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
);
920 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
922 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
925 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
929 if (copied
&& !(flags
& MSG_SENDPAGE_NOTLAST
))
930 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
937 return sk_stream_error(sk
, flags
, err
);
940 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
941 size_t size
, int flags
)
945 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
946 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
947 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
951 res
= do_tcp_sendpages(sk
, &page
, offset
, size
, flags
);
955 EXPORT_SYMBOL(tcp_sendpage
);
957 static inline int select_size(const struct sock
*sk
, bool sg
)
959 const struct tcp_sock
*tp
= tcp_sk(sk
);
960 int tmp
= tp
->mss_cache
;
963 if (sk_can_gso(sk
)) {
964 /* Small frames wont use a full page:
965 * Payload will immediately follow tcp header.
967 tmp
= SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER
);
969 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
971 if (tmp
>= pgbreak
&&
972 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
980 int tcp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
984 struct tcp_sock
*tp
= tcp_sk(sk
);
986 int iovlen
, flags
, err
, copied
;
987 int mss_now
= 0, size_goal
;
993 flags
= msg
->msg_flags
;
994 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
996 /* Wait for a connection to finish. */
997 if ((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
))
998 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
1001 if (unlikely(tp
->repair
)) {
1002 if (tp
->repair_queue
== TCP_RECV_QUEUE
) {
1003 copied
= tcp_send_rcvq(sk
, msg
, size
);
1008 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1011 /* 'common' sending to sendq */
1014 /* This should be in poll */
1015 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
1017 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1019 /* Ok commence sending. */
1020 iovlen
= msg
->msg_iovlen
;
1025 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
1028 sg
= !!(sk
->sk_route_caps
& NETIF_F_SG
);
1030 while (--iovlen
>= 0) {
1031 size_t seglen
= iov
->iov_len
;
1032 unsigned char __user
*from
= iov
->iov_base
;
1036 while (seglen
> 0) {
1038 int max
= size_goal
;
1040 skb
= tcp_write_queue_tail(sk
);
1041 if (tcp_send_head(sk
)) {
1042 if (skb
->ip_summed
== CHECKSUM_NONE
)
1044 copy
= max
- skb
->len
;
1049 /* Allocate new segment. If the interface is SG,
1050 * allocate skb fitting to single page.
1052 if (!sk_stream_memory_free(sk
))
1053 goto wait_for_sndbuf
;
1055 skb
= sk_stream_alloc_skb(sk
,
1056 select_size(sk
, sg
),
1059 goto wait_for_memory
;
1062 * Check whether we can use HW checksum.
1064 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
1065 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1067 skb_entail(sk
, skb
);
1072 /* Try to append data to the end of skb. */
1076 /* Where to copy to? */
1077 if (skb_availroom(skb
) > 0) {
1078 /* We have some space in skb head. Superb! */
1079 copy
= min_t(int, copy
, skb_availroom(skb
));
1080 err
= skb_add_data_nocache(sk
, skb
, from
, copy
);
1085 int i
= skb_shinfo(skb
)->nr_frags
;
1086 struct page
*page
= sk
->sk_sndmsg_page
;
1089 if (page
&& page_count(page
) == 1)
1090 sk
->sk_sndmsg_off
= 0;
1092 off
= sk
->sk_sndmsg_off
;
1094 if (skb_can_coalesce(skb
, i
, page
, off
) &&
1096 /* We can extend the last page
1099 } else if (i
== MAX_SKB_FRAGS
|| !sg
) {
1100 /* Need to add new fragment and cannot
1101 * do this because interface is non-SG,
1102 * or because all the page slots are
1104 tcp_mark_push(tp
, skb
);
1107 if (off
== PAGE_SIZE
) {
1109 sk
->sk_sndmsg_page
= page
= NULL
;
1115 if (copy
> PAGE_SIZE
- off
)
1116 copy
= PAGE_SIZE
- off
;
1118 if (!sk_wmem_schedule(sk
, copy
))
1119 goto wait_for_memory
;
1122 /* Allocate new cache page. */
1123 if (!(page
= sk_stream_alloc_page(sk
)))
1124 goto wait_for_memory
;
1127 /* Time to copy data. We are close to
1129 err
= skb_copy_to_page_nocache(sk
, from
, skb
,
1132 /* If this page was new, give it to the
1133 * socket so it does not get leaked.
1135 if (!sk
->sk_sndmsg_page
) {
1136 sk
->sk_sndmsg_page
= page
;
1137 sk
->sk_sndmsg_off
= 0;
1142 /* Update the skb. */
1144 skb_frag_size_add(&skb_shinfo(skb
)->frags
[i
- 1], copy
);
1146 skb_fill_page_desc(skb
, i
, page
, off
, copy
);
1147 if (sk
->sk_sndmsg_page
) {
1149 } else if (off
+ copy
< PAGE_SIZE
) {
1151 sk
->sk_sndmsg_page
= page
;
1155 sk
->sk_sndmsg_off
= off
+ copy
;
1159 TCP_SKB_CB(skb
)->tcp_flags
&= ~TCPHDR_PSH
;
1161 tp
->write_seq
+= copy
;
1162 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1163 skb_shinfo(skb
)->gso_segs
= 0;
1167 if ((seglen
-= copy
) == 0 && iovlen
== 0)
1170 if (skb
->len
< max
|| (flags
& MSG_OOB
) || unlikely(tp
->repair
))
1173 if (forced_push(tp
)) {
1174 tcp_mark_push(tp
, skb
);
1175 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1176 } else if (skb
== tcp_send_head(sk
))
1177 tcp_push_one(sk
, mss_now
);
1181 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1183 if (copied
&& likely(!tp
->repair
))
1184 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
1186 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1189 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1194 if (copied
&& likely(!tp
->repair
))
1195 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
1201 tcp_unlink_write_queue(skb
, sk
);
1202 /* It is the one place in all of TCP, except connection
1203 * reset, where we can be unlinking the send_head.
1205 tcp_check_send_head(sk
, skb
);
1206 sk_wmem_free_skb(sk
, skb
);
1213 err
= sk_stream_error(sk
, flags
, err
);
1217 EXPORT_SYMBOL(tcp_sendmsg
);
1220 * Handle reading urgent data. BSD has very simple semantics for
1221 * this, no blocking and very strange errors 8)
1224 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1226 struct tcp_sock
*tp
= tcp_sk(sk
);
1228 /* No URG data to read. */
1229 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1230 tp
->urg_data
== TCP_URG_READ
)
1231 return -EINVAL
; /* Yes this is right ! */
1233 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1236 if (tp
->urg_data
& TCP_URG_VALID
) {
1238 char c
= tp
->urg_data
;
1240 if (!(flags
& MSG_PEEK
))
1241 tp
->urg_data
= TCP_URG_READ
;
1243 /* Read urgent data. */
1244 msg
->msg_flags
|= MSG_OOB
;
1247 if (!(flags
& MSG_TRUNC
))
1248 err
= memcpy_toiovec(msg
->msg_iov
, &c
, 1);
1251 msg
->msg_flags
|= MSG_TRUNC
;
1253 return err
? -EFAULT
: len
;
1256 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1259 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1260 * the available implementations agree in this case:
1261 * this call should never block, independent of the
1262 * blocking state of the socket.
1263 * Mike <pall@rz.uni-karlsruhe.de>
1268 static int tcp_peek_sndq(struct sock
*sk
, struct msghdr
*msg
, int len
)
1270 struct sk_buff
*skb
;
1271 int copied
= 0, err
= 0;
1273 /* XXX -- need to support SO_PEEK_OFF */
1275 skb_queue_walk(&sk
->sk_write_queue
, skb
) {
1276 err
= skb_copy_datagram_iovec(skb
, 0, msg
->msg_iov
, skb
->len
);
1283 return err
?: copied
;
1286 /* Clean up the receive buffer for full frames taken by the user,
1287 * then send an ACK if necessary. COPIED is the number of bytes
1288 * tcp_recvmsg has given to the user so far, it speeds up the
1289 * calculation of whether or not we must ACK for the sake of
1292 void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1294 struct tcp_sock
*tp
= tcp_sk(sk
);
1295 bool time_to_ack
= false;
1297 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1299 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1300 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1301 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1303 if (inet_csk_ack_scheduled(sk
)) {
1304 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1305 /* Delayed ACKs frequently hit locked sockets during bulk
1307 if (icsk
->icsk_ack
.blocked
||
1308 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1309 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1311 * If this read emptied read buffer, we send ACK, if
1312 * connection is not bidirectional, user drained
1313 * receive buffer and there was a small segment
1317 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1318 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1319 !icsk
->icsk_ack
.pingpong
)) &&
1320 !atomic_read(&sk
->sk_rmem_alloc
)))
1324 /* We send an ACK if we can now advertise a non-zero window
1325 * which has been raised "significantly".
1327 * Even if window raised up to infinity, do not send window open ACK
1328 * in states, where we will not receive more. It is useless.
1330 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1331 __u32 rcv_window_now
= tcp_receive_window(tp
);
1333 /* Optimize, __tcp_select_window() is not cheap. */
1334 if (2*rcv_window_now
<= tp
->window_clamp
) {
1335 __u32 new_window
= __tcp_select_window(sk
);
1337 /* Send ACK now, if this read freed lots of space
1338 * in our buffer. Certainly, new_window is new window.
1339 * We can advertise it now, if it is not less than current one.
1340 * "Lots" means "at least twice" here.
1342 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1350 static void tcp_prequeue_process(struct sock
*sk
)
1352 struct sk_buff
*skb
;
1353 struct tcp_sock
*tp
= tcp_sk(sk
);
1355 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1357 /* RX process wants to run with disabled BHs, though it is not
1360 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1361 sk_backlog_rcv(sk
, skb
);
1364 /* Clear memory counter. */
1365 tp
->ucopy
.memory
= 0;
1368 #ifdef CONFIG_NET_DMA
1369 static void tcp_service_net_dma(struct sock
*sk
, bool wait
)
1371 dma_cookie_t done
, used
;
1372 dma_cookie_t last_issued
;
1373 struct tcp_sock
*tp
= tcp_sk(sk
);
1375 if (!tp
->ucopy
.dma_chan
)
1378 last_issued
= tp
->ucopy
.dma_cookie
;
1379 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1382 if (dma_async_memcpy_complete(tp
->ucopy
.dma_chan
,
1384 &used
) == DMA_SUCCESS
) {
1385 /* Safe to free early-copied skbs now */
1386 __skb_queue_purge(&sk
->sk_async_wait_queue
);
1389 struct sk_buff
*skb
;
1390 while ((skb
= skb_peek(&sk
->sk_async_wait_queue
)) &&
1391 (dma_async_is_complete(skb
->dma_cookie
, done
,
1392 used
) == DMA_SUCCESS
)) {
1393 __skb_dequeue(&sk
->sk_async_wait_queue
);
1401 static inline struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1403 struct sk_buff
*skb
;
1406 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1407 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1408 if (tcp_hdr(skb
)->syn
)
1410 if (offset
< skb
->len
|| tcp_hdr(skb
)->fin
) {
1419 * This routine provides an alternative to tcp_recvmsg() for routines
1420 * that would like to handle copying from skbuffs directly in 'sendfile'
1423 * - It is assumed that the socket was locked by the caller.
1424 * - The routine does not block.
1425 * - At present, there is no support for reading OOB data
1426 * or for 'peeking' the socket using this routine
1427 * (although both would be easy to implement).
1429 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1430 sk_read_actor_t recv_actor
)
1432 struct sk_buff
*skb
;
1433 struct tcp_sock
*tp
= tcp_sk(sk
);
1434 u32 seq
= tp
->copied_seq
;
1438 if (sk
->sk_state
== TCP_LISTEN
)
1440 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1441 if (offset
< skb
->len
) {
1445 len
= skb
->len
- offset
;
1446 /* Stop reading if we hit a patch of urgent data */
1448 u32 urg_offset
= tp
->urg_seq
- seq
;
1449 if (urg_offset
< len
)
1454 used
= recv_actor(desc
, skb
, offset
, len
);
1459 } else if (used
<= len
) {
1465 * If recv_actor drops the lock (e.g. TCP splice
1466 * receive) the skb pointer might be invalid when
1467 * getting here: tcp_collapse might have deleted it
1468 * while aggregating skbs from the socket queue.
1470 skb
= tcp_recv_skb(sk
, seq
-1, &offset
);
1471 if (!skb
|| (offset
+1 != skb
->len
))
1474 if (tcp_hdr(skb
)->fin
) {
1475 sk_eat_skb(sk
, skb
, false);
1479 sk_eat_skb(sk
, skb
, false);
1482 tp
->copied_seq
= seq
;
1484 tp
->copied_seq
= seq
;
1486 tcp_rcv_space_adjust(sk
);
1488 /* Clean up data we have read: This will do ACK frames. */
1490 tcp_cleanup_rbuf(sk
, copied
);
1493 EXPORT_SYMBOL(tcp_read_sock
);
1496 * This routine copies from a sock struct into the user buffer.
1498 * Technical note: in 2.3 we work on _locked_ socket, so that
1499 * tricks with *seq access order and skb->users are not required.
1500 * Probably, code can be easily improved even more.
1503 int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1504 size_t len
, int nonblock
, int flags
, int *addr_len
)
1506 struct tcp_sock
*tp
= tcp_sk(sk
);
1512 int target
; /* Read at least this many bytes */
1514 struct task_struct
*user_recv
= NULL
;
1515 bool copied_early
= false;
1516 struct sk_buff
*skb
;
1522 if (sk
->sk_state
== TCP_LISTEN
)
1525 timeo
= sock_rcvtimeo(sk
, nonblock
);
1527 /* Urgent data needs to be handled specially. */
1528 if (flags
& MSG_OOB
)
1531 if (unlikely(tp
->repair
)) {
1533 if (!(flags
& MSG_PEEK
))
1536 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
1540 if (tp
->repair_queue
== TCP_NO_QUEUE
)
1543 /* 'common' recv queue MSG_PEEK-ing */
1546 seq
= &tp
->copied_seq
;
1547 if (flags
& MSG_PEEK
) {
1548 peek_seq
= tp
->copied_seq
;
1552 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1554 #ifdef CONFIG_NET_DMA
1555 tp
->ucopy
.dma_chan
= NULL
;
1557 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
1562 available
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- (*seq
);
1563 if ((available
< target
) &&
1564 (len
> sysctl_tcp_dma_copybreak
) && !(flags
& MSG_PEEK
) &&
1565 !sysctl_tcp_low_latency
&&
1566 net_dma_find_channel()) {
1567 preempt_enable_no_resched();
1568 tp
->ucopy
.pinned_list
=
1569 dma_pin_iovec_pages(msg
->msg_iov
, len
);
1571 preempt_enable_no_resched();
1579 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1580 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1583 if (signal_pending(current
)) {
1584 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1589 /* Next get a buffer. */
1591 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1592 /* Now that we have two receive queues this
1595 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1596 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1597 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1601 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1602 if (tcp_hdr(skb
)->syn
)
1604 if (offset
< skb
->len
)
1606 if (tcp_hdr(skb
)->fin
)
1608 WARN(!(flags
& MSG_PEEK
),
1609 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1610 *seq
, TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
, flags
);
1613 /* Well, if we have backlog, try to process it now yet. */
1615 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1620 sk
->sk_state
== TCP_CLOSE
||
1621 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1623 signal_pending(current
))
1626 if (sock_flag(sk
, SOCK_DONE
))
1630 copied
= sock_error(sk
);
1634 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1637 if (sk
->sk_state
== TCP_CLOSE
) {
1638 if (!sock_flag(sk
, SOCK_DONE
)) {
1639 /* This occurs when user tries to read
1640 * from never connected socket.
1653 if (signal_pending(current
)) {
1654 copied
= sock_intr_errno(timeo
);
1659 tcp_cleanup_rbuf(sk
, copied
);
1661 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1662 /* Install new reader */
1663 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1664 user_recv
= current
;
1665 tp
->ucopy
.task
= user_recv
;
1666 tp
->ucopy
.iov
= msg
->msg_iov
;
1669 tp
->ucopy
.len
= len
;
1671 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1672 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1674 /* Ugly... If prequeue is not empty, we have to
1675 * process it before releasing socket, otherwise
1676 * order will be broken at second iteration.
1677 * More elegant solution is required!!!
1679 * Look: we have the following (pseudo)queues:
1681 * 1. packets in flight
1686 * Each queue can be processed only if the next ones
1687 * are empty. At this point we have empty receive_queue.
1688 * But prequeue _can_ be not empty after 2nd iteration,
1689 * when we jumped to start of loop because backlog
1690 * processing added something to receive_queue.
1691 * We cannot release_sock(), because backlog contains
1692 * packets arrived _after_ prequeued ones.
1694 * Shortly, algorithm is clear --- to process all
1695 * the queues in order. We could make it more directly,
1696 * requeueing packets from backlog to prequeue, if
1697 * is not empty. It is more elegant, but eats cycles,
1700 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1703 /* __ Set realtime policy in scheduler __ */
1706 #ifdef CONFIG_NET_DMA
1707 if (tp
->ucopy
.dma_chan
)
1708 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1710 if (copied
>= target
) {
1711 /* Do not sleep, just process backlog. */
1715 sk_wait_data(sk
, &timeo
);
1717 #ifdef CONFIG_NET_DMA
1718 tcp_service_net_dma(sk
, false); /* Don't block */
1719 tp
->ucopy
.wakeup
= 0;
1725 /* __ Restore normal policy in scheduler __ */
1727 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1728 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1733 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1734 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1736 tcp_prequeue_process(sk
);
1738 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1739 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1745 if ((flags
& MSG_PEEK
) &&
1746 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1747 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1749 task_pid_nr(current
));
1750 peek_seq
= tp
->copied_seq
;
1755 /* Ok so how much can we use? */
1756 used
= skb
->len
- offset
;
1760 /* Do we have urgent data here? */
1762 u32 urg_offset
= tp
->urg_seq
- *seq
;
1763 if (urg_offset
< used
) {
1765 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1778 if (!(flags
& MSG_TRUNC
)) {
1779 #ifdef CONFIG_NET_DMA
1780 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
1781 tp
->ucopy
.dma_chan
= net_dma_find_channel();
1783 if (tp
->ucopy
.dma_chan
) {
1784 tp
->ucopy
.dma_cookie
= dma_skb_copy_datagram_iovec(
1785 tp
->ucopy
.dma_chan
, skb
, offset
,
1787 tp
->ucopy
.pinned_list
);
1789 if (tp
->ucopy
.dma_cookie
< 0) {
1791 pr_alert("%s: dma_cookie < 0\n",
1794 /* Exception. Bailout! */
1800 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1802 if ((offset
+ used
) == skb
->len
)
1803 copied_early
= true;
1808 err
= skb_copy_datagram_iovec(skb
, offset
,
1809 msg
->msg_iov
, used
);
1811 /* Exception. Bailout! */
1823 tcp_rcv_space_adjust(sk
);
1826 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1828 tcp_fast_path_check(sk
);
1830 if (used
+ offset
< skb
->len
)
1833 if (tcp_hdr(skb
)->fin
)
1835 if (!(flags
& MSG_PEEK
)) {
1836 sk_eat_skb(sk
, skb
, copied_early
);
1837 copied_early
= false;
1842 /* Process the FIN. */
1844 if (!(flags
& MSG_PEEK
)) {
1845 sk_eat_skb(sk
, skb
, copied_early
);
1846 copied_early
= false;
1852 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1855 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1857 tcp_prequeue_process(sk
);
1859 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1860 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1866 tp
->ucopy
.task
= NULL
;
1870 #ifdef CONFIG_NET_DMA
1871 tcp_service_net_dma(sk
, true); /* Wait for queue to drain */
1872 tp
->ucopy
.dma_chan
= NULL
;
1874 if (tp
->ucopy
.pinned_list
) {
1875 dma_unpin_iovec_pages(tp
->ucopy
.pinned_list
);
1876 tp
->ucopy
.pinned_list
= NULL
;
1880 /* According to UNIX98, msg_name/msg_namelen are ignored
1881 * on connected socket. I was just happy when found this 8) --ANK
1884 /* Clean up data we have read: This will do ACK frames. */
1885 tcp_cleanup_rbuf(sk
, copied
);
1895 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1899 err
= tcp_peek_sndq(sk
, msg
, len
);
1902 EXPORT_SYMBOL(tcp_recvmsg
);
1904 void tcp_set_state(struct sock
*sk
, int state
)
1906 int oldstate
= sk
->sk_state
;
1909 case TCP_ESTABLISHED
:
1910 if (oldstate
!= TCP_ESTABLISHED
)
1911 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1915 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1916 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1918 sk
->sk_prot
->unhash(sk
);
1919 if (inet_csk(sk
)->icsk_bind_hash
&&
1920 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1924 if (oldstate
== TCP_ESTABLISHED
)
1925 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1928 /* Change state AFTER socket is unhashed to avoid closed
1929 * socket sitting in hash tables.
1931 sk
->sk_state
= state
;
1934 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
1937 EXPORT_SYMBOL_GPL(tcp_set_state
);
1940 * State processing on a close. This implements the state shift for
1941 * sending our FIN frame. Note that we only send a FIN for some
1942 * states. A shutdown() may have already sent the FIN, or we may be
1946 static const unsigned char new_state
[16] = {
1947 /* current state: new state: action: */
1948 /* (Invalid) */ TCP_CLOSE
,
1949 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1950 /* TCP_SYN_SENT */ TCP_CLOSE
,
1951 /* TCP_SYN_RECV */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1952 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1
,
1953 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2
,
1954 /* TCP_TIME_WAIT */ TCP_CLOSE
,
1955 /* TCP_CLOSE */ TCP_CLOSE
,
1956 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK
| TCP_ACTION_FIN
,
1957 /* TCP_LAST_ACK */ TCP_LAST_ACK
,
1958 /* TCP_LISTEN */ TCP_CLOSE
,
1959 /* TCP_CLOSING */ TCP_CLOSING
,
1962 static int tcp_close_state(struct sock
*sk
)
1964 int next
= (int)new_state
[sk
->sk_state
];
1965 int ns
= next
& TCP_STATE_MASK
;
1967 tcp_set_state(sk
, ns
);
1969 return next
& TCP_ACTION_FIN
;
1973 * Shutdown the sending side of a connection. Much like close except
1974 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1977 void tcp_shutdown(struct sock
*sk
, int how
)
1979 /* We need to grab some memory, and put together a FIN,
1980 * and then put it into the queue to be sent.
1981 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1983 if (!(how
& SEND_SHUTDOWN
))
1986 /* If we've already sent a FIN, or it's a closed state, skip this. */
1987 if ((1 << sk
->sk_state
) &
1988 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
1989 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
1990 /* Clear out any half completed packets. FIN if needed. */
1991 if (tcp_close_state(sk
))
1995 EXPORT_SYMBOL(tcp_shutdown
);
1997 bool tcp_check_oom(struct sock
*sk
, int shift
)
1999 bool too_many_orphans
, out_of_socket_memory
;
2001 too_many_orphans
= tcp_too_many_orphans(sk
, shift
);
2002 out_of_socket_memory
= tcp_out_of_memory(sk
);
2004 if (too_many_orphans
)
2005 net_info_ratelimited("too many orphaned sockets\n");
2006 if (out_of_socket_memory
)
2007 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2008 return too_many_orphans
|| out_of_socket_memory
;
2011 void tcp_close(struct sock
*sk
, long timeout
)
2013 struct sk_buff
*skb
;
2014 int data_was_unread
= 0;
2018 sk
->sk_shutdown
= SHUTDOWN_MASK
;
2020 if (sk
->sk_state
== TCP_LISTEN
) {
2021 tcp_set_state(sk
, TCP_CLOSE
);
2024 inet_csk_listen_stop(sk
);
2026 goto adjudge_to_death
;
2029 /* We need to flush the recv. buffs. We do this only on the
2030 * descriptor close, not protocol-sourced closes, because the
2031 * reader process may not have drained the data yet!
2033 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
2034 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
-
2036 data_was_unread
+= len
;
2042 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2043 if (sk
->sk_state
== TCP_CLOSE
)
2044 goto adjudge_to_death
;
2046 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2047 * data was lost. To witness the awful effects of the old behavior of
2048 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2049 * GET in an FTP client, suspend the process, wait for the client to
2050 * advertise a zero window, then kill -9 the FTP client, wheee...
2051 * Note: timeout is always zero in such a case.
2053 if (unlikely(tcp_sk(sk
)->repair
)) {
2054 sk
->sk_prot
->disconnect(sk
, 0);
2055 } else if (data_was_unread
) {
2056 /* Unread data was tossed, zap the connection. */
2057 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
2058 tcp_set_state(sk
, TCP_CLOSE
);
2059 tcp_send_active_reset(sk
, sk
->sk_allocation
);
2060 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
2061 /* Check zero linger _after_ checking for unread data. */
2062 sk
->sk_prot
->disconnect(sk
, 0);
2063 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
2064 } else if (tcp_close_state(sk
)) {
2065 /* We FIN if the application ate all the data before
2066 * zapping the connection.
2069 /* RED-PEN. Formally speaking, we have broken TCP state
2070 * machine. State transitions:
2072 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2073 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2074 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2076 * are legal only when FIN has been sent (i.e. in window),
2077 * rather than queued out of window. Purists blame.
2079 * F.e. "RFC state" is ESTABLISHED,
2080 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2082 * The visible declinations are that sometimes
2083 * we enter time-wait state, when it is not required really
2084 * (harmless), do not send active resets, when they are
2085 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2086 * they look as CLOSING or LAST_ACK for Linux)
2087 * Probably, I missed some more holelets.
2093 sk_stream_wait_close(sk
, timeout
);
2096 state
= sk
->sk_state
;
2100 /* It is the last release_sock in its life. It will remove backlog. */
2104 /* Now socket is owned by kernel and we acquire BH lock
2105 to finish close. No need to check for user refs.
2109 WARN_ON(sock_owned_by_user(sk
));
2111 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
2113 /* Have we already been destroyed by a softirq or backlog? */
2114 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
2117 /* This is a (useful) BSD violating of the RFC. There is a
2118 * problem with TCP as specified in that the other end could
2119 * keep a socket open forever with no application left this end.
2120 * We use a 3 minute timeout (about the same as BSD) then kill
2121 * our end. If they send after that then tough - BUT: long enough
2122 * that we won't make the old 4*rto = almost no time - whoops
2125 * Nope, it was not mistake. It is really desired behaviour
2126 * f.e. on http servers, when such sockets are useless, but
2127 * consume significant resources. Let's do it with special
2128 * linger2 option. --ANK
2131 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
2132 struct tcp_sock
*tp
= tcp_sk(sk
);
2133 if (tp
->linger2
< 0) {
2134 tcp_set_state(sk
, TCP_CLOSE
);
2135 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2136 NET_INC_STATS_BH(sock_net(sk
),
2137 LINUX_MIB_TCPABORTONLINGER
);
2139 const int tmo
= tcp_fin_time(sk
);
2141 if (tmo
> TCP_TIMEWAIT_LEN
) {
2142 inet_csk_reset_keepalive_timer(sk
,
2143 tmo
- TCP_TIMEWAIT_LEN
);
2145 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2150 if (sk
->sk_state
!= TCP_CLOSE
) {
2152 if (tcp_check_oom(sk
, 0)) {
2153 tcp_set_state(sk
, TCP_CLOSE
);
2154 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2155 NET_INC_STATS_BH(sock_net(sk
),
2156 LINUX_MIB_TCPABORTONMEMORY
);
2160 if (sk
->sk_state
== TCP_CLOSE
)
2161 inet_csk_destroy_sock(sk
);
2162 /* Otherwise, socket is reprieved until protocol close. */
2169 EXPORT_SYMBOL(tcp_close
);
2171 /* These states need RST on ABORT according to RFC793 */
2173 static inline bool tcp_need_reset(int state
)
2175 return (1 << state
) &
2176 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2177 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2180 int tcp_disconnect(struct sock
*sk
, int flags
)
2182 struct inet_sock
*inet
= inet_sk(sk
);
2183 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2184 struct tcp_sock
*tp
= tcp_sk(sk
);
2186 int old_state
= sk
->sk_state
;
2188 if (old_state
!= TCP_CLOSE
)
2189 tcp_set_state(sk
, TCP_CLOSE
);
2191 /* ABORT function of RFC793 */
2192 if (old_state
== TCP_LISTEN
) {
2193 inet_csk_listen_stop(sk
);
2194 } else if (unlikely(tp
->repair
)) {
2195 sk
->sk_err
= ECONNABORTED
;
2196 } else if (tcp_need_reset(old_state
) ||
2197 (tp
->snd_nxt
!= tp
->write_seq
&&
2198 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2199 /* The last check adjusts for discrepancy of Linux wrt. RFC
2202 tcp_send_active_reset(sk
, gfp_any());
2203 sk
->sk_err
= ECONNRESET
;
2204 } else if (old_state
== TCP_SYN_SENT
)
2205 sk
->sk_err
= ECONNRESET
;
2207 tcp_clear_xmit_timers(sk
);
2208 __skb_queue_purge(&sk
->sk_receive_queue
);
2209 tcp_write_queue_purge(sk
);
2210 __skb_queue_purge(&tp
->out_of_order_queue
);
2211 #ifdef CONFIG_NET_DMA
2212 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2215 inet
->inet_dport
= 0;
2217 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2218 inet_reset_saddr(sk
);
2220 sk
->sk_shutdown
= 0;
2221 sock_reset_flag(sk
, SOCK_DONE
);
2223 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2225 icsk
->icsk_backoff
= 0;
2227 icsk
->icsk_probes_out
= 0;
2228 tp
->packets_out
= 0;
2229 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2230 tp
->snd_cwnd_cnt
= 0;
2231 tp
->bytes_acked
= 0;
2232 tp
->window_clamp
= 0;
2233 tcp_set_ca_state(sk
, TCP_CA_Open
);
2234 tcp_clear_retrans(tp
);
2235 inet_csk_delack_init(sk
);
2236 tcp_init_send_head(sk
);
2237 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2240 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2242 sk
->sk_error_report(sk
);
2245 EXPORT_SYMBOL(tcp_disconnect
);
2247 static inline bool tcp_can_repair_sock(const struct sock
*sk
)
2249 return capable(CAP_NET_ADMIN
) &&
2250 ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_ESTABLISHED
));
2253 static int tcp_repair_options_est(struct tcp_sock
*tp
,
2254 struct tcp_repair_opt __user
*optbuf
, unsigned int len
)
2256 struct tcp_repair_opt opt
;
2258 while (len
>= sizeof(opt
)) {
2259 if (copy_from_user(&opt
, optbuf
, sizeof(opt
)))
2265 switch (opt
.opt_code
) {
2267 tp
->rx_opt
.mss_clamp
= opt
.opt_val
;
2270 if (opt
.opt_val
> 14)
2273 tp
->rx_opt
.snd_wscale
= opt
.opt_val
;
2275 case TCPOPT_SACK_PERM
:
2276 if (opt
.opt_val
!= 0)
2279 tp
->rx_opt
.sack_ok
|= TCP_SACK_SEEN
;
2280 if (sysctl_tcp_fack
)
2281 tcp_enable_fack(tp
);
2283 case TCPOPT_TIMESTAMP
:
2284 if (opt
.opt_val
!= 0)
2287 tp
->rx_opt
.tstamp_ok
= 1;
2296 * Socket option code for TCP.
2298 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2299 int optname
, char __user
*optval
, unsigned int optlen
)
2301 struct tcp_sock
*tp
= tcp_sk(sk
);
2302 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2306 /* These are data/string values, all the others are ints */
2308 case TCP_CONGESTION
: {
2309 char name
[TCP_CA_NAME_MAX
];
2314 val
= strncpy_from_user(name
, optval
,
2315 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2321 err
= tcp_set_congestion_control(sk
, name
);
2325 case TCP_COOKIE_TRANSACTIONS
: {
2326 struct tcp_cookie_transactions ctd
;
2327 struct tcp_cookie_values
*cvp
= NULL
;
2329 if (sizeof(ctd
) > optlen
)
2331 if (copy_from_user(&ctd
, optval
, sizeof(ctd
)))
2334 if (ctd
.tcpct_used
> sizeof(ctd
.tcpct_value
) ||
2335 ctd
.tcpct_s_data_desired
> TCP_MSS_DESIRED
)
2338 if (ctd
.tcpct_cookie_desired
== 0) {
2339 /* default to global value */
2340 } else if ((0x1 & ctd
.tcpct_cookie_desired
) ||
2341 ctd
.tcpct_cookie_desired
> TCP_COOKIE_MAX
||
2342 ctd
.tcpct_cookie_desired
< TCP_COOKIE_MIN
) {
2346 if (TCP_COOKIE_OUT_NEVER
& ctd
.tcpct_flags
) {
2347 /* Supercedes all other values */
2349 if (tp
->cookie_values
!= NULL
) {
2350 kref_put(&tp
->cookie_values
->kref
,
2351 tcp_cookie_values_release
);
2352 tp
->cookie_values
= NULL
;
2354 tp
->rx_opt
.cookie_in_always
= 0; /* false */
2355 tp
->rx_opt
.cookie_out_never
= 1; /* true */
2360 /* Allocate ancillary memory before locking.
2362 if (ctd
.tcpct_used
> 0 ||
2363 (tp
->cookie_values
== NULL
&&
2364 (sysctl_tcp_cookie_size
> 0 ||
2365 ctd
.tcpct_cookie_desired
> 0 ||
2366 ctd
.tcpct_s_data_desired
> 0))) {
2367 cvp
= kzalloc(sizeof(*cvp
) + ctd
.tcpct_used
,
2372 kref_init(&cvp
->kref
);
2375 tp
->rx_opt
.cookie_in_always
=
2376 (TCP_COOKIE_IN_ALWAYS
& ctd
.tcpct_flags
);
2377 tp
->rx_opt
.cookie_out_never
= 0; /* false */
2379 if (tp
->cookie_values
!= NULL
) {
2381 /* Changed values are recorded by a changed
2382 * pointer, ensuring the cookie will differ,
2383 * without separately hashing each value later.
2385 kref_put(&tp
->cookie_values
->kref
,
2386 tcp_cookie_values_release
);
2388 cvp
= tp
->cookie_values
;
2393 cvp
->cookie_desired
= ctd
.tcpct_cookie_desired
;
2395 if (ctd
.tcpct_used
> 0) {
2396 memcpy(cvp
->s_data_payload
, ctd
.tcpct_value
,
2398 cvp
->s_data_desired
= ctd
.tcpct_used
;
2399 cvp
->s_data_constant
= 1; /* true */
2401 /* No constant payload data. */
2402 cvp
->s_data_desired
= ctd
.tcpct_s_data_desired
;
2403 cvp
->s_data_constant
= 0; /* false */
2406 tp
->cookie_values
= cvp
;
2416 if (optlen
< sizeof(int))
2419 if (get_user(val
, (int __user
*)optval
))
2426 /* Values greater than interface MTU won't take effect. However
2427 * at the point when this call is done we typically don't yet
2428 * know which interface is going to be used */
2429 if (val
< TCP_MIN_MSS
|| val
> MAX_TCP_WINDOW
) {
2433 tp
->rx_opt
.user_mss
= val
;
2438 /* TCP_NODELAY is weaker than TCP_CORK, so that
2439 * this option on corked socket is remembered, but
2440 * it is not activated until cork is cleared.
2442 * However, when TCP_NODELAY is set we make
2443 * an explicit push, which overrides even TCP_CORK
2444 * for currently queued segments.
2446 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2447 tcp_push_pending_frames(sk
);
2449 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2453 case TCP_THIN_LINEAR_TIMEOUTS
:
2454 if (val
< 0 || val
> 1)
2460 case TCP_THIN_DUPACK
:
2461 if (val
< 0 || val
> 1)
2464 tp
->thin_dupack
= val
;
2465 if (tp
->thin_dupack
)
2466 tcp_disable_early_retrans(tp
);
2470 if (!tcp_can_repair_sock(sk
))
2472 else if (val
== 1) {
2474 sk
->sk_reuse
= SK_FORCE_REUSE
;
2475 tp
->repair_queue
= TCP_NO_QUEUE
;
2476 } else if (val
== 0) {
2478 sk
->sk_reuse
= SK_NO_REUSE
;
2479 tcp_send_window_probe(sk
);
2485 case TCP_REPAIR_QUEUE
:
2488 else if (val
< TCP_QUEUES_NR
)
2489 tp
->repair_queue
= val
;
2495 if (sk
->sk_state
!= TCP_CLOSE
)
2497 else if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2498 tp
->write_seq
= val
;
2499 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2505 case TCP_REPAIR_OPTIONS
:
2508 else if (sk
->sk_state
== TCP_ESTABLISHED
)
2509 err
= tcp_repair_options_est(tp
,
2510 (struct tcp_repair_opt __user
*)optval
,
2517 /* When set indicates to always queue non-full frames.
2518 * Later the user clears this option and we transmit
2519 * any pending partial frames in the queue. This is
2520 * meant to be used alongside sendfile() to get properly
2521 * filled frames when the user (for example) must write
2522 * out headers with a write() call first and then use
2523 * sendfile to send out the data parts.
2525 * TCP_CORK can be set together with TCP_NODELAY and it is
2526 * stronger than TCP_NODELAY.
2529 tp
->nonagle
|= TCP_NAGLE_CORK
;
2531 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2532 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2533 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2534 tcp_push_pending_frames(sk
);
2539 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2542 tp
->keepalive_time
= val
* HZ
;
2543 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2544 !((1 << sk
->sk_state
) &
2545 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2546 u32 elapsed
= keepalive_time_elapsed(tp
);
2547 if (tp
->keepalive_time
> elapsed
)
2548 elapsed
= tp
->keepalive_time
- elapsed
;
2551 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2556 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2559 tp
->keepalive_intvl
= val
* HZ
;
2562 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2565 tp
->keepalive_probes
= val
;
2568 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2571 icsk
->icsk_syn_retries
= val
;
2577 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2580 tp
->linger2
= val
* HZ
;
2583 case TCP_DEFER_ACCEPT
:
2584 /* Translate value in seconds to number of retransmits */
2585 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2586 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2590 case TCP_WINDOW_CLAMP
:
2592 if (sk
->sk_state
!= TCP_CLOSE
) {
2596 tp
->window_clamp
= 0;
2598 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2599 SOCK_MIN_RCVBUF
/ 2 : val
;
2604 icsk
->icsk_ack
.pingpong
= 1;
2606 icsk
->icsk_ack
.pingpong
= 0;
2607 if ((1 << sk
->sk_state
) &
2608 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2609 inet_csk_ack_scheduled(sk
)) {
2610 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2611 tcp_cleanup_rbuf(sk
, 1);
2613 icsk
->icsk_ack
.pingpong
= 1;
2618 #ifdef CONFIG_TCP_MD5SIG
2620 /* Read the IP->Key mappings from userspace */
2621 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2624 case TCP_USER_TIMEOUT
:
2625 /* Cap the max timeout in ms TCP will retry/retrans
2626 * before giving up and aborting (ETIMEDOUT) a connection.
2628 icsk
->icsk_user_timeout
= msecs_to_jiffies(val
);
2639 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2640 unsigned int optlen
)
2642 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2644 if (level
!= SOL_TCP
)
2645 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2647 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2649 EXPORT_SYMBOL(tcp_setsockopt
);
2651 #ifdef CONFIG_COMPAT
2652 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2653 char __user
*optval
, unsigned int optlen
)
2655 if (level
!= SOL_TCP
)
2656 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2658 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2660 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2663 /* Return information about state of tcp endpoint in API format. */
2664 void tcp_get_info(const struct sock
*sk
, struct tcp_info
*info
)
2666 const struct tcp_sock
*tp
= tcp_sk(sk
);
2667 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2668 u32 now
= tcp_time_stamp
;
2670 memset(info
, 0, sizeof(*info
));
2672 info
->tcpi_state
= sk
->sk_state
;
2673 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2674 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2675 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2676 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2678 if (tp
->rx_opt
.tstamp_ok
)
2679 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2680 if (tcp_is_sack(tp
))
2681 info
->tcpi_options
|= TCPI_OPT_SACK
;
2682 if (tp
->rx_opt
.wscale_ok
) {
2683 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2684 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2685 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2688 if (tp
->ecn_flags
& TCP_ECN_OK
)
2689 info
->tcpi_options
|= TCPI_OPT_ECN
;
2690 if (tp
->ecn_flags
& TCP_ECN_SEEN
)
2691 info
->tcpi_options
|= TCPI_OPT_ECN_SEEN
;
2693 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2694 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2695 info
->tcpi_snd_mss
= tp
->mss_cache
;
2696 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2698 if (sk
->sk_state
== TCP_LISTEN
) {
2699 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2700 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2702 info
->tcpi_unacked
= tp
->packets_out
;
2703 info
->tcpi_sacked
= tp
->sacked_out
;
2705 info
->tcpi_lost
= tp
->lost_out
;
2706 info
->tcpi_retrans
= tp
->retrans_out
;
2707 info
->tcpi_fackets
= tp
->fackets_out
;
2709 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2710 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2711 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2713 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2714 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2715 info
->tcpi_rtt
= jiffies_to_usecs(tp
->srtt
)>>3;
2716 info
->tcpi_rttvar
= jiffies_to_usecs(tp
->mdev
)>>2;
2717 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2718 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2719 info
->tcpi_advmss
= tp
->advmss
;
2720 info
->tcpi_reordering
= tp
->reordering
;
2722 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2723 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2725 info
->tcpi_total_retrans
= tp
->total_retrans
;
2727 EXPORT_SYMBOL_GPL(tcp_get_info
);
2729 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2730 int optname
, char __user
*optval
, int __user
*optlen
)
2732 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2733 struct tcp_sock
*tp
= tcp_sk(sk
);
2736 if (get_user(len
, optlen
))
2739 len
= min_t(unsigned int, len
, sizeof(int));
2746 val
= tp
->mss_cache
;
2747 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2748 val
= tp
->rx_opt
.user_mss
;
2750 val
= tp
->rx_opt
.mss_clamp
;
2753 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2756 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2759 val
= keepalive_time_when(tp
) / HZ
;
2762 val
= keepalive_intvl_when(tp
) / HZ
;
2765 val
= keepalive_probes(tp
);
2768 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2773 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2775 case TCP_DEFER_ACCEPT
:
2776 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2777 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2779 case TCP_WINDOW_CLAMP
:
2780 val
= tp
->window_clamp
;
2783 struct tcp_info info
;
2785 if (get_user(len
, optlen
))
2788 tcp_get_info(sk
, &info
);
2790 len
= min_t(unsigned int, len
, sizeof(info
));
2791 if (put_user(len
, optlen
))
2793 if (copy_to_user(optval
, &info
, len
))
2798 val
= !icsk
->icsk_ack
.pingpong
;
2801 case TCP_CONGESTION
:
2802 if (get_user(len
, optlen
))
2804 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2805 if (put_user(len
, optlen
))
2807 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2811 case TCP_COOKIE_TRANSACTIONS
: {
2812 struct tcp_cookie_transactions ctd
;
2813 struct tcp_cookie_values
*cvp
= tp
->cookie_values
;
2815 if (get_user(len
, optlen
))
2817 if (len
< sizeof(ctd
))
2820 memset(&ctd
, 0, sizeof(ctd
));
2821 ctd
.tcpct_flags
= (tp
->rx_opt
.cookie_in_always
?
2822 TCP_COOKIE_IN_ALWAYS
: 0)
2823 | (tp
->rx_opt
.cookie_out_never
?
2824 TCP_COOKIE_OUT_NEVER
: 0);
2827 ctd
.tcpct_flags
|= (cvp
->s_data_in
?
2829 | (cvp
->s_data_out
?
2830 TCP_S_DATA_OUT
: 0);
2832 ctd
.tcpct_cookie_desired
= cvp
->cookie_desired
;
2833 ctd
.tcpct_s_data_desired
= cvp
->s_data_desired
;
2835 memcpy(&ctd
.tcpct_value
[0], &cvp
->cookie_pair
[0],
2836 cvp
->cookie_pair_size
);
2837 ctd
.tcpct_used
= cvp
->cookie_pair_size
;
2840 if (put_user(sizeof(ctd
), optlen
))
2842 if (copy_to_user(optval
, &ctd
, sizeof(ctd
)))
2846 case TCP_THIN_LINEAR_TIMEOUTS
:
2849 case TCP_THIN_DUPACK
:
2850 val
= tp
->thin_dupack
;
2857 case TCP_REPAIR_QUEUE
:
2859 val
= tp
->repair_queue
;
2865 if (tp
->repair_queue
== TCP_SEND_QUEUE
)
2866 val
= tp
->write_seq
;
2867 else if (tp
->repair_queue
== TCP_RECV_QUEUE
)
2873 case TCP_USER_TIMEOUT
:
2874 val
= jiffies_to_msecs(icsk
->icsk_user_timeout
);
2877 return -ENOPROTOOPT
;
2880 if (put_user(len
, optlen
))
2882 if (copy_to_user(optval
, &val
, len
))
2887 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2890 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2892 if (level
!= SOL_TCP
)
2893 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2895 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2897 EXPORT_SYMBOL(tcp_getsockopt
);
2899 #ifdef CONFIG_COMPAT
2900 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2901 char __user
*optval
, int __user
*optlen
)
2903 if (level
!= SOL_TCP
)
2904 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2906 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2908 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2911 struct sk_buff
*tcp_tso_segment(struct sk_buff
*skb
,
2912 netdev_features_t features
)
2914 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
2919 unsigned int oldlen
;
2922 if (!pskb_may_pull(skb
, sizeof(*th
)))
2926 thlen
= th
->doff
* 4;
2927 if (thlen
< sizeof(*th
))
2930 if (!pskb_may_pull(skb
, thlen
))
2933 oldlen
= (u16
)~skb
->len
;
2934 __skb_pull(skb
, thlen
);
2936 mss
= skb_shinfo(skb
)->gso_size
;
2937 if (unlikely(skb
->len
<= mss
))
2940 if (skb_gso_ok(skb
, features
| NETIF_F_GSO_ROBUST
)) {
2941 /* Packet is from an untrusted source, reset gso_segs. */
2942 int type
= skb_shinfo(skb
)->gso_type
;
2950 !(type
& (SKB_GSO_TCPV4
| SKB_GSO_TCPV6
))))
2953 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(skb
->len
, mss
);
2959 segs
= skb_segment(skb
, features
);
2963 delta
= htonl(oldlen
+ (thlen
+ mss
));
2967 seq
= ntohl(th
->seq
);
2970 th
->fin
= th
->psh
= 0;
2972 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2973 (__force u32
)delta
));
2974 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2976 csum_fold(csum_partial(skb_transport_header(skb
),
2983 th
->seq
= htonl(seq
);
2985 } while (skb
->next
);
2987 delta
= htonl(oldlen
+ (skb
->tail
- skb
->transport_header
) +
2989 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2990 (__force u32
)delta
));
2991 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2992 th
->check
= csum_fold(csum_partial(skb_transport_header(skb
),
2998 EXPORT_SYMBOL(tcp_tso_segment
);
3000 struct sk_buff
**tcp_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
3002 struct sk_buff
**pp
= NULL
;
3009 unsigned int mss
= 1;
3015 off
= skb_gro_offset(skb
);
3016 hlen
= off
+ sizeof(*th
);
3017 th
= skb_gro_header_fast(skb
, off
);
3018 if (skb_gro_header_hard(skb
, hlen
)) {
3019 th
= skb_gro_header_slow(skb
, hlen
, off
);
3024 thlen
= th
->doff
* 4;
3025 if (thlen
< sizeof(*th
))
3029 if (skb_gro_header_hard(skb
, hlen
)) {
3030 th
= skb_gro_header_slow(skb
, hlen
, off
);
3035 skb_gro_pull(skb
, thlen
);
3037 len
= skb_gro_len(skb
);
3038 flags
= tcp_flag_word(th
);
3040 for (; (p
= *head
); head
= &p
->next
) {
3041 if (!NAPI_GRO_CB(p
)->same_flow
)
3046 if (*(u32
*)&th
->source
^ *(u32
*)&th2
->source
) {
3047 NAPI_GRO_CB(p
)->same_flow
= 0;
3054 goto out_check_final
;
3057 flush
= NAPI_GRO_CB(p
)->flush
;
3058 flush
|= (__force
int)(flags
& TCP_FLAG_CWR
);
3059 flush
|= (__force
int)((flags
^ tcp_flag_word(th2
)) &
3060 ~(TCP_FLAG_CWR
| TCP_FLAG_FIN
| TCP_FLAG_PSH
));
3061 flush
|= (__force
int)(th
->ack_seq
^ th2
->ack_seq
);
3062 for (i
= sizeof(*th
); i
< thlen
; i
+= 4)
3063 flush
|= *(u32
*)((u8
*)th
+ i
) ^
3064 *(u32
*)((u8
*)th2
+ i
);
3066 mss
= skb_shinfo(p
)->gso_size
;
3068 flush
|= (len
- 1) >= mss
;
3069 flush
|= (ntohl(th2
->seq
) + skb_gro_len(p
)) ^ ntohl(th
->seq
);
3071 if (flush
|| skb_gro_receive(head
, skb
)) {
3073 goto out_check_final
;
3078 tcp_flag_word(th2
) |= flags
& (TCP_FLAG_FIN
| TCP_FLAG_PSH
);
3082 flush
|= (__force
int)(flags
& (TCP_FLAG_URG
| TCP_FLAG_PSH
|
3083 TCP_FLAG_RST
| TCP_FLAG_SYN
|
3086 if (p
&& (!NAPI_GRO_CB(skb
)->same_flow
|| flush
))
3090 NAPI_GRO_CB(skb
)->flush
|= flush
;
3094 EXPORT_SYMBOL(tcp_gro_receive
);
3096 int tcp_gro_complete(struct sk_buff
*skb
)
3098 struct tcphdr
*th
= tcp_hdr(skb
);
3100 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
3101 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
3102 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3104 skb_shinfo(skb
)->gso_segs
= NAPI_GRO_CB(skb
)->count
;
3107 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
3111 EXPORT_SYMBOL(tcp_gro_complete
);
3113 #ifdef CONFIG_TCP_MD5SIG
3114 static unsigned long tcp_md5sig_users
;
3115 static struct tcp_md5sig_pool __percpu
*tcp_md5sig_pool
;
3116 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock
);
3118 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu
*pool
)
3122 for_each_possible_cpu(cpu
) {
3123 struct tcp_md5sig_pool
*p
= per_cpu_ptr(pool
, cpu
);
3125 if (p
->md5_desc
.tfm
)
3126 crypto_free_hash(p
->md5_desc
.tfm
);
3131 void tcp_free_md5sig_pool(void)
3133 struct tcp_md5sig_pool __percpu
*pool
= NULL
;
3135 spin_lock_bh(&tcp_md5sig_pool_lock
);
3136 if (--tcp_md5sig_users
== 0) {
3137 pool
= tcp_md5sig_pool
;
3138 tcp_md5sig_pool
= NULL
;
3140 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3142 __tcp_free_md5sig_pool(pool
);
3144 EXPORT_SYMBOL(tcp_free_md5sig_pool
);
3146 static struct tcp_md5sig_pool __percpu
*
3147 __tcp_alloc_md5sig_pool(struct sock
*sk
)
3150 struct tcp_md5sig_pool __percpu
*pool
;
3152 pool
= alloc_percpu(struct tcp_md5sig_pool
);
3156 for_each_possible_cpu(cpu
) {
3157 struct crypto_hash
*hash
;
3159 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
3160 if (!hash
|| IS_ERR(hash
))
3163 per_cpu_ptr(pool
, cpu
)->md5_desc
.tfm
= hash
;
3167 __tcp_free_md5sig_pool(pool
);
3171 struct tcp_md5sig_pool __percpu
*tcp_alloc_md5sig_pool(struct sock
*sk
)
3173 struct tcp_md5sig_pool __percpu
*pool
;
3177 spin_lock_bh(&tcp_md5sig_pool_lock
);
3178 pool
= tcp_md5sig_pool
;
3179 if (tcp_md5sig_users
++ == 0) {
3181 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3184 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3188 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3191 /* we cannot hold spinlock here because this may sleep. */
3192 struct tcp_md5sig_pool __percpu
*p
;
3194 p
= __tcp_alloc_md5sig_pool(sk
);
3195 spin_lock_bh(&tcp_md5sig_pool_lock
);
3198 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3201 pool
= tcp_md5sig_pool
;
3203 /* oops, it has already been assigned. */
3204 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3205 __tcp_free_md5sig_pool(p
);
3207 tcp_md5sig_pool
= pool
= p
;
3208 spin_unlock_bh(&tcp_md5sig_pool_lock
);
3213 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
3217 * tcp_get_md5sig_pool - get md5sig_pool for this user
3219 * We use percpu structure, so if we succeed, we exit with preemption
3220 * and BH disabled, to make sure another thread or softirq handling
3221 * wont try to get same context.
3223 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
3225 struct tcp_md5sig_pool __percpu
*p
;
3229 spin_lock(&tcp_md5sig_pool_lock
);
3230 p
= tcp_md5sig_pool
;
3233 spin_unlock(&tcp_md5sig_pool_lock
);
3236 return this_cpu_ptr(p
);
3241 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
3243 void tcp_put_md5sig_pool(void)
3246 tcp_free_md5sig_pool();
3248 EXPORT_SYMBOL(tcp_put_md5sig_pool
);
3250 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
3251 const struct tcphdr
*th
)
3253 struct scatterlist sg
;
3257 /* We are not allowed to change tcphdr, make a local copy */
3258 memcpy(&hdr
, th
, sizeof(hdr
));
3261 /* options aren't included in the hash */
3262 sg_init_one(&sg
, &hdr
, sizeof(hdr
));
3263 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(hdr
));
3266 EXPORT_SYMBOL(tcp_md5_hash_header
);
3268 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
3269 const struct sk_buff
*skb
, unsigned int header_len
)
3271 struct scatterlist sg
;
3272 const struct tcphdr
*tp
= tcp_hdr(skb
);
3273 struct hash_desc
*desc
= &hp
->md5_desc
;
3275 const unsigned int head_data_len
= skb_headlen(skb
) > header_len
?
3276 skb_headlen(skb
) - header_len
: 0;
3277 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
3278 struct sk_buff
*frag_iter
;
3280 sg_init_table(&sg
, 1);
3282 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
3283 if (crypto_hash_update(desc
, &sg
, head_data_len
))
3286 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
3287 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
3288 struct page
*page
= skb_frag_page(f
);
3289 sg_set_page(&sg
, page
, skb_frag_size(f
), f
->page_offset
);
3290 if (crypto_hash_update(desc
, &sg
, skb_frag_size(f
)))
3294 skb_walk_frags(skb
, frag_iter
)
3295 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3300 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3302 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, const struct tcp_md5sig_key
*key
)
3304 struct scatterlist sg
;
3306 sg_init_one(&sg
, key
->key
, key
->keylen
);
3307 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3309 EXPORT_SYMBOL(tcp_md5_hash_key
);
3314 * Each Responder maintains up to two secret values concurrently for
3315 * efficient secret rollover. Each secret value has 4 states:
3317 * Generating. (tcp_secret_generating != tcp_secret_primary)
3318 * Generates new Responder-Cookies, but not yet used for primary
3319 * verification. This is a short-term state, typically lasting only
3320 * one round trip time (RTT).
3322 * Primary. (tcp_secret_generating == tcp_secret_primary)
3323 * Used both for generation and primary verification.
3325 * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
3326 * Used for verification, until the first failure that can be
3327 * verified by the newer Generating secret. At that time, this
3328 * cookie's state is changed to Secondary, and the Generating
3329 * cookie's state is changed to Primary. This is a short-term state,
3330 * typically lasting only one round trip time (RTT).
3332 * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
3333 * Used for secondary verification, after primary verification
3334 * failures. This state lasts no more than twice the Maximum Segment
3335 * Lifetime (2MSL). Then, the secret is discarded.
3337 struct tcp_cookie_secret
{
3338 /* The secret is divided into two parts. The digest part is the
3339 * equivalent of previously hashing a secret and saving the state,
3340 * and serves as an initialization vector (IV). The message part
3341 * serves as the trailing secret.
3343 u32 secrets
[COOKIE_WORKSPACE_WORDS
];
3344 unsigned long expires
;
3347 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
3348 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
3349 #define TCP_SECRET_LIFE (HZ * 600)
3351 static struct tcp_cookie_secret tcp_secret_one
;
3352 static struct tcp_cookie_secret tcp_secret_two
;
3354 /* Essentially a circular list, without dynamic allocation. */
3355 static struct tcp_cookie_secret
*tcp_secret_generating
;
3356 static struct tcp_cookie_secret
*tcp_secret_primary
;
3357 static struct tcp_cookie_secret
*tcp_secret_retiring
;
3358 static struct tcp_cookie_secret
*tcp_secret_secondary
;
3360 static DEFINE_SPINLOCK(tcp_secret_locker
);
3362 /* Select a pseudo-random word in the cookie workspace.
3364 static inline u32
tcp_cookie_work(const u32
*ws
, const int n
)
3366 return ws
[COOKIE_DIGEST_WORDS
+ ((COOKIE_MESSAGE_WORDS
-1) & ws
[n
])];
3369 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
3370 * Called in softirq context.
3371 * Returns: 0 for success.
3373 int tcp_cookie_generator(u32
*bakery
)
3375 unsigned long jiffy
= jiffies
;
3377 if (unlikely(time_after_eq(jiffy
, tcp_secret_generating
->expires
))) {
3378 spin_lock_bh(&tcp_secret_locker
);
3379 if (!time_after_eq(jiffy
, tcp_secret_generating
->expires
)) {
3380 /* refreshed by another */
3382 &tcp_secret_generating
->secrets
[0],
3383 COOKIE_WORKSPACE_WORDS
);
3385 /* still needs refreshing */
3386 get_random_bytes(bakery
, COOKIE_WORKSPACE_WORDS
);
3388 /* The first time, paranoia assumes that the
3389 * randomization function isn't as strong. But,
3390 * this secret initialization is delayed until
3391 * the last possible moment (packet arrival).
3392 * Although that time is observable, it is
3393 * unpredictably variable. Mash in the most
3394 * volatile clock bits available, and expire the
3395 * secret extra quickly.
3397 if (unlikely(tcp_secret_primary
->expires
==
3398 tcp_secret_secondary
->expires
)) {
3401 getnstimeofday(&tv
);
3402 bakery
[COOKIE_DIGEST_WORDS
+0] ^=
3405 tcp_secret_secondary
->expires
= jiffy
3407 + (0x0f & tcp_cookie_work(bakery
, 0));
3409 tcp_secret_secondary
->expires
= jiffy
3411 + (0xff & tcp_cookie_work(bakery
, 1));
3412 tcp_secret_primary
->expires
= jiffy
3414 + (0x1f & tcp_cookie_work(bakery
, 2));
3416 memcpy(&tcp_secret_secondary
->secrets
[0],
3417 bakery
, COOKIE_WORKSPACE_WORDS
);
3419 rcu_assign_pointer(tcp_secret_generating
,
3420 tcp_secret_secondary
);
3421 rcu_assign_pointer(tcp_secret_retiring
,
3422 tcp_secret_primary
);
3424 * Neither call_rcu() nor synchronize_rcu() needed.
3425 * Retiring data is not freed. It is replaced after
3426 * further (locked) pointer updates, and a quiet time
3427 * (minimum 1MSL, maximum LIFE - 2MSL).
3430 spin_unlock_bh(&tcp_secret_locker
);
3434 &rcu_dereference(tcp_secret_generating
)->secrets
[0],
3435 COOKIE_WORKSPACE_WORDS
);
3436 rcu_read_unlock_bh();
3440 EXPORT_SYMBOL(tcp_cookie_generator
);
3442 void tcp_done(struct sock
*sk
)
3444 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3445 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3447 tcp_set_state(sk
, TCP_CLOSE
);
3448 tcp_clear_xmit_timers(sk
);
3450 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3452 if (!sock_flag(sk
, SOCK_DEAD
))
3453 sk
->sk_state_change(sk
);
3455 inet_csk_destroy_sock(sk
);
3457 EXPORT_SYMBOL_GPL(tcp_done
);
3459 extern struct tcp_congestion_ops tcp_reno
;
3461 static __initdata
unsigned long thash_entries
;
3462 static int __init
set_thash_entries(char *str
)
3469 ret
= kstrtoul(str
, 0, &thash_entries
);
3475 __setup("thash_entries=", set_thash_entries
);
3477 void tcp_init_mem(struct net
*net
)
3479 unsigned long limit
= nr_free_buffer_pages() / 8;
3480 limit
= max(limit
, 128UL);
3481 net
->ipv4
.sysctl_tcp_mem
[0] = limit
/ 4 * 3;
3482 net
->ipv4
.sysctl_tcp_mem
[1] = limit
;
3483 net
->ipv4
.sysctl_tcp_mem
[2] = net
->ipv4
.sysctl_tcp_mem
[0] * 2;
3486 void __init
tcp_init(void)
3488 struct sk_buff
*skb
= NULL
;
3489 unsigned long limit
;
3490 int max_rshare
, max_wshare
, cnt
;
3492 unsigned long jiffy
= jiffies
;
3494 BUILD_BUG_ON(sizeof(struct tcp_skb_cb
) > sizeof(skb
->cb
));
3496 percpu_counter_init(&tcp_sockets_allocated
, 0);
3497 percpu_counter_init(&tcp_orphan_count
, 0);
3498 tcp_hashinfo
.bind_bucket_cachep
=
3499 kmem_cache_create("tcp_bind_bucket",
3500 sizeof(struct inet_bind_bucket
), 0,
3501 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3503 /* Size and allocate the main established and bind bucket
3506 * The methodology is similar to that of the buffer cache.
3508 tcp_hashinfo
.ehash
=
3509 alloc_large_system_hash("TCP established",
3510 sizeof(struct inet_ehash_bucket
),
3512 (totalram_pages
>= 128 * 1024) ?
3516 &tcp_hashinfo
.ehash_mask
,
3518 thash_entries
? 0 : 512 * 1024);
3519 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++) {
3520 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3521 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].twchain
, i
);
3523 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3524 panic("TCP: failed to alloc ehash_locks");
3525 tcp_hashinfo
.bhash
=
3526 alloc_large_system_hash("TCP bind",
3527 sizeof(struct inet_bind_hashbucket
),
3528 tcp_hashinfo
.ehash_mask
+ 1,
3529 (totalram_pages
>= 128 * 1024) ?
3532 &tcp_hashinfo
.bhash_size
,
3536 tcp_hashinfo
.bhash_size
= 1U << tcp_hashinfo
.bhash_size
;
3537 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3538 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3539 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3543 cnt
= tcp_hashinfo
.ehash_mask
+ 1;
3545 tcp_death_row
.sysctl_max_tw_buckets
= cnt
/ 2;
3546 sysctl_tcp_max_orphans
= cnt
/ 2;
3547 sysctl_max_syn_backlog
= max(128, cnt
/ 256);
3549 tcp_init_mem(&init_net
);
3550 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3551 limit
= nr_free_buffer_pages() << (PAGE_SHIFT
- 7);
3552 max_wshare
= min(4UL*1024*1024, limit
);
3553 max_rshare
= min(6UL*1024*1024, limit
);
3555 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3556 sysctl_tcp_wmem
[1] = 16*1024;
3557 sysctl_tcp_wmem
[2] = max(64*1024, max_wshare
);
3559 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3560 sysctl_tcp_rmem
[1] = 87380;
3561 sysctl_tcp_rmem
[2] = max(87380, max_rshare
);
3563 pr_info("Hash tables configured (established %u bind %u)\n",
3564 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3566 tcp_register_congestion_control(&tcp_reno
);
3568 memset(&tcp_secret_one
.secrets
[0], 0, sizeof(tcp_secret_one
.secrets
));
3569 memset(&tcp_secret_two
.secrets
[0], 0, sizeof(tcp_secret_two
.secrets
));
3570 tcp_secret_one
.expires
= jiffy
; /* past due */
3571 tcp_secret_two
.expires
= jiffy
; /* past due */
3572 tcp_secret_generating
= &tcp_secret_one
;
3573 tcp_secret_primary
= &tcp_secret_one
;
3574 tcp_secret_retiring
= &tcp_secret_two
;
3575 tcp_secret_secondary
= &tcp_secret_two
;