tcp.c revision ee9952831cfd0bbe834f4a26489d7dce74582e37
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/tcp.h> 274#include <net/xfrm.h> 275#include <net/ip.h> 276#include <net/netdma.h> 277#include <net/sock.h> 278 279#include <asm/uaccess.h> 280#include <asm/ioctls.h> 281 282int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 283 284struct percpu_counter tcp_orphan_count; 285EXPORT_SYMBOL_GPL(tcp_orphan_count); 286 287int sysctl_tcp_wmem[3] __read_mostly; 288int sysctl_tcp_rmem[3] __read_mostly; 289 290EXPORT_SYMBOL(sysctl_tcp_rmem); 291EXPORT_SYMBOL(sysctl_tcp_wmem); 292 293atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ 294EXPORT_SYMBOL(tcp_memory_allocated); 295 296/* 297 * Current number of TCP sockets. 298 */ 299struct percpu_counter tcp_sockets_allocated; 300EXPORT_SYMBOL(tcp_sockets_allocated); 301 302/* 303 * TCP splice context 304 */ 305struct tcp_splice_state { 306 struct pipe_inode_info *pipe; 307 size_t len; 308 unsigned int flags; 309}; 310 311/* 312 * Pressure flag: try to collapse. 313 * Technical note: it is used by multiple contexts non atomically. 314 * All the __sk_mem_schedule() is of this nature: accounting 315 * is strict, actions are advisory and have some latency. 316 */ 317int tcp_memory_pressure __read_mostly; 318EXPORT_SYMBOL(tcp_memory_pressure); 319 320void tcp_enter_memory_pressure(struct sock *sk) 321{ 322 if (!tcp_memory_pressure) { 323 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES); 324 tcp_memory_pressure = 1; 325 } 326} 327EXPORT_SYMBOL(tcp_enter_memory_pressure); 328 329/* Convert seconds to retransmits based on initial and max timeout */ 330static u8 secs_to_retrans(int seconds, int timeout, int rto_max) 331{ 332 u8 res = 0; 333 334 if (seconds > 0) { 335 int period = timeout; 336 337 res = 1; 338 while (seconds > period && res < 255) { 339 res++; 340 timeout <<= 1; 341 if (timeout > rto_max) 342 timeout = rto_max; 343 period += timeout; 344 } 345 } 346 return res; 347} 348 349/* Convert retransmits to seconds based on initial and max timeout */ 350static int retrans_to_secs(u8 retrans, int timeout, int rto_max) 351{ 352 int period = 0; 353 354 if (retrans > 0) { 355 period = timeout; 356 while (--retrans) { 357 timeout <<= 1; 358 if (timeout > rto_max) 359 timeout = rto_max; 360 period += timeout; 361 } 362 } 363 return period; 364} 365 366/* 367 * Wait for a TCP event. 368 * 369 * Note that we don't need to lock the socket, as the upper poll layers 370 * take care of normal races (between the test and the event) and we don't 371 * go look at any of the socket buffers directly. 372 */ 373unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) 374{ 375 unsigned int mask; 376 struct sock *sk = sock->sk; 377 const struct tcp_sock *tp = tcp_sk(sk); 378 379 sock_poll_wait(file, sk_sleep(sk), wait); 380 if (sk->sk_state == TCP_LISTEN) 381 return inet_csk_listen_poll(sk); 382 383 /* Socket is not locked. We are protected from async events 384 * by poll logic and correct handling of state changes 385 * made by other threads is impossible in any case. 386 */ 387 388 mask = 0; 389 390 /* 391 * POLLHUP is certainly not done right. But poll() doesn't 392 * have a notion of HUP in just one direction, and for a 393 * socket the read side is more interesting. 394 * 395 * Some poll() documentation says that POLLHUP is incompatible 396 * with the POLLOUT/POLLWR flags, so somebody should check this 397 * all. But careful, it tends to be safer to return too many 398 * bits than too few, and you can easily break real applications 399 * if you don't tell them that something has hung up! 400 * 401 * Check-me. 402 * 403 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and 404 * our fs/select.c). It means that after we received EOF, 405 * poll always returns immediately, making impossible poll() on write() 406 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP 407 * if and only if shutdown has been made in both directions. 408 * Actually, it is interesting to look how Solaris and DUX 409 * solve this dilemma. I would prefer, if POLLHUP were maskable, 410 * then we could set it on SND_SHUTDOWN. BTW examples given 411 * in Stevens' books assume exactly this behaviour, it explains 412 * why POLLHUP is incompatible with POLLOUT. --ANK 413 * 414 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent 415 * blocking on fresh not-connected or disconnected socket. --ANK 416 */ 417 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) 418 mask |= POLLHUP; 419 if (sk->sk_shutdown & RCV_SHUTDOWN) 420 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 421 422 /* Connected? */ 423 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { 424 int target = sock_rcvlowat(sk, 0, INT_MAX); 425 426 if (tp->urg_seq == tp->copied_seq && 427 !sock_flag(sk, SOCK_URGINLINE) && 428 tp->urg_data) 429 target++; 430 431 /* Potential race condition. If read of tp below will 432 * escape above sk->sk_state, we can be illegally awaken 433 * in SYN_* states. */ 434 if (tp->rcv_nxt - tp->copied_seq >= target) 435 mask |= POLLIN | POLLRDNORM; 436 437 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 438 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 439 mask |= POLLOUT | POLLWRNORM; 440 } else { /* send SIGIO later */ 441 set_bit(SOCK_ASYNC_NOSPACE, 442 &sk->sk_socket->flags); 443 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 444 445 /* Race breaker. If space is freed after 446 * wspace test but before the flags are set, 447 * IO signal will be lost. 448 */ 449 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) 450 mask |= POLLOUT | POLLWRNORM; 451 } 452 } else 453 mask |= POLLOUT | POLLWRNORM; 454 455 if (tp->urg_data & TCP_URG_VALID) 456 mask |= POLLPRI; 457 } 458 /* This barrier is coupled with smp_wmb() in tcp_reset() */ 459 smp_rmb(); 460 if (sk->sk_err) 461 mask |= POLLERR; 462 463 return mask; 464} 465EXPORT_SYMBOL(tcp_poll); 466 467int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 468{ 469 struct tcp_sock *tp = tcp_sk(sk); 470 int answ; 471 472 switch (cmd) { 473 case SIOCINQ: 474 if (sk->sk_state == TCP_LISTEN) 475 return -EINVAL; 476 477 lock_sock(sk); 478 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 479 answ = 0; 480 else if (sock_flag(sk, SOCK_URGINLINE) || 481 !tp->urg_data || 482 before(tp->urg_seq, tp->copied_seq) || 483 !before(tp->urg_seq, tp->rcv_nxt)) { 484 struct sk_buff *skb; 485 486 answ = tp->rcv_nxt - tp->copied_seq; 487 488 /* Subtract 1, if FIN is in queue. */ 489 skb = skb_peek_tail(&sk->sk_receive_queue); 490 if (answ && skb) 491 answ -= tcp_hdr(skb)->fin; 492 } else 493 answ = tp->urg_seq - tp->copied_seq; 494 release_sock(sk); 495 break; 496 case SIOCATMARK: 497 answ = tp->urg_data && tp->urg_seq == tp->copied_seq; 498 break; 499 case SIOCOUTQ: 500 if (sk->sk_state == TCP_LISTEN) 501 return -EINVAL; 502 503 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 504 answ = 0; 505 else 506 answ = tp->write_seq - tp->snd_una; 507 break; 508 case SIOCOUTQNSD: 509 if (sk->sk_state == TCP_LISTEN) 510 return -EINVAL; 511 512 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 513 answ = 0; 514 else 515 answ = tp->write_seq - tp->snd_nxt; 516 break; 517 default: 518 return -ENOIOCTLCMD; 519 } 520 521 return put_user(answ, (int __user *)arg); 522} 523EXPORT_SYMBOL(tcp_ioctl); 524 525static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb) 526{ 527 TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; 528 tp->pushed_seq = tp->write_seq; 529} 530 531static inline int forced_push(const struct tcp_sock *tp) 532{ 533 return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); 534} 535 536static inline void skb_entail(struct sock *sk, struct sk_buff *skb) 537{ 538 struct tcp_sock *tp = tcp_sk(sk); 539 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); 540 541 skb->csum = 0; 542 tcb->seq = tcb->end_seq = tp->write_seq; 543 tcb->tcp_flags = TCPHDR_ACK; 544 tcb->sacked = 0; 545 skb_header_release(skb); 546 tcp_add_write_queue_tail(sk, skb); 547 sk->sk_wmem_queued += skb->truesize; 548 sk_mem_charge(sk, skb->truesize); 549 if (tp->nonagle & TCP_NAGLE_PUSH) 550 tp->nonagle &= ~TCP_NAGLE_PUSH; 551} 552 553static inline void tcp_mark_urg(struct tcp_sock *tp, int flags) 554{ 555 if (flags & MSG_OOB) 556 tp->snd_up = tp->write_seq; 557} 558 559static inline void tcp_push(struct sock *sk, int flags, int mss_now, 560 int nonagle) 561{ 562 if (tcp_send_head(sk)) { 563 struct tcp_sock *tp = tcp_sk(sk); 564 565 if (!(flags & MSG_MORE) || forced_push(tp)) 566 tcp_mark_push(tp, tcp_write_queue_tail(sk)); 567 568 tcp_mark_urg(tp, flags); 569 __tcp_push_pending_frames(sk, mss_now, 570 (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); 571 } 572} 573 574static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 575 unsigned int offset, size_t len) 576{ 577 struct tcp_splice_state *tss = rd_desc->arg.data; 578 int ret; 579 580 ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len), 581 tss->flags); 582 if (ret > 0) 583 rd_desc->count -= ret; 584 return ret; 585} 586 587static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss) 588{ 589 /* Store TCP splice context information in read_descriptor_t. */ 590 read_descriptor_t rd_desc = { 591 .arg.data = tss, 592 .count = tss->len, 593 }; 594 595 return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv); 596} 597 598/** 599 * tcp_splice_read - splice data from TCP socket to a pipe 600 * @sock: socket to splice from 601 * @ppos: position (not valid) 602 * @pipe: pipe to splice to 603 * @len: number of bytes to splice 604 * @flags: splice modifier flags 605 * 606 * Description: 607 * Will read pages from given socket and fill them into a pipe. 608 * 609 **/ 610ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, 611 struct pipe_inode_info *pipe, size_t len, 612 unsigned int flags) 613{ 614 struct sock *sk = sock->sk; 615 struct tcp_splice_state tss = { 616 .pipe = pipe, 617 .len = len, 618 .flags = flags, 619 }; 620 long timeo; 621 ssize_t spliced; 622 int ret; 623 624 sock_rps_record_flow(sk); 625 /* 626 * We can't seek on a socket input 627 */ 628 if (unlikely(*ppos)) 629 return -ESPIPE; 630 631 ret = spliced = 0; 632 633 lock_sock(sk); 634 635 timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK); 636 while (tss.len) { 637 ret = __tcp_splice_read(sk, &tss); 638 if (ret < 0) 639 break; 640 else if (!ret) { 641 if (spliced) 642 break; 643 if (sock_flag(sk, SOCK_DONE)) 644 break; 645 if (sk->sk_err) { 646 ret = sock_error(sk); 647 break; 648 } 649 if (sk->sk_shutdown & RCV_SHUTDOWN) 650 break; 651 if (sk->sk_state == TCP_CLOSE) { 652 /* 653 * This occurs when user tries to read 654 * from never connected socket. 655 */ 656 if (!sock_flag(sk, SOCK_DONE)) 657 ret = -ENOTCONN; 658 break; 659 } 660 if (!timeo) { 661 ret = -EAGAIN; 662 break; 663 } 664 sk_wait_data(sk, &timeo); 665 if (signal_pending(current)) { 666 ret = sock_intr_errno(timeo); 667 break; 668 } 669 continue; 670 } 671 tss.len -= ret; 672 spliced += ret; 673 674 if (!timeo) 675 break; 676 release_sock(sk); 677 lock_sock(sk); 678 679 if (sk->sk_err || sk->sk_state == TCP_CLOSE || 680 (sk->sk_shutdown & RCV_SHUTDOWN) || 681 signal_pending(current)) 682 break; 683 } 684 685 release_sock(sk); 686 687 if (spliced) 688 return spliced; 689 690 return ret; 691} 692EXPORT_SYMBOL(tcp_splice_read); 693 694struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) 695{ 696 struct sk_buff *skb; 697 698 /* The TCP header must be at least 32-bit aligned. */ 699 size = ALIGN(size, 4); 700 701 skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); 702 if (skb) { 703 if (sk_wmem_schedule(sk, skb->truesize)) { 704 skb_reserve(skb, sk->sk_prot->max_header); 705 /* 706 * Make sure that we have exactly size bytes 707 * available to the caller, no more, no less. 708 */ 709 skb->avail_size = size; 710 return skb; 711 } 712 __kfree_skb(skb); 713 } else { 714 sk->sk_prot->enter_memory_pressure(sk); 715 sk_stream_moderate_sndbuf(sk); 716 } 717 return NULL; 718} 719 720static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, 721 int large_allowed) 722{ 723 struct tcp_sock *tp = tcp_sk(sk); 724 u32 xmit_size_goal, old_size_goal; 725 726 xmit_size_goal = mss_now; 727 728 if (large_allowed && sk_can_gso(sk)) { 729 xmit_size_goal = ((sk->sk_gso_max_size - 1) - 730 inet_csk(sk)->icsk_af_ops->net_header_len - 731 inet_csk(sk)->icsk_ext_hdr_len - 732 tp->tcp_header_len); 733 734 xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal); 735 736 /* We try hard to avoid divides here */ 737 old_size_goal = tp->xmit_size_goal_segs * mss_now; 738 739 if (likely(old_size_goal <= xmit_size_goal && 740 old_size_goal + mss_now > xmit_size_goal)) { 741 xmit_size_goal = old_size_goal; 742 } else { 743 tp->xmit_size_goal_segs = xmit_size_goal / mss_now; 744 xmit_size_goal = tp->xmit_size_goal_segs * mss_now; 745 } 746 } 747 748 return max(xmit_size_goal, mss_now); 749} 750 751static int tcp_send_mss(struct sock *sk, int *size_goal, int flags) 752{ 753 int mss_now; 754 755 mss_now = tcp_current_mss(sk); 756 *size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB)); 757 758 return mss_now; 759} 760 761static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset, 762 size_t psize, int flags) 763{ 764 struct tcp_sock *tp = tcp_sk(sk); 765 int mss_now, size_goal; 766 int err; 767 ssize_t copied; 768 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 769 770 /* Wait for a connection to finish. */ 771 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 772 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 773 goto out_err; 774 775 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 776 777 mss_now = tcp_send_mss(sk, &size_goal, flags); 778 copied = 0; 779 780 err = -EPIPE; 781 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 782 goto out_err; 783 784 while (psize > 0) { 785 struct sk_buff *skb = tcp_write_queue_tail(sk); 786 struct page *page = pages[poffset / PAGE_SIZE]; 787 int copy, i, can_coalesce; 788 int offset = poffset % PAGE_SIZE; 789 int size = min_t(size_t, psize, PAGE_SIZE - offset); 790 791 if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) { 792new_segment: 793 if (!sk_stream_memory_free(sk)) 794 goto wait_for_sndbuf; 795 796 skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); 797 if (!skb) 798 goto wait_for_memory; 799 800 skb_entail(sk, skb); 801 copy = size_goal; 802 } 803 804 if (copy > size) 805 copy = size; 806 807 i = skb_shinfo(skb)->nr_frags; 808 can_coalesce = skb_can_coalesce(skb, i, page, offset); 809 if (!can_coalesce && i >= MAX_SKB_FRAGS) { 810 tcp_mark_push(tp, skb); 811 goto new_segment; 812 } 813 if (!sk_wmem_schedule(sk, copy)) 814 goto wait_for_memory; 815 816 if (can_coalesce) { 817 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 818 } else { 819 get_page(page); 820 skb_fill_page_desc(skb, i, page, offset, copy); 821 } 822 823 skb->len += copy; 824 skb->data_len += copy; 825 skb->truesize += copy; 826 sk->sk_wmem_queued += copy; 827 sk_mem_charge(sk, copy); 828 skb->ip_summed = CHECKSUM_PARTIAL; 829 tp->write_seq += copy; 830 TCP_SKB_CB(skb)->end_seq += copy; 831 skb_shinfo(skb)->gso_segs = 0; 832 833 if (!copied) 834 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 835 836 copied += copy; 837 poffset += copy; 838 if (!(psize -= copy)) 839 goto out; 840 841 if (skb->len < size_goal || (flags & MSG_OOB)) 842 continue; 843 844 if (forced_push(tp)) { 845 tcp_mark_push(tp, skb); 846 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 847 } else if (skb == tcp_send_head(sk)) 848 tcp_push_one(sk, mss_now); 849 continue; 850 851wait_for_sndbuf: 852 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 853wait_for_memory: 854 if (copied) 855 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 856 857 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 858 goto do_error; 859 860 mss_now = tcp_send_mss(sk, &size_goal, flags); 861 } 862 863out: 864 if (copied && !(flags & MSG_SENDPAGE_NOTLAST)) 865 tcp_push(sk, flags, mss_now, tp->nonagle); 866 return copied; 867 868do_error: 869 if (copied) 870 goto out; 871out_err: 872 return sk_stream_error(sk, flags, err); 873} 874 875int tcp_sendpage(struct sock *sk, struct page *page, int offset, 876 size_t size, int flags) 877{ 878 ssize_t res; 879 880 if (!(sk->sk_route_caps & NETIF_F_SG) || 881 !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) 882 return sock_no_sendpage(sk->sk_socket, page, offset, size, 883 flags); 884 885 lock_sock(sk); 886 res = do_tcp_sendpages(sk, &page, offset, size, flags); 887 release_sock(sk); 888 return res; 889} 890EXPORT_SYMBOL(tcp_sendpage); 891 892static inline int select_size(const struct sock *sk, bool sg) 893{ 894 const struct tcp_sock *tp = tcp_sk(sk); 895 int tmp = tp->mss_cache; 896 897 if (sg) { 898 if (sk_can_gso(sk)) { 899 /* Small frames wont use a full page: 900 * Payload will immediately follow tcp header. 901 */ 902 tmp = SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER); 903 } else { 904 int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER); 905 906 if (tmp >= pgbreak && 907 tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE) 908 tmp = pgbreak; 909 } 910 } 911 912 return tmp; 913} 914 915int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 916 size_t size) 917{ 918 struct iovec *iov; 919 struct tcp_sock *tp = tcp_sk(sk); 920 struct sk_buff *skb; 921 int iovlen, flags, err, copied; 922 int mss_now = 0, size_goal; 923 bool sg; 924 long timeo; 925 926 lock_sock(sk); 927 928 flags = msg->msg_flags; 929 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 930 931 /* Wait for a connection to finish. */ 932 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) 933 if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) 934 goto out_err; 935 936 /* This should be in poll */ 937 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); 938 939 mss_now = tcp_send_mss(sk, &size_goal, flags); 940 941 /* Ok commence sending. */ 942 iovlen = msg->msg_iovlen; 943 iov = msg->msg_iov; 944 copied = 0; 945 946 err = -EPIPE; 947 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) 948 goto out_err; 949 950 sg = !!(sk->sk_route_caps & NETIF_F_SG); 951 952 while (--iovlen >= 0) { 953 size_t seglen = iov->iov_len; 954 unsigned char __user *from = iov->iov_base; 955 956 iov++; 957 958 while (seglen > 0) { 959 int copy = 0; 960 int max = size_goal; 961 962 skb = tcp_write_queue_tail(sk); 963 if (tcp_send_head(sk)) { 964 if (skb->ip_summed == CHECKSUM_NONE) 965 max = mss_now; 966 copy = max - skb->len; 967 } 968 969 if (copy <= 0) { 970new_segment: 971 /* Allocate new segment. If the interface is SG, 972 * allocate skb fitting to single page. 973 */ 974 if (!sk_stream_memory_free(sk)) 975 goto wait_for_sndbuf; 976 977 skb = sk_stream_alloc_skb(sk, 978 select_size(sk, sg), 979 sk->sk_allocation); 980 if (!skb) 981 goto wait_for_memory; 982 983 /* 984 * Check whether we can use HW checksum. 985 */ 986 if (sk->sk_route_caps & NETIF_F_ALL_CSUM) 987 skb->ip_summed = CHECKSUM_PARTIAL; 988 989 skb_entail(sk, skb); 990 copy = size_goal; 991 max = size_goal; 992 } 993 994 /* Try to append data to the end of skb. */ 995 if (copy > seglen) 996 copy = seglen; 997 998 /* Where to copy to? */ 999 if (skb_availroom(skb) > 0) { 1000 /* We have some space in skb head. Superb! */ 1001 copy = min_t(int, copy, skb_availroom(skb)); 1002 err = skb_add_data_nocache(sk, skb, from, copy); 1003 if (err) 1004 goto do_fault; 1005 } else { 1006 int merge = 0; 1007 int i = skb_shinfo(skb)->nr_frags; 1008 struct page *page = sk->sk_sndmsg_page; 1009 int off; 1010 1011 if (page && page_count(page) == 1) 1012 sk->sk_sndmsg_off = 0; 1013 1014 off = sk->sk_sndmsg_off; 1015 1016 if (skb_can_coalesce(skb, i, page, off) && 1017 off != PAGE_SIZE) { 1018 /* We can extend the last page 1019 * fragment. */ 1020 merge = 1; 1021 } else if (i == MAX_SKB_FRAGS || !sg) { 1022 /* Need to add new fragment and cannot 1023 * do this because interface is non-SG, 1024 * or because all the page slots are 1025 * busy. */ 1026 tcp_mark_push(tp, skb); 1027 goto new_segment; 1028 } else if (page) { 1029 if (off == PAGE_SIZE) { 1030 put_page(page); 1031 sk->sk_sndmsg_page = page = NULL; 1032 off = 0; 1033 } 1034 } else 1035 off = 0; 1036 1037 if (copy > PAGE_SIZE - off) 1038 copy = PAGE_SIZE - off; 1039 1040 if (!sk_wmem_schedule(sk, copy)) 1041 goto wait_for_memory; 1042 1043 if (!page) { 1044 /* Allocate new cache page. */ 1045 if (!(page = sk_stream_alloc_page(sk))) 1046 goto wait_for_memory; 1047 } 1048 1049 /* Time to copy data. We are close to 1050 * the end! */ 1051 err = skb_copy_to_page_nocache(sk, from, skb, 1052 page, off, copy); 1053 if (err) { 1054 /* If this page was new, give it to the 1055 * socket so it does not get leaked. 1056 */ 1057 if (!sk->sk_sndmsg_page) { 1058 sk->sk_sndmsg_page = page; 1059 sk->sk_sndmsg_off = 0; 1060 } 1061 goto do_error; 1062 } 1063 1064 /* Update the skb. */ 1065 if (merge) { 1066 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1067 } else { 1068 skb_fill_page_desc(skb, i, page, off, copy); 1069 if (sk->sk_sndmsg_page) { 1070 get_page(page); 1071 } else if (off + copy < PAGE_SIZE) { 1072 get_page(page); 1073 sk->sk_sndmsg_page = page; 1074 } 1075 } 1076 1077 sk->sk_sndmsg_off = off + copy; 1078 } 1079 1080 if (!copied) 1081 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1082 1083 tp->write_seq += copy; 1084 TCP_SKB_CB(skb)->end_seq += copy; 1085 skb_shinfo(skb)->gso_segs = 0; 1086 1087 from += copy; 1088 copied += copy; 1089 if ((seglen -= copy) == 0 && iovlen == 0) 1090 goto out; 1091 1092 if (skb->len < max || (flags & MSG_OOB)) 1093 continue; 1094 1095 if (forced_push(tp)) { 1096 tcp_mark_push(tp, skb); 1097 __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); 1098 } else if (skb == tcp_send_head(sk)) 1099 tcp_push_one(sk, mss_now); 1100 continue; 1101 1102wait_for_sndbuf: 1103 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1104wait_for_memory: 1105 if (copied) 1106 tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); 1107 1108 if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) 1109 goto do_error; 1110 1111 mss_now = tcp_send_mss(sk, &size_goal, flags); 1112 } 1113 } 1114 1115out: 1116 if (copied) 1117 tcp_push(sk, flags, mss_now, tp->nonagle); 1118 release_sock(sk); 1119 return copied; 1120 1121do_fault: 1122 if (!skb->len) { 1123 tcp_unlink_write_queue(skb, sk); 1124 /* It is the one place in all of TCP, except connection 1125 * reset, where we can be unlinking the send_head. 1126 */ 1127 tcp_check_send_head(sk, skb); 1128 sk_wmem_free_skb(sk, skb); 1129 } 1130 1131do_error: 1132 if (copied) 1133 goto out; 1134out_err: 1135 err = sk_stream_error(sk, flags, err); 1136 release_sock(sk); 1137 return err; 1138} 1139EXPORT_SYMBOL(tcp_sendmsg); 1140 1141/* 1142 * Handle reading urgent data. BSD has very simple semantics for 1143 * this, no blocking and very strange errors 8) 1144 */ 1145 1146static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags) 1147{ 1148 struct tcp_sock *tp = tcp_sk(sk); 1149 1150 /* No URG data to read. */ 1151 if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data || 1152 tp->urg_data == TCP_URG_READ) 1153 return -EINVAL; /* Yes this is right ! */ 1154 1155 if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE)) 1156 return -ENOTCONN; 1157 1158 if (tp->urg_data & TCP_URG_VALID) { 1159 int err = 0; 1160 char c = tp->urg_data; 1161 1162 if (!(flags & MSG_PEEK)) 1163 tp->urg_data = TCP_URG_READ; 1164 1165 /* Read urgent data. */ 1166 msg->msg_flags |= MSG_OOB; 1167 1168 if (len > 0) { 1169 if (!(flags & MSG_TRUNC)) 1170 err = memcpy_toiovec(msg->msg_iov, &c, 1); 1171 len = 1; 1172 } else 1173 msg->msg_flags |= MSG_TRUNC; 1174 1175 return err ? -EFAULT : len; 1176 } 1177 1178 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 1179 return 0; 1180 1181 /* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and 1182 * the available implementations agree in this case: 1183 * this call should never block, independent of the 1184 * blocking state of the socket. 1185 * Mike <pall@rz.uni-karlsruhe.de> 1186 */ 1187 return -EAGAIN; 1188} 1189 1190/* Clean up the receive buffer for full frames taken by the user, 1191 * then send an ACK if necessary. COPIED is the number of bytes 1192 * tcp_recvmsg has given to the user so far, it speeds up the 1193 * calculation of whether or not we must ACK for the sake of 1194 * a window update. 1195 */ 1196void tcp_cleanup_rbuf(struct sock *sk, int copied) 1197{ 1198 struct tcp_sock *tp = tcp_sk(sk); 1199 int time_to_ack = 0; 1200 1201 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 1202 1203 WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), 1204 "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", 1205 tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); 1206 1207 if (inet_csk_ack_scheduled(sk)) { 1208 const struct inet_connection_sock *icsk = inet_csk(sk); 1209 /* Delayed ACKs frequently hit locked sockets during bulk 1210 * receive. */ 1211 if (icsk->icsk_ack.blocked || 1212 /* Once-per-two-segments ACK was not sent by tcp_input.c */ 1213 tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss || 1214 /* 1215 * If this read emptied read buffer, we send ACK, if 1216 * connection is not bidirectional, user drained 1217 * receive buffer and there was a small segment 1218 * in queue. 1219 */ 1220 (copied > 0 && 1221 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) || 1222 ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) && 1223 !icsk->icsk_ack.pingpong)) && 1224 !atomic_read(&sk->sk_rmem_alloc))) 1225 time_to_ack = 1; 1226 } 1227 1228 /* We send an ACK if we can now advertise a non-zero window 1229 * which has been raised "significantly". 1230 * 1231 * Even if window raised up to infinity, do not send window open ACK 1232 * in states, where we will not receive more. It is useless. 1233 */ 1234 if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) { 1235 __u32 rcv_window_now = tcp_receive_window(tp); 1236 1237 /* Optimize, __tcp_select_window() is not cheap. */ 1238 if (2*rcv_window_now <= tp->window_clamp) { 1239 __u32 new_window = __tcp_select_window(sk); 1240 1241 /* Send ACK now, if this read freed lots of space 1242 * in our buffer. Certainly, new_window is new window. 1243 * We can advertise it now, if it is not less than current one. 1244 * "Lots" means "at least twice" here. 1245 */ 1246 if (new_window && new_window >= 2 * rcv_window_now) 1247 time_to_ack = 1; 1248 } 1249 } 1250 if (time_to_ack) 1251 tcp_send_ack(sk); 1252} 1253 1254static void tcp_prequeue_process(struct sock *sk) 1255{ 1256 struct sk_buff *skb; 1257 struct tcp_sock *tp = tcp_sk(sk); 1258 1259 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED); 1260 1261 /* RX process wants to run with disabled BHs, though it is not 1262 * necessary */ 1263 local_bh_disable(); 1264 while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) 1265 sk_backlog_rcv(sk, skb); 1266 local_bh_enable(); 1267 1268 /* Clear memory counter. */ 1269 tp->ucopy.memory = 0; 1270} 1271 1272#ifdef CONFIG_NET_DMA 1273static void tcp_service_net_dma(struct sock *sk, bool wait) 1274{ 1275 dma_cookie_t done, used; 1276 dma_cookie_t last_issued; 1277 struct tcp_sock *tp = tcp_sk(sk); 1278 1279 if (!tp->ucopy.dma_chan) 1280 return; 1281 1282 last_issued = tp->ucopy.dma_cookie; 1283 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1284 1285 do { 1286 if (dma_async_memcpy_complete(tp->ucopy.dma_chan, 1287 last_issued, &done, 1288 &used) == DMA_SUCCESS) { 1289 /* Safe to free early-copied skbs now */ 1290 __skb_queue_purge(&sk->sk_async_wait_queue); 1291 break; 1292 } else { 1293 struct sk_buff *skb; 1294 while ((skb = skb_peek(&sk->sk_async_wait_queue)) && 1295 (dma_async_is_complete(skb->dma_cookie, done, 1296 used) == DMA_SUCCESS)) { 1297 __skb_dequeue(&sk->sk_async_wait_queue); 1298 kfree_skb(skb); 1299 } 1300 } 1301 } while (wait); 1302} 1303#endif 1304 1305static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) 1306{ 1307 struct sk_buff *skb; 1308 u32 offset; 1309 1310 skb_queue_walk(&sk->sk_receive_queue, skb) { 1311 offset = seq - TCP_SKB_CB(skb)->seq; 1312 if (tcp_hdr(skb)->syn) 1313 offset--; 1314 if (offset < skb->len || tcp_hdr(skb)->fin) { 1315 *off = offset; 1316 return skb; 1317 } 1318 } 1319 return NULL; 1320} 1321 1322/* 1323 * This routine provides an alternative to tcp_recvmsg() for routines 1324 * that would like to handle copying from skbuffs directly in 'sendfile' 1325 * fashion. 1326 * Note: 1327 * - It is assumed that the socket was locked by the caller. 1328 * - The routine does not block. 1329 * - At present, there is no support for reading OOB data 1330 * or for 'peeking' the socket using this routine 1331 * (although both would be easy to implement). 1332 */ 1333int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 1334 sk_read_actor_t recv_actor) 1335{ 1336 struct sk_buff *skb; 1337 struct tcp_sock *tp = tcp_sk(sk); 1338 u32 seq = tp->copied_seq; 1339 u32 offset; 1340 int copied = 0; 1341 1342 if (sk->sk_state == TCP_LISTEN) 1343 return -ENOTCONN; 1344 while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) { 1345 if (offset < skb->len) { 1346 int used; 1347 size_t len; 1348 1349 len = skb->len - offset; 1350 /* Stop reading if we hit a patch of urgent data */ 1351 if (tp->urg_data) { 1352 u32 urg_offset = tp->urg_seq - seq; 1353 if (urg_offset < len) 1354 len = urg_offset; 1355 if (!len) 1356 break; 1357 } 1358 used = recv_actor(desc, skb, offset, len); 1359 if (used < 0) { 1360 if (!copied) 1361 copied = used; 1362 break; 1363 } else if (used <= len) { 1364 seq += used; 1365 copied += used; 1366 offset += used; 1367 } 1368 /* 1369 * If recv_actor drops the lock (e.g. TCP splice 1370 * receive) the skb pointer might be invalid when 1371 * getting here: tcp_collapse might have deleted it 1372 * while aggregating skbs from the socket queue. 1373 */ 1374 skb = tcp_recv_skb(sk, seq-1, &offset); 1375 if (!skb || (offset+1 != skb->len)) 1376 break; 1377 } 1378 if (tcp_hdr(skb)->fin) { 1379 sk_eat_skb(sk, skb, 0); 1380 ++seq; 1381 break; 1382 } 1383 sk_eat_skb(sk, skb, 0); 1384 if (!desc->count) 1385 break; 1386 tp->copied_seq = seq; 1387 } 1388 tp->copied_seq = seq; 1389 1390 tcp_rcv_space_adjust(sk); 1391 1392 /* Clean up data we have read: This will do ACK frames. */ 1393 if (copied > 0) 1394 tcp_cleanup_rbuf(sk, copied); 1395 return copied; 1396} 1397EXPORT_SYMBOL(tcp_read_sock); 1398 1399/* 1400 * This routine copies from a sock struct into the user buffer. 1401 * 1402 * Technical note: in 2.3 we work on _locked_ socket, so that 1403 * tricks with *seq access order and skb->users are not required. 1404 * Probably, code can be easily improved even more. 1405 */ 1406 1407int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1408 size_t len, int nonblock, int flags, int *addr_len) 1409{ 1410 struct tcp_sock *tp = tcp_sk(sk); 1411 int copied = 0; 1412 u32 peek_seq; 1413 u32 *seq; 1414 unsigned long used; 1415 int err; 1416 int target; /* Read at least this many bytes */ 1417 long timeo; 1418 struct task_struct *user_recv = NULL; 1419 int copied_early = 0; 1420 struct sk_buff *skb; 1421 u32 urg_hole = 0; 1422 1423 lock_sock(sk); 1424 1425 err = -ENOTCONN; 1426 if (sk->sk_state == TCP_LISTEN) 1427 goto out; 1428 1429 timeo = sock_rcvtimeo(sk, nonblock); 1430 1431 /* Urgent data needs to be handled specially. */ 1432 if (flags & MSG_OOB) 1433 goto recv_urg; 1434 1435 seq = &tp->copied_seq; 1436 if (flags & MSG_PEEK) { 1437 peek_seq = tp->copied_seq; 1438 seq = &peek_seq; 1439 } 1440 1441 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 1442 1443#ifdef CONFIG_NET_DMA 1444 tp->ucopy.dma_chan = NULL; 1445 preempt_disable(); 1446 skb = skb_peek_tail(&sk->sk_receive_queue); 1447 { 1448 int available = 0; 1449 1450 if (skb) 1451 available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); 1452 if ((available < target) && 1453 (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && 1454 !sysctl_tcp_low_latency && 1455 net_dma_find_channel()) { 1456 preempt_enable_no_resched(); 1457 tp->ucopy.pinned_list = 1458 dma_pin_iovec_pages(msg->msg_iov, len); 1459 } else { 1460 preempt_enable_no_resched(); 1461 } 1462 } 1463#endif 1464 1465 do { 1466 u32 offset; 1467 1468 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ 1469 if (tp->urg_data && tp->urg_seq == *seq) { 1470 if (copied) 1471 break; 1472 if (signal_pending(current)) { 1473 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN; 1474 break; 1475 } 1476 } 1477 1478 /* Next get a buffer. */ 1479 1480 skb_queue_walk(&sk->sk_receive_queue, skb) { 1481 /* Now that we have two receive queues this 1482 * shouldn't happen. 1483 */ 1484 if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), 1485 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n", 1486 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, 1487 flags)) 1488 break; 1489 1490 offset = *seq - TCP_SKB_CB(skb)->seq; 1491 if (tcp_hdr(skb)->syn) 1492 offset--; 1493 if (offset < skb->len) 1494 goto found_ok_skb; 1495 if (tcp_hdr(skb)->fin) 1496 goto found_fin_ok; 1497 WARN(!(flags & MSG_PEEK), 1498 "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n", 1499 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags); 1500 } 1501 1502 /* Well, if we have backlog, try to process it now yet. */ 1503 1504 if (copied >= target && !sk->sk_backlog.tail) 1505 break; 1506 1507 if (copied) { 1508 if (sk->sk_err || 1509 sk->sk_state == TCP_CLOSE || 1510 (sk->sk_shutdown & RCV_SHUTDOWN) || 1511 !timeo || 1512 signal_pending(current)) 1513 break; 1514 } else { 1515 if (sock_flag(sk, SOCK_DONE)) 1516 break; 1517 1518 if (sk->sk_err) { 1519 copied = sock_error(sk); 1520 break; 1521 } 1522 1523 if (sk->sk_shutdown & RCV_SHUTDOWN) 1524 break; 1525 1526 if (sk->sk_state == TCP_CLOSE) { 1527 if (!sock_flag(sk, SOCK_DONE)) { 1528 /* This occurs when user tries to read 1529 * from never connected socket. 1530 */ 1531 copied = -ENOTCONN; 1532 break; 1533 } 1534 break; 1535 } 1536 1537 if (!timeo) { 1538 copied = -EAGAIN; 1539 break; 1540 } 1541 1542 if (signal_pending(current)) { 1543 copied = sock_intr_errno(timeo); 1544 break; 1545 } 1546 } 1547 1548 tcp_cleanup_rbuf(sk, copied); 1549 1550 if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) { 1551 /* Install new reader */ 1552 if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) { 1553 user_recv = current; 1554 tp->ucopy.task = user_recv; 1555 tp->ucopy.iov = msg->msg_iov; 1556 } 1557 1558 tp->ucopy.len = len; 1559 1560 WARN_ON(tp->copied_seq != tp->rcv_nxt && 1561 !(flags & (MSG_PEEK | MSG_TRUNC))); 1562 1563 /* Ugly... If prequeue is not empty, we have to 1564 * process it before releasing socket, otherwise 1565 * order will be broken at second iteration. 1566 * More elegant solution is required!!! 1567 * 1568 * Look: we have the following (pseudo)queues: 1569 * 1570 * 1. packets in flight 1571 * 2. backlog 1572 * 3. prequeue 1573 * 4. receive_queue 1574 * 1575 * Each queue can be processed only if the next ones 1576 * are empty. At this point we have empty receive_queue. 1577 * But prequeue _can_ be not empty after 2nd iteration, 1578 * when we jumped to start of loop because backlog 1579 * processing added something to receive_queue. 1580 * We cannot release_sock(), because backlog contains 1581 * packets arrived _after_ prequeued ones. 1582 * 1583 * Shortly, algorithm is clear --- to process all 1584 * the queues in order. We could make it more directly, 1585 * requeueing packets from backlog to prequeue, if 1586 * is not empty. It is more elegant, but eats cycles, 1587 * unfortunately. 1588 */ 1589 if (!skb_queue_empty(&tp->ucopy.prequeue)) 1590 goto do_prequeue; 1591 1592 /* __ Set realtime policy in scheduler __ */ 1593 } 1594 1595#ifdef CONFIG_NET_DMA 1596 if (tp->ucopy.dma_chan) 1597 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1598#endif 1599 if (copied >= target) { 1600 /* Do not sleep, just process backlog. */ 1601 release_sock(sk); 1602 lock_sock(sk); 1603 } else 1604 sk_wait_data(sk, &timeo); 1605 1606#ifdef CONFIG_NET_DMA 1607 tcp_service_net_dma(sk, false); /* Don't block */ 1608 tp->ucopy.wakeup = 0; 1609#endif 1610 1611 if (user_recv) { 1612 int chunk; 1613 1614 /* __ Restore normal policy in scheduler __ */ 1615 1616 if ((chunk = len - tp->ucopy.len) != 0) { 1617 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk); 1618 len -= chunk; 1619 copied += chunk; 1620 } 1621 1622 if (tp->rcv_nxt == tp->copied_seq && 1623 !skb_queue_empty(&tp->ucopy.prequeue)) { 1624do_prequeue: 1625 tcp_prequeue_process(sk); 1626 1627 if ((chunk = len - tp->ucopy.len) != 0) { 1628 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1629 len -= chunk; 1630 copied += chunk; 1631 } 1632 } 1633 } 1634 if ((flags & MSG_PEEK) && 1635 (peek_seq - copied - urg_hole != tp->copied_seq)) { 1636 if (net_ratelimit()) 1637 printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n", 1638 current->comm, task_pid_nr(current)); 1639 peek_seq = tp->copied_seq; 1640 } 1641 continue; 1642 1643 found_ok_skb: 1644 /* Ok so how much can we use? */ 1645 used = skb->len - offset; 1646 if (len < used) 1647 used = len; 1648 1649 /* Do we have urgent data here? */ 1650 if (tp->urg_data) { 1651 u32 urg_offset = tp->urg_seq - *seq; 1652 if (urg_offset < used) { 1653 if (!urg_offset) { 1654 if (!sock_flag(sk, SOCK_URGINLINE)) { 1655 ++*seq; 1656 urg_hole++; 1657 offset++; 1658 used--; 1659 if (!used) 1660 goto skip_copy; 1661 } 1662 } else 1663 used = urg_offset; 1664 } 1665 } 1666 1667 if (!(flags & MSG_TRUNC)) { 1668#ifdef CONFIG_NET_DMA 1669 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1670 tp->ucopy.dma_chan = net_dma_find_channel(); 1671 1672 if (tp->ucopy.dma_chan) { 1673 tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( 1674 tp->ucopy.dma_chan, skb, offset, 1675 msg->msg_iov, used, 1676 tp->ucopy.pinned_list); 1677 1678 if (tp->ucopy.dma_cookie < 0) { 1679 1680 pr_alert("%s: dma_cookie < 0\n", 1681 __func__); 1682 1683 /* Exception. Bailout! */ 1684 if (!copied) 1685 copied = -EFAULT; 1686 break; 1687 } 1688 1689 dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); 1690 1691 if ((offset + used) == skb->len) 1692 copied_early = 1; 1693 1694 } else 1695#endif 1696 { 1697 err = skb_copy_datagram_iovec(skb, offset, 1698 msg->msg_iov, used); 1699 if (err) { 1700 /* Exception. Bailout! */ 1701 if (!copied) 1702 copied = -EFAULT; 1703 break; 1704 } 1705 } 1706 } 1707 1708 *seq += used; 1709 copied += used; 1710 len -= used; 1711 1712 tcp_rcv_space_adjust(sk); 1713 1714skip_copy: 1715 if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) { 1716 tp->urg_data = 0; 1717 tcp_fast_path_check(sk); 1718 } 1719 if (used + offset < skb->len) 1720 continue; 1721 1722 if (tcp_hdr(skb)->fin) 1723 goto found_fin_ok; 1724 if (!(flags & MSG_PEEK)) { 1725 sk_eat_skb(sk, skb, copied_early); 1726 copied_early = 0; 1727 } 1728 continue; 1729 1730 found_fin_ok: 1731 /* Process the FIN. */ 1732 ++*seq; 1733 if (!(flags & MSG_PEEK)) { 1734 sk_eat_skb(sk, skb, copied_early); 1735 copied_early = 0; 1736 } 1737 break; 1738 } while (len > 0); 1739 1740 if (user_recv) { 1741 if (!skb_queue_empty(&tp->ucopy.prequeue)) { 1742 int chunk; 1743 1744 tp->ucopy.len = copied > 0 ? len : 0; 1745 1746 tcp_prequeue_process(sk); 1747 1748 if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) { 1749 NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk); 1750 len -= chunk; 1751 copied += chunk; 1752 } 1753 } 1754 1755 tp->ucopy.task = NULL; 1756 tp->ucopy.len = 0; 1757 } 1758 1759#ifdef CONFIG_NET_DMA 1760 tcp_service_net_dma(sk, true); /* Wait for queue to drain */ 1761 tp->ucopy.dma_chan = NULL; 1762 1763 if (tp->ucopy.pinned_list) { 1764 dma_unpin_iovec_pages(tp->ucopy.pinned_list); 1765 tp->ucopy.pinned_list = NULL; 1766 } 1767#endif 1768 1769 /* According to UNIX98, msg_name/msg_namelen are ignored 1770 * on connected socket. I was just happy when found this 8) --ANK 1771 */ 1772 1773 /* Clean up data we have read: This will do ACK frames. */ 1774 tcp_cleanup_rbuf(sk, copied); 1775 1776 release_sock(sk); 1777 return copied; 1778 1779out: 1780 release_sock(sk); 1781 return err; 1782 1783recv_urg: 1784 err = tcp_recv_urg(sk, msg, len, flags); 1785 goto out; 1786} 1787EXPORT_SYMBOL(tcp_recvmsg); 1788 1789void tcp_set_state(struct sock *sk, int state) 1790{ 1791 int oldstate = sk->sk_state; 1792 1793 switch (state) { 1794 case TCP_ESTABLISHED: 1795 if (oldstate != TCP_ESTABLISHED) 1796 TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1797 break; 1798 1799 case TCP_CLOSE: 1800 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) 1801 TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS); 1802 1803 sk->sk_prot->unhash(sk); 1804 if (inet_csk(sk)->icsk_bind_hash && 1805 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1806 inet_put_port(sk); 1807 /* fall through */ 1808 default: 1809 if (oldstate == TCP_ESTABLISHED) 1810 TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB); 1811 } 1812 1813 /* Change state AFTER socket is unhashed to avoid closed 1814 * socket sitting in hash tables. 1815 */ 1816 sk->sk_state = state; 1817 1818#ifdef STATE_TRACE 1819 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]); 1820#endif 1821} 1822EXPORT_SYMBOL_GPL(tcp_set_state); 1823 1824/* 1825 * State processing on a close. This implements the state shift for 1826 * sending our FIN frame. Note that we only send a FIN for some 1827 * states. A shutdown() may have already sent the FIN, or we may be 1828 * closed. 1829 */ 1830 1831static const unsigned char new_state[16] = { 1832 /* current state: new state: action: */ 1833 /* (Invalid) */ TCP_CLOSE, 1834 /* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1835 /* TCP_SYN_SENT */ TCP_CLOSE, 1836 /* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN, 1837 /* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1, 1838 /* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2, 1839 /* TCP_TIME_WAIT */ TCP_CLOSE, 1840 /* TCP_CLOSE */ TCP_CLOSE, 1841 /* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN, 1842 /* TCP_LAST_ACK */ TCP_LAST_ACK, 1843 /* TCP_LISTEN */ TCP_CLOSE, 1844 /* TCP_CLOSING */ TCP_CLOSING, 1845}; 1846 1847static int tcp_close_state(struct sock *sk) 1848{ 1849 int next = (int)new_state[sk->sk_state]; 1850 int ns = next & TCP_STATE_MASK; 1851 1852 tcp_set_state(sk, ns); 1853 1854 return next & TCP_ACTION_FIN; 1855} 1856 1857/* 1858 * Shutdown the sending side of a connection. Much like close except 1859 * that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD). 1860 */ 1861 1862void tcp_shutdown(struct sock *sk, int how) 1863{ 1864 /* We need to grab some memory, and put together a FIN, 1865 * and then put it into the queue to be sent. 1866 * Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92. 1867 */ 1868 if (!(how & SEND_SHUTDOWN)) 1869 return; 1870 1871 /* If we've already sent a FIN, or it's a closed state, skip this. */ 1872 if ((1 << sk->sk_state) & 1873 (TCPF_ESTABLISHED | TCPF_SYN_SENT | 1874 TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) { 1875 /* Clear out any half completed packets. FIN if needed. */ 1876 if (tcp_close_state(sk)) 1877 tcp_send_fin(sk); 1878 } 1879} 1880EXPORT_SYMBOL(tcp_shutdown); 1881 1882bool tcp_check_oom(struct sock *sk, int shift) 1883{ 1884 bool too_many_orphans, out_of_socket_memory; 1885 1886 too_many_orphans = tcp_too_many_orphans(sk, shift); 1887 out_of_socket_memory = tcp_out_of_memory(sk); 1888 1889 if (too_many_orphans && net_ratelimit()) 1890 pr_info("too many orphaned sockets\n"); 1891 if (out_of_socket_memory && net_ratelimit()) 1892 pr_info("out of memory -- consider tuning tcp_mem\n"); 1893 return too_many_orphans || out_of_socket_memory; 1894} 1895 1896void tcp_close(struct sock *sk, long timeout) 1897{ 1898 struct sk_buff *skb; 1899 int data_was_unread = 0; 1900 int state; 1901 1902 lock_sock(sk); 1903 sk->sk_shutdown = SHUTDOWN_MASK; 1904 1905 if (sk->sk_state == TCP_LISTEN) { 1906 tcp_set_state(sk, TCP_CLOSE); 1907 1908 /* Special case. */ 1909 inet_csk_listen_stop(sk); 1910 1911 goto adjudge_to_death; 1912 } 1913 1914 /* We need to flush the recv. buffs. We do this only on the 1915 * descriptor close, not protocol-sourced closes, because the 1916 * reader process may not have drained the data yet! 1917 */ 1918 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1919 u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq - 1920 tcp_hdr(skb)->fin; 1921 data_was_unread += len; 1922 __kfree_skb(skb); 1923 } 1924 1925 sk_mem_reclaim(sk); 1926 1927 /* If socket has been already reset (e.g. in tcp_reset()) - kill it. */ 1928 if (sk->sk_state == TCP_CLOSE) 1929 goto adjudge_to_death; 1930 1931 /* As outlined in RFC 2525, section 2.17, we send a RST here because 1932 * data was lost. To witness the awful effects of the old behavior of 1933 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk 1934 * GET in an FTP client, suspend the process, wait for the client to 1935 * advertise a zero window, then kill -9 the FTP client, wheee... 1936 * Note: timeout is always zero in such a case. 1937 */ 1938 if (unlikely(tcp_sk(sk)->repair)) { 1939 sk->sk_prot->disconnect(sk, 0); 1940 } else if (data_was_unread) { 1941 /* Unread data was tossed, zap the connection. */ 1942 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE); 1943 tcp_set_state(sk, TCP_CLOSE); 1944 tcp_send_active_reset(sk, sk->sk_allocation); 1945 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1946 /* Check zero linger _after_ checking for unread data. */ 1947 sk->sk_prot->disconnect(sk, 0); 1948 NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA); 1949 } else if (tcp_close_state(sk)) { 1950 /* We FIN if the application ate all the data before 1951 * zapping the connection. 1952 */ 1953 1954 /* RED-PEN. Formally speaking, we have broken TCP state 1955 * machine. State transitions: 1956 * 1957 * TCP_ESTABLISHED -> TCP_FIN_WAIT1 1958 * TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible) 1959 * TCP_CLOSE_WAIT -> TCP_LAST_ACK 1960 * 1961 * are legal only when FIN has been sent (i.e. in window), 1962 * rather than queued out of window. Purists blame. 1963 * 1964 * F.e. "RFC state" is ESTABLISHED, 1965 * if Linux state is FIN-WAIT-1, but FIN is still not sent. 1966 * 1967 * The visible declinations are that sometimes 1968 * we enter time-wait state, when it is not required really 1969 * (harmless), do not send active resets, when they are 1970 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when 1971 * they look as CLOSING or LAST_ACK for Linux) 1972 * Probably, I missed some more holelets. 1973 * --ANK 1974 */ 1975 tcp_send_fin(sk); 1976 } 1977 1978 sk_stream_wait_close(sk, timeout); 1979 1980adjudge_to_death: 1981 state = sk->sk_state; 1982 sock_hold(sk); 1983 sock_orphan(sk); 1984 1985 /* It is the last release_sock in its life. It will remove backlog. */ 1986 release_sock(sk); 1987 1988 1989 /* Now socket is owned by kernel and we acquire BH lock 1990 to finish close. No need to check for user refs. 1991 */ 1992 local_bh_disable(); 1993 bh_lock_sock(sk); 1994 WARN_ON(sock_owned_by_user(sk)); 1995 1996 percpu_counter_inc(sk->sk_prot->orphan_count); 1997 1998 /* Have we already been destroyed by a softirq or backlog? */ 1999 if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE) 2000 goto out; 2001 2002 /* This is a (useful) BSD violating of the RFC. There is a 2003 * problem with TCP as specified in that the other end could 2004 * keep a socket open forever with no application left this end. 2005 * We use a 3 minute timeout (about the same as BSD) then kill 2006 * our end. If they send after that then tough - BUT: long enough 2007 * that we won't make the old 4*rto = almost no time - whoops 2008 * reset mistake. 2009 * 2010 * Nope, it was not mistake. It is really desired behaviour 2011 * f.e. on http servers, when such sockets are useless, but 2012 * consume significant resources. Let's do it with special 2013 * linger2 option. --ANK 2014 */ 2015 2016 if (sk->sk_state == TCP_FIN_WAIT2) { 2017 struct tcp_sock *tp = tcp_sk(sk); 2018 if (tp->linger2 < 0) { 2019 tcp_set_state(sk, TCP_CLOSE); 2020 tcp_send_active_reset(sk, GFP_ATOMIC); 2021 NET_INC_STATS_BH(sock_net(sk), 2022 LINUX_MIB_TCPABORTONLINGER); 2023 } else { 2024 const int tmo = tcp_fin_time(sk); 2025 2026 if (tmo > TCP_TIMEWAIT_LEN) { 2027 inet_csk_reset_keepalive_timer(sk, 2028 tmo - TCP_TIMEWAIT_LEN); 2029 } else { 2030 tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); 2031 goto out; 2032 } 2033 } 2034 } 2035 if (sk->sk_state != TCP_CLOSE) { 2036 sk_mem_reclaim(sk); 2037 if (tcp_check_oom(sk, 0)) { 2038 tcp_set_state(sk, TCP_CLOSE); 2039 tcp_send_active_reset(sk, GFP_ATOMIC); 2040 NET_INC_STATS_BH(sock_net(sk), 2041 LINUX_MIB_TCPABORTONMEMORY); 2042 } 2043 } 2044 2045 if (sk->sk_state == TCP_CLOSE) 2046 inet_csk_destroy_sock(sk); 2047 /* Otherwise, socket is reprieved until protocol close. */ 2048 2049out: 2050 bh_unlock_sock(sk); 2051 local_bh_enable(); 2052 sock_put(sk); 2053} 2054EXPORT_SYMBOL(tcp_close); 2055 2056/* These states need RST on ABORT according to RFC793 */ 2057 2058static inline int tcp_need_reset(int state) 2059{ 2060 return (1 << state) & 2061 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | 2062 TCPF_FIN_WAIT2 | TCPF_SYN_RECV); 2063} 2064 2065int tcp_disconnect(struct sock *sk, int flags) 2066{ 2067 struct inet_sock *inet = inet_sk(sk); 2068 struct inet_connection_sock *icsk = inet_csk(sk); 2069 struct tcp_sock *tp = tcp_sk(sk); 2070 int err = 0; 2071 int old_state = sk->sk_state; 2072 2073 if (old_state != TCP_CLOSE) 2074 tcp_set_state(sk, TCP_CLOSE); 2075 2076 /* ABORT function of RFC793 */ 2077 if (old_state == TCP_LISTEN) { 2078 inet_csk_listen_stop(sk); 2079 } else if (unlikely(tp->repair)) { 2080 sk->sk_err = ECONNABORTED; 2081 } else if (tcp_need_reset(old_state) || 2082 (tp->snd_nxt != tp->write_seq && 2083 (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { 2084 /* The last check adjusts for discrepancy of Linux wrt. RFC 2085 * states 2086 */ 2087 tcp_send_active_reset(sk, gfp_any()); 2088 sk->sk_err = ECONNRESET; 2089 } else if (old_state == TCP_SYN_SENT) 2090 sk->sk_err = ECONNRESET; 2091 2092 tcp_clear_xmit_timers(sk); 2093 __skb_queue_purge(&sk->sk_receive_queue); 2094 tcp_write_queue_purge(sk); 2095 __skb_queue_purge(&tp->out_of_order_queue); 2096#ifdef CONFIG_NET_DMA 2097 __skb_queue_purge(&sk->sk_async_wait_queue); 2098#endif 2099 2100 inet->inet_dport = 0; 2101 2102 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 2103 inet_reset_saddr(sk); 2104 2105 sk->sk_shutdown = 0; 2106 sock_reset_flag(sk, SOCK_DONE); 2107 tp->srtt = 0; 2108 if ((tp->write_seq += tp->max_window + 2) == 0) 2109 tp->write_seq = 1; 2110 icsk->icsk_backoff = 0; 2111 tp->snd_cwnd = 2; 2112 icsk->icsk_probes_out = 0; 2113 tp->packets_out = 0; 2114 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 2115 tp->snd_cwnd_cnt = 0; 2116 tp->bytes_acked = 0; 2117 tp->window_clamp = 0; 2118 tcp_set_ca_state(sk, TCP_CA_Open); 2119 tcp_clear_retrans(tp); 2120 inet_csk_delack_init(sk); 2121 tcp_init_send_head(sk); 2122 memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); 2123 __sk_dst_reset(sk); 2124 2125 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 2126 2127 sk->sk_error_report(sk); 2128 return err; 2129} 2130EXPORT_SYMBOL(tcp_disconnect); 2131 2132static inline int tcp_can_repair_sock(struct sock *sk) 2133{ 2134 return capable(CAP_NET_ADMIN) && 2135 ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED)); 2136} 2137 2138/* 2139 * Socket option code for TCP. 2140 */ 2141static int do_tcp_setsockopt(struct sock *sk, int level, 2142 int optname, char __user *optval, unsigned int optlen) 2143{ 2144 struct tcp_sock *tp = tcp_sk(sk); 2145 struct inet_connection_sock *icsk = inet_csk(sk); 2146 int val; 2147 int err = 0; 2148 2149 /* These are data/string values, all the others are ints */ 2150 switch (optname) { 2151 case TCP_CONGESTION: { 2152 char name[TCP_CA_NAME_MAX]; 2153 2154 if (optlen < 1) 2155 return -EINVAL; 2156 2157 val = strncpy_from_user(name, optval, 2158 min_t(long, TCP_CA_NAME_MAX-1, optlen)); 2159 if (val < 0) 2160 return -EFAULT; 2161 name[val] = 0; 2162 2163 lock_sock(sk); 2164 err = tcp_set_congestion_control(sk, name); 2165 release_sock(sk); 2166 return err; 2167 } 2168 case TCP_COOKIE_TRANSACTIONS: { 2169 struct tcp_cookie_transactions ctd; 2170 struct tcp_cookie_values *cvp = NULL; 2171 2172 if (sizeof(ctd) > optlen) 2173 return -EINVAL; 2174 if (copy_from_user(&ctd, optval, sizeof(ctd))) 2175 return -EFAULT; 2176 2177 if (ctd.tcpct_used > sizeof(ctd.tcpct_value) || 2178 ctd.tcpct_s_data_desired > TCP_MSS_DESIRED) 2179 return -EINVAL; 2180 2181 if (ctd.tcpct_cookie_desired == 0) { 2182 /* default to global value */ 2183 } else if ((0x1 & ctd.tcpct_cookie_desired) || 2184 ctd.tcpct_cookie_desired > TCP_COOKIE_MAX || 2185 ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) { 2186 return -EINVAL; 2187 } 2188 2189 if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) { 2190 /* Supercedes all other values */ 2191 lock_sock(sk); 2192 if (tp->cookie_values != NULL) { 2193 kref_put(&tp->cookie_values->kref, 2194 tcp_cookie_values_release); 2195 tp->cookie_values = NULL; 2196 } 2197 tp->rx_opt.cookie_in_always = 0; /* false */ 2198 tp->rx_opt.cookie_out_never = 1; /* true */ 2199 release_sock(sk); 2200 return err; 2201 } 2202 2203 /* Allocate ancillary memory before locking. 2204 */ 2205 if (ctd.tcpct_used > 0 || 2206 (tp->cookie_values == NULL && 2207 (sysctl_tcp_cookie_size > 0 || 2208 ctd.tcpct_cookie_desired > 0 || 2209 ctd.tcpct_s_data_desired > 0))) { 2210 cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used, 2211 GFP_KERNEL); 2212 if (cvp == NULL) 2213 return -ENOMEM; 2214 2215 kref_init(&cvp->kref); 2216 } 2217 lock_sock(sk); 2218 tp->rx_opt.cookie_in_always = 2219 (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags); 2220 tp->rx_opt.cookie_out_never = 0; /* false */ 2221 2222 if (tp->cookie_values != NULL) { 2223 if (cvp != NULL) { 2224 /* Changed values are recorded by a changed 2225 * pointer, ensuring the cookie will differ, 2226 * without separately hashing each value later. 2227 */ 2228 kref_put(&tp->cookie_values->kref, 2229 tcp_cookie_values_release); 2230 } else { 2231 cvp = tp->cookie_values; 2232 } 2233 } 2234 2235 if (cvp != NULL) { 2236 cvp->cookie_desired = ctd.tcpct_cookie_desired; 2237 2238 if (ctd.tcpct_used > 0) { 2239 memcpy(cvp->s_data_payload, ctd.tcpct_value, 2240 ctd.tcpct_used); 2241 cvp->s_data_desired = ctd.tcpct_used; 2242 cvp->s_data_constant = 1; /* true */ 2243 } else { 2244 /* No constant payload data. */ 2245 cvp->s_data_desired = ctd.tcpct_s_data_desired; 2246 cvp->s_data_constant = 0; /* false */ 2247 } 2248 2249 tp->cookie_values = cvp; 2250 } 2251 release_sock(sk); 2252 return err; 2253 } 2254 default: 2255 /* fallthru */ 2256 break; 2257 } 2258 2259 if (optlen < sizeof(int)) 2260 return -EINVAL; 2261 2262 if (get_user(val, (int __user *)optval)) 2263 return -EFAULT; 2264 2265 lock_sock(sk); 2266 2267 switch (optname) { 2268 case TCP_MAXSEG: 2269 /* Values greater than interface MTU won't take effect. However 2270 * at the point when this call is done we typically don't yet 2271 * know which interface is going to be used */ 2272 if (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW) { 2273 err = -EINVAL; 2274 break; 2275 } 2276 tp->rx_opt.user_mss = val; 2277 break; 2278 2279 case TCP_NODELAY: 2280 if (val) { 2281 /* TCP_NODELAY is weaker than TCP_CORK, so that 2282 * this option on corked socket is remembered, but 2283 * it is not activated until cork is cleared. 2284 * 2285 * However, when TCP_NODELAY is set we make 2286 * an explicit push, which overrides even TCP_CORK 2287 * for currently queued segments. 2288 */ 2289 tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH; 2290 tcp_push_pending_frames(sk); 2291 } else { 2292 tp->nonagle &= ~TCP_NAGLE_OFF; 2293 } 2294 break; 2295 2296 case TCP_THIN_LINEAR_TIMEOUTS: 2297 if (val < 0 || val > 1) 2298 err = -EINVAL; 2299 else 2300 tp->thin_lto = val; 2301 break; 2302 2303 case TCP_THIN_DUPACK: 2304 if (val < 0 || val > 1) 2305 err = -EINVAL; 2306 else 2307 tp->thin_dupack = val; 2308 break; 2309 2310 case TCP_REPAIR: 2311 if (!tcp_can_repair_sock(sk)) 2312 err = -EPERM; 2313 else if (val == 1) { 2314 tp->repair = 1; 2315 sk->sk_reuse = SK_FORCE_REUSE; 2316 tp->repair_queue = TCP_NO_QUEUE; 2317 } else if (val == 0) { 2318 tp->repair = 0; 2319 sk->sk_reuse = SK_NO_REUSE; 2320 tcp_send_window_probe(sk); 2321 } else 2322 err = -EINVAL; 2323 2324 break; 2325 2326 case TCP_REPAIR_QUEUE: 2327 if (!tp->repair) 2328 err = -EPERM; 2329 else if (val < TCP_QUEUES_NR) 2330 tp->repair_queue = val; 2331 else 2332 err = -EINVAL; 2333 break; 2334 2335 case TCP_QUEUE_SEQ: 2336 if (sk->sk_state != TCP_CLOSE) 2337 err = -EPERM; 2338 else if (tp->repair_queue == TCP_SEND_QUEUE) 2339 tp->write_seq = val; 2340 else if (tp->repair_queue == TCP_RECV_QUEUE) 2341 tp->rcv_nxt = val; 2342 else 2343 err = -EINVAL; 2344 break; 2345 2346 case TCP_CORK: 2347 /* When set indicates to always queue non-full frames. 2348 * Later the user clears this option and we transmit 2349 * any pending partial frames in the queue. This is 2350 * meant to be used alongside sendfile() to get properly 2351 * filled frames when the user (for example) must write 2352 * out headers with a write() call first and then use 2353 * sendfile to send out the data parts. 2354 * 2355 * TCP_CORK can be set together with TCP_NODELAY and it is 2356 * stronger than TCP_NODELAY. 2357 */ 2358 if (val) { 2359 tp->nonagle |= TCP_NAGLE_CORK; 2360 } else { 2361 tp->nonagle &= ~TCP_NAGLE_CORK; 2362 if (tp->nonagle&TCP_NAGLE_OFF) 2363 tp->nonagle |= TCP_NAGLE_PUSH; 2364 tcp_push_pending_frames(sk); 2365 } 2366 break; 2367 2368 case TCP_KEEPIDLE: 2369 if (val < 1 || val > MAX_TCP_KEEPIDLE) 2370 err = -EINVAL; 2371 else { 2372 tp->keepalive_time = val * HZ; 2373 if (sock_flag(sk, SOCK_KEEPOPEN) && 2374 !((1 << sk->sk_state) & 2375 (TCPF_CLOSE | TCPF_LISTEN))) { 2376 u32 elapsed = keepalive_time_elapsed(tp); 2377 if (tp->keepalive_time > elapsed) 2378 elapsed = tp->keepalive_time - elapsed; 2379 else 2380 elapsed = 0; 2381 inet_csk_reset_keepalive_timer(sk, elapsed); 2382 } 2383 } 2384 break; 2385 case TCP_KEEPINTVL: 2386 if (val < 1 || val > MAX_TCP_KEEPINTVL) 2387 err = -EINVAL; 2388 else 2389 tp->keepalive_intvl = val * HZ; 2390 break; 2391 case TCP_KEEPCNT: 2392 if (val < 1 || val > MAX_TCP_KEEPCNT) 2393 err = -EINVAL; 2394 else 2395 tp->keepalive_probes = val; 2396 break; 2397 case TCP_SYNCNT: 2398 if (val < 1 || val > MAX_TCP_SYNCNT) 2399 err = -EINVAL; 2400 else 2401 icsk->icsk_syn_retries = val; 2402 break; 2403 2404 case TCP_LINGER2: 2405 if (val < 0) 2406 tp->linger2 = -1; 2407 else if (val > sysctl_tcp_fin_timeout / HZ) 2408 tp->linger2 = 0; 2409 else 2410 tp->linger2 = val * HZ; 2411 break; 2412 2413 case TCP_DEFER_ACCEPT: 2414 /* Translate value in seconds to number of retransmits */ 2415 icsk->icsk_accept_queue.rskq_defer_accept = 2416 secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, 2417 TCP_RTO_MAX / HZ); 2418 break; 2419 2420 case TCP_WINDOW_CLAMP: 2421 if (!val) { 2422 if (sk->sk_state != TCP_CLOSE) { 2423 err = -EINVAL; 2424 break; 2425 } 2426 tp->window_clamp = 0; 2427 } else 2428 tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ? 2429 SOCK_MIN_RCVBUF / 2 : val; 2430 break; 2431 2432 case TCP_QUICKACK: 2433 if (!val) { 2434 icsk->icsk_ack.pingpong = 1; 2435 } else { 2436 icsk->icsk_ack.pingpong = 0; 2437 if ((1 << sk->sk_state) & 2438 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && 2439 inet_csk_ack_scheduled(sk)) { 2440 icsk->icsk_ack.pending |= ICSK_ACK_PUSHED; 2441 tcp_cleanup_rbuf(sk, 1); 2442 if (!(val & 1)) 2443 icsk->icsk_ack.pingpong = 1; 2444 } 2445 } 2446 break; 2447 2448#ifdef CONFIG_TCP_MD5SIG 2449 case TCP_MD5SIG: 2450 /* Read the IP->Key mappings from userspace */ 2451 err = tp->af_specific->md5_parse(sk, optval, optlen); 2452 break; 2453#endif 2454 case TCP_USER_TIMEOUT: 2455 /* Cap the max timeout in ms TCP will retry/retrans 2456 * before giving up and aborting (ETIMEDOUT) a connection. 2457 */ 2458 icsk->icsk_user_timeout = msecs_to_jiffies(val); 2459 break; 2460 default: 2461 err = -ENOPROTOOPT; 2462 break; 2463 } 2464 2465 release_sock(sk); 2466 return err; 2467} 2468 2469int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 2470 unsigned int optlen) 2471{ 2472 const struct inet_connection_sock *icsk = inet_csk(sk); 2473 2474 if (level != SOL_TCP) 2475 return icsk->icsk_af_ops->setsockopt(sk, level, optname, 2476 optval, optlen); 2477 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2478} 2479EXPORT_SYMBOL(tcp_setsockopt); 2480 2481#ifdef CONFIG_COMPAT 2482int compat_tcp_setsockopt(struct sock *sk, int level, int optname, 2483 char __user *optval, unsigned int optlen) 2484{ 2485 if (level != SOL_TCP) 2486 return inet_csk_compat_setsockopt(sk, level, optname, 2487 optval, optlen); 2488 return do_tcp_setsockopt(sk, level, optname, optval, optlen); 2489} 2490EXPORT_SYMBOL(compat_tcp_setsockopt); 2491#endif 2492 2493/* Return information about state of tcp endpoint in API format. */ 2494void tcp_get_info(const struct sock *sk, struct tcp_info *info) 2495{ 2496 const struct tcp_sock *tp = tcp_sk(sk); 2497 const struct inet_connection_sock *icsk = inet_csk(sk); 2498 u32 now = tcp_time_stamp; 2499 2500 memset(info, 0, sizeof(*info)); 2501 2502 info->tcpi_state = sk->sk_state; 2503 info->tcpi_ca_state = icsk->icsk_ca_state; 2504 info->tcpi_retransmits = icsk->icsk_retransmits; 2505 info->tcpi_probes = icsk->icsk_probes_out; 2506 info->tcpi_backoff = icsk->icsk_backoff; 2507 2508 if (tp->rx_opt.tstamp_ok) 2509 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 2510 if (tcp_is_sack(tp)) 2511 info->tcpi_options |= TCPI_OPT_SACK; 2512 if (tp->rx_opt.wscale_ok) { 2513 info->tcpi_options |= TCPI_OPT_WSCALE; 2514 info->tcpi_snd_wscale = tp->rx_opt.snd_wscale; 2515 info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale; 2516 } 2517 2518 if (tp->ecn_flags & TCP_ECN_OK) 2519 info->tcpi_options |= TCPI_OPT_ECN; 2520 if (tp->ecn_flags & TCP_ECN_SEEN) 2521 info->tcpi_options |= TCPI_OPT_ECN_SEEN; 2522 2523 info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); 2524 info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); 2525 info->tcpi_snd_mss = tp->mss_cache; 2526 info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; 2527 2528 if (sk->sk_state == TCP_LISTEN) { 2529 info->tcpi_unacked = sk->sk_ack_backlog; 2530 info->tcpi_sacked = sk->sk_max_ack_backlog; 2531 } else { 2532 info->tcpi_unacked = tp->packets_out; 2533 info->tcpi_sacked = tp->sacked_out; 2534 } 2535 info->tcpi_lost = tp->lost_out; 2536 info->tcpi_retrans = tp->retrans_out; 2537 info->tcpi_fackets = tp->fackets_out; 2538 2539 info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime); 2540 info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime); 2541 info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); 2542 2543 info->tcpi_pmtu = icsk->icsk_pmtu_cookie; 2544 info->tcpi_rcv_ssthresh = tp->rcv_ssthresh; 2545 info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3; 2546 info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2; 2547 info->tcpi_snd_ssthresh = tp->snd_ssthresh; 2548 info->tcpi_snd_cwnd = tp->snd_cwnd; 2549 info->tcpi_advmss = tp->advmss; 2550 info->tcpi_reordering = tp->reordering; 2551 2552 info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3; 2553 info->tcpi_rcv_space = tp->rcvq_space.space; 2554 2555 info->tcpi_total_retrans = tp->total_retrans; 2556} 2557EXPORT_SYMBOL_GPL(tcp_get_info); 2558 2559static int do_tcp_getsockopt(struct sock *sk, int level, 2560 int optname, char __user *optval, int __user *optlen) 2561{ 2562 struct inet_connection_sock *icsk = inet_csk(sk); 2563 struct tcp_sock *tp = tcp_sk(sk); 2564 int val, len; 2565 2566 if (get_user(len, optlen)) 2567 return -EFAULT; 2568 2569 len = min_t(unsigned int, len, sizeof(int)); 2570 2571 if (len < 0) 2572 return -EINVAL; 2573 2574 switch (optname) { 2575 case TCP_MAXSEG: 2576 val = tp->mss_cache; 2577 if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) 2578 val = tp->rx_opt.user_mss; 2579 break; 2580 case TCP_NODELAY: 2581 val = !!(tp->nonagle&TCP_NAGLE_OFF); 2582 break; 2583 case TCP_CORK: 2584 val = !!(tp->nonagle&TCP_NAGLE_CORK); 2585 break; 2586 case TCP_KEEPIDLE: 2587 val = keepalive_time_when(tp) / HZ; 2588 break; 2589 case TCP_KEEPINTVL: 2590 val = keepalive_intvl_when(tp) / HZ; 2591 break; 2592 case TCP_KEEPCNT: 2593 val = keepalive_probes(tp); 2594 break; 2595 case TCP_SYNCNT: 2596 val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 2597 break; 2598 case TCP_LINGER2: 2599 val = tp->linger2; 2600 if (val >= 0) 2601 val = (val ? : sysctl_tcp_fin_timeout) / HZ; 2602 break; 2603 case TCP_DEFER_ACCEPT: 2604 val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, 2605 TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); 2606 break; 2607 case TCP_WINDOW_CLAMP: 2608 val = tp->window_clamp; 2609 break; 2610 case TCP_INFO: { 2611 struct tcp_info info; 2612 2613 if (get_user(len, optlen)) 2614 return -EFAULT; 2615 2616 tcp_get_info(sk, &info); 2617 2618 len = min_t(unsigned int, len, sizeof(info)); 2619 if (put_user(len, optlen)) 2620 return -EFAULT; 2621 if (copy_to_user(optval, &info, len)) 2622 return -EFAULT; 2623 return 0; 2624 } 2625 case TCP_QUICKACK: 2626 val = !icsk->icsk_ack.pingpong; 2627 break; 2628 2629 case TCP_CONGESTION: 2630 if (get_user(len, optlen)) 2631 return -EFAULT; 2632 len = min_t(unsigned int, len, TCP_CA_NAME_MAX); 2633 if (put_user(len, optlen)) 2634 return -EFAULT; 2635 if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) 2636 return -EFAULT; 2637 return 0; 2638 2639 case TCP_COOKIE_TRANSACTIONS: { 2640 struct tcp_cookie_transactions ctd; 2641 struct tcp_cookie_values *cvp = tp->cookie_values; 2642 2643 if (get_user(len, optlen)) 2644 return -EFAULT; 2645 if (len < sizeof(ctd)) 2646 return -EINVAL; 2647 2648 memset(&ctd, 0, sizeof(ctd)); 2649 ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ? 2650 TCP_COOKIE_IN_ALWAYS : 0) 2651 | (tp->rx_opt.cookie_out_never ? 2652 TCP_COOKIE_OUT_NEVER : 0); 2653 2654 if (cvp != NULL) { 2655 ctd.tcpct_flags |= (cvp->s_data_in ? 2656 TCP_S_DATA_IN : 0) 2657 | (cvp->s_data_out ? 2658 TCP_S_DATA_OUT : 0); 2659 2660 ctd.tcpct_cookie_desired = cvp->cookie_desired; 2661 ctd.tcpct_s_data_desired = cvp->s_data_desired; 2662 2663 memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0], 2664 cvp->cookie_pair_size); 2665 ctd.tcpct_used = cvp->cookie_pair_size; 2666 } 2667 2668 if (put_user(sizeof(ctd), optlen)) 2669 return -EFAULT; 2670 if (copy_to_user(optval, &ctd, sizeof(ctd))) 2671 return -EFAULT; 2672 return 0; 2673 } 2674 case TCP_THIN_LINEAR_TIMEOUTS: 2675 val = tp->thin_lto; 2676 break; 2677 case TCP_THIN_DUPACK: 2678 val = tp->thin_dupack; 2679 break; 2680 2681 case TCP_REPAIR: 2682 val = tp->repair; 2683 break; 2684 2685 case TCP_REPAIR_QUEUE: 2686 if (tp->repair) 2687 val = tp->repair_queue; 2688 else 2689 return -EINVAL; 2690 break; 2691 2692 case TCP_QUEUE_SEQ: 2693 if (tp->repair_queue == TCP_SEND_QUEUE) 2694 val = tp->write_seq; 2695 else if (tp->repair_queue == TCP_RECV_QUEUE) 2696 val = tp->rcv_nxt; 2697 else 2698 return -EINVAL; 2699 break; 2700 2701 case TCP_USER_TIMEOUT: 2702 val = jiffies_to_msecs(icsk->icsk_user_timeout); 2703 break; 2704 default: 2705 return -ENOPROTOOPT; 2706 } 2707 2708 if (put_user(len, optlen)) 2709 return -EFAULT; 2710 if (copy_to_user(optval, &val, len)) 2711 return -EFAULT; 2712 return 0; 2713} 2714 2715int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 2716 int __user *optlen) 2717{ 2718 struct inet_connection_sock *icsk = inet_csk(sk); 2719 2720 if (level != SOL_TCP) 2721 return icsk->icsk_af_ops->getsockopt(sk, level, optname, 2722 optval, optlen); 2723 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2724} 2725EXPORT_SYMBOL(tcp_getsockopt); 2726 2727#ifdef CONFIG_COMPAT 2728int compat_tcp_getsockopt(struct sock *sk, int level, int optname, 2729 char __user *optval, int __user *optlen) 2730{ 2731 if (level != SOL_TCP) 2732 return inet_csk_compat_getsockopt(sk, level, optname, 2733 optval, optlen); 2734 return do_tcp_getsockopt(sk, level, optname, optval, optlen); 2735} 2736EXPORT_SYMBOL(compat_tcp_getsockopt); 2737#endif 2738 2739struct sk_buff *tcp_tso_segment(struct sk_buff *skb, 2740 netdev_features_t features) 2741{ 2742 struct sk_buff *segs = ERR_PTR(-EINVAL); 2743 struct tcphdr *th; 2744 unsigned int thlen; 2745 unsigned int seq; 2746 __be32 delta; 2747 unsigned int oldlen; 2748 unsigned int mss; 2749 2750 if (!pskb_may_pull(skb, sizeof(*th))) 2751 goto out; 2752 2753 th = tcp_hdr(skb); 2754 thlen = th->doff * 4; 2755 if (thlen < sizeof(*th)) 2756 goto out; 2757 2758 if (!pskb_may_pull(skb, thlen)) 2759 goto out; 2760 2761 oldlen = (u16)~skb->len; 2762 __skb_pull(skb, thlen); 2763 2764 mss = skb_shinfo(skb)->gso_size; 2765 if (unlikely(skb->len <= mss)) 2766 goto out; 2767 2768 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2769 /* Packet is from an untrusted source, reset gso_segs. */ 2770 int type = skb_shinfo(skb)->gso_type; 2771 2772 if (unlikely(type & 2773 ~(SKB_GSO_TCPV4 | 2774 SKB_GSO_DODGY | 2775 SKB_GSO_TCP_ECN | 2776 SKB_GSO_TCPV6 | 2777 0) || 2778 !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) 2779 goto out; 2780 2781 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2782 2783 segs = NULL; 2784 goto out; 2785 } 2786 2787 segs = skb_segment(skb, features); 2788 if (IS_ERR(segs)) 2789 goto out; 2790 2791 delta = htonl(oldlen + (thlen + mss)); 2792 2793 skb = segs; 2794 th = tcp_hdr(skb); 2795 seq = ntohl(th->seq); 2796 2797 do { 2798 th->fin = th->psh = 0; 2799 2800 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2801 (__force u32)delta)); 2802 if (skb->ip_summed != CHECKSUM_PARTIAL) 2803 th->check = 2804 csum_fold(csum_partial(skb_transport_header(skb), 2805 thlen, skb->csum)); 2806 2807 seq += mss; 2808 skb = skb->next; 2809 th = tcp_hdr(skb); 2810 2811 th->seq = htonl(seq); 2812 th->cwr = 0; 2813 } while (skb->next); 2814 2815 delta = htonl(oldlen + (skb->tail - skb->transport_header) + 2816 skb->data_len); 2817 th->check = ~csum_fold((__force __wsum)((__force u32)th->check + 2818 (__force u32)delta)); 2819 if (skb->ip_summed != CHECKSUM_PARTIAL) 2820 th->check = csum_fold(csum_partial(skb_transport_header(skb), 2821 thlen, skb->csum)); 2822 2823out: 2824 return segs; 2825} 2826EXPORT_SYMBOL(tcp_tso_segment); 2827 2828struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb) 2829{ 2830 struct sk_buff **pp = NULL; 2831 struct sk_buff *p; 2832 struct tcphdr *th; 2833 struct tcphdr *th2; 2834 unsigned int len; 2835 unsigned int thlen; 2836 __be32 flags; 2837 unsigned int mss = 1; 2838 unsigned int hlen; 2839 unsigned int off; 2840 int flush = 1; 2841 int i; 2842 2843 off = skb_gro_offset(skb); 2844 hlen = off + sizeof(*th); 2845 th = skb_gro_header_fast(skb, off); 2846 if (skb_gro_header_hard(skb, hlen)) { 2847 th = skb_gro_header_slow(skb, hlen, off); 2848 if (unlikely(!th)) 2849 goto out; 2850 } 2851 2852 thlen = th->doff * 4; 2853 if (thlen < sizeof(*th)) 2854 goto out; 2855 2856 hlen = off + thlen; 2857 if (skb_gro_header_hard(skb, hlen)) { 2858 th = skb_gro_header_slow(skb, hlen, off); 2859 if (unlikely(!th)) 2860 goto out; 2861 } 2862 2863 skb_gro_pull(skb, thlen); 2864 2865 len = skb_gro_len(skb); 2866 flags = tcp_flag_word(th); 2867 2868 for (; (p = *head); head = &p->next) { 2869 if (!NAPI_GRO_CB(p)->same_flow) 2870 continue; 2871 2872 th2 = tcp_hdr(p); 2873 2874 if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { 2875 NAPI_GRO_CB(p)->same_flow = 0; 2876 continue; 2877 } 2878 2879 goto found; 2880 } 2881 2882 goto out_check_final; 2883 2884found: 2885 flush = NAPI_GRO_CB(p)->flush; 2886 flush |= (__force int)(flags & TCP_FLAG_CWR); 2887 flush |= (__force int)((flags ^ tcp_flag_word(th2)) & 2888 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); 2889 flush |= (__force int)(th->ack_seq ^ th2->ack_seq); 2890 for (i = sizeof(*th); i < thlen; i += 4) 2891 flush |= *(u32 *)((u8 *)th + i) ^ 2892 *(u32 *)((u8 *)th2 + i); 2893 2894 mss = skb_shinfo(p)->gso_size; 2895 2896 flush |= (len - 1) >= mss; 2897 flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); 2898 2899 if (flush || skb_gro_receive(head, skb)) { 2900 mss = 1; 2901 goto out_check_final; 2902 } 2903 2904 p = *head; 2905 th2 = tcp_hdr(p); 2906 tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); 2907 2908out_check_final: 2909 flush = len < mss; 2910 flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | 2911 TCP_FLAG_RST | TCP_FLAG_SYN | 2912 TCP_FLAG_FIN)); 2913 2914 if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) 2915 pp = head; 2916 2917out: 2918 NAPI_GRO_CB(skb)->flush |= flush; 2919 2920 return pp; 2921} 2922EXPORT_SYMBOL(tcp_gro_receive); 2923 2924int tcp_gro_complete(struct sk_buff *skb) 2925{ 2926 struct tcphdr *th = tcp_hdr(skb); 2927 2928 skb->csum_start = skb_transport_header(skb) - skb->head; 2929 skb->csum_offset = offsetof(struct tcphdr, check); 2930 skb->ip_summed = CHECKSUM_PARTIAL; 2931 2932 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 2933 2934 if (th->cwr) 2935 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; 2936 2937 return 0; 2938} 2939EXPORT_SYMBOL(tcp_gro_complete); 2940 2941#ifdef CONFIG_TCP_MD5SIG 2942static unsigned long tcp_md5sig_users; 2943static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool; 2944static DEFINE_SPINLOCK(tcp_md5sig_pool_lock); 2945 2946static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool) 2947{ 2948 int cpu; 2949 2950 for_each_possible_cpu(cpu) { 2951 struct tcp_md5sig_pool *p = per_cpu_ptr(pool, cpu); 2952 2953 if (p->md5_desc.tfm) 2954 crypto_free_hash(p->md5_desc.tfm); 2955 } 2956 free_percpu(pool); 2957} 2958 2959void tcp_free_md5sig_pool(void) 2960{ 2961 struct tcp_md5sig_pool __percpu *pool = NULL; 2962 2963 spin_lock_bh(&tcp_md5sig_pool_lock); 2964 if (--tcp_md5sig_users == 0) { 2965 pool = tcp_md5sig_pool; 2966 tcp_md5sig_pool = NULL; 2967 } 2968 spin_unlock_bh(&tcp_md5sig_pool_lock); 2969 if (pool) 2970 __tcp_free_md5sig_pool(pool); 2971} 2972EXPORT_SYMBOL(tcp_free_md5sig_pool); 2973 2974static struct tcp_md5sig_pool __percpu * 2975__tcp_alloc_md5sig_pool(struct sock *sk) 2976{ 2977 int cpu; 2978 struct tcp_md5sig_pool __percpu *pool; 2979 2980 pool = alloc_percpu(struct tcp_md5sig_pool); 2981 if (!pool) 2982 return NULL; 2983 2984 for_each_possible_cpu(cpu) { 2985 struct crypto_hash *hash; 2986 2987 hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 2988 if (!hash || IS_ERR(hash)) 2989 goto out_free; 2990 2991 per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash; 2992 } 2993 return pool; 2994out_free: 2995 __tcp_free_md5sig_pool(pool); 2996 return NULL; 2997} 2998 2999struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *sk) 3000{ 3001 struct tcp_md5sig_pool __percpu *pool; 3002 int alloc = 0; 3003 3004retry: 3005 spin_lock_bh(&tcp_md5sig_pool_lock); 3006 pool = tcp_md5sig_pool; 3007 if (tcp_md5sig_users++ == 0) { 3008 alloc = 1; 3009 spin_unlock_bh(&tcp_md5sig_pool_lock); 3010 } else if (!pool) { 3011 tcp_md5sig_users--; 3012 spin_unlock_bh(&tcp_md5sig_pool_lock); 3013 cpu_relax(); 3014 goto retry; 3015 } else 3016 spin_unlock_bh(&tcp_md5sig_pool_lock); 3017 3018 if (alloc) { 3019 /* we cannot hold spinlock here because this may sleep. */ 3020 struct tcp_md5sig_pool __percpu *p; 3021 3022 p = __tcp_alloc_md5sig_pool(sk); 3023 spin_lock_bh(&tcp_md5sig_pool_lock); 3024 if (!p) { 3025 tcp_md5sig_users--; 3026 spin_unlock_bh(&tcp_md5sig_pool_lock); 3027 return NULL; 3028 } 3029 pool = tcp_md5sig_pool; 3030 if (pool) { 3031 /* oops, it has already been assigned. */ 3032 spin_unlock_bh(&tcp_md5sig_pool_lock); 3033 __tcp_free_md5sig_pool(p); 3034 } else { 3035 tcp_md5sig_pool = pool = p; 3036 spin_unlock_bh(&tcp_md5sig_pool_lock); 3037 } 3038 } 3039 return pool; 3040} 3041EXPORT_SYMBOL(tcp_alloc_md5sig_pool); 3042 3043 3044/** 3045 * tcp_get_md5sig_pool - get md5sig_pool for this user 3046 * 3047 * We use percpu structure, so if we succeed, we exit with preemption 3048 * and BH disabled, to make sure another thread or softirq handling 3049 * wont try to get same context. 3050 */ 3051struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) 3052{ 3053 struct tcp_md5sig_pool __percpu *p; 3054 3055 local_bh_disable(); 3056 3057 spin_lock(&tcp_md5sig_pool_lock); 3058 p = tcp_md5sig_pool; 3059 if (p) 3060 tcp_md5sig_users++; 3061 spin_unlock(&tcp_md5sig_pool_lock); 3062 3063 if (p) 3064 return this_cpu_ptr(p); 3065 3066 local_bh_enable(); 3067 return NULL; 3068} 3069EXPORT_SYMBOL(tcp_get_md5sig_pool); 3070 3071void tcp_put_md5sig_pool(void) 3072{ 3073 local_bh_enable(); 3074 tcp_free_md5sig_pool(); 3075} 3076EXPORT_SYMBOL(tcp_put_md5sig_pool); 3077 3078int tcp_md5_hash_header(struct tcp_md5sig_pool *hp, 3079 const struct tcphdr *th) 3080{ 3081 struct scatterlist sg; 3082 struct tcphdr hdr; 3083 int err; 3084 3085 /* We are not allowed to change tcphdr, make a local copy */ 3086 memcpy(&hdr, th, sizeof(hdr)); 3087 hdr.check = 0; 3088 3089 /* options aren't included in the hash */ 3090 sg_init_one(&sg, &hdr, sizeof(hdr)); 3091 err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(hdr)); 3092 return err; 3093} 3094EXPORT_SYMBOL(tcp_md5_hash_header); 3095 3096int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp, 3097 const struct sk_buff *skb, unsigned int header_len) 3098{ 3099 struct scatterlist sg; 3100 const struct tcphdr *tp = tcp_hdr(skb); 3101 struct hash_desc *desc = &hp->md5_desc; 3102 unsigned int i; 3103 const unsigned int head_data_len = skb_headlen(skb) > header_len ? 3104 skb_headlen(skb) - header_len : 0; 3105 const struct skb_shared_info *shi = skb_shinfo(skb); 3106 struct sk_buff *frag_iter; 3107 3108 sg_init_table(&sg, 1); 3109 3110 sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len); 3111 if (crypto_hash_update(desc, &sg, head_data_len)) 3112 return 1; 3113 3114 for (i = 0; i < shi->nr_frags; ++i) { 3115 const struct skb_frag_struct *f = &shi->frags[i]; 3116 struct page *page = skb_frag_page(f); 3117 sg_set_page(&sg, page, skb_frag_size(f), f->page_offset); 3118 if (crypto_hash_update(desc, &sg, skb_frag_size(f))) 3119 return 1; 3120 } 3121 3122 skb_walk_frags(skb, frag_iter) 3123 if (tcp_md5_hash_skb_data(hp, frag_iter, 0)) 3124 return 1; 3125 3126 return 0; 3127} 3128EXPORT_SYMBOL(tcp_md5_hash_skb_data); 3129 3130int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key) 3131{ 3132 struct scatterlist sg; 3133 3134 sg_init_one(&sg, key->key, key->keylen); 3135 return crypto_hash_update(&hp->md5_desc, &sg, key->keylen); 3136} 3137EXPORT_SYMBOL(tcp_md5_hash_key); 3138 3139#endif 3140 3141/** 3142 * Each Responder maintains up to two secret values concurrently for 3143 * efficient secret rollover. Each secret value has 4 states: 3144 * 3145 * Generating. (tcp_secret_generating != tcp_secret_primary) 3146 * Generates new Responder-Cookies, but not yet used for primary 3147 * verification. This is a short-term state, typically lasting only 3148 * one round trip time (RTT). 3149 * 3150 * Primary. (tcp_secret_generating == tcp_secret_primary) 3151 * Used both for generation and primary verification. 3152 * 3153 * Retiring. (tcp_secret_retiring != tcp_secret_secondary) 3154 * Used for verification, until the first failure that can be 3155 * verified by the newer Generating secret. At that time, this 3156 * cookie's state is changed to Secondary, and the Generating 3157 * cookie's state is changed to Primary. This is a short-term state, 3158 * typically lasting only one round trip time (RTT). 3159 * 3160 * Secondary. (tcp_secret_retiring == tcp_secret_secondary) 3161 * Used for secondary verification, after primary verification 3162 * failures. This state lasts no more than twice the Maximum Segment 3163 * Lifetime (2MSL). Then, the secret is discarded. 3164 */ 3165struct tcp_cookie_secret { 3166 /* The secret is divided into two parts. The digest part is the 3167 * equivalent of previously hashing a secret and saving the state, 3168 * and serves as an initialization vector (IV). The message part 3169 * serves as the trailing secret. 3170 */ 3171 u32 secrets[COOKIE_WORKSPACE_WORDS]; 3172 unsigned long expires; 3173}; 3174 3175#define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL) 3176#define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2) 3177#define TCP_SECRET_LIFE (HZ * 600) 3178 3179static struct tcp_cookie_secret tcp_secret_one; 3180static struct tcp_cookie_secret tcp_secret_two; 3181 3182/* Essentially a circular list, without dynamic allocation. */ 3183static struct tcp_cookie_secret *tcp_secret_generating; 3184static struct tcp_cookie_secret *tcp_secret_primary; 3185static struct tcp_cookie_secret *tcp_secret_retiring; 3186static struct tcp_cookie_secret *tcp_secret_secondary; 3187 3188static DEFINE_SPINLOCK(tcp_secret_locker); 3189 3190/* Select a pseudo-random word in the cookie workspace. 3191 */ 3192static inline u32 tcp_cookie_work(const u32 *ws, const int n) 3193{ 3194 return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])]; 3195} 3196 3197/* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed. 3198 * Called in softirq context. 3199 * Returns: 0 for success. 3200 */ 3201int tcp_cookie_generator(u32 *bakery) 3202{ 3203 unsigned long jiffy = jiffies; 3204 3205 if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) { 3206 spin_lock_bh(&tcp_secret_locker); 3207 if (!time_after_eq(jiffy, tcp_secret_generating->expires)) { 3208 /* refreshed by another */ 3209 memcpy(bakery, 3210 &tcp_secret_generating->secrets[0], 3211 COOKIE_WORKSPACE_WORDS); 3212 } else { 3213 /* still needs refreshing */ 3214 get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS); 3215 3216 /* The first time, paranoia assumes that the 3217 * randomization function isn't as strong. But, 3218 * this secret initialization is delayed until 3219 * the last possible moment (packet arrival). 3220 * Although that time is observable, it is 3221 * unpredictably variable. Mash in the most 3222 * volatile clock bits available, and expire the 3223 * secret extra quickly. 3224 */ 3225 if (unlikely(tcp_secret_primary->expires == 3226 tcp_secret_secondary->expires)) { 3227 struct timespec tv; 3228 3229 getnstimeofday(&tv); 3230 bakery[COOKIE_DIGEST_WORDS+0] ^= 3231 (u32)tv.tv_nsec; 3232 3233 tcp_secret_secondary->expires = jiffy 3234 + TCP_SECRET_1MSL 3235 + (0x0f & tcp_cookie_work(bakery, 0)); 3236 } else { 3237 tcp_secret_secondary->expires = jiffy 3238 + TCP_SECRET_LIFE 3239 + (0xff & tcp_cookie_work(bakery, 1)); 3240 tcp_secret_primary->expires = jiffy 3241 + TCP_SECRET_2MSL 3242 + (0x1f & tcp_cookie_work(bakery, 2)); 3243 } 3244 memcpy(&tcp_secret_secondary->secrets[0], 3245 bakery, COOKIE_WORKSPACE_WORDS); 3246 3247 rcu_assign_pointer(tcp_secret_generating, 3248 tcp_secret_secondary); 3249 rcu_assign_pointer(tcp_secret_retiring, 3250 tcp_secret_primary); 3251 /* 3252 * Neither call_rcu() nor synchronize_rcu() needed. 3253 * Retiring data is not freed. It is replaced after 3254 * further (locked) pointer updates, and a quiet time 3255 * (minimum 1MSL, maximum LIFE - 2MSL). 3256 */ 3257 } 3258 spin_unlock_bh(&tcp_secret_locker); 3259 } else { 3260 rcu_read_lock_bh(); 3261 memcpy(bakery, 3262 &rcu_dereference(tcp_secret_generating)->secrets[0], 3263 COOKIE_WORKSPACE_WORDS); 3264 rcu_read_unlock_bh(); 3265 } 3266 return 0; 3267} 3268EXPORT_SYMBOL(tcp_cookie_generator); 3269 3270void tcp_done(struct sock *sk) 3271{ 3272 if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) 3273 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS); 3274 3275 tcp_set_state(sk, TCP_CLOSE); 3276 tcp_clear_xmit_timers(sk); 3277 3278 sk->sk_shutdown = SHUTDOWN_MASK; 3279 3280 if (!sock_flag(sk, SOCK_DEAD)) 3281 sk->sk_state_change(sk); 3282 else 3283 inet_csk_destroy_sock(sk); 3284} 3285EXPORT_SYMBOL_GPL(tcp_done); 3286 3287extern struct tcp_congestion_ops tcp_reno; 3288 3289static __initdata unsigned long thash_entries; 3290static int __init set_thash_entries(char *str) 3291{ 3292 if (!str) 3293 return 0; 3294 thash_entries = simple_strtoul(str, &str, 0); 3295 return 1; 3296} 3297__setup("thash_entries=", set_thash_entries); 3298 3299void tcp_init_mem(struct net *net) 3300{ 3301 unsigned long limit = nr_free_buffer_pages() / 8; 3302 limit = max(limit, 128UL); 3303 net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3; 3304 net->ipv4.sysctl_tcp_mem[1] = limit; 3305 net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2; 3306} 3307 3308void __init tcp_init(void) 3309{ 3310 struct sk_buff *skb = NULL; 3311 unsigned long limit; 3312 int max_share, cnt; 3313 unsigned int i; 3314 unsigned long jiffy = jiffies; 3315 3316 BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); 3317 3318 percpu_counter_init(&tcp_sockets_allocated, 0); 3319 percpu_counter_init(&tcp_orphan_count, 0); 3320 tcp_hashinfo.bind_bucket_cachep = 3321 kmem_cache_create("tcp_bind_bucket", 3322 sizeof(struct inet_bind_bucket), 0, 3323 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3324 3325 /* Size and allocate the main established and bind bucket 3326 * hash tables. 3327 * 3328 * The methodology is similar to that of the buffer cache. 3329 */ 3330 tcp_hashinfo.ehash = 3331 alloc_large_system_hash("TCP established", 3332 sizeof(struct inet_ehash_bucket), 3333 thash_entries, 3334 (totalram_pages >= 128 * 1024) ? 3335 13 : 15, 3336 0, 3337 NULL, 3338 &tcp_hashinfo.ehash_mask, 3339 thash_entries ? 0 : 512 * 1024); 3340 for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) { 3341 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i); 3342 INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i); 3343 } 3344 if (inet_ehash_locks_alloc(&tcp_hashinfo)) 3345 panic("TCP: failed to alloc ehash_locks"); 3346 tcp_hashinfo.bhash = 3347 alloc_large_system_hash("TCP bind", 3348 sizeof(struct inet_bind_hashbucket), 3349 tcp_hashinfo.ehash_mask + 1, 3350 (totalram_pages >= 128 * 1024) ? 3351 13 : 15, 3352 0, 3353 &tcp_hashinfo.bhash_size, 3354 NULL, 3355 64 * 1024); 3356 tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; 3357 for (i = 0; i < tcp_hashinfo.bhash_size; i++) { 3358 spin_lock_init(&tcp_hashinfo.bhash[i].lock); 3359 INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain); 3360 } 3361 3362 3363 cnt = tcp_hashinfo.ehash_mask + 1; 3364 3365 tcp_death_row.sysctl_max_tw_buckets = cnt / 2; 3366 sysctl_tcp_max_orphans = cnt / 2; 3367 sysctl_max_syn_backlog = max(128, cnt / 256); 3368 3369 tcp_init_mem(&init_net); 3370 /* Set per-socket limits to no more than 1/128 the pressure threshold */ 3371 limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7); 3372 max_share = min(4UL*1024*1024, limit); 3373 3374 sysctl_tcp_wmem[0] = SK_MEM_QUANTUM; 3375 sysctl_tcp_wmem[1] = 16*1024; 3376 sysctl_tcp_wmem[2] = max(64*1024, max_share); 3377 3378 sysctl_tcp_rmem[0] = SK_MEM_QUANTUM; 3379 sysctl_tcp_rmem[1] = 87380; 3380 sysctl_tcp_rmem[2] = max(87380, max_share); 3381 3382 pr_info("Hash tables configured (established %u bind %u)\n", 3383 tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size); 3384 3385 tcp_register_congestion_control(&tcp_reno); 3386 3387 memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets)); 3388 memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets)); 3389 tcp_secret_one.expires = jiffy; /* past due */ 3390 tcp_secret_two.expires = jiffy; /* past due */ 3391 tcp_secret_generating = &tcp_secret_one; 3392 tcp_secret_primary = &tcp_secret_one; 3393 tcp_secret_retiring = &tcp_secret_two; 3394 tcp_secret_secondary = &tcp_secret_two; 3395} 3396