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>
283 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
285 int sysctl_tcp_min_tso_segs __read_mostly = 2;
287 struct percpu_counter tcp_orphan_count;
288 EXPORT_SYMBOL_GPL(tcp_orphan_count);
290 int sysctl_tcp_wmem[3] __read_mostly;
291 int sysctl_tcp_rmem[3] __read_mostly;
293 EXPORT_SYMBOL(sysctl_tcp_rmem);
294 EXPORT_SYMBOL(sysctl_tcp_wmem);
296 atomic_long_t tcp_memory_allocated; /* Current allocated memory. */
297 EXPORT_SYMBOL(tcp_memory_allocated);
300 * Current number of TCP sockets.
302 struct percpu_counter tcp_sockets_allocated;
303 EXPORT_SYMBOL(tcp_sockets_allocated);
308 struct tcp_splice_state {
309 struct pipe_inode_info *pipe;
315 * Pressure flag: try to collapse.
316 * Technical note: it is used by multiple contexts non atomically.
317 * All the __sk_mem_schedule() is of this nature: accounting
318 * is strict, actions are advisory and have some latency.
320 int tcp_memory_pressure __read_mostly;
321 EXPORT_SYMBOL(tcp_memory_pressure);
323 void tcp_enter_memory_pressure(struct sock *sk)
325 if (!tcp_memory_pressure) {
326 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
327 tcp_memory_pressure = 1;
330 EXPORT_SYMBOL(tcp_enter_memory_pressure);
332 /* Convert seconds to retransmits based on initial and max timeout */
333 static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
338 int period = timeout;
341 while (seconds > period && res < 255) {
344 if (timeout > rto_max)
352 /* Convert retransmits to seconds based on initial and max timeout */
353 static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
361 if (timeout > rto_max)
369 /* Address-family independent initialization for a tcp_sock.
371 * NOTE: A lot of things set to zero explicitly by call to
372 * sk_alloc() so need not be done here.
374 void tcp_init_sock(struct sock *sk)
376 struct inet_connection_sock *icsk = inet_csk(sk);
377 struct tcp_sock *tp = tcp_sk(sk);
379 skb_queue_head_init(&tp->out_of_order_queue);
380 tcp_init_xmit_timers(sk);
381 tcp_prequeue_init(tp);
382 INIT_LIST_HEAD(&tp->tsq_node);
384 icsk->icsk_rto = TCP_TIMEOUT_INIT;
385 tp->mdev = TCP_TIMEOUT_INIT;
387 /* So many TCP implementations out there (incorrectly) count the
388 * initial SYN frame in their delayed-ACK and congestion control
389 * algorithms that we must have the following bandaid to talk
390 * efficiently to them. -DaveM
392 tp->snd_cwnd = TCP_INIT_CWND;
394 /* See draft-stevens-tcpca-spec-01 for discussion of the
395 * initialization of these values.
397 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
398 tp->snd_cwnd_clamp = ~0;
399 tp->mss_cache = TCP_MSS_DEFAULT;
401 tp->reordering = sysctl_tcp_reordering;
402 tcp_enable_early_retrans(tp);
403 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
407 sk->sk_state = TCP_CLOSE;
409 sk->sk_write_space = sk_stream_write_space;
410 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
412 icsk->icsk_sync_mss = tcp_sync_mss;
414 /* Presumed zeroed, in order of appearance:
415 * cookie_in_always, cookie_out_never,
416 * s_data_constant, s_data_in, s_data_out
418 sk->sk_sndbuf = sysctl_tcp_wmem[1];
419 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
422 sock_update_memcg(sk);
423 sk_sockets_allocated_inc(sk);
426 EXPORT_SYMBOL(tcp_init_sock);
429 * Wait for a TCP event.
431 * Note that we don't need to lock the socket, as the upper poll layers
432 * take care of normal races (between the test and the event) and we don't
433 * go look at any of the socket buffers directly.
435 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
438 struct sock *sk = sock->sk;
439 const struct tcp_sock *tp = tcp_sk(sk);
441 sock_poll_wait(file, sk_sleep(sk), wait);
442 if (sk->sk_state == TCP_LISTEN)
443 return inet_csk_listen_poll(sk);
445 /* Socket is not locked. We are protected from async events
446 * by poll logic and correct handling of state changes
447 * made by other threads is impossible in any case.
453 * POLLHUP is certainly not done right. But poll() doesn't
454 * have a notion of HUP in just one direction, and for a
455 * socket the read side is more interesting.
457 * Some poll() documentation says that POLLHUP is incompatible
458 * with the POLLOUT/POLLWR flags, so somebody should check this
459 * all. But careful, it tends to be safer to return too many
460 * bits than too few, and you can easily break real applications
461 * if you don't tell them that something has hung up!
465 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
466 * our fs/select.c). It means that after we received EOF,
467 * poll always returns immediately, making impossible poll() on write()
468 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
469 * if and only if shutdown has been made in both directions.
470 * Actually, it is interesting to look how Solaris and DUX
471 * solve this dilemma. I would prefer, if POLLHUP were maskable,
472 * then we could set it on SND_SHUTDOWN. BTW examples given
473 * in Stevens' books assume exactly this behaviour, it explains
474 * why POLLHUP is incompatible with POLLOUT. --ANK
476 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
477 * blocking on fresh not-connected or disconnected socket. --ANK
479 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
481 if (sk->sk_shutdown & RCV_SHUTDOWN)
482 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
484 /* Connected or passive Fast Open socket? */
485 if (sk->sk_state != TCP_SYN_SENT &&
486 (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk != NULL)) {
487 int target = sock_rcvlowat(sk, 0, INT_MAX);
489 if (tp->urg_seq == tp->copied_seq &&
490 !sock_flag(sk, SOCK_URGINLINE) &&
494 /* Potential race condition. If read of tp below will
495 * escape above sk->sk_state, we can be illegally awaken
496 * in SYN_* states. */
497 if (tp->rcv_nxt - tp->copied_seq >= target)
498 mask |= POLLIN | POLLRDNORM;
500 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
501 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
502 mask |= POLLOUT | POLLWRNORM;
503 } else { /* send SIGIO later */
504 set_bit(SOCK_ASYNC_NOSPACE,
505 &sk->sk_socket->flags);
506 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
508 /* Race breaker. If space is freed after
509 * wspace test but before the flags are set,
510 * IO signal will be lost.
512 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
513 mask |= POLLOUT | POLLWRNORM;
516 mask |= POLLOUT | POLLWRNORM;
518 if (tp->urg_data & TCP_URG_VALID)
521 /* This barrier is coupled with smp_wmb() in tcp_reset() */
528 EXPORT_SYMBOL(tcp_poll);
530 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
532 struct tcp_sock *tp = tcp_sk(sk);
538 if (sk->sk_state == TCP_LISTEN)
541 slow = lock_sock_fast(sk);
542 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
544 else if (sock_flag(sk, SOCK_URGINLINE) ||
546 before(tp->urg_seq, tp->copied_seq) ||
547 !before(tp->urg_seq, tp->rcv_nxt)) {
549 answ = tp->rcv_nxt - tp->copied_seq;
551 /* Subtract 1, if FIN was received */
552 if (answ && sock_flag(sk, SOCK_DONE))
555 answ = tp->urg_seq - tp->copied_seq;
556 unlock_sock_fast(sk, slow);
559 answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
562 if (sk->sk_state == TCP_LISTEN)
565 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
568 answ = tp->write_seq - tp->snd_una;
571 if (sk->sk_state == TCP_LISTEN)
574 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
577 answ = tp->write_seq - tp->snd_nxt;
583 return put_user(answ, (int __user *)arg);
585 EXPORT_SYMBOL(tcp_ioctl);
587 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
589 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
590 tp->pushed_seq = tp->write_seq;
593 static inline bool forced_push(const struct tcp_sock *tp)
595 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
598 static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
600 struct tcp_sock *tp = tcp_sk(sk);
601 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
604 tcb->seq = tcb->end_seq = tp->write_seq;
605 tcb->tcp_flags = TCPHDR_ACK;
607 skb_header_release(skb);
608 tcp_add_write_queue_tail(sk, skb);
609 sk->sk_wmem_queued += skb->truesize;
610 sk_mem_charge(sk, skb->truesize);
611 if (tp->nonagle & TCP_NAGLE_PUSH)
612 tp->nonagle &= ~TCP_NAGLE_PUSH;
615 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
618 tp->snd_up = tp->write_seq;
621 static inline void tcp_push(struct sock *sk, int flags, int mss_now,
624 if (tcp_send_head(sk)) {
625 struct tcp_sock *tp = tcp_sk(sk);
627 if (!(flags & MSG_MORE) || forced_push(tp))
628 tcp_mark_push(tp, tcp_write_queue_tail(sk));
630 tcp_mark_urg(tp, flags);
631 __tcp_push_pending_frames(sk, mss_now,
632 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
636 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
637 unsigned int offset, size_t len)
639 struct tcp_splice_state *tss = rd_desc->arg.data;
642 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
645 rd_desc->count -= ret;
649 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
651 /* Store TCP splice context information in read_descriptor_t. */
652 read_descriptor_t rd_desc = {
657 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
661 * tcp_splice_read - splice data from TCP socket to a pipe
662 * @sock: socket to splice from
663 * @ppos: position (not valid)
664 * @pipe: pipe to splice to
665 * @len: number of bytes to splice
666 * @flags: splice modifier flags
669 * Will read pages from given socket and fill them into a pipe.
672 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
673 struct pipe_inode_info *pipe, size_t len,
676 struct sock *sk = sock->sk;
677 struct tcp_splice_state tss = {
686 sock_rps_record_flow(sk);
688 * We can't seek on a socket input
697 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
699 ret = __tcp_splice_read(sk, &tss);
705 if (sock_flag(sk, SOCK_DONE))
708 ret = sock_error(sk);
711 if (sk->sk_shutdown & RCV_SHUTDOWN)
713 if (sk->sk_state == TCP_CLOSE) {
715 * This occurs when user tries to read
716 * from never connected socket.
718 if (!sock_flag(sk, SOCK_DONE))
726 sk_wait_data(sk, &timeo);
727 if (signal_pending(current)) {
728 ret = sock_intr_errno(timeo);
741 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
742 (sk->sk_shutdown & RCV_SHUTDOWN) ||
743 signal_pending(current))
754 EXPORT_SYMBOL(tcp_splice_read);
756 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
760 /* The TCP header must be at least 32-bit aligned. */
761 size = ALIGN(size, 4);
763 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
765 if (sk_wmem_schedule(sk, skb->truesize)) {
766 skb_reserve(skb, sk->sk_prot->max_header);
768 * Make sure that we have exactly size bytes
769 * available to the caller, no more, no less.
771 skb->reserved_tailroom = skb->end - skb->tail - size;
776 sk->sk_prot->enter_memory_pressure(sk);
777 sk_stream_moderate_sndbuf(sk);
782 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
785 struct tcp_sock *tp = tcp_sk(sk);
786 u32 xmit_size_goal, old_size_goal;
788 xmit_size_goal = mss_now;
790 if (large_allowed && sk_can_gso(sk)) {
793 /* Maybe we should/could use sk->sk_prot->max_header here ? */
794 hlen = inet_csk(sk)->icsk_af_ops->net_header_len +
795 inet_csk(sk)->icsk_ext_hdr_len +
798 /* Goal is to send at least one packet per ms,
799 * not one big TSO packet every 100 ms.
800 * This preserves ACK clocking and is consistent
801 * with tcp_tso_should_defer() heuristic.
803 gso_size = sk->sk_pacing_rate / (2 * MSEC_PER_SEC);
804 gso_size = max_t(u32, gso_size,
805 sysctl_tcp_min_tso_segs * mss_now);
807 xmit_size_goal = min_t(u32, gso_size,
808 sk->sk_gso_max_size - 1 - hlen);
810 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
812 /* We try hard to avoid divides here */
813 old_size_goal = tp->xmit_size_goal_segs * mss_now;
815 if (likely(old_size_goal <= xmit_size_goal &&
816 old_size_goal + mss_now > xmit_size_goal)) {
817 xmit_size_goal = old_size_goal;
819 tp->xmit_size_goal_segs =
820 min_t(u16, xmit_size_goal / mss_now,
821 sk->sk_gso_max_segs);
822 xmit_size_goal = tp->xmit_size_goal_segs * mss_now;
826 return max(xmit_size_goal, mss_now);
829 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
833 mss_now = tcp_current_mss(sk);
834 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
839 static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
840 size_t size, int flags)
842 struct tcp_sock *tp = tcp_sk(sk);
843 int mss_now, size_goal;
846 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
848 /* Wait for a connection to finish. One exception is TCP Fast Open
849 * (passive side) where data is allowed to be sent before a connection
850 * is fully established.
852 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
853 !tcp_passive_fastopen(sk)) {
854 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
858 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
860 mss_now = tcp_send_mss(sk, &size_goal, flags);
864 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
868 struct sk_buff *skb = tcp_write_queue_tail(sk);
872 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
874 if (!sk_stream_memory_free(sk))
875 goto wait_for_sndbuf;
877 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
879 goto wait_for_memory;
888 i = skb_shinfo(skb)->nr_frags;
889 can_coalesce = skb_can_coalesce(skb, i, page, offset);
890 if (!can_coalesce && i >= MAX_SKB_FRAGS) {
891 tcp_mark_push(tp, skb);
894 if (!sk_wmem_schedule(sk, copy))
895 goto wait_for_memory;
898 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
901 skb_fill_page_desc(skb, i, page, offset, copy);
903 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
906 skb->data_len += copy;
907 skb->truesize += copy;
908 sk->sk_wmem_queued += copy;
909 sk_mem_charge(sk, copy);
910 skb->ip_summed = CHECKSUM_PARTIAL;
911 tp->write_seq += copy;
912 TCP_SKB_CB(skb)->end_seq += copy;
913 skb_shinfo(skb)->gso_segs = 0;
916 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
923 if (skb->len < size_goal || (flags & MSG_OOB))
926 if (forced_push(tp)) {
927 tcp_mark_push(tp, skb);
928 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
929 } else if (skb == tcp_send_head(sk))
930 tcp_push_one(sk, mss_now);
934 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
936 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
938 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
941 mss_now = tcp_send_mss(sk, &size_goal, flags);
945 if (copied && !(flags & MSG_SENDPAGE_NOTLAST))
946 tcp_push(sk, flags, mss_now, tp->nonagle);
953 return sk_stream_error(sk, flags, err);
956 int tcp_sendpage(struct sock *sk, struct page *page, int offset,
957 size_t size, int flags)
961 if (!(sk->sk_route_caps & NETIF_F_SG) ||
962 !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
963 return sock_no_sendpage(sk->sk_socket, page, offset, size,
967 res = do_tcp_sendpages(sk, page, offset, size, flags);
971 EXPORT_SYMBOL(tcp_sendpage);
973 static inline int select_size(const struct sock *sk, bool sg)
975 const struct tcp_sock *tp = tcp_sk(sk);
976 int tmp = tp->mss_cache;
979 if (sk_can_gso(sk)) {
980 /* Small frames wont use a full page:
981 * Payload will immediately follow tcp header.
983 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
985 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
987 if (tmp >= pgbreak &&
988 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
996 void tcp_free_fastopen_req(struct tcp_sock *tp)
998 if (tp->fastopen_req != NULL) {
999 kfree(tp->fastopen_req);
1000 tp->fastopen_req = NULL;
1004 static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
1005 int *copied, size_t size)
1007 struct tcp_sock *tp = tcp_sk(sk);
1010 if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE))
1012 if (tp->fastopen_req != NULL)
1013 return -EALREADY; /* Another Fast Open is in progress */
1015 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
1017 if (unlikely(tp->fastopen_req == NULL))
1019 tp->fastopen_req->data = msg;
1020 tp->fastopen_req->size = size;
1022 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1023 err = __inet_stream_connect(sk->sk_socket, msg->msg_name,
1024 msg->msg_namelen, flags);
1025 *copied = tp->fastopen_req->copied;
1026 tcp_free_fastopen_req(tp);
1030 int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1034 struct tcp_sock *tp = tcp_sk(sk);
1035 struct sk_buff *skb;
1036 int iovlen, flags, err, copied = 0;
1037 int mss_now = 0, size_goal, copied_syn = 0, offset = 0;
1043 flags = msg->msg_flags;
1044 if (flags & MSG_FASTOPEN) {
1045 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1046 if (err == -EINPROGRESS && copied_syn > 0)
1050 offset = copied_syn;
1053 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1055 /* Wait for a connection to finish. One exception is TCP Fast Open
1056 * (passive side) where data is allowed to be sent before a connection
1057 * is fully established.
1059 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
1060 !tcp_passive_fastopen(sk)) {
1061 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
1065 if (unlikely(tp->repair)) {
1066 if (tp->repair_queue == TCP_RECV_QUEUE) {
1067 copied = tcp_send_rcvq(sk, msg, size);
1072 if (tp->repair_queue == TCP_NO_QUEUE)
1075 /* 'common' sending to sendq */
1078 /* This should be in poll */
1079 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1081 mss_now = tcp_send_mss(sk, &size_goal, flags);
1083 /* Ok commence sending. */
1084 iovlen = msg->msg_iovlen;
1089 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1092 sg = !!(sk->sk_route_caps & NETIF_F_SG);
1094 while (--iovlen >= 0) {
1095 size_t seglen = iov->iov_len;
1096 unsigned char __user *from = iov->iov_base;
1099 if (unlikely(offset > 0)) { /* Skip bytes copied in SYN */
1100 if (offset >= seglen) {
1109 while (seglen > 0) {
1111 int max = size_goal;
1113 skb = tcp_write_queue_tail(sk);
1114 if (tcp_send_head(sk)) {
1115 if (skb->ip_summed == CHECKSUM_NONE)
1117 copy = max - skb->len;
1122 /* Allocate new segment. If the interface is SG,
1123 * allocate skb fitting to single page.
1125 if (!sk_stream_memory_free(sk))
1126 goto wait_for_sndbuf;
1128 skb = sk_stream_alloc_skb(sk,
1129 select_size(sk, sg),
1132 goto wait_for_memory;
1135 * All packets are restored as if they have
1136 * already been sent.
1139 TCP_SKB_CB(skb)->when = tcp_time_stamp;
1142 * Check whether we can use HW checksum.
1144 if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
1145 skb->ip_summed = CHECKSUM_PARTIAL;
1147 skb_entail(sk, skb);
1152 /* Try to append data to the end of skb. */
1156 /* Where to copy to? */
1157 if (skb_availroom(skb) > 0) {
1158 /* We have some space in skb head. Superb! */
1159 copy = min_t(int, copy, skb_availroom(skb));
1160 err = skb_add_data_nocache(sk, skb, from, copy);
1165 int i = skb_shinfo(skb)->nr_frags;
1166 struct page_frag *pfrag = sk_page_frag(sk);
1168 if (!sk_page_frag_refill(sk, pfrag))
1169 goto wait_for_memory;
1171 if (!skb_can_coalesce(skb, i, pfrag->page,
1173 if (i == MAX_SKB_FRAGS || !sg) {
1174 tcp_mark_push(tp, skb);
1180 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1182 if (!sk_wmem_schedule(sk, copy))
1183 goto wait_for_memory;
1185 err = skb_copy_to_page_nocache(sk, from, skb,
1192 /* Update the skb. */
1194 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1196 skb_fill_page_desc(skb, i, pfrag->page,
1197 pfrag->offset, copy);
1198 get_page(pfrag->page);
1200 pfrag->offset += copy;
1204 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1206 tp->write_seq += copy;
1207 TCP_SKB_CB(skb)->end_seq += copy;
1208 skb_shinfo(skb)->gso_segs = 0;
1212 if ((seglen -= copy) == 0 && iovlen == 0)
1215 if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
1218 if (forced_push(tp)) {
1219 tcp_mark_push(tp, skb);
1220 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1221 } else if (skb == tcp_send_head(sk))
1222 tcp_push_one(sk, mss_now);
1226 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1229 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
1231 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
1234 mss_now = tcp_send_mss(sk, &size_goal, flags);
1240 tcp_push(sk, flags, mss_now, tp->nonagle);
1243 return copied + copied_syn;
1247 tcp_unlink_write_queue(skb, sk);
1248 /* It is the one place in all of TCP, except connection
1249 * reset, where we can be unlinking the send_head.
1251 tcp_check_send_head(sk, skb);
1252 sk_wmem_free_skb(sk, skb);
1256 if (copied + copied_syn)
1259 err = sk_stream_error(sk, flags, err);
1263 EXPORT_SYMBOL(tcp_sendmsg);
1266 * Handle reading urgent data. BSD has very simple semantics for
1267 * this, no blocking and very strange errors 8)
1270 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1272 struct tcp_sock *tp = tcp_sk(sk);
1274 /* No URG data to read. */
1275 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1276 tp->urg_data == TCP_URG_READ)
1277 return -EINVAL; /* Yes this is right ! */
1279 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1282 if (tp->urg_data & TCP_URG_VALID) {
1284 char c = tp->urg_data;
1286 if (!(flags & MSG_PEEK))
1287 tp->urg_data = TCP_URG_READ;
1289 /* Read urgent data. */
1290 msg->msg_flags |= MSG_OOB;
1293 if (!(flags & MSG_TRUNC))
1294 err = memcpy_toiovec(msg->msg_iov, &c, 1);
1297 msg->msg_flags |= MSG_TRUNC;
1299 return err ? -EFAULT : len;
1302 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1305 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1306 * the available implementations agree in this case:
1307 * this call should never block, independent of the
1308 * blocking state of the socket.
1309 * Mike <pall@rz.uni-karlsruhe.de>
1314 static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
1316 struct sk_buff *skb;
1317 int copied = 0, err = 0;
1319 /* XXX -- need to support SO_PEEK_OFF */
1321 skb_queue_walk(&sk->sk_write_queue, skb) {
1322 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, skb->len);
1329 return err ?: copied;
1332 /* Clean up the receive buffer for full frames taken by the user,
1333 * then send an ACK if necessary. COPIED is the number of bytes
1334 * tcp_recvmsg has given to the user so far, it speeds up the
1335 * calculation of whether or not we must ACK for the sake of
1338 void tcp_cleanup_rbuf(struct sock *sk, int copied)
1340 struct tcp_sock *tp = tcp_sk(sk);
1341 bool time_to_ack = false;
1343 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1345 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1346 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1347 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1349 if (inet_csk_ack_scheduled(sk)) {
1350 const struct inet_connection_sock *icsk = inet_csk(sk);
1351 /* Delayed ACKs frequently hit locked sockets during bulk
1353 if (icsk->icsk_ack.blocked ||
1354 /* Once-per-two-segments ACK was not sent by tcp_input.c */
1355 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1357 * If this read emptied read buffer, we send ACK, if
1358 * connection is not bidirectional, user drained
1359 * receive buffer and there was a small segment
1363 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1364 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1365 !icsk->icsk_ack.pingpong)) &&
1366 !atomic_read(&sk->sk_rmem_alloc)))
1370 /* We send an ACK if we can now advertise a non-zero window
1371 * which has been raised "significantly".
1373 * Even if window raised up to infinity, do not send window open ACK
1374 * in states, where we will not receive more. It is useless.
1376 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1377 __u32 rcv_window_now = tcp_receive_window(tp);
1379 /* Optimize, __tcp_select_window() is not cheap. */
1380 if (2*rcv_window_now <= tp->window_clamp) {
1381 __u32 new_window = __tcp_select_window(sk);
1383 /* Send ACK now, if this read freed lots of space
1384 * in our buffer. Certainly, new_window is new window.
1385 * We can advertise it now, if it is not less than current one.
1386 * "Lots" means "at least twice" here.
1388 if (new_window && new_window >= 2 * rcv_window_now)
1396 static void tcp_prequeue_process(struct sock *sk)
1398 struct sk_buff *skb;
1399 struct tcp_sock *tp = tcp_sk(sk);
1401 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
1403 /* RX process wants to run with disabled BHs, though it is not
1406 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
1407 sk_backlog_rcv(sk, skb);
1410 /* Clear memory counter. */
1411 tp->ucopy.memory = 0;
1414 #ifdef CONFIG_NET_DMA
1415 static void tcp_service_net_dma(struct sock *sk, bool wait)
1417 dma_cookie_t done, used;
1418 dma_cookie_t last_issued;
1419 struct tcp_sock *tp = tcp_sk(sk);
1421 if (!tp->ucopy.dma_chan)
1424 last_issued = tp->ucopy.dma_cookie;
1425 dma_async_issue_pending(tp->ucopy.dma_chan);
1428 if (dma_async_is_tx_complete(tp->ucopy.dma_chan,
1430 &used) == DMA_SUCCESS) {
1431 /* Safe to free early-copied skbs now */
1432 __skb_queue_purge(&sk->sk_async_wait_queue);
1435 struct sk_buff *skb;
1436 while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
1437 (dma_async_is_complete(skb->dma_cookie, done,
1438 used) == DMA_SUCCESS)) {
1439 __skb_dequeue(&sk->sk_async_wait_queue);
1447 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1449 struct sk_buff *skb;
1452 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1453 offset = seq - TCP_SKB_CB(skb)->seq;
1454 if (tcp_hdr(skb)->syn)
1456 if (offset < skb->len || tcp_hdr(skb)->fin) {
1460 /* This looks weird, but this can happen if TCP collapsing
1461 * splitted a fat GRO packet, while we released socket lock
1462 * in skb_splice_bits()
1464 sk_eat_skb(sk, skb, false);
1470 * This routine provides an alternative to tcp_recvmsg() for routines
1471 * that would like to handle copying from skbuffs directly in 'sendfile'
1474 * - It is assumed that the socket was locked by the caller.
1475 * - The routine does not block.
1476 * - At present, there is no support for reading OOB data
1477 * or for 'peeking' the socket using this routine
1478 * (although both would be easy to implement).
1480 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1481 sk_read_actor_t recv_actor)
1483 struct sk_buff *skb;
1484 struct tcp_sock *tp = tcp_sk(sk);
1485 u32 seq = tp->copied_seq;
1489 if (sk->sk_state == TCP_LISTEN)
1491 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1492 if (offset < skb->len) {
1496 len = skb->len - offset;
1497 /* Stop reading if we hit a patch of urgent data */
1499 u32 urg_offset = tp->urg_seq - seq;
1500 if (urg_offset < len)
1505 used = recv_actor(desc, skb, offset, len);
1510 } else if (used <= len) {
1515 /* If recv_actor drops the lock (e.g. TCP splice
1516 * receive) the skb pointer might be invalid when
1517 * getting here: tcp_collapse might have deleted it
1518 * while aggregating skbs from the socket queue.
1520 skb = tcp_recv_skb(sk, seq - 1, &offset);
1523 /* TCP coalescing might have appended data to the skb.
1524 * Try to splice more frags
1526 if (offset + 1 != skb->len)
1529 if (tcp_hdr(skb)->fin) {
1530 sk_eat_skb(sk, skb, false);
1534 sk_eat_skb(sk, skb, false);
1537 tp->copied_seq = seq;
1539 tp->copied_seq = seq;
1541 tcp_rcv_space_adjust(sk);
1543 /* Clean up data we have read: This will do ACK frames. */
1545 tcp_recv_skb(sk, seq, &offset);
1546 tcp_cleanup_rbuf(sk, copied);
1550 EXPORT_SYMBOL(tcp_read_sock);
1553 * This routine copies from a sock struct into the user buffer.
1555 * Technical note: in 2.3 we work on _locked_ socket, so that
1556 * tricks with *seq access order and skb->users are not required.
1557 * Probably, code can be easily improved even more.
1560 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1561 size_t len, int nonblock, int flags, int *addr_len)
1563 struct tcp_sock *tp = tcp_sk(sk);
1569 int target; /* Read at least this many bytes */
1571 struct task_struct *user_recv = NULL;
1572 bool copied_early = false;
1573 struct sk_buff *skb;
1579 if (sk->sk_state == TCP_LISTEN)
1582 timeo = sock_rcvtimeo(sk, nonblock);
1584 /* Urgent data needs to be handled specially. */
1585 if (flags & MSG_OOB)
1588 if (unlikely(tp->repair)) {
1590 if (!(flags & MSG_PEEK))
1593 if (tp->repair_queue == TCP_SEND_QUEUE)
1597 if (tp->repair_queue == TCP_NO_QUEUE)
1600 /* 'common' recv queue MSG_PEEK-ing */
1603 seq = &tp->copied_seq;
1604 if (flags & MSG_PEEK) {
1605 peek_seq = tp->copied_seq;
1609 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
1611 #ifdef CONFIG_NET_DMA
1612 tp->ucopy.dma_chan = NULL;
1614 skb = skb_peek_tail(&sk->sk_receive_queue);
1619 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
1620 if ((available < target) &&
1621 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
1622 !sysctl_tcp_low_latency &&
1623 net_dma_find_channel()) {
1624 preempt_enable_no_resched();
1625 tp->ucopy.pinned_list =
1626 dma_pin_iovec_pages(msg->msg_iov, len);
1628 preempt_enable_no_resched();
1636 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
1637 if (tp->urg_data && tp->urg_seq == *seq) {
1640 if (signal_pending(current)) {
1641 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
1646 /* Next get a buffer. */
1648 skb_queue_walk(&sk->sk_receive_queue, skb) {
1649 /* Now that we have two receive queues this
1652 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1653 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
1654 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
1658 offset = *seq - TCP_SKB_CB(skb)->seq;
1659 if (tcp_hdr(skb)->syn)
1661 if (offset < skb->len)
1663 if (tcp_hdr(skb)->fin)
1665 WARN(!(flags & MSG_PEEK),
1666 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
1667 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
1670 /* Well, if we have backlog, try to process it now yet. */
1672 if (copied >= target && !sk->sk_backlog.tail)
1677 sk->sk_state == TCP_CLOSE ||
1678 (sk->sk_shutdown & RCV_SHUTDOWN) ||
1680 signal_pending(current))
1683 if (sock_flag(sk, SOCK_DONE))
1687 copied = sock_error(sk);
1691 if (sk->sk_shutdown & RCV_SHUTDOWN)
1694 if (sk->sk_state == TCP_CLOSE) {
1695 if (!sock_flag(sk, SOCK_DONE)) {
1696 /* This occurs when user tries to read
1697 * from never connected socket.
1710 if (signal_pending(current)) {
1711 copied = sock_intr_errno(timeo);
1716 tcp_cleanup_rbuf(sk, copied);
1718 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
1719 /* Install new reader */
1720 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
1721 user_recv = current;
1722 tp->ucopy.task = user_recv;
1723 tp->ucopy.iov = msg->msg_iov;
1726 tp->ucopy.len = len;
1728 WARN_ON(tp->copied_seq != tp->rcv_nxt &&
1729 !(flags & (MSG_PEEK | MSG_TRUNC)));
1731 /* Ugly... If prequeue is not empty, we have to
1732 * process it before releasing socket, otherwise
1733 * order will be broken at second iteration.
1734 * More elegant solution is required!!!
1736 * Look: we have the following (pseudo)queues:
1738 * 1. packets in flight
1743 * Each queue can be processed only if the next ones
1744 * are empty. At this point we have empty receive_queue.
1745 * But prequeue _can_ be not empty after 2nd iteration,
1746 * when we jumped to start of loop because backlog
1747 * processing added something to receive_queue.
1748 * We cannot release_sock(), because backlog contains
1749 * packets arrived _after_ prequeued ones.
1751 * Shortly, algorithm is clear --- to process all
1752 * the queues in order. We could make it more directly,
1753 * requeueing packets from backlog to prequeue, if
1754 * is not empty. It is more elegant, but eats cycles,
1757 if (!skb_queue_empty(&tp->ucopy.prequeue))
1760 /* __ Set realtime policy in scheduler __ */
1763 #ifdef CONFIG_NET_DMA
1764 if (tp->ucopy.dma_chan) {
1765 if (tp->rcv_wnd == 0 &&
1766 !skb_queue_empty(&sk->sk_async_wait_queue)) {
1767 tcp_service_net_dma(sk, true);
1768 tcp_cleanup_rbuf(sk, copied);
1770 dma_async_issue_pending(tp->ucopy.dma_chan);
1773 if (copied >= target) {
1774 /* Do not sleep, just process backlog. */
1778 sk_wait_data(sk, &timeo);
1780 #ifdef CONFIG_NET_DMA
1781 tcp_service_net_dma(sk, false); /* Don't block */
1782 tp->ucopy.wakeup = 0;
1788 /* __ Restore normal policy in scheduler __ */
1790 if ((chunk = len - tp->ucopy.len) != 0) {
1791 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
1796 if (tp->rcv_nxt == tp->copied_seq &&
1797 !skb_queue_empty(&tp->ucopy.prequeue)) {
1799 tcp_prequeue_process(sk);
1801 if ((chunk = len - tp->ucopy.len) != 0) {
1802 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1808 if ((flags & MSG_PEEK) &&
1809 (peek_seq - copied - urg_hole != tp->copied_seq)) {
1810 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
1812 task_pid_nr(current));
1813 peek_seq = tp->copied_seq;
1818 /* Ok so how much can we use? */
1819 used = skb->len - offset;
1823 /* Do we have urgent data here? */
1825 u32 urg_offset = tp->urg_seq - *seq;
1826 if (urg_offset < used) {
1828 if (!sock_flag(sk, SOCK_URGINLINE)) {
1841 if (!(flags & MSG_TRUNC)) {
1842 #ifdef CONFIG_NET_DMA
1843 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1844 tp->ucopy.dma_chan = net_dma_find_channel();
1846 if (tp->ucopy.dma_chan) {
1847 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
1848 tp->ucopy.dma_chan, skb, offset,
1850 tp->ucopy.pinned_list);
1852 if (tp->ucopy.dma_cookie < 0) {
1854 pr_alert("%s: dma_cookie < 0\n",
1857 /* Exception. Bailout! */
1863 dma_async_issue_pending(tp->ucopy.dma_chan);
1865 if ((offset + used) == skb->len)
1866 copied_early = true;
1871 err = skb_copy_datagram_iovec(skb, offset,
1872 msg->msg_iov, used);
1874 /* Exception. Bailout! */
1886 tcp_rcv_space_adjust(sk);
1889 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
1891 tcp_fast_path_check(sk);
1893 if (used + offset < skb->len)
1896 if (tcp_hdr(skb)->fin)
1898 if (!(flags & MSG_PEEK)) {
1899 sk_eat_skb(sk, skb, copied_early);
1900 copied_early = false;
1905 /* Process the FIN. */
1907 if (!(flags & MSG_PEEK)) {
1908 sk_eat_skb(sk, skb, copied_early);
1909 copied_early = false;
1915 if (!skb_queue_empty(&tp->ucopy.prequeue)) {
1918 tp->ucopy.len = copied > 0 ? len : 0;
1920 tcp_prequeue_process(sk);
1922 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1923 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
1929 tp->ucopy.task = NULL;
1933 #ifdef CONFIG_NET_DMA
1934 tcp_service_net_dma(sk, true); /* Wait for queue to drain */
1935 tp->ucopy.dma_chan = NULL;
1937 if (tp->ucopy.pinned_list) {
1938 dma_unpin_iovec_pages(tp->ucopy.pinned_list);
1939 tp->ucopy.pinned_list = NULL;
1943 /* According to UNIX98, msg_name/msg_namelen are ignored
1944 * on connected socket. I was just happy when found this 8) --ANK
1947 /* Clean up data we have read: This will do ACK frames. */
1948 tcp_cleanup_rbuf(sk, copied);
1958 err = tcp_recv_urg(sk, msg, len, flags);
1962 err = tcp_peek_sndq(sk, msg, len);
1965 EXPORT_SYMBOL(tcp_recvmsg);
1967 void tcp_set_state(struct sock *sk, int state)
1969 int oldstate = sk->sk_state;
1972 case TCP_ESTABLISHED:
1973 if (oldstate != TCP_ESTABLISHED)
1974 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1978 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
1979 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
1981 sk->sk_prot->unhash(sk);
1982 if (inet_csk(sk)->icsk_bind_hash &&
1983 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1987 if (oldstate == TCP_ESTABLISHED)
1988 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
1991 /* Change state AFTER socket is unhashed to avoid closed
1992 * socket sitting in hash tables.
1994 sk->sk_state = state;
1997 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
2000 EXPORT_SYMBOL_GPL(tcp_set_state);
2003 * State processing on a close. This implements the state shift for
2004 * sending our FIN frame. Note that we only send a FIN for some
2005 * states. A shutdown() may have already sent the FIN, or we may be
2009 static const unsigned char new_state[16] = {
2010 /* current state: new state: action: */
2011 /* (Invalid) */ TCP_CLOSE,
2012 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2013 /* TCP_SYN_SENT */ TCP_CLOSE,
2014 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2015 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
2016 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
2017 /* TCP_TIME_WAIT */ TCP_CLOSE,
2018 /* TCP_CLOSE */ TCP_CLOSE,
2019 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
2020 /* TCP_LAST_ACK */ TCP_LAST_ACK,
2021 /* TCP_LISTEN */ TCP_CLOSE,
2022 /* TCP_CLOSING */ TCP_CLOSING,
2025 static int tcp_close_state(struct sock *sk)
2027 int next = (int)new_state[sk->sk_state];
2028 int ns = next & TCP_STATE_MASK;
2030 tcp_set_state(sk, ns);
2032 return next & TCP_ACTION_FIN;
2036 * Shutdown the sending side of a connection. Much like close except
2037 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
2040 void tcp_shutdown(struct sock *sk, int how)
2042 /* We need to grab some memory, and put together a FIN,
2043 * and then put it into the queue to be sent.
2044 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
2046 if (!(how & SEND_SHUTDOWN))
2049 /* If we've already sent a FIN, or it's a closed state, skip this. */
2050 if ((1 << sk->sk_state) &
2051 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
2052 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
2053 /* Clear out any half completed packets. FIN if needed. */
2054 if (tcp_close_state(sk))
2058 EXPORT_SYMBOL(tcp_shutdown);
2060 bool tcp_check_oom(struct sock *sk, int shift)
2062 bool too_many_orphans, out_of_socket_memory;
2064 too_many_orphans = tcp_too_many_orphans(sk, shift);
2065 out_of_socket_memory = tcp_out_of_memory(sk);
2067 if (too_many_orphans)
2068 net_info_ratelimited("too many orphaned sockets\n");
2069 if (out_of_socket_memory)
2070 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
2071 return too_many_orphans || out_of_socket_memory;
2074 void tcp_close(struct sock *sk, long timeout)
2076 struct sk_buff *skb;
2077 int data_was_unread = 0;
2081 sk->sk_shutdown = SHUTDOWN_MASK;
2083 if (sk->sk_state == TCP_LISTEN) {
2084 tcp_set_state(sk, TCP_CLOSE);
2087 inet_csk_listen_stop(sk);
2089 goto adjudge_to_death;
2092 /* We need to flush the recv. buffs. We do this only on the
2093 * descriptor close, not protocol-sourced closes, because the
2094 * reader process may not have drained the data yet!
2096 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
2097 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
2099 data_was_unread += len;
2105 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
2106 if (sk->sk_state == TCP_CLOSE)
2107 goto adjudge_to_death;
2109 /* As outlined in RFC 2525, section 2.17, we send a RST here because
2110 * data was lost. To witness the awful effects of the old behavior of
2111 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
2112 * GET in an FTP client, suspend the process, wait for the client to
2113 * advertise a zero window, then kill -9 the FTP client, wheee...
2114 * Note: timeout is always zero in such a case.
2116 if (unlikely(tcp_sk(sk)->repair)) {
2117 sk->sk_prot->disconnect(sk, 0);
2118 } else if (data_was_unread) {
2119 /* Unread data was tossed, zap the connection. */
2120 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
2121 tcp_set_state(sk, TCP_CLOSE);
2122 tcp_send_active_reset(sk, sk->sk_allocation);
2123 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
2124 /* Check zero linger _after_ checking for unread data. */
2125 sk->sk_prot->disconnect(sk, 0);
2126 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
2127 } else if (tcp_close_state(sk)) {
2128 /* We FIN if the application ate all the data before
2129 * zapping the connection.
2132 /* RED-PEN. Formally speaking, we have broken TCP state
2133 * machine. State transitions:
2135 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
2136 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
2137 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
2139 * are legal only when FIN has been sent (i.e. in window),
2140 * rather than queued out of window. Purists blame.
2142 * F.e. "RFC state" is ESTABLISHED,
2143 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
2145 * The visible declinations are that sometimes
2146 * we enter time-wait state, when it is not required really
2147 * (harmless), do not send active resets, when they are
2148 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
2149 * they look as CLOSING or LAST_ACK for Linux)
2150 * Probably, I missed some more holelets.
2152 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
2153 * in a single packet! (May consider it later but will
2154 * probably need API support or TCP_CORK SYN-ACK until
2155 * data is written and socket is closed.)
2160 sk_stream_wait_close(sk, timeout);
2163 state = sk->sk_state;
2167 /* It is the last release_sock in its life. It will remove backlog. */
2171 /* Now socket is owned by kernel and we acquire BH lock
2172 to finish close. No need to check for user refs.
2176 WARN_ON(sock_owned_by_user(sk));
2178 percpu_counter_inc(sk->sk_prot->orphan_count);
2180 /* Have we already been destroyed by a softirq or backlog? */
2181 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
2184 /* This is a (useful) BSD violating of the RFC. There is a
2185 * problem with TCP as specified in that the other end could
2186 * keep a socket open forever with no application left this end.
2187 * We use a 3 minute timeout (about the same as BSD) then kill
2188 * our end. If they send after that then tough - BUT: long enough
2189 * that we won't make the old 4*rto = almost no time - whoops
2192 * Nope, it was not mistake. It is really desired behaviour
2193 * f.e. on http servers, when such sockets are useless, but
2194 * consume significant resources. Let's do it with special
2195 * linger2 option. --ANK
2198 if (sk->sk_state == TCP_FIN_WAIT2) {
2199 struct tcp_sock *tp = tcp_sk(sk);
2200 if (tp->linger2 < 0) {
2201 tcp_set_state(sk, TCP_CLOSE);
2202 tcp_send_active_reset(sk, GFP_ATOMIC);
2203 NET_INC_STATS_BH(sock_net(sk),
2204 LINUX_MIB_TCPABORTONLINGER);
2206 const int tmo = tcp_fin_time(sk);
2208 if (tmo > TCP_TIMEWAIT_LEN) {
2209 inet_csk_reset_keepalive_timer(sk,
2210 tmo - TCP_TIMEWAIT_LEN);
2212 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
2217 if (sk->sk_state != TCP_CLOSE) {
2219 if (tcp_check_oom(sk, 0)) {
2220 tcp_set_state(sk, TCP_CLOSE);
2221 tcp_send_active_reset(sk, GFP_ATOMIC);
2222 NET_INC_STATS_BH(sock_net(sk),
2223 LINUX_MIB_TCPABORTONMEMORY);
2227 if (sk->sk_state == TCP_CLOSE) {
2228 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
2229 /* We could get here with a non-NULL req if the socket is
2230 * aborted (e.g., closed with unread data) before 3WHS
2234 reqsk_fastopen_remove(sk, req, false);
2235 inet_csk_destroy_sock(sk);
2237 /* Otherwise, socket is reprieved until protocol close. */
2244 EXPORT_SYMBOL(tcp_close);
2246 /* These states need RST on ABORT according to RFC793 */
2248 static inline bool tcp_need_reset(int state)
2250 return (1 << state) &
2251 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
2252 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
2255 int tcp_disconnect(struct sock *sk, int flags)
2257 struct inet_sock *inet = inet_sk(sk);
2258 struct inet_connection_sock *icsk = inet_csk(sk);
2259 struct tcp_sock *tp = tcp_sk(sk);
2261 int old_state = sk->sk_state;
2263 if (old_state != TCP_CLOSE)
2264 tcp_set_state(sk, TCP_CLOSE);
2266 /* ABORT function of RFC793 */
2267 if (old_state == TCP_LISTEN) {
2268 inet_csk_listen_stop(sk);
2269 } else if (unlikely(tp->repair)) {
2270 sk->sk_err = ECONNABORTED;
2271 } else if (tcp_need_reset(old_state) ||
2272 (tp->snd_nxt != tp->write_seq &&
2273 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
2274 /* The last check adjusts for discrepancy of Linux wrt. RFC
2277 tcp_send_active_reset(sk, gfp_any());
2278 sk->sk_err = ECONNRESET;
2279 } else if (old_state == TCP_SYN_SENT)
2280 sk->sk_err = ECONNRESET;
2282 tcp_clear_xmit_timers(sk);
2283 __skb_queue_purge(&sk->sk_receive_queue);
2284 tcp_write_queue_purge(sk);
2285 __skb_queue_purge(&tp->out_of_order_queue);
2286 #ifdef CONFIG_NET_DMA
2287 __skb_queue_purge(&sk->sk_async_wait_queue);
2290 inet->inet_dport = 0;
2292 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
2293 inet_reset_saddr(sk);
2295 sk->sk_shutdown = 0;
2296 sock_reset_flag(sk, SOCK_DONE);
2298 if ((tp->write_seq += tp->max_window + 2) == 0)
2300 icsk->icsk_backoff = 0;
2302 icsk->icsk_probes_out = 0;
2303 tp->packets_out = 0;
2304 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2305 tp->snd_cwnd_cnt = 0;
2306 tp->window_clamp = 0;
2307 tcp_set_ca_state(sk, TCP_CA_Open);
2308 tcp_clear_retrans(tp);
2309 inet_csk_delack_init(sk);
2310 tcp_init_send_head(sk);
2311 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
2314 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
2316 sk->sk_error_report(sk);
2319 EXPORT_SYMBOL(tcp_disconnect);
2321 void tcp_sock_destruct(struct sock *sk)
2323 inet_sock_destruct(sk);
2325 kfree(inet_csk(sk)->icsk_accept_queue.fastopenq);
2328 static inline bool tcp_can_repair_sock(const struct sock *sk)
2330 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2331 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED));
2334 static int tcp_repair_options_est(struct tcp_sock *tp,
2335 struct tcp_repair_opt __user *optbuf, unsigned int len)
2337 struct tcp_repair_opt opt;
2339 while (len >= sizeof(opt)) {
2340 if (copy_from_user(&opt, optbuf, sizeof(opt)))
2346 switch (opt.opt_code) {
2348 tp->rx_opt.mss_clamp = opt.opt_val;
2352 u16 snd_wscale = opt.opt_val & 0xFFFF;
2353 u16 rcv_wscale = opt.opt_val >> 16;
2355 if (snd_wscale > 14 || rcv_wscale > 14)
2358 tp->rx_opt.snd_wscale = snd_wscale;
2359 tp->rx_opt.rcv_wscale = rcv_wscale;
2360 tp->rx_opt.wscale_ok = 1;
2363 case TCPOPT_SACK_PERM:
2364 if (opt.opt_val != 0)
2367 tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
2368 if (sysctl_tcp_fack)
2369 tcp_enable_fack(tp);
2371 case TCPOPT_TIMESTAMP:
2372 if (opt.opt_val != 0)
2375 tp->rx_opt.tstamp_ok = 1;
2384 * Socket option code for TCP.
2386 static int do_tcp_setsockopt(struct sock *sk, int level,
2387 int optname, char __user *optval, unsigned int optlen)
2389 struct tcp_sock *tp = tcp_sk(sk);
2390 struct inet_connection_sock *icsk = inet_csk(sk);
2394 /* These are data/string values, all the others are ints */
2396 case TCP_CONGESTION: {
2397 char name[TCP_CA_NAME_MAX];
2402 val = strncpy_from_user(name, optval,
2403 min_t(long, TCP_CA_NAME_MAX-1, optlen));
2409 err = tcp_set_congestion_control(sk, name);
2418 if (optlen < sizeof(int))
2421 if (get_user(val, (int __user *)optval))
2428 /* Values greater than interface MTU won't take effect. However
2429 * at the point when this call is done we typically don't yet
2430 * know which interface is going to be used */
2431 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
2435 tp->rx_opt.user_mss = val;
2440 /* TCP_NODELAY is weaker than TCP_CORK, so that
2441 * this option on corked socket is remembered, but
2442 * it is not activated until cork is cleared.
2444 * However, when TCP_NODELAY is set we make
2445 * an explicit push, which overrides even TCP_CORK
2446 * for currently queued segments.
2448 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
2449 tcp_push_pending_frames(sk);
2451 tp->nonagle &= ~TCP_NAGLE_OFF;
2455 case TCP_THIN_LINEAR_TIMEOUTS:
2456 if (val < 0 || val > 1)
2462 case TCP_THIN_DUPACK:
2463 if (val < 0 || val > 1)
2466 tp->thin_dupack = val;
2467 if (tp->thin_dupack)
2468 tcp_disable_early_retrans(tp);
2473 if (!tcp_can_repair_sock(sk))
2475 else if (val == 1) {
2477 sk->sk_reuse = SK_FORCE_REUSE;
2478 tp->repair_queue = TCP_NO_QUEUE;
2479 } else if (val == 0) {
2481 sk->sk_reuse = SK_NO_REUSE;
2482 tcp_send_window_probe(sk);
2488 case TCP_REPAIR_QUEUE:
2491 else if (val < TCP_QUEUES_NR)
2492 tp->repair_queue = val;
2498 if (sk->sk_state != TCP_CLOSE)
2500 else if (tp->repair_queue == TCP_SEND_QUEUE)
2501 tp->write_seq = val;
2502 else if (tp->repair_queue == TCP_RECV_QUEUE)
2508 case TCP_REPAIR_OPTIONS:
2511 else if (sk->sk_state == TCP_ESTABLISHED)
2512 err = tcp_repair_options_est(tp,
2513 (struct tcp_repair_opt __user *)optval,
2520 /* When set indicates to always queue non-full frames.
2521 * Later the user clears this option and we transmit
2522 * any pending partial frames in the queue. This is
2523 * meant to be used alongside sendfile() to get properly
2524 * filled frames when the user (for example) must write
2525 * out headers with a write() call first and then use
2526 * sendfile to send out the data parts.
2528 * TCP_CORK can be set together with TCP_NODELAY and it is
2529 * stronger than TCP_NODELAY.
2532 tp->nonagle |= TCP_NAGLE_CORK;
2534 tp->nonagle &= ~TCP_NAGLE_CORK;
2535 if (tp->nonagle&TCP_NAGLE_OFF)
2536 tp->nonagle |= TCP_NAGLE_PUSH;
2537 tcp_push_pending_frames(sk);
2542 if (val < 1 || val > MAX_TCP_KEEPIDLE)
2545 tp->keepalive_time = val * HZ;
2546 if (sock_flag(sk, SOCK_KEEPOPEN) &&
2547 !((1 << sk->sk_state) &
2548 (TCPF_CLOSE | TCPF_LISTEN))) {
2549 u32 elapsed = keepalive_time_elapsed(tp);
2550 if (tp->keepalive_time > elapsed)
2551 elapsed = tp->keepalive_time - elapsed;
2554 inet_csk_reset_keepalive_timer(sk, elapsed);
2559 if (val < 1 || val > MAX_TCP_KEEPINTVL)
2562 tp->keepalive_intvl = val * HZ;
2565 if (val < 1 || val > MAX_TCP_KEEPCNT)
2568 tp->keepalive_probes = val;
2571 if (val < 1 || val > MAX_TCP_SYNCNT)
2574 icsk->icsk_syn_retries = val;
2580 else if (val > sysctl_tcp_fin_timeout / HZ)
2583 tp->linger2 = val * HZ;
2586 case TCP_DEFER_ACCEPT:
2587 /* Translate value in seconds to number of retransmits */
2588 icsk->icsk_accept_queue.rskq_defer_accept =
2589 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
2593 case TCP_WINDOW_CLAMP:
2595 if (sk->sk_state != TCP_CLOSE) {
2599 tp->window_clamp = 0;
2601 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
2602 SOCK_MIN_RCVBUF / 2 : val;
2607 icsk->icsk_ack.pingpong = 1;
2609 icsk->icsk_ack.pingpong = 0;
2610 if ((1 << sk->sk_state) &
2611 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2612 inet_csk_ack_scheduled(sk)) {
2613 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2614 tcp_cleanup_rbuf(sk, 1);
2616 icsk->icsk_ack.pingpong = 1;
2621 #ifdef CONFIG_TCP_MD5SIG
2623 /* Read the IP->Key mappings from userspace */
2624 err = tp->af_specific->md5_parse(sk, optval, optlen);
2627 case TCP_USER_TIMEOUT:
2628 /* Cap the max timeout in ms TCP will retry/retrans
2629 * before giving up and aborting (ETIMEDOUT) a connection.
2634 icsk->icsk_user_timeout = msecs_to_jiffies(val);
2638 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2640 err = fastopen_init_queue(sk, val);
2648 tp->tsoffset = val - tcp_time_stamp;
2659 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2660 unsigned int optlen)
2662 const struct inet_connection_sock *icsk = inet_csk(sk);
2664 if (level != SOL_TCP)
2665 return icsk->icsk_af_ops->setsockopt(sk, level, optname,
2667 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2669 EXPORT_SYMBOL(tcp_setsockopt);
2671 #ifdef CONFIG_COMPAT
2672 int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2673 char __user *optval, unsigned int optlen)
2675 if (level != SOL_TCP)
2676 return inet_csk_compat_setsockopt(sk, level, optname,
2678 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
2680 EXPORT_SYMBOL(compat_tcp_setsockopt);
2683 /* Return information about state of tcp endpoint in API format. */
2684 void tcp_get_info(const struct sock *sk, struct tcp_info *info)
2686 const struct tcp_sock *tp = tcp_sk(sk);
2687 const struct inet_connection_sock *icsk = inet_csk(sk);
2688 u32 now = tcp_time_stamp;
2690 memset(info, 0, sizeof(*info));
2692 info->tcpi_state = sk->sk_state;
2693 info->tcpi_ca_state = icsk->icsk_ca_state;
2694 info->tcpi_retransmits = icsk->icsk_retransmits;
2695 info->tcpi_probes = icsk->icsk_probes_out;
2696 info->tcpi_backoff = icsk->icsk_backoff;
2698 if (tp->rx_opt.tstamp_ok)
2699 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2700 if (tcp_is_sack(tp))
2701 info->tcpi_options |= TCPI_OPT_SACK;
2702 if (tp->rx_opt.wscale_ok) {
2703 info->tcpi_options |= TCPI_OPT_WSCALE;
2704 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
2705 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
2708 if (tp->ecn_flags & TCP_ECN_OK)
2709 info->tcpi_options |= TCPI_OPT_ECN;
2710 if (tp->ecn_flags & TCP_ECN_SEEN)
2711 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
2712 if (tp->syn_data_acked)
2713 info->tcpi_options |= TCPI_OPT_SYN_DATA;
2715 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
2716 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2717 info->tcpi_snd_mss = tp->mss_cache;
2718 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
2720 if (sk->sk_state == TCP_LISTEN) {
2721 info->tcpi_unacked = sk->sk_ack_backlog;
2722 info->tcpi_sacked = sk->sk_max_ack_backlog;
2724 info->tcpi_unacked = tp->packets_out;
2725 info->tcpi_sacked = tp->sacked_out;
2727 info->tcpi_lost = tp->lost_out;
2728 info->tcpi_retrans = tp->retrans_out;
2729 info->tcpi_fackets = tp->fackets_out;
2731 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2732 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
2733 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
2735 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
2736 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2737 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
2738 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
2739 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
2740 info->tcpi_snd_cwnd = tp->snd_cwnd;
2741 info->tcpi_advmss = tp->advmss;
2742 info->tcpi_reordering = tp->reordering;
2744 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
2745 info->tcpi_rcv_space = tp->rcvq_space.space;
2747 info->tcpi_total_retrans = tp->total_retrans;
2749 EXPORT_SYMBOL_GPL(tcp_get_info);
2751 static int do_tcp_getsockopt(struct sock *sk, int level,
2752 int optname, char __user *optval, int __user *optlen)
2754 struct inet_connection_sock *icsk = inet_csk(sk);
2755 struct tcp_sock *tp = tcp_sk(sk);
2758 if (get_user(len, optlen))
2761 len = min_t(unsigned int, len, sizeof(int));
2768 val = tp->mss_cache;
2769 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
2770 val = tp->rx_opt.user_mss;
2772 val = tp->rx_opt.mss_clamp;
2775 val = !!(tp->nonagle&TCP_NAGLE_OFF);
2778 val = !!(tp->nonagle&TCP_NAGLE_CORK);
2781 val = keepalive_time_when(tp) / HZ;
2784 val = keepalive_intvl_when(tp) / HZ;
2787 val = keepalive_probes(tp);
2790 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
2795 val = (val ? : sysctl_tcp_fin_timeout) / HZ;
2797 case TCP_DEFER_ACCEPT:
2798 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
2799 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
2801 case TCP_WINDOW_CLAMP:
2802 val = tp->window_clamp;
2805 struct tcp_info info;
2807 if (get_user(len, optlen))
2810 tcp_get_info(sk, &info);
2812 len = min_t(unsigned int, len, sizeof(info));
2813 if (put_user(len, optlen))
2815 if (copy_to_user(optval, &info, len))
2820 val = !icsk->icsk_ack.pingpong;
2823 case TCP_CONGESTION:
2824 if (get_user(len, optlen))
2826 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
2827 if (put_user(len, optlen))
2829 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2833 case TCP_THIN_LINEAR_TIMEOUTS:
2836 case TCP_THIN_DUPACK:
2837 val = tp->thin_dupack;
2844 case TCP_REPAIR_QUEUE:
2846 val = tp->repair_queue;
2852 if (tp->repair_queue == TCP_SEND_QUEUE)
2853 val = tp->write_seq;
2854 else if (tp->repair_queue == TCP_RECV_QUEUE)
2860 case TCP_USER_TIMEOUT:
2861 val = jiffies_to_msecs(icsk->icsk_user_timeout);
2864 val = tcp_time_stamp + tp->tsoffset;
2867 return -ENOPROTOOPT;
2870 if (put_user(len, optlen))
2872 if (copy_to_user(optval, &val, len))
2877 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
2880 struct inet_connection_sock *icsk = inet_csk(sk);
2882 if (level != SOL_TCP)
2883 return icsk->icsk_af_ops->getsockopt(sk, level, optname,
2885 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2887 EXPORT_SYMBOL(tcp_getsockopt);
2889 #ifdef CONFIG_COMPAT
2890 int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
2891 char __user *optval, int __user *optlen)
2893 if (level != SOL_TCP)
2894 return inet_csk_compat_getsockopt(sk, level, optname,
2896 return do_tcp_getsockopt(sk, level, optname, optval, optlen);
2898 EXPORT_SYMBOL(compat_tcp_getsockopt);
2901 struct sk_buff *tcp_tso_segment(struct sk_buff *skb,
2902 netdev_features_t features)
2904 struct sk_buff *segs = ERR_PTR(-EINVAL);
2905 unsigned int sum_truesize = 0;
2910 unsigned int oldlen;
2912 struct sk_buff *gso_skb = skb;
2914 bool ooo_okay, copy_destructor;
2916 if (!pskb_may_pull(skb, sizeof(*th)))
2920 thlen = th->doff * 4;
2921 if (thlen < sizeof(*th))
2924 if (!pskb_may_pull(skb, thlen))
2927 oldlen = (u16)~skb->len;
2928 __skb_pull(skb, thlen);
2930 mss = skb_shinfo(skb)->gso_size;
2931 if (unlikely(skb->len <= mss))
2934 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2935 /* Packet is from an untrusted source, reset gso_segs. */
2936 int type = skb_shinfo(skb)->gso_type;
2944 SKB_GSO_UDP_TUNNEL |
2946 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
2949 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2955 copy_destructor = gso_skb->destructor == tcp_wfree;
2956 ooo_okay = gso_skb->ooo_okay;
2957 /* All segments but the first should have ooo_okay cleared */
2960 segs = skb_segment(skb, features);
2964 /* Only first segment might have ooo_okay set */
2965 segs->ooo_okay = ooo_okay;
2967 delta = htonl(oldlen + (thlen + mss));
2971 seq = ntohl(th->seq);
2973 newcheck = ~csum_fold((__force __wsum)((__force u32)th->check +
2974 (__force u32)delta));
2977 th->fin = th->psh = 0;
2978 th->check = newcheck;
2980 if (skb->ip_summed != CHECKSUM_PARTIAL)
2982 csum_fold(csum_partial(skb_transport_header(skb),
2986 if (copy_destructor) {
2987 skb->destructor = gso_skb->destructor;
2988 skb->sk = gso_skb->sk;
2989 sum_truesize += skb->truesize;
2994 th->seq = htonl(seq);
2996 } while (skb->next);
2998 /* Following permits TCP Small Queues to work well with GSO :
2999 * The callback to TCP stack will be called at the time last frag
3000 * is freed at TX completion, and not right now when gso_skb
3001 * is freed by GSO engine
3003 if (copy_destructor) {
3004 swap(gso_skb->sk, skb->sk);
3005 swap(gso_skb->destructor, skb->destructor);
3006 sum_truesize += skb->truesize;
3007 atomic_add(sum_truesize - gso_skb->truesize,
3008 &skb->sk->sk_wmem_alloc);
3011 delta = htonl(oldlen + (skb->tail - skb->transport_header) +
3013 th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
3014 (__force u32)delta));
3015 if (skb->ip_summed != CHECKSUM_PARTIAL)
3016 th->check = csum_fold(csum_partial(skb_transport_header(skb),
3022 EXPORT_SYMBOL(tcp_tso_segment);
3024 struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
3026 struct sk_buff **pp = NULL;
3033 unsigned int mss = 1;
3039 off = skb_gro_offset(skb);
3040 hlen = off + sizeof(*th);
3041 th = skb_gro_header_fast(skb, off);
3042 if (skb_gro_header_hard(skb, hlen)) {
3043 th = skb_gro_header_slow(skb, hlen, off);
3048 thlen = th->doff * 4;
3049 if (thlen < sizeof(*th))
3053 if (skb_gro_header_hard(skb, hlen)) {
3054 th = skb_gro_header_slow(skb, hlen, off);
3059 skb_gro_pull(skb, thlen);
3061 len = skb_gro_len(skb);
3062 flags = tcp_flag_word(th);
3064 for (; (p = *head); head = &p->next) {
3065 if (!NAPI_GRO_CB(p)->same_flow)
3070 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
3071 NAPI_GRO_CB(p)->same_flow = 0;
3078 goto out_check_final;
3081 flush = NAPI_GRO_CB(p)->flush;
3082 flush |= (__force int)(flags & TCP_FLAG_CWR);
3083 flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
3084 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
3085 flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
3086 for (i = sizeof(*th); i < thlen; i += 4)
3087 flush |= *(u32 *)((u8 *)th + i) ^
3088 *(u32 *)((u8 *)th2 + i);
3090 mss = skb_shinfo(p)->gso_size;
3092 flush |= (len - 1) >= mss;
3093 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
3095 if (flush || skb_gro_receive(head, skb)) {
3097 goto out_check_final;
3102 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
3106 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH |
3107 TCP_FLAG_RST | TCP_FLAG_SYN |
3110 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
3114 NAPI_GRO_CB(skb)->flush |= flush;
3118 EXPORT_SYMBOL(tcp_gro_receive);
3120 int tcp_gro_complete(struct sk_buff *skb)
3122 struct tcphdr *th = tcp_hdr(skb);
3124 skb->csum_start = skb_transport_header(skb) - skb->head;
3125 skb->csum_offset = offsetof(struct tcphdr, check);
3126 skb->ip_summed = CHECKSUM_PARTIAL;
3128 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
3131 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
3135 EXPORT_SYMBOL(tcp_gro_complete);
3137 #ifdef CONFIG_TCP_MD5SIG
3138 static unsigned long tcp_md5sig_users;
3139 static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool;
3140 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
3142 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool)
3146 for_each_possible_cpu(cpu) {
3147 struct tcp_md5sig_pool *p = per_cpu_ptr(pool, cpu);
3149 if (p->md5_desc.tfm)
3150 crypto_free_hash(p->md5_desc.tfm);
3155 void tcp_free_md5sig_pool(void)
3157 struct tcp_md5sig_pool __percpu *pool = NULL;
3159 spin_lock_bh(&tcp_md5sig_pool_lock);
3160 if (--tcp_md5sig_users == 0) {
3161 pool = tcp_md5sig_pool;
3162 tcp_md5sig_pool = NULL;
3164 spin_unlock_bh(&tcp_md5sig_pool_lock);
3166 __tcp_free_md5sig_pool(pool);
3168 EXPORT_SYMBOL(tcp_free_md5sig_pool);
3170 static struct tcp_md5sig_pool __percpu *
3171 __tcp_alloc_md5sig_pool(struct sock *sk)
3174 struct tcp_md5sig_pool __percpu *pool;
3176 pool = alloc_percpu(struct tcp_md5sig_pool);
3180 for_each_possible_cpu(cpu) {
3181 struct crypto_hash *hash;
3183 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
3184 if (IS_ERR_OR_NULL(hash))
3187 per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash;
3191 __tcp_free_md5sig_pool(pool);
3195 struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *sk)
3197 struct tcp_md5sig_pool __percpu *pool;
3201 spin_lock_bh(&tcp_md5sig_pool_lock);
3202 pool = tcp_md5sig_pool;
3203 if (tcp_md5sig_users++ == 0) {
3205 spin_unlock_bh(&tcp_md5sig_pool_lock);
3208 spin_unlock_bh(&tcp_md5sig_pool_lock);
3212 spin_unlock_bh(&tcp_md5sig_pool_lock);
3215 /* we cannot hold spinlock here because this may sleep. */
3216 struct tcp_md5sig_pool __percpu *p;
3218 p = __tcp_alloc_md5sig_pool(sk);
3219 spin_lock_bh(&tcp_md5sig_pool_lock);
3222 spin_unlock_bh(&tcp_md5sig_pool_lock);
3225 pool = tcp_md5sig_pool;
3227 /* oops, it has already been assigned. */
3228 spin_unlock_bh(&tcp_md5sig_pool_lock);
3229 __tcp_free_md5sig_pool(p);
3231 tcp_md5sig_pool = pool = p;
3232 spin_unlock_bh(&tcp_md5sig_pool_lock);
3237 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
3241 * tcp_get_md5sig_pool - get md5sig_pool for this user
3243 * We use percpu structure, so if we succeed, we exit with preemption
3244 * and BH disabled, to make sure another thread or softirq handling
3245 * wont try to get same context.
3247 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
3249 struct tcp_md5sig_pool __percpu *p;
3253 spin_lock(&tcp_md5sig_pool_lock);
3254 p = tcp_md5sig_pool;
3257 spin_unlock(&tcp_md5sig_pool_lock);
3260 return this_cpu_ptr(p);
3265 EXPORT_SYMBOL(tcp_get_md5sig_pool);
3267 void tcp_put_md5sig_pool(void)
3270 tcp_free_md5sig_pool();
3272 EXPORT_SYMBOL(tcp_put_md5sig_pool);
3274 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
3275 const struct tcphdr *th)
3277 struct scatterlist sg;
3281 /* We are not allowed to change tcphdr, make a local copy */
3282 memcpy(&hdr, th, sizeof(hdr));
3285 /* options aren't included in the hash */
3286 sg_init_one(&sg, &hdr, sizeof(hdr));
3287 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr));
3290 EXPORT_SYMBOL(tcp_md5_hash_header);
3292 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3293 const struct sk_buff *skb, unsigned int header_len)
3295 struct scatterlist sg;
3296 const struct tcphdr *tp = tcp_hdr(skb);
3297 struct hash_desc *desc = &hp->md5_desc;
3299 const unsigned int head_data_len = skb_headlen(skb) > header_len ?
3300 skb_headlen(skb) - header_len : 0;
3301 const struct skb_shared_info *shi = skb_shinfo(skb);
3302 struct sk_buff *frag_iter;
3304 sg_init_table(&sg, 1);
3306 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
3307 if (crypto_hash_update(desc, &sg, head_data_len))
3310 for (i = 0; i < shi->nr_frags; ++i) {
3311 const struct skb_frag_struct *f = &shi->frags[i];
3312 unsigned int offset = f->page_offset;
3313 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
3315 sg_set_page(&sg, page, skb_frag_size(f),
3316 offset_in_page(offset));
3317 if (crypto_hash_update(desc, &sg, skb_frag_size(f)))
3321 skb_walk_frags(skb, frag_iter)
3322 if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
3327 EXPORT_SYMBOL(tcp_md5_hash_skb_data);
3329 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3331 struct scatterlist sg;
3333 sg_init_one(&sg, key->key, key->keylen);
3334 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
3336 EXPORT_SYMBOL(tcp_md5_hash_key);
3340 void tcp_done(struct sock *sk)
3342 struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
3344 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3345 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
3347 tcp_set_state(sk, TCP_CLOSE);
3348 tcp_clear_xmit_timers(sk);
3350 reqsk_fastopen_remove(sk, req, false);
3352 sk->sk_shutdown = SHUTDOWN_MASK;
3354 if (!sock_flag(sk, SOCK_DEAD))
3355 sk->sk_state_change(sk);
3357 inet_csk_destroy_sock(sk);
3359 EXPORT_SYMBOL_GPL(tcp_done);
3361 extern struct tcp_congestion_ops tcp_reno;
3363 static __initdata unsigned long thash_entries;
3364 static int __init set_thash_entries(char *str)
3371 ret = kstrtoul(str, 0, &thash_entries);
3377 __setup("thash_entries=", set_thash_entries);
3379 void tcp_init_mem(struct net *net)
3381 unsigned long limit = nr_free_buffer_pages() / 8;
3382 limit = max(limit, 128UL);
3383 net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3;
3384 net->ipv4.sysctl_tcp_mem[1] = limit;
3385 net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2;
3388 void __init tcp_init(void)
3390 struct sk_buff *skb = NULL;
3391 unsigned long limit;
3392 int max_rshare, max_wshare, cnt;
3395 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
3397 percpu_counter_init(&tcp_sockets_allocated, 0);
3398 percpu_counter_init(&tcp_orphan_count, 0);
3399 tcp_hashinfo.bind_bucket_cachep =
3400 kmem_cache_create("tcp_bind_bucket",
3401 sizeof(struct inet_bind_bucket), 0,
3402 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3404 /* Size and allocate the main established and bind bucket
3407 * The methodology is similar to that of the buffer cache.
3409 tcp_hashinfo.ehash =
3410 alloc_large_system_hash("TCP established",
3411 sizeof(struct inet_ehash_bucket),
3413 17, /* one slot per 128 KB of memory */
3416 &tcp_hashinfo.ehash_mask,
3418 thash_entries ? 0 : 512 * 1024);
3419 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
3420 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
3421 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
3423 if (inet_ehash_locks_alloc(&tcp_hashinfo))
3424 panic("TCP: failed to alloc ehash_locks");
3425 tcp_hashinfo.bhash =
3426 alloc_large_system_hash("TCP bind",
3427 sizeof(struct inet_bind_hashbucket),
3428 tcp_hashinfo.ehash_mask + 1,
3429 17, /* one slot per 128 KB of memory */
3431 &tcp_hashinfo.bhash_size,
3435 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3436 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
3437 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
3438 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
3442 cnt = tcp_hashinfo.ehash_mask + 1;
3444 tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
3445 sysctl_tcp_max_orphans = cnt / 2;
3446 sysctl_max_syn_backlog = max(128, cnt / 256);
3448 tcp_init_mem(&init_net);
3449 /* Set per-socket limits to no more than 1/128 the pressure threshold */
3450 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3451 max_wshare = min(4UL*1024*1024, limit);
3452 max_rshare = min(6UL*1024*1024, limit);
3454 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3455 sysctl_tcp_wmem[1] = 16*1024;
3456 sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3458 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3459 sysctl_tcp_rmem[1] = 87380;
3460 sysctl_tcp_rmem[2] = max(87380, max_rshare);
3462 pr_info("Hash tables configured (established %u bind %u)\n",
3463 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3467 tcp_register_congestion_control(&tcp_reno);