2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Implementation of the Transmission Control Protocol(TCP).
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Mark Evans, <evansmp@uhura.aston.ac.uk>
11 * Corey Minyard <wf-rch!minyard@relay.EU.net>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
14 * Linus Torvalds, <torvalds@cs.helsinki.fi>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Matthew Dillon, <dillon@apollo.west.oic.com>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Jorge Cwik, <jorge@laser.satlink.net>
21 * Alan Cox : Numerous verify_area() calls
22 * Alan Cox : Set the ACK bit on a reset
23 * Alan Cox : Stopped it crashing if it closed while
24 * sk->inuse=1 and was trying to connect
26 * Alan Cox : All icmp error handling was broken
27 * pointers passed where wrong and the
28 * socket was looked up backwards. Nobody
29 * tested any icmp error code obviously.
30 * Alan Cox : tcp_err() now handled properly. It
31 * wakes people on errors. poll
32 * behaves and the icmp error race
33 * has gone by moving it into sock.c
34 * Alan Cox : tcp_send_reset() fixed to work for
35 * everything not just packets for
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
40 * Herp Rosmanith : More reset fixes
41 * Alan Cox : No longer acks invalid rst frames.
42 * Acking any kind of RST is right out.
43 * Alan Cox : Sets an ignore me flag on an rst
44 * receive otherwise odd bits of prattle
46 * Alan Cox : Fixed another acking RST frame bug.
47 * Should stop LAN workplace lockups.
48 * Alan Cox : Some tidyups using the new skb list
50 * Alan Cox : sk->keepopen now seems to work
51 * Alan Cox : Pulls options out correctly on accepts
52 * Alan Cox : Fixed assorted sk->rqueue->next errors
53 * Alan Cox : PSH doesn't end a TCP read. Switched a
55 * Alan Cox : Tidied tcp_data to avoid a potential
57 * Alan Cox : Added some better commenting, as the
58 * tcp is hard to follow
59 * Alan Cox : Removed incorrect check for 20 * psh
60 * Michael O'Reilly : ack < copied bug fix.
61 * Johannes Stille : Misc tcp fixes (not all in yet).
62 * Alan Cox : FIN with no memory -> CRASH
63 * Alan Cox : Added socket option proto entries.
64 * Also added awareness of them to accept.
65 * Alan Cox : Added TCP options (SOL_TCP)
66 * Alan Cox : Switched wakeup calls to callbacks,
67 * so the kernel can layer network
69 * Alan Cox : Use ip_tos/ip_ttl settings.
70 * Alan Cox : Handle FIN (more) properly (we hope).
71 * Alan Cox : RST frames sent on unsynchronised
73 * Alan Cox : Put in missing check for SYN bit.
74 * Alan Cox : Added tcp_select_window() aka NET2E
75 * window non shrink trick.
76 * Alan Cox : Added a couple of small NET2E timer
78 * Charles Hedrick : TCP fixes
79 * Toomas Tamm : TCP window fixes
80 * Alan Cox : Small URG fix to rlogin ^C ack fight
81 * Charles Hedrick : Rewrote most of it to actually work
82 * Linus : Rewrote tcp_read() and URG handling
84 * Gerhard Koerting: Fixed some missing timer handling
85 * Matthew Dillon : Reworked TCP machine states as per RFC
86 * Gerhard Koerting: PC/TCP workarounds
87 * Adam Caldwell : Assorted timer/timing errors
88 * Matthew Dillon : Fixed another RST bug
89 * Alan Cox : Move to kernel side addressing changes.
90 * Alan Cox : Beginning work on TCP fastpathing
92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
93 * Alan Cox : TCP fast path debugging
94 * Alan Cox : Window clamping
95 * Michael Riepe : Bug in tcp_check()
96 * Matt Dillon : More TCP improvements and RST bug fixes
97 * Matt Dillon : Yet more small nasties remove from the
98 * TCP code (Be very nice to this man if
99 * tcp finally works 100%) 8)
100 * Alan Cox : BSD accept semantics.
101 * Alan Cox : Reset on closedown bug.
102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
103 * Michael Pall : Handle poll() after URG properly in
105 * Michael Pall : Undo the last fix in tcp_read_urg()
106 * (multi URG PUSH broke rlogin).
107 * Michael Pall : Fix the multi URG PUSH problem in
108 * tcp_readable(), poll() after URG
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
112 * Alan Cox : Changed the semantics of sk->socket to
113 * fix a race and a signal problem with
114 * accept() and async I/O.
115 * Alan Cox : Relaxed the rules on tcp_sendto().
116 * Yury Shevchuk : Really fixed accept() blocking problem.
117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
118 * clients/servers which listen in on
120 * Alan Cox : Cleaned the above up and shrank it to
121 * a sensible code size.
122 * Alan Cox : Self connect lockup fix.
123 * Alan Cox : No connect to multicast.
124 * Ross Biro : Close unaccepted children on master
126 * Alan Cox : Reset tracing code.
127 * Alan Cox : Spurious resets on shutdown.
128 * Alan Cox : Giant 15 minute/60 second timer error
129 * Alan Cox : Small whoops in polling before an
131 * Alan Cox : Kept the state trace facility since
132 * it's handy for debugging.
133 * Alan Cox : More reset handler fixes.
134 * Alan Cox : Started rewriting the code based on
135 * the RFC's for other useful protocol
136 * references see: Comer, KA9Q NOS, and
137 * for a reference on the difference
138 * between specifications and how BSD
139 * works see the 4.4lite source.
140 * A.N.Kuznetsov : Don't time wait on completion of tidy
142 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
143 * Linus Torvalds : Fixed BSD port reuse to work first syn
144 * Alan Cox : Reimplemented timers as per the RFC
145 * and using multiple timers for sanity.
146 * Alan Cox : Small bug fixes, and a lot of new
148 * Alan Cox : Fixed dual reader crash by locking
149 * the buffers (much like datagram.c)
150 * Alan Cox : Fixed stuck sockets in probe. A probe
151 * now gets fed up of retrying without
152 * (even a no space) answer.
153 * Alan Cox : Extracted closing code better
154 * Alan Cox : Fixed the closing state machine to
156 * Alan Cox : More 'per spec' fixes.
157 * Jorge Cwik : Even faster checksumming.
158 * Alan Cox : tcp_data() doesn't ack illegal PSH
159 * only frames. At least one pc tcp stack
161 * Alan Cox : Cache last socket.
162 * Alan Cox : Per route irtt.
163 * Matt Day : poll()->select() match BSD precisely on error
164 * Alan Cox : New buffers
165 * Marc Tamsky : Various sk->prot->retransmits and
166 * sk->retransmits misupdating fixed.
167 * Fixed tcp_write_timeout: stuck close,
168 * and TCP syn retries gets used now.
169 * Mark Yarvis : In tcp_read_wakeup(), don't send an
170 * ack if state is TCP_CLOSED.
171 * Alan Cox : Look up device on a retransmit - routes may
172 * change. Doesn't yet cope with MSS shrink right
174 * Marc Tamsky : Closing in closing fixes.
175 * Mike Shaver : RFC1122 verifications.
176 * Alan Cox : rcv_saddr errors.
177 * Alan Cox : Block double connect().
178 * Alan Cox : Small hooks for enSKIP.
179 * Alexey Kuznetsov: Path MTU discovery.
180 * Alan Cox : Support soft errors.
181 * Alan Cox : Fix MTU discovery pathological case
182 * when the remote claims no mtu!
183 * Marc Tamsky : TCP_CLOSE fix.
184 * Colin (G3TNE) : Send a reset on syn ack replies in
185 * window but wrong (fixes NT lpd problems)
186 * Pedro Roque : Better TCP window handling, delayed ack.
187 * Joerg Reuter : No modification of locked buffers in
188 * tcp_do_retransmit()
189 * Eric Schenk : Changed receiver side silly window
190 * avoidance algorithm to BSD style
191 * algorithm. This doubles throughput
192 * against machines running Solaris,
193 * and seems to result in general
195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
196 * Willy Konynenberg : Transparent proxying support.
197 * Mike McLagan : Routing by source
198 * Keith Owens : Do proper merging with partial SKB's in
199 * tcp_do_sendmsg to avoid burstiness.
200 * Eric Schenk : Fix fast close down bug with
201 * shutdown() followed by close().
202 * Andi Kleen : Make poll agree with SIGIO
203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
204 * lingertime == 0 (RFC 793 ABORT Call)
205 * Hirokazu Takahashi : Use copy_from_user() instead of
206 * csum_and_copy_from_user() if possible.
208 * This program is free software; you can redistribute it and/or
209 * modify it under the terms of the GNU General Public License
210 * as published by the Free Software Foundation; either version
211 * 2 of the License, or(at your option) any later version.
213 * Description of States:
215 * TCP_SYN_SENT sent a connection request, waiting for ack
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
220 * TCP_ESTABLISHED connection established
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
231 * TCP_TIME_WAIT timeout to catch resent junk before entering
232 * closed, can only be entered from FIN_WAIT2
233 * or CLOSING. Required because the other end
234 * may not have gotten our last ACK causing it
235 * to retransmit the data packet (which we ignore)
237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
238 * us to finish writing our data and to shutdown
239 * (we have to close() to move on to LAST_ACK)
241 * TCP_LAST_ACK out side has shutdown after remote has
242 * shutdown. There may still be data in our
243 * buffer that we have to finish sending
245 * TCP_CLOSE socket is finished
248 #include <linux/kernel.h>
249 #include <linux/module.h>
250 #include <linux/types.h>
251 #include <linux/fcntl.h>
252 #include <linux/poll.h>
253 #include <linux/init.h>
254 #include <linux/fs.h>
255 #include <linux/skbuff.h>
256 #include <linux/scatterlist.h>
257 #include <linux/splice.h>
258 #include <linux/net.h>
259 #include <linux/socket.h>
260 #include <linux/random.h>
261 #include <linux/bootmem.h>
262 #include <linux/highmem.h>
263 #include <linux/swap.h>
264 #include <linux/cache.h>
265 #include <linux/err.h>
266 #include <linux/crypto.h>
267 #include <linux/time.h>
268 #include <linux/slab.h>
270 #include <net/icmp.h>
272 #include <net/xfrm.h>
274 #include <net/netdma.h>
275 #include <net/sock.h>
277 #include <asm/uaccess.h>
278 #include <asm/ioctls.h>
280 int sysctl_tcp_fin_timeout __read_mostly
= TCP_FIN_TIMEOUT
;
282 struct percpu_counter tcp_orphan_count
;
283 EXPORT_SYMBOL_GPL(tcp_orphan_count
);
285 int sysctl_tcp_mem
[3] __read_mostly
;
286 int sysctl_tcp_wmem
[3] __read_mostly
;
287 int sysctl_tcp_rmem
[3] __read_mostly
;
289 EXPORT_SYMBOL(sysctl_tcp_mem
);
290 EXPORT_SYMBOL(sysctl_tcp_rmem
);
291 EXPORT_SYMBOL(sysctl_tcp_wmem
);
293 atomic_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
)
367 * Wait for a TCP event.
369 * Note that we don't need to lock the socket, as the upper poll layers
370 * take care of normal races (between the test and the event) and we don't
371 * go look at any of the socket buffers directly.
373 unsigned int tcp_poll(struct file
*file
, struct socket
*sock
, poll_table
*wait
)
376 struct sock
*sk
= sock
->sk
;
377 struct tcp_sock
*tp
= tcp_sk(sk
);
379 sock_poll_wait(file
, sk_sleep(sk
), wait
);
380 if (sk
->sk_state
== TCP_LISTEN
)
381 return inet_csk_listen_poll(sk
);
383 /* Socket is not locked. We are protected from async events
384 * by poll logic and correct handling of state changes
385 * made by other threads is impossible in any case.
393 * POLLHUP is certainly not done right. But poll() doesn't
394 * have a notion of HUP in just one direction, and for a
395 * socket the read side is more interesting.
397 * Some poll() documentation says that POLLHUP is incompatible
398 * with the POLLOUT/POLLWR flags, so somebody should check this
399 * all. But careful, it tends to be safer to return too many
400 * bits than too few, and you can easily break real applications
401 * if you don't tell them that something has hung up!
405 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
406 * our fs/select.c). It means that after we received EOF,
407 * poll always returns immediately, making impossible poll() on write()
408 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
409 * if and only if shutdown has been made in both directions.
410 * Actually, it is interesting to look how Solaris and DUX
411 * solve this dilemma. I would prefer, if POLLHUP were maskable,
412 * then we could set it on SND_SHUTDOWN. BTW examples given
413 * in Stevens' books assume exactly this behaviour, it explains
414 * why POLLHUP is incompatible with POLLOUT. --ANK
416 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
417 * blocking on fresh not-connected or disconnected socket. --ANK
419 if (sk
->sk_shutdown
== SHUTDOWN_MASK
|| sk
->sk_state
== TCP_CLOSE
)
421 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
422 mask
|= POLLIN
| POLLRDNORM
| POLLRDHUP
;
425 if ((1 << sk
->sk_state
) & ~(TCPF_SYN_SENT
| TCPF_SYN_RECV
)) {
426 int target
= sock_rcvlowat(sk
, 0, INT_MAX
);
428 if (tp
->urg_seq
== tp
->copied_seq
&&
429 !sock_flag(sk
, SOCK_URGINLINE
) &&
433 /* Potential race condition. If read of tp below will
434 * escape above sk->sk_state, we can be illegally awaken
435 * in SYN_* states. */
436 if (tp
->rcv_nxt
- tp
->copied_seq
>= target
)
437 mask
|= POLLIN
| POLLRDNORM
;
439 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
440 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
)) {
441 mask
|= POLLOUT
| POLLWRNORM
;
442 } else { /* send SIGIO later */
443 set_bit(SOCK_ASYNC_NOSPACE
,
444 &sk
->sk_socket
->flags
);
445 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
447 /* Race breaker. If space is freed after
448 * wspace test but before the flags are set,
449 * IO signal will be lost.
451 if (sk_stream_wspace(sk
) >= sk_stream_min_wspace(sk
))
452 mask
|= POLLOUT
| POLLWRNORM
;
456 if (tp
->urg_data
& TCP_URG_VALID
)
461 EXPORT_SYMBOL(tcp_poll
);
463 int tcp_ioctl(struct sock
*sk
, int cmd
, unsigned long arg
)
465 struct tcp_sock
*tp
= tcp_sk(sk
);
470 if (sk
->sk_state
== TCP_LISTEN
)
474 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
476 else if (sock_flag(sk
, SOCK_URGINLINE
) ||
478 before(tp
->urg_seq
, tp
->copied_seq
) ||
479 !before(tp
->urg_seq
, tp
->rcv_nxt
)) {
482 answ
= tp
->rcv_nxt
- tp
->copied_seq
;
484 /* Subtract 1, if FIN is in queue. */
485 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
487 answ
-= tcp_hdr(skb
)->fin
;
489 answ
= tp
->urg_seq
- tp
->copied_seq
;
493 answ
= tp
->urg_data
&& tp
->urg_seq
== tp
->copied_seq
;
496 if (sk
->sk_state
== TCP_LISTEN
)
499 if ((1 << sk
->sk_state
) & (TCPF_SYN_SENT
| TCPF_SYN_RECV
))
502 answ
= tp
->write_seq
- tp
->snd_una
;
508 return put_user(answ
, (int __user
*)arg
);
510 EXPORT_SYMBOL(tcp_ioctl
);
512 static inline void tcp_mark_push(struct tcp_sock
*tp
, struct sk_buff
*skb
)
514 TCP_SKB_CB(skb
)->flags
|= TCPHDR_PSH
;
515 tp
->pushed_seq
= tp
->write_seq
;
518 static inline int forced_push(struct tcp_sock
*tp
)
520 return after(tp
->write_seq
, tp
->pushed_seq
+ (tp
->max_window
>> 1));
523 static inline void skb_entail(struct sock
*sk
, struct sk_buff
*skb
)
525 struct tcp_sock
*tp
= tcp_sk(sk
);
526 struct tcp_skb_cb
*tcb
= TCP_SKB_CB(skb
);
529 tcb
->seq
= tcb
->end_seq
= tp
->write_seq
;
530 tcb
->flags
= TCPHDR_ACK
;
532 skb_header_release(skb
);
533 tcp_add_write_queue_tail(sk
, skb
);
534 sk
->sk_wmem_queued
+= skb
->truesize
;
535 sk_mem_charge(sk
, skb
->truesize
);
536 if (tp
->nonagle
& TCP_NAGLE_PUSH
)
537 tp
->nonagle
&= ~TCP_NAGLE_PUSH
;
540 static inline void tcp_mark_urg(struct tcp_sock
*tp
, int flags
)
543 tp
->snd_up
= tp
->write_seq
;
546 static inline void tcp_push(struct sock
*sk
, int flags
, int mss_now
,
549 if (tcp_send_head(sk
)) {
550 struct tcp_sock
*tp
= tcp_sk(sk
);
552 if (!(flags
& MSG_MORE
) || forced_push(tp
))
553 tcp_mark_push(tp
, tcp_write_queue_tail(sk
));
555 tcp_mark_urg(tp
, flags
);
556 __tcp_push_pending_frames(sk
, mss_now
,
557 (flags
& MSG_MORE
) ? TCP_NAGLE_CORK
: nonagle
);
561 static int tcp_splice_data_recv(read_descriptor_t
*rd_desc
, struct sk_buff
*skb
,
562 unsigned int offset
, size_t len
)
564 struct tcp_splice_state
*tss
= rd_desc
->arg
.data
;
567 ret
= skb_splice_bits(skb
, offset
, tss
->pipe
, min(rd_desc
->count
, len
),
570 rd_desc
->count
-= ret
;
574 static int __tcp_splice_read(struct sock
*sk
, struct tcp_splice_state
*tss
)
576 /* Store TCP splice context information in read_descriptor_t. */
577 read_descriptor_t rd_desc
= {
582 return tcp_read_sock(sk
, &rd_desc
, tcp_splice_data_recv
);
586 * tcp_splice_read - splice data from TCP socket to a pipe
587 * @sock: socket to splice from
588 * @ppos: position (not valid)
589 * @pipe: pipe to splice to
590 * @len: number of bytes to splice
591 * @flags: splice modifier flags
594 * Will read pages from given socket and fill them into a pipe.
597 ssize_t
tcp_splice_read(struct socket
*sock
, loff_t
*ppos
,
598 struct pipe_inode_info
*pipe
, size_t len
,
601 struct sock
*sk
= sock
->sk
;
602 struct tcp_splice_state tss
= {
612 * We can't seek on a socket input
621 timeo
= sock_rcvtimeo(sk
, sock
->file
->f_flags
& O_NONBLOCK
);
623 ret
= __tcp_splice_read(sk
, &tss
);
629 if (sock_flag(sk
, SOCK_DONE
))
632 ret
= sock_error(sk
);
635 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
637 if (sk
->sk_state
== TCP_CLOSE
) {
639 * This occurs when user tries to read
640 * from never connected socket.
642 if (!sock_flag(sk
, SOCK_DONE
))
650 sk_wait_data(sk
, &timeo
);
651 if (signal_pending(current
)) {
652 ret
= sock_intr_errno(timeo
);
665 if (sk
->sk_err
|| sk
->sk_state
== TCP_CLOSE
||
666 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
667 signal_pending(current
))
678 EXPORT_SYMBOL(tcp_splice_read
);
680 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
)
684 /* The TCP header must be at least 32-bit aligned. */
685 size
= ALIGN(size
, 4);
687 skb
= alloc_skb_fclone(size
+ sk
->sk_prot
->max_header
, gfp
);
689 if (sk_wmem_schedule(sk
, skb
->truesize
)) {
691 * Make sure that we have exactly size bytes
692 * available to the caller, no more, no less.
694 skb_reserve(skb
, skb_tailroom(skb
) - size
);
699 sk
->sk_prot
->enter_memory_pressure(sk
);
700 sk_stream_moderate_sndbuf(sk
);
705 static unsigned int tcp_xmit_size_goal(struct sock
*sk
, u32 mss_now
,
708 struct tcp_sock
*tp
= tcp_sk(sk
);
709 u32 xmit_size_goal
, old_size_goal
;
711 xmit_size_goal
= mss_now
;
713 if (large_allowed
&& sk_can_gso(sk
)) {
714 xmit_size_goal
= ((sk
->sk_gso_max_size
- 1) -
715 inet_csk(sk
)->icsk_af_ops
->net_header_len
-
716 inet_csk(sk
)->icsk_ext_hdr_len
-
719 xmit_size_goal
= tcp_bound_to_half_wnd(tp
, xmit_size_goal
);
721 /* We try hard to avoid divides here */
722 old_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
724 if (likely(old_size_goal
<= xmit_size_goal
&&
725 old_size_goal
+ mss_now
> xmit_size_goal
)) {
726 xmit_size_goal
= old_size_goal
;
728 tp
->xmit_size_goal_segs
= xmit_size_goal
/ mss_now
;
729 xmit_size_goal
= tp
->xmit_size_goal_segs
* mss_now
;
733 return max(xmit_size_goal
, mss_now
);
736 static int tcp_send_mss(struct sock
*sk
, int *size_goal
, int flags
)
740 mss_now
= tcp_current_mss(sk
);
741 *size_goal
= tcp_xmit_size_goal(sk
, mss_now
, !(flags
& MSG_OOB
));
746 static ssize_t
do_tcp_sendpages(struct sock
*sk
, struct page
**pages
, int poffset
,
747 size_t psize
, int flags
)
749 struct tcp_sock
*tp
= tcp_sk(sk
);
750 int mss_now
, size_goal
;
753 long timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
755 /* Wait for a connection to finish. */
756 if ((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
))
757 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
760 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
762 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
766 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
770 struct sk_buff
*skb
= tcp_write_queue_tail(sk
);
771 struct page
*page
= pages
[poffset
/ PAGE_SIZE
];
772 int copy
, i
, can_coalesce
;
773 int offset
= poffset
% PAGE_SIZE
;
774 int size
= min_t(size_t, psize
, PAGE_SIZE
- offset
);
776 if (!tcp_send_head(sk
) || (copy
= size_goal
- skb
->len
) <= 0) {
778 if (!sk_stream_memory_free(sk
))
779 goto wait_for_sndbuf
;
781 skb
= sk_stream_alloc_skb(sk
, 0, sk
->sk_allocation
);
783 goto wait_for_memory
;
792 i
= skb_shinfo(skb
)->nr_frags
;
793 can_coalesce
= skb_can_coalesce(skb
, i
, page
, offset
);
794 if (!can_coalesce
&& i
>= MAX_SKB_FRAGS
) {
795 tcp_mark_push(tp
, skb
);
798 if (!sk_wmem_schedule(sk
, copy
))
799 goto wait_for_memory
;
802 skb_shinfo(skb
)->frags
[i
- 1].size
+= copy
;
805 skb_fill_page_desc(skb
, i
, page
, offset
, copy
);
809 skb
->data_len
+= copy
;
810 skb
->truesize
+= copy
;
811 sk
->sk_wmem_queued
+= copy
;
812 sk_mem_charge(sk
, copy
);
813 skb
->ip_summed
= CHECKSUM_PARTIAL
;
814 tp
->write_seq
+= copy
;
815 TCP_SKB_CB(skb
)->end_seq
+= copy
;
816 skb_shinfo(skb
)->gso_segs
= 0;
819 TCP_SKB_CB(skb
)->flags
&= ~TCPHDR_PSH
;
823 if (!(psize
-= copy
))
826 if (skb
->len
< size_goal
|| (flags
& MSG_OOB
))
829 if (forced_push(tp
)) {
830 tcp_mark_push(tp
, skb
);
831 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
832 } else if (skb
== tcp_send_head(sk
))
833 tcp_push_one(sk
, mss_now
);
837 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
840 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
842 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
845 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
850 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
857 return sk_stream_error(sk
, flags
, err
);
860 int tcp_sendpage(struct sock
*sk
, struct page
*page
, int offset
,
861 size_t size
, int flags
)
865 if (!(sk
->sk_route_caps
& NETIF_F_SG
) ||
866 !(sk
->sk_route_caps
& NETIF_F_ALL_CSUM
))
867 return sock_no_sendpage(sk
->sk_socket
, page
, offset
, size
,
872 res
= do_tcp_sendpages(sk
, &page
, offset
, size
, flags
);
877 EXPORT_SYMBOL(tcp_sendpage
);
879 #define TCP_PAGE(sk) (sk->sk_sndmsg_page)
880 #define TCP_OFF(sk) (sk->sk_sndmsg_off)
882 static inline int select_size(struct sock
*sk
, int sg
)
884 struct tcp_sock
*tp
= tcp_sk(sk
);
885 int tmp
= tp
->mss_cache
;
891 int pgbreak
= SKB_MAX_HEAD(MAX_TCP_HEADER
);
893 if (tmp
>= pgbreak
&&
894 tmp
<= pgbreak
+ (MAX_SKB_FRAGS
- 1) * PAGE_SIZE
)
902 int tcp_sendmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
906 struct tcp_sock
*tp
= tcp_sk(sk
);
909 int mss_now
, size_goal
;
916 flags
= msg
->msg_flags
;
917 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
919 /* Wait for a connection to finish. */
920 if ((1 << sk
->sk_state
) & ~(TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
))
921 if ((err
= sk_stream_wait_connect(sk
, &timeo
)) != 0)
924 /* This should be in poll */
925 clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
927 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
929 /* Ok commence sending. */
930 iovlen
= msg
->msg_iovlen
;
935 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
))
938 sg
= sk
->sk_route_caps
& NETIF_F_SG
;
940 while (--iovlen
>= 0) {
941 int seglen
= iov
->iov_len
;
942 unsigned char __user
*from
= iov
->iov_base
;
950 skb
= tcp_write_queue_tail(sk
);
951 if (tcp_send_head(sk
)) {
952 if (skb
->ip_summed
== CHECKSUM_NONE
)
954 copy
= max
- skb
->len
;
959 /* Allocate new segment. If the interface is SG,
960 * allocate skb fitting to single page.
962 if (!sk_stream_memory_free(sk
))
963 goto wait_for_sndbuf
;
965 skb
= sk_stream_alloc_skb(sk
,
969 goto wait_for_memory
;
972 * Check whether we can use HW checksum.
974 if (sk
->sk_route_caps
& NETIF_F_ALL_CSUM
)
975 skb
->ip_summed
= CHECKSUM_PARTIAL
;
982 /* Try to append data to the end of skb. */
986 /* Where to copy to? */
987 if (skb_tailroom(skb
) > 0) {
988 /* We have some space in skb head. Superb! */
989 if (copy
> skb_tailroom(skb
))
990 copy
= skb_tailroom(skb
);
991 if ((err
= skb_add_data(skb
, from
, copy
)) != 0)
995 int i
= skb_shinfo(skb
)->nr_frags
;
996 struct page
*page
= TCP_PAGE(sk
);
997 int off
= TCP_OFF(sk
);
999 if (skb_can_coalesce(skb
, i
, page
, off
) &&
1001 /* We can extend the last page
1004 } else if (i
== MAX_SKB_FRAGS
|| !sg
) {
1005 /* Need to add new fragment and cannot
1006 * do this because interface is non-SG,
1007 * or because all the page slots are
1009 tcp_mark_push(tp
, skb
);
1012 if (off
== PAGE_SIZE
) {
1014 TCP_PAGE(sk
) = page
= NULL
;
1020 if (copy
> PAGE_SIZE
- off
)
1021 copy
= PAGE_SIZE
- off
;
1023 if (!sk_wmem_schedule(sk
, copy
))
1024 goto wait_for_memory
;
1027 /* Allocate new cache page. */
1028 if (!(page
= sk_stream_alloc_page(sk
)))
1029 goto wait_for_memory
;
1032 /* Time to copy data. We are close to
1034 err
= skb_copy_to_page(sk
, from
, skb
, page
,
1037 /* If this page was new, give it to the
1038 * socket so it does not get leaked.
1040 if (!TCP_PAGE(sk
)) {
1041 TCP_PAGE(sk
) = page
;
1047 /* Update the skb. */
1049 skb_shinfo(skb
)->frags
[i
- 1].size
+=
1052 skb_fill_page_desc(skb
, i
, page
, off
, copy
);
1055 } else if (off
+ copy
< PAGE_SIZE
) {
1057 TCP_PAGE(sk
) = page
;
1061 TCP_OFF(sk
) = off
+ copy
;
1065 TCP_SKB_CB(skb
)->flags
&= ~TCPHDR_PSH
;
1067 tp
->write_seq
+= copy
;
1068 TCP_SKB_CB(skb
)->end_seq
+= copy
;
1069 skb_shinfo(skb
)->gso_segs
= 0;
1073 if ((seglen
-= copy
) == 0 && iovlen
== 0)
1076 if (skb
->len
< max
|| (flags
& MSG_OOB
))
1079 if (forced_push(tp
)) {
1080 tcp_mark_push(tp
, skb
);
1081 __tcp_push_pending_frames(sk
, mss_now
, TCP_NAGLE_PUSH
);
1082 } else if (skb
== tcp_send_head(sk
))
1083 tcp_push_one(sk
, mss_now
);
1087 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
1090 tcp_push(sk
, flags
& ~MSG_MORE
, mss_now
, TCP_NAGLE_PUSH
);
1092 if ((err
= sk_stream_wait_memory(sk
, &timeo
)) != 0)
1095 mss_now
= tcp_send_mss(sk
, &size_goal
, flags
);
1101 tcp_push(sk
, flags
, mss_now
, tp
->nonagle
);
1102 TCP_CHECK_TIMER(sk
);
1108 tcp_unlink_write_queue(skb
, sk
);
1109 /* It is the one place in all of TCP, except connection
1110 * reset, where we can be unlinking the send_head.
1112 tcp_check_send_head(sk
, skb
);
1113 sk_wmem_free_skb(sk
, skb
);
1120 err
= sk_stream_error(sk
, flags
, err
);
1121 TCP_CHECK_TIMER(sk
);
1125 EXPORT_SYMBOL(tcp_sendmsg
);
1128 * Handle reading urgent data. BSD has very simple semantics for
1129 * this, no blocking and very strange errors 8)
1132 static int tcp_recv_urg(struct sock
*sk
, struct msghdr
*msg
, int len
, int flags
)
1134 struct tcp_sock
*tp
= tcp_sk(sk
);
1136 /* No URG data to read. */
1137 if (sock_flag(sk
, SOCK_URGINLINE
) || !tp
->urg_data
||
1138 tp
->urg_data
== TCP_URG_READ
)
1139 return -EINVAL
; /* Yes this is right ! */
1141 if (sk
->sk_state
== TCP_CLOSE
&& !sock_flag(sk
, SOCK_DONE
))
1144 if (tp
->urg_data
& TCP_URG_VALID
) {
1146 char c
= tp
->urg_data
;
1148 if (!(flags
& MSG_PEEK
))
1149 tp
->urg_data
= TCP_URG_READ
;
1151 /* Read urgent data. */
1152 msg
->msg_flags
|= MSG_OOB
;
1155 if (!(flags
& MSG_TRUNC
))
1156 err
= memcpy_toiovec(msg
->msg_iov
, &c
, 1);
1159 msg
->msg_flags
|= MSG_TRUNC
;
1161 return err
? -EFAULT
: len
;
1164 if (sk
->sk_state
== TCP_CLOSE
|| (sk
->sk_shutdown
& RCV_SHUTDOWN
))
1167 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1168 * the available implementations agree in this case:
1169 * this call should never block, independent of the
1170 * blocking state of the socket.
1171 * Mike <pall@rz.uni-karlsruhe.de>
1176 /* Clean up the receive buffer for full frames taken by the user,
1177 * then send an ACK if necessary. COPIED is the number of bytes
1178 * tcp_recvmsg has given to the user so far, it speeds up the
1179 * calculation of whether or not we must ACK for the sake of
1182 void tcp_cleanup_rbuf(struct sock
*sk
, int copied
)
1184 struct tcp_sock
*tp
= tcp_sk(sk
);
1185 int time_to_ack
= 0;
1188 struct sk_buff
*skb
= skb_peek(&sk
->sk_receive_queue
);
1190 WARN(skb
&& !before(tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
),
1191 KERN_INFO
"cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1192 tp
->copied_seq
, TCP_SKB_CB(skb
)->end_seq
, tp
->rcv_nxt
);
1195 if (inet_csk_ack_scheduled(sk
)) {
1196 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
1197 /* Delayed ACKs frequently hit locked sockets during bulk
1199 if (icsk
->icsk_ack
.blocked
||
1200 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1201 tp
->rcv_nxt
- tp
->rcv_wup
> icsk
->icsk_ack
.rcv_mss
||
1203 * If this read emptied read buffer, we send ACK, if
1204 * connection is not bidirectional, user drained
1205 * receive buffer and there was a small segment
1209 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED2
) ||
1210 ((icsk
->icsk_ack
.pending
& ICSK_ACK_PUSHED
) &&
1211 !icsk
->icsk_ack
.pingpong
)) &&
1212 !atomic_read(&sk
->sk_rmem_alloc
)))
1216 /* We send an ACK if we can now advertise a non-zero window
1217 * which has been raised "significantly".
1219 * Even if window raised up to infinity, do not send window open ACK
1220 * in states, where we will not receive more. It is useless.
1222 if (copied
> 0 && !time_to_ack
&& !(sk
->sk_shutdown
& RCV_SHUTDOWN
)) {
1223 __u32 rcv_window_now
= tcp_receive_window(tp
);
1225 /* Optimize, __tcp_select_window() is not cheap. */
1226 if (2*rcv_window_now
<= tp
->window_clamp
) {
1227 __u32 new_window
= __tcp_select_window(sk
);
1229 /* Send ACK now, if this read freed lots of space
1230 * in our buffer. Certainly, new_window is new window.
1231 * We can advertise it now, if it is not less than current one.
1232 * "Lots" means "at least twice" here.
1234 if (new_window
&& new_window
>= 2 * rcv_window_now
)
1242 static void tcp_prequeue_process(struct sock
*sk
)
1244 struct sk_buff
*skb
;
1245 struct tcp_sock
*tp
= tcp_sk(sk
);
1247 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPPREQUEUED
);
1249 /* RX process wants to run with disabled BHs, though it is not
1252 while ((skb
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
)
1253 sk_backlog_rcv(sk
, skb
);
1256 /* Clear memory counter. */
1257 tp
->ucopy
.memory
= 0;
1260 #ifdef CONFIG_NET_DMA
1261 static void tcp_service_net_dma(struct sock
*sk
, bool wait
)
1263 dma_cookie_t done
, used
;
1264 dma_cookie_t last_issued
;
1265 struct tcp_sock
*tp
= tcp_sk(sk
);
1267 if (!tp
->ucopy
.dma_chan
)
1270 last_issued
= tp
->ucopy
.dma_cookie
;
1271 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1274 if (dma_async_memcpy_complete(tp
->ucopy
.dma_chan
,
1276 &used
) == DMA_SUCCESS
) {
1277 /* Safe to free early-copied skbs now */
1278 __skb_queue_purge(&sk
->sk_async_wait_queue
);
1281 struct sk_buff
*skb
;
1282 while ((skb
= skb_peek(&sk
->sk_async_wait_queue
)) &&
1283 (dma_async_is_complete(skb
->dma_cookie
, done
,
1284 used
) == DMA_SUCCESS
)) {
1285 __skb_dequeue(&sk
->sk_async_wait_queue
);
1293 static inline struct sk_buff
*tcp_recv_skb(struct sock
*sk
, u32 seq
, u32
*off
)
1295 struct sk_buff
*skb
;
1298 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1299 offset
= seq
- TCP_SKB_CB(skb
)->seq
;
1300 if (tcp_hdr(skb
)->syn
)
1302 if (offset
< skb
->len
|| tcp_hdr(skb
)->fin
) {
1311 * This routine provides an alternative to tcp_recvmsg() for routines
1312 * that would like to handle copying from skbuffs directly in 'sendfile'
1315 * - It is assumed that the socket was locked by the caller.
1316 * - The routine does not block.
1317 * - At present, there is no support for reading OOB data
1318 * or for 'peeking' the socket using this routine
1319 * (although both would be easy to implement).
1321 int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
1322 sk_read_actor_t recv_actor
)
1324 struct sk_buff
*skb
;
1325 struct tcp_sock
*tp
= tcp_sk(sk
);
1326 u32 seq
= tp
->copied_seq
;
1330 if (sk
->sk_state
== TCP_LISTEN
)
1332 while ((skb
= tcp_recv_skb(sk
, seq
, &offset
)) != NULL
) {
1333 if (offset
< skb
->len
) {
1337 len
= skb
->len
- offset
;
1338 /* Stop reading if we hit a patch of urgent data */
1340 u32 urg_offset
= tp
->urg_seq
- seq
;
1341 if (urg_offset
< len
)
1346 used
= recv_actor(desc
, skb
, offset
, len
);
1351 } else if (used
<= len
) {
1357 * If recv_actor drops the lock (e.g. TCP splice
1358 * receive) the skb pointer might be invalid when
1359 * getting here: tcp_collapse might have deleted it
1360 * while aggregating skbs from the socket queue.
1362 skb
= tcp_recv_skb(sk
, seq
-1, &offset
);
1363 if (!skb
|| (offset
+1 != skb
->len
))
1366 if (tcp_hdr(skb
)->fin
) {
1367 sk_eat_skb(sk
, skb
, 0);
1371 sk_eat_skb(sk
, skb
, 0);
1374 tp
->copied_seq
= seq
;
1376 tp
->copied_seq
= seq
;
1378 tcp_rcv_space_adjust(sk
);
1380 /* Clean up data we have read: This will do ACK frames. */
1382 tcp_cleanup_rbuf(sk
, copied
);
1385 EXPORT_SYMBOL(tcp_read_sock
);
1388 * This routine copies from a sock struct into the user buffer.
1390 * Technical note: in 2.3 we work on _locked_ socket, so that
1391 * tricks with *seq access order and skb->users are not required.
1392 * Probably, code can be easily improved even more.
1395 int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
, struct msghdr
*msg
,
1396 size_t len
, int nonblock
, int flags
, int *addr_len
)
1398 struct tcp_sock
*tp
= tcp_sk(sk
);
1404 int target
; /* Read at least this many bytes */
1406 struct task_struct
*user_recv
= NULL
;
1407 int copied_early
= 0;
1408 struct sk_buff
*skb
;
1413 TCP_CHECK_TIMER(sk
);
1416 if (sk
->sk_state
== TCP_LISTEN
)
1419 timeo
= sock_rcvtimeo(sk
, nonblock
);
1421 /* Urgent data needs to be handled specially. */
1422 if (flags
& MSG_OOB
)
1425 seq
= &tp
->copied_seq
;
1426 if (flags
& MSG_PEEK
) {
1427 peek_seq
= tp
->copied_seq
;
1431 target
= sock_rcvlowat(sk
, flags
& MSG_WAITALL
, len
);
1433 #ifdef CONFIG_NET_DMA
1434 tp
->ucopy
.dma_chan
= NULL
;
1436 skb
= skb_peek_tail(&sk
->sk_receive_queue
);
1441 available
= TCP_SKB_CB(skb
)->seq
+ skb
->len
- (*seq
);
1442 if ((available
< target
) &&
1443 (len
> sysctl_tcp_dma_copybreak
) && !(flags
& MSG_PEEK
) &&
1444 !sysctl_tcp_low_latency
&&
1445 dma_find_channel(DMA_MEMCPY
)) {
1446 preempt_enable_no_resched();
1447 tp
->ucopy
.pinned_list
=
1448 dma_pin_iovec_pages(msg
->msg_iov
, len
);
1450 preempt_enable_no_resched();
1458 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1459 if (tp
->urg_data
&& tp
->urg_seq
== *seq
) {
1462 if (signal_pending(current
)) {
1463 copied
= timeo
? sock_intr_errno(timeo
) : -EAGAIN
;
1468 /* Next get a buffer. */
1470 skb_queue_walk(&sk
->sk_receive_queue
, skb
) {
1471 /* Now that we have two receive queues this
1474 if (WARN(before(*seq
, TCP_SKB_CB(skb
)->seq
),
1475 KERN_INFO
"recvmsg bug: copied %X "
1476 "seq %X rcvnxt %X fl %X\n", *seq
,
1477 TCP_SKB_CB(skb
)->seq
, tp
->rcv_nxt
,
1481 offset
= *seq
- TCP_SKB_CB(skb
)->seq
;
1482 if (tcp_hdr(skb
)->syn
)
1484 if (offset
< skb
->len
)
1486 if (tcp_hdr(skb
)->fin
)
1488 WARN(!(flags
& MSG_PEEK
), KERN_INFO
"recvmsg bug 2: "
1489 "copied %X seq %X rcvnxt %X fl %X\n",
1490 *seq
, TCP_SKB_CB(skb
)->seq
,
1491 tp
->rcv_nxt
, flags
);
1494 /* Well, if we have backlog, try to process it now yet. */
1496 if (copied
>= target
&& !sk
->sk_backlog
.tail
)
1501 sk
->sk_state
== TCP_CLOSE
||
1502 (sk
->sk_shutdown
& RCV_SHUTDOWN
) ||
1504 signal_pending(current
))
1507 if (sock_flag(sk
, SOCK_DONE
))
1511 copied
= sock_error(sk
);
1515 if (sk
->sk_shutdown
& RCV_SHUTDOWN
)
1518 if (sk
->sk_state
== TCP_CLOSE
) {
1519 if (!sock_flag(sk
, SOCK_DONE
)) {
1520 /* This occurs when user tries to read
1521 * from never connected socket.
1534 if (signal_pending(current
)) {
1535 copied
= sock_intr_errno(timeo
);
1540 tcp_cleanup_rbuf(sk
, copied
);
1542 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
== user_recv
) {
1543 /* Install new reader */
1544 if (!user_recv
&& !(flags
& (MSG_TRUNC
| MSG_PEEK
))) {
1545 user_recv
= current
;
1546 tp
->ucopy
.task
= user_recv
;
1547 tp
->ucopy
.iov
= msg
->msg_iov
;
1550 tp
->ucopy
.len
= len
;
1552 WARN_ON(tp
->copied_seq
!= tp
->rcv_nxt
&&
1553 !(flags
& (MSG_PEEK
| MSG_TRUNC
)));
1555 /* Ugly... If prequeue is not empty, we have to
1556 * process it before releasing socket, otherwise
1557 * order will be broken at second iteration.
1558 * More elegant solution is required!!!
1560 * Look: we have the following (pseudo)queues:
1562 * 1. packets in flight
1567 * Each queue can be processed only if the next ones
1568 * are empty. At this point we have empty receive_queue.
1569 * But prequeue _can_ be not empty after 2nd iteration,
1570 * when we jumped to start of loop because backlog
1571 * processing added something to receive_queue.
1572 * We cannot release_sock(), because backlog contains
1573 * packets arrived _after_ prequeued ones.
1575 * Shortly, algorithm is clear --- to process all
1576 * the queues in order. We could make it more directly,
1577 * requeueing packets from backlog to prequeue, if
1578 * is not empty. It is more elegant, but eats cycles,
1581 if (!skb_queue_empty(&tp
->ucopy
.prequeue
))
1584 /* __ Set realtime policy in scheduler __ */
1587 #ifdef CONFIG_NET_DMA
1588 if (tp
->ucopy
.dma_chan
)
1589 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1591 if (copied
>= target
) {
1592 /* Do not sleep, just process backlog. */
1596 sk_wait_data(sk
, &timeo
);
1598 #ifdef CONFIG_NET_DMA
1599 tcp_service_net_dma(sk
, false); /* Don't block */
1600 tp
->ucopy
.wakeup
= 0;
1606 /* __ Restore normal policy in scheduler __ */
1608 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1609 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG
, chunk
);
1614 if (tp
->rcv_nxt
== tp
->copied_seq
&&
1615 !skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1617 tcp_prequeue_process(sk
);
1619 if ((chunk
= len
- tp
->ucopy
.len
) != 0) {
1620 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1626 if ((flags
& MSG_PEEK
) &&
1627 (peek_seq
- copied
- urg_hole
!= tp
->copied_seq
)) {
1628 if (net_ratelimit())
1629 printk(KERN_DEBUG
"TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
1630 current
->comm
, task_pid_nr(current
));
1631 peek_seq
= tp
->copied_seq
;
1636 /* Ok so how much can we use? */
1637 used
= skb
->len
- offset
;
1641 /* Do we have urgent data here? */
1643 u32 urg_offset
= tp
->urg_seq
- *seq
;
1644 if (urg_offset
< used
) {
1646 if (!sock_flag(sk
, SOCK_URGINLINE
)) {
1659 if (!(flags
& MSG_TRUNC
)) {
1660 #ifdef CONFIG_NET_DMA
1661 if (!tp
->ucopy
.dma_chan
&& tp
->ucopy
.pinned_list
)
1662 tp
->ucopy
.dma_chan
= dma_find_channel(DMA_MEMCPY
);
1664 if (tp
->ucopy
.dma_chan
) {
1665 tp
->ucopy
.dma_cookie
= dma_skb_copy_datagram_iovec(
1666 tp
->ucopy
.dma_chan
, skb
, offset
,
1668 tp
->ucopy
.pinned_list
);
1670 if (tp
->ucopy
.dma_cookie
< 0) {
1672 printk(KERN_ALERT
"dma_cookie < 0\n");
1674 /* Exception. Bailout! */
1680 dma_async_memcpy_issue_pending(tp
->ucopy
.dma_chan
);
1682 if ((offset
+ used
) == skb
->len
)
1688 err
= skb_copy_datagram_iovec(skb
, offset
,
1689 msg
->msg_iov
, used
);
1691 /* Exception. Bailout! */
1703 tcp_rcv_space_adjust(sk
);
1706 if (tp
->urg_data
&& after(tp
->copied_seq
, tp
->urg_seq
)) {
1708 tcp_fast_path_check(sk
);
1710 if (used
+ offset
< skb
->len
)
1713 if (tcp_hdr(skb
)->fin
)
1715 if (!(flags
& MSG_PEEK
)) {
1716 sk_eat_skb(sk
, skb
, copied_early
);
1722 /* Process the FIN. */
1724 if (!(flags
& MSG_PEEK
)) {
1725 sk_eat_skb(sk
, skb
, copied_early
);
1732 if (!skb_queue_empty(&tp
->ucopy
.prequeue
)) {
1735 tp
->ucopy
.len
= copied
> 0 ? len
: 0;
1737 tcp_prequeue_process(sk
);
1739 if (copied
> 0 && (chunk
= len
- tp
->ucopy
.len
) != 0) {
1740 NET_ADD_STATS_USER(sock_net(sk
), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE
, chunk
);
1746 tp
->ucopy
.task
= NULL
;
1750 #ifdef CONFIG_NET_DMA
1751 tcp_service_net_dma(sk
, true); /* Wait for queue to drain */
1752 tp
->ucopy
.dma_chan
= NULL
;
1754 if (tp
->ucopy
.pinned_list
) {
1755 dma_unpin_iovec_pages(tp
->ucopy
.pinned_list
);
1756 tp
->ucopy
.pinned_list
= NULL
;
1760 /* According to UNIX98, msg_name/msg_namelen are ignored
1761 * on connected socket. I was just happy when found this 8) --ANK
1764 /* Clean up data we have read: This will do ACK frames. */
1765 tcp_cleanup_rbuf(sk
, copied
);
1767 TCP_CHECK_TIMER(sk
);
1772 TCP_CHECK_TIMER(sk
);
1777 err
= tcp_recv_urg(sk
, msg
, len
, flags
);
1780 EXPORT_SYMBOL(tcp_recvmsg
);
1782 void tcp_set_state(struct sock
*sk
, int state
)
1784 int oldstate
= sk
->sk_state
;
1787 case TCP_ESTABLISHED
:
1788 if (oldstate
!= TCP_ESTABLISHED
)
1789 TCP_INC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1793 if (oldstate
== TCP_CLOSE_WAIT
|| oldstate
== TCP_ESTABLISHED
)
1794 TCP_INC_STATS(sock_net(sk
), TCP_MIB_ESTABRESETS
);
1796 sk
->sk_prot
->unhash(sk
);
1797 if (inet_csk(sk
)->icsk_bind_hash
&&
1798 !(sk
->sk_userlocks
& SOCK_BINDPORT_LOCK
))
1802 if (oldstate
== TCP_ESTABLISHED
)
1803 TCP_DEC_STATS(sock_net(sk
), TCP_MIB_CURRESTAB
);
1806 /* Change state AFTER socket is unhashed to avoid closed
1807 * socket sitting in hash tables.
1809 sk
->sk_state
= state
;
1812 SOCK_DEBUG(sk
, "TCP sk=%p, State %s -> %s\n", sk
, statename
[oldstate
], statename
[state
]);
1815 EXPORT_SYMBOL_GPL(tcp_set_state
);
1818 * State processing on a close. This implements the state shift for
1819 * sending our FIN frame. Note that we only send a FIN for some
1820 * states. A shutdown() may have already sent the FIN, or we may be
1824 static const unsigned char new_state
[16] = {
1825 /* current state: new state: action: */
1826 /* (Invalid) */ TCP_CLOSE
,
1827 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1828 /* TCP_SYN_SENT */ TCP_CLOSE
,
1829 /* TCP_SYN_RECV */ TCP_FIN_WAIT1
| TCP_ACTION_FIN
,
1830 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1
,
1831 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2
,
1832 /* TCP_TIME_WAIT */ TCP_CLOSE
,
1833 /* TCP_CLOSE */ TCP_CLOSE
,
1834 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK
| TCP_ACTION_FIN
,
1835 /* TCP_LAST_ACK */ TCP_LAST_ACK
,
1836 /* TCP_LISTEN */ TCP_CLOSE
,
1837 /* TCP_CLOSING */ TCP_CLOSING
,
1840 static int tcp_close_state(struct sock
*sk
)
1842 int next
= (int)new_state
[sk
->sk_state
];
1843 int ns
= next
& TCP_STATE_MASK
;
1845 tcp_set_state(sk
, ns
);
1847 return next
& TCP_ACTION_FIN
;
1851 * Shutdown the sending side of a connection. Much like close except
1852 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
1855 void tcp_shutdown(struct sock
*sk
, int how
)
1857 /* We need to grab some memory, and put together a FIN,
1858 * and then put it into the queue to be sent.
1859 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
1861 if (!(how
& SEND_SHUTDOWN
))
1864 /* If we've already sent a FIN, or it's a closed state, skip this. */
1865 if ((1 << sk
->sk_state
) &
1866 (TCPF_ESTABLISHED
| TCPF_SYN_SENT
|
1867 TCPF_SYN_RECV
| TCPF_CLOSE_WAIT
)) {
1868 /* Clear out any half completed packets. FIN if needed. */
1869 if (tcp_close_state(sk
))
1873 EXPORT_SYMBOL(tcp_shutdown
);
1875 void tcp_close(struct sock
*sk
, long timeout
)
1877 struct sk_buff
*skb
;
1878 int data_was_unread
= 0;
1882 sk
->sk_shutdown
= SHUTDOWN_MASK
;
1884 if (sk
->sk_state
== TCP_LISTEN
) {
1885 tcp_set_state(sk
, TCP_CLOSE
);
1888 inet_csk_listen_stop(sk
);
1890 goto adjudge_to_death
;
1893 /* We need to flush the recv. buffs. We do this only on the
1894 * descriptor close, not protocol-sourced closes, because the
1895 * reader process may not have drained the data yet!
1897 while ((skb
= __skb_dequeue(&sk
->sk_receive_queue
)) != NULL
) {
1898 u32 len
= TCP_SKB_CB(skb
)->end_seq
- TCP_SKB_CB(skb
)->seq
-
1900 data_was_unread
+= len
;
1906 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
1907 if (sk
->sk_state
== TCP_CLOSE
)
1908 goto adjudge_to_death
;
1910 /* As outlined in RFC 2525, section 2.17, we send a RST here because
1911 * data was lost. To witness the awful effects of the old behavior of
1912 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
1913 * GET in an FTP client, suspend the process, wait for the client to
1914 * advertise a zero window, then kill -9 the FTP client, wheee...
1915 * Note: timeout is always zero in such a case.
1917 if (data_was_unread
) {
1918 /* Unread data was tossed, zap the connection. */
1919 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONCLOSE
);
1920 tcp_set_state(sk
, TCP_CLOSE
);
1921 tcp_send_active_reset(sk
, sk
->sk_allocation
);
1922 } else if (sock_flag(sk
, SOCK_LINGER
) && !sk
->sk_lingertime
) {
1923 /* Check zero linger _after_ checking for unread data. */
1924 sk
->sk_prot
->disconnect(sk
, 0);
1925 NET_INC_STATS_USER(sock_net(sk
), LINUX_MIB_TCPABORTONDATA
);
1926 } else if (tcp_close_state(sk
)) {
1927 /* We FIN if the application ate all the data before
1928 * zapping the connection.
1931 /* RED-PEN. Formally speaking, we have broken TCP state
1932 * machine. State transitions:
1934 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
1935 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
1936 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
1938 * are legal only when FIN has been sent (i.e. in window),
1939 * rather than queued out of window. Purists blame.
1941 * F.e. "RFC state" is ESTABLISHED,
1942 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
1944 * The visible declinations are that sometimes
1945 * we enter time-wait state, when it is not required really
1946 * (harmless), do not send active resets, when they are
1947 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
1948 * they look as CLOSING or LAST_ACK for Linux)
1949 * Probably, I missed some more holelets.
1955 sk_stream_wait_close(sk
, timeout
);
1958 state
= sk
->sk_state
;
1962 /* It is the last release_sock in its life. It will remove backlog. */
1966 /* Now socket is owned by kernel and we acquire BH lock
1967 to finish close. No need to check for user refs.
1971 WARN_ON(sock_owned_by_user(sk
));
1973 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
1975 /* Have we already been destroyed by a softirq or backlog? */
1976 if (state
!= TCP_CLOSE
&& sk
->sk_state
== TCP_CLOSE
)
1979 /* This is a (useful) BSD violating of the RFC. There is a
1980 * problem with TCP as specified in that the other end could
1981 * keep a socket open forever with no application left this end.
1982 * We use a 3 minute timeout (about the same as BSD) then kill
1983 * our end. If they send after that then tough - BUT: long enough
1984 * that we won't make the old 4*rto = almost no time - whoops
1987 * Nope, it was not mistake. It is really desired behaviour
1988 * f.e. on http servers, when such sockets are useless, but
1989 * consume significant resources. Let's do it with special
1990 * linger2 option. --ANK
1993 if (sk
->sk_state
== TCP_FIN_WAIT2
) {
1994 struct tcp_sock
*tp
= tcp_sk(sk
);
1995 if (tp
->linger2
< 0) {
1996 tcp_set_state(sk
, TCP_CLOSE
);
1997 tcp_send_active_reset(sk
, GFP_ATOMIC
);
1998 NET_INC_STATS_BH(sock_net(sk
),
1999 LINUX_MIB_TCPABORTONLINGER
);
2001 const int tmo
= tcp_fin_time(sk
);
2003 if (tmo
> TCP_TIMEWAIT_LEN
) {
2004 inet_csk_reset_keepalive_timer(sk
,
2005 tmo
- TCP_TIMEWAIT_LEN
);
2007 tcp_time_wait(sk
, TCP_FIN_WAIT2
, tmo
);
2012 if (sk
->sk_state
!= TCP_CLOSE
) {
2013 int orphan_count
= percpu_counter_read_positive(
2014 sk
->sk_prot
->orphan_count
);
2017 if (tcp_too_many_orphans(sk
, orphan_count
)) {
2018 if (net_ratelimit())
2019 printk(KERN_INFO
"TCP: too many of orphaned "
2021 tcp_set_state(sk
, TCP_CLOSE
);
2022 tcp_send_active_reset(sk
, GFP_ATOMIC
);
2023 NET_INC_STATS_BH(sock_net(sk
),
2024 LINUX_MIB_TCPABORTONMEMORY
);
2028 if (sk
->sk_state
== TCP_CLOSE
)
2029 inet_csk_destroy_sock(sk
);
2030 /* Otherwise, socket is reprieved until protocol close. */
2037 EXPORT_SYMBOL(tcp_close
);
2039 /* These states need RST on ABORT according to RFC793 */
2041 static inline int tcp_need_reset(int state
)
2043 return (1 << state
) &
2044 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
| TCPF_FIN_WAIT1
|
2045 TCPF_FIN_WAIT2
| TCPF_SYN_RECV
);
2048 int tcp_disconnect(struct sock
*sk
, int flags
)
2050 struct inet_sock
*inet
= inet_sk(sk
);
2051 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2052 struct tcp_sock
*tp
= tcp_sk(sk
);
2054 int old_state
= sk
->sk_state
;
2056 if (old_state
!= TCP_CLOSE
)
2057 tcp_set_state(sk
, TCP_CLOSE
);
2059 /* ABORT function of RFC793 */
2060 if (old_state
== TCP_LISTEN
) {
2061 inet_csk_listen_stop(sk
);
2062 } else if (tcp_need_reset(old_state
) ||
2063 (tp
->snd_nxt
!= tp
->write_seq
&&
2064 (1 << old_state
) & (TCPF_CLOSING
| TCPF_LAST_ACK
))) {
2065 /* The last check adjusts for discrepancy of Linux wrt. RFC
2068 tcp_send_active_reset(sk
, gfp_any());
2069 sk
->sk_err
= ECONNRESET
;
2070 } else if (old_state
== TCP_SYN_SENT
)
2071 sk
->sk_err
= ECONNRESET
;
2073 tcp_clear_xmit_timers(sk
);
2074 __skb_queue_purge(&sk
->sk_receive_queue
);
2075 tcp_write_queue_purge(sk
);
2076 __skb_queue_purge(&tp
->out_of_order_queue
);
2077 #ifdef CONFIG_NET_DMA
2078 __skb_queue_purge(&sk
->sk_async_wait_queue
);
2081 inet
->inet_dport
= 0;
2083 if (!(sk
->sk_userlocks
& SOCK_BINDADDR_LOCK
))
2084 inet_reset_saddr(sk
);
2086 sk
->sk_shutdown
= 0;
2087 sock_reset_flag(sk
, SOCK_DONE
);
2089 if ((tp
->write_seq
+= tp
->max_window
+ 2) == 0)
2091 icsk
->icsk_backoff
= 0;
2093 icsk
->icsk_probes_out
= 0;
2094 tp
->packets_out
= 0;
2095 tp
->snd_ssthresh
= TCP_INFINITE_SSTHRESH
;
2096 tp
->snd_cwnd_cnt
= 0;
2097 tp
->bytes_acked
= 0;
2098 tp
->window_clamp
= 0;
2099 tcp_set_ca_state(sk
, TCP_CA_Open
);
2100 tcp_clear_retrans(tp
);
2101 inet_csk_delack_init(sk
);
2102 tcp_init_send_head(sk
);
2103 memset(&tp
->rx_opt
, 0, sizeof(tp
->rx_opt
));
2106 WARN_ON(inet
->inet_num
&& !icsk
->icsk_bind_hash
);
2108 sk
->sk_error_report(sk
);
2111 EXPORT_SYMBOL(tcp_disconnect
);
2114 * Socket option code for TCP.
2116 static int do_tcp_setsockopt(struct sock
*sk
, int level
,
2117 int optname
, char __user
*optval
, unsigned int optlen
)
2119 struct tcp_sock
*tp
= tcp_sk(sk
);
2120 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2124 /* These are data/string values, all the others are ints */
2126 case TCP_CONGESTION
: {
2127 char name
[TCP_CA_NAME_MAX
];
2132 val
= strncpy_from_user(name
, optval
,
2133 min_t(long, TCP_CA_NAME_MAX
-1, optlen
));
2139 err
= tcp_set_congestion_control(sk
, name
);
2143 case TCP_COOKIE_TRANSACTIONS
: {
2144 struct tcp_cookie_transactions ctd
;
2145 struct tcp_cookie_values
*cvp
= NULL
;
2147 if (sizeof(ctd
) > optlen
)
2149 if (copy_from_user(&ctd
, optval
, sizeof(ctd
)))
2152 if (ctd
.tcpct_used
> sizeof(ctd
.tcpct_value
) ||
2153 ctd
.tcpct_s_data_desired
> TCP_MSS_DESIRED
)
2156 if (ctd
.tcpct_cookie_desired
== 0) {
2157 /* default to global value */
2158 } else if ((0x1 & ctd
.tcpct_cookie_desired
) ||
2159 ctd
.tcpct_cookie_desired
> TCP_COOKIE_MAX
||
2160 ctd
.tcpct_cookie_desired
< TCP_COOKIE_MIN
) {
2164 if (TCP_COOKIE_OUT_NEVER
& ctd
.tcpct_flags
) {
2165 /* Supercedes all other values */
2167 if (tp
->cookie_values
!= NULL
) {
2168 kref_put(&tp
->cookie_values
->kref
,
2169 tcp_cookie_values_release
);
2170 tp
->cookie_values
= NULL
;
2172 tp
->rx_opt
.cookie_in_always
= 0; /* false */
2173 tp
->rx_opt
.cookie_out_never
= 1; /* true */
2178 /* Allocate ancillary memory before locking.
2180 if (ctd
.tcpct_used
> 0 ||
2181 (tp
->cookie_values
== NULL
&&
2182 (sysctl_tcp_cookie_size
> 0 ||
2183 ctd
.tcpct_cookie_desired
> 0 ||
2184 ctd
.tcpct_s_data_desired
> 0))) {
2185 cvp
= kzalloc(sizeof(*cvp
) + ctd
.tcpct_used
,
2191 tp
->rx_opt
.cookie_in_always
=
2192 (TCP_COOKIE_IN_ALWAYS
& ctd
.tcpct_flags
);
2193 tp
->rx_opt
.cookie_out_never
= 0; /* false */
2195 if (tp
->cookie_values
!= NULL
) {
2197 /* Changed values are recorded by a changed
2198 * pointer, ensuring the cookie will differ,
2199 * without separately hashing each value later.
2201 kref_put(&tp
->cookie_values
->kref
,
2202 tcp_cookie_values_release
);
2203 kref_init(&cvp
->kref
);
2204 tp
->cookie_values
= cvp
;
2206 cvp
= tp
->cookie_values
;
2210 cvp
->cookie_desired
= ctd
.tcpct_cookie_desired
;
2212 if (ctd
.tcpct_used
> 0) {
2213 memcpy(cvp
->s_data_payload
, ctd
.tcpct_value
,
2215 cvp
->s_data_desired
= ctd
.tcpct_used
;
2216 cvp
->s_data_constant
= 1; /* true */
2218 /* No constant payload data. */
2219 cvp
->s_data_desired
= ctd
.tcpct_s_data_desired
;
2220 cvp
->s_data_constant
= 0; /* false */
2231 if (optlen
< sizeof(int))
2234 if (get_user(val
, (int __user
*)optval
))
2241 /* Values greater than interface MTU won't take effect. However
2242 * at the point when this call is done we typically don't yet
2243 * know which interface is going to be used */
2244 if (val
< 8 || val
> MAX_TCP_WINDOW
) {
2248 tp
->rx_opt
.user_mss
= val
;
2253 /* TCP_NODELAY is weaker than TCP_CORK, so that
2254 * this option on corked socket is remembered, but
2255 * it is not activated until cork is cleared.
2257 * However, when TCP_NODELAY is set we make
2258 * an explicit push, which overrides even TCP_CORK
2259 * for currently queued segments.
2261 tp
->nonagle
|= TCP_NAGLE_OFF
|TCP_NAGLE_PUSH
;
2262 tcp_push_pending_frames(sk
);
2264 tp
->nonagle
&= ~TCP_NAGLE_OFF
;
2268 case TCP_THIN_LINEAR_TIMEOUTS
:
2269 if (val
< 0 || val
> 1)
2275 case TCP_THIN_DUPACK
:
2276 if (val
< 0 || val
> 1)
2279 tp
->thin_dupack
= val
;
2283 /* When set indicates to always queue non-full frames.
2284 * Later the user clears this option and we transmit
2285 * any pending partial frames in the queue. This is
2286 * meant to be used alongside sendfile() to get properly
2287 * filled frames when the user (for example) must write
2288 * out headers with a write() call first and then use
2289 * sendfile to send out the data parts.
2291 * TCP_CORK can be set together with TCP_NODELAY and it is
2292 * stronger than TCP_NODELAY.
2295 tp
->nonagle
|= TCP_NAGLE_CORK
;
2297 tp
->nonagle
&= ~TCP_NAGLE_CORK
;
2298 if (tp
->nonagle
&TCP_NAGLE_OFF
)
2299 tp
->nonagle
|= TCP_NAGLE_PUSH
;
2300 tcp_push_pending_frames(sk
);
2305 if (val
< 1 || val
> MAX_TCP_KEEPIDLE
)
2308 tp
->keepalive_time
= val
* HZ
;
2309 if (sock_flag(sk
, SOCK_KEEPOPEN
) &&
2310 !((1 << sk
->sk_state
) &
2311 (TCPF_CLOSE
| TCPF_LISTEN
))) {
2312 u32 elapsed
= keepalive_time_elapsed(tp
);
2313 if (tp
->keepalive_time
> elapsed
)
2314 elapsed
= tp
->keepalive_time
- elapsed
;
2317 inet_csk_reset_keepalive_timer(sk
, elapsed
);
2322 if (val
< 1 || val
> MAX_TCP_KEEPINTVL
)
2325 tp
->keepalive_intvl
= val
* HZ
;
2328 if (val
< 1 || val
> MAX_TCP_KEEPCNT
)
2331 tp
->keepalive_probes
= val
;
2334 if (val
< 1 || val
> MAX_TCP_SYNCNT
)
2337 icsk
->icsk_syn_retries
= val
;
2343 else if (val
> sysctl_tcp_fin_timeout
/ HZ
)
2346 tp
->linger2
= val
* HZ
;
2349 case TCP_DEFER_ACCEPT
:
2350 /* Translate value in seconds to number of retransmits */
2351 icsk
->icsk_accept_queue
.rskq_defer_accept
=
2352 secs_to_retrans(val
, TCP_TIMEOUT_INIT
/ HZ
,
2356 case TCP_WINDOW_CLAMP
:
2358 if (sk
->sk_state
!= TCP_CLOSE
) {
2362 tp
->window_clamp
= 0;
2364 tp
->window_clamp
= val
< SOCK_MIN_RCVBUF
/ 2 ?
2365 SOCK_MIN_RCVBUF
/ 2 : val
;
2370 icsk
->icsk_ack
.pingpong
= 1;
2372 icsk
->icsk_ack
.pingpong
= 0;
2373 if ((1 << sk
->sk_state
) &
2374 (TCPF_ESTABLISHED
| TCPF_CLOSE_WAIT
) &&
2375 inet_csk_ack_scheduled(sk
)) {
2376 icsk
->icsk_ack
.pending
|= ICSK_ACK_PUSHED
;
2377 tcp_cleanup_rbuf(sk
, 1);
2379 icsk
->icsk_ack
.pingpong
= 1;
2384 #ifdef CONFIG_TCP_MD5SIG
2386 /* Read the IP->Key mappings from userspace */
2387 err
= tp
->af_specific
->md5_parse(sk
, optval
, optlen
);
2400 int tcp_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2401 unsigned int optlen
)
2403 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2405 if (level
!= SOL_TCP
)
2406 return icsk
->icsk_af_ops
->setsockopt(sk
, level
, optname
,
2408 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2410 EXPORT_SYMBOL(tcp_setsockopt
);
2412 #ifdef CONFIG_COMPAT
2413 int compat_tcp_setsockopt(struct sock
*sk
, int level
, int optname
,
2414 char __user
*optval
, unsigned int optlen
)
2416 if (level
!= SOL_TCP
)
2417 return inet_csk_compat_setsockopt(sk
, level
, optname
,
2419 return do_tcp_setsockopt(sk
, level
, optname
, optval
, optlen
);
2421 EXPORT_SYMBOL(compat_tcp_setsockopt
);
2424 /* Return information about state of tcp endpoint in API format. */
2425 void tcp_get_info(struct sock
*sk
, struct tcp_info
*info
)
2427 struct tcp_sock
*tp
= tcp_sk(sk
);
2428 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
2429 u32 now
= tcp_time_stamp
;
2431 memset(info
, 0, sizeof(*info
));
2433 info
->tcpi_state
= sk
->sk_state
;
2434 info
->tcpi_ca_state
= icsk
->icsk_ca_state
;
2435 info
->tcpi_retransmits
= icsk
->icsk_retransmits
;
2436 info
->tcpi_probes
= icsk
->icsk_probes_out
;
2437 info
->tcpi_backoff
= icsk
->icsk_backoff
;
2439 if (tp
->rx_opt
.tstamp_ok
)
2440 info
->tcpi_options
|= TCPI_OPT_TIMESTAMPS
;
2441 if (tcp_is_sack(tp
))
2442 info
->tcpi_options
|= TCPI_OPT_SACK
;
2443 if (tp
->rx_opt
.wscale_ok
) {
2444 info
->tcpi_options
|= TCPI_OPT_WSCALE
;
2445 info
->tcpi_snd_wscale
= tp
->rx_opt
.snd_wscale
;
2446 info
->tcpi_rcv_wscale
= tp
->rx_opt
.rcv_wscale
;
2449 if (tp
->ecn_flags
&TCP_ECN_OK
)
2450 info
->tcpi_options
|= TCPI_OPT_ECN
;
2452 info
->tcpi_rto
= jiffies_to_usecs(icsk
->icsk_rto
);
2453 info
->tcpi_ato
= jiffies_to_usecs(icsk
->icsk_ack
.ato
);
2454 info
->tcpi_snd_mss
= tp
->mss_cache
;
2455 info
->tcpi_rcv_mss
= icsk
->icsk_ack
.rcv_mss
;
2457 if (sk
->sk_state
== TCP_LISTEN
) {
2458 info
->tcpi_unacked
= sk
->sk_ack_backlog
;
2459 info
->tcpi_sacked
= sk
->sk_max_ack_backlog
;
2461 info
->tcpi_unacked
= tp
->packets_out
;
2462 info
->tcpi_sacked
= tp
->sacked_out
;
2464 info
->tcpi_lost
= tp
->lost_out
;
2465 info
->tcpi_retrans
= tp
->retrans_out
;
2466 info
->tcpi_fackets
= tp
->fackets_out
;
2468 info
->tcpi_last_data_sent
= jiffies_to_msecs(now
- tp
->lsndtime
);
2469 info
->tcpi_last_data_recv
= jiffies_to_msecs(now
- icsk
->icsk_ack
.lrcvtime
);
2470 info
->tcpi_last_ack_recv
= jiffies_to_msecs(now
- tp
->rcv_tstamp
);
2472 info
->tcpi_pmtu
= icsk
->icsk_pmtu_cookie
;
2473 info
->tcpi_rcv_ssthresh
= tp
->rcv_ssthresh
;
2474 info
->tcpi_rtt
= jiffies_to_usecs(tp
->srtt
)>>3;
2475 info
->tcpi_rttvar
= jiffies_to_usecs(tp
->mdev
)>>2;
2476 info
->tcpi_snd_ssthresh
= tp
->snd_ssthresh
;
2477 info
->tcpi_snd_cwnd
= tp
->snd_cwnd
;
2478 info
->tcpi_advmss
= tp
->advmss
;
2479 info
->tcpi_reordering
= tp
->reordering
;
2481 info
->tcpi_rcv_rtt
= jiffies_to_usecs(tp
->rcv_rtt_est
.rtt
)>>3;
2482 info
->tcpi_rcv_space
= tp
->rcvq_space
.space
;
2484 info
->tcpi_total_retrans
= tp
->total_retrans
;
2486 EXPORT_SYMBOL_GPL(tcp_get_info
);
2488 static int do_tcp_getsockopt(struct sock
*sk
, int level
,
2489 int optname
, char __user
*optval
, int __user
*optlen
)
2491 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2492 struct tcp_sock
*tp
= tcp_sk(sk
);
2495 if (get_user(len
, optlen
))
2498 len
= min_t(unsigned int, len
, sizeof(int));
2505 val
= tp
->mss_cache
;
2506 if (!val
&& ((1 << sk
->sk_state
) & (TCPF_CLOSE
| TCPF_LISTEN
)))
2507 val
= tp
->rx_opt
.user_mss
;
2510 val
= !!(tp
->nonagle
&TCP_NAGLE_OFF
);
2513 val
= !!(tp
->nonagle
&TCP_NAGLE_CORK
);
2516 val
= keepalive_time_when(tp
) / HZ
;
2519 val
= keepalive_intvl_when(tp
) / HZ
;
2522 val
= keepalive_probes(tp
);
2525 val
= icsk
->icsk_syn_retries
? : sysctl_tcp_syn_retries
;
2530 val
= (val
? : sysctl_tcp_fin_timeout
) / HZ
;
2532 case TCP_DEFER_ACCEPT
:
2533 val
= retrans_to_secs(icsk
->icsk_accept_queue
.rskq_defer_accept
,
2534 TCP_TIMEOUT_INIT
/ HZ
, TCP_RTO_MAX
/ HZ
);
2536 case TCP_WINDOW_CLAMP
:
2537 val
= tp
->window_clamp
;
2540 struct tcp_info info
;
2542 if (get_user(len
, optlen
))
2545 tcp_get_info(sk
, &info
);
2547 len
= min_t(unsigned int, len
, sizeof(info
));
2548 if (put_user(len
, optlen
))
2550 if (copy_to_user(optval
, &info
, len
))
2555 val
= !icsk
->icsk_ack
.pingpong
;
2558 case TCP_CONGESTION
:
2559 if (get_user(len
, optlen
))
2561 len
= min_t(unsigned int, len
, TCP_CA_NAME_MAX
);
2562 if (put_user(len
, optlen
))
2564 if (copy_to_user(optval
, icsk
->icsk_ca_ops
->name
, len
))
2568 case TCP_COOKIE_TRANSACTIONS
: {
2569 struct tcp_cookie_transactions ctd
;
2570 struct tcp_cookie_values
*cvp
= tp
->cookie_values
;
2572 if (get_user(len
, optlen
))
2574 if (len
< sizeof(ctd
))
2577 memset(&ctd
, 0, sizeof(ctd
));
2578 ctd
.tcpct_flags
= (tp
->rx_opt
.cookie_in_always
?
2579 TCP_COOKIE_IN_ALWAYS
: 0)
2580 | (tp
->rx_opt
.cookie_out_never
?
2581 TCP_COOKIE_OUT_NEVER
: 0);
2584 ctd
.tcpct_flags
|= (cvp
->s_data_in
?
2586 | (cvp
->s_data_out
?
2587 TCP_S_DATA_OUT
: 0);
2589 ctd
.tcpct_cookie_desired
= cvp
->cookie_desired
;
2590 ctd
.tcpct_s_data_desired
= cvp
->s_data_desired
;
2592 memcpy(&ctd
.tcpct_value
[0], &cvp
->cookie_pair
[0],
2593 cvp
->cookie_pair_size
);
2594 ctd
.tcpct_used
= cvp
->cookie_pair_size
;
2597 if (put_user(sizeof(ctd
), optlen
))
2599 if (copy_to_user(optval
, &ctd
, sizeof(ctd
)))
2604 return -ENOPROTOOPT
;
2607 if (put_user(len
, optlen
))
2609 if (copy_to_user(optval
, &val
, len
))
2614 int tcp_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
2617 struct inet_connection_sock
*icsk
= inet_csk(sk
);
2619 if (level
!= SOL_TCP
)
2620 return icsk
->icsk_af_ops
->getsockopt(sk
, level
, optname
,
2622 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2624 EXPORT_SYMBOL(tcp_getsockopt
);
2626 #ifdef CONFIG_COMPAT
2627 int compat_tcp_getsockopt(struct sock
*sk
, int level
, int optname
,
2628 char __user
*optval
, int __user
*optlen
)
2630 if (level
!= SOL_TCP
)
2631 return inet_csk_compat_getsockopt(sk
, level
, optname
,
2633 return do_tcp_getsockopt(sk
, level
, optname
, optval
, optlen
);
2635 EXPORT_SYMBOL(compat_tcp_getsockopt
);
2638 struct sk_buff
*tcp_tso_segment(struct sk_buff
*skb
, int features
)
2640 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
2645 unsigned int oldlen
;
2648 if (!pskb_may_pull(skb
, sizeof(*th
)))
2652 thlen
= th
->doff
* 4;
2653 if (thlen
< sizeof(*th
))
2656 if (!pskb_may_pull(skb
, thlen
))
2659 oldlen
= (u16
)~skb
->len
;
2660 __skb_pull(skb
, thlen
);
2662 mss
= skb_shinfo(skb
)->gso_size
;
2663 if (unlikely(skb
->len
<= mss
))
2666 if (skb_gso_ok(skb
, features
| NETIF_F_GSO_ROBUST
)) {
2667 /* Packet is from an untrusted source, reset gso_segs. */
2668 int type
= skb_shinfo(skb
)->gso_type
;
2676 !(type
& (SKB_GSO_TCPV4
| SKB_GSO_TCPV6
))))
2679 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(skb
->len
, mss
);
2685 segs
= skb_segment(skb
, features
);
2689 delta
= htonl(oldlen
+ (thlen
+ mss
));
2693 seq
= ntohl(th
->seq
);
2696 th
->fin
= th
->psh
= 0;
2698 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2699 (__force u32
)delta
));
2700 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2702 csum_fold(csum_partial(skb_transport_header(skb
),
2709 th
->seq
= htonl(seq
);
2711 } while (skb
->next
);
2713 delta
= htonl(oldlen
+ (skb
->tail
- skb
->transport_header
) +
2715 th
->check
= ~csum_fold((__force __wsum
)((__force u32
)th
->check
+
2716 (__force u32
)delta
));
2717 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
2718 th
->check
= csum_fold(csum_partial(skb_transport_header(skb
),
2724 EXPORT_SYMBOL(tcp_tso_segment
);
2726 struct sk_buff
**tcp_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
2728 struct sk_buff
**pp
= NULL
;
2735 unsigned int mss
= 1;
2741 off
= skb_gro_offset(skb
);
2742 hlen
= off
+ sizeof(*th
);
2743 th
= skb_gro_header_fast(skb
, off
);
2744 if (skb_gro_header_hard(skb
, hlen
)) {
2745 th
= skb_gro_header_slow(skb
, hlen
, off
);
2750 thlen
= th
->doff
* 4;
2751 if (thlen
< sizeof(*th
))
2755 if (skb_gro_header_hard(skb
, hlen
)) {
2756 th
= skb_gro_header_slow(skb
, hlen
, off
);
2761 skb_gro_pull(skb
, thlen
);
2763 len
= skb_gro_len(skb
);
2764 flags
= tcp_flag_word(th
);
2766 for (; (p
= *head
); head
= &p
->next
) {
2767 if (!NAPI_GRO_CB(p
)->same_flow
)
2772 if (*(u32
*)&th
->source
^ *(u32
*)&th2
->source
) {
2773 NAPI_GRO_CB(p
)->same_flow
= 0;
2780 goto out_check_final
;
2783 flush
= NAPI_GRO_CB(p
)->flush
;
2784 flush
|= (__force
int)(flags
& TCP_FLAG_CWR
);
2785 flush
|= (__force
int)((flags
^ tcp_flag_word(th2
)) &
2786 ~(TCP_FLAG_CWR
| TCP_FLAG_FIN
| TCP_FLAG_PSH
));
2787 flush
|= (__force
int)(th
->ack_seq
^ th2
->ack_seq
);
2788 for (i
= sizeof(*th
); i
< thlen
; i
+= 4)
2789 flush
|= *(u32
*)((u8
*)th
+ i
) ^
2790 *(u32
*)((u8
*)th2
+ i
);
2792 mss
= skb_shinfo(p
)->gso_size
;
2794 flush
|= (len
- 1) >= mss
;
2795 flush
|= (ntohl(th2
->seq
) + skb_gro_len(p
)) ^ ntohl(th
->seq
);
2797 if (flush
|| skb_gro_receive(head
, skb
)) {
2799 goto out_check_final
;
2804 tcp_flag_word(th2
) |= flags
& (TCP_FLAG_FIN
| TCP_FLAG_PSH
);
2808 flush
|= (__force
int)(flags
& (TCP_FLAG_URG
| TCP_FLAG_PSH
|
2809 TCP_FLAG_RST
| TCP_FLAG_SYN
|
2812 if (p
&& (!NAPI_GRO_CB(skb
)->same_flow
|| flush
))
2816 NAPI_GRO_CB(skb
)->flush
|= flush
;
2820 EXPORT_SYMBOL(tcp_gro_receive
);
2822 int tcp_gro_complete(struct sk_buff
*skb
)
2824 struct tcphdr
*th
= tcp_hdr(skb
);
2826 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
2827 skb
->csum_offset
= offsetof(struct tcphdr
, check
);
2828 skb
->ip_summed
= CHECKSUM_PARTIAL
;
2830 skb_shinfo(skb
)->gso_segs
= NAPI_GRO_CB(skb
)->count
;
2833 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
2837 EXPORT_SYMBOL(tcp_gro_complete
);
2839 #ifdef CONFIG_TCP_MD5SIG
2840 static unsigned long tcp_md5sig_users
;
2841 static struct tcp_md5sig_pool
* __percpu
*tcp_md5sig_pool
;
2842 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock
);
2844 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool
* __percpu
*pool
)
2847 for_each_possible_cpu(cpu
) {
2848 struct tcp_md5sig_pool
*p
= *per_cpu_ptr(pool
, cpu
);
2850 if (p
->md5_desc
.tfm
)
2851 crypto_free_hash(p
->md5_desc
.tfm
);
2858 void tcp_free_md5sig_pool(void)
2860 struct tcp_md5sig_pool
* __percpu
*pool
= NULL
;
2862 spin_lock_bh(&tcp_md5sig_pool_lock
);
2863 if (--tcp_md5sig_users
== 0) {
2864 pool
= tcp_md5sig_pool
;
2865 tcp_md5sig_pool
= NULL
;
2867 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2869 __tcp_free_md5sig_pool(pool
);
2871 EXPORT_SYMBOL(tcp_free_md5sig_pool
);
2873 static struct tcp_md5sig_pool
* __percpu
*
2874 __tcp_alloc_md5sig_pool(struct sock
*sk
)
2877 struct tcp_md5sig_pool
* __percpu
*pool
;
2879 pool
= alloc_percpu(struct tcp_md5sig_pool
*);
2883 for_each_possible_cpu(cpu
) {
2884 struct tcp_md5sig_pool
*p
;
2885 struct crypto_hash
*hash
;
2887 p
= kzalloc(sizeof(*p
), sk
->sk_allocation
);
2890 *per_cpu_ptr(pool
, cpu
) = p
;
2892 hash
= crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC
);
2893 if (!hash
|| IS_ERR(hash
))
2896 p
->md5_desc
.tfm
= hash
;
2900 __tcp_free_md5sig_pool(pool
);
2904 struct tcp_md5sig_pool
* __percpu
*tcp_alloc_md5sig_pool(struct sock
*sk
)
2906 struct tcp_md5sig_pool
* __percpu
*pool
;
2910 spin_lock_bh(&tcp_md5sig_pool_lock
);
2911 pool
= tcp_md5sig_pool
;
2912 if (tcp_md5sig_users
++ == 0) {
2914 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2917 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2921 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2924 /* we cannot hold spinlock here because this may sleep. */
2925 struct tcp_md5sig_pool
* __percpu
*p
;
2927 p
= __tcp_alloc_md5sig_pool(sk
);
2928 spin_lock_bh(&tcp_md5sig_pool_lock
);
2931 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2934 pool
= tcp_md5sig_pool
;
2936 /* oops, it has already been assigned. */
2937 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2938 __tcp_free_md5sig_pool(p
);
2940 tcp_md5sig_pool
= pool
= p
;
2941 spin_unlock_bh(&tcp_md5sig_pool_lock
);
2946 EXPORT_SYMBOL(tcp_alloc_md5sig_pool
);
2950 * tcp_get_md5sig_pool - get md5sig_pool for this user
2952 * We use percpu structure, so if we succeed, we exit with preemption
2953 * and BH disabled, to make sure another thread or softirq handling
2954 * wont try to get same context.
2956 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
2958 struct tcp_md5sig_pool
* __percpu
*p
;
2962 spin_lock(&tcp_md5sig_pool_lock
);
2963 p
= tcp_md5sig_pool
;
2966 spin_unlock(&tcp_md5sig_pool_lock
);
2969 return *this_cpu_ptr(p
);
2974 EXPORT_SYMBOL(tcp_get_md5sig_pool
);
2976 void tcp_put_md5sig_pool(void)
2979 tcp_free_md5sig_pool();
2981 EXPORT_SYMBOL(tcp_put_md5sig_pool
);
2983 int tcp_md5_hash_header(struct tcp_md5sig_pool
*hp
,
2986 struct scatterlist sg
;
2989 __sum16 old_checksum
= th
->check
;
2991 /* options aren't included in the hash */
2992 sg_init_one(&sg
, th
, sizeof(struct tcphdr
));
2993 err
= crypto_hash_update(&hp
->md5_desc
, &sg
, sizeof(struct tcphdr
));
2994 th
->check
= old_checksum
;
2997 EXPORT_SYMBOL(tcp_md5_hash_header
);
2999 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool
*hp
,
3000 struct sk_buff
*skb
, unsigned header_len
)
3002 struct scatterlist sg
;
3003 const struct tcphdr
*tp
= tcp_hdr(skb
);
3004 struct hash_desc
*desc
= &hp
->md5_desc
;
3006 const unsigned head_data_len
= skb_headlen(skb
) > header_len
?
3007 skb_headlen(skb
) - header_len
: 0;
3008 const struct skb_shared_info
*shi
= skb_shinfo(skb
);
3009 struct sk_buff
*frag_iter
;
3011 sg_init_table(&sg
, 1);
3013 sg_set_buf(&sg
, ((u8
*) tp
) + header_len
, head_data_len
);
3014 if (crypto_hash_update(desc
, &sg
, head_data_len
))
3017 for (i
= 0; i
< shi
->nr_frags
; ++i
) {
3018 const struct skb_frag_struct
*f
= &shi
->frags
[i
];
3019 sg_set_page(&sg
, f
->page
, f
->size
, f
->page_offset
);
3020 if (crypto_hash_update(desc
, &sg
, f
->size
))
3024 skb_walk_frags(skb
, frag_iter
)
3025 if (tcp_md5_hash_skb_data(hp
, frag_iter
, 0))
3030 EXPORT_SYMBOL(tcp_md5_hash_skb_data
);
3032 int tcp_md5_hash_key(struct tcp_md5sig_pool
*hp
, struct tcp_md5sig_key
*key
)
3034 struct scatterlist sg
;
3036 sg_init_one(&sg
, key
->key
, key
->keylen
);
3037 return crypto_hash_update(&hp
->md5_desc
, &sg
, key
->keylen
);
3039 EXPORT_SYMBOL(tcp_md5_hash_key
);
3044 * Each Responder maintains up to two secret values concurrently for
3045 * efficient secret rollover. Each secret value has 4 states:
3047 * Generating. (tcp_secret_generating != tcp_secret_primary)
3048 * Generates new Responder-Cookies, but not yet used for primary
3049 * verification. This is a short-term state, typically lasting only
3050 * one round trip time (RTT).
3052 * Primary. (tcp_secret_generating == tcp_secret_primary)
3053 * Used both for generation and primary verification.
3055 * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
3056 * Used for verification, until the first failure that can be
3057 * verified by the newer Generating secret. At that time, this
3058 * cookie's state is changed to Secondary, and the Generating
3059 * cookie's state is changed to Primary. This is a short-term state,
3060 * typically lasting only one round trip time (RTT).
3062 * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
3063 * Used for secondary verification, after primary verification
3064 * failures. This state lasts no more than twice the Maximum Segment
3065 * Lifetime (2MSL). Then, the secret is discarded.
3067 struct tcp_cookie_secret
{
3068 /* The secret is divided into two parts. The digest part is the
3069 * equivalent of previously hashing a secret and saving the state,
3070 * and serves as an initialization vector (IV). The message part
3071 * serves as the trailing secret.
3073 u32 secrets
[COOKIE_WORKSPACE_WORDS
];
3074 unsigned long expires
;
3077 #define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
3078 #define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
3079 #define TCP_SECRET_LIFE (HZ * 600)
3081 static struct tcp_cookie_secret tcp_secret_one
;
3082 static struct tcp_cookie_secret tcp_secret_two
;
3084 /* Essentially a circular list, without dynamic allocation. */
3085 static struct tcp_cookie_secret
*tcp_secret_generating
;
3086 static struct tcp_cookie_secret
*tcp_secret_primary
;
3087 static struct tcp_cookie_secret
*tcp_secret_retiring
;
3088 static struct tcp_cookie_secret
*tcp_secret_secondary
;
3090 static DEFINE_SPINLOCK(tcp_secret_locker
);
3092 /* Select a pseudo-random word in the cookie workspace.
3094 static inline u32
tcp_cookie_work(const u32
*ws
, const int n
)
3096 return ws
[COOKIE_DIGEST_WORDS
+ ((COOKIE_MESSAGE_WORDS
-1) & ws
[n
])];
3099 /* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
3100 * Called in softirq context.
3101 * Returns: 0 for success.
3103 int tcp_cookie_generator(u32
*bakery
)
3105 unsigned long jiffy
= jiffies
;
3107 if (unlikely(time_after_eq(jiffy
, tcp_secret_generating
->expires
))) {
3108 spin_lock_bh(&tcp_secret_locker
);
3109 if (!time_after_eq(jiffy
, tcp_secret_generating
->expires
)) {
3110 /* refreshed by another */
3112 &tcp_secret_generating
->secrets
[0],
3113 COOKIE_WORKSPACE_WORDS
);
3115 /* still needs refreshing */
3116 get_random_bytes(bakery
, COOKIE_WORKSPACE_WORDS
);
3118 /* The first time, paranoia assumes that the
3119 * randomization function isn't as strong. But,
3120 * this secret initialization is delayed until
3121 * the last possible moment (packet arrival).
3122 * Although that time is observable, it is
3123 * unpredictably variable. Mash in the most
3124 * volatile clock bits available, and expire the
3125 * secret extra quickly.
3127 if (unlikely(tcp_secret_primary
->expires
==
3128 tcp_secret_secondary
->expires
)) {
3131 getnstimeofday(&tv
);
3132 bakery
[COOKIE_DIGEST_WORDS
+0] ^=
3135 tcp_secret_secondary
->expires
= jiffy
3137 + (0x0f & tcp_cookie_work(bakery
, 0));
3139 tcp_secret_secondary
->expires
= jiffy
3141 + (0xff & tcp_cookie_work(bakery
, 1));
3142 tcp_secret_primary
->expires
= jiffy
3144 + (0x1f & tcp_cookie_work(bakery
, 2));
3146 memcpy(&tcp_secret_secondary
->secrets
[0],
3147 bakery
, COOKIE_WORKSPACE_WORDS
);
3149 rcu_assign_pointer(tcp_secret_generating
,
3150 tcp_secret_secondary
);
3151 rcu_assign_pointer(tcp_secret_retiring
,
3152 tcp_secret_primary
);
3154 * Neither call_rcu() nor synchronize_rcu() needed.
3155 * Retiring data is not freed. It is replaced after
3156 * further (locked) pointer updates, and a quiet time
3157 * (minimum 1MSL, maximum LIFE - 2MSL).
3160 spin_unlock_bh(&tcp_secret_locker
);
3164 &rcu_dereference(tcp_secret_generating
)->secrets
[0],
3165 COOKIE_WORKSPACE_WORDS
);
3166 rcu_read_unlock_bh();
3170 EXPORT_SYMBOL(tcp_cookie_generator
);
3172 void tcp_done(struct sock
*sk
)
3174 if (sk
->sk_state
== TCP_SYN_SENT
|| sk
->sk_state
== TCP_SYN_RECV
)
3175 TCP_INC_STATS_BH(sock_net(sk
), TCP_MIB_ATTEMPTFAILS
);
3177 tcp_set_state(sk
, TCP_CLOSE
);
3178 tcp_clear_xmit_timers(sk
);
3180 sk
->sk_shutdown
= SHUTDOWN_MASK
;
3182 if (!sock_flag(sk
, SOCK_DEAD
))
3183 sk
->sk_state_change(sk
);
3185 inet_csk_destroy_sock(sk
);
3187 EXPORT_SYMBOL_GPL(tcp_done
);
3189 extern struct tcp_congestion_ops tcp_reno
;
3191 static __initdata
unsigned long thash_entries
;
3192 static int __init
set_thash_entries(char *str
)
3196 thash_entries
= simple_strtoul(str
, &str
, 0);
3199 __setup("thash_entries=", set_thash_entries
);
3201 void __init
tcp_init(void)
3203 struct sk_buff
*skb
= NULL
;
3204 unsigned long nr_pages
, limit
;
3205 int order
, i
, max_share
;
3206 unsigned long jiffy
= jiffies
;
3208 BUILD_BUG_ON(sizeof(struct tcp_skb_cb
) > sizeof(skb
->cb
));
3210 percpu_counter_init(&tcp_sockets_allocated
, 0);
3211 percpu_counter_init(&tcp_orphan_count
, 0);
3212 tcp_hashinfo
.bind_bucket_cachep
=
3213 kmem_cache_create("tcp_bind_bucket",
3214 sizeof(struct inet_bind_bucket
), 0,
3215 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3217 /* Size and allocate the main established and bind bucket
3220 * The methodology is similar to that of the buffer cache.
3222 tcp_hashinfo
.ehash
=
3223 alloc_large_system_hash("TCP established",
3224 sizeof(struct inet_ehash_bucket
),
3226 (totalram_pages
>= 128 * 1024) ?
3230 &tcp_hashinfo
.ehash_mask
,
3231 thash_entries
? 0 : 512 * 1024);
3232 for (i
= 0; i
<= tcp_hashinfo
.ehash_mask
; i
++) {
3233 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].chain
, i
);
3234 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo
.ehash
[i
].twchain
, i
);
3236 if (inet_ehash_locks_alloc(&tcp_hashinfo
))
3237 panic("TCP: failed to alloc ehash_locks");
3238 tcp_hashinfo
.bhash
=
3239 alloc_large_system_hash("TCP bind",
3240 sizeof(struct inet_bind_hashbucket
),
3241 tcp_hashinfo
.ehash_mask
+ 1,
3242 (totalram_pages
>= 128 * 1024) ?
3245 &tcp_hashinfo
.bhash_size
,
3248 tcp_hashinfo
.bhash_size
= 1 << tcp_hashinfo
.bhash_size
;
3249 for (i
= 0; i
< tcp_hashinfo
.bhash_size
; i
++) {
3250 spin_lock_init(&tcp_hashinfo
.bhash
[i
].lock
);
3251 INIT_HLIST_HEAD(&tcp_hashinfo
.bhash
[i
].chain
);
3254 /* Try to be a bit smarter and adjust defaults depending
3255 * on available memory.
3257 for (order
= 0; ((1 << order
) << PAGE_SHIFT
) <
3258 (tcp_hashinfo
.bhash_size
* sizeof(struct inet_bind_hashbucket
));
3262 tcp_death_row
.sysctl_max_tw_buckets
= 180000;
3263 sysctl_tcp_max_orphans
= 4096 << (order
- 4);
3264 sysctl_max_syn_backlog
= 1024;
3265 } else if (order
< 3) {
3266 tcp_death_row
.sysctl_max_tw_buckets
>>= (3 - order
);
3267 sysctl_tcp_max_orphans
>>= (3 - order
);
3268 sysctl_max_syn_backlog
= 128;
3271 /* Set the pressure threshold to be a fraction of global memory that
3272 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
3273 * memory, with a floor of 128 pages.
3275 nr_pages
= totalram_pages
- totalhigh_pages
;
3276 limit
= min(nr_pages
, 1UL<<(28-PAGE_SHIFT
)) >> (20-PAGE_SHIFT
);
3277 limit
= (limit
* (nr_pages
>> (20-PAGE_SHIFT
))) >> (PAGE_SHIFT
-11);
3278 limit
= max(limit
, 128UL);
3279 sysctl_tcp_mem
[0] = limit
/ 4 * 3;
3280 sysctl_tcp_mem
[1] = limit
;
3281 sysctl_tcp_mem
[2] = sysctl_tcp_mem
[0] * 2;
3283 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3284 limit
= ((unsigned long)sysctl_tcp_mem
[1]) << (PAGE_SHIFT
- 7);
3285 max_share
= min(4UL*1024*1024, limit
);
3287 sysctl_tcp_wmem
[0] = SK_MEM_QUANTUM
;
3288 sysctl_tcp_wmem
[1] = 16*1024;
3289 sysctl_tcp_wmem
[2] = max(64*1024, max_share
);
3291 sysctl_tcp_rmem
[0] = SK_MEM_QUANTUM
;
3292 sysctl_tcp_rmem
[1] = 87380;
3293 sysctl_tcp_rmem
[2] = max(87380, max_share
);
3295 printk(KERN_INFO
"TCP: Hash tables configured "
3296 "(established %u bind %u)\n",
3297 tcp_hashinfo
.ehash_mask
+ 1, tcp_hashinfo
.bhash_size
);
3299 tcp_register_congestion_control(&tcp_reno
);
3301 memset(&tcp_secret_one
.secrets
[0], 0, sizeof(tcp_secret_one
.secrets
));
3302 memset(&tcp_secret_two
.secrets
[0], 0, sizeof(tcp_secret_two
.secrets
));
3303 tcp_secret_one
.expires
= jiffy
; /* past due */
3304 tcp_secret_two
.expires
= jiffy
; /* past due */
3305 tcp_secret_generating
= &tcp_secret_one
;
3306 tcp_secret_primary
= &tcp_secret_one
;
3307 tcp_secret_retiring
= &tcp_secret_two
;
3308 tcp_secret_secondary
= &tcp_secret_two
;