2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Implementation of the Transmission Control Protocol(TCP).
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Mark Evans, <evansmp@uhura.aston.ac.uk>
11 * Corey Minyard <wf-rch!minyard@relay.EU.net>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
14 * Linus Torvalds, <torvalds@cs.helsinki.fi>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Matthew Dillon, <dillon@apollo.west.oic.com>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Jorge Cwik, <jorge@laser.satlink.net>
21 * Alan Cox : Numerous verify_area() calls
22 * Alan Cox : Set the ACK bit on a reset
23 * Alan Cox : Stopped it crashing if it closed while
24 * sk->inuse=1 and was trying to connect
26 * Alan Cox : All icmp error handling was broken
27 * pointers passed where wrong and the
28 * socket was looked up backwards. Nobody
29 * tested any icmp error code obviously.
30 * Alan Cox : tcp_err() now handled properly. It
31 * wakes people on errors. poll
32 * behaves and the icmp error race
33 * has gone by moving it into sock.c
34 * Alan Cox : tcp_send_reset() fixed to work for
35 * everything not just packets for
37 * Alan Cox : tcp option processing.
38 * Alan Cox : Reset tweaked (still not 100%) [Had
40 * Herp Rosmanith : More reset fixes
41 * Alan Cox : No longer acks invalid rst frames.
42 * Acking any kind of RST is right out.
43 * Alan Cox : Sets an ignore me flag on an rst
44 * receive otherwise odd bits of prattle
46 * Alan Cox : Fixed another acking RST frame bug.
47 * Should stop LAN workplace lockups.
48 * Alan Cox : Some tidyups using the new skb list
50 * Alan Cox : sk->keepopen now seems to work
51 * Alan Cox : Pulls options out correctly on accepts
52 * Alan Cox : Fixed assorted sk->rqueue->next errors
53 * Alan Cox : PSH doesn't end a TCP read. Switched a
55 * Alan Cox : Tidied tcp_data to avoid a potential
57 * Alan Cox : Added some better commenting, as the
58 * tcp is hard to follow
59 * Alan Cox : Removed incorrect check for 20 * psh
60 * Michael O'Reilly : ack < copied bug fix.
61 * Johannes Stille : Misc tcp fixes (not all in yet).
62 * Alan Cox : FIN with no memory -> CRASH
63 * Alan Cox : Added socket option proto entries.
64 * Also added awareness of them to accept.
65 * Alan Cox : Added TCP options (SOL_TCP)
66 * Alan Cox : Switched wakeup calls to callbacks,
67 * so the kernel can layer network
69 * Alan Cox : Use ip_tos/ip_ttl settings.
70 * Alan Cox : Handle FIN (more) properly (we hope).
71 * Alan Cox : RST frames sent on unsynchronised
73 * Alan Cox : Put in missing check for SYN bit.
74 * Alan Cox : Added tcp_select_window() aka NET2E
75 * window non shrink trick.
76 * Alan Cox : Added a couple of small NET2E timer
78 * Charles Hedrick : TCP fixes
79 * Toomas Tamm : TCP window fixes
80 * Alan Cox : Small URG fix to rlogin ^C ack fight
81 * Charles Hedrick : Rewrote most of it to actually work
82 * Linus : Rewrote tcp_read() and URG handling
84 * Gerhard Koerting: Fixed some missing timer handling
85 * Matthew Dillon : Reworked TCP machine states as per RFC
86 * Gerhard Koerting: PC/TCP workarounds
87 * Adam Caldwell : Assorted timer/timing errors
88 * Matthew Dillon : Fixed another RST bug
89 * Alan Cox : Move to kernel side addressing changes.
90 * Alan Cox : Beginning work on TCP fastpathing
92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
93 * Alan Cox : TCP fast path debugging
94 * Alan Cox : Window clamping
95 * Michael Riepe : Bug in tcp_check()
96 * Matt Dillon : More TCP improvements and RST bug fixes
97 * Matt Dillon : Yet more small nasties remove from the
98 * TCP code (Be very nice to this man if
99 * tcp finally works 100%) 8)
100 * Alan Cox : BSD accept semantics.
101 * Alan Cox : Reset on closedown bug.
102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
103 * Michael Pall : Handle poll() after URG properly in
105 * Michael Pall : Undo the last fix in tcp_read_urg()
106 * (multi URG PUSH broke rlogin).
107 * Michael Pall : Fix the multi URG PUSH problem in
108 * tcp_readable(), poll() after URG
110 * Michael Pall : recv(...,MSG_OOB) never blocks in the
112 * Alan Cox : Changed the semantics of sk->socket to
113 * fix a race and a signal problem with
114 * accept() and async I/O.
115 * Alan Cox : Relaxed the rules on tcp_sendto().
116 * Yury Shevchuk : Really fixed accept() blocking problem.
117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
118 * clients/servers which listen in on
120 * Alan Cox : Cleaned the above up and shrank it to
121 * a sensible code size.
122 * Alan Cox : Self connect lockup fix.
123 * Alan Cox : No connect to multicast.
124 * Ross Biro : Close unaccepted children on master
126 * Alan Cox : Reset tracing code.
127 * Alan Cox : Spurious resets on shutdown.
128 * Alan Cox : Giant 15 minute/60 second timer error
129 * Alan Cox : Small whoops in polling before an
131 * Alan Cox : Kept the state trace facility since
132 * it's handy for debugging.
133 * Alan Cox : More reset handler fixes.
134 * Alan Cox : Started rewriting the code based on
135 * the RFC's for other useful protocol
136 * references see: Comer, KA9Q NOS, and
137 * for a reference on the difference
138 * between specifications and how BSD
139 * works see the 4.4lite source.
140 * A.N.Kuznetsov : Don't time wait on completion of tidy
142 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
143 * Linus Torvalds : Fixed BSD port reuse to work first syn
144 * Alan Cox : Reimplemented timers as per the RFC
145 * and using multiple timers for sanity.
146 * Alan Cox : Small bug fixes, and a lot of new
148 * Alan Cox : Fixed dual reader crash by locking
149 * the buffers (much like datagram.c)
150 * Alan Cox : Fixed stuck sockets in probe. A probe
151 * now gets fed up of retrying without
152 * (even a no space) answer.
153 * Alan Cox : Extracted closing code better
154 * Alan Cox : Fixed the closing state machine to
156 * Alan Cox : More 'per spec' fixes.
157 * Jorge Cwik : Even faster checksumming.
158 * Alan Cox : tcp_data() doesn't ack illegal PSH
159 * only frames. At least one pc tcp stack
161 * Alan Cox : Cache last socket.
162 * Alan Cox : Per route irtt.
163 * Matt Day : poll()->select() match BSD precisely on error
164 * Alan Cox : New buffers
165 * Marc Tamsky : Various sk->prot->retransmits and
166 * sk->retransmits misupdating fixed.
167 * Fixed tcp_write_timeout: stuck close,
168 * and TCP syn retries gets used now.
169 * Mark Yarvis : In tcp_read_wakeup(), don't send an
170 * ack if state is TCP_CLOSED.
171 * Alan Cox : Look up device on a retransmit - routes may
172 * change. Doesn't yet cope with MSS shrink right
174 * Marc Tamsky : Closing in closing fixes.
175 * Mike Shaver : RFC1122 verifications.
176 * Alan Cox : rcv_saddr errors.
177 * Alan Cox : Block double connect().
178 * Alan Cox : Small hooks for enSKIP.
179 * Alexey Kuznetsov: Path MTU discovery.
180 * Alan Cox : Support soft errors.
181 * Alan Cox : Fix MTU discovery pathological case
182 * when the remote claims no mtu!
183 * Marc Tamsky : TCP_CLOSE fix.
184 * Colin (G3TNE) : Send a reset on syn ack replies in
185 * window but wrong (fixes NT lpd problems)
186 * Pedro Roque : Better TCP window handling, delayed ack.
187 * Joerg Reuter : No modification of locked buffers in
188 * tcp_do_retransmit()
189 * Eric Schenk : Changed receiver side silly window
190 * avoidance algorithm to BSD style
191 * algorithm. This doubles throughput
192 * against machines running Solaris,
193 * and seems to result in general
195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
196 * Willy Konynenberg : Transparent proxying support.
197 * Mike McLagan : Routing by source
198 * Keith Owens : Do proper merging with partial SKB's in
199 * tcp_do_sendmsg to avoid burstiness.
200 * Eric Schenk : Fix fast close down bug with
201 * shutdown() followed by close().
202 * Andi Kleen : Make poll agree with SIGIO
203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
204 * lingertime == 0 (RFC 793 ABORT Call)
205 * Hirokazu Takahashi : Use copy_from_user() instead of
206 * csum_and_copy_from_user() if possible.
208 * This program is free software; you can redistribute it and/or
209 * modify it under the terms of the GNU General Public License
210 * as published by the Free Software Foundation; either version
211 * 2 of the License, or(at your option) any later version.
213 * Description of States:
215 * TCP_SYN_SENT sent a connection request, waiting for ack
217 * TCP_SYN_RECV received a connection request, sent ack,
218 * waiting for final ack in three-way handshake.
220 * TCP_ESTABLISHED connection established
222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
223 * transmission of remaining buffered data
225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
228 * TCP_CLOSING both sides have shutdown but we still have
229 * data we have to finish sending
231 * TCP_TIME_WAIT timeout to catch resent junk before entering
232 * closed, can only be entered from FIN_WAIT2
233 * or CLOSING. Required because the other end
234 * may not have gotten our last ACK causing it
235 * to retransmit the data packet (which we ignore)
237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
238 * us to finish writing our data and to shutdown
239 * (we have to close() to move on to LAST_ACK)
241 * TCP_LAST_ACK out side has shutdown after remote has
242 * shutdown. There may still be data in our
243 * buffer that we have to finish sending
245 * TCP_CLOSE socket is finished
248 #define pr_fmt(fmt) "TCP: " fmt
250 #include <linux/kernel.h>
251 #include <linux/module.h>
252 #include <linux/types.h>
253 #include <linux/fcntl.h>
254 #include <linux/poll.h>
255 #include <linux/init.h>
256 #include <linux/fs.h>
257 #include <linux/skbuff.h>
258 #include <linux/scatterlist.h>
259 #include <linux/splice.h>
260 #include <linux/net.h>
261 #include <linux/socket.h>
262 #include <linux/random.h>
263 #include <linux/bootmem.h>
264 #include <linux/highmem.h>
265 #include <linux/swap.h>
266 #include <linux/cache.h>
267 #include <linux/err.h>
268 #include <linux/crypto.h>
269 #include <linux/time.h>
270 #include <linux/slab.h>
272 #include <net/icmp.h>
273 #include <net/inet_common.h>
275 #include <net/xfrm.h>
277 #include <net/netdma.h>
278 #include <net/sock.h>
280 #include <asm/uaccess.h>
281 #include <asm/ioctls.h>
282 #include <net/busy_poll.h>
284 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
286 int sysctl_tcp_min_tso_segs __read_mostly = 2;
288 int sysctl_tcp_autocorking __read_mostly = 1;
290 struct percpu_counter tcp_orphan_count;
291 EXPORT_SYMBOL_GPL(tcp_orphan_count);
293 long sysctl_tcp_mem[3] __read_mostly;
294 int sysctl_tcp_wmem[3] __read_mostly;
295 int sysctl_tcp_rmem[3] __read_mostly;
297 EXPORT_SYMBOL(sysctl_tcp_mem);
298 EXPORT_SYMBOL(sysctl_tcp_rmem);
299 EXPORT_SYMBOL(sysctl_tcp_wmem);
301 atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
302 EXPORT_SYMBOL(tcp_memory_allocated);
305 * Current number of TCP sockets.
307 struct percpu_counter tcp_sockets_allocated;
308 EXPORT_SYMBOL(tcp_sockets_allocated);
313 struct tcp_splice_state {
314 struct pipe_inode_info *pipe;
320 * Pressure flag: try to collapse.
321 * Technical note: it is used by multiple contexts non atomically.
322 * All the __sk_mem_schedule() is of this nature: accounting
323 * is strict, actions are advisory and have some latency.
325 int tcp_memory_pressure __read_mostly;
326 EXPORT_SYMBOL(tcp_memory_pressure);
328 void tcp_enter_memory_pressure(struct sock *sk)
330 if (!tcp_memory_pressure) {
331 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
332 tcp_memory_pressure = 1;
335 EXPORT_SYMBOL(tcp_enter_memory_pressure);
337 /* Convert seconds to retransmits based on initial and max timeout */
338 static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
343 int period = timeout;
346 while (seconds > period && res < 255) {
349 if (timeout > rto_max)
357 /* Convert retransmits to seconds based on initial and max timeout */
358 static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
366 if (timeout > rto_max)
374 /* Address-family independent initialization for a tcp_sock.
376 * NOTE: A lot of things set to zero explicitly by call to
377 * sk_alloc() so need not be done here.
379 void tcp_init_sock(struct sock *sk)
381 struct inet_connection_sock *icsk = inet_csk(sk);
382 struct tcp_sock *tp = tcp_sk(sk);
384 __skb_queue_head_init(&tp->out_of_order_queue);
385 tcp_init_xmit_timers(sk);
386 tcp_prequeue_init(tp);
387 INIT_LIST_HEAD(&tp->tsq_node);
389 icsk->icsk_rto = TCP_TIMEOUT_INIT;
390 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
392 /* So many TCP implementations out there (incorrectly) count the
393 * initial SYN frame in their delayed-ACK and congestion control
394 * algorithms that we must have the following bandaid to talk
395 * efficiently to them. -DaveM
397 tp->snd_cwnd = TCP_INIT_CWND;
399 /* See draft-stevens-tcpca-spec-01 for discussion of the
400 * initialization of these values.
402 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
403 tp->snd_cwnd_clamp = ~0;
404 tp->mss_cache = TCP_MSS_DEFAULT;
406 tp->reordering = sysctl_tcp_reordering;
407 tcp_enable_early_retrans(tp);
408 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
412 sk->sk_state = TCP_CLOSE;
414 sk->sk_write_space = sk_stream_write_space;
415 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
417 icsk->icsk_sync_mss = tcp_sync_mss;
419 sk->sk_sndbuf = sysctl_tcp_wmem[1];
420 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
423 sock_update_memcg(sk);
424 sk_sockets_allocated_inc(sk);
427 EXPORT_SYMBOL(tcp_init_sock);
429 void tcp_tx_timestamp(struct sock *sk, struct sk_buff *skb)
431 struct skb_shared_info *shinfo = skb_shinfo(skb);
433 sock_tx_timestamp(sk, &shinfo->tx_flags);
434 if (shinfo->tx_flags & SKBTX_ANY_SW_TSTAMP)
435 shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
439 * Wait for a TCP event.
441 * Note that we don't need to lock the socket, as the upper poll layers
442 * take care of normal races (between the test and the event) and we don't
443 * go look at any of the socket buffers directly.
445 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
448 struct sock *sk = sock->sk;
449 const struct tcp_sock *tp = tcp_sk(sk);
451 sock_rps_record_flow(sk);
453 sock_poll_wait(file, sk_sleep(sk), wait);
454 if (sk->sk_state == TCP_LISTEN)
455 return inet_csk_listen_poll(sk);
457 /* Socket is not locked. We are protected from async events
458 * by poll logic and correct handling of state changes
459 * made by other threads is impossible in any case.
465 * POLLHUP is certainly not done right. But poll() doesn't
466 * have a notion of HUP in just one direction, and for a
467 * socket the read side is more interesting.
469 * Some poll() documentation says that POLLHUP is incompatible
470 * with the POLLOUT/POLLWR flags, so somebody should check this
471 * all. But careful, it tends to be safer to return too many
472 * bits than too few, and you can easily break real applications
473 * if you don't tell them that something has hung up!
477 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
478 * our fs/select.c). It means that after we received EOF,
479 * poll always returns immediately, making impossible poll() on write()
480 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
481 * if and only if shutdown has been made in both directions.
482 * Actually, it is interesting to look how Solaris and DUX
483 * solve this dilemma. I would prefer, if POLLHUP were maskable,
484 * then we could set it on SND_SHUTDOWN. BTW examples given
485 * in Stevens' books assume exactly this behaviour, it explains
486 * why POLLHUP is incompatible with POLLOUT. --ANK
488 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
489 * blocking on fresh not-connected or disconnected socket. --ANK
491 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
493 if (sk->sk_shutdown & RCV_SHUTDOWN)
494 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
496 /* Connected or passive Fast Open socket? */
497 if (sk->sk_state != TCP_SYN_SENT &&
498 (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk != NULL)) {
499 int target = sock_rcvlowat(sk, 0, INT_MAX);
501 if (tp->urg_seq == tp->copied_seq &&
502 !sock_flag(sk, SOCK_URGINLINE) &&
506 /* Potential race condition. If read of tp below will
507 * escape above sk->sk_state, we can be illegally awaken
508 * in SYN_* states. */
509 if (tp->rcv_nxt - tp->copied_seq >= target)
510 mask |= POLLIN | POLLRDNORM;
512 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
513 if (sk_stream_is_writeable(sk)) {
514 mask |= POLLOUT | POLLWRNORM;
515 } else { /* send SIGIO later */
516 set_bit(SOCK_ASYNC_NOSPACE,
517 &sk->sk_socket->flags);
518 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
520 /* Race breaker. If space is freed after
521 * wspace test but before the flags are set,
522 * IO signal will be lost.
524 if (sk_stream_is_writeable(sk))
525 mask |= POLLOUT | POLLWRNORM;
528 mask |= POLLOUT | POLLWRNORM;
530 if (tp->urg_data & TCP_URG_VALID)
533 /* This barrier is coupled with smp_wmb() in tcp_reset() */
535 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
540 EXPORT_SYMBOL(tcp_poll);
542 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
544 struct tcp_sock *tp = tcp_sk(sk);
550 if (sk->sk_state == TCP_LISTEN)
553 slow = lock_sock_fast(sk);
554 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
556 else if (sock_flag(sk, SOCK_URGINLINE) ||
558 before(tp->urg_seq, tp->copied_seq) ||
559 !before(tp->urg_seq, tp->rcv_nxt)) {
561 answ = tp->rcv_nxt - tp->copied_seq;
563 /* Subtract 1, if FIN was received */
564 if (answ && sock_flag(sk, SOCK_DONE))
567 answ = tp->urg_seq - tp->copied_seq;
568 unlock_sock_fast(sk, slow);
571 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
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_una;
583 if (sk->sk_state == TCP_LISTEN)
586 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
589 answ = tp->write_seq - tp->snd_nxt;
595 return put_user(answ, (int __user *)arg);
597 EXPORT_SYMBOL(tcp_ioctl);
599 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
601 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
602 tp->pushed_seq = tp->write_seq;
605 static inline bool forced_push(const struct tcp_sock *tp)
607 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
610 static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
612 struct tcp_sock *tp = tcp_sk(sk);
613 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
616 tcb->seq = tcb->end_seq = tp->write_seq;
617 tcb->tcp_flags = TCPHDR_ACK;
619 skb_header_release(skb);
620 tcp_add_write_queue_tail(sk, skb);
621 sk->sk_wmem_queued += skb->truesize;
622 sk_mem_charge(sk, skb->truesize);
623 if (tp->nonagle & TCP_NAGLE_PUSH)
624 tp->nonagle &= ~TCP_NAGLE_PUSH;
627 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
630 tp->snd_up = tp->write_seq;
633 /* If a not yet filled skb is pushed, do not send it if
634 * we have data packets in Qdisc or NIC queues :
635 * Because TX completion will happen shortly, it gives a chance
636 * to coalesce future sendmsg() payload into this skb, without
637 * need for a timer, and with no latency trade off.
638 * As packets containing data payload have a bigger truesize
639 * than pure acks (dataless) packets, the last checks prevent
640 * autocorking if we only have an ACK in Qdisc/NIC queues,
641 * or if TX completion was delayed after we processed ACK packet.
643 static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
646 return skb->len < size_goal &&
647 sysctl_tcp_autocorking &&
648 skb != tcp_write_queue_head(sk) &&
649 atomic_read(&sk->sk_wmem_alloc) > skb->truesize;
652 static void tcp_push(struct sock *sk, int flags, int mss_now,
653 int nonagle, int size_goal)
655 struct tcp_sock *tp = tcp_sk(sk);
658 if (!tcp_send_head(sk))
661 skb = tcp_write_queue_tail(sk);
662 if (!(flags & MSG_MORE) || forced_push(tp))
663 tcp_mark_push(tp, skb);
665 tcp_mark_urg(tp, flags);
667 if (tcp_should_autocork(sk, skb, size_goal)) {
669 /* avoid atomic op if TSQ_THROTTLED bit is already set */
670 if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) {
671 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
672 set_bit(TSQ_THROTTLED, &tp->tsq_flags);
674 /* It is possible TX completion already happened
675 * before we set TSQ_THROTTLED.
677 if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize)
681 if (flags & MSG_MORE)
682 nonagle = TCP_NAGLE_CORK;
684 __tcp_push_pending_frames(sk, mss_now, nonagle);
687 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
688 unsigned int offset, size_t len)
690 struct tcp_splice_state *tss = rd_desc->arg.data;
693 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
696 rd_desc->count -= ret;
700 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
702 /* Store TCP splice context information in read_descriptor_t. */
703 read_descriptor_t rd_desc = {
708 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
712 * tcp_splice_read - splice data from TCP socket to a pipe
713 * @sock: socket to splice from
714 * @ppos: position (not valid)
715 * @pipe: pipe to splice to
716 * @len: number of bytes to splice
717 * @flags: splice modifier flags
720 * Will read pages from given socket and fill them into a pipe.
723 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
724 struct pipe_inode_info *pipe, size_t len,
727 struct sock *sk = sock->sk;
728 struct tcp_splice_state tss = {
737 sock_rps_record_flow(sk);
739 * We can't seek on a socket input
748 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
750 ret = __tcp_splice_read(sk, &tss);
756 if (sock_flag(sk, SOCK_DONE))
759 ret = sock_error(sk);
762 if (sk->sk_shutdown & RCV_SHUTDOWN)
764 if (sk->sk_state == TCP_CLOSE) {
766 * This occurs when user tries to read
767 * from never connected socket.
769 if (!sock_flag(sk, SOCK_DONE))
777 sk_wait_data(sk, &timeo);
778 if (signal_pending(current)) {
779 ret = sock_intr_errno(timeo);
792 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
793 (sk->sk_shutdown & RCV_SHUTDOWN) ||
794 signal_pending(current))
805 EXPORT_SYMBOL(tcp_splice_read);
807 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
811 /* The TCP header must be at least 32-bit aligned. */
812 size = ALIGN(size, 4);
814 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
816 if (sk_wmem_schedule(sk, skb->truesize)) {
817 skb_reserve(skb, sk->sk_prot->max_header);
819 * Make sure that we have exactly size bytes
820 * available to the caller, no more, no less.
822 skb->reserved_tailroom = skb->end - skb->tail - size;
827 sk->sk_prot->enter_memory_pressure(sk);
828 sk_stream_moderate_sndbuf(sk);
833 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
836 struct tcp_sock *tp = tcp_sk(sk);
837 u32 xmit_size_goal, old_size_goal;
839 xmit_size_goal = mss_now;
841 if (large_allowed && sk_can_gso(sk)) {
844 /* Maybe we should/could use sk->sk_prot->max_header here ? */
845 hlen = inet_csk(sk)->icsk_af_ops->net_header_len +
846 inet_csk(sk)->icsk_ext_hdr_len +
849 /* Goal is to send at least one packet per ms,
850 * not one big TSO packet every 100 ms.
851 * This preserves ACK clocking and is consistent
852 * with tcp_tso_should_defer() heuristic.
854 gso_size = sk->sk_pacing_rate / (2 * MSEC_PER_SEC);
855 gso_size = max_t(u32, gso_size,
856 sysctl_tcp_min_tso_segs * mss_now);
858 xmit_size_goal = min_t(u32, gso_size,
859 sk->sk_gso_max_size - 1 - hlen);
861 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
863 /* We try hard to avoid divides here */
864 old_size_goal = tp->xmit_size_goal_segs * mss_now;
866 if (likely(old_size_goal <= xmit_size_goal &&
867 old_size_goal + mss_now > xmit_size_goal)) {
868 xmit_size_goal = old_size_goal;
870 tp->xmit_size_goal_segs =
871 min_t(u16, xmit_size_goal / mss_now,
872 sk->sk_gso_max_segs);
873 xmit_size_goal = tp->xmit_size_goal_segs * mss_now;
877 return max(xmit_size_goal, mss_now);
880 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
884 mss_now = tcp_current_mss(sk);
885 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
890 static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
891 size_t size, int flags)
893 struct tcp_sock *tp = tcp_sk(sk);
894 int mss_now, size_goal;
897 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
899 /* Wait for a connection to finish. One exception is TCP Fast Open
900 * (passive side) where data is allowed to be sent before a connection
901 * is fully established.
903 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
904 !tcp_passive_fastopen(sk)) {
905 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
909 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
911 mss_now = tcp_send_mss(sk, &size_goal, flags);
915 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
919 struct sk_buff *skb = tcp_write_queue_tail(sk);
923 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
925 if (!sk_stream_memory_free(sk))
926 goto wait_for_sndbuf;
928 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
930 goto wait_for_memory;
939 i = skb_shinfo(skb)->nr_frags;
940 can_coalesce = skb_can_coalesce(skb, i, page, offset);
941 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
942 tcp_mark_push(tp, skb);
945 if (!sk_wmem_schedule(sk, copy))
946 goto wait_for_memory;
949 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
952 skb_fill_page_desc(skb, i, page, offset, copy);
954 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
957 skb->data_len += copy;
958 skb->truesize += copy;
959 sk->sk_wmem_queued += copy;
960 sk_mem_charge(sk, copy);
961 skb->ip_summed = CHECKSUM_PARTIAL;
962 tp->write_seq += copy;
963 TCP_SKB_CB(skb)->end_seq += copy;
964 skb_shinfo(skb)->gso_segs = 0;
967 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
971 if (!(size -= copy)) {
972 tcp_tx_timestamp(sk, skb);
976 if (skb->len < size_goal || (flags & MSG_OOB))
979 if (forced_push(tp)) {
980 tcp_mark_push(tp, skb);
981 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
982 } else if (skb == tcp_send_head(sk))
983 tcp_push_one(sk, mss_now);
987 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
989 tcp_push(sk, flags & ~MSG_MORE, mss_now,
990 TCP_NAGLE_PUSH, size_goal);
992 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
995 mss_now = tcp_send_mss(sk, &size_goal, flags);
999 if (copied && !(flags & MSG_SENDPAGE_NOTLAST))
1000 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1007 return sk_stream_error(sk, flags, err);
1010 int tcp_sendpage(struct sock *sk, struct page *page, int offset,
1011 size_t size, int flags)
1015 if (!(sk->sk_route_caps & NETIF_F_SG) ||
1016 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
1017 return sock_no_sendpage(sk->sk_socket, page, offset, size,
1021 res = do_tcp_sendpages(sk, page, offset, size, flags);
1025 EXPORT_SYMBOL(tcp_sendpage);
1027 static inline int select_size(const struct sock *sk, bool sg)
1029 const struct tcp_sock *tp = tcp_sk(sk);
1030 int tmp = tp->mss_cache;
1033 if (sk_can_gso(sk)) {
1034 /* Small frames wont use a full page:
1035 * Payload will immediately follow tcp header.
1037 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
1039 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
1041 if (tmp >= pgbreak &&
1042 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
1050 void tcp_free_fastopen_req(struct tcp_sock *tp)
1052 if (tp->fastopen_req != NULL) {
1053 kfree(tp->fastopen_req);
1054 tp->fastopen_req = NULL;
1058 static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
1059 int *copied, size_t size)
1061 struct tcp_sock *tp = tcp_sk(sk);
1064 if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE))
1066 if (tp->fastopen_req != NULL)
1067 return -EALREADY; /* Another Fast Open is in progress */
1069 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
1071 if (unlikely(tp->fastopen_req == NULL))
1073 tp->fastopen_req->data = msg;
1074 tp->fastopen_req->size = size;
1076 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1077 err = __inet_stream_connect(sk->sk_socket, msg->msg_name,
1078 msg->msg_namelen, flags);
1079 *copied = tp->fastopen_req->copied;
1080 tcp_free_fastopen_req(tp);
1084 int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1088 struct tcp_sock *tp = tcp_sk(sk);
1089 struct sk_buff *skb;
1090 int iovlen, flags, err, copied = 0;
1091 int mss_now = 0, size_goal, copied_syn = 0, offset = 0;
1097 flags = msg->msg_flags;
1098 if (flags & MSG_FASTOPEN) {
1099 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1100 if (err == -EINPROGRESS && copied_syn > 0)
1104 offset = copied_syn;
1107 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1109 /* Wait for a connection to finish. One exception is TCP Fast Open
1110 * (passive side) where data is allowed to be sent before a connection
1111 * is fully established.
1113 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
1114 !tcp_passive_fastopen(sk)) {
1115 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
1119 if (unlikely(tp->repair)) {
1120 if (tp->repair_queue == TCP_RECV_QUEUE) {
1121 copied = tcp_send_rcvq(sk, msg, size);
1126 if (tp->repair_queue == TCP_NO_QUEUE)
1129 /* 'common' sending to sendq */
1132 /* This should be in poll */
1133 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1135 mss_now = tcp_send_mss(sk, &size_goal, flags);
1137 /* Ok commence sending. */
1138 iovlen = msg->msg_iovlen;
1143 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1146 sg = !!(sk->sk_route_caps & NETIF_F_SG);
1148 while (--iovlen >= 0) {
1149 size_t seglen = iov->iov_len;
1150 unsigned char __user *from = iov->iov_base;
1153 if (unlikely(offset > 0)) { /* Skip bytes copied in SYN */
1154 if (offset >= seglen) {
1163 while (seglen > 0) {
1165 int max = size_goal;
1167 skb = tcp_write_queue_tail(sk);
1168 if (tcp_send_head(sk)) {
1169 if (skb->ip_summed == CHECKSUM_NONE)
1171 copy = max - skb->len;
1176 /* Allocate new segment. If the interface is SG,
1177 * allocate skb fitting to single page.
1179 if (!sk_stream_memory_free(sk))
1180 goto wait_for_sndbuf;
1182 skb = sk_stream_alloc_skb(sk,
1183 select_size(sk, sg),
1186 goto wait_for_memory;
1189 * All packets are restored as if they have
1190 * already been sent.
1193 TCP_SKB_CB(skb)->when = tcp_time_stamp;
1196 * Check whether we can use HW checksum.
1198 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
1199 skb->ip_summed = CHECKSUM_PARTIAL;
1201 skb_entail(sk, skb);
1206 /* Try to append data to the end of skb. */
1210 /* Where to copy to? */
1211 if (skb_availroom(skb) > 0) {
1212 /* We have some space in skb head. Superb! */
1213 copy = min_t(int, copy, skb_availroom(skb));
1214 err = skb_add_data_nocache(sk, skb, from, copy);
1219 int i = skb_shinfo(skb)->nr_frags;
1220 struct page_frag *pfrag = sk_page_frag(sk);
1222 if (!sk_page_frag_refill(sk, pfrag))
1223 goto wait_for_memory;
1225 if (!skb_can_coalesce(skb, i, pfrag->page,
1227 if (i == MAX_SKB_FRAGS || !sg) {
1228 tcp_mark_push(tp, skb);
1234 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1236 if (!sk_wmem_schedule(sk, copy))
1237 goto wait_for_memory;
1239 err = skb_copy_to_page_nocache(sk, from, skb,
1246 /* Update the skb. */
1248 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1250 skb_fill_page_desc(skb, i, pfrag->page,
1251 pfrag->offset, copy);
1252 get_page(pfrag->page);
1254 pfrag->offset += copy;
1258 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1260 tp->write_seq += copy;
1261 TCP_SKB_CB(skb)->end_seq += copy;
1262 skb_shinfo(skb)->gso_segs = 0;
1266 if ((seglen -= copy) == 0 && iovlen == 0) {
1267 tcp_tx_timestamp(sk, skb);
1271 if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
1274 if (forced_push(tp)) {
1275 tcp_mark_push(tp, skb);
1276 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1277 } else if (skb == tcp_send_head(sk))
1278 tcp_push_one(sk, mss_now);
1282 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1285 tcp_push(sk, flags & ~MSG_MORE, mss_now,
1286 TCP_NAGLE_PUSH, size_goal);
1288 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1291 mss_now = tcp_send_mss(sk, &size_goal, flags);
1297 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1300 return copied + copied_syn;
1304 tcp_unlink_write_queue(skb, sk);
1305 /* It is the one place in all of TCP, except connection
1306 * reset, where we can be unlinking the send_head.
1308 tcp_check_send_head(sk, skb);
1309 sk_wmem_free_skb(sk, skb);
1313 if (copied + copied_syn)
1316 err = sk_stream_error(sk, flags, err);
1320 EXPORT_SYMBOL(tcp_sendmsg);
1323 * Handle reading urgent data. BSD has very simple semantics for
1324 * this, no blocking and very strange errors 8)
1327 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1329 struct tcp_sock *tp = tcp_sk(sk);
1331 /* No URG data to read. */
1332 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1333 tp->urg_data == TCP_URG_READ)
1334 return -EINVAL; /* Yes this is right ! */
1336 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1339 if (tp->urg_data & TCP_URG_VALID) {
1341 char c = tp->urg_data;
1343 if (!(flags & MSG_PEEK))
1344 tp->urg_data = TCP_URG_READ;
1346 /* Read urgent data. */
1347 msg->msg_flags |= MSG_OOB;
1350 if (!(flags & MSG_TRUNC))
1351 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1354 msg->msg_flags |= MSG_TRUNC;
1356 return err ? -EFAULT : len;
1359 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1362 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1363 * the available implementations agree in this case:
1364 * this call should never block, independent of the
1365 * blocking state of the socket.
1366 * Mike <pall@rz.uni-karlsruhe.de>
1371 static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
1373 struct sk_buff *skb;
1374 int copied = 0, err = 0;
1376 /* XXX -- need to support SO_PEEK_OFF */
1378 skb_queue_walk(&sk->sk_write_queue, skb) {
1379 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, skb->len);
1386 return err ?: copied;
1389 /* Clean up the receive buffer for full frames taken by the user,
1390 * then send an ACK if necessary. COPIED is the number of bytes
1391 * tcp_recvmsg has given to the user so far, it speeds up the
1392 * calculation of whether or not we must ACK for the sake of
1395 void tcp_cleanup_rbuf(struct sock *sk, int copied)
1397 struct tcp_sock *tp = tcp_sk(sk);
1398 bool time_to_ack = false;
1400 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1402 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1403 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1404 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1406 if (inet_csk_ack_scheduled(sk)) {
1407 const struct inet_connection_sock *icsk = inet_csk(sk);
1408 /* Delayed ACKs frequently hit locked sockets during bulk
1410 if (icsk->icsk_ack.blocked ||
1411 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1412 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1414 * If this read emptied read buffer, we send ACK, if
1415 * connection is not bidirectional, user drained
1416 * receive buffer and there was a small segment
1420 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1421 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1422 !icsk->icsk_ack.pingpong)) &&
1423 !atomic_read(&sk->sk_rmem_alloc)))
1427 /* We send an ACK if we can now advertise a non-zero window
1428 * which has been raised "significantly".
1430 * Even if window raised up to infinity, do not send window open ACK
1431 * in states, where we will not receive more. It is useless.
1433 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1434 __u32 rcv_window_now = tcp_receive_window(tp);
1436 /* Optimize, __tcp_select_window() is not cheap. */
1437 if (2*rcv_window_now <= tp->window_clamp) {
1438 __u32 new_window = __tcp_select_window(sk);
1440 /* Send ACK now, if this read freed lots of space
1441 * in our buffer. Certainly, new_window is new window.
1442 * We can advertise it now, if it is not less than current one.
1443 * "Lots" means "at least twice" here.
1445 if (new_window && new_window >= 2 * rcv_window_now)
1453 static void tcp_prequeue_process(struct sock *sk)
1455 struct sk_buff *skb;
1456 struct tcp_sock *tp = tcp_sk(sk);
1458 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
1460 /* RX process wants to run with disabled BHs, though it is not
1463 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1464 sk_backlog_rcv(sk, skb);
1467 /* Clear memory counter. */
1468 tp->ucopy.memory = 0;
1471 #ifdef CONFIG_NET_DMA
1472 static void tcp_service_net_dma(struct sock *sk, bool wait)
1474 dma_cookie_t done, used;
1475 dma_cookie_t last_issued;
1476 struct tcp_sock *tp = tcp_sk(sk);
1478 if (!tp->ucopy.dma_chan)
1481 last_issued = tp->ucopy.dma_cookie;
1482 dma_async_issue_pending(tp->ucopy.dma_chan);
1485 if (dma_async_is_tx_complete(tp->ucopy.dma_chan,
1487 &used) == DMA_COMPLETE) {
1488 /* Safe to free early-copied skbs now */
1489 __skb_queue_purge(&sk->sk_async_wait_queue);
1492 struct sk_buff *skb;
1493 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1494 (dma_async_is_complete(skb->dma_cookie, done,
1495 used) == DMA_COMPLETE)) {
1496 __skb_dequeue(&sk->sk_async_wait_queue);
1504 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1506 struct sk_buff *skb;
1509 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1510 offset = seq - TCP_SKB_CB(skb)->seq;
1511 if (tcp_hdr(skb)->syn)
1513 if (offset < skb->len || tcp_hdr(skb)->fin) {
1517 /* This looks weird, but this can happen if TCP collapsing
1518 * splitted a fat GRO packet, while we released socket lock
1519 * in skb_splice_bits()
1521 sk_eat_skb(sk, skb, false);
1527 * This routine provides an alternative to tcp_recvmsg() for routines
1528 * that would like to handle copying from skbuffs directly in 'sendfile'
1531 * - It is assumed that the socket was locked by the caller.
1532 * - The routine does not block.
1533 * - At present, there is no support for reading OOB data
1534 * or for 'peeking' the socket using this routine
1535 * (although both would be easy to implement).
1537 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1538 sk_read_actor_t recv_actor)
1540 struct sk_buff *skb;
1541 struct tcp_sock *tp = tcp_sk(sk);
1542 u32 seq = tp->copied_seq;
1546 if (sk->sk_state == TCP_LISTEN)
1548 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1549 if (offset < skb->len) {
1553 len = skb->len - offset;
1554 /* Stop reading if we hit a patch of urgent data */
1556 u32 urg_offset = tp->urg_seq - seq;
1557 if (urg_offset < len)
1562 used = recv_actor(desc, skb, offset, len);
1567 } else if (used <= len) {
1572 /* If recv_actor drops the lock (e.g. TCP splice
1573 * receive) the skb pointer might be invalid when
1574 * getting here: tcp_collapse might have deleted it
1575 * while aggregating skbs from the socket queue.
1577 skb = tcp_recv_skb(sk, seq - 1, &offset);
1580 /* TCP coalescing might have appended data to the skb.
1581 * Try to splice more frags
1583 if (offset + 1 != skb->len)
1586 if (tcp_hdr(skb)->fin) {
1587 sk_eat_skb(sk, skb, false);
1591 sk_eat_skb(sk, skb, false);
1594 tp->copied_seq = seq;
1596 tp->copied_seq = seq;
1598 tcp_rcv_space_adjust(sk);
1600 /* Clean up data we have read: This will do ACK frames. */
1602 tcp_recv_skb(sk, seq, &offset);
1603 tcp_cleanup_rbuf(sk, copied);
1607 EXPORT_SYMBOL(tcp_read_sock);
1610 * This routine copies from a sock struct into the user buffer.
1612 * Technical note: in 2.3 we work on _locked_ socket, so that
1613 * tricks with *seq access order and skb->users are not required.
1614 * Probably, code can be easily improved even more.
1617 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1618 size_t len, int nonblock, int flags, int *addr_len)
1620 struct tcp_sock *tp = tcp_sk(sk);
1626 int target; /* Read at least this many bytes */
1628 struct task_struct *user_recv = NULL;
1629 bool copied_early = false;
1630 struct sk_buff *skb;
1633 if (unlikely(flags & MSG_ERRQUEUE))
1634 return ip_recv_error(sk, msg, len, addr_len);
1636 if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
1637 (sk->sk_state == TCP_ESTABLISHED))
1638 sk_busy_loop(sk, nonblock);
1643 if (sk->sk_state == TCP_LISTEN)
1646 timeo = sock_rcvtimeo(sk, nonblock);
1648 /* Urgent data needs to be handled specially. */
1649 if (flags & MSG_OOB)
1652 if (unlikely(tp->repair)) {
1654 if (!(flags & MSG_PEEK))
1657 if (tp->repair_queue == TCP_SEND_QUEUE)
1661 if (tp->repair_queue == TCP_NO_QUEUE)
1664 /* 'common' recv queue MSG_PEEK-ing */
1667 seq = &tp->copied_seq;
1668 if (flags & MSG_PEEK) {
1669 peek_seq = tp->copied_seq;
1673 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1675 #ifdef CONFIG_NET_DMA
1676 tp->ucopy.dma_chan = NULL;
1678 skb = skb_peek_tail(&sk->sk_receive_queue);
1683 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1684 if ((available < target) &&
1685 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1686 !sysctl_tcp_low_latency &&
1687 net_dma_find_channel()) {
1689 tp->ucopy.pinned_list =
1690 dma_pin_iovec_pages(msg->msg_iov, len);
1700 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1701 if (tp->urg_data && tp->urg_seq == *seq) {
1704 if (signal_pending(current)) {
1705 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1710 /* Next get a buffer. */
1712 skb_queue_walk(&sk->sk_receive_queue, skb) {
1713 /* Now that we have two receive queues this
1716 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1717 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1718 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1722 offset = *seq - TCP_SKB_CB(skb)->seq;
1723 if (tcp_hdr(skb)->syn)
1725 if (offset < skb->len)
1727 if (tcp_hdr(skb)->fin)
1729 WARN(!(flags & MSG_PEEK),
1730 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1731 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
1734 /* Well, if we have backlog, try to process it now yet. */
1736 if (copied >= target && !sk->sk_backlog.tail)
1741 sk->sk_state == TCP_CLOSE ||
1742 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1744 signal_pending(current))
1747 if (sock_flag(sk, SOCK_DONE))
1751 copied = sock_error(sk);
1755 if (sk->sk_shutdown & RCV_SHUTDOWN)
1758 if (sk->sk_state == TCP_CLOSE) {
1759 if (!sock_flag(sk, SOCK_DONE)) {
1760 /* This occurs when user tries to read
1761 * from never connected socket.
1774 if (signal_pending(current)) {
1775 copied = sock_intr_errno(timeo);
1780 tcp_cleanup_rbuf(sk, copied);
1782 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1783 /* Install new reader */
1784 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1785 user_recv = current;
1786 tp->ucopy.task = user_recv;
1787 tp->ucopy.iov = msg->msg_iov;
1790 tp->ucopy.len = len;
1792 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1793 !(flags & (MSG_PEEK | MSG_TRUNC)));
1795 /* Ugly... If prequeue is not empty, we have to
1796 * process it before releasing socket, otherwise
1797 * order will be broken at second iteration.
1798 * More elegant solution is required!!!
1800 * Look: we have the following (pseudo)queues:
1802 * 1. packets in flight
1807 * Each queue can be processed only if the next ones
1808 * are empty. At this point we have empty receive_queue.
1809 * But prequeue _can_ be not empty after 2nd iteration,
1810 * when we jumped to start of loop because backlog
1811 * processing added something to receive_queue.
1812 * We cannot release_sock(), because backlog contains
1813 * packets arrived _after_ prequeued ones.
1815 * Shortly, algorithm is clear --- to process all
1816 * the queues in order. We could make it more directly,
1817 * requeueing packets from backlog to prequeue, if
1818 * is not empty. It is more elegant, but eats cycles,
1821 if (!skb_queue_empty(&tp->ucopy.prequeue))
1824 /* __ Set realtime policy in scheduler __ */
1827 #ifdef CONFIG_NET_DMA
1828 if (tp->ucopy.dma_chan) {
1829 if (tp->rcv_wnd == 0 &&
1830 !skb_queue_empty(&sk->sk_async_wait_queue)) {
1831 tcp_service_net_dma(sk, true);
1832 tcp_cleanup_rbuf(sk, copied);
1834 dma_async_issue_pending(tp->ucopy.dma_chan);
1837 if (copied >= target) {
1838 /* Do not sleep, just process backlog. */
1842 sk_wait_data(sk, &timeo);
1844 #ifdef CONFIG_NET_DMA
1845 tcp_service_net_dma(sk, false); /* Don't block */
1846 tp->ucopy.wakeup = 0;
1852 /* __ Restore normal policy in scheduler __ */
1854 if ((chunk = len - tp->ucopy.len) != 0) {
1855 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1860 if (tp->rcv_nxt == tp->copied_seq &&
1861 !skb_queue_empty(&tp->ucopy.prequeue)) {
1863 tcp_prequeue_process(sk);
1865 if ((chunk = len - tp->ucopy.len) != 0) {
1866 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1872 if ((flags & MSG_PEEK) &&
1873 (peek_seq - copied - urg_hole != tp->copied_seq)) {
1874 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1876 task_pid_nr(current));
1877 peek_seq = tp->copied_seq;
1882 /* Ok so how much can we use? */
1883 used = skb->len - offset;
1887 /* Do we have urgent data here? */
1889 u32 urg_offset = tp->urg_seq - *seq;
1890 if (urg_offset < used) {
1892 if (!sock_flag(sk, SOCK_URGINLINE)) {
1905 if (!(flags & MSG_TRUNC)) {
1906 #ifdef CONFIG_NET_DMA
1907 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1908 tp->ucopy.dma_chan = net_dma_find_channel();
1910 if (tp->ucopy.dma_chan) {
1911 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1912 tp->ucopy.dma_chan, skb, offset,
1914 tp->ucopy.pinned_list);
1916 if (tp->ucopy.dma_cookie < 0) {
1918 pr_alert("%s: dma_cookie < 0\n",
1921 /* Exception. Bailout! */
1927 dma_async_issue_pending(tp->ucopy.dma_chan);
1929 if ((offset + used) == skb->len)
1930 copied_early = true;
1935 err = skb_copy_datagram_iovec(skb, offset,
1936 msg->msg_iov, used);
1938 /* Exception. Bailout! */
1950 tcp_rcv_space_adjust(sk);
1953 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1955 tcp_fast_path_check(sk);
1957 if (used + offset < skb->len)
1960 if (tcp_hdr(skb)->fin)
1962 if (!(flags & MSG_PEEK)) {
1963 sk_eat_skb(sk, skb, copied_early);
1964 copied_early = false;
1969 /* Process the FIN. */
1971 if (!(flags & MSG_PEEK)) {
1972 sk_eat_skb(sk, skb, copied_early);
1973 copied_early = false;
1979 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1982 tp->ucopy.len = copied > 0 ? len : 0;
1984 tcp_prequeue_process(sk);
1986 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1987 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1993 tp->ucopy.task = NULL;
1997 #ifdef CONFIG_NET_DMA
1998 tcp_service_net_dma(sk, true); /* Wait for queue to drain */
1999 tp->ucopy.dma_chan = NULL;
2001 if (tp->ucopy.pinned_list) {
2002 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
2003 tp->ucopy.pinned_list = NULL;
2007 /* According to UNIX98, msg_name/msg_namelen are ignored
2008 * on connected socket. I was just happy when found this 8) --ANK
2011 /* Clean up data we have read: This will do ACK frames. */
2012 tcp_cleanup_rbuf(sk, copied);
2022 err = tcp_recv_urg(sk, msg, len, flags);
2026 err = tcp_peek_sndq(sk, msg, len);
2029 EXPORT_SYMBOL(tcp_recvmsg);
2031 void tcp_set_state(struct sock *sk, int state)
2033 int oldstate = sk->sk_state;
2036 case TCP_ESTABLISHED:
2037 if (oldstate != TCP_ESTABLISHED)
2038 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2042 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
2043 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
2045 sk->sk_prot->unhash(sk);
2046 if (inet_csk(sk)->icsk_bind_hash &&
2047 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2051 if (oldstate == TCP_ESTABLISHED)
2052 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2055 /* Change state AFTER socket is unhashed to avoid closed
2056 * socket sitting in hash tables.
2058 sk->sk_state = state;
2061 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
2064 EXPORT_SYMBOL_GPL(tcp_set_state);
2067 * State processing on a close. This implements the state shift for
2068 * sending our FIN frame. Note that we only send a FIN for some
2069 * states. A shutdown() may have already sent the FIN, or we may be
2073 static const unsigned char new_state[16] = {
2074 /* current state: new state: action: */
2075 /* (Invalid) */ TCP_CLOSE,
2076 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2077 /* TCP_SYN_SENT */ TCP_CLOSE,
2078 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2079 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
2080 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
2081 /* TCP_TIME_WAIT */ TCP_CLOSE,
2082 /* TCP_CLOSE */ TCP_CLOSE,
2083 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
2084 /* TCP_LAST_ACK */ TCP_LAST_ACK,
2085 /* TCP_LISTEN */ TCP_CLOSE,
2086 /* TCP_CLOSING */ TCP_CLOSING,
2089 static int tcp_close_state(struct sock *sk)
2091 int next = (int)new_state[sk->sk_state];
2092 int ns = next & TCP_STATE_MASK;
2094 tcp_set_state(sk, ns);
2096 return next & TCP_ACTION_FIN;
2100 * Shutdown the sending side of a connection. Much like close except
2101 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
2104 void tcp_shutdown(struct sock *sk, int how)
2106 /* We need to grab some memory, and put together a FIN,
2107 * and then put it into the queue to be sent.
2108 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
2110 if (!(how & SEND_SHUTDOWN))
2113 /* If we've already sent a FIN, or it's a closed state, skip this. */
2114 if ((1 << sk->sk_state) &
2115 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
2116 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
2117 /* Clear out any half completed packets. FIN if needed. */
2118 if (tcp_close_state(sk))
2122 EXPORT_SYMBOL(tcp_shutdown);
2124 bool tcp_check_oom(struct sock *sk, int shift)
2126 bool too_many_orphans, out_of_socket_memory;
2128 too_many_orphans = tcp_too_many_orphans(sk, shift);
2129 out_of_socket_memory = tcp_out_of_memory(sk);
2131 if (too_many_orphans)
2132 net_info_ratelimited("too many orphaned sockets\n");
2133 if (out_of_socket_memory)
2134 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2135 return too_many_orphans || out_of_socket_memory;
2138 void tcp_close(struct sock *sk, long timeout)
2140 struct sk_buff *skb;
2141 int data_was_unread = 0;
2145 sk->sk_shutdown = SHUTDOWN_MASK;
2147 if (sk->sk_state == TCP_LISTEN) {
2148 tcp_set_state(sk, TCP_CLOSE);
2151 inet_csk_listen_stop(sk);
2153 goto adjudge_to_death;
2156 /* We need to flush the recv. buffs. We do this only on the
2157 * descriptor close, not protocol-sourced closes, because the
2158 * reader process may not have drained the data yet!
2160 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
2161 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
2163 data_was_unread += len;
2169 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2170 if (sk->sk_state == TCP_CLOSE)
2171 goto adjudge_to_death;
2173 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2174 * data was lost. To witness the awful effects of the old behavior of
2175 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2176 * GET in an FTP client, suspend the process, wait for the client to
2177 * advertise a zero window, then kill -9 the FTP client, wheee...
2178 * Note: timeout is always zero in such a case.
2180 if (unlikely(tcp_sk(sk)->repair)) {
2181 sk->sk_prot->disconnect(sk, 0);
2182 } else if (data_was_unread) {
2183 /* Unread data was tossed, zap the connection. */
2184 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
2185 tcp_set_state(sk, TCP_CLOSE);
2186 tcp_send_active_reset(sk, sk->sk_allocation);
2187 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
2188 /* Check zero linger _after_ checking for unread data. */
2189 sk->sk_prot->disconnect(sk, 0);
2190 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
2191 } else if (tcp_close_state(sk)) {
2192 /* We FIN if the application ate all the data before
2193 * zapping the connection.
2196 /* RED-PEN. Formally speaking, we have broken TCP state
2197 * machine. State transitions:
2199 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2200 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2201 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2203 * are legal only when FIN has been sent (i.e. in window),
2204 * rather than queued out of window. Purists blame.
2206 * F.e. "RFC state" is ESTABLISHED,
2207 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2209 * The visible declinations are that sometimes
2210 * we enter time-wait state, when it is not required really
2211 * (harmless), do not send active resets, when they are
2212 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2213 * they look as CLOSING or LAST_ACK for Linux)
2214 * Probably, I missed some more holelets.
2216 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2217 * in a single packet! (May consider it later but will
2218 * probably need API support or TCP_CORK SYN-ACK until
2219 * data is written and socket is closed.)
2224 sk_stream_wait_close(sk, timeout);
2227 state = sk->sk_state;
2231 /* It is the last release_sock in its life. It will remove backlog. */
2235 /* Now socket is owned by kernel and we acquire BH lock
2236 to finish close. No need to check for user refs.
2240 WARN_ON(sock_owned_by_user(sk));
2242 percpu_counter_inc(sk->sk_prot->orphan_count);
2244 /* Have we already been destroyed by a softirq or backlog? */
2245 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
2248 /* This is a (useful) BSD violating of the RFC. There is a
2249 * problem with TCP as specified in that the other end could
2250 * keep a socket open forever with no application left this end.
2251 * We use a 1 minute timeout (about the same as BSD) then kill
2252 * our end. If they send after that then tough - BUT: long enough
2253 * that we won't make the old 4*rto = almost no time - whoops
2256 * Nope, it was not mistake. It is really desired behaviour
2257 * f.e. on http servers, when such sockets are useless, but
2258 * consume significant resources. Let's do it with special
2259 * linger2 option. --ANK
2262 if (sk->sk_state == TCP_FIN_WAIT2) {
2263 struct tcp_sock *tp = tcp_sk(sk);
2264 if (tp->linger2 < 0) {
2265 tcp_set_state(sk, TCP_CLOSE);
2266 tcp_send_active_reset(sk, GFP_ATOMIC);
2267 NET_INC_STATS_BH(sock_net(sk),
2268 LINUX_MIB_TCPABORTONLINGER);
2270 const int tmo = tcp_fin_time(sk);
2272 if (tmo > TCP_TIMEWAIT_LEN) {
2273 inet_csk_reset_keepalive_timer(sk,
2274 tmo - TCP_TIMEWAIT_LEN);
2276 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2281 if (sk->sk_state != TCP_CLOSE) {
2283 if (tcp_check_oom(sk, 0)) {
2284 tcp_set_state(sk, TCP_CLOSE);
2285 tcp_send_active_reset(sk, GFP_ATOMIC);
2286 NET_INC_STATS_BH(sock_net(sk),
2287 LINUX_MIB_TCPABORTONMEMORY);
2291 if (sk->sk_state == TCP_CLOSE) {
2292 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
2293 /* We could get here with a non-NULL req if the socket is
2294 * aborted (e.g., closed with unread data) before 3WHS
2298 reqsk_fastopen_remove(sk, req, false);
2299 inet_csk_destroy_sock(sk);
2301 /* Otherwise, socket is reprieved until protocol close. */
2308 EXPORT_SYMBOL(tcp_close);
2310 /* These states need RST on ABORT according to RFC793 */
2312 static inline bool tcp_need_reset(int state)
2314 return (1 << state) &
2315 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2316 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2319 int tcp_disconnect(struct sock *sk, int flags)
2321 struct inet_sock *inet = inet_sk(sk);
2322 struct inet_connection_sock *icsk = inet_csk(sk);
2323 struct tcp_sock *tp = tcp_sk(sk);
2325 int old_state = sk->sk_state;
2327 if (old_state != TCP_CLOSE)
2328 tcp_set_state(sk, TCP_CLOSE);
2330 /* ABORT function of RFC793 */
2331 if (old_state == TCP_LISTEN) {
2332 inet_csk_listen_stop(sk);
2333 } else if (unlikely(tp->repair)) {
2334 sk->sk_err = ECONNABORTED;
2335 } else if (tcp_need_reset(old_state) ||
2336 (tp->snd_nxt != tp->write_seq &&
2337 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2338 /* The last check adjusts for discrepancy of Linux wrt. RFC
2341 tcp_send_active_reset(sk, gfp_any());
2342 sk->sk_err = ECONNRESET;
2343 } else if (old_state == TCP_SYN_SENT)
2344 sk->sk_err = ECONNRESET;
2346 tcp_clear_xmit_timers(sk);
2347 __skb_queue_purge(&sk->sk_receive_queue);
2348 tcp_write_queue_purge(sk);
2349 __skb_queue_purge(&tp->out_of_order_queue);
2350 #ifdef CONFIG_NET_DMA
2351 __skb_queue_purge(&sk->sk_async_wait_queue);
2354 inet->inet_dport = 0;
2356 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2357 inet_reset_saddr(sk);
2359 sk->sk_shutdown = 0;
2360 sock_reset_flag(sk, SOCK_DONE);
2362 if ((tp->write_seq += tp->max_window + 2) == 0)
2364 icsk->icsk_backoff = 0;
2366 icsk->icsk_probes_out = 0;
2367 tp->packets_out = 0;
2368 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2369 tp->snd_cwnd_cnt = 0;
2370 tp->window_clamp = 0;
2371 tcp_set_ca_state(sk, TCP_CA_Open);
2372 tcp_clear_retrans(tp);
2373 inet_csk_delack_init(sk);
2374 tcp_init_send_head(sk);
2375 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2378 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2380 sk->sk_error_report(sk);
2383 EXPORT_SYMBOL(tcp_disconnect);
2385 void tcp_sock_destruct(struct sock *sk)
2387 inet_sock_destruct(sk);
2389 kfree(inet_csk(sk)->icsk_accept_queue.fastopenq);
2392 static inline bool tcp_can_repair_sock(const struct sock *sk)
2394 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2395 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED));
2398 static int tcp_repair_options_est(struct tcp_sock *tp,
2399 struct tcp_repair_opt __user *optbuf, unsigned int len)
2401 struct tcp_repair_opt opt;
2403 while (len >= sizeof(opt)) {
2404 if (copy_from_user(&opt, optbuf, sizeof(opt)))
2410 switch (opt.opt_code) {
2412 tp->rx_opt.mss_clamp = opt.opt_val;
2416 u16 snd_wscale = opt.opt_val & 0xFFFF;
2417 u16 rcv_wscale = opt.opt_val >> 16;
2419 if (snd_wscale > 14 || rcv_wscale > 14)
2422 tp->rx_opt.snd_wscale = snd_wscale;
2423 tp->rx_opt.rcv_wscale = rcv_wscale;
2424 tp->rx_opt.wscale_ok = 1;
2427 case TCPOPT_SACK_PERM:
2428 if (opt.opt_val != 0)
2431 tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
2432 if (sysctl_tcp_fack)
2433 tcp_enable_fack(tp);
2435 case TCPOPT_TIMESTAMP:
2436 if (opt.opt_val != 0)
2439 tp->rx_opt.tstamp_ok = 1;
2448 * Socket option code for TCP.
2450 static int do_tcp_setsockopt(struct sock *sk, int level,
2451 int optname, char __user *optval, unsigned int optlen)
2453 struct tcp_sock *tp = tcp_sk(sk);
2454 struct inet_connection_sock *icsk = inet_csk(sk);
2458 /* These are data/string values, all the others are ints */
2460 case TCP_CONGESTION: {
2461 char name[TCP_CA_NAME_MAX];
2466 val = strncpy_from_user(name, optval,
2467 min_t(long, TCP_CA_NAME_MAX-1, optlen));
2473 err = tcp_set_congestion_control(sk, name);
2482 if (optlen < sizeof(int))
2485 if (get_user(val, (int __user *)optval))
2492 /* Values greater than interface MTU won't take effect. However
2493 * at the point when this call is done we typically don't yet
2494 * know which interface is going to be used */
2495 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
2499 tp->rx_opt.user_mss = val;
2504 /* TCP_NODELAY is weaker than TCP_CORK, so that
2505 * this option on corked socket is remembered, but
2506 * it is not activated until cork is cleared.
2508 * However, when TCP_NODELAY is set we make
2509 * an explicit push, which overrides even TCP_CORK
2510 * for currently queued segments.
2512 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2513 tcp_push_pending_frames(sk);
2515 tp->nonagle &= ~TCP_NAGLE_OFF;
2519 case TCP_THIN_LINEAR_TIMEOUTS:
2520 if (val < 0 || val > 1)
2526 case TCP_THIN_DUPACK:
2527 if (val < 0 || val > 1)
2530 tp->thin_dupack = val;
2531 if (tp->thin_dupack)
2532 tcp_disable_early_retrans(tp);
2537 if (!tcp_can_repair_sock(sk))
2539 else if (val == 1) {
2541 sk->sk_reuse = SK_FORCE_REUSE;
2542 tp->repair_queue = TCP_NO_QUEUE;
2543 } else if (val == 0) {
2545 sk->sk_reuse = SK_NO_REUSE;
2546 tcp_send_window_probe(sk);
2552 case TCP_REPAIR_QUEUE:
2555 else if (val < TCP_QUEUES_NR)
2556 tp->repair_queue = val;
2562 if (sk->sk_state != TCP_CLOSE)
2564 else if (tp->repair_queue == TCP_SEND_QUEUE)
2565 tp->write_seq = val;
2566 else if (tp->repair_queue == TCP_RECV_QUEUE)
2572 case TCP_REPAIR_OPTIONS:
2575 else if (sk->sk_state == TCP_ESTABLISHED)
2576 err = tcp_repair_options_est(tp,
2577 (struct tcp_repair_opt __user *)optval,
2584 /* When set indicates to always queue non-full frames.
2585 * Later the user clears this option and we transmit
2586 * any pending partial frames in the queue. This is
2587 * meant to be used alongside sendfile() to get properly
2588 * filled frames when the user (for example) must write
2589 * out headers with a write() call first and then use
2590 * sendfile to send out the data parts.
2592 * TCP_CORK can be set together with TCP_NODELAY and it is
2593 * stronger than TCP_NODELAY.
2596 tp->nonagle |= TCP_NAGLE_CORK;
2598 tp->nonagle &= ~TCP_NAGLE_CORK;
2599 if (tp->nonagle&TCP_NAGLE_OFF)
2600 tp->nonagle |= TCP_NAGLE_PUSH;
2601 tcp_push_pending_frames(sk);
2606 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2609 tp->keepalive_time = val * HZ;
2610 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2611 !((1 << sk->sk_state) &
2612 (TCPF_CLOSE | TCPF_LISTEN))) {
2613 u32 elapsed = keepalive_time_elapsed(tp);
2614 if (tp->keepalive_time > elapsed)
2615 elapsed = tp->keepalive_time - elapsed;
2618 inet_csk_reset_keepalive_timer(sk, elapsed);
2623 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2626 tp->keepalive_intvl = val * HZ;
2629 if (val < 1 || val > MAX_TCP_KEEPCNT)
2632 tp->keepalive_probes = val;
2635 if (val < 1 || val > MAX_TCP_SYNCNT)
2638 icsk->icsk_syn_retries = val;
2644 else if (val > sysctl_tcp_fin_timeout / HZ)
2647 tp->linger2 = val * HZ;
2650 case TCP_DEFER_ACCEPT:
2651 /* Translate value in seconds to number of retransmits */
2652 icsk->icsk_accept_queue.rskq_defer_accept =
2653 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2657 case TCP_WINDOW_CLAMP:
2659 if (sk->sk_state != TCP_CLOSE) {
2663 tp->window_clamp = 0;
2665 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2666 SOCK_MIN_RCVBUF / 2 : val;
2671 icsk->icsk_ack.pingpong = 1;
2673 icsk->icsk_ack.pingpong = 0;
2674 if ((1 << sk->sk_state) &
2675 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2676 inet_csk_ack_scheduled(sk)) {
2677 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2678 tcp_cleanup_rbuf(sk, 1);
2680 icsk->icsk_ack.pingpong = 1;
2685 #ifdef CONFIG_TCP_MD5SIG
2687 /* Read the IP->Key mappings from userspace */
2688 err = tp->af_specific->md5_parse(sk, optval, optlen);
2691 case TCP_USER_TIMEOUT:
2692 /* Cap the max timeout in ms TCP will retry/retrans
2693 * before giving up and aborting (ETIMEDOUT) a connection.
2698 icsk->icsk_user_timeout = msecs_to_jiffies(val);
2702 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2704 err = fastopen_init_queue(sk, val);
2712 tp->tsoffset = val - tcp_time_stamp;
2714 case TCP_NOTSENT_LOWAT:
2715 tp->notsent_lowat = val;
2716 sk->sk_write_space(sk);
2727 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2728 unsigned int optlen)
2730 const struct inet_connection_sock *icsk = inet_csk(sk);
2732 if (level != SOL_TCP)
2733 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2735 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2737 EXPORT_SYMBOL(tcp_setsockopt);
2739 #ifdef CONFIG_COMPAT
2740 int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2741 char __user *optval, unsigned int optlen)
2743 if (level != SOL_TCP)
2744 return inet_csk_compat_setsockopt(sk, level, optname,
2746 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2748 EXPORT_SYMBOL(compat_tcp_setsockopt);
2751 /* Return information about state of tcp endpoint in API format. */
2752 void tcp_get_info(const struct sock *sk, struct tcp_info *info)
2754 const struct tcp_sock *tp = tcp_sk(sk);
2755 const struct inet_connection_sock *icsk = inet_csk(sk);
2756 u32 now = tcp_time_stamp;
2758 memset(info, 0, sizeof(*info));
2760 info->tcpi_state = sk->sk_state;
2761 info->tcpi_ca_state = icsk->icsk_ca_state;
2762 info->tcpi_retransmits = icsk->icsk_retransmits;
2763 info->tcpi_probes = icsk->icsk_probes_out;
2764 info->tcpi_backoff = icsk->icsk_backoff;
2766 if (tp->rx_opt.tstamp_ok)
2767 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2768 if (tcp_is_sack(tp))
2769 info->tcpi_options |= TCPI_OPT_SACK;
2770 if (tp->rx_opt.wscale_ok) {
2771 info->tcpi_options |= TCPI_OPT_WSCALE;
2772 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2773 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2776 if (tp->ecn_flags & TCP_ECN_OK)
2777 info->tcpi_options |= TCPI_OPT_ECN;
2778 if (tp->ecn_flags & TCP_ECN_SEEN)
2779 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
2780 if (tp->syn_data_acked)
2781 info->tcpi_options |= TCPI_OPT_SYN_DATA;
2783 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2784 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2785 info->tcpi_snd_mss = tp->mss_cache;
2786 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2788 if (sk->sk_state == TCP_LISTEN) {
2789 info->tcpi_unacked = sk->sk_ack_backlog;
2790 info->tcpi_sacked = sk->sk_max_ack_backlog;
2792 info->tcpi_unacked = tp->packets_out;
2793 info->tcpi_sacked = tp->sacked_out;
2795 info->tcpi_lost = tp->lost_out;
2796 info->tcpi_retrans = tp->retrans_out;
2797 info->tcpi_fackets = tp->fackets_out;
2799 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2800 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2801 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2803 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2804 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2805 info->tcpi_rtt = tp->srtt_us >> 3;
2806 info->tcpi_rttvar = tp->mdev_us >> 2;
2807 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2808 info->tcpi_snd_cwnd = tp->snd_cwnd;
2809 info->tcpi_advmss = tp->advmss;
2810 info->tcpi_reordering = tp->reordering;
2812 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2813 info->tcpi_rcv_space = tp->rcvq_space.space;
2815 info->tcpi_total_retrans = tp->total_retrans;
2817 info->tcpi_pacing_rate = sk->sk_pacing_rate != ~0U ?
2818 sk->sk_pacing_rate : ~0ULL;
2819 info->tcpi_max_pacing_rate = sk->sk_max_pacing_rate != ~0U ?
2820 sk->sk_max_pacing_rate : ~0ULL;
2822 EXPORT_SYMBOL_GPL(tcp_get_info);
2824 static int do_tcp_getsockopt(struct sock *sk, int level,
2825 int optname, char __user *optval, int __user *optlen)
2827 struct inet_connection_sock *icsk = inet_csk(sk);
2828 struct tcp_sock *tp = tcp_sk(sk);
2831 if (get_user(len, optlen))
2834 len = min_t(unsigned int, len, sizeof(int));
2841 val = tp->mss_cache;
2842 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2843 val = tp->rx_opt.user_mss;
2845 val = tp->rx_opt.mss_clamp;
2848 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2851 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2854 val = keepalive_time_when(tp) / HZ;
2857 val = keepalive_intvl_when(tp) / HZ;
2860 val = keepalive_probes(tp);
2863 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2868 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2870 case TCP_DEFER_ACCEPT:
2871 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2872 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
2874 case TCP_WINDOW_CLAMP:
2875 val = tp->window_clamp;
2878 struct tcp_info info;
2880 if (get_user(len, optlen))
2883 tcp_get_info(sk, &info);
2885 len = min_t(unsigned int, len, sizeof(info));
2886 if (put_user(len, optlen))
2888 if (copy_to_user(optval, &info, len))
2893 val = !icsk->icsk_ack.pingpong;
2896 case TCP_CONGESTION:
2897 if (get_user(len, optlen))
2899 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2900 if (put_user(len, optlen))
2902 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2906 case TCP_THIN_LINEAR_TIMEOUTS:
2909 case TCP_THIN_DUPACK:
2910 val = tp->thin_dupack;
2917 case TCP_REPAIR_QUEUE:
2919 val = tp->repair_queue;
2925 if (tp->repair_queue == TCP_SEND_QUEUE)
2926 val = tp->write_seq;
2927 else if (tp->repair_queue == TCP_RECV_QUEUE)
2933 case TCP_USER_TIMEOUT:
2934 val = jiffies_to_msecs(icsk->icsk_user_timeout);
2938 if (icsk->icsk_accept_queue.fastopenq != NULL)
2939 val = icsk->icsk_accept_queue.fastopenq->max_qlen;
2945 val = tcp_time_stamp + tp->tsoffset;
2947 case TCP_NOTSENT_LOWAT:
2948 val = tp->notsent_lowat;
2951 return -ENOPROTOOPT;
2954 if (put_user(len, optlen))
2956 if (copy_to_user(optval, &val, len))
2961 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2964 struct inet_connection_sock *icsk = inet_csk(sk);
2966 if (level != SOL_TCP)
2967 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2969 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2971 EXPORT_SYMBOL(tcp_getsockopt);
2973 #ifdef CONFIG_COMPAT
2974 int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2975 char __user *optval, int __user *optlen)
2977 if (level != SOL_TCP)
2978 return inet_csk_compat_getsockopt(sk, level, optname,
2980 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2982 EXPORT_SYMBOL(compat_tcp_getsockopt);
2985 #ifdef CONFIG_TCP_MD5SIG
2986 static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool __read_mostly;
2987 static DEFINE_MUTEX(tcp_md5sig_mutex);
2989 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool)
2993 for_each_possible_cpu(cpu) {
2994 struct tcp_md5sig_pool *p = per_cpu_ptr(pool, cpu);
2996 if (p->md5_desc.tfm)
2997 crypto_free_hash(p->md5_desc.tfm);
3002 static void __tcp_alloc_md5sig_pool(void)
3005 struct tcp_md5sig_pool __percpu *pool;
3007 pool = alloc_percpu(struct tcp_md5sig_pool);
3011 for_each_possible_cpu(cpu) {
3012 struct crypto_hash *hash;
3014 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
3015 if (IS_ERR_OR_NULL(hash))
3018 per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash;
3020 /* before setting tcp_md5sig_pool, we must commit all writes
3021 * to memory. See ACCESS_ONCE() in tcp_get_md5sig_pool()
3024 tcp_md5sig_pool = pool;
3027 __tcp_free_md5sig_pool(pool);
3030 bool tcp_alloc_md5sig_pool(void)
3032 if (unlikely(!tcp_md5sig_pool)) {
3033 mutex_lock(&tcp_md5sig_mutex);
3035 if (!tcp_md5sig_pool)
3036 __tcp_alloc_md5sig_pool();
3038 mutex_unlock(&tcp_md5sig_mutex);
3040 return tcp_md5sig_pool != NULL;
3042 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
3046 * tcp_get_md5sig_pool - get md5sig_pool for this user
3048 * We use percpu structure, so if we succeed, we exit with preemption
3049 * and BH disabled, to make sure another thread or softirq handling
3050 * wont try to get same context.
3052 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
3054 struct tcp_md5sig_pool __percpu *p;
3057 p = ACCESS_ONCE(tcp_md5sig_pool);
3059 return __this_cpu_ptr(p);
3064 EXPORT_SYMBOL(tcp_get_md5sig_pool);
3066 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
3067 const struct tcphdr *th)
3069 struct scatterlist sg;
3073 /* We are not allowed to change tcphdr, make a local copy */
3074 memcpy(&hdr, th, sizeof(hdr));
3077 /* options aren't included in the hash */
3078 sg_init_one(&sg, &hdr, sizeof(hdr));
3079 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr));
3082 EXPORT_SYMBOL(tcp_md5_hash_header);
3084 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3085 const struct sk_buff *skb, unsigned int header_len)
3087 struct scatterlist sg;
3088 const struct tcphdr *tp = tcp_hdr(skb);
3089 struct hash_desc *desc = &hp->md5_desc;
3091 const unsigned int head_data_len = skb_headlen(skb) > header_len ?
3092 skb_headlen(skb) - header_len : 0;
3093 const struct skb_shared_info *shi = skb_shinfo(skb);
3094 struct sk_buff *frag_iter;
3096 sg_init_table(&sg, 1);
3098 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3099 if (crypto_hash_update(desc, &sg, head_data_len))
3102 for (i = 0; i < shi->nr_frags; ++i) {
3103 const struct skb_frag_struct *f = &shi->frags[i];
3104 unsigned int offset = f->page_offset;
3105 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
3107 sg_set_page(&sg, page, skb_frag_size(f),
3108 offset_in_page(offset));
3109 if (crypto_hash_update(desc, &sg, skb_frag_size(f)))
3113 skb_walk_frags(skb, frag_iter)
3114 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3119 EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3121 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3123 struct scatterlist sg;
3125 sg_init_one(&sg, key->key, key->keylen);
3126 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
3128 EXPORT_SYMBOL(tcp_md5_hash_key);
3132 void tcp_done(struct sock *sk)
3134 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
3136 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3137 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
3139 tcp_set_state(sk, TCP_CLOSE);
3140 tcp_clear_xmit_timers(sk);
3142 reqsk_fastopen_remove(sk, req, false);
3144 sk->sk_shutdown = SHUTDOWN_MASK;
3146 if (!sock_flag(sk, SOCK_DEAD))
3147 sk->sk_state_change(sk);
3149 inet_csk_destroy_sock(sk);
3151 EXPORT_SYMBOL_GPL(tcp_done);
3153 extern struct tcp_congestion_ops tcp_reno;
3155 static __initdata unsigned long thash_entries;
3156 static int __init set_thash_entries(char *str)
3163 ret = kstrtoul(str, 0, &thash_entries);
3169 __setup("thash_entries=", set_thash_entries);
3171 static void tcp_init_mem(void)
3173 unsigned long limit = nr_free_buffer_pages() / 8;
3174 limit = max(limit, 128UL);
3175 sysctl_tcp_mem[0] = limit / 4 * 3;
3176 sysctl_tcp_mem[1] = limit;
3177 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
3180 void __init tcp_init(void)
3182 struct sk_buff *skb = NULL;
3183 unsigned long limit;
3184 int max_rshare, max_wshare, cnt;
3187 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
3189 percpu_counter_init(&tcp_sockets_allocated, 0);
3190 percpu_counter_init(&tcp_orphan_count, 0);
3191 tcp_hashinfo.bind_bucket_cachep =
3192 kmem_cache_create("tcp_bind_bucket",
3193 sizeof(struct inet_bind_bucket), 0,
3194 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3196 /* Size and allocate the main established and bind bucket
3199 * The methodology is similar to that of the buffer cache.
3201 tcp_hashinfo.ehash =
3202 alloc_large_system_hash("TCP established",
3203 sizeof(struct inet_ehash_bucket),
3205 17, /* one slot per 128 KB of memory */
3208 &tcp_hashinfo.ehash_mask,
3210 thash_entries ? 0 : 512 * 1024);
3211 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3212 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
3214 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3215 panic("TCP: failed to alloc ehash_locks");
3216 tcp_hashinfo.bhash =
3217 alloc_large_system_hash("TCP bind",
3218 sizeof(struct inet_bind_hashbucket),
3219 tcp_hashinfo.ehash_mask + 1,
3220 17, /* one slot per 128 KB of memory */
3222 &tcp_hashinfo.bhash_size,
3226 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3227 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3228 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3229 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
3233 cnt = tcp_hashinfo.ehash_mask + 1;
3235 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3236 sysctl_tcp_max_orphans = cnt / 2;
3237 sysctl_max_syn_backlog = max(128, cnt / 256);
3240 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3241 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3242 max_wshare = min(4UL*1024*1024, limit);
3243 max_rshare = min(6UL*1024*1024, limit);
3245 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3246 sysctl_tcp_wmem[1] = 16*1024;
3247 sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3249 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3250 sysctl_tcp_rmem[1] = 87380;
3251 sysctl_tcp_rmem[2] = max(87380, max_rshare);
3253 pr_info("Hash tables configured (established %u bind %u)\n",
3254 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3258 tcp_register_congestion_control(&tcp_reno);