1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Implementation of the Transmission Control Protocol(TCP).
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Mark Evans, <evansmp@uhura.aston.ac.uk>
12 * Corey Minyard <wf-rch!minyard@relay.EU.net>
13 * Florian La Roche, <flla@stud.uni-sb.de>
14 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
15 * Linus Torvalds, <torvalds@cs.helsinki.fi>
16 * Alan Cox, <gw4pts@gw4pts.ampr.org>
17 * Matthew Dillon, <dillon@apollo.west.oic.com>
18 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
19 * Jorge Cwik, <jorge@laser.satlink.net>
20 *
21 * Fixes:
22 * Alan Cox : Numerous verify_area() calls
23 * Alan Cox : Set the ACK bit on a reset
24 * Alan Cox : Stopped it crashing if it closed while
25 * sk->inuse=1 and was trying to connect
26 * (tcp_err()).
27 * Alan Cox : All icmp error handling was broken
28 * pointers passed where wrong and the
29 * socket was looked up backwards. Nobody
30 * tested any icmp error code obviously.
31 * Alan Cox : tcp_err() now handled properly. It
32 * wakes people on errors. poll
33 * behaves and the icmp error race
34 * has gone by moving it into sock.c
35 * Alan Cox : tcp_send_reset() fixed to work for
36 * everything not just packets for
37 * unknown sockets.
38 * Alan Cox : tcp option processing.
39 * Alan Cox : Reset tweaked (still not 100%) [Had
40 * syn rule wrong]
41 * Herp Rosmanith : More reset fixes
42 * Alan Cox : No longer acks invalid rst frames.
43 * Acking any kind of RST is right out.
44 * Alan Cox : Sets an ignore me flag on an rst
45 * receive otherwise odd bits of prattle
46 * escape still
47 * Alan Cox : Fixed another acking RST frame bug.
48 * Should stop LAN workplace lockups.
49 * Alan Cox : Some tidyups using the new skb list
50 * facilities
51 * Alan Cox : sk->keepopen now seems to work
52 * Alan Cox : Pulls options out correctly on accepts
53 * Alan Cox : Fixed assorted sk->rqueue->next errors
54 * Alan Cox : PSH doesn't end a TCP read. Switched a
55 * bit to skb ops.
56 * Alan Cox : Tidied tcp_data to avoid a potential
57 * nasty.
58 * Alan Cox : Added some better commenting, as the
59 * tcp is hard to follow
60 * Alan Cox : Removed incorrect check for 20 * psh
61 * Michael O'Reilly : ack < copied bug fix.
62 * Johannes Stille : Misc tcp fixes (not all in yet).
63 * Alan Cox : FIN with no memory -> CRASH
64 * Alan Cox : Added socket option proto entries.
65 * Also added awareness of them to accept.
66 * Alan Cox : Added TCP options (SOL_TCP)
67 * Alan Cox : Switched wakeup calls to callbacks,
68 * so the kernel can layer network
69 * sockets.
70 * Alan Cox : Use ip_tos/ip_ttl settings.
71 * Alan Cox : Handle FIN (more) properly (we hope).
72 * Alan Cox : RST frames sent on unsynchronised
73 * state ack error.
74 * Alan Cox : Put in missing check for SYN bit.
75 * Alan Cox : Added tcp_select_window() aka NET2E
76 * window non shrink trick.
77 * Alan Cox : Added a couple of small NET2E timer
78 * fixes
79 * Charles Hedrick : TCP fixes
80 * Toomas Tamm : TCP window fixes
81 * Alan Cox : Small URG fix to rlogin ^C ack fight
82 * Charles Hedrick : Rewrote most of it to actually work
83 * Linus : Rewrote tcp_read() and URG handling
84 * completely
85 * Gerhard Koerting: Fixed some missing timer handling
86 * Matthew Dillon : Reworked TCP machine states as per RFC
87 * Gerhard Koerting: PC/TCP workarounds
88 * Adam Caldwell : Assorted timer/timing errors
89 * Matthew Dillon : Fixed another RST bug
90 * Alan Cox : Move to kernel side addressing changes.
91 * Alan Cox : Beginning work on TCP fastpathing
92 * (not yet usable)
93 * Arnt Gulbrandsen: Turbocharged tcp_check() routine.
94 * Alan Cox : TCP fast path debugging
95 * Alan Cox : Window clamping
96 * Michael Riepe : Bug in tcp_check()
97 * Matt Dillon : More TCP improvements and RST bug fixes
98 * Matt Dillon : Yet more small nasties remove from the
99 * TCP code (Be very nice to this man if
100 * tcp finally works 100%) 8)
101 * Alan Cox : BSD accept semantics.
102 * Alan Cox : Reset on closedown bug.
103 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
104 * Michael Pall : Handle poll() after URG properly in
105 * all cases.
106 * Michael Pall : Undo the last fix in tcp_read_urg()
107 * (multi URG PUSH broke rlogin).
108 * Michael Pall : Fix the multi URG PUSH problem in
109 * tcp_readable(), poll() after URG
110 * works now.
111 * Michael Pall : recv(...,MSG_OOB) never blocks in the
112 * BSD api.
113 * Alan Cox : Changed the semantics of sk->socket to
114 * fix a race and a signal problem with
115 * accept() and async I/O.
116 * Alan Cox : Relaxed the rules on tcp_sendto().
117 * Yury Shevchuk : Really fixed accept() blocking problem.
118 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
119 * clients/servers which listen in on
120 * fixed ports.
121 * Alan Cox : Cleaned the above up and shrank it to
122 * a sensible code size.
123 * Alan Cox : Self connect lockup fix.
124 * Alan Cox : No connect to multicast.
125 * Ross Biro : Close unaccepted children on master
126 * socket close.
127 * Alan Cox : Reset tracing code.
128 * Alan Cox : Spurious resets on shutdown.
129 * Alan Cox : Giant 15 minute/60 second timer error
130 * Alan Cox : Small whoops in polling before an
131 * accept.
132 * Alan Cox : Kept the state trace facility since
133 * it's handy for debugging.
134 * Alan Cox : More reset handler fixes.
135 * Alan Cox : Started rewriting the code based on
136 * the RFC's for other useful protocol
137 * references see: Comer, KA9Q NOS, and
138 * for a reference on the difference
139 * between specifications and how BSD
140 * works see the 4.4lite source.
141 * A.N.Kuznetsov : Don't time wait on completion of tidy
142 * close.
143 * Linus Torvalds : Fin/Shutdown & copied_seq changes.
144 * Linus Torvalds : Fixed BSD port reuse to work first syn
145 * Alan Cox : Reimplemented timers as per the RFC
146 * and using multiple timers for sanity.
147 * Alan Cox : Small bug fixes, and a lot of new
148 * comments.
149 * Alan Cox : Fixed dual reader crash by locking
150 * the buffers (much like datagram.c)
151 * Alan Cox : Fixed stuck sockets in probe. A probe
152 * now gets fed up of retrying without
153 * (even a no space) answer.
154 * Alan Cox : Extracted closing code better
155 * Alan Cox : Fixed the closing state machine to
156 * resemble the RFC.
157 * Alan Cox : More 'per spec' fixes.
158 * Jorge Cwik : Even faster checksumming.
159 * Alan Cox : tcp_data() doesn't ack illegal PSH
160 * only frames. At least one pc tcp stack
161 * generates them.
162 * Alan Cox : Cache last socket.
163 * Alan Cox : Per route irtt.
164 * Matt Day : poll()->select() match BSD precisely on error
165 * Alan Cox : New buffers
166 * Marc Tamsky : Various sk->prot->retransmits and
167 * sk->retransmits misupdating fixed.
168 * Fixed tcp_write_timeout: stuck close,
169 * and TCP syn retries gets used now.
170 * Mark Yarvis : In tcp_read_wakeup(), don't send an
171 * ack if state is TCP_CLOSED.
172 * Alan Cox : Look up device on a retransmit - routes may
173 * change. Doesn't yet cope with MSS shrink right
174 * but it's a start!
175 * Marc Tamsky : Closing in closing fixes.
176 * Mike Shaver : RFC1122 verifications.
177 * Alan Cox : rcv_saddr errors.
178 * Alan Cox : Block double connect().
179 * Alan Cox : Small hooks for enSKIP.
180 * Alexey Kuznetsov: Path MTU discovery.
181 * Alan Cox : Support soft errors.
182 * Alan Cox : Fix MTU discovery pathological case
183 * when the remote claims no mtu!
184 * Marc Tamsky : TCP_CLOSE fix.
185 * Colin (G3TNE) : Send a reset on syn ack replies in
186 * window but wrong (fixes NT lpd problems)
187 * Pedro Roque : Better TCP window handling, delayed ack.
188 * Joerg Reuter : No modification of locked buffers in
189 * tcp_do_retransmit()
190 * Eric Schenk : Changed receiver side silly window
191 * avoidance algorithm to BSD style
192 * algorithm. This doubles throughput
193 * against machines running Solaris,
194 * and seems to result in general
195 * improvement.
196 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
197 * Willy Konynenberg : Transparent proxying support.
198 * Mike McLagan : Routing by source
199 * Keith Owens : Do proper merging with partial SKB's in
200 * tcp_do_sendmsg to avoid burstiness.
201 * Eric Schenk : Fix fast close down bug with
202 * shutdown() followed by close().
203 * Andi Kleen : Make poll agree with SIGIO
204 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
205 * lingertime == 0 (RFC 793 ABORT Call)
206 * Hirokazu Takahashi : Use copy_from_user() instead of
207 * csum_and_copy_from_user() if possible.
208 *
209 * Description of States:
210 *
211 * TCP_SYN_SENT sent a connection request, waiting for ack
212 *
213 * TCP_SYN_RECV received a connection request, sent ack,
214 * waiting for final ack in three-way handshake.
215 *
216 * TCP_ESTABLISHED connection established
217 *
218 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete
219 * transmission of remaining buffered data
220 *
221 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote
222 * to shutdown
223 *
224 * TCP_CLOSING both sides have shutdown but we still have
225 * data we have to finish sending
226 *
227 * TCP_TIME_WAIT timeout to catch resent junk before entering
228 * closed, can only be entered from FIN_WAIT2
229 * or CLOSING. Required because the other end
230 * may not have gotten our last ACK causing it
231 * to retransmit the data packet (which we ignore)
232 *
233 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for
234 * us to finish writing our data and to shutdown
235 * (we have to close() to move on to LAST_ACK)
236 *
237 * TCP_LAST_ACK out side has shutdown after remote has
238 * shutdown. There may still be data in our
239 * buffer that we have to finish sending
240 *
241 * TCP_CLOSE socket is finished
242 */
243
244 #define pr_fmt(fmt) "TCP: " fmt
245
246 #include <crypto/hash.h>
247 #include <linux/kernel.h>
248 #include <linux/module.h>
249 #include <linux/types.h>
250 #include <linux/fcntl.h>
251 #include <linux/poll.h>
252 #include <linux/inet_diag.h>
253 #include <linux/init.h>
254 #include <linux/fs.h>
255 #include <linux/skbuff.h>
256 #include <linux/scatterlist.h>
257 #include <linux/splice.h>
258 #include <linux/net.h>
259 #include <linux/socket.h>
260 #include <linux/random.h>
261 #include <linux/memblock.h>
262 #include <linux/highmem.h>
263 #include <linux/cache.h>
264 #include <linux/err.h>
265 #include <linux/time.h>
266 #include <linux/slab.h>
267 #include <linux/errqueue.h>
268 #include <linux/static_key.h>
269 #include <linux/btf.h>
270
271 #include <net/icmp.h>
272 #include <net/inet_common.h>
273 #include <net/tcp.h>
274 #include <net/mptcp.h>
275 #include <net/proto_memory.h>
276 #include <net/xfrm.h>
277 #include <net/ip.h>
278 #include <net/sock.h>
279 #include <net/rstreason.h>
280
281 #include <linux/uaccess.h>
282 #include <asm/ioctls.h>
283 #include <net/busy_poll.h>
284 #include <net/hotdata.h>
285 #include <trace/events/tcp.h>
286 #include <net/rps.h>
287
288 #include "../core/devmem.h"
289
290 /* Track pending CMSGs. */
291 enum {
292 TCP_CMSG_INQ = 1,
293 TCP_CMSG_TS = 2
294 };
295
296 DEFINE_PER_CPU(unsigned int, tcp_orphan_count);
297 EXPORT_PER_CPU_SYMBOL_GPL(tcp_orphan_count);
298
299 DEFINE_PER_CPU(u32, tcp_tw_isn);
300 EXPORT_PER_CPU_SYMBOL_GPL(tcp_tw_isn);
301
302 long sysctl_tcp_mem[3] __read_mostly;
303 EXPORT_SYMBOL(sysctl_tcp_mem);
304
305 atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp; /* Current allocated memory. */
306 EXPORT_SYMBOL(tcp_memory_allocated);
307 DEFINE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc);
308 EXPORT_PER_CPU_SYMBOL_GPL(tcp_memory_per_cpu_fw_alloc);
309
310 #if IS_ENABLED(CONFIG_SMC)
311 DEFINE_STATIC_KEY_FALSE(tcp_have_smc);
312 EXPORT_SYMBOL(tcp_have_smc);
313 #endif
314
315 /*
316 * Current number of TCP sockets.
317 */
318 struct percpu_counter tcp_sockets_allocated ____cacheline_aligned_in_smp;
319 EXPORT_SYMBOL(tcp_sockets_allocated);
320
321 /*
322 * TCP splice context
323 */
324 struct tcp_splice_state {
325 struct pipe_inode_info *pipe;
326 size_t len;
327 unsigned int flags;
328 };
329
330 /*
331 * Pressure flag: try to collapse.
332 * Technical note: it is used by multiple contexts non atomically.
333 * All the __sk_mem_schedule() is of this nature: accounting
334 * is strict, actions are advisory and have some latency.
335 */
336 unsigned long tcp_memory_pressure __read_mostly;
337 EXPORT_SYMBOL_GPL(tcp_memory_pressure);
338
tcp_enter_memory_pressure(struct sock * sk)339 void tcp_enter_memory_pressure(struct sock *sk)
340 {
341 unsigned long val;
342
343 if (READ_ONCE(tcp_memory_pressure))
344 return;
345 val = jiffies;
346
347 if (!val)
348 val--;
349 if (!cmpxchg(&tcp_memory_pressure, 0, val))
350 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
351 }
352 EXPORT_SYMBOL_GPL(tcp_enter_memory_pressure);
353
tcp_leave_memory_pressure(struct sock * sk)354 void tcp_leave_memory_pressure(struct sock *sk)
355 {
356 unsigned long val;
357
358 if (!READ_ONCE(tcp_memory_pressure))
359 return;
360 val = xchg(&tcp_memory_pressure, 0);
361 if (val)
362 NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURESCHRONO,
363 jiffies_to_msecs(jiffies - val));
364 }
365 EXPORT_SYMBOL_GPL(tcp_leave_memory_pressure);
366
367 /* Convert seconds to retransmits based on initial and max timeout */
secs_to_retrans(int seconds,int timeout,int rto_max)368 static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
369 {
370 u8 res = 0;
371
372 if (seconds > 0) {
373 int period = timeout;
374
375 res = 1;
376 while (seconds > period && res < 255) {
377 res++;
378 timeout <<= 1;
379 if (timeout > rto_max)
380 timeout = rto_max;
381 period += timeout;
382 }
383 }
384 return res;
385 }
386
387 /* Convert retransmits to seconds based on initial and max timeout */
retrans_to_secs(u8 retrans,int timeout,int rto_max)388 static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
389 {
390 int period = 0;
391
392 if (retrans > 0) {
393 period = timeout;
394 while (--retrans) {
395 timeout <<= 1;
396 if (timeout > rto_max)
397 timeout = rto_max;
398 period += timeout;
399 }
400 }
401 return period;
402 }
403
tcp_compute_delivery_rate(const struct tcp_sock * tp)404 static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp)
405 {
406 u32 rate = READ_ONCE(tp->rate_delivered);
407 u32 intv = READ_ONCE(tp->rate_interval_us);
408 u64 rate64 = 0;
409
410 if (rate && intv) {
411 rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC;
412 do_div(rate64, intv);
413 }
414 return rate64;
415 }
416
417 /* Address-family independent initialization for a tcp_sock.
418 *
419 * NOTE: A lot of things set to zero explicitly by call to
420 * sk_alloc() so need not be done here.
421 */
tcp_init_sock(struct sock * sk)422 void tcp_init_sock(struct sock *sk)
423 {
424 struct inet_connection_sock *icsk = inet_csk(sk);
425 struct tcp_sock *tp = tcp_sk(sk);
426 int rto_min_us;
427
428 tp->out_of_order_queue = RB_ROOT;
429 sk->tcp_rtx_queue = RB_ROOT;
430 tcp_init_xmit_timers(sk);
431 INIT_LIST_HEAD(&tp->tsq_node);
432 INIT_LIST_HEAD(&tp->tsorted_sent_queue);
433
434 icsk->icsk_rto = TCP_TIMEOUT_INIT;
435 rto_min_us = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rto_min_us);
436 icsk->icsk_rto_min = usecs_to_jiffies(rto_min_us);
437 icsk->icsk_delack_max = TCP_DELACK_MAX;
438 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
439 minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U);
440
441 /* So many TCP implementations out there (incorrectly) count the
442 * initial SYN frame in their delayed-ACK and congestion control
443 * algorithms that we must have the following bandaid to talk
444 * efficiently to them. -DaveM
445 */
446 tcp_snd_cwnd_set(tp, TCP_INIT_CWND);
447
448 /* There's a bubble in the pipe until at least the first ACK. */
449 tp->app_limited = ~0U;
450 tp->rate_app_limited = 1;
451
452 /* See draft-stevens-tcpca-spec-01 for discussion of the
453 * initialization of these values.
454 */
455 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
456 tp->snd_cwnd_clamp = ~0;
457 tp->mss_cache = TCP_MSS_DEFAULT;
458
459 tp->reordering = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reordering);
460 tcp_assign_congestion_control(sk);
461
462 tp->tsoffset = 0;
463 tp->rack.reo_wnd_steps = 1;
464
465 sk->sk_write_space = sk_stream_write_space;
466 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
467
468 icsk->icsk_sync_mss = tcp_sync_mss;
469
470 WRITE_ONCE(sk->sk_sndbuf, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[1]));
471 WRITE_ONCE(sk->sk_rcvbuf, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[1]));
472 tcp_scaling_ratio_init(sk);
473
474 set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
475 sk_sockets_allocated_inc(sk);
476 xa_init_flags(&sk->sk_user_frags, XA_FLAGS_ALLOC1);
477 }
478 EXPORT_SYMBOL(tcp_init_sock);
479
tcp_tx_timestamp(struct sock * sk,struct sockcm_cookie * sockc)480 static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc)
481 {
482 struct sk_buff *skb = tcp_write_queue_tail(sk);
483 u32 tsflags = sockc->tsflags;
484
485 if (tsflags && skb) {
486 struct skb_shared_info *shinfo = skb_shinfo(skb);
487 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
488
489 sock_tx_timestamp(sk, sockc, &shinfo->tx_flags);
490 if (tsflags & SOF_TIMESTAMPING_TX_ACK)
491 tcb->txstamp_ack = 1;
492 if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
493 shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
494 }
495 }
496
tcp_stream_is_readable(struct sock * sk,int target)497 static bool tcp_stream_is_readable(struct sock *sk, int target)
498 {
499 if (tcp_epollin_ready(sk, target))
500 return true;
501 return sk_is_readable(sk);
502 }
503
504 /*
505 * Wait for a TCP event.
506 *
507 * Note that we don't need to lock the socket, as the upper poll layers
508 * take care of normal races (between the test and the event) and we don't
509 * go look at any of the socket buffers directly.
510 */
tcp_poll(struct file * file,struct socket * sock,poll_table * wait)511 __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
512 {
513 __poll_t mask;
514 struct sock *sk = sock->sk;
515 const struct tcp_sock *tp = tcp_sk(sk);
516 u8 shutdown;
517 int state;
518
519 sock_poll_wait(file, sock, wait);
520
521 state = inet_sk_state_load(sk);
522 if (state == TCP_LISTEN)
523 return inet_csk_listen_poll(sk);
524
525 /* Socket is not locked. We are protected from async events
526 * by poll logic and correct handling of state changes
527 * made by other threads is impossible in any case.
528 */
529
530 mask = 0;
531
532 /*
533 * EPOLLHUP is certainly not done right. But poll() doesn't
534 * have a notion of HUP in just one direction, and for a
535 * socket the read side is more interesting.
536 *
537 * Some poll() documentation says that EPOLLHUP is incompatible
538 * with the EPOLLOUT/POLLWR flags, so somebody should check this
539 * all. But careful, it tends to be safer to return too many
540 * bits than too few, and you can easily break real applications
541 * if you don't tell them that something has hung up!
542 *
543 * Check-me.
544 *
545 * Check number 1. EPOLLHUP is _UNMASKABLE_ event (see UNIX98 and
546 * our fs/select.c). It means that after we received EOF,
547 * poll always returns immediately, making impossible poll() on write()
548 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP
549 * if and only if shutdown has been made in both directions.
550 * Actually, it is interesting to look how Solaris and DUX
551 * solve this dilemma. I would prefer, if EPOLLHUP were maskable,
552 * then we could set it on SND_SHUTDOWN. BTW examples given
553 * in Stevens' books assume exactly this behaviour, it explains
554 * why EPOLLHUP is incompatible with EPOLLOUT. --ANK
555 *
556 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
557 * blocking on fresh not-connected or disconnected socket. --ANK
558 */
559 shutdown = READ_ONCE(sk->sk_shutdown);
560 if (shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
561 mask |= EPOLLHUP;
562 if (shutdown & RCV_SHUTDOWN)
563 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
564
565 /* Connected or passive Fast Open socket? */
566 if (state != TCP_SYN_SENT &&
567 (state != TCP_SYN_RECV || rcu_access_pointer(tp->fastopen_rsk))) {
568 int target = sock_rcvlowat(sk, 0, INT_MAX);
569 u16 urg_data = READ_ONCE(tp->urg_data);
570
571 if (unlikely(urg_data) &&
572 READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq) &&
573 !sock_flag(sk, SOCK_URGINLINE))
574 target++;
575
576 if (tcp_stream_is_readable(sk, target))
577 mask |= EPOLLIN | EPOLLRDNORM;
578
579 if (!(shutdown & SEND_SHUTDOWN)) {
580 if (__sk_stream_is_writeable(sk, 1)) {
581 mask |= EPOLLOUT | EPOLLWRNORM;
582 } else { /* send SIGIO later */
583 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
584 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
585
586 /* Race breaker. If space is freed after
587 * wspace test but before the flags are set,
588 * IO signal will be lost. Memory barrier
589 * pairs with the input side.
590 */
591 smp_mb__after_atomic();
592 if (__sk_stream_is_writeable(sk, 1))
593 mask |= EPOLLOUT | EPOLLWRNORM;
594 }
595 } else
596 mask |= EPOLLOUT | EPOLLWRNORM;
597
598 if (urg_data & TCP_URG_VALID)
599 mask |= EPOLLPRI;
600 } else if (state == TCP_SYN_SENT &&
601 inet_test_bit(DEFER_CONNECT, sk)) {
602 /* Active TCP fastopen socket with defer_connect
603 * Return EPOLLOUT so application can call write()
604 * in order for kernel to generate SYN+data
605 */
606 mask |= EPOLLOUT | EPOLLWRNORM;
607 }
608 /* This barrier is coupled with smp_wmb() in tcp_done_with_error() */
609 smp_rmb();
610 if (READ_ONCE(sk->sk_err) ||
611 !skb_queue_empty_lockless(&sk->sk_error_queue))
612 mask |= EPOLLERR;
613
614 return mask;
615 }
616 EXPORT_SYMBOL(tcp_poll);
617
tcp_ioctl(struct sock * sk,int cmd,int * karg)618 int tcp_ioctl(struct sock *sk, int cmd, int *karg)
619 {
620 struct tcp_sock *tp = tcp_sk(sk);
621 int answ;
622 bool slow;
623
624 switch (cmd) {
625 case SIOCINQ:
626 if (sk->sk_state == TCP_LISTEN)
627 return -EINVAL;
628
629 slow = lock_sock_fast(sk);
630 answ = tcp_inq(sk);
631 unlock_sock_fast(sk, slow);
632 break;
633 case SIOCATMARK:
634 answ = READ_ONCE(tp->urg_data) &&
635 READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq);
636 break;
637 case SIOCOUTQ:
638 if (sk->sk_state == TCP_LISTEN)
639 return -EINVAL;
640
641 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
642 answ = 0;
643 else
644 answ = READ_ONCE(tp->write_seq) - tp->snd_una;
645 break;
646 case SIOCOUTQNSD:
647 if (sk->sk_state == TCP_LISTEN)
648 return -EINVAL;
649
650 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
651 answ = 0;
652 else
653 answ = READ_ONCE(tp->write_seq) -
654 READ_ONCE(tp->snd_nxt);
655 break;
656 default:
657 return -ENOIOCTLCMD;
658 }
659
660 *karg = answ;
661 return 0;
662 }
663 EXPORT_SYMBOL(tcp_ioctl);
664
tcp_mark_push(struct tcp_sock * tp,struct sk_buff * skb)665 void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
666 {
667 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
668 tp->pushed_seq = tp->write_seq;
669 }
670
forced_push(const struct tcp_sock * tp)671 static inline bool forced_push(const struct tcp_sock *tp)
672 {
673 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
674 }
675
tcp_skb_entail(struct sock * sk,struct sk_buff * skb)676 void tcp_skb_entail(struct sock *sk, struct sk_buff *skb)
677 {
678 struct tcp_sock *tp = tcp_sk(sk);
679 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
680
681 tcb->seq = tcb->end_seq = tp->write_seq;
682 tcb->tcp_flags = TCPHDR_ACK;
683 __skb_header_release(skb);
684 tcp_add_write_queue_tail(sk, skb);
685 sk_wmem_queued_add(sk, skb->truesize);
686 sk_mem_charge(sk, skb->truesize);
687 if (tp->nonagle & TCP_NAGLE_PUSH)
688 tp->nonagle &= ~TCP_NAGLE_PUSH;
689
690 tcp_slow_start_after_idle_check(sk);
691 }
692
tcp_mark_urg(struct tcp_sock * tp,int flags)693 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
694 {
695 if (flags & MSG_OOB)
696 tp->snd_up = tp->write_seq;
697 }
698
699 /* If a not yet filled skb is pushed, do not send it if
700 * we have data packets in Qdisc or NIC queues :
701 * Because TX completion will happen shortly, it gives a chance
702 * to coalesce future sendmsg() payload into this skb, without
703 * need for a timer, and with no latency trade off.
704 * As packets containing data payload have a bigger truesize
705 * than pure acks (dataless) packets, the last checks prevent
706 * autocorking if we only have an ACK in Qdisc/NIC queues,
707 * or if TX completion was delayed after we processed ACK packet.
708 */
tcp_should_autocork(struct sock * sk,struct sk_buff * skb,int size_goal)709 static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
710 int size_goal)
711 {
712 return skb->len < size_goal &&
713 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_autocorking) &&
714 !tcp_rtx_queue_empty(sk) &&
715 refcount_read(&sk->sk_wmem_alloc) > skb->truesize &&
716 tcp_skb_can_collapse_to(skb);
717 }
718
tcp_push(struct sock * sk,int flags,int mss_now,int nonagle,int size_goal)719 void tcp_push(struct sock *sk, int flags, int mss_now,
720 int nonagle, int size_goal)
721 {
722 struct tcp_sock *tp = tcp_sk(sk);
723 struct sk_buff *skb;
724
725 skb = tcp_write_queue_tail(sk);
726 if (!skb)
727 return;
728 if (!(flags & MSG_MORE) || forced_push(tp))
729 tcp_mark_push(tp, skb);
730
731 tcp_mark_urg(tp, flags);
732
733 if (tcp_should_autocork(sk, skb, size_goal)) {
734
735 /* avoid atomic op if TSQ_THROTTLED bit is already set */
736 if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
737 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
738 set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
739 smp_mb__after_atomic();
740 }
741 /* It is possible TX completion already happened
742 * before we set TSQ_THROTTLED.
743 */
744 if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
745 return;
746 }
747
748 if (flags & MSG_MORE)
749 nonagle = TCP_NAGLE_CORK;
750
751 __tcp_push_pending_frames(sk, mss_now, nonagle);
752 }
753
tcp_splice_data_recv(read_descriptor_t * rd_desc,struct sk_buff * skb,unsigned int offset,size_t len)754 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
755 unsigned int offset, size_t len)
756 {
757 struct tcp_splice_state *tss = rd_desc->arg.data;
758 int ret;
759
760 ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
761 min(rd_desc->count, len), tss->flags);
762 if (ret > 0)
763 rd_desc->count -= ret;
764 return ret;
765 }
766
__tcp_splice_read(struct sock * sk,struct tcp_splice_state * tss)767 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
768 {
769 /* Store TCP splice context information in read_descriptor_t. */
770 read_descriptor_t rd_desc = {
771 .arg.data = tss,
772 .count = tss->len,
773 };
774
775 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
776 }
777
778 /**
779 * tcp_splice_read - splice data from TCP socket to a pipe
780 * @sock: socket to splice from
781 * @ppos: position (not valid)
782 * @pipe: pipe to splice to
783 * @len: number of bytes to splice
784 * @flags: splice modifier flags
785 *
786 * Description:
787 * Will read pages from given socket and fill them into a pipe.
788 *
789 **/
tcp_splice_read(struct socket * sock,loff_t * ppos,struct pipe_inode_info * pipe,size_t len,unsigned int flags)790 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
791 struct pipe_inode_info *pipe, size_t len,
792 unsigned int flags)
793 {
794 struct sock *sk = sock->sk;
795 struct tcp_splice_state tss = {
796 .pipe = pipe,
797 .len = len,
798 .flags = flags,
799 };
800 long timeo;
801 ssize_t spliced;
802 int ret;
803
804 sock_rps_record_flow(sk);
805 /*
806 * We can't seek on a socket input
807 */
808 if (unlikely(*ppos))
809 return -ESPIPE;
810
811 ret = spliced = 0;
812
813 lock_sock(sk);
814
815 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
816 while (tss.len) {
817 ret = __tcp_splice_read(sk, &tss);
818 if (ret < 0)
819 break;
820 else if (!ret) {
821 if (spliced)
822 break;
823 if (sock_flag(sk, SOCK_DONE))
824 break;
825 if (sk->sk_err) {
826 ret = sock_error(sk);
827 break;
828 }
829 if (sk->sk_shutdown & RCV_SHUTDOWN)
830 break;
831 if (sk->sk_state == TCP_CLOSE) {
832 /*
833 * This occurs when user tries to read
834 * from never connected socket.
835 */
836 ret = -ENOTCONN;
837 break;
838 }
839 if (!timeo) {
840 ret = -EAGAIN;
841 break;
842 }
843 /* if __tcp_splice_read() got nothing while we have
844 * an skb in receive queue, we do not want to loop.
845 * This might happen with URG data.
846 */
847 if (!skb_queue_empty(&sk->sk_receive_queue))
848 break;
849 ret = sk_wait_data(sk, &timeo, NULL);
850 if (ret < 0)
851 break;
852 if (signal_pending(current)) {
853 ret = sock_intr_errno(timeo);
854 break;
855 }
856 continue;
857 }
858 tss.len -= ret;
859 spliced += ret;
860
861 if (!tss.len || !timeo)
862 break;
863 release_sock(sk);
864 lock_sock(sk);
865
866 if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
867 (sk->sk_shutdown & RCV_SHUTDOWN) ||
868 signal_pending(current))
869 break;
870 }
871
872 release_sock(sk);
873
874 if (spliced)
875 return spliced;
876
877 return ret;
878 }
879 EXPORT_SYMBOL(tcp_splice_read);
880
tcp_stream_alloc_skb(struct sock * sk,gfp_t gfp,bool force_schedule)881 struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp,
882 bool force_schedule)
883 {
884 struct sk_buff *skb;
885
886 skb = alloc_skb_fclone(MAX_TCP_HEADER, gfp);
887 if (likely(skb)) {
888 bool mem_scheduled;
889
890 skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
891 if (force_schedule) {
892 mem_scheduled = true;
893 sk_forced_mem_schedule(sk, skb->truesize);
894 } else {
895 mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
896 }
897 if (likely(mem_scheduled)) {
898 skb_reserve(skb, MAX_TCP_HEADER);
899 skb->ip_summed = CHECKSUM_PARTIAL;
900 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
901 return skb;
902 }
903 __kfree_skb(skb);
904 } else {
905 sk->sk_prot->enter_memory_pressure(sk);
906 sk_stream_moderate_sndbuf(sk);
907 }
908 return NULL;
909 }
910
tcp_xmit_size_goal(struct sock * sk,u32 mss_now,int large_allowed)911 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
912 int large_allowed)
913 {
914 struct tcp_sock *tp = tcp_sk(sk);
915 u32 new_size_goal, size_goal;
916
917 if (!large_allowed)
918 return mss_now;
919
920 /* Note : tcp_tso_autosize() will eventually split this later */
921 new_size_goal = tcp_bound_to_half_wnd(tp, sk->sk_gso_max_size);
922
923 /* We try hard to avoid divides here */
924 size_goal = tp->gso_segs * mss_now;
925 if (unlikely(new_size_goal < size_goal ||
926 new_size_goal >= size_goal + mss_now)) {
927 tp->gso_segs = min_t(u16, new_size_goal / mss_now,
928 sk->sk_gso_max_segs);
929 size_goal = tp->gso_segs * mss_now;
930 }
931
932 return max(size_goal, mss_now);
933 }
934
tcp_send_mss(struct sock * sk,int * size_goal,int flags)935 int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
936 {
937 int mss_now;
938
939 mss_now = tcp_current_mss(sk);
940 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
941
942 return mss_now;
943 }
944
945 /* In some cases, sendmsg() could have added an skb to the write queue,
946 * but failed adding payload on it. We need to remove it to consume less
947 * memory, but more importantly be able to generate EPOLLOUT for Edge Trigger
948 * epoll() users. Another reason is that tcp_write_xmit() does not like
949 * finding an empty skb in the write queue.
950 */
tcp_remove_empty_skb(struct sock * sk)951 void tcp_remove_empty_skb(struct sock *sk)
952 {
953 struct sk_buff *skb = tcp_write_queue_tail(sk);
954
955 if (skb && TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) {
956 tcp_unlink_write_queue(skb, sk);
957 if (tcp_write_queue_empty(sk))
958 tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
959 tcp_wmem_free_skb(sk, skb);
960 }
961 }
962
963 /* skb changing from pure zc to mixed, must charge zc */
tcp_downgrade_zcopy_pure(struct sock * sk,struct sk_buff * skb)964 static int tcp_downgrade_zcopy_pure(struct sock *sk, struct sk_buff *skb)
965 {
966 if (unlikely(skb_zcopy_pure(skb))) {
967 u32 extra = skb->truesize -
968 SKB_TRUESIZE(skb_end_offset(skb));
969
970 if (!sk_wmem_schedule(sk, extra))
971 return -ENOMEM;
972
973 sk_mem_charge(sk, extra);
974 skb_shinfo(skb)->flags &= ~SKBFL_PURE_ZEROCOPY;
975 }
976 return 0;
977 }
978
979
tcp_wmem_schedule(struct sock * sk,int copy)980 int tcp_wmem_schedule(struct sock *sk, int copy)
981 {
982 int left;
983
984 if (likely(sk_wmem_schedule(sk, copy)))
985 return copy;
986
987 /* We could be in trouble if we have nothing queued.
988 * Use whatever is left in sk->sk_forward_alloc and tcp_wmem[0]
989 * to guarantee some progress.
990 */
991 left = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[0]) - sk->sk_wmem_queued;
992 if (left > 0)
993 sk_forced_mem_schedule(sk, min(left, copy));
994 return min(copy, sk->sk_forward_alloc);
995 }
996
tcp_free_fastopen_req(struct tcp_sock * tp)997 void tcp_free_fastopen_req(struct tcp_sock *tp)
998 {
999 if (tp->fastopen_req) {
1000 kfree(tp->fastopen_req);
1001 tp->fastopen_req = NULL;
1002 }
1003 }
1004
tcp_sendmsg_fastopen(struct sock * sk,struct msghdr * msg,int * copied,size_t size,struct ubuf_info * uarg)1005 int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied,
1006 size_t size, struct ubuf_info *uarg)
1007 {
1008 struct tcp_sock *tp = tcp_sk(sk);
1009 struct inet_sock *inet = inet_sk(sk);
1010 struct sockaddr *uaddr = msg->msg_name;
1011 int err, flags;
1012
1013 if (!(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen) &
1014 TFO_CLIENT_ENABLE) ||
1015 (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
1016 uaddr->sa_family == AF_UNSPEC))
1017 return -EOPNOTSUPP;
1018 if (tp->fastopen_req)
1019 return -EALREADY; /* Another Fast Open is in progress */
1020
1021 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
1022 sk->sk_allocation);
1023 if (unlikely(!tp->fastopen_req))
1024 return -ENOBUFS;
1025 tp->fastopen_req->data = msg;
1026 tp->fastopen_req->size = size;
1027 tp->fastopen_req->uarg = uarg;
1028
1029 if (inet_test_bit(DEFER_CONNECT, sk)) {
1030 err = tcp_connect(sk);
1031 /* Same failure procedure as in tcp_v4/6_connect */
1032 if (err) {
1033 tcp_set_state(sk, TCP_CLOSE);
1034 inet->inet_dport = 0;
1035 sk->sk_route_caps = 0;
1036 }
1037 }
1038 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1039 err = __inet_stream_connect(sk->sk_socket, uaddr,
1040 msg->msg_namelen, flags, 1);
1041 /* fastopen_req could already be freed in __inet_stream_connect
1042 * if the connection times out or gets rst
1043 */
1044 if (tp->fastopen_req) {
1045 *copied = tp->fastopen_req->copied;
1046 tcp_free_fastopen_req(tp);
1047 inet_clear_bit(DEFER_CONNECT, sk);
1048 }
1049 return err;
1050 }
1051
tcp_sendmsg_locked(struct sock * sk,struct msghdr * msg,size_t size)1052 int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
1053 {
1054 struct tcp_sock *tp = tcp_sk(sk);
1055 struct ubuf_info *uarg = NULL;
1056 struct sk_buff *skb;
1057 struct sockcm_cookie sockc;
1058 int flags, err, copied = 0;
1059 int mss_now = 0, size_goal, copied_syn = 0;
1060 int process_backlog = 0;
1061 int zc = 0;
1062 long timeo;
1063
1064 flags = msg->msg_flags;
1065
1066 if ((flags & MSG_ZEROCOPY) && size) {
1067 if (msg->msg_ubuf) {
1068 uarg = msg->msg_ubuf;
1069 if (sk->sk_route_caps & NETIF_F_SG)
1070 zc = MSG_ZEROCOPY;
1071 } else if (sock_flag(sk, SOCK_ZEROCOPY)) {
1072 skb = tcp_write_queue_tail(sk);
1073 uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb));
1074 if (!uarg) {
1075 err = -ENOBUFS;
1076 goto out_err;
1077 }
1078 if (sk->sk_route_caps & NETIF_F_SG)
1079 zc = MSG_ZEROCOPY;
1080 else
1081 uarg_to_msgzc(uarg)->zerocopy = 0;
1082 }
1083 } else if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES) && size) {
1084 if (sk->sk_route_caps & NETIF_F_SG)
1085 zc = MSG_SPLICE_PAGES;
1086 }
1087
1088 if (unlikely(flags & MSG_FASTOPEN ||
1089 inet_test_bit(DEFER_CONNECT, sk)) &&
1090 !tp->repair) {
1091 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size, uarg);
1092 if (err == -EINPROGRESS && copied_syn > 0)
1093 goto out;
1094 else if (err)
1095 goto out_err;
1096 }
1097
1098 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1099
1100 tcp_rate_check_app_limited(sk); /* is sending application-limited? */
1101
1102 /* Wait for a connection to finish. One exception is TCP Fast Open
1103 * (passive side) where data is allowed to be sent before a connection
1104 * is fully established.
1105 */
1106 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
1107 !tcp_passive_fastopen(sk)) {
1108 err = sk_stream_wait_connect(sk, &timeo);
1109 if (err != 0)
1110 goto do_error;
1111 }
1112
1113 if (unlikely(tp->repair)) {
1114 if (tp->repair_queue == TCP_RECV_QUEUE) {
1115 copied = tcp_send_rcvq(sk, msg, size);
1116 goto out_nopush;
1117 }
1118
1119 err = -EINVAL;
1120 if (tp->repair_queue == TCP_NO_QUEUE)
1121 goto out_err;
1122
1123 /* 'common' sending to sendq */
1124 }
1125
1126 sockcm_init(&sockc, sk);
1127 if (msg->msg_controllen) {
1128 err = sock_cmsg_send(sk, msg, &sockc);
1129 if (unlikely(err)) {
1130 err = -EINVAL;
1131 goto out_err;
1132 }
1133 }
1134
1135 /* This should be in poll */
1136 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1137
1138 /* Ok commence sending. */
1139 copied = 0;
1140
1141 restart:
1142 mss_now = tcp_send_mss(sk, &size_goal, flags);
1143
1144 err = -EPIPE;
1145 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1146 goto do_error;
1147
1148 while (msg_data_left(msg)) {
1149 ssize_t copy = 0;
1150
1151 skb = tcp_write_queue_tail(sk);
1152 if (skb)
1153 copy = size_goal - skb->len;
1154
1155 if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1156 bool first_skb;
1157
1158 new_segment:
1159 if (!sk_stream_memory_free(sk))
1160 goto wait_for_space;
1161
1162 if (unlikely(process_backlog >= 16)) {
1163 process_backlog = 0;
1164 if (sk_flush_backlog(sk))
1165 goto restart;
1166 }
1167 first_skb = tcp_rtx_and_write_queues_empty(sk);
1168 skb = tcp_stream_alloc_skb(sk, sk->sk_allocation,
1169 first_skb);
1170 if (!skb)
1171 goto wait_for_space;
1172
1173 process_backlog++;
1174
1175 #ifdef CONFIG_SKB_DECRYPTED
1176 skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED);
1177 #endif
1178 tcp_skb_entail(sk, skb);
1179 copy = size_goal;
1180
1181 /* All packets are restored as if they have
1182 * already been sent. skb_mstamp_ns isn't set to
1183 * avoid wrong rtt estimation.
1184 */
1185 if (tp->repair)
1186 TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
1187 }
1188
1189 /* Try to append data to the end of skb. */
1190 if (copy > msg_data_left(msg))
1191 copy = msg_data_left(msg);
1192
1193 if (zc == 0) {
1194 bool merge = true;
1195 int i = skb_shinfo(skb)->nr_frags;
1196 struct page_frag *pfrag = sk_page_frag(sk);
1197
1198 if (!sk_page_frag_refill(sk, pfrag))
1199 goto wait_for_space;
1200
1201 if (!skb_can_coalesce(skb, i, pfrag->page,
1202 pfrag->offset)) {
1203 if (i >= READ_ONCE(net_hotdata.sysctl_max_skb_frags)) {
1204 tcp_mark_push(tp, skb);
1205 goto new_segment;
1206 }
1207 merge = false;
1208 }
1209
1210 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1211
1212 if (unlikely(skb_zcopy_pure(skb) || skb_zcopy_managed(skb))) {
1213 if (tcp_downgrade_zcopy_pure(sk, skb))
1214 goto wait_for_space;
1215 skb_zcopy_downgrade_managed(skb);
1216 }
1217
1218 copy = tcp_wmem_schedule(sk, copy);
1219 if (!copy)
1220 goto wait_for_space;
1221
1222 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
1223 pfrag->page,
1224 pfrag->offset,
1225 copy);
1226 if (err)
1227 goto do_error;
1228
1229 /* Update the skb. */
1230 if (merge) {
1231 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1232 } else {
1233 skb_fill_page_desc(skb, i, pfrag->page,
1234 pfrag->offset, copy);
1235 page_ref_inc(pfrag->page);
1236 }
1237 pfrag->offset += copy;
1238 } else if (zc == MSG_ZEROCOPY) {
1239 /* First append to a fragless skb builds initial
1240 * pure zerocopy skb
1241 */
1242 if (!skb->len)
1243 skb_shinfo(skb)->flags |= SKBFL_PURE_ZEROCOPY;
1244
1245 if (!skb_zcopy_pure(skb)) {
1246 copy = tcp_wmem_schedule(sk, copy);
1247 if (!copy)
1248 goto wait_for_space;
1249 }
1250
1251 err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
1252 if (err == -EMSGSIZE || err == -EEXIST) {
1253 tcp_mark_push(tp, skb);
1254 goto new_segment;
1255 }
1256 if (err < 0)
1257 goto do_error;
1258 copy = err;
1259 } else if (zc == MSG_SPLICE_PAGES) {
1260 /* Splice in data if we can; copy if we can't. */
1261 if (tcp_downgrade_zcopy_pure(sk, skb))
1262 goto wait_for_space;
1263 copy = tcp_wmem_schedule(sk, copy);
1264 if (!copy)
1265 goto wait_for_space;
1266
1267 err = skb_splice_from_iter(skb, &msg->msg_iter, copy,
1268 sk->sk_allocation);
1269 if (err < 0) {
1270 if (err == -EMSGSIZE) {
1271 tcp_mark_push(tp, skb);
1272 goto new_segment;
1273 }
1274 goto do_error;
1275 }
1276 copy = err;
1277
1278 if (!(flags & MSG_NO_SHARED_FRAGS))
1279 skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG;
1280
1281 sk_wmem_queued_add(sk, copy);
1282 sk_mem_charge(sk, copy);
1283 }
1284
1285 if (!copied)
1286 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
1287
1288 WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
1289 TCP_SKB_CB(skb)->end_seq += copy;
1290 tcp_skb_pcount_set(skb, 0);
1291
1292 copied += copy;
1293 if (!msg_data_left(msg)) {
1294 if (unlikely(flags & MSG_EOR))
1295 TCP_SKB_CB(skb)->eor = 1;
1296 goto out;
1297 }
1298
1299 if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
1300 continue;
1301
1302 if (forced_push(tp)) {
1303 tcp_mark_push(tp, skb);
1304 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1305 } else if (skb == tcp_send_head(sk))
1306 tcp_push_one(sk, mss_now);
1307 continue;
1308
1309 wait_for_space:
1310 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1311 tcp_remove_empty_skb(sk);
1312 if (copied)
1313 tcp_push(sk, flags & ~MSG_MORE, mss_now,
1314 TCP_NAGLE_PUSH, size_goal);
1315
1316 err = sk_stream_wait_memory(sk, &timeo);
1317 if (err != 0)
1318 goto do_error;
1319
1320 mss_now = tcp_send_mss(sk, &size_goal, flags);
1321 }
1322
1323 out:
1324 if (copied) {
1325 tcp_tx_timestamp(sk, &sockc);
1326 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1327 }
1328 out_nopush:
1329 /* msg->msg_ubuf is pinned by the caller so we don't take extra refs */
1330 if (uarg && !msg->msg_ubuf)
1331 net_zcopy_put(uarg);
1332 return copied + copied_syn;
1333
1334 do_error:
1335 tcp_remove_empty_skb(sk);
1336
1337 if (copied + copied_syn)
1338 goto out;
1339 out_err:
1340 /* msg->msg_ubuf is pinned by the caller so we don't take extra refs */
1341 if (uarg && !msg->msg_ubuf)
1342 net_zcopy_put_abort(uarg, true);
1343 err = sk_stream_error(sk, flags, err);
1344 /* make sure we wake any epoll edge trigger waiter */
1345 if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) {
1346 sk->sk_write_space(sk);
1347 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
1348 }
1349 return err;
1350 }
1351 EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1352
tcp_sendmsg(struct sock * sk,struct msghdr * msg,size_t size)1353 int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
1354 {
1355 int ret;
1356
1357 lock_sock(sk);
1358 ret = tcp_sendmsg_locked(sk, msg, size);
1359 release_sock(sk);
1360
1361 return ret;
1362 }
1363 EXPORT_SYMBOL(tcp_sendmsg);
1364
tcp_splice_eof(struct socket * sock)1365 void tcp_splice_eof(struct socket *sock)
1366 {
1367 struct sock *sk = sock->sk;
1368 struct tcp_sock *tp = tcp_sk(sk);
1369 int mss_now, size_goal;
1370
1371 if (!tcp_write_queue_tail(sk))
1372 return;
1373
1374 lock_sock(sk);
1375 mss_now = tcp_send_mss(sk, &size_goal, 0);
1376 tcp_push(sk, 0, mss_now, tp->nonagle, size_goal);
1377 release_sock(sk);
1378 }
1379 EXPORT_SYMBOL_GPL(tcp_splice_eof);
1380
1381 /*
1382 * Handle reading urgent data. BSD has very simple semantics for
1383 * this, no blocking and very strange errors 8)
1384 */
1385
tcp_recv_urg(struct sock * sk,struct msghdr * msg,int len,int flags)1386 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
1387 {
1388 struct tcp_sock *tp = tcp_sk(sk);
1389
1390 /* No URG data to read. */
1391 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
1392 tp->urg_data == TCP_URG_READ)
1393 return -EINVAL; /* Yes this is right ! */
1394
1395 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
1396 return -ENOTCONN;
1397
1398 if (tp->urg_data & TCP_URG_VALID) {
1399 int err = 0;
1400 char c = tp->urg_data;
1401
1402 if (!(flags & MSG_PEEK))
1403 WRITE_ONCE(tp->urg_data, TCP_URG_READ);
1404
1405 /* Read urgent data. */
1406 msg->msg_flags |= MSG_OOB;
1407
1408 if (len > 0) {
1409 if (!(flags & MSG_TRUNC))
1410 err = memcpy_to_msg(msg, &c, 1);
1411 len = 1;
1412 } else
1413 msg->msg_flags |= MSG_TRUNC;
1414
1415 return err ? -EFAULT : len;
1416 }
1417
1418 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
1419 return 0;
1420
1421 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
1422 * the available implementations agree in this case:
1423 * this call should never block, independent of the
1424 * blocking state of the socket.
1425 * Mike <pall@rz.uni-karlsruhe.de>
1426 */
1427 return -EAGAIN;
1428 }
1429
tcp_peek_sndq(struct sock * sk,struct msghdr * msg,int len)1430 static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
1431 {
1432 struct sk_buff *skb;
1433 int copied = 0, err = 0;
1434
1435 skb_rbtree_walk(skb, &sk->tcp_rtx_queue) {
1436 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
1437 if (err)
1438 return err;
1439 copied += skb->len;
1440 }
1441
1442 skb_queue_walk(&sk->sk_write_queue, skb) {
1443 err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
1444 if (err)
1445 break;
1446
1447 copied += skb->len;
1448 }
1449
1450 return err ?: copied;
1451 }
1452
1453 /* Clean up the receive buffer for full frames taken by the user,
1454 * then send an ACK if necessary. COPIED is the number of bytes
1455 * tcp_recvmsg has given to the user so far, it speeds up the
1456 * calculation of whether or not we must ACK for the sake of
1457 * a window update.
1458 */
__tcp_cleanup_rbuf(struct sock * sk,int copied)1459 void __tcp_cleanup_rbuf(struct sock *sk, int copied)
1460 {
1461 struct tcp_sock *tp = tcp_sk(sk);
1462 bool time_to_ack = false;
1463
1464 if (inet_csk_ack_scheduled(sk)) {
1465 const struct inet_connection_sock *icsk = inet_csk(sk);
1466
1467 if (/* Once-per-two-segments ACK was not sent by tcp_input.c */
1468 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
1469 /*
1470 * If this read emptied read buffer, we send ACK, if
1471 * connection is not bidirectional, user drained
1472 * receive buffer and there was a small segment
1473 * in queue.
1474 */
1475 (copied > 0 &&
1476 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
1477 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
1478 !inet_csk_in_pingpong_mode(sk))) &&
1479 !atomic_read(&sk->sk_rmem_alloc)))
1480 time_to_ack = true;
1481 }
1482
1483 /* We send an ACK if we can now advertise a non-zero window
1484 * which has been raised "significantly".
1485 *
1486 * Even if window raised up to infinity, do not send window open ACK
1487 * in states, where we will not receive more. It is useless.
1488 */
1489 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1490 __u32 rcv_window_now = tcp_receive_window(tp);
1491
1492 /* Optimize, __tcp_select_window() is not cheap. */
1493 if (2*rcv_window_now <= tp->window_clamp) {
1494 __u32 new_window = __tcp_select_window(sk);
1495
1496 /* Send ACK now, if this read freed lots of space
1497 * in our buffer. Certainly, new_window is new window.
1498 * We can advertise it now, if it is not less than current one.
1499 * "Lots" means "at least twice" here.
1500 */
1501 if (new_window && new_window >= 2 * rcv_window_now)
1502 time_to_ack = true;
1503 }
1504 }
1505 if (time_to_ack)
1506 tcp_send_ack(sk);
1507 }
1508
tcp_cleanup_rbuf(struct sock * sk,int copied)1509 void tcp_cleanup_rbuf(struct sock *sk, int copied)
1510 {
1511 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1512 struct tcp_sock *tp = tcp_sk(sk);
1513
1514 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
1515 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1516 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
1517 __tcp_cleanup_rbuf(sk, copied);
1518 }
1519
tcp_eat_recv_skb(struct sock * sk,struct sk_buff * skb)1520 static void tcp_eat_recv_skb(struct sock *sk, struct sk_buff *skb)
1521 {
1522 __skb_unlink(skb, &sk->sk_receive_queue);
1523 if (likely(skb->destructor == sock_rfree)) {
1524 sock_rfree(skb);
1525 skb->destructor = NULL;
1526 skb->sk = NULL;
1527 return skb_attempt_defer_free(skb);
1528 }
1529 __kfree_skb(skb);
1530 }
1531
tcp_recv_skb(struct sock * sk,u32 seq,u32 * off)1532 struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
1533 {
1534 struct sk_buff *skb;
1535 u32 offset;
1536
1537 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1538 offset = seq - TCP_SKB_CB(skb)->seq;
1539 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
1540 pr_err_once("%s: found a SYN, please report !\n", __func__);
1541 offset--;
1542 }
1543 if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
1544 *off = offset;
1545 return skb;
1546 }
1547 /* This looks weird, but this can happen if TCP collapsing
1548 * splitted a fat GRO packet, while we released socket lock
1549 * in skb_splice_bits()
1550 */
1551 tcp_eat_recv_skb(sk, skb);
1552 }
1553 return NULL;
1554 }
1555 EXPORT_SYMBOL(tcp_recv_skb);
1556
1557 /*
1558 * This routine provides an alternative to tcp_recvmsg() for routines
1559 * that would like to handle copying from skbuffs directly in 'sendfile'
1560 * fashion.
1561 * Note:
1562 * - It is assumed that the socket was locked by the caller.
1563 * - The routine does not block.
1564 * - At present, there is no support for reading OOB data
1565 * or for 'peeking' the socket using this routine
1566 * (although both would be easy to implement).
1567 */
__tcp_read_sock(struct sock * sk,read_descriptor_t * desc,sk_read_actor_t recv_actor,bool noack,u32 * copied_seq)1568 static int __tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1569 sk_read_actor_t recv_actor, bool noack,
1570 u32 *copied_seq)
1571 {
1572 struct sk_buff *skb;
1573 struct tcp_sock *tp = tcp_sk(sk);
1574 u32 seq = *copied_seq;
1575 u32 offset;
1576 int copied = 0;
1577
1578 if (sk->sk_state == TCP_LISTEN)
1579 return -ENOTCONN;
1580 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1581 if (offset < skb->len) {
1582 int used;
1583 size_t len;
1584
1585 len = skb->len - offset;
1586 /* Stop reading if we hit a patch of urgent data */
1587 if (unlikely(tp->urg_data)) {
1588 u32 urg_offset = tp->urg_seq - seq;
1589 if (urg_offset < len)
1590 len = urg_offset;
1591 if (!len)
1592 break;
1593 }
1594 used = recv_actor(desc, skb, offset, len);
1595 if (used <= 0) {
1596 if (!copied)
1597 copied = used;
1598 break;
1599 }
1600 if (WARN_ON_ONCE(used > len))
1601 used = len;
1602 seq += used;
1603 copied += used;
1604 offset += used;
1605
1606 /* If recv_actor drops the lock (e.g. TCP splice
1607 * receive) the skb pointer might be invalid when
1608 * getting here: tcp_collapse might have deleted it
1609 * while aggregating skbs from the socket queue.
1610 */
1611 skb = tcp_recv_skb(sk, seq - 1, &offset);
1612 if (!skb)
1613 break;
1614 /* TCP coalescing might have appended data to the skb.
1615 * Try to splice more frags
1616 */
1617 if (offset + 1 != skb->len)
1618 continue;
1619 }
1620 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
1621 tcp_eat_recv_skb(sk, skb);
1622 ++seq;
1623 break;
1624 }
1625 tcp_eat_recv_skb(sk, skb);
1626 if (!desc->count)
1627 break;
1628 WRITE_ONCE(*copied_seq, seq);
1629 }
1630 WRITE_ONCE(*copied_seq, seq);
1631
1632 if (noack)
1633 goto out;
1634
1635 tcp_rcv_space_adjust(sk);
1636
1637 /* Clean up data we have read: This will do ACK frames. */
1638 if (copied > 0) {
1639 tcp_recv_skb(sk, seq, &offset);
1640 tcp_cleanup_rbuf(sk, copied);
1641 }
1642 out:
1643 return copied;
1644 }
1645
tcp_read_sock(struct sock * sk,read_descriptor_t * desc,sk_read_actor_t recv_actor)1646 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
1647 sk_read_actor_t recv_actor)
1648 {
1649 return __tcp_read_sock(sk, desc, recv_actor, false,
1650 &tcp_sk(sk)->copied_seq);
1651 }
1652 EXPORT_SYMBOL(tcp_read_sock);
1653
tcp_read_sock_noack(struct sock * sk,read_descriptor_t * desc,sk_read_actor_t recv_actor,bool noack,u32 * copied_seq)1654 int tcp_read_sock_noack(struct sock *sk, read_descriptor_t *desc,
1655 sk_read_actor_t recv_actor, bool noack,
1656 u32 *copied_seq)
1657 {
1658 return __tcp_read_sock(sk, desc, recv_actor, noack, copied_seq);
1659 }
1660
tcp_read_skb(struct sock * sk,skb_read_actor_t recv_actor)1661 int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
1662 {
1663 struct sk_buff *skb;
1664 int copied = 0;
1665
1666 if (sk->sk_state == TCP_LISTEN)
1667 return -ENOTCONN;
1668
1669 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
1670 u8 tcp_flags;
1671 int used;
1672
1673 __skb_unlink(skb, &sk->sk_receive_queue);
1674 WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
1675 tcp_flags = TCP_SKB_CB(skb)->tcp_flags;
1676 used = recv_actor(sk, skb);
1677 if (used < 0) {
1678 if (!copied)
1679 copied = used;
1680 break;
1681 }
1682 copied += used;
1683
1684 if (tcp_flags & TCPHDR_FIN)
1685 break;
1686 }
1687 return copied;
1688 }
1689 EXPORT_SYMBOL(tcp_read_skb);
1690
tcp_read_done(struct sock * sk,size_t len)1691 void tcp_read_done(struct sock *sk, size_t len)
1692 {
1693 struct tcp_sock *tp = tcp_sk(sk);
1694 u32 seq = tp->copied_seq;
1695 struct sk_buff *skb;
1696 size_t left;
1697 u32 offset;
1698
1699 if (sk->sk_state == TCP_LISTEN)
1700 return;
1701
1702 left = len;
1703 while (left && (skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
1704 int used;
1705
1706 used = min_t(size_t, skb->len - offset, left);
1707 seq += used;
1708 left -= used;
1709
1710 if (skb->len > offset + used)
1711 break;
1712
1713 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
1714 tcp_eat_recv_skb(sk, skb);
1715 ++seq;
1716 break;
1717 }
1718 tcp_eat_recv_skb(sk, skb);
1719 }
1720 WRITE_ONCE(tp->copied_seq, seq);
1721
1722 tcp_rcv_space_adjust(sk);
1723
1724 /* Clean up data we have read: This will do ACK frames. */
1725 if (left != len)
1726 tcp_cleanup_rbuf(sk, len - left);
1727 }
1728 EXPORT_SYMBOL(tcp_read_done);
1729
tcp_peek_len(struct socket * sock)1730 int tcp_peek_len(struct socket *sock)
1731 {
1732 return tcp_inq(sock->sk);
1733 }
1734 EXPORT_SYMBOL(tcp_peek_len);
1735
1736 /* Make sure sk_rcvbuf is big enough to satisfy SO_RCVLOWAT hint */
tcp_set_rcvlowat(struct sock * sk,int val)1737 int tcp_set_rcvlowat(struct sock *sk, int val)
1738 {
1739 int space, cap;
1740
1741 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
1742 cap = sk->sk_rcvbuf >> 1;
1743 else
1744 cap = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2]) >> 1;
1745 val = min(val, cap);
1746 WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1747
1748 /* Check if we need to signal EPOLLIN right now */
1749 tcp_data_ready(sk);
1750
1751 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
1752 return 0;
1753
1754 space = tcp_space_from_win(sk, val);
1755 if (space > sk->sk_rcvbuf) {
1756 WRITE_ONCE(sk->sk_rcvbuf, space);
1757 WRITE_ONCE(tcp_sk(sk)->window_clamp, val);
1758 }
1759 return 0;
1760 }
1761 EXPORT_SYMBOL(tcp_set_rcvlowat);
1762
tcp_update_recv_tstamps(struct sk_buff * skb,struct scm_timestamping_internal * tss)1763 void tcp_update_recv_tstamps(struct sk_buff *skb,
1764 struct scm_timestamping_internal *tss)
1765 {
1766 if (skb->tstamp)
1767 tss->ts[0] = ktime_to_timespec64(skb->tstamp);
1768 else
1769 tss->ts[0] = (struct timespec64) {0};
1770
1771 if (skb_hwtstamps(skb)->hwtstamp)
1772 tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp);
1773 else
1774 tss->ts[2] = (struct timespec64) {0};
1775 }
1776
1777 #ifdef CONFIG_MMU
1778 static const struct vm_operations_struct tcp_vm_ops = {
1779 };
1780
tcp_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)1781 int tcp_mmap(struct file *file, struct socket *sock,
1782 struct vm_area_struct *vma)
1783 {
1784 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
1785 return -EPERM;
1786 vm_flags_clear(vma, VM_MAYWRITE | VM_MAYEXEC);
1787
1788 /* Instruct vm_insert_page() to not mmap_read_lock(mm) */
1789 vm_flags_set(vma, VM_MIXEDMAP);
1790
1791 vma->vm_ops = &tcp_vm_ops;
1792 return 0;
1793 }
1794 EXPORT_SYMBOL(tcp_mmap);
1795
skb_advance_to_frag(struct sk_buff * skb,u32 offset_skb,u32 * offset_frag)1796 static skb_frag_t *skb_advance_to_frag(struct sk_buff *skb, u32 offset_skb,
1797 u32 *offset_frag)
1798 {
1799 skb_frag_t *frag;
1800
1801 if (unlikely(offset_skb >= skb->len))
1802 return NULL;
1803
1804 offset_skb -= skb_headlen(skb);
1805 if ((int)offset_skb < 0 || skb_has_frag_list(skb))
1806 return NULL;
1807
1808 frag = skb_shinfo(skb)->frags;
1809 while (offset_skb) {
1810 if (skb_frag_size(frag) > offset_skb) {
1811 *offset_frag = offset_skb;
1812 return frag;
1813 }
1814 offset_skb -= skb_frag_size(frag);
1815 ++frag;
1816 }
1817 *offset_frag = 0;
1818 return frag;
1819 }
1820
can_map_frag(const skb_frag_t * frag)1821 static bool can_map_frag(const skb_frag_t *frag)
1822 {
1823 struct page *page;
1824
1825 if (skb_frag_size(frag) != PAGE_SIZE || skb_frag_off(frag))
1826 return false;
1827
1828 page = skb_frag_page(frag);
1829
1830 if (PageCompound(page) || page->mapping)
1831 return false;
1832
1833 return true;
1834 }
1835
find_next_mappable_frag(const skb_frag_t * frag,int remaining_in_skb)1836 static int find_next_mappable_frag(const skb_frag_t *frag,
1837 int remaining_in_skb)
1838 {
1839 int offset = 0;
1840
1841 if (likely(can_map_frag(frag)))
1842 return 0;
1843
1844 while (offset < remaining_in_skb && !can_map_frag(frag)) {
1845 offset += skb_frag_size(frag);
1846 ++frag;
1847 }
1848 return offset;
1849 }
1850
tcp_zerocopy_set_hint_for_skb(struct sock * sk,struct tcp_zerocopy_receive * zc,struct sk_buff * skb,u32 offset)1851 static void tcp_zerocopy_set_hint_for_skb(struct sock *sk,
1852 struct tcp_zerocopy_receive *zc,
1853 struct sk_buff *skb, u32 offset)
1854 {
1855 u32 frag_offset, partial_frag_remainder = 0;
1856 int mappable_offset;
1857 skb_frag_t *frag;
1858
1859 /* worst case: skip to next skb. try to improve on this case below */
1860 zc->recv_skip_hint = skb->len - offset;
1861
1862 /* Find the frag containing this offset (and how far into that frag) */
1863 frag = skb_advance_to_frag(skb, offset, &frag_offset);
1864 if (!frag)
1865 return;
1866
1867 if (frag_offset) {
1868 struct skb_shared_info *info = skb_shinfo(skb);
1869
1870 /* We read part of the last frag, must recvmsg() rest of skb. */
1871 if (frag == &info->frags[info->nr_frags - 1])
1872 return;
1873
1874 /* Else, we must at least read the remainder in this frag. */
1875 partial_frag_remainder = skb_frag_size(frag) - frag_offset;
1876 zc->recv_skip_hint -= partial_frag_remainder;
1877 ++frag;
1878 }
1879
1880 /* partial_frag_remainder: If part way through a frag, must read rest.
1881 * mappable_offset: Bytes till next mappable frag, *not* counting bytes
1882 * in partial_frag_remainder.
1883 */
1884 mappable_offset = find_next_mappable_frag(frag, zc->recv_skip_hint);
1885 zc->recv_skip_hint = mappable_offset + partial_frag_remainder;
1886 }
1887
1888 static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
1889 int flags, struct scm_timestamping_internal *tss,
1890 int *cmsg_flags);
receive_fallback_to_copy(struct sock * sk,struct tcp_zerocopy_receive * zc,int inq,struct scm_timestamping_internal * tss)1891 static int receive_fallback_to_copy(struct sock *sk,
1892 struct tcp_zerocopy_receive *zc, int inq,
1893 struct scm_timestamping_internal *tss)
1894 {
1895 unsigned long copy_address = (unsigned long)zc->copybuf_address;
1896 struct msghdr msg = {};
1897 int err;
1898
1899 zc->length = 0;
1900 zc->recv_skip_hint = 0;
1901
1902 if (copy_address != zc->copybuf_address)
1903 return -EINVAL;
1904
1905 err = import_ubuf(ITER_DEST, (void __user *)copy_address, inq,
1906 &msg.msg_iter);
1907 if (err)
1908 return err;
1909
1910 err = tcp_recvmsg_locked(sk, &msg, inq, MSG_DONTWAIT,
1911 tss, &zc->msg_flags);
1912 if (err < 0)
1913 return err;
1914
1915 zc->copybuf_len = err;
1916 if (likely(zc->copybuf_len)) {
1917 struct sk_buff *skb;
1918 u32 offset;
1919
1920 skb = tcp_recv_skb(sk, tcp_sk(sk)->copied_seq, &offset);
1921 if (skb)
1922 tcp_zerocopy_set_hint_for_skb(sk, zc, skb, offset);
1923 }
1924 return 0;
1925 }
1926
tcp_copy_straggler_data(struct tcp_zerocopy_receive * zc,struct sk_buff * skb,u32 copylen,u32 * offset,u32 * seq)1927 static int tcp_copy_straggler_data(struct tcp_zerocopy_receive *zc,
1928 struct sk_buff *skb, u32 copylen,
1929 u32 *offset, u32 *seq)
1930 {
1931 unsigned long copy_address = (unsigned long)zc->copybuf_address;
1932 struct msghdr msg = {};
1933 int err;
1934
1935 if (copy_address != zc->copybuf_address)
1936 return -EINVAL;
1937
1938 err = import_ubuf(ITER_DEST, (void __user *)copy_address, copylen,
1939 &msg.msg_iter);
1940 if (err)
1941 return err;
1942 err = skb_copy_datagram_msg(skb, *offset, &msg, copylen);
1943 if (err)
1944 return err;
1945 zc->recv_skip_hint -= copylen;
1946 *offset += copylen;
1947 *seq += copylen;
1948 return (__s32)copylen;
1949 }
1950
tcp_zc_handle_leftover(struct tcp_zerocopy_receive * zc,struct sock * sk,struct sk_buff * skb,u32 * seq,s32 copybuf_len,struct scm_timestamping_internal * tss)1951 static int tcp_zc_handle_leftover(struct tcp_zerocopy_receive *zc,
1952 struct sock *sk,
1953 struct sk_buff *skb,
1954 u32 *seq,
1955 s32 copybuf_len,
1956 struct scm_timestamping_internal *tss)
1957 {
1958 u32 offset, copylen = min_t(u32, copybuf_len, zc->recv_skip_hint);
1959
1960 if (!copylen)
1961 return 0;
1962 /* skb is null if inq < PAGE_SIZE. */
1963 if (skb) {
1964 offset = *seq - TCP_SKB_CB(skb)->seq;
1965 } else {
1966 skb = tcp_recv_skb(sk, *seq, &offset);
1967 if (TCP_SKB_CB(skb)->has_rxtstamp) {
1968 tcp_update_recv_tstamps(skb, tss);
1969 zc->msg_flags |= TCP_CMSG_TS;
1970 }
1971 }
1972
1973 zc->copybuf_len = tcp_copy_straggler_data(zc, skb, copylen, &offset,
1974 seq);
1975 return zc->copybuf_len < 0 ? 0 : copylen;
1976 }
1977
tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct * vma,struct page ** pending_pages,unsigned long pages_remaining,unsigned long * address,u32 * length,u32 * seq,struct tcp_zerocopy_receive * zc,u32 total_bytes_to_map,int err)1978 static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma,
1979 struct page **pending_pages,
1980 unsigned long pages_remaining,
1981 unsigned long *address,
1982 u32 *length,
1983 u32 *seq,
1984 struct tcp_zerocopy_receive *zc,
1985 u32 total_bytes_to_map,
1986 int err)
1987 {
1988 /* At least one page did not map. Try zapping if we skipped earlier. */
1989 if (err == -EBUSY &&
1990 zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT) {
1991 u32 maybe_zap_len;
1992
1993 maybe_zap_len = total_bytes_to_map - /* All bytes to map */
1994 *length + /* Mapped or pending */
1995 (pages_remaining * PAGE_SIZE); /* Failed map. */
1996 zap_page_range_single(vma, *address, maybe_zap_len, NULL);
1997 err = 0;
1998 }
1999
2000 if (!err) {
2001 unsigned long leftover_pages = pages_remaining;
2002 int bytes_mapped;
2003
2004 /* We called zap_page_range_single, try to reinsert. */
2005 err = vm_insert_pages(vma, *address,
2006 pending_pages,
2007 &pages_remaining);
2008 bytes_mapped = PAGE_SIZE * (leftover_pages - pages_remaining);
2009 *seq += bytes_mapped;
2010 *address += bytes_mapped;
2011 }
2012 if (err) {
2013 /* Either we were unable to zap, OR we zapped, retried an
2014 * insert, and still had an issue. Either ways, pages_remaining
2015 * is the number of pages we were unable to map, and we unroll
2016 * some state we speculatively touched before.
2017 */
2018 const int bytes_not_mapped = PAGE_SIZE * pages_remaining;
2019
2020 *length -= bytes_not_mapped;
2021 zc->recv_skip_hint += bytes_not_mapped;
2022 }
2023 return err;
2024 }
2025
tcp_zerocopy_vm_insert_batch(struct vm_area_struct * vma,struct page ** pages,unsigned int pages_to_map,unsigned long * address,u32 * length,u32 * seq,struct tcp_zerocopy_receive * zc,u32 total_bytes_to_map)2026 static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma,
2027 struct page **pages,
2028 unsigned int pages_to_map,
2029 unsigned long *address,
2030 u32 *length,
2031 u32 *seq,
2032 struct tcp_zerocopy_receive *zc,
2033 u32 total_bytes_to_map)
2034 {
2035 unsigned long pages_remaining = pages_to_map;
2036 unsigned int pages_mapped;
2037 unsigned int bytes_mapped;
2038 int err;
2039
2040 err = vm_insert_pages(vma, *address, pages, &pages_remaining);
2041 pages_mapped = pages_to_map - (unsigned int)pages_remaining;
2042 bytes_mapped = PAGE_SIZE * pages_mapped;
2043 /* Even if vm_insert_pages fails, it may have partially succeeded in
2044 * mapping (some but not all of the pages).
2045 */
2046 *seq += bytes_mapped;
2047 *address += bytes_mapped;
2048
2049 if (likely(!err))
2050 return 0;
2051
2052 /* Error: maybe zap and retry + rollback state for failed inserts. */
2053 return tcp_zerocopy_vm_insert_batch_error(vma, pages + pages_mapped,
2054 pages_remaining, address, length, seq, zc, total_bytes_to_map,
2055 err);
2056 }
2057
2058 #define TCP_VALID_ZC_MSG_FLAGS (TCP_CMSG_TS)
tcp_zc_finalize_rx_tstamp(struct sock * sk,struct tcp_zerocopy_receive * zc,struct scm_timestamping_internal * tss)2059 static void tcp_zc_finalize_rx_tstamp(struct sock *sk,
2060 struct tcp_zerocopy_receive *zc,
2061 struct scm_timestamping_internal *tss)
2062 {
2063 unsigned long msg_control_addr;
2064 struct msghdr cmsg_dummy;
2065
2066 msg_control_addr = (unsigned long)zc->msg_control;
2067 cmsg_dummy.msg_control_user = (void __user *)msg_control_addr;
2068 cmsg_dummy.msg_controllen =
2069 (__kernel_size_t)zc->msg_controllen;
2070 cmsg_dummy.msg_flags = in_compat_syscall()
2071 ? MSG_CMSG_COMPAT : 0;
2072 cmsg_dummy.msg_control_is_user = true;
2073 zc->msg_flags = 0;
2074 if (zc->msg_control == msg_control_addr &&
2075 zc->msg_controllen == cmsg_dummy.msg_controllen) {
2076 tcp_recv_timestamp(&cmsg_dummy, sk, tss);
2077 zc->msg_control = (__u64)
2078 ((uintptr_t)cmsg_dummy.msg_control_user);
2079 zc->msg_controllen =
2080 (__u64)cmsg_dummy.msg_controllen;
2081 zc->msg_flags = (__u32)cmsg_dummy.msg_flags;
2082 }
2083 }
2084
find_tcp_vma(struct mm_struct * mm,unsigned long address,bool * mmap_locked)2085 static struct vm_area_struct *find_tcp_vma(struct mm_struct *mm,
2086 unsigned long address,
2087 bool *mmap_locked)
2088 {
2089 struct vm_area_struct *vma = lock_vma_under_rcu(mm, address);
2090
2091 if (vma) {
2092 if (vma->vm_ops != &tcp_vm_ops) {
2093 vma_end_read(vma);
2094 return NULL;
2095 }
2096 *mmap_locked = false;
2097 return vma;
2098 }
2099
2100 mmap_read_lock(mm);
2101 vma = vma_lookup(mm, address);
2102 if (!vma || vma->vm_ops != &tcp_vm_ops) {
2103 mmap_read_unlock(mm);
2104 return NULL;
2105 }
2106 *mmap_locked = true;
2107 return vma;
2108 }
2109
2110 #define TCP_ZEROCOPY_PAGE_BATCH_SIZE 32
tcp_zerocopy_receive(struct sock * sk,struct tcp_zerocopy_receive * zc,struct scm_timestamping_internal * tss)2111 static int tcp_zerocopy_receive(struct sock *sk,
2112 struct tcp_zerocopy_receive *zc,
2113 struct scm_timestamping_internal *tss)
2114 {
2115 u32 length = 0, offset, vma_len, avail_len, copylen = 0;
2116 unsigned long address = (unsigned long)zc->address;
2117 struct page *pages[TCP_ZEROCOPY_PAGE_BATCH_SIZE];
2118 s32 copybuf_len = zc->copybuf_len;
2119 struct tcp_sock *tp = tcp_sk(sk);
2120 const skb_frag_t *frags = NULL;
2121 unsigned int pages_to_map = 0;
2122 struct vm_area_struct *vma;
2123 struct sk_buff *skb = NULL;
2124 u32 seq = tp->copied_seq;
2125 u32 total_bytes_to_map;
2126 int inq = tcp_inq(sk);
2127 bool mmap_locked;
2128 int ret;
2129
2130 zc->copybuf_len = 0;
2131 zc->msg_flags = 0;
2132
2133 if (address & (PAGE_SIZE - 1) || address != zc->address)
2134 return -EINVAL;
2135
2136 if (sk->sk_state == TCP_LISTEN)
2137 return -ENOTCONN;
2138
2139 sock_rps_record_flow(sk);
2140
2141 if (inq && inq <= copybuf_len)
2142 return receive_fallback_to_copy(sk, zc, inq, tss);
2143
2144 if (inq < PAGE_SIZE) {
2145 zc->length = 0;
2146 zc->recv_skip_hint = inq;
2147 if (!inq && sock_flag(sk, SOCK_DONE))
2148 return -EIO;
2149 return 0;
2150 }
2151
2152 vma = find_tcp_vma(current->mm, address, &mmap_locked);
2153 if (!vma)
2154 return -EINVAL;
2155
2156 vma_len = min_t(unsigned long, zc->length, vma->vm_end - address);
2157 avail_len = min_t(u32, vma_len, inq);
2158 total_bytes_to_map = avail_len & ~(PAGE_SIZE - 1);
2159 if (total_bytes_to_map) {
2160 if (!(zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT))
2161 zap_page_range_single(vma, address, total_bytes_to_map,
2162 NULL);
2163 zc->length = total_bytes_to_map;
2164 zc->recv_skip_hint = 0;
2165 } else {
2166 zc->length = avail_len;
2167 zc->recv_skip_hint = avail_len;
2168 }
2169 ret = 0;
2170 while (length + PAGE_SIZE <= zc->length) {
2171 int mappable_offset;
2172 struct page *page;
2173
2174 if (zc->recv_skip_hint < PAGE_SIZE) {
2175 u32 offset_frag;
2176
2177 if (skb) {
2178 if (zc->recv_skip_hint > 0)
2179 break;
2180 skb = skb->next;
2181 offset = seq - TCP_SKB_CB(skb)->seq;
2182 } else {
2183 skb = tcp_recv_skb(sk, seq, &offset);
2184 }
2185
2186 if (!skb_frags_readable(skb))
2187 break;
2188
2189 if (TCP_SKB_CB(skb)->has_rxtstamp) {
2190 tcp_update_recv_tstamps(skb, tss);
2191 zc->msg_flags |= TCP_CMSG_TS;
2192 }
2193 zc->recv_skip_hint = skb->len - offset;
2194 frags = skb_advance_to_frag(skb, offset, &offset_frag);
2195 if (!frags || offset_frag)
2196 break;
2197 }
2198
2199 mappable_offset = find_next_mappable_frag(frags,
2200 zc->recv_skip_hint);
2201 if (mappable_offset) {
2202 zc->recv_skip_hint = mappable_offset;
2203 break;
2204 }
2205 page = skb_frag_page(frags);
2206 if (WARN_ON_ONCE(!page))
2207 break;
2208
2209 prefetchw(page);
2210 pages[pages_to_map++] = page;
2211 length += PAGE_SIZE;
2212 zc->recv_skip_hint -= PAGE_SIZE;
2213 frags++;
2214 if (pages_to_map == TCP_ZEROCOPY_PAGE_BATCH_SIZE ||
2215 zc->recv_skip_hint < PAGE_SIZE) {
2216 /* Either full batch, or we're about to go to next skb
2217 * (and we cannot unroll failed ops across skbs).
2218 */
2219 ret = tcp_zerocopy_vm_insert_batch(vma, pages,
2220 pages_to_map,
2221 &address, &length,
2222 &seq, zc,
2223 total_bytes_to_map);
2224 if (ret)
2225 goto out;
2226 pages_to_map = 0;
2227 }
2228 }
2229 if (pages_to_map) {
2230 ret = tcp_zerocopy_vm_insert_batch(vma, pages, pages_to_map,
2231 &address, &length, &seq,
2232 zc, total_bytes_to_map);
2233 }
2234 out:
2235 if (mmap_locked)
2236 mmap_read_unlock(current->mm);
2237 else
2238 vma_end_read(vma);
2239 /* Try to copy straggler data. */
2240 if (!ret)
2241 copylen = tcp_zc_handle_leftover(zc, sk, skb, &seq, copybuf_len, tss);
2242
2243 if (length + copylen) {
2244 WRITE_ONCE(tp->copied_seq, seq);
2245 tcp_rcv_space_adjust(sk);
2246
2247 /* Clean up data we have read: This will do ACK frames. */
2248 tcp_recv_skb(sk, seq, &offset);
2249 tcp_cleanup_rbuf(sk, length + copylen);
2250 ret = 0;
2251 if (length == zc->length)
2252 zc->recv_skip_hint = 0;
2253 } else {
2254 if (!zc->recv_skip_hint && sock_flag(sk, SOCK_DONE))
2255 ret = -EIO;
2256 }
2257 zc->length = length;
2258 return ret;
2259 }
2260 #endif
2261
2262 /* Similar to __sock_recv_timestamp, but does not require an skb */
tcp_recv_timestamp(struct msghdr * msg,const struct sock * sk,struct scm_timestamping_internal * tss)2263 void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
2264 struct scm_timestamping_internal *tss)
2265 {
2266 int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
2267 u32 tsflags = READ_ONCE(sk->sk_tsflags);
2268 bool has_timestamping = false;
2269
2270 if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) {
2271 if (sock_flag(sk, SOCK_RCVTSTAMP)) {
2272 if (sock_flag(sk, SOCK_RCVTSTAMPNS)) {
2273 if (new_tstamp) {
2274 struct __kernel_timespec kts = {
2275 .tv_sec = tss->ts[0].tv_sec,
2276 .tv_nsec = tss->ts[0].tv_nsec,
2277 };
2278 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
2279 sizeof(kts), &kts);
2280 } else {
2281 struct __kernel_old_timespec ts_old = {
2282 .tv_sec = tss->ts[0].tv_sec,
2283 .tv_nsec = tss->ts[0].tv_nsec,
2284 };
2285 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
2286 sizeof(ts_old), &ts_old);
2287 }
2288 } else {
2289 if (new_tstamp) {
2290 struct __kernel_sock_timeval stv = {
2291 .tv_sec = tss->ts[0].tv_sec,
2292 .tv_usec = tss->ts[0].tv_nsec / 1000,
2293 };
2294 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
2295 sizeof(stv), &stv);
2296 } else {
2297 struct __kernel_old_timeval tv = {
2298 .tv_sec = tss->ts[0].tv_sec,
2299 .tv_usec = tss->ts[0].tv_nsec / 1000,
2300 };
2301 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
2302 sizeof(tv), &tv);
2303 }
2304 }
2305 }
2306
2307 if (tsflags & SOF_TIMESTAMPING_SOFTWARE &&
2308 (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE ||
2309 !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER)))
2310 has_timestamping = true;
2311 else
2312 tss->ts[0] = (struct timespec64) {0};
2313 }
2314
2315 if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
2316 if (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE &&
2317 (tsflags & SOF_TIMESTAMPING_RX_HARDWARE ||
2318 !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER)))
2319 has_timestamping = true;
2320 else
2321 tss->ts[2] = (struct timespec64) {0};
2322 }
2323
2324 if (has_timestamping) {
2325 tss->ts[1] = (struct timespec64) {0};
2326 if (sock_flag(sk, SOCK_TSTAMP_NEW))
2327 put_cmsg_scm_timestamping64(msg, tss);
2328 else
2329 put_cmsg_scm_timestamping(msg, tss);
2330 }
2331 }
2332
tcp_inq_hint(struct sock * sk)2333 static int tcp_inq_hint(struct sock *sk)
2334 {
2335 const struct tcp_sock *tp = tcp_sk(sk);
2336 u32 copied_seq = READ_ONCE(tp->copied_seq);
2337 u32 rcv_nxt = READ_ONCE(tp->rcv_nxt);
2338 int inq;
2339
2340 inq = rcv_nxt - copied_seq;
2341 if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) {
2342 lock_sock(sk);
2343 inq = tp->rcv_nxt - tp->copied_seq;
2344 release_sock(sk);
2345 }
2346 /* After receiving a FIN, tell the user-space to continue reading
2347 * by returning a non-zero inq.
2348 */
2349 if (inq == 0 && sock_flag(sk, SOCK_DONE))
2350 inq = 1;
2351 return inq;
2352 }
2353
2354 /* batch __xa_alloc() calls and reduce xa_lock()/xa_unlock() overhead. */
2355 struct tcp_xa_pool {
2356 u8 max; /* max <= MAX_SKB_FRAGS */
2357 u8 idx; /* idx <= max */
2358 __u32 tokens[MAX_SKB_FRAGS];
2359 netmem_ref netmems[MAX_SKB_FRAGS];
2360 };
2361
tcp_xa_pool_commit_locked(struct sock * sk,struct tcp_xa_pool * p)2362 static void tcp_xa_pool_commit_locked(struct sock *sk, struct tcp_xa_pool *p)
2363 {
2364 int i;
2365
2366 /* Commit part that has been copied to user space. */
2367 for (i = 0; i < p->idx; i++)
2368 __xa_cmpxchg(&sk->sk_user_frags, p->tokens[i], XA_ZERO_ENTRY,
2369 (__force void *)p->netmems[i], GFP_KERNEL);
2370 /* Rollback what has been pre-allocated and is no longer needed. */
2371 for (; i < p->max; i++)
2372 __xa_erase(&sk->sk_user_frags, p->tokens[i]);
2373
2374 p->max = 0;
2375 p->idx = 0;
2376 }
2377
tcp_xa_pool_commit(struct sock * sk,struct tcp_xa_pool * p)2378 static void tcp_xa_pool_commit(struct sock *sk, struct tcp_xa_pool *p)
2379 {
2380 if (!p->max)
2381 return;
2382
2383 xa_lock_bh(&sk->sk_user_frags);
2384
2385 tcp_xa_pool_commit_locked(sk, p);
2386
2387 xa_unlock_bh(&sk->sk_user_frags);
2388 }
2389
tcp_xa_pool_refill(struct sock * sk,struct tcp_xa_pool * p,unsigned int max_frags)2390 static int tcp_xa_pool_refill(struct sock *sk, struct tcp_xa_pool *p,
2391 unsigned int max_frags)
2392 {
2393 int err, k;
2394
2395 if (p->idx < p->max)
2396 return 0;
2397
2398 xa_lock_bh(&sk->sk_user_frags);
2399
2400 tcp_xa_pool_commit_locked(sk, p);
2401
2402 for (k = 0; k < max_frags; k++) {
2403 err = __xa_alloc(&sk->sk_user_frags, &p->tokens[k],
2404 XA_ZERO_ENTRY, xa_limit_31b, GFP_KERNEL);
2405 if (err)
2406 break;
2407 }
2408
2409 xa_unlock_bh(&sk->sk_user_frags);
2410
2411 p->max = k;
2412 p->idx = 0;
2413 return k ? 0 : err;
2414 }
2415
2416 /* On error, returns the -errno. On success, returns number of bytes sent to the
2417 * user. May not consume all of @remaining_len.
2418 */
tcp_recvmsg_dmabuf(struct sock * sk,const struct sk_buff * skb,unsigned int offset,struct msghdr * msg,int remaining_len)2419 static int tcp_recvmsg_dmabuf(struct sock *sk, const struct sk_buff *skb,
2420 unsigned int offset, struct msghdr *msg,
2421 int remaining_len)
2422 {
2423 struct dmabuf_cmsg dmabuf_cmsg = { 0 };
2424 struct tcp_xa_pool tcp_xa_pool;
2425 unsigned int start;
2426 int i, copy, n;
2427 int sent = 0;
2428 int err = 0;
2429
2430 tcp_xa_pool.max = 0;
2431 tcp_xa_pool.idx = 0;
2432 do {
2433 start = skb_headlen(skb);
2434
2435 if (skb_frags_readable(skb)) {
2436 err = -ENODEV;
2437 goto out;
2438 }
2439
2440 /* Copy header. */
2441 copy = start - offset;
2442 if (copy > 0) {
2443 copy = min(copy, remaining_len);
2444
2445 n = copy_to_iter(skb->data + offset, copy,
2446 &msg->msg_iter);
2447 if (n != copy) {
2448 err = -EFAULT;
2449 goto out;
2450 }
2451
2452 offset += copy;
2453 remaining_len -= copy;
2454
2455 /* First a dmabuf_cmsg for # bytes copied to user
2456 * buffer.
2457 */
2458 memset(&dmabuf_cmsg, 0, sizeof(dmabuf_cmsg));
2459 dmabuf_cmsg.frag_size = copy;
2460 err = put_cmsg_notrunc(msg, SOL_SOCKET,
2461 SO_DEVMEM_LINEAR,
2462 sizeof(dmabuf_cmsg),
2463 &dmabuf_cmsg);
2464 if (err)
2465 goto out;
2466
2467 sent += copy;
2468
2469 if (remaining_len == 0)
2470 goto out;
2471 }
2472
2473 /* after that, send information of dmabuf pages through a
2474 * sequence of cmsg
2475 */
2476 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2477 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2478 struct net_iov *niov;
2479 u64 frag_offset;
2480 int end;
2481
2482 /* !skb_frags_readable() should indicate that ALL the
2483 * frags in this skb are dmabuf net_iovs. We're checking
2484 * for that flag above, but also check individual frags
2485 * here. If the tcp stack is not setting
2486 * skb_frags_readable() correctly, we still don't want
2487 * to crash here.
2488 */
2489 if (!skb_frag_net_iov(frag)) {
2490 net_err_ratelimited("Found non-dmabuf skb with net_iov");
2491 err = -ENODEV;
2492 goto out;
2493 }
2494
2495 niov = skb_frag_net_iov(frag);
2496 end = start + skb_frag_size(frag);
2497 copy = end - offset;
2498
2499 if (copy > 0) {
2500 copy = min(copy, remaining_len);
2501
2502 frag_offset = net_iov_virtual_addr(niov) +
2503 skb_frag_off(frag) + offset -
2504 start;
2505 dmabuf_cmsg.frag_offset = frag_offset;
2506 dmabuf_cmsg.frag_size = copy;
2507 err = tcp_xa_pool_refill(sk, &tcp_xa_pool,
2508 skb_shinfo(skb)->nr_frags - i);
2509 if (err)
2510 goto out;
2511
2512 /* Will perform the exchange later */
2513 dmabuf_cmsg.frag_token = tcp_xa_pool.tokens[tcp_xa_pool.idx];
2514 dmabuf_cmsg.dmabuf_id = net_iov_binding_id(niov);
2515
2516 offset += copy;
2517 remaining_len -= copy;
2518
2519 err = put_cmsg_notrunc(msg, SOL_SOCKET,
2520 SO_DEVMEM_DMABUF,
2521 sizeof(dmabuf_cmsg),
2522 &dmabuf_cmsg);
2523 if (err)
2524 goto out;
2525
2526 atomic_long_inc(&niov->pp_ref_count);
2527 tcp_xa_pool.netmems[tcp_xa_pool.idx++] = skb_frag_netmem(frag);
2528
2529 sent += copy;
2530
2531 if (remaining_len == 0)
2532 goto out;
2533 }
2534 start = end;
2535 }
2536
2537 tcp_xa_pool_commit(sk, &tcp_xa_pool);
2538 if (!remaining_len)
2539 goto out;
2540
2541 /* if remaining_len is not satisfied yet, we need to go to the
2542 * next frag in the frag_list to satisfy remaining_len.
2543 */
2544 skb = skb_shinfo(skb)->frag_list ?: skb->next;
2545
2546 offset = offset - start;
2547 } while (skb);
2548
2549 if (remaining_len) {
2550 err = -EFAULT;
2551 goto out;
2552 }
2553
2554 out:
2555 tcp_xa_pool_commit(sk, &tcp_xa_pool);
2556 if (!sent)
2557 sent = err;
2558
2559 return sent;
2560 }
2561
2562 /*
2563 * This routine copies from a sock struct into the user buffer.
2564 *
2565 * Technical note: in 2.3 we work on _locked_ socket, so that
2566 * tricks with *seq access order and skb->users are not required.
2567 * Probably, code can be easily improved even more.
2568 */
2569
tcp_recvmsg_locked(struct sock * sk,struct msghdr * msg,size_t len,int flags,struct scm_timestamping_internal * tss,int * cmsg_flags)2570 static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
2571 int flags, struct scm_timestamping_internal *tss,
2572 int *cmsg_flags)
2573 {
2574 struct tcp_sock *tp = tcp_sk(sk);
2575 int last_copied_dmabuf = -1; /* uninitialized */
2576 int copied = 0;
2577 u32 peek_seq;
2578 u32 *seq;
2579 unsigned long used;
2580 int err;
2581 int target; /* Read at least this many bytes */
2582 long timeo;
2583 struct sk_buff *skb, *last;
2584 u32 peek_offset = 0;
2585 u32 urg_hole = 0;
2586
2587 err = -ENOTCONN;
2588 if (sk->sk_state == TCP_LISTEN)
2589 goto out;
2590
2591 if (tp->recvmsg_inq) {
2592 *cmsg_flags = TCP_CMSG_INQ;
2593 msg->msg_get_inq = 1;
2594 }
2595 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
2596
2597 /* Urgent data needs to be handled specially. */
2598 if (flags & MSG_OOB)
2599 goto recv_urg;
2600
2601 if (unlikely(tp->repair)) {
2602 err = -EPERM;
2603 if (!(flags & MSG_PEEK))
2604 goto out;
2605
2606 if (tp->repair_queue == TCP_SEND_QUEUE)
2607 goto recv_sndq;
2608
2609 err = -EINVAL;
2610 if (tp->repair_queue == TCP_NO_QUEUE)
2611 goto out;
2612
2613 /* 'common' recv queue MSG_PEEK-ing */
2614 }
2615
2616 seq = &tp->copied_seq;
2617 if (flags & MSG_PEEK) {
2618 peek_offset = max(sk_peek_offset(sk, flags), 0);
2619 peek_seq = tp->copied_seq + peek_offset;
2620 seq = &peek_seq;
2621 }
2622
2623 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
2624
2625 do {
2626 u32 offset;
2627
2628 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
2629 if (unlikely(tp->urg_data) && tp->urg_seq == *seq) {
2630 if (copied)
2631 break;
2632 if (signal_pending(current)) {
2633 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
2634 break;
2635 }
2636 }
2637
2638 /* Next get a buffer. */
2639
2640 last = skb_peek_tail(&sk->sk_receive_queue);
2641 skb_queue_walk(&sk->sk_receive_queue, skb) {
2642 last = skb;
2643 /* Now that we have two receive queues this
2644 * shouldn't happen.
2645 */
2646 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
2647 "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n",
2648 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
2649 flags))
2650 break;
2651
2652 offset = *seq - TCP_SKB_CB(skb)->seq;
2653 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
2654 pr_err_once("%s: found a SYN, please report !\n", __func__);
2655 offset--;
2656 }
2657 if (offset < skb->len)
2658 goto found_ok_skb;
2659 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2660 goto found_fin_ok;
2661 WARN(!(flags & MSG_PEEK),
2662 "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n",
2663 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
2664 }
2665
2666 /* Well, if we have backlog, try to process it now yet. */
2667
2668 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
2669 break;
2670
2671 if (copied) {
2672 if (!timeo ||
2673 sk->sk_err ||
2674 sk->sk_state == TCP_CLOSE ||
2675 (sk->sk_shutdown & RCV_SHUTDOWN) ||
2676 signal_pending(current))
2677 break;
2678 } else {
2679 if (sock_flag(sk, SOCK_DONE))
2680 break;
2681
2682 if (sk->sk_err) {
2683 copied = sock_error(sk);
2684 break;
2685 }
2686
2687 if (sk->sk_shutdown & RCV_SHUTDOWN)
2688 break;
2689
2690 if (sk->sk_state == TCP_CLOSE) {
2691 /* This occurs when user tries to read
2692 * from never connected socket.
2693 */
2694 copied = -ENOTCONN;
2695 break;
2696 }
2697
2698 if (!timeo) {
2699 copied = -EAGAIN;
2700 break;
2701 }
2702
2703 if (signal_pending(current)) {
2704 copied = sock_intr_errno(timeo);
2705 break;
2706 }
2707 }
2708
2709 if (copied >= target) {
2710 /* Do not sleep, just process backlog. */
2711 __sk_flush_backlog(sk);
2712 } else {
2713 tcp_cleanup_rbuf(sk, copied);
2714 err = sk_wait_data(sk, &timeo, last);
2715 if (err < 0) {
2716 err = copied ? : err;
2717 goto out;
2718 }
2719 }
2720
2721 if ((flags & MSG_PEEK) &&
2722 (peek_seq - peek_offset - copied - urg_hole != tp->copied_seq)) {
2723 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
2724 current->comm,
2725 task_pid_nr(current));
2726 peek_seq = tp->copied_seq + peek_offset;
2727 }
2728 continue;
2729
2730 found_ok_skb:
2731 /* Ok so how much can we use? */
2732 used = skb->len - offset;
2733 if (len < used)
2734 used = len;
2735
2736 /* Do we have urgent data here? */
2737 if (unlikely(tp->urg_data)) {
2738 u32 urg_offset = tp->urg_seq - *seq;
2739 if (urg_offset < used) {
2740 if (!urg_offset) {
2741 if (!sock_flag(sk, SOCK_URGINLINE)) {
2742 WRITE_ONCE(*seq, *seq + 1);
2743 urg_hole++;
2744 offset++;
2745 used--;
2746 if (!used)
2747 goto skip_copy;
2748 }
2749 } else
2750 used = urg_offset;
2751 }
2752 }
2753
2754 if (!(flags & MSG_TRUNC)) {
2755 if (last_copied_dmabuf != -1 &&
2756 last_copied_dmabuf != !skb_frags_readable(skb))
2757 break;
2758
2759 if (skb_frags_readable(skb)) {
2760 err = skb_copy_datagram_msg(skb, offset, msg,
2761 used);
2762 if (err) {
2763 /* Exception. Bailout! */
2764 if (!copied)
2765 copied = -EFAULT;
2766 break;
2767 }
2768 } else {
2769 if (!(flags & MSG_SOCK_DEVMEM)) {
2770 /* dmabuf skbs can only be received
2771 * with the MSG_SOCK_DEVMEM flag.
2772 */
2773 if (!copied)
2774 copied = -EFAULT;
2775
2776 break;
2777 }
2778
2779 err = tcp_recvmsg_dmabuf(sk, skb, offset, msg,
2780 used);
2781 if (err <= 0) {
2782 if (!copied)
2783 copied = -EFAULT;
2784
2785 break;
2786 }
2787 used = err;
2788 }
2789 }
2790
2791 last_copied_dmabuf = !skb_frags_readable(skb);
2792
2793 WRITE_ONCE(*seq, *seq + used);
2794 copied += used;
2795 len -= used;
2796 if (flags & MSG_PEEK)
2797 sk_peek_offset_fwd(sk, used);
2798 else
2799 sk_peek_offset_bwd(sk, used);
2800 tcp_rcv_space_adjust(sk);
2801
2802 skip_copy:
2803 if (unlikely(tp->urg_data) && after(tp->copied_seq, tp->urg_seq)) {
2804 WRITE_ONCE(tp->urg_data, 0);
2805 tcp_fast_path_check(sk);
2806 }
2807
2808 if (TCP_SKB_CB(skb)->has_rxtstamp) {
2809 tcp_update_recv_tstamps(skb, tss);
2810 *cmsg_flags |= TCP_CMSG_TS;
2811 }
2812
2813 if (used + offset < skb->len)
2814 continue;
2815
2816 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
2817 goto found_fin_ok;
2818 if (!(flags & MSG_PEEK))
2819 tcp_eat_recv_skb(sk, skb);
2820 continue;
2821
2822 found_fin_ok:
2823 /* Process the FIN. */
2824 WRITE_ONCE(*seq, *seq + 1);
2825 if (!(flags & MSG_PEEK))
2826 tcp_eat_recv_skb(sk, skb);
2827 break;
2828 } while (len > 0);
2829
2830 /* According to UNIX98, msg_name/msg_namelen are ignored
2831 * on connected socket. I was just happy when found this 8) --ANK
2832 */
2833
2834 /* Clean up data we have read: This will do ACK frames. */
2835 tcp_cleanup_rbuf(sk, copied);
2836 return copied;
2837
2838 out:
2839 return err;
2840
2841 recv_urg:
2842 err = tcp_recv_urg(sk, msg, len, flags);
2843 goto out;
2844
2845 recv_sndq:
2846 err = tcp_peek_sndq(sk, msg, len);
2847 goto out;
2848 }
2849
tcp_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)2850 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
2851 int *addr_len)
2852 {
2853 int cmsg_flags = 0, ret;
2854 struct scm_timestamping_internal tss;
2855
2856 if (unlikely(flags & MSG_ERRQUEUE))
2857 return inet_recv_error(sk, msg, len, addr_len);
2858
2859 if (sk_can_busy_loop(sk) &&
2860 skb_queue_empty_lockless(&sk->sk_receive_queue) &&
2861 sk->sk_state == TCP_ESTABLISHED)
2862 sk_busy_loop(sk, flags & MSG_DONTWAIT);
2863
2864 lock_sock(sk);
2865 ret = tcp_recvmsg_locked(sk, msg, len, flags, &tss, &cmsg_flags);
2866 release_sock(sk);
2867
2868 if ((cmsg_flags || msg->msg_get_inq) && ret >= 0) {
2869 if (cmsg_flags & TCP_CMSG_TS)
2870 tcp_recv_timestamp(msg, sk, &tss);
2871 if (msg->msg_get_inq) {
2872 msg->msg_inq = tcp_inq_hint(sk);
2873 if (cmsg_flags & TCP_CMSG_INQ)
2874 put_cmsg(msg, SOL_TCP, TCP_CM_INQ,
2875 sizeof(msg->msg_inq), &msg->msg_inq);
2876 }
2877 }
2878 return ret;
2879 }
2880 EXPORT_SYMBOL(tcp_recvmsg);
2881
tcp_set_state(struct sock * sk,int state)2882 void tcp_set_state(struct sock *sk, int state)
2883 {
2884 int oldstate = sk->sk_state;
2885
2886 /* We defined a new enum for TCP states that are exported in BPF
2887 * so as not force the internal TCP states to be frozen. The
2888 * following checks will detect if an internal state value ever
2889 * differs from the BPF value. If this ever happens, then we will
2890 * need to remap the internal value to the BPF value before calling
2891 * tcp_call_bpf_2arg.
2892 */
2893 BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED);
2894 BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT);
2895 BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV);
2896 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1);
2897 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2);
2898 BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT);
2899 BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE);
2900 BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT);
2901 BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK);
2902 BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN);
2903 BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING);
2904 BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV);
2905 BUILD_BUG_ON((int)BPF_TCP_BOUND_INACTIVE != (int)TCP_BOUND_INACTIVE);
2906 BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES);
2907
2908 /* bpf uapi header bpf.h defines an anonymous enum with values
2909 * BPF_TCP_* used by bpf programs. Currently gcc built vmlinux
2910 * is able to emit this enum in DWARF due to the above BUILD_BUG_ON.
2911 * But clang built vmlinux does not have this enum in DWARF
2912 * since clang removes the above code before generating IR/debuginfo.
2913 * Let us explicitly emit the type debuginfo to ensure the
2914 * above-mentioned anonymous enum in the vmlinux DWARF and hence BTF
2915 * regardless of which compiler is used.
2916 */
2917 BTF_TYPE_EMIT_ENUM(BPF_TCP_ESTABLISHED);
2918
2919 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG))
2920 tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state);
2921
2922 switch (state) {
2923 case TCP_ESTABLISHED:
2924 if (oldstate != TCP_ESTABLISHED)
2925 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2926 break;
2927 case TCP_CLOSE_WAIT:
2928 if (oldstate == TCP_SYN_RECV)
2929 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2930 break;
2931
2932 case TCP_CLOSE:
2933 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
2934 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
2935
2936 sk->sk_prot->unhash(sk);
2937 if (inet_csk(sk)->icsk_bind_hash &&
2938 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2939 inet_put_port(sk);
2940 fallthrough;
2941 default:
2942 if (oldstate == TCP_ESTABLISHED || oldstate == TCP_CLOSE_WAIT)
2943 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
2944 }
2945
2946 /* Change state AFTER socket is unhashed to avoid closed
2947 * socket sitting in hash tables.
2948 */
2949 inet_sk_state_store(sk, state);
2950 }
2951 EXPORT_SYMBOL_GPL(tcp_set_state);
2952
2953 /*
2954 * State processing on a close. This implements the state shift for
2955 * sending our FIN frame. Note that we only send a FIN for some
2956 * states. A shutdown() may have already sent the FIN, or we may be
2957 * closed.
2958 */
2959
2960 static const unsigned char new_state[16] = {
2961 /* current state: new state: action: */
2962 [0 /* (Invalid) */] = TCP_CLOSE,
2963 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2964 [TCP_SYN_SENT] = TCP_CLOSE,
2965 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN,
2966 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1,
2967 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2,
2968 [TCP_TIME_WAIT] = TCP_CLOSE,
2969 [TCP_CLOSE] = TCP_CLOSE,
2970 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN,
2971 [TCP_LAST_ACK] = TCP_LAST_ACK,
2972 [TCP_LISTEN] = TCP_CLOSE,
2973 [TCP_CLOSING] = TCP_CLOSING,
2974 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */
2975 };
2976
tcp_close_state(struct sock * sk)2977 static int tcp_close_state(struct sock *sk)
2978 {
2979 int next = (int)new_state[sk->sk_state];
2980 int ns = next & TCP_STATE_MASK;
2981
2982 tcp_set_state(sk, ns);
2983
2984 return next & TCP_ACTION_FIN;
2985 }
2986
2987 /*
2988 * Shutdown the sending side of a connection. Much like close except
2989 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
2990 */
2991
tcp_shutdown(struct sock * sk,int how)2992 void tcp_shutdown(struct sock *sk, int how)
2993 {
2994 /* We need to grab some memory, and put together a FIN,
2995 * and then put it into the queue to be sent.
2996 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
2997 */
2998 if (!(how & SEND_SHUTDOWN))
2999 return;
3000
3001 /* If we've already sent a FIN, or it's a closed state, skip this. */
3002 if ((1 << sk->sk_state) &
3003 (TCPF_ESTABLISHED | TCPF_SYN_SENT |
3004 TCPF_CLOSE_WAIT)) {
3005 /* Clear out any half completed packets. FIN if needed. */
3006 if (tcp_close_state(sk))
3007 tcp_send_fin(sk);
3008 }
3009 }
3010 EXPORT_SYMBOL(tcp_shutdown);
3011
tcp_orphan_count_sum(void)3012 int tcp_orphan_count_sum(void)
3013 {
3014 int i, total = 0;
3015
3016 for_each_possible_cpu(i)
3017 total += per_cpu(tcp_orphan_count, i);
3018
3019 return max(total, 0);
3020 }
3021
3022 static int tcp_orphan_cache;
3023 static struct timer_list tcp_orphan_timer;
3024 #define TCP_ORPHAN_TIMER_PERIOD msecs_to_jiffies(100)
3025
tcp_orphan_update(struct timer_list * unused)3026 static void tcp_orphan_update(struct timer_list *unused)
3027 {
3028 WRITE_ONCE(tcp_orphan_cache, tcp_orphan_count_sum());
3029 mod_timer(&tcp_orphan_timer, jiffies + TCP_ORPHAN_TIMER_PERIOD);
3030 }
3031
tcp_too_many_orphans(int shift)3032 static bool tcp_too_many_orphans(int shift)
3033 {
3034 return READ_ONCE(tcp_orphan_cache) << shift >
3035 READ_ONCE(sysctl_tcp_max_orphans);
3036 }
3037
tcp_out_of_memory(const struct sock * sk)3038 static bool tcp_out_of_memory(const struct sock *sk)
3039 {
3040 if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
3041 sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2))
3042 return true;
3043 return false;
3044 }
3045
tcp_check_oom(const struct sock * sk,int shift)3046 bool tcp_check_oom(const struct sock *sk, int shift)
3047 {
3048 bool too_many_orphans, out_of_socket_memory;
3049
3050 too_many_orphans = tcp_too_many_orphans(shift);
3051 out_of_socket_memory = tcp_out_of_memory(sk);
3052
3053 if (too_many_orphans)
3054 net_info_ratelimited("too many orphaned sockets\n");
3055 if (out_of_socket_memory)
3056 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
3057 return too_many_orphans || out_of_socket_memory;
3058 }
3059
__tcp_close(struct sock * sk,long timeout)3060 void __tcp_close(struct sock *sk, long timeout)
3061 {
3062 struct sk_buff *skb;
3063 int data_was_unread = 0;
3064 int state;
3065
3066 WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);
3067
3068 if (sk->sk_state == TCP_LISTEN) {
3069 tcp_set_state(sk, TCP_CLOSE);
3070
3071 /* Special case. */
3072 inet_csk_listen_stop(sk);
3073
3074 goto adjudge_to_death;
3075 }
3076
3077 /* We need to flush the recv. buffs. We do this only on the
3078 * descriptor close, not protocol-sourced closes, because the
3079 * reader process may not have drained the data yet!
3080 */
3081 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
3082 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq;
3083
3084 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
3085 len--;
3086 data_was_unread += len;
3087 __kfree_skb(skb);
3088 }
3089
3090 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
3091 if (sk->sk_state == TCP_CLOSE)
3092 goto adjudge_to_death;
3093
3094 /* As outlined in RFC 2525, section 2.17, we send a RST here because
3095 * data was lost. To witness the awful effects of the old behavior of
3096 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
3097 * GET in an FTP client, suspend the process, wait for the client to
3098 * advertise a zero window, then kill -9 the FTP client, wheee...
3099 * Note: timeout is always zero in such a case.
3100 */
3101 if (unlikely(tcp_sk(sk)->repair)) {
3102 sk->sk_prot->disconnect(sk, 0);
3103 } else if (data_was_unread) {
3104 /* Unread data was tossed, zap the connection. */
3105 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
3106 tcp_set_state(sk, TCP_CLOSE);
3107 tcp_send_active_reset(sk, sk->sk_allocation,
3108 SK_RST_REASON_TCP_ABORT_ON_CLOSE);
3109 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
3110 /* Check zero linger _after_ checking for unread data. */
3111 sk->sk_prot->disconnect(sk, 0);
3112 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
3113 } else if (tcp_close_state(sk)) {
3114 /* We FIN if the application ate all the data before
3115 * zapping the connection.
3116 */
3117
3118 /* RED-PEN. Formally speaking, we have broken TCP state
3119 * machine. State transitions:
3120 *
3121 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
3122 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (it is difficult)
3123 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
3124 *
3125 * are legal only when FIN has been sent (i.e. in window),
3126 * rather than queued out of window. Purists blame.
3127 *
3128 * F.e. "RFC state" is ESTABLISHED,
3129 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
3130 *
3131 * The visible declinations are that sometimes
3132 * we enter time-wait state, when it is not required really
3133 * (harmless), do not send active resets, when they are
3134 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
3135 * they look as CLOSING or LAST_ACK for Linux)
3136 * Probably, I missed some more holelets.
3137 * --ANK
3138 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
3139 * in a single packet! (May consider it later but will
3140 * probably need API support or TCP_CORK SYN-ACK until
3141 * data is written and socket is closed.)
3142 */
3143 tcp_send_fin(sk);
3144 }
3145
3146 sk_stream_wait_close(sk, timeout);
3147
3148 adjudge_to_death:
3149 state = sk->sk_state;
3150 sock_hold(sk);
3151 sock_orphan(sk);
3152
3153 local_bh_disable();
3154 bh_lock_sock(sk);
3155 /* remove backlog if any, without releasing ownership. */
3156 __release_sock(sk);
3157
3158 this_cpu_inc(tcp_orphan_count);
3159
3160 /* Have we already been destroyed by a softirq or backlog? */
3161 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
3162 goto out;
3163
3164 /* This is a (useful) BSD violating of the RFC. There is a
3165 * problem with TCP as specified in that the other end could
3166 * keep a socket open forever with no application left this end.
3167 * We use a 1 minute timeout (about the same as BSD) then kill
3168 * our end. If they send after that then tough - BUT: long enough
3169 * that we won't make the old 4*rto = almost no time - whoops
3170 * reset mistake.
3171 *
3172 * Nope, it was not mistake. It is really desired behaviour
3173 * f.e. on http servers, when such sockets are useless, but
3174 * consume significant resources. Let's do it with special
3175 * linger2 option. --ANK
3176 */
3177
3178 if (sk->sk_state == TCP_FIN_WAIT2) {
3179 struct tcp_sock *tp = tcp_sk(sk);
3180 if (READ_ONCE(tp->linger2) < 0) {
3181 tcp_set_state(sk, TCP_CLOSE);
3182 tcp_send_active_reset(sk, GFP_ATOMIC,
3183 SK_RST_REASON_TCP_ABORT_ON_LINGER);
3184 __NET_INC_STATS(sock_net(sk),
3185 LINUX_MIB_TCPABORTONLINGER);
3186 } else {
3187 const int tmo = tcp_fin_time(sk);
3188
3189 if (tmo > TCP_TIMEWAIT_LEN) {
3190 inet_csk_reset_keepalive_timer(sk,
3191 tmo - TCP_TIMEWAIT_LEN);
3192 } else {
3193 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
3194 goto out;
3195 }
3196 }
3197 }
3198 if (sk->sk_state != TCP_CLOSE) {
3199 if (tcp_check_oom(sk, 0)) {
3200 tcp_set_state(sk, TCP_CLOSE);
3201 tcp_send_active_reset(sk, GFP_ATOMIC,
3202 SK_RST_REASON_TCP_ABORT_ON_MEMORY);
3203 __NET_INC_STATS(sock_net(sk),
3204 LINUX_MIB_TCPABORTONMEMORY);
3205 } else if (!check_net(sock_net(sk))) {
3206 /* Not possible to send reset; just close */
3207 tcp_set_state(sk, TCP_CLOSE);
3208 }
3209 }
3210
3211 if (sk->sk_state == TCP_CLOSE) {
3212 struct request_sock *req;
3213
3214 req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk,
3215 lockdep_sock_is_held(sk));
3216 /* We could get here with a non-NULL req if the socket is
3217 * aborted (e.g., closed with unread data) before 3WHS
3218 * finishes.
3219 */
3220 if (req)
3221 reqsk_fastopen_remove(sk, req, false);
3222 inet_csk_destroy_sock(sk);
3223 }
3224 /* Otherwise, socket is reprieved until protocol close. */
3225
3226 out:
3227 bh_unlock_sock(sk);
3228 local_bh_enable();
3229 }
3230
tcp_close(struct sock * sk,long timeout)3231 void tcp_close(struct sock *sk, long timeout)
3232 {
3233 lock_sock(sk);
3234 __tcp_close(sk, timeout);
3235 release_sock(sk);
3236 if (!sk->sk_net_refcnt)
3237 inet_csk_clear_xmit_timers_sync(sk);
3238 sock_put(sk);
3239 }
3240 EXPORT_SYMBOL(tcp_close);
3241
3242 /* These states need RST on ABORT according to RFC793 */
3243
tcp_need_reset(int state)3244 static inline bool tcp_need_reset(int state)
3245 {
3246 return (1 << state) &
3247 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
3248 TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
3249 }
3250
tcp_rtx_queue_purge(struct sock * sk)3251 static void tcp_rtx_queue_purge(struct sock *sk)
3252 {
3253 struct rb_node *p = rb_first(&sk->tcp_rtx_queue);
3254
3255 tcp_sk(sk)->highest_sack = NULL;
3256 while (p) {
3257 struct sk_buff *skb = rb_to_skb(p);
3258
3259 p = rb_next(p);
3260 /* Since we are deleting whole queue, no need to
3261 * list_del(&skb->tcp_tsorted_anchor)
3262 */
3263 tcp_rtx_queue_unlink(skb, sk);
3264 tcp_wmem_free_skb(sk, skb);
3265 }
3266 }
3267
tcp_write_queue_purge(struct sock * sk)3268 void tcp_write_queue_purge(struct sock *sk)
3269 {
3270 struct sk_buff *skb;
3271
3272 tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
3273 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
3274 tcp_skb_tsorted_anchor_cleanup(skb);
3275 tcp_wmem_free_skb(sk, skb);
3276 }
3277 tcp_rtx_queue_purge(sk);
3278 INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
3279 tcp_clear_all_retrans_hints(tcp_sk(sk));
3280 tcp_sk(sk)->packets_out = 0;
3281 inet_csk(sk)->icsk_backoff = 0;
3282 }
3283
tcp_disconnect(struct sock * sk,int flags)3284 int tcp_disconnect(struct sock *sk, int flags)
3285 {
3286 struct inet_sock *inet = inet_sk(sk);
3287 struct inet_connection_sock *icsk = inet_csk(sk);
3288 struct tcp_sock *tp = tcp_sk(sk);
3289 int old_state = sk->sk_state;
3290 u32 seq;
3291
3292 if (old_state != TCP_CLOSE)
3293 tcp_set_state(sk, TCP_CLOSE);
3294
3295 /* ABORT function of RFC793 */
3296 if (old_state == TCP_LISTEN) {
3297 inet_csk_listen_stop(sk);
3298 } else if (unlikely(tp->repair)) {
3299 WRITE_ONCE(sk->sk_err, ECONNABORTED);
3300 } else if (tcp_need_reset(old_state)) {
3301 tcp_send_active_reset(sk, gfp_any(), SK_RST_REASON_TCP_STATE);
3302 WRITE_ONCE(sk->sk_err, ECONNRESET);
3303 } else if (tp->snd_nxt != tp->write_seq &&
3304 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK)) {
3305 /* The last check adjusts for discrepancy of Linux wrt. RFC
3306 * states
3307 */
3308 tcp_send_active_reset(sk, gfp_any(),
3309 SK_RST_REASON_TCP_DISCONNECT_WITH_DATA);
3310 WRITE_ONCE(sk->sk_err, ECONNRESET);
3311 } else if (old_state == TCP_SYN_SENT)
3312 WRITE_ONCE(sk->sk_err, ECONNRESET);
3313
3314 tcp_clear_xmit_timers(sk);
3315 __skb_queue_purge(&sk->sk_receive_queue);
3316 WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
3317 WRITE_ONCE(tp->urg_data, 0);
3318 sk_set_peek_off(sk, -1);
3319 tcp_write_queue_purge(sk);
3320 tcp_fastopen_active_disable_ofo_check(sk);
3321 skb_rbtree_purge(&tp->out_of_order_queue);
3322
3323 inet->inet_dport = 0;
3324
3325 inet_bhash2_reset_saddr(sk);
3326
3327 WRITE_ONCE(sk->sk_shutdown, 0);
3328 sock_reset_flag(sk, SOCK_DONE);
3329 tp->srtt_us = 0;
3330 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
3331 tp->rcv_rtt_last_tsecr = 0;
3332
3333 seq = tp->write_seq + tp->max_window + 2;
3334 if (!seq)
3335 seq = 1;
3336 WRITE_ONCE(tp->write_seq, seq);
3337
3338 icsk->icsk_backoff = 0;
3339 icsk->icsk_probes_out = 0;
3340 icsk->icsk_probes_tstamp = 0;
3341 icsk->icsk_rto = TCP_TIMEOUT_INIT;
3342 icsk->icsk_rto_min = TCP_RTO_MIN;
3343 icsk->icsk_delack_max = TCP_DELACK_MAX;
3344 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
3345 tcp_snd_cwnd_set(tp, TCP_INIT_CWND);
3346 tp->snd_cwnd_cnt = 0;
3347 tp->is_cwnd_limited = 0;
3348 tp->max_packets_out = 0;
3349 tp->window_clamp = 0;
3350 tp->delivered = 0;
3351 tp->delivered_ce = 0;
3352 if (icsk->icsk_ca_initialized && icsk->icsk_ca_ops->release)
3353 icsk->icsk_ca_ops->release(sk);
3354 memset(icsk->icsk_ca_priv, 0, sizeof(icsk->icsk_ca_priv));
3355 icsk->icsk_ca_initialized = 0;
3356 tcp_set_ca_state(sk, TCP_CA_Open);
3357 tp->is_sack_reneg = 0;
3358 tcp_clear_retrans(tp);
3359 tp->total_retrans = 0;
3360 inet_csk_delack_init(sk);
3361 /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0
3362 * issue in __tcp_select_window()
3363 */
3364 icsk->icsk_ack.rcv_mss = TCP_MIN_MSS;
3365 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
3366 __sk_dst_reset(sk);
3367 dst_release(unrcu_pointer(xchg(&sk->sk_rx_dst, NULL)));
3368 tcp_saved_syn_free(tp);
3369 tp->compressed_ack = 0;
3370 tp->segs_in = 0;
3371 tp->segs_out = 0;
3372 tp->bytes_sent = 0;
3373 tp->bytes_acked = 0;
3374 tp->bytes_received = 0;
3375 tp->bytes_retrans = 0;
3376 tp->data_segs_in = 0;
3377 tp->data_segs_out = 0;
3378 tp->duplicate_sack[0].start_seq = 0;
3379 tp->duplicate_sack[0].end_seq = 0;
3380 tp->dsack_dups = 0;
3381 tp->reord_seen = 0;
3382 tp->retrans_out = 0;
3383 tp->sacked_out = 0;
3384 tp->tlp_high_seq = 0;
3385 tp->last_oow_ack_time = 0;
3386 tp->plb_rehash = 0;
3387 /* There's a bubble in the pipe until at least the first ACK. */
3388 tp->app_limited = ~0U;
3389 tp->rate_app_limited = 1;
3390 tp->rack.mstamp = 0;
3391 tp->rack.advanced = 0;
3392 tp->rack.reo_wnd_steps = 1;
3393 tp->rack.last_delivered = 0;
3394 tp->rack.reo_wnd_persist = 0;
3395 tp->rack.dsack_seen = 0;
3396 tp->syn_data_acked = 0;
3397 tp->rx_opt.saw_tstamp = 0;
3398 tp->rx_opt.dsack = 0;
3399 tp->rx_opt.num_sacks = 0;
3400 tp->rcv_ooopack = 0;
3401
3402
3403 /* Clean up fastopen related fields */
3404 tcp_free_fastopen_req(tp);
3405 inet_clear_bit(DEFER_CONNECT, sk);
3406 tp->fastopen_client_fail = 0;
3407
3408 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
3409
3410 if (sk->sk_frag.page) {
3411 put_page(sk->sk_frag.page);
3412 sk->sk_frag.page = NULL;
3413 sk->sk_frag.offset = 0;
3414 }
3415 sk_error_report(sk);
3416 return 0;
3417 }
3418 EXPORT_SYMBOL(tcp_disconnect);
3419
tcp_can_repair_sock(const struct sock * sk)3420 static inline bool tcp_can_repair_sock(const struct sock *sk)
3421 {
3422 return sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
3423 (sk->sk_state != TCP_LISTEN);
3424 }
3425
tcp_repair_set_window(struct tcp_sock * tp,sockptr_t optbuf,int len)3426 static int tcp_repair_set_window(struct tcp_sock *tp, sockptr_t optbuf, int len)
3427 {
3428 struct tcp_repair_window opt;
3429
3430 if (!tp->repair)
3431 return -EPERM;
3432
3433 if (len != sizeof(opt))
3434 return -EINVAL;
3435
3436 if (copy_from_sockptr(&opt, optbuf, sizeof(opt)))
3437 return -EFAULT;
3438
3439 if (opt.max_window < opt.snd_wnd)
3440 return -EINVAL;
3441
3442 if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd))
3443 return -EINVAL;
3444
3445 if (after(opt.rcv_wup, tp->rcv_nxt))
3446 return -EINVAL;
3447
3448 tp->snd_wl1 = opt.snd_wl1;
3449 tp->snd_wnd = opt.snd_wnd;
3450 tp->max_window = opt.max_window;
3451
3452 tp->rcv_wnd = opt.rcv_wnd;
3453 tp->rcv_wup = opt.rcv_wup;
3454
3455 return 0;
3456 }
3457
tcp_repair_options_est(struct sock * sk,sockptr_t optbuf,unsigned int len)3458 static int tcp_repair_options_est(struct sock *sk, sockptr_t optbuf,
3459 unsigned int len)
3460 {
3461 struct tcp_sock *tp = tcp_sk(sk);
3462 struct tcp_repair_opt opt;
3463 size_t offset = 0;
3464
3465 while (len >= sizeof(opt)) {
3466 if (copy_from_sockptr_offset(&opt, optbuf, offset, sizeof(opt)))
3467 return -EFAULT;
3468
3469 offset += sizeof(opt);
3470 len -= sizeof(opt);
3471
3472 switch (opt.opt_code) {
3473 case TCPOPT_MSS:
3474 tp->rx_opt.mss_clamp = opt.opt_val;
3475 tcp_mtup_init(sk);
3476 break;
3477 case TCPOPT_WINDOW:
3478 {
3479 u16 snd_wscale = opt.opt_val & 0xFFFF;
3480 u16 rcv_wscale = opt.opt_val >> 16;
3481
3482 if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
3483 return -EFBIG;
3484
3485 tp->rx_opt.snd_wscale = snd_wscale;
3486 tp->rx_opt.rcv_wscale = rcv_wscale;
3487 tp->rx_opt.wscale_ok = 1;
3488 }
3489 break;
3490 case TCPOPT_SACK_PERM:
3491 if (opt.opt_val != 0)
3492 return -EINVAL;
3493
3494 tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
3495 break;
3496 case TCPOPT_TIMESTAMP:
3497 if (opt.opt_val != 0)
3498 return -EINVAL;
3499
3500 tp->rx_opt.tstamp_ok = 1;
3501 break;
3502 }
3503 }
3504
3505 return 0;
3506 }
3507
3508 DEFINE_STATIC_KEY_FALSE(tcp_tx_delay_enabled);
3509 EXPORT_SYMBOL(tcp_tx_delay_enabled);
3510
tcp_enable_tx_delay(void)3511 static void tcp_enable_tx_delay(void)
3512 {
3513 if (!static_branch_unlikely(&tcp_tx_delay_enabled)) {
3514 static int __tcp_tx_delay_enabled = 0;
3515
3516 if (cmpxchg(&__tcp_tx_delay_enabled, 0, 1) == 0) {
3517 static_branch_enable(&tcp_tx_delay_enabled);
3518 pr_info("TCP_TX_DELAY enabled\n");
3519 }
3520 }
3521 }
3522
3523 /* When set indicates to always queue non-full frames. Later the user clears
3524 * this option and we transmit any pending partial frames in the queue. This is
3525 * meant to be used alongside sendfile() to get properly filled frames when the
3526 * user (for example) must write out headers with a write() call first and then
3527 * use sendfile to send out the data parts.
3528 *
3529 * TCP_CORK can be set together with TCP_NODELAY and it is stronger than
3530 * TCP_NODELAY.
3531 */
__tcp_sock_set_cork(struct sock * sk,bool on)3532 void __tcp_sock_set_cork(struct sock *sk, bool on)
3533 {
3534 struct tcp_sock *tp = tcp_sk(sk);
3535
3536 if (on) {
3537 tp->nonagle |= TCP_NAGLE_CORK;
3538 } else {
3539 tp->nonagle &= ~TCP_NAGLE_CORK;
3540 if (tp->nonagle & TCP_NAGLE_OFF)
3541 tp->nonagle |= TCP_NAGLE_PUSH;
3542 tcp_push_pending_frames(sk);
3543 }
3544 }
3545
tcp_sock_set_cork(struct sock * sk,bool on)3546 void tcp_sock_set_cork(struct sock *sk, bool on)
3547 {
3548 lock_sock(sk);
3549 __tcp_sock_set_cork(sk, on);
3550 release_sock(sk);
3551 }
3552 EXPORT_SYMBOL(tcp_sock_set_cork);
3553
3554 /* TCP_NODELAY is weaker than TCP_CORK, so that this option on corked socket is
3555 * remembered, but it is not activated until cork is cleared.
3556 *
3557 * However, when TCP_NODELAY is set we make an explicit push, which overrides
3558 * even TCP_CORK for currently queued segments.
3559 */
__tcp_sock_set_nodelay(struct sock * sk,bool on)3560 void __tcp_sock_set_nodelay(struct sock *sk, bool on)
3561 {
3562 if (on) {
3563 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
3564 tcp_push_pending_frames(sk);
3565 } else {
3566 tcp_sk(sk)->nonagle &= ~TCP_NAGLE_OFF;
3567 }
3568 }
3569
tcp_sock_set_nodelay(struct sock * sk)3570 void tcp_sock_set_nodelay(struct sock *sk)
3571 {
3572 lock_sock(sk);
3573 __tcp_sock_set_nodelay(sk, true);
3574 release_sock(sk);
3575 }
3576 EXPORT_SYMBOL(tcp_sock_set_nodelay);
3577
__tcp_sock_set_quickack(struct sock * sk,int val)3578 static void __tcp_sock_set_quickack(struct sock *sk, int val)
3579 {
3580 if (!val) {
3581 inet_csk_enter_pingpong_mode(sk);
3582 return;
3583 }
3584
3585 inet_csk_exit_pingpong_mode(sk);
3586 if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
3587 inet_csk_ack_scheduled(sk)) {
3588 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_PUSHED;
3589 tcp_cleanup_rbuf(sk, 1);
3590 if (!(val & 1))
3591 inet_csk_enter_pingpong_mode(sk);
3592 }
3593 }
3594
tcp_sock_set_quickack(struct sock * sk,int val)3595 void tcp_sock_set_quickack(struct sock *sk, int val)
3596 {
3597 lock_sock(sk);
3598 __tcp_sock_set_quickack(sk, val);
3599 release_sock(sk);
3600 }
3601 EXPORT_SYMBOL(tcp_sock_set_quickack);
3602
tcp_sock_set_syncnt(struct sock * sk,int val)3603 int tcp_sock_set_syncnt(struct sock *sk, int val)
3604 {
3605 if (val < 1 || val > MAX_TCP_SYNCNT)
3606 return -EINVAL;
3607
3608 WRITE_ONCE(inet_csk(sk)->icsk_syn_retries, val);
3609 return 0;
3610 }
3611 EXPORT_SYMBOL(tcp_sock_set_syncnt);
3612
tcp_sock_set_user_timeout(struct sock * sk,int val)3613 int tcp_sock_set_user_timeout(struct sock *sk, int val)
3614 {
3615 /* Cap the max time in ms TCP will retry or probe the window
3616 * before giving up and aborting (ETIMEDOUT) a connection.
3617 */
3618 if (val < 0)
3619 return -EINVAL;
3620
3621 WRITE_ONCE(inet_csk(sk)->icsk_user_timeout, val);
3622 return 0;
3623 }
3624 EXPORT_SYMBOL(tcp_sock_set_user_timeout);
3625
tcp_sock_set_keepidle_locked(struct sock * sk,int val)3626 int tcp_sock_set_keepidle_locked(struct sock *sk, int val)
3627 {
3628 struct tcp_sock *tp = tcp_sk(sk);
3629
3630 if (val < 1 || val > MAX_TCP_KEEPIDLE)
3631 return -EINVAL;
3632
3633 /* Paired with WRITE_ONCE() in keepalive_time_when() */
3634 WRITE_ONCE(tp->keepalive_time, val * HZ);
3635 if (sock_flag(sk, SOCK_KEEPOPEN) &&
3636 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
3637 u32 elapsed = keepalive_time_elapsed(tp);
3638
3639 if (tp->keepalive_time > elapsed)
3640 elapsed = tp->keepalive_time - elapsed;
3641 else
3642 elapsed = 0;
3643 inet_csk_reset_keepalive_timer(sk, elapsed);
3644 }
3645
3646 return 0;
3647 }
3648
tcp_sock_set_keepidle(struct sock * sk,int val)3649 int tcp_sock_set_keepidle(struct sock *sk, int val)
3650 {
3651 int err;
3652
3653 lock_sock(sk);
3654 err = tcp_sock_set_keepidle_locked(sk, val);
3655 release_sock(sk);
3656 return err;
3657 }
3658 EXPORT_SYMBOL(tcp_sock_set_keepidle);
3659
tcp_sock_set_keepintvl(struct sock * sk,int val)3660 int tcp_sock_set_keepintvl(struct sock *sk, int val)
3661 {
3662 if (val < 1 || val > MAX_TCP_KEEPINTVL)
3663 return -EINVAL;
3664
3665 WRITE_ONCE(tcp_sk(sk)->keepalive_intvl, val * HZ);
3666 return 0;
3667 }
3668 EXPORT_SYMBOL(tcp_sock_set_keepintvl);
3669
tcp_sock_set_keepcnt(struct sock * sk,int val)3670 int tcp_sock_set_keepcnt(struct sock *sk, int val)
3671 {
3672 if (val < 1 || val > MAX_TCP_KEEPCNT)
3673 return -EINVAL;
3674
3675 /* Paired with READ_ONCE() in keepalive_probes() */
3676 WRITE_ONCE(tcp_sk(sk)->keepalive_probes, val);
3677 return 0;
3678 }
3679 EXPORT_SYMBOL(tcp_sock_set_keepcnt);
3680
tcp_set_window_clamp(struct sock * sk,int val)3681 int tcp_set_window_clamp(struct sock *sk, int val)
3682 {
3683 struct tcp_sock *tp = tcp_sk(sk);
3684
3685 if (!val) {
3686 if (sk->sk_state != TCP_CLOSE)
3687 return -EINVAL;
3688 WRITE_ONCE(tp->window_clamp, 0);
3689 } else {
3690 u32 new_rcv_ssthresh, old_window_clamp = tp->window_clamp;
3691 u32 new_window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
3692 SOCK_MIN_RCVBUF / 2 : val;
3693
3694 if (new_window_clamp == old_window_clamp)
3695 return 0;
3696
3697 WRITE_ONCE(tp->window_clamp, new_window_clamp);
3698 if (new_window_clamp < old_window_clamp) {
3699 /* need to apply the reserved mem provisioning only
3700 * when shrinking the window clamp
3701 */
3702 __tcp_adjust_rcv_ssthresh(sk, tp->window_clamp);
3703
3704 } else {
3705 new_rcv_ssthresh = min(tp->rcv_wnd, tp->window_clamp);
3706 tp->rcv_ssthresh = max(new_rcv_ssthresh,
3707 tp->rcv_ssthresh);
3708 }
3709 }
3710 return 0;
3711 }
3712
3713 /*
3714 * Socket option code for TCP.
3715 */
do_tcp_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)3716 int do_tcp_setsockopt(struct sock *sk, int level, int optname,
3717 sockptr_t optval, unsigned int optlen)
3718 {
3719 struct tcp_sock *tp = tcp_sk(sk);
3720 struct inet_connection_sock *icsk = inet_csk(sk);
3721 struct net *net = sock_net(sk);
3722 int val;
3723 int err = 0;
3724
3725 /* These are data/string values, all the others are ints */
3726 switch (optname) {
3727 case TCP_CONGESTION: {
3728 char name[TCP_CA_NAME_MAX];
3729
3730 if (optlen < 1)
3731 return -EINVAL;
3732
3733 val = strncpy_from_sockptr(name, optval,
3734 min_t(long, TCP_CA_NAME_MAX-1, optlen));
3735 if (val < 0)
3736 return -EFAULT;
3737 name[val] = 0;
3738
3739 sockopt_lock_sock(sk);
3740 err = tcp_set_congestion_control(sk, name, !has_current_bpf_ctx(),
3741 sockopt_ns_capable(sock_net(sk)->user_ns,
3742 CAP_NET_ADMIN));
3743 sockopt_release_sock(sk);
3744 return err;
3745 }
3746 case TCP_ULP: {
3747 char name[TCP_ULP_NAME_MAX];
3748
3749 if (optlen < 1)
3750 return -EINVAL;
3751
3752 val = strncpy_from_sockptr(name, optval,
3753 min_t(long, TCP_ULP_NAME_MAX - 1,
3754 optlen));
3755 if (val < 0)
3756 return -EFAULT;
3757 name[val] = 0;
3758
3759 sockopt_lock_sock(sk);
3760 err = tcp_set_ulp(sk, name);
3761 sockopt_release_sock(sk);
3762 return err;
3763 }
3764 case TCP_FASTOPEN_KEY: {
3765 __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH];
3766 __u8 *backup_key = NULL;
3767
3768 /* Allow a backup key as well to facilitate key rotation
3769 * First key is the active one.
3770 */
3771 if (optlen != TCP_FASTOPEN_KEY_LENGTH &&
3772 optlen != TCP_FASTOPEN_KEY_BUF_LENGTH)
3773 return -EINVAL;
3774
3775 if (copy_from_sockptr(key, optval, optlen))
3776 return -EFAULT;
3777
3778 if (optlen == TCP_FASTOPEN_KEY_BUF_LENGTH)
3779 backup_key = key + TCP_FASTOPEN_KEY_LENGTH;
3780
3781 return tcp_fastopen_reset_cipher(net, sk, key, backup_key);
3782 }
3783 default:
3784 /* fallthru */
3785 break;
3786 }
3787
3788 if (optlen < sizeof(int))
3789 return -EINVAL;
3790
3791 if (copy_from_sockptr(&val, optval, sizeof(val)))
3792 return -EFAULT;
3793
3794 /* Handle options that can be set without locking the socket. */
3795 switch (optname) {
3796 case TCP_SYNCNT:
3797 return tcp_sock_set_syncnt(sk, val);
3798 case TCP_USER_TIMEOUT:
3799 return tcp_sock_set_user_timeout(sk, val);
3800 case TCP_KEEPINTVL:
3801 return tcp_sock_set_keepintvl(sk, val);
3802 case TCP_KEEPCNT:
3803 return tcp_sock_set_keepcnt(sk, val);
3804 case TCP_LINGER2:
3805 if (val < 0)
3806 WRITE_ONCE(tp->linger2, -1);
3807 else if (val > TCP_FIN_TIMEOUT_MAX / HZ)
3808 WRITE_ONCE(tp->linger2, TCP_FIN_TIMEOUT_MAX);
3809 else
3810 WRITE_ONCE(tp->linger2, val * HZ);
3811 return 0;
3812 case TCP_DEFER_ACCEPT:
3813 /* Translate value in seconds to number of retransmits */
3814 WRITE_ONCE(icsk->icsk_accept_queue.rskq_defer_accept,
3815 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
3816 TCP_RTO_MAX / HZ));
3817 return 0;
3818 }
3819
3820 sockopt_lock_sock(sk);
3821
3822 switch (optname) {
3823 case TCP_MAXSEG:
3824 /* Values greater than interface MTU won't take effect. However
3825 * at the point when this call is done we typically don't yet
3826 * know which interface is going to be used
3827 */
3828 if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
3829 err = -EINVAL;
3830 break;
3831 }
3832 tp->rx_opt.user_mss = val;
3833 break;
3834
3835 case TCP_NODELAY:
3836 __tcp_sock_set_nodelay(sk, val);
3837 break;
3838
3839 case TCP_THIN_LINEAR_TIMEOUTS:
3840 if (val < 0 || val > 1)
3841 err = -EINVAL;
3842 else
3843 tp->thin_lto = val;
3844 break;
3845
3846 case TCP_THIN_DUPACK:
3847 if (val < 0 || val > 1)
3848 err = -EINVAL;
3849 break;
3850
3851 case TCP_REPAIR:
3852 if (!tcp_can_repair_sock(sk))
3853 err = -EPERM;
3854 else if (val == TCP_REPAIR_ON) {
3855 tp->repair = 1;
3856 sk->sk_reuse = SK_FORCE_REUSE;
3857 tp->repair_queue = TCP_NO_QUEUE;
3858 } else if (val == TCP_REPAIR_OFF) {
3859 tp->repair = 0;
3860 sk->sk_reuse = SK_NO_REUSE;
3861 tcp_send_window_probe(sk);
3862 } else if (val == TCP_REPAIR_OFF_NO_WP) {
3863 tp->repair = 0;
3864 sk->sk_reuse = SK_NO_REUSE;
3865 } else
3866 err = -EINVAL;
3867
3868 break;
3869
3870 case TCP_REPAIR_QUEUE:
3871 if (!tp->repair)
3872 err = -EPERM;
3873 else if ((unsigned int)val < TCP_QUEUES_NR)
3874 tp->repair_queue = val;
3875 else
3876 err = -EINVAL;
3877 break;
3878
3879 case TCP_QUEUE_SEQ:
3880 if (sk->sk_state != TCP_CLOSE) {
3881 err = -EPERM;
3882 } else if (tp->repair_queue == TCP_SEND_QUEUE) {
3883 if (!tcp_rtx_queue_empty(sk))
3884 err = -EPERM;
3885 else
3886 WRITE_ONCE(tp->write_seq, val);
3887 } else if (tp->repair_queue == TCP_RECV_QUEUE) {
3888 if (tp->rcv_nxt != tp->copied_seq) {
3889 err = -EPERM;
3890 } else {
3891 WRITE_ONCE(tp->rcv_nxt, val);
3892 WRITE_ONCE(tp->copied_seq, val);
3893 }
3894 } else {
3895 err = -EINVAL;
3896 }
3897 break;
3898
3899 case TCP_REPAIR_OPTIONS:
3900 if (!tp->repair)
3901 err = -EINVAL;
3902 else if (sk->sk_state == TCP_ESTABLISHED && !tp->bytes_sent)
3903 err = tcp_repair_options_est(sk, optval, optlen);
3904 else
3905 err = -EPERM;
3906 break;
3907
3908 case TCP_CORK:
3909 __tcp_sock_set_cork(sk, val);
3910 break;
3911
3912 case TCP_KEEPIDLE:
3913 err = tcp_sock_set_keepidle_locked(sk, val);
3914 break;
3915 case TCP_SAVE_SYN:
3916 /* 0: disable, 1: enable, 2: start from ether_header */
3917 if (val < 0 || val > 2)
3918 err = -EINVAL;
3919 else
3920 tp->save_syn = val;
3921 break;
3922
3923 case TCP_WINDOW_CLAMP:
3924 err = tcp_set_window_clamp(sk, val);
3925 break;
3926
3927 case TCP_QUICKACK:
3928 __tcp_sock_set_quickack(sk, val);
3929 break;
3930
3931 case TCP_AO_REPAIR:
3932 if (!tcp_can_repair_sock(sk)) {
3933 err = -EPERM;
3934 break;
3935 }
3936 err = tcp_ao_set_repair(sk, optval, optlen);
3937 break;
3938 #ifdef CONFIG_TCP_AO
3939 case TCP_AO_ADD_KEY:
3940 case TCP_AO_DEL_KEY:
3941 case TCP_AO_INFO: {
3942 /* If this is the first TCP-AO setsockopt() on the socket,
3943 * sk_state has to be LISTEN or CLOSE. Allow TCP_REPAIR
3944 * in any state.
3945 */
3946 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
3947 goto ao_parse;
3948 if (rcu_dereference_protected(tcp_sk(sk)->ao_info,
3949 lockdep_sock_is_held(sk)))
3950 goto ao_parse;
3951 if (tp->repair)
3952 goto ao_parse;
3953 err = -EISCONN;
3954 break;
3955 ao_parse:
3956 err = tp->af_specific->ao_parse(sk, optname, optval, optlen);
3957 break;
3958 }
3959 #endif
3960 #ifdef CONFIG_TCP_MD5SIG
3961 case TCP_MD5SIG:
3962 case TCP_MD5SIG_EXT:
3963 err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
3964 break;
3965 #endif
3966 case TCP_FASTOPEN:
3967 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
3968 TCPF_LISTEN))) {
3969 tcp_fastopen_init_key_once(net);
3970
3971 fastopen_queue_tune(sk, val);
3972 } else {
3973 err = -EINVAL;
3974 }
3975 break;
3976 case TCP_FASTOPEN_CONNECT:
3977 if (val > 1 || val < 0) {
3978 err = -EINVAL;
3979 } else if (READ_ONCE(net->ipv4.sysctl_tcp_fastopen) &
3980 TFO_CLIENT_ENABLE) {
3981 if (sk->sk_state == TCP_CLOSE)
3982 tp->fastopen_connect = val;
3983 else
3984 err = -EINVAL;
3985 } else {
3986 err = -EOPNOTSUPP;
3987 }
3988 break;
3989 case TCP_FASTOPEN_NO_COOKIE:
3990 if (val > 1 || val < 0)
3991 err = -EINVAL;
3992 else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
3993 err = -EINVAL;
3994 else
3995 tp->fastopen_no_cookie = val;
3996 break;
3997 case TCP_TIMESTAMP:
3998 if (!tp->repair) {
3999 err = -EPERM;
4000 break;
4001 }
4002 /* val is an opaque field,
4003 * and low order bit contains usec_ts enable bit.
4004 * Its a best effort, and we do not care if user makes an error.
4005 */
4006 tp->tcp_usec_ts = val & 1;
4007 WRITE_ONCE(tp->tsoffset, val - tcp_clock_ts(tp->tcp_usec_ts));
4008 break;
4009 case TCP_REPAIR_WINDOW:
4010 err = tcp_repair_set_window(tp, optval, optlen);
4011 break;
4012 case TCP_NOTSENT_LOWAT:
4013 WRITE_ONCE(tp->notsent_lowat, val);
4014 sk->sk_write_space(sk);
4015 break;
4016 case TCP_INQ:
4017 if (val > 1 || val < 0)
4018 err = -EINVAL;
4019 else
4020 tp->recvmsg_inq = val;
4021 break;
4022 case TCP_TX_DELAY:
4023 if (val)
4024 tcp_enable_tx_delay();
4025 WRITE_ONCE(tp->tcp_tx_delay, val);
4026 break;
4027 default:
4028 err = -ENOPROTOOPT;
4029 break;
4030 }
4031
4032 sockopt_release_sock(sk);
4033 return err;
4034 }
4035
tcp_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)4036 int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
4037 unsigned int optlen)
4038 {
4039 const struct inet_connection_sock *icsk = inet_csk(sk);
4040
4041 if (level != SOL_TCP)
4042 /* Paired with WRITE_ONCE() in do_ipv6_setsockopt() and tcp_v6_connect() */
4043 return READ_ONCE(icsk->icsk_af_ops)->setsockopt(sk, level, optname,
4044 optval, optlen);
4045 return do_tcp_setsockopt(sk, level, optname, optval, optlen);
4046 }
4047 EXPORT_SYMBOL(tcp_setsockopt);
4048
tcp_get_info_chrono_stats(const struct tcp_sock * tp,struct tcp_info * info)4049 static void tcp_get_info_chrono_stats(const struct tcp_sock *tp,
4050 struct tcp_info *info)
4051 {
4052 u64 stats[__TCP_CHRONO_MAX], total = 0;
4053 enum tcp_chrono i;
4054
4055 for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) {
4056 stats[i] = tp->chrono_stat[i - 1];
4057 if (i == tp->chrono_type)
4058 stats[i] += tcp_jiffies32 - tp->chrono_start;
4059 stats[i] *= USEC_PER_SEC / HZ;
4060 total += stats[i];
4061 }
4062
4063 info->tcpi_busy_time = total;
4064 info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED];
4065 info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED];
4066 }
4067
4068 /* Return information about state of tcp endpoint in API format. */
tcp_get_info(struct sock * sk,struct tcp_info * info)4069 void tcp_get_info(struct sock *sk, struct tcp_info *info)
4070 {
4071 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
4072 const struct inet_connection_sock *icsk = inet_csk(sk);
4073 unsigned long rate;
4074 u32 now;
4075 u64 rate64;
4076 bool slow;
4077
4078 memset(info, 0, sizeof(*info));
4079 if (sk->sk_type != SOCK_STREAM)
4080 return;
4081
4082 info->tcpi_state = inet_sk_state_load(sk);
4083
4084 /* Report meaningful fields for all TCP states, including listeners */
4085 rate = READ_ONCE(sk->sk_pacing_rate);
4086 rate64 = (rate != ~0UL) ? rate : ~0ULL;
4087 info->tcpi_pacing_rate = rate64;
4088
4089 rate = READ_ONCE(sk->sk_max_pacing_rate);
4090 rate64 = (rate != ~0UL) ? rate : ~0ULL;
4091 info->tcpi_max_pacing_rate = rate64;
4092
4093 info->tcpi_reordering = tp->reordering;
4094 info->tcpi_snd_cwnd = tcp_snd_cwnd(tp);
4095
4096 if (info->tcpi_state == TCP_LISTEN) {
4097 /* listeners aliased fields :
4098 * tcpi_unacked -> Number of children ready for accept()
4099 * tcpi_sacked -> max backlog
4100 */
4101 info->tcpi_unacked = READ_ONCE(sk->sk_ack_backlog);
4102 info->tcpi_sacked = READ_ONCE(sk->sk_max_ack_backlog);
4103 return;
4104 }
4105
4106 slow = lock_sock_fast(sk);
4107
4108 info->tcpi_ca_state = icsk->icsk_ca_state;
4109 info->tcpi_retransmits = icsk->icsk_retransmits;
4110 info->tcpi_probes = icsk->icsk_probes_out;
4111 info->tcpi_backoff = icsk->icsk_backoff;
4112
4113 if (tp->rx_opt.tstamp_ok)
4114 info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
4115 if (tcp_is_sack(tp))
4116 info->tcpi_options |= TCPI_OPT_SACK;
4117 if (tp->rx_opt.wscale_ok) {
4118 info->tcpi_options |= TCPI_OPT_WSCALE;
4119 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
4120 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
4121 }
4122
4123 if (tp->ecn_flags & TCP_ECN_OK)
4124 info->tcpi_options |= TCPI_OPT_ECN;
4125 if (tp->ecn_flags & TCP_ECN_SEEN)
4126 info->tcpi_options |= TCPI_OPT_ECN_SEEN;
4127 if (tp->syn_data_acked)
4128 info->tcpi_options |= TCPI_OPT_SYN_DATA;
4129 if (tp->tcp_usec_ts)
4130 info->tcpi_options |= TCPI_OPT_USEC_TS;
4131
4132 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
4133 info->tcpi_ato = jiffies_to_usecs(min_t(u32, icsk->icsk_ack.ato,
4134 tcp_delack_max(sk)));
4135 info->tcpi_snd_mss = tp->mss_cache;
4136 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
4137
4138 info->tcpi_unacked = tp->packets_out;
4139 info->tcpi_sacked = tp->sacked_out;
4140
4141 info->tcpi_lost = tp->lost_out;
4142 info->tcpi_retrans = tp->retrans_out;
4143
4144 now = tcp_jiffies32;
4145 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
4146 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
4147 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
4148
4149 info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
4150 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
4151 info->tcpi_rtt = tp->srtt_us >> 3;
4152 info->tcpi_rttvar = tp->mdev_us >> 2;
4153 info->tcpi_snd_ssthresh = tp->snd_ssthresh;
4154 info->tcpi_advmss = tp->advmss;
4155
4156 info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
4157 info->tcpi_rcv_space = tp->rcvq_space.space;
4158
4159 info->tcpi_total_retrans = tp->total_retrans;
4160
4161 info->tcpi_bytes_acked = tp->bytes_acked;
4162 info->tcpi_bytes_received = tp->bytes_received;
4163 info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
4164 tcp_get_info_chrono_stats(tp, info);
4165
4166 info->tcpi_segs_out = tp->segs_out;
4167
4168 /* segs_in and data_segs_in can be updated from tcp_segs_in() from BH */
4169 info->tcpi_segs_in = READ_ONCE(tp->segs_in);
4170 info->tcpi_data_segs_in = READ_ONCE(tp->data_segs_in);
4171
4172 info->tcpi_min_rtt = tcp_min_rtt(tp);
4173 info->tcpi_data_segs_out = tp->data_segs_out;
4174
4175 info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
4176 rate64 = tcp_compute_delivery_rate(tp);
4177 if (rate64)
4178 info->tcpi_delivery_rate = rate64;
4179 info->tcpi_delivered = tp->delivered;
4180 info->tcpi_delivered_ce = tp->delivered_ce;
4181 info->tcpi_bytes_sent = tp->bytes_sent;
4182 info->tcpi_bytes_retrans = tp->bytes_retrans;
4183 info->tcpi_dsack_dups = tp->dsack_dups;
4184 info->tcpi_reord_seen = tp->reord_seen;
4185 info->tcpi_rcv_ooopack = tp->rcv_ooopack;
4186 info->tcpi_snd_wnd = tp->snd_wnd;
4187 info->tcpi_rcv_wnd = tp->rcv_wnd;
4188 info->tcpi_rehash = tp->plb_rehash + tp->timeout_rehash;
4189 info->tcpi_fastopen_client_fail = tp->fastopen_client_fail;
4190
4191 info->tcpi_total_rto = tp->total_rto;
4192 info->tcpi_total_rto_recoveries = tp->total_rto_recoveries;
4193 info->tcpi_total_rto_time = tp->total_rto_time;
4194 if (tp->rto_stamp)
4195 info->tcpi_total_rto_time += tcp_clock_ms() - tp->rto_stamp;
4196
4197 unlock_sock_fast(sk, slow);
4198 }
4199 EXPORT_SYMBOL_GPL(tcp_get_info);
4200
tcp_opt_stats_get_size(void)4201 static size_t tcp_opt_stats_get_size(void)
4202 {
4203 return
4204 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BUSY */
4205 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_RWND_LIMITED */
4206 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_SNDBUF_LIMITED */
4207 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DATA_SEGS_OUT */
4208 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_TOTAL_RETRANS */
4209 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_PACING_RATE */
4210 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DELIVERY_RATE */
4211 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_CWND */
4212 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORDERING */
4213 nla_total_size(sizeof(u32)) + /* TCP_NLA_MIN_RTT */
4214 nla_total_size(sizeof(u8)) + /* TCP_NLA_RECUR_RETRANS */
4215 nla_total_size(sizeof(u8)) + /* TCP_NLA_DELIVERY_RATE_APP_LMT */
4216 nla_total_size(sizeof(u32)) + /* TCP_NLA_SNDQ_SIZE */
4217 nla_total_size(sizeof(u8)) + /* TCP_NLA_CA_STATE */
4218 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_SSTHRESH */
4219 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED */
4220 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */
4221 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */
4222 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */
4223 nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */
4224 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */
4225 nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */
4226 nla_total_size(sizeof(u16)) + /* TCP_NLA_TIMEOUT_REHASH */
4227 nla_total_size(sizeof(u32)) + /* TCP_NLA_BYTES_NOTSENT */
4228 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_EDT */
4229 nla_total_size(sizeof(u8)) + /* TCP_NLA_TTL */
4230 nla_total_size(sizeof(u32)) + /* TCP_NLA_REHASH */
4231 0;
4232 }
4233
4234 /* Returns TTL or hop limit of an incoming packet from skb. */
tcp_skb_ttl_or_hop_limit(const struct sk_buff * skb)4235 static u8 tcp_skb_ttl_or_hop_limit(const struct sk_buff *skb)
4236 {
4237 if (skb->protocol == htons(ETH_P_IP))
4238 return ip_hdr(skb)->ttl;
4239 else if (skb->protocol == htons(ETH_P_IPV6))
4240 return ipv6_hdr(skb)->hop_limit;
4241 else
4242 return 0;
4243 }
4244
tcp_get_timestamping_opt_stats(const struct sock * sk,const struct sk_buff * orig_skb,const struct sk_buff * ack_skb)4245 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
4246 const struct sk_buff *orig_skb,
4247 const struct sk_buff *ack_skb)
4248 {
4249 const struct tcp_sock *tp = tcp_sk(sk);
4250 struct sk_buff *stats;
4251 struct tcp_info info;
4252 unsigned long rate;
4253 u64 rate64;
4254
4255 stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC);
4256 if (!stats)
4257 return NULL;
4258
4259 tcp_get_info_chrono_stats(tp, &info);
4260 nla_put_u64_64bit(stats, TCP_NLA_BUSY,
4261 info.tcpi_busy_time, TCP_NLA_PAD);
4262 nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED,
4263 info.tcpi_rwnd_limited, TCP_NLA_PAD);
4264 nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED,
4265 info.tcpi_sndbuf_limited, TCP_NLA_PAD);
4266 nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT,
4267 tp->data_segs_out, TCP_NLA_PAD);
4268 nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS,
4269 tp->total_retrans, TCP_NLA_PAD);
4270
4271 rate = READ_ONCE(sk->sk_pacing_rate);
4272 rate64 = (rate != ~0UL) ? rate : ~0ULL;
4273 nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD);
4274
4275 rate64 = tcp_compute_delivery_rate(tp);
4276 nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD);
4277
4278 nla_put_u32(stats, TCP_NLA_SND_CWND, tcp_snd_cwnd(tp));
4279 nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering);
4280 nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp));
4281
4282 nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits);
4283 nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited);
4284 nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh);
4285 nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered);
4286 nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce);
4287
4288 nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
4289 nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state);
4290
4291 nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent,
4292 TCP_NLA_PAD);
4293 nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans,
4294 TCP_NLA_PAD);
4295 nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups);
4296 nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen);
4297 nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3);
4298 nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash);
4299 nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT,
4300 max_t(int, 0, tp->write_seq - tp->snd_nxt));
4301 nla_put_u64_64bit(stats, TCP_NLA_EDT, orig_skb->skb_mstamp_ns,
4302 TCP_NLA_PAD);
4303 if (ack_skb)
4304 nla_put_u8(stats, TCP_NLA_TTL,
4305 tcp_skb_ttl_or_hop_limit(ack_skb));
4306
4307 nla_put_u32(stats, TCP_NLA_REHASH, tp->plb_rehash + tp->timeout_rehash);
4308 return stats;
4309 }
4310
do_tcp_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)4311 int do_tcp_getsockopt(struct sock *sk, int level,
4312 int optname, sockptr_t optval, sockptr_t optlen)
4313 {
4314 struct inet_connection_sock *icsk = inet_csk(sk);
4315 struct tcp_sock *tp = tcp_sk(sk);
4316 struct net *net = sock_net(sk);
4317 int val, len;
4318
4319 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4320 return -EFAULT;
4321
4322 if (len < 0)
4323 return -EINVAL;
4324
4325 len = min_t(unsigned int, len, sizeof(int));
4326
4327 switch (optname) {
4328 case TCP_MAXSEG:
4329 val = tp->mss_cache;
4330 if (tp->rx_opt.user_mss &&
4331 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
4332 val = tp->rx_opt.user_mss;
4333 if (tp->repair)
4334 val = tp->rx_opt.mss_clamp;
4335 break;
4336 case TCP_NODELAY:
4337 val = !!(tp->nonagle&TCP_NAGLE_OFF);
4338 break;
4339 case TCP_CORK:
4340 val = !!(tp->nonagle&TCP_NAGLE_CORK);
4341 break;
4342 case TCP_KEEPIDLE:
4343 val = keepalive_time_when(tp) / HZ;
4344 break;
4345 case TCP_KEEPINTVL:
4346 val = keepalive_intvl_when(tp) / HZ;
4347 break;
4348 case TCP_KEEPCNT:
4349 val = keepalive_probes(tp);
4350 break;
4351 case TCP_SYNCNT:
4352 val = READ_ONCE(icsk->icsk_syn_retries) ? :
4353 READ_ONCE(net->ipv4.sysctl_tcp_syn_retries);
4354 break;
4355 case TCP_LINGER2:
4356 val = READ_ONCE(tp->linger2);
4357 if (val >= 0)
4358 val = (val ? : READ_ONCE(net->ipv4.sysctl_tcp_fin_timeout)) / HZ;
4359 break;
4360 case TCP_DEFER_ACCEPT:
4361 val = READ_ONCE(icsk->icsk_accept_queue.rskq_defer_accept);
4362 val = retrans_to_secs(val, TCP_TIMEOUT_INIT / HZ,
4363 TCP_RTO_MAX / HZ);
4364 break;
4365 case TCP_WINDOW_CLAMP:
4366 val = READ_ONCE(tp->window_clamp);
4367 break;
4368 case TCP_INFO: {
4369 struct tcp_info info;
4370
4371 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4372 return -EFAULT;
4373
4374 tcp_get_info(sk, &info);
4375
4376 len = min_t(unsigned int, len, sizeof(info));
4377 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4378 return -EFAULT;
4379 if (copy_to_sockptr(optval, &info, len))
4380 return -EFAULT;
4381 return 0;
4382 }
4383 case TCP_CC_INFO: {
4384 const struct tcp_congestion_ops *ca_ops;
4385 union tcp_cc_info info;
4386 size_t sz = 0;
4387 int attr;
4388
4389 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4390 return -EFAULT;
4391
4392 ca_ops = icsk->icsk_ca_ops;
4393 if (ca_ops && ca_ops->get_info)
4394 sz = ca_ops->get_info(sk, ~0U, &attr, &info);
4395
4396 len = min_t(unsigned int, len, sz);
4397 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4398 return -EFAULT;
4399 if (copy_to_sockptr(optval, &info, len))
4400 return -EFAULT;
4401 return 0;
4402 }
4403 case TCP_QUICKACK:
4404 val = !inet_csk_in_pingpong_mode(sk);
4405 break;
4406
4407 case TCP_CONGESTION:
4408 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4409 return -EFAULT;
4410 len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
4411 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4412 return -EFAULT;
4413 if (copy_to_sockptr(optval, icsk->icsk_ca_ops->name, len))
4414 return -EFAULT;
4415 return 0;
4416
4417 case TCP_ULP:
4418 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4419 return -EFAULT;
4420 len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
4421 if (!icsk->icsk_ulp_ops) {
4422 len = 0;
4423 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4424 return -EFAULT;
4425 return 0;
4426 }
4427 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4428 return -EFAULT;
4429 if (copy_to_sockptr(optval, icsk->icsk_ulp_ops->name, len))
4430 return -EFAULT;
4431 return 0;
4432
4433 case TCP_FASTOPEN_KEY: {
4434 u64 key[TCP_FASTOPEN_KEY_BUF_LENGTH / sizeof(u64)];
4435 unsigned int key_len;
4436
4437 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4438 return -EFAULT;
4439
4440 key_len = tcp_fastopen_get_cipher(net, icsk, key) *
4441 TCP_FASTOPEN_KEY_LENGTH;
4442 len = min_t(unsigned int, len, key_len);
4443 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4444 return -EFAULT;
4445 if (copy_to_sockptr(optval, key, len))
4446 return -EFAULT;
4447 return 0;
4448 }
4449 case TCP_THIN_LINEAR_TIMEOUTS:
4450 val = tp->thin_lto;
4451 break;
4452
4453 case TCP_THIN_DUPACK:
4454 val = 0;
4455 break;
4456
4457 case TCP_REPAIR:
4458 val = tp->repair;
4459 break;
4460
4461 case TCP_REPAIR_QUEUE:
4462 if (tp->repair)
4463 val = tp->repair_queue;
4464 else
4465 return -EINVAL;
4466 break;
4467
4468 case TCP_REPAIR_WINDOW: {
4469 struct tcp_repair_window opt;
4470
4471 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4472 return -EFAULT;
4473
4474 if (len != sizeof(opt))
4475 return -EINVAL;
4476
4477 if (!tp->repair)
4478 return -EPERM;
4479
4480 opt.snd_wl1 = tp->snd_wl1;
4481 opt.snd_wnd = tp->snd_wnd;
4482 opt.max_window = tp->max_window;
4483 opt.rcv_wnd = tp->rcv_wnd;
4484 opt.rcv_wup = tp->rcv_wup;
4485
4486 if (copy_to_sockptr(optval, &opt, len))
4487 return -EFAULT;
4488 return 0;
4489 }
4490 case TCP_QUEUE_SEQ:
4491 if (tp->repair_queue == TCP_SEND_QUEUE)
4492 val = tp->write_seq;
4493 else if (tp->repair_queue == TCP_RECV_QUEUE)
4494 val = tp->rcv_nxt;
4495 else
4496 return -EINVAL;
4497 break;
4498
4499 case TCP_USER_TIMEOUT:
4500 val = READ_ONCE(icsk->icsk_user_timeout);
4501 break;
4502
4503 case TCP_FASTOPEN:
4504 val = READ_ONCE(icsk->icsk_accept_queue.fastopenq.max_qlen);
4505 break;
4506
4507 case TCP_FASTOPEN_CONNECT:
4508 val = tp->fastopen_connect;
4509 break;
4510
4511 case TCP_FASTOPEN_NO_COOKIE:
4512 val = tp->fastopen_no_cookie;
4513 break;
4514
4515 case TCP_TX_DELAY:
4516 val = READ_ONCE(tp->tcp_tx_delay);
4517 break;
4518
4519 case TCP_TIMESTAMP:
4520 val = tcp_clock_ts(tp->tcp_usec_ts) + READ_ONCE(tp->tsoffset);
4521 if (tp->tcp_usec_ts)
4522 val |= 1;
4523 else
4524 val &= ~1;
4525 break;
4526 case TCP_NOTSENT_LOWAT:
4527 val = READ_ONCE(tp->notsent_lowat);
4528 break;
4529 case TCP_INQ:
4530 val = tp->recvmsg_inq;
4531 break;
4532 case TCP_SAVE_SYN:
4533 val = tp->save_syn;
4534 break;
4535 case TCP_SAVED_SYN: {
4536 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4537 return -EFAULT;
4538
4539 sockopt_lock_sock(sk);
4540 if (tp->saved_syn) {
4541 if (len < tcp_saved_syn_len(tp->saved_syn)) {
4542 len = tcp_saved_syn_len(tp->saved_syn);
4543 if (copy_to_sockptr(optlen, &len, sizeof(int))) {
4544 sockopt_release_sock(sk);
4545 return -EFAULT;
4546 }
4547 sockopt_release_sock(sk);
4548 return -EINVAL;
4549 }
4550 len = tcp_saved_syn_len(tp->saved_syn);
4551 if (copy_to_sockptr(optlen, &len, sizeof(int))) {
4552 sockopt_release_sock(sk);
4553 return -EFAULT;
4554 }
4555 if (copy_to_sockptr(optval, tp->saved_syn->data, len)) {
4556 sockopt_release_sock(sk);
4557 return -EFAULT;
4558 }
4559 tcp_saved_syn_free(tp);
4560 sockopt_release_sock(sk);
4561 } else {
4562 sockopt_release_sock(sk);
4563 len = 0;
4564 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4565 return -EFAULT;
4566 }
4567 return 0;
4568 }
4569 #ifdef CONFIG_MMU
4570 case TCP_ZEROCOPY_RECEIVE: {
4571 struct scm_timestamping_internal tss;
4572 struct tcp_zerocopy_receive zc = {};
4573 int err;
4574
4575 if (copy_from_sockptr(&len, optlen, sizeof(int)))
4576 return -EFAULT;
4577 if (len < 0 ||
4578 len < offsetofend(struct tcp_zerocopy_receive, length))
4579 return -EINVAL;
4580 if (unlikely(len > sizeof(zc))) {
4581 err = check_zeroed_sockptr(optval, sizeof(zc),
4582 len - sizeof(zc));
4583 if (err < 1)
4584 return err == 0 ? -EINVAL : err;
4585 len = sizeof(zc);
4586 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4587 return -EFAULT;
4588 }
4589 if (copy_from_sockptr(&zc, optval, len))
4590 return -EFAULT;
4591 if (zc.reserved)
4592 return -EINVAL;
4593 if (zc.msg_flags & ~(TCP_VALID_ZC_MSG_FLAGS))
4594 return -EINVAL;
4595 sockopt_lock_sock(sk);
4596 err = tcp_zerocopy_receive(sk, &zc, &tss);
4597 err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname,
4598 &zc, &len, err);
4599 sockopt_release_sock(sk);
4600 if (len >= offsetofend(struct tcp_zerocopy_receive, msg_flags))
4601 goto zerocopy_rcv_cmsg;
4602 switch (len) {
4603 case offsetofend(struct tcp_zerocopy_receive, msg_flags):
4604 goto zerocopy_rcv_cmsg;
4605 case offsetofend(struct tcp_zerocopy_receive, msg_controllen):
4606 case offsetofend(struct tcp_zerocopy_receive, msg_control):
4607 case offsetofend(struct tcp_zerocopy_receive, flags):
4608 case offsetofend(struct tcp_zerocopy_receive, copybuf_len):
4609 case offsetofend(struct tcp_zerocopy_receive, copybuf_address):
4610 case offsetofend(struct tcp_zerocopy_receive, err):
4611 goto zerocopy_rcv_sk_err;
4612 case offsetofend(struct tcp_zerocopy_receive, inq):
4613 goto zerocopy_rcv_inq;
4614 case offsetofend(struct tcp_zerocopy_receive, length):
4615 default:
4616 goto zerocopy_rcv_out;
4617 }
4618 zerocopy_rcv_cmsg:
4619 if (zc.msg_flags & TCP_CMSG_TS)
4620 tcp_zc_finalize_rx_tstamp(sk, &zc, &tss);
4621 else
4622 zc.msg_flags = 0;
4623 zerocopy_rcv_sk_err:
4624 if (!err)
4625 zc.err = sock_error(sk);
4626 zerocopy_rcv_inq:
4627 zc.inq = tcp_inq_hint(sk);
4628 zerocopy_rcv_out:
4629 if (!err && copy_to_sockptr(optval, &zc, len))
4630 err = -EFAULT;
4631 return err;
4632 }
4633 #endif
4634 case TCP_AO_REPAIR:
4635 if (!tcp_can_repair_sock(sk))
4636 return -EPERM;
4637 return tcp_ao_get_repair(sk, optval, optlen);
4638 case TCP_AO_GET_KEYS:
4639 case TCP_AO_INFO: {
4640 int err;
4641
4642 sockopt_lock_sock(sk);
4643 if (optname == TCP_AO_GET_KEYS)
4644 err = tcp_ao_get_mkts(sk, optval, optlen);
4645 else
4646 err = tcp_ao_get_sock_info(sk, optval, optlen);
4647 sockopt_release_sock(sk);
4648
4649 return err;
4650 }
4651 case TCP_IS_MPTCP:
4652 val = 0;
4653 break;
4654 default:
4655 return -ENOPROTOOPT;
4656 }
4657
4658 if (copy_to_sockptr(optlen, &len, sizeof(int)))
4659 return -EFAULT;
4660 if (copy_to_sockptr(optval, &val, len))
4661 return -EFAULT;
4662 return 0;
4663 }
4664
tcp_bpf_bypass_getsockopt(int level,int optname)4665 bool tcp_bpf_bypass_getsockopt(int level, int optname)
4666 {
4667 /* TCP do_tcp_getsockopt has optimized getsockopt implementation
4668 * to avoid extra socket lock for TCP_ZEROCOPY_RECEIVE.
4669 */
4670 if (level == SOL_TCP && optname == TCP_ZEROCOPY_RECEIVE)
4671 return true;
4672
4673 return false;
4674 }
4675 EXPORT_SYMBOL(tcp_bpf_bypass_getsockopt);
4676
tcp_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)4677 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
4678 int __user *optlen)
4679 {
4680 struct inet_connection_sock *icsk = inet_csk(sk);
4681
4682 if (level != SOL_TCP)
4683 /* Paired with WRITE_ONCE() in do_ipv6_setsockopt() and tcp_v6_connect() */
4684 return READ_ONCE(icsk->icsk_af_ops)->getsockopt(sk, level, optname,
4685 optval, optlen);
4686 return do_tcp_getsockopt(sk, level, optname, USER_SOCKPTR(optval),
4687 USER_SOCKPTR(optlen));
4688 }
4689 EXPORT_SYMBOL(tcp_getsockopt);
4690
4691 #ifdef CONFIG_TCP_MD5SIG
4692 int tcp_md5_sigpool_id = -1;
4693 EXPORT_SYMBOL_GPL(tcp_md5_sigpool_id);
4694
tcp_md5_alloc_sigpool(void)4695 int tcp_md5_alloc_sigpool(void)
4696 {
4697 size_t scratch_size;
4698 int ret;
4699
4700 scratch_size = sizeof(union tcp_md5sum_block) + sizeof(struct tcphdr);
4701 ret = tcp_sigpool_alloc_ahash("md5", scratch_size);
4702 if (ret >= 0) {
4703 /* As long as any md5 sigpool was allocated, the return
4704 * id would stay the same. Re-write the id only for the case
4705 * when previously all MD5 keys were deleted and this call
4706 * allocates the first MD5 key, which may return a different
4707 * sigpool id than was used previously.
4708 */
4709 WRITE_ONCE(tcp_md5_sigpool_id, ret); /* Avoids the compiler potentially being smart here */
4710 return 0;
4711 }
4712 return ret;
4713 }
4714
tcp_md5_release_sigpool(void)4715 void tcp_md5_release_sigpool(void)
4716 {
4717 tcp_sigpool_release(READ_ONCE(tcp_md5_sigpool_id));
4718 }
4719
tcp_md5_add_sigpool(void)4720 void tcp_md5_add_sigpool(void)
4721 {
4722 tcp_sigpool_get(READ_ONCE(tcp_md5_sigpool_id));
4723 }
4724
tcp_md5_hash_key(struct tcp_sigpool * hp,const struct tcp_md5sig_key * key)4725 int tcp_md5_hash_key(struct tcp_sigpool *hp,
4726 const struct tcp_md5sig_key *key)
4727 {
4728 u8 keylen = READ_ONCE(key->keylen); /* paired with WRITE_ONCE() in tcp_md5_do_add */
4729 struct scatterlist sg;
4730
4731 sg_init_one(&sg, key->key, keylen);
4732 ahash_request_set_crypt(hp->req, &sg, NULL, keylen);
4733
4734 /* We use data_race() because tcp_md5_do_add() might change
4735 * key->key under us
4736 */
4737 return data_race(crypto_ahash_update(hp->req));
4738 }
4739 EXPORT_SYMBOL(tcp_md5_hash_key);
4740
4741 /* Called with rcu_read_lock() */
4742 static enum skb_drop_reason
tcp_inbound_md5_hash(const struct sock * sk,const struct sk_buff * skb,const void * saddr,const void * daddr,int family,int l3index,const __u8 * hash_location)4743 tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
4744 const void *saddr, const void *daddr,
4745 int family, int l3index, const __u8 *hash_location)
4746 {
4747 /* This gets called for each TCP segment that has TCP-MD5 option.
4748 * We have 3 drop cases:
4749 * o No MD5 hash and one expected.
4750 * o MD5 hash and we're not expecting one.
4751 * o MD5 hash and its wrong.
4752 */
4753 const struct tcp_sock *tp = tcp_sk(sk);
4754 struct tcp_md5sig_key *key;
4755 u8 newhash[16];
4756 int genhash;
4757
4758 key = tcp_md5_do_lookup(sk, l3index, saddr, family);
4759
4760 if (!key && hash_location) {
4761 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
4762 trace_tcp_hash_md5_unexpected(sk, skb);
4763 return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
4764 }
4765
4766 /* Check the signature.
4767 * To support dual stack listeners, we need to handle
4768 * IPv4-mapped case.
4769 */
4770 if (family == AF_INET)
4771 genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
4772 else
4773 genhash = tp->af_specific->calc_md5_hash(newhash, key,
4774 NULL, skb);
4775 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
4776 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
4777 trace_tcp_hash_md5_mismatch(sk, skb);
4778 return SKB_DROP_REASON_TCP_MD5FAILURE;
4779 }
4780 return SKB_NOT_DROPPED_YET;
4781 }
4782 #else
4783 static inline enum skb_drop_reason
tcp_inbound_md5_hash(const struct sock * sk,const struct sk_buff * skb,const void * saddr,const void * daddr,int family,int l3index,const __u8 * hash_location)4784 tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
4785 const void *saddr, const void *daddr,
4786 int family, int l3index, const __u8 *hash_location)
4787 {
4788 return SKB_NOT_DROPPED_YET;
4789 }
4790
4791 #endif
4792
4793 /* Called with rcu_read_lock() */
4794 enum skb_drop_reason
tcp_inbound_hash(struct sock * sk,const struct request_sock * req,const struct sk_buff * skb,const void * saddr,const void * daddr,int family,int dif,int sdif)4795 tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
4796 const struct sk_buff *skb,
4797 const void *saddr, const void *daddr,
4798 int family, int dif, int sdif)
4799 {
4800 const struct tcphdr *th = tcp_hdr(skb);
4801 const struct tcp_ao_hdr *aoh;
4802 const __u8 *md5_location;
4803 int l3index;
4804
4805 /* Invalid option or two times meet any of auth options */
4806 if (tcp_parse_auth_options(th, &md5_location, &aoh)) {
4807 trace_tcp_hash_bad_header(sk, skb);
4808 return SKB_DROP_REASON_TCP_AUTH_HDR;
4809 }
4810
4811 if (req) {
4812 if (tcp_rsk_used_ao(req) != !!aoh) {
4813 u8 keyid, rnext, maclen;
4814
4815 if (aoh) {
4816 keyid = aoh->keyid;
4817 rnext = aoh->rnext_keyid;
4818 maclen = tcp_ao_hdr_maclen(aoh);
4819 } else {
4820 keyid = rnext = maclen = 0;
4821 }
4822
4823 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
4824 trace_tcp_ao_handshake_failure(sk, skb, keyid, rnext, maclen);
4825 return SKB_DROP_REASON_TCP_AOFAILURE;
4826 }
4827 }
4828
4829 /* sdif set, means packet ingressed via a device
4830 * in an L3 domain and dif is set to the l3mdev
4831 */
4832 l3index = sdif ? dif : 0;
4833
4834 /* Fast path: unsigned segments */
4835 if (likely(!md5_location && !aoh)) {
4836 /* Drop if there's TCP-MD5 or TCP-AO key with any rcvid/sndid
4837 * for the remote peer. On TCP-AO established connection
4838 * the last key is impossible to remove, so there's
4839 * always at least one current_key.
4840 */
4841 if (tcp_ao_required(sk, saddr, family, l3index, true)) {
4842 trace_tcp_hash_ao_required(sk, skb);
4843 return SKB_DROP_REASON_TCP_AONOTFOUND;
4844 }
4845 if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
4846 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
4847 trace_tcp_hash_md5_required(sk, skb);
4848 return SKB_DROP_REASON_TCP_MD5NOTFOUND;
4849 }
4850 return SKB_NOT_DROPPED_YET;
4851 }
4852
4853 if (aoh)
4854 return tcp_inbound_ao_hash(sk, skb, family, req, l3index, aoh);
4855
4856 return tcp_inbound_md5_hash(sk, skb, saddr, daddr, family,
4857 l3index, md5_location);
4858 }
4859 EXPORT_SYMBOL_GPL(tcp_inbound_hash);
4860
tcp_done(struct sock * sk)4861 void tcp_done(struct sock *sk)
4862 {
4863 struct request_sock *req;
4864
4865 /* We might be called with a new socket, after
4866 * inet_csk_prepare_forced_close() has been called
4867 * so we can not use lockdep_sock_is_held(sk)
4868 */
4869 req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, 1);
4870
4871 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
4872 TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
4873
4874 tcp_set_state(sk, TCP_CLOSE);
4875 tcp_clear_xmit_timers(sk);
4876 if (req)
4877 reqsk_fastopen_remove(sk, req, false);
4878
4879 WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);
4880
4881 if (!sock_flag(sk, SOCK_DEAD))
4882 sk->sk_state_change(sk);
4883 else
4884 inet_csk_destroy_sock(sk);
4885 }
4886 EXPORT_SYMBOL_GPL(tcp_done);
4887
tcp_abort(struct sock * sk,int err)4888 int tcp_abort(struct sock *sk, int err)
4889 {
4890 int state = inet_sk_state_load(sk);
4891
4892 if (state == TCP_NEW_SYN_RECV) {
4893 struct request_sock *req = inet_reqsk(sk);
4894
4895 local_bh_disable();
4896 inet_csk_reqsk_queue_drop(req->rsk_listener, req);
4897 local_bh_enable();
4898 return 0;
4899 }
4900 if (state == TCP_TIME_WAIT) {
4901 struct inet_timewait_sock *tw = inet_twsk(sk);
4902
4903 refcount_inc(&tw->tw_refcnt);
4904 local_bh_disable();
4905 inet_twsk_deschedule_put(tw);
4906 local_bh_enable();
4907 return 0;
4908 }
4909
4910 /* BPF context ensures sock locking. */
4911 if (!has_current_bpf_ctx())
4912 /* Don't race with userspace socket closes such as tcp_close. */
4913 lock_sock(sk);
4914
4915 /* Avoid closing the same socket twice. */
4916 if (sk->sk_state == TCP_CLOSE) {
4917 if (!has_current_bpf_ctx())
4918 release_sock(sk);
4919 return -ENOENT;
4920 }
4921
4922 if (sk->sk_state == TCP_LISTEN) {
4923 tcp_set_state(sk, TCP_CLOSE);
4924 inet_csk_listen_stop(sk);
4925 }
4926
4927 /* Don't race with BH socket closes such as inet_csk_listen_stop. */
4928 local_bh_disable();
4929 bh_lock_sock(sk);
4930
4931 if (tcp_need_reset(sk->sk_state))
4932 tcp_send_active_reset(sk, GFP_ATOMIC,
4933 SK_RST_REASON_TCP_STATE);
4934 tcp_done_with_error(sk, err);
4935
4936 bh_unlock_sock(sk);
4937 local_bh_enable();
4938 if (!has_current_bpf_ctx())
4939 release_sock(sk);
4940 return 0;
4941 }
4942 EXPORT_SYMBOL_GPL(tcp_abort);
4943
4944 extern struct tcp_congestion_ops tcp_reno;
4945
4946 static __initdata unsigned long thash_entries;
set_thash_entries(char * str)4947 static int __init set_thash_entries(char *str)
4948 {
4949 ssize_t ret;
4950
4951 if (!str)
4952 return 0;
4953
4954 ret = kstrtoul(str, 0, &thash_entries);
4955 if (ret)
4956 return 0;
4957
4958 return 1;
4959 }
4960 __setup("thash_entries=", set_thash_entries);
4961
tcp_init_mem(void)4962 static void __init tcp_init_mem(void)
4963 {
4964 unsigned long limit = nr_free_buffer_pages() / 16;
4965
4966 limit = max(limit, 128UL);
4967 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */
4968 sysctl_tcp_mem[1] = limit; /* 6.25 % */
4969 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */
4970 }
4971
tcp_struct_check(void)4972 static void __init tcp_struct_check(void)
4973 {
4974 /* TX read-mostly hotpath cache lines */
4975 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, max_window);
4976 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, rcv_ssthresh);
4977 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, reordering);
4978 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, notsent_lowat);
4979 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, gso_segs);
4980 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, lost_skb_hint);
4981 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_tx, retransmit_skb_hint);
4982 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_read_tx, 40);
4983
4984 /* TXRX read-mostly hotpath cache lines */
4985 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, tsoffset);
4986 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, snd_wnd);
4987 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, mss_cache);
4988 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, snd_cwnd);
4989 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, prr_out);
4990 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, lost_out);
4991 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, sacked_out);
4992 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_txrx, scaling_ratio);
4993 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_read_txrx, 32);
4994
4995 /* RX read-mostly hotpath cache lines */
4996 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, copied_seq);
4997 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, rcv_tstamp);
4998 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, snd_wl1);
4999 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, tlp_high_seq);
5000 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, rttvar_us);
5001 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, retrans_out);
5002 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, advmss);
5003 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, urg_data);
5004 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, lost);
5005 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, rtt_min);
5006 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, out_of_order_queue);
5007 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_read_rx, snd_ssthresh);
5008 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_read_rx, 69);
5009
5010 /* TX read-write hotpath cache lines */
5011 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, segs_out);
5012 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, data_segs_out);
5013 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, bytes_sent);
5014 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, snd_sml);
5015 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, chrono_start);
5016 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, chrono_stat);
5017 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, write_seq);
5018 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, pushed_seq);
5019 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, lsndtime);
5020 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, mdev_us);
5021 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, tcp_wstamp_ns);
5022 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, rtt_seq);
5023 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, tsorted_sent_queue);
5024 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, highest_sack);
5025 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_tx, ecn_flags);
5026 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_tx, 89);
5027
5028 /* TXRX read-write hotpath cache lines */
5029 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, pred_flags);
5030 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, tcp_clock_cache);
5031 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, tcp_mstamp);
5032 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_nxt);
5033 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, snd_nxt);
5034 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, snd_una);
5035 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, window_clamp);
5036 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, srtt_us);
5037 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, packets_out);
5038 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, snd_up);
5039 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, delivered);
5040 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, delivered_ce);
5041 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, app_limited);
5042 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_wnd);
5043 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rx_opt);
5044
5045 /* 32bit arches with 8byte alignment on u64 fields might need padding
5046 * before tcp_clock_cache.
5047 */
5048 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_txrx, 92 + 4);
5049
5050 /* RX read-write hotpath cache lines */
5051 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, bytes_received);
5052 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, segs_in);
5053 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, data_segs_in);
5054 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcv_wup);
5055 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, max_packets_out);
5056 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, cwnd_usage_seq);
5057 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rate_delivered);
5058 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rate_interval_us);
5059 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcv_rtt_last_tsecr);
5060 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, first_tx_mstamp);
5061 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, delivered_mstamp);
5062 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, bytes_acked);
5063 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcv_rtt_est);
5064 CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, rcvq_space);
5065 CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_rx, 99);
5066 }
5067
tcp_init(void)5068 void __init tcp_init(void)
5069 {
5070 int max_rshare, max_wshare, cnt;
5071 unsigned long limit;
5072 unsigned int i;
5073
5074 BUILD_BUG_ON(TCP_MIN_SND_MSS <= MAX_TCP_OPTION_SPACE);
5075 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
5076 sizeof_field(struct sk_buff, cb));
5077
5078 tcp_struct_check();
5079
5080 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
5081
5082 timer_setup(&tcp_orphan_timer, tcp_orphan_update, TIMER_DEFERRABLE);
5083 mod_timer(&tcp_orphan_timer, jiffies + TCP_ORPHAN_TIMER_PERIOD);
5084
5085 inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash",
5086 thash_entries, 21, /* one slot per 2 MB*/
5087 0, 64 * 1024);
5088 tcp_hashinfo.bind_bucket_cachep =
5089 kmem_cache_create("tcp_bind_bucket",
5090 sizeof(struct inet_bind_bucket), 0,
5091 SLAB_HWCACHE_ALIGN | SLAB_PANIC |
5092 SLAB_ACCOUNT,
5093 NULL);
5094 tcp_hashinfo.bind2_bucket_cachep =
5095 kmem_cache_create("tcp_bind2_bucket",
5096 sizeof(struct inet_bind2_bucket), 0,
5097 SLAB_HWCACHE_ALIGN | SLAB_PANIC |
5098 SLAB_ACCOUNT,
5099 NULL);
5100
5101 /* Size and allocate the main established and bind bucket
5102 * hash tables.
5103 *
5104 * The methodology is similar to that of the buffer cache.
5105 */
5106 tcp_hashinfo.ehash =
5107 alloc_large_system_hash("TCP established",
5108 sizeof(struct inet_ehash_bucket),
5109 thash_entries,
5110 17, /* one slot per 128 KB of memory */
5111 0,
5112 NULL,
5113 &tcp_hashinfo.ehash_mask,
5114 0,
5115 thash_entries ? 0 : 512 * 1024);
5116 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
5117 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
5118
5119 if (inet_ehash_locks_alloc(&tcp_hashinfo))
5120 panic("TCP: failed to alloc ehash_locks");
5121 tcp_hashinfo.bhash =
5122 alloc_large_system_hash("TCP bind",
5123 2 * sizeof(struct inet_bind_hashbucket),
5124 tcp_hashinfo.ehash_mask + 1,
5125 17, /* one slot per 128 KB of memory */
5126 0,
5127 &tcp_hashinfo.bhash_size,
5128 NULL,
5129 0,
5130 64 * 1024);
5131 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
5132 tcp_hashinfo.bhash2 = tcp_hashinfo.bhash + tcp_hashinfo.bhash_size;
5133 for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
5134 spin_lock_init(&tcp_hashinfo.bhash[i].lock);
5135 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
5136 spin_lock_init(&tcp_hashinfo.bhash2[i].lock);
5137 INIT_HLIST_HEAD(&tcp_hashinfo.bhash2[i].chain);
5138 }
5139
5140 tcp_hashinfo.pernet = false;
5141
5142 cnt = tcp_hashinfo.ehash_mask + 1;
5143 sysctl_tcp_max_orphans = cnt / 2;
5144
5145 tcp_init_mem();
5146 /* Set per-socket limits to no more than 1/128 the pressure threshold */
5147 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
5148 max_wshare = min(4UL*1024*1024, limit);
5149 max_rshare = min(6UL*1024*1024, limit);
5150
5151 init_net.ipv4.sysctl_tcp_wmem[0] = PAGE_SIZE;
5152 init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024;
5153 init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
5154
5155 init_net.ipv4.sysctl_tcp_rmem[0] = PAGE_SIZE;
5156 init_net.ipv4.sysctl_tcp_rmem[1] = 131072;
5157 init_net.ipv4.sysctl_tcp_rmem[2] = max(131072, max_rshare);
5158
5159 pr_info("Hash tables configured (established %u bind %u)\n",
5160 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
5161
5162 tcp_v4_init();
5163 tcp_metrics_init();
5164 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
5165 tcp_tasklet_init();
5166 mptcp_init();
5167 }
5168