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 <linux/kernel.h> 251 #include <linux/module.h> 252 #include <linux/types.h> 253 #include <linux/fcntl.h> 254 #include <linux/poll.h> 255 #include <linux/init.h> 256 #include <linux/fs.h> 257 #include <linux/skbuff.h> 258 #include <linux/scatterlist.h> 259 #include <linux/splice.h> 260 #include <linux/net.h> 261 #include <linux/socket.h> 262 #include <linux/random.h> 263 #include <linux/bootmem.h> 264 #include <linux/highmem.h> 265 #include <linux/swap.h> 266 #include <linux/cache.h> 267 #include <linux/err.h> 268 #include <linux/crypto.h> 269 #include <linux/time.h> 270 #include <linux/slab.h> 271 272 #include <net/icmp.h> 273 #include <net/inet_common.h> 274 #include <net/tcp.h> 275 #include <net/xfrm.h> 276 #include <net/ip.h> 277 #include <net/netdma.h> 278 #include <net/sock.h> 279 280 #include <asm/uaccess.h> 281 #include <asm/ioctls.h> 282 #include <net/busy_poll.h> 283 284 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 285 286 int sysctl_tcp_min_tso_segs __read_mostly = 2; 287 288 int sysctl_tcp_autocorking __read_mostly = 1; 289 290 struct percpu_counter tcp_orphan_count; 291 EXPORT_SYMBOL_GPL(tcp_orphan_count); 292 293 long sysctl_tcp_mem[3] __read_mostly; 294 int sysctl_tcp_wmem[3] __read_mostly; 295 int sysctl_tcp_rmem[3] __read_mostly; 296 297 EXPORT_SYMBOL(sysctl_tcp_mem); 298 EXPORT_SYMBOL(sysctl_tcp_rmem); 299 EXPORT_SYMBOL(sysctl_tcp_wmem); 300 301 atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ 302 EXPORT_SYMBOL(tcp_memory_allocated); 303 304 /* 305 * Current number of TCP sockets. 306 */ 307 struct percpu_counter tcp_sockets_allocated; 308 EXPORT_SYMBOL(tcp_sockets_allocated); 309 310 /* 311 * TCP splice context 312 */ 313 struct tcp_splice_state { 314 struct pipe_inode_info *pipe; 315 size_t len; 316 unsigned int flags; 317 }; 318 319 /* 320 * Pressure flag: try to collapse. 321 * Technical note: it is used by multiple contexts non atomically. 322 * All the __sk_mem_schedule() is of this nature: accounting 323 * is strict, actions are advisory and have some latency. 324 */ 325 int tcp_memory_pressure __read_mostly; 326 EXPORT_SYMBOL(tcp_memory_pressure); 327 328 void tcp_enter_memory_pressure(struct sock *sk) 329 { 330 if (!tcp_memory_pressure) { 331 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); 332 tcp_memory_pressure = 1; 333 } 334 } 335 EXPORT_SYMBOL(tcp_enter_memory_pressure); 336 337 /* Convert seconds to retransmits based on initial and max timeout */ 338 static u8 secs_to_retrans(int seconds, int timeout, int rto_max) 339 { 340 u8 res = 0; 341 342 if (seconds > 0) { 343 int period = timeout; 344 345 res = 1; 346 while (seconds > period && res < 255) { 347 res++; 348 timeout <<= 1; 349 if (timeout > rto_max) 350 timeout = rto_max; 351 period += timeout; 352 } 353 } 354 return res; 355 } 356 357 /* Convert retransmits to seconds based on initial and max timeout */ 358 static int retrans_to_secs(u8 retrans, int timeout, int rto_max) 359 { 360 int period = 0; 361 362 if (retrans > 0) { 363 period = timeout; 364 while (--retrans) { 365 timeout <<= 1; 366 if (timeout > rto_max) 367 timeout = rto_max; 368 period += timeout; 369 } 370 } 371 return period; 372 } 373 374 /* Address-family independent initialization for a tcp_sock. 375 * 376 * NOTE: A lot of things set to zero explicitly by call to 377 * sk_alloc() so need not be done here. 378 */ 379 void tcp_init_sock(struct sock *sk) 380 { 381 struct inet_connection_sock *icsk = inet_csk(sk); 382 struct tcp_sock *tp = tcp_sk(sk); 383 384 __skb_queue_head_init(&tp->out_of_order_queue); 385 tcp_init_xmit_timers(sk); 386 tcp_prequeue_init(tp); 387 INIT_LIST_HEAD(&tp->tsq_node); 388 389 icsk->icsk_rto = TCP_TIMEOUT_INIT; 390 tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); 391 392 /* So many TCP implementations out there (incorrectly) count the 393 * initial SYN frame in their delayed-ACK and congestion control 394 * algorithms that we must have the following bandaid to talk 395 * efficiently to them. -DaveM 396 */ 397 tp->snd_cwnd = TCP_INIT_CWND; 398 399 /* See draft-stevens-tcpca-spec-01 for discussion of the 400 * initialization of these values. 401 */ 402 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 403 tp->snd_cwnd_clamp = ~0; 404 tp->mss_cache = TCP_MSS_DEFAULT; 405 406 tp->reordering = sysctl_tcp_reordering; 407 tcp_enable_early_retrans(tp); 408 icsk->icsk_ca_ops = &tcp_init_congestion_ops; 409 410 tp->tsoffset = 0; 411 412 sk->sk_state = TCP_CLOSE; 413 414 sk->sk_write_space = sk_stream_write_space; 415 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); 416 417 icsk->icsk_sync_mss = tcp_sync_mss; 418 419 sk->sk_sndbuf = sysctl_tcp_wmem[1]; 420 sk->sk_rcvbuf = sysctl_tcp_rmem[1]; 421 422 local_bh_disable(); 423 sock_update_memcg(sk); 424 sk_sockets_allocated_inc(sk); 425 local_bh_enable(); 426 } 427 EXPORT_SYMBOL(tcp_init_sock); 428 429 /* 430 * Wait for a TCP event. 431 * 432 * Note that we don't need to lock the socket, as the upper poll layers 433 * take care of normal races (between the test and the event) and we don't 434 * go look at any of the socket buffers directly. 435 */ 436 unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 437 { 438 unsigned int mask; 439 struct sock *sk = sock->sk; 440 const struct tcp_sock *tp = tcp_sk(sk); 441 442 sock_rps_record_flow(sk); 443 444 sock_poll_wait(file, sk_sleep(sk), wait); 445 if (sk->sk_state == TCP_LISTEN) 446 return inet_csk_listen_poll(sk); 447 448 /* Socket is not locked. We are protected from async events 449 * by poll logic and correct handling of state changes 450 * made by other threads is impossible in any case. 451 */ 452 453 mask = 0; 454 455 /* 456 * POLLHUP is certainly not done right. But poll() doesn't 457 * have a notion of HUP in just one direction, and for a 458 * socket the read side is more interesting. 459 * 460 * Some poll() documentation says that POLLHUP is incompatible 461 * with the POLLOUT/POLLWR flags, so somebody should check this 462 * all. But careful, it tends to be safer to return too many 463 * bits than too few, and you can easily break real applications 464 * if you don't tell them that something has hung up! 465 * 466 * Check-me. 467 * 468 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and 469 * our fs/select.c). It means that after we received EOF, 470 * poll always returns immediately, making impossible poll() on write() 471 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP 472 * if and only if shutdown has been made in both directions. 473 * Actually, it is interesting to look how Solaris and DUX 474 * solve this dilemma. I would prefer, if POLLHUP were maskable, 475 * then we could set it on SND_SHUTDOWN. BTW examples given 476 * in Stevens' books assume exactly this behaviour, it explains 477 * why POLLHUP is incompatible with POLLOUT. --ANK 478 * 479 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 480 * blocking on fresh not-connected or disconnected socket. --ANK 481 */ 482 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) 483 mask |= POLLHUP; 484 if (sk->sk_shutdown & RCV_SHUTDOWN) 485 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 486 487 /* Connected or passive Fast Open socket? */ 488 if (sk->sk_state != TCP_SYN_SENT && 489 (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk != NULL)) { 490 int target = sock_rcvlowat(sk, 0, INT_MAX); 491 492 if (tp->urg_seq == tp->copied_seq && 493 !sock_flag(sk, SOCK_URGINLINE) && 494 tp->urg_data) 495 target++; 496 497 /* Potential race condition. If read of tp below will 498 * escape above sk->sk_state, we can be illegally awaken 499 * in SYN_* states. */ 500 if (tp->rcv_nxt - tp->copied_seq >= target) 501 mask |= POLLIN | POLLRDNORM; 502 503 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 504 if (sk_stream_is_writeable(sk)) { 505 mask |= POLLOUT | POLLWRNORM; 506 } else { /* send SIGIO later */ 507 set_bit(SOCK_ASYNC_NOSPACE, 508 &sk->sk_socket->flags); 509 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 510 511 /* Race breaker. If space is freed after 512 * wspace test but before the flags are set, 513 * IO signal will be lost. 514 */ 515 if (sk_stream_is_writeable(sk)) 516 mask |= POLLOUT | POLLWRNORM; 517 } 518 } else 519 mask |= POLLOUT | POLLWRNORM; 520 521 if (tp->urg_data & TCP_URG_VALID) 522 mask |= POLLPRI; 523 } 524 /* This barrier is coupled with smp_wmb() in tcp_reset() */ 525 smp_rmb(); 526 if (sk->sk_err) 527 mask |= POLLERR; 528 529 return mask; 530 } 531 EXPORT_SYMBOL(tcp_poll); 532 533 int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 534 { 535 struct tcp_sock *tp = tcp_sk(sk); 536 int answ; 537 bool slow; 538 539 switch (cmd) { 540 case SIOCINQ: 541 if (sk->sk_state == TCP_LISTEN) 542 return -EINVAL; 543 544 slow = lock_sock_fast(sk); 545 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 546 answ = 0; 547 else if (sock_flag(sk, SOCK_URGINLINE) || 548 !tp->urg_data || 549 before(tp->urg_seq, tp->copied_seq) || 550 !before(tp->urg_seq, tp->rcv_nxt)) { 551 552 answ = tp->rcv_nxt - tp->copied_seq; 553 554 /* Subtract 1, if FIN was received */ 555 if (answ && sock_flag(sk, SOCK_DONE)) 556 answ--; 557 } else 558 answ = tp->urg_seq - tp->copied_seq; 559 unlock_sock_fast(sk, slow); 560 break; 561 case SIOCATMARK: 562 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 563 break; 564 case SIOCOUTQ: 565 if (sk->sk_state == TCP_LISTEN) 566 return -EINVAL; 567 568 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 569 answ = 0; 570 else 571 answ = tp->write_seq - tp->snd_una; 572 break; 573 case SIOCOUTQNSD: 574 if (sk->sk_state == TCP_LISTEN) 575 return -EINVAL; 576 577 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 578 answ = 0; 579 else 580 answ = tp->write_seq - tp->snd_nxt; 581 break; 582 default: 583 return -ENOIOCTLCMD; 584 } 585 586 return put_user(answ, (int __user *)arg); 587 } 588 EXPORT_SYMBOL(tcp_ioctl); 589 590 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 591 { 592 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; 593 tp->pushed_seq = tp->write_seq; 594 } 595 596 static inline bool forced_push(const struct tcp_sock *tp) 597 { 598 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 599 } 600 601 static inline void skb_entail(struct sock *sk, struct sk_buff *skb) 602 { 603 struct tcp_sock *tp = tcp_sk(sk); 604 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 605 606 skb->csum = 0; 607 tcb->seq = tcb->end_seq = tp->write_seq; 608 tcb->tcp_flags = TCPHDR_ACK; 609 tcb->sacked = 0; 610 skb_header_release(skb); 611 tcp_add_write_queue_tail(sk, skb); 612 sk->sk_wmem_queued += skb->truesize; 613 sk_mem_charge(sk, skb->truesize); 614 if (tp->nonagle & TCP_NAGLE_PUSH) 615 tp->nonagle &= ~TCP_NAGLE_PUSH; 616 } 617 618 static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) 619 { 620 if (flags & MSG_OOB) 621 tp->snd_up = tp->write_seq; 622 } 623 624 /* If a not yet filled skb is pushed, do not send it if 625 * we have data packets in Qdisc or NIC queues : 626 * Because TX completion will happen shortly, it gives a chance 627 * to coalesce future sendmsg() payload into this skb, without 628 * need for a timer, and with no latency trade off. 629 * As packets containing data payload have a bigger truesize 630 * than pure acks (dataless) packets, the last checks prevent 631 * autocorking if we only have an ACK in Qdisc/NIC queues, 632 * or if TX completion was delayed after we processed ACK packet. 633 */ 634 static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, 635 int size_goal) 636 { 637 return skb->len < size_goal && 638 sysctl_tcp_autocorking && 639 skb != tcp_write_queue_head(sk) && 640 atomic_read(&sk->sk_wmem_alloc) > skb->truesize; 641 } 642 643 static void tcp_push(struct sock *sk, int flags, int mss_now, 644 int nonagle, int size_goal) 645 { 646 struct tcp_sock *tp = tcp_sk(sk); 647 struct sk_buff *skb; 648 649 if (!tcp_send_head(sk)) 650 return; 651 652 skb = tcp_write_queue_tail(sk); 653 if (!(flags & MSG_MORE) || forced_push(tp)) 654 tcp_mark_push(tp, skb); 655 656 tcp_mark_urg(tp, flags); 657 658 if (tcp_should_autocork(sk, skb, size_goal)) { 659 660 /* avoid atomic op if TSQ_THROTTLED bit is already set */ 661 if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) { 662 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING); 663 set_bit(TSQ_THROTTLED, &tp->tsq_flags); 664 } 665 /* It is possible TX completion already happened 666 * before we set TSQ_THROTTLED. 667 */ 668 if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize) 669 return; 670 } 671 672 if (flags & MSG_MORE) 673 nonagle = TCP_NAGLE_CORK; 674 675 __tcp_push_pending_frames(sk, mss_now, nonagle); 676 } 677 678 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 679 unsigned int offset, size_t len) 680 { 681 struct tcp_splice_state *tss = rd_desc->arg.data; 682 int ret; 683 684 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len), 685 tss->flags); 686 if (ret > 0) 687 rd_desc->count -= ret; 688 return ret; 689 } 690 691 static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 692 { 693 /* Store TCP splice context information in read_descriptor_t. */ 694 read_descriptor_t rd_desc = { 695 .arg.data = tss, 696 .count = tss->len, 697 }; 698 699 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 700 } 701 702 /** 703 * tcp_splice_read - splice data from TCP socket to a pipe 704 * @sock: socket to splice from 705 * @ppos: position (not valid) 706 * @pipe: pipe to splice to 707 * @len: number of bytes to splice 708 * @flags: splice modifier flags 709 * 710 * Description: 711 * Will read pages from given socket and fill them into a pipe. 712 * 713 **/ 714 ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 715 struct pipe_inode_info *pipe, size_t len, 716 unsigned int flags) 717 { 718 struct sock *sk = sock->sk; 719 struct tcp_splice_state tss = { 720 .pipe = pipe, 721 .len = len, 722 .flags = flags, 723 }; 724 long timeo; 725 ssize_t spliced; 726 int ret; 727 728 sock_rps_record_flow(sk); 729 /* 730 * We can't seek on a socket input 731 */ 732 if (unlikely(*ppos)) 733 return -ESPIPE; 734 735 ret = spliced = 0; 736 737 lock_sock(sk); 738 739 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 740 while (tss.len) { 741 ret = __tcp_splice_read(sk, &tss); 742 if (ret < 0) 743 break; 744 else if (!ret) { 745 if (spliced) 746 break; 747 if (sock_flag(sk, SOCK_DONE)) 748 break; 749 if (sk->sk_err) { 750 ret = sock_error(sk); 751 break; 752 } 753 if (sk->sk_shutdown & RCV_SHUTDOWN) 754 break; 755 if (sk->sk_state == TCP_CLOSE) { 756 /* 757 * This occurs when user tries to read 758 * from never connected socket. 759 */ 760 if (!sock_flag(sk, SOCK_DONE)) 761 ret = -ENOTCONN; 762 break; 763 } 764 if (!timeo) { 765 ret = -EAGAIN; 766 break; 767 } 768 sk_wait_data(sk, &timeo); 769 if (signal_pending(current)) { 770 ret = sock_intr_errno(timeo); 771 break; 772 } 773 continue; 774 } 775 tss.len -= ret; 776 spliced += ret; 777 778 if (!timeo) 779 break; 780 release_sock(sk); 781 lock_sock(sk); 782 783 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 784 (sk->sk_shutdown & RCV_SHUTDOWN) || 785 signal_pending(current)) 786 break; 787 } 788 789 release_sock(sk); 790 791 if (spliced) 792 return spliced; 793 794 return ret; 795 } 796 EXPORT_SYMBOL(tcp_splice_read); 797 798 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 799 { 800 struct sk_buff *skb; 801 802 /* The TCP header must be at least 32-bit aligned. */ 803 size = ALIGN(size, 4); 804 805 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 806 if (skb) { 807 if (sk_wmem_schedule(sk, skb->truesize)) { 808 skb_reserve(skb, sk->sk_prot->max_header); 809 /* 810 * Make sure that we have exactly size bytes 811 * available to the caller, no more, no less. 812 */ 813 skb->reserved_tailroom = skb->end - skb->tail - size; 814 return skb; 815 } 816 __kfree_skb(skb); 817 } else { 818 sk->sk_prot->enter_memory_pressure(sk); 819 sk_stream_moderate_sndbuf(sk); 820 } 821 return NULL; 822 } 823 824 static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 825 int large_allowed) 826 { 827 struct tcp_sock *tp = tcp_sk(sk); 828 u32 xmit_size_goal, old_size_goal; 829 830 xmit_size_goal = mss_now; 831 832 if (large_allowed && sk_can_gso(sk)) { 833 u32 gso_size, hlen; 834 835 /* Maybe we should/could use sk->sk_prot->max_header here ? */ 836 hlen = inet_csk(sk)->icsk_af_ops->net_header_len + 837 inet_csk(sk)->icsk_ext_hdr_len + 838 tp->tcp_header_len; 839 840 /* Goal is to send at least one packet per ms, 841 * not one big TSO packet every 100 ms. 842 * This preserves ACK clocking and is consistent 843 * with tcp_tso_should_defer() heuristic. 844 */ 845 gso_size = sk->sk_pacing_rate / (2 * MSEC_PER_SEC); 846 gso_size = max_t(u32, gso_size, 847 sysctl_tcp_min_tso_segs * mss_now); 848 849 xmit_size_goal = min_t(u32, gso_size, 850 sk->sk_gso_max_size - 1 - hlen); 851 852 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal); 853 854 /* We try hard to avoid divides here */ 855 old_size_goal = tp->xmit_size_goal_segs * mss_now; 856 857 if (likely(old_size_goal <= xmit_size_goal && 858 old_size_goal + mss_now > xmit_size_goal)) { 859 xmit_size_goal = old_size_goal; 860 } else { 861 tp->xmit_size_goal_segs = 862 min_t(u16, xmit_size_goal / mss_now, 863 sk->sk_gso_max_segs); 864 xmit_size_goal = tp->xmit_size_goal_segs * mss_now; 865 } 866 } 867 868 return max(xmit_size_goal, mss_now); 869 } 870 871 static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 872 { 873 int mss_now; 874 875 mss_now = tcp_current_mss(sk); 876 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 877 878 return mss_now; 879 } 880 881 static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, 882 size_t size, int flags) 883 { 884 struct tcp_sock *tp = tcp_sk(sk); 885 int mss_now, size_goal; 886 int err; 887 ssize_t copied; 888 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 889 890 /* Wait for a connection to finish. One exception is TCP Fast Open 891 * (passive side) where data is allowed to be sent before a connection 892 * is fully established. 893 */ 894 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && 895 !tcp_passive_fastopen(sk)) { 896 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 897 goto out_err; 898 } 899 900 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 901 902 mss_now = tcp_send_mss(sk, &size_goal, flags); 903 copied = 0; 904 905 err = -EPIPE; 906 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 907 goto out_err; 908 909 while (size > 0) { 910 struct sk_buff *skb = tcp_write_queue_tail(sk); 911 int copy, i; 912 bool can_coalesce; 913 914 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 915 new_segment: 916 if (!sk_stream_memory_free(sk)) 917 goto wait_for_sndbuf; 918 919 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 920 if (!skb) 921 goto wait_for_memory; 922 923 skb_entail(sk, skb); 924 copy = size_goal; 925 } 926 927 if (copy > size) 928 copy = size; 929 930 i = skb_shinfo(skb)->nr_frags; 931 can_coalesce = skb_can_coalesce(skb, i, page, offset); 932 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 933 tcp_mark_push(tp, skb); 934 goto new_segment; 935 } 936 if (!sk_wmem_schedule(sk, copy)) 937 goto wait_for_memory; 938 939 if (can_coalesce) { 940 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 941 } else { 942 get_page(page); 943 skb_fill_page_desc(skb, i, page, offset, copy); 944 } 945 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 946 947 skb->len += copy; 948 skb->data_len += copy; 949 skb->truesize += copy; 950 sk->sk_wmem_queued += copy; 951 sk_mem_charge(sk, copy); 952 skb->ip_summed = CHECKSUM_PARTIAL; 953 tp->write_seq += copy; 954 TCP_SKB_CB(skb)->end_seq += copy; 955 skb_shinfo(skb)->gso_segs = 0; 956 957 if (!copied) 958 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 959 960 copied += copy; 961 offset += copy; 962 if (!(size -= copy)) 963 goto out; 964 965 if (skb->len < size_goal || (flags & MSG_OOB)) 966 continue; 967 968 if (forced_push(tp)) { 969 tcp_mark_push(tp, skb); 970 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 971 } else if (skb == tcp_send_head(sk)) 972 tcp_push_one(sk, mss_now); 973 continue; 974 975 wait_for_sndbuf: 976 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 977 wait_for_memory: 978 tcp_push(sk, flags & ~MSG_MORE, mss_now, 979 TCP_NAGLE_PUSH, size_goal); 980 981 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 982 goto do_error; 983 984 mss_now = tcp_send_mss(sk, &size_goal, flags); 985 } 986 987 out: 988 if (copied && !(flags & MSG_SENDPAGE_NOTLAST)) 989 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); 990 return copied; 991 992 do_error: 993 if (copied) 994 goto out; 995 out_err: 996 return sk_stream_error(sk, flags, err); 997 } 998 999 int tcp_sendpage(struct sock *sk, struct page *page, int offset, 1000 size_t size, int flags) 1001 { 1002 ssize_t res; 1003 1004 if (!(sk->sk_route_caps & NETIF_F_SG) || 1005 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 1006 return sock_no_sendpage(sk->sk_socket, page, offset, size, 1007 flags); 1008 1009 lock_sock(sk); 1010 res = do_tcp_sendpages(sk, page, offset, size, flags); 1011 release_sock(sk); 1012 return res; 1013 } 1014 EXPORT_SYMBOL(tcp_sendpage); 1015 1016 static inline int select_size(const struct sock *sk, bool sg) 1017 { 1018 const struct tcp_sock *tp = tcp_sk(sk); 1019 int tmp = tp->mss_cache; 1020 1021 if (sg) { 1022 if (sk_can_gso(sk)) { 1023 /* Small frames wont use a full page: 1024 * Payload will immediately follow tcp header. 1025 */ 1026 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); 1027 } else { 1028 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 1029 1030 if (tmp >= pgbreak && 1031 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 1032 tmp = pgbreak; 1033 } 1034 } 1035 1036 return tmp; 1037 } 1038 1039 void tcp_free_fastopen_req(struct tcp_sock *tp) 1040 { 1041 if (tp->fastopen_req != NULL) { 1042 kfree(tp->fastopen_req); 1043 tp->fastopen_req = NULL; 1044 } 1045 } 1046 1047 static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, 1048 int *copied, size_t size) 1049 { 1050 struct tcp_sock *tp = tcp_sk(sk); 1051 int err, flags; 1052 1053 if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE)) 1054 return -EOPNOTSUPP; 1055 if (tp->fastopen_req != NULL) 1056 return -EALREADY; /* Another Fast Open is in progress */ 1057 1058 tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request), 1059 sk->sk_allocation); 1060 if (unlikely(tp->fastopen_req == NULL)) 1061 return -ENOBUFS; 1062 tp->fastopen_req->data = msg; 1063 tp->fastopen_req->size = size; 1064 1065 flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0; 1066 err = __inet_stream_connect(sk->sk_socket, msg->msg_name, 1067 msg->msg_namelen, flags); 1068 *copied = tp->fastopen_req->copied; 1069 tcp_free_fastopen_req(tp); 1070 return err; 1071 } 1072 1073 int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1074 size_t size) 1075 { 1076 struct iovec *iov; 1077 struct tcp_sock *tp = tcp_sk(sk); 1078 struct sk_buff *skb; 1079 int iovlen, flags, err, copied = 0; 1080 int mss_now = 0, size_goal, copied_syn = 0, offset = 0; 1081 bool sg; 1082 long timeo; 1083 1084 lock_sock(sk); 1085 1086 flags = msg->msg_flags; 1087 if (flags & MSG_FASTOPEN) { 1088 err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size); 1089 if (err == -EINPROGRESS && copied_syn > 0) 1090 goto out; 1091 else if (err) 1092 goto out_err; 1093 offset = copied_syn; 1094 } 1095 1096 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 1097 1098 /* Wait for a connection to finish. One exception is TCP Fast Open 1099 * (passive side) where data is allowed to be sent before a connection 1100 * is fully established. 1101 */ 1102 if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && 1103 !tcp_passive_fastopen(sk)) { 1104 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 1105 goto do_error; 1106 } 1107 1108 if (unlikely(tp->repair)) { 1109 if (tp->repair_queue == TCP_RECV_QUEUE) { 1110 copied = tcp_send_rcvq(sk, msg, size); 1111 goto out; 1112 } 1113 1114 err = -EINVAL; 1115 if (tp->repair_queue == TCP_NO_QUEUE) 1116 goto out_err; 1117 1118 /* 'common' sending to sendq */ 1119 } 1120 1121 /* This should be in poll */ 1122 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 1123 1124 mss_now = tcp_send_mss(sk, &size_goal, flags); 1125 1126 /* Ok commence sending. */ 1127 iovlen = msg->msg_iovlen; 1128 iov = msg->msg_iov; 1129 copied = 0; 1130 1131 err = -EPIPE; 1132 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 1133 goto out_err; 1134 1135 sg = !!(sk->sk_route_caps & NETIF_F_SG); 1136 1137 while (--iovlen >= 0) { 1138 size_t seglen = iov->iov_len; 1139 unsigned char __user *from = iov->iov_base; 1140 1141 iov++; 1142 if (unlikely(offset > 0)) { /* Skip bytes copied in SYN */ 1143 if (offset >= seglen) { 1144 offset -= seglen; 1145 continue; 1146 } 1147 seglen -= offset; 1148 from += offset; 1149 offset = 0; 1150 } 1151 1152 while (seglen > 0) { 1153 int copy = 0; 1154 int max = size_goal; 1155 1156 skb = tcp_write_queue_tail(sk); 1157 if (tcp_send_head(sk)) { 1158 if (skb->ip_summed == CHECKSUM_NONE) 1159 max = mss_now; 1160 copy = max - skb->len; 1161 } 1162 1163 if (copy <= 0) { 1164 new_segment: 1165 /* Allocate new segment. If the interface is SG, 1166 * allocate skb fitting to single page. 1167 */ 1168 if (!sk_stream_memory_free(sk)) 1169 goto wait_for_sndbuf; 1170 1171 skb = sk_stream_alloc_skb(sk, 1172 select_size(sk, sg), 1173 sk->sk_allocation); 1174 if (!skb) 1175 goto wait_for_memory; 1176 1177 /* 1178 * All packets are restored as if they have 1179 * already been sent. 1180 */ 1181 if (tp->repair) 1182 TCP_SKB_CB(skb)->when = tcp_time_stamp; 1183 1184 /* 1185 * Check whether we can use HW checksum. 1186 */ 1187 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 1188 skb->ip_summed = CHECKSUM_PARTIAL; 1189 1190 skb_entail(sk, skb); 1191 copy = size_goal; 1192 max = size_goal; 1193 } 1194 1195 /* Try to append data to the end of skb. */ 1196 if (copy > seglen) 1197 copy = seglen; 1198 1199 /* Where to copy to? */ 1200 if (skb_availroom(skb) > 0) { 1201 /* We have some space in skb head. Superb! */ 1202 copy = min_t(int, copy, skb_availroom(skb)); 1203 err = skb_add_data_nocache(sk, skb, from, copy); 1204 if (err) 1205 goto do_fault; 1206 } else { 1207 bool merge = true; 1208 int i = skb_shinfo(skb)->nr_frags; 1209 struct page_frag *pfrag = sk_page_frag(sk); 1210 1211 if (!sk_page_frag_refill(sk, pfrag)) 1212 goto wait_for_memory; 1213 1214 if (!skb_can_coalesce(skb, i, pfrag->page, 1215 pfrag->offset)) { 1216 if (i == MAX_SKB_FRAGS || !sg) { 1217 tcp_mark_push(tp, skb); 1218 goto new_segment; 1219 } 1220 merge = false; 1221 } 1222 1223 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1224 1225 if (!sk_wmem_schedule(sk, copy)) 1226 goto wait_for_memory; 1227 1228 err = skb_copy_to_page_nocache(sk, from, skb, 1229 pfrag->page, 1230 pfrag->offset, 1231 copy); 1232 if (err) 1233 goto do_error; 1234 1235 /* Update the skb. */ 1236 if (merge) { 1237 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1238 } else { 1239 skb_fill_page_desc(skb, i, pfrag->page, 1240 pfrag->offset, copy); 1241 get_page(pfrag->page); 1242 } 1243 pfrag->offset += copy; 1244 } 1245 1246 if (!copied) 1247 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1248 1249 tp->write_seq += copy; 1250 TCP_SKB_CB(skb)->end_seq += copy; 1251 skb_shinfo(skb)->gso_segs = 0; 1252 1253 from += copy; 1254 copied += copy; 1255 if ((seglen -= copy) == 0 && iovlen == 0) 1256 goto out; 1257 1258 if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair)) 1259 continue; 1260 1261 if (forced_push(tp)) { 1262 tcp_mark_push(tp, skb); 1263 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1264 } else if (skb == tcp_send_head(sk)) 1265 tcp_push_one(sk, mss_now); 1266 continue; 1267 1268 wait_for_sndbuf: 1269 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1270 wait_for_memory: 1271 if (copied) 1272 tcp_push(sk, flags & ~MSG_MORE, mss_now, 1273 TCP_NAGLE_PUSH, size_goal); 1274 1275 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1276 goto do_error; 1277 1278 mss_now = tcp_send_mss(sk, &size_goal, flags); 1279 } 1280 } 1281 1282 out: 1283 if (copied) 1284 tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); 1285 release_sock(sk); 1286 return copied + copied_syn; 1287 1288 do_fault: 1289 if (!skb->len) { 1290 tcp_unlink_write_queue(skb, sk); 1291 /* It is the one place in all of TCP, except connection 1292 * reset, where we can be unlinking the send_head. 1293 */ 1294 tcp_check_send_head(sk, skb); 1295 sk_wmem_free_skb(sk, skb); 1296 } 1297 1298 do_error: 1299 if (copied + copied_syn) 1300 goto out; 1301 out_err: 1302 err = sk_stream_error(sk, flags, err); 1303 release_sock(sk); 1304 return err; 1305 } 1306 EXPORT_SYMBOL(tcp_sendmsg); 1307 1308 /* 1309 * Handle reading urgent data. BSD has very simple semantics for 1310 * this, no blocking and very strange errors 8) 1311 */ 1312 1313 static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1314 { 1315 struct tcp_sock *tp = tcp_sk(sk); 1316 1317 /* No URG data to read. */ 1318 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1319 tp->urg_data == TCP_URG_READ) 1320 return -EINVAL; /* Yes this is right ! */ 1321 1322 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1323 return -ENOTCONN; 1324 1325 if (tp->urg_data & TCP_URG_VALID) { 1326 int err = 0; 1327 char c = tp->urg_data; 1328 1329 if (!(flags & MSG_PEEK)) 1330 tp->urg_data = TCP_URG_READ; 1331 1332 /* Read urgent data. */ 1333 msg->msg_flags |= MSG_OOB; 1334 1335 if (len > 0) { 1336 if (!(flags & MSG_TRUNC)) 1337 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1338 len = 1; 1339 } else 1340 msg->msg_flags |= MSG_TRUNC; 1341 1342 return err ? -EFAULT : len; 1343 } 1344 1345 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1346 return 0; 1347 1348 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1349 * the available implementations agree in this case: 1350 * this call should never block, independent of the 1351 * blocking state of the socket. 1352 * Mike <pall@rz.uni-karlsruhe.de> 1353 */ 1354 return -EAGAIN; 1355 } 1356 1357 static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len) 1358 { 1359 struct sk_buff *skb; 1360 int copied = 0, err = 0; 1361 1362 /* XXX -- need to support SO_PEEK_OFF */ 1363 1364 skb_queue_walk(&sk->sk_write_queue, skb) { 1365 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, skb->len); 1366 if (err) 1367 break; 1368 1369 copied += skb->len; 1370 } 1371 1372 return err ?: copied; 1373 } 1374 1375 /* Clean up the receive buffer for full frames taken by the user, 1376 * then send an ACK if necessary. COPIED is the number of bytes 1377 * tcp_recvmsg has given to the user so far, it speeds up the 1378 * calculation of whether or not we must ACK for the sake of 1379 * a window update. 1380 */ 1381 void tcp_cleanup_rbuf(struct sock *sk, int copied) 1382 { 1383 struct tcp_sock *tp = tcp_sk(sk); 1384 bool time_to_ack = false; 1385 1386 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1387 1388 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1389 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1390 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1391 1392 if (inet_csk_ack_scheduled(sk)) { 1393 const struct inet_connection_sock *icsk = inet_csk(sk); 1394 /* Delayed ACKs frequently hit locked sockets during bulk 1395 * receive. */ 1396 if (icsk->icsk_ack.blocked || 1397 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1398 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1399 /* 1400 * If this read emptied read buffer, we send ACK, if 1401 * connection is not bidirectional, user drained 1402 * receive buffer and there was a small segment 1403 * in queue. 1404 */ 1405 (copied > 0 && 1406 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1407 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1408 !icsk->icsk_ack.pingpong)) && 1409 !atomic_read(&sk->sk_rmem_alloc))) 1410 time_to_ack = true; 1411 } 1412 1413 /* We send an ACK if we can now advertise a non-zero window 1414 * which has been raised "significantly". 1415 * 1416 * Even if window raised up to infinity, do not send window open ACK 1417 * in states, where we will not receive more. It is useless. 1418 */ 1419 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1420 __u32 rcv_window_now = tcp_receive_window(tp); 1421 1422 /* Optimize, __tcp_select_window() is not cheap. */ 1423 if (2*rcv_window_now <= tp->window_clamp) { 1424 __u32 new_window = __tcp_select_window(sk); 1425 1426 /* Send ACK now, if this read freed lots of space 1427 * in our buffer. Certainly, new_window is new window. 1428 * We can advertise it now, if it is not less than current one. 1429 * "Lots" means "at least twice" here. 1430 */ 1431 if (new_window && new_window >= 2 * rcv_window_now) 1432 time_to_ack = true; 1433 } 1434 } 1435 if (time_to_ack) 1436 tcp_send_ack(sk); 1437 } 1438 1439 static void tcp_prequeue_process(struct sock *sk) 1440 { 1441 struct sk_buff *skb; 1442 struct tcp_sock *tp = tcp_sk(sk); 1443 1444 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); 1445 1446 /* RX process wants to run with disabled BHs, though it is not 1447 * necessary */ 1448 local_bh_disable(); 1449 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1450 sk_backlog_rcv(sk, skb); 1451 local_bh_enable(); 1452 1453 /* Clear memory counter. */ 1454 tp->ucopy.memory = 0; 1455 } 1456 1457 #ifdef CONFIG_NET_DMA 1458 static void tcp_service_net_dma(struct sock *sk, bool wait) 1459 { 1460 dma_cookie_t done, used; 1461 dma_cookie_t last_issued; 1462 struct tcp_sock *tp = tcp_sk(sk); 1463 1464 if (!tp->ucopy.dma_chan) 1465 return; 1466 1467 last_issued = tp->ucopy.dma_cookie; 1468 dma_async_issue_pending(tp->ucopy.dma_chan); 1469 1470 do { 1471 if (dma_async_is_tx_complete(tp->ucopy.dma_chan, 1472 last_issued, &done, 1473 &used) == DMA_COMPLETE) { 1474 /* Safe to free early-copied skbs now */ 1475 __skb_queue_purge(&sk->sk_async_wait_queue); 1476 break; 1477 } else { 1478 struct sk_buff *skb; 1479 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1480 (dma_async_is_complete(skb->dma_cookie, done, 1481 used) == DMA_COMPLETE)) { 1482 __skb_dequeue(&sk->sk_async_wait_queue); 1483 kfree_skb(skb); 1484 } 1485 } 1486 } while (wait); 1487 } 1488 #endif 1489 1490 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1491 { 1492 struct sk_buff *skb; 1493 u32 offset; 1494 1495 while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { 1496 offset = seq - TCP_SKB_CB(skb)->seq; 1497 if (tcp_hdr(skb)->syn) 1498 offset--; 1499 if (offset < skb->len || tcp_hdr(skb)->fin) { 1500 *off = offset; 1501 return skb; 1502 } 1503 /* This looks weird, but this can happen if TCP collapsing 1504 * splitted a fat GRO packet, while we released socket lock 1505 * in skb_splice_bits() 1506 */ 1507 sk_eat_skb(sk, skb, false); 1508 } 1509 return NULL; 1510 } 1511 1512 /* 1513 * This routine provides an alternative to tcp_recvmsg() for routines 1514 * that would like to handle copying from skbuffs directly in 'sendfile' 1515 * fashion. 1516 * Note: 1517 * - It is assumed that the socket was locked by the caller. 1518 * - The routine does not block. 1519 * - At present, there is no support for reading OOB data 1520 * or for 'peeking' the socket using this routine 1521 * (although both would be easy to implement). 1522 */ 1523 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1524 sk_read_actor_t recv_actor) 1525 { 1526 struct sk_buff *skb; 1527 struct tcp_sock *tp = tcp_sk(sk); 1528 u32 seq = tp->copied_seq; 1529 u32 offset; 1530 int copied = 0; 1531 1532 if (sk->sk_state == TCP_LISTEN) 1533 return -ENOTCONN; 1534 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1535 if (offset < skb->len) { 1536 int used; 1537 size_t len; 1538 1539 len = skb->len - offset; 1540 /* Stop reading if we hit a patch of urgent data */ 1541 if (tp->urg_data) { 1542 u32 urg_offset = tp->urg_seq - seq; 1543 if (urg_offset < len) 1544 len = urg_offset; 1545 if (!len) 1546 break; 1547 } 1548 used = recv_actor(desc, skb, offset, len); 1549 if (used <= 0) { 1550 if (!copied) 1551 copied = used; 1552 break; 1553 } else if (used <= len) { 1554 seq += used; 1555 copied += used; 1556 offset += used; 1557 } 1558 /* If recv_actor drops the lock (e.g. TCP splice 1559 * receive) the skb pointer might be invalid when 1560 * getting here: tcp_collapse might have deleted it 1561 * while aggregating skbs from the socket queue. 1562 */ 1563 skb = tcp_recv_skb(sk, seq - 1, &offset); 1564 if (!skb) 1565 break; 1566 /* TCP coalescing might have appended data to the skb. 1567 * Try to splice more frags 1568 */ 1569 if (offset + 1 != skb->len) 1570 continue; 1571 } 1572 if (tcp_hdr(skb)->fin) { 1573 sk_eat_skb(sk, skb, false); 1574 ++seq; 1575 break; 1576 } 1577 sk_eat_skb(sk, skb, false); 1578 if (!desc->count) 1579 break; 1580 tp->copied_seq = seq; 1581 } 1582 tp->copied_seq = seq; 1583 1584 tcp_rcv_space_adjust(sk); 1585 1586 /* Clean up data we have read: This will do ACK frames. */ 1587 if (copied > 0) { 1588 tcp_recv_skb(sk, seq, &offset); 1589 tcp_cleanup_rbuf(sk, copied); 1590 } 1591 return copied; 1592 } 1593 EXPORT_SYMBOL(tcp_read_sock); 1594 1595 /* 1596 * This routine copies from a sock struct into the user buffer. 1597 * 1598 * Technical note: in 2.3 we work on _locked_ socket, so that 1599 * tricks with *seq access order and skb->users are not required. 1600 * Probably, code can be easily improved even more. 1601 */ 1602 1603 int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1604 size_t len, int nonblock, int flags, int *addr_len) 1605 { 1606 struct tcp_sock *tp = tcp_sk(sk); 1607 int copied = 0; 1608 u32 peek_seq; 1609 u32 *seq; 1610 unsigned long used; 1611 int err; 1612 int target; /* Read at least this many bytes */ 1613 long timeo; 1614 struct task_struct *user_recv = NULL; 1615 bool copied_early = false; 1616 struct sk_buff *skb; 1617 u32 urg_hole = 0; 1618 1619 if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) && 1620 (sk->sk_state == TCP_ESTABLISHED)) 1621 sk_busy_loop(sk, nonblock); 1622 1623 lock_sock(sk); 1624 1625 err = -ENOTCONN; 1626 if (sk->sk_state == TCP_LISTEN) 1627 goto out; 1628 1629 timeo = sock_rcvtimeo(sk, nonblock); 1630 1631 /* Urgent data needs to be handled specially. */ 1632 if (flags & MSG_OOB) 1633 goto recv_urg; 1634 1635 if (unlikely(tp->repair)) { 1636 err = -EPERM; 1637 if (!(flags & MSG_PEEK)) 1638 goto out; 1639 1640 if (tp->repair_queue == TCP_SEND_QUEUE) 1641 goto recv_sndq; 1642 1643 err = -EINVAL; 1644 if (tp->repair_queue == TCP_NO_QUEUE) 1645 goto out; 1646 1647 /* 'common' recv queue MSG_PEEK-ing */ 1648 } 1649 1650 seq = &tp->copied_seq; 1651 if (flags & MSG_PEEK) { 1652 peek_seq = tp->copied_seq; 1653 seq = &peek_seq; 1654 } 1655 1656 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1657 1658 #ifdef CONFIG_NET_DMA 1659 tp->ucopy.dma_chan = NULL; 1660 preempt_disable(); 1661 skb = skb_peek_tail(&sk->sk_receive_queue); 1662 { 1663 int available = 0; 1664 1665 if (skb) 1666 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1667 if ((available < target) && 1668 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1669 !sysctl_tcp_low_latency && 1670 net_dma_find_channel()) { 1671 preempt_enable(); 1672 tp->ucopy.pinned_list = 1673 dma_pin_iovec_pages(msg->msg_iov, len); 1674 } else { 1675 preempt_enable(); 1676 } 1677 } 1678 #endif 1679 1680 do { 1681 u32 offset; 1682 1683 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1684 if (tp->urg_data && tp->urg_seq == *seq) { 1685 if (copied) 1686 break; 1687 if (signal_pending(current)) { 1688 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1689 break; 1690 } 1691 } 1692 1693 /* Next get a buffer. */ 1694 1695 skb_queue_walk(&sk->sk_receive_queue, skb) { 1696 /* Now that we have two receive queues this 1697 * shouldn't happen. 1698 */ 1699 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 1700 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n", 1701 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 1702 flags)) 1703 break; 1704 1705 offset = *seq - TCP_SKB_CB(skb)->seq; 1706 if (tcp_hdr(skb)->syn) 1707 offset--; 1708 if (offset < skb->len) 1709 goto found_ok_skb; 1710 if (tcp_hdr(skb)->fin) 1711 goto found_fin_ok; 1712 WARN(!(flags & MSG_PEEK), 1713 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n", 1714 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); 1715 } 1716 1717 /* Well, if we have backlog, try to process it now yet. */ 1718 1719 if (copied >= target && !sk->sk_backlog.tail) 1720 break; 1721 1722 if (copied) { 1723 if (sk->sk_err || 1724 sk->sk_state == TCP_CLOSE || 1725 (sk->sk_shutdown & RCV_SHUTDOWN) || 1726 !timeo || 1727 signal_pending(current)) 1728 break; 1729 } else { 1730 if (sock_flag(sk, SOCK_DONE)) 1731 break; 1732 1733 if (sk->sk_err) { 1734 copied = sock_error(sk); 1735 break; 1736 } 1737 1738 if (sk->sk_shutdown & RCV_SHUTDOWN) 1739 break; 1740 1741 if (sk->sk_state == TCP_CLOSE) { 1742 if (!sock_flag(sk, SOCK_DONE)) { 1743 /* This occurs when user tries to read 1744 * from never connected socket. 1745 */ 1746 copied = -ENOTCONN; 1747 break; 1748 } 1749 break; 1750 } 1751 1752 if (!timeo) { 1753 copied = -EAGAIN; 1754 break; 1755 } 1756 1757 if (signal_pending(current)) { 1758 copied = sock_intr_errno(timeo); 1759 break; 1760 } 1761 } 1762 1763 tcp_cleanup_rbuf(sk, copied); 1764 1765 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1766 /* Install new reader */ 1767 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1768 user_recv = current; 1769 tp->ucopy.task = user_recv; 1770 tp->ucopy.iov = msg->msg_iov; 1771 } 1772 1773 tp->ucopy.len = len; 1774 1775 WARN_ON(tp->copied_seq != tp->rcv_nxt && 1776 !(flags & (MSG_PEEK | MSG_TRUNC))); 1777 1778 /* Ugly... If prequeue is not empty, we have to 1779 * process it before releasing socket, otherwise 1780 * order will be broken at second iteration. 1781 * More elegant solution is required!!! 1782 * 1783 * Look: we have the following (pseudo)queues: 1784 * 1785 * 1. packets in flight 1786 * 2. backlog 1787 * 3. prequeue 1788 * 4. receive_queue 1789 * 1790 * Each queue can be processed only if the next ones 1791 * are empty. At this point we have empty receive_queue. 1792 * But prequeue _can_ be not empty after 2nd iteration, 1793 * when we jumped to start of loop because backlog 1794 * processing added something to receive_queue. 1795 * We cannot release_sock(), because backlog contains 1796 * packets arrived _after_ prequeued ones. 1797 * 1798 * Shortly, algorithm is clear --- to process all 1799 * the queues in order. We could make it more directly, 1800 * requeueing packets from backlog to prequeue, if 1801 * is not empty. It is more elegant, but eats cycles, 1802 * unfortunately. 1803 */ 1804 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1805 goto do_prequeue; 1806 1807 /* __ Set realtime policy in scheduler __ */ 1808 } 1809 1810 #ifdef CONFIG_NET_DMA 1811 if (tp->ucopy.dma_chan) { 1812 if (tp->rcv_wnd == 0 && 1813 !skb_queue_empty(&sk->sk_async_wait_queue)) { 1814 tcp_service_net_dma(sk, true); 1815 tcp_cleanup_rbuf(sk, copied); 1816 } else 1817 dma_async_issue_pending(tp->ucopy.dma_chan); 1818 } 1819 #endif 1820 if (copied >= target) { 1821 /* Do not sleep, just process backlog. */ 1822 release_sock(sk); 1823 lock_sock(sk); 1824 } else 1825 sk_wait_data(sk, &timeo); 1826 1827 #ifdef CONFIG_NET_DMA 1828 tcp_service_net_dma(sk, false); /* Don't block */ 1829 tp->ucopy.wakeup = 0; 1830 #endif 1831 1832 if (user_recv) { 1833 int chunk; 1834 1835 /* __ Restore normal policy in scheduler __ */ 1836 1837 if ((chunk = len - tp->ucopy.len) != 0) { 1838 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1839 len -= chunk; 1840 copied += chunk; 1841 } 1842 1843 if (tp->rcv_nxt == tp->copied_seq && 1844 !skb_queue_empty(&tp->ucopy.prequeue)) { 1845 do_prequeue: 1846 tcp_prequeue_process(sk); 1847 1848 if ((chunk = len - tp->ucopy.len) != 0) { 1849 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1850 len -= chunk; 1851 copied += chunk; 1852 } 1853 } 1854 } 1855 if ((flags & MSG_PEEK) && 1856 (peek_seq - copied - urg_hole != tp->copied_seq)) { 1857 net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n", 1858 current->comm, 1859 task_pid_nr(current)); 1860 peek_seq = tp->copied_seq; 1861 } 1862 continue; 1863 1864 found_ok_skb: 1865 /* Ok so how much can we use? */ 1866 used = skb->len - offset; 1867 if (len < used) 1868 used = len; 1869 1870 /* Do we have urgent data here? */ 1871 if (tp->urg_data) { 1872 u32 urg_offset = tp->urg_seq - *seq; 1873 if (urg_offset < used) { 1874 if (!urg_offset) { 1875 if (!sock_flag(sk, SOCK_URGINLINE)) { 1876 ++*seq; 1877 urg_hole++; 1878 offset++; 1879 used--; 1880 if (!used) 1881 goto skip_copy; 1882 } 1883 } else 1884 used = urg_offset; 1885 } 1886 } 1887 1888 if (!(flags & MSG_TRUNC)) { 1889 #ifdef CONFIG_NET_DMA 1890 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1891 tp->ucopy.dma_chan = net_dma_find_channel(); 1892 1893 if (tp->ucopy.dma_chan) { 1894 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1895 tp->ucopy.dma_chan, skb, offset, 1896 msg->msg_iov, used, 1897 tp->ucopy.pinned_list); 1898 1899 if (tp->ucopy.dma_cookie < 0) { 1900 1901 pr_alert("%s: dma_cookie < 0\n", 1902 __func__); 1903 1904 /* Exception. Bailout! */ 1905 if (!copied) 1906 copied = -EFAULT; 1907 break; 1908 } 1909 1910 dma_async_issue_pending(tp->ucopy.dma_chan); 1911 1912 if ((offset + used) == skb->len) 1913 copied_early = true; 1914 1915 } else 1916 #endif 1917 { 1918 err = skb_copy_datagram_iovec(skb, offset, 1919 msg->msg_iov, used); 1920 if (err) { 1921 /* Exception. Bailout! */ 1922 if (!copied) 1923 copied = -EFAULT; 1924 break; 1925 } 1926 } 1927 } 1928 1929 *seq += used; 1930 copied += used; 1931 len -= used; 1932 1933 tcp_rcv_space_adjust(sk); 1934 1935 skip_copy: 1936 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1937 tp->urg_data = 0; 1938 tcp_fast_path_check(sk); 1939 } 1940 if (used + offset < skb->len) 1941 continue; 1942 1943 if (tcp_hdr(skb)->fin) 1944 goto found_fin_ok; 1945 if (!(flags & MSG_PEEK)) { 1946 sk_eat_skb(sk, skb, copied_early); 1947 copied_early = false; 1948 } 1949 continue; 1950 1951 found_fin_ok: 1952 /* Process the FIN. */ 1953 ++*seq; 1954 if (!(flags & MSG_PEEK)) { 1955 sk_eat_skb(sk, skb, copied_early); 1956 copied_early = false; 1957 } 1958 break; 1959 } while (len > 0); 1960 1961 if (user_recv) { 1962 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1963 int chunk; 1964 1965 tp->ucopy.len = copied > 0 ? len : 0; 1966 1967 tcp_prequeue_process(sk); 1968 1969 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1970 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1971 len -= chunk; 1972 copied += chunk; 1973 } 1974 } 1975 1976 tp->ucopy.task = NULL; 1977 tp->ucopy.len = 0; 1978 } 1979 1980 #ifdef CONFIG_NET_DMA 1981 tcp_service_net_dma(sk, true); /* Wait for queue to drain */ 1982 tp->ucopy.dma_chan = NULL; 1983 1984 if (tp->ucopy.pinned_list) { 1985 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1986 tp->ucopy.pinned_list = NULL; 1987 } 1988 #endif 1989 1990 /* According to UNIX98, msg_name/msg_namelen are ignored 1991 * on connected socket. I was just happy when found this 8) --ANK 1992 */ 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 switch (state) { 2019 case TCP_ESTABLISHED: 2020 if (oldstate != TCP_ESTABLISHED) 2021 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2022 break; 2023 2024 case TCP_CLOSE: 2025 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 2026 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 2027 2028 sk->sk_prot->unhash(sk); 2029 if (inet_csk(sk)->icsk_bind_hash && 2030 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 2031 inet_put_port(sk); 2032 /* fall through */ 2033 default: 2034 if (oldstate == TCP_ESTABLISHED) 2035 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 2036 } 2037 2038 /* Change state AFTER socket is unhashed to avoid closed 2039 * socket sitting in hash tables. 2040 */ 2041 sk->sk_state = state; 2042 2043 #ifdef STATE_TRACE 2044 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 2045 #endif 2046 } 2047 EXPORT_SYMBOL_GPL(tcp_set_state); 2048 2049 /* 2050 * State processing on a close. This implements the state shift for 2051 * sending our FIN frame. Note that we only send a FIN for some 2052 * states. A shutdown() may have already sent the FIN, or we may be 2053 * closed. 2054 */ 2055 2056 static const unsigned char new_state[16] = { 2057 /* current state: new state: action: */ 2058 /* (Invalid) */ TCP_CLOSE, 2059 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2060 /* TCP_SYN_SENT */ TCP_CLOSE, 2061 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2062 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 2063 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 2064 /* TCP_TIME_WAIT */ TCP_CLOSE, 2065 /* TCP_CLOSE */ TCP_CLOSE, 2066 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 2067 /* TCP_LAST_ACK */ TCP_LAST_ACK, 2068 /* TCP_LISTEN */ TCP_CLOSE, 2069 /* TCP_CLOSING */ TCP_CLOSING, 2070 }; 2071 2072 static int tcp_close_state(struct sock *sk) 2073 { 2074 int next = (int)new_state[sk->sk_state]; 2075 int ns = next & TCP_STATE_MASK; 2076 2077 tcp_set_state(sk, ns); 2078 2079 return next & TCP_ACTION_FIN; 2080 } 2081 2082 /* 2083 * Shutdown the sending side of a connection. Much like close except 2084 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 2085 */ 2086 2087 void tcp_shutdown(struct sock *sk, int how) 2088 { 2089 /* We need to grab some memory, and put together a FIN, 2090 * and then put it into the queue to be sent. 2091 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 2092 */ 2093 if (!(how & SEND_SHUTDOWN)) 2094 return; 2095 2096 /* If we've already sent a FIN, or it's a closed state, skip this. */ 2097 if ((1 << sk->sk_state) & 2098 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 2099 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 2100 /* Clear out any half completed packets. FIN if needed. */ 2101 if (tcp_close_state(sk)) 2102 tcp_send_fin(sk); 2103 } 2104 } 2105 EXPORT_SYMBOL(tcp_shutdown); 2106 2107 bool tcp_check_oom(struct sock *sk, int shift) 2108 { 2109 bool too_many_orphans, out_of_socket_memory; 2110 2111 too_many_orphans = tcp_too_many_orphans(sk, shift); 2112 out_of_socket_memory = tcp_out_of_memory(sk); 2113 2114 if (too_many_orphans) 2115 net_info_ratelimited("too many orphaned sockets\n"); 2116 if (out_of_socket_memory) 2117 net_info_ratelimited("out of memory -- consider tuning tcp_mem\n"); 2118 return too_many_orphans || out_of_socket_memory; 2119 } 2120 2121 void tcp_close(struct sock *sk, long timeout) 2122 { 2123 struct sk_buff *skb; 2124 int data_was_unread = 0; 2125 int state; 2126 2127 lock_sock(sk); 2128 sk->sk_shutdown = SHUTDOWN_MASK; 2129 2130 if (sk->sk_state == TCP_LISTEN) { 2131 tcp_set_state(sk, TCP_CLOSE); 2132 2133 /* Special case. */ 2134 inet_csk_listen_stop(sk); 2135 2136 goto adjudge_to_death; 2137 } 2138 2139 /* We need to flush the recv. buffs. We do this only on the 2140 * descriptor close, not protocol-sourced closes, because the 2141 * reader process may not have drained the data yet! 2142 */ 2143 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 2144 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 2145 tcp_hdr(skb)->fin; 2146 data_was_unread += len; 2147 __kfree_skb(skb); 2148 } 2149 2150 sk_mem_reclaim(sk); 2151 2152 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ 2153 if (sk->sk_state == TCP_CLOSE) 2154 goto adjudge_to_death; 2155 2156 /* As outlined in RFC 2525, section 2.17, we send a RST here because 2157 * data was lost. To witness the awful effects of the old behavior of 2158 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 2159 * GET in an FTP client, suspend the process, wait for the client to 2160 * advertise a zero window, then kill -9 the FTP client, wheee... 2161 * Note: timeout is always zero in such a case. 2162 */ 2163 if (unlikely(tcp_sk(sk)->repair)) { 2164 sk->sk_prot->disconnect(sk, 0); 2165 } else if (data_was_unread) { 2166 /* Unread data was tossed, zap the connection. */ 2167 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 2168 tcp_set_state(sk, TCP_CLOSE); 2169 tcp_send_active_reset(sk, sk->sk_allocation); 2170 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 2171 /* Check zero linger _after_ checking for unread data. */ 2172 sk->sk_prot->disconnect(sk, 0); 2173 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 2174 } else if (tcp_close_state(sk)) { 2175 /* We FIN if the application ate all the data before 2176 * zapping the connection. 2177 */ 2178 2179 /* RED-PEN. Formally speaking, we have broken TCP state 2180 * machine. State transitions: 2181 * 2182 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 2183 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 2184 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 2185 * 2186 * are legal only when FIN has been sent (i.e. in window), 2187 * rather than queued out of window. Purists blame. 2188 * 2189 * F.e. "RFC state" is ESTABLISHED, 2190 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 2191 * 2192 * The visible declinations are that sometimes 2193 * we enter time-wait state, when it is not required really 2194 * (harmless), do not send active resets, when they are 2195 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 2196 * they look as CLOSING or LAST_ACK for Linux) 2197 * Probably, I missed some more holelets. 2198 * --ANK 2199 * XXX (TFO) - To start off we don't support SYN+ACK+FIN 2200 * in a single packet! (May consider it later but will 2201 * probably need API support or TCP_CORK SYN-ACK until 2202 * data is written and socket is closed.) 2203 */ 2204 tcp_send_fin(sk); 2205 } 2206 2207 sk_stream_wait_close(sk, timeout); 2208 2209 adjudge_to_death: 2210 state = sk->sk_state; 2211 sock_hold(sk); 2212 sock_orphan(sk); 2213 2214 /* It is the last release_sock in its life. It will remove backlog. */ 2215 release_sock(sk); 2216 2217 2218 /* Now socket is owned by kernel and we acquire BH lock 2219 to finish close. No need to check for user refs. 2220 */ 2221 local_bh_disable(); 2222 bh_lock_sock(sk); 2223 WARN_ON(sock_owned_by_user(sk)); 2224 2225 percpu_counter_inc(sk->sk_prot->orphan_count); 2226 2227 /* Have we already been destroyed by a softirq or backlog? */ 2228 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 2229 goto out; 2230 2231 /* This is a (useful) BSD violating of the RFC. There is a 2232 * problem with TCP as specified in that the other end could 2233 * keep a socket open forever with no application left this end. 2234 * We use a 1 minute timeout (about the same as BSD) then kill 2235 * our end. If they send after that then tough - BUT: long enough 2236 * that we won't make the old 4*rto = almost no time - whoops 2237 * reset mistake. 2238 * 2239 * Nope, it was not mistake. It is really desired behaviour 2240 * f.e. on http servers, when such sockets are useless, but 2241 * consume significant resources. Let's do it with special 2242 * linger2 option. --ANK 2243 */ 2244 2245 if (sk->sk_state == TCP_FIN_WAIT2) { 2246 struct tcp_sock *tp = tcp_sk(sk); 2247 if (tp->linger2 < 0) { 2248 tcp_set_state(sk, TCP_CLOSE); 2249 tcp_send_active_reset(sk, GFP_ATOMIC); 2250 NET_INC_STATS_BH(sock_net(sk), 2251 LINUX_MIB_TCPABORTONLINGER); 2252 } else { 2253 const int tmo = tcp_fin_time(sk); 2254 2255 if (tmo > TCP_TIMEWAIT_LEN) { 2256 inet_csk_reset_keepalive_timer(sk, 2257 tmo - TCP_TIMEWAIT_LEN); 2258 } else { 2259 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 2260 goto out; 2261 } 2262 } 2263 } 2264 if (sk->sk_state != TCP_CLOSE) { 2265 sk_mem_reclaim(sk); 2266 if (tcp_check_oom(sk, 0)) { 2267 tcp_set_state(sk, TCP_CLOSE); 2268 tcp_send_active_reset(sk, GFP_ATOMIC); 2269 NET_INC_STATS_BH(sock_net(sk), 2270 LINUX_MIB_TCPABORTONMEMORY); 2271 } 2272 } 2273 2274 if (sk->sk_state == TCP_CLOSE) { 2275 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 2276 /* We could get here with a non-NULL req if the socket is 2277 * aborted (e.g., closed with unread data) before 3WHS 2278 * finishes. 2279 */ 2280 if (req != NULL) 2281 reqsk_fastopen_remove(sk, req, false); 2282 inet_csk_destroy_sock(sk); 2283 } 2284 /* Otherwise, socket is reprieved until protocol close. */ 2285 2286 out: 2287 bh_unlock_sock(sk); 2288 local_bh_enable(); 2289 sock_put(sk); 2290 } 2291 EXPORT_SYMBOL(tcp_close); 2292 2293 /* These states need RST on ABORT according to RFC793 */ 2294 2295 static inline bool tcp_need_reset(int state) 2296 { 2297 return (1 << state) & 2298 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2299 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2300 } 2301 2302 int tcp_disconnect(struct sock *sk, int flags) 2303 { 2304 struct inet_sock *inet = inet_sk(sk); 2305 struct inet_connection_sock *icsk = inet_csk(sk); 2306 struct tcp_sock *tp = tcp_sk(sk); 2307 int err = 0; 2308 int old_state = sk->sk_state; 2309 2310 if (old_state != TCP_CLOSE) 2311 tcp_set_state(sk, TCP_CLOSE); 2312 2313 /* ABORT function of RFC793 */ 2314 if (old_state == TCP_LISTEN) { 2315 inet_csk_listen_stop(sk); 2316 } else if (unlikely(tp->repair)) { 2317 sk->sk_err = ECONNABORTED; 2318 } else if (tcp_need_reset(old_state) || 2319 (tp->snd_nxt != tp->write_seq && 2320 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2321 /* The last check adjusts for discrepancy of Linux wrt. RFC 2322 * states 2323 */ 2324 tcp_send_active_reset(sk, gfp_any()); 2325 sk->sk_err = ECONNRESET; 2326 } else if (old_state == TCP_SYN_SENT) 2327 sk->sk_err = ECONNRESET; 2328 2329 tcp_clear_xmit_timers(sk); 2330 __skb_queue_purge(&sk->sk_receive_queue); 2331 tcp_write_queue_purge(sk); 2332 __skb_queue_purge(&tp->out_of_order_queue); 2333 #ifdef CONFIG_NET_DMA 2334 __skb_queue_purge(&sk->sk_async_wait_queue); 2335 #endif 2336 2337 inet->inet_dport = 0; 2338 2339 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2340 inet_reset_saddr(sk); 2341 2342 sk->sk_shutdown = 0; 2343 sock_reset_flag(sk, SOCK_DONE); 2344 tp->srtt_us = 0; 2345 if ((tp->write_seq += tp->max_window + 2) == 0) 2346 tp->write_seq = 1; 2347 icsk->icsk_backoff = 0; 2348 tp->snd_cwnd = 2; 2349 icsk->icsk_probes_out = 0; 2350 tp->packets_out = 0; 2351 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2352 tp->snd_cwnd_cnt = 0; 2353 tp->window_clamp = 0; 2354 tcp_set_ca_state(sk, TCP_CA_Open); 2355 tcp_clear_retrans(tp); 2356 inet_csk_delack_init(sk); 2357 tcp_init_send_head(sk); 2358 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2359 __sk_dst_reset(sk); 2360 2361 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2362 2363 sk->sk_error_report(sk); 2364 return err; 2365 } 2366 EXPORT_SYMBOL(tcp_disconnect); 2367 2368 void tcp_sock_destruct(struct sock *sk) 2369 { 2370 inet_sock_destruct(sk); 2371 2372 kfree(inet_csk(sk)->icsk_accept_queue.fastopenq); 2373 } 2374 2375 static inline bool tcp_can_repair_sock(const struct sock *sk) 2376 { 2377 return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) && 2378 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED)); 2379 } 2380 2381 static int tcp_repair_options_est(struct tcp_sock *tp, 2382 struct tcp_repair_opt __user *optbuf, unsigned int len) 2383 { 2384 struct tcp_repair_opt opt; 2385 2386 while (len >= sizeof(opt)) { 2387 if (copy_from_user(&opt, optbuf, sizeof(opt))) 2388 return -EFAULT; 2389 2390 optbuf++; 2391 len -= sizeof(opt); 2392 2393 switch (opt.opt_code) { 2394 case TCPOPT_MSS: 2395 tp->rx_opt.mss_clamp = opt.opt_val; 2396 break; 2397 case TCPOPT_WINDOW: 2398 { 2399 u16 snd_wscale = opt.opt_val & 0xFFFF; 2400 u16 rcv_wscale = opt.opt_val >> 16; 2401 2402 if (snd_wscale > 14 || rcv_wscale > 14) 2403 return -EFBIG; 2404 2405 tp->rx_opt.snd_wscale = snd_wscale; 2406 tp->rx_opt.rcv_wscale = rcv_wscale; 2407 tp->rx_opt.wscale_ok = 1; 2408 } 2409 break; 2410 case TCPOPT_SACK_PERM: 2411 if (opt.opt_val != 0) 2412 return -EINVAL; 2413 2414 tp->rx_opt.sack_ok |= TCP_SACK_SEEN; 2415 if (sysctl_tcp_fack) 2416 tcp_enable_fack(tp); 2417 break; 2418 case TCPOPT_TIMESTAMP: 2419 if (opt.opt_val != 0) 2420 return -EINVAL; 2421 2422 tp->rx_opt.tstamp_ok = 1; 2423 break; 2424 } 2425 } 2426 2427 return 0; 2428 } 2429 2430 /* 2431 * Socket option code for TCP. 2432 */ 2433 static int do_tcp_setsockopt(struct sock *sk, int level, 2434 int optname, char __user *optval, unsigned int optlen) 2435 { 2436 struct tcp_sock *tp = tcp_sk(sk); 2437 struct inet_connection_sock *icsk = inet_csk(sk); 2438 int val; 2439 int err = 0; 2440 2441 /* These are data/string values, all the others are ints */ 2442 switch (optname) { 2443 case TCP_CONGESTION: { 2444 char name[TCP_CA_NAME_MAX]; 2445 2446 if (optlen < 1) 2447 return -EINVAL; 2448 2449 val = strncpy_from_user(name, optval, 2450 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2451 if (val < 0) 2452 return -EFAULT; 2453 name[val] = 0; 2454 2455 lock_sock(sk); 2456 err = tcp_set_congestion_control(sk, name); 2457 release_sock(sk); 2458 return err; 2459 } 2460 default: 2461 /* fallthru */ 2462 break; 2463 } 2464 2465 if (optlen < sizeof(int)) 2466 return -EINVAL; 2467 2468 if (get_user(val, (int __user *)optval)) 2469 return -EFAULT; 2470 2471 lock_sock(sk); 2472 2473 switch (optname) { 2474 case TCP_MAXSEG: 2475 /* Values greater than interface MTU won't take effect. However 2476 * at the point when this call is done we typically don't yet 2477 * know which interface is going to be used */ 2478 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) { 2479 err = -EINVAL; 2480 break; 2481 } 2482 tp->rx_opt.user_mss = val; 2483 break; 2484 2485 case TCP_NODELAY: 2486 if (val) { 2487 /* TCP_NODELAY is weaker than TCP_CORK, so that 2488 * this option on corked socket is remembered, but 2489 * it is not activated until cork is cleared. 2490 * 2491 * However, when TCP_NODELAY is set we make 2492 * an explicit push, which overrides even TCP_CORK 2493 * for currently queued segments. 2494 */ 2495 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2496 tcp_push_pending_frames(sk); 2497 } else { 2498 tp->nonagle &= ~TCP_NAGLE_OFF; 2499 } 2500 break; 2501 2502 case TCP_THIN_LINEAR_TIMEOUTS: 2503 if (val < 0 || val > 1) 2504 err = -EINVAL; 2505 else 2506 tp->thin_lto = val; 2507 break; 2508 2509 case TCP_THIN_DUPACK: 2510 if (val < 0 || val > 1) 2511 err = -EINVAL; 2512 else { 2513 tp->thin_dupack = val; 2514 if (tp->thin_dupack) 2515 tcp_disable_early_retrans(tp); 2516 } 2517 break; 2518 2519 case TCP_REPAIR: 2520 if (!tcp_can_repair_sock(sk)) 2521 err = -EPERM; 2522 else if (val == 1) { 2523 tp->repair = 1; 2524 sk->sk_reuse = SK_FORCE_REUSE; 2525 tp->repair_queue = TCP_NO_QUEUE; 2526 } else if (val == 0) { 2527 tp->repair = 0; 2528 sk->sk_reuse = SK_NO_REUSE; 2529 tcp_send_window_probe(sk); 2530 } else 2531 err = -EINVAL; 2532 2533 break; 2534 2535 case TCP_REPAIR_QUEUE: 2536 if (!tp->repair) 2537 err = -EPERM; 2538 else if (val < TCP_QUEUES_NR) 2539 tp->repair_queue = val; 2540 else 2541 err = -EINVAL; 2542 break; 2543 2544 case TCP_QUEUE_SEQ: 2545 if (sk->sk_state != TCP_CLOSE) 2546 err = -EPERM; 2547 else if (tp->repair_queue == TCP_SEND_QUEUE) 2548 tp->write_seq = val; 2549 else if (tp->repair_queue == TCP_RECV_QUEUE) 2550 tp->rcv_nxt = val; 2551 else 2552 err = -EINVAL; 2553 break; 2554 2555 case TCP_REPAIR_OPTIONS: 2556 if (!tp->repair) 2557 err = -EINVAL; 2558 else if (sk->sk_state == TCP_ESTABLISHED) 2559 err = tcp_repair_options_est(tp, 2560 (struct tcp_repair_opt __user *)optval, 2561 optlen); 2562 else 2563 err = -EPERM; 2564 break; 2565 2566 case TCP_CORK: 2567 /* When set indicates to always queue non-full frames. 2568 * Later the user clears this option and we transmit 2569 * any pending partial frames in the queue. This is 2570 * meant to be used alongside sendfile() to get properly 2571 * filled frames when the user (for example) must write 2572 * out headers with a write() call first and then use 2573 * sendfile to send out the data parts. 2574 * 2575 * TCP_CORK can be set together with TCP_NODELAY and it is 2576 * stronger than TCP_NODELAY. 2577 */ 2578 if (val) { 2579 tp->nonagle |= TCP_NAGLE_CORK; 2580 } else { 2581 tp->nonagle &= ~TCP_NAGLE_CORK; 2582 if (tp->nonagle&TCP_NAGLE_OFF) 2583 tp->nonagle |= TCP_NAGLE_PUSH; 2584 tcp_push_pending_frames(sk); 2585 } 2586 break; 2587 2588 case TCP_KEEPIDLE: 2589 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2590 err = -EINVAL; 2591 else { 2592 tp->keepalive_time = val * HZ; 2593 if (sock_flag(sk, SOCK_KEEPOPEN) && 2594 !((1 << sk->sk_state) & 2595 (TCPF_CLOSE | TCPF_LISTEN))) { 2596 u32 elapsed = keepalive_time_elapsed(tp); 2597 if (tp->keepalive_time > elapsed) 2598 elapsed = tp->keepalive_time - elapsed; 2599 else 2600 elapsed = 0; 2601 inet_csk_reset_keepalive_timer(sk, elapsed); 2602 } 2603 } 2604 break; 2605 case TCP_KEEPINTVL: 2606 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2607 err = -EINVAL; 2608 else 2609 tp->keepalive_intvl = val * HZ; 2610 break; 2611 case TCP_KEEPCNT: 2612 if (val < 1 || val > MAX_TCP_KEEPCNT) 2613 err = -EINVAL; 2614 else 2615 tp->keepalive_probes = val; 2616 break; 2617 case TCP_SYNCNT: 2618 if (val < 1 || val > MAX_TCP_SYNCNT) 2619 err = -EINVAL; 2620 else 2621 icsk->icsk_syn_retries = val; 2622 break; 2623 2624 case TCP_LINGER2: 2625 if (val < 0) 2626 tp->linger2 = -1; 2627 else if (val > sysctl_tcp_fin_timeout / HZ) 2628 tp->linger2 = 0; 2629 else 2630 tp->linger2 = val * HZ; 2631 break; 2632 2633 case TCP_DEFER_ACCEPT: 2634 /* Translate value in seconds to number of retransmits */ 2635 icsk->icsk_accept_queue.rskq_defer_accept = 2636 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2637 TCP_RTO_MAX / HZ); 2638 break; 2639 2640 case TCP_WINDOW_CLAMP: 2641 if (!val) { 2642 if (sk->sk_state != TCP_CLOSE) { 2643 err = -EINVAL; 2644 break; 2645 } 2646 tp->window_clamp = 0; 2647 } else 2648 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2649 SOCK_MIN_RCVBUF / 2 : val; 2650 break; 2651 2652 case TCP_QUICKACK: 2653 if (!val) { 2654 icsk->icsk_ack.pingpong = 1; 2655 } else { 2656 icsk->icsk_ack.pingpong = 0; 2657 if ((1 << sk->sk_state) & 2658 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2659 inet_csk_ack_scheduled(sk)) { 2660 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2661 tcp_cleanup_rbuf(sk, 1); 2662 if (!(val & 1)) 2663 icsk->icsk_ack.pingpong = 1; 2664 } 2665 } 2666 break; 2667 2668 #ifdef CONFIG_TCP_MD5SIG 2669 case TCP_MD5SIG: 2670 /* Read the IP->Key mappings from userspace */ 2671 err = tp->af_specific->md5_parse(sk, optval, optlen); 2672 break; 2673 #endif 2674 case TCP_USER_TIMEOUT: 2675 /* Cap the max timeout in ms TCP will retry/retrans 2676 * before giving up and aborting (ETIMEDOUT) a connection. 2677 */ 2678 if (val < 0) 2679 err = -EINVAL; 2680 else 2681 icsk->icsk_user_timeout = msecs_to_jiffies(val); 2682 break; 2683 2684 case TCP_FASTOPEN: 2685 if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE | 2686 TCPF_LISTEN))) 2687 err = fastopen_init_queue(sk, val); 2688 else 2689 err = -EINVAL; 2690 break; 2691 case TCP_TIMESTAMP: 2692 if (!tp->repair) 2693 err = -EPERM; 2694 else 2695 tp->tsoffset = val - tcp_time_stamp; 2696 break; 2697 case TCP_NOTSENT_LOWAT: 2698 tp->notsent_lowat = val; 2699 sk->sk_write_space(sk); 2700 break; 2701 default: 2702 err = -ENOPROTOOPT; 2703 break; 2704 } 2705 2706 release_sock(sk); 2707 return err; 2708 } 2709 2710 int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2711 unsigned int optlen) 2712 { 2713 const struct inet_connection_sock *icsk = inet_csk(sk); 2714 2715 if (level != SOL_TCP) 2716 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2717 optval, optlen); 2718 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2719 } 2720 EXPORT_SYMBOL(tcp_setsockopt); 2721 2722 #ifdef CONFIG_COMPAT 2723 int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2724 char __user *optval, unsigned int optlen) 2725 { 2726 if (level != SOL_TCP) 2727 return inet_csk_compat_setsockopt(sk, level, optname, 2728 optval, optlen); 2729 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2730 } 2731 EXPORT_SYMBOL(compat_tcp_setsockopt); 2732 #endif 2733 2734 /* Return information about state of tcp endpoint in API format. */ 2735 void tcp_get_info(const struct sock *sk, struct tcp_info *info) 2736 { 2737 const struct tcp_sock *tp = tcp_sk(sk); 2738 const struct inet_connection_sock *icsk = inet_csk(sk); 2739 u32 now = tcp_time_stamp; 2740 2741 memset(info, 0, sizeof(*info)); 2742 2743 info->tcpi_state = sk->sk_state; 2744 info->tcpi_ca_state = icsk->icsk_ca_state; 2745 info->tcpi_retransmits = icsk->icsk_retransmits; 2746 info->tcpi_probes = icsk->icsk_probes_out; 2747 info->tcpi_backoff = icsk->icsk_backoff; 2748 2749 if (tp->rx_opt.tstamp_ok) 2750 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2751 if (tcp_is_sack(tp)) 2752 info->tcpi_options |= TCPI_OPT_SACK; 2753 if (tp->rx_opt.wscale_ok) { 2754 info->tcpi_options |= TCPI_OPT_WSCALE; 2755 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2756 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2757 } 2758 2759 if (tp->ecn_flags & TCP_ECN_OK) 2760 info->tcpi_options |= TCPI_OPT_ECN; 2761 if (tp->ecn_flags & TCP_ECN_SEEN) 2762 info->tcpi_options |= TCPI_OPT_ECN_SEEN; 2763 if (tp->syn_data_acked) 2764 info->tcpi_options |= TCPI_OPT_SYN_DATA; 2765 2766 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2767 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2768 info->tcpi_snd_mss = tp->mss_cache; 2769 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2770 2771 if (sk->sk_state == TCP_LISTEN) { 2772 info->tcpi_unacked = sk->sk_ack_backlog; 2773 info->tcpi_sacked = sk->sk_max_ack_backlog; 2774 } else { 2775 info->tcpi_unacked = tp->packets_out; 2776 info->tcpi_sacked = tp->sacked_out; 2777 } 2778 info->tcpi_lost = tp->lost_out; 2779 info->tcpi_retrans = tp->retrans_out; 2780 info->tcpi_fackets = tp->fackets_out; 2781 2782 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2783 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2784 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2785 2786 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2787 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2788 info->tcpi_rtt = tp->srtt_us >> 3; 2789 info->tcpi_rttvar = tp->mdev_us >> 2; 2790 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2791 info->tcpi_snd_cwnd = tp->snd_cwnd; 2792 info->tcpi_advmss = tp->advmss; 2793 info->tcpi_reordering = tp->reordering; 2794 2795 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2796 info->tcpi_rcv_space = tp->rcvq_space.space; 2797 2798 info->tcpi_total_retrans = tp->total_retrans; 2799 2800 info->tcpi_pacing_rate = sk->sk_pacing_rate != ~0U ? 2801 sk->sk_pacing_rate : ~0ULL; 2802 info->tcpi_max_pacing_rate = sk->sk_max_pacing_rate != ~0U ? 2803 sk->sk_max_pacing_rate : ~0ULL; 2804 } 2805 EXPORT_SYMBOL_GPL(tcp_get_info); 2806 2807 static int do_tcp_getsockopt(struct sock *sk, int level, 2808 int optname, char __user *optval, int __user *optlen) 2809 { 2810 struct inet_connection_sock *icsk = inet_csk(sk); 2811 struct tcp_sock *tp = tcp_sk(sk); 2812 int val, len; 2813 2814 if (get_user(len, optlen)) 2815 return -EFAULT; 2816 2817 len = min_t(unsigned int, len, sizeof(int)); 2818 2819 if (len < 0) 2820 return -EINVAL; 2821 2822 switch (optname) { 2823 case TCP_MAXSEG: 2824 val = tp->mss_cache; 2825 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2826 val = tp->rx_opt.user_mss; 2827 if (tp->repair) 2828 val = tp->rx_opt.mss_clamp; 2829 break; 2830 case TCP_NODELAY: 2831 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2832 break; 2833 case TCP_CORK: 2834 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2835 break; 2836 case TCP_KEEPIDLE: 2837 val = keepalive_time_when(tp) / HZ; 2838 break; 2839 case TCP_KEEPINTVL: 2840 val = keepalive_intvl_when(tp) / HZ; 2841 break; 2842 case TCP_KEEPCNT: 2843 val = keepalive_probes(tp); 2844 break; 2845 case TCP_SYNCNT: 2846 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2847 break; 2848 case TCP_LINGER2: 2849 val = tp->linger2; 2850 if (val >= 0) 2851 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2852 break; 2853 case TCP_DEFER_ACCEPT: 2854 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 2855 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 2856 break; 2857 case TCP_WINDOW_CLAMP: 2858 val = tp->window_clamp; 2859 break; 2860 case TCP_INFO: { 2861 struct tcp_info info; 2862 2863 if (get_user(len, optlen)) 2864 return -EFAULT; 2865 2866 tcp_get_info(sk, &info); 2867 2868 len = min_t(unsigned int, len, sizeof(info)); 2869 if (put_user(len, optlen)) 2870 return -EFAULT; 2871 if (copy_to_user(optval, &info, len)) 2872 return -EFAULT; 2873 return 0; 2874 } 2875 case TCP_QUICKACK: 2876 val = !icsk->icsk_ack.pingpong; 2877 break; 2878 2879 case TCP_CONGESTION: 2880 if (get_user(len, optlen)) 2881 return -EFAULT; 2882 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2883 if (put_user(len, optlen)) 2884 return -EFAULT; 2885 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2886 return -EFAULT; 2887 return 0; 2888 2889 case TCP_THIN_LINEAR_TIMEOUTS: 2890 val = tp->thin_lto; 2891 break; 2892 case TCP_THIN_DUPACK: 2893 val = tp->thin_dupack; 2894 break; 2895 2896 case TCP_REPAIR: 2897 val = tp->repair; 2898 break; 2899 2900 case TCP_REPAIR_QUEUE: 2901 if (tp->repair) 2902 val = tp->repair_queue; 2903 else 2904 return -EINVAL; 2905 break; 2906 2907 case TCP_QUEUE_SEQ: 2908 if (tp->repair_queue == TCP_SEND_QUEUE) 2909 val = tp->write_seq; 2910 else if (tp->repair_queue == TCP_RECV_QUEUE) 2911 val = tp->rcv_nxt; 2912 else 2913 return -EINVAL; 2914 break; 2915 2916 case TCP_USER_TIMEOUT: 2917 val = jiffies_to_msecs(icsk->icsk_user_timeout); 2918 break; 2919 case TCP_TIMESTAMP: 2920 val = tcp_time_stamp + tp->tsoffset; 2921 break; 2922 case TCP_NOTSENT_LOWAT: 2923 val = tp->notsent_lowat; 2924 break; 2925 default: 2926 return -ENOPROTOOPT; 2927 } 2928 2929 if (put_user(len, optlen)) 2930 return -EFAULT; 2931 if (copy_to_user(optval, &val, len)) 2932 return -EFAULT; 2933 return 0; 2934 } 2935 2936 int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2937 int __user *optlen) 2938 { 2939 struct inet_connection_sock *icsk = inet_csk(sk); 2940 2941 if (level != SOL_TCP) 2942 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2943 optval, optlen); 2944 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2945 } 2946 EXPORT_SYMBOL(tcp_getsockopt); 2947 2948 #ifdef CONFIG_COMPAT 2949 int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2950 char __user *optval, int __user *optlen) 2951 { 2952 if (level != SOL_TCP) 2953 return inet_csk_compat_getsockopt(sk, level, optname, 2954 optval, optlen); 2955 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2956 } 2957 EXPORT_SYMBOL(compat_tcp_getsockopt); 2958 #endif 2959 2960 #ifdef CONFIG_TCP_MD5SIG 2961 static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool __read_mostly; 2962 static DEFINE_MUTEX(tcp_md5sig_mutex); 2963 2964 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool) 2965 { 2966 int cpu; 2967 2968 for_each_possible_cpu(cpu) { 2969 struct tcp_md5sig_pool *p = per_cpu_ptr(pool, cpu); 2970 2971 if (p->md5_desc.tfm) 2972 crypto_free_hash(p->md5_desc.tfm); 2973 } 2974 free_percpu(pool); 2975 } 2976 2977 static void __tcp_alloc_md5sig_pool(void) 2978 { 2979 int cpu; 2980 struct tcp_md5sig_pool __percpu *pool; 2981 2982 pool = alloc_percpu(struct tcp_md5sig_pool); 2983 if (!pool) 2984 return; 2985 2986 for_each_possible_cpu(cpu) { 2987 struct crypto_hash *hash; 2988 2989 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2990 if (IS_ERR_OR_NULL(hash)) 2991 goto out_free; 2992 2993 per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash; 2994 } 2995 /* before setting tcp_md5sig_pool, we must commit all writes 2996 * to memory. See ACCESS_ONCE() in tcp_get_md5sig_pool() 2997 */ 2998 smp_wmb(); 2999 tcp_md5sig_pool = pool; 3000 return; 3001 out_free: 3002 __tcp_free_md5sig_pool(pool); 3003 } 3004 3005 bool tcp_alloc_md5sig_pool(void) 3006 { 3007 if (unlikely(!tcp_md5sig_pool)) { 3008 mutex_lock(&tcp_md5sig_mutex); 3009 3010 if (!tcp_md5sig_pool) 3011 __tcp_alloc_md5sig_pool(); 3012 3013 mutex_unlock(&tcp_md5sig_mutex); 3014 } 3015 return tcp_md5sig_pool != NULL; 3016 } 3017 EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 3018 3019 3020 /** 3021 * tcp_get_md5sig_pool - get md5sig_pool for this user 3022 * 3023 * We use percpu structure, so if we succeed, we exit with preemption 3024 * and BH disabled, to make sure another thread or softirq handling 3025 * wont try to get same context. 3026 */ 3027 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 3028 { 3029 struct tcp_md5sig_pool __percpu *p; 3030 3031 local_bh_disable(); 3032 p = ACCESS_ONCE(tcp_md5sig_pool); 3033 if (p) 3034 return __this_cpu_ptr(p); 3035 3036 local_bh_enable(); 3037 return NULL; 3038 } 3039 EXPORT_SYMBOL(tcp_get_md5sig_pool); 3040 3041 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, 3042 const struct tcphdr *th) 3043 { 3044 struct scatterlist sg; 3045 struct tcphdr hdr; 3046 int err; 3047 3048 /* We are not allowed to change tcphdr, make a local copy */ 3049 memcpy(&hdr, th, sizeof(hdr)); 3050 hdr.check = 0; 3051 3052 /* options aren't included in the hash */ 3053 sg_init_one(&sg, &hdr, sizeof(hdr)); 3054 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr)); 3055 return err; 3056 } 3057 EXPORT_SYMBOL(tcp_md5_hash_header); 3058 3059 int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 3060 const struct sk_buff *skb, unsigned int header_len) 3061 { 3062 struct scatterlist sg; 3063 const struct tcphdr *tp = tcp_hdr(skb); 3064 struct hash_desc *desc = &hp->md5_desc; 3065 unsigned int i; 3066 const unsigned int head_data_len = skb_headlen(skb) > header_len ? 3067 skb_headlen(skb) - header_len : 0; 3068 const struct skb_shared_info *shi = skb_shinfo(skb); 3069 struct sk_buff *frag_iter; 3070 3071 sg_init_table(&sg, 1); 3072 3073 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3074 if (crypto_hash_update(desc, &sg, head_data_len)) 3075 return 1; 3076 3077 for (i = 0; i < shi->nr_frags; ++i) { 3078 const struct skb_frag_struct *f = &shi->frags[i]; 3079 unsigned int offset = f->page_offset; 3080 struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT); 3081 3082 sg_set_page(&sg, page, skb_frag_size(f), 3083 offset_in_page(offset)); 3084 if (crypto_hash_update(desc, &sg, skb_frag_size(f))) 3085 return 1; 3086 } 3087 3088 skb_walk_frags(skb, frag_iter) 3089 if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) 3090 return 1; 3091 3092 return 0; 3093 } 3094 EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3095 3096 int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) 3097 { 3098 struct scatterlist sg; 3099 3100 sg_init_one(&sg, key->key, key->keylen); 3101 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); 3102 } 3103 EXPORT_SYMBOL(tcp_md5_hash_key); 3104 3105 #endif 3106 3107 void tcp_done(struct sock *sk) 3108 { 3109 struct request_sock *req = tcp_sk(sk)->fastopen_rsk; 3110 3111 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3112 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3113 3114 tcp_set_state(sk, TCP_CLOSE); 3115 tcp_clear_xmit_timers(sk); 3116 if (req != NULL) 3117 reqsk_fastopen_remove(sk, req, false); 3118 3119 sk->sk_shutdown = SHUTDOWN_MASK; 3120 3121 if (!sock_flag(sk, SOCK_DEAD)) 3122 sk->sk_state_change(sk); 3123 else 3124 inet_csk_destroy_sock(sk); 3125 } 3126 EXPORT_SYMBOL_GPL(tcp_done); 3127 3128 extern struct tcp_congestion_ops tcp_reno; 3129 3130 static __initdata unsigned long thash_entries; 3131 static int __init set_thash_entries(char *str) 3132 { 3133 ssize_t ret; 3134 3135 if (!str) 3136 return 0; 3137 3138 ret = kstrtoul(str, 0, &thash_entries); 3139 if (ret) 3140 return 0; 3141 3142 return 1; 3143 } 3144 __setup("thash_entries=", set_thash_entries); 3145 3146 static void tcp_init_mem(void) 3147 { 3148 unsigned long limit = nr_free_buffer_pages() / 8; 3149 limit = max(limit, 128UL); 3150 sysctl_tcp_mem[0] = limit / 4 * 3; 3151 sysctl_tcp_mem[1] = limit; 3152 sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; 3153 } 3154 3155 void __init tcp_init(void) 3156 { 3157 struct sk_buff *skb = NULL; 3158 unsigned long limit; 3159 int max_rshare, max_wshare, cnt; 3160 unsigned int i; 3161 3162 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 3163 3164 percpu_counter_init(&tcp_sockets_allocated, 0); 3165 percpu_counter_init(&tcp_orphan_count, 0); 3166 tcp_hashinfo.bind_bucket_cachep = 3167 kmem_cache_create("tcp_bind_bucket", 3168 sizeof(struct inet_bind_bucket), 0, 3169 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3170 3171 /* Size and allocate the main established and bind bucket 3172 * hash tables. 3173 * 3174 * The methodology is similar to that of the buffer cache. 3175 */ 3176 tcp_hashinfo.ehash = 3177 alloc_large_system_hash("TCP established", 3178 sizeof(struct inet_ehash_bucket), 3179 thash_entries, 3180 17, /* one slot per 128 KB of memory */ 3181 0, 3182 NULL, 3183 &tcp_hashinfo.ehash_mask, 3184 0, 3185 thash_entries ? 0 : 512 * 1024); 3186 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) 3187 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3188 3189 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3190 panic("TCP: failed to alloc ehash_locks"); 3191 tcp_hashinfo.bhash = 3192 alloc_large_system_hash("TCP bind", 3193 sizeof(struct inet_bind_hashbucket), 3194 tcp_hashinfo.ehash_mask + 1, 3195 17, /* one slot per 128 KB of memory */ 3196 0, 3197 &tcp_hashinfo.bhash_size, 3198 NULL, 3199 0, 3200 64 * 1024); 3201 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; 3202 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3203 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3204 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3205 } 3206 3207 3208 cnt = tcp_hashinfo.ehash_mask + 1; 3209 3210 tcp_death_row.sysctl_max_tw_buckets = cnt / 2; 3211 sysctl_tcp_max_orphans = cnt / 2; 3212 sysctl_max_syn_backlog = max(128, cnt / 256); 3213 3214 tcp_init_mem(); 3215 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3216 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); 3217 max_wshare = min(4UL*1024*1024, limit); 3218 max_rshare = min(6UL*1024*1024, limit); 3219 3220 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3221 sysctl_tcp_wmem[1] = 16*1024; 3222 sysctl_tcp_wmem[2] = max(64*1024, max_wshare); 3223 3224 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3225 sysctl_tcp_rmem[1] = 87380; 3226 sysctl_tcp_rmem[2] = max(87380, max_rshare); 3227 3228 pr_info("Hash tables configured (established %u bind %u)\n", 3229 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3230 3231 tcp_metrics_init(); 3232 3233 tcp_register_congestion_control(&tcp_reno); 3234 3235 tcp_tasklet_init(); 3236 } 3237