= alloc_skb_fclone(size
+ sk
->sk_prot
->max_header
, gfp
);
766 if (sk_wmem_schedule(sk
, skb
->truesize
)) {
767 skb_reserve(skb
, sk
->sk_prot
->max_header
);
769 * Make sure that we have exactly size bytes
770 * available to the caller, no more, no less.
772 skb
->reserved_tailroom
= skb
->end
- skb
->tail
- size
;
777 sk
->sk_prot
->enter_memory_pressure(sk
);
778 sk_stream_moderate_sndbuf(sk
);
783 static unsigned int tcp_xmit_size_goal(struct sock
*sk
, u32 mss_now
,
786 struct tcp_sock
*tp
= tcp_sk(sk
);
787 u32 xmit_size_goal
, old_size_goal
;
789 xmit_size_goal
= mss_now
;
791 if (large_allowed
&& sk_can_gso(sk
)) {
794 /* Maybe we should/could use sk->sk_prot->max_header here ? */
795 hlen
= inet_csk(sk
)->icsk_af_ops
->net_header_len
+
796 inet_csk(sk
)->icsk_ext_hdr_len
+
799 /* Goal is to send at least one packet per ms,
800 * not one big TSO packet every 100 ms.
801 * This preserves ACK clocking and is consistent
802 * with tcp_tso_should_defer() heuristic.
804 gso_size
= sk
->sk_pacing_rate
/ (2 * MSEC_PER_SEC
);
805 gso_size
= max_t(u32
, gso_size
,
806 sysctl_tcp_min_tso_segs
* mss_now
);
808 xmit_size_goal
= min_t(u32
, gso_size
,
809 sk
->sk_gso_max_size
- 1 - hlen
);
811 xmit_size_goal
= tcp_bound_to_half_wnd(tp
, xmit_size_goal
);
813 /* We try hard to avoid divides here */
814 old_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
816 if (likely(old_size_goal
<= xmit_size_goal
&&
817 old_size_goal
+ mss_now
> xmit_size_goal
)) {
818 xmit_size_goal
= old_size_goal
;
820 tp
->xmit_size_goal_segs
=
821 min_t(u16
, xmit_size_goal
/ mss_now
,
822 sk
->sk_gso_max_segs
);
823 xmit_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
827 return max(xmit_size_goal
, mss_now
);
830 static int tcp_send_mss(struct sock
*sk
, int *size_goal
, int flags
)
834 mss_now
= tcp_current_mss(sk
);
835 *size_goal
= tcp_xmit_size_goal(sk
, mss_now
, !(flags
& MSG_OOB
));
840 static ssize_t
do_tcp_sendpages(struct sock
*sk
, struct page
*page
, int offset
,
841 size_t size
, int flags
)
843 struct tcp_sock
*tp
= tcp_sk(sk
);
844 int mss_now
, size_goal
;
847 long timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
849 /* Wait for a connection to finish. One exception is TCP Fast Open
850 * (passive side) where data is allowed to be sent before a connection
851 * is fully established.
853 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
854 !tcp_passive_fastopen(sk
)) {
855 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
859 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
861 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
865 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
869 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
873 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
875 if (!sk_stream_memory_free(sk
))
876 goto wait_for_sndbuf
;
878 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
);
880 goto wait_for_memory
;
889 i
= skb_shinfo(skb
)->nr_frags
;
890 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
891 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
892 tcp_mark_push(tp
, skb
);
895 if (!sk_wmem_schedule(sk
, copy
))
896 goto wait_for_memory
;
899 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
902 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
904 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
907 skb
->data_len
+= copy
;
908 skb
->truesize
+= copy
;
909 sk
->sk_wmem_queued
+= copy
;
910 sk_mem_charge(sk
, copy
);
911 skb
->ip_summed
= CHECKSUM_PARTIAL
;
912 tp
->write_seq
+= copy
;
913 TCP_SKB_CB(skb
)->end_seq
+= copy
;
914 skb_shinfo(skb
)->gso_segs
= 0;
917 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
924 if (skb
->len
< size_goal
|| (flags
& MSG_OOB
))
927 if (forced_push(tp
)) {
928 tcp_mark_push(tp
, skb
);
929 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
930 } else if (skb
== tcp_send_head(sk
))
931 tcp_push_one(sk
, mss_now
);
935 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
937 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
939 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
942 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
946 if (copied
&& !(flags
& MSG_SENDPAGE_NOTLAST
))
947 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
954 return sk_stream_error(sk
, flags
, err
);
957 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
958 size_t size
, int flags
)
962 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
963 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
964 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
968 res
= do_tcp_sendpages(sk
, page
, offset
, size
, flags
);
972 EXPORT_SYMBOL(tcp_sendpage
);
974 static inline int select_size(const struct sock
*sk
, bool sg
)
976 const struct tcp_sock
*tp
= tcp_sk(sk
);
977 int tmp
= tp
->mss_cache
;
980 if (sk_can_gso(sk
)) {
981 /* Small frames wont use a full page:
982 * Payload will immediately follow tcp header.
984 tmp
= SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER
);
986 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
988 if (tmp
>= pgbreak
&&
989 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
997 void tcp_free_fastopen_req(struct tcp_sock
*tp
)
999 if (tp
->fastopen_req
!= NULL
) {
1000 kfree(tp
->fastopen_req
);
1001 tp
->fastopen_req
= NULL
;
1005 static int tcp_sendmsg_fastopen(struct sock
*sk
, struct msghdr
*msg
, int *size
)
1007 struct tcp_sock
*tp
= tcp_sk(sk
);
1010 if (!(sysctl_tcp_fastopen
& TFO_CLIENT_ENABLE
))
1012 if (tp
->fastopen_req
!= NULL
)
1013 return -EALREADY
; /* Another Fast Open is in progress */
1015 tp
->fastopen_req
= kzalloc(sizeof(struct tcp_fastopen_request
),
1017 if (unlikely(tp
->fastopen_req
== NULL
))
1019 tp
->fastopen_req
->data
= msg
;
1021 flags
= (msg
->msg_flags
& MSG_DONTWAIT
) ? O_NONBLOCK
: 0;
1022 err
= __inet_stream_connect(sk
->sk_socket
, msg
->msg_name
,
1023 msg
->msg_namelen
, flags
);
1024 *size
= tp
->fastopen_req
->copied
;
1025 tcp_free_fastopen_req(tp
);
1029 int tcp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1033 struct tcp_sock
*tp
= tcp_sk(sk
);
1034 struct sk_buff
*skb
;
1035 int iovlen
, flags
, err
, copied
= 0;
1036 int mss_now
= 0, size_goal
, copied_syn
= 0, offset
= 0;
1042 flags
= msg
->msg_flags
;
1043 if (flags
& MSG_FASTOPEN
) {
1044 err
= tcp_sendmsg_fastopen(sk
, msg
, &copied_syn
);
1045 if (err
== -EINPROGRESS
&& copied_syn
> 0)
1049 offset
= copied_syn
;
1052 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
1054 /* Wait for a connection to finish. One exception is TCP Fast Open
1055 * (passive side) where data is allowed to be sent before a connection
1056 * is fully established.
1058 if (((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
)) &&
1059 !tcp_passive_fastopen(sk
)) {
1060 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
1064 if (unlikely(tp
->repair
)) {
1065 if (tp
->repair_queue
== TCP_RECV_QUEUE
) {
1066 copied
= tcp_send_rcvq(sk
, msg
, size
);
1071 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1074 /* 'common' sending to sendq */
1077 /* This should be in poll */
1078 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
1080 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1082 /* Ok commence sending. */
1083 iovlen
= msg
->msg_iovlen
;
1088 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
1091 sg
= !!(sk
->sk_route_caps
& NETIF_F_SG
);
1093 while (--iovlen
>= 0) {
1094 size_t seglen
= iov
->iov_len
;
1095 unsigned char __user
*from
= iov
->iov_base
;
1098 if (unlikely(offset
> 0)) { /* Skip bytes copied in SYN */
1099 if (offset
>= seglen
) {
1108 while (seglen
> 0) {
1110 int max
= size_goal
;
1112 skb
= tcp_write_queue_tail(sk
);
1113 if (tcp_send_head(sk
)) {
1114 if (skb
->ip_summed
== CHECKSUM_NONE
)
1116 copy
= max
- skb
->len
;
1121 /* Allocate new segment. If the interface is SG,
1122 * allocate skb fitting to single page.
1124 if (!sk_stream_memory_free(sk
))
1125 goto wait_for_sndbuf
;
1127 skb
= sk_stream_alloc_skb(sk
,
1128 select_size(sk
, sg
),
1131 goto wait_for_memory
;
1134 * All packets are restored as if they have
1135 * already been sent.
1138 TCP_SKB_CB(skb
)->when
= tcp_time_stamp
;
1141 * Check whether we can use HW checksum.
1143 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
1144 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1146 skb_entail(sk
, skb
);
1151 /* Try to append data to the end of skb. */
1155 /* Where to copy to? */
1156 if (skb_availroom(skb
) > 0) {
1157 /* We have some space in skb head. Superb! */
1158 copy
= min_t(int, copy
, skb_availroom(skb
));
1159 err
= skb_add_data_nocache(sk
, skb
, from
, copy
);
1164 int i
= skb_shinfo(skb
)->nr_frags
;
1165 struct page_frag
*pfrag
= sk_page_frag(sk
);
1167 if (!sk_page_frag_refill(sk
, pfrag
))
1168 goto wait_for_memory
;
1170 if (!skb_can_coalesce(skb
, i
, pfrag
->page
,
1172 if (i
== MAX_SKB_FRAGS
|| !sg
) {
1173 tcp_mark_push(tp
, skb
);
1179 copy
= min_t(int, copy
, pfrag
->size
- pfrag
->offset
);
1181 if (!sk_wmem_schedule(sk
, copy
))
1182 goto wait_for_memory
;
1184 err
= skb_copy_to_page_nocache(sk
, from
, skb
,
1191 /* Update the skb. */
1193 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
1195 skb_fill_page_desc(skb
, i
, pfrag
->page
,
1196 pfrag
->offset
, copy
);
1197 get_page(pfrag
->page
);
1199 pfrag
->offset
+= copy
;
1203 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
1205 tp
->write_seq
+= copy
;
1206 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1207 skb_shinfo(skb
)->gso_segs
= 0;
1211 if ((seglen
-= copy
) == 0 && iovlen
== 0)
1214 if (skb
->len
< max
|| (flags
& MSG_OOB
) || unlikely(tp
->repair
))
1217 if (forced_push(tp
)) {
1218 tcp_mark_push(tp
, skb
);
1219 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1220 } else if (skb
== tcp_send_head(sk
))
1221 tcp_push_one(sk
, mss_now
);
1225 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1228 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
1230 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1233 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1239 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
1241 return copied
+ copied_syn
;
1245 tcp_unlink_write_queue(skb
, sk
);
1246 /* It is the one place in all of TCP, except connection
1247 * reset, where we can be unlinking the send_head.
1249 tcp_check_send_head(sk
, skb
);
1250 sk_wmem_free_skb(sk
, skb
);
1254 if (copied
+ copied_syn
)
1257 err
= sk_stream_error(sk
, flags
, err
);
1261 EXPORT_SYMBOL(tcp_sendmsg
);
1264 * Handle reading urgent data. BSD has very simple semantics for
1265 * this, no blocking and very strange errors 8)
1268 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1270 struct tcp_sock
*tp
= tcp_sk(sk
);
1272 /* No URG data to read. */
1273 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1274 tp
->urg_data
== TCP_URG_READ
)
1275 return -EINVAL
; /* Yes this is right ! */
1277 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1280 if (tp
->urg_data
& TCP_URG_VALID
) {
1282 char c
= tp
->urg_data
;
1284 if (!(flags
& MSG_PEEK
))
1285 tp
->urg_data
= TCP_URG_READ
;
1287 /* Read urgent data. */
1288 msg
->msg_flags
|= MSG_OOB
;
1291 if (!(flags
& MSG_TRUNC
))
1292 err
= memcpy_toiovec(msg
->msg_iov
, &c
, 1);
1295 msg
->msg_flags
|= MSG_TRUNC
;
1297 return err
? -EFAULT
: len
;
1300 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1303 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1304 * the available implementations agree in this case:
1305 * this call should never block, independent of the
1306 * blocking state of the socket.
1307 * Mike <pall@rz.uni-karlsruhe.de>
1312 static int tcp_peek_sndq(struct sock
*sk
, struct msghdr
*msg
, int len
)
1314 struct sk_buff
*skb
;
1315 int copied
= 0, err
= 0;
1317 /* XXX -- need to support SO_PEEK_OFF */
1319 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
1320 err
= skb_copy_datagram_iovec(skb
, 0, msg
->msg_iov
, skb
->len
);
1327 return err
?: copied
;
1330 /* Clean up the receive buffer for full frames taken by the user,
1331 * then send an ACK if necessary. COPIED is the number of bytes
1332 * tcp_recvmsg has given to the user so far, it speeds up the
1333 * calculation of whether or not we must ACK for the sake of
1336 void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1338 struct tcp_sock
*tp
= tcp_sk(sk
);
1339 bool time_to_ack
= false;
1341 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1343 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1344 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1345 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1347 if (inet_csk_ack_scheduled(sk
)) {
1348 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1349 /* Delayed ACKs frequently hit locked sockets during bulk
1351 if (icsk
->icsk_ack
.blocked
||
1352 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1353 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1355 * If this read emptied read buffer, we send ACK, if
1356 * connection is not bidirectional, user drained
1357 * receive buffer and there was a small segment
1361 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1362 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1363 !icsk
->icsk_ack
.pingpong
)) &&
1364 !atomic_read(&sk
->sk_rmem_alloc
)))
1368 /* We send an ACK if we can now advertise a non-zero window
1369 * which has been raised "significantly".
1371 * Even if window raised up to infinity, do not send window open ACK
1372 * in states, where we will not receive more. It is useless.
1374 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1375 __u32 rcv_window_now
= tcp_receive_window(tp
);
1377 /* Optimize, __tcp_select_window() is not cheap. */
1378 if (2*rcv_window_now
<= tp
->window_clamp
) {
1379 __u32 new_window
= __tcp_select_window(sk
);
1381 /* Send ACK now, if this read freed lots of space
1382 * in our buffer. Certainly, new_window is new window.
1383 * We can advertise it now, if it is not less than current one.
1384 * "Lots" means "at least twice" here.
1386 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1394 static void tcp_prequeue_process(struct sock
*sk
)
1396 struct sk_buff
*skb
;
1397 struct tcp_sock
*tp
= tcp_sk(sk
);
1399 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1401 /* RX process wants to run with disabled BHs, though it is not
1404 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1405 sk_backlog_rcv(sk
, skb
);
1408 /* Clear memory counter. */
1409 tp
->ucopy
.memory
= 0;
1412 #ifdef CONFIG_NET_DMA
1413 static void tcp_service_net_dma(struct sock
*sk
, bool wait
)
1415 dma_cookie_t done
, used
;
1416 dma_cookie_t last_issued
;
1417 struct tcp_sock
*tp
= tcp_sk(sk
);
1419 if (!tp
->ucopy
.dma_chan
)
1422 last_issued
= tp
->ucopy
.dma_cookie
;
1423 dma_async_issue_pending(tp
->ucopy
.dma_chan
);
1426 if (dma_async_is_tx_complete(tp
->ucopy
.dma_chan
,
1428 &used
) == DMA_COMPLETE
) {
1429 /* Safe to free early-copied skbs now */
1430 __skb_queue_purge(&sk
->sk_async_wait_queue
);
1433 struct sk_buff
*skb
;
1434 while ((skb
= skb_peek(&sk
->sk_async_wait_queue
)) &&
1435 (dma_async_is_complete(skb
->dma_cookie
, done
,
1436 used
) == DMA_COMPLETE
)) {
1437 __skb_dequeue(&sk
->sk_async_wait_queue
);
1445 static struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1447 struct sk_buff
*skb
;
1450 while ((skb
= skb_peek(&sk
->sk_receive_queue
)) != NULL
) {
1451 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1452 if (tcp_hdr(skb
)->syn
)
1454 if (offset
< skb
->len
|| tcp_hdr(skb
)->fin
) {
1458 /* This looks weird, but this can happen if TCP collapsing
1459 * splitted a fat GRO packet, while we released socket lock
1460 * in skb_splice_bits()
1462 sk_eat_skb(sk
, skb
, false);
1468 * This routine provides an alternative to tcp_recvmsg() for routines
1469 * that would like to handle copying from skbuffs directly in 'sendfile'
1472 * - It is assumed that the socket was locked by the caller.
1473 * - The routine does not block.
1474 * - At present, there is no support for reading OOB data
1475 * or for 'peeking' the socket using this routine
1476 * (although both would be easy to implement).
1478 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1479 sk_read_actor_t recv_actor
)
1481 struct sk_buff
*skb
;
1482 struct tcp_sock
*tp
= tcp_sk(sk
);
1483 u32 seq
= tp
->copied_seq
;
1487 if (sk
->sk_state
== TCP_LISTEN
)
1489 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1490 if (offset
< skb
->len
) {
1494 len
= skb
->len
- offset
;
1495 /* Stop reading if we hit a patch of urgent data */
1497 u32 urg_offset
= tp
->urg_seq
- seq
;
1498 if (urg_offset
< len
)
1503 used
= recv_actor(desc
, skb
, offset
, len
);
1508 } else if (used
<= len
) {
1513 /* If recv_actor drops the lock (e.g. TCP splice
1514 * receive) the skb pointer might be invalid when
1515 * getting here: tcp_collapse might have deleted it
1516 * while aggregating skbs from the socket queue.
1518 skb
= tcp_recv_skb(sk
, seq
- 1, &offset
);
1521 /* TCP coalescing might have appended data to the skb.
1522 * Try to splice more frags
1524 if (offset
+ 1 != skb
->len
)
1527 if (tcp_hdr(skb
)->fin
) {
1528 sk_eat_skb(sk
, skb
, false);
1532 sk_eat_skb(sk
, skb
, false);
1535 tp
->copied_seq
= seq
;
1537 tp
->copied_seq
= seq
;
1539 tcp_rcv_space_adjust(sk
);
1541 /* Clean up data we have read: This will do ACK frames. */
1543 tcp_recv_skb(sk
, seq
, &offset
);
1544 tcp_cleanup_rbuf(sk
, copied
);
1548 EXPORT_SYMBOL(tcp_read_sock
);
1551 * This routine copies from a sock struct into the user buffer.
1553 * Technical note: in 2.3 we work on _locked_ socket, so that
1554 * tricks with *seq access order and skb->users are not required.
1555 * Probably, code can be easily improved even more.
1558 int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1559 size_t len
, int nonblock
, int flags
, int *addr_len
)
1561 struct tcp_sock
*tp
= tcp_sk(sk
);
1567 int target
; /* Read at least this many bytes */
1569 struct task_struct
*user_recv
= NULL
;
1570 bool copied_early
= false;
1571 struct sk_buff
*skb
;
1574 if (sk_can_busy_loop(sk
) && skb_queue_empty(&sk
->sk_receive_queue
) &&
1575 (sk
->sk_state
== TCP_ESTABLISHED
))
1576 sk_busy_loop(sk
, nonblock
);
1581 if (sk
->sk_state
== TCP_LISTEN
)
1584 timeo
= sock_rcvtimeo(sk
, nonblock
);
1586 /* Urgent data needs to be handled specially. */
1587 if (flags
& MSG_OOB
)
1590 if (unlikely(tp
->repair
)) {
1592 if (!(flags
& MSG_PEEK
))
1595 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
1599 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1602 /* 'common' recv queue MSG_PEEK-ing */
1605 seq
= &tp
->copied_seq
;
1606 if (flags
& MSG_PEEK
) {
1607 peek_seq
= tp
->copied_seq
;
1611 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1613 #ifdef CONFIG_NET_DMA
1614 tp
->ucopy
.dma_chan
= NULL
;
1616 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
1621 available
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- (*seq
);
1622 if ((available
< target
) &&
1623 (len
> sysctl_tcp_dma_copybreak
) && !(flags
& MSG_PEEK
) &&
1624 !sysctl_tcp_low_latency
&&
1625 net_dma_find_channel()) {
1626 preempt_enable_no_resched();
1627 tp
->ucopy
.pinned_list
=
1628 dma_pin_iovec_pages(msg
->msg_iov
, len
);
1630 preempt_enable_no_resched();
1638 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1639 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1642 if (signal_pending(current
)) {
1643 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1648 /* Next get a buffer. */
1650 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1651 /* Now that we have two receive queues this
1654 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1655 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1656 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1660 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1661 if (tcp_hdr(skb
)->syn
)
1663 if (offset
< skb
->len
)
1665 if (tcp_hdr(skb
)->fin
)
1667 WARN(!(flags
& MSG_PEEK
),
1668 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1669 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
, flags
);
1672 /* Well, if we have backlog, try to process it now yet. */
1674 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1679 sk
->sk_state
== TCP_CLOSE
||
1680 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1682 signal_pending(current
))
1685 if (sock_flag(sk
, SOCK_DONE
))
1689 copied
= sock_error(sk
);
1693 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1696 if (sk
->sk_state
== TCP_CLOSE
) {
1697 if (!sock_flag(sk
, SOCK_DONE
)) {
1698 /* This occurs when user tries to read
1699 * from never connected socket.
1712 if (signal_pending(current
)) {
1713 copied
= sock_intr_errno(timeo
);
1718 tcp_cleanup_rbuf(sk
, copied
);
1720 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1721 /* Install new reader */
1722 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1723 user_recv
= current
;
1724 tp
->ucopy
.task
= user_recv
;
1725 tp
->ucopy
.iov
= msg
->msg_iov
;
1728 tp
->ucopy
.len
= len
;
1730 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1731 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1733 /* Ugly... If prequeue is not empty, we have to
1734 * process it before releasing socket, otherwise
1735 * order will be broken at second iteration.
1736 * More elegant solution is required!!!
1738 * Look: we have the following (pseudo)queues:
1740 * 1. packets in flight
1745 * Each queue can be processed only if the next ones
1746 * are empty. At this point we have empty receive_queue.
1747 * But prequeue _can_ be not empty after 2nd iteration,
1748 * when we jumped to start of loop because backlog
1749 * processing added something to receive_queue.
1750 * We cannot release_sock(), because backlog contains
1751 * packets arrived _after_ prequeued ones.
1753 * Shortly, algorithm is clear --- to process all
1754 * the queues in order. We could make it more directly,
1755 * requeueing packets from backlog to prequeue, if
1756 * is not empty. It is more elegant, but eats cycles,
1759 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1762 /* __ Set realtime policy in scheduler __ */
1765 #ifdef CONFIG_NET_DMA
1766 if (tp
->ucopy
.dma_chan
) {
1767 if (tp
->rcv_wnd
== 0 &&
1768 !skb_queue_empty(&sk
->sk_async_wait_queue
)) {
1769 tcp_service_net_dma(sk
, true);
1770 tcp_cleanup_rbuf(sk
, copied
);
1772 dma_async_issue_pending(tp
->ucopy
.dma_chan
);
1775 if (copied
>= target
) {
1776 /* Do not sleep, just process backlog. */
1780 sk_wait_data(sk
, &timeo
);
1782 #ifdef CONFIG_NET_DMA
1783 tcp_service_net_dma(sk
, false); /* Don't block */
1784 tp
->ucopy
.wakeup
= 0;
1790 /* __ Restore normal policy in scheduler __ */
1792 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1793 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1798 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1799 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1801 tcp_prequeue_process(sk
);
1803 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1804 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1810 if ((flags
& MSG_PEEK
) &&
1811 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1812 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1814 task_pid_nr(current
));
1815 peek_seq
= tp
->copied_seq
;
1820 /* Ok so how much can we use? */
1821 used
= skb
->len
- offset
;
1825 /* Do we have urgent data here? */
1827 u32 urg_offset
= tp
->urg_seq
- *seq
;
1828 if (urg_offset
< used
) {
1830 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1843 if (!(flags
& MSG_TRUNC
)) {
1844 #ifdef CONFIG_NET_DMA
1845 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
1846 tp
->ucopy
.dma_chan
= net_dma_find_channel();
1848 if (tp
->ucopy
.dma_chan
) {
1849 tp
->ucopy
.dma_cookie
= dma_skb_copy_datagram_iovec(
1850 tp
->ucopy
.dma_chan
, skb
, offset
,
1852 tp
->ucopy
.pinned_list
);
1854 if (tp
->ucopy
.dma_cookie
< 0) {
1856 pr_alert("%s: dma_cookie < 0\n",
1859 /* Exception. Bailout! */
1865 dma_async_issue_pending(tp
->ucopy
.dma_chan
);
1867 if ((offset
+ used
) == skb
->len
)
1868 copied_early
= true;
1873 err
= skb_copy_datagram_iovec(skb
, offset
,
1874 msg
->msg_iov
, used
);
1876 /* Exception. Bailout! */
1888 tcp_rcv_space_adjust(sk
);
1891 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1893 tcp_fast_path_check(sk
);
1895 if (used
+ offset
< skb
->len
)
1898 if (tcp_hdr(skb
)->fin
)
1900 if (!(flags
& MSG_PEEK
)) {
1901 sk_eat_skb(sk
, skb
, copied_early
);
1902 copied_early
= false;
1907 /* Process the FIN. */
1909 if (!(flags
& MSG_PEEK
)) {
1910 sk_eat_skb(sk
, skb
, copied_early
);
1911 copied_early
= false;
1917 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1920 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1922 tcp_prequeue_process(sk
);
1924 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1925 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1931 tp
->ucopy
.task
= NULL
;
1935 #ifdef CONFIG_NET_DMA
1936 tcp_service_net_dma(sk
, true); /* Wait for queue to drain */
1937 tp
->ucopy
.dma_chan
= NULL
;
1939 if (tp
->ucopy
.pinned_list
) {
1940 dma_unpin_iovec_pages(tp
->ucopy
.pinned_list
);
1941 tp
->ucopy
.pinned_list
= NULL
;
1945 /* According to UNIX98, msg_name/msg_namelen are ignored
1946 * on connected socket. I was just happy when found this 8) --ANK
1949 /* Clean up data we have read: This will do ACK frames. */
1950 tcp_cleanup_rbuf(sk
, copied
);
1960 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1964 err
= tcp_peek_sndq(sk
, msg
, len
);
1967 EXPORT_SYMBOL(tcp_recvmsg
);
1969 void tcp_set_state(struct sock
*sk
, int state
)
1971 int oldstate
= sk
->sk_state
;
1974 case TCP_ESTABLISHED
:
1975 if (oldstate
!= TCP_ESTABLISHED
)
1976 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1980 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1981 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1983 sk
->sk_prot
->unhash(sk
);
1984 if (inet_csk(sk
)->icsk_bind_hash
&&
1985 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1989 if (oldstate
== TCP_ESTABLISHED
)
1990 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1993 /* Change state AFTER socket is unhashed to avoid closed
1994 * socket sitting in hash tables.
1996 sk
->sk_state
= state
;
1999 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
2002 EXPORT_SYMBOL_GPL(tcp_set_state
);
2005 * State processing on a close. This implements the state shift for
2006 * sending our FIN frame. Note that we only send a FIN for some
2007 * states. A shutdown() may have already sent the FIN, or we may be
2011 static const unsigned char new_state
[16] = {
2012 /* current state: new state: action: */
2013 /* (Invalid) */ TCP_CLOSE
,
2014 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
2015 /* TCP_SYN_SENT */ TCP_CLOSE
,
2016 /* TCP_SYN_RECV */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
2017 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1
,
2018 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2
,
2019 /* TCP_TIME_WAIT */ TCP_CLOSE
,
2020 /* TCP_CLOSE */ TCP_CLOSE
,
2021 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK
| TCP_ACTION_FIN
,
2022 /* TCP_LAST_ACK */ TCP_LAST_ACK
,
2023 /* TCP_LISTEN */ TCP_CLOSE
,
2024 /* TCP_CLOSING */ TCP_CLOSING
,
2027 static int tcp_close_state(struct sock
*sk
)
2029 int next
= (int)new_state
[sk
->sk_state
];
2030 int ns
= next
& TCP_STATE_MASK
;
2032 tcp_set_state(sk
, ns
);
2034 return next
& TCP_ACTION_FIN
;
2038 * Shutdown the sending side of a connection. Much like close except
2039 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
2042 void tcp_shutdown(struct sock
*sk
, int how
)
2044 /* We need to grab some memory, and put together a FIN,
2045 * and then put it into the queue to be sent.
2046 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
2048 if (!(how
& SEND_SHUTDOWN
))
2051 /* If we've already sent a FIN, or it's a closed state, skip this. */
2052 if ((1 << sk
->sk_state
) &
2053 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
2054 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
2055 /* Clear out any half completed packets. FIN if needed. */
2056 if (tcp_close_state(sk
))
2060 EXPORT_SYMBOL(tcp_shutdown
);
2062 bool tcp_check_oom(struct sock
*sk
, int shift
)
2064 bool too_many_orphans
, out_of_socket_memory
;
2066 too_many_orphans
= tcp_too_many_orphans(sk
, shift
);
2067 out_of_socket_memory
= tcp_out_of_memory(sk
);
2069 if (too_many_orphans
)
2070 net_info_ratelimited("too many orphaned sockets\n");
2071 if (out_of_socket_memory
)
2072 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2073 return too_many_orphans
|| out_of_socket_memory
;
2076 void tcp_close(struct sock
*sk
, long timeout
)
2078 struct sk_buff
*skb
;
2079 int data_was_unread
= 0;
2083 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2085 if (sk
->sk_state
== TCP_LISTEN
) {
2086 tcp_set_state(sk
, TCP_CLOSE
);
2089 inet_csk_listen_stop(sk
);
2091 goto adjudge_to_death
;
2094 /* We need to flush the recv. buffs. We do this only on the
2095 * descriptor close, not protocol-sourced closes, because the
2096 * reader process may not have drained the data yet!
2098 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
2099 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
-
2101 data_was_unread
+= len
;
2107 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2108 if (sk
->sk_state
== TCP_CLOSE
)
2109 goto adjudge_to_death
;
2111 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2112 * data was lost. To witness the awful effects of the old behavior of
2113 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2114 * GET in an FTP client, suspend the process, wait for the client to
2115 * advertise a zero window, then kill -9 the FTP client, wheee...
2116 * Note: timeout is always zero in such a case.
2118 if (unlikely(tcp_sk(sk
)->repair
)) {
2119 sk
->sk_prot
->disconnect(sk
, 0);
2120 } else if (data_was_unread
) {
2121 /* Unread data was tossed, zap the connection. */
2122 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
2123 tcp_set_state(sk
, TCP_CLOSE
);
2124 tcp_send_active_reset(sk
, sk
->sk_allocation
);
2125 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
2126 /* Check zero linger _after_ checking for unread data. */
2127 sk
->sk_prot
->disconnect(sk
, 0);
2128 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
2129 } else if (tcp_close_state(sk
)) {
2130 /* We FIN if the application ate all the data before
2131 * zapping the connection.
2134 /* RED-PEN. Formally speaking, we have broken TCP state
2135 * machine. State transitions:
2137 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2138 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2139 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2141 * are legal only when FIN has been sent (i.e. in window),
2142 * rather than queued out of window. Purists blame.
2144 * F.e. "RFC state" is ESTABLISHED,
2145 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2147 * The visible declinations are that sometimes
2148 * we enter time-wait state, when it is not required really
2149 * (harmless), do not send active resets, when they are
2150 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2151 * they look as CLOSING or LAST_ACK for Linux)
2152 * Probably, I missed some more holelets.
2154 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2155 * in a single packet! (May consider it later but will
2156 * probably need API support or TCP_CORK SYN-ACK until
2157 * data is written and socket is closed.)
2162 sk_stream_wait_close(sk
, timeout
);
2165 state
= sk
->sk_state
;
2169 /* It is the last release_sock in its life. It will remove backlog. */
2173 /* Now socket is owned by kernel and we acquire BH lock
2174 to finish close. No need to check for user refs.
2178 WARN_ON(sock_owned_by_user(sk
));
2180 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
2182 /* Have we already been destroyed by a softirq or backlog? */
2183 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
2186 /* This is a (useful) BSD violating of the RFC. There is a
2187 * problem with TCP as specified in that the other end could
2188 * keep a socket open forever with no application left this end.
2189 * We use a 3 minute timeout (about the same as BSD) then kill
2190 * our end. If they send after that then tough - BUT: long enough
2191 * that we won't make the old 4*rto = almost no time - whoops
2194 * Nope, it was not mistake. It is really desired behaviour
2195 * f.e. on http servers, when such sockets are useless, but
2196 * consume significant resources. Let's do it with special
2197 * linger2 option. --ANK
2200 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
2201 struct tcp_sock
*tp
= tcp_sk(sk
);
2202 if (tp
->linger2
< 0) {
2203 tcp_set_state(sk
, TCP_CLOSE
);
2204 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2205 NET_INC_STATS_BH(sock_net(sk
),
2206 LINUX_MIB_TCPABORTONLINGER
);
2208 const int tmo
= tcp_fin_time(sk
);
2210 if (tmo
> TCP_TIMEWAIT_LEN
) {
2211 inet_csk_reset_keepalive_timer(sk
,
2212 tmo
- TCP_TIMEWAIT_LEN
);
2214 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2219 if (sk
->sk_state
!= TCP_CLOSE
) {
2221 if (tcp_check_oom(sk
, 0)) {
2222 tcp_set_state(sk
, TCP_CLOSE
);
2223 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2224 NET_INC_STATS_BH(sock_net(sk
),
2225 LINUX_MIB_TCPABORTONMEMORY
);
2229 if (sk
->sk_state
== TCP_CLOSE
) {
2230 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
2231 /* We could get here with a non-NULL req if the socket is
2232 * aborted (e.g., closed with unread data) before 3WHS
2236 reqsk_fastopen_remove(sk
, req
, false);
2237 inet_csk_destroy_sock(sk
);
2239 /* Otherwise, socket is reprieved until protocol close. */
2246 EXPORT_SYMBOL(tcp_close
);
2248 /* These states need RST on ABORT according to RFC793 */
2250 static inline bool tcp_need_reset(int state
)
2252 return (1 << state
) &
2253 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2254 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2257 int tcp_disconnect(struct sock
*sk
, int flags
)
2259 struct inet_sock
*inet
= inet_sk(sk
);
2260 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2261 struct tcp_sock
*tp
= tcp_sk(sk
);
2263 int old_state
= sk
->sk_state
;
2265 if (old_state
!= TCP_CLOSE
)
2266 tcp_set_state(sk
, TCP_CLOSE
);
2268 /* ABORT function of RFC793 */
2269 if (old_state
== TCP_LISTEN
) {
2270 inet_csk_listen_stop(sk
);
2271 } else if (unlikely(tp
->repair
)) {
2272 sk
->sk_err
= ECONNABORTED
;
2273 } else if (tcp_need_reset(old_state
) ||
2274 (tp
->snd_nxt
!= tp
->write_seq
&&
2275 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2276 /* The last check adjusts for discrepancy of Linux wrt. RFC
2279 tcp_send_active_reset(sk
, gfp_any());
2280 sk
->sk_err
= ECONNRESET
;
2281 } else if (old_state
== TCP_SYN_SENT
)
2282 sk
->sk_err
= ECONNRESET
;
2284 tcp_clear_xmit_timers(sk
);
2285 __skb_queue_purge(&sk
->sk_receive_queue
);
2286 tcp_write_queue_purge(sk
);
2287 __skb_queue_purge(&tp
->out_of_order_queue
);
2288 #ifdef CONFIG_NET_DMA
2289 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2292 inet
->inet_dport
= 0;
2294 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2295 inet_reset_saddr(sk
);
2297 sk
->sk_shutdown
= 0;
2298 sock_reset_flag(sk
, SOCK_DONE
);
2300 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2302 icsk
->icsk_backoff
= 0;
2304 icsk
->icsk_probes_out
= 0;
2305 tp
->packets_out
= 0;
2306 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2307 tp
->snd_cwnd_cnt
= 0;
2308 tp
->window_clamp
= 0;
2309 tcp_set_ca_state(sk
, TCP_CA_Open
);
2310 tcp_clear_retrans(tp
);
2311 inet_csk_delack_init(sk
);
2312 tcp_init_send_head(sk
);
2313 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2316 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2318 sk
->sk_error_report(sk
);
2321 EXPORT_SYMBOL(tcp_disconnect
);
2323 void tcp_sock_destruct(struct sock
*sk
)
2325 inet_sock_destruct(sk
);
2327 kfree(inet_csk(sk
)->icsk_accept_queue
.fastopenq
);
2330 static inline bool tcp_can_repair_sock(const struct sock
*sk
)
2332 return ns_capable(sock_net(sk
)->user_ns
, CAP_NET_ADMIN
) &&
2333 ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_ESTABLISHED
));
2336 static int tcp_repair_options_est(struct tcp_sock
*tp
,
2337 struct tcp_repair_opt __user
*optbuf
, unsigned int len
)
2339 struct tcp_repair_opt opt
;
2341 while (len
>= sizeof(opt
)) {
2342 if (copy_from_user(&opt
, optbuf
, sizeof(opt
)))
2348 switch (opt
.opt_code
) {
2350 tp
->rx_opt
.mss_clamp
= opt
.opt_val
;
2354 u16 snd_wscale
= opt
.opt_val
& 0xFFFF;
2355 u16 rcv_wscale
= opt
.opt_val
>> 16;
2357 if (snd_wscale
> 14 || rcv_wscale
> 14)
2360 tp
->rx_opt
.snd_wscale
= snd_wscale
;
2361 tp
->rx_opt
.rcv_wscale
= rcv_wscale
;
2362 tp
->rx_opt
.wscale_ok
= 1;
2365 case TCPOPT_SACK_PERM
:
2366 if (opt
.opt_val
!= 0)
2369 tp
->rx_opt
.sack_ok
|= TCP_SACK_SEEN
;
2370 if (sysctl_tcp_fack
)
2371 tcp_enable_fack(tp
);
2373 case TCPOPT_TIMESTAMP
:
2374 if (opt
.opt_val
!= 0)
2377 tp
->rx_opt
.tstamp_ok
= 1;
2386 * Socket option code for TCP.
2388 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2389 int optname
, char __user
*optval
, unsigned int optlen
)
2391 struct tcp_sock
*tp
= tcp_sk(sk
);
2392 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2396 /* These are data/string values, all the others are ints */
2398 case TCP_CONGESTION
: {
2399 char name
[TCP_CA_NAME_MAX
];
2404 val
= strncpy_from_user(name
, optval
,
2405 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2411 err
= tcp_set_congestion_control(sk
, name
);
2420 if (optlen
< sizeof(int))
2423 if (get_user(val
, (int __user
*)optval
))
2430 /* Values greater than interface MTU won't take effect. However
2431 * at the point when this call is done we typically don't yet
2432 * know which interface is going to be used */
2433 if (val
< TCP_MIN_MSS
|| val
> MAX_TCP_WINDOW
) {
2437 tp
->rx_opt
.user_mss
= val
;
2442 /* TCP_NODELAY is weaker than TCP_CORK, so that
2443 * this option on corked socket is remembered, but
2444 * it is not activated until cork is cleared.
2446 * However, when TCP_NODELAY is set we make
2447 * an explicit push, which overrides even TCP_CORK
2448 * for currently queued segments.
2450 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2451 tcp_push_pending_frames(sk
);
2453 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2457 case TCP_THIN_LINEAR_TIMEOUTS
:
2458 if (val
< 0 || val
> 1)
2464 case TCP_THIN_DUPACK
:
2465 if (val
< 0 || val
> 1)
2468 tp
->thin_dupack
= val
;
2469 if (tp
->thin_dupack
)
2470 tcp_disable_early_retrans(tp
);
2475 if (!tcp_can_repair_sock(sk
))
2477 else if (val
== 1) {
2479 sk
->sk_reuse
= SK_FORCE_REUSE
;
2480 tp
->repair_queue
= TCP_NO_QUEUE
;
2481 } else if (val
== 0) {
2483 sk
->sk_reuse
= SK_NO_REUSE
;
2484 tcp_send_window_probe(sk
);
2490 case TCP_REPAIR_QUEUE
:
2493 else if (val
< TCP_QUEUES_NR
)
2494 tp
->repair_queue
= val
;
2500 if (sk
->sk_state
!= TCP_CLOSE
)
2502 else if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2503 tp
->write_seq
= val
;
2504 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2510 case TCP_REPAIR_OPTIONS
:
2513 else if (sk
->sk_state
== TCP_ESTABLISHED
)
2514 err
= tcp_repair_options_est(tp
,
2515 (struct tcp_repair_opt __user
*)optval
,
2522 /* When set indicates to always queue non-full frames.
2523 * Later the user clears this option and we transmit
2524 * any pending partial frames in the queue. This is
2525 * meant to be used alongside sendfile() to get properly
2526 * filled frames when the user (for example) must write
2527 * out headers with a write() call first and then use
2528 * sendfile to send out the data parts.
2530 * TCP_CORK can be set together with TCP_NODELAY and it is
2531 * stronger than TCP_NODELAY.
2534 tp
->nonagle
|= TCP_NAGLE_CORK
;
2536 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2537 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2538 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2539 tcp_push_pending_frames(sk
);
2544 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2547 tp
->keepalive_time
= val
* HZ
;
2548 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2549 !((1 << sk
->sk_state
) &
2550 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2551 u32 elapsed
= keepalive_time_elapsed(tp
);
2552 if (tp
->keepalive_time
> elapsed
)
2553 elapsed
= tp
->keepalive_time
- elapsed
;
2556 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2561 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2564 tp
->keepalive_intvl
= val
* HZ
;
2567 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2570 tp
->keepalive_probes
= val
;
2573 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2576 icsk
->icsk_syn_retries
= val
;
2582 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2585 tp
->linger2
= val
* HZ
;
2588 case TCP_DEFER_ACCEPT
:
2589 /* Translate value in seconds to number of retransmits */
2590 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2591 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2595 case TCP_WINDOW_CLAMP
:
2597 if (sk
->sk_state
!= TCP_CLOSE
) {
2601 tp
->window_clamp
= 0;
2603 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2604 SOCK_MIN_RCVBUF
/ 2 : val
;
2609 icsk
->icsk_ack
.pingpong
= 1;
2611 icsk
->icsk_ack
.pingpong
= 0;
2612 if ((1 << sk
->sk_state
) &
2613 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2614 inet_csk_ack_scheduled(sk
)) {
2615 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2616 tcp_cleanup_rbuf(sk
, 1);
2618 icsk
->icsk_ack
.pingpong
= 1;
2623 #ifdef CONFIG_TCP_MD5SIG
2625 /* Read the IP->Key mappings from userspace */
2626 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2629 case TCP_USER_TIMEOUT
:
2630 /* Cap the max timeout in ms TCP will retry/retrans
2631 * before giving up and aborting (ETIMEDOUT) a connection.
2636 icsk
->icsk_user_timeout
= msecs_to_jiffies(val
);
2640 if (val
>= 0 && ((1 << sk
->sk_state
) & (TCPF_CLOSE
|
2642 err
= fastopen_init_queue(sk
, val
);
2650 tp
->tsoffset
= val
- tcp_time_stamp
;
2652 case TCP_NOTSENT_LOWAT
:
2653 tp
->notsent_lowat
= val
;
2654 sk
->sk_write_space(sk
);
2665 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2666 unsigned int optlen
)
2668 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2670 if (level
!= SOL_TCP
)
2671 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2673 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2675 EXPORT_SYMBOL(tcp_setsockopt
);
2677 #ifdef CONFIG_COMPAT
2678 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2679 char __user
*optval
, unsigned int optlen
)
2681 if (level
!= SOL_TCP
)
2682 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2684 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2686 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2689 /* Return information about state of tcp endpoint in API format. */
2690 void tcp_get_info(const struct sock
*sk
, struct tcp_info
*info
)
2692 const struct tcp_sock
*tp
= tcp_sk(sk
);
2693 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2694 u32 now
= tcp_time_stamp
;
2696 memset(info
, 0, sizeof(*info
));
2698 info
->tcpi_state
= sk
->sk_state
;
2699 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2700 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2701 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2702 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2704 if (tp
->rx_opt
.tstamp_ok
)
2705 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2706 if (tcp_is_sack(tp
))
2707 info
->tcpi_options
|= TCPI_OPT_SACK
;
2708 if (tp
->rx_opt
.wscale_ok
) {
2709 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2710 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2711 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2714 if (tp
->ecn_flags
& TCP_ECN_OK
)
2715 info
->tcpi_options
|= TCPI_OPT_ECN
;
2716 if (tp
->ecn_flags
& TCP_ECN_SEEN
)
2717 info
->tcpi_options
|= TCPI_OPT_ECN_SEEN
;
2718 if (tp
->syn_data_acked
)
2719 info
->tcpi_options
|= TCPI_OPT_SYN_DATA
;
2721 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2722 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2723 info
->tcpi_snd_mss
= tp
->mss_cache
;
2724 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2726 if (sk
->sk_state
== TCP_LISTEN
) {
2727 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2728 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2730 info
->tcpi_unacked
= tp
->packets_out
;
2731 info
->tcpi_sacked
= tp
->sacked_out
;
2733 info
->tcpi_lost
= tp
->lost_out
;
2734 info
->tcpi_retrans
= tp
->retrans_out
;
2735 info
->tcpi_fackets
= tp
->fackets_out
;
2737 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2738 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2739 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2741 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2742 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2743 info
->tcpi_rtt
= jiffies_to_usecs(tp
->srtt
)>>3;
2744 info
->tcpi_rttvar
= jiffies_to_usecs(tp
->mdev
)>>2;
2745 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2746 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2747 info
->tcpi_advmss
= tp
->advmss
;
2748 info
->tcpi_reordering
= tp
->reordering
;
2750 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2751 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2753 info
->tcpi_total_retrans
= tp
->total_retrans
;
2755 EXPORT_SYMBOL_GPL(tcp_get_info
);
2757 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2758 int optname
, char __user
*optval
, int __user
*optlen
)
2760 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2761 struct tcp_sock
*tp
= tcp_sk(sk
);
2764 if (get_user(len
, optlen
))
2767 len
= min_t(unsigned int, len
, sizeof(int));
2774 val
= tp
->mss_cache
;
2775 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2776 val
= tp
->rx_opt
.user_mss
;
2778 val
= tp
->rx_opt
.mss_clamp
;
2781 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2784 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2787 val
= keepalive_time_when(tp
) / HZ
;
2790 val
= keepalive_intvl_when(tp
) / HZ
;
2793 val
= keepalive_probes(tp
);
2796 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2801 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2803 case TCP_DEFER_ACCEPT
:
2804 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2805 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2807 case TCP_WINDOW_CLAMP
:
2808 val
= tp
->window_clamp
;
2811 struct tcp_info info
;
2813 if (get_user(len
, optlen
))
2816 tcp_get_info(sk
, &info
);
2818 len
= min_t(unsigned int, len
, sizeof(info
));
2819 if (put_user(len
, optlen
))
2821 if (copy_to_user(optval
, &info
, len
))
2826 val
= !icsk
->icsk_ack
.pingpong
;
2829 case TCP_CONGESTION
:
2830 if (get_user(len
, optlen
))
2832 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2833 if (put_user(len
, optlen
))
2835 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2839 case TCP_THIN_LINEAR_TIMEOUTS
:
2842 case TCP_THIN_DUPACK
:
2843 val
= tp
->thin_dupack
;
2850 case TCP_REPAIR_QUEUE
:
2852 val
= tp
->repair_queue
;
2858 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2859 val
= tp
->write_seq
;
2860 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2866 case TCP_USER_TIMEOUT
:
2867 val
= jiffies_to_msecs(icsk
->icsk_user_timeout
);
2870 val
= tcp_time_stamp
+ tp
->tsoffset
;
2872 case TCP_NOTSENT_LOWAT
:
2873 val
= tp
->notsent_lowat
;
2876 return -ENOPROTOOPT
;
2879 if (put_user(len
, optlen
))
2881 if (copy_to_user(optval
, &val
, len
))
2886 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2889 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2891 if (level
!= SOL_TCP
)
2892 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2894 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2896 EXPORT_SYMBOL(tcp_getsockopt
);
2898 #ifdef CONFIG_COMPAT
2899 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2900 char __user
*optval
, int __user
*optlen
)
2902 if (level
!= SOL_TCP
)
2903 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2905 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2907 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2910 #ifdef CONFIG_TCP_MD5SIG
2911 static struct tcp_md5sig_pool __percpu
*tcp_md5sig_pool __read_mostly
;
2912 static DEFINE_MUTEX(tcp_md5sig_mutex
);
2914 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu
*pool
)
2918 for_each_possible_cpu(cpu
) {
2919 struct tcp_md5sig_pool
*p
= per_cpu_ptr(pool
, cpu
);
2921 if (p
->md5_desc
.tfm
)
2922 crypto_free_hash(p
->md5_desc
.tfm
);
2927 static void __tcp_alloc_md5sig_pool(void)
2930 struct tcp_md5sig_pool __percpu
*pool
;
2932 pool
= alloc_percpu(struct tcp_md5sig_pool
);
2936 for_each_possible_cpu(cpu
) {
2937 struct crypto_hash
*hash
;
2939 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
2940 if (IS_ERR_OR_NULL(hash
))
2943 per_cpu_ptr(pool
, cpu
)->md5_desc
.tfm
= hash
;
2945 /* before setting tcp_md5sig_pool, we must commit all writes
2946 * to memory. See ACCESS_ONCE() in tcp_get_md5sig_pool()
2949 tcp_md5sig_pool
= pool
;
2952 __tcp_free_md5sig_pool(pool
);
2955 bool tcp_alloc_md5sig_pool(void)
2957 if (unlikely(!tcp_md5sig_pool
)) {
2958 mutex_lock(&tcp_md5sig_mutex
);
2960 if (!tcp_md5sig_pool
)
2961 __tcp_alloc_md5sig_pool();
2963 mutex_unlock(&tcp_md5sig_mutex
);
2965 return tcp_md5sig_pool
!= NULL
;
2967 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
2971 * tcp_get_md5sig_pool - get md5sig_pool for this user
2973 * We use percpu structure, so if we succeed, we exit with preemption
2974 * and BH disabled, to make sure another thread or softirq handling
2975 * wont try to get same context.
2977 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
2979 struct tcp_md5sig_pool __percpu
*p
;
2982 p
= ACCESS_ONCE(tcp_md5sig_pool
);
2984 return __this_cpu_ptr(p
);
2989 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
2991 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
2992 const struct tcphdr
*th
)
2994 struct scatterlist sg
;
2998 /* We are not allowed to change tcphdr, make a local copy */
2999 memcpy(&hdr
, th
, sizeof(hdr
));
3002 /* options aren't included in the hash */
3003 sg_init_one(&sg
, &hdr
, sizeof(hdr
));
3004 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(hdr
));
3007 EXPORT_SYMBOL(tcp_md5_hash_header
);
3009 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
3010 const struct sk_buff
*skb
, unsigned int header_len
)
3012 struct scatterlist sg
;
3013 const struct tcphdr
*tp
= tcp_hdr(skb
);
3014 struct hash_desc
*desc
= &hp
->md5_desc
;
3016 const unsigned int head_data_len
= skb_headlen(skb
) > header_len
?
3017 skb_headlen(skb
) - header_len
: 0;
3018 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
3019 struct sk_buff
*frag_iter
;
3021 sg_init_table(&sg
, 1);
3023 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
3024 if (crypto_hash_update(desc
, &sg
, head_data_len
))
3027 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
3028 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
3029 unsigned int offset
= f
->page_offset
;
3030 struct page
*page
= skb_frag_page(f
) + (offset
>> PAGE_SHIFT
);
3032 sg_set_page(&sg
, page
, skb_frag_size(f
),
3033 offset_in_page(offset
));
3034 if (crypto_hash_update(desc
, &sg
, skb_frag_size(f
)))
3038 skb_walk_frags(skb
, frag_iter
)
3039 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3044 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3046 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, const struct tcp_md5sig_key
*key
)
3048 struct scatterlist sg
;
3050 sg_init_one(&sg
, key
->key
, key
->keylen
);
3051 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3053 EXPORT_SYMBOL(tcp_md5_hash_key
);
3057 void tcp_done(struct sock
*sk
)
3059 struct request_sock
*req
= tcp_sk(sk
)->fastopen_rsk
;
3061 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3062 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3064 tcp_set_state(sk
, TCP_CLOSE
);
3065 tcp_clear_xmit_timers(sk
);
3067 reqsk_fastopen_remove(sk
, req
, false);
3069 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3071 if (!sock_flag(sk
, SOCK_DEAD
))
3072 sk
->sk_state_change(sk
);
3074 inet_csk_destroy_sock(sk
);
3076 EXPORT_SYMBOL_GPL(tcp_done
);
3078 extern struct tcp_congestion_ops tcp_reno
;
3080 static __initdata
unsigned long thash_entries
;
3081 static int __init
set_thash_entries(char *str
)
3088 ret
= kstrtoul(str
, 0, &thash_entries
);
3094 __setup("thash_entries=", set_thash_entries
);
3096 static void tcp_init_mem(void)
3098 unsigned long limit
= nr_free_buffer_pages() / 8;
3099 limit
= max(limit
, 128UL);
3100 sysctl_tcp_mem
[0] = limit
/ 4 * 3;
3101 sysctl_tcp_mem
[1] = limit
;
3102 sysctl_tcp_mem
[2] = sysctl_tcp_mem
[0] * 2;
3105 void __init
tcp_init(void)
3107 struct sk_buff
*skb
= NULL
;
3108 unsigned long limit
;
3109 int max_rshare
, max_wshare
, cnt
;
3112 BUILD_BUG_ON(sizeof(struct tcp_skb_cb
) > sizeof(skb
->cb
));
3114 percpu_counter_init(&tcp_sockets_allocated
, 0);
3115 percpu_counter_init(&tcp_orphan_count
, 0);
3116 tcp_hashinfo
.bind_bucket_cachep
=
3117 kmem_cache_create("tcp_bind_bucket",
3118 sizeof(struct inet_bind_bucket
), 0,
3119 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3121 /* Size and allocate the main established and bind bucket
3124 * The methodology is similar to that of the buffer cache.
3126 tcp_hashinfo
.ehash
=
3127 alloc_large_system_hash("TCP established",
3128 sizeof(struct inet_ehash_bucket
),
3130 17, /* one slot per 128 KB of memory */
3133 &tcp_hashinfo
.ehash_mask
,
3135 thash_entries
? 0 : 512 * 1024);
3136 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++)
3137 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3139 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3140 panic("TCP: failed to alloc ehash_locks");
3141 tcp_hashinfo
.bhash
=
3142 alloc_large_system_hash("TCP bind",
3143 sizeof(struct inet_bind_hashbucket
),
3144 tcp_hashinfo
.ehash_mask
+ 1,
3145 17, /* one slot per 128 KB of memory */
3147 &tcp_hashinfo
.bhash_size
,
3151 tcp_hashinfo
.bhash_size
= 1U << tcp_hashinfo
.bhash_size
;
3152 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3153 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3154 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3158 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
3160 tcp_death_row
.sysctl_max_tw_buckets
= cnt
/ 2;
3161 sysctl_tcp_max_orphans
= cnt
/ 2;
3162 sysctl_max_syn_backlog
= max(128, cnt
/ 256);
3165 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3166 limit
= nr_free_buffer_pages() << (PAGE_SHIFT
- 7);
3167 max_wshare
= min(4UL*1024*1024, limit
);
3168 max_rshare
= min(6UL*1024*1024, limit
);
3170 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3171 sysctl_tcp_wmem
[1] = 16*1024;
3172 sysctl_tcp_wmem
[2] = max(64*1024, max_wshare
);
3174 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3175 sysctl_tcp_rmem
[1] = 87380;
3176 sysctl_tcp_rmem
[2] = max(87380, max_rshare
);
3178 pr_info("Hash tables configured (established %u bind %u)\n",
3179 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3183 tcp_register_congestion_control(&tcp_reno
);