1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Implementation of the Transmission Control Protocol(TCP). 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Mark Evans, <evansmp@uhura.aston.ac.uk> 11 * Corey Minyard <wf-rch!minyard@relay.EU.net> 12 * Florian La Roche, <flla@stud.uni-sb.de> 13 * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> 14 * Linus Torvalds, <torvalds@cs.helsinki.fi> 15 * Alan Cox, <gw4pts@gw4pts.ampr.org> 16 * Matthew Dillon, <dillon@apollo.west.oic.com> 17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 18 * Jorge Cwik, <jorge@laser.satlink.net> 19 * 20 * Fixes: 21 * Alan Cox : Numerous verify_area() calls 22 * Alan Cox : Set the ACK bit on a reset 23 * Alan Cox : Stopped it crashing if it closed while 24 * sk->inuse=1 and was trying to connect 25 * (tcp_err()). 26 * Alan Cox : All icmp error handling was broken 27 * pointers passed where wrong and the 28 * socket was looked up backwards. Nobody 29 * tested any icmp error code obviously. 30 * Alan Cox : tcp_err() now handled properly. It 31 * wakes people on errors. poll 32 * behaves and the icmp error race 33 * has gone by moving it into sock.c 34 * Alan Cox : tcp_send_reset() fixed to work for 35 * everything not just packets for 36 * unknown sockets. 37 * Alan Cox : tcp option processing. 38 * Alan Cox : Reset tweaked (still not 100%) [Had 39 * syn rule wrong] 40 * Herp Rosmanith : More reset fixes 41 * Alan Cox : No longer acks invalid rst frames. 42 * Acking any kind of RST is right out. 43 * Alan Cox : Sets an ignore me flag on an rst 44 * receive otherwise odd bits of prattle 45 * escape still 46 * Alan Cox : Fixed another acking RST frame bug. 47 * Should stop LAN workplace lockups. 48 * Alan Cox : Some tidyups using the new skb list 49 * facilities 50 * Alan Cox : sk->keepopen now seems to work 51 * Alan Cox : Pulls options out correctly on accepts 52 * Alan Cox : Fixed assorted sk->rqueue->next errors 53 * Alan Cox : PSH doesn't end a TCP read. Switched a 54 * bit to skb ops. 55 * Alan Cox : Tidied tcp_data to avoid a potential 56 * nasty. 57 * Alan Cox : Added some better commenting, as the 58 * tcp is hard to follow 59 * Alan Cox : Removed incorrect check for 20 * psh 60 * Michael O'Reilly : ack < copied bug fix. 61 * Johannes Stille : Misc tcp fixes (not all in yet). 62 * Alan Cox : FIN with no memory -> CRASH 63 * Alan Cox : Added socket option proto entries. 64 * Also added awareness of them to accept. 65 * Alan Cox : Added TCP options (SOL_TCP) 66 * Alan Cox : Switched wakeup calls to callbacks, 67 * so the kernel can layer network 68 * sockets. 69 * Alan Cox : Use ip_tos/ip_ttl settings. 70 * Alan Cox : Handle FIN (more) properly (we hope). 71 * Alan Cox : RST frames sent on unsynchronised 72 * state ack error. 73 * Alan Cox : Put in missing check for SYN bit. 74 * Alan Cox : Added tcp_select_window() aka NET2E 75 * window non shrink trick. 76 * Alan Cox : Added a couple of small NET2E timer 77 * fixes 78 * Charles Hedrick : TCP fixes 79 * Toomas Tamm : TCP window fixes 80 * Alan Cox : Small URG fix to rlogin ^C ack fight 81 * Charles Hedrick : Rewrote most of it to actually work 82 * Linus : Rewrote tcp_read() and URG handling 83 * completely 84 * Gerhard Koerting: Fixed some missing timer handling 85 * Matthew Dillon : Reworked TCP machine states as per RFC 86 * Gerhard Koerting: PC/TCP workarounds 87 * Adam Caldwell : Assorted timer/timing errors 88 * Matthew Dillon : Fixed another RST bug 89 * Alan Cox : Move to kernel side addressing changes. 90 * Alan Cox : Beginning work on TCP fastpathing 91 * (not yet usable) 92 * Arnt Gulbrandsen: Turbocharged tcp_check() routine. 93 * Alan Cox : TCP fast path debugging 94 * Alan Cox : Window clamping 95 * Michael Riepe : Bug in tcp_check() 96 * Matt Dillon : More TCP improvements and RST bug fixes 97 * Matt Dillon : Yet more small nasties remove from the 98 * TCP code (Be very nice to this man if 99 * tcp finally works 100%) 8) 100 * Alan Cox : BSD accept semantics. 101 * Alan Cox : Reset on closedown bug. 102 * Peter De Schrijver : ENOTCONN check missing in tcp_sendto(). 103 * Michael Pall : Handle poll() after URG properly in 104 * all cases. 105 * Michael Pall : Undo the last fix in tcp_read_urg() 106 * (multi URG PUSH broke rlogin). 107 * Michael Pall : Fix the multi URG PUSH problem in 108 * tcp_readable(), poll() after URG 109 * works now. 110 * Michael Pall : recv(...,MSG_OOB) never blocks in the 111 * BSD api. 112 * Alan Cox : Changed the semantics of sk->socket to 113 * fix a race and a signal problem with 114 * accept() and async I/O. 115 * Alan Cox : Relaxed the rules on tcp_sendto(). 116 * Yury Shevchuk : Really fixed accept() blocking problem. 117 * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for 118 * clients/servers which listen in on 119 * fixed ports. 120 * Alan Cox : Cleaned the above up and shrank it to 121 * a sensible code size. 122 * Alan Cox : Self connect lockup fix. 123 * Alan Cox : No connect to multicast. 124 * Ross Biro : Close unaccepted children on master 125 * socket close. 126 * Alan Cox : Reset tracing code. 127 * Alan Cox : Spurious resets on shutdown. 128 * Alan Cox : Giant 15 minute/60 second timer error 129 * Alan Cox : Small whoops in polling before an 130 * accept. 131 * Alan Cox : Kept the state trace facility since 132 * it's handy for debugging. 133 * Alan Cox : More reset handler fixes. 134 * Alan Cox : Started rewriting the code based on 135 * the RFC's for other useful protocol 136 * references see: Comer, KA9Q NOS, and 137 * for a reference on the difference 138 * between specifications and how BSD 139 * works see the 4.4lite source. 140 * A.N.Kuznetsov : Don't time wait on completion of tidy 141 * close. 142 * Linus Torvalds : Fin/Shutdown & copied_seq changes. 143 * Linus Torvalds : Fixed BSD port reuse to work first syn 144 * Alan Cox : Reimplemented timers as per the RFC 145 * and using multiple timers for sanity. 146 * Alan Cox : Small bug fixes, and a lot of new 147 * comments. 148 * Alan Cox : Fixed dual reader crash by locking 149 * the buffers (much like datagram.c) 150 * Alan Cox : Fixed stuck sockets in probe. A probe 151 * now gets fed up of retrying without 152 * (even a no space) answer. 153 * Alan Cox : Extracted closing code better 154 * Alan Cox : Fixed the closing state machine to 155 * resemble the RFC. 156 * Alan Cox : More 'per spec' fixes. 157 * Jorge Cwik : Even faster checksumming. 158 * Alan Cox : tcp_data() doesn't ack illegal PSH 159 * only frames. At least one pc tcp stack 160 * generates them. 161 * Alan Cox : Cache last socket. 162 * Alan Cox : Per route irtt. 163 * Matt Day : poll()->select() match BSD precisely on error 164 * Alan Cox : New buffers 165 * Marc Tamsky : Various sk->prot->retransmits and 166 * sk->retransmits misupdating fixed. 167 * Fixed tcp_write_timeout: stuck close, 168 * and TCP syn retries gets used now. 169 * Mark Yarvis : In tcp_read_wakeup(), don't send an 170 * ack if state is TCP_CLOSED. 171 * Alan Cox : Look up device on a retransmit - routes may 172 * change. Doesn't yet cope with MSS shrink right 173 * but it's a start! 174 * Marc Tamsky : Closing in closing fixes. 175 * Mike Shaver : RFC1122 verifications. 176 * Alan Cox : rcv_saddr errors. 177 * Alan Cox : Block double connect(). 178 * Alan Cox : Small hooks for enSKIP. 179 * Alexey Kuznetsov: Path MTU discovery. 180 * Alan Cox : Support soft errors. 181 * Alan Cox : Fix MTU discovery pathological case 182 * when the remote claims no mtu! 183 * Marc Tamsky : TCP_CLOSE fix. 184 * Colin (G3TNE) : Send a reset on syn ack replies in 185 * window but wrong (fixes NT lpd problems) 186 * Pedro Roque : Better TCP window handling, delayed ack. 187 * Joerg Reuter : No modification of locked buffers in 188 * tcp_do_retransmit() 189 * Eric Schenk : Changed receiver side silly window 190 * avoidance algorithm to BSD style 191 * algorithm. This doubles throughput 192 * against machines running Solaris, 193 * and seems to result in general 194 * improvement. 195 * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD 196 * Willy Konynenberg : Transparent proxying support. 197 * Mike McLagan : Routing by source 198 * Keith Owens : Do proper merging with partial SKB's in 199 * tcp_do_sendmsg to avoid burstiness. 200 * Eric Schenk : Fix fast close down bug with 201 * shutdown() followed by close(). 202 * Andi Kleen : Make poll agree with SIGIO 203 * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and 204 * lingertime == 0 (RFC 793 ABORT Call) 205 * Hirokazu Takahashi : Use copy_from_user() instead of 206 * csum_and_copy_from_user() if possible. 207 * 208 * This program is free software; you can redistribute it and/or 209 * modify it under the terms of the GNU General Public License 210 * as published by the Free Software Foundation; either version 211 * 2 of the License, or(at your option) any later version. 212 * 213 * Description of States: 214 * 215 * TCP_SYN_SENT sent a connection request, waiting for ack 216 * 217 * TCP_SYN_RECV received a connection request, sent ack, 218 * waiting for final ack in three-way handshake. 219 * 220 * TCP_ESTABLISHED connection established 221 * 222 * TCP_FIN_WAIT1 our side has shutdown, waiting to complete 223 * transmission of remaining buffered data 224 * 225 * TCP_FIN_WAIT2 all buffered data sent, waiting for remote 226 * to shutdown 227 * 228 * TCP_CLOSING both sides have shutdown but we still have 229 * data we have to finish sending 230 * 231 * TCP_TIME_WAIT timeout to catch resent junk before entering 232 * closed, can only be entered from FIN_WAIT2 233 * or CLOSING. Required because the other end 234 * may not have gotten our last ACK causing it 235 * to retransmit the data packet (which we ignore) 236 * 237 * TCP_CLOSE_WAIT remote side has shutdown and is waiting for 238 * us to finish writing our data and to shutdown 239 * (we have to close() to move on to LAST_ACK) 240 * 241 * TCP_LAST_ACK out side has shutdown after remote has 242 * shutdown. There may still be data in our 243 * buffer that we have to finish sending 244 * 245 * TCP_CLOSE socket is finished 246 */ 247 248 #define pr_fmt(fmt) "TCP: " fmt 249 250 #include <crypto/hash.h> 251 #include <linux/kernel.h> 252 #include <linux/module.h> 253 #include <linux/types.h> 254 #include <linux/fcntl.h> 255 #include <linux/poll.h> 256 #include <linux/inet_diag.h> 257 #include <linux/init.h> 258 #include <linux/fs.h> 259 #include <linux/skbuff.h> 260 #include <linux/scatterlist.h> 261 #include <linux/splice.h> 262 #include <linux/net.h> 263 #include <linux/socket.h> 264 #include <linux/random.h> 265 #include <linux/memblock.h> 266 #include <linux/highmem.h> 267 #include <linux/swap.h> 268 #include <linux/cache.h> 269 #include <linux/err.h> 270 #include <linux/time.h> 271 #include <linux/slab.h> 272 #include <linux/errqueue.h> 273 #include <linux/static_key.h> 274 275 #include <net/icmp.h> 276 #include <net/inet_common.h> 277 #include <net/tcp.h> 278 #include <net/xfrm.h> 279 #include <net/ip.h> 280 #include <net/sock.h> 281 282 #include <linux/uaccess.h> 283 #include <asm/ioctls.h> 284 #include <net/busy_poll.h> 285 286 struct percpu_counter tcp_orphan_count; 287 EXPORT_SYMBOL_GPL(tcp_orphan_count); 288 289 long sysctl_tcp_mem[3] __read_mostly; 290 EXPORT_SYMBOL(sysctl_tcp_mem); 291 292 atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ 293 EXPORT_SYMBOL(tcp_memory_allocated); 294 295 #if IS_ENABLED(CONFIG_SMC) 296 DEFINE_STATIC_KEY_FALSE(tcp_have_smc); 297 EXPORT_SYMBOL(tcp_have_smc); 298 #endif 299 300 /* 301 * Current number of TCP sockets. 302 */ 303 struct percpu_counter tcp_sockets_allocated; 304 EXPORT_SYMBOL(tcp_sockets_allocated); 305 306 /* 307 * TCP splice context 308 */ 309 struct tcp_splice_state { 310 struct pipe_inode_info *pipe; 311 size_t len; 312 unsigned int flags; 313 }; 314 315 /* 316 * Pressure flag: try to collapse. 317 * Technical note: it is used by multiple contexts non atomically. 318 * All the __sk_mem_schedule() is of this nature: accounting 319 * is strict, actions are advisory and have some latency. 320 */ 321 unsigned long tcp_memory_pressure __read_mostly; 322 EXPORT_SYMBOL_GPL(tcp_memory_pressure); 323 324 void tcp_enter_memory_pressure(struct sock *sk) 325 { 326 unsigned long val; 327 328 if (tcp_memory_pressure) 329 return; 330 val = jiffies; 331 332 if (!val) 333 val--; 334 if (!cmpxchg(&tcp_memory_pressure, 0, val)) 335 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); 336 } 337 EXPORT_SYMBOL_GPL(tcp_enter_memory_pressure); 338 339 void tcp_leave_memory_pressure(struct sock *sk) 340 { 341 unsigned long val; 342 343 if (!tcp_memory_pressure) 344 return; 345 val = xchg(&tcp_memory_pressure, 0); 346 if (val) 347 NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURESCHRONO, 348 jiffies_to_msecs(jiffies - val)); 349 } 350 EXPORT_SYMBOL_GPL(tcp_leave_memory_pressure); 351 352 /* Convert seconds to retransmits based on initial and max timeout */ 353 static u8 secs_to_retrans(int seconds, int timeout, int rto_max) 354 { 355 u8 res = 0; 356 357 if (seconds > 0) { 358 int period = timeout; 359 360 res = 1; 361 while (seconds > period && res < 255) { 362 res++; 363 timeout <<= 1; 364 if (timeout > rto_max) 365 timeout = rto_max; 366 period += timeout; 367 } 368 } 369 return res; 370 } 371 372 /* Convert retransmits to seconds based on initial and max timeout */ 373 static int retrans_to_secs(u8 retrans, int timeout, int rto_max) 374 { 375 int period = 0; 376 377 if (retrans > 0) { 378 period = timeout; 379 while (--retrans) { 380 timeout <<= 1; 381 if (timeout > rto_max) 382 timeout = rto_max; 383 period += timeout; 384 } 385 } 386 return period; 387 } 388 389 static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp) 390 { 391 u32 rate = READ_ONCE(tp->rate_delivered); 392 u32 intv = READ_ONCE(tp->rate_interval_us); 393 u64 rate64 = 0; 394 395 if (rate && intv) { 396 rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC; 397 do_div(rate64, intv); 398 } 399 return rate64; 400 } 401 402 /* Address-family independent initialization for a tcp_sock. 403 * 404 * NOTE: A lot of things set to zero explicitly by call to 405 * sk_alloc() so need not be done here. 406 */ 407 void tcp_init_sock(struct sock *sk) 408 { 409 struct inet_connection_sock *icsk = inet_csk(sk); 410 struct tcp_sock *tp = tcp_sk(sk); 411 412 tp->out_of_order_queue = RB_ROOT; 413 sk->tcp_rtx_queue = RB_ROOT; 414 tcp_init_xmit_timers(sk); 415 INIT_LIST_HEAD(&tp->tsq_node); 416 INIT_LIST_HEAD(&tp->tsorted_sent_queue); 417 418 icsk->icsk_rto = TCP_TIMEOUT_INIT; 419 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); 420 minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U); 421 422 /* So many TCP implementations out there (incorrectly) count the 423 * initial SYN frame in their delayed-ACK and congestion control 424 * algorithms that we must have the following bandaid to talk 425 * efficiently to them. -DaveM 426 */ 427 tp->snd_cwnd = TCP_INIT_CWND; 428 429 /* There's a bubble in the pipe until at least the first ACK. */ 430 tp->app_limited = ~0U; 431 432 /* See draft-stevens-tcpca-spec-01 for discussion of the 433 * initialization of these values. 434 */ 435 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 436 tp->snd_cwnd_clamp = ~0; 437 tp->mss_cache = TCP_MSS_DEFAULT; 438 439 tp->reordering = sock_net(sk)->ipv4.sysctl_tcp_reordering; 440 tcp_assign_congestion_control(sk); 441 442 tp->tsoffset = 0; 443 tp->rack.reo_wnd_steps = 1; 444 445 sk->sk_state = TCP_CLOSE; 446 447 sk->sk_write_space = sk_stream_write_space; 448 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); 449 450 icsk->icsk_sync_mss = tcp_sync_mss; 451 452 sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1]; 453 sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1]; 454 455 sk_sockets_allocated_inc(sk); 456 sk->sk_route_forced_caps = NETIF_F_GSO; 457 } 458 EXPORT_SYMBOL(tcp_init_sock); 459 460 void tcp_init_transfer(struct sock *sk, int bpf_op) 461 { 462 struct inet_connection_sock *icsk = inet_csk(sk); 463 464 tcp_mtup_init(sk); 465 icsk->icsk_af_ops->rebuild_header(sk); 466 tcp_init_metrics(sk); 467 tcp_call_bpf(sk, bpf_op, 0, NULL); 468 tcp_init_congestion_control(sk); 469 tcp_init_buffer_space(sk); 470 } 471 472 static void tcp_tx_timestamp(struct sock *sk, u16 tsflags) 473 { 474 struct sk_buff *skb = tcp_write_queue_tail(sk); 475 476 if (tsflags && skb) { 477 struct skb_shared_info *shinfo = skb_shinfo(skb); 478 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 479 480 sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags); 481 if (tsflags & SOF_TIMESTAMPING_TX_ACK) 482 tcb->txstamp_ack = 1; 483 if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) 484 shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; 485 } 486 } 487 488 static inline bool tcp_stream_is_readable(const struct tcp_sock *tp, 489 int target, struct sock *sk) 490 { 491 return (tp->rcv_nxt - tp->copied_seq >= target) || 492 (sk->sk_prot->stream_memory_read ? 493 sk->sk_prot->stream_memory_read(sk) : false); 494 } 495 496 /* 497 * Wait for a TCP event. 498 * 499 * Note that we don't need to lock the socket, as the upper poll layers 500 * take care of normal races (between the test and the event) and we don't 501 * go look at any of the socket buffers directly. 502 */ 503 __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 504 { 505 __poll_t mask; 506 struct sock *sk = sock->sk; 507 const struct tcp_sock *tp = tcp_sk(sk); 508 int state; 509 510 sock_poll_wait(file, sock, wait); 511 512 state = inet_sk_state_load(sk); 513 if (state == TCP_LISTEN) 514 return inet_csk_listen_poll(sk); 515 516 /* Socket is not locked. We are protected from async events 517 * by poll logic and correct handling of state changes 518 * made by other threads is impossible in any case. 519 */ 520 521 mask = 0; 522 523 /* 524 * EPOLLHUP is certainly not done right. But poll() doesn't 525 * have a notion of HUP in just one direction, and for a 526 * socket the read side is more interesting. 527 * 528 * Some poll() documentation says that EPOLLHUP is incompatible 529 * with the EPOLLOUT/POLLWR flags, so somebody should check this 530 * all. But careful, it tends to be safer to return too many 531 * bits than too few, and you can easily break real applications 532 * if you don't tell them that something has hung up! 533 * 534 * Check-me. 535 * 536 * Check number 1. EPOLLHUP is _UNMASKABLE_ event (see UNIX98 and 537 * our fs/select.c). It means that after we received EOF, 538 * poll always returns immediately, making impossible poll() on write() 539 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP 540 * if and only if shutdown has been made in both directions. 541 * Actually, it is interesting to look how Solaris and DUX 542 * solve this dilemma. I would prefer, if EPOLLHUP were maskable, 543 * then we could set it on SND_SHUTDOWN. BTW examples given 544 * in Stevens' books assume exactly this behaviour, it explains 545 * why EPOLLHUP is incompatible with EPOLLOUT. --ANK 546 * 547 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 548 * blocking on fresh not-connected or disconnected socket. --ANK 549 */ 550 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE) 551 mask |= EPOLLHUP; 552 if (sk->sk_shutdown & RCV_SHUTDOWN) 553 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; 554 555 /* Connected or passive Fast Open socket? */ 556 if (state != TCP_SYN_SENT && 557 (state != TCP_SYN_RECV || tp->fastopen_rsk)) { 558 int target = sock_rcvlowat(sk, 0, INT_MAX); 559 560 if (tp->urg_seq == tp->copied_seq && 561 !sock_flag(sk, SOCK_URGINLINE) && 562 tp->urg_data) 563 target++; 564 565 if (tcp_stream_is_readable(tp, target, sk)) 566 mask |= EPOLLIN | EPOLLRDNORM; 567 568 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 569 if (sk_stream_is_writeable(sk)) { 570 mask |= EPOLLOUT | EPOLLWRNORM; 571 } else { /* send SIGIO later */ 572 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 573 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 574 575 /* Race breaker. If space is freed after 576 * wspace test but before the flags are set, 577 * IO signal will be lost. Memory barrier 578 * pairs with the input side. 579 */ 580 smp_mb__after_atomic(); 581 if (sk_stream_is_writeable(sk)) 582 mask |= EPOLLOUT | EPOLLWRNORM; 583 } 584 } else 585 mask |= EPOLLOUT | EPOLLWRNORM; 586 587 if (tp->urg_data & TCP_URG_VALID) 588 mask |= EPOLLPRI; 589 } else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) { 590 /* Active TCP fastopen socket with defer_connect 591 * Return EPOLLOUT so application can call write() 592 * in order for kernel to generate SYN+data 593 */ 594 mask |= EPOLLOUT | EPOLLWRNORM; 595 } 596 /* This barrier is coupled with smp_wmb() in tcp_reset() */ 597 smp_rmb(); 598 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 599 mask |= EPOLLERR; 600 601 return mask; 602 } 603 EXPORT_SYMBOL(tcp_poll); 604 605 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 606 { 607 struct tcp_sock *tp = tcp_sk(sk); 608 int answ; 609 bool slow; 610 611 switch (cmd) { 612 case SIOCINQ: 613 if (sk->sk_state == TCP_LISTEN) 614 return -EINVAL; 615 616 slow = lock_sock_fast(sk); 617 answ = tcp_inq(sk); 618 unlock_sock_fast(sk, slow); 619 break; 620 case SIOCATMARK: 621 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 622 break; 623 case SIOCOUTQ: 624 if (sk->sk_state == TCP_LISTEN) 625 return -EINVAL; 626 627 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 628 answ = 0; 629 else 630 answ = tp->write_seq - tp->snd_una; 631 break; 632 case SIOCOUTQNSD: 633 if (sk->sk_state == TCP_LISTEN) 634 return -EINVAL; 635 636 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 637 answ = 0; 638 else 639 answ = tp->write_seq - tp->snd_nxt; 640 break; 641 default: 642 return -ENOIOCTLCMD; 643 } 644 645 return put_user(answ, (int __user *)arg); 646 } 647 EXPORT_SYMBOL(tcp_ioctl); 648 649 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 650 { 651 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; 652 tp->pushed_seq = tp->write_seq; 653 } 654 655 static inline bool forced_push(const struct tcp_sock *tp) 656 { 657 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 658 } 659 660 static void skb_entail(struct sock *sk, struct sk_buff *skb) 661 { 662 struct tcp_sock *tp = tcp_sk(sk); 663 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 664 665 skb->csum = 0; 666 tcb->seq = tcb->end_seq = tp->write_seq; 667 tcb->tcp_flags = TCPHDR_ACK; 668 tcb->sacked = 0; 669 __skb_header_release(skb); 670 tcp_add_write_queue_tail(sk, skb); 671 sk->sk_wmem_queued += skb->truesize; 672 sk_mem_charge(sk, skb->truesize); 673 if (tp->nonagle & TCP_NAGLE_PUSH) 674 tp->nonagle &= ~TCP_NAGLE_PUSH; 675 676 tcp_slow_start_after_idle_check(sk); 677 } 678 679 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) 680 { 681 if (flags & MSG_OOB) 682 tp->snd_up = tp->write_seq; 683 } 684 685 /* If a not yet filled skb is pushed, do not send it if 686 * we have data packets in Qdisc or NIC queues : 687 * Because TX completion will happen shortly, it gives a chance 688 * to coalesce future sendmsg() payload into this skb, without 689 * need for a timer, and with no latency trade off. 690 * As packets containing data payload have a bigger truesize 691 * than pure acks (dataless) packets, the last checks prevent 692 * autocorking if we only have an ACK in Qdisc/NIC queues, 693 * or if TX completion was delayed after we processed ACK packet. 694 */ 695 static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, 696 int size_goal) 697 { 698 return skb->len < size_goal && 699 sock_net(sk)->ipv4.sysctl_tcp_autocorking && 700 !tcp_rtx_queue_empty(sk) && 701 refcount_read(&sk->sk_wmem_alloc) > skb->truesize; 702 } 703 704 static void tcp_push(struct sock *sk, int flags, int mss_now, 705 int nonagle, int size_goal) 706 { 707 struct tcp_sock *tp = tcp_sk(sk); 708 struct sk_buff *skb; 709 710 skb = tcp_write_queue_tail(sk); 711 if (!skb) 712 return; 713 if (!(flags & MSG_MORE) || forced_push(tp)) 714 tcp_mark_push(tp, skb); 715 716 tcp_mark_urg(tp, flags); 717 718 if (tcp_should_autocork(sk, skb, size_goal)) { 719 720 /* avoid atomic op if TSQ_THROTTLED bit is already set */ 721 if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) { 722 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); 723 set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags); 724 } 725 /* It is possible TX completion already happened 726 * before we set TSQ_THROTTLED. 727 */ 728 if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize) 729 return; 730 } 731 732 if (flags & MSG_MORE) 733 nonagle = TCP_NAGLE_CORK; 734 735 __tcp_push_pending_frames(sk, mss_now, nonagle); 736 } 737 738 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 739 unsigned int offset, size_t len) 740 { 741 struct tcp_splice_state *tss = rd_desc->arg.data; 742 int ret; 743 744 ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe, 745 min(rd_desc->count, len), tss->flags); 746 if (ret > 0) 747 rd_desc->count -= ret; 748 return ret; 749 } 750 751 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 752 { 753 /* Store TCP splice context information in read_descriptor_t. */ 754 read_descriptor_t rd_desc = { 755 .arg.data = tss, 756 .count = tss->len, 757 }; 758 759 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 760 } 761 762 /** 763 * tcp_splice_read - splice data from TCP socket to a pipe 764 * @sock: socket to splice from 765 * @ppos: position (not valid) 766 * @pipe: pipe to splice to 767 * @len: number of bytes to splice 768 * @flags: splice modifier flags 769 * 770 * Description: 771 * Will read pages from given socket and fill them into a pipe. 772 * 773 **/ 774 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 775 struct pipe_inode_info *pipe, size_t len, 776 unsigned int flags) 777 { 778 struct sock *sk = sock->sk; 779 struct tcp_splice_state tss = { 780 .pipe = pipe, 781 .len = len, 782 .flags = flags, 783 }; 784 long timeo; 785 ssize_t spliced; 786 int ret; 787 788 sock_rps_record_flow(sk); 789 /* 790 * We can't seek on a socket input 791 */ 792 if (unlikely(*ppos)) 793 return -ESPIPE; 794 795 ret = spliced = 0; 796 797 lock_sock(sk); 798 799 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 800 while (tss.len) { 801 ret = __tcp_splice_read(sk, &tss); 802 if (ret < 0) 803 break; 804 else if (!ret) { 805 if (spliced) 806 break; 807 if (sock_flag(sk, SOCK_DONE)) 808 break; 809 if (sk->sk_err) { 810 ret = sock_error(sk); 811 break; 812 } 813 if (sk->sk_shutdown & RCV_SHUTDOWN) 814 break; 815 if (sk->sk_state == TCP_CLOSE) { 816 /* 817 * This occurs when user tries to read 818 * from never connected socket. 819 */ 820 ret = -ENOTCONN; 821 break; 822 } 823 if (!timeo) { 824 ret = -EAGAIN; 825 break; 826 } 827 /* if __tcp_splice_read() got nothing while we have 828 * an skb in receive queue, we do not want to loop. 829 * This might happen with URG data. 830 */ 831 if (!skb_queue_empty(&sk->sk_receive_queue)) 832 break; 833 sk_wait_data(sk, &timeo, NULL); 834 if (signal_pending(current)) { 835 ret = sock_intr_errno(timeo); 836 break; 837 } 838 continue; 839 } 840 tss.len -= ret; 841 spliced += ret; 842 843 if (!timeo) 844 break; 845 release_sock(sk); 846 lock_sock(sk); 847 848 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 849 (sk->sk_shutdown & RCV_SHUTDOWN) || 850 signal_pending(current)) 851 break; 852 } 853 854 release_sock(sk); 855 856 if (spliced) 857 return spliced; 858 859 return ret; 860 } 861 EXPORT_SYMBOL(tcp_splice_read); 862 863 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, 864 bool force_schedule) 865 { 866 struct sk_buff *skb; 867 868 /* The TCP header must be at least 32-bit aligned. */ 869 size = ALIGN(size, 4); 870 871 if (unlikely(tcp_under_memory_pressure(sk))) 872 sk_mem_reclaim_partial(sk); 873 874 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 875 if (likely(skb)) { 876 bool mem_scheduled; 877 878 if (force_schedule) { 879 mem_scheduled = true; 880 sk_forced_mem_schedule(sk, skb->truesize); 881 } else { 882 mem_scheduled = sk_wmem_schedule(sk, skb->truesize); 883 } 884 if (likely(mem_scheduled)) { 885 skb_reserve(skb, sk->sk_prot->max_header); 886 /* 887 * Make sure that we have exactly size bytes 888 * available to the caller, no more, no less. 889 */ 890 skb->reserved_tailroom = skb->end - skb->tail - size; 891 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); 892 return skb; 893 } 894 __kfree_skb(skb); 895 } else { 896 sk->sk_prot->enter_memory_pressure(sk); 897 sk_stream_moderate_sndbuf(sk); 898 } 899 return NULL; 900 } 901 902 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 903 int large_allowed) 904 { 905 struct tcp_sock *tp = tcp_sk(sk); 906 u32 new_size_goal, size_goal; 907 908 if (!large_allowed) 909 return mss_now; 910 911 /* Note : tcp_tso_autosize() will eventually split this later */ 912 new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER; 913 new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal); 914 915 /* We try hard to avoid divides here */ 916 size_goal = tp->gso_segs * mss_now; 917 if (unlikely(new_size_goal < size_goal || 918 new_size_goal >= size_goal + mss_now)) { 919 tp->gso_segs = min_t(u16, new_size_goal / mss_now, 920 sk->sk_gso_max_segs); 921 size_goal = tp->gso_segs * mss_now; 922 } 923 924 return max(size_goal, mss_now); 925 } 926 927 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 928 { 929 int mss_now; 930 931 mss_now = tcp_current_mss(sk); 932 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 933 934 return mss_now; 935 } 936 937 ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, 938 size_t size, int flags) 939 { 940 struct tcp_sock *tp = tcp_sk(sk); 941 int mss_now, size_goal; 942 int err; 943 ssize_t copied; 944 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 945 946 /* Wait for a connection to finish. One exception is TCP Fast Open 947 * (passive side) where data is allowed to be sent before a connection 948 * is fully established. 949 */ 950 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && 951 !tcp_passive_fastopen(sk)) { 952 err = sk_stream_wait_connect(sk, &timeo); 953 if (err != 0) 954 goto out_err; 955 } 956 957 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 958 959 mss_now = tcp_send_mss(sk, &size_goal, flags); 960 copied = 0; 961 962 err = -EPIPE; 963 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 964 goto out_err; 965 966 while (size > 0) { 967 struct sk_buff *skb = tcp_write_queue_tail(sk); 968 int copy, i; 969 bool can_coalesce; 970 971 if (!skb || (copy = size_goal - skb->len) <= 0 || 972 !tcp_skb_can_collapse_to(skb)) { 973 new_segment: 974 if (!sk_stream_memory_free(sk)) 975 goto wait_for_sndbuf; 976 977 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, 978 tcp_rtx_and_write_queues_empty(sk)); 979 if (!skb) 980 goto wait_for_memory; 981 982 skb_entail(sk, skb); 983 copy = size_goal; 984 } 985 986 if (copy > size) 987 copy = size; 988 989 i = skb_shinfo(skb)->nr_frags; 990 can_coalesce = skb_can_coalesce(skb, i, page, offset); 991 if (!can_coalesce && i >= sysctl_max_skb_frags) { 992 tcp_mark_push(tp, skb); 993 goto new_segment; 994 } 995 if (!sk_wmem_schedule(sk, copy)) 996 goto wait_for_memory; 997 998 if (can_coalesce) { 999 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1000 } else { 1001 get_page(page); 1002 skb_fill_page_desc(skb, i, page, offset, copy); 1003 } 1004 1005 if (!(flags & MSG_NO_SHARED_FRAGS)) 1006 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 1007 1008 skb->len += copy; 1009 skb->data_len += copy; 1010 skb->truesize += copy; 1011 sk->sk_wmem_queued += copy; 1012 sk_mem_charge(sk, copy); 1013 skb->ip_summed = CHECKSUM_PARTIAL; 1014 tp->write_seq += copy; 1015 TCP_SKB_CB(skb)->end_seq += copy; 1016 tcp_skb_pcount_set(skb, 0); 1017 1018 if (!copied) 1019 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1020 1021 copied += copy; 1022 offset += copy; 1023 size -= copy; 1024 if (!size) 1025 goto out; 1026 1027 if (skb->len < size_goal || (flags & MSG_OOB)) 1028 continue; 1029 1030 if (forced_push(tp)) { 1031 tcp_mark_push(tp, skb); 1032 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1033 } else if (skb == tcp_send_head(sk)) 1034 tcp_push_one(sk, mss_now); 1035 continue; 1036 1037 wait_for_sndbuf: 1038 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1039 wait_for_memory: 1040 tcp_push(sk, flags & ~MSG_MORE, mss_now, 1041 TCP_NAGLE_PUSH, size_goal); 1042 1043 err = sk_stream_wait_memory(sk, &timeo); 1044 if (err != 0) 1045 goto do_error; 1046 1047 mss_now = tcp_send_mss(sk, &size_goal, flags); 1048 } 1049 1050 out: 1051 if (copied) { 1052 tcp_tx_timestamp(sk, sk->sk_tsflags); 1053 if (!(flags & MSG_SENDPAGE_NOTLAST)) 1054 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); 1055 } 1056 return copied; 1057 1058 do_error: 1059 if (copied) 1060 goto out; 1061 out_err: 1062 /* make sure we wake any epoll edge trigger waiter */ 1063 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && 1064 err == -EAGAIN)) { 1065 sk->sk_write_space(sk); 1066 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); 1067 } 1068 return sk_stream_error(sk, flags, err); 1069 } 1070 EXPORT_SYMBOL_GPL(do_tcp_sendpages); 1071 1072 int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset, 1073 size_t size, int flags) 1074 { 1075 if (!(sk->sk_route_caps & NETIF_F_SG)) 1076 return sock_no_sendpage_locked(sk, page, offset, size, flags); 1077 1078 tcp_rate_check_app_limited(sk); /* is sending application-limited? */ 1079 1080 return do_tcp_sendpages(sk, page, offset, size, flags); 1081 } 1082 EXPORT_SYMBOL_GPL(tcp_sendpage_locked); 1083 1084 int tcp_sendpage(struct sock *sk, struct page *page, int offset, 1085 size_t size, int flags) 1086 { 1087 int ret; 1088 1089 lock_sock(sk); 1090 ret = tcp_sendpage_locked(sk, page, offset, size, flags); 1091 release_sock(sk); 1092 1093 return ret; 1094 } 1095 EXPORT_SYMBOL(tcp_sendpage); 1096 1097 /* Do not bother using a page frag for very small frames. 1098 * But use this heuristic only for the first skb in write queue. 1099 * 1100 * Having no payload in skb->head allows better SACK shifting 1101 * in tcp_shift_skb_data(), reducing sack/rack overhead, because 1102 * write queue has less skbs. 1103 * Each skb can hold up to MAX_SKB_FRAGS * 32Kbytes, or ~0.5 MB. 1104 * This also speeds up tso_fragment(), since it wont fallback 1105 * to tcp_fragment(). 1106 */ 1107 static int linear_payload_sz(bool first_skb) 1108 { 1109 if (first_skb) 1110 return SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); 1111 return 0; 1112 } 1113 1114 static int select_size(bool first_skb, bool zc) 1115 { 1116 if (zc) 1117 return 0; 1118 return linear_payload_sz(first_skb); 1119 } 1120 1121 void tcp_free_fastopen_req(struct tcp_sock *tp) 1122 { 1123 if (tp->fastopen_req) { 1124 kfree(tp->fastopen_req); 1125 tp->fastopen_req = NULL; 1126 } 1127 } 1128 1129 static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, 1130 int *copied, size_t size, 1131 struct ubuf_info *uarg) 1132 { 1133 struct tcp_sock *tp = tcp_sk(sk); 1134 struct inet_sock *inet = inet_sk(sk); 1135 struct sockaddr *uaddr = msg->msg_name; 1136 int err, flags; 1137 1138 if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) || 1139 (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) && 1140 uaddr->sa_family == AF_UNSPEC)) 1141 return -EOPNOTSUPP; 1142 if (tp->fastopen_req) 1143 return -EALREADY; /* Another Fast Open is in progress */ 1144 1145 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), 1146 sk->sk_allocation); 1147 if (unlikely(!tp->fastopen_req)) 1148 return -ENOBUFS; 1149 tp->fastopen_req->data = msg; 1150 tp->fastopen_req->size = size; 1151 tp->fastopen_req->uarg = uarg; 1152 1153 if (inet->defer_connect) { 1154 err = tcp_connect(sk); 1155 /* Same failure procedure as in tcp_v4/6_connect */ 1156 if (err) { 1157 tcp_set_state(sk, TCP_CLOSE); 1158 inet->inet_dport = 0; 1159 sk->sk_route_caps = 0; 1160 } 1161 } 1162 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; 1163 err = __inet_stream_connect(sk->sk_socket, uaddr, 1164 msg->msg_namelen, flags, 1); 1165 /* fastopen_req could already be freed in __inet_stream_connect 1166 * if the connection times out or gets rst 1167 */ 1168 if (tp->fastopen_req) { 1169 *copied = tp->fastopen_req->copied; 1170 tcp_free_fastopen_req(tp); 1171 inet->defer_connect = 0; 1172 } 1173 return err; 1174 } 1175 1176 int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) 1177 { 1178 struct tcp_sock *tp = tcp_sk(sk); 1179 struct ubuf_info *uarg = NULL; 1180 struct sk_buff *skb; 1181 struct sockcm_cookie sockc; 1182 int flags, err, copied = 0; 1183 int mss_now = 0, size_goal, copied_syn = 0; 1184 bool process_backlog = false; 1185 bool zc = false; 1186 long timeo; 1187 1188 flags = msg->msg_flags; 1189 1190 if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) { 1191 skb = tcp_write_queue_tail(sk); 1192 uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb)); 1193 if (!uarg) { 1194 err = -ENOBUFS; 1195 goto out_err; 1196 } 1197 1198 zc = sk->sk_route_caps & NETIF_F_SG; 1199 if (!zc) 1200 uarg->zerocopy = 0; 1201 } 1202 1203 if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) && 1204 !tp->repair) { 1205 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size, uarg); 1206 if (err == -EINPROGRESS && copied_syn > 0) 1207 goto out; 1208 else if (err) 1209 goto out_err; 1210 } 1211 1212 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 1213 1214 tcp_rate_check_app_limited(sk); /* is sending application-limited? */ 1215 1216 /* Wait for a connection to finish. One exception is TCP Fast Open 1217 * (passive side) where data is allowed to be sent before a connection 1218 * is fully established. 1219 */ 1220 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && 1221 !tcp_passive_fastopen(sk)) { 1222 err = sk_stream_wait_connect(sk, &timeo); 1223 if (err != 0) 1224 goto do_error; 1225 } 1226 1227 if (unlikely(tp->repair)) { 1228 if (tp->repair_queue == TCP_RECV_QUEUE) { 1229 copied = tcp_send_rcvq(sk, msg, size); 1230 goto out_nopush; 1231 } 1232 1233 err = -EINVAL; 1234 if (tp->repair_queue == TCP_NO_QUEUE) 1235 goto out_err; 1236 1237 /* 'common' sending to sendq */ 1238 } 1239 1240 sockcm_init(&sockc, sk); 1241 if (msg->msg_controllen) { 1242 err = sock_cmsg_send(sk, msg, &sockc); 1243 if (unlikely(err)) { 1244 err = -EINVAL; 1245 goto out_err; 1246 } 1247 } 1248 1249 /* This should be in poll */ 1250 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 1251 1252 /* Ok commence sending. */ 1253 copied = 0; 1254 1255 restart: 1256 mss_now = tcp_send_mss(sk, &size_goal, flags); 1257 1258 err = -EPIPE; 1259 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 1260 goto do_error; 1261 1262 while (msg_data_left(msg)) { 1263 int copy = 0; 1264 1265 skb = tcp_write_queue_tail(sk); 1266 if (skb) 1267 copy = size_goal - skb->len; 1268 1269 if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) { 1270 bool first_skb; 1271 int linear; 1272 1273 new_segment: 1274 if (!sk_stream_memory_free(sk)) 1275 goto wait_for_sndbuf; 1276 1277 if (process_backlog && sk_flush_backlog(sk)) { 1278 process_backlog = false; 1279 goto restart; 1280 } 1281 first_skb = tcp_rtx_and_write_queues_empty(sk); 1282 linear = select_size(first_skb, zc); 1283 skb = sk_stream_alloc_skb(sk, linear, sk->sk_allocation, 1284 first_skb); 1285 if (!skb) 1286 goto wait_for_memory; 1287 1288 process_backlog = true; 1289 skb->ip_summed = CHECKSUM_PARTIAL; 1290 1291 skb_entail(sk, skb); 1292 copy = size_goal; 1293 1294 /* All packets are restored as if they have 1295 * already been sent. skb_mstamp_ns isn't set to 1296 * avoid wrong rtt estimation. 1297 */ 1298 if (tp->repair) 1299 TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED; 1300 } 1301 1302 /* Try to append data to the end of skb. */ 1303 if (copy > msg_data_left(msg)) 1304 copy = msg_data_left(msg); 1305 1306 /* Where to copy to? */ 1307 if (skb_availroom(skb) > 0 && !zc) { 1308 /* We have some space in skb head. Superb! */ 1309 copy = min_t(int, copy, skb_availroom(skb)); 1310 err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy); 1311 if (err) 1312 goto do_fault; 1313 } else if (!zc) { 1314 bool merge = true; 1315 int i = skb_shinfo(skb)->nr_frags; 1316 struct page_frag *pfrag = sk_page_frag(sk); 1317 1318 if (!sk_page_frag_refill(sk, pfrag)) 1319 goto wait_for_memory; 1320 1321 if (!skb_can_coalesce(skb, i, pfrag->page, 1322 pfrag->offset)) { 1323 if (i >= sysctl_max_skb_frags) { 1324 tcp_mark_push(tp, skb); 1325 goto new_segment; 1326 } 1327 merge = false; 1328 } 1329 1330 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1331 1332 if (!sk_wmem_schedule(sk, copy)) 1333 goto wait_for_memory; 1334 1335 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, 1336 pfrag->page, 1337 pfrag->offset, 1338 copy); 1339 if (err) 1340 goto do_error; 1341 1342 /* Update the skb. */ 1343 if (merge) { 1344 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1345 } else { 1346 skb_fill_page_desc(skb, i, pfrag->page, 1347 pfrag->offset, copy); 1348 page_ref_inc(pfrag->page); 1349 } 1350 pfrag->offset += copy; 1351 } else { 1352 err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg); 1353 if (err == -EMSGSIZE || err == -EEXIST) { 1354 tcp_mark_push(tp, skb); 1355 goto new_segment; 1356 } 1357 if (err < 0) 1358 goto do_error; 1359 copy = err; 1360 } 1361 1362 if (!copied) 1363 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1364 1365 tp->write_seq += copy; 1366 TCP_SKB_CB(skb)->end_seq += copy; 1367 tcp_skb_pcount_set(skb, 0); 1368 1369 copied += copy; 1370 if (!msg_data_left(msg)) { 1371 if (unlikely(flags & MSG_EOR)) 1372 TCP_SKB_CB(skb)->eor = 1; 1373 goto out; 1374 } 1375 1376 if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair)) 1377 continue; 1378 1379 if (forced_push(tp)) { 1380 tcp_mark_push(tp, skb); 1381 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1382 } else if (skb == tcp_send_head(sk)) 1383 tcp_push_one(sk, mss_now); 1384 continue; 1385 1386 wait_for_sndbuf: 1387 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1388 wait_for_memory: 1389 if (copied) 1390 tcp_push(sk, flags & ~MSG_MORE, mss_now, 1391 TCP_NAGLE_PUSH, size_goal); 1392 1393 err = sk_stream_wait_memory(sk, &timeo); 1394 if (err != 0) 1395 goto do_error; 1396 1397 mss_now = tcp_send_mss(sk, &size_goal, flags); 1398 } 1399 1400 out: 1401 if (copied) { 1402 tcp_tx_timestamp(sk, sockc.tsflags); 1403 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); 1404 } 1405 out_nopush: 1406 sock_zerocopy_put(uarg); 1407 return copied + copied_syn; 1408 1409 do_fault: 1410 if (!skb->len) { 1411 tcp_unlink_write_queue(skb, sk); 1412 /* It is the one place in all of TCP, except connection 1413 * reset, where we can be unlinking the send_head. 1414 */ 1415 tcp_check_send_head(sk, skb); 1416 sk_wmem_free_skb(sk, skb); 1417 } 1418 1419 do_error: 1420 if (copied + copied_syn) 1421 goto out; 1422 out_err: 1423 sock_zerocopy_put_abort(uarg, true); 1424 err = sk_stream_error(sk, flags, err); 1425 /* make sure we wake any epoll edge trigger waiter */ 1426 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && 1427 err == -EAGAIN)) { 1428 sk->sk_write_space(sk); 1429 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); 1430 } 1431 return err; 1432 } 1433 EXPORT_SYMBOL_GPL(tcp_sendmsg_locked); 1434 1435 int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) 1436 { 1437 int ret; 1438 1439 lock_sock(sk); 1440 ret = tcp_sendmsg_locked(sk, msg, size); 1441 release_sock(sk); 1442 1443 return ret; 1444 } 1445 EXPORT_SYMBOL(tcp_sendmsg); 1446 1447 /* 1448 * Handle reading urgent data. BSD has very simple semantics for 1449 * this, no blocking and very strange errors 8) 1450 */ 1451 1452 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1453 { 1454 struct tcp_sock *tp = tcp_sk(sk); 1455 1456 /* No URG data to read. */ 1457 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1458 tp->urg_data == TCP_URG_READ) 1459 return -EINVAL; /* Yes this is right ! */ 1460 1461 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1462 return -ENOTCONN; 1463 1464 if (tp->urg_data & TCP_URG_VALID) { 1465 int err = 0; 1466 char c = tp->urg_data; 1467 1468 if (!(flags & MSG_PEEK)) 1469 tp->urg_data = TCP_URG_READ; 1470 1471 /* Read urgent data. */ 1472 msg->msg_flags |= MSG_OOB; 1473 1474 if (len > 0) { 1475 if (!(flags & MSG_TRUNC)) 1476 err = memcpy_to_msg(msg, &c, 1); 1477 len = 1; 1478 } else 1479 msg->msg_flags |= MSG_TRUNC; 1480 1481 return err ? -EFAULT : len; 1482 } 1483 1484 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1485 return 0; 1486 1487 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1488 * the available implementations agree in this case: 1489 * this call should never block, independent of the 1490 * blocking state of the socket. 1491 * Mike <pall@rz.uni-karlsruhe.de> 1492 */ 1493 return -EAGAIN; 1494 } 1495 1496 static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len) 1497 { 1498 struct sk_buff *skb; 1499 int copied = 0, err = 0; 1500 1501 /* XXX -- need to support SO_PEEK_OFF */ 1502 1503 skb_rbtree_walk(skb, &sk->tcp_rtx_queue) { 1504 err = skb_copy_datagram_msg(skb, 0, msg, skb->len); 1505 if (err) 1506 return err; 1507 copied += skb->len; 1508 } 1509 1510 skb_queue_walk(&sk->sk_write_queue, skb) { 1511 err = skb_copy_datagram_msg(skb, 0, msg, skb->len); 1512 if (err) 1513 break; 1514 1515 copied += skb->len; 1516 } 1517 1518 return err ?: copied; 1519 } 1520 1521 /* Clean up the receive buffer for full frames taken by the user, 1522 * then send an ACK if necessary. COPIED is the number of bytes 1523 * tcp_recvmsg has given to the user so far, it speeds up the 1524 * calculation of whether or not we must ACK for the sake of 1525 * a window update. 1526 */ 1527 static void tcp_cleanup_rbuf(struct sock *sk, int copied) 1528 { 1529 struct tcp_sock *tp = tcp_sk(sk); 1530 bool time_to_ack = false; 1531 1532 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1533 1534 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1535 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1536 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1537 1538 if (inet_csk_ack_scheduled(sk)) { 1539 const struct inet_connection_sock *icsk = inet_csk(sk); 1540 /* Delayed ACKs frequently hit locked sockets during bulk 1541 * receive. */ 1542 if (icsk->icsk_ack.blocked || 1543 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1544 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1545 /* 1546 * If this read emptied read buffer, we send ACK, if 1547 * connection is not bidirectional, user drained 1548 * receive buffer and there was a small segment 1549 * in queue. 1550 */ 1551 (copied > 0 && 1552 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1553 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1554 !inet_csk_in_pingpong_mode(sk))) && 1555 !atomic_read(&sk->sk_rmem_alloc))) 1556 time_to_ack = true; 1557 } 1558 1559 /* We send an ACK if we can now advertise a non-zero window 1560 * which has been raised "significantly". 1561 * 1562 * Even if window raised up to infinity, do not send window open ACK 1563 * in states, where we will not receive more. It is useless. 1564 */ 1565 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1566 __u32 rcv_window_now = tcp_receive_window(tp); 1567 1568 /* Optimize, __tcp_select_window() is not cheap. */ 1569 if (2*rcv_window_now <= tp->window_clamp) { 1570 __u32 new_window = __tcp_select_window(sk); 1571 1572 /* Send ACK now, if this read freed lots of space 1573 * in our buffer. Certainly, new_window is new window. 1574 * We can advertise it now, if it is not less than current one. 1575 * "Lots" means "at least twice" here. 1576 */ 1577 if (new_window && new_window >= 2 * rcv_window_now) 1578 time_to_ack = true; 1579 } 1580 } 1581 if (time_to_ack) 1582 tcp_send_ack(sk); 1583 } 1584 1585 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1586 { 1587 struct sk_buff *skb; 1588 u32 offset; 1589 1590 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { 1591 offset = seq - TCP_SKB_CB(skb)->seq; 1592 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { 1593 pr_err_once("%s: found a SYN, please report !\n", __func__); 1594 offset--; 1595 } 1596 if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) { 1597 *off = offset; 1598 return skb; 1599 } 1600 /* This looks weird, but this can happen if TCP collapsing 1601 * splitted a fat GRO packet, while we released socket lock 1602 * in skb_splice_bits() 1603 */ 1604 sk_eat_skb(sk, skb); 1605 } 1606 return NULL; 1607 } 1608 1609 /* 1610 * This routine provides an alternative to tcp_recvmsg() for routines 1611 * that would like to handle copying from skbuffs directly in 'sendfile' 1612 * fashion. 1613 * Note: 1614 * - It is assumed that the socket was locked by the caller. 1615 * - The routine does not block. 1616 * - At present, there is no support for reading OOB data 1617 * or for 'peeking' the socket using this routine 1618 * (although both would be easy to implement). 1619 */ 1620 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1621 sk_read_actor_t recv_actor) 1622 { 1623 struct sk_buff *skb; 1624 struct tcp_sock *tp = tcp_sk(sk); 1625 u32 seq = tp->copied_seq; 1626 u32 offset; 1627 int copied = 0; 1628 1629 if (sk->sk_state == TCP_LISTEN) 1630 return -ENOTCONN; 1631 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1632 if (offset < skb->len) { 1633 int used; 1634 size_t len; 1635 1636 len = skb->len - offset; 1637 /* Stop reading if we hit a patch of urgent data */ 1638 if (tp->urg_data) { 1639 u32 urg_offset = tp->urg_seq - seq; 1640 if (urg_offset < len) 1641 len = urg_offset; 1642 if (!len) 1643 break; 1644 } 1645 used = recv_actor(desc, skb, offset, len); 1646 if (used <= 0) { 1647 if (!copied) 1648 copied = used; 1649 break; 1650 } else if (used <= len) { 1651 seq += used; 1652 copied += used; 1653 offset += used; 1654 } 1655 /* If recv_actor drops the lock (e.g. TCP splice 1656 * receive) the skb pointer might be invalid when 1657 * getting here: tcp_collapse might have deleted it 1658 * while aggregating skbs from the socket queue. 1659 */ 1660 skb = tcp_recv_skb(sk, seq - 1, &offset); 1661 if (!skb) 1662 break; 1663 /* TCP coalescing might have appended data to the skb. 1664 * Try to splice more frags 1665 */ 1666 if (offset + 1 != skb->len) 1667 continue; 1668 } 1669 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) { 1670 sk_eat_skb(sk, skb); 1671 ++seq; 1672 break; 1673 } 1674 sk_eat_skb(sk, skb); 1675 if (!desc->count) 1676 break; 1677 tp->copied_seq = seq; 1678 } 1679 tp->copied_seq = seq; 1680 1681 tcp_rcv_space_adjust(sk); 1682 1683 /* Clean up data we have read: This will do ACK frames. */ 1684 if (copied > 0) { 1685 tcp_recv_skb(sk, seq, &offset); 1686 tcp_cleanup_rbuf(sk, copied); 1687 } 1688 return copied; 1689 } 1690 EXPORT_SYMBOL(tcp_read_sock); 1691 1692 int tcp_peek_len(struct socket *sock) 1693 { 1694 return tcp_inq(sock->sk); 1695 } 1696 EXPORT_SYMBOL(tcp_peek_len); 1697 1698 /* Make sure sk_rcvbuf is big enough to satisfy SO_RCVLOWAT hint */ 1699 int tcp_set_rcvlowat(struct sock *sk, int val) 1700 { 1701 int cap; 1702 1703 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) 1704 cap = sk->sk_rcvbuf >> 1; 1705 else 1706 cap = sock_net(sk)->ipv4.sysctl_tcp_rmem[2] >> 1; 1707 val = min(val, cap); 1708 sk->sk_rcvlowat = val ? : 1; 1709 1710 /* Check if we need to signal EPOLLIN right now */ 1711 tcp_data_ready(sk); 1712 1713 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) 1714 return 0; 1715 1716 val <<= 1; 1717 if (val > sk->sk_rcvbuf) { 1718 sk->sk_rcvbuf = val; 1719 tcp_sk(sk)->window_clamp = tcp_win_from_space(sk, val); 1720 } 1721 return 0; 1722 } 1723 EXPORT_SYMBOL(tcp_set_rcvlowat); 1724 1725 #ifdef CONFIG_MMU 1726 static const struct vm_operations_struct tcp_vm_ops = { 1727 }; 1728 1729 int tcp_mmap(struct file *file, struct socket *sock, 1730 struct vm_area_struct *vma) 1731 { 1732 if (vma->vm_flags & (VM_WRITE | VM_EXEC)) 1733 return -EPERM; 1734 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC); 1735 1736 /* Instruct vm_insert_page() to not down_read(mmap_sem) */ 1737 vma->vm_flags |= VM_MIXEDMAP; 1738 1739 vma->vm_ops = &tcp_vm_ops; 1740 return 0; 1741 } 1742 EXPORT_SYMBOL(tcp_mmap); 1743 1744 static int tcp_zerocopy_receive(struct sock *sk, 1745 struct tcp_zerocopy_receive *zc) 1746 { 1747 unsigned long address = (unsigned long)zc->address; 1748 const skb_frag_t *frags = NULL; 1749 u32 length = 0, seq, offset; 1750 struct vm_area_struct *vma; 1751 struct sk_buff *skb = NULL; 1752 struct tcp_sock *tp; 1753 int inq; 1754 int ret; 1755 1756 if (address & (PAGE_SIZE - 1) || address != zc->address) 1757 return -EINVAL; 1758 1759 if (sk->sk_state == TCP_LISTEN) 1760 return -ENOTCONN; 1761 1762 sock_rps_record_flow(sk); 1763 1764 down_read(¤t->mm->mmap_sem); 1765 1766 ret = -EINVAL; 1767 vma = find_vma(current->mm, address); 1768 if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops) 1769 goto out; 1770 zc->length = min_t(unsigned long, zc->length, vma->vm_end - address); 1771 1772 tp = tcp_sk(sk); 1773 seq = tp->copied_seq; 1774 inq = tcp_inq(sk); 1775 zc->length = min_t(u32, zc->length, inq); 1776 zc->length &= ~(PAGE_SIZE - 1); 1777 if (zc->length) { 1778 zap_page_range(vma, address, zc->length); 1779 zc->recv_skip_hint = 0; 1780 } else { 1781 zc->recv_skip_hint = inq; 1782 } 1783 ret = 0; 1784 while (length + PAGE_SIZE <= zc->length) { 1785 if (zc->recv_skip_hint < PAGE_SIZE) { 1786 if (skb) { 1787 skb = skb->next; 1788 offset = seq - TCP_SKB_CB(skb)->seq; 1789 } else { 1790 skb = tcp_recv_skb(sk, seq, &offset); 1791 } 1792 1793 zc->recv_skip_hint = skb->len - offset; 1794 offset -= skb_headlen(skb); 1795 if ((int)offset < 0 || skb_has_frag_list(skb)) 1796 break; 1797 frags = skb_shinfo(skb)->frags; 1798 while (offset) { 1799 if (frags->size > offset) 1800 goto out; 1801 offset -= frags->size; 1802 frags++; 1803 } 1804 } 1805 if (frags->size != PAGE_SIZE || frags->page_offset) { 1806 int remaining = zc->recv_skip_hint; 1807 1808 while (remaining && (frags->size != PAGE_SIZE || 1809 frags->page_offset)) { 1810 remaining -= frags->size; 1811 frags++; 1812 } 1813 zc->recv_skip_hint -= remaining; 1814 break; 1815 } 1816 ret = vm_insert_page(vma, address + length, 1817 skb_frag_page(frags)); 1818 if (ret) 1819 break; 1820 length += PAGE_SIZE; 1821 seq += PAGE_SIZE; 1822 zc->recv_skip_hint -= PAGE_SIZE; 1823 frags++; 1824 } 1825 out: 1826 up_read(¤t->mm->mmap_sem); 1827 if (length) { 1828 tp->copied_seq = seq; 1829 tcp_rcv_space_adjust(sk); 1830 1831 /* Clean up data we have read: This will do ACK frames. */ 1832 tcp_recv_skb(sk, seq, &offset); 1833 tcp_cleanup_rbuf(sk, length); 1834 ret = 0; 1835 if (length == zc->length) 1836 zc->recv_skip_hint = 0; 1837 } else { 1838 if (!zc->recv_skip_hint && sock_flag(sk, SOCK_DONE)) 1839 ret = -EIO; 1840 } 1841 zc->length = length; 1842 return ret; 1843 } 1844 #endif 1845 1846 static void tcp_update_recv_tstamps(struct sk_buff *skb, 1847 struct scm_timestamping *tss) 1848 { 1849 if (skb->tstamp) 1850 tss->ts[0] = ktime_to_timespec(skb->tstamp); 1851 else 1852 tss->ts[0] = (struct timespec) {0}; 1853 1854 if (skb_hwtstamps(skb)->hwtstamp) 1855 tss->ts[2] = ktime_to_timespec(skb_hwtstamps(skb)->hwtstamp); 1856 else 1857 tss->ts[2] = (struct timespec) {0}; 1858 } 1859 1860 /* Similar to __sock_recv_timestamp, but does not require an skb */ 1861 static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, 1862 struct scm_timestamping *tss) 1863 { 1864 struct timeval tv; 1865 bool has_timestamping = false; 1866 1867 if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) { 1868 if (sock_flag(sk, SOCK_RCVTSTAMP)) { 1869 if (sock_flag(sk, SOCK_RCVTSTAMPNS)) { 1870 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS, 1871 sizeof(tss->ts[0]), &tss->ts[0]); 1872 } else { 1873 tv.tv_sec = tss->ts[0].tv_sec; 1874 tv.tv_usec = tss->ts[0].tv_nsec / 1000; 1875 1876 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP, 1877 sizeof(tv), &tv); 1878 } 1879 } 1880 1881 if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) 1882 has_timestamping = true; 1883 else 1884 tss->ts[0] = (struct timespec) {0}; 1885 } 1886 1887 if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) { 1888 if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) 1889 has_timestamping = true; 1890 else 1891 tss->ts[2] = (struct timespec) {0}; 1892 } 1893 1894 if (has_timestamping) { 1895 tss->ts[1] = (struct timespec) {0}; 1896 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING, 1897 sizeof(*tss), tss); 1898 } 1899 } 1900 1901 static int tcp_inq_hint(struct sock *sk) 1902 { 1903 const struct tcp_sock *tp = tcp_sk(sk); 1904 u32 copied_seq = READ_ONCE(tp->copied_seq); 1905 u32 rcv_nxt = READ_ONCE(tp->rcv_nxt); 1906 int inq; 1907 1908 inq = rcv_nxt - copied_seq; 1909 if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) { 1910 lock_sock(sk); 1911 inq = tp->rcv_nxt - tp->copied_seq; 1912 release_sock(sk); 1913 } 1914 return inq; 1915 } 1916 1917 /* 1918 * This routine copies from a sock struct into the user buffer. 1919 * 1920 * Technical note: in 2.3 we work on _locked_ socket, so that 1921 * tricks with *seq access order and skb->users are not required. 1922 * Probably, code can be easily improved even more. 1923 */ 1924 1925 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 1926 int flags, int *addr_len) 1927 { 1928 struct tcp_sock *tp = tcp_sk(sk); 1929 int copied = 0; 1930 u32 peek_seq; 1931 u32 *seq; 1932 unsigned long used; 1933 int err, inq; 1934 int target; /* Read at least this many bytes */ 1935 long timeo; 1936 struct sk_buff *skb, *last; 1937 u32 urg_hole = 0; 1938 struct scm_timestamping tss; 1939 bool has_tss = false; 1940 bool has_cmsg; 1941 1942 if (unlikely(flags & MSG_ERRQUEUE)) 1943 return inet_recv_error(sk, msg, len, addr_len); 1944 1945 if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) && 1946 (sk->sk_state == TCP_ESTABLISHED)) 1947 sk_busy_loop(sk, nonblock); 1948 1949 lock_sock(sk); 1950 1951 err = -ENOTCONN; 1952 if (sk->sk_state == TCP_LISTEN) 1953 goto out; 1954 1955 has_cmsg = tp->recvmsg_inq; 1956 timeo = sock_rcvtimeo(sk, nonblock); 1957 1958 /* Urgent data needs to be handled specially. */ 1959 if (flags & MSG_OOB) 1960 goto recv_urg; 1961 1962 if (unlikely(tp->repair)) { 1963 err = -EPERM; 1964 if (!(flags & MSG_PEEK)) 1965 goto out; 1966 1967 if (tp->repair_queue == TCP_SEND_QUEUE) 1968 goto recv_sndq; 1969 1970 err = -EINVAL; 1971 if (tp->repair_queue == TCP_NO_QUEUE) 1972 goto out; 1973 1974 /* 'common' recv queue MSG_PEEK-ing */ 1975 } 1976 1977 seq = &tp->copied_seq; 1978 if (flags & MSG_PEEK) { 1979 peek_seq = tp->copied_seq; 1980 seq = &peek_seq; 1981 } 1982 1983 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1984 1985 do { 1986 u32 offset; 1987 1988 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1989 if (tp->urg_data && tp->urg_seq == *seq) { 1990 if (copied) 1991 break; 1992 if (signal_pending(current)) { 1993 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1994 break; 1995 } 1996 } 1997 1998 /* Next get a buffer. */ 1999 2000 last = skb_peek_tail(&sk->sk_receive_queue); 2001 skb_queue_walk(&sk->sk_receive_queue, skb) { 2002 last = skb; 2003 /* Now that we have two receive queues this 2004 * shouldn't happen. 2005 */ 2006 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 2007 "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n", 2008 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 2009 flags)) 2010 break; 2011 2012 offset = *seq - TCP_SKB_CB(skb)->seq; 2013 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { 2014 pr_err_once("%s: found a SYN, please report !\n", __func__); 2015 offset--; 2016 } 2017 if (offset < skb->len) 2018 goto found_ok_skb; 2019 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 2020 goto found_fin_ok; 2021 WARN(!(flags & MSG_PEEK), 2022 "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n", 2023 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); 2024 } 2025 2026 /* Well, if we have backlog, try to process it now yet. */ 2027 2028 if (copied >= target && !sk->sk_backlog.tail) 2029 break; 2030 2031 if (copied) { 2032 if (sk->sk_err || 2033 sk->sk_state == TCP_CLOSE || 2034 (sk->sk_shutdown & RCV_SHUTDOWN) || 2035 !timeo || 2036 signal_pending(current)) 2037 break; 2038 } else { 2039 if (sock_flag(sk, SOCK_DONE)) 2040 break; 2041 2042 if (sk->sk_err) { 2043 copied = sock_error(sk); 2044 break; 2045 } 2046 2047 if (sk->sk_shutdown & RCV_SHUTDOWN) 2048 break; 2049 2050 if (sk->sk_state == TCP_CLOSE) { 2051 /* This occurs when user tries to read 2052 * from never connected socket. 2053 */ 2054 copied = -ENOTCONN; 2055 break; 2056 } 2057 2058 if (!timeo) { 2059 copied = -EAGAIN; 2060 break; 2061 } 2062 2063 if (signal_pending(current)) { 2064 copied = sock_intr_errno(timeo); 2065 break; 2066 } 2067 } 2068 2069 tcp_cleanup_rbuf(sk, copied); 2070 2071 if (copied >= target) { 2072 /* Do not sleep, just process backlog. */ 2073 release_sock(sk); 2074 lock_sock(sk); 2075 } else { 2076 sk_wait_data(sk, &timeo, last); 2077 } 2078 2079 if ((flags & MSG_PEEK) && 2080 (peek_seq - copied - urg_hole != tp->copied_seq)) { 2081 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", 2082 current->comm, 2083 task_pid_nr(current)); 2084 peek_seq = tp->copied_seq; 2085 } 2086 continue; 2087 2088 found_ok_skb: 2089 /* Ok so how much can we use? */ 2090 used = skb->len - offset; 2091 if (len < used) 2092 used = len; 2093 2094 /* Do we have urgent data here? */ 2095 if (tp->urg_data) { 2096 u32 urg_offset = tp->urg_seq - *seq; 2097 if (urg_offset < used) { 2098 if (!urg_offset) { 2099 if (!sock_flag(sk, SOCK_URGINLINE)) { 2100 ++*seq; 2101 urg_hole++; 2102 offset++; 2103 used--; 2104 if (!used) 2105 goto skip_copy; 2106 } 2107 } else 2108 used = urg_offset; 2109 } 2110 } 2111 2112 if (!(flags & MSG_TRUNC)) { 2113 err = skb_copy_datagram_msg(skb, offset, msg, used); 2114 if (err) { 2115 /* Exception. Bailout! */ 2116 if (!copied) 2117 copied = -EFAULT; 2118 break; 2119 } 2120 } 2121 2122 *seq += used; 2123 copied += used; 2124 len -= used; 2125 2126 tcp_rcv_space_adjust(sk); 2127 2128 skip_copy: 2129 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 2130 tp->urg_data = 0; 2131 tcp_fast_path_check(sk); 2132 } 2133 if (used + offset < skb->len) 2134 continue; 2135 2136 if (TCP_SKB_CB(skb)->has_rxtstamp) { 2137 tcp_update_recv_tstamps(skb, &tss); 2138 has_tss = true; 2139 has_cmsg = true; 2140 } 2141 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 2142 goto found_fin_ok; 2143 if (!(flags & MSG_PEEK)) 2144 sk_eat_skb(sk, skb); 2145 continue; 2146 2147 found_fin_ok: 2148 /* Process the FIN. */ 2149 ++*seq; 2150 if (!(flags & MSG_PEEK)) 2151 sk_eat_skb(sk, skb); 2152 break; 2153 } while (len > 0); 2154 2155 /* According to UNIX98, msg_name/msg_namelen are ignored 2156 * on connected socket. I was just happy when found this 8) --ANK 2157 */ 2158 2159 /* Clean up data we have read: This will do ACK frames. */ 2160 tcp_cleanup_rbuf(sk, copied); 2161 2162 release_sock(sk); 2163 2164 if (has_cmsg) { 2165 if (has_tss) 2166 tcp_recv_timestamp(msg, sk, &tss); 2167 if (tp->recvmsg_inq) { 2168 inq = tcp_inq_hint(sk); 2169 put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq); 2170 } 2171 } 2172 2173 return copied; 2174 2175 out: 2176 release_sock(sk); 2177 return err; 2178 2179 recv_urg: 2180 err = tcp_recv_urg(sk, msg, len, flags); 2181 goto out; 2182 2183 recv_sndq: 2184 err = tcp_peek_sndq(sk, msg, len); 2185 goto out; 2186 } 2187 EXPORT_SYMBOL(tcp_recvmsg); 2188 2189 void tcp_set_state(struct sock *sk, int state) 2190 { 2191 int oldstate = sk->sk_state; 2192 2193 /* We defined a new enum for TCP states that are exported in BPF 2194 * so as not force the internal TCP states to be frozen. The 2195 * following checks will detect if an internal state value ever 2196 * differs from the BPF value. If this ever happens, then we will 2197 * need to remap the internal value to the BPF value before calling 2198 * tcp_call_bpf_2arg. 2199 */ 2200 BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED); 2201 BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT); 2202 BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV); 2203 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1); 2204 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2); 2205 BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT); 2206 BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE); 2207 BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT); 2208 BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK); 2209 BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN); 2210 BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING); 2211 BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV); 2212 BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES); 2213 2214 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG)) 2215 tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state); 2216 2217 switch (state) { 2218 case TCP_ESTABLISHED: 2219 if (oldstate != TCP_ESTABLISHED) 2220 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2221 break; 2222 2223 case TCP_CLOSE: 2224 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 2225 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 2226 2227 sk->sk_prot->unhash(sk); 2228 if (inet_csk(sk)->icsk_bind_hash && 2229 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 2230 inet_put_port(sk); 2231 /* fall through */ 2232 default: 2233 if (oldstate == TCP_ESTABLISHED) 2234 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2235 } 2236 2237 /* Change state AFTER socket is unhashed to avoid closed 2238 * socket sitting in hash tables. 2239 */ 2240 inet_sk_state_store(sk, state); 2241 } 2242 EXPORT_SYMBOL_GPL(tcp_set_state); 2243 2244 /* 2245 * State processing on a close. This implements the state shift for 2246 * sending our FIN frame. Note that we only send a FIN for some 2247 * states. A shutdown() may have already sent the FIN, or we may be 2248 * closed. 2249 */ 2250 2251 static const unsigned char new_state[16] = { 2252 /* current state: new state: action: */ 2253 [0 /* (Invalid) */] = TCP_CLOSE, 2254 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2255 [TCP_SYN_SENT] = TCP_CLOSE, 2256 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2257 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, 2258 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, 2259 [TCP_TIME_WAIT] = TCP_CLOSE, 2260 [TCP_CLOSE] = TCP_CLOSE, 2261 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, 2262 [TCP_LAST_ACK] = TCP_LAST_ACK, 2263 [TCP_LISTEN] = TCP_CLOSE, 2264 [TCP_CLOSING] = TCP_CLOSING, 2265 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ 2266 }; 2267 2268 static int tcp_close_state(struct sock *sk) 2269 { 2270 int next = (int)new_state[sk->sk_state]; 2271 int ns = next & TCP_STATE_MASK; 2272 2273 tcp_set_state(sk, ns); 2274 2275 return next & TCP_ACTION_FIN; 2276 } 2277 2278 /* 2279 * Shutdown the sending side of a connection. Much like close except 2280 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 2281 */ 2282 2283 void tcp_shutdown(struct sock *sk, int how) 2284 { 2285 /* We need to grab some memory, and put together a FIN, 2286 * and then put it into the queue to be sent. 2287 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 2288 */ 2289 if (!(how & SEND_SHUTDOWN)) 2290 return; 2291 2292 /* If we've already sent a FIN, or it's a closed state, skip this. */ 2293 if ((1 << sk->sk_state) & 2294 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 2295 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 2296 /* Clear out any half completed packets. FIN if needed. */ 2297 if (tcp_close_state(sk)) 2298 tcp_send_fin(sk); 2299 } 2300 } 2301 EXPORT_SYMBOL(tcp_shutdown); 2302 2303 bool tcp_check_oom(struct sock *sk, int shift) 2304 { 2305 bool too_many_orphans, out_of_socket_memory; 2306 2307 too_many_orphans = tcp_too_many_orphans(sk, shift); 2308 out_of_socket_memory = tcp_out_of_memory(sk); 2309 2310 if (too_many_orphans) 2311 net_info_ratelimited("too many orphaned sockets\n"); 2312 if (out_of_socket_memory) 2313 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); 2314 return too_many_orphans || out_of_socket_memory; 2315 } 2316 2317 void tcp_close(struct sock *sk, long timeout) 2318 { 2319 struct sk_buff *skb; 2320 int data_was_unread = 0; 2321 int state; 2322 2323 lock_sock(sk); 2324 sk->sk_shutdown = SHUTDOWN_MASK; 2325 2326 if (sk->sk_state == TCP_LISTEN) { 2327 tcp_set_state(sk, TCP_CLOSE); 2328 2329 /* Special case. */ 2330 inet_csk_listen_stop(sk); 2331 2332 goto adjudge_to_death; 2333 } 2334 2335 /* We need to flush the recv. buffs. We do this only on the 2336 * descriptor close, not protocol-sourced closes, because the 2337 * reader process may not have drained the data yet! 2338 */ 2339 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 2340 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; 2341 2342 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 2343 len--; 2344 data_was_unread += len; 2345 __kfree_skb(skb); 2346 } 2347 2348 sk_mem_reclaim(sk); 2349 2350 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ 2351 if (sk->sk_state == TCP_CLOSE) 2352 goto adjudge_to_death; 2353 2354 /* As outlined in RFC 2525, section 2.17, we send a RST here because 2355 * data was lost. To witness the awful effects of the old behavior of 2356 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 2357 * GET in an FTP client, suspend the process, wait for the client to 2358 * advertise a zero window, then kill -9 the FTP client, wheee... 2359 * Note: timeout is always zero in such a case. 2360 */ 2361 if (unlikely(tcp_sk(sk)->repair)) { 2362 sk->sk_prot->disconnect(sk, 0); 2363 } else if (data_was_unread) { 2364 /* Unread data was tossed, zap the connection. */ 2365 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 2366 tcp_set_state(sk, TCP_CLOSE); 2367 tcp_send_active_reset(sk, sk->sk_allocation); 2368 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 2369 /* Check zero linger _after_ checking for unread data. */ 2370 sk->sk_prot->disconnect(sk, 0); 2371 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 2372 } else if (tcp_close_state(sk)) { 2373 /* We FIN if the application ate all the data before 2374 * zapping the connection. 2375 */ 2376 2377 /* RED-PEN. Formally speaking, we have broken TCP state 2378 * machine. State transitions: 2379 * 2380 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 2381 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 2382 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 2383 * 2384 * are legal only when FIN has been sent (i.e. in window), 2385 * rather than queued out of window. Purists blame. 2386 * 2387 * F.e. "RFC state" is ESTABLISHED, 2388 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 2389 * 2390 * The visible declinations are that sometimes 2391 * we enter time-wait state, when it is not required really 2392 * (harmless), do not send active resets, when they are 2393 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 2394 * they look as CLOSING or LAST_ACK for Linux) 2395 * Probably, I missed some more holelets. 2396 * --ANK 2397 * XXX (TFO) - To start off we don't support SYN+ACK+FIN 2398 * in a single packet! (May consider it later but will 2399 * probably need API support or TCP_CORK SYN-ACK until 2400 * data is written and socket is closed.) 2401 */ 2402 tcp_send_fin(sk); 2403 } 2404 2405 sk_stream_wait_close(sk, timeout); 2406 2407 adjudge_to_death: 2408 state = sk->sk_state; 2409 sock_hold(sk); 2410 sock_orphan(sk); 2411 2412 local_bh_disable(); 2413 bh_lock_sock(sk); 2414 /* remove backlog if any, without releasing ownership. */ 2415 __release_sock(sk); 2416 2417 percpu_counter_inc(sk->sk_prot->orphan_count); 2418 2419 /* Have we already been destroyed by a softirq or backlog? */ 2420 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 2421 goto out; 2422 2423 /* This is a (useful) BSD violating of the RFC. There is a 2424 * problem with TCP as specified in that the other end could 2425 * keep a socket open forever with no application left this end. 2426 * We use a 1 minute timeout (about the same as BSD) then kill 2427 * our end. If they send after that then tough - BUT: long enough 2428 * that we won't make the old 4*rto = almost no time - whoops 2429 * reset mistake. 2430 * 2431 * Nope, it was not mistake. It is really desired behaviour 2432 * f.e. on http servers, when such sockets are useless, but 2433 * consume significant resources. Let's do it with special 2434 * linger2 option. --ANK 2435 */ 2436 2437 if (sk->sk_state == TCP_FIN_WAIT2) { 2438 struct tcp_sock *tp = tcp_sk(sk); 2439 if (tp->linger2 < 0) { 2440 tcp_set_state(sk, TCP_CLOSE); 2441 tcp_send_active_reset(sk, GFP_ATOMIC); 2442 __NET_INC_STATS(sock_net(sk), 2443 LINUX_MIB_TCPABORTONLINGER); 2444 } else { 2445 const int tmo = tcp_fin_time(sk); 2446 2447 if (tmo > TCP_TIMEWAIT_LEN) { 2448 inet_csk_reset_keepalive_timer(sk, 2449 tmo - TCP_TIMEWAIT_LEN); 2450 } else { 2451 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 2452 goto out; 2453 } 2454 } 2455 } 2456 if (sk->sk_state != TCP_CLOSE) { 2457 sk_mem_reclaim(sk); 2458 if (tcp_check_oom(sk, 0)) { 2459 tcp_set_state(sk, TCP_CLOSE); 2460 tcp_send_active_reset(sk, GFP_ATOMIC); 2461 __NET_INC_STATS(sock_net(sk), 2462 LINUX_MIB_TCPABORTONMEMORY); 2463 } else if (!check_net(sock_net(sk))) { 2464 /* Not possible to send reset; just close */ 2465 tcp_set_state(sk, TCP_CLOSE); 2466 } 2467 } 2468 2469 if (sk->sk_state == TCP_CLOSE) { 2470 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 2471 /* We could get here with a non-NULL req if the socket is 2472 * aborted (e.g., closed with unread data) before 3WHS 2473 * finishes. 2474 */ 2475 if (req) 2476 reqsk_fastopen_remove(sk, req, false); 2477 inet_csk_destroy_sock(sk); 2478 } 2479 /* Otherwise, socket is reprieved until protocol close. */ 2480 2481 out: 2482 bh_unlock_sock(sk); 2483 local_bh_enable(); 2484 release_sock(sk); 2485 sock_put(sk); 2486 } 2487 EXPORT_SYMBOL(tcp_close); 2488 2489 /* These states need RST on ABORT according to RFC793 */ 2490 2491 static inline bool tcp_need_reset(int state) 2492 { 2493 return (1 << state) & 2494 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2495 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2496 } 2497 2498 static void tcp_rtx_queue_purge(struct sock *sk) 2499 { 2500 struct rb_node *p = rb_first(&sk->tcp_rtx_queue); 2501 2502 while (p) { 2503 struct sk_buff *skb = rb_to_skb(p); 2504 2505 p = rb_next(p); 2506 /* Since we are deleting whole queue, no need to 2507 * list_del(&skb->tcp_tsorted_anchor) 2508 */ 2509 tcp_rtx_queue_unlink(skb, sk); 2510 sk_wmem_free_skb(sk, skb); 2511 } 2512 } 2513 2514 void tcp_write_queue_purge(struct sock *sk) 2515 { 2516 struct sk_buff *skb; 2517 2518 tcp_chrono_stop(sk, TCP_CHRONO_BUSY); 2519 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 2520 tcp_skb_tsorted_anchor_cleanup(skb); 2521 sk_wmem_free_skb(sk, skb); 2522 } 2523 tcp_rtx_queue_purge(sk); 2524 INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue); 2525 sk_mem_reclaim(sk); 2526 tcp_clear_all_retrans_hints(tcp_sk(sk)); 2527 tcp_sk(sk)->packets_out = 0; 2528 } 2529 2530 int tcp_disconnect(struct sock *sk, int flags) 2531 { 2532 struct inet_sock *inet = inet_sk(sk); 2533 struct inet_connection_sock *icsk = inet_csk(sk); 2534 struct tcp_sock *tp = tcp_sk(sk); 2535 int old_state = sk->sk_state; 2536 2537 if (old_state != TCP_CLOSE) 2538 tcp_set_state(sk, TCP_CLOSE); 2539 2540 /* ABORT function of RFC793 */ 2541 if (old_state == TCP_LISTEN) { 2542 inet_csk_listen_stop(sk); 2543 } else if (unlikely(tp->repair)) { 2544 sk->sk_err = ECONNABORTED; 2545 } else if (tcp_need_reset(old_state) || 2546 (tp->snd_nxt != tp->write_seq && 2547 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2548 /* The last check adjusts for discrepancy of Linux wrt. RFC 2549 * states 2550 */ 2551 tcp_send_active_reset(sk, gfp_any()); 2552 sk->sk_err = ECONNRESET; 2553 } else if (old_state == TCP_SYN_SENT) 2554 sk->sk_err = ECONNRESET; 2555 2556 tcp_clear_xmit_timers(sk); 2557 __skb_queue_purge(&sk->sk_receive_queue); 2558 tp->copied_seq = tp->rcv_nxt; 2559 tp->urg_data = 0; 2560 tcp_write_queue_purge(sk); 2561 tcp_fastopen_active_disable_ofo_check(sk); 2562 skb_rbtree_purge(&tp->out_of_order_queue); 2563 2564 inet->inet_dport = 0; 2565 2566 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2567 inet_reset_saddr(sk); 2568 2569 sk->sk_shutdown = 0; 2570 sock_reset_flag(sk, SOCK_DONE); 2571 tp->srtt_us = 0; 2572 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); 2573 tp->rcv_rtt_last_tsecr = 0; 2574 tp->write_seq += tp->max_window + 2; 2575 if (tp->write_seq == 0) 2576 tp->write_seq = 1; 2577 icsk->icsk_backoff = 0; 2578 icsk->icsk_probes_out = 0; 2579 icsk->icsk_rto = TCP_TIMEOUT_INIT; 2580 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2581 tp->snd_cwnd = TCP_INIT_CWND; 2582 tp->snd_cwnd_cnt = 0; 2583 tp->window_clamp = 0; 2584 tp->delivered_ce = 0; 2585 tcp_set_ca_state(sk, TCP_CA_Open); 2586 tp->is_sack_reneg = 0; 2587 tcp_clear_retrans(tp); 2588 inet_csk_delack_init(sk); 2589 /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 2590 * issue in __tcp_select_window() 2591 */ 2592 icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; 2593 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2594 __sk_dst_reset(sk); 2595 dst_release(sk->sk_rx_dst); 2596 sk->sk_rx_dst = NULL; 2597 tcp_saved_syn_free(tp); 2598 tp->compressed_ack = 0; 2599 tp->bytes_sent = 0; 2600 tp->bytes_retrans = 0; 2601 tp->duplicate_sack[0].start_seq = 0; 2602 tp->duplicate_sack[0].end_seq = 0; 2603 tp->dsack_dups = 0; 2604 tp->reord_seen = 0; 2605 tp->retrans_out = 0; 2606 tp->sacked_out = 0; 2607 tp->tlp_high_seq = 0; 2608 tp->last_oow_ack_time = 0; 2609 /* There's a bubble in the pipe until at least the first ACK. */ 2610 tp->app_limited = ~0U; 2611 tp->rack.mstamp = 0; 2612 tp->rack.advanced = 0; 2613 tp->rack.reo_wnd_steps = 1; 2614 tp->rack.last_delivered = 0; 2615 tp->rack.reo_wnd_persist = 0; 2616 tp->rack.dsack_seen = 0; 2617 tp->syn_data_acked = 0; 2618 tp->rx_opt.saw_tstamp = 0; 2619 tp->rx_opt.dsack = 0; 2620 tp->rx_opt.num_sacks = 0; 2621 2622 2623 /* Clean up fastopen related fields */ 2624 tcp_free_fastopen_req(tp); 2625 inet->defer_connect = 0; 2626 2627 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2628 2629 if (sk->sk_frag.page) { 2630 put_page(sk->sk_frag.page); 2631 sk->sk_frag.page = NULL; 2632 sk->sk_frag.offset = 0; 2633 } 2634 2635 sk->sk_error_report(sk); 2636 return 0; 2637 } 2638 EXPORT_SYMBOL(tcp_disconnect); 2639 2640 static inline bool tcp_can_repair_sock(const struct sock *sk) 2641 { 2642 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && 2643 (sk->sk_state != TCP_LISTEN); 2644 } 2645 2646 static int tcp_repair_set_window(struct tcp_sock *tp, char __user *optbuf, int len) 2647 { 2648 struct tcp_repair_window opt; 2649 2650 if (!tp->repair) 2651 return -EPERM; 2652 2653 if (len != sizeof(opt)) 2654 return -EINVAL; 2655 2656 if (copy_from_user(&opt, optbuf, sizeof(opt))) 2657 return -EFAULT; 2658 2659 if (opt.max_window < opt.snd_wnd) 2660 return -EINVAL; 2661 2662 if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd)) 2663 return -EINVAL; 2664 2665 if (after(opt.rcv_wup, tp->rcv_nxt)) 2666 return -EINVAL; 2667 2668 tp->snd_wl1 = opt.snd_wl1; 2669 tp->snd_wnd = opt.snd_wnd; 2670 tp->max_window = opt.max_window; 2671 2672 tp->rcv_wnd = opt.rcv_wnd; 2673 tp->rcv_wup = opt.rcv_wup; 2674 2675 return 0; 2676 } 2677 2678 static int tcp_repair_options_est(struct sock *sk, 2679 struct tcp_repair_opt __user *optbuf, unsigned int len) 2680 { 2681 struct tcp_sock *tp = tcp_sk(sk); 2682 struct tcp_repair_opt opt; 2683 2684 while (len >= sizeof(opt)) { 2685 if (copy_from_user(&opt, optbuf, sizeof(opt))) 2686 return -EFAULT; 2687 2688 optbuf++; 2689 len -= sizeof(opt); 2690 2691 switch (opt.opt_code) { 2692 case TCPOPT_MSS: 2693 tp->rx_opt.mss_clamp = opt.opt_val; 2694 tcp_mtup_init(sk); 2695 break; 2696 case TCPOPT_WINDOW: 2697 { 2698 u16 snd_wscale = opt.opt_val & 0xFFFF; 2699 u16 rcv_wscale = opt.opt_val >> 16; 2700 2701 if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE) 2702 return -EFBIG; 2703 2704 tp->rx_opt.snd_wscale = snd_wscale; 2705 tp->rx_opt.rcv_wscale = rcv_wscale; 2706 tp->rx_opt.wscale_ok = 1; 2707 } 2708 break; 2709 case TCPOPT_SACK_PERM: 2710 if (opt.opt_val != 0) 2711 return -EINVAL; 2712 2713 tp->rx_opt.sack_ok |= TCP_SACK_SEEN; 2714 break; 2715 case TCPOPT_TIMESTAMP: 2716 if (opt.opt_val != 0) 2717 return -EINVAL; 2718 2719 tp->rx_opt.tstamp_ok = 1; 2720 break; 2721 } 2722 } 2723 2724 return 0; 2725 } 2726 2727 /* 2728 * Socket option code for TCP. 2729 */ 2730 static int do_tcp_setsockopt(struct sock *sk, int level, 2731 int optname, char __user *optval, unsigned int optlen) 2732 { 2733 struct tcp_sock *tp = tcp_sk(sk); 2734 struct inet_connection_sock *icsk = inet_csk(sk); 2735 struct net *net = sock_net(sk); 2736 int val; 2737 int err = 0; 2738 2739 /* These are data/string values, all the others are ints */ 2740 switch (optname) { 2741 case TCP_CONGESTION: { 2742 char name[TCP_CA_NAME_MAX]; 2743 2744 if (optlen < 1) 2745 return -EINVAL; 2746 2747 val = strncpy_from_user(name, optval, 2748 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2749 if (val < 0) 2750 return -EFAULT; 2751 name[val] = 0; 2752 2753 lock_sock(sk); 2754 err = tcp_set_congestion_control(sk, name, true, true); 2755 release_sock(sk); 2756 return err; 2757 } 2758 case TCP_ULP: { 2759 char name[TCP_ULP_NAME_MAX]; 2760 2761 if (optlen < 1) 2762 return -EINVAL; 2763 2764 val = strncpy_from_user(name, optval, 2765 min_t(long, TCP_ULP_NAME_MAX - 1, 2766 optlen)); 2767 if (val < 0) 2768 return -EFAULT; 2769 name[val] = 0; 2770 2771 lock_sock(sk); 2772 err = tcp_set_ulp(sk, name); 2773 release_sock(sk); 2774 return err; 2775 } 2776 case TCP_FASTOPEN_KEY: { 2777 __u8 key[TCP_FASTOPEN_KEY_LENGTH]; 2778 2779 if (optlen != sizeof(key)) 2780 return -EINVAL; 2781 2782 if (copy_from_user(key, optval, optlen)) 2783 return -EFAULT; 2784 2785 return tcp_fastopen_reset_cipher(net, sk, key, sizeof(key)); 2786 } 2787 default: 2788 /* fallthru */ 2789 break; 2790 } 2791 2792 if (optlen < sizeof(int)) 2793 return -EINVAL; 2794 2795 if (get_user(val, (int __user *)optval)) 2796 return -EFAULT; 2797 2798 lock_sock(sk); 2799 2800 switch (optname) { 2801 case TCP_MAXSEG: 2802 /* Values greater than interface MTU won't take effect. However 2803 * at the point when this call is done we typically don't yet 2804 * know which interface is going to be used 2805 */ 2806 if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) { 2807 err = -EINVAL; 2808 break; 2809 } 2810 tp->rx_opt.user_mss = val; 2811 break; 2812 2813 case TCP_NODELAY: 2814 if (val) { 2815 /* TCP_NODELAY is weaker than TCP_CORK, so that 2816 * this option on corked socket is remembered, but 2817 * it is not activated until cork is cleared. 2818 * 2819 * However, when TCP_NODELAY is set we make 2820 * an explicit push, which overrides even TCP_CORK 2821 * for currently queued segments. 2822 */ 2823 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2824 tcp_push_pending_frames(sk); 2825 } else { 2826 tp->nonagle &= ~TCP_NAGLE_OFF; 2827 } 2828 break; 2829 2830 case TCP_THIN_LINEAR_TIMEOUTS: 2831 if (val < 0 || val > 1) 2832 err = -EINVAL; 2833 else 2834 tp->thin_lto = val; 2835 break; 2836 2837 case TCP_THIN_DUPACK: 2838 if (val < 0 || val > 1) 2839 err = -EINVAL; 2840 break; 2841 2842 case TCP_REPAIR: 2843 if (!tcp_can_repair_sock(sk)) 2844 err = -EPERM; 2845 else if (val == TCP_REPAIR_ON) { 2846 tp->repair = 1; 2847 sk->sk_reuse = SK_FORCE_REUSE; 2848 tp->repair_queue = TCP_NO_QUEUE; 2849 } else if (val == TCP_REPAIR_OFF) { 2850 tp->repair = 0; 2851 sk->sk_reuse = SK_NO_REUSE; 2852 tcp_send_window_probe(sk); 2853 } else if (val == TCP_REPAIR_OFF_NO_WP) { 2854 tp->repair = 0; 2855 sk->sk_reuse = SK_NO_REUSE; 2856 } else 2857 err = -EINVAL; 2858 2859 break; 2860 2861 case TCP_REPAIR_QUEUE: 2862 if (!tp->repair) 2863 err = -EPERM; 2864 else if ((unsigned int)val < TCP_QUEUES_NR) 2865 tp->repair_queue = val; 2866 else 2867 err = -EINVAL; 2868 break; 2869 2870 case TCP_QUEUE_SEQ: 2871 if (sk->sk_state != TCP_CLOSE) 2872 err = -EPERM; 2873 else if (tp->repair_queue == TCP_SEND_QUEUE) 2874 tp->write_seq = val; 2875 else if (tp->repair_queue == TCP_RECV_QUEUE) 2876 tp->rcv_nxt = val; 2877 else 2878 err = -EINVAL; 2879 break; 2880 2881 case TCP_REPAIR_OPTIONS: 2882 if (!tp->repair) 2883 err = -EINVAL; 2884 else if (sk->sk_state == TCP_ESTABLISHED) 2885 err = tcp_repair_options_est(sk, 2886 (struct tcp_repair_opt __user *)optval, 2887 optlen); 2888 else 2889 err = -EPERM; 2890 break; 2891 2892 case TCP_CORK: 2893 /* When set indicates to always queue non-full frames. 2894 * Later the user clears this option and we transmit 2895 * any pending partial frames in the queue. This is 2896 * meant to be used alongside sendfile() to get properly 2897 * filled frames when the user (for example) must write 2898 * out headers with a write() call first and then use 2899 * sendfile to send out the data parts. 2900 * 2901 * TCP_CORK can be set together with TCP_NODELAY and it is 2902 * stronger than TCP_NODELAY. 2903 */ 2904 if (val) { 2905 tp->nonagle |= TCP_NAGLE_CORK; 2906 } else { 2907 tp->nonagle &= ~TCP_NAGLE_CORK; 2908 if (tp->nonagle&TCP_NAGLE_OFF) 2909 tp->nonagle |= TCP_NAGLE_PUSH; 2910 tcp_push_pending_frames(sk); 2911 } 2912 break; 2913 2914 case TCP_KEEPIDLE: 2915 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2916 err = -EINVAL; 2917 else { 2918 tp->keepalive_time = val * HZ; 2919 if (sock_flag(sk, SOCK_KEEPOPEN) && 2920 !((1 << sk->sk_state) & 2921 (TCPF_CLOSE | TCPF_LISTEN))) { 2922 u32 elapsed = keepalive_time_elapsed(tp); 2923 if (tp->keepalive_time > elapsed) 2924 elapsed = tp->keepalive_time - elapsed; 2925 else 2926 elapsed = 0; 2927 inet_csk_reset_keepalive_timer(sk, elapsed); 2928 } 2929 } 2930 break; 2931 case TCP_KEEPINTVL: 2932 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2933 err = -EINVAL; 2934 else 2935 tp->keepalive_intvl = val * HZ; 2936 break; 2937 case TCP_KEEPCNT: 2938 if (val < 1 || val > MAX_TCP_KEEPCNT) 2939 err = -EINVAL; 2940 else 2941 tp->keepalive_probes = val; 2942 break; 2943 case TCP_SYNCNT: 2944 if (val < 1 || val > MAX_TCP_SYNCNT) 2945 err = -EINVAL; 2946 else 2947 icsk->icsk_syn_retries = val; 2948 break; 2949 2950 case TCP_SAVE_SYN: 2951 if (val < 0 || val > 1) 2952 err = -EINVAL; 2953 else 2954 tp->save_syn = val; 2955 break; 2956 2957 case TCP_LINGER2: 2958 if (val < 0) 2959 tp->linger2 = -1; 2960 else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ) 2961 tp->linger2 = 0; 2962 else 2963 tp->linger2 = val * HZ; 2964 break; 2965 2966 case TCP_DEFER_ACCEPT: 2967 /* Translate value in seconds to number of retransmits */ 2968 icsk->icsk_accept_queue.rskq_defer_accept = 2969 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2970 TCP_RTO_MAX / HZ); 2971 break; 2972 2973 case TCP_WINDOW_CLAMP: 2974 if (!val) { 2975 if (sk->sk_state != TCP_CLOSE) { 2976 err = -EINVAL; 2977 break; 2978 } 2979 tp->window_clamp = 0; 2980 } else 2981 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2982 SOCK_MIN_RCVBUF / 2 : val; 2983 break; 2984 2985 case TCP_QUICKACK: 2986 if (!val) { 2987 inet_csk_enter_pingpong_mode(sk); 2988 } else { 2989 inet_csk_exit_pingpong_mode(sk); 2990 if ((1 << sk->sk_state) & 2991 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2992 inet_csk_ack_scheduled(sk)) { 2993 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2994 tcp_cleanup_rbuf(sk, 1); 2995 if (!(val & 1)) 2996 inet_csk_enter_pingpong_mode(sk); 2997 } 2998 } 2999 break; 3000 3001 #ifdef CONFIG_TCP_MD5SIG 3002 case TCP_MD5SIG: 3003 case TCP_MD5SIG_EXT: 3004 if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) 3005 err = tp->af_specific->md5_parse(sk, optname, optval, optlen); 3006 else 3007 err = -EINVAL; 3008 break; 3009 #endif 3010 case TCP_USER_TIMEOUT: 3011 /* Cap the max time in ms TCP will retry or probe the window 3012 * before giving up and aborting (ETIMEDOUT) a connection. 3013 */ 3014 if (val < 0) 3015 err = -EINVAL; 3016 else 3017 icsk->icsk_user_timeout = val; 3018 break; 3019 3020 case TCP_FASTOPEN: 3021 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | 3022 TCPF_LISTEN))) { 3023 tcp_fastopen_init_key_once(net); 3024 3025 fastopen_queue_tune(sk, val); 3026 } else { 3027 err = -EINVAL; 3028 } 3029 break; 3030 case TCP_FASTOPEN_CONNECT: 3031 if (val > 1 || val < 0) { 3032 err = -EINVAL; 3033 } else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) { 3034 if (sk->sk_state == TCP_CLOSE) 3035 tp->fastopen_connect = val; 3036 else 3037 err = -EINVAL; 3038 } else { 3039 err = -EOPNOTSUPP; 3040 } 3041 break; 3042 case TCP_FASTOPEN_NO_COOKIE: 3043 if (val > 1 || val < 0) 3044 err = -EINVAL; 3045 else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 3046 err = -EINVAL; 3047 else 3048 tp->fastopen_no_cookie = val; 3049 break; 3050 case TCP_TIMESTAMP: 3051 if (!tp->repair) 3052 err = -EPERM; 3053 else 3054 tp->tsoffset = val - tcp_time_stamp_raw(); 3055 break; 3056 case TCP_REPAIR_WINDOW: 3057 err = tcp_repair_set_window(tp, optval, optlen); 3058 break; 3059 case TCP_NOTSENT_LOWAT: 3060 tp->notsent_lowat = val; 3061 sk->sk_write_space(sk); 3062 break; 3063 case TCP_INQ: 3064 if (val > 1 || val < 0) 3065 err = -EINVAL; 3066 else 3067 tp->recvmsg_inq = val; 3068 break; 3069 default: 3070 err = -ENOPROTOOPT; 3071 break; 3072 } 3073 3074 release_sock(sk); 3075 return err; 3076 } 3077 3078 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 3079 unsigned int optlen) 3080 { 3081 const struct inet_connection_sock *icsk = inet_csk(sk); 3082 3083 if (level != SOL_TCP) 3084 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 3085 optval, optlen); 3086 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 3087 } 3088 EXPORT_SYMBOL(tcp_setsockopt); 3089 3090 #ifdef CONFIG_COMPAT 3091 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 3092 char __user *optval, unsigned int optlen) 3093 { 3094 if (level != SOL_TCP) 3095 return inet_csk_compat_setsockopt(sk, level, optname, 3096 optval, optlen); 3097 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 3098 } 3099 EXPORT_SYMBOL(compat_tcp_setsockopt); 3100 #endif 3101 3102 static void tcp_get_info_chrono_stats(const struct tcp_sock *tp, 3103 struct tcp_info *info) 3104 { 3105 u64 stats[__TCP_CHRONO_MAX], total = 0; 3106 enum tcp_chrono i; 3107 3108 for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) { 3109 stats[i] = tp->chrono_stat[i - 1]; 3110 if (i == tp->chrono_type) 3111 stats[i] += tcp_jiffies32 - tp->chrono_start; 3112 stats[i] *= USEC_PER_SEC / HZ; 3113 total += stats[i]; 3114 } 3115 3116 info->tcpi_busy_time = total; 3117 info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED]; 3118 info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED]; 3119 } 3120 3121 /* Return information about state of tcp endpoint in API format. */ 3122 void tcp_get_info(struct sock *sk, struct tcp_info *info) 3123 { 3124 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ 3125 const struct inet_connection_sock *icsk = inet_csk(sk); 3126 unsigned long rate; 3127 u32 now; 3128 u64 rate64; 3129 bool slow; 3130 3131 memset(info, 0, sizeof(*info)); 3132 if (sk->sk_type != SOCK_STREAM) 3133 return; 3134 3135 info->tcpi_state = inet_sk_state_load(sk); 3136 3137 /* Report meaningful fields for all TCP states, including listeners */ 3138 rate = READ_ONCE(sk->sk_pacing_rate); 3139 rate64 = (rate != ~0UL) ? rate : ~0ULL; 3140 info->tcpi_pacing_rate = rate64; 3141 3142 rate = READ_ONCE(sk->sk_max_pacing_rate); 3143 rate64 = (rate != ~0UL) ? rate : ~0ULL; 3144 info->tcpi_max_pacing_rate = rate64; 3145 3146 info->tcpi_reordering = tp->reordering; 3147 info->tcpi_snd_cwnd = tp->snd_cwnd; 3148 3149 if (info->tcpi_state == TCP_LISTEN) { 3150 /* listeners aliased fields : 3151 * tcpi_unacked -> Number of children ready for accept() 3152 * tcpi_sacked -> max backlog 3153 */ 3154 info->tcpi_unacked = sk->sk_ack_backlog; 3155 info->tcpi_sacked = sk->sk_max_ack_backlog; 3156 return; 3157 } 3158 3159 slow = lock_sock_fast(sk); 3160 3161 info->tcpi_ca_state = icsk->icsk_ca_state; 3162 info->tcpi_retransmits = icsk->icsk_retransmits; 3163 info->tcpi_probes = icsk->icsk_probes_out; 3164 info->tcpi_backoff = icsk->icsk_backoff; 3165 3166 if (tp->rx_opt.tstamp_ok) 3167 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 3168 if (tcp_is_sack(tp)) 3169 info->tcpi_options |= TCPI_OPT_SACK; 3170 if (tp->rx_opt.wscale_ok) { 3171 info->tcpi_options |= TCPI_OPT_WSCALE; 3172 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 3173 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 3174 } 3175 3176 if (tp->ecn_flags & TCP_ECN_OK) 3177 info->tcpi_options |= TCPI_OPT_ECN; 3178 if (tp->ecn_flags & TCP_ECN_SEEN) 3179 info->tcpi_options |= TCPI_OPT_ECN_SEEN; 3180 if (tp->syn_data_acked) 3181 info->tcpi_options |= TCPI_OPT_SYN_DATA; 3182 3183 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 3184 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 3185 info->tcpi_snd_mss = tp->mss_cache; 3186 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 3187 3188 info->tcpi_unacked = tp->packets_out; 3189 info->tcpi_sacked = tp->sacked_out; 3190 3191 info->tcpi_lost = tp->lost_out; 3192 info->tcpi_retrans = tp->retrans_out; 3193 3194 now = tcp_jiffies32; 3195 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 3196 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 3197 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 3198 3199 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 3200 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 3201 info->tcpi_rtt = tp->srtt_us >> 3; 3202 info->tcpi_rttvar = tp->mdev_us >> 2; 3203 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 3204 info->tcpi_advmss = tp->advmss; 3205 3206 info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3; 3207 info->tcpi_rcv_space = tp->rcvq_space.space; 3208 3209 info->tcpi_total_retrans = tp->total_retrans; 3210 3211 info->tcpi_bytes_acked = tp->bytes_acked; 3212 info->tcpi_bytes_received = tp->bytes_received; 3213 info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt); 3214 tcp_get_info_chrono_stats(tp, info); 3215 3216 info->tcpi_segs_out = tp->segs_out; 3217 info->tcpi_segs_in = tp->segs_in; 3218 3219 info->tcpi_min_rtt = tcp_min_rtt(tp); 3220 info->tcpi_data_segs_in = tp->data_segs_in; 3221 info->tcpi_data_segs_out = tp->data_segs_out; 3222 3223 info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0; 3224 rate64 = tcp_compute_delivery_rate(tp); 3225 if (rate64) 3226 info->tcpi_delivery_rate = rate64; 3227 info->tcpi_delivered = tp->delivered; 3228 info->tcpi_delivered_ce = tp->delivered_ce; 3229 info->tcpi_bytes_sent = tp->bytes_sent; 3230 info->tcpi_bytes_retrans = tp->bytes_retrans; 3231 info->tcpi_dsack_dups = tp->dsack_dups; 3232 info->tcpi_reord_seen = tp->reord_seen; 3233 unlock_sock_fast(sk, slow); 3234 } 3235 EXPORT_SYMBOL_GPL(tcp_get_info); 3236 3237 static size_t tcp_opt_stats_get_size(void) 3238 { 3239 return 3240 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BUSY */ 3241 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_RWND_LIMITED */ 3242 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_SNDBUF_LIMITED */ 3243 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DATA_SEGS_OUT */ 3244 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_TOTAL_RETRANS */ 3245 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_PACING_RATE */ 3246 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DELIVERY_RATE */ 3247 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_CWND */ 3248 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORDERING */ 3249 nla_total_size(sizeof(u32)) + /* TCP_NLA_MIN_RTT */ 3250 nla_total_size(sizeof(u8)) + /* TCP_NLA_RECUR_RETRANS */ 3251 nla_total_size(sizeof(u8)) + /* TCP_NLA_DELIVERY_RATE_APP_LMT */ 3252 nla_total_size(sizeof(u32)) + /* TCP_NLA_SNDQ_SIZE */ 3253 nla_total_size(sizeof(u8)) + /* TCP_NLA_CA_STATE */ 3254 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_SSTHRESH */ 3255 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED */ 3256 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */ 3257 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */ 3258 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */ 3259 nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */ 3260 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */ 3261 nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */ 3262 0; 3263 } 3264 3265 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk) 3266 { 3267 const struct tcp_sock *tp = tcp_sk(sk); 3268 struct sk_buff *stats; 3269 struct tcp_info info; 3270 unsigned long rate; 3271 u64 rate64; 3272 3273 stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC); 3274 if (!stats) 3275 return NULL; 3276 3277 tcp_get_info_chrono_stats(tp, &info); 3278 nla_put_u64_64bit(stats, TCP_NLA_BUSY, 3279 info.tcpi_busy_time, TCP_NLA_PAD); 3280 nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED, 3281 info.tcpi_rwnd_limited, TCP_NLA_PAD); 3282 nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED, 3283 info.tcpi_sndbuf_limited, TCP_NLA_PAD); 3284 nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT, 3285 tp->data_segs_out, TCP_NLA_PAD); 3286 nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS, 3287 tp->total_retrans, TCP_NLA_PAD); 3288 3289 rate = READ_ONCE(sk->sk_pacing_rate); 3290 rate64 = (rate != ~0UL) ? rate : ~0ULL; 3291 nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD); 3292 3293 rate64 = tcp_compute_delivery_rate(tp); 3294 nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD); 3295 3296 nla_put_u32(stats, TCP_NLA_SND_CWND, tp->snd_cwnd); 3297 nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering); 3298 nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp)); 3299 3300 nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits); 3301 nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited); 3302 nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh); 3303 nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered); 3304 nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce); 3305 3306 nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una); 3307 nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state); 3308 3309 nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent, 3310 TCP_NLA_PAD); 3311 nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans, 3312 TCP_NLA_PAD); 3313 nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups); 3314 nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen); 3315 nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3); 3316 3317 return stats; 3318 } 3319 3320 static int do_tcp_getsockopt(struct sock *sk, int level, 3321 int optname, char __user *optval, int __user *optlen) 3322 { 3323 struct inet_connection_sock *icsk = inet_csk(sk); 3324 struct tcp_sock *tp = tcp_sk(sk); 3325 struct net *net = sock_net(sk); 3326 int val, len; 3327 3328 if (get_user(len, optlen)) 3329 return -EFAULT; 3330 3331 len = min_t(unsigned int, len, sizeof(int)); 3332 3333 if (len < 0) 3334 return -EINVAL; 3335 3336 switch (optname) { 3337 case TCP_MAXSEG: 3338 val = tp->mss_cache; 3339 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 3340 val = tp->rx_opt.user_mss; 3341 if (tp->repair) 3342 val = tp->rx_opt.mss_clamp; 3343 break; 3344 case TCP_NODELAY: 3345 val = !!(tp->nonagle&TCP_NAGLE_OFF); 3346 break; 3347 case TCP_CORK: 3348 val = !!(tp->nonagle&TCP_NAGLE_CORK); 3349 break; 3350 case TCP_KEEPIDLE: 3351 val = keepalive_time_when(tp) / HZ; 3352 break; 3353 case TCP_KEEPINTVL: 3354 val = keepalive_intvl_when(tp) / HZ; 3355 break; 3356 case TCP_KEEPCNT: 3357 val = keepalive_probes(tp); 3358 break; 3359 case TCP_SYNCNT: 3360 val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; 3361 break; 3362 case TCP_LINGER2: 3363 val = tp->linger2; 3364 if (val >= 0) 3365 val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ; 3366 break; 3367 case TCP_DEFER_ACCEPT: 3368 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 3369 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 3370 break; 3371 case TCP_WINDOW_CLAMP: 3372 val = tp->window_clamp; 3373 break; 3374 case TCP_INFO: { 3375 struct tcp_info info; 3376 3377 if (get_user(len, optlen)) 3378 return -EFAULT; 3379 3380 tcp_get_info(sk, &info); 3381 3382 len = min_t(unsigned int, len, sizeof(info)); 3383 if (put_user(len, optlen)) 3384 return -EFAULT; 3385 if (copy_to_user(optval, &info, len)) 3386 return -EFAULT; 3387 return 0; 3388 } 3389 case TCP_CC_INFO: { 3390 const struct tcp_congestion_ops *ca_ops; 3391 union tcp_cc_info info; 3392 size_t sz = 0; 3393 int attr; 3394 3395 if (get_user(len, optlen)) 3396 return -EFAULT; 3397 3398 ca_ops = icsk->icsk_ca_ops; 3399 if (ca_ops && ca_ops->get_info) 3400 sz = ca_ops->get_info(sk, ~0U, &attr, &info); 3401 3402 len = min_t(unsigned int, len, sz); 3403 if (put_user(len, optlen)) 3404 return -EFAULT; 3405 if (copy_to_user(optval, &info, len)) 3406 return -EFAULT; 3407 return 0; 3408 } 3409 case TCP_QUICKACK: 3410 val = !inet_csk_in_pingpong_mode(sk); 3411 break; 3412 3413 case TCP_CONGESTION: 3414 if (get_user(len, optlen)) 3415 return -EFAULT; 3416 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 3417 if (put_user(len, optlen)) 3418 return -EFAULT; 3419 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 3420 return -EFAULT; 3421 return 0; 3422 3423 case TCP_ULP: 3424 if (get_user(len, optlen)) 3425 return -EFAULT; 3426 len = min_t(unsigned int, len, TCP_ULP_NAME_MAX); 3427 if (!icsk->icsk_ulp_ops) { 3428 if (put_user(0, optlen)) 3429 return -EFAULT; 3430 return 0; 3431 } 3432 if (put_user(len, optlen)) 3433 return -EFAULT; 3434 if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len)) 3435 return -EFAULT; 3436 return 0; 3437 3438 case TCP_FASTOPEN_KEY: { 3439 __u8 key[TCP_FASTOPEN_KEY_LENGTH]; 3440 struct tcp_fastopen_context *ctx; 3441 3442 if (get_user(len, optlen)) 3443 return -EFAULT; 3444 3445 rcu_read_lock(); 3446 ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx); 3447 if (ctx) 3448 memcpy(key, ctx->key, sizeof(key)); 3449 else 3450 len = 0; 3451 rcu_read_unlock(); 3452 3453 len = min_t(unsigned int, len, sizeof(key)); 3454 if (put_user(len, optlen)) 3455 return -EFAULT; 3456 if (copy_to_user(optval, key, len)) 3457 return -EFAULT; 3458 return 0; 3459 } 3460 case TCP_THIN_LINEAR_TIMEOUTS: 3461 val = tp->thin_lto; 3462 break; 3463 3464 case TCP_THIN_DUPACK: 3465 val = 0; 3466 break; 3467 3468 case TCP_REPAIR: 3469 val = tp->repair; 3470 break; 3471 3472 case TCP_REPAIR_QUEUE: 3473 if (tp->repair) 3474 val = tp->repair_queue; 3475 else 3476 return -EINVAL; 3477 break; 3478 3479 case TCP_REPAIR_WINDOW: { 3480 struct tcp_repair_window opt; 3481 3482 if (get_user(len, optlen)) 3483 return -EFAULT; 3484 3485 if (len != sizeof(opt)) 3486 return -EINVAL; 3487 3488 if (!tp->repair) 3489 return -EPERM; 3490 3491 opt.snd_wl1 = tp->snd_wl1; 3492 opt.snd_wnd = tp->snd_wnd; 3493 opt.max_window = tp->max_window; 3494 opt.rcv_wnd = tp->rcv_wnd; 3495 opt.rcv_wup = tp->rcv_wup; 3496 3497 if (copy_to_user(optval, &opt, len)) 3498 return -EFAULT; 3499 return 0; 3500 } 3501 case TCP_QUEUE_SEQ: 3502 if (tp->repair_queue == TCP_SEND_QUEUE) 3503 val = tp->write_seq; 3504 else if (tp->repair_queue == TCP_RECV_QUEUE) 3505 val = tp->rcv_nxt; 3506 else 3507 return -EINVAL; 3508 break; 3509 3510 case TCP_USER_TIMEOUT: 3511 val = icsk->icsk_user_timeout; 3512 break; 3513 3514 case TCP_FASTOPEN: 3515 val = icsk->icsk_accept_queue.fastopenq.max_qlen; 3516 break; 3517 3518 case TCP_FASTOPEN_CONNECT: 3519 val = tp->fastopen_connect; 3520 break; 3521 3522 case TCP_FASTOPEN_NO_COOKIE: 3523 val = tp->fastopen_no_cookie; 3524 break; 3525 3526 case TCP_TIMESTAMP: 3527 val = tcp_time_stamp_raw() + tp->tsoffset; 3528 break; 3529 case TCP_NOTSENT_LOWAT: 3530 val = tp->notsent_lowat; 3531 break; 3532 case TCP_INQ: 3533 val = tp->recvmsg_inq; 3534 break; 3535 case TCP_SAVE_SYN: 3536 val = tp->save_syn; 3537 break; 3538 case TCP_SAVED_SYN: { 3539 if (get_user(len, optlen)) 3540 return -EFAULT; 3541 3542 lock_sock(sk); 3543 if (tp->saved_syn) { 3544 if (len < tp->saved_syn[0]) { 3545 if (put_user(tp->saved_syn[0], optlen)) { 3546 release_sock(sk); 3547 return -EFAULT; 3548 } 3549 release_sock(sk); 3550 return -EINVAL; 3551 } 3552 len = tp->saved_syn[0]; 3553 if (put_user(len, optlen)) { 3554 release_sock(sk); 3555 return -EFAULT; 3556 } 3557 if (copy_to_user(optval, tp->saved_syn + 1, len)) { 3558 release_sock(sk); 3559 return -EFAULT; 3560 } 3561 tcp_saved_syn_free(tp); 3562 release_sock(sk); 3563 } else { 3564 release_sock(sk); 3565 len = 0; 3566 if (put_user(len, optlen)) 3567 return -EFAULT; 3568 } 3569 return 0; 3570 } 3571 #ifdef CONFIG_MMU 3572 case TCP_ZEROCOPY_RECEIVE: { 3573 struct tcp_zerocopy_receive zc; 3574 int err; 3575 3576 if (get_user(len, optlen)) 3577 return -EFAULT; 3578 if (len != sizeof(zc)) 3579 return -EINVAL; 3580 if (copy_from_user(&zc, optval, len)) 3581 return -EFAULT; 3582 lock_sock(sk); 3583 err = tcp_zerocopy_receive(sk, &zc); 3584 release_sock(sk); 3585 if (!err && copy_to_user(optval, &zc, len)) 3586 err = -EFAULT; 3587 return err; 3588 } 3589 #endif 3590 default: 3591 return -ENOPROTOOPT; 3592 } 3593 3594 if (put_user(len, optlen)) 3595 return -EFAULT; 3596 if (copy_to_user(optval, &val, len)) 3597 return -EFAULT; 3598 return 0; 3599 } 3600 3601 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 3602 int __user *optlen) 3603 { 3604 struct inet_connection_sock *icsk = inet_csk(sk); 3605 3606 if (level != SOL_TCP) 3607 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 3608 optval, optlen); 3609 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 3610 } 3611 EXPORT_SYMBOL(tcp_getsockopt); 3612 3613 #ifdef CONFIG_COMPAT 3614 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 3615 char __user *optval, int __user *optlen) 3616 { 3617 if (level != SOL_TCP) 3618 return inet_csk_compat_getsockopt(sk, level, optname, 3619 optval, optlen); 3620 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 3621 } 3622 EXPORT_SYMBOL(compat_tcp_getsockopt); 3623 #endif 3624 3625 #ifdef CONFIG_TCP_MD5SIG 3626 static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool); 3627 static DEFINE_MUTEX(tcp_md5sig_mutex); 3628 static bool tcp_md5sig_pool_populated = false; 3629 3630 static void __tcp_alloc_md5sig_pool(void) 3631 { 3632 struct crypto_ahash *hash; 3633 int cpu; 3634 3635 hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC); 3636 if (IS_ERR(hash)) 3637 return; 3638 3639 for_each_possible_cpu(cpu) { 3640 void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch; 3641 struct ahash_request *req; 3642 3643 if (!scratch) { 3644 scratch = kmalloc_node(sizeof(union tcp_md5sum_block) + 3645 sizeof(struct tcphdr), 3646 GFP_KERNEL, 3647 cpu_to_node(cpu)); 3648 if (!scratch) 3649 return; 3650 per_cpu(tcp_md5sig_pool, cpu).scratch = scratch; 3651 } 3652 if (per_cpu(tcp_md5sig_pool, cpu).md5_req) 3653 continue; 3654 3655 req = ahash_request_alloc(hash, GFP_KERNEL); 3656 if (!req) 3657 return; 3658 3659 ahash_request_set_callback(req, 0, NULL, NULL); 3660 3661 per_cpu(tcp_md5sig_pool, cpu).md5_req = req; 3662 } 3663 /* before setting tcp_md5sig_pool_populated, we must commit all writes 3664 * to memory. See smp_rmb() in tcp_get_md5sig_pool() 3665 */ 3666 smp_wmb(); 3667 tcp_md5sig_pool_populated = true; 3668 } 3669 3670 bool tcp_alloc_md5sig_pool(void) 3671 { 3672 if (unlikely(!tcp_md5sig_pool_populated)) { 3673 mutex_lock(&tcp_md5sig_mutex); 3674 3675 if (!tcp_md5sig_pool_populated) { 3676 __tcp_alloc_md5sig_pool(); 3677 if (tcp_md5sig_pool_populated) 3678 static_key_slow_inc(&tcp_md5_needed); 3679 } 3680 3681 mutex_unlock(&tcp_md5sig_mutex); 3682 } 3683 return tcp_md5sig_pool_populated; 3684 } 3685 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 3686 3687 3688 /** 3689 * tcp_get_md5sig_pool - get md5sig_pool for this user 3690 * 3691 * We use percpu structure, so if we succeed, we exit with preemption 3692 * and BH disabled, to make sure another thread or softirq handling 3693 * wont try to get same context. 3694 */ 3695 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 3696 { 3697 local_bh_disable(); 3698 3699 if (tcp_md5sig_pool_populated) { 3700 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */ 3701 smp_rmb(); 3702 return this_cpu_ptr(&tcp_md5sig_pool); 3703 } 3704 local_bh_enable(); 3705 return NULL; 3706 } 3707 EXPORT_SYMBOL(tcp_get_md5sig_pool); 3708 3709 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 3710 const struct sk_buff *skb, unsigned int header_len) 3711 { 3712 struct scatterlist sg; 3713 const struct tcphdr *tp = tcp_hdr(skb); 3714 struct ahash_request *req = hp->md5_req; 3715 unsigned int i; 3716 const unsigned int head_data_len = skb_headlen(skb) > header_len ? 3717 skb_headlen(skb) - header_len : 0; 3718 const struct skb_shared_info *shi = skb_shinfo(skb); 3719 struct sk_buff *frag_iter; 3720 3721 sg_init_table(&sg, 1); 3722 3723 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3724 ahash_request_set_crypt(req, &sg, NULL, head_data_len); 3725 if (crypto_ahash_update(req)) 3726 return 1; 3727 3728 for (i = 0; i < shi->nr_frags; ++i) { 3729 const struct skb_frag_struct *f = &shi->frags[i]; 3730 unsigned int offset = f->page_offset; 3731 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); 3732 3733 sg_set_page(&sg, page, skb_frag_size(f), 3734 offset_in_page(offset)); 3735 ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f)); 3736 if (crypto_ahash_update(req)) 3737 return 1; 3738 } 3739 3740 skb_walk_frags(skb, frag_iter) 3741 if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) 3742 return 1; 3743 3744 return 0; 3745 } 3746 EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3747 3748 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) 3749 { 3750 struct scatterlist sg; 3751 3752 sg_init_one(&sg, key->key, key->keylen); 3753 ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen); 3754 return crypto_ahash_update(hp->md5_req); 3755 } 3756 EXPORT_SYMBOL(tcp_md5_hash_key); 3757 3758 #endif 3759 3760 void tcp_done(struct sock *sk) 3761 { 3762 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 3763 3764 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3765 TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3766 3767 tcp_set_state(sk, TCP_CLOSE); 3768 tcp_clear_xmit_timers(sk); 3769 if (req) 3770 reqsk_fastopen_remove(sk, req, false); 3771 3772 sk->sk_shutdown = SHUTDOWN_MASK; 3773 3774 if (!sock_flag(sk, SOCK_DEAD)) 3775 sk->sk_state_change(sk); 3776 else 3777 inet_csk_destroy_sock(sk); 3778 } 3779 EXPORT_SYMBOL_GPL(tcp_done); 3780 3781 int tcp_abort(struct sock *sk, int err) 3782 { 3783 if (!sk_fullsock(sk)) { 3784 if (sk->sk_state == TCP_NEW_SYN_RECV) { 3785 struct request_sock *req = inet_reqsk(sk); 3786 3787 local_bh_disable(); 3788 inet_csk_reqsk_queue_drop(req->rsk_listener, req); 3789 local_bh_enable(); 3790 return 0; 3791 } 3792 return -EOPNOTSUPP; 3793 } 3794 3795 /* Don't race with userspace socket closes such as tcp_close. */ 3796 lock_sock(sk); 3797 3798 if (sk->sk_state == TCP_LISTEN) { 3799 tcp_set_state(sk, TCP_CLOSE); 3800 inet_csk_listen_stop(sk); 3801 } 3802 3803 /* Don't race with BH socket closes such as inet_csk_listen_stop. */ 3804 local_bh_disable(); 3805 bh_lock_sock(sk); 3806 3807 if (!sock_flag(sk, SOCK_DEAD)) { 3808 sk->sk_err = err; 3809 /* This barrier is coupled with smp_rmb() in tcp_poll() */ 3810 smp_wmb(); 3811 sk->sk_error_report(sk); 3812 if (tcp_need_reset(sk->sk_state)) 3813 tcp_send_active_reset(sk, GFP_ATOMIC); 3814 tcp_done(sk); 3815 } 3816 3817 bh_unlock_sock(sk); 3818 local_bh_enable(); 3819 tcp_write_queue_purge(sk); 3820 release_sock(sk); 3821 return 0; 3822 } 3823 EXPORT_SYMBOL_GPL(tcp_abort); 3824 3825 extern struct tcp_congestion_ops tcp_reno; 3826 3827 static __initdata unsigned long thash_entries; 3828 static int __init set_thash_entries(char *str) 3829 { 3830 ssize_t ret; 3831 3832 if (!str) 3833 return 0; 3834 3835 ret = kstrtoul(str, 0, &thash_entries); 3836 if (ret) 3837 return 0; 3838 3839 return 1; 3840 } 3841 __setup("thash_entries=", set_thash_entries); 3842 3843 static void __init tcp_init_mem(void) 3844 { 3845 unsigned long limit = nr_free_buffer_pages() / 16; 3846 3847 limit = max(limit, 128UL); 3848 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */ 3849 sysctl_tcp_mem[1] = limit; /* 6.25 % */ 3850 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */ 3851 } 3852 3853 void __init tcp_init(void) 3854 { 3855 int max_rshare, max_wshare, cnt; 3856 unsigned long limit; 3857 unsigned int i; 3858 3859 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > 3860 FIELD_SIZEOF(struct sk_buff, cb)); 3861 3862 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); 3863 percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); 3864 inet_hashinfo_init(&tcp_hashinfo); 3865 inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash", 3866 thash_entries, 21, /* one slot per 2 MB*/ 3867 0, 64 * 1024); 3868 tcp_hashinfo.bind_bucket_cachep = 3869 kmem_cache_create("tcp_bind_bucket", 3870 sizeof(struct inet_bind_bucket), 0, 3871 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3872 3873 /* Size and allocate the main established and bind bucket 3874 * hash tables. 3875 * 3876 * The methodology is similar to that of the buffer cache. 3877 */ 3878 tcp_hashinfo.ehash = 3879 alloc_large_system_hash("TCP established", 3880 sizeof(struct inet_ehash_bucket), 3881 thash_entries, 3882 17, /* one slot per 128 KB of memory */ 3883 0, 3884 NULL, 3885 &tcp_hashinfo.ehash_mask, 3886 0, 3887 thash_entries ? 0 : 512 * 1024); 3888 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) 3889 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3890 3891 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3892 panic("TCP: failed to alloc ehash_locks"); 3893 tcp_hashinfo.bhash = 3894 alloc_large_system_hash("TCP bind", 3895 sizeof(struct inet_bind_hashbucket), 3896 tcp_hashinfo.ehash_mask + 1, 3897 17, /* one slot per 128 KB of memory */ 3898 0, 3899 &tcp_hashinfo.bhash_size, 3900 NULL, 3901 0, 3902 64 * 1024); 3903 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; 3904 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3905 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3906 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3907 } 3908 3909 3910 cnt = tcp_hashinfo.ehash_mask + 1; 3911 sysctl_tcp_max_orphans = cnt / 2; 3912 3913 tcp_init_mem(); 3914 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3915 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); 3916 max_wshare = min(4UL*1024*1024, limit); 3917 max_rshare = min(6UL*1024*1024, limit); 3918 3919 init_net.ipv4.sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3920 init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024; 3921 init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare); 3922 3923 init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3924 init_net.ipv4.sysctl_tcp_rmem[1] = 131072; 3925 init_net.ipv4.sysctl_tcp_rmem[2] = max(131072, max_rshare); 3926 3927 pr_info("Hash tables configured (established %u bind %u)\n", 3928 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3929 3930 tcp_v4_init(); 3931 tcp_metrics_init(); 3932 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); 3933 tcp_tasklet_init(); 3934 } 3935