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 #include <linux/kernel.h>
249 #include <linux/module.h>
250 #include <linux/types.h>
251 #include <linux/fcntl.h>
252 #include <linux/poll.h>
253 #include <linux/init.h>
254 #include <linux/fs.h>
255 #include <linux/skbuff.h>
256 #include <linux/scatterlist.h>
257 #include <linux/splice.h>
258 #include <linux/net.h>
259 #include <linux/socket.h>
260 #include <linux/random.h>
261 #include <linux/bootmem.h>
262 #include <linux/highmem.h>
263 #include <linux/swap.h>
264 #include <linux/cache.h>
265 #include <linux/err.h>
266 #include <linux/crypto.h>
268 #include <net/icmp.h>
270 #include <net/xfrm.h>
272 #include <net/netdma.h>
273 #include <net/sock.h>
275 #include <asm/uaccess.h>
276 #include <asm/ioctls.h>
278 int sysctl_tcp_fin_timeout __read_mostly
= TCP_FIN_TIMEOUT
;
280 struct percpu_counter tcp_orphan_count
;
281 EXPORT_SYMBOL_GPL(tcp_orphan_count
);
283 int sysctl_tcp_mem
[3] __read_mostly
;
284 int sysctl_tcp_wmem
[3] __read_mostly
;
285 int sysctl_tcp_rmem
[3] __read_mostly
;
287 EXPORT_SYMBOL(sysctl_tcp_mem
);
288 EXPORT_SYMBOL(sysctl_tcp_rmem
);
289 EXPORT_SYMBOL(sysctl_tcp_wmem
);
291 atomic_t tcp_memory_allocated
; /* Current allocated memory. */
292 EXPORT_SYMBOL(tcp_memory_allocated
);
295 * Current number of TCP sockets.
297 struct percpu_counter tcp_sockets_allocated
;
298 EXPORT_SYMBOL(tcp_sockets_allocated
);
303 struct tcp_splice_state
{
304 struct pipe_inode_info
*pipe
;
310 * Pressure flag: try to collapse.
311 * Technical note: it is used by multiple contexts non atomically.
312 * All the __sk_mem_schedule() is of this nature: accounting
313 * is strict, actions are advisory and have some latency.
315 int tcp_memory_pressure __read_mostly
;
317 EXPORT_SYMBOL(tcp_memory_pressure
);
319 void tcp_enter_memory_pressure(struct sock
*sk
)
321 if (!tcp_memory_pressure
) {
322 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMEMORYPRESSURES
);
323 tcp_memory_pressure
= 1;
327 EXPORT_SYMBOL(tcp_enter_memory_pressure
);
330 * Wait for a TCP event.
332 * Note that we don't need to lock the socket, as the upper poll layers
333 * take care of normal races (between the test and the event) and we don't
334 * go look at any of the socket buffers directly.
336 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
339 struct sock
*sk
= sock
->sk
;
340 struct tcp_sock
*tp
= tcp_sk(sk
);
342 sock_poll_wait(file
, sk
->sk_sleep
, wait
);
343 if (sk
->sk_state
== TCP_LISTEN
)
344 return inet_csk_listen_poll(sk
);
346 /* Socket is not locked. We are protected from async events
347 * by poll logic and correct handling of state changes
348 * made by other threads is impossible in any case.
356 * POLLHUP is certainly not done right. But poll() doesn't
357 * have a notion of HUP in just one direction, and for a
358 * socket the read side is more interesting.
360 * Some poll() documentation says that POLLHUP is incompatible
361 * with the POLLOUT/POLLWR flags, so somebody should check this
362 * all. But careful, it tends to be safer to return too many
363 * bits than too few, and you can easily break real applications
364 * if you don't tell them that something has hung up!
368 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
369 * our fs/select.c). It means that after we received EOF,
370 * poll always returns immediately, making impossible poll() on write()
371 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
372 * if and only if shutdown has been made in both directions.
373 * Actually, it is interesting to look how Solaris and DUX
374 * solve this dilemma. I would prefer, if POLLHUP were maskable,
375 * then we could set it on SND_SHUTDOWN. BTW examples given
376 * in Stevens' books assume exactly this behaviour, it explains
377 * why POLLHUP is incompatible with POLLOUT. --ANK
379 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
380 * blocking on fresh not-connected or disconnected socket. --ANK
382 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== TCP_CLOSE
)
384 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
385 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
388 if ((1 << sk
->sk_state
) & ~(TCPF_SYN_SENT
| TCPF_SYN_RECV
)) {
389 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
391 if (tp
->urg_seq
== tp
->copied_seq
&&
392 !sock_flag(sk
, SOCK_URGINLINE
) &&
396 /* Potential race condition. If read of tp below will
397 * escape above sk->sk_state, we can be illegally awaken
398 * in SYN_* states. */
399 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
400 mask
|= POLLIN
| POLLRDNORM
;
402 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
403 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
)) {
404 mask
|= POLLOUT
| POLLWRNORM
;
405 } else { /* send SIGIO later */
406 set_bit(SOCK_ASYNC_NOSPACE
,
407 &sk
->sk_socket
->flags
);
408 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
410 /* Race breaker. If space is freed after
411 * wspace test but before the flags are set,
412 * IO signal will be lost.
414 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
))
415 mask
|= POLLOUT
| POLLWRNORM
;
419 if (tp
->urg_data
& TCP_URG_VALID
)
425 int tcp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
427 struct tcp_sock
*tp
= tcp_sk(sk
);
432 if (sk
->sk_state
== TCP_LISTEN
)
436 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
438 else if (sock_flag(sk
, SOCK_URGINLINE
) ||
440 before(tp
->urg_seq
, tp
->copied_seq
) ||
441 !before(tp
->urg_seq
, tp
->rcv_nxt
)) {
444 answ
= tp
->rcv_nxt
- tp
->copied_seq
;
446 /* Subtract 1, if FIN is in queue. */
447 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
449 answ
-= tcp_hdr(skb
)->fin
;
451 answ
= tp
->urg_seq
- tp
->copied_seq
;
455 answ
= tp
->urg_data
&& tp
->urg_seq
== tp
->copied_seq
;
458 if (sk
->sk_state
== TCP_LISTEN
)
461 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
464 answ
= tp
->write_seq
- tp
->snd_una
;
470 return put_user(answ
, (int __user
*)arg
);
473 static inline void tcp_mark_push(struct tcp_sock
*tp
, struct sk_buff
*skb
)
475 TCP_SKB_CB(skb
)->flags
|= TCPCB_FLAG_PSH
;
476 tp
->pushed_seq
= tp
->write_seq
;
479 static inline int forced_push(struct tcp_sock
*tp
)
481 return after(tp
->write_seq
, tp
->pushed_seq
+ (tp
->max_window
>> 1));
484 static inline void skb_entail(struct sock
*sk
, struct sk_buff
*skb
)
486 struct tcp_sock
*tp
= tcp_sk(sk
);
487 struct tcp_skb_cb
*tcb
= TCP_SKB_CB(skb
);
490 tcb
->seq
= tcb
->end_seq
= tp
->write_seq
;
491 tcb
->flags
= TCPCB_FLAG_ACK
;
493 skb_header_release(skb
);
494 tcp_add_write_queue_tail(sk
, skb
);
495 sk
->sk_wmem_queued
+= skb
->truesize
;
496 sk_mem_charge(sk
, skb
->truesize
);
497 if (tp
->nonagle
& TCP_NAGLE_PUSH
)
498 tp
->nonagle
&= ~TCP_NAGLE_PUSH
;
501 static inline void tcp_mark_urg(struct tcp_sock
*tp
, int flags
,
505 tp
->snd_up
= tp
->write_seq
;
508 static inline void tcp_push(struct sock
*sk
, int flags
, int mss_now
,
511 struct tcp_sock
*tp
= tcp_sk(sk
);
513 if (tcp_send_head(sk
)) {
514 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
515 if (!(flags
& MSG_MORE
) || forced_push(tp
))
516 tcp_mark_push(tp
, skb
);
517 tcp_mark_urg(tp
, flags
, skb
);
518 __tcp_push_pending_frames(sk
, mss_now
,
519 (flags
& MSG_MORE
) ? TCP_NAGLE_CORK
: nonagle
);
523 static int tcp_splice_data_recv(read_descriptor_t
*rd_desc
, struct sk_buff
*skb
,
524 unsigned int offset
, size_t len
)
526 struct tcp_splice_state
*tss
= rd_desc
->arg
.data
;
529 ret
= skb_splice_bits(skb
, offset
, tss
->pipe
, min(rd_desc
->count
, len
),
532 rd_desc
->count
-= ret
;
536 static int __tcp_splice_read(struct sock
*sk
, struct tcp_splice_state
*tss
)
538 /* Store TCP splice context information in read_descriptor_t. */
539 read_descriptor_t rd_desc
= {
544 return tcp_read_sock(sk
, &rd_desc
, tcp_splice_data_recv
);
548 * tcp_splice_read - splice data from TCP socket to a pipe
549 * @sock: socket to splice from
550 * @ppos: position (not valid)
551 * @pipe: pipe to splice to
552 * @len: number of bytes to splice
553 * @flags: splice modifier flags
556 * Will read pages from given socket and fill them into a pipe.
559 ssize_t
tcp_splice_read(struct socket
*sock
, loff_t
*ppos
,
560 struct pipe_inode_info
*pipe
, size_t len
,
563 struct sock
*sk
= sock
->sk
;
564 struct tcp_splice_state tss
= {
574 * We can't seek on a socket input
583 timeo
= sock_rcvtimeo(sk
, sock
->file
->f_flags
& O_NONBLOCK
);
585 ret
= __tcp_splice_read(sk
, &tss
);
591 if (sock_flag(sk
, SOCK_DONE
))
594 ret
= sock_error(sk
);
597 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
599 if (sk
->sk_state
== TCP_CLOSE
) {
601 * This occurs when user tries to read
602 * from never connected socket.
604 if (!sock_flag(sk
, SOCK_DONE
))
612 sk_wait_data(sk
, &timeo
);
613 if (signal_pending(current
)) {
614 ret
= sock_intr_errno(timeo
);
627 if (sk
->sk_err
|| sk
->sk_state
== TCP_CLOSE
||
628 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
629 signal_pending(current
))
641 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
)
645 /* The TCP header must be at least 32-bit aligned. */
646 size
= ALIGN(size
, 4);
648 skb
= alloc_skb_fclone(size
+ sk
->sk_prot
->max_header
, gfp
);
650 if (sk_wmem_schedule(sk
, skb
->truesize
)) {
652 * Make sure that we have exactly size bytes
653 * available to the caller, no more, no less.
655 skb_reserve(skb
, skb_tailroom(skb
) - size
);
660 sk
->sk_prot
->enter_memory_pressure(sk
);
661 sk_stream_moderate_sndbuf(sk
);
666 static unsigned int tcp_xmit_size_goal(struct sock
*sk
, u32 mss_now
,
669 struct tcp_sock
*tp
= tcp_sk(sk
);
670 u32 xmit_size_goal
, old_size_goal
;
672 xmit_size_goal
= mss_now
;
674 if (large_allowed
&& sk_can_gso(sk
)) {
675 xmit_size_goal
= ((sk
->sk_gso_max_size
- 1) -
676 inet_csk(sk
)->icsk_af_ops
->net_header_len
-
677 inet_csk(sk
)->icsk_ext_hdr_len
-
680 xmit_size_goal
= tcp_bound_to_half_wnd(tp
, xmit_size_goal
);
682 /* We try hard to avoid divides here */
683 old_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
685 if (likely(old_size_goal
<= xmit_size_goal
&&
686 old_size_goal
+ mss_now
> xmit_size_goal
)) {
687 xmit_size_goal
= old_size_goal
;
689 tp
->xmit_size_goal_segs
= xmit_size_goal
/ mss_now
;
690 xmit_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
694 return max(xmit_size_goal
, mss_now
);
697 static int tcp_send_mss(struct sock
*sk
, int *size_goal
, int flags
)
701 mss_now
= tcp_current_mss(sk
);
702 *size_goal
= tcp_xmit_size_goal(sk
, mss_now
, !(flags
& MSG_OOB
));
707 static ssize_t
do_tcp_sendpages(struct sock
*sk
, struct page
**pages
, int poffset
,
708 size_t psize
, int flags
)
710 struct tcp_sock
*tp
= tcp_sk(sk
);
711 int mss_now
, size_goal
;
714 long timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
716 /* Wait for a connection to finish. */
717 if ((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
))
718 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
721 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
723 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
727 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
731 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
732 struct page
*page
= pages
[poffset
/ PAGE_SIZE
];
733 int copy
, i
, can_coalesce
;
734 int offset
= poffset
% PAGE_SIZE
;
735 int size
= min_t(size_t, psize
, PAGE_SIZE
- offset
);
737 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
739 if (!sk_stream_memory_free(sk
))
740 goto wait_for_sndbuf
;
742 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
);
744 goto wait_for_memory
;
753 i
= skb_shinfo(skb
)->nr_frags
;
754 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
755 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
756 tcp_mark_push(tp
, skb
);
759 if (!sk_wmem_schedule(sk
, copy
))
760 goto wait_for_memory
;
763 skb_shinfo(skb
)->frags
[i
- 1].size
+= copy
;
766 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
770 skb
->data_len
+= copy
;
771 skb
->truesize
+= copy
;
772 sk
->sk_wmem_queued
+= copy
;
773 sk_mem_charge(sk
, copy
);
774 skb
->ip_summed
= CHECKSUM_PARTIAL
;
775 tp
->write_seq
+= copy
;
776 TCP_SKB_CB(skb
)->end_seq
+= copy
;
777 skb_shinfo(skb
)->gso_segs
= 0;
780 TCP_SKB_CB(skb
)->flags
&= ~TCPCB_FLAG_PSH
;
784 if (!(psize
-= copy
))
787 if (skb
->len
< size_goal
|| (flags
& MSG_OOB
))
790 if (forced_push(tp
)) {
791 tcp_mark_push(tp
, skb
);
792 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
793 } else if (skb
== tcp_send_head(sk
))
794 tcp_push_one(sk
, mss_now
);
798 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
801 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
803 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
806 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
811 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
818 return sk_stream_error(sk
, flags
, err
);
821 ssize_t
tcp_sendpage(struct socket
*sock
, struct page
*page
, int offset
,
822 size_t size
, int flags
)
825 struct sock
*sk
= sock
->sk
;
827 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
828 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
829 return sock_no_sendpage(sock
, page
, offset
, size
, flags
);
833 res
= do_tcp_sendpages(sk
, &page
, offset
, size
, flags
);
839 #define TCP_PAGE(sk) (sk->sk_sndmsg_page)
840 #define TCP_OFF(sk) (sk->sk_sndmsg_off)
842 static inline int select_size(struct sock
*sk
)
844 struct tcp_sock
*tp
= tcp_sk(sk
);
845 int tmp
= tp
->mss_cache
;
847 if (sk
->sk_route_caps
& NETIF_F_SG
) {
851 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
853 if (tmp
>= pgbreak
&&
854 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
862 int tcp_sendmsg(struct kiocb
*iocb
, struct socket
*sock
, struct msghdr
*msg
,
865 struct sock
*sk
= sock
->sk
;
867 struct tcp_sock
*tp
= tcp_sk(sk
);
870 int mss_now
, size_goal
;
877 flags
= msg
->msg_flags
;
878 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
880 /* Wait for a connection to finish. */
881 if ((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
))
882 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
885 /* This should be in poll */
886 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
888 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
890 /* Ok commence sending. */
891 iovlen
= msg
->msg_iovlen
;
896 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
899 while (--iovlen
>= 0) {
900 int seglen
= iov
->iov_len
;
901 unsigned char __user
*from
= iov
->iov_base
;
909 skb
= tcp_write_queue_tail(sk
);
910 if (tcp_send_head(sk
)) {
911 if (skb
->ip_summed
== CHECKSUM_NONE
)
913 copy
= max
- skb
->len
;
918 /* Allocate new segment. If the interface is SG,
919 * allocate skb fitting to single page.
921 if (!sk_stream_memory_free(sk
))
922 goto wait_for_sndbuf
;
924 skb
= sk_stream_alloc_skb(sk
, select_size(sk
),
927 goto wait_for_memory
;
930 * Check whether we can use HW checksum.
932 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
933 skb
->ip_summed
= CHECKSUM_PARTIAL
;
940 /* Try to append data to the end of skb. */
944 /* Where to copy to? */
945 if (skb_tailroom(skb
) > 0) {
946 /* We have some space in skb head. Superb! */
947 if (copy
> skb_tailroom(skb
))
948 copy
= skb_tailroom(skb
);
949 if ((err
= skb_add_data(skb
, from
, copy
)) != 0)
953 int i
= skb_shinfo(skb
)->nr_frags
;
954 struct page
*page
= TCP_PAGE(sk
);
955 int off
= TCP_OFF(sk
);
957 if (skb_can_coalesce(skb
, i
, page
, off
) &&
959 /* We can extend the last page
962 } else if (i
== MAX_SKB_FRAGS
||
964 !(sk
->sk_route_caps
& NETIF_F_SG
))) {
965 /* Need to add new fragment and cannot
966 * do this because interface is non-SG,
967 * or because all the page slots are
969 tcp_mark_push(tp
, skb
);
972 if (off
== PAGE_SIZE
) {
974 TCP_PAGE(sk
) = page
= NULL
;
980 if (copy
> PAGE_SIZE
- off
)
981 copy
= PAGE_SIZE
- off
;
983 if (!sk_wmem_schedule(sk
, copy
))
984 goto wait_for_memory
;
987 /* Allocate new cache page. */
988 if (!(page
= sk_stream_alloc_page(sk
)))
989 goto wait_for_memory
;
992 /* Time to copy data. We are close to
994 err
= skb_copy_to_page(sk
, from
, skb
, page
,
997 /* If this page was new, give it to the
998 * socket so it does not get leaked.
1000 if (!TCP_PAGE(sk
)) {
1001 TCP_PAGE(sk
) = page
;
1007 /* Update the skb. */
1009 skb_shinfo(skb
)->frags
[i
- 1].size
+=
1012 skb_fill_page_desc(skb
, i
, page
, off
, copy
);
1015 } else if (off
+ copy
< PAGE_SIZE
) {
1017 TCP_PAGE(sk
) = page
;
1021 TCP_OFF(sk
) = off
+ copy
;
1025 TCP_SKB_CB(skb
)->flags
&= ~TCPCB_FLAG_PSH
;
1027 tp
->write_seq
+= copy
;
1028 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1029 skb_shinfo(skb
)->gso_segs
= 0;
1033 if ((seglen
-= copy
) == 0 && iovlen
== 0)
1036 if (skb
->len
< max
|| (flags
& MSG_OOB
))
1039 if (forced_push(tp
)) {
1040 tcp_mark_push(tp
, skb
);
1041 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1042 } else if (skb
== tcp_send_head(sk
))
1043 tcp_push_one(sk
, mss_now
);
1047 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1050 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
1052 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1055 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1061 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
1062 TCP_CHECK_TIMER(sk
);
1068 tcp_unlink_write_queue(skb
, sk
);
1069 /* It is the one place in all of TCP, except connection
1070 * reset, where we can be unlinking the send_head.
1072 tcp_check_send_head(sk
, skb
);
1073 sk_wmem_free_skb(sk
, skb
);
1080 err
= sk_stream_error(sk
, flags
, err
);
1081 TCP_CHECK_TIMER(sk
);
1087 * Handle reading urgent data. BSD has very simple semantics for
1088 * this, no blocking and very strange errors 8)
1091 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1093 struct tcp_sock
*tp
= tcp_sk(sk
);
1095 /* No URG data to read. */
1096 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1097 tp
->urg_data
== TCP_URG_READ
)
1098 return -EINVAL
; /* Yes this is right ! */
1100 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1103 if (tp
->urg_data
& TCP_URG_VALID
) {
1105 char c
= tp
->urg_data
;
1107 if (!(flags
& MSG_PEEK
))
1108 tp
->urg_data
= TCP_URG_READ
;
1110 /* Read urgent data. */
1111 msg
->msg_flags
|= MSG_OOB
;
1114 if (!(flags
& MSG_TRUNC
))
1115 err
= memcpy_toiovec(msg
->msg_iov
, &c
, 1);
1118 msg
->msg_flags
|= MSG_TRUNC
;
1120 return err
? -EFAULT
: len
;
1123 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1126 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1127 * the available implementations agree in this case:
1128 * this call should never block, independent of the
1129 * blocking state of the socket.
1130 * Mike <pall@rz.uni-karlsruhe.de>
1135 /* Clean up the receive buffer for full frames taken by the user,
1136 * then send an ACK if necessary. COPIED is the number of bytes
1137 * tcp_recvmsg has given to the user so far, it speeds up the
1138 * calculation of whether or not we must ACK for the sake of
1141 void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1143 struct tcp_sock
*tp
= tcp_sk(sk
);
1144 int time_to_ack
= 0;
1147 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1149 WARN_ON(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
));
1152 if (inet_csk_ack_scheduled(sk
)) {
1153 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1154 /* Delayed ACKs frequently hit locked sockets during bulk
1156 if (icsk
->icsk_ack
.blocked
||
1157 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1158 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1160 * If this read emptied read buffer, we send ACK, if
1161 * connection is not bidirectional, user drained
1162 * receive buffer and there was a small segment
1166 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1167 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1168 !icsk
->icsk_ack
.pingpong
)) &&
1169 !atomic_read(&sk
->sk_rmem_alloc
)))
1173 /* We send an ACK if we can now advertise a non-zero window
1174 * which has been raised "significantly".
1176 * Even if window raised up to infinity, do not send window open ACK
1177 * in states, where we will not receive more. It is useless.
1179 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1180 __u32 rcv_window_now
= tcp_receive_window(tp
);
1182 /* Optimize, __tcp_select_window() is not cheap. */
1183 if (2*rcv_window_now
<= tp
->window_clamp
) {
1184 __u32 new_window
= __tcp_select_window(sk
);
1186 /* Send ACK now, if this read freed lots of space
1187 * in our buffer. Certainly, new_window is new window.
1188 * We can advertise it now, if it is not less than current one.
1189 * "Lots" means "at least twice" here.
1191 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1199 static void tcp_prequeue_process(struct sock
*sk
)
1201 struct sk_buff
*skb
;
1202 struct tcp_sock
*tp
= tcp_sk(sk
);
1204 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1206 /* RX process wants to run with disabled BHs, though it is not
1209 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1210 sk_backlog_rcv(sk
, skb
);
1213 /* Clear memory counter. */
1214 tp
->ucopy
.memory
= 0;
1217 static inline struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1219 struct sk_buff
*skb
;
1222 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1223 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1224 if (tcp_hdr(skb
)->syn
)
1226 if (offset
< skb
->len
|| tcp_hdr(skb
)->fin
) {
1235 * This routine provides an alternative to tcp_recvmsg() for routines
1236 * that would like to handle copying from skbuffs directly in 'sendfile'
1239 * - It is assumed that the socket was locked by the caller.
1240 * - The routine does not block.
1241 * - At present, there is no support for reading OOB data
1242 * or for 'peeking' the socket using this routine
1243 * (although both would be easy to implement).
1245 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1246 sk_read_actor_t recv_actor
)
1248 struct sk_buff
*skb
;
1249 struct tcp_sock
*tp
= tcp_sk(sk
);
1250 u32 seq
= tp
->copied_seq
;
1254 if (sk
->sk_state
== TCP_LISTEN
)
1256 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1257 if (offset
< skb
->len
) {
1261 len
= skb
->len
- offset
;
1262 /* Stop reading if we hit a patch of urgent data */
1264 u32 urg_offset
= tp
->urg_seq
- seq
;
1265 if (urg_offset
< len
)
1270 used
= recv_actor(desc
, skb
, offset
, len
);
1275 } else if (used
<= len
) {
1281 * If recv_actor drops the lock (e.g. TCP splice
1282 * receive) the skb pointer might be invalid when
1283 * getting here: tcp_collapse might have deleted it
1284 * while aggregating skbs from the socket queue.
1286 skb
= tcp_recv_skb(sk
, seq
-1, &offset
);
1287 if (!skb
|| (offset
+1 != skb
->len
))
1290 if (tcp_hdr(skb
)->fin
) {
1291 sk_eat_skb(sk
, skb
, 0);
1295 sk_eat_skb(sk
, skb
, 0);
1299 tp
->copied_seq
= seq
;
1301 tcp_rcv_space_adjust(sk
);
1303 /* Clean up data we have read: This will do ACK frames. */
1305 tcp_cleanup_rbuf(sk
, copied
);
1310 * This routine copies from a sock struct into the user buffer.
1312 * Technical note: in 2.3 we work on _locked_ socket, so that
1313 * tricks with *seq access order and skb->users are not required.
1314 * Probably, code can be easily improved even more.
1317 int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1318 size_t len
, int nonblock
, int flags
, int *addr_len
)
1320 struct tcp_sock
*tp
= tcp_sk(sk
);
1326 int target
; /* Read at least this many bytes */
1328 struct task_struct
*user_recv
= NULL
;
1329 int copied_early
= 0;
1330 struct sk_buff
*skb
;
1335 TCP_CHECK_TIMER(sk
);
1338 if (sk
->sk_state
== TCP_LISTEN
)
1341 timeo
= sock_rcvtimeo(sk
, nonblock
);
1343 /* Urgent data needs to be handled specially. */
1344 if (flags
& MSG_OOB
)
1347 seq
= &tp
->copied_seq
;
1348 if (flags
& MSG_PEEK
) {
1349 peek_seq
= tp
->copied_seq
;
1353 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1355 #ifdef CONFIG_NET_DMA
1356 tp
->ucopy
.dma_chan
= NULL
;
1358 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
1363 available
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- (*seq
);
1364 if ((available
< target
) &&
1365 (len
> sysctl_tcp_dma_copybreak
) && !(flags
& MSG_PEEK
) &&
1366 !sysctl_tcp_low_latency
&&
1367 dma_find_channel(DMA_MEMCPY
)) {
1368 preempt_enable_no_resched();
1369 tp
->ucopy
.pinned_list
=
1370 dma_pin_iovec_pages(msg
->msg_iov
, len
);
1372 preempt_enable_no_resched();
1380 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1381 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1384 if (signal_pending(current
)) {
1385 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1390 /* Next get a buffer. */
1392 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1393 /* Now that we have two receive queues this
1396 if (before(*seq
, TCP_SKB_CB(skb
)->seq
)) {
1397 printk(KERN_INFO
"recvmsg bug: copied %X "
1398 "seq %X\n", *seq
, TCP_SKB_CB(skb
)->seq
);
1401 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1402 if (tcp_hdr(skb
)->syn
)
1404 if (offset
< skb
->len
)
1406 if (tcp_hdr(skb
)->fin
)
1408 WARN_ON(!(flags
& MSG_PEEK
));
1411 /* Well, if we have backlog, try to process it now yet. */
1413 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1418 sk
->sk_state
== TCP_CLOSE
||
1419 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1421 signal_pending(current
))
1424 if (sock_flag(sk
, SOCK_DONE
))
1428 copied
= sock_error(sk
);
1432 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1435 if (sk
->sk_state
== TCP_CLOSE
) {
1436 if (!sock_flag(sk
, SOCK_DONE
)) {
1437 /* This occurs when user tries to read
1438 * from never connected socket.
1451 if (signal_pending(current
)) {
1452 copied
= sock_intr_errno(timeo
);
1457 tcp_cleanup_rbuf(sk
, copied
);
1459 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1460 /* Install new reader */
1461 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1462 user_recv
= current
;
1463 tp
->ucopy
.task
= user_recv
;
1464 tp
->ucopy
.iov
= msg
->msg_iov
;
1467 tp
->ucopy
.len
= len
;
1469 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1470 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1472 /* Ugly... If prequeue is not empty, we have to
1473 * process it before releasing socket, otherwise
1474 * order will be broken at second iteration.
1475 * More elegant solution is required!!!
1477 * Look: we have the following (pseudo)queues:
1479 * 1. packets in flight
1484 * Each queue can be processed only if the next ones
1485 * are empty. At this point we have empty receive_queue.
1486 * But prequeue _can_ be not empty after 2nd iteration,
1487 * when we jumped to start of loop because backlog
1488 * processing added something to receive_queue.
1489 * We cannot release_sock(), because backlog contains
1490 * packets arrived _after_ prequeued ones.
1492 * Shortly, algorithm is clear --- to process all
1493 * the queues in order. We could make it more directly,
1494 * requeueing packets from backlog to prequeue, if
1495 * is not empty. It is more elegant, but eats cycles,
1498 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1501 /* __ Set realtime policy in scheduler __ */
1504 if (copied
>= target
) {
1505 /* Do not sleep, just process backlog. */
1509 sk_wait_data(sk
, &timeo
);
1511 #ifdef CONFIG_NET_DMA
1512 tp
->ucopy
.wakeup
= 0;
1518 /* __ Restore normal policy in scheduler __ */
1520 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1521 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1526 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1527 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1529 tcp_prequeue_process(sk
);
1531 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1532 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1538 if ((flags
& MSG_PEEK
) &&
1539 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1540 if (net_ratelimit())
1541 printk(KERN_DEBUG
"TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1542 current
->comm
, task_pid_nr(current
));
1543 peek_seq
= tp
->copied_seq
;
1548 /* Ok so how much can we use? */
1549 used
= skb
->len
- offset
;
1553 /* Do we have urgent data here? */
1555 u32 urg_offset
= tp
->urg_seq
- *seq
;
1556 if (urg_offset
< used
) {
1558 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1571 if (!(flags
& MSG_TRUNC
)) {
1572 #ifdef CONFIG_NET_DMA
1573 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
1574 tp
->ucopy
.dma_chan
= dma_find_channel(DMA_MEMCPY
);
1576 if (tp
->ucopy
.dma_chan
) {
1577 tp
->ucopy
.dma_cookie
= dma_skb_copy_datagram_iovec(
1578 tp
->ucopy
.dma_chan
, skb
, offset
,
1580 tp
->ucopy
.pinned_list
);
1582 if (tp
->ucopy
.dma_cookie
< 0) {
1584 printk(KERN_ALERT
"dma_cookie < 0\n");
1586 /* Exception. Bailout! */
1591 if ((offset
+ used
) == skb
->len
)
1597 err
= skb_copy_datagram_iovec(skb
, offset
,
1598 msg
->msg_iov
, used
);
1600 /* Exception. Bailout! */
1612 tcp_rcv_space_adjust(sk
);
1615 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1617 tcp_fast_path_check(sk
);
1619 if (used
+ offset
< skb
->len
)
1622 if (tcp_hdr(skb
)->fin
)
1624 if (!(flags
& MSG_PEEK
)) {
1625 sk_eat_skb(sk
, skb
, copied_early
);
1631 /* Process the FIN. */
1633 if (!(flags
& MSG_PEEK
)) {
1634 sk_eat_skb(sk
, skb
, copied_early
);
1641 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1644 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1646 tcp_prequeue_process(sk
);
1648 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1649 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1655 tp
->ucopy
.task
= NULL
;
1659 #ifdef CONFIG_NET_DMA
1660 if (tp
->ucopy
.dma_chan
) {
1661 dma_cookie_t done
, used
;
1663 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1665 while (dma_async_memcpy_complete(tp
->ucopy
.dma_chan
,
1666 tp
->ucopy
.dma_cookie
, &done
,
1667 &used
) == DMA_IN_PROGRESS
) {
1668 /* do partial cleanup of sk_async_wait_queue */
1669 while ((skb
= skb_peek(&sk
->sk_async_wait_queue
)) &&
1670 (dma_async_is_complete(skb
->dma_cookie
, done
,
1671 used
) == DMA_SUCCESS
)) {
1672 __skb_dequeue(&sk
->sk_async_wait_queue
);
1677 /* Safe to free early-copied skbs now */
1678 __skb_queue_purge(&sk
->sk_async_wait_queue
);
1679 tp
->ucopy
.dma_chan
= NULL
;
1681 if (tp
->ucopy
.pinned_list
) {
1682 dma_unpin_iovec_pages(tp
->ucopy
.pinned_list
);
1683 tp
->ucopy
.pinned_list
= NULL
;
1687 /* According to UNIX98, msg_name/msg_namelen are ignored
1688 * on connected socket. I was just happy when found this 8) --ANK
1691 /* Clean up data we have read: This will do ACK frames. */
1692 tcp_cleanup_rbuf(sk
, copied
);
1694 TCP_CHECK_TIMER(sk
);
1699 TCP_CHECK_TIMER(sk
);
1704 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1708 void tcp_set_state(struct sock
*sk
, int state
)
1710 int oldstate
= sk
->sk_state
;
1713 case TCP_ESTABLISHED
:
1714 if (oldstate
!= TCP_ESTABLISHED
)
1715 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1719 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1720 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1722 sk
->sk_prot
->unhash(sk
);
1723 if (inet_csk(sk
)->icsk_bind_hash
&&
1724 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1728 if (oldstate
== TCP_ESTABLISHED
)
1729 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1732 /* Change state AFTER socket is unhashed to avoid closed
1733 * socket sitting in hash tables.
1735 sk
->sk_state
= state
;
1738 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
1741 EXPORT_SYMBOL_GPL(tcp_set_state
);
1744 * State processing on a close. This implements the state shift for
1745 * sending our FIN frame. Note that we only send a FIN for some
1746 * states. A shutdown() may have already sent the FIN, or we may be
1750 static const unsigned char new_state
[16] = {
1751 /* current state: new state: action: */
1752 /* (Invalid) */ TCP_CLOSE
,
1753 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1754 /* TCP_SYN_SENT */ TCP_CLOSE
,
1755 /* TCP_SYN_RECV */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1756 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1
,
1757 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2
,
1758 /* TCP_TIME_WAIT */ TCP_CLOSE
,
1759 /* TCP_CLOSE */ TCP_CLOSE
,
1760 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK
| TCP_ACTION_FIN
,
1761 /* TCP_LAST_ACK */ TCP_LAST_ACK
,
1762 /* TCP_LISTEN */ TCP_CLOSE
,
1763 /* TCP_CLOSING */ TCP_CLOSING
,
1766 static int tcp_close_state(struct sock
*sk
)
1768 int next
= (int)new_state
[sk
->sk_state
];
1769 int ns
= next
& TCP_STATE_MASK
;
1771 tcp_set_state(sk
, ns
);
1773 return next
& TCP_ACTION_FIN
;
1777 * Shutdown the sending side of a connection. Much like close except
1778 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1781 void tcp_shutdown(struct sock
*sk
, int how
)
1783 /* We need to grab some memory, and put together a FIN,
1784 * and then put it into the queue to be sent.
1785 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1787 if (!(how
& SEND_SHUTDOWN
))
1790 /* If we've already sent a FIN, or it's a closed state, skip this. */
1791 if ((1 << sk
->sk_state
) &
1792 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
1793 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
1794 /* Clear out any half completed packets. FIN if needed. */
1795 if (tcp_close_state(sk
))
1800 void tcp_close(struct sock
*sk
, long timeout
)
1802 struct sk_buff
*skb
;
1803 int data_was_unread
= 0;
1807 sk
->sk_shutdown
= SHUTDOWN_MASK
;
1809 if (sk
->sk_state
== TCP_LISTEN
) {
1810 tcp_set_state(sk
, TCP_CLOSE
);
1813 inet_csk_listen_stop(sk
);
1815 goto adjudge_to_death
;
1818 /* We need to flush the recv. buffs. We do this only on the
1819 * descriptor close, not protocol-sourced closes, because the
1820 * reader process may not have drained the data yet!
1822 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
1823 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
-
1825 data_was_unread
+= len
;
1831 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1832 * data was lost. To witness the awful effects of the old behavior of
1833 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1834 * GET in an FTP client, suspend the process, wait for the client to
1835 * advertise a zero window, then kill -9 the FTP client, wheee...
1836 * Note: timeout is always zero in such a case.
1838 if (data_was_unread
) {
1839 /* Unread data was tossed, zap the connection. */
1840 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
1841 tcp_set_state(sk
, TCP_CLOSE
);
1842 tcp_send_active_reset(sk
, sk
->sk_allocation
);
1843 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
1844 /* Check zero linger _after_ checking for unread data. */
1845 sk
->sk_prot
->disconnect(sk
, 0);
1846 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
1847 } else if (tcp_close_state(sk
)) {
1848 /* We FIN if the application ate all the data before
1849 * zapping the connection.
1852 /* RED-PEN. Formally speaking, we have broken TCP state
1853 * machine. State transitions:
1855 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1856 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1857 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1859 * are legal only when FIN has been sent (i.e. in window),
1860 * rather than queued out of window. Purists blame.
1862 * F.e. "RFC state" is ESTABLISHED,
1863 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1865 * The visible declinations are that sometimes
1866 * we enter time-wait state, when it is not required really
1867 * (harmless), do not send active resets, when they are
1868 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1869 * they look as CLOSING or LAST_ACK for Linux)
1870 * Probably, I missed some more holelets.
1876 sk_stream_wait_close(sk
, timeout
);
1879 state
= sk
->sk_state
;
1883 /* It is the last release_sock in its life. It will remove backlog. */
1887 /* Now socket is owned by kernel and we acquire BH lock
1888 to finish close. No need to check for user refs.
1892 WARN_ON(sock_owned_by_user(sk
));
1894 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
1896 /* Have we already been destroyed by a softirq or backlog? */
1897 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
1900 /* This is a (useful) BSD violating of the RFC. There is a
1901 * problem with TCP as specified in that the other end could
1902 * keep a socket open forever with no application left this end.
1903 * We use a 3 minute timeout (about the same as BSD) then kill
1904 * our end. If they send after that then tough - BUT: long enough
1905 * that we won't make the old 4*rto = almost no time - whoops
1908 * Nope, it was not mistake. It is really desired behaviour
1909 * f.e. on http servers, when such sockets are useless, but
1910 * consume significant resources. Let's do it with special
1911 * linger2 option. --ANK
1914 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
1915 struct tcp_sock
*tp
= tcp_sk(sk
);
1916 if (tp
->linger2
< 0) {
1917 tcp_set_state(sk
, TCP_CLOSE
);
1918 tcp_send_active_reset(sk
, GFP_ATOMIC
);
1919 NET_INC_STATS_BH(sock_net(sk
),
1920 LINUX_MIB_TCPABORTONLINGER
);
1922 const int tmo
= tcp_fin_time(sk
);
1924 if (tmo
> TCP_TIMEWAIT_LEN
) {
1925 inet_csk_reset_keepalive_timer(sk
,
1926 tmo
- TCP_TIMEWAIT_LEN
);
1928 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
1933 if (sk
->sk_state
!= TCP_CLOSE
) {
1934 int orphan_count
= percpu_counter_read_positive(
1935 sk
->sk_prot
->orphan_count
);
1938 if (tcp_too_many_orphans(sk
, orphan_count
)) {
1939 if (net_ratelimit())
1940 printk(KERN_INFO
"TCP: too many of orphaned "
1942 tcp_set_state(sk
, TCP_CLOSE
);
1943 tcp_send_active_reset(sk
, GFP_ATOMIC
);
1944 NET_INC_STATS_BH(sock_net(sk
),
1945 LINUX_MIB_TCPABORTONMEMORY
);
1949 if (sk
->sk_state
== TCP_CLOSE
)
1950 inet_csk_destroy_sock(sk
);
1951 /* Otherwise, socket is reprieved until protocol close. */
1959 /* These states need RST on ABORT according to RFC793 */
1961 static inline int tcp_need_reset(int state
)
1963 return (1 << state
) &
1964 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
1965 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
1968 int tcp_disconnect(struct sock
*sk
, int flags
)
1970 struct inet_sock
*inet
= inet_sk(sk
);
1971 struct inet_connection_sock
*icsk
= inet_csk(sk
);
1972 struct tcp_sock
*tp
= tcp_sk(sk
);
1974 int old_state
= sk
->sk_state
;
1976 if (old_state
!= TCP_CLOSE
)
1977 tcp_set_state(sk
, TCP_CLOSE
);
1979 /* ABORT function of RFC793 */
1980 if (old_state
== TCP_LISTEN
) {
1981 inet_csk_listen_stop(sk
);
1982 } else if (tcp_need_reset(old_state
) ||
1983 (tp
->snd_nxt
!= tp
->write_seq
&&
1984 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
1985 /* The last check adjusts for discrepancy of Linux wrt. RFC
1988 tcp_send_active_reset(sk
, gfp_any());
1989 sk
->sk_err
= ECONNRESET
;
1990 } else if (old_state
== TCP_SYN_SENT
)
1991 sk
->sk_err
= ECONNRESET
;
1993 tcp_clear_xmit_timers(sk
);
1994 __skb_queue_purge(&sk
->sk_receive_queue
);
1995 tcp_write_queue_purge(sk
);
1996 __skb_queue_purge(&tp
->out_of_order_queue
);
1997 #ifdef CONFIG_NET_DMA
1998 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2003 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2004 inet_reset_saddr(sk
);
2006 sk
->sk_shutdown
= 0;
2007 sock_reset_flag(sk
, SOCK_DONE
);
2009 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2011 icsk
->icsk_backoff
= 0;
2013 icsk
->icsk_probes_out
= 0;
2014 tp
->packets_out
= 0;
2015 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2016 tp
->snd_cwnd_cnt
= 0;
2017 tp
->bytes_acked
= 0;
2018 tcp_set_ca_state(sk
, TCP_CA_Open
);
2019 tcp_clear_retrans(tp
);
2020 inet_csk_delack_init(sk
);
2021 tcp_init_send_head(sk
);
2022 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2025 WARN_ON(inet
->num
&& !icsk
->icsk_bind_hash
);
2027 sk
->sk_error_report(sk
);
2032 * Socket option code for TCP.
2034 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2035 int optname
, char __user
*optval
, unsigned int optlen
)
2037 struct tcp_sock
*tp
= tcp_sk(sk
);
2038 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2042 /* This is a string value all the others are int's */
2043 if (optname
== TCP_CONGESTION
) {
2044 char name
[TCP_CA_NAME_MAX
];
2049 val
= strncpy_from_user(name
, optval
,
2050 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2056 err
= tcp_set_congestion_control(sk
, name
);
2061 if (optlen
< sizeof(int))
2064 if (get_user(val
, (int __user
*)optval
))
2071 /* Values greater than interface MTU won't take effect. However
2072 * at the point when this call is done we typically don't yet
2073 * know which interface is going to be used */
2074 if (val
< 8 || val
> MAX_TCP_WINDOW
) {
2078 tp
->rx_opt
.user_mss
= val
;
2083 /* TCP_NODELAY is weaker than TCP_CORK, so that
2084 * this option on corked socket is remembered, but
2085 * it is not activated until cork is cleared.
2087 * However, when TCP_NODELAY is set we make
2088 * an explicit push, which overrides even TCP_CORK
2089 * for currently queued segments.
2091 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2092 tcp_push_pending_frames(sk
);
2094 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2099 /* When set indicates to always queue non-full frames.
2100 * Later the user clears this option and we transmit
2101 * any pending partial frames in the queue. This is
2102 * meant to be used alongside sendfile() to get properly
2103 * filled frames when the user (for example) must write
2104 * out headers with a write() call first and then use
2105 * sendfile to send out the data parts.
2107 * TCP_CORK can be set together with TCP_NODELAY and it is
2108 * stronger than TCP_NODELAY.
2111 tp
->nonagle
|= TCP_NAGLE_CORK
;
2113 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2114 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2115 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2116 tcp_push_pending_frames(sk
);
2121 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2124 tp
->keepalive_time
= val
* HZ
;
2125 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2126 !((1 << sk
->sk_state
) &
2127 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2128 __u32 elapsed
= tcp_time_stamp
- tp
->rcv_tstamp
;
2129 if (tp
->keepalive_time
> elapsed
)
2130 elapsed
= tp
->keepalive_time
- elapsed
;
2133 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2138 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2141 tp
->keepalive_intvl
= val
* HZ
;
2144 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2147 tp
->keepalive_probes
= val
;
2150 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2153 icsk
->icsk_syn_retries
= val
;
2159 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2162 tp
->linger2
= val
* HZ
;
2165 case TCP_DEFER_ACCEPT
:
2166 icsk
->icsk_accept_queue
.rskq_defer_accept
= 0;
2168 /* Translate value in seconds to number of
2170 while (icsk
->icsk_accept_queue
.rskq_defer_accept
< 32 &&
2171 val
> ((TCP_TIMEOUT_INIT
/ HZ
) <<
2172 icsk
->icsk_accept_queue
.rskq_defer_accept
))
2173 icsk
->icsk_accept_queue
.rskq_defer_accept
++;
2174 icsk
->icsk_accept_queue
.rskq_defer_accept
++;
2178 case TCP_WINDOW_CLAMP
:
2180 if (sk
->sk_state
!= TCP_CLOSE
) {
2184 tp
->window_clamp
= 0;
2186 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2187 SOCK_MIN_RCVBUF
/ 2 : val
;
2192 icsk
->icsk_ack
.pingpong
= 1;
2194 icsk
->icsk_ack
.pingpong
= 0;
2195 if ((1 << sk
->sk_state
) &
2196 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2197 inet_csk_ack_scheduled(sk
)) {
2198 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2199 tcp_cleanup_rbuf(sk
, 1);
2201 icsk
->icsk_ack
.pingpong
= 1;
2206 #ifdef CONFIG_TCP_MD5SIG
2208 /* Read the IP->Key mappings from userspace */
2209 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2222 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2223 unsigned int optlen
)
2225 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2227 if (level
!= SOL_TCP
)
2228 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2230 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2233 #ifdef CONFIG_COMPAT
2234 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2235 char __user
*optval
, unsigned int optlen
)
2237 if (level
!= SOL_TCP
)
2238 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2240 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2243 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2246 /* Return information about state of tcp endpoint in API format. */
2247 void tcp_get_info(struct sock
*sk
, struct tcp_info
*info
)
2249 struct tcp_sock
*tp
= tcp_sk(sk
);
2250 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2251 u32 now
= tcp_time_stamp
;
2253 memset(info
, 0, sizeof(*info
));
2255 info
->tcpi_state
= sk
->sk_state
;
2256 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2257 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2258 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2259 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2261 if (tp
->rx_opt
.tstamp_ok
)
2262 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2263 if (tcp_is_sack(tp
))
2264 info
->tcpi_options
|= TCPI_OPT_SACK
;
2265 if (tp
->rx_opt
.wscale_ok
) {
2266 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2267 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2268 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2271 if (tp
->ecn_flags
&TCP_ECN_OK
)
2272 info
->tcpi_options
|= TCPI_OPT_ECN
;
2274 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2275 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2276 info
->tcpi_snd_mss
= tp
->mss_cache
;
2277 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2279 if (sk
->sk_state
== TCP_LISTEN
) {
2280 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2281 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2283 info
->tcpi_unacked
= tp
->packets_out
;
2284 info
->tcpi_sacked
= tp
->sacked_out
;
2286 info
->tcpi_lost
= tp
->lost_out
;
2287 info
->tcpi_retrans
= tp
->retrans_out
;
2288 info
->tcpi_fackets
= tp
->fackets_out
;
2290 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2291 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2292 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2294 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2295 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2296 info
->tcpi_rtt
= jiffies_to_usecs(tp
->srtt
)>>3;
2297 info
->tcpi_rttvar
= jiffies_to_usecs(tp
->mdev
)>>2;
2298 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2299 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2300 info
->tcpi_advmss
= tp
->advmss
;
2301 info
->tcpi_reordering
= tp
->reordering
;
2303 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2304 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2306 info
->tcpi_total_retrans
= tp
->total_retrans
;
2309 EXPORT_SYMBOL_GPL(tcp_get_info
);
2311 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2312 int optname
, char __user
*optval
, int __user
*optlen
)
2314 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2315 struct tcp_sock
*tp
= tcp_sk(sk
);
2318 if (get_user(len
, optlen
))
2321 len
= min_t(unsigned int, len
, sizeof(int));
2328 val
= tp
->mss_cache
;
2329 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2330 val
= tp
->rx_opt
.user_mss
;
2333 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2336 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2339 val
= keepalive_time_when(tp
) / HZ
;
2342 val
= keepalive_intvl_when(tp
) / HZ
;
2345 val
= keepalive_probes(tp
);
2348 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2353 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2355 case TCP_DEFER_ACCEPT
:
2356 val
= !icsk
->icsk_accept_queue
.rskq_defer_accept
? 0 :
2357 ((TCP_TIMEOUT_INIT
/ HZ
) << (icsk
->icsk_accept_queue
.rskq_defer_accept
- 1));
2359 case TCP_WINDOW_CLAMP
:
2360 val
= tp
->window_clamp
;
2363 struct tcp_info info
;
2365 if (get_user(len
, optlen
))
2368 tcp_get_info(sk
, &info
);
2370 len
= min_t(unsigned int, len
, sizeof(info
));
2371 if (put_user(len
, optlen
))
2373 if (copy_to_user(optval
, &info
, len
))
2378 val
= !icsk
->icsk_ack
.pingpong
;
2381 case TCP_CONGESTION
:
2382 if (get_user(len
, optlen
))
2384 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2385 if (put_user(len
, optlen
))
2387 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2391 return -ENOPROTOOPT
;
2394 if (put_user(len
, optlen
))
2396 if (copy_to_user(optval
, &val
, len
))
2401 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2404 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2406 if (level
!= SOL_TCP
)
2407 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2409 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2412 #ifdef CONFIG_COMPAT
2413 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2414 char __user
*optval
, int __user
*optlen
)
2416 if (level
!= SOL_TCP
)
2417 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2419 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2422 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2425 struct sk_buff
*tcp_tso_segment(struct sk_buff
*skb
, int features
)
2427 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
2432 unsigned int oldlen
;
2435 if (!pskb_may_pull(skb
, sizeof(*th
)))
2439 thlen
= th
->doff
* 4;
2440 if (thlen
< sizeof(*th
))
2443 if (!pskb_may_pull(skb
, thlen
))
2446 oldlen
= (u16
)~skb
->len
;
2447 __skb_pull(skb
, thlen
);
2449 mss
= skb_shinfo(skb
)->gso_size
;
2450 if (unlikely(skb
->len
<= mss
))
2453 if (skb_gso_ok(skb
, features
| NETIF_F_GSO_ROBUST
)) {
2454 /* Packet is from an untrusted source, reset gso_segs. */
2455 int type
= skb_shinfo(skb
)->gso_type
;
2463 !(type
& (SKB_GSO_TCPV4
| SKB_GSO_TCPV6
))))
2466 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(skb
->len
, mss
);
2472 segs
= skb_segment(skb
, features
);
2476 delta
= htonl(oldlen
+ (thlen
+ mss
));
2480 seq
= ntohl(th
->seq
);
2483 th
->fin
= th
->psh
= 0;
2485 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2486 (__force u32
)delta
));
2487 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2489 csum_fold(csum_partial(skb_transport_header(skb
),
2496 th
->seq
= htonl(seq
);
2498 } while (skb
->next
);
2500 delta
= htonl(oldlen
+ (skb
->tail
- skb
->transport_header
) +
2502 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2503 (__force u32
)delta
));
2504 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2505 th
->check
= csum_fold(csum_partial(skb_transport_header(skb
),
2511 EXPORT_SYMBOL(tcp_tso_segment
);
2513 struct sk_buff
**tcp_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
2515 struct sk_buff
**pp
= NULL
;
2522 unsigned int mss
= 1;
2528 off
= skb_gro_offset(skb
);
2529 hlen
= off
+ sizeof(*th
);
2530 th
= skb_gro_header_fast(skb
, off
);
2531 if (skb_gro_header_hard(skb
, hlen
)) {
2532 th
= skb_gro_header_slow(skb
, hlen
, off
);
2537 thlen
= th
->doff
* 4;
2538 if (thlen
< sizeof(*th
))
2542 if (skb_gro_header_hard(skb
, hlen
)) {
2543 th
= skb_gro_header_slow(skb
, hlen
, off
);
2548 skb_gro_pull(skb
, thlen
);
2550 len
= skb_gro_len(skb
);
2551 flags
= tcp_flag_word(th
);
2553 for (; (p
= *head
); head
= &p
->next
) {
2554 if (!NAPI_GRO_CB(p
)->same_flow
)
2559 if (*(u32
*)&th
->source
^ *(u32
*)&th2
->source
) {
2560 NAPI_GRO_CB(p
)->same_flow
= 0;
2567 goto out_check_final
;
2570 flush
= NAPI_GRO_CB(p
)->flush
;
2571 flush
|= flags
& TCP_FLAG_CWR
;
2572 flush
|= (flags
^ tcp_flag_word(th2
)) &
2573 ~(TCP_FLAG_CWR
| TCP_FLAG_FIN
| TCP_FLAG_PSH
);
2574 flush
|= th
->ack_seq
^ th2
->ack_seq
;
2575 for (i
= sizeof(*th
); i
< thlen
; i
+= 4)
2576 flush
|= *(u32
*)((u8
*)th
+ i
) ^
2577 *(u32
*)((u8
*)th2
+ i
);
2579 mss
= skb_shinfo(p
)->gso_size
;
2581 flush
|= (len
- 1) >= mss
;
2582 flush
|= (ntohl(th2
->seq
) + skb_gro_len(p
)) ^ ntohl(th
->seq
);
2584 if (flush
|| skb_gro_receive(head
, skb
)) {
2586 goto out_check_final
;
2591 tcp_flag_word(th2
) |= flags
& (TCP_FLAG_FIN
| TCP_FLAG_PSH
);
2595 flush
|= flags
& (TCP_FLAG_URG
| TCP_FLAG_PSH
| TCP_FLAG_RST
|
2596 TCP_FLAG_SYN
| TCP_FLAG_FIN
);
2598 if (p
&& (!NAPI_GRO_CB(skb
)->same_flow
|| flush
))
2602 NAPI_GRO_CB(skb
)->flush
|= flush
;
2606 EXPORT_SYMBOL(tcp_gro_receive
);
2608 int tcp_gro_complete(struct sk_buff
*skb
)
2610 struct tcphdr
*th
= tcp_hdr(skb
);
2612 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
2613 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
2614 skb
->ip_summed
= CHECKSUM_PARTIAL
;
2616 skb_shinfo(skb
)->gso_segs
= NAPI_GRO_CB(skb
)->count
;
2619 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
2623 EXPORT_SYMBOL(tcp_gro_complete
);
2625 #ifdef CONFIG_TCP_MD5SIG
2626 static unsigned long tcp_md5sig_users
;
2627 static struct tcp_md5sig_pool
**tcp_md5sig_pool
;
2628 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock
);
2630 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool
**pool
)
2633 for_each_possible_cpu(cpu
) {
2634 struct tcp_md5sig_pool
*p
= *per_cpu_ptr(pool
, cpu
);
2636 if (p
->md5_desc
.tfm
)
2637 crypto_free_hash(p
->md5_desc
.tfm
);
2645 void tcp_free_md5sig_pool(void)
2647 struct tcp_md5sig_pool
**pool
= NULL
;
2649 spin_lock_bh(&tcp_md5sig_pool_lock
);
2650 if (--tcp_md5sig_users
== 0) {
2651 pool
= tcp_md5sig_pool
;
2652 tcp_md5sig_pool
= NULL
;
2654 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2656 __tcp_free_md5sig_pool(pool
);
2659 EXPORT_SYMBOL(tcp_free_md5sig_pool
);
2661 static struct tcp_md5sig_pool
**__tcp_alloc_md5sig_pool(struct sock
*sk
)
2664 struct tcp_md5sig_pool
**pool
;
2666 pool
= alloc_percpu(struct tcp_md5sig_pool
*);
2670 for_each_possible_cpu(cpu
) {
2671 struct tcp_md5sig_pool
*p
;
2672 struct crypto_hash
*hash
;
2674 p
= kzalloc(sizeof(*p
), sk
->sk_allocation
);
2677 *per_cpu_ptr(pool
, cpu
) = p
;
2679 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
2680 if (!hash
|| IS_ERR(hash
))
2683 p
->md5_desc
.tfm
= hash
;
2687 __tcp_free_md5sig_pool(pool
);
2691 struct tcp_md5sig_pool
**tcp_alloc_md5sig_pool(struct sock
*sk
)
2693 struct tcp_md5sig_pool
**pool
;
2697 spin_lock_bh(&tcp_md5sig_pool_lock
);
2698 pool
= tcp_md5sig_pool
;
2699 if (tcp_md5sig_users
++ == 0) {
2701 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2704 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2708 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2711 /* we cannot hold spinlock here because this may sleep. */
2712 struct tcp_md5sig_pool
**p
= __tcp_alloc_md5sig_pool(sk
);
2713 spin_lock_bh(&tcp_md5sig_pool_lock
);
2716 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2719 pool
= tcp_md5sig_pool
;
2721 /* oops, it has already been assigned. */
2722 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2723 __tcp_free_md5sig_pool(p
);
2725 tcp_md5sig_pool
= pool
= p
;
2726 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2732 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
2734 struct tcp_md5sig_pool
*__tcp_get_md5sig_pool(int cpu
)
2736 struct tcp_md5sig_pool
**p
;
2737 spin_lock_bh(&tcp_md5sig_pool_lock
);
2738 p
= tcp_md5sig_pool
;
2741 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2742 return (p
? *per_cpu_ptr(p
, cpu
) : NULL
);
2745 EXPORT_SYMBOL(__tcp_get_md5sig_pool
);
2747 void __tcp_put_md5sig_pool(void)
2749 tcp_free_md5sig_pool();
2752 EXPORT_SYMBOL(__tcp_put_md5sig_pool
);
2754 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
2757 struct scatterlist sg
;
2760 __sum16 old_checksum
= th
->check
;
2762 /* options aren't included in the hash */
2763 sg_init_one(&sg
, th
, sizeof(struct tcphdr
));
2764 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(struct tcphdr
));
2765 th
->check
= old_checksum
;
2769 EXPORT_SYMBOL(tcp_md5_hash_header
);
2771 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
2772 struct sk_buff
*skb
, unsigned header_len
)
2774 struct scatterlist sg
;
2775 const struct tcphdr
*tp
= tcp_hdr(skb
);
2776 struct hash_desc
*desc
= &hp
->md5_desc
;
2778 const unsigned head_data_len
= skb_headlen(skb
) > header_len
?
2779 skb_headlen(skb
) - header_len
: 0;
2780 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
2782 sg_init_table(&sg
, 1);
2784 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
2785 if (crypto_hash_update(desc
, &sg
, head_data_len
))
2788 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
2789 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
2790 sg_set_page(&sg
, f
->page
, f
->size
, f
->page_offset
);
2791 if (crypto_hash_update(desc
, &sg
, f
->size
))
2798 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
2800 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, struct tcp_md5sig_key
*key
)
2802 struct scatterlist sg
;
2804 sg_init_one(&sg
, key
->key
, key
->keylen
);
2805 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
2808 EXPORT_SYMBOL(tcp_md5_hash_key
);
2812 void tcp_done(struct sock
*sk
)
2814 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
2815 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
2817 tcp_set_state(sk
, TCP_CLOSE
);
2818 tcp_clear_xmit_timers(sk
);
2820 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2822 if (!sock_flag(sk
, SOCK_DEAD
))
2823 sk
->sk_state_change(sk
);
2825 inet_csk_destroy_sock(sk
);
2827 EXPORT_SYMBOL_GPL(tcp_done
);
2829 extern struct tcp_congestion_ops tcp_reno
;
2831 static __initdata
unsigned long thash_entries
;
2832 static int __init
set_thash_entries(char *str
)
2836 thash_entries
= simple_strtoul(str
, &str
, 0);
2839 __setup("thash_entries=", set_thash_entries
);
2841 void __init
tcp_init(void)
2843 struct sk_buff
*skb
= NULL
;
2844 unsigned long nr_pages
, limit
;
2845 int order
, i
, max_share
;
2847 BUILD_BUG_ON(sizeof(struct tcp_skb_cb
) > sizeof(skb
->cb
));
2849 percpu_counter_init(&tcp_sockets_allocated
, 0);
2850 percpu_counter_init(&tcp_orphan_count
, 0);
2851 tcp_hashinfo
.bind_bucket_cachep
=
2852 kmem_cache_create("tcp_bind_bucket",
2853 sizeof(struct inet_bind_bucket
), 0,
2854 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
2856 /* Size and allocate the main established and bind bucket
2859 * The methodology is similar to that of the buffer cache.
2861 tcp_hashinfo
.ehash
=
2862 alloc_large_system_hash("TCP established",
2863 sizeof(struct inet_ehash_bucket
),
2865 (totalram_pages
>= 128 * 1024) ?
2868 &tcp_hashinfo
.ehash_size
,
2870 thash_entries
? 0 : 512 * 1024);
2871 tcp_hashinfo
.ehash_size
= 1 << tcp_hashinfo
.ehash_size
;
2872 for (i
= 0; i
< tcp_hashinfo
.ehash_size
; i
++) {
2873 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
2874 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].twchain
, i
);
2876 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
2877 panic("TCP: failed to alloc ehash_locks");
2878 tcp_hashinfo
.bhash
=
2879 alloc_large_system_hash("TCP bind",
2880 sizeof(struct inet_bind_hashbucket
),
2881 tcp_hashinfo
.ehash_size
,
2882 (totalram_pages
>= 128 * 1024) ?
2885 &tcp_hashinfo
.bhash_size
,
2888 tcp_hashinfo
.bhash_size
= 1 << tcp_hashinfo
.bhash_size
;
2889 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
2890 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
2891 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
2894 /* Try to be a bit smarter and adjust defaults depending
2895 * on available memory.
2897 for (order
= 0; ((1 << order
) << PAGE_SHIFT
) <
2898 (tcp_hashinfo
.bhash_size
* sizeof(struct inet_bind_hashbucket
));
2902 tcp_death_row
.sysctl_max_tw_buckets
= 180000;
2903 sysctl_tcp_max_orphans
= 4096 << (order
- 4);
2904 sysctl_max_syn_backlog
= 1024;
2905 } else if (order
< 3) {
2906 tcp_death_row
.sysctl_max_tw_buckets
>>= (3 - order
);
2907 sysctl_tcp_max_orphans
>>= (3 - order
);
2908 sysctl_max_syn_backlog
= 128;
2911 /* Set the pressure threshold to be a fraction of global memory that
2912 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
2913 * memory, with a floor of 128 pages.
2915 nr_pages
= totalram_pages
- totalhigh_pages
;
2916 limit
= min(nr_pages
, 1UL<<(28-PAGE_SHIFT
)) >> (20-PAGE_SHIFT
);
2917 limit
= (limit
* (nr_pages
>> (20-PAGE_SHIFT
))) >> (PAGE_SHIFT
-11);
2918 limit
= max(limit
, 128UL);
2919 sysctl_tcp_mem
[0] = limit
/ 4 * 3;
2920 sysctl_tcp_mem
[1] = limit
;
2921 sysctl_tcp_mem
[2] = sysctl_tcp_mem
[0] * 2;
2923 /* Set per-socket limits to no more than 1/128 the pressure threshold */
2924 limit
= ((unsigned long)sysctl_tcp_mem
[1]) << (PAGE_SHIFT
- 7);
2925 max_share
= min(4UL*1024*1024, limit
);
2927 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
2928 sysctl_tcp_wmem
[1] = 16*1024;
2929 sysctl_tcp_wmem
[2] = max(64*1024, max_share
);
2931 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
2932 sysctl_tcp_rmem
[1] = 87380;
2933 sysctl_tcp_rmem
[2] = max(87380, max_share
);
2935 printk(KERN_INFO
"TCP: Hash tables configured "
2936 "(established %d bind %d)\n",
2937 tcp_hashinfo
.ehash_size
, tcp_hashinfo
.bhash_size
);
2939 tcp_register_congestion_control(&tcp_reno
);
2942 EXPORT_SYMBOL(tcp_close
);
2943 EXPORT_SYMBOL(tcp_disconnect
);
2944 EXPORT_SYMBOL(tcp_getsockopt
);
2945 EXPORT_SYMBOL(tcp_ioctl
);
2946 EXPORT_SYMBOL(tcp_poll
);
2947 EXPORT_SYMBOL(tcp_read_sock
);
2948 EXPORT_SYMBOL(tcp_recvmsg
);
2949 EXPORT_SYMBOL(tcp_sendmsg
);
2950 EXPORT_SYMBOL(tcp_splice_read
);
2951 EXPORT_SYMBOL(tcp_sendpage
);
2952 EXPORT_SYMBOL(tcp_setsockopt
);
2953 EXPORT_SYMBOL(tcp_shutdown
);