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_internal *tss) 1848 { 1849 if (skb->tstamp) 1850 tss->ts[0] = ktime_to_timespec64(skb->tstamp); 1851 else 1852 tss->ts[0] = (struct timespec64) {0}; 1853 1854 if (skb_hwtstamps(skb)->hwtstamp) 1855 tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp); 1856 else 1857 tss->ts[2] = (struct timespec64) {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_internal *tss) 1863 { 1864 int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW); 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 if (new_tstamp) { 1871 struct __kernel_timespec kts = {tss->ts[0].tv_sec, tss->ts[0].tv_nsec}; 1872 1873 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW, 1874 sizeof(kts), &kts); 1875 } else { 1876 struct timespec ts_old = timespec64_to_timespec(tss->ts[0]); 1877 1878 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD, 1879 sizeof(ts_old), &ts_old); 1880 } 1881 } else { 1882 if (new_tstamp) { 1883 struct __kernel_sock_timeval stv; 1884 1885 stv.tv_sec = tss->ts[0].tv_sec; 1886 stv.tv_usec = tss->ts[0].tv_nsec / 1000; 1887 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW, 1888 sizeof(stv), &stv); 1889 } else { 1890 struct __kernel_old_timeval tv; 1891 1892 tv.tv_sec = tss->ts[0].tv_sec; 1893 tv.tv_usec = tss->ts[0].tv_nsec / 1000; 1894 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD, 1895 sizeof(tv), &tv); 1896 } 1897 } 1898 } 1899 1900 if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) 1901 has_timestamping = true; 1902 else 1903 tss->ts[0] = (struct timespec64) {0}; 1904 } 1905 1906 if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) { 1907 if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) 1908 has_timestamping = true; 1909 else 1910 tss->ts[2] = (struct timespec64) {0}; 1911 } 1912 1913 if (has_timestamping) { 1914 tss->ts[1] = (struct timespec64) {0}; 1915 if (sock_flag(sk, SOCK_TSTAMP_NEW)) 1916 put_cmsg_scm_timestamping64(msg, tss); 1917 else 1918 put_cmsg_scm_timestamping(msg, tss); 1919 } 1920 } 1921 1922 static int tcp_inq_hint(struct sock *sk) 1923 { 1924 const struct tcp_sock *tp = tcp_sk(sk); 1925 u32 copied_seq = READ_ONCE(tp->copied_seq); 1926 u32 rcv_nxt = READ_ONCE(tp->rcv_nxt); 1927 int inq; 1928 1929 inq = rcv_nxt - copied_seq; 1930 if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) { 1931 lock_sock(sk); 1932 inq = tp->rcv_nxt - tp->copied_seq; 1933 release_sock(sk); 1934 } 1935 return inq; 1936 } 1937 1938 /* 1939 * This routine copies from a sock struct into the user buffer. 1940 * 1941 * Technical note: in 2.3 we work on _locked_ socket, so that 1942 * tricks with *seq access order and skb->users are not required. 1943 * Probably, code can be easily improved even more. 1944 */ 1945 1946 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 1947 int flags, int *addr_len) 1948 { 1949 struct tcp_sock *tp = tcp_sk(sk); 1950 int copied = 0; 1951 u32 peek_seq; 1952 u32 *seq; 1953 unsigned long used; 1954 int err, inq; 1955 int target; /* Read at least this many bytes */ 1956 long timeo; 1957 struct sk_buff *skb, *last; 1958 u32 urg_hole = 0; 1959 struct scm_timestamping_internal tss; 1960 bool has_tss = false; 1961 bool has_cmsg; 1962 1963 if (unlikely(flags & MSG_ERRQUEUE)) 1964 return inet_recv_error(sk, msg, len, addr_len); 1965 1966 if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) && 1967 (sk->sk_state == TCP_ESTABLISHED)) 1968 sk_busy_loop(sk, nonblock); 1969 1970 lock_sock(sk); 1971 1972 err = -ENOTCONN; 1973 if (sk->sk_state == TCP_LISTEN) 1974 goto out; 1975 1976 has_cmsg = tp->recvmsg_inq; 1977 timeo = sock_rcvtimeo(sk, nonblock); 1978 1979 /* Urgent data needs to be handled specially. */ 1980 if (flags & MSG_OOB) 1981 goto recv_urg; 1982 1983 if (unlikely(tp->repair)) { 1984 err = -EPERM; 1985 if (!(flags & MSG_PEEK)) 1986 goto out; 1987 1988 if (tp->repair_queue == TCP_SEND_QUEUE) 1989 goto recv_sndq; 1990 1991 err = -EINVAL; 1992 if (tp->repair_queue == TCP_NO_QUEUE) 1993 goto out; 1994 1995 /* 'common' recv queue MSG_PEEK-ing */ 1996 } 1997 1998 seq = &tp->copied_seq; 1999 if (flags & MSG_PEEK) { 2000 peek_seq = tp->copied_seq; 2001 seq = &peek_seq; 2002 } 2003 2004 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 2005 2006 do { 2007 u32 offset; 2008 2009 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 2010 if (tp->urg_data && tp->urg_seq == *seq) { 2011 if (copied) 2012 break; 2013 if (signal_pending(current)) { 2014 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 2015 break; 2016 } 2017 } 2018 2019 /* Next get a buffer. */ 2020 2021 last = skb_peek_tail(&sk->sk_receive_queue); 2022 skb_queue_walk(&sk->sk_receive_queue, skb) { 2023 last = skb; 2024 /* Now that we have two receive queues this 2025 * shouldn't happen. 2026 */ 2027 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 2028 "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n", 2029 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 2030 flags)) 2031 break; 2032 2033 offset = *seq - TCP_SKB_CB(skb)->seq; 2034 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { 2035 pr_err_once("%s: found a SYN, please report !\n", __func__); 2036 offset--; 2037 } 2038 if (offset < skb->len) 2039 goto found_ok_skb; 2040 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 2041 goto found_fin_ok; 2042 WARN(!(flags & MSG_PEEK), 2043 "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n", 2044 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); 2045 } 2046 2047 /* Well, if we have backlog, try to process it now yet. */ 2048 2049 if (copied >= target && !sk->sk_backlog.tail) 2050 break; 2051 2052 if (copied) { 2053 if (sk->sk_err || 2054 sk->sk_state == TCP_CLOSE || 2055 (sk->sk_shutdown & RCV_SHUTDOWN) || 2056 !timeo || 2057 signal_pending(current)) 2058 break; 2059 } else { 2060 if (sock_flag(sk, SOCK_DONE)) 2061 break; 2062 2063 if (sk->sk_err) { 2064 copied = sock_error(sk); 2065 break; 2066 } 2067 2068 if (sk->sk_shutdown & RCV_SHUTDOWN) 2069 break; 2070 2071 if (sk->sk_state == TCP_CLOSE) { 2072 /* This occurs when user tries to read 2073 * from never connected socket. 2074 */ 2075 copied = -ENOTCONN; 2076 break; 2077 } 2078 2079 if (!timeo) { 2080 copied = -EAGAIN; 2081 break; 2082 } 2083 2084 if (signal_pending(current)) { 2085 copied = sock_intr_errno(timeo); 2086 break; 2087 } 2088 } 2089 2090 tcp_cleanup_rbuf(sk, copied); 2091 2092 if (copied >= target) { 2093 /* Do not sleep, just process backlog. */ 2094 release_sock(sk); 2095 lock_sock(sk); 2096 } else { 2097 sk_wait_data(sk, &timeo, last); 2098 } 2099 2100 if ((flags & MSG_PEEK) && 2101 (peek_seq - copied - urg_hole != tp->copied_seq)) { 2102 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", 2103 current->comm, 2104 task_pid_nr(current)); 2105 peek_seq = tp->copied_seq; 2106 } 2107 continue; 2108 2109 found_ok_skb: 2110 /* Ok so how much can we use? */ 2111 used = skb->len - offset; 2112 if (len < used) 2113 used = len; 2114 2115 /* Do we have urgent data here? */ 2116 if (tp->urg_data) { 2117 u32 urg_offset = tp->urg_seq - *seq; 2118 if (urg_offset < used) { 2119 if (!urg_offset) { 2120 if (!sock_flag(sk, SOCK_URGINLINE)) { 2121 ++*seq; 2122 urg_hole++; 2123 offset++; 2124 used--; 2125 if (!used) 2126 goto skip_copy; 2127 } 2128 } else 2129 used = urg_offset; 2130 } 2131 } 2132 2133 if (!(flags & MSG_TRUNC)) { 2134 err = skb_copy_datagram_msg(skb, offset, msg, used); 2135 if (err) { 2136 /* Exception. Bailout! */ 2137 if (!copied) 2138 copied = -EFAULT; 2139 break; 2140 } 2141 } 2142 2143 *seq += used; 2144 copied += used; 2145 len -= used; 2146 2147 tcp_rcv_space_adjust(sk); 2148 2149 skip_copy: 2150 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 2151 tp->urg_data = 0; 2152 tcp_fast_path_check(sk); 2153 } 2154 if (used + offset < skb->len) 2155 continue; 2156 2157 if (TCP_SKB_CB(skb)->has_rxtstamp) { 2158 tcp_update_recv_tstamps(skb, &tss); 2159 has_tss = true; 2160 has_cmsg = true; 2161 } 2162 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 2163 goto found_fin_ok; 2164 if (!(flags & MSG_PEEK)) 2165 sk_eat_skb(sk, skb); 2166 continue; 2167 2168 found_fin_ok: 2169 /* Process the FIN. */ 2170 ++*seq; 2171 if (!(flags & MSG_PEEK)) 2172 sk_eat_skb(sk, skb); 2173 break; 2174 } while (len > 0); 2175 2176 /* According to UNIX98, msg_name/msg_namelen are ignored 2177 * on connected socket. I was just happy when found this 8) --ANK 2178 */ 2179 2180 /* Clean up data we have read: This will do ACK frames. */ 2181 tcp_cleanup_rbuf(sk, copied); 2182 2183 release_sock(sk); 2184 2185 if (has_cmsg) { 2186 if (has_tss) 2187 tcp_recv_timestamp(msg, sk, &tss); 2188 if (tp->recvmsg_inq) { 2189 inq = tcp_inq_hint(sk); 2190 put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq); 2191 } 2192 } 2193 2194 return copied; 2195 2196 out: 2197 release_sock(sk); 2198 return err; 2199 2200 recv_urg: 2201 err = tcp_recv_urg(sk, msg, len, flags); 2202 goto out; 2203 2204 recv_sndq: 2205 err = tcp_peek_sndq(sk, msg, len); 2206 goto out; 2207 } 2208 EXPORT_SYMBOL(tcp_recvmsg); 2209 2210 void tcp_set_state(struct sock *sk, int state) 2211 { 2212 int oldstate = sk->sk_state; 2213 2214 /* We defined a new enum for TCP states that are exported in BPF 2215 * so as not force the internal TCP states to be frozen. The 2216 * following checks will detect if an internal state value ever 2217 * differs from the BPF value. If this ever happens, then we will 2218 * need to remap the internal value to the BPF value before calling 2219 * tcp_call_bpf_2arg. 2220 */ 2221 BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED); 2222 BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT); 2223 BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV); 2224 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1); 2225 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2); 2226 BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT); 2227 BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE); 2228 BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT); 2229 BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK); 2230 BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN); 2231 BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING); 2232 BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV); 2233 BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES); 2234 2235 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG)) 2236 tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state); 2237 2238 switch (state) { 2239 case TCP_ESTABLISHED: 2240 if (oldstate != TCP_ESTABLISHED) 2241 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2242 break; 2243 2244 case TCP_CLOSE: 2245 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 2246 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 2247 2248 sk->sk_prot->unhash(sk); 2249 if (inet_csk(sk)->icsk_bind_hash && 2250 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 2251 inet_put_port(sk); 2252 /* fall through */ 2253 default: 2254 if (oldstate == TCP_ESTABLISHED) 2255 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2256 } 2257 2258 /* Change state AFTER socket is unhashed to avoid closed 2259 * socket sitting in hash tables. 2260 */ 2261 inet_sk_state_store(sk, state); 2262 } 2263 EXPORT_SYMBOL_GPL(tcp_set_state); 2264 2265 /* 2266 * State processing on a close. This implements the state shift for 2267 * sending our FIN frame. Note that we only send a FIN for some 2268 * states. A shutdown() may have already sent the FIN, or we may be 2269 * closed. 2270 */ 2271 2272 static const unsigned char new_state[16] = { 2273 /* current state: new state: action: */ 2274 [0 /* (Invalid) */] = TCP_CLOSE, 2275 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2276 [TCP_SYN_SENT] = TCP_CLOSE, 2277 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2278 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, 2279 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, 2280 [TCP_TIME_WAIT] = TCP_CLOSE, 2281 [TCP_CLOSE] = TCP_CLOSE, 2282 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, 2283 [TCP_LAST_ACK] = TCP_LAST_ACK, 2284 [TCP_LISTEN] = TCP_CLOSE, 2285 [TCP_CLOSING] = TCP_CLOSING, 2286 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ 2287 }; 2288 2289 static int tcp_close_state(struct sock *sk) 2290 { 2291 int next = (int)new_state[sk->sk_state]; 2292 int ns = next & TCP_STATE_MASK; 2293 2294 tcp_set_state(sk, ns); 2295 2296 return next & TCP_ACTION_FIN; 2297 } 2298 2299 /* 2300 * Shutdown the sending side of a connection. Much like close except 2301 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 2302 */ 2303 2304 void tcp_shutdown(struct sock *sk, int how) 2305 { 2306 /* We need to grab some memory, and put together a FIN, 2307 * and then put it into the queue to be sent. 2308 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 2309 */ 2310 if (!(how & SEND_SHUTDOWN)) 2311 return; 2312 2313 /* If we've already sent a FIN, or it's a closed state, skip this. */ 2314 if ((1 << sk->sk_state) & 2315 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 2316 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 2317 /* Clear out any half completed packets. FIN if needed. */ 2318 if (tcp_close_state(sk)) 2319 tcp_send_fin(sk); 2320 } 2321 } 2322 EXPORT_SYMBOL(tcp_shutdown); 2323 2324 bool tcp_check_oom(struct sock *sk, int shift) 2325 { 2326 bool too_many_orphans, out_of_socket_memory; 2327 2328 too_many_orphans = tcp_too_many_orphans(sk, shift); 2329 out_of_socket_memory = tcp_out_of_memory(sk); 2330 2331 if (too_many_orphans) 2332 net_info_ratelimited("too many orphaned sockets\n"); 2333 if (out_of_socket_memory) 2334 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); 2335 return too_many_orphans || out_of_socket_memory; 2336 } 2337 2338 void tcp_close(struct sock *sk, long timeout) 2339 { 2340 struct sk_buff *skb; 2341 int data_was_unread = 0; 2342 int state; 2343 2344 lock_sock(sk); 2345 sk->sk_shutdown = SHUTDOWN_MASK; 2346 2347 if (sk->sk_state == TCP_LISTEN) { 2348 tcp_set_state(sk, TCP_CLOSE); 2349 2350 /* Special case. */ 2351 inet_csk_listen_stop(sk); 2352 2353 goto adjudge_to_death; 2354 } 2355 2356 /* We need to flush the recv. buffs. We do this only on the 2357 * descriptor close, not protocol-sourced closes, because the 2358 * reader process may not have drained the data yet! 2359 */ 2360 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 2361 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; 2362 2363 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 2364 len--; 2365 data_was_unread += len; 2366 __kfree_skb(skb); 2367 } 2368 2369 sk_mem_reclaim(sk); 2370 2371 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ 2372 if (sk->sk_state == TCP_CLOSE) 2373 goto adjudge_to_death; 2374 2375 /* As outlined in RFC 2525, section 2.17, we send a RST here because 2376 * data was lost. To witness the awful effects of the old behavior of 2377 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 2378 * GET in an FTP client, suspend the process, wait for the client to 2379 * advertise a zero window, then kill -9 the FTP client, wheee... 2380 * Note: timeout is always zero in such a case. 2381 */ 2382 if (unlikely(tcp_sk(sk)->repair)) { 2383 sk->sk_prot->disconnect(sk, 0); 2384 } else if (data_was_unread) { 2385 /* Unread data was tossed, zap the connection. */ 2386 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 2387 tcp_set_state(sk, TCP_CLOSE); 2388 tcp_send_active_reset(sk, sk->sk_allocation); 2389 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 2390 /* Check zero linger _after_ checking for unread data. */ 2391 sk->sk_prot->disconnect(sk, 0); 2392 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 2393 } else if (tcp_close_state(sk)) { 2394 /* We FIN if the application ate all the data before 2395 * zapping the connection. 2396 */ 2397 2398 /* RED-PEN. Formally speaking, we have broken TCP state 2399 * machine. State transitions: 2400 * 2401 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 2402 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 2403 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 2404 * 2405 * are legal only when FIN has been sent (i.e. in window), 2406 * rather than queued out of window. Purists blame. 2407 * 2408 * F.e. "RFC state" is ESTABLISHED, 2409 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 2410 * 2411 * The visible declinations are that sometimes 2412 * we enter time-wait state, when it is not required really 2413 * (harmless), do not send active resets, when they are 2414 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 2415 * they look as CLOSING or LAST_ACK for Linux) 2416 * Probably, I missed some more holelets. 2417 * --ANK 2418 * XXX (TFO) - To start off we don't support SYN+ACK+FIN 2419 * in a single packet! (May consider it later but will 2420 * probably need API support or TCP_CORK SYN-ACK until 2421 * data is written and socket is closed.) 2422 */ 2423 tcp_send_fin(sk); 2424 } 2425 2426 sk_stream_wait_close(sk, timeout); 2427 2428 adjudge_to_death: 2429 state = sk->sk_state; 2430 sock_hold(sk); 2431 sock_orphan(sk); 2432 2433 local_bh_disable(); 2434 bh_lock_sock(sk); 2435 /* remove backlog if any, without releasing ownership. */ 2436 __release_sock(sk); 2437 2438 percpu_counter_inc(sk->sk_prot->orphan_count); 2439 2440 /* Have we already been destroyed by a softirq or backlog? */ 2441 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 2442 goto out; 2443 2444 /* This is a (useful) BSD violating of the RFC. There is a 2445 * problem with TCP as specified in that the other end could 2446 * keep a socket open forever with no application left this end. 2447 * We use a 1 minute timeout (about the same as BSD) then kill 2448 * our end. If they send after that then tough - BUT: long enough 2449 * that we won't make the old 4*rto = almost no time - whoops 2450 * reset mistake. 2451 * 2452 * Nope, it was not mistake. It is really desired behaviour 2453 * f.e. on http servers, when such sockets are useless, but 2454 * consume significant resources. Let's do it with special 2455 * linger2 option. --ANK 2456 */ 2457 2458 if (sk->sk_state == TCP_FIN_WAIT2) { 2459 struct tcp_sock *tp = tcp_sk(sk); 2460 if (tp->linger2 < 0) { 2461 tcp_set_state(sk, TCP_CLOSE); 2462 tcp_send_active_reset(sk, GFP_ATOMIC); 2463 __NET_INC_STATS(sock_net(sk), 2464 LINUX_MIB_TCPABORTONLINGER); 2465 } else { 2466 const int tmo = tcp_fin_time(sk); 2467 2468 if (tmo > TCP_TIMEWAIT_LEN) { 2469 inet_csk_reset_keepalive_timer(sk, 2470 tmo - TCP_TIMEWAIT_LEN); 2471 } else { 2472 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 2473 goto out; 2474 } 2475 } 2476 } 2477 if (sk->sk_state != TCP_CLOSE) { 2478 sk_mem_reclaim(sk); 2479 if (tcp_check_oom(sk, 0)) { 2480 tcp_set_state(sk, TCP_CLOSE); 2481 tcp_send_active_reset(sk, GFP_ATOMIC); 2482 __NET_INC_STATS(sock_net(sk), 2483 LINUX_MIB_TCPABORTONMEMORY); 2484 } else if (!check_net(sock_net(sk))) { 2485 /* Not possible to send reset; just close */ 2486 tcp_set_state(sk, TCP_CLOSE); 2487 } 2488 } 2489 2490 if (sk->sk_state == TCP_CLOSE) { 2491 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 2492 /* We could get here with a non-NULL req if the socket is 2493 * aborted (e.g., closed with unread data) before 3WHS 2494 * finishes. 2495 */ 2496 if (req) 2497 reqsk_fastopen_remove(sk, req, false); 2498 inet_csk_destroy_sock(sk); 2499 } 2500 /* Otherwise, socket is reprieved until protocol close. */ 2501 2502 out: 2503 bh_unlock_sock(sk); 2504 local_bh_enable(); 2505 release_sock(sk); 2506 sock_put(sk); 2507 } 2508 EXPORT_SYMBOL(tcp_close); 2509 2510 /* These states need RST on ABORT according to RFC793 */ 2511 2512 static inline bool tcp_need_reset(int state) 2513 { 2514 return (1 << state) & 2515 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2516 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2517 } 2518 2519 static void tcp_rtx_queue_purge(struct sock *sk) 2520 { 2521 struct rb_node *p = rb_first(&sk->tcp_rtx_queue); 2522 2523 while (p) { 2524 struct sk_buff *skb = rb_to_skb(p); 2525 2526 p = rb_next(p); 2527 /* Since we are deleting whole queue, no need to 2528 * list_del(&skb->tcp_tsorted_anchor) 2529 */ 2530 tcp_rtx_queue_unlink(skb, sk); 2531 sk_wmem_free_skb(sk, skb); 2532 } 2533 } 2534 2535 void tcp_write_queue_purge(struct sock *sk) 2536 { 2537 struct sk_buff *skb; 2538 2539 tcp_chrono_stop(sk, TCP_CHRONO_BUSY); 2540 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 2541 tcp_skb_tsorted_anchor_cleanup(skb); 2542 sk_wmem_free_skb(sk, skb); 2543 } 2544 tcp_rtx_queue_purge(sk); 2545 INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue); 2546 sk_mem_reclaim(sk); 2547 tcp_clear_all_retrans_hints(tcp_sk(sk)); 2548 tcp_sk(sk)->packets_out = 0; 2549 } 2550 2551 int tcp_disconnect(struct sock *sk, int flags) 2552 { 2553 struct inet_sock *inet = inet_sk(sk); 2554 struct inet_connection_sock *icsk = inet_csk(sk); 2555 struct tcp_sock *tp = tcp_sk(sk); 2556 int old_state = sk->sk_state; 2557 2558 if (old_state != TCP_CLOSE) 2559 tcp_set_state(sk, TCP_CLOSE); 2560 2561 /* ABORT function of RFC793 */ 2562 if (old_state == TCP_LISTEN) { 2563 inet_csk_listen_stop(sk); 2564 } else if (unlikely(tp->repair)) { 2565 sk->sk_err = ECONNABORTED; 2566 } else if (tcp_need_reset(old_state) || 2567 (tp->snd_nxt != tp->write_seq && 2568 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2569 /* The last check adjusts for discrepancy of Linux wrt. RFC 2570 * states 2571 */ 2572 tcp_send_active_reset(sk, gfp_any()); 2573 sk->sk_err = ECONNRESET; 2574 } else if (old_state == TCP_SYN_SENT) 2575 sk->sk_err = ECONNRESET; 2576 2577 tcp_clear_xmit_timers(sk); 2578 __skb_queue_purge(&sk->sk_receive_queue); 2579 tp->copied_seq = tp->rcv_nxt; 2580 tp->urg_data = 0; 2581 tcp_write_queue_purge(sk); 2582 tcp_fastopen_active_disable_ofo_check(sk); 2583 skb_rbtree_purge(&tp->out_of_order_queue); 2584 2585 inet->inet_dport = 0; 2586 2587 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2588 inet_reset_saddr(sk); 2589 2590 sk->sk_shutdown = 0; 2591 sock_reset_flag(sk, SOCK_DONE); 2592 tp->srtt_us = 0; 2593 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); 2594 tp->rcv_rtt_last_tsecr = 0; 2595 tp->write_seq += tp->max_window + 2; 2596 if (tp->write_seq == 0) 2597 tp->write_seq = 1; 2598 icsk->icsk_backoff = 0; 2599 icsk->icsk_probes_out = 0; 2600 icsk->icsk_rto = TCP_TIMEOUT_INIT; 2601 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2602 tp->snd_cwnd = TCP_INIT_CWND; 2603 tp->snd_cwnd_cnt = 0; 2604 tp->window_clamp = 0; 2605 tp->delivered_ce = 0; 2606 tcp_set_ca_state(sk, TCP_CA_Open); 2607 tp->is_sack_reneg = 0; 2608 tcp_clear_retrans(tp); 2609 inet_csk_delack_init(sk); 2610 /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 2611 * issue in __tcp_select_window() 2612 */ 2613 icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; 2614 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2615 __sk_dst_reset(sk); 2616 dst_release(sk->sk_rx_dst); 2617 sk->sk_rx_dst = NULL; 2618 tcp_saved_syn_free(tp); 2619 tp->compressed_ack = 0; 2620 tp->bytes_sent = 0; 2621 tp->bytes_retrans = 0; 2622 tp->duplicate_sack[0].start_seq = 0; 2623 tp->duplicate_sack[0].end_seq = 0; 2624 tp->dsack_dups = 0; 2625 tp->reord_seen = 0; 2626 tp->retrans_out = 0; 2627 tp->sacked_out = 0; 2628 tp->tlp_high_seq = 0; 2629 tp->last_oow_ack_time = 0; 2630 /* There's a bubble in the pipe until at least the first ACK. */ 2631 tp->app_limited = ~0U; 2632 tp->rack.mstamp = 0; 2633 tp->rack.advanced = 0; 2634 tp->rack.reo_wnd_steps = 1; 2635 tp->rack.last_delivered = 0; 2636 tp->rack.reo_wnd_persist = 0; 2637 tp->rack.dsack_seen = 0; 2638 tp->syn_data_acked = 0; 2639 tp->rx_opt.saw_tstamp = 0; 2640 tp->rx_opt.dsack = 0; 2641 tp->rx_opt.num_sacks = 0; 2642 2643 2644 /* Clean up fastopen related fields */ 2645 tcp_free_fastopen_req(tp); 2646 inet->defer_connect = 0; 2647 2648 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2649 2650 if (sk->sk_frag.page) { 2651 put_page(sk->sk_frag.page); 2652 sk->sk_frag.page = NULL; 2653 sk->sk_frag.offset = 0; 2654 } 2655 2656 sk->sk_error_report(sk); 2657 return 0; 2658 } 2659 EXPORT_SYMBOL(tcp_disconnect); 2660 2661 static inline bool tcp_can_repair_sock(const struct sock *sk) 2662 { 2663 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && 2664 (sk->sk_state != TCP_LISTEN); 2665 } 2666 2667 static int tcp_repair_set_window(struct tcp_sock *tp, char __user *optbuf, int len) 2668 { 2669 struct tcp_repair_window opt; 2670 2671 if (!tp->repair) 2672 return -EPERM; 2673 2674 if (len != sizeof(opt)) 2675 return -EINVAL; 2676 2677 if (copy_from_user(&opt, optbuf, sizeof(opt))) 2678 return -EFAULT; 2679 2680 if (opt.max_window < opt.snd_wnd) 2681 return -EINVAL; 2682 2683 if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd)) 2684 return -EINVAL; 2685 2686 if (after(opt.rcv_wup, tp->rcv_nxt)) 2687 return -EINVAL; 2688 2689 tp->snd_wl1 = opt.snd_wl1; 2690 tp->snd_wnd = opt.snd_wnd; 2691 tp->max_window = opt.max_window; 2692 2693 tp->rcv_wnd = opt.rcv_wnd; 2694 tp->rcv_wup = opt.rcv_wup; 2695 2696 return 0; 2697 } 2698 2699 static int tcp_repair_options_est(struct sock *sk, 2700 struct tcp_repair_opt __user *optbuf, unsigned int len) 2701 { 2702 struct tcp_sock *tp = tcp_sk(sk); 2703 struct tcp_repair_opt opt; 2704 2705 while (len >= sizeof(opt)) { 2706 if (copy_from_user(&opt, optbuf, sizeof(opt))) 2707 return -EFAULT; 2708 2709 optbuf++; 2710 len -= sizeof(opt); 2711 2712 switch (opt.opt_code) { 2713 case TCPOPT_MSS: 2714 tp->rx_opt.mss_clamp = opt.opt_val; 2715 tcp_mtup_init(sk); 2716 break; 2717 case TCPOPT_WINDOW: 2718 { 2719 u16 snd_wscale = opt.opt_val & 0xFFFF; 2720 u16 rcv_wscale = opt.opt_val >> 16; 2721 2722 if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE) 2723 return -EFBIG; 2724 2725 tp->rx_opt.snd_wscale = snd_wscale; 2726 tp->rx_opt.rcv_wscale = rcv_wscale; 2727 tp->rx_opt.wscale_ok = 1; 2728 } 2729 break; 2730 case TCPOPT_SACK_PERM: 2731 if (opt.opt_val != 0) 2732 return -EINVAL; 2733 2734 tp->rx_opt.sack_ok |= TCP_SACK_SEEN; 2735 break; 2736 case TCPOPT_TIMESTAMP: 2737 if (opt.opt_val != 0) 2738 return -EINVAL; 2739 2740 tp->rx_opt.tstamp_ok = 1; 2741 break; 2742 } 2743 } 2744 2745 return 0; 2746 } 2747 2748 /* 2749 * Socket option code for TCP. 2750 */ 2751 static int do_tcp_setsockopt(struct sock *sk, int level, 2752 int optname, char __user *optval, unsigned int optlen) 2753 { 2754 struct tcp_sock *tp = tcp_sk(sk); 2755 struct inet_connection_sock *icsk = inet_csk(sk); 2756 struct net *net = sock_net(sk); 2757 int val; 2758 int err = 0; 2759 2760 /* These are data/string values, all the others are ints */ 2761 switch (optname) { 2762 case TCP_CONGESTION: { 2763 char name[TCP_CA_NAME_MAX]; 2764 2765 if (optlen < 1) 2766 return -EINVAL; 2767 2768 val = strncpy_from_user(name, optval, 2769 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2770 if (val < 0) 2771 return -EFAULT; 2772 name[val] = 0; 2773 2774 lock_sock(sk); 2775 err = tcp_set_congestion_control(sk, name, true, true); 2776 release_sock(sk); 2777 return err; 2778 } 2779 case TCP_ULP: { 2780 char name[TCP_ULP_NAME_MAX]; 2781 2782 if (optlen < 1) 2783 return -EINVAL; 2784 2785 val = strncpy_from_user(name, optval, 2786 min_t(long, TCP_ULP_NAME_MAX - 1, 2787 optlen)); 2788 if (val < 0) 2789 return -EFAULT; 2790 name[val] = 0; 2791 2792 lock_sock(sk); 2793 err = tcp_set_ulp(sk, name); 2794 release_sock(sk); 2795 return err; 2796 } 2797 case TCP_FASTOPEN_KEY: { 2798 __u8 key[TCP_FASTOPEN_KEY_LENGTH]; 2799 2800 if (optlen != sizeof(key)) 2801 return -EINVAL; 2802 2803 if (copy_from_user(key, optval, optlen)) 2804 return -EFAULT; 2805 2806 return tcp_fastopen_reset_cipher(net, sk, key, sizeof(key)); 2807 } 2808 default: 2809 /* fallthru */ 2810 break; 2811 } 2812 2813 if (optlen < sizeof(int)) 2814 return -EINVAL; 2815 2816 if (get_user(val, (int __user *)optval)) 2817 return -EFAULT; 2818 2819 lock_sock(sk); 2820 2821 switch (optname) { 2822 case TCP_MAXSEG: 2823 /* Values greater than interface MTU won't take effect. However 2824 * at the point when this call is done we typically don't yet 2825 * know which interface is going to be used 2826 */ 2827 if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) { 2828 err = -EINVAL; 2829 break; 2830 } 2831 tp->rx_opt.user_mss = val; 2832 break; 2833 2834 case TCP_NODELAY: 2835 if (val) { 2836 /* TCP_NODELAY is weaker than TCP_CORK, so that 2837 * this option on corked socket is remembered, but 2838 * it is not activated until cork is cleared. 2839 * 2840 * However, when TCP_NODELAY is set we make 2841 * an explicit push, which overrides even TCP_CORK 2842 * for currently queued segments. 2843 */ 2844 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2845 tcp_push_pending_frames(sk); 2846 } else { 2847 tp->nonagle &= ~TCP_NAGLE_OFF; 2848 } 2849 break; 2850 2851 case TCP_THIN_LINEAR_TIMEOUTS: 2852 if (val < 0 || val > 1) 2853 err = -EINVAL; 2854 else 2855 tp->thin_lto = val; 2856 break; 2857 2858 case TCP_THIN_DUPACK: 2859 if (val < 0 || val > 1) 2860 err = -EINVAL; 2861 break; 2862 2863 case TCP_REPAIR: 2864 if (!tcp_can_repair_sock(sk)) 2865 err = -EPERM; 2866 else if (val == TCP_REPAIR_ON) { 2867 tp->repair = 1; 2868 sk->sk_reuse = SK_FORCE_REUSE; 2869 tp->repair_queue = TCP_NO_QUEUE; 2870 } else if (val == TCP_REPAIR_OFF) { 2871 tp->repair = 0; 2872 sk->sk_reuse = SK_NO_REUSE; 2873 tcp_send_window_probe(sk); 2874 } else if (val == TCP_REPAIR_OFF_NO_WP) { 2875 tp->repair = 0; 2876 sk->sk_reuse = SK_NO_REUSE; 2877 } else 2878 err = -EINVAL; 2879 2880 break; 2881 2882 case TCP_REPAIR_QUEUE: 2883 if (!tp->repair) 2884 err = -EPERM; 2885 else if ((unsigned int)val < TCP_QUEUES_NR) 2886 tp->repair_queue = val; 2887 else 2888 err = -EINVAL; 2889 break; 2890 2891 case TCP_QUEUE_SEQ: 2892 if (sk->sk_state != TCP_CLOSE) 2893 err = -EPERM; 2894 else if (tp->repair_queue == TCP_SEND_QUEUE) 2895 tp->write_seq = val; 2896 else if (tp->repair_queue == TCP_RECV_QUEUE) 2897 tp->rcv_nxt = val; 2898 else 2899 err = -EINVAL; 2900 break; 2901 2902 case TCP_REPAIR_OPTIONS: 2903 if (!tp->repair) 2904 err = -EINVAL; 2905 else if (sk->sk_state == TCP_ESTABLISHED) 2906 err = tcp_repair_options_est(sk, 2907 (struct tcp_repair_opt __user *)optval, 2908 optlen); 2909 else 2910 err = -EPERM; 2911 break; 2912 2913 case TCP_CORK: 2914 /* When set indicates to always queue non-full frames. 2915 * Later the user clears this option and we transmit 2916 * any pending partial frames in the queue. This is 2917 * meant to be used alongside sendfile() to get properly 2918 * filled frames when the user (for example) must write 2919 * out headers with a write() call first and then use 2920 * sendfile to send out the data parts. 2921 * 2922 * TCP_CORK can be set together with TCP_NODELAY and it is 2923 * stronger than TCP_NODELAY. 2924 */ 2925 if (val) { 2926 tp->nonagle |= TCP_NAGLE_CORK; 2927 } else { 2928 tp->nonagle &= ~TCP_NAGLE_CORK; 2929 if (tp->nonagle&TCP_NAGLE_OFF) 2930 tp->nonagle |= TCP_NAGLE_PUSH; 2931 tcp_push_pending_frames(sk); 2932 } 2933 break; 2934 2935 case TCP_KEEPIDLE: 2936 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2937 err = -EINVAL; 2938 else { 2939 tp->keepalive_time = val * HZ; 2940 if (sock_flag(sk, SOCK_KEEPOPEN) && 2941 !((1 << sk->sk_state) & 2942 (TCPF_CLOSE | TCPF_LISTEN))) { 2943 u32 elapsed = keepalive_time_elapsed(tp); 2944 if (tp->keepalive_time > elapsed) 2945 elapsed = tp->keepalive_time - elapsed; 2946 else 2947 elapsed = 0; 2948 inet_csk_reset_keepalive_timer(sk, elapsed); 2949 } 2950 } 2951 break; 2952 case TCP_KEEPINTVL: 2953 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2954 err = -EINVAL; 2955 else 2956 tp->keepalive_intvl = val * HZ; 2957 break; 2958 case TCP_KEEPCNT: 2959 if (val < 1 || val > MAX_TCP_KEEPCNT) 2960 err = -EINVAL; 2961 else 2962 tp->keepalive_probes = val; 2963 break; 2964 case TCP_SYNCNT: 2965 if (val < 1 || val > MAX_TCP_SYNCNT) 2966 err = -EINVAL; 2967 else 2968 icsk->icsk_syn_retries = val; 2969 break; 2970 2971 case TCP_SAVE_SYN: 2972 if (val < 0 || val > 1) 2973 err = -EINVAL; 2974 else 2975 tp->save_syn = val; 2976 break; 2977 2978 case TCP_LINGER2: 2979 if (val < 0) 2980 tp->linger2 = -1; 2981 else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ) 2982 tp->linger2 = 0; 2983 else 2984 tp->linger2 = val * HZ; 2985 break; 2986 2987 case TCP_DEFER_ACCEPT: 2988 /* Translate value in seconds to number of retransmits */ 2989 icsk->icsk_accept_queue.rskq_defer_accept = 2990 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2991 TCP_RTO_MAX / HZ); 2992 break; 2993 2994 case TCP_WINDOW_CLAMP: 2995 if (!val) { 2996 if (sk->sk_state != TCP_CLOSE) { 2997 err = -EINVAL; 2998 break; 2999 } 3000 tp->window_clamp = 0; 3001 } else 3002 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 3003 SOCK_MIN_RCVBUF / 2 : val; 3004 break; 3005 3006 case TCP_QUICKACK: 3007 if (!val) { 3008 inet_csk_enter_pingpong_mode(sk); 3009 } else { 3010 inet_csk_exit_pingpong_mode(sk); 3011 if ((1 << sk->sk_state) & 3012 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 3013 inet_csk_ack_scheduled(sk)) { 3014 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 3015 tcp_cleanup_rbuf(sk, 1); 3016 if (!(val & 1)) 3017 inet_csk_enter_pingpong_mode(sk); 3018 } 3019 } 3020 break; 3021 3022 #ifdef CONFIG_TCP_MD5SIG 3023 case TCP_MD5SIG: 3024 case TCP_MD5SIG_EXT: 3025 if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) 3026 err = tp->af_specific->md5_parse(sk, optname, optval, optlen); 3027 else 3028 err = -EINVAL; 3029 break; 3030 #endif 3031 case TCP_USER_TIMEOUT: 3032 /* Cap the max time in ms TCP will retry or probe the window 3033 * before giving up and aborting (ETIMEDOUT) a connection. 3034 */ 3035 if (val < 0) 3036 err = -EINVAL; 3037 else 3038 icsk->icsk_user_timeout = val; 3039 break; 3040 3041 case TCP_FASTOPEN: 3042 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | 3043 TCPF_LISTEN))) { 3044 tcp_fastopen_init_key_once(net); 3045 3046 fastopen_queue_tune(sk, val); 3047 } else { 3048 err = -EINVAL; 3049 } 3050 break; 3051 case TCP_FASTOPEN_CONNECT: 3052 if (val > 1 || val < 0) { 3053 err = -EINVAL; 3054 } else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) { 3055 if (sk->sk_state == TCP_CLOSE) 3056 tp->fastopen_connect = val; 3057 else 3058 err = -EINVAL; 3059 } else { 3060 err = -EOPNOTSUPP; 3061 } 3062 break; 3063 case TCP_FASTOPEN_NO_COOKIE: 3064 if (val > 1 || val < 0) 3065 err = -EINVAL; 3066 else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 3067 err = -EINVAL; 3068 else 3069 tp->fastopen_no_cookie = val; 3070 break; 3071 case TCP_TIMESTAMP: 3072 if (!tp->repair) 3073 err = -EPERM; 3074 else 3075 tp->tsoffset = val - tcp_time_stamp_raw(); 3076 break; 3077 case TCP_REPAIR_WINDOW: 3078 err = tcp_repair_set_window(tp, optval, optlen); 3079 break; 3080 case TCP_NOTSENT_LOWAT: 3081 tp->notsent_lowat = val; 3082 sk->sk_write_space(sk); 3083 break; 3084 case TCP_INQ: 3085 if (val > 1 || val < 0) 3086 err = -EINVAL; 3087 else 3088 tp->recvmsg_inq = val; 3089 break; 3090 default: 3091 err = -ENOPROTOOPT; 3092 break; 3093 } 3094 3095 release_sock(sk); 3096 return err; 3097 } 3098 3099 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 3100 unsigned int optlen) 3101 { 3102 const struct inet_connection_sock *icsk = inet_csk(sk); 3103 3104 if (level != SOL_TCP) 3105 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 3106 optval, optlen); 3107 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 3108 } 3109 EXPORT_SYMBOL(tcp_setsockopt); 3110 3111 #ifdef CONFIG_COMPAT 3112 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 3113 char __user *optval, unsigned int optlen) 3114 { 3115 if (level != SOL_TCP) 3116 return inet_csk_compat_setsockopt(sk, level, optname, 3117 optval, optlen); 3118 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 3119 } 3120 EXPORT_SYMBOL(compat_tcp_setsockopt); 3121 #endif 3122 3123 static void tcp_get_info_chrono_stats(const struct tcp_sock *tp, 3124 struct tcp_info *info) 3125 { 3126 u64 stats[__TCP_CHRONO_MAX], total = 0; 3127 enum tcp_chrono i; 3128 3129 for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) { 3130 stats[i] = tp->chrono_stat[i - 1]; 3131 if (i == tp->chrono_type) 3132 stats[i] += tcp_jiffies32 - tp->chrono_start; 3133 stats[i] *= USEC_PER_SEC / HZ; 3134 total += stats[i]; 3135 } 3136 3137 info->tcpi_busy_time = total; 3138 info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED]; 3139 info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED]; 3140 } 3141 3142 /* Return information about state of tcp endpoint in API format. */ 3143 void tcp_get_info(struct sock *sk, struct tcp_info *info) 3144 { 3145 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ 3146 const struct inet_connection_sock *icsk = inet_csk(sk); 3147 unsigned long rate; 3148 u32 now; 3149 u64 rate64; 3150 bool slow; 3151 3152 memset(info, 0, sizeof(*info)); 3153 if (sk->sk_type != SOCK_STREAM) 3154 return; 3155 3156 info->tcpi_state = inet_sk_state_load(sk); 3157 3158 /* Report meaningful fields for all TCP states, including listeners */ 3159 rate = READ_ONCE(sk->sk_pacing_rate); 3160 rate64 = (rate != ~0UL) ? rate : ~0ULL; 3161 info->tcpi_pacing_rate = rate64; 3162 3163 rate = READ_ONCE(sk->sk_max_pacing_rate); 3164 rate64 = (rate != ~0UL) ? rate : ~0ULL; 3165 info->tcpi_max_pacing_rate = rate64; 3166 3167 info->tcpi_reordering = tp->reordering; 3168 info->tcpi_snd_cwnd = tp->snd_cwnd; 3169 3170 if (info->tcpi_state == TCP_LISTEN) { 3171 /* listeners aliased fields : 3172 * tcpi_unacked -> Number of children ready for accept() 3173 * tcpi_sacked -> max backlog 3174 */ 3175 info->tcpi_unacked = sk->sk_ack_backlog; 3176 info->tcpi_sacked = sk->sk_max_ack_backlog; 3177 return; 3178 } 3179 3180 slow = lock_sock_fast(sk); 3181 3182 info->tcpi_ca_state = icsk->icsk_ca_state; 3183 info->tcpi_retransmits = icsk->icsk_retransmits; 3184 info->tcpi_probes = icsk->icsk_probes_out; 3185 info->tcpi_backoff = icsk->icsk_backoff; 3186 3187 if (tp->rx_opt.tstamp_ok) 3188 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 3189 if (tcp_is_sack(tp)) 3190 info->tcpi_options |= TCPI_OPT_SACK; 3191 if (tp->rx_opt.wscale_ok) { 3192 info->tcpi_options |= TCPI_OPT_WSCALE; 3193 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 3194 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 3195 } 3196 3197 if (tp->ecn_flags & TCP_ECN_OK) 3198 info->tcpi_options |= TCPI_OPT_ECN; 3199 if (tp->ecn_flags & TCP_ECN_SEEN) 3200 info->tcpi_options |= TCPI_OPT_ECN_SEEN; 3201 if (tp->syn_data_acked) 3202 info->tcpi_options |= TCPI_OPT_SYN_DATA; 3203 3204 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 3205 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 3206 info->tcpi_snd_mss = tp->mss_cache; 3207 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 3208 3209 info->tcpi_unacked = tp->packets_out; 3210 info->tcpi_sacked = tp->sacked_out; 3211 3212 info->tcpi_lost = tp->lost_out; 3213 info->tcpi_retrans = tp->retrans_out; 3214 3215 now = tcp_jiffies32; 3216 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 3217 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 3218 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 3219 3220 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 3221 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 3222 info->tcpi_rtt = tp->srtt_us >> 3; 3223 info->tcpi_rttvar = tp->mdev_us >> 2; 3224 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 3225 info->tcpi_advmss = tp->advmss; 3226 3227 info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3; 3228 info->tcpi_rcv_space = tp->rcvq_space.space; 3229 3230 info->tcpi_total_retrans = tp->total_retrans; 3231 3232 info->tcpi_bytes_acked = tp->bytes_acked; 3233 info->tcpi_bytes_received = tp->bytes_received; 3234 info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt); 3235 tcp_get_info_chrono_stats(tp, info); 3236 3237 info->tcpi_segs_out = tp->segs_out; 3238 info->tcpi_segs_in = tp->segs_in; 3239 3240 info->tcpi_min_rtt = tcp_min_rtt(tp); 3241 info->tcpi_data_segs_in = tp->data_segs_in; 3242 info->tcpi_data_segs_out = tp->data_segs_out; 3243 3244 info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0; 3245 rate64 = tcp_compute_delivery_rate(tp); 3246 if (rate64) 3247 info->tcpi_delivery_rate = rate64; 3248 info->tcpi_delivered = tp->delivered; 3249 info->tcpi_delivered_ce = tp->delivered_ce; 3250 info->tcpi_bytes_sent = tp->bytes_sent; 3251 info->tcpi_bytes_retrans = tp->bytes_retrans; 3252 info->tcpi_dsack_dups = tp->dsack_dups; 3253 info->tcpi_reord_seen = tp->reord_seen; 3254 unlock_sock_fast(sk, slow); 3255 } 3256 EXPORT_SYMBOL_GPL(tcp_get_info); 3257 3258 static size_t tcp_opt_stats_get_size(void) 3259 { 3260 return 3261 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BUSY */ 3262 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_RWND_LIMITED */ 3263 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_SNDBUF_LIMITED */ 3264 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DATA_SEGS_OUT */ 3265 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_TOTAL_RETRANS */ 3266 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_PACING_RATE */ 3267 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DELIVERY_RATE */ 3268 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_CWND */ 3269 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORDERING */ 3270 nla_total_size(sizeof(u32)) + /* TCP_NLA_MIN_RTT */ 3271 nla_total_size(sizeof(u8)) + /* TCP_NLA_RECUR_RETRANS */ 3272 nla_total_size(sizeof(u8)) + /* TCP_NLA_DELIVERY_RATE_APP_LMT */ 3273 nla_total_size(sizeof(u32)) + /* TCP_NLA_SNDQ_SIZE */ 3274 nla_total_size(sizeof(u8)) + /* TCP_NLA_CA_STATE */ 3275 nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_SSTHRESH */ 3276 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED */ 3277 nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */ 3278 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */ 3279 nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */ 3280 nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */ 3281 nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */ 3282 nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */ 3283 0; 3284 } 3285 3286 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk) 3287 { 3288 const struct tcp_sock *tp = tcp_sk(sk); 3289 struct sk_buff *stats; 3290 struct tcp_info info; 3291 unsigned long rate; 3292 u64 rate64; 3293 3294 stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC); 3295 if (!stats) 3296 return NULL; 3297 3298 tcp_get_info_chrono_stats(tp, &info); 3299 nla_put_u64_64bit(stats, TCP_NLA_BUSY, 3300 info.tcpi_busy_time, TCP_NLA_PAD); 3301 nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED, 3302 info.tcpi_rwnd_limited, TCP_NLA_PAD); 3303 nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED, 3304 info.tcpi_sndbuf_limited, TCP_NLA_PAD); 3305 nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT, 3306 tp->data_segs_out, TCP_NLA_PAD); 3307 nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS, 3308 tp->total_retrans, TCP_NLA_PAD); 3309 3310 rate = READ_ONCE(sk->sk_pacing_rate); 3311 rate64 = (rate != ~0UL) ? rate : ~0ULL; 3312 nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD); 3313 3314 rate64 = tcp_compute_delivery_rate(tp); 3315 nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD); 3316 3317 nla_put_u32(stats, TCP_NLA_SND_CWND, tp->snd_cwnd); 3318 nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering); 3319 nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp)); 3320 3321 nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits); 3322 nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited); 3323 nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh); 3324 nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered); 3325 nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce); 3326 3327 nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una); 3328 nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state); 3329 3330 nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent, 3331 TCP_NLA_PAD); 3332 nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans, 3333 TCP_NLA_PAD); 3334 nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups); 3335 nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen); 3336 nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3); 3337 3338 return stats; 3339 } 3340 3341 static int do_tcp_getsockopt(struct sock *sk, int level, 3342 int optname, char __user *optval, int __user *optlen) 3343 { 3344 struct inet_connection_sock *icsk = inet_csk(sk); 3345 struct tcp_sock *tp = tcp_sk(sk); 3346 struct net *net = sock_net(sk); 3347 int val, len; 3348 3349 if (get_user(len, optlen)) 3350 return -EFAULT; 3351 3352 len = min_t(unsigned int, len, sizeof(int)); 3353 3354 if (len < 0) 3355 return -EINVAL; 3356 3357 switch (optname) { 3358 case TCP_MAXSEG: 3359 val = tp->mss_cache; 3360 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 3361 val = tp->rx_opt.user_mss; 3362 if (tp->repair) 3363 val = tp->rx_opt.mss_clamp; 3364 break; 3365 case TCP_NODELAY: 3366 val = !!(tp->nonagle&TCP_NAGLE_OFF); 3367 break; 3368 case TCP_CORK: 3369 val = !!(tp->nonagle&TCP_NAGLE_CORK); 3370 break; 3371 case TCP_KEEPIDLE: 3372 val = keepalive_time_when(tp) / HZ; 3373 break; 3374 case TCP_KEEPINTVL: 3375 val = keepalive_intvl_when(tp) / HZ; 3376 break; 3377 case TCP_KEEPCNT: 3378 val = keepalive_probes(tp); 3379 break; 3380 case TCP_SYNCNT: 3381 val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; 3382 break; 3383 case TCP_LINGER2: 3384 val = tp->linger2; 3385 if (val >= 0) 3386 val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ; 3387 break; 3388 case TCP_DEFER_ACCEPT: 3389 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 3390 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 3391 break; 3392 case TCP_WINDOW_CLAMP: 3393 val = tp->window_clamp; 3394 break; 3395 case TCP_INFO: { 3396 struct tcp_info info; 3397 3398 if (get_user(len, optlen)) 3399 return -EFAULT; 3400 3401 tcp_get_info(sk, &info); 3402 3403 len = min_t(unsigned int, len, sizeof(info)); 3404 if (put_user(len, optlen)) 3405 return -EFAULT; 3406 if (copy_to_user(optval, &info, len)) 3407 return -EFAULT; 3408 return 0; 3409 } 3410 case TCP_CC_INFO: { 3411 const struct tcp_congestion_ops *ca_ops; 3412 union tcp_cc_info info; 3413 size_t sz = 0; 3414 int attr; 3415 3416 if (get_user(len, optlen)) 3417 return -EFAULT; 3418 3419 ca_ops = icsk->icsk_ca_ops; 3420 if (ca_ops && ca_ops->get_info) 3421 sz = ca_ops->get_info(sk, ~0U, &attr, &info); 3422 3423 len = min_t(unsigned int, len, sz); 3424 if (put_user(len, optlen)) 3425 return -EFAULT; 3426 if (copy_to_user(optval, &info, len)) 3427 return -EFAULT; 3428 return 0; 3429 } 3430 case TCP_QUICKACK: 3431 val = !inet_csk_in_pingpong_mode(sk); 3432 break; 3433 3434 case TCP_CONGESTION: 3435 if (get_user(len, optlen)) 3436 return -EFAULT; 3437 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 3438 if (put_user(len, optlen)) 3439 return -EFAULT; 3440 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 3441 return -EFAULT; 3442 return 0; 3443 3444 case TCP_ULP: 3445 if (get_user(len, optlen)) 3446 return -EFAULT; 3447 len = min_t(unsigned int, len, TCP_ULP_NAME_MAX); 3448 if (!icsk->icsk_ulp_ops) { 3449 if (put_user(0, optlen)) 3450 return -EFAULT; 3451 return 0; 3452 } 3453 if (put_user(len, optlen)) 3454 return -EFAULT; 3455 if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len)) 3456 return -EFAULT; 3457 return 0; 3458 3459 case TCP_FASTOPEN_KEY: { 3460 __u8 key[TCP_FASTOPEN_KEY_LENGTH]; 3461 struct tcp_fastopen_context *ctx; 3462 3463 if (get_user(len, optlen)) 3464 return -EFAULT; 3465 3466 rcu_read_lock(); 3467 ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx); 3468 if (ctx) 3469 memcpy(key, ctx->key, sizeof(key)); 3470 else 3471 len = 0; 3472 rcu_read_unlock(); 3473 3474 len = min_t(unsigned int, len, sizeof(key)); 3475 if (put_user(len, optlen)) 3476 return -EFAULT; 3477 if (copy_to_user(optval, key, len)) 3478 return -EFAULT; 3479 return 0; 3480 } 3481 case TCP_THIN_LINEAR_TIMEOUTS: 3482 val = tp->thin_lto; 3483 break; 3484 3485 case TCP_THIN_DUPACK: 3486 val = 0; 3487 break; 3488 3489 case TCP_REPAIR: 3490 val = tp->repair; 3491 break; 3492 3493 case TCP_REPAIR_QUEUE: 3494 if (tp->repair) 3495 val = tp->repair_queue; 3496 else 3497 return -EINVAL; 3498 break; 3499 3500 case TCP_REPAIR_WINDOW: { 3501 struct tcp_repair_window opt; 3502 3503 if (get_user(len, optlen)) 3504 return -EFAULT; 3505 3506 if (len != sizeof(opt)) 3507 return -EINVAL; 3508 3509 if (!tp->repair) 3510 return -EPERM; 3511 3512 opt.snd_wl1 = tp->snd_wl1; 3513 opt.snd_wnd = tp->snd_wnd; 3514 opt.max_window = tp->max_window; 3515 opt.rcv_wnd = tp->rcv_wnd; 3516 opt.rcv_wup = tp->rcv_wup; 3517 3518 if (copy_to_user(optval, &opt, len)) 3519 return -EFAULT; 3520 return 0; 3521 } 3522 case TCP_QUEUE_SEQ: 3523 if (tp->repair_queue == TCP_SEND_QUEUE) 3524 val = tp->write_seq; 3525 else if (tp->repair_queue == TCP_RECV_QUEUE) 3526 val = tp->rcv_nxt; 3527 else 3528 return -EINVAL; 3529 break; 3530 3531 case TCP_USER_TIMEOUT: 3532 val = icsk->icsk_user_timeout; 3533 break; 3534 3535 case TCP_FASTOPEN: 3536 val = icsk->icsk_accept_queue.fastopenq.max_qlen; 3537 break; 3538 3539 case TCP_FASTOPEN_CONNECT: 3540 val = tp->fastopen_connect; 3541 break; 3542 3543 case TCP_FASTOPEN_NO_COOKIE: 3544 val = tp->fastopen_no_cookie; 3545 break; 3546 3547 case TCP_TIMESTAMP: 3548 val = tcp_time_stamp_raw() + tp->tsoffset; 3549 break; 3550 case TCP_NOTSENT_LOWAT: 3551 val = tp->notsent_lowat; 3552 break; 3553 case TCP_INQ: 3554 val = tp->recvmsg_inq; 3555 break; 3556 case TCP_SAVE_SYN: 3557 val = tp->save_syn; 3558 break; 3559 case TCP_SAVED_SYN: { 3560 if (get_user(len, optlen)) 3561 return -EFAULT; 3562 3563 lock_sock(sk); 3564 if (tp->saved_syn) { 3565 if (len < tp->saved_syn[0]) { 3566 if (put_user(tp->saved_syn[0], optlen)) { 3567 release_sock(sk); 3568 return -EFAULT; 3569 } 3570 release_sock(sk); 3571 return -EINVAL; 3572 } 3573 len = tp->saved_syn[0]; 3574 if (put_user(len, optlen)) { 3575 release_sock(sk); 3576 return -EFAULT; 3577 } 3578 if (copy_to_user(optval, tp->saved_syn + 1, len)) { 3579 release_sock(sk); 3580 return -EFAULT; 3581 } 3582 tcp_saved_syn_free(tp); 3583 release_sock(sk); 3584 } else { 3585 release_sock(sk); 3586 len = 0; 3587 if (put_user(len, optlen)) 3588 return -EFAULT; 3589 } 3590 return 0; 3591 } 3592 #ifdef CONFIG_MMU 3593 case TCP_ZEROCOPY_RECEIVE: { 3594 struct tcp_zerocopy_receive zc; 3595 int err; 3596 3597 if (get_user(len, optlen)) 3598 return -EFAULT; 3599 if (len != sizeof(zc)) 3600 return -EINVAL; 3601 if (copy_from_user(&zc, optval, len)) 3602 return -EFAULT; 3603 lock_sock(sk); 3604 err = tcp_zerocopy_receive(sk, &zc); 3605 release_sock(sk); 3606 if (!err && copy_to_user(optval, &zc, len)) 3607 err = -EFAULT; 3608 return err; 3609 } 3610 #endif 3611 default: 3612 return -ENOPROTOOPT; 3613 } 3614 3615 if (put_user(len, optlen)) 3616 return -EFAULT; 3617 if (copy_to_user(optval, &val, len)) 3618 return -EFAULT; 3619 return 0; 3620 } 3621 3622 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 3623 int __user *optlen) 3624 { 3625 struct inet_connection_sock *icsk = inet_csk(sk); 3626 3627 if (level != SOL_TCP) 3628 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 3629 optval, optlen); 3630 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 3631 } 3632 EXPORT_SYMBOL(tcp_getsockopt); 3633 3634 #ifdef CONFIG_COMPAT 3635 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 3636 char __user *optval, int __user *optlen) 3637 { 3638 if (level != SOL_TCP) 3639 return inet_csk_compat_getsockopt(sk, level, optname, 3640 optval, optlen); 3641 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 3642 } 3643 EXPORT_SYMBOL(compat_tcp_getsockopt); 3644 #endif 3645 3646 #ifdef CONFIG_TCP_MD5SIG 3647 static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool); 3648 static DEFINE_MUTEX(tcp_md5sig_mutex); 3649 static bool tcp_md5sig_pool_populated = false; 3650 3651 static void __tcp_alloc_md5sig_pool(void) 3652 { 3653 struct crypto_ahash *hash; 3654 int cpu; 3655 3656 hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC); 3657 if (IS_ERR(hash)) 3658 return; 3659 3660 for_each_possible_cpu(cpu) { 3661 void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch; 3662 struct ahash_request *req; 3663 3664 if (!scratch) { 3665 scratch = kmalloc_node(sizeof(union tcp_md5sum_block) + 3666 sizeof(struct tcphdr), 3667 GFP_KERNEL, 3668 cpu_to_node(cpu)); 3669 if (!scratch) 3670 return; 3671 per_cpu(tcp_md5sig_pool, cpu).scratch = scratch; 3672 } 3673 if (per_cpu(tcp_md5sig_pool, cpu).md5_req) 3674 continue; 3675 3676 req = ahash_request_alloc(hash, GFP_KERNEL); 3677 if (!req) 3678 return; 3679 3680 ahash_request_set_callback(req, 0, NULL, NULL); 3681 3682 per_cpu(tcp_md5sig_pool, cpu).md5_req = req; 3683 } 3684 /* before setting tcp_md5sig_pool_populated, we must commit all writes 3685 * to memory. See smp_rmb() in tcp_get_md5sig_pool() 3686 */ 3687 smp_wmb(); 3688 tcp_md5sig_pool_populated = true; 3689 } 3690 3691 bool tcp_alloc_md5sig_pool(void) 3692 { 3693 if (unlikely(!tcp_md5sig_pool_populated)) { 3694 mutex_lock(&tcp_md5sig_mutex); 3695 3696 if (!tcp_md5sig_pool_populated) { 3697 __tcp_alloc_md5sig_pool(); 3698 if (tcp_md5sig_pool_populated) 3699 static_key_slow_inc(&tcp_md5_needed); 3700 } 3701 3702 mutex_unlock(&tcp_md5sig_mutex); 3703 } 3704 return tcp_md5sig_pool_populated; 3705 } 3706 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 3707 3708 3709 /** 3710 * tcp_get_md5sig_pool - get md5sig_pool for this user 3711 * 3712 * We use percpu structure, so if we succeed, we exit with preemption 3713 * and BH disabled, to make sure another thread or softirq handling 3714 * wont try to get same context. 3715 */ 3716 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 3717 { 3718 local_bh_disable(); 3719 3720 if (tcp_md5sig_pool_populated) { 3721 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */ 3722 smp_rmb(); 3723 return this_cpu_ptr(&tcp_md5sig_pool); 3724 } 3725 local_bh_enable(); 3726 return NULL; 3727 } 3728 EXPORT_SYMBOL(tcp_get_md5sig_pool); 3729 3730 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 3731 const struct sk_buff *skb, unsigned int header_len) 3732 { 3733 struct scatterlist sg; 3734 const struct tcphdr *tp = tcp_hdr(skb); 3735 struct ahash_request *req = hp->md5_req; 3736 unsigned int i; 3737 const unsigned int head_data_len = skb_headlen(skb) > header_len ? 3738 skb_headlen(skb) - header_len : 0; 3739 const struct skb_shared_info *shi = skb_shinfo(skb); 3740 struct sk_buff *frag_iter; 3741 3742 sg_init_table(&sg, 1); 3743 3744 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3745 ahash_request_set_crypt(req, &sg, NULL, head_data_len); 3746 if (crypto_ahash_update(req)) 3747 return 1; 3748 3749 for (i = 0; i < shi->nr_frags; ++i) { 3750 const struct skb_frag_struct *f = &shi->frags[i]; 3751 unsigned int offset = f->page_offset; 3752 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); 3753 3754 sg_set_page(&sg, page, skb_frag_size(f), 3755 offset_in_page(offset)); 3756 ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f)); 3757 if (crypto_ahash_update(req)) 3758 return 1; 3759 } 3760 3761 skb_walk_frags(skb, frag_iter) 3762 if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) 3763 return 1; 3764 3765 return 0; 3766 } 3767 EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3768 3769 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) 3770 { 3771 struct scatterlist sg; 3772 3773 sg_init_one(&sg, key->key, key->keylen); 3774 ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen); 3775 return crypto_ahash_update(hp->md5_req); 3776 } 3777 EXPORT_SYMBOL(tcp_md5_hash_key); 3778 3779 #endif 3780 3781 void tcp_done(struct sock *sk) 3782 { 3783 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 3784 3785 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3786 TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3787 3788 tcp_set_state(sk, TCP_CLOSE); 3789 tcp_clear_xmit_timers(sk); 3790 if (req) 3791 reqsk_fastopen_remove(sk, req, false); 3792 3793 sk->sk_shutdown = SHUTDOWN_MASK; 3794 3795 if (!sock_flag(sk, SOCK_DEAD)) 3796 sk->sk_state_change(sk); 3797 else 3798 inet_csk_destroy_sock(sk); 3799 } 3800 EXPORT_SYMBOL_GPL(tcp_done); 3801 3802 int tcp_abort(struct sock *sk, int err) 3803 { 3804 if (!sk_fullsock(sk)) { 3805 if (sk->sk_state == TCP_NEW_SYN_RECV) { 3806 struct request_sock *req = inet_reqsk(sk); 3807 3808 local_bh_disable(); 3809 inet_csk_reqsk_queue_drop(req->rsk_listener, req); 3810 local_bh_enable(); 3811 return 0; 3812 } 3813 return -EOPNOTSUPP; 3814 } 3815 3816 /* Don't race with userspace socket closes such as tcp_close. */ 3817 lock_sock(sk); 3818 3819 if (sk->sk_state == TCP_LISTEN) { 3820 tcp_set_state(sk, TCP_CLOSE); 3821 inet_csk_listen_stop(sk); 3822 } 3823 3824 /* Don't race with BH socket closes such as inet_csk_listen_stop. */ 3825 local_bh_disable(); 3826 bh_lock_sock(sk); 3827 3828 if (!sock_flag(sk, SOCK_DEAD)) { 3829 sk->sk_err = err; 3830 /* This barrier is coupled with smp_rmb() in tcp_poll() */ 3831 smp_wmb(); 3832 sk->sk_error_report(sk); 3833 if (tcp_need_reset(sk->sk_state)) 3834 tcp_send_active_reset(sk, GFP_ATOMIC); 3835 tcp_done(sk); 3836 } 3837 3838 bh_unlock_sock(sk); 3839 local_bh_enable(); 3840 tcp_write_queue_purge(sk); 3841 release_sock(sk); 3842 return 0; 3843 } 3844 EXPORT_SYMBOL_GPL(tcp_abort); 3845 3846 extern struct tcp_congestion_ops tcp_reno; 3847 3848 static __initdata unsigned long thash_entries; 3849 static int __init set_thash_entries(char *str) 3850 { 3851 ssize_t ret; 3852 3853 if (!str) 3854 return 0; 3855 3856 ret = kstrtoul(str, 0, &thash_entries); 3857 if (ret) 3858 return 0; 3859 3860 return 1; 3861 } 3862 __setup("thash_entries=", set_thash_entries); 3863 3864 static void __init tcp_init_mem(void) 3865 { 3866 unsigned long limit = nr_free_buffer_pages() / 16; 3867 3868 limit = max(limit, 128UL); 3869 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */ 3870 sysctl_tcp_mem[1] = limit; /* 6.25 % */ 3871 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */ 3872 } 3873 3874 void __init tcp_init(void) 3875 { 3876 int max_rshare, max_wshare, cnt; 3877 unsigned long limit; 3878 unsigned int i; 3879 3880 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > 3881 FIELD_SIZEOF(struct sk_buff, cb)); 3882 3883 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); 3884 percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); 3885 inet_hashinfo_init(&tcp_hashinfo); 3886 inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash", 3887 thash_entries, 21, /* one slot per 2 MB*/ 3888 0, 64 * 1024); 3889 tcp_hashinfo.bind_bucket_cachep = 3890 kmem_cache_create("tcp_bind_bucket", 3891 sizeof(struct inet_bind_bucket), 0, 3892 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3893 3894 /* Size and allocate the main established and bind bucket 3895 * hash tables. 3896 * 3897 * The methodology is similar to that of the buffer cache. 3898 */ 3899 tcp_hashinfo.ehash = 3900 alloc_large_system_hash("TCP established", 3901 sizeof(struct inet_ehash_bucket), 3902 thash_entries, 3903 17, /* one slot per 128 KB of memory */ 3904 0, 3905 NULL, 3906 &tcp_hashinfo.ehash_mask, 3907 0, 3908 thash_entries ? 0 : 512 * 1024); 3909 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) 3910 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3911 3912 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3913 panic("TCP: failed to alloc ehash_locks"); 3914 tcp_hashinfo.bhash = 3915 alloc_large_system_hash("TCP bind", 3916 sizeof(struct inet_bind_hashbucket), 3917 tcp_hashinfo.ehash_mask + 1, 3918 17, /* one slot per 128 KB of memory */ 3919 0, 3920 &tcp_hashinfo.bhash_size, 3921 NULL, 3922 0, 3923 64 * 1024); 3924 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; 3925 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3926 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3927 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3928 } 3929 3930 3931 cnt = tcp_hashinfo.ehash_mask + 1; 3932 sysctl_tcp_max_orphans = cnt / 2; 3933 3934 tcp_init_mem(); 3935 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3936 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); 3937 max_wshare = min(4UL*1024*1024, limit); 3938 max_rshare = min(6UL*1024*1024, limit); 3939 3940 init_net.ipv4.sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3941 init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024; 3942 init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare); 3943 3944 init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3945 init_net.ipv4.sysctl_tcp_rmem[1] = 131072; 3946 init_net.ipv4.sysctl_tcp_rmem[2] = max(131072, max_rshare); 3947 3948 pr_info("Hash tables configured (established %u bind %u)\n", 3949 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3950 3951 tcp_v4_init(); 3952 tcp_metrics_init(); 3953 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); 3954 tcp_tasklet_init(); 3955 } 3956