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/bootmem.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 /* 489 * Wait for a TCP event. 490 * 491 * Note that we don't need to lock the socket, as the upper poll layers 492 * take care of normal races (between the test and the event) and we don't 493 * go look at any of the socket buffers directly. 494 */ 495 __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 496 { 497 __poll_t mask; 498 struct sock *sk = sock->sk; 499 const struct tcp_sock *tp = tcp_sk(sk); 500 int state; 501 502 sock_poll_wait(file, sk_sleep(sk), wait); 503 504 state = inet_sk_state_load(sk); 505 if (state == TCP_LISTEN) 506 return inet_csk_listen_poll(sk); 507 508 /* Socket is not locked. We are protected from async events 509 * by poll logic and correct handling of state changes 510 * made by other threads is impossible in any case. 511 */ 512 513 mask = 0; 514 515 /* 516 * EPOLLHUP is certainly not done right. But poll() doesn't 517 * have a notion of HUP in just one direction, and for a 518 * socket the read side is more interesting. 519 * 520 * Some poll() documentation says that EPOLLHUP is incompatible 521 * with the EPOLLOUT/POLLWR flags, so somebody should check this 522 * all. But careful, it tends to be safer to return too many 523 * bits than too few, and you can easily break real applications 524 * if you don't tell them that something has hung up! 525 * 526 * Check-me. 527 * 528 * Check number 1. EPOLLHUP is _UNMASKABLE_ event (see UNIX98 and 529 * our fs/select.c). It means that after we received EOF, 530 * poll always returns immediately, making impossible poll() on write() 531 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP 532 * if and only if shutdown has been made in both directions. 533 * Actually, it is interesting to look how Solaris and DUX 534 * solve this dilemma. I would prefer, if EPOLLHUP were maskable, 535 * then we could set it on SND_SHUTDOWN. BTW examples given 536 * in Stevens' books assume exactly this behaviour, it explains 537 * why EPOLLHUP is incompatible with EPOLLOUT. --ANK 538 * 539 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 540 * blocking on fresh not-connected or disconnected socket. --ANK 541 */ 542 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE) 543 mask |= EPOLLHUP; 544 if (sk->sk_shutdown & RCV_SHUTDOWN) 545 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; 546 547 /* Connected or passive Fast Open socket? */ 548 if (state != TCP_SYN_SENT && 549 (state != TCP_SYN_RECV || tp->fastopen_rsk)) { 550 int target = sock_rcvlowat(sk, 0, INT_MAX); 551 552 if (tp->urg_seq == tp->copied_seq && 553 !sock_flag(sk, SOCK_URGINLINE) && 554 tp->urg_data) 555 target++; 556 557 if (tp->rcv_nxt - tp->copied_seq >= target) 558 mask |= EPOLLIN | EPOLLRDNORM; 559 560 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 561 if (sk_stream_is_writeable(sk)) { 562 mask |= EPOLLOUT | EPOLLWRNORM; 563 } else { /* send SIGIO later */ 564 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 565 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 566 567 /* Race breaker. If space is freed after 568 * wspace test but before the flags are set, 569 * IO signal will be lost. Memory barrier 570 * pairs with the input side. 571 */ 572 smp_mb__after_atomic(); 573 if (sk_stream_is_writeable(sk)) 574 mask |= EPOLLOUT | EPOLLWRNORM; 575 } 576 } else 577 mask |= EPOLLOUT | EPOLLWRNORM; 578 579 if (tp->urg_data & TCP_URG_VALID) 580 mask |= EPOLLPRI; 581 } else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) { 582 /* Active TCP fastopen socket with defer_connect 583 * Return EPOLLOUT so application can call write() 584 * in order for kernel to generate SYN+data 585 */ 586 mask |= EPOLLOUT | EPOLLWRNORM; 587 } 588 /* This barrier is coupled with smp_wmb() in tcp_reset() */ 589 smp_rmb(); 590 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) 591 mask |= EPOLLERR; 592 593 return mask; 594 } 595 EXPORT_SYMBOL(tcp_poll); 596 597 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 598 { 599 struct tcp_sock *tp = tcp_sk(sk); 600 int answ; 601 bool slow; 602 603 switch (cmd) { 604 case SIOCINQ: 605 if (sk->sk_state == TCP_LISTEN) 606 return -EINVAL; 607 608 slow = lock_sock_fast(sk); 609 answ = tcp_inq(sk); 610 unlock_sock_fast(sk, slow); 611 break; 612 case SIOCATMARK: 613 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 614 break; 615 case SIOCOUTQ: 616 if (sk->sk_state == TCP_LISTEN) 617 return -EINVAL; 618 619 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 620 answ = 0; 621 else 622 answ = tp->write_seq - tp->snd_una; 623 break; 624 case SIOCOUTQNSD: 625 if (sk->sk_state == TCP_LISTEN) 626 return -EINVAL; 627 628 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 629 answ = 0; 630 else 631 answ = tp->write_seq - tp->snd_nxt; 632 break; 633 default: 634 return -ENOIOCTLCMD; 635 } 636 637 return put_user(answ, (int __user *)arg); 638 } 639 EXPORT_SYMBOL(tcp_ioctl); 640 641 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 642 { 643 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; 644 tp->pushed_seq = tp->write_seq; 645 } 646 647 static inline bool forced_push(const struct tcp_sock *tp) 648 { 649 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 650 } 651 652 static void skb_entail(struct sock *sk, struct sk_buff *skb) 653 { 654 struct tcp_sock *tp = tcp_sk(sk); 655 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 656 657 skb->csum = 0; 658 tcb->seq = tcb->end_seq = tp->write_seq; 659 tcb->tcp_flags = TCPHDR_ACK; 660 tcb->sacked = 0; 661 __skb_header_release(skb); 662 tcp_add_write_queue_tail(sk, skb); 663 sk->sk_wmem_queued += skb->truesize; 664 sk_mem_charge(sk, skb->truesize); 665 if (tp->nonagle & TCP_NAGLE_PUSH) 666 tp->nonagle &= ~TCP_NAGLE_PUSH; 667 668 tcp_slow_start_after_idle_check(sk); 669 } 670 671 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) 672 { 673 if (flags & MSG_OOB) 674 tp->snd_up = tp->write_seq; 675 } 676 677 /* If a not yet filled skb is pushed, do not send it if 678 * we have data packets in Qdisc or NIC queues : 679 * Because TX completion will happen shortly, it gives a chance 680 * to coalesce future sendmsg() payload into this skb, without 681 * need for a timer, and with no latency trade off. 682 * As packets containing data payload have a bigger truesize 683 * than pure acks (dataless) packets, the last checks prevent 684 * autocorking if we only have an ACK in Qdisc/NIC queues, 685 * or if TX completion was delayed after we processed ACK packet. 686 */ 687 static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, 688 int size_goal) 689 { 690 return skb->len < size_goal && 691 sock_net(sk)->ipv4.sysctl_tcp_autocorking && 692 skb != tcp_write_queue_head(sk) && 693 refcount_read(&sk->sk_wmem_alloc) > skb->truesize; 694 } 695 696 static void tcp_push(struct sock *sk, int flags, int mss_now, 697 int nonagle, int size_goal) 698 { 699 struct tcp_sock *tp = tcp_sk(sk); 700 struct sk_buff *skb; 701 702 skb = tcp_write_queue_tail(sk); 703 if (!skb) 704 return; 705 if (!(flags & MSG_MORE) || forced_push(tp)) 706 tcp_mark_push(tp, skb); 707 708 tcp_mark_urg(tp, flags); 709 710 if (tcp_should_autocork(sk, skb, size_goal)) { 711 712 /* avoid atomic op if TSQ_THROTTLED bit is already set */ 713 if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) { 714 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); 715 set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags); 716 } 717 /* It is possible TX completion already happened 718 * before we set TSQ_THROTTLED. 719 */ 720 if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize) 721 return; 722 } 723 724 if (flags & MSG_MORE) 725 nonagle = TCP_NAGLE_CORK; 726 727 __tcp_push_pending_frames(sk, mss_now, nonagle); 728 } 729 730 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 731 unsigned int offset, size_t len) 732 { 733 struct tcp_splice_state *tss = rd_desc->arg.data; 734 int ret; 735 736 ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe, 737 min(rd_desc->count, len), tss->flags); 738 if (ret > 0) 739 rd_desc->count -= ret; 740 return ret; 741 } 742 743 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 744 { 745 /* Store TCP splice context information in read_descriptor_t. */ 746 read_descriptor_t rd_desc = { 747 .arg.data = tss, 748 .count = tss->len, 749 }; 750 751 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 752 } 753 754 /** 755 * tcp_splice_read - splice data from TCP socket to a pipe 756 * @sock: socket to splice from 757 * @ppos: position (not valid) 758 * @pipe: pipe to splice to 759 * @len: number of bytes to splice 760 * @flags: splice modifier flags 761 * 762 * Description: 763 * Will read pages from given socket and fill them into a pipe. 764 * 765 **/ 766 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 767 struct pipe_inode_info *pipe, size_t len, 768 unsigned int flags) 769 { 770 struct sock *sk = sock->sk; 771 struct tcp_splice_state tss = { 772 .pipe = pipe, 773 .len = len, 774 .flags = flags, 775 }; 776 long timeo; 777 ssize_t spliced; 778 int ret; 779 780 sock_rps_record_flow(sk); 781 /* 782 * We can't seek on a socket input 783 */ 784 if (unlikely(*ppos)) 785 return -ESPIPE; 786 787 ret = spliced = 0; 788 789 lock_sock(sk); 790 791 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 792 while (tss.len) { 793 ret = __tcp_splice_read(sk, &tss); 794 if (ret < 0) 795 break; 796 else if (!ret) { 797 if (spliced) 798 break; 799 if (sock_flag(sk, SOCK_DONE)) 800 break; 801 if (sk->sk_err) { 802 ret = sock_error(sk); 803 break; 804 } 805 if (sk->sk_shutdown & RCV_SHUTDOWN) 806 break; 807 if (sk->sk_state == TCP_CLOSE) { 808 /* 809 * This occurs when user tries to read 810 * from never connected socket. 811 */ 812 if (!sock_flag(sk, SOCK_DONE)) 813 ret = -ENOTCONN; 814 break; 815 } 816 if (!timeo) { 817 ret = -EAGAIN; 818 break; 819 } 820 /* if __tcp_splice_read() got nothing while we have 821 * an skb in receive queue, we do not want to loop. 822 * This might happen with URG data. 823 */ 824 if (!skb_queue_empty(&sk->sk_receive_queue)) 825 break; 826 sk_wait_data(sk, &timeo, NULL); 827 if (signal_pending(current)) { 828 ret = sock_intr_errno(timeo); 829 break; 830 } 831 continue; 832 } 833 tss.len -= ret; 834 spliced += ret; 835 836 if (!timeo) 837 break; 838 release_sock(sk); 839 lock_sock(sk); 840 841 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 842 (sk->sk_shutdown & RCV_SHUTDOWN) || 843 signal_pending(current)) 844 break; 845 } 846 847 release_sock(sk); 848 849 if (spliced) 850 return spliced; 851 852 return ret; 853 } 854 EXPORT_SYMBOL(tcp_splice_read); 855 856 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, 857 bool force_schedule) 858 { 859 struct sk_buff *skb; 860 861 /* The TCP header must be at least 32-bit aligned. */ 862 size = ALIGN(size, 4); 863 864 if (unlikely(tcp_under_memory_pressure(sk))) 865 sk_mem_reclaim_partial(sk); 866 867 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 868 if (likely(skb)) { 869 bool mem_scheduled; 870 871 if (force_schedule) { 872 mem_scheduled = true; 873 sk_forced_mem_schedule(sk, skb->truesize); 874 } else { 875 mem_scheduled = sk_wmem_schedule(sk, skb->truesize); 876 } 877 if (likely(mem_scheduled)) { 878 skb_reserve(skb, sk->sk_prot->max_header); 879 /* 880 * Make sure that we have exactly size bytes 881 * available to the caller, no more, no less. 882 */ 883 skb->reserved_tailroom = skb->end - skb->tail - size; 884 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); 885 return skb; 886 } 887 __kfree_skb(skb); 888 } else { 889 sk->sk_prot->enter_memory_pressure(sk); 890 sk_stream_moderate_sndbuf(sk); 891 } 892 return NULL; 893 } 894 895 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 896 int large_allowed) 897 { 898 struct tcp_sock *tp = tcp_sk(sk); 899 u32 new_size_goal, size_goal; 900 901 if (!large_allowed) 902 return mss_now; 903 904 /* Note : tcp_tso_autosize() will eventually split this later */ 905 new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER; 906 new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal); 907 908 /* We try hard to avoid divides here */ 909 size_goal = tp->gso_segs * mss_now; 910 if (unlikely(new_size_goal < size_goal || 911 new_size_goal >= size_goal + mss_now)) { 912 tp->gso_segs = min_t(u16, new_size_goal / mss_now, 913 sk->sk_gso_max_segs); 914 size_goal = tp->gso_segs * mss_now; 915 } 916 917 return max(size_goal, mss_now); 918 } 919 920 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 921 { 922 int mss_now; 923 924 mss_now = tcp_current_mss(sk); 925 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 926 927 return mss_now; 928 } 929 930 ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, 931 size_t size, int flags) 932 { 933 struct tcp_sock *tp = tcp_sk(sk); 934 int mss_now, size_goal; 935 int err; 936 ssize_t copied; 937 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 938 939 /* Wait for a connection to finish. One exception is TCP Fast Open 940 * (passive side) where data is allowed to be sent before a connection 941 * is fully established. 942 */ 943 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && 944 !tcp_passive_fastopen(sk)) { 945 err = sk_stream_wait_connect(sk, &timeo); 946 if (err != 0) 947 goto out_err; 948 } 949 950 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 951 952 mss_now = tcp_send_mss(sk, &size_goal, flags); 953 copied = 0; 954 955 err = -EPIPE; 956 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 957 goto out_err; 958 959 while (size > 0) { 960 struct sk_buff *skb = tcp_write_queue_tail(sk); 961 int copy, i; 962 bool can_coalesce; 963 964 if (!skb || (copy = size_goal - skb->len) <= 0 || 965 !tcp_skb_can_collapse_to(skb)) { 966 new_segment: 967 if (!sk_stream_memory_free(sk)) 968 goto wait_for_sndbuf; 969 970 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, 971 tcp_rtx_and_write_queues_empty(sk)); 972 if (!skb) 973 goto wait_for_memory; 974 975 skb_entail(sk, skb); 976 copy = size_goal; 977 } 978 979 if (copy > size) 980 copy = size; 981 982 i = skb_shinfo(skb)->nr_frags; 983 can_coalesce = skb_can_coalesce(skb, i, page, offset); 984 if (!can_coalesce && i >= sysctl_max_skb_frags) { 985 tcp_mark_push(tp, skb); 986 goto new_segment; 987 } 988 if (!sk_wmem_schedule(sk, copy)) 989 goto wait_for_memory; 990 991 if (can_coalesce) { 992 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 993 } else { 994 get_page(page); 995 skb_fill_page_desc(skb, i, page, offset, copy); 996 } 997 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 998 999 skb->len += copy; 1000 skb->data_len += copy; 1001 skb->truesize += copy; 1002 sk->sk_wmem_queued += copy; 1003 sk_mem_charge(sk, copy); 1004 skb->ip_summed = CHECKSUM_PARTIAL; 1005 tp->write_seq += copy; 1006 TCP_SKB_CB(skb)->end_seq += copy; 1007 tcp_skb_pcount_set(skb, 0); 1008 1009 if (!copied) 1010 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1011 1012 copied += copy; 1013 offset += copy; 1014 size -= copy; 1015 if (!size) 1016 goto out; 1017 1018 if (skb->len < size_goal || (flags & MSG_OOB)) 1019 continue; 1020 1021 if (forced_push(tp)) { 1022 tcp_mark_push(tp, skb); 1023 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1024 } else if (skb == tcp_send_head(sk)) 1025 tcp_push_one(sk, mss_now); 1026 continue; 1027 1028 wait_for_sndbuf: 1029 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1030 wait_for_memory: 1031 tcp_push(sk, flags & ~MSG_MORE, mss_now, 1032 TCP_NAGLE_PUSH, size_goal); 1033 1034 err = sk_stream_wait_memory(sk, &timeo); 1035 if (err != 0) 1036 goto do_error; 1037 1038 mss_now = tcp_send_mss(sk, &size_goal, flags); 1039 } 1040 1041 out: 1042 if (copied) { 1043 tcp_tx_timestamp(sk, sk->sk_tsflags); 1044 if (!(flags & MSG_SENDPAGE_NOTLAST)) 1045 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); 1046 } 1047 return copied; 1048 1049 do_error: 1050 if (copied) 1051 goto out; 1052 out_err: 1053 /* make sure we wake any epoll edge trigger waiter */ 1054 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && 1055 err == -EAGAIN)) { 1056 sk->sk_write_space(sk); 1057 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); 1058 } 1059 return sk_stream_error(sk, flags, err); 1060 } 1061 EXPORT_SYMBOL_GPL(do_tcp_sendpages); 1062 1063 int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset, 1064 size_t size, int flags) 1065 { 1066 if (!(sk->sk_route_caps & NETIF_F_SG)) 1067 return sock_no_sendpage_locked(sk, page, offset, size, flags); 1068 1069 tcp_rate_check_app_limited(sk); /* is sending application-limited? */ 1070 1071 return do_tcp_sendpages(sk, page, offset, size, flags); 1072 } 1073 EXPORT_SYMBOL_GPL(tcp_sendpage_locked); 1074 1075 int tcp_sendpage(struct sock *sk, struct page *page, int offset, 1076 size_t size, int flags) 1077 { 1078 int ret; 1079 1080 lock_sock(sk); 1081 ret = tcp_sendpage_locked(sk, page, offset, size, flags); 1082 release_sock(sk); 1083 1084 return ret; 1085 } 1086 EXPORT_SYMBOL(tcp_sendpage); 1087 1088 /* Do not bother using a page frag for very small frames. 1089 * But use this heuristic only for the first skb in write queue. 1090 * 1091 * Having no payload in skb->head allows better SACK shifting 1092 * in tcp_shift_skb_data(), reducing sack/rack overhead, because 1093 * write queue has less skbs. 1094 * Each skb can hold up to MAX_SKB_FRAGS * 32Kbytes, or ~0.5 MB. 1095 * This also speeds up tso_fragment(), since it wont fallback 1096 * to tcp_fragment(). 1097 */ 1098 static int linear_payload_sz(bool first_skb) 1099 { 1100 if (first_skb) 1101 return SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); 1102 return 0; 1103 } 1104 1105 static int select_size(bool first_skb, bool zc) 1106 { 1107 if (zc) 1108 return 0; 1109 return linear_payload_sz(first_skb); 1110 } 1111 1112 void tcp_free_fastopen_req(struct tcp_sock *tp) 1113 { 1114 if (tp->fastopen_req) { 1115 kfree(tp->fastopen_req); 1116 tp->fastopen_req = NULL; 1117 } 1118 } 1119 1120 static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, 1121 int *copied, size_t size) 1122 { 1123 struct tcp_sock *tp = tcp_sk(sk); 1124 struct inet_sock *inet = inet_sk(sk); 1125 struct sockaddr *uaddr = msg->msg_name; 1126 int err, flags; 1127 1128 if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) || 1129 (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) && 1130 uaddr->sa_family == AF_UNSPEC)) 1131 return -EOPNOTSUPP; 1132 if (tp->fastopen_req) 1133 return -EALREADY; /* Another Fast Open is in progress */ 1134 1135 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), 1136 sk->sk_allocation); 1137 if (unlikely(!tp->fastopen_req)) 1138 return -ENOBUFS; 1139 tp->fastopen_req->data = msg; 1140 tp->fastopen_req->size = size; 1141 1142 if (inet->defer_connect) { 1143 err = tcp_connect(sk); 1144 /* Same failure procedure as in tcp_v4/6_connect */ 1145 if (err) { 1146 tcp_set_state(sk, TCP_CLOSE); 1147 inet->inet_dport = 0; 1148 sk->sk_route_caps = 0; 1149 } 1150 } 1151 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; 1152 err = __inet_stream_connect(sk->sk_socket, uaddr, 1153 msg->msg_namelen, flags, 1); 1154 /* fastopen_req could already be freed in __inet_stream_connect 1155 * if the connection times out or gets rst 1156 */ 1157 if (tp->fastopen_req) { 1158 *copied = tp->fastopen_req->copied; 1159 tcp_free_fastopen_req(tp); 1160 inet->defer_connect = 0; 1161 } 1162 return err; 1163 } 1164 1165 int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) 1166 { 1167 struct tcp_sock *tp = tcp_sk(sk); 1168 struct ubuf_info *uarg = NULL; 1169 struct sk_buff *skb; 1170 struct sockcm_cookie sockc; 1171 int flags, err, copied = 0; 1172 int mss_now = 0, size_goal, copied_syn = 0; 1173 bool process_backlog = false; 1174 bool zc = false; 1175 long timeo; 1176 1177 flags = msg->msg_flags; 1178 1179 if (flags & MSG_ZEROCOPY && size) { 1180 if (sk->sk_state != TCP_ESTABLISHED) { 1181 err = -EINVAL; 1182 goto out_err; 1183 } 1184 1185 skb = tcp_write_queue_tail(sk); 1186 uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb)); 1187 if (!uarg) { 1188 err = -ENOBUFS; 1189 goto out_err; 1190 } 1191 1192 zc = sk->sk_route_caps & NETIF_F_SG; 1193 if (!zc) 1194 uarg->zerocopy = 0; 1195 } 1196 1197 if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect)) { 1198 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size); 1199 if (err == -EINPROGRESS && copied_syn > 0) 1200 goto out; 1201 else if (err) 1202 goto out_err; 1203 } 1204 1205 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 1206 1207 tcp_rate_check_app_limited(sk); /* is sending application-limited? */ 1208 1209 /* Wait for a connection to finish. One exception is TCP Fast Open 1210 * (passive side) where data is allowed to be sent before a connection 1211 * is fully established. 1212 */ 1213 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && 1214 !tcp_passive_fastopen(sk)) { 1215 err = sk_stream_wait_connect(sk, &timeo); 1216 if (err != 0) 1217 goto do_error; 1218 } 1219 1220 if (unlikely(tp->repair)) { 1221 if (tp->repair_queue == TCP_RECV_QUEUE) { 1222 copied = tcp_send_rcvq(sk, msg, size); 1223 goto out_nopush; 1224 } 1225 1226 err = -EINVAL; 1227 if (tp->repair_queue == TCP_NO_QUEUE) 1228 goto out_err; 1229 1230 /* 'common' sending to sendq */ 1231 } 1232 1233 sockc.tsflags = sk->sk_tsflags; 1234 if (msg->msg_controllen) { 1235 err = sock_cmsg_send(sk, msg, &sockc); 1236 if (unlikely(err)) { 1237 err = -EINVAL; 1238 goto out_err; 1239 } 1240 } 1241 1242 /* This should be in poll */ 1243 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 1244 1245 /* Ok commence sending. */ 1246 copied = 0; 1247 1248 restart: 1249 mss_now = tcp_send_mss(sk, &size_goal, flags); 1250 1251 err = -EPIPE; 1252 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 1253 goto do_error; 1254 1255 while (msg_data_left(msg)) { 1256 int copy = 0; 1257 1258 skb = tcp_write_queue_tail(sk); 1259 if (skb) 1260 copy = size_goal - skb->len; 1261 1262 if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) { 1263 bool first_skb; 1264 int linear; 1265 1266 new_segment: 1267 /* Allocate new segment. If the interface is SG, 1268 * allocate skb fitting to single page. 1269 */ 1270 if (!sk_stream_memory_free(sk)) 1271 goto wait_for_sndbuf; 1272 1273 if (process_backlog && sk_flush_backlog(sk)) { 1274 process_backlog = false; 1275 goto restart; 1276 } 1277 first_skb = tcp_rtx_and_write_queues_empty(sk); 1278 linear = select_size(first_skb, zc); 1279 skb = sk_stream_alloc_skb(sk, linear, sk->sk_allocation, 1280 first_skb); 1281 if (!skb) 1282 goto wait_for_memory; 1283 1284 process_backlog = true; 1285 skb->ip_summed = CHECKSUM_PARTIAL; 1286 1287 skb_entail(sk, skb); 1288 copy = size_goal; 1289 1290 /* All packets are restored as if they have 1291 * already been sent. skb_mstamp isn't set to 1292 * avoid wrong rtt estimation. 1293 */ 1294 if (tp->repair) 1295 TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED; 1296 } 1297 1298 /* Try to append data to the end of skb. */ 1299 if (copy > msg_data_left(msg)) 1300 copy = msg_data_left(msg); 1301 1302 /* Where to copy to? */ 1303 if (skb_availroom(skb) > 0 && !zc) { 1304 /* We have some space in skb head. Superb! */ 1305 copy = min_t(int, copy, skb_availroom(skb)); 1306 err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy); 1307 if (err) 1308 goto do_fault; 1309 } else if (!zc) { 1310 bool merge = true; 1311 int i = skb_shinfo(skb)->nr_frags; 1312 struct page_frag *pfrag = sk_page_frag(sk); 1313 1314 if (!sk_page_frag_refill(sk, pfrag)) 1315 goto wait_for_memory; 1316 1317 if (!skb_can_coalesce(skb, i, pfrag->page, 1318 pfrag->offset)) { 1319 if (i >= sysctl_max_skb_frags) { 1320 tcp_mark_push(tp, skb); 1321 goto new_segment; 1322 } 1323 merge = false; 1324 } 1325 1326 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1327 1328 if (!sk_wmem_schedule(sk, copy)) 1329 goto wait_for_memory; 1330 1331 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, 1332 pfrag->page, 1333 pfrag->offset, 1334 copy); 1335 if (err) 1336 goto do_error; 1337 1338 /* Update the skb. */ 1339 if (merge) { 1340 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1341 } else { 1342 skb_fill_page_desc(skb, i, pfrag->page, 1343 pfrag->offset, copy); 1344 page_ref_inc(pfrag->page); 1345 } 1346 pfrag->offset += copy; 1347 } else { 1348 err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg); 1349 if (err == -EMSGSIZE || err == -EEXIST) { 1350 tcp_mark_push(tp, skb); 1351 goto new_segment; 1352 } 1353 if (err < 0) 1354 goto do_error; 1355 copy = err; 1356 } 1357 1358 if (!copied) 1359 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1360 1361 tp->write_seq += copy; 1362 TCP_SKB_CB(skb)->end_seq += copy; 1363 tcp_skb_pcount_set(skb, 0); 1364 1365 copied += copy; 1366 if (!msg_data_left(msg)) { 1367 if (unlikely(flags & MSG_EOR)) 1368 TCP_SKB_CB(skb)->eor = 1; 1369 goto out; 1370 } 1371 1372 if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair)) 1373 continue; 1374 1375 if (forced_push(tp)) { 1376 tcp_mark_push(tp, skb); 1377 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1378 } else if (skb == tcp_send_head(sk)) 1379 tcp_push_one(sk, mss_now); 1380 continue; 1381 1382 wait_for_sndbuf: 1383 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1384 wait_for_memory: 1385 if (copied) 1386 tcp_push(sk, flags & ~MSG_MORE, mss_now, 1387 TCP_NAGLE_PUSH, size_goal); 1388 1389 err = sk_stream_wait_memory(sk, &timeo); 1390 if (err != 0) 1391 goto do_error; 1392 1393 mss_now = tcp_send_mss(sk, &size_goal, flags); 1394 } 1395 1396 out: 1397 if (copied) { 1398 tcp_tx_timestamp(sk, sockc.tsflags); 1399 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); 1400 } 1401 out_nopush: 1402 sock_zerocopy_put(uarg); 1403 return copied + copied_syn; 1404 1405 do_fault: 1406 if (!skb->len) { 1407 tcp_unlink_write_queue(skb, sk); 1408 /* It is the one place in all of TCP, except connection 1409 * reset, where we can be unlinking the send_head. 1410 */ 1411 tcp_check_send_head(sk, skb); 1412 sk_wmem_free_skb(sk, skb); 1413 } 1414 1415 do_error: 1416 if (copied + copied_syn) 1417 goto out; 1418 out_err: 1419 sock_zerocopy_put_abort(uarg); 1420 err = sk_stream_error(sk, flags, err); 1421 /* make sure we wake any epoll edge trigger waiter */ 1422 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && 1423 err == -EAGAIN)) { 1424 sk->sk_write_space(sk); 1425 tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); 1426 } 1427 return err; 1428 } 1429 EXPORT_SYMBOL_GPL(tcp_sendmsg_locked); 1430 1431 int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) 1432 { 1433 int ret; 1434 1435 lock_sock(sk); 1436 ret = tcp_sendmsg_locked(sk, msg, size); 1437 release_sock(sk); 1438 1439 return ret; 1440 } 1441 EXPORT_SYMBOL(tcp_sendmsg); 1442 1443 /* 1444 * Handle reading urgent data. BSD has very simple semantics for 1445 * this, no blocking and very strange errors 8) 1446 */ 1447 1448 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1449 { 1450 struct tcp_sock *tp = tcp_sk(sk); 1451 1452 /* No URG data to read. */ 1453 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1454 tp->urg_data == TCP_URG_READ) 1455 return -EINVAL; /* Yes this is right ! */ 1456 1457 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1458 return -ENOTCONN; 1459 1460 if (tp->urg_data & TCP_URG_VALID) { 1461 int err = 0; 1462 char c = tp->urg_data; 1463 1464 if (!(flags & MSG_PEEK)) 1465 tp->urg_data = TCP_URG_READ; 1466 1467 /* Read urgent data. */ 1468 msg->msg_flags |= MSG_OOB; 1469 1470 if (len > 0) { 1471 if (!(flags & MSG_TRUNC)) 1472 err = memcpy_to_msg(msg, &c, 1); 1473 len = 1; 1474 } else 1475 msg->msg_flags |= MSG_TRUNC; 1476 1477 return err ? -EFAULT : len; 1478 } 1479 1480 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1481 return 0; 1482 1483 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1484 * the available implementations agree in this case: 1485 * this call should never block, independent of the 1486 * blocking state of the socket. 1487 * Mike <pall@rz.uni-karlsruhe.de> 1488 */ 1489 return -EAGAIN; 1490 } 1491 1492 static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len) 1493 { 1494 struct sk_buff *skb; 1495 int copied = 0, err = 0; 1496 1497 /* XXX -- need to support SO_PEEK_OFF */ 1498 1499 skb_rbtree_walk(skb, &sk->tcp_rtx_queue) { 1500 err = skb_copy_datagram_msg(skb, 0, msg, skb->len); 1501 if (err) 1502 return err; 1503 copied += skb->len; 1504 } 1505 1506 skb_queue_walk(&sk->sk_write_queue, skb) { 1507 err = skb_copy_datagram_msg(skb, 0, msg, skb->len); 1508 if (err) 1509 break; 1510 1511 copied += skb->len; 1512 } 1513 1514 return err ?: copied; 1515 } 1516 1517 /* Clean up the receive buffer for full frames taken by the user, 1518 * then send an ACK if necessary. COPIED is the number of bytes 1519 * tcp_recvmsg has given to the user so far, it speeds up the 1520 * calculation of whether or not we must ACK for the sake of 1521 * a window update. 1522 */ 1523 static void tcp_cleanup_rbuf(struct sock *sk, int copied) 1524 { 1525 struct tcp_sock *tp = tcp_sk(sk); 1526 bool time_to_ack = false; 1527 1528 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1529 1530 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1531 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1532 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1533 1534 if (inet_csk_ack_scheduled(sk)) { 1535 const struct inet_connection_sock *icsk = inet_csk(sk); 1536 /* Delayed ACKs frequently hit locked sockets during bulk 1537 * receive. */ 1538 if (icsk->icsk_ack.blocked || 1539 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1540 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1541 /* 1542 * If this read emptied read buffer, we send ACK, if 1543 * connection is not bidirectional, user drained 1544 * receive buffer and there was a small segment 1545 * in queue. 1546 */ 1547 (copied > 0 && 1548 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1549 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1550 !icsk->icsk_ack.pingpong)) && 1551 !atomic_read(&sk->sk_rmem_alloc))) 1552 time_to_ack = true; 1553 } 1554 1555 /* We send an ACK if we can now advertise a non-zero window 1556 * which has been raised "significantly". 1557 * 1558 * Even if window raised up to infinity, do not send window open ACK 1559 * in states, where we will not receive more. It is useless. 1560 */ 1561 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1562 __u32 rcv_window_now = tcp_receive_window(tp); 1563 1564 /* Optimize, __tcp_select_window() is not cheap. */ 1565 if (2*rcv_window_now <= tp->window_clamp) { 1566 __u32 new_window = __tcp_select_window(sk); 1567 1568 /* Send ACK now, if this read freed lots of space 1569 * in our buffer. Certainly, new_window is new window. 1570 * We can advertise it now, if it is not less than current one. 1571 * "Lots" means "at least twice" here. 1572 */ 1573 if (new_window && new_window >= 2 * rcv_window_now) 1574 time_to_ack = true; 1575 } 1576 } 1577 if (time_to_ack) 1578 tcp_send_ack(sk); 1579 } 1580 1581 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1582 { 1583 struct sk_buff *skb; 1584 u32 offset; 1585 1586 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { 1587 offset = seq - TCP_SKB_CB(skb)->seq; 1588 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { 1589 pr_err_once("%s: found a SYN, please report !\n", __func__); 1590 offset--; 1591 } 1592 if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) { 1593 *off = offset; 1594 return skb; 1595 } 1596 /* This looks weird, but this can happen if TCP collapsing 1597 * splitted a fat GRO packet, while we released socket lock 1598 * in skb_splice_bits() 1599 */ 1600 sk_eat_skb(sk, skb); 1601 } 1602 return NULL; 1603 } 1604 1605 /* 1606 * This routine provides an alternative to tcp_recvmsg() for routines 1607 * that would like to handle copying from skbuffs directly in 'sendfile' 1608 * fashion. 1609 * Note: 1610 * - It is assumed that the socket was locked by the caller. 1611 * - The routine does not block. 1612 * - At present, there is no support for reading OOB data 1613 * or for 'peeking' the socket using this routine 1614 * (although both would be easy to implement). 1615 */ 1616 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1617 sk_read_actor_t recv_actor) 1618 { 1619 struct sk_buff *skb; 1620 struct tcp_sock *tp = tcp_sk(sk); 1621 u32 seq = tp->copied_seq; 1622 u32 offset; 1623 int copied = 0; 1624 1625 if (sk->sk_state == TCP_LISTEN) 1626 return -ENOTCONN; 1627 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1628 if (offset < skb->len) { 1629 int used; 1630 size_t len; 1631 1632 len = skb->len - offset; 1633 /* Stop reading if we hit a patch of urgent data */ 1634 if (tp->urg_data) { 1635 u32 urg_offset = tp->urg_seq - seq; 1636 if (urg_offset < len) 1637 len = urg_offset; 1638 if (!len) 1639 break; 1640 } 1641 used = recv_actor(desc, skb, offset, len); 1642 if (used <= 0) { 1643 if (!copied) 1644 copied = used; 1645 break; 1646 } else if (used <= len) { 1647 seq += used; 1648 copied += used; 1649 offset += used; 1650 } 1651 /* If recv_actor drops the lock (e.g. TCP splice 1652 * receive) the skb pointer might be invalid when 1653 * getting here: tcp_collapse might have deleted it 1654 * while aggregating skbs from the socket queue. 1655 */ 1656 skb = tcp_recv_skb(sk, seq - 1, &offset); 1657 if (!skb) 1658 break; 1659 /* TCP coalescing might have appended data to the skb. 1660 * Try to splice more frags 1661 */ 1662 if (offset + 1 != skb->len) 1663 continue; 1664 } 1665 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) { 1666 sk_eat_skb(sk, skb); 1667 ++seq; 1668 break; 1669 } 1670 sk_eat_skb(sk, skb); 1671 if (!desc->count) 1672 break; 1673 tp->copied_seq = seq; 1674 } 1675 tp->copied_seq = seq; 1676 1677 tcp_rcv_space_adjust(sk); 1678 1679 /* Clean up data we have read: This will do ACK frames. */ 1680 if (copied > 0) { 1681 tcp_recv_skb(sk, seq, &offset); 1682 tcp_cleanup_rbuf(sk, copied); 1683 } 1684 return copied; 1685 } 1686 EXPORT_SYMBOL(tcp_read_sock); 1687 1688 int tcp_peek_len(struct socket *sock) 1689 { 1690 return tcp_inq(sock->sk); 1691 } 1692 EXPORT_SYMBOL(tcp_peek_len); 1693 1694 static void tcp_update_recv_tstamps(struct sk_buff *skb, 1695 struct scm_timestamping *tss) 1696 { 1697 if (skb->tstamp) 1698 tss->ts[0] = ktime_to_timespec(skb->tstamp); 1699 else 1700 tss->ts[0] = (struct timespec) {0}; 1701 1702 if (skb_hwtstamps(skb)->hwtstamp) 1703 tss->ts[2] = ktime_to_timespec(skb_hwtstamps(skb)->hwtstamp); 1704 else 1705 tss->ts[2] = (struct timespec) {0}; 1706 } 1707 1708 /* Similar to __sock_recv_timestamp, but does not require an skb */ 1709 static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, 1710 struct scm_timestamping *tss) 1711 { 1712 struct timeval tv; 1713 bool has_timestamping = false; 1714 1715 if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) { 1716 if (sock_flag(sk, SOCK_RCVTSTAMP)) { 1717 if (sock_flag(sk, SOCK_RCVTSTAMPNS)) { 1718 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS, 1719 sizeof(tss->ts[0]), &tss->ts[0]); 1720 } else { 1721 tv.tv_sec = tss->ts[0].tv_sec; 1722 tv.tv_usec = tss->ts[0].tv_nsec / 1000; 1723 1724 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP, 1725 sizeof(tv), &tv); 1726 } 1727 } 1728 1729 if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) 1730 has_timestamping = true; 1731 else 1732 tss->ts[0] = (struct timespec) {0}; 1733 } 1734 1735 if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) { 1736 if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) 1737 has_timestamping = true; 1738 else 1739 tss->ts[2] = (struct timespec) {0}; 1740 } 1741 1742 if (has_timestamping) { 1743 tss->ts[1] = (struct timespec) {0}; 1744 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING, 1745 sizeof(*tss), tss); 1746 } 1747 } 1748 1749 /* 1750 * This routine copies from a sock struct into the user buffer. 1751 * 1752 * Technical note: in 2.3 we work on _locked_ socket, so that 1753 * tricks with *seq access order and skb->users are not required. 1754 * Probably, code can be easily improved even more. 1755 */ 1756 1757 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 1758 int flags, int *addr_len) 1759 { 1760 struct tcp_sock *tp = tcp_sk(sk); 1761 int copied = 0; 1762 u32 peek_seq; 1763 u32 *seq; 1764 unsigned long used; 1765 int err; 1766 int target; /* Read at least this many bytes */ 1767 long timeo; 1768 struct sk_buff *skb, *last; 1769 u32 urg_hole = 0; 1770 struct scm_timestamping tss; 1771 bool has_tss = false; 1772 1773 if (unlikely(flags & MSG_ERRQUEUE)) 1774 return inet_recv_error(sk, msg, len, addr_len); 1775 1776 if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) && 1777 (sk->sk_state == TCP_ESTABLISHED)) 1778 sk_busy_loop(sk, nonblock); 1779 1780 lock_sock(sk); 1781 1782 err = -ENOTCONN; 1783 if (sk->sk_state == TCP_LISTEN) 1784 goto out; 1785 1786 timeo = sock_rcvtimeo(sk, nonblock); 1787 1788 /* Urgent data needs to be handled specially. */ 1789 if (flags & MSG_OOB) 1790 goto recv_urg; 1791 1792 if (unlikely(tp->repair)) { 1793 err = -EPERM; 1794 if (!(flags & MSG_PEEK)) 1795 goto out; 1796 1797 if (tp->repair_queue == TCP_SEND_QUEUE) 1798 goto recv_sndq; 1799 1800 err = -EINVAL; 1801 if (tp->repair_queue == TCP_NO_QUEUE) 1802 goto out; 1803 1804 /* 'common' recv queue MSG_PEEK-ing */ 1805 } 1806 1807 seq = &tp->copied_seq; 1808 if (flags & MSG_PEEK) { 1809 peek_seq = tp->copied_seq; 1810 seq = &peek_seq; 1811 } 1812 1813 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1814 1815 do { 1816 u32 offset; 1817 1818 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1819 if (tp->urg_data && tp->urg_seq == *seq) { 1820 if (copied) 1821 break; 1822 if (signal_pending(current)) { 1823 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1824 break; 1825 } 1826 } 1827 1828 /* Next get a buffer. */ 1829 1830 last = skb_peek_tail(&sk->sk_receive_queue); 1831 skb_queue_walk(&sk->sk_receive_queue, skb) { 1832 last = skb; 1833 /* Now that we have two receive queues this 1834 * shouldn't happen. 1835 */ 1836 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 1837 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n", 1838 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 1839 flags)) 1840 break; 1841 1842 offset = *seq - TCP_SKB_CB(skb)->seq; 1843 if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { 1844 pr_err_once("%s: found a SYN, please report !\n", __func__); 1845 offset--; 1846 } 1847 if (offset < skb->len) 1848 goto found_ok_skb; 1849 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 1850 goto found_fin_ok; 1851 WARN(!(flags & MSG_PEEK), 1852 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n", 1853 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); 1854 } 1855 1856 /* Well, if we have backlog, try to process it now yet. */ 1857 1858 if (copied >= target && !sk->sk_backlog.tail) 1859 break; 1860 1861 if (copied) { 1862 if (sk->sk_err || 1863 sk->sk_state == TCP_CLOSE || 1864 (sk->sk_shutdown & RCV_SHUTDOWN) || 1865 !timeo || 1866 signal_pending(current)) 1867 break; 1868 } else { 1869 if (sock_flag(sk, SOCK_DONE)) 1870 break; 1871 1872 if (sk->sk_err) { 1873 copied = sock_error(sk); 1874 break; 1875 } 1876 1877 if (sk->sk_shutdown & RCV_SHUTDOWN) 1878 break; 1879 1880 if (sk->sk_state == TCP_CLOSE) { 1881 if (!sock_flag(sk, SOCK_DONE)) { 1882 /* This occurs when user tries to read 1883 * from never connected socket. 1884 */ 1885 copied = -ENOTCONN; 1886 break; 1887 } 1888 break; 1889 } 1890 1891 if (!timeo) { 1892 copied = -EAGAIN; 1893 break; 1894 } 1895 1896 if (signal_pending(current)) { 1897 copied = sock_intr_errno(timeo); 1898 break; 1899 } 1900 } 1901 1902 tcp_cleanup_rbuf(sk, copied); 1903 1904 if (copied >= target) { 1905 /* Do not sleep, just process backlog. */ 1906 release_sock(sk); 1907 lock_sock(sk); 1908 } else { 1909 sk_wait_data(sk, &timeo, last); 1910 } 1911 1912 if ((flags & MSG_PEEK) && 1913 (peek_seq - copied - urg_hole != tp->copied_seq)) { 1914 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", 1915 current->comm, 1916 task_pid_nr(current)); 1917 peek_seq = tp->copied_seq; 1918 } 1919 continue; 1920 1921 found_ok_skb: 1922 /* Ok so how much can we use? */ 1923 used = skb->len - offset; 1924 if (len < used) 1925 used = len; 1926 1927 /* Do we have urgent data here? */ 1928 if (tp->urg_data) { 1929 u32 urg_offset = tp->urg_seq - *seq; 1930 if (urg_offset < used) { 1931 if (!urg_offset) { 1932 if (!sock_flag(sk, SOCK_URGINLINE)) { 1933 ++*seq; 1934 urg_hole++; 1935 offset++; 1936 used--; 1937 if (!used) 1938 goto skip_copy; 1939 } 1940 } else 1941 used = urg_offset; 1942 } 1943 } 1944 1945 if (!(flags & MSG_TRUNC)) { 1946 err = skb_copy_datagram_msg(skb, offset, msg, used); 1947 if (err) { 1948 /* Exception. Bailout! */ 1949 if (!copied) 1950 copied = -EFAULT; 1951 break; 1952 } 1953 } 1954 1955 *seq += used; 1956 copied += used; 1957 len -= used; 1958 1959 tcp_rcv_space_adjust(sk); 1960 1961 skip_copy: 1962 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1963 tp->urg_data = 0; 1964 tcp_fast_path_check(sk); 1965 } 1966 if (used + offset < skb->len) 1967 continue; 1968 1969 if (TCP_SKB_CB(skb)->has_rxtstamp) { 1970 tcp_update_recv_tstamps(skb, &tss); 1971 has_tss = true; 1972 } 1973 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 1974 goto found_fin_ok; 1975 if (!(flags & MSG_PEEK)) 1976 sk_eat_skb(sk, skb); 1977 continue; 1978 1979 found_fin_ok: 1980 /* Process the FIN. */ 1981 ++*seq; 1982 if (!(flags & MSG_PEEK)) 1983 sk_eat_skb(sk, skb); 1984 break; 1985 } while (len > 0); 1986 1987 /* According to UNIX98, msg_name/msg_namelen are ignored 1988 * on connected socket. I was just happy when found this 8) --ANK 1989 */ 1990 1991 if (has_tss) 1992 tcp_recv_timestamp(msg, sk, &tss); 1993 1994 /* Clean up data we have read: This will do ACK frames. */ 1995 tcp_cleanup_rbuf(sk, copied); 1996 1997 release_sock(sk); 1998 return copied; 1999 2000 out: 2001 release_sock(sk); 2002 return err; 2003 2004 recv_urg: 2005 err = tcp_recv_urg(sk, msg, len, flags); 2006 goto out; 2007 2008 recv_sndq: 2009 err = tcp_peek_sndq(sk, msg, len); 2010 goto out; 2011 } 2012 EXPORT_SYMBOL(tcp_recvmsg); 2013 2014 void tcp_set_state(struct sock *sk, int state) 2015 { 2016 int oldstate = sk->sk_state; 2017 2018 /* We defined a new enum for TCP states that are exported in BPF 2019 * so as not force the internal TCP states to be frozen. The 2020 * following checks will detect if an internal state value ever 2021 * differs from the BPF value. If this ever happens, then we will 2022 * need to remap the internal value to the BPF value before calling 2023 * tcp_call_bpf_2arg. 2024 */ 2025 BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED); 2026 BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT); 2027 BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV); 2028 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1); 2029 BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2); 2030 BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT); 2031 BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE); 2032 BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT); 2033 BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK); 2034 BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN); 2035 BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING); 2036 BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV); 2037 BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES); 2038 2039 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG)) 2040 tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state); 2041 2042 switch (state) { 2043 case TCP_ESTABLISHED: 2044 if (oldstate != TCP_ESTABLISHED) 2045 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2046 break; 2047 2048 case TCP_CLOSE: 2049 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 2050 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 2051 2052 sk->sk_prot->unhash(sk); 2053 if (inet_csk(sk)->icsk_bind_hash && 2054 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 2055 inet_put_port(sk); 2056 /* fall through */ 2057 default: 2058 if (oldstate == TCP_ESTABLISHED) 2059 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2060 } 2061 2062 /* Change state AFTER socket is unhashed to avoid closed 2063 * socket sitting in hash tables. 2064 */ 2065 inet_sk_state_store(sk, state); 2066 2067 #ifdef STATE_TRACE 2068 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 2069 #endif 2070 } 2071 EXPORT_SYMBOL_GPL(tcp_set_state); 2072 2073 /* 2074 * State processing on a close. This implements the state shift for 2075 * sending our FIN frame. Note that we only send a FIN for some 2076 * states. A shutdown() may have already sent the FIN, or we may be 2077 * closed. 2078 */ 2079 2080 static const unsigned char new_state[16] = { 2081 /* current state: new state: action: */ 2082 [0 /* (Invalid) */] = TCP_CLOSE, 2083 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2084 [TCP_SYN_SENT] = TCP_CLOSE, 2085 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2086 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, 2087 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, 2088 [TCP_TIME_WAIT] = TCP_CLOSE, 2089 [TCP_CLOSE] = TCP_CLOSE, 2090 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, 2091 [TCP_LAST_ACK] = TCP_LAST_ACK, 2092 [TCP_LISTEN] = TCP_CLOSE, 2093 [TCP_CLOSING] = TCP_CLOSING, 2094 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ 2095 }; 2096 2097 static int tcp_close_state(struct sock *sk) 2098 { 2099 int next = (int)new_state[sk->sk_state]; 2100 int ns = next & TCP_STATE_MASK; 2101 2102 tcp_set_state(sk, ns); 2103 2104 return next & TCP_ACTION_FIN; 2105 } 2106 2107 /* 2108 * Shutdown the sending side of a connection. Much like close except 2109 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 2110 */ 2111 2112 void tcp_shutdown(struct sock *sk, int how) 2113 { 2114 /* We need to grab some memory, and put together a FIN, 2115 * and then put it into the queue to be sent. 2116 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 2117 */ 2118 if (!(how & SEND_SHUTDOWN)) 2119 return; 2120 2121 /* If we've already sent a FIN, or it's a closed state, skip this. */ 2122 if ((1 << sk->sk_state) & 2123 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 2124 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 2125 /* Clear out any half completed packets. FIN if needed. */ 2126 if (tcp_close_state(sk)) 2127 tcp_send_fin(sk); 2128 } 2129 } 2130 EXPORT_SYMBOL(tcp_shutdown); 2131 2132 bool tcp_check_oom(struct sock *sk, int shift) 2133 { 2134 bool too_many_orphans, out_of_socket_memory; 2135 2136 too_many_orphans = tcp_too_many_orphans(sk, shift); 2137 out_of_socket_memory = tcp_out_of_memory(sk); 2138 2139 if (too_many_orphans) 2140 net_info_ratelimited("too many orphaned sockets\n"); 2141 if (out_of_socket_memory) 2142 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); 2143 return too_many_orphans || out_of_socket_memory; 2144 } 2145 2146 void tcp_close(struct sock *sk, long timeout) 2147 { 2148 struct sk_buff *skb; 2149 int data_was_unread = 0; 2150 int state; 2151 2152 lock_sock(sk); 2153 sk->sk_shutdown = SHUTDOWN_MASK; 2154 2155 if (sk->sk_state == TCP_LISTEN) { 2156 tcp_set_state(sk, TCP_CLOSE); 2157 2158 /* Special case. */ 2159 inet_csk_listen_stop(sk); 2160 2161 goto adjudge_to_death; 2162 } 2163 2164 /* We need to flush the recv. buffs. We do this only on the 2165 * descriptor close, not protocol-sourced closes, because the 2166 * reader process may not have drained the data yet! 2167 */ 2168 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 2169 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; 2170 2171 if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) 2172 len--; 2173 data_was_unread += len; 2174 __kfree_skb(skb); 2175 } 2176 2177 sk_mem_reclaim(sk); 2178 2179 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ 2180 if (sk->sk_state == TCP_CLOSE) 2181 goto adjudge_to_death; 2182 2183 /* As outlined in RFC 2525, section 2.17, we send a RST here because 2184 * data was lost. To witness the awful effects of the old behavior of 2185 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 2186 * GET in an FTP client, suspend the process, wait for the client to 2187 * advertise a zero window, then kill -9 the FTP client, wheee... 2188 * Note: timeout is always zero in such a case. 2189 */ 2190 if (unlikely(tcp_sk(sk)->repair)) { 2191 sk->sk_prot->disconnect(sk, 0); 2192 } else if (data_was_unread) { 2193 /* Unread data was tossed, zap the connection. */ 2194 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 2195 tcp_set_state(sk, TCP_CLOSE); 2196 tcp_send_active_reset(sk, sk->sk_allocation); 2197 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 2198 /* Check zero linger _after_ checking for unread data. */ 2199 sk->sk_prot->disconnect(sk, 0); 2200 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 2201 } else if (tcp_close_state(sk)) { 2202 /* We FIN if the application ate all the data before 2203 * zapping the connection. 2204 */ 2205 2206 /* RED-PEN. Formally speaking, we have broken TCP state 2207 * machine. State transitions: 2208 * 2209 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 2210 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 2211 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 2212 * 2213 * are legal only when FIN has been sent (i.e. in window), 2214 * rather than queued out of window. Purists blame. 2215 * 2216 * F.e. "RFC state" is ESTABLISHED, 2217 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 2218 * 2219 * The visible declinations are that sometimes 2220 * we enter time-wait state, when it is not required really 2221 * (harmless), do not send active resets, when they are 2222 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 2223 * they look as CLOSING or LAST_ACK for Linux) 2224 * Probably, I missed some more holelets. 2225 * --ANK 2226 * XXX (TFO) - To start off we don't support SYN+ACK+FIN 2227 * in a single packet! (May consider it later but will 2228 * probably need API support or TCP_CORK SYN-ACK until 2229 * data is written and socket is closed.) 2230 */ 2231 tcp_send_fin(sk); 2232 } 2233 2234 sk_stream_wait_close(sk, timeout); 2235 2236 adjudge_to_death: 2237 state = sk->sk_state; 2238 sock_hold(sk); 2239 sock_orphan(sk); 2240 2241 /* It is the last release_sock in its life. It will remove backlog. */ 2242 release_sock(sk); 2243 2244 2245 /* Now socket is owned by kernel and we acquire BH lock 2246 * to finish close. No need to check for user refs. 2247 */ 2248 local_bh_disable(); 2249 bh_lock_sock(sk); 2250 WARN_ON(sock_owned_by_user(sk)); 2251 2252 percpu_counter_inc(sk->sk_prot->orphan_count); 2253 2254 /* Have we already been destroyed by a softirq or backlog? */ 2255 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 2256 goto out; 2257 2258 /* This is a (useful) BSD violating of the RFC. There is a 2259 * problem with TCP as specified in that the other end could 2260 * keep a socket open forever with no application left this end. 2261 * We use a 1 minute timeout (about the same as BSD) then kill 2262 * our end. If they send after that then tough - BUT: long enough 2263 * that we won't make the old 4*rto = almost no time - whoops 2264 * reset mistake. 2265 * 2266 * Nope, it was not mistake. It is really desired behaviour 2267 * f.e. on http servers, when such sockets are useless, but 2268 * consume significant resources. Let's do it with special 2269 * linger2 option. --ANK 2270 */ 2271 2272 if (sk->sk_state == TCP_FIN_WAIT2) { 2273 struct tcp_sock *tp = tcp_sk(sk); 2274 if (tp->linger2 < 0) { 2275 tcp_set_state(sk, TCP_CLOSE); 2276 tcp_send_active_reset(sk, GFP_ATOMIC); 2277 __NET_INC_STATS(sock_net(sk), 2278 LINUX_MIB_TCPABORTONLINGER); 2279 } else { 2280 const int tmo = tcp_fin_time(sk); 2281 2282 if (tmo > TCP_TIMEWAIT_LEN) { 2283 inet_csk_reset_keepalive_timer(sk, 2284 tmo - TCP_TIMEWAIT_LEN); 2285 } else { 2286 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 2287 goto out; 2288 } 2289 } 2290 } 2291 if (sk->sk_state != TCP_CLOSE) { 2292 sk_mem_reclaim(sk); 2293 if (tcp_check_oom(sk, 0)) { 2294 tcp_set_state(sk, TCP_CLOSE); 2295 tcp_send_active_reset(sk, GFP_ATOMIC); 2296 __NET_INC_STATS(sock_net(sk), 2297 LINUX_MIB_TCPABORTONMEMORY); 2298 } else if (!check_net(sock_net(sk))) { 2299 /* Not possible to send reset; just close */ 2300 tcp_set_state(sk, TCP_CLOSE); 2301 } 2302 } 2303 2304 if (sk->sk_state == TCP_CLOSE) { 2305 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 2306 /* We could get here with a non-NULL req if the socket is 2307 * aborted (e.g., closed with unread data) before 3WHS 2308 * finishes. 2309 */ 2310 if (req) 2311 reqsk_fastopen_remove(sk, req, false); 2312 inet_csk_destroy_sock(sk); 2313 } 2314 /* Otherwise, socket is reprieved until protocol close. */ 2315 2316 out: 2317 bh_unlock_sock(sk); 2318 local_bh_enable(); 2319 sock_put(sk); 2320 } 2321 EXPORT_SYMBOL(tcp_close); 2322 2323 /* These states need RST on ABORT according to RFC793 */ 2324 2325 static inline bool tcp_need_reset(int state) 2326 { 2327 return (1 << state) & 2328 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2329 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2330 } 2331 2332 static void tcp_rtx_queue_purge(struct sock *sk) 2333 { 2334 struct rb_node *p = rb_first(&sk->tcp_rtx_queue); 2335 2336 while (p) { 2337 struct sk_buff *skb = rb_to_skb(p); 2338 2339 p = rb_next(p); 2340 /* Since we are deleting whole queue, no need to 2341 * list_del(&skb->tcp_tsorted_anchor) 2342 */ 2343 tcp_rtx_queue_unlink(skb, sk); 2344 sk_wmem_free_skb(sk, skb); 2345 } 2346 } 2347 2348 void tcp_write_queue_purge(struct sock *sk) 2349 { 2350 struct sk_buff *skb; 2351 2352 tcp_chrono_stop(sk, TCP_CHRONO_BUSY); 2353 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 2354 tcp_skb_tsorted_anchor_cleanup(skb); 2355 sk_wmem_free_skb(sk, skb); 2356 } 2357 tcp_rtx_queue_purge(sk); 2358 INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue); 2359 sk_mem_reclaim(sk); 2360 tcp_clear_all_retrans_hints(tcp_sk(sk)); 2361 } 2362 2363 int tcp_disconnect(struct sock *sk, int flags) 2364 { 2365 struct inet_sock *inet = inet_sk(sk); 2366 struct inet_connection_sock *icsk = inet_csk(sk); 2367 struct tcp_sock *tp = tcp_sk(sk); 2368 int err = 0; 2369 int old_state = sk->sk_state; 2370 2371 if (old_state != TCP_CLOSE) 2372 tcp_set_state(sk, TCP_CLOSE); 2373 2374 /* ABORT function of RFC793 */ 2375 if (old_state == TCP_LISTEN) { 2376 inet_csk_listen_stop(sk); 2377 } else if (unlikely(tp->repair)) { 2378 sk->sk_err = ECONNABORTED; 2379 } else if (tcp_need_reset(old_state) || 2380 (tp->snd_nxt != tp->write_seq && 2381 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2382 /* The last check adjusts for discrepancy of Linux wrt. RFC 2383 * states 2384 */ 2385 tcp_send_active_reset(sk, gfp_any()); 2386 sk->sk_err = ECONNRESET; 2387 } else if (old_state == TCP_SYN_SENT) 2388 sk->sk_err = ECONNRESET; 2389 2390 tcp_clear_xmit_timers(sk); 2391 __skb_queue_purge(&sk->sk_receive_queue); 2392 tcp_write_queue_purge(sk); 2393 tcp_fastopen_active_disable_ofo_check(sk); 2394 skb_rbtree_purge(&tp->out_of_order_queue); 2395 2396 inet->inet_dport = 0; 2397 2398 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2399 inet_reset_saddr(sk); 2400 2401 sk->sk_shutdown = 0; 2402 sock_reset_flag(sk, SOCK_DONE); 2403 tp->srtt_us = 0; 2404 tp->write_seq += tp->max_window + 2; 2405 if (tp->write_seq == 0) 2406 tp->write_seq = 1; 2407 icsk->icsk_backoff = 0; 2408 tp->snd_cwnd = 2; 2409 icsk->icsk_probes_out = 0; 2410 tp->packets_out = 0; 2411 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2412 tp->snd_cwnd_cnt = 0; 2413 tp->window_clamp = 0; 2414 tcp_set_ca_state(sk, TCP_CA_Open); 2415 tp->is_sack_reneg = 0; 2416 tcp_clear_retrans(tp); 2417 inet_csk_delack_init(sk); 2418 /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 2419 * issue in __tcp_select_window() 2420 */ 2421 icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; 2422 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2423 __sk_dst_reset(sk); 2424 dst_release(sk->sk_rx_dst); 2425 sk->sk_rx_dst = NULL; 2426 tcp_saved_syn_free(tp); 2427 2428 /* Clean up fastopen related fields */ 2429 tcp_free_fastopen_req(tp); 2430 inet->defer_connect = 0; 2431 2432 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2433 2434 if (sk->sk_frag.page) { 2435 put_page(sk->sk_frag.page); 2436 sk->sk_frag.page = NULL; 2437 sk->sk_frag.offset = 0; 2438 } 2439 2440 sk->sk_error_report(sk); 2441 return err; 2442 } 2443 EXPORT_SYMBOL(tcp_disconnect); 2444 2445 static inline bool tcp_can_repair_sock(const struct sock *sk) 2446 { 2447 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && 2448 (sk->sk_state != TCP_LISTEN); 2449 } 2450 2451 static int tcp_repair_set_window(struct tcp_sock *tp, char __user *optbuf, int len) 2452 { 2453 struct tcp_repair_window opt; 2454 2455 if (!tp->repair) 2456 return -EPERM; 2457 2458 if (len != sizeof(opt)) 2459 return -EINVAL; 2460 2461 if (copy_from_user(&opt, optbuf, sizeof(opt))) 2462 return -EFAULT; 2463 2464 if (opt.max_window < opt.snd_wnd) 2465 return -EINVAL; 2466 2467 if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd)) 2468 return -EINVAL; 2469 2470 if (after(opt.rcv_wup, tp->rcv_nxt)) 2471 return -EINVAL; 2472 2473 tp->snd_wl1 = opt.snd_wl1; 2474 tp->snd_wnd = opt.snd_wnd; 2475 tp->max_window = opt.max_window; 2476 2477 tp->rcv_wnd = opt.rcv_wnd; 2478 tp->rcv_wup = opt.rcv_wup; 2479 2480 return 0; 2481 } 2482 2483 static int tcp_repair_options_est(struct sock *sk, 2484 struct tcp_repair_opt __user *optbuf, unsigned int len) 2485 { 2486 struct tcp_sock *tp = tcp_sk(sk); 2487 struct tcp_repair_opt opt; 2488 2489 while (len >= sizeof(opt)) { 2490 if (copy_from_user(&opt, optbuf, sizeof(opt))) 2491 return -EFAULT; 2492 2493 optbuf++; 2494 len -= sizeof(opt); 2495 2496 switch (opt.opt_code) { 2497 case TCPOPT_MSS: 2498 tp->rx_opt.mss_clamp = opt.opt_val; 2499 tcp_mtup_init(sk); 2500 break; 2501 case TCPOPT_WINDOW: 2502 { 2503 u16 snd_wscale = opt.opt_val & 0xFFFF; 2504 u16 rcv_wscale = opt.opt_val >> 16; 2505 2506 if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE) 2507 return -EFBIG; 2508 2509 tp->rx_opt.snd_wscale = snd_wscale; 2510 tp->rx_opt.rcv_wscale = rcv_wscale; 2511 tp->rx_opt.wscale_ok = 1; 2512 } 2513 break; 2514 case TCPOPT_SACK_PERM: 2515 if (opt.opt_val != 0) 2516 return -EINVAL; 2517 2518 tp->rx_opt.sack_ok |= TCP_SACK_SEEN; 2519 break; 2520 case TCPOPT_TIMESTAMP: 2521 if (opt.opt_val != 0) 2522 return -EINVAL; 2523 2524 tp->rx_opt.tstamp_ok = 1; 2525 break; 2526 } 2527 } 2528 2529 return 0; 2530 } 2531 2532 /* 2533 * Socket option code for TCP. 2534 */ 2535 static int do_tcp_setsockopt(struct sock *sk, int level, 2536 int optname, char __user *optval, unsigned int optlen) 2537 { 2538 struct tcp_sock *tp = tcp_sk(sk); 2539 struct inet_connection_sock *icsk = inet_csk(sk); 2540 struct net *net = sock_net(sk); 2541 int val; 2542 int err = 0; 2543 2544 /* These are data/string values, all the others are ints */ 2545 switch (optname) { 2546 case TCP_CONGESTION: { 2547 char name[TCP_CA_NAME_MAX]; 2548 2549 if (optlen < 1) 2550 return -EINVAL; 2551 2552 val = strncpy_from_user(name, optval, 2553 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2554 if (val < 0) 2555 return -EFAULT; 2556 name[val] = 0; 2557 2558 lock_sock(sk); 2559 err = tcp_set_congestion_control(sk, name, true, true); 2560 release_sock(sk); 2561 return err; 2562 } 2563 case TCP_ULP: { 2564 char name[TCP_ULP_NAME_MAX]; 2565 2566 if (optlen < 1) 2567 return -EINVAL; 2568 2569 val = strncpy_from_user(name, optval, 2570 min_t(long, TCP_ULP_NAME_MAX - 1, 2571 optlen)); 2572 if (val < 0) 2573 return -EFAULT; 2574 name[val] = 0; 2575 2576 lock_sock(sk); 2577 err = tcp_set_ulp(sk, name); 2578 release_sock(sk); 2579 return err; 2580 } 2581 case TCP_FASTOPEN_KEY: { 2582 __u8 key[TCP_FASTOPEN_KEY_LENGTH]; 2583 2584 if (optlen != sizeof(key)) 2585 return -EINVAL; 2586 2587 if (copy_from_user(key, optval, optlen)) 2588 return -EFAULT; 2589 2590 return tcp_fastopen_reset_cipher(net, sk, key, sizeof(key)); 2591 } 2592 default: 2593 /* fallthru */ 2594 break; 2595 } 2596 2597 if (optlen < sizeof(int)) 2598 return -EINVAL; 2599 2600 if (get_user(val, (int __user *)optval)) 2601 return -EFAULT; 2602 2603 lock_sock(sk); 2604 2605 switch (optname) { 2606 case TCP_MAXSEG: 2607 /* Values greater than interface MTU won't take effect. However 2608 * at the point when this call is done we typically don't yet 2609 * know which interface is going to be used 2610 */ 2611 if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) { 2612 err = -EINVAL; 2613 break; 2614 } 2615 tp->rx_opt.user_mss = val; 2616 break; 2617 2618 case TCP_NODELAY: 2619 if (val) { 2620 /* TCP_NODELAY is weaker than TCP_CORK, so that 2621 * this option on corked socket is remembered, but 2622 * it is not activated until cork is cleared. 2623 * 2624 * However, when TCP_NODELAY is set we make 2625 * an explicit push, which overrides even TCP_CORK 2626 * for currently queued segments. 2627 */ 2628 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2629 tcp_push_pending_frames(sk); 2630 } else { 2631 tp->nonagle &= ~TCP_NAGLE_OFF; 2632 } 2633 break; 2634 2635 case TCP_THIN_LINEAR_TIMEOUTS: 2636 if (val < 0 || val > 1) 2637 err = -EINVAL; 2638 else 2639 tp->thin_lto = val; 2640 break; 2641 2642 case TCP_THIN_DUPACK: 2643 if (val < 0 || val > 1) 2644 err = -EINVAL; 2645 break; 2646 2647 case TCP_REPAIR: 2648 if (!tcp_can_repair_sock(sk)) 2649 err = -EPERM; 2650 else if (val == 1) { 2651 tp->repair = 1; 2652 sk->sk_reuse = SK_FORCE_REUSE; 2653 tp->repair_queue = TCP_NO_QUEUE; 2654 } else if (val == 0) { 2655 tp->repair = 0; 2656 sk->sk_reuse = SK_NO_REUSE; 2657 tcp_send_window_probe(sk); 2658 } else 2659 err = -EINVAL; 2660 2661 break; 2662 2663 case TCP_REPAIR_QUEUE: 2664 if (!tp->repair) 2665 err = -EPERM; 2666 else if (val < TCP_QUEUES_NR) 2667 tp->repair_queue = val; 2668 else 2669 err = -EINVAL; 2670 break; 2671 2672 case TCP_QUEUE_SEQ: 2673 if (sk->sk_state != TCP_CLOSE) 2674 err = -EPERM; 2675 else if (tp->repair_queue == TCP_SEND_QUEUE) 2676 tp->write_seq = val; 2677 else if (tp->repair_queue == TCP_RECV_QUEUE) 2678 tp->rcv_nxt = val; 2679 else 2680 err = -EINVAL; 2681 break; 2682 2683 case TCP_REPAIR_OPTIONS: 2684 if (!tp->repair) 2685 err = -EINVAL; 2686 else if (sk->sk_state == TCP_ESTABLISHED) 2687 err = tcp_repair_options_est(sk, 2688 (struct tcp_repair_opt __user *)optval, 2689 optlen); 2690 else 2691 err = -EPERM; 2692 break; 2693 2694 case TCP_CORK: 2695 /* When set indicates to always queue non-full frames. 2696 * Later the user clears this option and we transmit 2697 * any pending partial frames in the queue. This is 2698 * meant to be used alongside sendfile() to get properly 2699 * filled frames when the user (for example) must write 2700 * out headers with a write() call first and then use 2701 * sendfile to send out the data parts. 2702 * 2703 * TCP_CORK can be set together with TCP_NODELAY and it is 2704 * stronger than TCP_NODELAY. 2705 */ 2706 if (val) { 2707 tp->nonagle |= TCP_NAGLE_CORK; 2708 } else { 2709 tp->nonagle &= ~TCP_NAGLE_CORK; 2710 if (tp->nonagle&TCP_NAGLE_OFF) 2711 tp->nonagle |= TCP_NAGLE_PUSH; 2712 tcp_push_pending_frames(sk); 2713 } 2714 break; 2715 2716 case TCP_KEEPIDLE: 2717 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2718 err = -EINVAL; 2719 else { 2720 tp->keepalive_time = val * HZ; 2721 if (sock_flag(sk, SOCK_KEEPOPEN) && 2722 !((1 << sk->sk_state) & 2723 (TCPF_CLOSE | TCPF_LISTEN))) { 2724 u32 elapsed = keepalive_time_elapsed(tp); 2725 if (tp->keepalive_time > elapsed) 2726 elapsed = tp->keepalive_time - elapsed; 2727 else 2728 elapsed = 0; 2729 inet_csk_reset_keepalive_timer(sk, elapsed); 2730 } 2731 } 2732 break; 2733 case TCP_KEEPINTVL: 2734 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2735 err = -EINVAL; 2736 else 2737 tp->keepalive_intvl = val * HZ; 2738 break; 2739 case TCP_KEEPCNT: 2740 if (val < 1 || val > MAX_TCP_KEEPCNT) 2741 err = -EINVAL; 2742 else 2743 tp->keepalive_probes = val; 2744 break; 2745 case TCP_SYNCNT: 2746 if (val < 1 || val > MAX_TCP_SYNCNT) 2747 err = -EINVAL; 2748 else 2749 icsk->icsk_syn_retries = val; 2750 break; 2751 2752 case TCP_SAVE_SYN: 2753 if (val < 0 || val > 1) 2754 err = -EINVAL; 2755 else 2756 tp->save_syn = val; 2757 break; 2758 2759 case TCP_LINGER2: 2760 if (val < 0) 2761 tp->linger2 = -1; 2762 else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ) 2763 tp->linger2 = 0; 2764 else 2765 tp->linger2 = val * HZ; 2766 break; 2767 2768 case TCP_DEFER_ACCEPT: 2769 /* Translate value in seconds to number of retransmits */ 2770 icsk->icsk_accept_queue.rskq_defer_accept = 2771 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2772 TCP_RTO_MAX / HZ); 2773 break; 2774 2775 case TCP_WINDOW_CLAMP: 2776 if (!val) { 2777 if (sk->sk_state != TCP_CLOSE) { 2778 err = -EINVAL; 2779 break; 2780 } 2781 tp->window_clamp = 0; 2782 } else 2783 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2784 SOCK_MIN_RCVBUF / 2 : val; 2785 break; 2786 2787 case TCP_QUICKACK: 2788 if (!val) { 2789 icsk->icsk_ack.pingpong = 1; 2790 } else { 2791 icsk->icsk_ack.pingpong = 0; 2792 if ((1 << sk->sk_state) & 2793 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2794 inet_csk_ack_scheduled(sk)) { 2795 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2796 tcp_cleanup_rbuf(sk, 1); 2797 if (!(val & 1)) 2798 icsk->icsk_ack.pingpong = 1; 2799 } 2800 } 2801 break; 2802 2803 #ifdef CONFIG_TCP_MD5SIG 2804 case TCP_MD5SIG: 2805 case TCP_MD5SIG_EXT: 2806 /* Read the IP->Key mappings from userspace */ 2807 err = tp->af_specific->md5_parse(sk, optname, optval, optlen); 2808 break; 2809 #endif 2810 case TCP_USER_TIMEOUT: 2811 /* Cap the max time in ms TCP will retry or probe the window 2812 * before giving up and aborting (ETIMEDOUT) a connection. 2813 */ 2814 if (val < 0) 2815 err = -EINVAL; 2816 else 2817 icsk->icsk_user_timeout = msecs_to_jiffies(val); 2818 break; 2819 2820 case TCP_FASTOPEN: 2821 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | 2822 TCPF_LISTEN))) { 2823 tcp_fastopen_init_key_once(net); 2824 2825 fastopen_queue_tune(sk, val); 2826 } else { 2827 err = -EINVAL; 2828 } 2829 break; 2830 case TCP_FASTOPEN_CONNECT: 2831 if (val > 1 || val < 0) { 2832 err = -EINVAL; 2833 } else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) { 2834 if (sk->sk_state == TCP_CLOSE) 2835 tp->fastopen_connect = val; 2836 else 2837 err = -EINVAL; 2838 } else { 2839 err = -EOPNOTSUPP; 2840 } 2841 break; 2842 case TCP_FASTOPEN_NO_COOKIE: 2843 if (val > 1 || val < 0) 2844 err = -EINVAL; 2845 else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2846 err = -EINVAL; 2847 else 2848 tp->fastopen_no_cookie = val; 2849 break; 2850 case TCP_TIMESTAMP: 2851 if (!tp->repair) 2852 err = -EPERM; 2853 else 2854 tp->tsoffset = val - tcp_time_stamp_raw(); 2855 break; 2856 case TCP_REPAIR_WINDOW: 2857 err = tcp_repair_set_window(tp, optval, optlen); 2858 break; 2859 case TCP_NOTSENT_LOWAT: 2860 tp->notsent_lowat = val; 2861 sk->sk_write_space(sk); 2862 break; 2863 default: 2864 err = -ENOPROTOOPT; 2865 break; 2866 } 2867 2868 release_sock(sk); 2869 return err; 2870 } 2871 2872 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2873 unsigned int optlen) 2874 { 2875 const struct inet_connection_sock *icsk = inet_csk(sk); 2876 2877 if (level != SOL_TCP) 2878 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2879 optval, optlen); 2880 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2881 } 2882 EXPORT_SYMBOL(tcp_setsockopt); 2883 2884 #ifdef CONFIG_COMPAT 2885 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2886 char __user *optval, unsigned int optlen) 2887 { 2888 if (level != SOL_TCP) 2889 return inet_csk_compat_setsockopt(sk, level, optname, 2890 optval, optlen); 2891 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2892 } 2893 EXPORT_SYMBOL(compat_tcp_setsockopt); 2894 #endif 2895 2896 static void tcp_get_info_chrono_stats(const struct tcp_sock *tp, 2897 struct tcp_info *info) 2898 { 2899 u64 stats[__TCP_CHRONO_MAX], total = 0; 2900 enum tcp_chrono i; 2901 2902 for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) { 2903 stats[i] = tp->chrono_stat[i - 1]; 2904 if (i == tp->chrono_type) 2905 stats[i] += tcp_jiffies32 - tp->chrono_start; 2906 stats[i] *= USEC_PER_SEC / HZ; 2907 total += stats[i]; 2908 } 2909 2910 info->tcpi_busy_time = total; 2911 info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED]; 2912 info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED]; 2913 } 2914 2915 /* Return information about state of tcp endpoint in API format. */ 2916 void tcp_get_info(struct sock *sk, struct tcp_info *info) 2917 { 2918 const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */ 2919 const struct inet_connection_sock *icsk = inet_csk(sk); 2920 u32 now; 2921 u64 rate64; 2922 bool slow; 2923 u32 rate; 2924 2925 memset(info, 0, sizeof(*info)); 2926 if (sk->sk_type != SOCK_STREAM) 2927 return; 2928 2929 info->tcpi_state = inet_sk_state_load(sk); 2930 2931 /* Report meaningful fields for all TCP states, including listeners */ 2932 rate = READ_ONCE(sk->sk_pacing_rate); 2933 rate64 = rate != ~0U ? rate : ~0ULL; 2934 info->tcpi_pacing_rate = rate64; 2935 2936 rate = READ_ONCE(sk->sk_max_pacing_rate); 2937 rate64 = rate != ~0U ? rate : ~0ULL; 2938 info->tcpi_max_pacing_rate = rate64; 2939 2940 info->tcpi_reordering = tp->reordering; 2941 info->tcpi_snd_cwnd = tp->snd_cwnd; 2942 2943 if (info->tcpi_state == TCP_LISTEN) { 2944 /* listeners aliased fields : 2945 * tcpi_unacked -> Number of children ready for accept() 2946 * tcpi_sacked -> max backlog 2947 */ 2948 info->tcpi_unacked = sk->sk_ack_backlog; 2949 info->tcpi_sacked = sk->sk_max_ack_backlog; 2950 return; 2951 } 2952 2953 slow = lock_sock_fast(sk); 2954 2955 info->tcpi_ca_state = icsk->icsk_ca_state; 2956 info->tcpi_retransmits = icsk->icsk_retransmits; 2957 info->tcpi_probes = icsk->icsk_probes_out; 2958 info->tcpi_backoff = icsk->icsk_backoff; 2959 2960 if (tp->rx_opt.tstamp_ok) 2961 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2962 if (tcp_is_sack(tp)) 2963 info->tcpi_options |= TCPI_OPT_SACK; 2964 if (tp->rx_opt.wscale_ok) { 2965 info->tcpi_options |= TCPI_OPT_WSCALE; 2966 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2967 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2968 } 2969 2970 if (tp->ecn_flags & TCP_ECN_OK) 2971 info->tcpi_options |= TCPI_OPT_ECN; 2972 if (tp->ecn_flags & TCP_ECN_SEEN) 2973 info->tcpi_options |= TCPI_OPT_ECN_SEEN; 2974 if (tp->syn_data_acked) 2975 info->tcpi_options |= TCPI_OPT_SYN_DATA; 2976 2977 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2978 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2979 info->tcpi_snd_mss = tp->mss_cache; 2980 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2981 2982 info->tcpi_unacked = tp->packets_out; 2983 info->tcpi_sacked = tp->sacked_out; 2984 2985 info->tcpi_lost = tp->lost_out; 2986 info->tcpi_retrans = tp->retrans_out; 2987 2988 now = tcp_jiffies32; 2989 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2990 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2991 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2992 2993 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2994 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2995 info->tcpi_rtt = tp->srtt_us >> 3; 2996 info->tcpi_rttvar = tp->mdev_us >> 2; 2997 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2998 info->tcpi_advmss = tp->advmss; 2999 3000 info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3; 3001 info->tcpi_rcv_space = tp->rcvq_space.space; 3002 3003 info->tcpi_total_retrans = tp->total_retrans; 3004 3005 info->tcpi_bytes_acked = tp->bytes_acked; 3006 info->tcpi_bytes_received = tp->bytes_received; 3007 info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt); 3008 tcp_get_info_chrono_stats(tp, info); 3009 3010 info->tcpi_segs_out = tp->segs_out; 3011 info->tcpi_segs_in = tp->segs_in; 3012 3013 info->tcpi_min_rtt = tcp_min_rtt(tp); 3014 info->tcpi_data_segs_in = tp->data_segs_in; 3015 info->tcpi_data_segs_out = tp->data_segs_out; 3016 3017 info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0; 3018 rate64 = tcp_compute_delivery_rate(tp); 3019 if (rate64) 3020 info->tcpi_delivery_rate = rate64; 3021 unlock_sock_fast(sk, slow); 3022 } 3023 EXPORT_SYMBOL_GPL(tcp_get_info); 3024 3025 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk) 3026 { 3027 const struct tcp_sock *tp = tcp_sk(sk); 3028 struct sk_buff *stats; 3029 struct tcp_info info; 3030 u64 rate64; 3031 u32 rate; 3032 3033 stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) + 3034 3 * nla_total_size(sizeof(u32)) + 3035 2 * nla_total_size(sizeof(u8)), GFP_ATOMIC); 3036 if (!stats) 3037 return NULL; 3038 3039 tcp_get_info_chrono_stats(tp, &info); 3040 nla_put_u64_64bit(stats, TCP_NLA_BUSY, 3041 info.tcpi_busy_time, TCP_NLA_PAD); 3042 nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED, 3043 info.tcpi_rwnd_limited, TCP_NLA_PAD); 3044 nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED, 3045 info.tcpi_sndbuf_limited, TCP_NLA_PAD); 3046 nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT, 3047 tp->data_segs_out, TCP_NLA_PAD); 3048 nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS, 3049 tp->total_retrans, TCP_NLA_PAD); 3050 3051 rate = READ_ONCE(sk->sk_pacing_rate); 3052 rate64 = rate != ~0U ? rate : ~0ULL; 3053 nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD); 3054 3055 rate64 = tcp_compute_delivery_rate(tp); 3056 nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD); 3057 3058 nla_put_u32(stats, TCP_NLA_SND_CWND, tp->snd_cwnd); 3059 nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering); 3060 nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp)); 3061 3062 nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits); 3063 nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited); 3064 return stats; 3065 } 3066 3067 static int do_tcp_getsockopt(struct sock *sk, int level, 3068 int optname, char __user *optval, int __user *optlen) 3069 { 3070 struct inet_connection_sock *icsk = inet_csk(sk); 3071 struct tcp_sock *tp = tcp_sk(sk); 3072 struct net *net = sock_net(sk); 3073 int val, len; 3074 3075 if (get_user(len, optlen)) 3076 return -EFAULT; 3077 3078 len = min_t(unsigned int, len, sizeof(int)); 3079 3080 if (len < 0) 3081 return -EINVAL; 3082 3083 switch (optname) { 3084 case TCP_MAXSEG: 3085 val = tp->mss_cache; 3086 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 3087 val = tp->rx_opt.user_mss; 3088 if (tp->repair) 3089 val = tp->rx_opt.mss_clamp; 3090 break; 3091 case TCP_NODELAY: 3092 val = !!(tp->nonagle&TCP_NAGLE_OFF); 3093 break; 3094 case TCP_CORK: 3095 val = !!(tp->nonagle&TCP_NAGLE_CORK); 3096 break; 3097 case TCP_KEEPIDLE: 3098 val = keepalive_time_when(tp) / HZ; 3099 break; 3100 case TCP_KEEPINTVL: 3101 val = keepalive_intvl_when(tp) / HZ; 3102 break; 3103 case TCP_KEEPCNT: 3104 val = keepalive_probes(tp); 3105 break; 3106 case TCP_SYNCNT: 3107 val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; 3108 break; 3109 case TCP_LINGER2: 3110 val = tp->linger2; 3111 if (val >= 0) 3112 val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ; 3113 break; 3114 case TCP_DEFER_ACCEPT: 3115 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 3116 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 3117 break; 3118 case TCP_WINDOW_CLAMP: 3119 val = tp->window_clamp; 3120 break; 3121 case TCP_INFO: { 3122 struct tcp_info info; 3123 3124 if (get_user(len, optlen)) 3125 return -EFAULT; 3126 3127 tcp_get_info(sk, &info); 3128 3129 len = min_t(unsigned int, len, sizeof(info)); 3130 if (put_user(len, optlen)) 3131 return -EFAULT; 3132 if (copy_to_user(optval, &info, len)) 3133 return -EFAULT; 3134 return 0; 3135 } 3136 case TCP_CC_INFO: { 3137 const struct tcp_congestion_ops *ca_ops; 3138 union tcp_cc_info info; 3139 size_t sz = 0; 3140 int attr; 3141 3142 if (get_user(len, optlen)) 3143 return -EFAULT; 3144 3145 ca_ops = icsk->icsk_ca_ops; 3146 if (ca_ops && ca_ops->get_info) 3147 sz = ca_ops->get_info(sk, ~0U, &attr, &info); 3148 3149 len = min_t(unsigned int, len, sz); 3150 if (put_user(len, optlen)) 3151 return -EFAULT; 3152 if (copy_to_user(optval, &info, len)) 3153 return -EFAULT; 3154 return 0; 3155 } 3156 case TCP_QUICKACK: 3157 val = !icsk->icsk_ack.pingpong; 3158 break; 3159 3160 case TCP_CONGESTION: 3161 if (get_user(len, optlen)) 3162 return -EFAULT; 3163 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 3164 if (put_user(len, optlen)) 3165 return -EFAULT; 3166 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 3167 return -EFAULT; 3168 return 0; 3169 3170 case TCP_ULP: 3171 if (get_user(len, optlen)) 3172 return -EFAULT; 3173 len = min_t(unsigned int, len, TCP_ULP_NAME_MAX); 3174 if (!icsk->icsk_ulp_ops) { 3175 if (put_user(0, optlen)) 3176 return -EFAULT; 3177 return 0; 3178 } 3179 if (put_user(len, optlen)) 3180 return -EFAULT; 3181 if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len)) 3182 return -EFAULT; 3183 return 0; 3184 3185 case TCP_FASTOPEN_KEY: { 3186 __u8 key[TCP_FASTOPEN_KEY_LENGTH]; 3187 struct tcp_fastopen_context *ctx; 3188 3189 if (get_user(len, optlen)) 3190 return -EFAULT; 3191 3192 rcu_read_lock(); 3193 ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx); 3194 if (ctx) 3195 memcpy(key, ctx->key, sizeof(key)); 3196 else 3197 len = 0; 3198 rcu_read_unlock(); 3199 3200 len = min_t(unsigned int, len, sizeof(key)); 3201 if (put_user(len, optlen)) 3202 return -EFAULT; 3203 if (copy_to_user(optval, key, len)) 3204 return -EFAULT; 3205 return 0; 3206 } 3207 case TCP_THIN_LINEAR_TIMEOUTS: 3208 val = tp->thin_lto; 3209 break; 3210 3211 case TCP_THIN_DUPACK: 3212 val = 0; 3213 break; 3214 3215 case TCP_REPAIR: 3216 val = tp->repair; 3217 break; 3218 3219 case TCP_REPAIR_QUEUE: 3220 if (tp->repair) 3221 val = tp->repair_queue; 3222 else 3223 return -EINVAL; 3224 break; 3225 3226 case TCP_REPAIR_WINDOW: { 3227 struct tcp_repair_window opt; 3228 3229 if (get_user(len, optlen)) 3230 return -EFAULT; 3231 3232 if (len != sizeof(opt)) 3233 return -EINVAL; 3234 3235 if (!tp->repair) 3236 return -EPERM; 3237 3238 opt.snd_wl1 = tp->snd_wl1; 3239 opt.snd_wnd = tp->snd_wnd; 3240 opt.max_window = tp->max_window; 3241 opt.rcv_wnd = tp->rcv_wnd; 3242 opt.rcv_wup = tp->rcv_wup; 3243 3244 if (copy_to_user(optval, &opt, len)) 3245 return -EFAULT; 3246 return 0; 3247 } 3248 case TCP_QUEUE_SEQ: 3249 if (tp->repair_queue == TCP_SEND_QUEUE) 3250 val = tp->write_seq; 3251 else if (tp->repair_queue == TCP_RECV_QUEUE) 3252 val = tp->rcv_nxt; 3253 else 3254 return -EINVAL; 3255 break; 3256 3257 case TCP_USER_TIMEOUT: 3258 val = jiffies_to_msecs(icsk->icsk_user_timeout); 3259 break; 3260 3261 case TCP_FASTOPEN: 3262 val = icsk->icsk_accept_queue.fastopenq.max_qlen; 3263 break; 3264 3265 case TCP_FASTOPEN_CONNECT: 3266 val = tp->fastopen_connect; 3267 break; 3268 3269 case TCP_FASTOPEN_NO_COOKIE: 3270 val = tp->fastopen_no_cookie; 3271 break; 3272 3273 case TCP_TIMESTAMP: 3274 val = tcp_time_stamp_raw() + tp->tsoffset; 3275 break; 3276 case TCP_NOTSENT_LOWAT: 3277 val = tp->notsent_lowat; 3278 break; 3279 case TCP_SAVE_SYN: 3280 val = tp->save_syn; 3281 break; 3282 case TCP_SAVED_SYN: { 3283 if (get_user(len, optlen)) 3284 return -EFAULT; 3285 3286 lock_sock(sk); 3287 if (tp->saved_syn) { 3288 if (len < tp->saved_syn[0]) { 3289 if (put_user(tp->saved_syn[0], optlen)) { 3290 release_sock(sk); 3291 return -EFAULT; 3292 } 3293 release_sock(sk); 3294 return -EINVAL; 3295 } 3296 len = tp->saved_syn[0]; 3297 if (put_user(len, optlen)) { 3298 release_sock(sk); 3299 return -EFAULT; 3300 } 3301 if (copy_to_user(optval, tp->saved_syn + 1, len)) { 3302 release_sock(sk); 3303 return -EFAULT; 3304 } 3305 tcp_saved_syn_free(tp); 3306 release_sock(sk); 3307 } else { 3308 release_sock(sk); 3309 len = 0; 3310 if (put_user(len, optlen)) 3311 return -EFAULT; 3312 } 3313 return 0; 3314 } 3315 default: 3316 return -ENOPROTOOPT; 3317 } 3318 3319 if (put_user(len, optlen)) 3320 return -EFAULT; 3321 if (copy_to_user(optval, &val, len)) 3322 return -EFAULT; 3323 return 0; 3324 } 3325 3326 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 3327 int __user *optlen) 3328 { 3329 struct inet_connection_sock *icsk = inet_csk(sk); 3330 3331 if (level != SOL_TCP) 3332 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 3333 optval, optlen); 3334 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 3335 } 3336 EXPORT_SYMBOL(tcp_getsockopt); 3337 3338 #ifdef CONFIG_COMPAT 3339 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 3340 char __user *optval, int __user *optlen) 3341 { 3342 if (level != SOL_TCP) 3343 return inet_csk_compat_getsockopt(sk, level, optname, 3344 optval, optlen); 3345 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 3346 } 3347 EXPORT_SYMBOL(compat_tcp_getsockopt); 3348 #endif 3349 3350 #ifdef CONFIG_TCP_MD5SIG 3351 static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool); 3352 static DEFINE_MUTEX(tcp_md5sig_mutex); 3353 static bool tcp_md5sig_pool_populated = false; 3354 3355 static void __tcp_alloc_md5sig_pool(void) 3356 { 3357 struct crypto_ahash *hash; 3358 int cpu; 3359 3360 hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC); 3361 if (IS_ERR(hash)) 3362 return; 3363 3364 for_each_possible_cpu(cpu) { 3365 void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch; 3366 struct ahash_request *req; 3367 3368 if (!scratch) { 3369 scratch = kmalloc_node(sizeof(union tcp_md5sum_block) + 3370 sizeof(struct tcphdr), 3371 GFP_KERNEL, 3372 cpu_to_node(cpu)); 3373 if (!scratch) 3374 return; 3375 per_cpu(tcp_md5sig_pool, cpu).scratch = scratch; 3376 } 3377 if (per_cpu(tcp_md5sig_pool, cpu).md5_req) 3378 continue; 3379 3380 req = ahash_request_alloc(hash, GFP_KERNEL); 3381 if (!req) 3382 return; 3383 3384 ahash_request_set_callback(req, 0, NULL, NULL); 3385 3386 per_cpu(tcp_md5sig_pool, cpu).md5_req = req; 3387 } 3388 /* before setting tcp_md5sig_pool_populated, we must commit all writes 3389 * to memory. See smp_rmb() in tcp_get_md5sig_pool() 3390 */ 3391 smp_wmb(); 3392 tcp_md5sig_pool_populated = true; 3393 } 3394 3395 bool tcp_alloc_md5sig_pool(void) 3396 { 3397 if (unlikely(!tcp_md5sig_pool_populated)) { 3398 mutex_lock(&tcp_md5sig_mutex); 3399 3400 if (!tcp_md5sig_pool_populated) 3401 __tcp_alloc_md5sig_pool(); 3402 3403 mutex_unlock(&tcp_md5sig_mutex); 3404 } 3405 return tcp_md5sig_pool_populated; 3406 } 3407 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 3408 3409 3410 /** 3411 * tcp_get_md5sig_pool - get md5sig_pool for this user 3412 * 3413 * We use percpu structure, so if we succeed, we exit with preemption 3414 * and BH disabled, to make sure another thread or softirq handling 3415 * wont try to get same context. 3416 */ 3417 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 3418 { 3419 local_bh_disable(); 3420 3421 if (tcp_md5sig_pool_populated) { 3422 /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */ 3423 smp_rmb(); 3424 return this_cpu_ptr(&tcp_md5sig_pool); 3425 } 3426 local_bh_enable(); 3427 return NULL; 3428 } 3429 EXPORT_SYMBOL(tcp_get_md5sig_pool); 3430 3431 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 3432 const struct sk_buff *skb, unsigned int header_len) 3433 { 3434 struct scatterlist sg; 3435 const struct tcphdr *tp = tcp_hdr(skb); 3436 struct ahash_request *req = hp->md5_req; 3437 unsigned int i; 3438 const unsigned int head_data_len = skb_headlen(skb) > header_len ? 3439 skb_headlen(skb) - header_len : 0; 3440 const struct skb_shared_info *shi = skb_shinfo(skb); 3441 struct sk_buff *frag_iter; 3442 3443 sg_init_table(&sg, 1); 3444 3445 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3446 ahash_request_set_crypt(req, &sg, NULL, head_data_len); 3447 if (crypto_ahash_update(req)) 3448 return 1; 3449 3450 for (i = 0; i < shi->nr_frags; ++i) { 3451 const struct skb_frag_struct *f = &shi->frags[i]; 3452 unsigned int offset = f->page_offset; 3453 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); 3454 3455 sg_set_page(&sg, page, skb_frag_size(f), 3456 offset_in_page(offset)); 3457 ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f)); 3458 if (crypto_ahash_update(req)) 3459 return 1; 3460 } 3461 3462 skb_walk_frags(skb, frag_iter) 3463 if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) 3464 return 1; 3465 3466 return 0; 3467 } 3468 EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3469 3470 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) 3471 { 3472 struct scatterlist sg; 3473 3474 sg_init_one(&sg, key->key, key->keylen); 3475 ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen); 3476 return crypto_ahash_update(hp->md5_req); 3477 } 3478 EXPORT_SYMBOL(tcp_md5_hash_key); 3479 3480 #endif 3481 3482 void tcp_done(struct sock *sk) 3483 { 3484 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 3485 3486 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3487 TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3488 3489 tcp_set_state(sk, TCP_CLOSE); 3490 tcp_clear_xmit_timers(sk); 3491 if (req) 3492 reqsk_fastopen_remove(sk, req, false); 3493 3494 sk->sk_shutdown = SHUTDOWN_MASK; 3495 3496 if (!sock_flag(sk, SOCK_DEAD)) 3497 sk->sk_state_change(sk); 3498 else 3499 inet_csk_destroy_sock(sk); 3500 } 3501 EXPORT_SYMBOL_GPL(tcp_done); 3502 3503 int tcp_abort(struct sock *sk, int err) 3504 { 3505 if (!sk_fullsock(sk)) { 3506 if (sk->sk_state == TCP_NEW_SYN_RECV) { 3507 struct request_sock *req = inet_reqsk(sk); 3508 3509 local_bh_disable(); 3510 inet_csk_reqsk_queue_drop_and_put(req->rsk_listener, 3511 req); 3512 local_bh_enable(); 3513 return 0; 3514 } 3515 return -EOPNOTSUPP; 3516 } 3517 3518 /* Don't race with userspace socket closes such as tcp_close. */ 3519 lock_sock(sk); 3520 3521 if (sk->sk_state == TCP_LISTEN) { 3522 tcp_set_state(sk, TCP_CLOSE); 3523 inet_csk_listen_stop(sk); 3524 } 3525 3526 /* Don't race with BH socket closes such as inet_csk_listen_stop. */ 3527 local_bh_disable(); 3528 bh_lock_sock(sk); 3529 3530 if (!sock_flag(sk, SOCK_DEAD)) { 3531 sk->sk_err = err; 3532 /* This barrier is coupled with smp_rmb() in tcp_poll() */ 3533 smp_wmb(); 3534 sk->sk_error_report(sk); 3535 if (tcp_need_reset(sk->sk_state)) 3536 tcp_send_active_reset(sk, GFP_ATOMIC); 3537 tcp_done(sk); 3538 } 3539 3540 bh_unlock_sock(sk); 3541 local_bh_enable(); 3542 release_sock(sk); 3543 return 0; 3544 } 3545 EXPORT_SYMBOL_GPL(tcp_abort); 3546 3547 extern struct tcp_congestion_ops tcp_reno; 3548 3549 static __initdata unsigned long thash_entries; 3550 static int __init set_thash_entries(char *str) 3551 { 3552 ssize_t ret; 3553 3554 if (!str) 3555 return 0; 3556 3557 ret = kstrtoul(str, 0, &thash_entries); 3558 if (ret) 3559 return 0; 3560 3561 return 1; 3562 } 3563 __setup("thash_entries=", set_thash_entries); 3564 3565 static void __init tcp_init_mem(void) 3566 { 3567 unsigned long limit = nr_free_buffer_pages() / 16; 3568 3569 limit = max(limit, 128UL); 3570 sysctl_tcp_mem[0] = limit / 4 * 3; /* 4.68 % */ 3571 sysctl_tcp_mem[1] = limit; /* 6.25 % */ 3572 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; /* 9.37 % */ 3573 } 3574 3575 void __init tcp_init(void) 3576 { 3577 int max_rshare, max_wshare, cnt; 3578 unsigned long limit; 3579 unsigned int i; 3580 3581 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > 3582 FIELD_SIZEOF(struct sk_buff, cb)); 3583 3584 percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); 3585 percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); 3586 inet_hashinfo_init(&tcp_hashinfo); 3587 inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash", 3588 thash_entries, 21, /* one slot per 2 MB*/ 3589 0, 64 * 1024); 3590 tcp_hashinfo.bind_bucket_cachep = 3591 kmem_cache_create("tcp_bind_bucket", 3592 sizeof(struct inet_bind_bucket), 0, 3593 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3594 3595 /* Size and allocate the main established and bind bucket 3596 * hash tables. 3597 * 3598 * The methodology is similar to that of the buffer cache. 3599 */ 3600 tcp_hashinfo.ehash = 3601 alloc_large_system_hash("TCP established", 3602 sizeof(struct inet_ehash_bucket), 3603 thash_entries, 3604 17, /* one slot per 128 KB of memory */ 3605 0, 3606 NULL, 3607 &tcp_hashinfo.ehash_mask, 3608 0, 3609 thash_entries ? 0 : 512 * 1024); 3610 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) 3611 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3612 3613 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3614 panic("TCP: failed to alloc ehash_locks"); 3615 tcp_hashinfo.bhash = 3616 alloc_large_system_hash("TCP bind", 3617 sizeof(struct inet_bind_hashbucket), 3618 tcp_hashinfo.ehash_mask + 1, 3619 17, /* one slot per 128 KB of memory */ 3620 0, 3621 &tcp_hashinfo.bhash_size, 3622 NULL, 3623 0, 3624 64 * 1024); 3625 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; 3626 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3627 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3628 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3629 } 3630 3631 3632 cnt = tcp_hashinfo.ehash_mask + 1; 3633 sysctl_tcp_max_orphans = cnt / 2; 3634 3635 tcp_init_mem(); 3636 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3637 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); 3638 max_wshare = min(4UL*1024*1024, limit); 3639 max_rshare = min(6UL*1024*1024, limit); 3640 3641 init_net.ipv4.sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3642 init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024; 3643 init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare); 3644 3645 init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3646 init_net.ipv4.sysctl_tcp_rmem[1] = 87380; 3647 init_net.ipv4.sysctl_tcp_rmem[2] = max(87380, max_rshare); 3648 3649 pr_info("Hash tables configured (established %u bind %u)\n", 3650 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3651 3652 tcp_v4_init(); 3653 tcp_metrics_init(); 3654 BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0); 3655 tcp_tasklet_init(); 3656 } 3657