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>
274 #include <net/xfrm.h>
276 #include <net/netdma.h>
277 #include <net/sock.h>
279 #include <asm/uaccess.h>
280 #include <asm/ioctls.h>
282 int sysctl_tcp_fin_timeout __read_mostly
= TCP_FIN_TIMEOUT
;
284 struct percpu_counter tcp_orphan_count
;
285 EXPORT_SYMBOL_GPL(tcp_orphan_count
);
287 int sysctl_tcp_wmem
[3] __read_mostly
;
288 int sysctl_tcp_rmem
[3] __read_mostly
;
290 EXPORT_SYMBOL(sysctl_tcp_rmem
);
291 EXPORT_SYMBOL(sysctl_tcp_wmem
);
293 atomic_long_t tcp_memory_allocated
; /* Current allocated memory. */
294 EXPORT_SYMBOL(tcp_memory_allocated
);
297 * Current number of TCP sockets.
299 struct percpu_counter tcp_sockets_allocated
;
300 EXPORT_SYMBOL(tcp_sockets_allocated
);
305 struct tcp_splice_state
{
306 struct pipe_inode_info
*pipe
;
312 * Pressure flag: try to collapse.
313 * Technical note: it is used by multiple contexts non atomically.
314 * All the __sk_mem_schedule() is of this nature: accounting
315 * is strict, actions are advisory and have some latency.
317 int tcp_memory_pressure __read_mostly
;
318 EXPORT_SYMBOL(tcp_memory_pressure
);
320 void tcp_enter_memory_pressure(struct sock
*sk
)
322 if (!tcp_memory_pressure
) {
323 NET_INC_STATS(sock_net(sk
), LINUX_MIB_TCPMEMORYPRESSURES
);
324 tcp_memory_pressure
= 1;
327 EXPORT_SYMBOL(tcp_enter_memory_pressure
);
329 /* Convert seconds to retransmits based on initial and max timeout */
330 static u8
secs_to_retrans(int seconds
, int timeout
, int rto_max
)
335 int period
= timeout
;
338 while (seconds
> period
&& res
< 255) {
341 if (timeout
> rto_max
)
349 /* Convert retransmits to seconds based on initial and max timeout */
350 static int retrans_to_secs(u8 retrans
, int timeout
, int rto_max
)
358 if (timeout
> rto_max
)
366 /* Address-family independent initialization for a tcp_sock.
368 * NOTE: A lot of things set to zero explicitly by call to
369 * sk_alloc() so need not be done here.
371 void tcp_init_sock(struct sock
*sk
)
373 struct inet_connection_sock
*icsk
= inet_csk(sk
);
374 struct tcp_sock
*tp
= tcp_sk(sk
);
376 skb_queue_head_init(&tp
->out_of_order_queue
);
377 tcp_init_xmit_timers(sk
);
378 tcp_prequeue_init(tp
);
380 icsk
->icsk_rto
= TCP_TIMEOUT_INIT
;
381 tp
->mdev
= TCP_TIMEOUT_INIT
;
383 /* So many TCP implementations out there (incorrectly) count the
384 * initial SYN frame in their delayed-ACK and congestion control
385 * algorithms that we must have the following bandaid to talk
386 * efficiently to them. -DaveM
388 tp
->snd_cwnd
= TCP_INIT_CWND
;
390 /* See draft-stevens-tcpca-spec-01 for discussion of the
391 * initialization of these values.
393 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
394 tp
->snd_cwnd_clamp
= ~0;
395 tp
->mss_cache
= TCP_MSS_DEFAULT
;
397 tp
->reordering
= sysctl_tcp_reordering
;
398 tcp_enable_early_retrans(tp
);
399 icsk
->icsk_ca_ops
= &tcp_init_congestion_ops
;
401 sk
->sk_state
= TCP_CLOSE
;
403 sk
->sk_write_space
= sk_stream_write_space
;
404 sock_set_flag(sk
, SOCK_USE_WRITE_QUEUE
);
406 icsk
->icsk_sync_mss
= tcp_sync_mss
;
408 /* TCP Cookie Transactions */
409 if (sysctl_tcp_cookie_size
> 0) {
410 /* Default, cookies without s_data_payload. */
412 kzalloc(sizeof(*tp
->cookie_values
),
414 if (tp
->cookie_values
!= NULL
)
415 kref_init(&tp
->cookie_values
->kref
);
417 /* Presumed zeroed, in order of appearance:
418 * cookie_in_always, cookie_out_never,
419 * s_data_constant, s_data_in, s_data_out
421 sk
->sk_sndbuf
= sysctl_tcp_wmem
[1];
422 sk
->sk_rcvbuf
= sysctl_tcp_rmem
[1];
425 sock_update_memcg(sk
);
426 sk_sockets_allocated_inc(sk
);
429 EXPORT_SYMBOL(tcp_init_sock
);
432 * Wait for a TCP event.
434 * Note that we don't need to lock the socket, as the upper poll layers
435 * take care of normal races (between the test and the event) and we don't
436 * go look at any of the socket buffers directly.
438 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
441 struct sock
*sk
= sock
->sk
;
442 const struct tcp_sock
*tp
= tcp_sk(sk
);
444 sock_poll_wait(file
, sk_sleep(sk
), wait
);
445 if (sk
->sk_state
== TCP_LISTEN
)
446 return inet_csk_listen_poll(sk
);
448 /* Socket is not locked. We are protected from async events
449 * by poll logic and correct handling of state changes
450 * made by other threads is impossible in any case.
456 * POLLHUP is certainly not done right. But poll() doesn't
457 * have a notion of HUP in just one direction, and for a
458 * socket the read side is more interesting.
460 * Some poll() documentation says that POLLHUP is incompatible
461 * with the POLLOUT/POLLWR flags, so somebody should check this
462 * all. But careful, it tends to be safer to return too many
463 * bits than too few, and you can easily break real applications
464 * if you don't tell them that something has hung up!
468 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
469 * our fs/select.c). It means that after we received EOF,
470 * poll always returns immediately, making impossible poll() on write()
471 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
472 * if and only if shutdown has been made in both directions.
473 * Actually, it is interesting to look how Solaris and DUX
474 * solve this dilemma. I would prefer, if POLLHUP were maskable,
475 * then we could set it on SND_SHUTDOWN. BTW examples given
476 * in Stevens' books assume exactly this behaviour, it explains
477 * why POLLHUP is incompatible with POLLOUT. --ANK
479 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
480 * blocking on fresh not-connected or disconnected socket. --ANK
482 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== TCP_CLOSE
)
484 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
485 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
488 if ((1 << sk
->sk_state
) & ~(TCPF_SYN_SENT
| TCPF_SYN_RECV
)) {
489 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
491 if (tp
->urg_seq
== tp
->copied_seq
&&
492 !sock_flag(sk
, SOCK_URGINLINE
) &&
496 /* Potential race condition. If read of tp below will
497 * escape above sk->sk_state, we can be illegally awaken
498 * in SYN_* states. */
499 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
500 mask
|= POLLIN
| POLLRDNORM
;
502 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
503 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
)) {
504 mask
|= POLLOUT
| POLLWRNORM
;
505 } else { /* send SIGIO later */
506 set_bit(SOCK_ASYNC_NOSPACE
,
507 &sk
->sk_socket
->flags
);
508 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
510 /* Race breaker. If space is freed after
511 * wspace test but before the flags are set,
512 * IO signal will be lost.
514 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
))
515 mask
|= POLLOUT
| POLLWRNORM
;
518 mask
|= POLLOUT
| POLLWRNORM
;
520 if (tp
->urg_data
& TCP_URG_VALID
)
523 /* This barrier is coupled with smp_wmb() in tcp_reset() */
530 EXPORT_SYMBOL(tcp_poll
);
532 int tcp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
534 struct tcp_sock
*tp
= tcp_sk(sk
);
539 if (sk
->sk_state
== TCP_LISTEN
)
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
)) {
551 answ
= tp
->rcv_nxt
- tp
->copied_seq
;
553 /* Subtract 1, if FIN is in queue. */
554 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
556 answ
-= tcp_hdr(skb
)->fin
;
558 answ
= tp
->urg_seq
- tp
->copied_seq
;
562 answ
= tp
->urg_data
&& tp
->urg_seq
== tp
->copied_seq
;
565 if (sk
->sk_state
== TCP_LISTEN
)
568 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
571 answ
= tp
->write_seq
- tp
->snd_una
;
574 if (sk
->sk_state
== TCP_LISTEN
)
577 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
580 answ
= tp
->write_seq
- tp
->snd_nxt
;
586 return put_user(answ
, (int __user
*)arg
);
588 EXPORT_SYMBOL(tcp_ioctl
);
590 static inline void tcp_mark_push(struct tcp_sock
*tp
, struct sk_buff
*skb
)
592 TCP_SKB_CB(skb
)->tcp_flags
|= TCPHDR_PSH
;
593 tp
->pushed_seq
= tp
->write_seq
;
596 static inline bool forced_push(const struct tcp_sock
*tp
)
598 return after(tp
->write_seq
, tp
->pushed_seq
+ (tp
->max_window
>> 1));
601 static inline void skb_entail(struct sock
*sk
, struct sk_buff
*skb
)
603 struct tcp_sock
*tp
= tcp_sk(sk
);
604 struct tcp_skb_cb
*tcb
= TCP_SKB_CB(skb
);
607 tcb
->seq
= tcb
->end_seq
= tp
->write_seq
;
608 tcb
->tcp_flags
= TCPHDR_ACK
;
610 skb_header_release(skb
);
611 tcp_add_write_queue_tail(sk
, skb
);
612 sk
->sk_wmem_queued
+= skb
->truesize
;
613 sk_mem_charge(sk
, skb
->truesize
);
614 if (tp
->nonagle
& TCP_NAGLE_PUSH
)
615 tp
->nonagle
&= ~TCP_NAGLE_PUSH
;
618 static inline void tcp_mark_urg(struct tcp_sock
*tp
, int flags
)
621 tp
->snd_up
= tp
->write_seq
;
624 static inline void tcp_push(struct sock
*sk
, int flags
, int mss_now
,
627 if (tcp_send_head(sk
)) {
628 struct tcp_sock
*tp
= tcp_sk(sk
);
630 if (!(flags
& MSG_MORE
) || forced_push(tp
))
631 tcp_mark_push(tp
, tcp_write_queue_tail(sk
));
633 tcp_mark_urg(tp
, flags
);
634 __tcp_push_pending_frames(sk
, mss_now
,
635 (flags
& MSG_MORE
) ? TCP_NAGLE_CORK
: nonagle
);
639 static int tcp_splice_data_recv(read_descriptor_t
*rd_desc
, struct sk_buff
*skb
,
640 unsigned int offset
, size_t len
)
642 struct tcp_splice_state
*tss
= rd_desc
->arg
.data
;
645 ret
= skb_splice_bits(skb
, offset
, tss
->pipe
, min(rd_desc
->count
, len
),
648 rd_desc
->count
-= ret
;
652 static int __tcp_splice_read(struct sock
*sk
, struct tcp_splice_state
*tss
)
654 /* Store TCP splice context information in read_descriptor_t. */
655 read_descriptor_t rd_desc
= {
660 return tcp_read_sock(sk
, &rd_desc
, tcp_splice_data_recv
);
664 * tcp_splice_read - splice data from TCP socket to a pipe
665 * @sock: socket to splice from
666 * @ppos: position (not valid)
667 * @pipe: pipe to splice to
668 * @len: number of bytes to splice
669 * @flags: splice modifier flags
672 * Will read pages from given socket and fill them into a pipe.
675 ssize_t
tcp_splice_read(struct socket
*sock
, loff_t
*ppos
,
676 struct pipe_inode_info
*pipe
, size_t len
,
679 struct sock
*sk
= sock
->sk
;
680 struct tcp_splice_state tss
= {
689 sock_rps_record_flow(sk
);
691 * We can't seek on a socket input
700 timeo
= sock_rcvtimeo(sk
, sock
->file
->f_flags
& O_NONBLOCK
);
702 ret
= __tcp_splice_read(sk
, &tss
);
708 if (sock_flag(sk
, SOCK_DONE
))
711 ret
= sock_error(sk
);
714 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
716 if (sk
->sk_state
== TCP_CLOSE
) {
718 * This occurs when user tries to read
719 * from never connected socket.
721 if (!sock_flag(sk
, SOCK_DONE
))
729 sk_wait_data(sk
, &timeo
);
730 if (signal_pending(current
)) {
731 ret
= sock_intr_errno(timeo
);
744 if (sk
->sk_err
|| sk
->sk_state
== TCP_CLOSE
||
745 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
746 signal_pending(current
))
757 EXPORT_SYMBOL(tcp_splice_read
);
759 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
)
763 /* The TCP header must be at least 32-bit aligned. */
764 size
= ALIGN(size
, 4);
766 skb
= alloc_skb_fclone(size
+ sk
->sk_prot
->max_header
, gfp
);
768 if (sk_wmem_schedule(sk
, skb
->truesize
)) {
769 skb_reserve(skb
, sk
->sk_prot
->max_header
);
771 * Make sure that we have exactly size bytes
772 * available to the caller, no more, no less.
774 skb
->avail_size
= size
;
779 sk
->sk_prot
->enter_memory_pressure(sk
);
780 sk_stream_moderate_sndbuf(sk
);
785 static unsigned int tcp_xmit_size_goal(struct sock
*sk
, u32 mss_now
,
788 struct tcp_sock
*tp
= tcp_sk(sk
);
789 u32 xmit_size_goal
, old_size_goal
;
791 xmit_size_goal
= mss_now
;
793 if (large_allowed
&& sk_can_gso(sk
)) {
794 xmit_size_goal
= ((sk
->sk_gso_max_size
- 1) -
795 inet_csk(sk
)->icsk_af_ops
->net_header_len
-
796 inet_csk(sk
)->icsk_ext_hdr_len
-
799 xmit_size_goal
= tcp_bound_to_half_wnd(tp
, xmit_size_goal
);
801 /* We try hard to avoid divides here */
802 old_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
804 if (likely(old_size_goal
<= xmit_size_goal
&&
805 old_size_goal
+ mss_now
> xmit_size_goal
)) {
806 xmit_size_goal
= old_size_goal
;
808 tp
->xmit_size_goal_segs
= xmit_size_goal
/ mss_now
;
809 xmit_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
813 return max(xmit_size_goal
, mss_now
);
816 static int tcp_send_mss(struct sock
*sk
, int *size_goal
, int flags
)
820 mss_now
= tcp_current_mss(sk
);
821 *size_goal
= tcp_xmit_size_goal(sk
, mss_now
, !(flags
& MSG_OOB
));
826 static ssize_t
do_tcp_sendpages(struct sock
*sk
, struct page
**pages
, int poffset
,
827 size_t psize
, int flags
)
829 struct tcp_sock
*tp
= tcp_sk(sk
);
830 int mss_now
, size_goal
;
833 long timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
835 /* Wait for a connection to finish. */
836 if ((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
))
837 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
840 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
842 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
846 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
850 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
851 struct page
*page
= pages
[poffset
/ PAGE_SIZE
];
853 int offset
= poffset
% PAGE_SIZE
;
854 int size
= min_t(size_t, psize
, PAGE_SIZE
- offset
);
857 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
859 if (!sk_stream_memory_free(sk
))
860 goto wait_for_sndbuf
;
862 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
);
864 goto wait_for_memory
;
873 i
= skb_shinfo(skb
)->nr_frags
;
874 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
875 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
876 tcp_mark_push(tp
, skb
);
879 if (!sk_wmem_schedule(sk
, copy
))
880 goto wait_for_memory
;
883 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
886 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
890 skb
->data_len
+= copy
;
891 skb
->truesize
+= copy
;
892 sk
->sk_wmem_queued
+= copy
;
893 sk_mem_charge(sk
, copy
);
894 skb
->ip_summed
= CHECKSUM_PARTIAL
;
895 tp
->write_seq
+= copy
;
896 TCP_SKB_CB(skb
)->end_seq
+= copy
;
897 skb_shinfo(skb
)->gso_segs
= 0;
900 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
904 if (!(psize
-= copy
))
907 if (skb
->len
< size_goal
|| (flags
& MSG_OOB
))
910 if (forced_push(tp
)) {
911 tcp_mark_push(tp
, skb
);
912 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
913 } else if (skb
== tcp_send_head(sk
))
914 tcp_push_one(sk
, mss_now
);
918 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
921 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
923 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
926 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
930 if (copied
&& !(flags
& MSG_SENDPAGE_NOTLAST
))
931 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
938 return sk_stream_error(sk
, flags
, err
);
941 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
942 size_t size
, int flags
)
946 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
947 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
948 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
952 res
= do_tcp_sendpages(sk
, &page
, offset
, size
, flags
);
956 EXPORT_SYMBOL(tcp_sendpage
);
958 static inline int select_size(const struct sock
*sk
, bool sg
)
960 const struct tcp_sock
*tp
= tcp_sk(sk
);
961 int tmp
= tp
->mss_cache
;
964 if (sk_can_gso(sk
)) {
965 /* Small frames wont use a full page:
966 * Payload will immediately follow tcp header.
968 tmp
= SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER
);
970 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
972 if (tmp
>= pgbreak
&&
973 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
981 int tcp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
985 struct tcp_sock
*tp
= tcp_sk(sk
);
987 int iovlen
, flags
, err
, copied
;
988 int mss_now
= 0, size_goal
;
994 flags
= msg
->msg_flags
;
995 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
997 /* Wait for a connection to finish. */
998 if ((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
))
999 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
1002 if (unlikely(tp
->repair
)) {
1003 if (tp
->repair_queue
== TCP_RECV_QUEUE
) {
1004 copied
= tcp_send_rcvq(sk
, msg
, size
);
1009 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1012 /* 'common' sending to sendq */
1015 /* This should be in poll */
1016 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
1018 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1020 /* Ok commence sending. */
1021 iovlen
= msg
->msg_iovlen
;
1026 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
1029 sg
= !!(sk
->sk_route_caps
& NETIF_F_SG
);
1031 while (--iovlen
>= 0) {
1032 size_t seglen
= iov
->iov_len
;
1033 unsigned char __user
*from
= iov
->iov_base
;
1037 while (seglen
> 0) {
1039 int max
= size_goal
;
1041 skb
= tcp_write_queue_tail(sk
);
1042 if (tcp_send_head(sk
)) {
1043 if (skb
->ip_summed
== CHECKSUM_NONE
)
1045 copy
= max
- skb
->len
;
1050 /* Allocate new segment. If the interface is SG,
1051 * allocate skb fitting to single page.
1053 if (!sk_stream_memory_free(sk
))
1054 goto wait_for_sndbuf
;
1056 skb
= sk_stream_alloc_skb(sk
,
1057 select_size(sk
, sg
),
1060 goto wait_for_memory
;
1063 * Check whether we can use HW checksum.
1065 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
1066 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1068 skb_entail(sk
, skb
);
1073 /* Try to append data to the end of skb. */
1077 /* Where to copy to? */
1078 if (skb_availroom(skb
) > 0) {
1079 /* We have some space in skb head. Superb! */
1080 copy
= min_t(int, copy
, skb_availroom(skb
));
1081 err
= skb_add_data_nocache(sk
, skb
, from
, copy
);
1086 int i
= skb_shinfo(skb
)->nr_frags
;
1087 struct page
*page
= sk
->sk_sndmsg_page
;
1090 if (page
&& page_count(page
) == 1)
1091 sk
->sk_sndmsg_off
= 0;
1093 off
= sk
->sk_sndmsg_off
;
1095 if (skb_can_coalesce(skb
, i
, page
, off
) &&
1097 /* We can extend the last page
1100 } else if (i
== MAX_SKB_FRAGS
|| !sg
) {
1101 /* Need to add new fragment and cannot
1102 * do this because interface is non-SG,
1103 * or because all the page slots are
1105 tcp_mark_push(tp
, skb
);
1108 if (off
== PAGE_SIZE
) {
1110 sk
->sk_sndmsg_page
= page
= NULL
;
1116 if (copy
> PAGE_SIZE
- off
)
1117 copy
= PAGE_SIZE
- off
;
1119 if (!sk_wmem_schedule(sk
, copy
))
1120 goto wait_for_memory
;
1123 /* Allocate new cache page. */
1124 if (!(page
= sk_stream_alloc_page(sk
)))
1125 goto wait_for_memory
;
1128 /* Time to copy data. We are close to
1130 err
= skb_copy_to_page_nocache(sk
, from
, skb
,
1133 /* If this page was new, give it to the
1134 * socket so it does not get leaked.
1136 if (!sk
->sk_sndmsg_page
) {
1137 sk
->sk_sndmsg_page
= page
;
1138 sk
->sk_sndmsg_off
= 0;
1143 /* Update the skb. */
1145 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
1147 skb_fill_page_desc(skb
, i
, page
, off
, copy
);
1148 if (sk
->sk_sndmsg_page
) {
1150 } else if (off
+ copy
< PAGE_SIZE
) {
1152 sk
->sk_sndmsg_page
= page
;
1156 sk
->sk_sndmsg_off
= off
+ copy
;
1160 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
1162 tp
->write_seq
+= copy
;
1163 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1164 skb_shinfo(skb
)->gso_segs
= 0;
1168 if ((seglen
-= copy
) == 0 && iovlen
== 0)
1171 if (skb
->len
< max
|| (flags
& MSG_OOB
) || unlikely(tp
->repair
))
1174 if (forced_push(tp
)) {
1175 tcp_mark_push(tp
, skb
);
1176 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1177 } else if (skb
== tcp_send_head(sk
))
1178 tcp_push_one(sk
, mss_now
);
1182 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1184 if (copied
&& likely(!tp
->repair
))
1185 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
1187 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1190 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1195 if (copied
&& likely(!tp
->repair
))
1196 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
1202 tcp_unlink_write_queue(skb
, sk
);
1203 /* It is the one place in all of TCP, except connection
1204 * reset, where we can be unlinking the send_head.
1206 tcp_check_send_head(sk
, skb
);
1207 sk_wmem_free_skb(sk
, skb
);
1214 err
= sk_stream_error(sk
, flags
, err
);
1218 EXPORT_SYMBOL(tcp_sendmsg
);
1221 * Handle reading urgent data. BSD has very simple semantics for
1222 * this, no blocking and very strange errors 8)
1225 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1227 struct tcp_sock
*tp
= tcp_sk(sk
);
1229 /* No URG data to read. */
1230 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1231 tp
->urg_data
== TCP_URG_READ
)
1232 return -EINVAL
; /* Yes this is right ! */
1234 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1237 if (tp
->urg_data
& TCP_URG_VALID
) {
1239 char c
= tp
->urg_data
;
1241 if (!(flags
& MSG_PEEK
))
1242 tp
->urg_data
= TCP_URG_READ
;
1244 /* Read urgent data. */
1245 msg
->msg_flags
|= MSG_OOB
;
1248 if (!(flags
& MSG_TRUNC
))
1249 err
= memcpy_toiovec(msg
->msg_iov
, &c
, 1);
1252 msg
->msg_flags
|= MSG_TRUNC
;
1254 return err
? -EFAULT
: len
;
1257 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1260 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1261 * the available implementations agree in this case:
1262 * this call should never block, independent of the
1263 * blocking state of the socket.
1264 * Mike <pall@rz.uni-karlsruhe.de>
1269 static int tcp_peek_sndq(struct sock
*sk
, struct msghdr
*msg
, int len
)
1271 struct sk_buff
*skb
;
1272 int copied
= 0, err
= 0;
1274 /* XXX -- need to support SO_PEEK_OFF */
1276 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
1277 err
= skb_copy_datagram_iovec(skb
, 0, msg
->msg_iov
, skb
->len
);
1284 return err
?: copied
;
1287 /* Clean up the receive buffer for full frames taken by the user,
1288 * then send an ACK if necessary. COPIED is the number of bytes
1289 * tcp_recvmsg has given to the user so far, it speeds up the
1290 * calculation of whether or not we must ACK for the sake of
1293 void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1295 struct tcp_sock
*tp
= tcp_sk(sk
);
1296 bool time_to_ack
= false;
1298 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1300 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1301 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1302 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1304 if (inet_csk_ack_scheduled(sk
)) {
1305 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1306 /* Delayed ACKs frequently hit locked sockets during bulk
1308 if (icsk
->icsk_ack
.blocked
||
1309 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1310 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1312 * If this read emptied read buffer, we send ACK, if
1313 * connection is not bidirectional, user drained
1314 * receive buffer and there was a small segment
1318 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1319 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1320 !icsk
->icsk_ack
.pingpong
)) &&
1321 !atomic_read(&sk
->sk_rmem_alloc
)))
1325 /* We send an ACK if we can now advertise a non-zero window
1326 * which has been raised "significantly".
1328 * Even if window raised up to infinity, do not send window open ACK
1329 * in states, where we will not receive more. It is useless.
1331 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1332 __u32 rcv_window_now
= tcp_receive_window(tp
);
1334 /* Optimize, __tcp_select_window() is not cheap. */
1335 if (2*rcv_window_now
<= tp
->window_clamp
) {
1336 __u32 new_window
= __tcp_select_window(sk
);
1338 /* Send ACK now, if this read freed lots of space
1339 * in our buffer. Certainly, new_window is new window.
1340 * We can advertise it now, if it is not less than current one.
1341 * "Lots" means "at least twice" here.
1343 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1351 static void tcp_prequeue_process(struct sock
*sk
)
1353 struct sk_buff
*skb
;
1354 struct tcp_sock
*tp
= tcp_sk(sk
);
1356 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1358 /* RX process wants to run with disabled BHs, though it is not
1361 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1362 sk_backlog_rcv(sk
, skb
);
1365 /* Clear memory counter. */
1366 tp
->ucopy
.memory
= 0;
1369 #ifdef CONFIG_NET_DMA
1370 static void tcp_service_net_dma(struct sock
*sk
, bool wait
)
1372 dma_cookie_t done
, used
;
1373 dma_cookie_t last_issued
;
1374 struct tcp_sock
*tp
= tcp_sk(sk
);
1376 if (!tp
->ucopy
.dma_chan
)
1379 last_issued
= tp
->ucopy
.dma_cookie
;
1380 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1383 if (dma_async_memcpy_complete(tp
->ucopy
.dma_chan
,
1385 &used
) == DMA_SUCCESS
) {
1386 /* Safe to free early-copied skbs now */
1387 __skb_queue_purge(&sk
->sk_async_wait_queue
);
1390 struct sk_buff
*skb
;
1391 while ((skb
= skb_peek(&sk
->sk_async_wait_queue
)) &&
1392 (dma_async_is_complete(skb
->dma_cookie
, done
,
1393 used
) == DMA_SUCCESS
)) {
1394 __skb_dequeue(&sk
->sk_async_wait_queue
);
1402 static inline struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1404 struct sk_buff
*skb
;
1407 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1408 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1409 if (tcp_hdr(skb
)->syn
)
1411 if (offset
< skb
->len
|| tcp_hdr(skb
)->fin
) {
1420 * This routine provides an alternative to tcp_recvmsg() for routines
1421 * that would like to handle copying from skbuffs directly in 'sendfile'
1424 * - It is assumed that the socket was locked by the caller.
1425 * - The routine does not block.
1426 * - At present, there is no support for reading OOB data
1427 * or for 'peeking' the socket using this routine
1428 * (although both would be easy to implement).
1430 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1431 sk_read_actor_t recv_actor
)
1433 struct sk_buff
*skb
;
1434 struct tcp_sock
*tp
= tcp_sk(sk
);
1435 u32 seq
= tp
->copied_seq
;
1439 if (sk
->sk_state
== TCP_LISTEN
)
1441 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1442 if (offset
< skb
->len
) {
1446 len
= skb
->len
- offset
;
1447 /* Stop reading if we hit a patch of urgent data */
1449 u32 urg_offset
= tp
->urg_seq
- seq
;
1450 if (urg_offset
< len
)
1455 used
= recv_actor(desc
, skb
, offset
, len
);
1460 } else if (used
<= len
) {
1466 * If recv_actor drops the lock (e.g. TCP splice
1467 * receive) the skb pointer might be invalid when
1468 * getting here: tcp_collapse might have deleted it
1469 * while aggregating skbs from the socket queue.
1471 skb
= tcp_recv_skb(sk
, seq
-1, &offset
);
1472 if (!skb
|| (offset
+1 != skb
->len
))
1475 if (tcp_hdr(skb
)->fin
) {
1476 sk_eat_skb(sk
, skb
, false);
1480 sk_eat_skb(sk
, skb
, false);
1483 tp
->copied_seq
= seq
;
1485 tp
->copied_seq
= seq
;
1487 tcp_rcv_space_adjust(sk
);
1489 /* Clean up data we have read: This will do ACK frames. */
1491 tcp_cleanup_rbuf(sk
, copied
);
1494 EXPORT_SYMBOL(tcp_read_sock
);
1497 * This routine copies from a sock struct into the user buffer.
1499 * Technical note: in 2.3 we work on _locked_ socket, so that
1500 * tricks with *seq access order and skb->users are not required.
1501 * Probably, code can be easily improved even more.
1504 int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1505 size_t len
, int nonblock
, int flags
, int *addr_len
)
1507 struct tcp_sock
*tp
= tcp_sk(sk
);
1513 int target
; /* Read at least this many bytes */
1515 struct task_struct
*user_recv
= NULL
;
1516 bool copied_early
= false;
1517 struct sk_buff
*skb
;
1523 if (sk
->sk_state
== TCP_LISTEN
)
1526 timeo
= sock_rcvtimeo(sk
, nonblock
);
1528 /* Urgent data needs to be handled specially. */
1529 if (flags
& MSG_OOB
)
1532 if (unlikely(tp
->repair
)) {
1534 if (!(flags
& MSG_PEEK
))
1537 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
1541 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1544 /* 'common' recv queue MSG_PEEK-ing */
1547 seq
= &tp
->copied_seq
;
1548 if (flags
& MSG_PEEK
) {
1549 peek_seq
= tp
->copied_seq
;
1553 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1555 #ifdef CONFIG_NET_DMA
1556 tp
->ucopy
.dma_chan
= NULL
;
1558 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
1563 available
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- (*seq
);
1564 if ((available
< target
) &&
1565 (len
> sysctl_tcp_dma_copybreak
) && !(flags
& MSG_PEEK
) &&
1566 !sysctl_tcp_low_latency
&&
1567 net_dma_find_channel()) {
1568 preempt_enable_no_resched();
1569 tp
->ucopy
.pinned_list
=
1570 dma_pin_iovec_pages(msg
->msg_iov
, len
);
1572 preempt_enable_no_resched();
1580 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1581 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1584 if (signal_pending(current
)) {
1585 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1590 /* Next get a buffer. */
1592 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1593 /* Now that we have two receive queues this
1596 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1597 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1598 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1602 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1603 if (tcp_hdr(skb
)->syn
)
1605 if (offset
< skb
->len
)
1607 if (tcp_hdr(skb
)->fin
)
1609 WARN(!(flags
& MSG_PEEK
),
1610 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1611 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
, flags
);
1614 /* Well, if we have backlog, try to process it now yet. */
1616 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1621 sk
->sk_state
== TCP_CLOSE
||
1622 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1624 signal_pending(current
))
1627 if (sock_flag(sk
, SOCK_DONE
))
1631 copied
= sock_error(sk
);
1635 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1638 if (sk
->sk_state
== TCP_CLOSE
) {
1639 if (!sock_flag(sk
, SOCK_DONE
)) {
1640 /* This occurs when user tries to read
1641 * from never connected socket.
1654 if (signal_pending(current
)) {
1655 copied
= sock_intr_errno(timeo
);
1660 tcp_cleanup_rbuf(sk
, copied
);
1662 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1663 /* Install new reader */
1664 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1665 user_recv
= current
;
1666 tp
->ucopy
.task
= user_recv
;
1667 tp
->ucopy
.iov
= msg
->msg_iov
;
1670 tp
->ucopy
.len
= len
;
1672 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1673 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1675 /* Ugly... If prequeue is not empty, we have to
1676 * process it before releasing socket, otherwise
1677 * order will be broken at second iteration.
1678 * More elegant solution is required!!!
1680 * Look: we have the following (pseudo)queues:
1682 * 1. packets in flight
1687 * Each queue can be processed only if the next ones
1688 * are empty. At this point we have empty receive_queue.
1689 * But prequeue _can_ be not empty after 2nd iteration,
1690 * when we jumped to start of loop because backlog
1691 * processing added something to receive_queue.
1692 * We cannot release_sock(), because backlog contains
1693 * packets arrived _after_ prequeued ones.
1695 * Shortly, algorithm is clear --- to process all
1696 * the queues in order. We could make it more directly,
1697 * requeueing packets from backlog to prequeue, if
1698 * is not empty. It is more elegant, but eats cycles,
1701 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1704 /* __ Set realtime policy in scheduler __ */
1707 #ifdef CONFIG_NET_DMA
1708 if (tp
->ucopy
.dma_chan
)
1709 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1711 if (copied
>= target
) {
1712 /* Do not sleep, just process backlog. */
1716 sk_wait_data(sk
, &timeo
);
1718 #ifdef CONFIG_NET_DMA
1719 tcp_service_net_dma(sk
, false); /* Don't block */
1720 tp
->ucopy
.wakeup
= 0;
1726 /* __ Restore normal policy in scheduler __ */
1728 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1729 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1734 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1735 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1737 tcp_prequeue_process(sk
);
1739 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1740 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1746 if ((flags
& MSG_PEEK
) &&
1747 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1748 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1750 task_pid_nr(current
));
1751 peek_seq
= tp
->copied_seq
;
1756 /* Ok so how much can we use? */
1757 used
= skb
->len
- offset
;
1761 /* Do we have urgent data here? */
1763 u32 urg_offset
= tp
->urg_seq
- *seq
;
1764 if (urg_offset
< used
) {
1766 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1779 if (!(flags
& MSG_TRUNC
)) {
1780 #ifdef CONFIG_NET_DMA
1781 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
1782 tp
->ucopy
.dma_chan
= net_dma_find_channel();
1784 if (tp
->ucopy
.dma_chan
) {
1785 tp
->ucopy
.dma_cookie
= dma_skb_copy_datagram_iovec(
1786 tp
->ucopy
.dma_chan
, skb
, offset
,
1788 tp
->ucopy
.pinned_list
);
1790 if (tp
->ucopy
.dma_cookie
< 0) {
1792 pr_alert("%s: dma_cookie < 0\n",
1795 /* Exception. Bailout! */
1801 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1803 if ((offset
+ used
) == skb
->len
)
1804 copied_early
= true;
1809 err
= skb_copy_datagram_iovec(skb
, offset
,
1810 msg
->msg_iov
, used
);
1812 /* Exception. Bailout! */
1824 tcp_rcv_space_adjust(sk
);
1827 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1829 tcp_fast_path_check(sk
);
1831 if (used
+ offset
< skb
->len
)
1834 if (tcp_hdr(skb
)->fin
)
1836 if (!(flags
& MSG_PEEK
)) {
1837 sk_eat_skb(sk
, skb
, copied_early
);
1838 copied_early
= false;
1843 /* Process the FIN. */
1845 if (!(flags
& MSG_PEEK
)) {
1846 sk_eat_skb(sk
, skb
, copied_early
);
1847 copied_early
= false;
1853 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1856 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1858 tcp_prequeue_process(sk
);
1860 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1861 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1867 tp
->ucopy
.task
= NULL
;
1871 #ifdef CONFIG_NET_DMA
1872 tcp_service_net_dma(sk
, true); /* Wait for queue to drain */
1873 tp
->ucopy
.dma_chan
= NULL
;
1875 if (tp
->ucopy
.pinned_list
) {
1876 dma_unpin_iovec_pages(tp
->ucopy
.pinned_list
);
1877 tp
->ucopy
.pinned_list
= NULL
;
1881 /* According to UNIX98, msg_name/msg_namelen are ignored
1882 * on connected socket. I was just happy when found this 8) --ANK
1885 /* Clean up data we have read: This will do ACK frames. */
1886 tcp_cleanup_rbuf(sk
, copied
);
1896 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1900 err
= tcp_peek_sndq(sk
, msg
, len
);
1903 EXPORT_SYMBOL(tcp_recvmsg
);
1905 void tcp_set_state(struct sock
*sk
, int state
)
1907 int oldstate
= sk
->sk_state
;
1910 case TCP_ESTABLISHED
:
1911 if (oldstate
!= TCP_ESTABLISHED
)
1912 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1916 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1917 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1919 sk
->sk_prot
->unhash(sk
);
1920 if (inet_csk(sk
)->icsk_bind_hash
&&
1921 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1925 if (oldstate
== TCP_ESTABLISHED
)
1926 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1929 /* Change state AFTER socket is unhashed to avoid closed
1930 * socket sitting in hash tables.
1932 sk
->sk_state
= state
;
1935 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
1938 EXPORT_SYMBOL_GPL(tcp_set_state
);
1941 * State processing on a close. This implements the state shift for
1942 * sending our FIN frame. Note that we only send a FIN for some
1943 * states. A shutdown() may have already sent the FIN, or we may be
1947 static const unsigned char new_state
[16] = {
1948 /* current state: new state: action: */
1949 /* (Invalid) */ TCP_CLOSE
,
1950 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1951 /* TCP_SYN_SENT */ TCP_CLOSE
,
1952 /* TCP_SYN_RECV */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1953 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1
,
1954 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2
,
1955 /* TCP_TIME_WAIT */ TCP_CLOSE
,
1956 /* TCP_CLOSE */ TCP_CLOSE
,
1957 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK
| TCP_ACTION_FIN
,
1958 /* TCP_LAST_ACK */ TCP_LAST_ACK
,
1959 /* TCP_LISTEN */ TCP_CLOSE
,
1960 /* TCP_CLOSING */ TCP_CLOSING
,
1963 static int tcp_close_state(struct sock
*sk
)
1965 int next
= (int)new_state
[sk
->sk_state
];
1966 int ns
= next
& TCP_STATE_MASK
;
1968 tcp_set_state(sk
, ns
);
1970 return next
& TCP_ACTION_FIN
;
1974 * Shutdown the sending side of a connection. Much like close except
1975 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1978 void tcp_shutdown(struct sock
*sk
, int how
)
1980 /* We need to grab some memory, and put together a FIN,
1981 * and then put it into the queue to be sent.
1982 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1984 if (!(how
& SEND_SHUTDOWN
))
1987 /* If we've already sent a FIN, or it's a closed state, skip this. */
1988 if ((1 << sk
->sk_state
) &
1989 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
1990 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
1991 /* Clear out any half completed packets. FIN if needed. */
1992 if (tcp_close_state(sk
))
1996 EXPORT_SYMBOL(tcp_shutdown
);
1998 bool tcp_check_oom(struct sock
*sk
, int shift
)
2000 bool too_many_orphans
, out_of_socket_memory
;
2002 too_many_orphans
= tcp_too_many_orphans(sk
, shift
);
2003 out_of_socket_memory
= tcp_out_of_memory(sk
);
2005 if (too_many_orphans
)
2006 net_info_ratelimited("too many orphaned sockets\n");
2007 if (out_of_socket_memory
)
2008 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2009 return too_many_orphans
|| out_of_socket_memory
;
2012 void tcp_close(struct sock
*sk
, long timeout
)
2014 struct sk_buff
*skb
;
2015 int data_was_unread
= 0;
2019 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2021 if (sk
->sk_state
== TCP_LISTEN
) {
2022 tcp_set_state(sk
, TCP_CLOSE
);
2025 inet_csk_listen_stop(sk
);
2027 goto adjudge_to_death
;
2030 /* We need to flush the recv. buffs. We do this only on the
2031 * descriptor close, not protocol-sourced closes, because the
2032 * reader process may not have drained the data yet!
2034 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
2035 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
-
2037 data_was_unread
+= len
;
2043 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2044 if (sk
->sk_state
== TCP_CLOSE
)
2045 goto adjudge_to_death
;
2047 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2048 * data was lost. To witness the awful effects of the old behavior of
2049 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2050 * GET in an FTP client, suspend the process, wait for the client to
2051 * advertise a zero window, then kill -9 the FTP client, wheee...
2052 * Note: timeout is always zero in such a case.
2054 if (unlikely(tcp_sk(sk
)->repair
)) {
2055 sk
->sk_prot
->disconnect(sk
, 0);
2056 } else if (data_was_unread
) {
2057 /* Unread data was tossed, zap the connection. */
2058 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
2059 tcp_set_state(sk
, TCP_CLOSE
);
2060 tcp_send_active_reset(sk
, sk
->sk_allocation
);
2061 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
2062 /* Check zero linger _after_ checking for unread data. */
2063 sk
->sk_prot
->disconnect(sk
, 0);
2064 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
2065 } else if (tcp_close_state(sk
)) {
2066 /* We FIN if the application ate all the data before
2067 * zapping the connection.
2070 /* RED-PEN. Formally speaking, we have broken TCP state
2071 * machine. State transitions:
2073 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2074 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2075 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2077 * are legal only when FIN has been sent (i.e. in window),
2078 * rather than queued out of window. Purists blame.
2080 * F.e. "RFC state" is ESTABLISHED,
2081 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2083 * The visible declinations are that sometimes
2084 * we enter time-wait state, when it is not required really
2085 * (harmless), do not send active resets, when they are
2086 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2087 * they look as CLOSING or LAST_ACK for Linux)
2088 * Probably, I missed some more holelets.
2094 sk_stream_wait_close(sk
, timeout
);
2097 state
= sk
->sk_state
;
2101 /* It is the last release_sock in its life. It will remove backlog. */
2105 /* Now socket is owned by kernel and we acquire BH lock
2106 to finish close. No need to check for user refs.
2110 WARN_ON(sock_owned_by_user(sk
));
2112 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
2114 /* Have we already been destroyed by a softirq or backlog? */
2115 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
2118 /* This is a (useful) BSD violating of the RFC. There is a
2119 * problem with TCP as specified in that the other end could
2120 * keep a socket open forever with no application left this end.
2121 * We use a 3 minute timeout (about the same as BSD) then kill
2122 * our end. If they send after that then tough - BUT: long enough
2123 * that we won't make the old 4*rto = almost no time - whoops
2126 * Nope, it was not mistake. It is really desired behaviour
2127 * f.e. on http servers, when such sockets are useless, but
2128 * consume significant resources. Let's do it with special
2129 * linger2 option. --ANK
2132 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
2133 struct tcp_sock
*tp
= tcp_sk(sk
);
2134 if (tp
->linger2
< 0) {
2135 tcp_set_state(sk
, TCP_CLOSE
);
2136 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2137 NET_INC_STATS_BH(sock_net(sk
),
2138 LINUX_MIB_TCPABORTONLINGER
);
2140 const int tmo
= tcp_fin_time(sk
);
2142 if (tmo
> TCP_TIMEWAIT_LEN
) {
2143 inet_csk_reset_keepalive_timer(sk
,
2144 tmo
- TCP_TIMEWAIT_LEN
);
2146 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2151 if (sk
->sk_state
!= TCP_CLOSE
) {
2153 if (tcp_check_oom(sk
, 0)) {
2154 tcp_set_state(sk
, TCP_CLOSE
);
2155 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2156 NET_INC_STATS_BH(sock_net(sk
),
2157 LINUX_MIB_TCPABORTONMEMORY
);
2161 if (sk
->sk_state
== TCP_CLOSE
)
2162 inet_csk_destroy_sock(sk
);
2163 /* Otherwise, socket is reprieved until protocol close. */
2170 EXPORT_SYMBOL(tcp_close
);
2172 /* These states need RST on ABORT according to RFC793 */
2174 static inline bool tcp_need_reset(int state
)
2176 return (1 << state
) &
2177 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2178 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2181 int tcp_disconnect(struct sock
*sk
, int flags
)
2183 struct inet_sock
*inet
= inet_sk(sk
);
2184 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2185 struct tcp_sock
*tp
= tcp_sk(sk
);
2187 int old_state
= sk
->sk_state
;
2189 if (old_state
!= TCP_CLOSE
)
2190 tcp_set_state(sk
, TCP_CLOSE
);
2192 /* ABORT function of RFC793 */
2193 if (old_state
== TCP_LISTEN
) {
2194 inet_csk_listen_stop(sk
);
2195 } else if (unlikely(tp
->repair
)) {
2196 sk
->sk_err
= ECONNABORTED
;
2197 } else if (tcp_need_reset(old_state
) ||
2198 (tp
->snd_nxt
!= tp
->write_seq
&&
2199 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2200 /* The last check adjusts for discrepancy of Linux wrt. RFC
2203 tcp_send_active_reset(sk
, gfp_any());
2204 sk
->sk_err
= ECONNRESET
;
2205 } else if (old_state
== TCP_SYN_SENT
)
2206 sk
->sk_err
= ECONNRESET
;
2208 tcp_clear_xmit_timers(sk
);
2209 __skb_queue_purge(&sk
->sk_receive_queue
);
2210 tcp_write_queue_purge(sk
);
2211 __skb_queue_purge(&tp
->out_of_order_queue
);
2212 #ifdef CONFIG_NET_DMA
2213 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2216 inet
->inet_dport
= 0;
2218 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2219 inet_reset_saddr(sk
);
2221 sk
->sk_shutdown
= 0;
2222 sock_reset_flag(sk
, SOCK_DONE
);
2224 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2226 icsk
->icsk_backoff
= 0;
2228 icsk
->icsk_probes_out
= 0;
2229 tp
->packets_out
= 0;
2230 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2231 tp
->snd_cwnd_cnt
= 0;
2232 tp
->bytes_acked
= 0;
2233 tp
->window_clamp
= 0;
2234 tcp_set_ca_state(sk
, TCP_CA_Open
);
2235 tcp_clear_retrans(tp
);
2236 inet_csk_delack_init(sk
);
2237 tcp_init_send_head(sk
);
2238 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2241 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2243 sk
->sk_error_report(sk
);
2246 EXPORT_SYMBOL(tcp_disconnect
);
2248 static inline bool tcp_can_repair_sock(const struct sock
*sk
)
2250 return capable(CAP_NET_ADMIN
) &&
2251 ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_ESTABLISHED
));
2254 static int tcp_repair_options_est(struct tcp_sock
*tp
,
2255 struct tcp_repair_opt __user
*optbuf
, unsigned int len
)
2257 struct tcp_repair_opt opt
;
2259 while (len
>= sizeof(opt
)) {
2260 if (copy_from_user(&opt
, optbuf
, sizeof(opt
)))
2266 switch (opt
.opt_code
) {
2268 tp
->rx_opt
.mss_clamp
= opt
.opt_val
;
2271 if (opt
.opt_val
> 14)
2274 tp
->rx_opt
.snd_wscale
= opt
.opt_val
;
2276 case TCPOPT_SACK_PERM
:
2277 if (opt
.opt_val
!= 0)
2280 tp
->rx_opt
.sack_ok
|= TCP_SACK_SEEN
;
2281 if (sysctl_tcp_fack
)
2282 tcp_enable_fack(tp
);
2284 case TCPOPT_TIMESTAMP
:
2285 if (opt
.opt_val
!= 0)
2288 tp
->rx_opt
.tstamp_ok
= 1;
2297 * Socket option code for TCP.
2299 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2300 int optname
, char __user
*optval
, unsigned int optlen
)
2302 struct tcp_sock
*tp
= tcp_sk(sk
);
2303 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2307 /* These are data/string values, all the others are ints */
2309 case TCP_CONGESTION
: {
2310 char name
[TCP_CA_NAME_MAX
];
2315 val
= strncpy_from_user(name
, optval
,
2316 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2322 err
= tcp_set_congestion_control(sk
, name
);
2326 case TCP_COOKIE_TRANSACTIONS
: {
2327 struct tcp_cookie_transactions ctd
;
2328 struct tcp_cookie_values
*cvp
= NULL
;
2330 if (sizeof(ctd
) > optlen
)
2332 if (copy_from_user(&ctd
, optval
, sizeof(ctd
)))
2335 if (ctd
.tcpct_used
> sizeof(ctd
.tcpct_value
) ||
2336 ctd
.tcpct_s_data_desired
> TCP_MSS_DESIRED
)
2339 if (ctd
.tcpct_cookie_desired
== 0) {
2340 /* default to global value */
2341 } else if ((0x1 & ctd
.tcpct_cookie_desired
) ||
2342 ctd
.tcpct_cookie_desired
> TCP_COOKIE_MAX
||
2343 ctd
.tcpct_cookie_desired
< TCP_COOKIE_MIN
) {
2347 if (TCP_COOKIE_OUT_NEVER
& ctd
.tcpct_flags
) {
2348 /* Supercedes all other values */
2350 if (tp
->cookie_values
!= NULL
) {
2351 kref_put(&tp
->cookie_values
->kref
,
2352 tcp_cookie_values_release
);
2353 tp
->cookie_values
= NULL
;
2355 tp
->rx_opt
.cookie_in_always
= 0; /* false */
2356 tp
->rx_opt
.cookie_out_never
= 1; /* true */
2361 /* Allocate ancillary memory before locking.
2363 if (ctd
.tcpct_used
> 0 ||
2364 (tp
->cookie_values
== NULL
&&
2365 (sysctl_tcp_cookie_size
> 0 ||
2366 ctd
.tcpct_cookie_desired
> 0 ||
2367 ctd
.tcpct_s_data_desired
> 0))) {
2368 cvp
= kzalloc(sizeof(*cvp
) + ctd
.tcpct_used
,
2373 kref_init(&cvp
->kref
);
2376 tp
->rx_opt
.cookie_in_always
=
2377 (TCP_COOKIE_IN_ALWAYS
& ctd
.tcpct_flags
);
2378 tp
->rx_opt
.cookie_out_never
= 0; /* false */
2380 if (tp
->cookie_values
!= NULL
) {
2382 /* Changed values are recorded by a changed
2383 * pointer, ensuring the cookie will differ,
2384 * without separately hashing each value later.
2386 kref_put(&tp
->cookie_values
->kref
,
2387 tcp_cookie_values_release
);
2389 cvp
= tp
->cookie_values
;
2394 cvp
->cookie_desired
= ctd
.tcpct_cookie_desired
;
2396 if (ctd
.tcpct_used
> 0) {
2397 memcpy(cvp
->s_data_payload
, ctd
.tcpct_value
,
2399 cvp
->s_data_desired
= ctd
.tcpct_used
;
2400 cvp
->s_data_constant
= 1; /* true */
2402 /* No constant payload data. */
2403 cvp
->s_data_desired
= ctd
.tcpct_s_data_desired
;
2404 cvp
->s_data_constant
= 0; /* false */
2407 tp
->cookie_values
= cvp
;
2417 if (optlen
< sizeof(int))
2420 if (get_user(val
, (int __user
*)optval
))
2427 /* Values greater than interface MTU won't take effect. However
2428 * at the point when this call is done we typically don't yet
2429 * know which interface is going to be used */
2430 if (val
< TCP_MIN_MSS
|| val
> MAX_TCP_WINDOW
) {
2434 tp
->rx_opt
.user_mss
= val
;
2439 /* TCP_NODELAY is weaker than TCP_CORK, so that
2440 * this option on corked socket is remembered, but
2441 * it is not activated until cork is cleared.
2443 * However, when TCP_NODELAY is set we make
2444 * an explicit push, which overrides even TCP_CORK
2445 * for currently queued segments.
2447 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2448 tcp_push_pending_frames(sk
);
2450 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2454 case TCP_THIN_LINEAR_TIMEOUTS
:
2455 if (val
< 0 || val
> 1)
2461 case TCP_THIN_DUPACK
:
2462 if (val
< 0 || val
> 1)
2465 tp
->thin_dupack
= val
;
2466 if (tp
->thin_dupack
)
2467 tcp_disable_early_retrans(tp
);
2471 if (!tcp_can_repair_sock(sk
))
2473 else if (val
== 1) {
2475 sk
->sk_reuse
= SK_FORCE_REUSE
;
2476 tp
->repair_queue
= TCP_NO_QUEUE
;
2477 } else if (val
== 0) {
2479 sk
->sk_reuse
= SK_NO_REUSE
;
2480 tcp_send_window_probe(sk
);
2486 case TCP_REPAIR_QUEUE
:
2489 else if (val
< TCP_QUEUES_NR
)
2490 tp
->repair_queue
= val
;
2496 if (sk
->sk_state
!= TCP_CLOSE
)
2498 else if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2499 tp
->write_seq
= val
;
2500 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2506 case TCP_REPAIR_OPTIONS
:
2509 else if (sk
->sk_state
== TCP_ESTABLISHED
)
2510 err
= tcp_repair_options_est(tp
,
2511 (struct tcp_repair_opt __user
*)optval
,
2518 /* When set indicates to always queue non-full frames.
2519 * Later the user clears this option and we transmit
2520 * any pending partial frames in the queue. This is
2521 * meant to be used alongside sendfile() to get properly
2522 * filled frames when the user (for example) must write
2523 * out headers with a write() call first and then use
2524 * sendfile to send out the data parts.
2526 * TCP_CORK can be set together with TCP_NODELAY and it is
2527 * stronger than TCP_NODELAY.
2530 tp
->nonagle
|= TCP_NAGLE_CORK
;
2532 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2533 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2534 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2535 tcp_push_pending_frames(sk
);
2540 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2543 tp
->keepalive_time
= val
* HZ
;
2544 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2545 !((1 << sk
->sk_state
) &
2546 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2547 u32 elapsed
= keepalive_time_elapsed(tp
);
2548 if (tp
->keepalive_time
> elapsed
)
2549 elapsed
= tp
->keepalive_time
- elapsed
;
2552 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2557 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2560 tp
->keepalive_intvl
= val
* HZ
;
2563 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2566 tp
->keepalive_probes
= val
;
2569 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2572 icsk
->icsk_syn_retries
= val
;
2578 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2581 tp
->linger2
= val
* HZ
;
2584 case TCP_DEFER_ACCEPT
:
2585 /* Translate value in seconds to number of retransmits */
2586 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2587 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2591 case TCP_WINDOW_CLAMP
:
2593 if (sk
->sk_state
!= TCP_CLOSE
) {
2597 tp
->window_clamp
= 0;
2599 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2600 SOCK_MIN_RCVBUF
/ 2 : val
;
2605 icsk
->icsk_ack
.pingpong
= 1;
2607 icsk
->icsk_ack
.pingpong
= 0;
2608 if ((1 << sk
->sk_state
) &
2609 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2610 inet_csk_ack_scheduled(sk
)) {
2611 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2612 tcp_cleanup_rbuf(sk
, 1);
2614 icsk
->icsk_ack
.pingpong
= 1;
2619 #ifdef CONFIG_TCP_MD5SIG
2621 /* Read the IP->Key mappings from userspace */
2622 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2625 case TCP_USER_TIMEOUT
:
2626 /* Cap the max timeout in ms TCP will retry/retrans
2627 * before giving up and aborting (ETIMEDOUT) a connection.
2629 icsk
->icsk_user_timeout
= msecs_to_jiffies(val
);
2640 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2641 unsigned int optlen
)
2643 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2645 if (level
!= SOL_TCP
)
2646 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2648 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2650 EXPORT_SYMBOL(tcp_setsockopt
);
2652 #ifdef CONFIG_COMPAT
2653 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2654 char __user
*optval
, unsigned int optlen
)
2656 if (level
!= SOL_TCP
)
2657 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2659 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2661 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2664 /* Return information about state of tcp endpoint in API format. */
2665 void tcp_get_info(const struct sock
*sk
, struct tcp_info
*info
)
2667 const struct tcp_sock
*tp
= tcp_sk(sk
);
2668 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2669 u32 now
= tcp_time_stamp
;
2671 memset(info
, 0, sizeof(*info
));
2673 info
->tcpi_state
= sk
->sk_state
;
2674 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2675 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2676 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2677 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2679 if (tp
->rx_opt
.tstamp_ok
)
2680 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2681 if (tcp_is_sack(tp
))
2682 info
->tcpi_options
|= TCPI_OPT_SACK
;
2683 if (tp
->rx_opt
.wscale_ok
) {
2684 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2685 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2686 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2689 if (tp
->ecn_flags
& TCP_ECN_OK
)
2690 info
->tcpi_options
|= TCPI_OPT_ECN
;
2691 if (tp
->ecn_flags
& TCP_ECN_SEEN
)
2692 info
->tcpi_options
|= TCPI_OPT_ECN_SEEN
;
2694 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2695 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2696 info
->tcpi_snd_mss
= tp
->mss_cache
;
2697 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2699 if (sk
->sk_state
== TCP_LISTEN
) {
2700 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2701 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2703 info
->tcpi_unacked
= tp
->packets_out
;
2704 info
->tcpi_sacked
= tp
->sacked_out
;
2706 info
->tcpi_lost
= tp
->lost_out
;
2707 info
->tcpi_retrans
= tp
->retrans_out
;
2708 info
->tcpi_fackets
= tp
->fackets_out
;
2710 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2711 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2712 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2714 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2715 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2716 info
->tcpi_rtt
= jiffies_to_usecs(tp
->srtt
)>>3;
2717 info
->tcpi_rttvar
= jiffies_to_usecs(tp
->mdev
)>>2;
2718 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2719 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2720 info
->tcpi_advmss
= tp
->advmss
;
2721 info
->tcpi_reordering
= tp
->reordering
;
2723 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2724 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2726 info
->tcpi_total_retrans
= tp
->total_retrans
;
2728 EXPORT_SYMBOL_GPL(tcp_get_info
);
2730 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2731 int optname
, char __user
*optval
, int __user
*optlen
)
2733 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2734 struct tcp_sock
*tp
= tcp_sk(sk
);
2737 if (get_user(len
, optlen
))
2740 len
= min_t(unsigned int, len
, sizeof(int));
2747 val
= tp
->mss_cache
;
2748 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2749 val
= tp
->rx_opt
.user_mss
;
2751 val
= tp
->rx_opt
.mss_clamp
;
2754 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2757 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2760 val
= keepalive_time_when(tp
) / HZ
;
2763 val
= keepalive_intvl_when(tp
) / HZ
;
2766 val
= keepalive_probes(tp
);
2769 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2774 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2776 case TCP_DEFER_ACCEPT
:
2777 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2778 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2780 case TCP_WINDOW_CLAMP
:
2781 val
= tp
->window_clamp
;
2784 struct tcp_info info
;
2786 if (get_user(len
, optlen
))
2789 tcp_get_info(sk
, &info
);
2791 len
= min_t(unsigned int, len
, sizeof(info
));
2792 if (put_user(len
, optlen
))
2794 if (copy_to_user(optval
, &info
, len
))
2799 val
= !icsk
->icsk_ack
.pingpong
;
2802 case TCP_CONGESTION
:
2803 if (get_user(len
, optlen
))
2805 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2806 if (put_user(len
, optlen
))
2808 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2812 case TCP_COOKIE_TRANSACTIONS
: {
2813 struct tcp_cookie_transactions ctd
;
2814 struct tcp_cookie_values
*cvp
= tp
->cookie_values
;
2816 if (get_user(len
, optlen
))
2818 if (len
< sizeof(ctd
))
2821 memset(&ctd
, 0, sizeof(ctd
));
2822 ctd
.tcpct_flags
= (tp
->rx_opt
.cookie_in_always
?
2823 TCP_COOKIE_IN_ALWAYS
: 0)
2824 | (tp
->rx_opt
.cookie_out_never
?
2825 TCP_COOKIE_OUT_NEVER
: 0);
2828 ctd
.tcpct_flags
|= (cvp
->s_data_in
?
2830 | (cvp
->s_data_out
?
2831 TCP_S_DATA_OUT
: 0);
2833 ctd
.tcpct_cookie_desired
= cvp
->cookie_desired
;
2834 ctd
.tcpct_s_data_desired
= cvp
->s_data_desired
;
2836 memcpy(&ctd
.tcpct_value
[0], &cvp
->cookie_pair
[0],
2837 cvp
->cookie_pair_size
);
2838 ctd
.tcpct_used
= cvp
->cookie_pair_size
;
2841 if (put_user(sizeof(ctd
), optlen
))
2843 if (copy_to_user(optval
, &ctd
, sizeof(ctd
)))
2847 case TCP_THIN_LINEAR_TIMEOUTS
:
2850 case TCP_THIN_DUPACK
:
2851 val
= tp
->thin_dupack
;
2858 case TCP_REPAIR_QUEUE
:
2860 val
= tp
->repair_queue
;
2866 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2867 val
= tp
->write_seq
;
2868 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2874 case TCP_USER_TIMEOUT
:
2875 val
= jiffies_to_msecs(icsk
->icsk_user_timeout
);
2878 return -ENOPROTOOPT
;
2881 if (put_user(len
, optlen
))
2883 if (copy_to_user(optval
, &val
, len
))
2888 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2891 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2893 if (level
!= SOL_TCP
)
2894 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2896 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2898 EXPORT_SYMBOL(tcp_getsockopt
);
2900 #ifdef CONFIG_COMPAT
2901 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2902 char __user
*optval
, int __user
*optlen
)
2904 if (level
!= SOL_TCP
)
2905 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2907 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2909 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2912 struct sk_buff
*tcp_tso_segment(struct sk_buff
*skb
,
2913 netdev_features_t features
)
2915 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
2920 unsigned int oldlen
;
2923 if (!pskb_may_pull(skb
, sizeof(*th
)))
2927 thlen
= th
->doff
* 4;
2928 if (thlen
< sizeof(*th
))
2931 if (!pskb_may_pull(skb
, thlen
))
2934 oldlen
= (u16
)~skb
->len
;
2935 __skb_pull(skb
, thlen
);
2937 mss
= skb_shinfo(skb
)->gso_size
;
2938 if (unlikely(skb
->len
<= mss
))
2941 if (skb_gso_ok(skb
, features
| NETIF_F_GSO_ROBUST
)) {
2942 /* Packet is from an untrusted source, reset gso_segs. */
2943 int type
= skb_shinfo(skb
)->gso_type
;
2951 !(type
& (SKB_GSO_TCPV4
| SKB_GSO_TCPV6
))))
2954 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(skb
->len
, mss
);
2960 segs
= skb_segment(skb
, features
);
2964 delta
= htonl(oldlen
+ (thlen
+ mss
));
2968 seq
= ntohl(th
->seq
);
2971 th
->fin
= th
->psh
= 0;
2973 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2974 (__force u32
)delta
));
2975 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2977 csum_fold(csum_partial(skb_transport_header(skb
),
2984 th
->seq
= htonl(seq
);
2986 } while (skb
->next
);
2988 delta
= htonl(oldlen
+ (skb
->tail
- skb
->transport_header
) +
2990 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2991 (__force u32
)delta
));
2992 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2993 th
->check
= csum_fold(csum_partial(skb_transport_header(skb
),
2999 EXPORT_SYMBOL(tcp_tso_segment
);
3001 struct sk_buff
**tcp_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
3003 struct sk_buff
**pp
= NULL
;
3010 unsigned int mss
= 1;
3016 off
= skb_gro_offset(skb
);
3017 hlen
= off
+ sizeof(*th
);
3018 th
= skb_gro_header_fast(skb
, off
);
3019 if (skb_gro_header_hard(skb
, hlen
)) {
3020 th
= skb_gro_header_slow(skb
, hlen
, off
);
3025 thlen
= th
->doff
* 4;
3026 if (thlen
< sizeof(*th
))
3030 if (skb_gro_header_hard(skb
, hlen
)) {
3031 th
= skb_gro_header_slow(skb
, hlen
, off
);
3036 skb_gro_pull(skb
, thlen
);
3038 len
= skb_gro_len(skb
);
3039 flags
= tcp_flag_word(th
);
3041 for (; (p
= *head
); head
= &p
->next
) {
3042 if (!NAPI_GRO_CB(p
)->same_flow
)
3047 if (*(u32
*)&th
->source
^ *(u32
*)&th2
->source
) {
3048 NAPI_GRO_CB(p
)->same_flow
= 0;
3055 goto out_check_final
;
3058 flush
= NAPI_GRO_CB(p
)->flush
;
3059 flush
|= (__force
int)(flags
& TCP_FLAG_CWR
);
3060 flush
|= (__force
int)((flags
^ tcp_flag_word(th2
)) &
3061 ~(TCP_FLAG_CWR
| TCP_FLAG_FIN
| TCP_FLAG_PSH
));
3062 flush
|= (__force
int)(th
->ack_seq
^ th2
->ack_seq
);
3063 for (i
= sizeof(*th
); i
< thlen
; i
+= 4)
3064 flush
|= *(u32
*)((u8
*)th
+ i
) ^
3065 *(u32
*)((u8
*)th2
+ i
);
3067 mss
= skb_shinfo(p
)->gso_size
;
3069 flush
|= (len
- 1) >= mss
;
3070 flush
|= (ntohl(th2
->seq
) + skb_gro_len(p
)) ^ ntohl(th
->seq
);
3072 if (flush
|| skb_gro_receive(head
, skb
)) {
3074 goto out_check_final
;
3079 tcp_flag_word(th2
) |= flags
& (TCP_FLAG_FIN
| TCP_FLAG_PSH
);
3083 flush
|= (__force
int)(flags
& (TCP_FLAG_URG
| TCP_FLAG_PSH
|
3084 TCP_FLAG_RST
| TCP_FLAG_SYN
|
3087 if (p
&& (!NAPI_GRO_CB(skb
)->same_flow
|| flush
))
3091 NAPI_GRO_CB(skb
)->flush
|= flush
;
3095 EXPORT_SYMBOL(tcp_gro_receive
);
3097 int tcp_gro_complete(struct sk_buff
*skb
)
3099 struct tcphdr
*th
= tcp_hdr(skb
);
3101 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
3102 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
3103 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3105 skb_shinfo(skb
)->gso_segs
= NAPI_GRO_CB(skb
)->count
;
3108 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
3112 EXPORT_SYMBOL(tcp_gro_complete
);
3114 #ifdef CONFIG_TCP_MD5SIG
3115 static unsigned long tcp_md5sig_users
;
3116 static struct tcp_md5sig_pool __percpu
*tcp_md5sig_pool
;
3117 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock
);
3119 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu
*pool
)
3123 for_each_possible_cpu(cpu
) {
3124 struct tcp_md5sig_pool
*p
= per_cpu_ptr(pool
, cpu
);
3126 if (p
->md5_desc
.tfm
)
3127 crypto_free_hash(p
->md5_desc
.tfm
);
3132 void tcp_free_md5sig_pool(void)
3134 struct tcp_md5sig_pool __percpu
*pool
= NULL
;
3136 spin_lock_bh(&tcp_md5sig_pool_lock
);
3137 if (--tcp_md5sig_users
== 0) {
3138 pool
= tcp_md5sig_pool
;
3139 tcp_md5sig_pool
= NULL
;
3141 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3143 __tcp_free_md5sig_pool(pool
);
3145 EXPORT_SYMBOL(tcp_free_md5sig_pool
);
3147 static struct tcp_md5sig_pool __percpu
*
3148 __tcp_alloc_md5sig_pool(struct sock
*sk
)
3151 struct tcp_md5sig_pool __percpu
*pool
;
3153 pool
= alloc_percpu(struct tcp_md5sig_pool
);
3157 for_each_possible_cpu(cpu
) {
3158 struct crypto_hash
*hash
;
3160 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
3161 if (!hash
|| IS_ERR(hash
))
3164 per_cpu_ptr(pool
, cpu
)->md5_desc
.tfm
= hash
;
3168 __tcp_free_md5sig_pool(pool
);
3172 struct tcp_md5sig_pool __percpu
*tcp_alloc_md5sig_pool(struct sock
*sk
)
3174 struct tcp_md5sig_pool __percpu
*pool
;
3178 spin_lock_bh(&tcp_md5sig_pool_lock
);
3179 pool
= tcp_md5sig_pool
;
3180 if (tcp_md5sig_users
++ == 0) {
3182 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3185 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3189 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3192 /* we cannot hold spinlock here because this may sleep. */
3193 struct tcp_md5sig_pool __percpu
*p
;
3195 p
= __tcp_alloc_md5sig_pool(sk
);
3196 spin_lock_bh(&tcp_md5sig_pool_lock
);
3199 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3202 pool
= tcp_md5sig_pool
;
3204 /* oops, it has already been assigned. */
3205 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3206 __tcp_free_md5sig_pool(p
);
3208 tcp_md5sig_pool
= pool
= p
;
3209 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3214 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
3218 * tcp_get_md5sig_pool - get md5sig_pool for this user
3220 * We use percpu structure, so if we succeed, we exit with preemption
3221 * and BH disabled, to make sure another thread or softirq handling
3222 * wont try to get same context.
3224 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
3226 struct tcp_md5sig_pool __percpu
*p
;
3230 spin_lock(&tcp_md5sig_pool_lock
);
3231 p
= tcp_md5sig_pool
;
3234 spin_unlock(&tcp_md5sig_pool_lock
);
3237 return this_cpu_ptr(p
);
3242 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
3244 void tcp_put_md5sig_pool(void)
3247 tcp_free_md5sig_pool();
3249 EXPORT_SYMBOL(tcp_put_md5sig_pool
);
3251 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
3252 const struct tcphdr
*th
)
3254 struct scatterlist sg
;
3258 /* We are not allowed to change tcphdr, make a local copy */
3259 memcpy(&hdr
, th
, sizeof(hdr
));
3262 /* options aren't included in the hash */
3263 sg_init_one(&sg
, &hdr
, sizeof(hdr
));
3264 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(hdr
));
3267 EXPORT_SYMBOL(tcp_md5_hash_header
);
3269 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
3270 const struct sk_buff
*skb
, unsigned int header_len
)
3272 struct scatterlist sg
;
3273 const struct tcphdr
*tp
= tcp_hdr(skb
);
3274 struct hash_desc
*desc
= &hp
->md5_desc
;
3276 const unsigned int head_data_len
= skb_headlen(skb
) > header_len
?
3277 skb_headlen(skb
) - header_len
: 0;
3278 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
3279 struct sk_buff
*frag_iter
;
3281 sg_init_table(&sg
, 1);
3283 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
3284 if (crypto_hash_update(desc
, &sg
, head_data_len
))
3287 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
3288 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
3289 struct page
*page
= skb_frag_page(f
);
3290 sg_set_page(&sg
, page
, skb_frag_size(f
), f
->page_offset
);
3291 if (crypto_hash_update(desc
, &sg
, skb_frag_size(f
)))
3295 skb_walk_frags(skb
, frag_iter
)
3296 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3301 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3303 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, const struct tcp_md5sig_key
*key
)
3305 struct scatterlist sg
;
3307 sg_init_one(&sg
, key
->key
, key
->keylen
);
3308 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3310 EXPORT_SYMBOL(tcp_md5_hash_key
);
3315 * Each Responder maintains up to two secret values concurrently for
3316 * efficient secret rollover. Each secret value has 4 states:
3318 * Generating. (tcp_secret_generating != tcp_secret_primary)
3319 * Generates new Responder-Cookies, but not yet used for primary
3320 * verification. This is a short-term state, typically lasting only
3321 * one round trip time (RTT).
3323 * Primary. (tcp_secret_generating == tcp_secret_primary)
3324 * Used both for generation and primary verification.
3326 * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
3327 * Used for verification, until the first failure that can be
3328 * verified by the newer Generating secret. At that time, this
3329 * cookie's state is changed to Secondary, and the Generating
3330 * cookie's state is changed to Primary. This is a short-term state,
3331 * typically lasting only one round trip time (RTT).
3333 * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
3334 * Used for secondary verification, after primary verification
3335 * failures. This state lasts no more than twice the Maximum Segment
3336 * Lifetime (2MSL). Then, the secret is discarded.
3338 struct tcp_cookie_secret
{
3339 /* The secret is divided into two parts. The digest part is the
3340 * equivalent of previously hashing a secret and saving the state,
3341 * and serves as an initialization vector (IV). The message part
3342 * serves as the trailing secret.
3344 u32 secrets
[COOKIE_WORKSPACE_WORDS
];
3345 unsigned long expires
;
3348 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
3349 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
3350 #define TCP_SECRET_LIFE (HZ * 600)
3352 static struct tcp_cookie_secret tcp_secret_one
;
3353 static struct tcp_cookie_secret tcp_secret_two
;
3355 /* Essentially a circular list, without dynamic allocation. */
3356 static struct tcp_cookie_secret
*tcp_secret_generating
;
3357 static struct tcp_cookie_secret
*tcp_secret_primary
;
3358 static struct tcp_cookie_secret
*tcp_secret_retiring
;
3359 static struct tcp_cookie_secret
*tcp_secret_secondary
;
3361 static DEFINE_SPINLOCK(tcp_secret_locker
);
3363 /* Select a pseudo-random word in the cookie workspace.
3365 static inline u32
tcp_cookie_work(const u32
*ws
, const int n
)
3367 return ws
[COOKIE_DIGEST_WORDS
+ ((COOKIE_MESSAGE_WORDS
-1) & ws
[n
])];
3370 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
3371 * Called in softirq context.
3372 * Returns: 0 for success.
3374 int tcp_cookie_generator(u32
*bakery
)
3376 unsigned long jiffy
= jiffies
;
3378 if (unlikely(time_after_eq(jiffy
, tcp_secret_generating
->expires
))) {
3379 spin_lock_bh(&tcp_secret_locker
);
3380 if (!time_after_eq(jiffy
, tcp_secret_generating
->expires
)) {
3381 /* refreshed by another */
3383 &tcp_secret_generating
->secrets
[0],
3384 COOKIE_WORKSPACE_WORDS
);
3386 /* still needs refreshing */
3387 get_random_bytes(bakery
, COOKIE_WORKSPACE_WORDS
);
3389 /* The first time, paranoia assumes that the
3390 * randomization function isn't as strong. But,
3391 * this secret initialization is delayed until
3392 * the last possible moment (packet arrival).
3393 * Although that time is observable, it is
3394 * unpredictably variable. Mash in the most
3395 * volatile clock bits available, and expire the
3396 * secret extra quickly.
3398 if (unlikely(tcp_secret_primary
->expires
==
3399 tcp_secret_secondary
->expires
)) {
3402 getnstimeofday(&tv
);
3403 bakery
[COOKIE_DIGEST_WORDS
+0] ^=
3406 tcp_secret_secondary
->expires
= jiffy
3408 + (0x0f & tcp_cookie_work(bakery
, 0));
3410 tcp_secret_secondary
->expires
= jiffy
3412 + (0xff & tcp_cookie_work(bakery
, 1));
3413 tcp_secret_primary
->expires
= jiffy
3415 + (0x1f & tcp_cookie_work(bakery
, 2));
3417 memcpy(&tcp_secret_secondary
->secrets
[0],
3418 bakery
, COOKIE_WORKSPACE_WORDS
);
3420 rcu_assign_pointer(tcp_secret_generating
,
3421 tcp_secret_secondary
);
3422 rcu_assign_pointer(tcp_secret_retiring
,
3423 tcp_secret_primary
);
3425 * Neither call_rcu() nor synchronize_rcu() needed.
3426 * Retiring data is not freed. It is replaced after
3427 * further (locked) pointer updates, and a quiet time
3428 * (minimum 1MSL, maximum LIFE - 2MSL).
3431 spin_unlock_bh(&tcp_secret_locker
);
3435 &rcu_dereference(tcp_secret_generating
)->secrets
[0],
3436 COOKIE_WORKSPACE_WORDS
);
3437 rcu_read_unlock_bh();
3441 EXPORT_SYMBOL(tcp_cookie_generator
);
3443 void tcp_done(struct sock
*sk
)
3445 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3446 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3448 tcp_set_state(sk
, TCP_CLOSE
);
3449 tcp_clear_xmit_timers(sk
);
3451 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3453 if (!sock_flag(sk
, SOCK_DEAD
))
3454 sk
->sk_state_change(sk
);
3456 inet_csk_destroy_sock(sk
);
3458 EXPORT_SYMBOL_GPL(tcp_done
);
3460 extern struct tcp_congestion_ops tcp_reno
;
3462 static __initdata
unsigned long thash_entries
;
3463 static int __init
set_thash_entries(char *str
)
3467 thash_entries
= simple_strtoul(str
, &str
, 0);
3470 __setup("thash_entries=", set_thash_entries
);
3472 void tcp_init_mem(struct net
*net
)
3474 unsigned long limit
= nr_free_buffer_pages() / 8;
3475 limit
= max(limit
, 128UL);
3476 net
->ipv4
.sysctl_tcp_mem
[0] = limit
/ 4 * 3;
3477 net
->ipv4
.sysctl_tcp_mem
[1] = limit
;
3478 net
->ipv4
.sysctl_tcp_mem
[2] = net
->ipv4
.sysctl_tcp_mem
[0] * 2;
3481 void __init
tcp_init(void)
3483 struct sk_buff
*skb
= NULL
;
3484 unsigned long limit
;
3485 int max_rshare
, max_wshare
, cnt
;
3487 unsigned long jiffy
= jiffies
;
3489 BUILD_BUG_ON(sizeof(struct tcp_skb_cb
) > sizeof(skb
->cb
));
3491 percpu_counter_init(&tcp_sockets_allocated
, 0);
3492 percpu_counter_init(&tcp_orphan_count
, 0);
3493 tcp_hashinfo
.bind_bucket_cachep
=
3494 kmem_cache_create("tcp_bind_bucket",
3495 sizeof(struct inet_bind_bucket
), 0,
3496 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3498 /* Size and allocate the main established and bind bucket
3501 * The methodology is similar to that of the buffer cache.
3503 tcp_hashinfo
.ehash
=
3504 alloc_large_system_hash("TCP established",
3505 sizeof(struct inet_ehash_bucket
),
3507 (totalram_pages
>= 128 * 1024) ?
3511 &tcp_hashinfo
.ehash_mask
,
3512 thash_entries
? 0 : 512 * 1024);
3513 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++) {
3514 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3515 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].twchain
, i
);
3517 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3518 panic("TCP: failed to alloc ehash_locks");
3519 tcp_hashinfo
.bhash
=
3520 alloc_large_system_hash("TCP bind",
3521 sizeof(struct inet_bind_hashbucket
),
3522 tcp_hashinfo
.ehash_mask
+ 1,
3523 (totalram_pages
>= 128 * 1024) ?
3526 &tcp_hashinfo
.bhash_size
,
3529 tcp_hashinfo
.bhash_size
= 1U << tcp_hashinfo
.bhash_size
;
3530 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3531 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3532 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3536 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
3538 tcp_death_row
.sysctl_max_tw_buckets
= cnt
/ 2;
3539 sysctl_tcp_max_orphans
= cnt
/ 2;
3540 sysctl_max_syn_backlog
= max(128, cnt
/ 256);
3542 tcp_init_mem(&init_net
);
3543 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3544 limit
= nr_free_buffer_pages() << (PAGE_SHIFT
- 7);
3545 max_wshare
= min(4UL*1024*1024, limit
);
3546 max_rshare
= min(6UL*1024*1024, limit
);
3548 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3549 sysctl_tcp_wmem
[1] = 16*1024;
3550 sysctl_tcp_wmem
[2] = max(64*1024, max_wshare
);
3552 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3553 sysctl_tcp_rmem
[1] = 87380;
3554 sysctl_tcp_rmem
[2] = max(87380, max_rshare
);
3556 pr_info("Hash tables configured (established %u bind %u)\n",
3557 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3559 tcp_register_congestion_control(&tcp_reno
);
3561 memset(&tcp_secret_one
.secrets
[0], 0, sizeof(tcp_secret_one
.secrets
));
3562 memset(&tcp_secret_two
.secrets
[0], 0, sizeof(tcp_secret_two
.secrets
));
3563 tcp_secret_one
.expires
= jiffy
; /* past due */
3564 tcp_secret_two
.expires
= jiffy
; /* past due */
3565 tcp_secret_generating
= &tcp_secret_one
;
3566 tcp_secret_primary
= &tcp_secret_one
;
3567 tcp_secret_retiring
= &tcp_secret_two
;
3568 tcp_secret_secondary
= &tcp_secret_two
;